[PATCH V3 00/13] drm: bridge: icn6211: Fix hard-coded panel settings and add I2C support
This series fixes multiple problems with the ICN6211 driver and adds support for configuration of the chip via I2C bus.
First, in the current state, the ICN6211 driver hard-codes DPI timing and clock settings specific to some unknown panel. The settings provided by panel driver are ignored. Using any other panel than the one for which this driver is currently hard-coded can lead to permanent damage of the panel (per display supplier warning, and it sure did in my case. The damage looks like multiple rows of dead pixels at the bottom of the panel, and this is not going away even after long power off time).
Much of this series thus fixes incorrect register layout, DPI timing programming, clock generation by adding actual PLL configuration code. This series also adds lane count decoding instead of using hard-coded value, and fills in a couple of registers with likely correct default values.
Second, this series adds support for I2C configuration of the ICN6211. The device can be configured either via DSI command mode or via I2C, the register layout is the same in both cases.
Since the datasheet for this device is very hard to come by, a lot of information has been salvaged from [1] and [2].
[1] https://github.com/rockchip-linux/kernel/blob/develop-4.19/drivers/gpu/drm/b... [2] https://github.com/tdjastrzebski/ICN6211-Configurator
Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org
Marek Vasut (13): dt-bindings: display: bridge: icn6211: Document DSI data-lanes property drm: bridge: icn6211: Fix register layout drm: bridge: icn6211: Fix HFP_HSW_HBP_HI and HFP_MIN handling drm: bridge: icn6211: Add HS/VS/DE polarity handling drm: bridge: icn6211: Add DSI lane count DT property parsing drm: bridge: icn6211: Add generic DSI-to-DPI PLL configuration drm: bridge: icn6211: Use DSI burst mode without EoT and with LP command mode drm: bridge: icn6211: Disable DPI color swap drm: bridge: icn6211: Set SYS_CTRL_1 to value used in examples drm: bridge: icn6211: Implement atomic_get_input_bus_fmts drm: bridge: icn6211: Add I2C configuration support drm: bridge: icn6211: Rework ICN6211_DSI to chipone_writeb() drm: bridge: icn6211: Read and validate chip IDs before configuration
.../display/bridge/chipone,icn6211.yaml | 18 +- drivers/gpu/drm/bridge/chipone-icn6211.c | 534 ++++++++++++++++-- 2 files changed, 496 insertions(+), 56 deletions(-)
It is necessary to specify the number of connected/used DSI data lanes when using the DSI input port of this bridge. Document the 'data-lanes' property of the DSI input port.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Rob Herring robh+dt@kernel.org Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de Cc: devicetree@vger.kernel.org To: dri-devel@lists.freedesktop.org --- V3: New patch --- .../display/bridge/chipone,icn6211.yaml | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml b/Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml index 62c3bd4cb28d8..f8cac721a7330 100644 --- a/Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml +++ b/Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml @@ -41,10 +41,26 @@ properties:
properties: port@0: - $ref: /schemas/graph.yaml#/properties/port + $ref: /schemas/graph.yaml#/$defs/port-base + unevaluatedProperties: false description: Video port for MIPI DSI input
+ properties: + endpoint: + $ref: /schemas/media/video-interfaces.yaml# + unevaluatedProperties: false + + properties: + data-lanes: + description: array of physical DSI data lane indexes. + minItems: 1 + items: + - const: 1 + - const: 2 + - const: 3 + - const: 4 + port@1: $ref: /schemas/graph.yaml#/properties/port description:
On Fri, 04 Mar 2022 01:24:56 +0100, Marek Vasut wrote:
It is necessary to specify the number of connected/used DSI data lanes when using the DSI input port of this bridge. Document the 'data-lanes' property of the DSI input port.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Rob Herring robh+dt@kernel.org Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de Cc: devicetree@vger.kernel.org To: dri-devel@lists.freedesktop.org
V3: New patch
.../display/bridge/chipone,icn6211.yaml | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
Reviewed-by: Rob Herring robh@kernel.org
On Fri, Mar 04, 2022 at 01:24:56AM +0100, Marek Vasut wrote:
It is necessary to specify the number of connected/used DSI data lanes when using the DSI input port of this bridge. Document the 'data-lanes' property of the DSI input port.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Rob Herring robh+dt@kernel.org Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de Cc: devicetree@vger.kernel.org To: dri-devel@lists.freedesktop.org
Acked-by: Maxime Ripard maxime@cerno.tech
Maxime
The chip register layout has nothing to do with MIPI DCS, the registers incorrectly marked as MIPI DCS in the driver are regular chip registers often with completely different function.
Fill in the actual register names and bits from [1] and [2] and add the entire register layout, since the documentation for this chip is hard to come by.
[1] https://github.com/rockchip-linux/kernel/blob/develop-4.19/drivers/gpu/drm/b... [2] https://github.com/tdjastrzebski/ICN6211-Configurator
Acked-by: Maxime Ripard maxime@cerno.tech Fixes: ce517f18944e3 ("drm: bridge: Add Chipone ICN6211 MIPI-DSI to RGB bridge") Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 134 ++++++++++++++++++++--- 1 file changed, 117 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index e8f36dca56b33..4b8d1a5a50302 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -15,8 +15,19 @@ #include <linux/of_device.h> #include <linux/regulator/consumer.h>
-#include <video/mipi_display.h> - +#define VENDOR_ID 0x00 +#define DEVICE_ID_H 0x01 +#define DEVICE_ID_L 0x02 +#define VERSION_ID 0x03 +#define FIRMWARE_VERSION 0x08 +#define CONFIG_FINISH 0x09 +#define PD_CTRL(n) (0x0a + ((n) & 0x3)) /* 0..3 */ +#define RST_CTRL(n) (0x0e + ((n) & 0x1)) /* 0..1 */ +#define SYS_CTRL(n) (0x10 + ((n) & 0x7)) /* 0..4 */ +#define RGB_DRV(n) (0x18 + ((n) & 0x3)) /* 0..3 */ +#define RGB_DLY(n) (0x1c + ((n) & 0x1)) /* 0..1 */ +#define RGB_TEST_CTRL 0x1e +#define ATE_PLL_EN 0x1f #define HACTIVE_LI 0x20 #define VACTIVE_LI 0x21 #define VACTIVE_HACTIVE_HI 0x22 @@ -27,6 +38,95 @@ #define VFP 0x27 #define VSYNC 0x28 #define VBP 0x29 +#define BIST_POL 0x2a +#define BIST_POL_BIST_MODE(n) (((n) & 0xf) << 4) +#define BIST_POL_BIST_GEN BIT(3) +#define BIST_POL_HSYNC_POL BIT(2) +#define BIST_POL_VSYNC_POL BIT(1) +#define BIST_POL_DE_POL BIT(0) +#define BIST_RED 0x2b +#define BIST_GREEN 0x2c +#define BIST_BLUE 0x2d +#define BIST_CHESS_X 0x2e +#define BIST_CHESS_Y 0x2f +#define BIST_CHESS_XY_H 0x30 +#define BIST_FRAME_TIME_L 0x31 +#define BIST_FRAME_TIME_H 0x32 +#define FIFO_MAX_ADDR_LOW 0x33 +#define SYNC_EVENT_DLY 0x34 +#define HSW_MIN 0x35 +#define HFP_MIN 0x36 +#define LOGIC_RST_NUM 0x37 +#define OSC_CTRL(n) (0x48 + ((n) & 0x7)) /* 0..5 */ +#define BG_CTRL 0x4e +#define LDO_PLL 0x4f +#define PLL_CTRL(n) (0x50 + ((n) & 0xf)) /* 0..15 */ +#define PLL_CTRL_6_EXTERNAL 0x90 +#define PLL_CTRL_6_MIPI_CLK 0x92 +#define PLL_CTRL_6_INTERNAL 0x93 +#define PLL_REM(n) (0x60 + ((n) & 0x3)) /* 0..2 */ +#define PLL_DIV(n) (0x63 + ((n) & 0x3)) /* 0..2 */ +#define PLL_FRAC(n) (0x66 + ((n) & 0x3)) /* 0..2 */ +#define PLL_INT(n) (0x69 + ((n) & 0x1)) /* 0..1 */ +#define PLL_REF_DIV 0x6b +#define PLL_REF_DIV_P(n) ((n) & 0xf) +#define PLL_REF_DIV_Pe BIT(4) +#define PLL_REF_DIV_S(n) (((n) & 0x7) << 5) +#define PLL_SSC_P(n) (0x6c + ((n) & 0x3)) /* 0..2 */ +#define PLL_SSC_STEP(n) (0x6f + ((n) & 0x3)) /* 0..2 */ +#define PLL_SSC_OFFSET(n) (0x72 + ((n) & 0x3)) /* 0..3 */ +#define GPIO_OEN 0x79 +#define MIPI_CFG_PW 0x7a +#define MIPI_CFG_PW_CONFIG_DSI 0xc1 +#define MIPI_CFG_PW_CONFIG_I2C 0x3e +#define GPIO_SEL(n) (0x7b + ((n) & 0x1)) /* 0..1 */ +#define IRQ_SEL 0x7d +#define DBG_SEL 0x7e +#define DBG_SIGNAL 0x7f +#define MIPI_ERR_VECTOR_L 0x80 +#define MIPI_ERR_VECTOR_H 0x81 +#define MIPI_ERR_VECTOR_EN_L 0x82 +#define MIPI_ERR_VECTOR_EN_H 0x83 +#define MIPI_MAX_SIZE_L 0x84 +#define MIPI_MAX_SIZE_H 0x85 +#define DSI_CTRL 0x86 +#define DSI_CTRL_UNKNOWN 0x28 +#define DSI_CTRL_DSI_LANES(n) ((n) & 0x3) +#define MIPI_PN_SWAP 0x87 +#define MIPI_PN_SWAP_CLK BIT(4) +#define MIPI_PN_SWAP_D(n) BIT((n) & 0x3) +#define MIPI_SOT_SYNC_BIT_(n) (0x88 + ((n) & 0x1)) /* 0..1 */ +#define MIPI_ULPS_CTRL 0x8a +#define MIPI_CLK_CHK_VAR 0x8e +#define MIPI_CLK_CHK_INI 0x8f +#define MIPI_T_TERM_EN 0x90 +#define MIPI_T_HS_SETTLE 0x91 +#define MIPI_T_TA_SURE_PRE 0x92 +#define MIPI_T_LPX_SET 0x94 +#define MIPI_T_CLK_MISS 0x95 +#define MIPI_INIT_TIME_L 0x96 +#define MIPI_INIT_TIME_H 0x97 +#define MIPI_T_CLK_TERM_EN 0x99 +#define MIPI_T_CLK_SETTLE 0x9a +#define MIPI_TO_HS_RX_L 0x9e +#define MIPI_TO_HS_RX_H 0x9f +#define MIPI_PHY_(n) (0xa0 + ((n) & 0x7)) /* 0..5 */ +#define MIPI_PD_RX 0xb0 +#define MIPI_PD_TERM 0xb1 +#define MIPI_PD_HSRX 0xb2 +#define MIPI_PD_LPTX 0xb3 +#define MIPI_PD_LPRX 0xb4 +#define MIPI_PD_CK_LANE 0xb5 +#define MIPI_FORCE_0 0xb6 +#define MIPI_RST_CTRL 0xb7 +#define MIPI_RST_NUM 0xb8 +#define MIPI_DBG_SET_(n) (0xc0 + ((n) & 0xf)) /* 0..9 */ +#define MIPI_DBG_SEL 0xe0 +#define MIPI_DBG_DATA 0xe1 +#define MIPI_ATE_TEST_SEL 0xe2 +#define MIPI_ATE_STATUS_(n) (0xe3 + ((n) & 0x1)) /* 0..1 */ +#define MIPI_ATE_STATUS_1 0xe4 +#define ICN6211_MAX_REGISTER MIPI_ATE_STATUS(1)
struct chipone { struct device *dev; @@ -64,13 +164,13 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, struct chipone *icn = bridge_to_chipone(bridge); struct drm_display_mode *mode = &icn->mode;
- ICN6211_DSI(icn, 0x7a, 0xc1); + ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI);
ICN6211_DSI(icn, HACTIVE_LI, mode->hdisplay & 0xff);
ICN6211_DSI(icn, VACTIVE_LI, mode->vdisplay & 0xff);
- /** + /* * lsb nibble: 2nd nibble of hdisplay * msb nibble: 2nd nibble of vdisplay */ @@ -93,21 +193,21 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, ICN6211_DSI(icn, VBP, mode->vtotal - mode->vsync_end);
/* dsi specific sequence */ - ICN6211_DSI(icn, MIPI_DCS_SET_TEAR_OFF, 0x80); - ICN6211_DSI(icn, MIPI_DCS_SET_ADDRESS_MODE, 0x28); - ICN6211_DSI(icn, 0xb5, 0xa0); - ICN6211_DSI(icn, 0x5c, 0xff); - ICN6211_DSI(icn, MIPI_DCS_SET_COLUMN_ADDRESS, 0x01); - ICN6211_DSI(icn, MIPI_DCS_GET_POWER_SAVE, 0x92); - ICN6211_DSI(icn, 0x6b, 0x71); - ICN6211_DSI(icn, 0x69, 0x2b); - ICN6211_DSI(icn, MIPI_DCS_ENTER_SLEEP_MODE, 0x40); - ICN6211_DSI(icn, MIPI_DCS_EXIT_SLEEP_MODE, 0x98); + ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80); + ICN6211_DSI(icn, HFP_MIN, 0x28); + ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0); + ICN6211_DSI(icn, PLL_CTRL(12), 0xff); + ICN6211_DSI(icn, BIST_POL, BIST_POL_DE_POL); + ICN6211_DSI(icn, PLL_CTRL(6), PLL_CTRL_6_MIPI_CLK); + ICN6211_DSI(icn, PLL_REF_DIV, 0x71); + ICN6211_DSI(icn, PLL_INT(0), 0x2b); + ICN6211_DSI(icn, SYS_CTRL(0), 0x40); + ICN6211_DSI(icn, SYS_CTRL(1), 0x98);
/* icn6211 specific sequence */ - ICN6211_DSI(icn, 0xb6, 0x20); - ICN6211_DSI(icn, 0x51, 0x20); - ICN6211_DSI(icn, 0x09, 0x10); + ICN6211_DSI(icn, MIPI_FORCE_0, 0x20); + ICN6211_DSI(icn, PLL_CTRL(1), 0x20); + ICN6211_DSI(icn, CONFIG_FINISH, 0x10);
usleep_range(10000, 11000); }
The HFP_HSW_HBP_HI register must be programmed with 2 LSbits of each Horizontal Front Porch/Sync/Back Porch. Currently the driver programs this register to 0, which breaks displays with either value above 255.
The HFP_MIN register must be set to the same value as HFP_LI, otherwise there is visible image distortion, usually in the form of missing lines at the bottom of the panel.
Fix this by correctly programming the HFP_HSW_HBP_HI and HFP_MIN registers.
Acked-by: Maxime Ripard maxime@cerno.tech Fixes: ce517f18944e3 ("drm: bridge: Add Chipone ICN6211 MIPI-DSI to RGB bridge") Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index 4b8d1a5a50302..e29e6a84c39a6 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -35,6 +35,9 @@ #define HSYNC_LI 0x24 #define HBP_LI 0x25 #define HFP_HSW_HBP_HI 0x26 +#define HFP_HSW_HBP_HI_HFP(n) (((n) & 0x300) >> 4) +#define HFP_HSW_HBP_HI_HS(n) (((n) & 0x300) >> 6) +#define HFP_HSW_HBP_HI_HBP(n) (((n) & 0x300) >> 8) #define VFP 0x27 #define VSYNC 0x28 #define VBP 0x29 @@ -163,6 +166,7 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, { struct chipone *icn = bridge_to_chipone(bridge); struct drm_display_mode *mode = &icn->mode; + u16 hfp, hbp, hsync;
ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI);
@@ -178,13 +182,18 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, ((mode->hdisplay >> 8) & 0xf) | (((mode->vdisplay >> 8) & 0xf) << 4));
- ICN6211_DSI(icn, HFP_LI, mode->hsync_start - mode->hdisplay); + hfp = mode->hsync_start - mode->hdisplay; + hsync = mode->hsync_end - mode->hsync_start; + hbp = mode->htotal - mode->hsync_end;
- ICN6211_DSI(icn, HSYNC_LI, mode->hsync_end - mode->hsync_start); - - ICN6211_DSI(icn, HBP_LI, mode->htotal - mode->hsync_end); - - ICN6211_DSI(icn, HFP_HSW_HBP_HI, 0x00); + ICN6211_DSI(icn, HFP_LI, hfp & 0xff); + ICN6211_DSI(icn, HSYNC_LI, hsync & 0xff); + ICN6211_DSI(icn, HBP_LI, hbp & 0xff); + /* Top two bits of Horizontal Front porch/Sync/Back porch */ + ICN6211_DSI(icn, HFP_HSW_HBP_HI, + HFP_HSW_HBP_HI_HFP(hfp) | + HFP_HSW_HBP_HI_HS(hsync) | + HFP_HSW_HBP_HI_HBP(hbp));
ICN6211_DSI(icn, VFP, mode->vsync_start - mode->vdisplay);
@@ -194,7 +203,7 @@ static void chipone_atomic_enable(struct drm_bridge *bridge,
/* dsi specific sequence */ ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80); - ICN6211_DSI(icn, HFP_MIN, 0x28); + ICN6211_DSI(icn, HFP_MIN, hfp & 0xff); ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0); ICN6211_DSI(icn, PLL_CTRL(12), 0xff); ICN6211_DSI(icn, BIST_POL, BIST_POL_DE_POL);
The driver currently hard-codes HS/VS polarity to active-low and DE to active-high, which is not correct for a lot of supported DPI panels. Add the missing mode flag handling for HS/VS/DE polarity.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: No change --- drivers/gpu/drm/bridge/chipone-icn6211.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index e29e6a84c39a6..2ac8eb7e25f52 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -165,8 +165,16 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, struct drm_bridge_state *old_bridge_state) { struct chipone *icn = bridge_to_chipone(bridge); + struct drm_atomic_state *state = old_bridge_state->base.state; struct drm_display_mode *mode = &icn->mode; + const struct drm_bridge_state *bridge_state; u16 hfp, hbp, hsync; + u32 bus_flags; + u8 pol; + + /* Get the DPI flags from the bridge state. */ + bridge_state = drm_atomic_get_new_bridge_state(state, bridge); + bus_flags = bridge_state->output_bus_cfg.flags;
ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI);
@@ -206,7 +214,13 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, ICN6211_DSI(icn, HFP_MIN, hfp & 0xff); ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0); ICN6211_DSI(icn, PLL_CTRL(12), 0xff); - ICN6211_DSI(icn, BIST_POL, BIST_POL_DE_POL); + + /* DPI HS/VS/DE polarity */ + pol = ((mode->flags & DRM_MODE_FLAG_PHSYNC) ? BIST_POL_HSYNC_POL : 0) | + ((mode->flags & DRM_MODE_FLAG_PVSYNC) ? BIST_POL_VSYNC_POL : 0) | + ((bus_flags & DRM_BUS_FLAG_DE_HIGH) ? BIST_POL_DE_POL : 0); + ICN6211_DSI(icn, BIST_POL, pol); + ICN6211_DSI(icn, PLL_CTRL(6), PLL_CTRL_6_MIPI_CLK); ICN6211_DSI(icn, PLL_REF_DIV, 0x71); ICN6211_DSI(icn, PLL_INT(0), 0x2b);
On Fri, Mar 04, 2022 at 01:24:59AM +0100, Marek Vasut wrote:
The driver currently hard-codes HS/VS polarity to active-low and DE to active-high, which is not correct for a lot of supported DPI panels. Add the missing mode flag handling for HS/VS/DE polarity.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org
Acked-by: Maxime Ripard maxime@cerno.tech
Maxime
The driver currently hard-codes DSI lane count to two, however the chip is capable of operating in 1..4 DSI lanes mode. Parse 'data-lanes' DT property and program the result into DSI_CTRL register.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Default to 4 data lanes unless specified otherwise --- drivers/gpu/drm/bridge/chipone-icn6211.c | 45 +++++++++++++++++++++--- 1 file changed, 41 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index 2ac8eb7e25f52..df8e75a068ad0 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -136,10 +136,12 @@ struct chipone { struct drm_bridge bridge; struct drm_display_mode mode; struct drm_bridge *panel_bridge; + struct device_node *host_node; struct gpio_desc *enable_gpio; struct regulator *vdd1; struct regulator *vdd2; struct regulator *vdd3; + int dsi_lanes; };
static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge) @@ -212,6 +214,11 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, /* dsi specific sequence */ ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80); ICN6211_DSI(icn, HFP_MIN, hfp & 0xff); + + /* DSI data lane count */ + ICN6211_DSI(icn, DSI_CTRL, + DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi_lanes - 1)); + ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0); ICN6211_DSI(icn, PLL_CTRL(12), 0xff);
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev; + struct device_node *endpoint; struct drm_panel *panel; + int dsi_lanes; int ret;
icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
+ endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); + icn->host_node = of_graph_get_remote_port_parent(endpoint); + of_node_put(endpoint); + + if (!icn->host_node) + return -ENODEV; + + /* + * If the 'data-lanes' property does not exist in DT or is invalid, + * default to previously hard-coded behavior, which was 4 data lanes. + */ + if (dsi_lanes < 0) { + icn->dsi_lanes = 4; + } else if (dsi_lanes > 4) { + ret = -EINVAL; + goto err_data_lanes; + } else { + icn->dsi_lanes = dsi_lanes; + } + ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL); if (ret) - return ret; + goto err_data_lanes;
icn->panel_bridge = devm_drm_panel_bridge_add(dev, panel); - if (IS_ERR(icn->panel_bridge)) - return PTR_ERR(icn->panel_bridge); + if (IS_ERR(icn->panel_bridge)) { + ret = PTR_ERR(icn->panel_bridge); + goto err_data_lanes; + }
return 0; + +err_data_lanes: + of_node_put(icn->host_node); + return ret; }
static int chipone_probe(struct mipi_dsi_device *dsi) @@ -384,7 +420,7 @@ static int chipone_probe(struct mipi_dsi_device *dsi)
drm_bridge_add(&icn->bridge);
- dsi->lanes = 4; + dsi->lanes = icn->dsi_lanes; dsi->format = MIPI_DSI_FMT_RGB888; dsi->mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
@@ -403,6 +439,7 @@ static int chipone_remove(struct mipi_dsi_device *dsi)
mipi_dsi_detach(dsi); drm_bridge_remove(&icn->bridge); + of_node_put(icn->host_node);
return 0; }
Hi Marek,
On Fri, Mar 4, 2022 at 5:55 AM Marek Vasut marex@denx.de wrote:
The driver currently hard-codes DSI lane count to two, however the chip is capable of operating in 1..4 DSI lanes mode. Parse 'data-lanes' DT property and program the result into DSI_CTRL register.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org
V2: Rebase on next-20220214 V3: Default to 4 data lanes unless specified otherwise
drivers/gpu/drm/bridge/chipone-icn6211.c | 45 +++++++++++++++++++++--- 1 file changed, 41 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index 2ac8eb7e25f52..df8e75a068ad0 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -136,10 +136,12 @@ struct chipone { struct drm_bridge bridge; struct drm_display_mode mode; struct drm_bridge *panel_bridge;
struct device_node *host_node; struct gpio_desc *enable_gpio; struct regulator *vdd1; struct regulator *vdd2; struct regulator *vdd3;int dsi_lanes;};
static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge) @@ -212,6 +214,11 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, /* dsi specific sequence */ ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80); ICN6211_DSI(icn, HFP_MIN, hfp & 0xff);
/* DSI data lane count */ICN6211_DSI(icn, DSI_CTRL,DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi_lanes - 1));ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0); ICN6211_DSI(icn, PLL_CTRL(12), 0xff);@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;
The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
[1] https://patchwork.amarulasolutions.com/patch/1805/
Thanks, Jagan.
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
Example OF-graph is on the commit message. https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/d...
Jagan.
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1
So port@0 is mandatory.
So I don't think any change is needed to this patch ?
Example OF-graph is on the commit message. https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/d...
It seems the current upstream DT bindings only support DSI hosts which do provide an endpoint, because port@0 is required per DT binding document. If you want to support the other options as listed in the aforementioned commit, then you would have to extend this driver and its bindings, but that is out of scope of this series.
Hi Marek,
On Tue, Mar 8, 2022 at 4:00 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
So I don't think any change is needed to this patch ?
Example OF-graph is on the commit message. https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/d...
It seems the current upstream DT bindings only support DSI hosts which do provide an endpoint, because port@0 is required per DT binding document. If you want to support the other options as listed in the aforementioned commit, then you would have to extend this driver and its bindings, but that is out of scope of this series.
Your comments seem to be valid, thanks.
Jagan.
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
Maxime
On 3/8/22 13:51, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
That's out of scope of this series anyway, so Jagan can implement patches for that mode if needed.
On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote:
On 3/8/22 13:51, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > static int chipone_parse_dt(struct chipone *icn) > { > struct device *dev = icn->dev; > + struct device_node *endpoint; > struct drm_panel *panel; > + int dsi_lanes; > int ret; > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > return PTR_ERR(icn->enable_gpio); > } > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > + of_node_put(endpoint); > + > + if (!icn->host_node) > + return -ENODEV;
The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
That's out of scope of this series anyway, so Jagan can implement patches for that mode if needed.
Not really? You can't count on the port@0 being there generally speaking, so you can't count on data-lanes being there either, which exactly what you're doing in this patch.
Maxime
On 3/8/22 14:49, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote:
On 3/8/22 13:51, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >> static int chipone_parse_dt(struct chipone *icn) >> { >> struct device *dev = icn->dev; >> + struct device_node *endpoint; >> struct drm_panel *panel; >> + int dsi_lanes; >> int ret; >> >> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >> return PTR_ERR(icn->enable_gpio); >> } >> >> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >> + of_node_put(endpoint); >> + >> + if (!icn->host_node) >> + return -ENODEV; > > The non-ports-based OF graph returns a -19 example on the Allwinner > Display pipeline in R16 [1]. > > We need to have a helper to return host_node for non-ports as I have > done it for drm_of_find_bridge. > > [1] https://patchwork.amarulasolutions.com/patch/1805/
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
That's out of scope of this series anyway, so Jagan can implement patches for that mode if needed.
Not really? You can't count on the port@0 being there generally speaking, so you can't count on data-lanes being there either, which exactly what you're doing in this patch.
I can because the upstream DT bindings currently say port@0 must be present, see above. If that requirement should be relaxed, sure, but that's a separate series.
On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote:
On 3/8/22 14:49, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote:
On 3/8/22 13:51, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: > > On 3/8/22 09:03, Jagan Teki wrote: > > Hi, > > [...] > > > > @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > > > static int chipone_parse_dt(struct chipone *icn) > > > { > > > struct device *dev = icn->dev; > > > + struct device_node *endpoint; > > > struct drm_panel *panel; > > > + int dsi_lanes; > > > int ret; > > > > > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > > > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > > > return PTR_ERR(icn->enable_gpio); > > > } > > > > > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > > > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > > > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > > > + of_node_put(endpoint); > > > + > > > + if (!icn->host_node) > > > + return -ENODEV; > > > > The non-ports-based OF graph returns a -19 example on the Allwinner > > Display pipeline in R16 [1]. > > > > We need to have a helper to return host_node for non-ports as I have > > done it for drm_of_find_bridge. > > > > [1] https://patchwork.amarulasolutions.com/patch/1805/ > > The link points to a patch marked "DO NOT MERGE", maybe that patch is > missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are > required, see: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... > > What is "non-ports-based OF graph" ? > > I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
That's out of scope of this series anyway, so Jagan can implement patches for that mode if needed.
Not really? You can't count on the port@0 being there generally speaking, so you can't count on data-lanes being there either, which exactly what you're doing in this patch.
I can because the upstream DT bindings currently say port@0 must be present, see above. If that requirement should be relaxed, sure, but that's a separate series.
And another upstream DT bindings say that you don't need them at all. Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI binding is far more relevant than a single bridge driver.
So figuring it out is very much a prerequisite to that series, especially since those patches effectively make the OF-graph mandatory in some situations, while it was purely aesthetics before.
Maxime
On 3/8/22 17:21, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote:
On 3/8/22 14:49, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote:
On 3/8/22 13:51, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote: > On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: >> >> On 3/8/22 09:03, Jagan Teki wrote: >> >> Hi, >> >> [...] >> >>>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >>>> static int chipone_parse_dt(struct chipone *icn) >>>> { >>>> struct device *dev = icn->dev; >>>> + struct device_node *endpoint; >>>> struct drm_panel *panel; >>>> + int dsi_lanes; >>>> int ret; >>>> >>>> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >>>> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >>>> return PTR_ERR(icn->enable_gpio); >>>> } >>>> >>>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >>>> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >>>> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >>>> + of_node_put(endpoint); >>>> + >>>> + if (!icn->host_node) >>>> + return -ENODEV; >>> >>> The non-ports-based OF graph returns a -19 example on the Allwinner >>> Display pipeline in R16 [1]. >>> >>> We need to have a helper to return host_node for non-ports as I have >>> done it for drm_of_find_bridge. >>> >>> [1] https://patchwork.amarulasolutions.com/patch/1805/ >> >> The link points to a patch marked "DO NOT MERGE", maybe that patch is >> missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are >> required, see: >> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >> >> What is "non-ports-based OF graph" ? >> >> I don't see drm_of_find_bridge() in linux-next , what is that ? > > port@0 is optional as some of the DSI host OF-graph represent the > bridge or panel as child nodes instead of ports. (i think dt-binding > has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
That's out of scope of this series anyway, so Jagan can implement patches for that mode if needed.
Not really? You can't count on the port@0 being there generally speaking, so you can't count on data-lanes being there either, which exactly what you're doing in this patch.
I can because the upstream DT bindings currently say port@0 must be present, see above. If that requirement should be relaxed, sure, but that's a separate series.
And another upstream DT bindings say that you don't need them at all.
Which "another upstream DT bindings" do you refer to ?
Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI binding is far more relevant than a single bridge driver.
That seems to be the wrong way around, how can generic subsystem-wide binding take precedence over specific driver binding ?
So figuring it out is very much a prerequisite to that series, especially since those patches effectively make the OF-graph mandatory in some situations, while it was purely aesthetics before.
The OF-graph is mandatory per the DT bindings of this driver. If you implement invalid DT which does not contain port@0, it will fail DT validation.
If this requirement should be relaxed, sure, it can and I don't think it would be hard to do, but I don't see why that should be part of this series, which follows the upstream DT binding document for this driver.
If I cannot trust the driver DT bindings to indicate what is and is not mandatory, what other document can I trust then ...
On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote:
On 3/8/22 17:21, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote:
On 3/8/22 14:49, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote:
On 3/8/22 13:51, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: > On 3/8/22 11:07, Jagan Teki wrote: > > On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: > > > > > > On 3/8/22 09:03, Jagan Teki wrote: > > > > > > Hi, > > > > > > [...] > > > > > > > > @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > > > > > static int chipone_parse_dt(struct chipone *icn) > > > > > { > > > > > struct device *dev = icn->dev; > > > > > + struct device_node *endpoint; > > > > > struct drm_panel *panel; > > > > > + int dsi_lanes; > > > > > int ret; > > > > > > > > > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > > > > > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > > > > > return PTR_ERR(icn->enable_gpio); > > > > > } > > > > > > > > > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > > > > > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > > > > > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > > > > > + of_node_put(endpoint); > > > > > + > > > > > + if (!icn->host_node) > > > > > + return -ENODEV; > > > > > > > > The non-ports-based OF graph returns a -19 example on the Allwinner > > > > Display pipeline in R16 [1]. > > > > > > > > We need to have a helper to return host_node for non-ports as I have > > > > done it for drm_of_find_bridge. > > > > > > > > [1] https://patchwork.amarulasolutions.com/patch/1805/ > > > > > > The link points to a patch marked "DO NOT MERGE", maybe that patch is > > > missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are > > > required, see: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... > > > > > > What is "non-ports-based OF graph" ? > > > > > > I don't see drm_of_find_bridge() in linux-next , what is that ? > > > > port@0 is optional as some of the DSI host OF-graph represent the > > bridge or panel as child nodes instead of ports. (i think dt-binding > > has to fix it to make port@0 optional) > > The current upstream DT binding document says: > > required: > - port@0 > - port@1 > > So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
That's out of scope of this series anyway, so Jagan can implement patches for that mode if needed.
Not really? You can't count on the port@0 being there generally speaking, so you can't count on data-lanes being there either, which exactly what you're doing in this patch.
I can because the upstream DT bindings currently say port@0 must be present, see above. If that requirement should be relaxed, sure, but that's a separate series.
And another upstream DT bindings say that you don't need them at all.
Which "another upstream DT bindings" do you refer to ?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI binding is far more relevant than a single bridge driver.
That seems to be the wrong way around, how can generic subsystem-wide binding take precedence over specific driver binding ?
This is the binding of the bus. You're part of that bus. You're a child node of that bus, but nothing ever mandates that your parent node uses the same convention. And some don't. And since your bridge can be connected to pretty much any DSI controller, you have to use the lowest common denominator, not make up some new constraints that not all controller will be able to comply with.
So figuring it out is very much a prerequisite to that series, especially since those patches effectively make the OF-graph mandatory in some situations, while it was purely aesthetics before.
The OF-graph is mandatory per the DT bindings of this driver. If you implement invalid DT which does not contain port@0, it will fail DT validation.
If this requirement should be relaxed, sure, it can and I don't think it would be hard to do, but I don't see why that should be part of this series, which follows the upstream DT binding document for this driver.
If I cannot trust the driver DT bindings to indicate what is and is not mandatory, what other document can I trust then ...
Oh, come on. Doing that, you also require OF-Graph support for the DSI controller you attach to, and you can't require that. This is very different from just requiring a property that doesn't have any impact on any other device, and you know that very well.
Anyway, you wanted my review. You have it. Do what you want with it.
Maxime
On 3/10/22 11:53, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote:
On 3/8/22 17:21, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote:
On 3/8/22 14:49, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote:
On 3/8/22 13:51, Maxime Ripard wrote: > On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: >> On 3/8/22 11:07, Jagan Teki wrote: >>> On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: >>>> >>>> On 3/8/22 09:03, Jagan Teki wrote: >>>> >>>> Hi, >>>> >>>> [...] >>>> >>>>>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >>>>>> static int chipone_parse_dt(struct chipone *icn) >>>>>> { >>>>>> struct device *dev = icn->dev; >>>>>> + struct device_node *endpoint; >>>>>> struct drm_panel *panel; >>>>>> + int dsi_lanes; >>>>>> int ret; >>>>>> >>>>>> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >>>>>> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >>>>>> return PTR_ERR(icn->enable_gpio); >>>>>> } >>>>>> >>>>>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >>>>>> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >>>>>> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >>>>>> + of_node_put(endpoint); >>>>>> + >>>>>> + if (!icn->host_node) >>>>>> + return -ENODEV; >>>>> >>>>> The non-ports-based OF graph returns a -19 example on the Allwinner >>>>> Display pipeline in R16 [1]. >>>>> >>>>> We need to have a helper to return host_node for non-ports as I have >>>>> done it for drm_of_find_bridge. >>>>> >>>>> [1] https://patchwork.amarulasolutions.com/patch/1805/ >>>> >>>> The link points to a patch marked "DO NOT MERGE", maybe that patch is >>>> missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are >>>> required, see: >>>> >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >>>> >>>> What is "non-ports-based OF graph" ? >>>> >>>> I don't see drm_of_find_bridge() in linux-next , what is that ? >>> >>> port@0 is optional as some of the DSI host OF-graph represent the >>> bridge or panel as child nodes instead of ports. (i think dt-binding >>> has to fix it to make port@0 optional) >> >> The current upstream DT binding document says: >> >> required: >> - port@0 >> - port@1 >> >> So port@0 is mandatory. > > In the binding, sure, but fundamentally the DT excerpt Jagan provided is > correct. If the bridge supports DCS, there's no reason to use the OF > graph in the first place: the bridge node will be a child node of the > MIPI-DSI controller (and there's no obligation to use the OF-graph for a > MIPI-DSI controller). > > I believe port@0 should be made optional (or downright removed if > MIPI-DCS in the only control bus).
That's out of scope of this series anyway, so Jagan can implement patches for that mode if needed.
Not really? You can't count on the port@0 being there generally speaking, so you can't count on data-lanes being there either, which exactly what you're doing in this patch.
I can because the upstream DT bindings currently say port@0 must be present, see above. If that requirement should be relaxed, sure, but that's a separate series.
And another upstream DT bindings say that you don't need them at all.
Which "another upstream DT bindings" do you refer to ?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI binding is far more relevant than a single bridge driver.
That seems to be the wrong way around, how can generic subsystem-wide binding take precedence over specific driver binding ?
This is the binding of the bus. You're part of that bus. You're a child node of that bus, but nothing ever mandates that your parent node uses the same convention. And some don't. And since your bridge can be connected to pretty much any DSI controller, you have to use the lowest common denominator, not make up some new constraints that not all controller will be able to comply with.
It seems to me the ICN6211 DT bindings currently further constraint the generic DSI bus bindings, and that seems OK to me.
Let me reiterate this again -- if someone wants to relax the requirements currently imposed by the ICN6211 DT bindings, fine, but that can be done in a separate patchset AND that needs DT bindings update. Furthermore, there are no users of this ICN6211 bridge in upstream DTs, so there is currently no bridge which would operate without OF graph using this driver.
So figuring it out is very much a prerequisite to that series, especially since those patches effectively make the OF-graph mandatory in some situations, while it was purely aesthetics before.
The OF-graph is mandatory per the DT bindings of this driver. If you implement invalid DT which does not contain port@0, it will fail DT validation.
If this requirement should be relaxed, sure, it can and I don't think it would be hard to do, but I don't see why that should be part of this series, which follows the upstream DT binding document for this driver.
If I cannot trust the driver DT bindings to indicate what is and is not mandatory, what other document can I trust then ...
Oh, come on. Doing that, you also require OF-Graph support for the DSI controller you attach to, and you can't require that. This is very different from just requiring a property that doesn't have any impact on any other device, and you know that very well.
Currently the ICN6211 DT bindings DO require that kind of bridge.
The new ad-hoc requirement to support operation with invalid DT bindings is something I don't agree with, sorry. But there is a way to cater for this new requirement, see above. It just won't be in this series, because I have no such bridge and I cannot test it in any way, so someone else has to do that.
Anyway, you wanted my review. You have it. Do what you want with it.
I see.
On Thu, Mar 10, 2022 at 01:47:13PM +0100, Marek Vasut wrote:
On 3/10/22 11:53, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote:
On 3/8/22 17:21, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote:
On 3/8/22 14:49, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote: > On 3/8/22 13:51, Maxime Ripard wrote: > > On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: > > > On 3/8/22 11:07, Jagan Teki wrote: > > > > On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: > > > > > > > > > > On 3/8/22 09:03, Jagan Teki wrote: > > > > > > > > > > Hi, > > > > > > > > > > [...] > > > > > > > > > > > > @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > > > > > > > static int chipone_parse_dt(struct chipone *icn) > > > > > > > { > > > > > > > struct device *dev = icn->dev; > > > > > > > + struct device_node *endpoint; > > > > > > > struct drm_panel *panel; > > > > > > > + int dsi_lanes; > > > > > > > int ret; > > > > > > > > > > > > > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > > > > > > > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > > > > > > > return PTR_ERR(icn->enable_gpio); > > > > > > > } > > > > > > > > > > > > > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > > > > > > > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > > > > > > > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > > > > > > > + of_node_put(endpoint); > > > > > > > + > > > > > > > + if (!icn->host_node) > > > > > > > + return -ENODEV; > > > > > > > > > > > > The non-ports-based OF graph returns a -19 example on the Allwinner > > > > > > Display pipeline in R16 [1]. > > > > > > > > > > > > We need to have a helper to return host_node for non-ports as I have > > > > > > done it for drm_of_find_bridge. > > > > > > > > > > > > [1] https://patchwork.amarulasolutions.com/patch/1805/ > > > > > > > > > > The link points to a patch marked "DO NOT MERGE", maybe that patch is > > > > > missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are > > > > > required, see: > > > > > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... > > > > > > > > > > What is "non-ports-based OF graph" ? > > > > > > > > > > I don't see drm_of_find_bridge() in linux-next , what is that ? > > > > > > > > port@0 is optional as some of the DSI host OF-graph represent the > > > > bridge or panel as child nodes instead of ports. (i think dt-binding > > > > has to fix it to make port@0 optional) > > > > > > The current upstream DT binding document says: > > > > > > required: > > > - port@0 > > > - port@1 > > > > > > So port@0 is mandatory. > > > > In the binding, sure, but fundamentally the DT excerpt Jagan provided is > > correct. If the bridge supports DCS, there's no reason to use the OF > > graph in the first place: the bridge node will be a child node of the > > MIPI-DSI controller (and there's no obligation to use the OF-graph for a > > MIPI-DSI controller). > > > > I believe port@0 should be made optional (or downright removed if > > MIPI-DCS in the only control bus). > > That's out of scope of this series anyway, so Jagan can implement patches > for that mode if needed.
Not really? You can't count on the port@0 being there generally speaking, so you can't count on data-lanes being there either, which exactly what you're doing in this patch.
I can because the upstream DT bindings currently say port@0 must be present, see above. If that requirement should be relaxed, sure, but that's a separate series.
And another upstream DT bindings say that you don't need them at all.
Which "another upstream DT bindings" do you refer to ?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI binding is far more relevant than a single bridge driver.
That seems to be the wrong way around, how can generic subsystem-wide binding take precedence over specific driver binding ?
This is the binding of the bus. You're part of that bus. You're a child node of that bus, but nothing ever mandates that your parent node uses the same convention. And some don't. And since your bridge can be connected to pretty much any DSI controller, you have to use the lowest common denominator, not make up some new constraints that not all controller will be able to comply with.
It seems to me the ICN6211 DT bindings currently further constraint the generic DSI bus bindings, and that seems OK to me.
Let me reiterate this again -- if someone wants to relax the requirements currently imposed by the ICN6211 DT bindings, fine, but that can be done in a separate patchset AND that needs DT bindings update. Furthermore, there are no users of this ICN6211 bridge in upstream DTs, so there is currently no bridge which would operate without OF graph using this driver.
And let me reiterate this again: something that used to work for a user doesn't anymore when your series is applied. This is a textbook regression. I suggested a way forward, that you don't like for some reason, fine. But pushing through a regression is just not acceptable.
So figuring it out is very much a prerequisite to that series, especially since those patches effectively make the OF-graph mandatory in some situations, while it was purely aesthetics before.
The OF-graph is mandatory per the DT bindings of this driver. If you implement invalid DT which does not contain port@0, it will fail DT validation.
If this requirement should be relaxed, sure, it can and I don't think it would be hard to do, but I don't see why that should be part of this series, which follows the upstream DT binding document for this driver.
If I cannot trust the driver DT bindings to indicate what is and is not mandatory, what other document can I trust then ...
Oh, come on. Doing that, you also require OF-Graph support for the DSI controller you attach to, and you can't require that. This is very different from just requiring a property that doesn't have any impact on any other device, and you know that very well.
Currently the ICN6211 DT bindings DO require that kind of bridge.
And while this wasn't enforced before, you make it a hard requirement with this series. This is what changed, and what caused this whole discussion.
Maxime
On 3/10/22 15:18, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 01:47:13PM +0100, Marek Vasut wrote:
On 3/10/22 11:53, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote:
On 3/8/22 17:21, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote:
On 3/8/22 14:49, Maxime Ripard wrote: > On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote: >> On 3/8/22 13:51, Maxime Ripard wrote: >>> On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: >>>> On 3/8/22 11:07, Jagan Teki wrote: >>>>> On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: >>>>>> >>>>>> On 3/8/22 09:03, Jagan Teki wrote: >>>>>> >>>>>> Hi, >>>>>> >>>>>> [...] >>>>>> >>>>>>>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >>>>>>>> static int chipone_parse_dt(struct chipone *icn) >>>>>>>> { >>>>>>>> struct device *dev = icn->dev; >>>>>>>> + struct device_node *endpoint; >>>>>>>> struct drm_panel *panel; >>>>>>>> + int dsi_lanes; >>>>>>>> int ret; >>>>>>>> >>>>>>>> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >>>>>>>> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >>>>>>>> return PTR_ERR(icn->enable_gpio); >>>>>>>> } >>>>>>>> >>>>>>>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >>>>>>>> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >>>>>>>> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >>>>>>>> + of_node_put(endpoint); >>>>>>>> + >>>>>>>> + if (!icn->host_node) >>>>>>>> + return -ENODEV; >>>>>>> >>>>>>> The non-ports-based OF graph returns a -19 example on the Allwinner >>>>>>> Display pipeline in R16 [1]. >>>>>>> >>>>>>> We need to have a helper to return host_node for non-ports as I have >>>>>>> done it for drm_of_find_bridge. >>>>>>> >>>>>>> [1] https://patchwork.amarulasolutions.com/patch/1805/ >>>>>> >>>>>> The link points to a patch marked "DO NOT MERGE", maybe that patch is >>>>>> missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are >>>>>> required, see: >>>>>> >>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >>>>>> >>>>>> What is "non-ports-based OF graph" ? >>>>>> >>>>>> I don't see drm_of_find_bridge() in linux-next , what is that ? >>>>> >>>>> port@0 is optional as some of the DSI host OF-graph represent the >>>>> bridge or panel as child nodes instead of ports. (i think dt-binding >>>>> has to fix it to make port@0 optional) >>>> >>>> The current upstream DT binding document says: >>>> >>>> required: >>>> - port@0 >>>> - port@1 >>>> >>>> So port@0 is mandatory. >>> >>> In the binding, sure, but fundamentally the DT excerpt Jagan provided is >>> correct. If the bridge supports DCS, there's no reason to use the OF >>> graph in the first place: the bridge node will be a child node of the >>> MIPI-DSI controller (and there's no obligation to use the OF-graph for a >>> MIPI-DSI controller). >>> >>> I believe port@0 should be made optional (or downright removed if >>> MIPI-DCS in the only control bus). >> >> That's out of scope of this series anyway, so Jagan can implement patches >> for that mode if needed. > > Not really? You can't count on the port@0 being there generally > speaking, so you can't count on data-lanes being there either, which > exactly what you're doing in this patch.
I can because the upstream DT bindings currently say port@0 must be present, see above. If that requirement should be relaxed, sure, but that's a separate series.
And another upstream DT bindings say that you don't need them at all.
Which "another upstream DT bindings" do you refer to ?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI binding is far more relevant than a single bridge driver.
That seems to be the wrong way around, how can generic subsystem-wide binding take precedence over specific driver binding ?
This is the binding of the bus. You're part of that bus. You're a child node of that bus, but nothing ever mandates that your parent node uses the same convention. And some don't. And since your bridge can be connected to pretty much any DSI controller, you have to use the lowest common denominator, not make up some new constraints that not all controller will be able to comply with.
It seems to me the ICN6211 DT bindings currently further constraint the generic DSI bus bindings, and that seems OK to me.
Let me reiterate this again -- if someone wants to relax the requirements currently imposed by the ICN6211 DT bindings, fine, but that can be done in a separate patchset AND that needs DT bindings update. Furthermore, there are no users of this ICN6211 bridge in upstream DTs, so there is currently no bridge which would operate without OF graph using this driver.
And let me reiterate this again: something that used to work for a user doesn't anymore when your series is applied. This is a textbook regression. I suggested a way forward, that you don't like for some reason, fine. But pushing through a regression is just not acceptable.
How can this be a regression if this mode of operation could not have ever been supported with valid upstream DT bindings in the first place ?
Should we now require that kernel drivers somehow magically support all kinds of random broken DT bindings in addition to ones which pass YAML DT validation ?
So figuring it out is very much a prerequisite to that series, especially since those patches effectively make the OF-graph mandatory in some situations, while it was purely aesthetics before.
The OF-graph is mandatory per the DT bindings of this driver. If you implement invalid DT which does not contain port@0, it will fail DT validation.
If this requirement should be relaxed, sure, it can and I don't think it would be hard to do, but I don't see why that should be part of this series, which follows the upstream DT binding document for this driver.
If I cannot trust the driver DT bindings to indicate what is and is not mandatory, what other document can I trust then ...
Oh, come on. Doing that, you also require OF-Graph support for the DSI controller you attach to, and you can't require that. This is very different from just requiring a property that doesn't have any impact on any other device, and you know that very well.
Currently the ICN6211 DT bindings DO require that kind of bridge.
And while this wasn't enforced before, you make it a hard requirement with this series. This is what changed, and what caused this whole discussion.
The current DT bindings already make it a hard requirement, so no, nothing changed here.
Unless what you are trying to ask for is support for broken DT bindings which do not pass YAML DT validation by this driver, but that is very dangerous, because then the question is, how far should we support such broken bindings. What kind of broken is still OK and what kind of broken is no longer OK ?
On Fri, Mar 11, 2022 at 11:36:58AM +0100, Marek Vasut wrote:
On 3/10/22 15:18, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 01:47:13PM +0100, Marek Vasut wrote:
On 3/10/22 11:53, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote:
On 3/8/22 17:21, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote: > On 3/8/22 14:49, Maxime Ripard wrote: > > On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote: > > > On 3/8/22 13:51, Maxime Ripard wrote: > > > > On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: > > > > > On 3/8/22 11:07, Jagan Teki wrote: > > > > > > On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: > > > > > > > > > > > > > > On 3/8/22 09:03, Jagan Teki wrote: > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > [...] > > > > > > > > > > > > > > > > @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > > > > > > > > > static int chipone_parse_dt(struct chipone *icn) > > > > > > > > > { > > > > > > > > > struct device *dev = icn->dev; > > > > > > > > > + struct device_node *endpoint; > > > > > > > > > struct drm_panel *panel; > > > > > > > > > + int dsi_lanes; > > > > > > > > > int ret; > > > > > > > > > > > > > > > > > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > > > > > > > > > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > > > > > > > > > return PTR_ERR(icn->enable_gpio); > > > > > > > > > } > > > > > > > > > > > > > > > > > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > > > > > > > > > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > > > > > > > > > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > > > > > > > > > + of_node_put(endpoint); > > > > > > > > > + > > > > > > > > > + if (!icn->host_node) > > > > > > > > > + return -ENODEV; > > > > > > > > > > > > > > > > The non-ports-based OF graph returns a -19 example on the Allwinner > > > > > > > > Display pipeline in R16 [1]. > > > > > > > > > > > > > > > > We need to have a helper to return host_node for non-ports as I have > > > > > > > > done it for drm_of_find_bridge. > > > > > > > > > > > > > > > > [1] https://patchwork.amarulasolutions.com/patch/1805/ > > > > > > > > > > > > > > The link points to a patch marked "DO NOT MERGE", maybe that patch is > > > > > > > missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are > > > > > > > required, see: > > > > > > > > > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... > > > > > > > > > > > > > > What is "non-ports-based OF graph" ? > > > > > > > > > > > > > > I don't see drm_of_find_bridge() in linux-next , what is that ? > > > > > > > > > > > > port@0 is optional as some of the DSI host OF-graph represent the > > > > > > bridge or panel as child nodes instead of ports. (i think dt-binding > > > > > > has to fix it to make port@0 optional) > > > > > > > > > > The current upstream DT binding document says: > > > > > > > > > > required: > > > > > - port@0 > > > > > - port@1 > > > > > > > > > > So port@0 is mandatory. > > > > > > > > In the binding, sure, but fundamentally the DT excerpt Jagan provided is > > > > correct. If the bridge supports DCS, there's no reason to use the OF > > > > graph in the first place: the bridge node will be a child node of the > > > > MIPI-DSI controller (and there's no obligation to use the OF-graph for a > > > > MIPI-DSI controller). > > > > > > > > I believe port@0 should be made optional (or downright removed if > > > > MIPI-DCS in the only control bus). > > > > > > That's out of scope of this series anyway, so Jagan can implement patches > > > for that mode if needed. > > > > Not really? You can't count on the port@0 being there generally > > speaking, so you can't count on data-lanes being there either, which > > exactly what you're doing in this patch. > > I can because the upstream DT bindings currently say port@0 must be present, > see above. If that requirement should be relaxed, sure, but that's a > separate series.
And another upstream DT bindings say that you don't need them at all.
Which "another upstream DT bindings" do you refer to ?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI binding is far more relevant than a single bridge driver.
That seems to be the wrong way around, how can generic subsystem-wide binding take precedence over specific driver binding ?
This is the binding of the bus. You're part of that bus. You're a child node of that bus, but nothing ever mandates that your parent node uses the same convention. And some don't. And since your bridge can be connected to pretty much any DSI controller, you have to use the lowest common denominator, not make up some new constraints that not all controller will be able to comply with.
It seems to me the ICN6211 DT bindings currently further constraint the generic DSI bus bindings, and that seems OK to me.
Let me reiterate this again -- if someone wants to relax the requirements currently imposed by the ICN6211 DT bindings, fine, but that can be done in a separate patchset AND that needs DT bindings update. Furthermore, there are no users of this ICN6211 bridge in upstream DTs, so there is currently no bridge which would operate without OF graph using this driver.
And let me reiterate this again: something that used to work for a user doesn't anymore when your series is applied. This is a textbook regression. I suggested a way forward, that you don't like for some reason, fine. But pushing through a regression is just not acceptable.
How can this be a regression if this mode of operation could not have ever been supported with valid upstream DT bindings in the first place ?
Should we now require that kernel drivers somehow magically support all kinds of random broken DT bindings in addition to ones which pass YAML DT validation ?
The thing is, as I told you multiple times already, it was broken from the bridge standpoint, but not from the controller's. If it had been correct for the bridge, it wouldn't have been for the controller. So, same story.
The only difference is that it wouldn't affect you, but I don't see how it's relevant.
So figuring it out is very much a prerequisite to that series, especially since those patches effectively make the OF-graph mandatory in some situations, while it was purely aesthetics before.
The OF-graph is mandatory per the DT bindings of this driver. If you implement invalid DT which does not contain port@0, it will fail DT validation.
If this requirement should be relaxed, sure, it can and I don't think it would be hard to do, but I don't see why that should be part of this series, which follows the upstream DT binding document for this driver.
If I cannot trust the driver DT bindings to indicate what is and is not mandatory, what other document can I trust then ...
Oh, come on. Doing that, you also require OF-Graph support for the DSI controller you attach to, and you can't require that. This is very different from just requiring a property that doesn't have any impact on any other device, and you know that very well.
Currently the ICN6211 DT bindings DO require that kind of bridge.
And while this wasn't enforced before, you make it a hard requirement with this series. This is what changed, and what caused this whole discussion.
The current DT bindings already make it a hard requirement, so no, nothing changed here.
Unless what you are trying to ask for is support for broken DT bindings which do not pass YAML DT validation by this driver, but that is very dangerous, because then the question is, how far should we support such broken bindings. What kind of broken is still OK and what kind of broken is no longer OK ?
If it ever worked in a mainline release, it must always work. See: https://www.kernel.org/doc/html/latest/devicetree/bindings/ABI.html
As far as I'm concerned, it's the sole criteria. So to answer your question, if it was broken but worked at some point, yes, we need to keep supporting it. If it never worked, no, we don't.
Honestly, I don't get the push-back. To fix this properly would require: - to remove port@0 being mandatory - to move the data-lanes property to the bridge node itself.
That's it. It takes 5 minutes, 30 minutes with the test and the commit log. We've spent more time arguing about it already.
So if you want to continue debating on whether it's a regression or not, or whether DT ABI stability is a good thing or not, go ahead. But as far as I'm concerned, this isn't really up for debate.
Maxime
On 3/11/22 17:29, Maxime Ripard wrote:
On Fri, Mar 11, 2022 at 11:36:58AM +0100, Marek Vasut wrote:
On 3/10/22 15:18, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 01:47:13PM +0100, Marek Vasut wrote:
On 3/10/22 11:53, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote:
On 3/8/22 17:21, Maxime Ripard wrote: > On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote: >> On 3/8/22 14:49, Maxime Ripard wrote: >>> On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote: >>>> On 3/8/22 13:51, Maxime Ripard wrote: >>>>> On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: >>>>>> On 3/8/22 11:07, Jagan Teki wrote: >>>>>>> On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: >>>>>>>> >>>>>>>> On 3/8/22 09:03, Jagan Teki wrote: >>>>>>>> >>>>>>>> Hi, >>>>>>>> >>>>>>>> [...] >>>>>>>> >>>>>>>>>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >>>>>>>>>> static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>> { >>>>>>>>>> struct device *dev = icn->dev; >>>>>>>>>> + struct device_node *endpoint; >>>>>>>>>> struct drm_panel *panel; >>>>>>>>>> + int dsi_lanes; >>>>>>>>>> int ret; >>>>>>>>>> >>>>>>>>>> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >>>>>>>>>> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>> return PTR_ERR(icn->enable_gpio); >>>>>>>>>> } >>>>>>>>>> >>>>>>>>>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >>>>>>>>>> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >>>>>>>>>> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >>>>>>>>>> + of_node_put(endpoint); >>>>>>>>>> + >>>>>>>>>> + if (!icn->host_node) >>>>>>>>>> + return -ENODEV; >>>>>>>>> >>>>>>>>> The non-ports-based OF graph returns a -19 example on the Allwinner >>>>>>>>> Display pipeline in R16 [1]. >>>>>>>>> >>>>>>>>> We need to have a helper to return host_node for non-ports as I have >>>>>>>>> done it for drm_of_find_bridge. >>>>>>>>> >>>>>>>>> [1] https://patchwork.amarulasolutions.com/patch/1805/ >>>>>>>> >>>>>>>> The link points to a patch marked "DO NOT MERGE", maybe that patch is >>>>>>>> missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are >>>>>>>> required, see: >>>>>>>> >>>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >>>>>>>> >>>>>>>> What is "non-ports-based OF graph" ? >>>>>>>> >>>>>>>> I don't see drm_of_find_bridge() in linux-next , what is that ? >>>>>>> >>>>>>> port@0 is optional as some of the DSI host OF-graph represent the >>>>>>> bridge or panel as child nodes instead of ports. (i think dt-binding >>>>>>> has to fix it to make port@0 optional) >>>>>> >>>>>> The current upstream DT binding document says: >>>>>> >>>>>> required: >>>>>> - port@0 >>>>>> - port@1 >>>>>> >>>>>> So port@0 is mandatory. >>>>> >>>>> In the binding, sure, but fundamentally the DT excerpt Jagan provided is >>>>> correct. If the bridge supports DCS, there's no reason to use the OF >>>>> graph in the first place: the bridge node will be a child node of the >>>>> MIPI-DSI controller (and there's no obligation to use the OF-graph for a >>>>> MIPI-DSI controller). >>>>> >>>>> I believe port@0 should be made optional (or downright removed if >>>>> MIPI-DCS in the only control bus). >>>> >>>> That's out of scope of this series anyway, so Jagan can implement patches >>>> for that mode if needed. >>> >>> Not really? You can't count on the port@0 being there generally >>> speaking, so you can't count on data-lanes being there either, which >>> exactly what you're doing in this patch. >> >> I can because the upstream DT bindings currently say port@0 must be present, >> see above. If that requirement should be relaxed, sure, but that's a >> separate series. > > And another upstream DT bindings say that you don't need them at all.
Which "another upstream DT bindings" do you refer to ?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
> Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI > binding is far more relevant than a single bridge driver.
That seems to be the wrong way around, how can generic subsystem-wide binding take precedence over specific driver binding ?
This is the binding of the bus. You're part of that bus. You're a child node of that bus, but nothing ever mandates that your parent node uses the same convention. And some don't. And since your bridge can be connected to pretty much any DSI controller, you have to use the lowest common denominator, not make up some new constraints that not all controller will be able to comply with.
It seems to me the ICN6211 DT bindings currently further constraint the generic DSI bus bindings, and that seems OK to me.
Let me reiterate this again -- if someone wants to relax the requirements currently imposed by the ICN6211 DT bindings, fine, but that can be done in a separate patchset AND that needs DT bindings update. Furthermore, there are no users of this ICN6211 bridge in upstream DTs, so there is currently no bridge which would operate without OF graph using this driver.
And let me reiterate this again: something that used to work for a user doesn't anymore when your series is applied. This is a textbook regression. I suggested a way forward, that you don't like for some reason, fine. But pushing through a regression is just not acceptable.
How can this be a regression if this mode of operation could not have ever been supported with valid upstream DT bindings in the first place ?
Should we now require that kernel drivers somehow magically support all kinds of random broken DT bindings in addition to ones which pass YAML DT validation ?
The thing is, as I told you multiple times already, it was broken from the bridge standpoint, but not from the controller's. If it had been correct for the bridge, it wouldn't have been for the controller. So, same story.
The only difference is that it wouldn't affect you, but I don't see how it's relevant.
I'm sorry, I do not understand this answer.
> So figuring it out is very much a prerequisite to that series, > especially since those patches effectively make the OF-graph mandatory > in some situations, while it was purely aesthetics before.
The OF-graph is mandatory per the DT bindings of this driver. If you implement invalid DT which does not contain port@0, it will fail DT validation.
If this requirement should be relaxed, sure, it can and I don't think it would be hard to do, but I don't see why that should be part of this series, which follows the upstream DT binding document for this driver.
If I cannot trust the driver DT bindings to indicate what is and is not mandatory, what other document can I trust then ...
Oh, come on. Doing that, you also require OF-Graph support for the DSI controller you attach to, and you can't require that. This is very different from just requiring a property that doesn't have any impact on any other device, and you know that very well.
Currently the ICN6211 DT bindings DO require that kind of bridge.
And while this wasn't enforced before, you make it a hard requirement with this series. This is what changed, and what caused this whole discussion.
The current DT bindings already make it a hard requirement, so no, nothing changed here.
Unless what you are trying to ask for is support for broken DT bindings which do not pass YAML DT validation by this driver, but that is very dangerous, because then the question is, how far should we support such broken bindings. What kind of broken is still OK and what kind of broken is no longer OK ?
If it ever worked in a mainline release, it must always work. See: https://www.kernel.org/doc/html/latest/devicetree/bindings/ABI.html
As far as I'm concerned, it's the sole criteria. So to answer your question, if it was broken but worked at some point, yes, we need to keep supporting it. If it never worked, no, we don't.
There are no users of this driver in any mainline release.
DT is ABI, and ICN6211 DT bindings says port@0 is mandatory. If this driver worked with some broken downstream DT without port@0, then that downstream depended on undefined behavior which I cannot fathom how it can be considered part of kernel ABI. That downstream should fix its DT instead.
Honestly, I don't get the push-back.
Because what I am being asked to do here is implement some sort of undefined behavior backward compatibility. For behavior which has no users. Worse, for behavior which can only be triggered if your DT is broken and does not even pass the YAML DT validation.
That kind of new requirement seems bonkers to me.
To fix this properly would require:
- to remove port@0 being mandatory
- to move the data-lanes property to the bridge node itself.
That does not work, data-lanes is port property.
That's it. It takes 5 minutes, 30 minutes with the test and the commit log. We've spent more time arguing about it already.
How can I test this bug compatibility requirement ?
I don't have a broken DT, my DT does pass the YAML DT validation, so should I explicitly break my DT to perform the test ?
Are we going to start asking people to implement support for randomly broken DTs in their drivers during code review too ?
So if you want to continue debating on whether it's a regression or not, or whether DT ABI stability is a good thing or not, go ahead. But as far as I'm concerned, this isn't really up for debate.
As far as I can tell, undefined behavior can hardly be part of stable ABI.
[...]
Hi Marek,
On Sat, Mar 12, 2022 at 1:32 AM Marek Vasut marex@denx.de wrote:
On 3/11/22 17:29, Maxime Ripard wrote:
On Fri, Mar 11, 2022 at 11:36:58AM +0100, Marek Vasut wrote:
On 3/10/22 15:18, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 01:47:13PM +0100, Marek Vasut wrote:
On 3/10/22 11:53, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote: > On 3/8/22 17:21, Maxime Ripard wrote: >> On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote: >>> On 3/8/22 14:49, Maxime Ripard wrote: >>>> On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote: >>>>> On 3/8/22 13:51, Maxime Ripard wrote: >>>>>> On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: >>>>>>> On 3/8/22 11:07, Jagan Teki wrote: >>>>>>>> On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: >>>>>>>>> >>>>>>>>> On 3/8/22 09:03, Jagan Teki wrote: >>>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> [...] >>>>>>>>> >>>>>>>>>>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >>>>>>>>>>> static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>>> { >>>>>>>>>>> struct device *dev = icn->dev; >>>>>>>>>>> + struct device_node *endpoint; >>>>>>>>>>> struct drm_panel *panel; >>>>>>>>>>> + int dsi_lanes; >>>>>>>>>>> int ret; >>>>>>>>>>> >>>>>>>>>>> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >>>>>>>>>>> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>>> return PTR_ERR(icn->enable_gpio); >>>>>>>>>>> } >>>>>>>>>>> >>>>>>>>>>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >>>>>>>>>>> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >>>>>>>>>>> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >>>>>>>>>>> + of_node_put(endpoint); >>>>>>>>>>> + >>>>>>>>>>> + if (!icn->host_node) >>>>>>>>>>> + return -ENODEV; >>>>>>>>>> >>>>>>>>>> The non-ports-based OF graph returns a -19 example on the Allwinner >>>>>>>>>> Display pipeline in R16 [1]. >>>>>>>>>> >>>>>>>>>> We need to have a helper to return host_node for non-ports as I have >>>>>>>>>> done it for drm_of_find_bridge. >>>>>>>>>> >>>>>>>>>> [1] https://patchwork.amarulasolutions.com/patch/1805/ >>>>>>>>> >>>>>>>>> The link points to a patch marked "DO NOT MERGE", maybe that patch is >>>>>>>>> missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are >>>>>>>>> required, see: >>>>>>>>> >>>>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >>>>>>>>> >>>>>>>>> What is "non-ports-based OF graph" ? >>>>>>>>> >>>>>>>>> I don't see drm_of_find_bridge() in linux-next , what is that ? >>>>>>>> >>>>>>>> port@0 is optional as some of the DSI host OF-graph represent the >>>>>>>> bridge or panel as child nodes instead of ports. (i think dt-binding >>>>>>>> has to fix it to make port@0 optional) >>>>>>> >>>>>>> The current upstream DT binding document says: >>>>>>> >>>>>>> required: >>>>>>> - port@0 >>>>>>> - port@1 >>>>>>> >>>>>>> So port@0 is mandatory. >>>>>> >>>>>> In the binding, sure, but fundamentally the DT excerpt Jagan provided is >>>>>> correct. If the bridge supports DCS, there's no reason to use the OF >>>>>> graph in the first place: the bridge node will be a child node of the >>>>>> MIPI-DSI controller (and there's no obligation to use the OF-graph for a >>>>>> MIPI-DSI controller). >>>>>> >>>>>> I believe port@0 should be made optional (or downright removed if >>>>>> MIPI-DCS in the only control bus). >>>>> >>>>> That's out of scope of this series anyway, so Jagan can implement patches >>>>> for that mode if needed. >>>> >>>> Not really? You can't count on the port@0 being there generally >>>> speaking, so you can't count on data-lanes being there either, which >>>> exactly what you're doing in this patch. >>> >>> I can because the upstream DT bindings currently say port@0 must be present, >>> see above. If that requirement should be relaxed, sure, but that's a >>> separate series. >> >> And another upstream DT bindings say that you don't need them at all. > > Which "another upstream DT bindings" do you refer to ?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
>> Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI >> binding is far more relevant than a single bridge driver. > > That seems to be the wrong way around, how can generic subsystem-wide > binding take precedence over specific driver binding ?
This is the binding of the bus. You're part of that bus. You're a child node of that bus, but nothing ever mandates that your parent node uses the same convention. And some don't. And since your bridge can be connected to pretty much any DSI controller, you have to use the lowest common denominator, not make up some new constraints that not all controller will be able to comply with.
It seems to me the ICN6211 DT bindings currently further constraint the generic DSI bus bindings, and that seems OK to me.
Let me reiterate this again -- if someone wants to relax the requirements currently imposed by the ICN6211 DT bindings, fine, but that can be done in a separate patchset AND that needs DT bindings update. Furthermore, there are no users of this ICN6211 bridge in upstream DTs, so there is currently no bridge which would operate without OF graph using this driver.
And let me reiterate this again: something that used to work for a user doesn't anymore when your series is applied. This is a textbook regression. I suggested a way forward, that you don't like for some reason, fine. But pushing through a regression is just not acceptable.
How can this be a regression if this mode of operation could not have ever been supported with valid upstream DT bindings in the first place ?
Should we now require that kernel drivers somehow magically support all kinds of random broken DT bindings in addition to ones which pass YAML DT validation ?
The thing is, as I told you multiple times already, it was broken from the bridge standpoint, but not from the controller's. If it had been correct for the bridge, it wouldn't have been for the controller. So, same story.
The only difference is that it wouldn't affect you, but I don't see how it's relevant.
I'm sorry, I do not understand this answer.
>> So figuring it out is very much a prerequisite to that series, >> especially since those patches effectively make the OF-graph mandatory >> in some situations, while it was purely aesthetics before. > > The OF-graph is mandatory per the DT bindings of this driver. If you > implement invalid DT which does not contain port@0, it will fail DT > validation. > > If this requirement should be relaxed, sure, it can and I don't think it > would be hard to do, but I don't see why that should be part of this series, > which follows the upstream DT binding document for this driver. > > If I cannot trust the driver DT bindings to indicate what is and is not > mandatory, what other document can I trust then ...
Oh, come on. Doing that, you also require OF-Graph support for the DSI controller you attach to, and you can't require that. This is very different from just requiring a property that doesn't have any impact on any other device, and you know that very well.
Currently the ICN6211 DT bindings DO require that kind of bridge.
And while this wasn't enforced before, you make it a hard requirement with this series. This is what changed, and what caused this whole discussion.
The current DT bindings already make it a hard requirement, so no, nothing changed here.
Unless what you are trying to ask for is support for broken DT bindings which do not pass YAML DT validation by this driver, but that is very dangerous, because then the question is, how far should we support such broken bindings. What kind of broken is still OK and what kind of broken is no longer OK ?
If it ever worked in a mainline release, it must always work. See: https://www.kernel.org/doc/html/latest/devicetree/bindings/ABI.html
As far as I'm concerned, it's the sole criteria. So to answer your question, if it was broken but worked at some point, yes, we need to keep supporting it. If it never worked, no, we don't.
There are no users of this driver in any mainline release.
DT is ABI, and ICN6211 DT bindings says port@0 is mandatory. If this driver worked with some broken downstream DT without port@0, then that downstream depended on undefined behavior which I cannot fathom how it can be considered part of kernel ABI. That downstream should fix its DT instead.
Yes, agreed that ICN6211 DT bindings say port@0 is mandatory. However, marking port@0 (after fixing DT binding) with non-I2C-ICN6211 is still valid and we can see many examples of adding a bridge as a child to the DSI host (without port@0) and it is not broken DT binding at all (at least when it comes to DSI). You are correct and port@0 is mandatory for I2C-ICN6211.
Since the driver and this series trying to support the non-I2C and I2C based ICN6211 bridge. I think it is valid to make changes according to this series - IMHO.
Thanks, Jagan.
Hi Marek,
Small correction in the previous comment.
On Sat, Mar 12, 2022 at 2:05 AM Jagan Teki jagan@amarulasolutions.com wrote:
Hi Marek,
On Sat, Mar 12, 2022 at 1:32 AM Marek Vasut marex@denx.de wrote:
On 3/11/22 17:29, Maxime Ripard wrote:
On Fri, Mar 11, 2022 at 11:36:58AM +0100, Marek Vasut wrote:
On 3/10/22 15:18, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 01:47:13PM +0100, Marek Vasut wrote:
On 3/10/22 11:53, Maxime Ripard wrote: > On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote: >> On 3/8/22 17:21, Maxime Ripard wrote: >>> On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote: >>>> On 3/8/22 14:49, Maxime Ripard wrote: >>>>> On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote: >>>>>> On 3/8/22 13:51, Maxime Ripard wrote: >>>>>>> On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: >>>>>>>> On 3/8/22 11:07, Jagan Teki wrote: >>>>>>>>> On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: >>>>>>>>>> >>>>>>>>>> On 3/8/22 09:03, Jagan Teki wrote: >>>>>>>>>> >>>>>>>>>> Hi, >>>>>>>>>> >>>>>>>>>> [...] >>>>>>>>>> >>>>>>>>>>>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >>>>>>>>>>>> static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>>>> { >>>>>>>>>>>> struct device *dev = icn->dev; >>>>>>>>>>>> + struct device_node *endpoint; >>>>>>>>>>>> struct drm_panel *panel; >>>>>>>>>>>> + int dsi_lanes; >>>>>>>>>>>> int ret; >>>>>>>>>>>> >>>>>>>>>>>> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >>>>>>>>>>>> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>>>> return PTR_ERR(icn->enable_gpio); >>>>>>>>>>>> } >>>>>>>>>>>> >>>>>>>>>>>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >>>>>>>>>>>> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >>>>>>>>>>>> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >>>>>>>>>>>> + of_node_put(endpoint); >>>>>>>>>>>> + >>>>>>>>>>>> + if (!icn->host_node) >>>>>>>>>>>> + return -ENODEV; >>>>>>>>>>> >>>>>>>>>>> The non-ports-based OF graph returns a -19 example on the Allwinner >>>>>>>>>>> Display pipeline in R16 [1]. >>>>>>>>>>> >>>>>>>>>>> We need to have a helper to return host_node for non-ports as I have >>>>>>>>>>> done it for drm_of_find_bridge. >>>>>>>>>>> >>>>>>>>>>> [1] https://patchwork.amarulasolutions.com/patch/1805/ >>>>>>>>>> >>>>>>>>>> The link points to a patch marked "DO NOT MERGE", maybe that patch is >>>>>>>>>> missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are >>>>>>>>>> required, see: >>>>>>>>>> >>>>>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >>>>>>>>>> >>>>>>>>>> What is "non-ports-based OF graph" ? >>>>>>>>>> >>>>>>>>>> I don't see drm_of_find_bridge() in linux-next , what is that ? >>>>>>>>> >>>>>>>>> port@0 is optional as some of the DSI host OF-graph represent the >>>>>>>>> bridge or panel as child nodes instead of ports. (i think dt-binding >>>>>>>>> has to fix it to make port@0 optional) >>>>>>>> >>>>>>>> The current upstream DT binding document says: >>>>>>>> >>>>>>>> required: >>>>>>>> - port@0 >>>>>>>> - port@1 >>>>>>>> >>>>>>>> So port@0 is mandatory. >>>>>>> >>>>>>> In the binding, sure, but fundamentally the DT excerpt Jagan provided is >>>>>>> correct. If the bridge supports DCS, there's no reason to use the OF >>>>>>> graph in the first place: the bridge node will be a child node of the >>>>>>> MIPI-DSI controller (and there's no obligation to use the OF-graph for a >>>>>>> MIPI-DSI controller). >>>>>>> >>>>>>> I believe port@0 should be made optional (or downright removed if >>>>>>> MIPI-DCS in the only control bus). >>>>>> >>>>>> That's out of scope of this series anyway, so Jagan can implement patches >>>>>> for that mode if needed. >>>>> >>>>> Not really? You can't count on the port@0 being there generally >>>>> speaking, so you can't count on data-lanes being there either, which >>>>> exactly what you're doing in this patch. >>>> >>>> I can because the upstream DT bindings currently say port@0 must be present, >>>> see above. If that requirement should be relaxed, sure, but that's a >>>> separate series. >>> >>> And another upstream DT bindings say that you don't need them at all. >> >> Which "another upstream DT bindings" do you refer to ? > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... > >>> Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI >>> binding is far more relevant than a single bridge driver. >> >> That seems to be the wrong way around, how can generic subsystem-wide >> binding take precedence over specific driver binding ? > > This is the binding of the bus. You're part of that bus. You're a child > node of that bus, but nothing ever mandates that your parent node uses > the same convention. And some don't. And since your bridge can be > connected to pretty much any DSI controller, you have to use the lowest > common denominator, not make up some new constraints that not all > controller will be able to comply with.
It seems to me the ICN6211 DT bindings currently further constraint the generic DSI bus bindings, and that seems OK to me.
Let me reiterate this again -- if someone wants to relax the requirements currently imposed by the ICN6211 DT bindings, fine, but that can be done in a separate patchset AND that needs DT bindings update. Furthermore, there are no users of this ICN6211 bridge in upstream DTs, so there is currently no bridge which would operate without OF graph using this driver.
And let me reiterate this again: something that used to work for a user doesn't anymore when your series is applied. This is a textbook regression. I suggested a way forward, that you don't like for some reason, fine. But pushing through a regression is just not acceptable.
How can this be a regression if this mode of operation could not have ever been supported with valid upstream DT bindings in the first place ?
Should we now require that kernel drivers somehow magically support all kinds of random broken DT bindings in addition to ones which pass YAML DT validation ?
The thing is, as I told you multiple times already, it was broken from the bridge standpoint, but not from the controller's. If it had been correct for the bridge, it wouldn't have been for the controller. So, same story.
The only difference is that it wouldn't affect you, but I don't see how it's relevant.
I'm sorry, I do not understand this answer.
>>> So figuring it out is very much a prerequisite to that series, >>> especially since those patches effectively make the OF-graph mandatory >>> in some situations, while it was purely aesthetics before. >> >> The OF-graph is mandatory per the DT bindings of this driver. If you >> implement invalid DT which does not contain port@0, it will fail DT >> validation. >> >> If this requirement should be relaxed, sure, it can and I don't think it >> would be hard to do, but I don't see why that should be part of this series, >> which follows the upstream DT binding document for this driver. >> >> If I cannot trust the driver DT bindings to indicate what is and is not >> mandatory, what other document can I trust then ... > > Oh, come on. Doing that, you also require OF-Graph support for the DSI > controller you attach to, and you can't require that. This is very > different from just requiring a property that doesn't have any impact on > any other device, and you know that very well.
Currently the ICN6211 DT bindings DO require that kind of bridge.
And while this wasn't enforced before, you make it a hard requirement with this series. This is what changed, and what caused this whole discussion.
The current DT bindings already make it a hard requirement, so no, nothing changed here.
Unless what you are trying to ask for is support for broken DT bindings which do not pass YAML DT validation by this driver, but that is very dangerous, because then the question is, how far should we support such broken bindings. What kind of broken is still OK and what kind of broken is no longer OK ?
If it ever worked in a mainline release, it must always work. See: https://www.kernel.org/doc/html/latest/devicetree/bindings/ABI.html
As far as I'm concerned, it's the sole criteria. So to answer your question, if it was broken but worked at some point, yes, we need to keep supporting it. If it never worked, no, we don't.
There are no users of this driver in any mainline release.
DT is ABI, and ICN6211 DT bindings says port@0 is mandatory. If this driver worked with some broken downstream DT without port@0, then that downstream depended on undefined behavior which I cannot fathom how it can be considered part of kernel ABI. That downstream should fix its DT instead.
Yes, agreed that ICN6211 DT bindings say port@0 is mandatory. However, marking port@0 (after fixing DT binding) with non-I2C-ICN6211 is still
s/port@0/port@0 as optional/
On 3/11/22 21:38, Jagan Teki wrote:
Hi Marek,
Small correction in the previous comment.
On Sat, Mar 12, 2022 at 2:05 AM Jagan Teki jagan@amarulasolutions.com wrote:
Hi Marek,
On Sat, Mar 12, 2022 at 1:32 AM Marek Vasut marex@denx.de wrote:
On 3/11/22 17:29, Maxime Ripard wrote:
On Fri, Mar 11, 2022 at 11:36:58AM +0100, Marek Vasut wrote:
On 3/10/22 15:18, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 01:47:13PM +0100, Marek Vasut wrote: > On 3/10/22 11:53, Maxime Ripard wrote: >> On Tue, Mar 08, 2022 at 10:41:05PM +0100, Marek Vasut wrote: >>> On 3/8/22 17:21, Maxime Ripard wrote: >>>> On Tue, Mar 08, 2022 at 03:47:22PM +0100, Marek Vasut wrote: >>>>> On 3/8/22 14:49, Maxime Ripard wrote: >>>>>> On Tue, Mar 08, 2022 at 02:27:40PM +0100, Marek Vasut wrote: >>>>>>> On 3/8/22 13:51, Maxime Ripard wrote: >>>>>>>> On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote: >>>>>>>>> On 3/8/22 11:07, Jagan Teki wrote: >>>>>>>>>> On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: >>>>>>>>>>> >>>>>>>>>>> On 3/8/22 09:03, Jagan Teki wrote: >>>>>>>>>>> >>>>>>>>>>> Hi, >>>>>>>>>>> >>>>>>>>>>> [...] >>>>>>>>>>> >>>>>>>>>>>>> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { >>>>>>>>>>>>> static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>>>>> { >>>>>>>>>>>>> struct device *dev = icn->dev; >>>>>>>>>>>>> + struct device_node *endpoint; >>>>>>>>>>>>> struct drm_panel *panel; >>>>>>>>>>>>> + int dsi_lanes; >>>>>>>>>>>>> int ret; >>>>>>>>>>>>> >>>>>>>>>>>>> icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); >>>>>>>>>>>>> @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) >>>>>>>>>>>>> return PTR_ERR(icn->enable_gpio); >>>>>>>>>>>>> } >>>>>>>>>>>>> >>>>>>>>>>>>> + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); >>>>>>>>>>>>> + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); >>>>>>>>>>>>> + icn->host_node = of_graph_get_remote_port_parent(endpoint); >>>>>>>>>>>>> + of_node_put(endpoint); >>>>>>>>>>>>> + >>>>>>>>>>>>> + if (!icn->host_node) >>>>>>>>>>>>> + return -ENODEV; >>>>>>>>>>>> >>>>>>>>>>>> The non-ports-based OF graph returns a -19 example on the Allwinner >>>>>>>>>>>> Display pipeline in R16 [1]. >>>>>>>>>>>> >>>>>>>>>>>> We need to have a helper to return host_node for non-ports as I have >>>>>>>>>>>> done it for drm_of_find_bridge. >>>>>>>>>>>> >>>>>>>>>>>> [1] https://patchwork.amarulasolutions.com/patch/1805/ >>>>>>>>>>> >>>>>>>>>>> The link points to a patch marked "DO NOT MERGE", maybe that patch is >>>>>>>>>>> missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are >>>>>>>>>>> required, see: >>>>>>>>>>> >>>>>>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >>>>>>>>>>> >>>>>>>>>>> What is "non-ports-based OF graph" ? >>>>>>>>>>> >>>>>>>>>>> I don't see drm_of_find_bridge() in linux-next , what is that ? >>>>>>>>>> >>>>>>>>>> port@0 is optional as some of the DSI host OF-graph represent the >>>>>>>>>> bridge or panel as child nodes instead of ports. (i think dt-binding >>>>>>>>>> has to fix it to make port@0 optional) >>>>>>>>> >>>>>>>>> The current upstream DT binding document says: >>>>>>>>> >>>>>>>>> required: >>>>>>>>> - port@0 >>>>>>>>> - port@1 >>>>>>>>> >>>>>>>>> So port@0 is mandatory. >>>>>>>> >>>>>>>> In the binding, sure, but fundamentally the DT excerpt Jagan provided is >>>>>>>> correct. If the bridge supports DCS, there's no reason to use the OF >>>>>>>> graph in the first place: the bridge node will be a child node of the >>>>>>>> MIPI-DSI controller (and there's no obligation to use the OF-graph for a >>>>>>>> MIPI-DSI controller). >>>>>>>> >>>>>>>> I believe port@0 should be made optional (or downright removed if >>>>>>>> MIPI-DCS in the only control bus). >>>>>>> >>>>>>> That's out of scope of this series anyway, so Jagan can implement patches >>>>>>> for that mode if needed. >>>>>> >>>>>> Not really? You can't count on the port@0 being there generally >>>>>> speaking, so you can't count on data-lanes being there either, which >>>>>> exactly what you're doing in this patch. >>>>> >>>>> I can because the upstream DT bindings currently say port@0 must be present, >>>>> see above. If that requirement should be relaxed, sure, but that's a >>>>> separate series. >>>> >>>> And another upstream DT bindings say that you don't need them at all. >>> >>> Which "another upstream DT bindings" do you refer to ? >> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... >> >>>> Yes, there's a conflict. Yes, it's unfortunate. But the generic DSI >>>> binding is far more relevant than a single bridge driver. >>> >>> That seems to be the wrong way around, how can generic subsystem-wide >>> binding take precedence over specific driver binding ? >> >> This is the binding of the bus. You're part of that bus. You're a child >> node of that bus, but nothing ever mandates that your parent node uses >> the same convention. And some don't. And since your bridge can be >> connected to pretty much any DSI controller, you have to use the lowest >> common denominator, not make up some new constraints that not all >> controller will be able to comply with. > > It seems to me the ICN6211 DT bindings currently further constraint the > generic DSI bus bindings, and that seems OK to me. > > Let me reiterate this again -- if someone wants to relax the requirements > currently imposed by the ICN6211 DT bindings, fine, but that can be done in > a separate patchset AND that needs DT bindings update. Furthermore, there > are no users of this ICN6211 bridge in upstream DTs, so there is currently > no bridge which would operate without OF graph using this driver.
And let me reiterate this again: something that used to work for a user doesn't anymore when your series is applied. This is a textbook regression. I suggested a way forward, that you don't like for some reason, fine. But pushing through a regression is just not acceptable.
How can this be a regression if this mode of operation could not have ever been supported with valid upstream DT bindings in the first place ?
Should we now require that kernel drivers somehow magically support all kinds of random broken DT bindings in addition to ones which pass YAML DT validation ?
The thing is, as I told you multiple times already, it was broken from the bridge standpoint, but not from the controller's. If it had been correct for the bridge, it wouldn't have been for the controller. So, same story.
The only difference is that it wouldn't affect you, but I don't see how it's relevant.
I'm sorry, I do not understand this answer.
>>>> So figuring it out is very much a prerequisite to that series, >>>> especially since those patches effectively make the OF-graph mandatory >>>> in some situations, while it was purely aesthetics before. >>> >>> The OF-graph is mandatory per the DT bindings of this driver. If you >>> implement invalid DT which does not contain port@0, it will fail DT >>> validation. >>> >>> If this requirement should be relaxed, sure, it can and I don't think it >>> would be hard to do, but I don't see why that should be part of this series, >>> which follows the upstream DT binding document for this driver. >>> >>> If I cannot trust the driver DT bindings to indicate what is and is not >>> mandatory, what other document can I trust then ... >> >> Oh, come on. Doing that, you also require OF-Graph support for the DSI >> controller you attach to, and you can't require that. This is very >> different from just requiring a property that doesn't have any impact on >> any other device, and you know that very well. > > Currently the ICN6211 DT bindings DO require that kind of bridge.
And while this wasn't enforced before, you make it a hard requirement with this series. This is what changed, and what caused this whole discussion.
The current DT bindings already make it a hard requirement, so no, nothing changed here.
Unless what you are trying to ask for is support for broken DT bindings which do not pass YAML DT validation by this driver, but that is very dangerous, because then the question is, how far should we support such broken bindings. What kind of broken is still OK and what kind of broken is no longer OK ?
If it ever worked in a mainline release, it must always work. See: https://www.kernel.org/doc/html/latest/devicetree/bindings/ABI.html
As far as I'm concerned, it's the sole criteria. So to answer your question, if it was broken but worked at some point, yes, we need to keep supporting it. If it never worked, no, we don't.
There are no users of this driver in any mainline release.
DT is ABI, and ICN6211 DT bindings says port@0 is mandatory. If this driver worked with some broken downstream DT without port@0, then that downstream depended on undefined behavior which I cannot fathom how it can be considered part of kernel ABI. That downstream should fix its DT instead.
Yes, agreed that ICN6211 DT bindings say port@0 is mandatory. However, marking port@0 (after fixing DT binding) with non-I2C-ICN6211 is still
s/port@0/port@0 as optional/
The V4 requires the port@0 only for I2C bus option now, that should at least retain the "compatibility".
Hi Maxime,
On Tue, Mar 08, 2022 at 01:51:40PM +0100, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
@@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { static int chipone_parse_dt(struct chipone *icn) { struct device *dev = icn->dev;
struct device_node *endpoint; struct drm_panel *panel;int dsi_lanes; int ret; icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");@@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) return PTR_ERR(icn->enable_gpio); }
endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");icn->host_node = of_graph_get_remote_port_parent(endpoint);of_node_put(endpoint);if (!icn->host_node)return -ENODEV;The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
I think we should make ports mandatory in all cases actually.
The DT parent-child hierarchy is meant to model control relations between devices, so a DSI device controlled through DCS should be a child of the DSI controller. No disagreement there.
The OF graph is meant to model data connections. While a DSI device controlled through DCS will use the same DSI link for data transfer, the two concepts are different. We have taken shortcuts and decided to not use OF graph for some DSI devices (not necessarily as a well thought decision, it was sometimes just not considered). This has led to different issues that we're having to deal with today, making it more difficult to develop generic code. Going forward, I think new bindings should always use OF graph to model the data connection.
On Thu, Mar 10, 2022 at 12:42:12PM +0200, Laurent Pinchart wrote:
Hi Maxime,
On Tue, Mar 08, 2022 at 01:51:40PM +0100, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
> @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > static int chipone_parse_dt(struct chipone *icn) > { > struct device *dev = icn->dev; > + struct device_node *endpoint; > struct drm_panel *panel; > + int dsi_lanes; > int ret; > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > return PTR_ERR(icn->enable_gpio); > } > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > + of_node_put(endpoint); > + > + if (!icn->host_node) > + return -ENODEV;
The non-ports-based OF graph returns a -19 example on the Allwinner Display pipeline in R16 [1].
We need to have a helper to return host_node for non-ports as I have done it for drm_of_find_bridge.
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
I think we should make ports mandatory in all cases actually.
The DT parent-child hierarchy is meant to model control relations between devices, so a DSI device controlled through DCS should be a child of the DSI controller. No disagreement there.
The OF graph is meant to model data connections. While a DSI device controlled through DCS will use the same DSI link for data transfer, the two concepts are different. We have taken shortcuts and decided to not use OF graph for some DSI devices (not necessarily as a well thought decision, it was sometimes just not considered).
I disagree. Unless the data path is explicitly stated using the OF-graph or some other binding, it's inferred. We never asked ourselves where the data from an i2c chip, an ethernet controller or an v4l2 output device was coming from. It comes from the parent bus, because it's what makes sense. Making a requirement on the OF-Graph to model this would create a big inconsistency.
This has led to different issues that we're having to deal with today, making it more difficult to develop generic code. Going forward, I think new bindings should always use OF graph to model the data connection.
Either way, that discussion is irrelevant. Not all DSI controllers use OF-Graph, a bridge can be attached to any of them, so we can't require OF-Graph support in any bridge.
Maxime
Hi Maxime,
On Thu, Mar 10, 2022 at 11:57:38AM +0100, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 12:42:12PM +0200, Laurent Pinchart wrote:
On Tue, Mar 08, 2022 at 01:51:40PM +0100, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote:
On 3/8/22 09:03, Jagan Teki wrote:
Hi,
[...]
> > @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > > static int chipone_parse_dt(struct chipone *icn) > > { > > struct device *dev = icn->dev; > > + struct device_node *endpoint; > > struct drm_panel *panel; > > + int dsi_lanes; > > int ret; > > > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > > return PTR_ERR(icn->enable_gpio); > > } > > > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > > + of_node_put(endpoint); > > + > > + if (!icn->host_node) > > + return -ENODEV; > > The non-ports-based OF graph returns a -19 example on the Allwinner > Display pipeline in R16 [1]. > > We need to have a helper to return host_node for non-ports as I have > done it for drm_of_find_bridge. > > [1] https://patchwork.amarulasolutions.com/patch/1805/
The link points to a patch marked "DO NOT MERGE", maybe that patch is missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are required, see:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
What is "non-ports-based OF graph" ?
I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
I think we should make ports mandatory in all cases actually.
The DT parent-child hierarchy is meant to model control relations between devices, so a DSI device controlled through DCS should be a child of the DSI controller. No disagreement there.
The OF graph is meant to model data connections. While a DSI device controlled through DCS will use the same DSI link for data transfer, the two concepts are different. We have taken shortcuts and decided to not use OF graph for some DSI devices (not necessarily as a well thought decision, it was sometimes just not considered).
I disagree. Unless the data path is explicitly stated using the OF-graph or some other binding, it's inferred.
It is today, and for video data, I think it's showing to be a problem :-)
We never asked ourselves where the data from an i2c chip, an ethernet controller or an v4l2 output device was coming from. It comes from the parent bus, because it's what makes sense. Making a requirement on the OF-Graph to model this would create a big inconsistency.
I'm afraid I disagree, especially when it comes to data transfers from device to device. The device tree has never tried to model those until OF graph.
This has led to different issues that we're having to deal with today, making it more difficult to develop generic code. Going forward, I think new bindings should always use OF graph to model the data connection.
Either way, that discussion is irrelevant. Not all DSI controllers use OF-Graph, a bridge can be attached to any of them, so we can't require OF-Graph support in any bridge.
Not in any bridge, but we could in new ones, and we could also require it in new DT for existing bridge to support new features.
On Thu, Mar 10, 2022 at 01:16:57PM +0200, Laurent Pinchart wrote:
On Thu, Mar 10, 2022 at 11:57:38AM +0100, Maxime Ripard wrote:
On Thu, Mar 10, 2022 at 12:42:12PM +0200, Laurent Pinchart wrote:
On Tue, Mar 08, 2022 at 01:51:40PM +0100, Maxime Ripard wrote:
On Tue, Mar 08, 2022 at 11:29:59AM +0100, Marek Vasut wrote:
On 3/8/22 11:07, Jagan Teki wrote:
On Tue, Mar 8, 2022 at 3:19 PM Marek Vasut marex@denx.de wrote: > > On 3/8/22 09:03, Jagan Teki wrote: > > Hi, > > [...] > > > > @@ -314,7 +321,9 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { > > > static int chipone_parse_dt(struct chipone *icn) > > > { > > > struct device *dev = icn->dev; > > > + struct device_node *endpoint; > > > struct drm_panel *panel; > > > + int dsi_lanes; > > > int ret; > > > > > > icn->vdd1 = devm_regulator_get_optional(dev, "vdd1"); > > > @@ -350,15 +359,42 @@ static int chipone_parse_dt(struct chipone *icn) > > > return PTR_ERR(icn->enable_gpio); > > > } > > > > > > + endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0); > > > + dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes"); > > > + icn->host_node = of_graph_get_remote_port_parent(endpoint); > > > + of_node_put(endpoint); > > > + > > > + if (!icn->host_node) > > > + return -ENODEV; > > > > The non-ports-based OF graph returns a -19 example on the Allwinner > > Display pipeline in R16 [1]. > > > > We need to have a helper to return host_node for non-ports as I have > > done it for drm_of_find_bridge. > > > > [1] https://patchwork.amarulasolutions.com/patch/1805/ > > The link points to a patch marked "DO NOT MERGE", maybe that patch is > missing the DSI host port@0 OF graph link ? Both port@0 and port@1 are > required, see: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... > > What is "non-ports-based OF graph" ? > > I don't see drm_of_find_bridge() in linux-next , what is that ?
port@0 is optional as some of the DSI host OF-graph represent the bridge or panel as child nodes instead of ports. (i think dt-binding has to fix it to make port@0 optional)
The current upstream DT binding document says:
required: - port@0 - port@1So port@0 is mandatory.
In the binding, sure, but fundamentally the DT excerpt Jagan provided is correct. If the bridge supports DCS, there's no reason to use the OF graph in the first place: the bridge node will be a child node of the MIPI-DSI controller (and there's no obligation to use the OF-graph for a MIPI-DSI controller).
I believe port@0 should be made optional (or downright removed if MIPI-DCS in the only control bus).
I think we should make ports mandatory in all cases actually.
The DT parent-child hierarchy is meant to model control relations between devices, so a DSI device controlled through DCS should be a child of the DSI controller. No disagreement there.
The OF graph is meant to model data connections. While a DSI device controlled through DCS will use the same DSI link for data transfer, the two concepts are different. We have taken shortcuts and decided to not use OF graph for some DSI devices (not necessarily as a well thought decision, it was sometimes just not considered).
I disagree. Unless the data path is explicitly stated using the OF-graph or some other binding, it's inferred.
It is today, and for video data, I think it's showing to be a problem :-)
We never asked ourselves where the data from an i2c chip, an ethernet controller or an v4l2 output device was coming from. It comes from the parent bus, because it's what makes sense. Making a requirement on the OF-Graph to model this would create a big inconsistency.
I'm afraid I disagree, especially when it comes to data transfers from device to device. The device tree has never tried to model those until OF graph.
Except the data transfer isn't happening between "siblings" devices like a CRTC and an HDMI controller that the OF-Graph describes perfectly fine. Here the transfer happens between a parent device and its child. So it's a bus to device transfer, just like any DMA transfer, or MDIO transfer, or SPI transfer, etc.
This has led to different issues that we're having to deal with today, making it more difficult to develop generic code. Going forward, I think new bindings should always use OF graph to model the data connection.
Either way, that discussion is irrelevant. Not all DSI controllers use OF-Graph, a bridge can be attached to any of them, so we can't require OF-Graph support in any bridge.
Not in any bridge, but we could in new ones, and we could also require it in new DT for existing bridge to support new features.
Above disagreement aside, since not all controllers are using it, it would effectively prevent those new bridges from being used with !OF-Graph controllers. I don't see how that can be an option.
Maxime
The chip contains fractional PLL, however the driver currently hard-codes one specific PLL setting. Implement generic PLL parameter calculation code, so any DPI panel with arbitrary pixel clock can be attached to this bridge.
The datasheet for this bridge is not available, the PLL behavior has been inferred from [1] and [2] and by analyzing the DPI pixel clock with scope. The PLL limits might be wrong, but at least the calculated values match all the example code available. This is better than one hard-coded pixel clock value anyway.
[1] https://github.com/rockchip-linux/kernel/blob/develop-4.19/drivers/gpu/drm/b... [2] https://github.com/tdjastrzebski/ICN6211-Configurator
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 87 +++++++++++++++++++++++- 1 file changed, 84 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index df8e75a068ad0..71c83a18984fa 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -163,6 +163,87 @@ static inline int chipone_dsi_write(struct chipone *icn, const void *seq, chipone_dsi_write(icn, d, ARRAY_SIZE(d)); \ }
+static void chipone_configure_pll(struct chipone *icn, + const struct drm_display_mode *mode) +{ + unsigned int best_p = 0, best_m = 0, best_s = 0; + unsigned int delta, min_delta = 0xffffffff; + unsigned int freq_p, freq_s, freq_out; + unsigned int p_min, p_max; + unsigned int p, m, s; + unsigned int fin; + + /* + * DSI clock lane frequency (input into PLL) is calculated as: + * DSI_CLK = mode clock * bpp / dsi_data_lanes / 2 + * the 2 is there because the bus is DDR. + * + * DPI pixel clock frequency (output from PLL) is mode clock. + * + * The chip contains fractional PLL which works as follows: + * DPI_CLK = ((DSI_CLK / P) * M) / S + * P is pre-divider, register PLL_REF_DIV[3:0] is 2^(n+1) divider + * register PLL_REF_DIV[4] is extra 1:2 divider + * M is integer multiplier, register PLL_INT(0) is multiplier + * S is post-divider, register PLL_REF_DIV[7:5] is 2^(n+1) divider + * + * It seems the PLL input clock after applying P pre-divider have + * to be lower than 20 MHz. + */ + fin = mode->clock * mipi_dsi_pixel_format_to_bpp(icn->dsi->format) / + icn->dsi_lanes / 2; /* in kHz */ + + /* Minimum value of P predivider for PLL input in 5..20 MHz */ + p_min = ffs(fin / 20000); + p_max = (fls(fin / 5000) - 1) & 0x1f; + + for (p = p_min; p < p_max; p++) { /* PLL_REF_DIV[4,3:0] */ + freq_p = fin / BIT(p + 1); + if (freq_p == 0) /* Divider too high */ + break; + + for (s = 0; s < 0x7; s++) { /* PLL_REF_DIV[7:5] */ + freq_s = freq_p / BIT(s + 1); + if (freq_s == 0) /* Divider too high */ + break; + + m = mode->clock / freq_s; + + /* Multiplier is 8 bit */ + if (m > 0xff) + continue; + + /* Limit PLL VCO frequency to 1 GHz */ + freq_out = (fin * m) / BIT(p + 1); + if (freq_out > 1000000) + continue; + + /* Apply post-divider */ + freq_out /= BIT(s + 1); + + delta = abs(mode->clock - freq_out); + if (delta < min_delta) { + best_p = p; + best_m = m; + best_s = s; + min_delta = delta; + } + } + } + + dev_dbg(icn->dev, + "PLL: P[3:0]=2^%d P[4]=2*%d M=%d S[7:5]=2^%d delta=%d => DSI f_in=%d kHz ; DPI f_out=%ld kHz\n", + best_p, !!best_p, best_m, best_s + 1, min_delta, fin, + (fin * best_m) / BIT(best_p + best_s + 2)); + + /* Clock source selection fixed to MIPI DSI clock lane */ + ICN6211_DSI(icn, PLL_CTRL(6), PLL_CTRL_6_MIPI_CLK); + ICN6211_DSI(icn, PLL_REF_DIV, + (best_p ? PLL_REF_DIV_Pe : 0) | /* Prefer /2 pre-divider */ + PLL_REF_DIV_P(best_p) | PLL_REF_DIV_S(best_s)); + ICN6211_DSI(icn, PLL_INT(0), best_m); +} + static void chipone_atomic_enable(struct drm_bridge *bridge, struct drm_bridge_state *old_bridge_state) { @@ -228,9 +309,9 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, ((bus_flags & DRM_BUS_FLAG_DE_HIGH) ? BIST_POL_DE_POL : 0); ICN6211_DSI(icn, BIST_POL, pol);
- ICN6211_DSI(icn, PLL_CTRL(6), PLL_CTRL_6_MIPI_CLK); - ICN6211_DSI(icn, PLL_REF_DIV, 0x71); - ICN6211_DSI(icn, PLL_INT(0), 0x2b); + /* Configure PLL settings */ + chipone_configure_pll(icn, mode); + ICN6211_DSI(icn, SYS_CTRL(0), 0x40); ICN6211_DSI(icn, SYS_CTRL(1), 0x98);
On Fri, Mar 4, 2022 at 5:55 AM Marek Vasut marex@denx.de wrote:
The chip contains fractional PLL, however the driver currently hard-codes one specific PLL setting. Implement generic PLL parameter calculation code, so any DPI panel with arbitrary pixel clock can be attached to this bridge.
The datasheet for this bridge is not available, the PLL behavior has been inferred from [1] and [2] and by analyzing the DPI pixel clock with scope. The PLL limits might be wrong, but at least the calculated values match all the example code available. This is better than one hard-coded pixel clock value anyway.
[1] https://github.com/rockchip-linux/kernel/blob/develop-4.19/drivers/gpu/drm/b... [2] https://github.com/tdjastrzebski/ICN6211-Configurator
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org
V2: Rebase on next-20220214 V3: Add AB from Maxime
drivers/gpu/drm/bridge/chipone-icn6211.c | 87 +++++++++++++++++++++++- 1 file changed, 84 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index df8e75a068ad0..71c83a18984fa 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -163,6 +163,87 @@ static inline int chipone_dsi_write(struct chipone *icn, const void *seq, chipone_dsi_write(icn, d, ARRAY_SIZE(d)); \ }
+static void chipone_configure_pll(struct chipone *icn,
const struct drm_display_mode *mode)+{
unsigned int best_p = 0, best_m = 0, best_s = 0;unsigned int delta, min_delta = 0xffffffff;unsigned int freq_p, freq_s, freq_out;unsigned int p_min, p_max;unsigned int p, m, s;unsigned int fin;/** DSI clock lane frequency (input into PLL) is calculated as:* DSI_CLK = mode clock * bpp / dsi_data_lanes / 2* the 2 is there because the bus is DDR.** DPI pixel clock frequency (output from PLL) is mode clock.** The chip contains fractional PLL which works as follows:* DPI_CLK = ((DSI_CLK / P) * M) / S* P is pre-divider, register PLL_REF_DIV[3:0] is 2^(n+1) divider* register PLL_REF_DIV[4] is extra 1:2 divider* M is integer multiplier, register PLL_INT(0) is multiplier* S is post-divider, register PLL_REF_DIV[7:5] is 2^(n+1) divider** It seems the PLL input clock after applying P pre-divider have* to be lower than 20 MHz.*/fin = mode->clock * mipi_dsi_pixel_format_to_bpp(icn->dsi->format) /
no dsi in chipone structure. please preserve format during the probe.
drivers/gpu/drm/bridge/chipone-icn6211.c:193:61: error: ‘struct chipone’ has no member named ‘dsi’ 193 | fin = mode->clock * mipi_dsi_pixel_format_to_bpp(icn->dsi->format) /
Thanks, Jagan.
On 3/8/22 09:07, Jagan Teki wrote:
On Fri, Mar 4, 2022 at 5:55 AM Marek Vasut marex@denx.de wrote:
The chip contains fractional PLL, however the driver currently hard-codes one specific PLL setting. Implement generic PLL parameter calculation code, so any DPI panel with arbitrary pixel clock can be attached to this bridge.
The datasheet for this bridge is not available, the PLL behavior has been inferred from [1] and [2] and by analyzing the DPI pixel clock with scope. The PLL limits might be wrong, but at least the calculated values match all the example code available. This is better than one hard-coded pixel clock value anyway.
[1] https://github.com/rockchip-linux/kernel/blob/develop-4.19/drivers/gpu/drm/b... [2] https://github.com/tdjastrzebski/ICN6211-Configurator
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org
V2: Rebase on next-20220214 V3: Add AB from Maxime
drivers/gpu/drm/bridge/chipone-icn6211.c | 87 +++++++++++++++++++++++- 1 file changed, 84 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index df8e75a068ad0..71c83a18984fa 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -163,6 +163,87 @@ static inline int chipone_dsi_write(struct chipone *icn, const void *seq, chipone_dsi_write(icn, d, ARRAY_SIZE(d)); \ }
+static void chipone_configure_pll(struct chipone *icn,
const struct drm_display_mode *mode)+{
unsigned int best_p = 0, best_m = 0, best_s = 0;unsigned int delta, min_delta = 0xffffffff;unsigned int freq_p, freq_s, freq_out;unsigned int p_min, p_max;unsigned int p, m, s;unsigned int fin;/** DSI clock lane frequency (input into PLL) is calculated as:* DSI_CLK = mode clock * bpp / dsi_data_lanes / 2* the 2 is there because the bus is DDR.** DPI pixel clock frequency (output from PLL) is mode clock.** The chip contains fractional PLL which works as follows:* DPI_CLK = ((DSI_CLK / P) * M) / S* P is pre-divider, register PLL_REF_DIV[3:0] is 2^(n+1) divider* register PLL_REF_DIV[4] is extra 1:2 divider* M is integer multiplier, register PLL_INT(0) is multiplier* S is post-divider, register PLL_REF_DIV[7:5] is 2^(n+1) divider** It seems the PLL input clock after applying P pre-divider have* to be lower than 20 MHz.*/fin = mode->clock * mipi_dsi_pixel_format_to_bpp(icn->dsi->format) /no dsi in chipone structure. please preserve format during the probe.
drivers/gpu/drm/bridge/chipone-icn6211.c:193:61: error: ‘struct chipone’ has no member named ‘dsi’ 193 | fin = mode->clock * mipi_dsi_pixel_format_to_bpp(icn->dsi->format) /
Ah , yes, this was added in [PATCH V3 11/13] drm: bridge: icn6211: Add I2C configuration support and needs to be moved here.
The DSI burst mode is more energy efficient than the DSI sync pulse mode, make use of the burst mode since the chip supports it as well. Disable the generation of EoT packet, the chip ignores it, so no point in emitting it. Enable transmission of data in LP mode, otherwise register read via DSI does not work with this chip.
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index 71c83a18984fa..b4e886c2b92a5 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -503,7 +503,8 @@ static int chipone_probe(struct mipi_dsi_device *dsi)
dsi->lanes = icn->dsi_lanes; dsi->format = MIPI_DSI_FMT_RGB888; - dsi->mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE; + dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST | + MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;
ret = mipi_dsi_attach(dsi); if (ret < 0) {
The chip is capable of swapping DPI RGB channels. The driver currently does not implement support for this functionality. Write the MIPI_PN_SWAP register to 0 to assure the color swap is disabled.
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index b4e886c2b92a5..1a3afefcc9e80 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -302,6 +302,7 @@ static void chipone_atomic_enable(struct drm_bridge *bridge,
ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0); ICN6211_DSI(icn, PLL_CTRL(12), 0xff); + ICN6211_DSI(icn, MIPI_PN_SWAP, 0x00);
/* DPI HS/VS/DE polarity */ pol = ((mode->flags & DRM_MODE_FLAG_PHSYNC) ? BIST_POL_HSYNC_POL : 0) |
Both example code [1], [2] as well as one provided by custom panel vendor set register SYS_CTRL_1 to 0x88. What exactly does the value mean is unknown due to unavailable datasheet. Align this register value with example code.
[1] https://github.com/rockchip-linux/kernel/blob/develop-4.19/drivers/gpu/drm/b... [2] https://github.com/tdjastrzebski/ICN6211-Configurator
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index 1a3afefcc9e80..095002a40d0e8 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -314,7 +314,7 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, chipone_configure_pll(icn, mode);
ICN6211_DSI(icn, SYS_CTRL(0), 0x40); - ICN6211_DSI(icn, SYS_CTRL(1), 0x98); + ICN6211_DSI(icn, SYS_CTRL(1), 0x88);
/* icn6211 specific sequence */ ICN6211_DSI(icn, MIPI_FORCE_0, 0x20);
Implement .atomic_get_input_bus_fmts callback, which sets up the input (DSI-end) format, and that format can then be used in pipeline format negotiation between the DSI-end of this bridge and the other component closer to the scanout engine.
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 27 ++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index 095002a40d0e8..afc619e215c3b 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -389,6 +389,32 @@ static int chipone_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flag return drm_bridge_attach(bridge->encoder, icn->panel_bridge, bridge, flags); }
+#define MAX_INPUT_SEL_FORMATS 1 + +static u32 * +chipone_atomic_get_input_bus_fmts(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + u32 output_fmt, + unsigned int *num_input_fmts) +{ + u32 *input_fmts; + + *num_input_fmts = 0; + + input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts), + GFP_KERNEL); + if (!input_fmts) + return NULL; + + /* This is the DSI-end bus format */ + input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24; + *num_input_fmts = 1; + + return input_fmts; +} + static const struct drm_bridge_funcs chipone_bridge_funcs = { .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, @@ -398,6 +424,7 @@ static const struct drm_bridge_funcs chipone_bridge_funcs = { .atomic_post_disable = chipone_atomic_post_disable, .mode_set = chipone_mode_set, .attach = chipone_attach, + .atomic_get_input_bus_fmts = chipone_atomic_get_input_bus_fmts, };
static int chipone_parse_dt(struct chipone *icn)
The ICN6211 chip starts in I2C configuration mode after cold boot. Implement support for configuring the chip via I2C in addition to the current DSI LP command mode configuration support. The later seems to be available only on chips which have additional MCU on the panel/bridge board which preconfigures the ICN6211, while the I2C configuration mode added by this patch does not require any such MCU.
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: - Drop the abridge variable - Rename chipone_dsi_setup to chipone_dsi_host_attach and call it from chipone_i2c_probe() V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 183 ++++++++++++++++++++--- 1 file changed, 161 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index afc619e215c3b..4ad149c13f599 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -11,6 +11,7 @@
#include <linux/delay.h> #include <linux/gpio/consumer.h> +#include <linux/i2c.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/regulator/consumer.h> @@ -133,15 +134,18 @@
struct chipone { struct device *dev; + struct i2c_client *client; struct drm_bridge bridge; struct drm_display_mode mode; struct drm_bridge *panel_bridge; struct device_node *host_node; + struct mipi_dsi_device *dsi; struct gpio_desc *enable_gpio; struct regulator *vdd1; struct regulator *vdd2; struct regulator *vdd3; int dsi_lanes; + bool interface_i2c; };
static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge) @@ -152,9 +156,10 @@ static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge) static inline int chipone_dsi_write(struct chipone *icn, const void *seq, size_t len) { - struct mipi_dsi_device *dsi = to_mipi_dsi_device(icn->dev); - - return mipi_dsi_generic_write(dsi, seq, len); + if (icn->interface_i2c) + i2c_smbus_write_byte_data(icn->client, reg, val); + else + mipi_dsi_generic_write(icn->dsi, (u8[]){reg, val}, 2); }
#define ICN6211_DSI(icn, seq...) \ @@ -259,7 +264,10 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, bridge_state = drm_atomic_get_new_bridge_state(state, bridge); bus_flags = bridge_state->output_bus_cfg.flags;
- ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI); + if (icn->interface_i2c) + ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_I2C); + else + ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI);
ICN6211_DSI(icn, HACTIVE_LI, mode->hdisplay & 0xff);
@@ -380,6 +388,57 @@ static void chipone_mode_set(struct drm_bridge *bridge, struct chipone *icn = bridge_to_chipone(bridge);
drm_mode_copy(&icn->mode, adjusted_mode); +}; + +static int chipone_dsi_attach(struct chipone *icn) +{ + struct mipi_dsi_device *dsi = icn->dsi; + int ret; + + dsi->lanes = icn->dsi_lanes; + dsi->format = MIPI_DSI_FMT_RGB888; + dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST | + MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET; + + ret = mipi_dsi_attach(dsi); + if (ret < 0) + dev_err(icn->dev, "failed to attach dsi\n"); + + return ret; +} + +static int chipone_dsi_host_attach(struct chipone *icn) +{ + struct device *dev = icn->dev; + struct mipi_dsi_device *dsi; + struct mipi_dsi_host *host; + int ret = 0; + + const struct mipi_dsi_device_info info = { + .type = "chipone", + .channel = 0, + .node = NULL, + }; + + host = of_find_mipi_dsi_host_by_node(icn->host_node); + if (!host) { + dev_err(dev, "failed to find dsi host\n"); + return -EPROBE_DEFER; + } + + dsi = mipi_dsi_device_register_full(host, &info); + if (IS_ERR(dsi)) { + return dev_err_probe(dev, PTR_ERR(dsi), + "failed to create dsi device\n"); + } + + icn->dsi = dsi; + + ret = chipone_dsi_attach(icn); + if (ret < 0) + mipi_dsi_device_unregister(dsi); + + return ret; }
static int chipone_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags) @@ -506,9 +565,8 @@ static int chipone_parse_dt(struct chipone *icn) return ret; }
-static int chipone_probe(struct mipi_dsi_device *dsi) +static int chipone_common_probe(struct device *dev, struct chipone **icnr) { - struct device *dev = &dsi->dev; struct chipone *icn; int ret;
@@ -516,7 +574,6 @@ static int chipone_probe(struct mipi_dsi_device *dsi) if (!icn) return -ENOMEM;
- mipi_dsi_set_drvdata(dsi, icn); icn->dev = dev;
ret = chipone_parse_dt(icn); @@ -527,29 +584,77 @@ static int chipone_probe(struct mipi_dsi_device *dsi) icn->bridge.type = DRM_MODE_CONNECTOR_DPI; icn->bridge.of_node = dev->of_node;
- drm_bridge_add(&icn->bridge); + *icnr = icn;
- dsi->lanes = icn->dsi_lanes; - dsi->format = MIPI_DSI_FMT_RGB888; - dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST | - MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET; + return ret; +}
- ret = mipi_dsi_attach(dsi); - if (ret < 0) { +static int chipone_dsi_probe(struct mipi_dsi_device *dsi) +{ + struct device *dev = &dsi->dev; + struct chipone *icn; + int ret; + + ret = chipone_common_probe(dev, &icn); + if (ret) + return ret; + + icn->interface_i2c = false; + icn->dsi = dsi; + + mipi_dsi_set_drvdata(dsi, icn); + + drm_bridge_add(&icn->bridge); + + ret = chipone_dsi_attach(icn); + if (ret) drm_bridge_remove(&icn->bridge); - dev_err(dev, "failed to attach dsi\n"); - }
return ret; }
-static int chipone_remove(struct mipi_dsi_device *dsi) +static int chipone_i2c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct chipone *icn; + int ret; + + ret = chipone_common_probe(dev, &icn); + if (ret) + return ret; + + icn->interface_i2c = true; + icn->client = client; + dev_set_drvdata(dev, icn); + i2c_set_clientdata(client, icn); + + drm_bridge_add(&icn->bridge); + + return chipone_dsi_host_attach(icn); +} + +static void chipone_common_remove(struct chipone *icn) +{ + of_node_put(icn->host_node); +} + +static int chipone_dsi_remove(struct mipi_dsi_device *dsi) { struct chipone *icn = mipi_dsi_get_drvdata(dsi);
mipi_dsi_detach(dsi); drm_bridge_remove(&icn->bridge); - of_node_put(icn->host_node); + chipone_common_remove(icn); + + return 0; +} + +static int chipone_i2c_remove(struct i2c_client *client) +{ + struct chipone *icn = i2c_get_clientdata(client); + + chipone_common_remove(icn);
return 0; } @@ -560,16 +665,50 @@ static const struct of_device_id chipone_of_match[] = { }; MODULE_DEVICE_TABLE(of, chipone_of_match);
-static struct mipi_dsi_driver chipone_driver = { - .probe = chipone_probe, - .remove = chipone_remove, +static struct mipi_dsi_driver chipone_dsi_driver = { + .probe = chipone_dsi_probe, + .remove = chipone_dsi_remove, .driver = { .name = "chipone-icn6211", .owner = THIS_MODULE, .of_match_table = chipone_of_match, }, }; -module_mipi_dsi_driver(chipone_driver); + +static struct i2c_device_id chipone_i2c_id[] = { + { "chipone,icn6211" }, + {}, +}; +MODULE_DEVICE_TABLE(i2c, chipone_i2c_id); + +static struct i2c_driver chipone_i2c_driver = { + .probe = chipone_i2c_probe, + .remove = chipone_i2c_remove, + .id_table = chipone_i2c_id, + .driver = { + .name = "chipone-icn6211-i2c", + .owner = THIS_MODULE, + .of_match_table = chipone_of_match, + }, +}; + +static int __init chipone_init(void) +{ + if (IS_ENABLED(CONFIG_DRM_MIPI_DSI)) + mipi_dsi_driver_register(&chipone_dsi_driver); + + return i2c_add_driver(&chipone_i2c_driver); +} +module_init(chipone_init); + +static void __init chipone_exit(void) +{ + i2c_del_driver(&chipone_i2c_driver); + + if (IS_ENABLED(CONFIG_DRM_MIPI_DSI)) + mipi_dsi_driver_unregister(&chipone_dsi_driver); +} +module_exit(chipone_exit);
MODULE_AUTHOR("Jagan Teki jagan@amarulasolutions.com"); MODULE_DESCRIPTION("Chipone ICN6211 MIPI-DSI to RGB Converter Bridge");
Rename and inline macro ICN6211_DSI() into function chipone_writeb() to keep all function names lower-case. No functional change.
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 63 +++++++++++------------- 1 file changed, 28 insertions(+), 35 deletions(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index 4ad149c13f599..c66eacc6b1e2a 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -153,8 +153,7 @@ static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge) return container_of(bridge, struct chipone, bridge); }
-static inline int chipone_dsi_write(struct chipone *icn, const void *seq, - size_t len) +static void chipone_writeb(struct chipone *icn, u8 reg, u8 val) { if (icn->interface_i2c) i2c_smbus_write_byte_data(icn->client, reg, val); @@ -162,12 +161,6 @@ static inline int chipone_dsi_write(struct chipone *icn, const void *seq, mipi_dsi_generic_write(icn->dsi, (u8[]){reg, val}, 2); }
-#define ICN6211_DSI(icn, seq...) \ - { \ - const u8 d[] = { seq }; \ - chipone_dsi_write(icn, d, ARRAY_SIZE(d)); \ - } - static void chipone_configure_pll(struct chipone *icn, const struct drm_display_mode *mode) { @@ -242,11 +235,11 @@ static void chipone_configure_pll(struct chipone *icn, (fin * best_m) / BIT(best_p + best_s + 2));
/* Clock source selection fixed to MIPI DSI clock lane */ - ICN6211_DSI(icn, PLL_CTRL(6), PLL_CTRL_6_MIPI_CLK); - ICN6211_DSI(icn, PLL_REF_DIV, + chipone_writeb(icn, PLL_CTRL(6), PLL_CTRL_6_MIPI_CLK); + chipone_writeb(icn, PLL_REF_DIV, (best_p ? PLL_REF_DIV_Pe : 0) | /* Prefer /2 pre-divider */ PLL_REF_DIV_P(best_p) | PLL_REF_DIV_S(best_s)); - ICN6211_DSI(icn, PLL_INT(0), best_m); + chipone_writeb(icn, PLL_INT(0), best_m); }
static void chipone_atomic_enable(struct drm_bridge *bridge, @@ -265,19 +258,19 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, bus_flags = bridge_state->output_bus_cfg.flags;
if (icn->interface_i2c) - ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_I2C); + chipone_writeb(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_I2C); else - ICN6211_DSI(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI); + chipone_writeb(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI);
- ICN6211_DSI(icn, HACTIVE_LI, mode->hdisplay & 0xff); + chipone_writeb(icn, HACTIVE_LI, mode->hdisplay & 0xff);
- ICN6211_DSI(icn, VACTIVE_LI, mode->vdisplay & 0xff); + chipone_writeb(icn, VACTIVE_LI, mode->vdisplay & 0xff);
/* * lsb nibble: 2nd nibble of hdisplay * msb nibble: 2nd nibble of vdisplay */ - ICN6211_DSI(icn, VACTIVE_HACTIVE_HI, + chipone_writeb(icn, VACTIVE_HACTIVE_HI, ((mode->hdisplay >> 8) & 0xf) | (((mode->vdisplay >> 8) & 0xf) << 4));
@@ -285,49 +278,49 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, hsync = mode->hsync_end - mode->hsync_start; hbp = mode->htotal - mode->hsync_end;
- ICN6211_DSI(icn, HFP_LI, hfp & 0xff); - ICN6211_DSI(icn, HSYNC_LI, hsync & 0xff); - ICN6211_DSI(icn, HBP_LI, hbp & 0xff); + chipone_writeb(icn, HFP_LI, hfp & 0xff); + chipone_writeb(icn, HSYNC_LI, hsync & 0xff); + chipone_writeb(icn, HBP_LI, hbp & 0xff); /* Top two bits of Horizontal Front porch/Sync/Back porch */ - ICN6211_DSI(icn, HFP_HSW_HBP_HI, + chipone_writeb(icn, HFP_HSW_HBP_HI, HFP_HSW_HBP_HI_HFP(hfp) | HFP_HSW_HBP_HI_HS(hsync) | HFP_HSW_HBP_HI_HBP(hbp));
- ICN6211_DSI(icn, VFP, mode->vsync_start - mode->vdisplay); + chipone_writeb(icn, VFP, mode->vsync_start - mode->vdisplay);
- ICN6211_DSI(icn, VSYNC, mode->vsync_end - mode->vsync_start); + chipone_writeb(icn, VSYNC, mode->vsync_end - mode->vsync_start);
- ICN6211_DSI(icn, VBP, mode->vtotal - mode->vsync_end); + chipone_writeb(icn, VBP, mode->vtotal - mode->vsync_end);
/* dsi specific sequence */ - ICN6211_DSI(icn, SYNC_EVENT_DLY, 0x80); - ICN6211_DSI(icn, HFP_MIN, hfp & 0xff); + chipone_writeb(icn, SYNC_EVENT_DLY, 0x80); + chipone_writeb(icn, HFP_MIN, hfp & 0xff);
/* DSI data lane count */ - ICN6211_DSI(icn, DSI_CTRL, + chipone_writeb(icn, DSI_CTRL, DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi_lanes - 1));
- ICN6211_DSI(icn, MIPI_PD_CK_LANE, 0xa0); - ICN6211_DSI(icn, PLL_CTRL(12), 0xff); - ICN6211_DSI(icn, MIPI_PN_SWAP, 0x00); + chipone_writeb(icn, MIPI_PD_CK_LANE, 0xa0); + chipone_writeb(icn, PLL_CTRL(12), 0xff); + chipone_writeb(icn, MIPI_PN_SWAP, 0x00);
/* DPI HS/VS/DE polarity */ pol = ((mode->flags & DRM_MODE_FLAG_PHSYNC) ? BIST_POL_HSYNC_POL : 0) | ((mode->flags & DRM_MODE_FLAG_PVSYNC) ? BIST_POL_VSYNC_POL : 0) | ((bus_flags & DRM_BUS_FLAG_DE_HIGH) ? BIST_POL_DE_POL : 0); - ICN6211_DSI(icn, BIST_POL, pol); + chipone_writeb(icn, BIST_POL, pol);
/* Configure PLL settings */ chipone_configure_pll(icn, mode);
- ICN6211_DSI(icn, SYS_CTRL(0), 0x40); - ICN6211_DSI(icn, SYS_CTRL(1), 0x88); + chipone_writeb(icn, SYS_CTRL(0), 0x40); + chipone_writeb(icn, SYS_CTRL(1), 0x88);
/* icn6211 specific sequence */ - ICN6211_DSI(icn, MIPI_FORCE_0, 0x20); - ICN6211_DSI(icn, PLL_CTRL(1), 0x20); - ICN6211_DSI(icn, CONFIG_FINISH, 0x10); + chipone_writeb(icn, MIPI_FORCE_0, 0x20); + chipone_writeb(icn, PLL_CTRL(1), 0x20); + chipone_writeb(icn, CONFIG_FINISH, 0x10);
usleep_range(10000, 11000); }
Read out the Vendor/Chip/Version ID registers from the chip before performing any configuration, and validate that the registers have correct values. This is mostly a simple test whether DSI register access does work, since that tends to be broken on various bridges.
Acked-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org --- V2: Rebase on next-20220214 V3: Add AB from Maxime --- drivers/gpu/drm/bridge/chipone-icn6211.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c index c66eacc6b1e2a..0a07023d0aeec 100644 --- a/drivers/gpu/drm/bridge/chipone-icn6211.c +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c @@ -153,6 +153,14 @@ static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge) return container_of(bridge, struct chipone, bridge); }
+static void chipone_readb(struct chipone *icn, u8 reg, u8 *val) +{ + if (icn->interface_i2c) + *val = i2c_smbus_read_byte_data(icn->client, reg); + else + mipi_dsi_generic_read(icn->dsi, (u8[]){reg, 1}, 2, val, 1); +} + static void chipone_writeb(struct chipone *icn, u8 reg, u8 val) { if (icn->interface_i2c) @@ -251,7 +259,21 @@ static void chipone_atomic_enable(struct drm_bridge *bridge, const struct drm_bridge_state *bridge_state; u16 hfp, hbp, hsync; u32 bus_flags; - u8 pol; + u8 pol, id[4]; + + chipone_readb(icn, VENDOR_ID, id); + chipone_readb(icn, DEVICE_ID_H, id + 1); + chipone_readb(icn, DEVICE_ID_L, id + 2); + chipone_readb(icn, VERSION_ID, id + 3); + + dev_dbg(icn->dev, + "Chip IDs: Vendor=0x%02x Device=0x%02x:0x%02x Version=0x%02x\n", + id[0], id[1], id[2], id[3]); + + if (id[0] != 0xc1 || id[1] != 0x62 || id[2] != 0x11) { + dev_dbg(icn->dev, "Invalid Chip IDs, aborting configuration\n"); + return; + }
/* Get the DPI flags from the bridge state. */ bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
dri-devel@lists.freedesktop.org
-
Jagan Teki -
Laurent Pinchart -
Marek Vasut -
Maxime Ripard -
Rob Herring