Existing host driver will keep looking for DRM pointer in sun6i_dsi_attach and defers even if the particular DSI device is found for the first time. Meanwhile it triggers the bind callback and gets the DRM pointer and then continues the sun6i_dsi_attach.

This makes a deadlock situation if sun6i_dsi_attach is trying to find the bridge.

If interface bridge is trying to call host attach, then host sun6i_dsi_attach is trying to find bridge and defers the interface bridge even if it found the bridge as bind callback does not complete at the movement. So, this sun6i_dsi_attach defers interface bridge and triggers the bind callback and tries to attach the bridge with a bridge pointer which is not available at the moment.

Eventually these callbacks are triggered recursively, as sun6i_dsi_attach defers interface bridge and bind callback defers sun6i_dsi_attach due to invalid bridge ponter.

This patch prevents this situation by probing all DSI devices on the pipeline first and then triggers the bind callback by dropping exing DRM binding logic.

Signed-off-by: Jagan Teki jagan@amarulasolutions.com --- Changes for v6: - none Changes for v5: - new patch

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 10 +--------- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 1 - 2 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 527c7b2474da..4bdcce8f1d84 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -967,14 +967,10 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,

if (IS_ERR(panel)) return PTR_ERR(panel); - if (!dsi->drm || !dsi->drm->registered) - return -EPROBE_DEFER;

dsi->panel = panel; dsi->device = device;

- drm_kms_helper_hotplug_event(dsi->drm); - dev_info(host->dev, "Attached device %s\n", device->name);

return 0; @@ -988,8 +984,6 @@ static int sun6i_dsi_detach(struct mipi_dsi_host *host, dsi->panel = NULL; dsi->device = NULL;

- drm_kms_helper_hotplug_event(dsi->drm); - return 0; }

@@ -1077,8 +1071,6 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,

drm_connector_attach_encoder(&dsi->connector, &dsi->encoder);

- dsi->drm = drm; - return 0;

err_cleanup_connector: @@ -1091,7 +1083,7 @@ static void sun6i_dsi_unbind(struct device *dev, struct device *master, { struct sun6i_dsi *dsi = dev_get_drvdata(dev);

- dsi->drm = NULL; + drm_encoder_cleanup(&dsi->encoder); }

static const struct component_ops sun6i_dsi_ops = { diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h index c863900ae3b4..61e88ea6044d 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h @@ -29,7 +29,6 @@ struct sun6i_dsi {

struct device *dev; struct mipi_dsi_device *device; - struct drm_device *drm; struct drm_panel *panel; };

Having component_add for running all drm bind callbacks returns error or unbound due to chain of DSI devices connected across bridge topology on a display pipeline.

In a typical bridge oriented display pipeline where the host is connected to the bridge converter and that indeed connected to a panel.

DRM => SUN6I DSI Host => Chipone ICN6211 => BananaPi Panel

The bridge converter is looking for a panel to probe first and then attach the host. The host attach is looking for a bridge converter to probe and preserve bridge pointer, at this movement the host is trying to bind the all callbacks and one of the bind callback in the DSI host is trying to find the bridge using the bridge pointer in sun6i_dsi_attach call.

chipone_probe().start drm_of_find_panel_or_bridge mipi_dsi_attach sun6i_dsi_attach drm_of_find_panel_or_bridge chipone_probe().done

sun6i_dsi_probe().start mipi_dsi_host_register component_add sun6i_dsi_probe().done

However, the movement when panel defers the probe, will make the bridge converter defer the host attach call which eventually found a NULL bridge pointer during DSI component bind callback.

So, in order to prevent this scenario of binding invalid bridge, wait for DSI devices on the pipeline to probe first and start the binding process by moving component_add in host probe to attach call.

chipone_probe().start drm_of_find_panel_or_bridge mipi_dsi_attach sun6i_dsi_attach drm_of_find_panel_or_bridge component_add chipone_probe().done

sun6i_dsi_probe().start mipi_dsi_host_register sun6i_dsi_probe().done

Signed-off-by: Jagan Teki jagan@amarulasolutions.com --- Changes for v6: - none Changes for v5: - new patch

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 120 +++++++++++++------------ 1 file changed, 61 insertions(+), 59 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 4bdcce8f1d84..9cf91dcac3f2 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -959,11 +959,63 @@ static int sun6i_dsi_dcs_read(struct sun6i_dsi *dsi, return 1; }

+static int sun6i_dsi_bind(struct device *dev, struct device *master, + void *data) +{ + struct drm_device *drm = data; + struct sun6i_dsi *dsi = dev_get_drvdata(dev); + int ret; + + drm_encoder_helper_add(&dsi->encoder, + &sun6i_dsi_enc_helper_funcs); + ret = drm_simple_encoder_init(drm, &dsi->encoder, + DRM_MODE_ENCODER_DSI); + if (ret) { + dev_err(dsi->dev, "Couldn't initialise the DSI encoder\n"); + return ret; + } + dsi->encoder.possible_crtcs = BIT(0); + + drm_connector_helper_add(&dsi->connector, + &sun6i_dsi_connector_helper_funcs); + ret = drm_connector_init(drm, &dsi->connector, + &sun6i_dsi_connector_funcs, + DRM_MODE_CONNECTOR_DSI); + if (ret) { + dev_err(dsi->dev, + "Couldn't initialise the DSI connector\n"); + goto err_cleanup_connector; + } + + drm_connector_attach_encoder(&dsi->connector, &dsi->encoder); + + return 0; + +err_cleanup_connector: + drm_encoder_cleanup(&dsi->encoder); + return ret; +} + +static void sun6i_dsi_unbind(struct device *dev, struct device *master, + void *data) +{ + struct sun6i_dsi *dsi = dev_get_drvdata(dev); + + drm_encoder_cleanup(&dsi->encoder); +} + +static const struct component_ops sun6i_dsi_ops = { + .bind = sun6i_dsi_bind, + .unbind = sun6i_dsi_unbind, +}; + static int sun6i_dsi_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *device) { struct sun6i_dsi *dsi = host_to_sun6i_dsi(host); struct drm_panel *panel = of_drm_find_panel(device->dev.of_node); + struct device *dev = dsi->dev; + int ret;

if (IS_ERR(panel)) return PTR_ERR(panel); @@ -973,6 +1025,13 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,

dev_info(host->dev, "Attached device %s\n", device->name);

+ ret = component_add(dev, &sun6i_dsi_ops); + if (ret) { + dev_err(dev, "Couldn't register our component\n"); + mipi_dsi_host_unregister(&dsi->host); + return ret; + } + return 0; }

@@ -984,6 +1043,8 @@ static int sun6i_dsi_detach(struct mipi_dsi_host *host, dsi->panel = NULL; dsi->device = NULL;

+ component_del(dsi->dev, &sun6i_dsi_ops); + return 0; }

@@ -1041,56 +1102,6 @@ static const struct regmap_config sun6i_dsi_regmap_config = { .name = "mipi-dsi", };

-static int sun6i_dsi_bind(struct device *dev, struct device *master, - void *data) -{ - struct drm_device *drm = data; - struct sun6i_dsi *dsi = dev_get_drvdata(dev); - int ret; - - drm_encoder_helper_add(&dsi->encoder, - &sun6i_dsi_enc_helper_funcs); - ret = drm_simple_encoder_init(drm, &dsi->encoder, - DRM_MODE_ENCODER_DSI); - if (ret) { - dev_err(dsi->dev, "Couldn't initialise the DSI encoder\n"); - return ret; - } - dsi->encoder.possible_crtcs = BIT(0); - - drm_connector_helper_add(&dsi->connector, - &sun6i_dsi_connector_helper_funcs); - ret = drm_connector_init(drm, &dsi->connector, - &sun6i_dsi_connector_funcs, - DRM_MODE_CONNECTOR_DSI); - if (ret) { - dev_err(dsi->dev, - "Couldn't initialise the DSI connector\n"); - goto err_cleanup_connector; - } - - drm_connector_attach_encoder(&dsi->connector, &dsi->encoder); - - return 0; - -err_cleanup_connector: - drm_encoder_cleanup(&dsi->encoder); - return ret; -} - -static void sun6i_dsi_unbind(struct device *dev, struct device *master, - void *data) -{ - struct sun6i_dsi *dsi = dev_get_drvdata(dev); - - drm_encoder_cleanup(&dsi->encoder); -} - -static const struct component_ops sun6i_dsi_ops = { - .bind = sun6i_dsi_bind, - .unbind = sun6i_dsi_unbind, -}; - static int sun6i_dsi_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -1172,16 +1183,8 @@ static int sun6i_dsi_probe(struct platform_device *pdev) goto err_unprotect_clk; }

- ret = component_add(&pdev->dev, &sun6i_dsi_ops); - if (ret) { - dev_err(dev, "Couldn't register our component\n"); - goto err_remove_dsi_host; - } - return 0;

-err_remove_dsi_host: - mipi_dsi_host_unregister(&dsi->host); err_unprotect_clk: clk_rate_exclusive_put(dsi->mod_clk); err_attach_clk: @@ -1195,7 +1198,6 @@ static int sun6i_dsi_remove(struct platform_device *pdev) struct device *dev = &pdev->dev; struct sun6i_dsi *dsi = dev_get_drvdata(dev);

- component_del(&pdev->dev, &sun6i_dsi_ops); mipi_dsi_host_unregister(&dsi->host); clk_rate_exclusive_put(dsi->mod_clk);

Some display panels would come up with a non-DSI output, those can have an option to connect the DSI host by means of interface bridge converter.

This DSI to non-DSI interface bridge converter would require DSI Host to handle drm bridge functionalities in order to communicate interface bridge.

This patch adds support for bridge functionalities in Allwinner DSI controller.

Supporting down-stream bridge makes few changes in the driver.

- It drops drm_connector and related operations as drm_bridge_attach creates connector during attachment.

- It drop panel pointer and iterate the bridge, so-that it can operate the normal bridge and panel_bridge in constitutive callbacks.

- It uses devm_drm_of_get_bridge for panel or bridge lookup. It uses port 0 and endpoint 0 to support I2C-based bridges eventhough the usual Allwinner DSI OF graph doesn't require this for panel and non-I2C based downstream bridges.

Signed-off-by: Jagan Teki jagan@amarulasolutions.com --- Changes for v6: - support donwstream bridge - drop bridge conversion - devm_drm_of_get_bridge() require child lookup https://patchwork.kernel.org/project/dri-devel/cover/20211207054747.461029-1... Changes for v5: - add atomic APIs - find host and device variant DSI devices. Changes for v4, v3: - none

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 83 ++++++++++---------------- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 9 +-- 2 files changed, 33 insertions(+), 59 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 9cf91dcac3f2..f1d612bf1a0b 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -21,6 +21,7 @@

#include <drm/drm_atomic_helper.h> #include <drm/drm_mipi_dsi.h> +#include <drm/drm_of.h> #include <drm/drm_panel.h> #include <drm/drm_print.h> #include <drm/drm_probe_helper.h> @@ -720,6 +721,7 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) struct mipi_dsi_device *device = dsi->device; union phy_configure_opts opts = { }; struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy; + struct drm_bridge *iter; u16 delay; int err;

@@ -769,8 +771,10 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) phy_configure(dsi->dphy, &opts); phy_power_on(dsi->dphy);

- if (dsi->panel) - drm_panel_prepare(dsi->panel); + list_for_each_entry(iter, &dsi->bridge_chain, chain_node) { + if (iter->funcs->pre_enable) + iter->funcs->pre_enable(iter); + }

/* * FIXME: This should be moved after the switch to HS mode. @@ -784,8 +788,10 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) * ordering on the panels I've tested it with, so I guess this * will do for now, until that IP is better understood. */ - if (dsi->panel) - drm_panel_enable(dsi->panel); + list_for_each_entry(iter, &dsi->bridge_chain, chain_node) { + if (iter->funcs->enable) + iter->funcs->enable(iter); + }

sun6i_dsi_start(dsi, DSI_START_HSC);

@@ -797,12 +803,16 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder) static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder) { struct sun6i_dsi *dsi = encoder_to_sun6i_dsi(encoder); + struct drm_bridge *iter;

DRM_DEBUG_DRIVER("Disabling DSI output\n");

- if (dsi->panel) { - drm_panel_disable(dsi->panel); - drm_panel_unprepare(dsi->panel); + list_for_each_entry(iter, &dsi->bridge_chain, chain_node) { + if (iter->funcs->disable) + iter->funcs->disable(iter); + + if (iter->funcs->post_disable) + iter->funcs->post_disable(iter); }

phy_power_off(dsi->dphy); @@ -813,35 +823,6 @@ static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder) regulator_disable(dsi->regulator); }

-static int sun6i_dsi_get_modes(struct drm_connector *connector) -{ - struct sun6i_dsi *dsi = connector_to_sun6i_dsi(connector); - - return drm_panel_get_modes(dsi->panel, connector); -} - -static const struct drm_connector_helper_funcs sun6i_dsi_connector_helper_funcs = { - .get_modes = sun6i_dsi_get_modes, -}; - -static enum drm_connector_status -sun6i_dsi_connector_detect(struct drm_connector *connector, bool force) -{ - struct sun6i_dsi *dsi = connector_to_sun6i_dsi(connector); - - return dsi->panel ? connector_status_connected : - connector_status_disconnected; -} - -static const struct drm_connector_funcs sun6i_dsi_connector_funcs = { - .detect = sun6i_dsi_connector_detect, - .fill_modes = drm_helper_probe_single_connector_modes, - .destroy = drm_connector_cleanup, - .reset = drm_atomic_helper_connector_reset, - .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state, - .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, -}; - static const struct drm_encoder_helper_funcs sun6i_dsi_enc_helper_funcs = { .disable = sun6i_dsi_encoder_disable, .enable = sun6i_dsi_encoder_enable, @@ -976,22 +957,17 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master, } dsi->encoder.possible_crtcs = BIT(0);

- drm_connector_helper_add(&dsi->connector, - &sun6i_dsi_connector_helper_funcs); - ret = drm_connector_init(drm, &dsi->connector, - &sun6i_dsi_connector_funcs, - DRM_MODE_CONNECTOR_DSI); + ret = drm_bridge_attach(&dsi->encoder, dsi->next_bridge, NULL, 0); if (ret) { - dev_err(dsi->dev, - "Couldn't initialise the DSI connector\n"); - goto err_cleanup_connector; + dev_err(dsi->dev, "Couldn't attach drm bridge\n"); + goto err_cleanup_encoder; }

- drm_connector_attach_encoder(&dsi->connector, &dsi->encoder); + list_splice_init(&dsi->encoder.bridge_chain, &dsi->bridge_chain);

return 0;

-err_cleanup_connector: +err_cleanup_encoder: drm_encoder_cleanup(&dsi->encoder); return ret; } @@ -1013,17 +989,18 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *device) { struct sun6i_dsi *dsi = host_to_sun6i_dsi(host); - struct drm_panel *panel = of_drm_find_panel(device->dev.of_node); struct device *dev = dsi->dev; int ret;

- if (IS_ERR(panel)) - return PTR_ERR(panel); + dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0); + if (IS_ERR(dsi->next_bridge)) { + dev_err(dsi->dev, "Couldn't find the bridge\n"); + return PTR_ERR(dsi->next_bridge); + }

- dsi->panel = panel; dsi->device = device;

- dev_info(host->dev, "Attached device %s\n", device->name); + dev_info(host->dev, "Attached %s\n", device->name);

ret = component_add(dev, &sun6i_dsi_ops); if (ret) { @@ -1040,7 +1017,7 @@ static int sun6i_dsi_detach(struct mipi_dsi_host *host, { struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);

- dsi->panel = NULL; + dsi->next_bridge = NULL; dsi->device = NULL;

component_del(dsi->dev, &sun6i_dsi_ops); @@ -1118,6 +1095,8 @@ static int sun6i_dsi_probe(struct platform_device *pdev) dsi->host.ops = &sun6i_dsi_host_ops; dsi->host.dev = dev;

+ INIT_LIST_HEAD(&dsi->bridge_chain); + if (of_device_is_compatible(dev->of_node, "allwinner,sun6i-a31-mipi-dsi")) bus_clk_name = "bus"; diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h index 61e88ea6044d..96a219b9c275 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h @@ -16,7 +16,6 @@ #define SUN6I_DSI_TCON_DIV 4

struct sun6i_dsi { - struct drm_connector connector; struct drm_encoder encoder; struct mipi_dsi_host host;

@@ -29,7 +28,8 @@ struct sun6i_dsi {

struct device *dev; struct mipi_dsi_device *device; - struct drm_panel *panel; + struct drm_bridge *next_bridge; + struct list_head bridge_chain; };

static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host) @@ -37,11 +37,6 @@ static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host) return container_of(host, struct sun6i_dsi, host); };

-static inline struct sun6i_dsi *connector_to_sun6i_dsi(struct drm_connector *connector) -{ - return container_of(connector, struct sun6i_dsi, connector); -}; - static inline struct sun6i_dsi *encoder_to_sun6i_dsi(const struct drm_encoder *encoder) { return container_of(encoder, struct sun6i_dsi, encoder);

Bananapi S070WV20-CT16 is a pure RGB output panel with ICN6211 DSI/RGB convertor bridge.

Enable bridge along with associated panel.

Signed-off-by: Jagan Teki jagan@amarulasolutions.com --- arch/arm/boot/dts/sun8i-r16-bananapi-m2m.dts | 64 ++++++++++++++++++++ 1 file changed, 64 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-r16-bananapi-m2m.dts b/arch/arm/boot/dts/sun8i-r16-bananapi-m2m.dts index bf5b5e2f6168..501666dfb5ee 100644 --- a/arch/arm/boot/dts/sun8i-r16-bananapi-m2m.dts +++ b/arch/arm/boot/dts/sun8i-r16-bananapi-m2m.dts @@ -44,6 +44,7 @@ #include "sun8i-a33.dtsi"

#include <dt-bindings/gpio/gpio.h> +#include <dt-bindings/pwm/pwm.h>

/ { model = "BananaPi M2 Magic"; @@ -55,12 +56,21 @@ aliases { i2c2 = &i2c2; serial0 = &uart0; serial1 = &uart1; + mmc0 = &mmc0; };

chosen { stdout-path = "serial0:115200n8"; };

+ backlight: backlight { + compatible = "pwm-backlight"; + pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>; + brightness-levels = <1 2 4 8 16 32 64 128 255>; + default-brightness-level = <8>; + enable-gpios = <&r_pio 0 4 GPIO_ACTIVE_HIGH>; /* LCD-BL-EN: PL4 */ + }; + leds { compatible = "gpio-leds";

@@ -81,6 +91,18 @@ led-2 { }; };

+ panel { + compatible = "bananapi,s070wv20-ct16"; + enable-gpios = <&pio 1 7 GPIO_ACTIVE_HIGH>; /* LCD-PWR-EN: PB7 */ + backlight = <&backlight>; + + port { + panel_out_bridge: endpoint { + remote-endpoint = <&bridge_out_panel>; + }; + }; + }; + reg_vcc5v0: vcc5v0 { compatible = "regulator-fixed"; regulator-name = "vcc5v0"; @@ -122,6 +144,38 @@ &dai { status = "okay"; };

+&de { + status = "okay"; +}; + +&dphy { + status = "okay"; +}; + +&dsi { + vcc-dsi-supply = <&reg_dcdc1>; /* VCC-DSI */ + status = "okay"; + + bridge@0 { + compatible = "chipone,icn6211"; + reg = <0>; + enable-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /* LCD-RST: PL5 */ + + ports { + #address-cells = <1>; + #size-cells = <0>; + + bridge_out: port@1 { + reg = <1>; + + bridge_out_panel: endpoint { + remote-endpoint = <&panel_out_bridge>; + }; + }; + }; + }; +}; + &ehci0 { status = "okay"; }; @@ -157,6 +211,12 @@ &ohci0 { status = "okay"; };

+&pwm { + pinctrl-names = "default"; + pinctrl-0 = <&pwm0_pin>; + status = "okay"; +}; + &r_rsb { status = "okay";

@@ -269,6 +329,10 @@ &sound { status = "okay"; };

+&tcon0 { + status = "okay"; +}; + &uart0 { pinctrl-names = "default"; pinctrl-0 = <&uart0_pb_pins>;