Re: [PATCH 2/2] drm/bridge: Add tc358768 driver

Hi Andrzej,

On 16/01/2020 16.35, Andrzej Hajda wrote:

On 17.12.2019 11:15, Peter Ujfalusi wrote:

...

Add basic support for the Toshiba TC358768 RGB to DSI bridge. Not all the features of the TC358768 is implemented by the initial driver: MIPI_DSI_MODE_VIDEO and MIPI_DSI_FMT_RGB888 is only supported and tested.

Only write is implemented for mipi_dsi_host_ops.transfer.

Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com

drivers/gpu/drm/bridge/Kconfig | 10 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/tc358768.c | 963 ++++++++++++++++++++++++++++++ 3 files changed, 974 insertions(+) create mode 100644 drivers/gpu/drm/bridge/tc358768.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index ccc698c44f58..fd65666702e1 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -122,6 +122,16 @@ config DRM_TOSHIBA_TC358767 ---help--- Toshiba TC358767 eDP bridge chip driver.

+config DRM_TOSHIBA_TC358768

• tristate "Toshiba TC358768 MIPI DSI bridge"
• depends on OF
• select DRM_KMS_HELPER
• select REGMAP_I2C
• select DRM_PANEL
• select DRM_MIPI_DSI
• help

•  Toshiba TC358768AXBG/TC358778XBG DSI bridge chip driver.
  

config DRM_TI_TFP410 tristate "TI TFP410 DVI/HDMI bridge" depends on OF diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index a6c7dd7727ea..204696e30572 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_DRM_SII9234) += sii9234.o obj-$(CONFIG_DRM_THINE_THC63LVD1024) += thc63lvd1024.o obj-$(CONFIG_DRM_TOSHIBA_TC358764) += tc358764.o obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o +obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/ obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c new file mode 100644 index 000000000000..63571191b1c4 --- /dev/null +++ b/drivers/gpu/drm/bridge/tc358768.c @@ -0,0 +1,963 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com

Just FYI, we have 2020 already, maybe update needed.

Oh, how time flies ;)

...

• • Author: Peter Ujfalusi peter.ujfalusi@ti.com
• */

+#include <linux/clk.h> +#include <linux/device.h> +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/regulator/consumer.h>

alphabetic order

Ok.

...

+#include <drm/drm_atomic_helper.h> +#include <drm/drm_crtc_helper.h> +#include <drm/drm_drv.h> +#include <drm/drm_of.h> +#include <drm/drm_panel.h> +#include <drm/drm_mipi_dsi.h> +#include <video/mipi_display.h> +#include <video/videomode.h>

+/* Global (16-bit addressable) */ +#define TC358768_CHIPID 0x0000 +#define TC358768_SYSCTL 0x0002 +#define TC358768_CONFCTL 0x0004 +#define TC358768_VSDLY 0x0006 +#define TC358768_DATAFMT 0x0008 +#define TC358768_GPIOEN 0x000E +#define TC358768_GPIODIR 0x0010 +#define TC358768_GPIOIN 0x0012 +#define TC358768_GPIOOUT 0x0014 +#define TC358768_PLLCTL0 0x0016 +#define TC358768_PLLCTL1 0x0018 +#define TC358768_CMDBYTE 0x0022 +#define TC358768_PP_MISC 0x0032 +#define TC358768_DSITX_DT 0x0050 +#define TC358768_FIFOSTATUS 0x00F8

+/* Debug (16-bit addressable) */ +#define TC358768_VBUFCTRL 0x00E0 +#define TC358768_DBG_WIDTH 0x00E2 +#define TC358768_DBG_VBLANK 0x00E4 +#define TC358768_DBG_DATA 0x00E8

+/* TX PHY (32-bit addressable) */ +#define TC358768_CLW_DPHYCONTTX 0x0100 +#define TC358768_D0W_DPHYCONTTX 0x0104 +#define TC358768_D1W_DPHYCONTTX 0x0108 +#define TC358768_D2W_DPHYCONTTX 0x010C +#define TC358768_D3W_DPHYCONTTX 0x0110 +#define TC358768_CLW_CNTRL 0x0140 +#define TC358768_D0W_CNTRL 0x0144 +#define TC358768_D1W_CNTRL 0x0148 +#define TC358768_D2W_CNTRL 0x014C +#define TC358768_D3W_CNTRL 0x0150

+/* TX PPI (32-bit addressable) */ +#define TC358768_STARTCNTRL 0x0204 +#define TC358768_DSITXSTATUS 0x0208 +#define TC358768_LINEINITCNT 0x0210 +#define TC358768_LPTXTIMECNT 0x0214 +#define TC358768_TCLK_HEADERCNT 0x0218 +#define TC358768_TCLK_TRAILCNT 0x021C +#define TC358768_THS_HEADERCNT 0x0220 +#define TC358768_TWAKEUP 0x0224 +#define TC358768_TCLK_POSTCNT 0x0228 +#define TC358768_THS_TRAILCNT 0x022C +#define TC358768_HSTXVREGCNT 0x0230 +#define TC358768_HSTXVREGEN 0x0234 +#define TC358768_TXOPTIONCNTRL 0x0238 +#define TC358768_BTACNTRL1 0x023C

+/* TX CTRL (32-bit addressable) */ +#define TC358768_DSI_CONTROL 0x040C +#define TC358768_DSI_STATUS 0x0410 +#define TC358768_DSI_INT 0x0414 +#define TC358768_DSI_INT_ENA 0x0418 +#define TC358768_DSICMD_RDFIFO 0x0430 +#define TC358768_DSI_ACKERR 0x0434 +#define TC358768_DSI_ACKERR_INTENA 0x0438 +#define TC358768_DSI_ACKERR_HALT 0x043c +#define TC358768_DSI_RXERR 0x0440 +#define TC358768_DSI_RXERR_INTENA 0x0444 +#define TC358768_DSI_RXERR_HALT 0x0448 +#define TC358768_DSI_ERR 0x044C +#define TC358768_DSI_ERR_INTENA 0x0450 +#define TC358768_DSI_ERR_HALT 0x0454 +#define TC358768_DSI_CONFW 0x0500 +#define TC358768_DSI_LPCMD 0x0500 +#define TC358768_DSI_RESET 0x0504 +#define TC358768_DSI_INT_CLR 0x050C +#define TC358768_DSI_START 0x0518

+/* DSITX CTRL (16-bit addressable) */ +#define TC358768_DSICMD_TX 0x0600 +#define TC358768_DSICMD_TYPE 0x0602 +#define TC358768_DSICMD_WC 0x0604 +#define TC358768_DSICMD_WD0 0x0610 +#define TC358768_DSICMD_WD1 0x0612 +#define TC358768_DSICMD_WD2 0x0614 +#define TC358768_DSICMD_WD3 0x0616 +#define TC358768_DSI_EVENT 0x0620 +#define TC358768_DSI_VSW 0x0622 +#define TC358768_DSI_VBPR 0x0624 +#define TC358768_DSI_VACT 0x0626 +#define TC358768_DSI_HSW 0x0628 +#define TC358768_DSI_HBPR 0x062A +#define TC358768_DSI_HACT 0x062C

+static const char * const tc358768_supplies[] = {

• "vddc", "vddmipi", "vddio"

+};

+struct tc358768_dsi_output {

• struct mipi_dsi_device *dev;
• struct drm_panel *panel;
• struct drm_bridge *bridge;

+};

+struct tc358768_priv {

• struct device *dev;
• struct regmap *regmap;
• struct gpio_desc *reset_gpio;
• struct regulator_bulk_data supplies[ARRAY_SIZE(tc358768_supplies)];
• struct clk *refclk;
• struct mipi_dsi_host dsi_host;
• struct drm_bridge bridge;
• struct tc358768_dsi_output output;

Since tc358768_dsi_output is used only here, you can define it here as well, up to you.

I think I have done it like this to avoid thinking about prefixes for what is under the tc358768_dsi_output. I'll take a look if it will look better unpacked here.

...

• const struct drm_display_mode *mode;
• u32 pd_lines; /* number of Parallel Port Input Data Lines */
• u32 dsi_lanes; /* number of DSI Lanes */
• u32 fbd;
• u32 prd;
• u32 frs;

Looks ugly, please rename these 3 vars to sth more readable, or at least document them (if the names comes from the specification).

Sure, I agree.

...

• u32 dsiclk; /* pll_clk / 2 */

+};

+static inline struct tc358768_priv *dsi_host_to_tc358768(struct mipi_dsi_host

• 					 *host)
  

+{

• return container_of(host, struct tc358768_priv, dsi_host);

+}

+static inline struct tc358768_priv *bridge_to_tc358768(struct drm_bridge

• 				       *bridge)
  

+{

• return container_of(bridge, struct tc358768_priv, bridge);

+}

+static int tc358768_write(struct tc358768_priv *priv, u32 reg, u32 val) +{

• size_t count = 2;
• /* 16-bit register? */
• if (reg < 0x100 || reg >= 0x600)

• count = 1;
  

• return regmap_bulk_write(priv->regmap, reg, &val, count);

+}

+static int tc358768_read(struct tc358768_priv *priv, u32 reg, u32 *val) +{

• size_t count = 2;
• /* 16-bit register? */
• if (reg < 0x100 || reg >= 0x600) {

• *val = 0;
  

• count = 1;
  

• }
• return regmap_bulk_read(priv->regmap, reg, val, count);

+}

+static int tc358768_update_bits(struct tc358768_priv *priv, u32 reg, u32 mask,

• 		u32 val)
  

+{

• int ret;
• u32 tmp, orig;
• ret = tc358768_read(priv, reg, &orig);
• if (ret != 0)

• return ret;
  

• tmp = orig & ~mask;
• tmp |= val & mask;
• if (tmp != orig)

• ret = tc358768_write(priv, reg, tmp);
  

• return ret;

+}

You have defined 3 hw access functions which can fail but you do not check their return values in later usage. Does regmap/i2c logs sth in case of error?

If not, maybe error logging should be added at least in these accessors.

The best would be to propagate errors to callers, either traditional way (add check after each call), either you can use 'error state' pattern, which I recommend (see for example to 'ctx->error' usage in sil-sii8620.c).

OK, I'll clean this up

...

+static void tc358768_sw_reset(struct tc358768_priv *priv) +{

• /* Assert Reset */
• tc358768_write(priv, TC358768_SYSCTL, 1);
• /* Release Reset, Exit Sleep */
• tc358768_write(priv, TC358768_SYSCTL, 0);

+}

+static void tc358768_hw_enable(struct tc358768_priv *priv, bool enable) +{

• int ret;
• if (enable) {

• ret = regulator_bulk_enable(ARRAY_SIZE(priv->supplies),
  

• 			    priv->supplies);
  

• if (ret < 0)
  

• 	dev_err(priv->dev, "error enabling regulators (%d)\n",
  

• 		ret);
  

• usleep_range(200, 300);
  

• }
• /*

• * The RESX is active low (GPIO_ACTIVE_LOW).
  

• * Invert the 'enable' value to get correct assertion for the gpio:
  

• * enable == true: reset_gpio needs to be DEASSERTED (value = 0)
  

• * enable == false: reset_gpio needs to be ASSERTED (value = 1)
  

• */
  

• gpiod_set_value_cansleep(priv->reset_gpio, !enable);
• regcache_cache_only(priv->regmap, !enable);
• if (enable) {

• /* wait for encoder clocks to stabilize */
  

• usleep_range(1000, 2000);
  

• regcache_sync(priv->regmap);
  

What do you need to sync here?

Right, we do a full reconfiguration after this, you are correct, there is no need to sync and the regmap's REGCACHE_RBTREE can be REGCACHE_NONE safely.

...

• } else {

• ret = regulator_bulk_disable(ARRAY_SIZE(priv->supplies),
  

• 			     priv->supplies);
  

• if (ret < 0)
  

• 	dev_err(priv->dev, "error disabling regulators (%d)\n",
  

• 		ret);
  

• }

+}

Above function looks ugly - these 'if (enable)' and similar are hard to read, maybe two separate hw_enable, hw_disable function would look better, more readable, up to you.

OK, I'll separate the enable and disable.

...

+static u32 tc358768_pll_to_pclk(struct tc358768_priv *priv, u32 pll_clk) +{

• return (u32)div_u64((u64)pll_clk * priv->dsi_lanes, priv->pd_lines);

+}

+static u32 tc358768_pclk_to_pll(struct tc358768_priv *priv, u32 pclk) +{

• return (u32)div_u64((u64)pclk * priv->pd_lines, priv->dsi_lanes);

+}

+static int tc358768_calc_pll(struct tc358768_priv *priv) +{

• const u32 frs_limits[] = {

• 1000000000,
  

• 500000000,
  

• 250000000,
  

• 125000000,
  

• 62500000
  

• };
• unsigned long refclk;
• u32 prd, target_pll, i, max_pll, min_pll;
• u32 frs, best_diff, best_pll, best_prd, best_fbd;
• target_pll = tc358768_pclk_to_pll(priv, priv->mode->clock * 1000);
• /* pll_clk = RefClk * [(FBD + 1)/ (PRD + 1)] * [1 / (2^FRS)] */

I guess below code:

...

• frs = UINT_MAX;
• for (i = 0; i < ARRAY_SIZE(frs_limits) - 1; i++) {

• if (target_pll < frs_limits[i] &&
  

•     target_pll >= frs_limits[i + 1]) {
  

• 	frs = i;
  

• 	max_pll = frs_limits[i];
  

• 	min_pll = frs_limits[i + 1];
  

• 	break;
  

• }
  

• }
• if (frs == UINT_MAX)

• return -EINVAL;
  

can be simplified:

for (i = 0; i < ARRAY_SIZE(frs_limits); i++)

if (target_pll >= frs_limits[i])

break;

if (i == ARRAY_SIZE(frs_limits) || i == 0)

return -EINVAL;

frs = i - 1;

max_pll = frs_limits[i-1];

min_pll = frs_limits[i];

Yes, it enhances readability as well.

...

• refclk = clk_get_rate(priv->refclk);
• best_diff = UINT_MAX;
• best_pll = 0;
• best_prd = 0;
• best_fbd = 0;
• for (prd = 0; prd < 16; ++prd) {

• u32 divisor = (prd + 1) * (1 << frs);
  

• u32 fbd;
  

• for (fbd = 0; fbd < 512; ++fbd) {
  

• 	u32 pll, diff;
  

• 	pll = (u32)div_u64((u64)refclk * (fbd + 1), divisor);
  

• 	if (pll >= max_pll || pll < min_pll)
  

• 		continue;
  

• 	diff = max(pll, target_pll) - min(pll, target_pll);
  

• 	if (diff < best_diff) {
  

• 		best_diff = diff;
  

• 		best_pll = pll;
  

• 		best_prd = prd;
  

• 		best_fbd = fbd;
  

• 	}
  

• 	if (best_diff == 0)
  

• 		break;
  

• }
  

• if (best_diff == 0)
  

• 	break;
  

why another check here?

To break out from the top for() loop also in case exact match has been found.

...

• }
• if (best_diff == UINT_MAX) {

• dev_err(priv->dev, "could not find suitable PLL setup\n");
  

• return -EINVAL;
  

• }
• priv->fbd = best_fbd;
• priv->prd = best_prd;
• priv->frs = frs;
• priv->dsiclk = best_pll / 2;
• return 0;

+}

+static int tc358768_dsi_host_attach(struct mipi_dsi_host *host,

• 		    struct mipi_dsi_device *dev)
  

+{

• struct tc358768_priv *priv = dsi_host_to_tc358768(host);
• struct drm_bridge *bridge;
• struct drm_panel *panel;
• struct device_node *ep;
• int ret;
• if (dev->lanes > 4) {

• dev_err(priv->dev, "unsupported number of data lanes(%u)\n",
  

• 	dev->lanes);
  

• return -EINVAL;
  

• }
• /*

• * tc358768 supports both Video and Pulse mode, but the driver only
  

• * implements Video (event) mode currently
  

• */
  

• if (!(dev->mode_flags & MIPI_DSI_MODE_VIDEO)) {

• dev_err(priv->dev, "Only MIPI_DSI_MODE_VIDEO is supported\n");
  

• return -ENOTSUPP;
  

• }
• /*

• * tc358768 supports RGB888, RGB666, RGB666_PACKED and RGB565, but only
  

• * RGB888 is verified.
  

• */
  

• if (dev->format != MIPI_DSI_FMT_RGB888) {

• dev_warn(priv->dev, "Only MIPI_DSI_FMT_RGB888 tested!\n");
  

• return -ENOTSUPP;
  

• }
• ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0, &panel,

• 			  &bridge);
  

• if (ret)

• return ret;
  

• if (panel) {

• bridge = drm_panel_bridge_add_typed(panel,
  

• 				    DRM_MODE_CONNECTOR_DSI);
  

• if (IS_ERR(bridge))
  

• 	return PTR_ERR(bridge);
  

• }
• priv->output.dev = dev;
• priv->output.bridge = bridge;
• priv->output.panel = panel;
• priv->dsi_lanes = dev->lanes;
• /* get input ep (port0/endpoint0) */
• ret = -EINVAL;
• ep = of_graph_get_endpoint_by_regs(host->dev->of_node, 0, 0);
• if (ep) {

• ret = of_property_read_u32(ep, "data-lines", &priv->pd_lines);
  

• of_node_put(ep);
  

• }
• if (ret)

• priv->pd_lines = mipi_dsi_pixel_format_to_bpp(dev->format);
  

• drm_bridge_add(&priv->bridge);
• return 0;

+}

+static int tc358768_dsi_host_detach(struct mipi_dsi_host *host,

• 		    struct mipi_dsi_device *dev)
  

+{

• struct tc358768_priv *priv = dsi_host_to_tc358768(host);
• drm_bridge_remove(&priv->bridge);
• if (priv->output.panel)

• drm_panel_bridge_remove(priv->output.bridge);
  

• return 0;

+}

+static ssize_t tc358768_dsi_host_transfer(struct mipi_dsi_host *host,

• 			  const struct mipi_dsi_msg *msg)
  

+{

• struct tc358768_priv *priv = dsi_host_to_tc358768(host);
• struct mipi_dsi_packet packet;
• int ret;
• if (msg->rx_len) {

• dev_warn(priv->dev, "MIPI rx is not supported\n");
  

• return -ENOTSUPP;
  

• }
• if (msg->tx_len > 8) {

• dev_warn(priv->dev, "Maximum 8 byte MIPI tx is supported\n");
  

• return -ENOTSUPP;
  

• }
• ret = mipi_dsi_create_packet(&packet, msg);
• if (ret)

• return ret;
  

• tc358768_hw_enable(priv, true);
• if (mipi_dsi_packet_format_is_short(msg->type)) {

• tc358768_write(priv, TC358768_DSICMD_TYPE,
  

• 	       (0x10 << 8) | (packet.header[0] & 0x3f));
  

• tc358768_write(priv, TC358768_DSICMD_WC, 0);
  

• tc358768_write(priv, TC358768_DSICMD_WD0,
  

• 	       (packet.header[2] << 8) | packet.header[1]);
  

• } else {

• int i, j;
  

• tc358768_write(priv, TC358768_DSICMD_TYPE,
  

• 	       (0x40 << 8) | (packet.header[0] & 0x3f));
  

• tc358768_write(priv, TC358768_DSICMD_WC, packet.payload_length);
  

• for (i = 0; i < packet.payload_length; i += 2) {
  

• 	u16 val = 0;
  

• 	for (j = 0; j < 2 && i + j < packet.payload_length; j++)
  

• 		val |= packet.payload[i + j] << (8 * j);
  

Quite clever, but barely readable, maybe:

u16 val = packet.payload[i];

if (i + 1 < packet.payload_length)

val |= packet.payload[i + 1] << 8;

yes, looks simpler.

...

• 	tc358768_write(priv, TC358768_DSICMD_WD0 + i, val);
  

• }
  

• }
• /* start transfer */
• tc358768_write(priv, TC358768_DSICMD_TX, 1);
• tc358768_hw_enable(priv, false);
• return 0;

+}

+static const struct mipi_dsi_host_ops tc358768_dsi_host_ops = {

• .attach = tc358768_dsi_host_attach,
• .detach = tc358768_dsi_host_detach,
• .transfer = tc358768_dsi_host_transfer,

+};

+static int tc358768_bridge_attach(struct drm_bridge *bridge) +{

• struct tc358768_priv *priv = bridge_to_tc358768(bridge);
• if (!drm_core_check_feature(bridge->dev, DRIVER_ATOMIC)) {

• dev_err(priv->dev, "needs atomic updates support\n");
  

• return -ENOTSUPP;
  

• }
• return drm_bridge_attach(bridge->encoder, priv->output.bridge, bridge);

+}

+static enum drm_mode_status +tc358768_bridge_mode_valid(struct drm_bridge *bridge,

• 	   const struct drm_display_mode *mode)
  

+{

• struct tc358768_priv *priv = bridge_to_tc358768(bridge);
• priv->mode = mode;

This is dangerous, you should assume mode pointer provided in this callback is valid only till end of function.

If you need mode later you can use this ugly pointer:

priv->bridge.encoder->crtc->state->adjusted_mode

or alternatively copy mode to priv (also ugly, but at least no dangling pointers).

OK, I'll see how it can be reworked.

...

• if (tc358768_calc_pll(priv))

• return MODE_CLOCK_RANGE;
  

tc358768_calc_pll modifies state, mode_valid callback shouldn't do it.

Regards

Andrzej

Thank you for the review, - Péter

...

• return MODE_OK;

+}

+static void tc358768_bridge_disable(struct drm_bridge *bridge) +{

• struct tc358768_priv *priv = bridge_to_tc358768(bridge);
• /* set FrmStop */
• tc358768_update_bits(priv, TC358768_PP_MISC, BIT(15), BIT(15));
• /* wait at least for one frame */
• msleep(50);
• /* clear PP_en */
• tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), 0);
• /* set RstPtr */
• tc358768_update_bits(priv, TC358768_PP_MISC, BIT(14), BIT(14));
• tc358768_hw_enable(priv, false);

+}

+static void tc358768_setup_pll(struct tc358768_priv *priv) +{

• u32 fbd, prd, frs;
• fbd = priv->fbd;
• prd = priv->prd;
• frs = priv->frs;
• dev_dbg(priv->dev, "PLL: refclk %lu, fbd %u, prd %u, frs %u\n",

• clk_get_rate(priv->refclk), fbd, prd, frs);
  

• dev_dbg(priv->dev, "PLL: pll_clk: %u, DSIClk %u, DSIByteClk %u\n",

• priv->dsiclk * 2, priv->dsiclk, priv->dsiclk / 4);
  

• dev_dbg(priv->dev, "PLL: pclk %u (panel: %u)\n",

• tc358768_pll_to_pclk(priv, priv->dsiclk * 2),
  

• priv->mode->clock * 1000);
  

• /* PRD[15:12] FBD[8:0] */
• tc358768_write(priv, TC358768_PLLCTL0, (prd << 12) | fbd);
• /* FRS[11:10] LBWS[9:8] CKEN[4] RESETB[1] EN[0] */
• tc358768_write(priv, TC358768_PLLCTL1,

•        (frs << 10) | (0x2 << 8) | BIT(1) | BIT(0));
  

• /* wait for lock */
• usleep_range(1000, 2000);
• /* FRS[11:10] LBWS[9:8] CKEN[4] PLL_CKEN[4] RESETB[1] EN[0] */
• tc358768_write(priv, TC358768_PLLCTL1,

•        (frs << 10) | (0x2 << 8) | BIT(4) | BIT(1) | BIT(0));
  

+}

+#define TC358768_PRECISION 1000 +static u32 tc358768_ns_to_cnt(u32 ns, u32 period_nsk) +{

• return (ns * TC358768_PRECISION + period_nsk) / period_nsk;

+}

+static u32 tc358768_to_ns(u32 nsk) +{

• return (nsk / TC358768_PRECISION);

+}

+static void tc358768_bridge_enable(struct drm_bridge *bridge) +{

• struct tc358768_priv *priv = bridge_to_tc358768(bridge);
• const struct drm_display_mode *mode = priv->mode;
• struct mipi_dsi_device *dsi_dev = priv->output.dev;
• u32 val, val2, lptxcnt, hact, data_type;
• u32 dsiclk = priv->dsiclk;
• u32 dsibclk = dsiclk / 4;
• u32 dsibclk_nsk, dsiclk_nsk, ui_nsk, phy_delay_nsk;
• int i;
• tc358768_hw_enable(priv, true);
• tc358768_sw_reset(priv);
• tc358768_setup_pll(priv);
• /* VSDly[9:0] */
• tc358768_write(priv, TC358768_VSDLY, 1);
• /* Data Format Control Register */
• val = BIT(2) | BIT(1) | BIT(0); /* rdswap_en | dsitx_en | txdt_en */
• switch (dsi_dev->format) {
• case MIPI_DSI_FMT_RGB888:

• val |= (0x3 << 4);
  

• hact = mode->hdisplay * 3;
  

• data_type = MIPI_DSI_PACKED_PIXEL_STREAM_24;
  

• break;
  

• case MIPI_DSI_FMT_RGB666:

• val |= (0x4 << 4);
  

• hact = mode->hdisplay * 3;
  

• data_type = MIPI_DSI_PACKED_PIXEL_STREAM_18;
  

• break;
  

• case MIPI_DSI_FMT_RGB666_PACKED:

• val |= (0x4 << 4) | BIT(3);
  

• hact = mode->hdisplay * 18 / 8;
  

• data_type = MIPI_DSI_PIXEL_STREAM_3BYTE_18;
  

• break;
  

• case MIPI_DSI_FMT_RGB565:

• val |= (0x5 << 4);
  

• hact = mode->hdisplay * 2;
  

• data_type = MIPI_DSI_PACKED_PIXEL_STREAM_16;
  

• break;
  

• default:

• dev_err(priv->dev, "Invalid data format (%u)\n",
  

• 	dsi_dev->format);
  

• return;
  

• }
• tc358768_write(priv, TC358768_DATAFMT, val);
• tc358768_write(priv, TC358768_DSITX_DT, data_type);
• /* Enable D-PHY (HiZ->LP11) */
• tc358768_write(priv, TC358768_CLW_CNTRL, 0x0000);
• /* Enable lanes */
• for (i = 0; i < dsi_dev->lanes; i++)

• tc358768_write(priv, TC358768_D0W_CNTRL + i * 4, 0x0000);
  

• /* DSI Timings */
• dsibclk_nsk = (u32)div_u64((u64)1000000000 * TC358768_PRECISION,

• 		  dsibclk);
  

• dsiclk_nsk = (u32)div_u64((u64)1000000000 * TC358768_PRECISION, dsiclk);
• ui_nsk = dsiclk_nsk / 2;
• phy_delay_nsk = dsibclk_nsk + 2 * dsiclk_nsk;
• dev_dbg(priv->dev, "dsiclk_nsk: %u\n", dsiclk_nsk);
• dev_dbg(priv->dev, "ui_nsk: %u\n", ui_nsk);
• dev_dbg(priv->dev, "dsibclk_nsk: %u\n", dsibclk_nsk);
• dev_dbg(priv->dev, "phy_delay_nsk: %u\n", phy_delay_nsk);
• /* LP11 > 100us for D-PHY Rx Init */
• val = tc358768_ns_to_cnt(100 * 1000, dsibclk_nsk) - 1;
• dev_dbg(priv->dev, "LINEINITCNT: 0x%x\n", val);
• tc358768_write(priv, TC358768_LINEINITCNT, val);
• /* LPTimeCnt > 50ns */
• val = tc358768_ns_to_cnt(50, dsibclk_nsk) - 1;
• lptxcnt = val;
• dev_dbg(priv->dev, "LPTXTIMECNT: 0x%x\n", val);
• tc358768_write(priv, TC358768_LPTXTIMECNT, val);
• /* 38ns < TCLK_PREPARE < 95ns */
• val = tc358768_ns_to_cnt(65, dsibclk_nsk) - 1;
• /* TCLK_PREPARE > 300ns */
• val2 = tc358768_ns_to_cnt(300 + tc358768_to_ns(3 * ui_nsk),

• 		  dsibclk_nsk);
  

• val |= (val2 - tc358768_to_ns(phy_delay_nsk - dsibclk_nsk)) << 8;
• dev_dbg(priv->dev, "TCLK_HEADERCNT: 0x%x\n", val);
• tc358768_write(priv, TC358768_TCLK_HEADERCNT, val);
• /* TCLK_TRAIL > 60ns + 3*UI */
• val = 60 + tc358768_to_ns(3 * ui_nsk);
• val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 5;
• dev_dbg(priv->dev, "TCLK_TRAILCNT: 0x%x\n", val);
• tc358768_write(priv, TC358768_TCLK_TRAILCNT, val);
• /* 40ns + 4*UI < THS_PREPARE < 85ns + 6*UI */
• val = 50 + tc358768_to_ns(4 * ui_nsk);
• val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1;
• /* THS_ZERO > 145ns + 10*UI */
• val2 = tc358768_ns_to_cnt(145 - tc358768_to_ns(ui_nsk), dsibclk_nsk);
• val |= (val2 - tc358768_to_ns(phy_delay_nsk)) << 8;
• dev_dbg(priv->dev, "THS_HEADERCNT: 0x%x\n", val);
• tc358768_write(priv, TC358768_THS_HEADERCNT, val);
• /* TWAKEUP > 1ms in lptxcnt steps */
• val = tc358768_ns_to_cnt(1020000, dsibclk_nsk);
• val = val / (lptxcnt + 1) - 1;
• dev_dbg(priv->dev, "TWAKEUP: 0x%x\n", val);
• tc358768_write(priv, TC358768_TWAKEUP, val);
• /* TCLK_POSTCNT > 60ns + 52*UI */
• val = tc358768_ns_to_cnt(60 + tc358768_to_ns(52 * ui_nsk),

• 		 dsibclk_nsk) - 3;
  

• dev_dbg(priv->dev, "TCLK_POSTCNT: 0x%x\n", val);
• tc358768_write(priv, TC358768_TCLK_POSTCNT, val);
• /* 60ns + 4*UI < THS_PREPARE < 105ns + 12*UI */
• val = tc358768_ns_to_cnt(60 + tc358768_to_ns(15 * ui_nsk),

• 		 dsibclk_nsk) - 5;
  

• dev_dbg(priv->dev, "THS_TRAILCNT: 0x%x\n", val);
• tc358768_write(priv, TC358768_THS_TRAILCNT, val);
• val = BIT(0);
• for (i = 0; i < dsi_dev->lanes; i++)

• val |= BIT(i + 1);
  

• tc358768_write(priv, TC358768_HSTXVREGEN, val);
• if (!(dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))

• tc358768_write(priv, TC358768_TXOPTIONCNTRL, 0x1);
  

• /* TXTAGOCNT[26:16] RXTASURECNT[10:0] */
• val = tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk * 4);
• val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1;
• val2 = tc358768_ns_to_cnt(tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk),

• 		  dsibclk_nsk) - 2;
  

• val |= val2 << 16;
• dev_dbg(priv->dev, "BTACNTRL1: 0x%x\n", val);
• tc358768_write(priv, TC358768_BTACNTRL1, val);
• /* START[0] */
• tc358768_write(priv, TC358768_STARTCNTRL, 1);
• /* Set event mode */
• tc358768_write(priv, TC358768_DSI_EVENT, 1);
• /* vsw (+ vbp) */
• tc358768_write(priv, TC358768_DSI_VSW,

•        mode->vtotal - mode->vsync_start);
  

• /* vbp (not used in event mode) */
• tc358768_write(priv, TC358768_DSI_VBPR, 0);
• /* vact */
• tc358768_write(priv, TC358768_DSI_VACT, mode->vdisplay);
• /* (hsw + hbp) * byteclk * ndl / pclk */
• val = (u32)div_u64((mode->htotal - mode->hsync_start) *

• 	   ((u64)priv->dsiclk / 4) * priv->dsi_lanes,
  

• 	   mode->clock * 1000);
  

• tc358768_write(priv, TC358768_DSI_HSW, val);
• /* hbp (not used in event mode) */
• tc358768_write(priv, TC358768_DSI_HBPR, 0);
• /* hact (bytes) */
• tc358768_write(priv, TC358768_DSI_HACT, hact);
• /* VSYNC polarity */
• if (!(mode->flags & DRM_MODE_FLAG_NVSYNC))

• tc358768_update_bits(priv, TC358768_CONFCTL, BIT(5), BIT(5));
  

• /* HSYNC polarity */
• if (mode->flags & DRM_MODE_FLAG_PHSYNC)

• tc358768_update_bits(priv, TC358768_PP_MISC, BIT(0), BIT(0));
  

• /* Start DSI Tx */
• tc358768_write(priv, TC358768_DSI_START, 0x1);
• /* Configure DSI_Control register */
• val = (6 << 29) | (0x3 << 24); /* CLEAR, DSI_Control */
• val |= BIT(7) | BIT(5) | 0x3 << 1 | BIT(0);
• tc358768_write(priv, TC358768_DSI_CONFW, val);
• val = (5 << 29) | (0x3 << 24); /* SET, DSI_Control */
• if (!(dsi_dev->mode_flags & MIPI_DSI_MODE_LPM))

• val |= BIT(7);
  

• if (!(dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))

• val |= BIT(5);
  

• val |= (dsi_dev->lanes - 1) << 1;
• if (dsi_dev->mode_flags & MIPI_DSI_MODE_EOT_PACKET)

• val |= BIT(0);
  

• tc358768_write(priv, TC358768_DSI_CONFW, val);
• val = (6 << 29) | (0x3 << 24); /* CLEAR, DSI_Control */
• val |= 0x8000; /* DSI mode */
• tc358768_write(priv, TC358768_DSI_CONFW, val);
• /* clear FrmStop and RstPtr */
• tc358768_update_bits(priv, TC358768_PP_MISC, 0x3 << 14, 0);
• /* set PP_en */
• tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), BIT(6));

+}

+static const struct drm_bridge_funcs tc358768_bridge_funcs = {

• .attach = tc358768_bridge_attach,
• .mode_valid = tc358768_bridge_mode_valid,
• .disable = tc358768_bridge_disable,
• .enable = tc358768_bridge_enable,

+};

+static const struct drm_bridge_timings default_tc358768_timings = {

• .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE

•  | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
  

•  | DRM_BUS_FLAG_DE_HIGH,
  

+};

+static bool tc358768_is_reserved_reg(unsigned int reg) +{

• switch (reg) {
• case 0x114 ... 0x13f:
• case 0x200:
• case 0x20c:
• case 0x400 ... 0x408:
• case 0x41c ... 0x42f:

• return true;
  

• default:

• return false;
  

• }

+}

+static bool tc358768_writeable_reg(struct device *dev, unsigned int reg) +{

• if (tc358768_is_reserved_reg(reg))

• return false;
  

• switch (reg) {
• case TC358768_CHIPID:
• case TC358768_FIFOSTATUS:
• case TC358768_DSITXSTATUS ... (TC358768_DSITXSTATUS + 2):
• case TC358768_DSI_CONTROL ... (TC358768_DSI_INT_ENA + 2):
• case TC358768_DSICMD_RDFIFO ... (TC358768_DSI_ERR_HALT + 2):

• return false;
  

• default:

• return true;
  

• }

+}

+static bool tc358768_readable_reg(struct device *dev, unsigned int reg) +{

• if (tc358768_is_reserved_reg(reg))

• return false;
  

• switch (reg) {
• case TC358768_STARTCNTRL:
• case TC358768_DSI_CONFW ... (TC358768_DSI_CONFW + 2):
• case TC358768_DSI_INT_CLR ... (TC358768_DSI_INT_CLR + 2):
• case TC358768_DSI_START ... (TC358768_DSI_START + 2):
• case TC358768_DBG_DATA:

• return false;
  

• default:

• return true;
  

• }

+}

+static bool tc358768_volatile_reg(struct device *dev, unsigned int reg) +{

• switch (reg) {
• case TC358768_FIFOSTATUS:
• case TC358768_STARTCNTRL ... (TC358768_DSITXSTATUS + 2):
• case TC358768_DSI_CONTROL ... (TC358768_DSI_INT_ENA + 2):
• case TC358768_DSICMD_RDFIFO ... (TC358768_DSI_ERR_HALT + 2):
• case TC358768_DSICMD_TX:

• return true;
  

• default:

• return false;
  

• }

+}

+static const struct regmap_config tc358768_regmap_config = {

• .name = "tc358768",
• .reg_bits = 16,
• .val_bits = 16,
• .max_register = TC358768_DSI_HACT,
• .cache_type = REGCACHE_RBTREE,
• .writeable_reg = tc358768_writeable_reg,
• .readable_reg = tc358768_readable_reg,
• .volatile_reg = tc358768_volatile_reg,
• .reg_format_endian = REGMAP_ENDIAN_BIG,
• .val_format_endian = REGMAP_ENDIAN_BIG,

+};

+static const struct i2c_device_id tc358768_i2c_ids[] = {

• { "tc358768", 0 },
• { "tc358778", 0 },
• { }

+}; +MODULE_DEVICE_TABLE(i2c, tc358768_i2c_ids);

+static const struct of_device_id tc358768_of_ids[] = {

• { .compatible = "toshiba,tc358768", },
• { .compatible = "toshiba,tc358778", },
• { }

+}; +MODULE_DEVICE_TABLE(of, tc358768_of_ids);

+static int tc358768_get_regulators(struct tc358768_priv *priv) +{

• int i, ret;
• for (i = 0; i < ARRAY_SIZE(priv->supplies); ++i)

• priv->supplies[i].supply = tc358768_supplies[i];
  

• ret = devm_regulator_bulk_get(priv->dev, ARRAY_SIZE(priv->supplies),

• 		      priv->supplies);
  

• if (ret < 0)

• dev_err(priv->dev, "failed to get regulators: %d\n", ret);
  

• return ret;

+}

+static int tc358768_i2c_probe(struct i2c_client *client,

• 	      const struct i2c_device_id *id)
  

+{

• struct tc358768_priv *priv;
• struct device *dev = &client->dev;
• struct device_node *np = dev->of_node;
• int ret;
• if (!np)

• return -ENODEV;
  

• priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
• if (!priv)

• return -ENOMEM;
  

• dev_set_drvdata(dev, priv);
• priv->dev = dev;
• ret = tc358768_get_regulators(priv);
• if (ret)

• return ret;
  

• priv->refclk = devm_clk_get(dev, "refclk");
• if (IS_ERR(priv->refclk))

• return PTR_ERR(priv->refclk);
  

• /*

• * RESX is low active, to disable tc358768 initially (keep in reset)
  

• * the gpio line must be LOW. This is the ASSERTED state of
  

• * GPIO_ACTIVE_LOW (GPIOD_OUT_HIGH == ASSERTED).
  

• */
  

• priv->reset_gpio = devm_gpiod_get_optional(dev, "reset",

• 				    GPIOD_OUT_HIGH);
  

• if (IS_ERR(priv->reset_gpio))

• return PTR_ERR(priv->reset_gpio);
  

• priv->regmap = devm_regmap_init_i2c(client, &tc358768_regmap_config);
• if (IS_ERR(priv->regmap)) {

• dev_err(dev, "Failed to init regmap\n");
  

• return PTR_ERR(priv->regmap);
  

• }
• if (priv->reset_gpio)

• regcache_cache_only(priv->regmap, true);
  

• priv->dsi_host.dev = dev;
• priv->dsi_host.ops = &tc358768_dsi_host_ops;
• priv->bridge.funcs = &tc358768_bridge_funcs;
• priv->bridge.timings = &default_tc358768_timings;
• priv->bridge.of_node = np;
• i2c_set_clientdata(client, priv);
• ret = mipi_dsi_host_register(&priv->dsi_host);
• if (ret)

• return ret;
  

• return 0;

+}

+static int tc358768_i2c_remove(struct i2c_client *client) +{

• struct tc358768_priv *priv = i2c_get_clientdata(client);
• mipi_dsi_host_unregister(&priv->dsi_host);
• return 0;

+}

+static struct i2c_driver tc358768_driver = {

• .driver = {

• .name = "tc358768",
  

• .of_match_table = tc358768_of_ids,
  

• },
• .id_table = tc358768_i2c_ids,
• .probe = tc358768_i2c_probe,
• .remove = tc358768_i2c_remove,

+}; +module_i2c_driver(tc358768_driver);

+MODULE_AUTHOR("Peter Ujfalusi peter.ujfalusi@ti.com"); +MODULE_DESCRIPTION("TC358768AXBG/TC358778XBG DSI bridge"); +MODULE_LICENSE("GPL v2");

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