[v3,05/11] drm/bridge: Add Analogix anx6345 support

Commit Message

Vasily Khoruzhick Feb. 15, 2019, 5:09 a.m. UTC

From: Icenowy Zheng <[e-mail]>

The ANX6345 is an ultra-low power DisplayPower/eDP transmitter designed
for portable devices. This driver adds initial support for RGB to eDP
mode, without HPD and interrupts.

This is a configuration usually seen in eDP applications.

Signed-off-by: Icenowy Zheng <[e-mail]>
Signed-off-by: Vasily Khoruzhick <[e-mail]>
---
 drivers/gpu/drm/bridge/analogix/Kconfig       |  11 +
 drivers/gpu/drm/bridge/analogix/Makefile      |   1 +
 .../drm/bridge/analogix/analogix-anx6345.c    | 845 ++++++++++++++++++
 .../drm/bridge/analogix/analogix-i2c-dptx.c   |   2 +-
 .../drm/bridge/analogix/analogix-i2c-dptx.h   |   8 +
 .../bridge/analogix/analogix-i2c-txcommon.h   |   3 +
 6 files changed, 869 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-anx6345.c

Comments

Priit Laes Feb. 15, 2019, 8:23 a.m. UTC | #1

On Thu, Feb 14, 2019 at 09:09:51PM -0800, Vasily Khoruzhick wrote:
> From: Icenowy Zheng <[e-mail]>
> 
> The ANX6345 is an ultra-low power DisplayPower/eDP transmitter designed
> for portable devices. This driver adds initial support for RGB to eDP
> mode, without HPD and interrupts.
> 
> This is a configuration usually seen in eDP applications.
> 
> Signed-off-by: Icenowy Zheng <[e-mail]>
> Signed-off-by: Vasily Khoruzhick <[e-mail]>
> ---
>  drivers/gpu/drm/bridge/analogix/Kconfig       |  11 +
>  drivers/gpu/drm/bridge/analogix/Makefile      |   1 +
>  .../drm/bridge/analogix/analogix-anx6345.c    | 845 ++++++++++++++++++
>  .../drm/bridge/analogix/analogix-i2c-dptx.c   |   2 +-
>  .../drm/bridge/analogix/analogix-i2c-dptx.h   |   8 +
>  .../bridge/analogix/analogix-i2c-txcommon.h   |   3 +
>  6 files changed, 869 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
> 

[ ... ]

> +
> +static int anx6345_start(struct anx6345 *anx6345)
> +{
> +	int err;
> +
> +	if (!anx6345->powered)
> +		anx6345_poweron(anx6345);
> +
> +	/* Power on needed modules */
> +	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
> +				 SP_POWERDOWN_CTRL_REG,
> +				 SP_VIDEO_PD | SP_LINK_PD);
> +
> +	err = anx6345_tx_initialization(anx6345);
> +	if (err) {
> +		DRM_ERROR("Failed transmitter initialization: %d\n", err);
> +		goto err_poweroff;

You can move the whole err_poweroff section from below here and drop the goto.

> +	}
> +
> +	/*
> +	 * This delay seems to help keep the hardware in a good state. Without
> +	 * it, there are times where it fails silently.
> +	 */
> +	usleep_range(10000, 15000);
> +
> +	return 0;
> +
> +err_poweroff:
> +	DRM_ERROR("Failed DisplayPort transmitter initialization: %d\n", err);
> +	anx6345_poweroff(anx6345);
> +
> +	return err;
> +}
> +

[ ... ]

Andrzej Hajda Feb. 15, 2019, 9:13 a.m. UTC | #2

On 15.02.2019 06:09, Vasily Khoruzhick wrote:
> From: Icenowy Zheng <[e-mail]>
>
> The ANX6345 is an ultra-low power DisplayPower/eDP transmitter designed
> for portable devices. This driver adds initial support for RGB to eDP
> mode, without HPD and interrupts.
>
> This is a configuration usually seen in eDP applications.
>
> Signed-off-by: Icenowy Zheng <[e-mail]>
> Signed-off-by: Vasily Khoruzhick <[e-mail]>
> ---
>  drivers/gpu/drm/bridge/analogix/Kconfig       |  11 +
>  drivers/gpu/drm/bridge/analogix/Makefile      |   1 +
>  .../drm/bridge/analogix/analogix-anx6345.c    | 845 ++++++++++++++++++
>  .../drm/bridge/analogix/analogix-i2c-dptx.c   |   2 +-
>  .../drm/bridge/analogix/analogix-i2c-dptx.h   |   8 +
>  .../bridge/analogix/analogix-i2c-txcommon.h   |   3 +
>  6 files changed, 869 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
>
> diff --git a/drivers/gpu/drm/bridge/analogix/Kconfig b/drivers/gpu/drm/bridge/analogix/Kconfig
> index ed2d05c12546..3c6ec535d361 100644
> --- a/drivers/gpu/drm/bridge/analogix/Kconfig
> +++ b/drivers/gpu/drm/bridge/analogix/Kconfig
> @@ -1,3 +1,14 @@
> +config DRM_ANALOGIX_ANX6345
> +	tristate "Analogix ANX6345 bridge"
> +	select DRM_ANALOGIX_DP_I2C
> +	select DRM_KMS_HELPER
> +	select REGMAP_I2C
> +	help
> +	  ANX6345 is an ultra-low Full-HD DisplayPort/eDP
> +	  transmitter designed for portable devices. The
> +	  ANX6345 transforms the LVTTL RGB output of an
> +	  application processor to eDP or DisplayPort.
> +
>  config DRM_ANALOGIX_ANX78XX
>  	tristate "Analogix ANX78XX bridge"
>  	select DRM_ANALOGIX_DP_I2C
> diff --git a/drivers/gpu/drm/bridge/analogix/Makefile b/drivers/gpu/drm/bridge/analogix/Makefile
> index 2d523b67487d..12fed7b04e1e 100644
> --- a/drivers/gpu/drm/bridge/analogix/Makefile
> +++ b/drivers/gpu/drm/bridge/analogix/Makefile
> @@ -1,5 +1,6 @@
>  analogix_dp-objs := analogix_dp_core.o analogix_dp_reg.o
>  analogix_dp_i2c-objs := analogix-i2c-dptx.o
> +obj-$(CONFIG_DRM_ANALOGIX_ANX6345) += analogix-anx6345.o
>  obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
>  obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix_dp.o
>  obj-$(CONFIG_DRM_ANALOGIX_DP_I2C) += analogix_dp_i2c.o
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
> new file mode 100644
> index 000000000000..6098e245e074
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
> @@ -0,0 +1,845 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright(c) Icenowy Zheng <[e-mail]>
> + * Based on analogix-anx6345.c, which is:
> + *   Copyright(c) 2016, Analogix Semiconductor.
> + */
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_gpio.h>
Do you need this header?
> +#include <linux/of_platform.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <drm/drmP.h>


drmP.h is/should be deprecated.


> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_dp_helper.h>
> +#include <drm/drm_edid.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +
> +#include "analogix-i2c-dptx.h"
> +#include "analogix-i2c-txcommon.h"
> +
> +#define I2C_NUM_ADDRESSES	2
> +#define I2C_IDX_DPTX		0
> +#define I2C_IDX_TXCOM		1
> +
> +#define XTAL_CLK		270 /* 27M */
> +
> +#define POLL_DELAY		50000 /* us */
> +#define POLL_TIMEOUT		5000000 /* us */
> +
> +static const u8 anx6345_i2c_addresses[] = {
> +	[I2C_IDX_DPTX]	= ANALOGIX_I2C_DPTX,
> +	[I2C_IDX_TXCOM]	= ANALOGIX_I2C_TXCOMMON,
> +};
> +
> +struct anx6345_platform_data {
> +	struct regulator *dvdd12;
> +	struct regulator *dvdd25;
> +	struct gpio_desc *gpiod_reset;
> +};


Why do you need this struct, why just do not embed it's fields directly
into struct anx6345 ?


> +
> +struct anx6345 {
> +	struct drm_dp_aux aux;
> +	struct drm_bridge bridge;
> +	struct i2c_client *client;
> +	struct edid *edid;
> +	struct drm_connector connector;
> +	struct drm_dp_link link;
> +	struct drm_panel *panel;
> +	struct anx6345_platform_data pdata;
> +	struct mutex lock;
> +
> +	/*
> +	 * I2C Slave addresses of ANX6345 are mapped as DPTX and SYS
> +	 */
> +	struct i2c_client *i2c_clients[I2C_NUM_ADDRESSES];
> +	struct regmap *map[I2C_NUM_ADDRESSES];
> +
> +	u16 chipid;
> +	u8 dpcd[DP_RECEIVER_CAP_SIZE];
> +
> +	bool powered;
> +};
> +
> +static inline struct anx6345 *connector_to_anx6345(struct drm_connector *c)
> +{
> +	return container_of(c, struct anx6345, connector);
> +}
> +
> +static inline struct anx6345 *bridge_to_anx6345(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct anx6345, bridge);
> +}
> +
> +static int anx6345_set_bits(struct regmap *map, u8 reg, u8 mask)
> +{
> +	return regmap_update_bits(map, reg, mask, mask);
> +}
> +
> +static int anx6345_clear_bits(struct regmap *map, u8 reg, u8 mask)
> +{
> +	return regmap_update_bits(map, reg, mask, 0);
> +}
> +
> +static ssize_t anx6345_aux_transfer(struct drm_dp_aux *aux,
> +				    struct drm_dp_aux_msg *msg)
> +{
> +	struct anx6345 *anx6345 = container_of(aux, struct anx6345, aux);
> +
> +	return anx_aux_transfer(anx6345->map[I2C_IDX_DPTX], msg);
> +}
> +
> +static int anx6345_dp_link_training(struct anx6345 *anx6345)
> +{
> +	unsigned int value;
> +	u8 dp_bw;
> +	int err;
> +
> +	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
> +				 SP_POWERDOWN_CTRL_REG,
> +				 SP_TOTAL_PD);
> +	if (err)
> +		return err;
> +
> +	err = drm_dp_dpcd_readb(&anx6345->aux, DP_MAX_LINK_RATE, &dp_bw);
> +	if (err < 0)
> +		return err;
> +
> +	switch (dp_bw) {
> +	case DP_LINK_BW_1_62:
> +	case DP_LINK_BW_2_7:
> +		break;
> +
> +	default:
> +		DRM_DEBUG_KMS("DP bandwidth (%#02x) not supported\n", dp_bw);
> +		return -EINVAL;
> +	}
> +
> +	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
> +			       SP_VIDEO_MUTE);
> +	if (err)
> +		return err;
> +
> +	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
> +				 SP_VID_CTRL1_REG, SP_VIDEO_EN);
> +	if (err)
> +		return err;
> +
> +	/* Get DPCD info */
> +	err = drm_dp_dpcd_read(&anx6345->aux, DP_DPCD_REV,
> +			       &anx6345->dpcd, DP_RECEIVER_CAP_SIZE);
> +	if (err < 0) {
> +		DRM_ERROR("Failed to read DPCD: %d\n", err);
> +		return err;
> +	}
> +
> +	/* Clear channel x SERDES power down */
> +	err = anx6345_clear_bits(anx6345->map[I2C_IDX_DPTX],
> +				 SP_DP_ANALOG_POWER_DOWN_REG, SP_CH0_PD);
> +	if (err)
> +		return err;
> +
> +	/* Check link capabilities */
> +	err = drm_dp_link_probe(&anx6345->aux, &anx6345->link);
> +	if (err < 0) {
> +		DRM_ERROR("Failed to probe link capabilities: %d\n", err);
> +		return err;
> +	}
> +
> +	/* Power up the sink */
> +	err = drm_dp_link_power_up(&anx6345->aux, &anx6345->link);
> +	if (err < 0) {
> +		DRM_ERROR("Failed to power up DisplayPort link: %d\n", err);
> +		return err;
> +	}
> +
> +	/* Possibly enable downspread on the sink */
> +	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
> +			   SP_DP_DOWNSPREAD_CTRL1_REG, 0);
> +	if (err)
> +		return err;
> +
> +	if (anx6345->dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5) {
> +		DRM_DEBUG("Enable downspread on the sink\n");
> +		/* 4000PPM */
> +		err = regmap_write(anx6345->map[I2C_IDX_DPTX],
> +				   SP_DP_DOWNSPREAD_CTRL1_REG, 8);
> +		if (err)
> +			return err;
> +
> +		err = drm_dp_dpcd_writeb(&anx6345->aux, DP_DOWNSPREAD_CTRL,
> +					 DP_SPREAD_AMP_0_5);
> +		if (err < 0)
> +			return err;
> +	} else {
> +		err = drm_dp_dpcd_writeb(&anx6345->aux, DP_DOWNSPREAD_CTRL, 0);
> +		if (err < 0)
> +			return err;
> +	}
> +
> +	/* Set the lane count and the link rate on the sink */
> +	if (drm_dp_enhanced_frame_cap(anx6345->dpcd))
> +		err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
> +				       SP_DP_SYSTEM_CTRL_BASE + 4,
> +				       SP_ENHANCED_MODE);
> +	else
> +		err = anx6345_clear_bits(anx6345->map[I2C_IDX_DPTX],
> +					 SP_DP_SYSTEM_CTRL_BASE + 4,
> +					 SP_ENHANCED_MODE);
> +	if (err)
> +		return err;
> +
> +	value = drm_dp_link_rate_to_bw_code(anx6345->link.rate);
> +	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
> +			   SP_DP_MAIN_LINK_BW_SET_REG, value);
> +	if (err)
> +		return err;
> +
> +	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
> +			   SP_DP_LANE_COUNT_SET_REG, anx6345->link.num_lanes);
> +	if (err)
> +		return err;
> +
> +	err = drm_dp_link_configure(&anx6345->aux, &anx6345->link);
> +	if (err < 0) {
> +		DRM_ERROR("Failed to configure DisplayPort link: %d\n", err);
> +		return err;
> +	}
> +
> +	/* Start training on the source */
> +	err = regmap_write(anx6345->map[I2C_IDX_DPTX], SP_DP_LT_CTRL_REG,
> +			   SP_LT_EN);
> +	if (err)
> +		return err;
> +
> +	err = regmap_read_poll_timeout(anx6345->map[I2C_IDX_DPTX],
> +				       SP_DP_LT_CTRL_REG,
> +				       value, !(value & SP_DP_LT_INPROGRESS),
> +				       POLL_DELAY, POLL_TIMEOUT);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static int anx6345_tx_initialization(struct anx6345 *anx6345)
> +{
> +	int err, i;
> +
> +	/* FIXME: hardcode color depth now */
> +	err = regmap_write(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL2_REG,
> +			   SP_IN_BPC_6BIT << SP_IN_BPC_SHIFT);
> +	if (err)
> +		return err;
> +
> +	err = regmap_write(anx6345->map[I2C_IDX_DPTX], SP_DP_PLL_CTRL_REG, 0);
> +	if (err)
> +		return err;
> +
> +	err = regmap_write(anx6345->map[I2C_IDX_TXCOM],
> +			   SP_ANALOG_DEBUG1_REG, 0);
> +	if (err)
> +		return err;
> +
> +	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
> +			   SP_DP_LINK_DEBUG_CTRL_REG,
> +			   SP_NEW_PRBS7 | SP_M_VID_DEBUG);
> +	if (err)
> +		return err;
> +
> +	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
> +			   SP_DP_ANALOG_POWER_DOWN_REG, 0);
> +	if (err)
> +		return err;
> +
> +	/* Force HPD */
> +	err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
> +			       SP_DP_SYSTEM_CTRL_BASE + 3,
> +			       SP_HPD_FORCE | SP_HPD_CTRL);
> +	if (err)
> +		return err;
> +
> +	for (i = 0; i < 4; i++) {
> +		/* 4 lanes */
> +		err = regmap_write(anx6345->map[I2C_IDX_DPTX],
> +				   SP_DP_LANE0_LT_CTRL_REG + i, 0);
> +		if (err)
> +			return err;
> +	}
> +
> +	/* Reset AUX */
> +	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM],
> +			       SP_RESET_CTRL2_REG, SP_AUX_RST);
> +	if (err)
> +		return err;
> +
> +	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
> +				 SP_RESET_CTRL2_REG, SP_AUX_RST);
> +	if (err)
> +		return err;
> +
> +	err = anx6345_dp_link_training(anx6345);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static void anx6345_poweron(struct anx6345 *anx6345)
> +{
> +	struct anx6345_platform_data *pdata = &anx6345->pdata;
> +	int err;
> +
> +	if (WARN_ON(anx6345->powered))
> +		return;

It should not happen, you can remove this warn.

> +
> +	if (pdata->dvdd12) {


If regulators are required this will be never null.


> +		err = regulator_enable(pdata->dvdd12);
> +		if (err) {
> +			DRM_ERROR("Failed to enable DVDD12 regulator: %d\n",
> +				  err);
> +			return;
> +		}
> +
> +		usleep_range(1000, 2000);
> +	}
> +
> +	if (pdata->dvdd25) {


ditto


> +		err = regulator_enable(pdata->dvdd25);
> +		if (err) {
> +			DRM_ERROR("Failed to enable DVDD25 regulator: %d\n",
> +				  err);
> +			return;
> +		}
> +
> +		usleep_range(5000, 10000);
> +	}
> +
> +	if (anx6345->panel)
> +		drm_panel_prepare(anx6345->panel);


again, here and below: panel is never null, check can be removed.


> +
> +	gpiod_set_value_cansleep(pdata->gpiod_reset, 0);
> +	usleep_range(1000, 2000);
> +
> +	gpiod_set_value_cansleep(pdata->gpiod_reset, 1);


Start/stop sequence seems odd regarding reset gpio:

1. In probe reset is set to low, in poweroff to high - incosistent.

2. If in case of disabled device reset should be 0, there is no point to
set it again to 0 three lines above.

3. I suspect in dts reset gpio should be declared as active_low, and the
logic in the driver should be reverted, in power off it should be set to
high, in power on it should be lowered (logically).


> +
> +	/* Power on registers module */
> +	anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
> +			 SP_HDCP_PD | SP_AUDIO_PD | SP_VIDEO_PD | SP_LINK_PD);
> +	anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
> +			   SP_REGISTER_PD | SP_TOTAL_PD);
> +
> +	anx6345->powered = true;
> +}
> +
> +static void anx6345_poweroff(struct anx6345 *anx6345)
> +{
> +	struct anx6345_platform_data *pdata = &anx6345->pdata;
> +	int err;
> +
> +	if (WARN_ON(!anx6345->powered))
> +		return;
> +
> +	gpiod_set_value_cansleep(pdata->gpiod_reset, 1);
> +	usleep_range(1000, 2000);
> +
> +	if (anx6345->panel)
> +		drm_panel_unprepare(anx6345->panel);
> +
> +	if (pdata->dvdd25) {
> +		err = regulator_disable(pdata->dvdd25);
> +		if (err) {
> +			DRM_ERROR("Failed to disable DVDD25 regulator: %d\n",
> +				  err);
> +			return;
> +		}
> +
> +		usleep_range(5000, 10000);
> +	}
> +
> +	if (pdata->dvdd12) {
> +		err = regulator_disable(pdata->dvdd12);
> +		if (err) {
> +			DRM_ERROR("Failed to disable DVDD12 regulator: %d\n",
> +				  err);
> +			return;
> +		}
> +
> +		usleep_range(1000, 2000);
> +	}
> +
> +	anx6345->powered = false;
> +}
> +
> +static int anx6345_start(struct anx6345 *anx6345)
> +{
> +	int err;
> +
> +	if (!anx6345->powered)
> +		anx6345_poweron(anx6345);
> +
> +	/* Power on needed modules */
> +	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
> +				 SP_POWERDOWN_CTRL_REG,
> +				 SP_VIDEO_PD | SP_LINK_PD);
> +
> +	err = anx6345_tx_initialization(anx6345);
> +	if (err) {
> +		DRM_ERROR("Failed transmitter initialization: %d\n", err);
> +		goto err_poweroff;
> +	}
> +
> +	/*
> +	 * This delay seems to help keep the hardware in a good state. Without
> +	 * it, there are times where it fails silently.
> +	 */
> +	usleep_range(10000, 15000);
> +
> +	return 0;
> +
> +err_poweroff:
> +	DRM_ERROR("Failed DisplayPort transmitter initialization: %d\n", err);


redundant message


> +	anx6345_poweroff(anx6345);
> +
> +	return err;
> +}
> +
> +static int anx6345_init_pdata(struct anx6345 *anx6345)
> +{
> +	struct anx6345_platform_data *pdata = &anx6345->pdata;
> +	struct device *dev = &anx6345->client->dev;
> +
> +	/* 1.2V digital core power regulator  */
> +	pdata->dvdd12 = devm_regulator_get(dev, "dvdd12");
> +	if (IS_ERR(pdata->dvdd12)) {
> +		DRM_ERROR("DVDD12 regulator not found\n");
> +		return PTR_ERR(pdata->dvdd12);
> +	}
> +
> +	/* 2.5V digital core power regulator  */
> +	pdata->dvdd25 = devm_regulator_get(dev, "dvdd25");
> +	if (IS_ERR(pdata->dvdd25)) {
> +		DRM_ERROR("DVDD25 regulator not found\n");
> +		return PTR_ERR(pdata->dvdd25);
> +	}
> +
> +	/* GPIO for chip reset */
> +	pdata->gpiod_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +
> +	return PTR_ERR_OR_ZERO(pdata->gpiod_reset);
> +}
> +
> +static int anx6345_config_dp_output(struct anx6345 *anx6345)
> +{
> +	int err;
> +
> +	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
> +				 SP_VIDEO_MUTE);
> +	if (err)
> +		return err;
> +
> +	/* Enable DP output */
> +	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
> +			       SP_VIDEO_EN);
> +	if (err)
> +		return err;
> +
> +	/* Force stream valid */
> +	err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
> +			       SP_DP_SYSTEM_CTRL_BASE + 3,
> +			       SP_STRM_FORCE | SP_STRM_CTRL);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static int anx6345_get_downstream_info(struct anx6345 *anx6345)
> +{
> +	u8 value;
> +	int err;
> +
> +	err = drm_dp_dpcd_readb(&anx6345->aux, DP_SINK_COUNT, &value);
> +	if (err < 0) {
> +		DRM_ERROR("Get sink count failed %d\n", err);


The rule of thumb I heard is that if you start message capitalized you
should end with dot. Since I do not know if it is enforced in kernel I
leave the decision up to you.


> +		return err;
> +	}
> +
> +	if (!DP_GET_SINK_COUNT(value)) {
> +		DRM_ERROR("Downstream disconnected\n");
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> +static int anx6345_get_modes(struct drm_connector *connector)
> +{
> +	struct anx6345 *anx6345 = connector_to_anx6345(connector);
> +	int err, num_modes = 0;
> +
> +	if (WARN_ON(!anx6345->powered))
> +		return 0;
> +
> +	mutex_lock(&anx6345->lock);
> +
> +	if (!anx6345->edid) {
> +		err = anx6345_get_downstream_info(anx6345);
> +		if (err) {
> +			DRM_ERROR("Failed to get downstream info: %d\n", err);
> +			goto unlock;
> +		}
> +
> +		anx6345->edid = drm_get_edid(connector, &anx6345->aux.ddc);
> +		if (!anx6345->edid)
> +			DRM_ERROR("Failed to read EDID from panel\n");
> +
> +		err = drm_connector_update_edid_property(connector,
> +							 anx6345->edid);
> +		if (err) {
> +			DRM_ERROR("Failed to update EDID property: %d\n", err);
> +			goto unlock;
> +		}
> +	}
> +
> +	num_modes += drm_add_edid_modes(connector, anx6345->edid);
> +
> +unlock:
> +	mutex_unlock(&anx6345->lock);
> +
> +	if (!num_modes && anx6345->panel)
> +		num_modes += drm_panel_get_modes(anx6345->panel);
> +
> +	return num_modes;
> +}
> +
> +static const struct drm_connector_helper_funcs anx6345_connector_helper_funcs = {
> +	.get_modes = anx6345_get_modes,
> +};
> +
> +static enum drm_connector_status anx6345_detect(struct drm_connector *connector,
> +						bool force)
> +{
> +	return connector_status_connected;
> +}
> +
> +static void
> +anx6345_connector_destroy(struct drm_connector *connector)
> +{
> +	struct anx6345 *anx6345 = connector_to_anx6345(connector);
> +
> +	if (anx6345->panel)
> +		drm_panel_detach(anx6345->panel);
> +	drm_connector_cleanup(connector);
> +}
> +
> +static const struct drm_connector_funcs anx6345_connector_funcs = {
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.detect = anx6345_detect,
> +	.destroy = anx6345_connector_destroy,
> +	.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 int anx6345_bridge_attach(struct drm_bridge *bridge)
> +{
> +	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
> +	int err;
> +
> +	if (!bridge->encoder) {
> +		DRM_ERROR("Parent encoder object not found");
> +		return -ENODEV;
> +	}
> +
> +	/* Register aux channel */
> +	anx6345->aux.name = "DP-AUX";
> +	anx6345->aux.dev = &anx6345->client->dev;
> +	anx6345->aux.transfer = anx6345_aux_transfer;
> +
> +	err = drm_dp_aux_register(&anx6345->aux);
> +	if (err < 0) {
> +		DRM_ERROR("Failed to register aux channel: %d\n", err);
> +		return err;
> +	}
> +
> +	err = drm_connector_init(bridge->dev, &anx6345->connector,
> +				 &anx6345_connector_funcs,
> +				 DRM_MODE_CONNECTOR_eDP);
> +	if (err) {
> +		DRM_ERROR("Failed to initialize connector: %d\n", err);
> +		return err;
> +	}
> +
> +	drm_connector_helper_add(&anx6345->connector,
> +				 &anx6345_connector_helper_funcs);
> +
> +	err = drm_connector_register(&anx6345->connector);
> +	if (err) {
> +		DRM_ERROR("Failed to register connector: %d\n", err);
> +		return err;
> +	}
> +
> +	anx6345->connector.polled = DRM_CONNECTOR_POLL_HPD;
> +
> +	err = drm_connector_attach_encoder(&anx6345->connector,
> +					   bridge->encoder);
> +	if (err) {
> +		DRM_ERROR("Failed to link up connector to encoder: %d\n", err);
> +		return err;
> +	}
> +
> +	if (anx6345->panel) {
> +		err = drm_panel_attach(anx6345->panel, &anx6345->connector);
> +		if (err) {
> +			DRM_ERROR("Failed to attach panel: %d\n", err);
> +			return err;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static bool anx6345_bridge_mode_fixup(struct drm_bridge *bridge,
> +				      const struct drm_display_mode *mode,
> +				      struct drm_display_mode *adjusted_mode)
> +{
> +	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
> +		return false;
> +
> +	/* Max 1200p at 5.4 Ghz, one lane */
> +	if (mode->clock > 154000)
> +		return false;


These checks should be in mode_valid callback.


> +
> +	return true;
> +}
> +
> +static void anx6345_bridge_disable(struct drm_bridge *bridge)
> +{
> +	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
> +
> +	/* Power off all modules except configuration registers access */
> +	anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
> +			 SP_HDCP_PD | SP_AUDIO_PD | SP_VIDEO_PD | SP_LINK_PD);
> +	if (anx6345->panel)
> +		drm_panel_disable(anx6345->panel);
> +}
> +
> +static void anx6345_bridge_mode_set(struct drm_bridge *bridge,
> +				    struct drm_display_mode *mode,
> +				    struct drm_display_mode *adjusted_mode)
> +{
> +	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
> +
> +	if (WARN_ON(!anx6345->powered))
> +		return;
> +}
> +
> +static void anx6345_bridge_enable(struct drm_bridge *bridge)
> +{
> +	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
> +	int err;
> +
> +	if (anx6345->panel)
> +		drm_panel_enable(anx6345->panel);
> +
> +	err = anx6345_start(anx6345);
> +	if (err) {
> +		DRM_ERROR("Failed to initialize: %d\n", err);
> +		return;
> +	}
> +
> +	err = anx6345_config_dp_output(anx6345);
> +	if (err)
> +		DRM_ERROR("Failed to enable DP output: %d\n", err);
> +}
> +
> +static const struct drm_bridge_funcs anx6345_bridge_funcs = {
> +	.attach = anx6345_bridge_attach,
> +	.mode_fixup = anx6345_bridge_mode_fixup,
> +	.disable = anx6345_bridge_disable,
> +	.mode_set = anx6345_bridge_mode_set,
> +	.enable = anx6345_bridge_enable,
> +};
> +
> +static void unregister_i2c_dummy_clients(struct anx6345 *anx6345)
> +{
> +	unsigned int i;
> +
> +	for (i = 1; i < ARRAY_SIZE(anx6345->i2c_clients); i++)
> +		if (anx6345->i2c_clients[i] &&
> +		    anx6345->i2c_clients[i]->addr != anx6345->client->addr)
> +			i2c_unregister_device(anx6345->i2c_clients[i]);
> +}
> +
> +static const struct regmap_config anx6345_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0xff,
> +};
> +
> +static const u16 anx6345_chipid_list[] = {
> +	0x6345,
> +};
> +
> +static int anx6345_i2c_probe(struct i2c_client *client,
> +			     const struct i2c_device_id *id)
> +{
> +	struct anx6345 *anx6345;
> +	struct anx6345_platform_data *pdata;
> +	unsigned int i, idl, idh, version;
> +	bool found = false;
> +	int err;
> +
> +	anx6345 = devm_kzalloc(&client->dev, sizeof(*anx6345), GFP_KERNEL);
> +	if (!anx6345)
> +		return -ENOMEM;
> +
> +	pdata = &anx6345->pdata;
> +
> +	mutex_init(&anx6345->lock);
> +
> +	anx6345->bridge.of_node = client->dev.of_node;
> +
> +	anx6345->client = client;
> +	i2c_set_clientdata(client, anx6345);
> +
> +	err = drm_of_find_panel_or_bridge(client->dev.of_node, 1, 0,
> +					  &anx6345->panel, NULL);
> +	if (err == -EPROBE_DEFER)
> +		return err;
> +
> +	if (err)
> +		DRM_DEBUG("No panel found\n");
> +
> +	err = anx6345_init_pdata(anx6345);
> +	if (err) {
> +		DRM_ERROR("Failed to initialize pdata: %d\n", err);
> +		return err;
> +	}
> +
> +	/* Map slave addresses of ANX6345 */
> +	for (i = 0; i < I2C_NUM_ADDRESSES; i++) {
> +		if (anx6345_i2c_addresses[i] >> 1 != client->addr)
> +			anx6345->i2c_clients[i] = i2c_new_dummy(client->adapter,
> +						anx6345_i2c_addresses[i] >> 1);
> +		else
> +			anx6345->i2c_clients[i] = client;


I see this contredanse is copy/pasted from anx78*, but it looks quite
complicated. As I understand there are two i2c addresses, why we cannot
assume one address is for control interfaces and another

is dummy? It would simplify the code here and in other places.


> +
> +		if (!anx6345->i2c_clients[i]) {
> +			err = -ENOMEM;
> +			DRM_ERROR("Failed to reserve I2C bus %02x\n",
> +				  anx6345_i2c_addresses[i]);
> +			goto err_unregister_i2c;
> +		}
> +
> +		anx6345->map[i] = devm_regmap_init_i2c(anx6345->i2c_clients[i],
> +						       &anx6345_regmap_config);
> +		if (IS_ERR(anx6345->map[i])) {
> +			err = PTR_ERR(anx6345->map[i]);
> +			DRM_ERROR("Failed regmap initialization %02x\n",
> +				  anx6345_i2c_addresses[i]);
> +			goto err_unregister_i2c;
> +		}
> +	}
> +
> +	/* Look for supported chip ID */
> +	anx6345_poweron(anx6345);
> +
> +	err = regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_IDL_REG,
> +			  &idl);
> +	if (err)
> +		goto err_poweroff;
> +
> +	err = regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_IDH_REG,
> +			  &idh);
> +	if (err)
> +		goto err_poweroff;
> +
> +	anx6345->chipid = (u8)idl | ((u8)idh << 8);
> +
> +	err = regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_VERSION_REG,
> +			  &version);
> +	if (err)
> +		goto err_poweroff;
> +
> +	for (i = 0; i < ARRAY_SIZE(anx6345_chipid_list); i++) {
> +		if (anx6345->chipid == anx6345_chipid_list[i]) {
> +			DRM_INFO("Found ANX%x (ver. %d) eDP Transmitter\n",
> +				 anx6345->chipid, version);
> +			found = true;
> +			break;
> +		}
> +	}
> +
> +	if (!found) {
> +		DRM_ERROR("ANX%x (ver. %d) not supported by this driver\n",
> +			  anx6345->chipid, version);
> +		err = -ENODEV;
> +		goto err_poweroff;
> +	}


As I see chip becomes powered forever, is it OK? Usually it should be
powered only when pipeline starts, and powered-off after pipeline stops.


Regards

Andrzej


> +
> +	anx6345->bridge.funcs = &anx6345_bridge_funcs;
> +
> +	drm_bridge_add(&anx6345->bridge);
> +
> +	return 0;
> +
> +err_poweroff:
> +	anx6345_poweroff(anx6345);
> +
> +err_unregister_i2c:
> +	unregister_i2c_dummy_clients(anx6345);
> +	return err;
> +}
> +
> +static int anx6345_i2c_remove(struct i2c_client *client)
> +{
> +	struct anx6345 *anx6345 = i2c_get_clientdata(client);
> +
> +	drm_bridge_remove(&anx6345->bridge);
> +
> +	unregister_i2c_dummy_clients(anx6345);
> +
> +	kfree(anx6345->edid);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id anx6345_id[] = {
> +	{ "anx6345", 0 },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, anx6345_id);
> +
> +static const struct of_device_id anx6345_match_table[] = {
> +	{ .compatible = "analogix,anx6345", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, anx6345_match_table);
> +
> +static struct i2c_driver anx6345_driver = {
> +	.driver = {
> +		   .name = "anx6345",
> +		   .of_match_table = of_match_ptr(anx6345_match_table),
> +		  },
> +	.probe = anx6345_i2c_probe,
> +	.remove = anx6345_i2c_remove,
> +	.id_table = anx6345_id,
> +};
> +module_i2c_driver(anx6345_driver);
> +
> +MODULE_DESCRIPTION("ANX6345 eDP Transmitter driver");
> +MODULE_AUTHOR("Icenowy Zheng <[e-mail]>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> index 9cb30962032e..53b0e73d6a24 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
> @@ -117,7 +117,7 @@ ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg)
>  	else	/* For non-zero-sized set the length field. */
>  		ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
>  
> -	if ((msg->request & DP_AUX_I2C_READ) == 0) {
> +	if ((msg->size > 0) && ((msg->request & DP_AUX_I2C_READ) == 0)) {
>  		/* When WRITE | MOT write values to data buffer */
>  		err = regmap_bulk_write(map_dptx,
>  					SP_DP_BUF_DATA0_REG, buffer,
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
> index c2ca854613a0..b29a0b3bc23c 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
> @@ -75,7 +75,11 @@
>  #define SP_CHA_STA			BIT(2)
>  /* Bits for DP System Control Register 3 */
>  #define SP_HPD_STATUS			BIT(6)
> +#define SP_HPD_FORCE			BIT(5)
> +#define SP_HPD_CTRL			BIT(4)
>  #define SP_STRM_VALID			BIT(2)
> +#define SP_STRM_FORCE			BIT(1)
> +#define SP_STRM_CTRL			BIT(0)
>  /* Bits for DP System Control Register 4 */
>  #define SP_ENHANCED_MODE		BIT(3)
>  
> @@ -120,6 +124,9 @@
>  #define SP_LINK_BW_SET_MASK		0x1f
>  #define SP_INITIAL_SLIM_M_AUD_SEL	BIT(5)
>  
> +/* DP Lane Count Setting Register */
> +#define SP_DP_LANE_COUNT_SET_REG	0xa1
> +
>  /* DP Training Pattern Set Register */
>  #define SP_DP_TRAINING_PATTERN_SET_REG	0xa2
>  
> @@ -133,6 +140,7 @@
>  
>  /* DP Link Training Control Register */
>  #define SP_DP_LT_CTRL_REG		0xa8
> +#define SP_DP_LT_INPROGRESS		0x80
>  #define SP_LT_ERROR_TYPE_MASK		0x70
>  #  define SP_LT_NO_ERROR		0x00
>  #  define SP_LT_AUX_WRITE_ERROR		0x01
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h b/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h
> index 7d683573e970..480c98a225b1 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h
> +++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h
> @@ -183,6 +183,9 @@
>  #define SP_VBIT				BIT(1)
>  #define SP_AUDIO_LAYOUT			BIT(0)
>  
> +/* Analog Debug Register 1 */
> +#define SP_ANALOG_DEBUG1_REG		0xdc
> +
>  /* Analog Debug Register 2 */
>  #define SP_ANALOG_DEBUG2_REG		0xdd
>  #define SP_FORCE_SW_OFF_BYPASS		0x20

Vasily Khoruzhick Feb. 15, 2019, 7:21 p.m. UTC | #3

On Fri, Feb 15, 2019 at 12:23 AM Priit Laes <[e-mail]> wrote:

> > +     err = anx6345_tx_initialization(anx6345);
> > +     if (err) {
> > +             DRM_ERROR("Failed transmitter initialization: %d\n", err);
> > +             goto err_poweroff;
>
> You can move the whole err_poweroff section from below here and drop the goto.

Thanks, will do.

Vasily Khoruzhick Feb. 15, 2019, 7:36 p.m. UTC | #4

On Fri, Feb 15, 2019 at 1:13 AM Andrzej Hajda <[e-mail]> wrote:

Hi Andrzej,

Thanks for review!

> > +#include <linux/of_gpio.h>
> Do you need this header?

I'll drop it.

> > +#include <drm/drmP.h>
>
> drmP.h is/should be deprecated.

Same here

> > +struct anx6345_platform_data {
> > +     struct regulator *dvdd12;
> > +     struct regulator *dvdd25;
> > +     struct gpio_desc *gpiod_reset;
> > +};
>
> Why do you need this struct, why just do not embed it's fields directly
> into struct anx6345 ?

OK, I'll embed it into struct anx6345

> > +     if (WARN_ON(anx6345->powered))
> > +             return;
>
> It should not happen, you can remove this warn.

OK

> > +     if (pdata->dvdd12) {
>
> If regulators are required this will be never null.

Right, and regulator subsystem will return dummy regulator if it's
missing in dts.
I'll remove redundant checks.

> > +
> > +     if (pdata->dvdd25) {
>
> ditto

OK

> > +
> > +     if (anx6345->panel)
> > +             drm_panel_prepare(anx6345->panel);
>
> again, here and below: panel is never null, check can be removed.

That's not true, panel is optional. It can be DP connector, not a panel.

> > +
> > +     gpiod_set_value_cansleep(pdata->gpiod_reset, 0);
> > +     usleep_range(1000, 2000);
> > +
> > +     gpiod_set_value_cansleep(pdata->gpiod_reset, 1);
>
>
> Start/stop sequence seems odd regarding reset gpio:
>
> 1. In probe reset is set to low, in poweroff to high - incosistent.
>
> 2. If in case of disabled device reset should be 0, there is no point to
> set it again to 0 three lines above.
>
> 3. I suspect in dts reset gpio should be declared as active_low, and the
> logic in the driver should be reverted, in power off it should be set to
> high, in power on it should be lowered (logically).

OK, I'll look into it.

> > +err_poweroff:
> > +     DRM_ERROR("Failed DisplayPort transmitter initialization: %d\n", err);
>
> redundant message

OK, will drop.

> > +             DRM_ERROR("Get sink count failed %d\n", err);
>
> The rule of thumb I heard is that if you start message capitalized you
> should end with dot. Since I do not know if it is enforced in kernel I
> leave the decision up to you.

I grepped DRM_ERROR in driver/gpu/drm and they do exactly the same as here.
So I'll just keep it as is for consistency.

> > +static bool anx6345_bridge_mode_fixup(struct drm_bridge *bridge,
> > +                                   const struct drm_display_mode *mode,
> > +                                   struct drm_display_mode *adjusted_mode)
> > +{
> > +     if (mode->flags & DRM_MODE_FLAG_INTERLACE)
> > +             return false;
> > +
> > +     /* Max 1200p at 5.4 Ghz, one lane */
> > +     if (mode->clock > 154000)
> > +             return false;
>
> These checks should be in mode_valid callback.

OK

> > +     /* Map slave addresses of ANX6345 */
> > +     for (i = 0; i < I2C_NUM_ADDRESSES; i++) {
> > +             if (anx6345_i2c_addresses[i] >> 1 != client->addr)
> > +                     anx6345->i2c_clients[i] = i2c_new_dummy(client->adapter,
> > +                                             anx6345_i2c_addresses[i] >> 1);
> > +             else
> > +                     anx6345->i2c_clients[i] = client;
>
>
> I see this contredanse is copy/pasted from anx78*, but it looks quite
> complicated. As I understand there are two i2c addresses, why we cannot
> assume one address is for control interfaces and another  is dummy? It would
> simplify the code here and in other places.

Sorry, I don't get you, could you elaborate? Note that anx6345 uses
both addresses,
i2c_new_dummy() just registers new i2c device bound to a dummy driver and it's
supposed to be used for devices that consume more than one i2c address.

> > +     if (!found) {
> > +             DRM_ERROR("ANX%x (ver. %d) not supported by this driver\n",
> > +                       anx6345->chipid, version);
> > +             err = -ENODEV;
> > +             goto err_poweroff;
> > +     }
>
>
> As I see chip becomes powered forever, is it OK? Usually it should be
> powered only when pipeline starts, and powered-off after pipeline stops.

I'll look into how hard it would be to implement but personally I
think it's OK for now.
We can add more sophisticated power management once this driver is merged.

Andrzej Hajda Feb. 26, 2019, 7:12 a.m. UTC | #5

On 15.02.2019 20:36, Vasily Khoruzhick wrote:
> On Fri, Feb 15, 2019 at 1:13 AM Andrzej Hajda <[e-mail]> wrote:
>
> Hi Andrzej,
>
> Thanks for review!
>
>>> +#include <linux/of_gpio.h>
>> Do you need this header?
> I'll drop it.
>
>>> +#include <drm/drmP.h>
>> drmP.h is/should be deprecated.
> Same here
>
>>> +struct anx6345_platform_data {
>>> +     struct regulator *dvdd12;
>>> +     struct regulator *dvdd25;
>>> +     struct gpio_desc *gpiod_reset;
>>> +};
>> Why do you need this struct, why just do not embed it's fields directly
>> into struct anx6345 ?
> OK, I'll embed it into struct anx6345
>
>>> +     if (WARN_ON(anx6345->powered))
>>> +             return;
>> It should not happen, you can remove this warn.
> OK
>
>>> +     if (pdata->dvdd12) {
>> If regulators are required this will be never null.
> Right, and regulator subsystem will return dummy regulator if it's
> missing in dts.
> I'll remove redundant checks.
>
>>> +
>>> +     if (pdata->dvdd25) {
>> ditto
> OK
>
>>> +
>>> +     if (anx6345->panel)
>>> +             drm_panel_prepare(anx6345->panel);
>> again, here and below: panel is never null, check can be removed.
> That's not true, panel is optional. It can be DP connector, not a panel.
>
>>> +
>>> +     gpiod_set_value_cansleep(pdata->gpiod_reset, 0);
>>> +     usleep_range(1000, 2000);
>>> +
>>> +     gpiod_set_value_cansleep(pdata->gpiod_reset, 1);
>>
>> Start/stop sequence seems odd regarding reset gpio:
>>
>> 1. In probe reset is set to low, in poweroff to high - incosistent.
>>
>> 2. If in case of disabled device reset should be 0, there is no point to
>> set it again to 0 three lines above.
>>
>> 3. I suspect in dts reset gpio should be declared as active_low, and the
>> logic in the driver should be reverted, in power off it should be set to
>> high, in power on it should be lowered (logically).
> OK, I'll look into it.
>
>>> +err_poweroff:
>>> +     DRM_ERROR("Failed DisplayPort transmitter initialization: %d\n", err);
>> redundant message
> OK, will drop.
>
>>> +             DRM_ERROR("Get sink count failed %d\n", err);
>> The rule of thumb I heard is that if you start message capitalized you
>> should end with dot. Since I do not know if it is enforced in kernel I
>> leave the decision up to you.
> I grepped DRM_ERROR in driver/gpu/drm and they do exactly the same as here.
> So I'll just keep it as is for consistency.
>
>>> +static bool anx6345_bridge_mode_fixup(struct drm_bridge *bridge,
>>> +                                   const struct drm_display_mode *mode,
>>> +                                   struct drm_display_mode *adjusted_mode)
>>> +{
>>> +     if (mode->flags & DRM_MODE_FLAG_INTERLACE)
>>> +             return false;
>>> +
>>> +     /* Max 1200p at 5.4 Ghz, one lane */
>>> +     if (mode->clock > 154000)
>>> +             return false;
>> These checks should be in mode_valid callback.
> OK
>
>>> +     /* Map slave addresses of ANX6345 */
>>> +     for (i = 0; i < I2C_NUM_ADDRESSES; i++) {
>>> +             if (anx6345_i2c_addresses[i] >> 1 != client->addr)
>>> +                     anx6345->i2c_clients[i] = i2c_new_dummy(client->adapter,
>>> +                                             anx6345_i2c_addresses[i] >> 1);
>>> +             else
>>> +                     anx6345->i2c_clients[i] = client;
>>
>> I see this contredanse is copy/pasted from anx78*, but it looks quite
>> complicated. As I understand there are two i2c addresses, why we cannot
>> assume one address is for control interfaces and another  is dummy? It would
>> simplify the code here and in other places.
> Sorry, I don't get you, could you elaborate? Note that anx6345 uses
> both addresses,
> i2c_new_dummy() just registers new i2c device bound to a dummy driver and it's
> supposed to be used for devices that consume more than one i2c address.


My idea was to assume that ANALOGIX_I2C_DPTX is the main address, ie.
address which should be set in dts in device node reg property.

Other addresses should be registered as dummy devices during probe -
simple loop without conditionals, without redundant fields in anx6345
context - i2c_clients, client.

I do not insist on this change but I suggest as it should simplify the code.

And moreover, you can consider removing direction bit from i2c
addresses, it could be also confusing and against i2c kernel api.

>
>>> +     if (!found) {
>>> +             DRM_ERROR("ANX%x (ver. %d) not supported by this driver\n",
>>> +                       anx6345->chipid, version);
>>> +             err = -ENODEV;
>>> +             goto err_poweroff;
>>> +     }
>>
>> As I see chip becomes powered forever, is it OK? Usually it should be
>> powered only when pipeline starts, and powered-off after pipeline stops.
> I'll look into how hard it would be to implement but personally I
> think it's OK for now.
> We can add more sophisticated power management once this driver is merged.


But the rule is every resource allocated/set during lifetime of the
driver should be dropped on driver removal, so please do it at least in
remove callback.


Regards

Andrzej

Patch

diff --git a/drivers/gpu/drm/bridge/analogix/Kconfig b/drivers/gpu/drm/bridge/analogix/Kconfig
index ed2d05c12546..3c6ec535d361 100644
--- a/drivers/gpu/drm/bridge/analogix/Kconfig
+++ b/drivers/gpu/drm/bridge/analogix/Kconfig
@@ -1,3 +1,14 @@ 
+config DRM_ANALOGIX_ANX6345
+	tristate "Analogix ANX6345 bridge"
+	select DRM_ANALOGIX_DP_I2C
+	select DRM_KMS_HELPER
+	select REGMAP_I2C
+	help
+	  ANX6345 is an ultra-low Full-HD DisplayPort/eDP
+	  transmitter designed for portable devices. The
+	  ANX6345 transforms the LVTTL RGB output of an
+	  application processor to eDP or DisplayPort.
+
 config DRM_ANALOGIX_ANX78XX
 	tristate "Analogix ANX78XX bridge"
 	select DRM_ANALOGIX_DP_I2C
diff --git a/drivers/gpu/drm/bridge/analogix/Makefile b/drivers/gpu/drm/bridge/analogix/Makefile
index 2d523b67487d..12fed7b04e1e 100644
--- a/drivers/gpu/drm/bridge/analogix/Makefile
+++ b/drivers/gpu/drm/bridge/analogix/Makefile
@@ -1,5 +1,6 @@ 
 analogix_dp-objs := analogix_dp_core.o analogix_dp_reg.o
 analogix_dp_i2c-objs := analogix-i2c-dptx.o
+obj-$(CONFIG_DRM_ANALOGIX_ANX6345) += analogix-anx6345.o
 obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
 obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix_dp.o
 obj-$(CONFIG_DRM_ANALOGIX_DP_I2C) += analogix_dp_i2c.o
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
new file mode 100644
index 000000000000..6098e245e074
--- /dev/null
+++ b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
@@ -0,0 +1,845 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(c) Icenowy Zheng <[e-mail]>
+ * Based on analogix-anx6345.c, which is:
+ *   Copyright(c) 2016, Analogix Semiconductor.
+ */
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_dp_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+
+#include "analogix-i2c-dptx.h"
+#include "analogix-i2c-txcommon.h"
+
+#define I2C_NUM_ADDRESSES	2
+#define I2C_IDX_DPTX		0
+#define I2C_IDX_TXCOM		1
+
+#define XTAL_CLK		270 /* 27M */
+
+#define POLL_DELAY		50000 /* us */
+#define POLL_TIMEOUT		5000000 /* us */
+
+static const u8 anx6345_i2c_addresses[] = {
+	[I2C_IDX_DPTX]	= ANALOGIX_I2C_DPTX,
+	[I2C_IDX_TXCOM]	= ANALOGIX_I2C_TXCOMMON,
+};
+
+struct anx6345_platform_data {
+	struct regulator *dvdd12;
+	struct regulator *dvdd25;
+	struct gpio_desc *gpiod_reset;
+};
+
+struct anx6345 {
+	struct drm_dp_aux aux;
+	struct drm_bridge bridge;
+	struct i2c_client *client;
+	struct edid *edid;
+	struct drm_connector connector;
+	struct drm_dp_link link;
+	struct drm_panel *panel;
+	struct anx6345_platform_data pdata;
+	struct mutex lock;
+
+	/*
+	 * I2C Slave addresses of ANX6345 are mapped as DPTX and SYS
+	 */
+	struct i2c_client *i2c_clients[I2C_NUM_ADDRESSES];
+	struct regmap *map[I2C_NUM_ADDRESSES];
+
+	u16 chipid;
+	u8 dpcd[DP_RECEIVER_CAP_SIZE];
+
+	bool powered;
+};
+
+static inline struct anx6345 *connector_to_anx6345(struct drm_connector *c)
+{
+	return container_of(c, struct anx6345, connector);
+}
+
+static inline struct anx6345 *bridge_to_anx6345(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct anx6345, bridge);
+}
+
+static int anx6345_set_bits(struct regmap *map, u8 reg, u8 mask)
+{
+	return regmap_update_bits(map, reg, mask, mask);
+}
+
+static int anx6345_clear_bits(struct regmap *map, u8 reg, u8 mask)
+{
+	return regmap_update_bits(map, reg, mask, 0);
+}
+
+static ssize_t anx6345_aux_transfer(struct drm_dp_aux *aux,
+				    struct drm_dp_aux_msg *msg)
+{
+	struct anx6345 *anx6345 = container_of(aux, struct anx6345, aux);
+
+	return anx_aux_transfer(anx6345->map[I2C_IDX_DPTX], msg);
+}
+
+static int anx6345_dp_link_training(struct anx6345 *anx6345)
+{
+	unsigned int value;
+	u8 dp_bw;
+	int err;
+
+	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
+				 SP_POWERDOWN_CTRL_REG,
+				 SP_TOTAL_PD);
+	if (err)
+		return err;
+
+	err = drm_dp_dpcd_readb(&anx6345->aux, DP_MAX_LINK_RATE, &dp_bw);
+	if (err < 0)
+		return err;
+
+	switch (dp_bw) {
+	case DP_LINK_BW_1_62:
+	case DP_LINK_BW_2_7:
+		break;
+
+	default:
+		DRM_DEBUG_KMS("DP bandwidth (%#02x) not supported\n", dp_bw);
+		return -EINVAL;
+	}
+
+	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
+			       SP_VIDEO_MUTE);
+	if (err)
+		return err;
+
+	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
+				 SP_VID_CTRL1_REG, SP_VIDEO_EN);
+	if (err)
+		return err;
+
+	/* Get DPCD info */
+	err = drm_dp_dpcd_read(&anx6345->aux, DP_DPCD_REV,
+			       &anx6345->dpcd, DP_RECEIVER_CAP_SIZE);
+	if (err < 0) {
+		DRM_ERROR("Failed to read DPCD: %d\n", err);
+		return err;
+	}
+
+	/* Clear channel x SERDES power down */
+	err = anx6345_clear_bits(anx6345->map[I2C_IDX_DPTX],
+				 SP_DP_ANALOG_POWER_DOWN_REG, SP_CH0_PD);
+	if (err)
+		return err;
+
+	/* Check link capabilities */
+	err = drm_dp_link_probe(&anx6345->aux, &anx6345->link);
+	if (err < 0) {
+		DRM_ERROR("Failed to probe link capabilities: %d\n", err);
+		return err;
+	}
+
+	/* Power up the sink */
+	err = drm_dp_link_power_up(&anx6345->aux, &anx6345->link);
+	if (err < 0) {
+		DRM_ERROR("Failed to power up DisplayPort link: %d\n", err);
+		return err;
+	}
+
+	/* Possibly enable downspread on the sink */
+	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
+			   SP_DP_DOWNSPREAD_CTRL1_REG, 0);
+	if (err)
+		return err;
+
+	if (anx6345->dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5) {
+		DRM_DEBUG("Enable downspread on the sink\n");
+		/* 4000PPM */
+		err = regmap_write(anx6345->map[I2C_IDX_DPTX],
+				   SP_DP_DOWNSPREAD_CTRL1_REG, 8);
+		if (err)
+			return err;
+
+		err = drm_dp_dpcd_writeb(&anx6345->aux, DP_DOWNSPREAD_CTRL,
+					 DP_SPREAD_AMP_0_5);
+		if (err < 0)
+			return err;
+	} else {
+		err = drm_dp_dpcd_writeb(&anx6345->aux, DP_DOWNSPREAD_CTRL, 0);
+		if (err < 0)
+			return err;
+	}
+
+	/* Set the lane count and the link rate on the sink */
+	if (drm_dp_enhanced_frame_cap(anx6345->dpcd))
+		err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
+				       SP_DP_SYSTEM_CTRL_BASE + 4,
+				       SP_ENHANCED_MODE);
+	else
+		err = anx6345_clear_bits(anx6345->map[I2C_IDX_DPTX],
+					 SP_DP_SYSTEM_CTRL_BASE + 4,
+					 SP_ENHANCED_MODE);
+	if (err)
+		return err;
+
+	value = drm_dp_link_rate_to_bw_code(anx6345->link.rate);
+	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
+			   SP_DP_MAIN_LINK_BW_SET_REG, value);
+	if (err)
+		return err;
+
+	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
+			   SP_DP_LANE_COUNT_SET_REG, anx6345->link.num_lanes);
+	if (err)
+		return err;
+
+	err = drm_dp_link_configure(&anx6345->aux, &anx6345->link);
+	if (err < 0) {
+		DRM_ERROR("Failed to configure DisplayPort link: %d\n", err);
+		return err;
+	}
+
+	/* Start training on the source */
+	err = regmap_write(anx6345->map[I2C_IDX_DPTX], SP_DP_LT_CTRL_REG,
+			   SP_LT_EN);
+	if (err)
+		return err;
+
+	err = regmap_read_poll_timeout(anx6345->map[I2C_IDX_DPTX],
+				       SP_DP_LT_CTRL_REG,
+				       value, !(value & SP_DP_LT_INPROGRESS),
+				       POLL_DELAY, POLL_TIMEOUT);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int anx6345_tx_initialization(struct anx6345 *anx6345)
+{
+	int err, i;
+
+	/* FIXME: hardcode color depth now */
+	err = regmap_write(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL2_REG,
+			   SP_IN_BPC_6BIT << SP_IN_BPC_SHIFT);
+	if (err)
+		return err;
+
+	err = regmap_write(anx6345->map[I2C_IDX_DPTX], SP_DP_PLL_CTRL_REG, 0);
+	if (err)
+		return err;
+
+	err = regmap_write(anx6345->map[I2C_IDX_TXCOM],
+			   SP_ANALOG_DEBUG1_REG, 0);
+	if (err)
+		return err;
+
+	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
+			   SP_DP_LINK_DEBUG_CTRL_REG,
+			   SP_NEW_PRBS7 | SP_M_VID_DEBUG);
+	if (err)
+		return err;
+
+	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
+			   SP_DP_ANALOG_POWER_DOWN_REG, 0);
+	if (err)
+		return err;
+
+	/* Force HPD */
+	err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
+			       SP_DP_SYSTEM_CTRL_BASE + 3,
+			       SP_HPD_FORCE | SP_HPD_CTRL);
+	if (err)
+		return err;
+
+	for (i = 0; i < 4; i++) {
+		/* 4 lanes */
+		err = regmap_write(anx6345->map[I2C_IDX_DPTX],
+				   SP_DP_LANE0_LT_CTRL_REG + i, 0);
+		if (err)
+			return err;
+	}
+
+	/* Reset AUX */
+	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM],
+			       SP_RESET_CTRL2_REG, SP_AUX_RST);
+	if (err)
+		return err;
+
+	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
+				 SP_RESET_CTRL2_REG, SP_AUX_RST);
+	if (err)
+		return err;
+
+	err = anx6345_dp_link_training(anx6345);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static void anx6345_poweron(struct anx6345 *anx6345)
+{
+	struct anx6345_platform_data *pdata = &anx6345->pdata;
+	int err;
+
+	if (WARN_ON(anx6345->powered))
+		return;
+
+	if (pdata->dvdd12) {
+		err = regulator_enable(pdata->dvdd12);
+		if (err) {
+			DRM_ERROR("Failed to enable DVDD12 regulator: %d\n",
+				  err);
+			return;
+		}
+
+		usleep_range(1000, 2000);
+	}
+
+	if (pdata->dvdd25) {
+		err = regulator_enable(pdata->dvdd25);
+		if (err) {
+			DRM_ERROR("Failed to enable DVDD25 regulator: %d\n",
+				  err);
+			return;
+		}
+
+		usleep_range(5000, 10000);
+	}
+
+	if (anx6345->panel)
+		drm_panel_prepare(anx6345->panel);
+
+	gpiod_set_value_cansleep(pdata->gpiod_reset, 0);
+	usleep_range(1000, 2000);
+
+	gpiod_set_value_cansleep(pdata->gpiod_reset, 1);
+
+	/* Power on registers module */
+	anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
+			 SP_HDCP_PD | SP_AUDIO_PD | SP_VIDEO_PD | SP_LINK_PD);
+	anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
+			   SP_REGISTER_PD | SP_TOTAL_PD);
+
+	anx6345->powered = true;
+}
+
+static void anx6345_poweroff(struct anx6345 *anx6345)
+{
+	struct anx6345_platform_data *pdata = &anx6345->pdata;
+	int err;
+
+	if (WARN_ON(!anx6345->powered))
+		return;
+
+	gpiod_set_value_cansleep(pdata->gpiod_reset, 1);
+	usleep_range(1000, 2000);
+
+	if (anx6345->panel)
+		drm_panel_unprepare(anx6345->panel);
+
+	if (pdata->dvdd25) {
+		err = regulator_disable(pdata->dvdd25);
+		if (err) {
+			DRM_ERROR("Failed to disable DVDD25 regulator: %d\n",
+				  err);
+			return;
+		}
+
+		usleep_range(5000, 10000);
+	}
+
+	if (pdata->dvdd12) {
+		err = regulator_disable(pdata->dvdd12);
+		if (err) {
+			DRM_ERROR("Failed to disable DVDD12 regulator: %d\n",
+				  err);
+			return;
+		}
+
+		usleep_range(1000, 2000);
+	}
+
+	anx6345->powered = false;
+}
+
+static int anx6345_start(struct anx6345 *anx6345)
+{
+	int err;
+
+	if (!anx6345->powered)
+		anx6345_poweron(anx6345);
+
+	/* Power on needed modules */
+	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
+				 SP_POWERDOWN_CTRL_REG,
+				 SP_VIDEO_PD | SP_LINK_PD);
+
+	err = anx6345_tx_initialization(anx6345);
+	if (err) {
+		DRM_ERROR("Failed transmitter initialization: %d\n", err);
+		goto err_poweroff;
+	}
+
+	/*
+	 * This delay seems to help keep the hardware in a good state. Without
+	 * it, there are times where it fails silently.
+	 */
+	usleep_range(10000, 15000);
+
+	return 0;
+
+err_poweroff:
+	DRM_ERROR("Failed DisplayPort transmitter initialization: %d\n", err);
+	anx6345_poweroff(anx6345);
+
+	return err;
+}
+
+static int anx6345_init_pdata(struct anx6345 *anx6345)
+{
+	struct anx6345_platform_data *pdata = &anx6345->pdata;
+	struct device *dev = &anx6345->client->dev;
+
+	/* 1.2V digital core power regulator  */
+	pdata->dvdd12 = devm_regulator_get(dev, "dvdd12");
+	if (IS_ERR(pdata->dvdd12)) {
+		DRM_ERROR("DVDD12 regulator not found\n");
+		return PTR_ERR(pdata->dvdd12);
+	}
+
+	/* 2.5V digital core power regulator  */
+	pdata->dvdd25 = devm_regulator_get(dev, "dvdd25");
+	if (IS_ERR(pdata->dvdd25)) {
+		DRM_ERROR("DVDD25 regulator not found\n");
+		return PTR_ERR(pdata->dvdd25);
+	}
+
+	/* GPIO for chip reset */
+	pdata->gpiod_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+
+	return PTR_ERR_OR_ZERO(pdata->gpiod_reset);
+}
+
+static int anx6345_config_dp_output(struct anx6345 *anx6345)
+{
+	int err;
+
+	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
+				 SP_VIDEO_MUTE);
+	if (err)
+		return err;
+
+	/* Enable DP output */
+	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
+			       SP_VIDEO_EN);
+	if (err)
+		return err;
+
+	/* Force stream valid */
+	err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
+			       SP_DP_SYSTEM_CTRL_BASE + 3,
+			       SP_STRM_FORCE | SP_STRM_CTRL);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int anx6345_get_downstream_info(struct anx6345 *anx6345)
+{
+	u8 value;
+	int err;
+
+	err = drm_dp_dpcd_readb(&anx6345->aux, DP_SINK_COUNT, &value);
+	if (err < 0) {
+		DRM_ERROR("Get sink count failed %d\n", err);
+		return err;
+	}
+
+	if (!DP_GET_SINK_COUNT(value)) {
+		DRM_ERROR("Downstream disconnected\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int anx6345_get_modes(struct drm_connector *connector)
+{
+	struct anx6345 *anx6345 = connector_to_anx6345(connector);
+	int err, num_modes = 0;
+
+	if (WARN_ON(!anx6345->powered))
+		return 0;
+
+	mutex_lock(&anx6345->lock);
+
+	if (!anx6345->edid) {
+		err = anx6345_get_downstream_info(anx6345);
+		if (err) {
+			DRM_ERROR("Failed to get downstream info: %d\n", err);
+			goto unlock;
+		}
+
+		anx6345->edid = drm_get_edid(connector, &anx6345->aux.ddc);
+		if (!anx6345->edid)
+			DRM_ERROR("Failed to read EDID from panel\n");
+
+		err = drm_connector_update_edid_property(connector,
+							 anx6345->edid);
+		if (err) {
+			DRM_ERROR("Failed to update EDID property: %d\n", err);
+			goto unlock;
+		}
+	}
+
+	num_modes += drm_add_edid_modes(connector, anx6345->edid);
+
+unlock:
+	mutex_unlock(&anx6345->lock);
+
+	if (!num_modes && anx6345->panel)
+		num_modes += drm_panel_get_modes(anx6345->panel);
+
+	return num_modes;
+}
+
+static const struct drm_connector_helper_funcs anx6345_connector_helper_funcs = {
+	.get_modes = anx6345_get_modes,
+};
+
+static enum drm_connector_status anx6345_detect(struct drm_connector *connector,
+						bool force)
+{
+	return connector_status_connected;
+}
+
+static void
+anx6345_connector_destroy(struct drm_connector *connector)
+{
+	struct anx6345 *anx6345 = connector_to_anx6345(connector);
+
+	if (anx6345->panel)
+		drm_panel_detach(anx6345->panel);
+	drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs anx6345_connector_funcs = {
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = anx6345_detect,
+	.destroy = anx6345_connector_destroy,
+	.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 int anx6345_bridge_attach(struct drm_bridge *bridge)
+{
+	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
+	int err;
+
+	if (!bridge->encoder) {
+		DRM_ERROR("Parent encoder object not found");
+		return -ENODEV;
+	}
+
+	/* Register aux channel */
+	anx6345->aux.name = "DP-AUX";
+	anx6345->aux.dev = &anx6345->client->dev;
+	anx6345->aux.transfer = anx6345_aux_transfer;
+
+	err = drm_dp_aux_register(&anx6345->aux);
+	if (err < 0) {
+		DRM_ERROR("Failed to register aux channel: %d\n", err);
+		return err;
+	}
+
+	err = drm_connector_init(bridge->dev, &anx6345->connector,
+				 &anx6345_connector_funcs,
+				 DRM_MODE_CONNECTOR_eDP);
+	if (err) {
+		DRM_ERROR("Failed to initialize connector: %d\n", err);
+		return err;
+	}
+
+	drm_connector_helper_add(&anx6345->connector,
+				 &anx6345_connector_helper_funcs);
+
+	err = drm_connector_register(&anx6345->connector);
+	if (err) {
+		DRM_ERROR("Failed to register connector: %d\n", err);
+		return err;
+	}
+
+	anx6345->connector.polled = DRM_CONNECTOR_POLL_HPD;
+
+	err = drm_connector_attach_encoder(&anx6345->connector,
+					   bridge->encoder);
+	if (err) {
+		DRM_ERROR("Failed to link up connector to encoder: %d\n", err);
+		return err;
+	}
+
+	if (anx6345->panel) {
+		err = drm_panel_attach(anx6345->panel, &anx6345->connector);
+		if (err) {
+			DRM_ERROR("Failed to attach panel: %d\n", err);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static bool anx6345_bridge_mode_fixup(struct drm_bridge *bridge,
+				      const struct drm_display_mode *mode,
+				      struct drm_display_mode *adjusted_mode)
+{
+	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+		return false;
+
+	/* Max 1200p at 5.4 Ghz, one lane */
+	if (mode->clock > 154000)
+		return false;
+
+	return true;
+}
+
+static void anx6345_bridge_disable(struct drm_bridge *bridge)
+{
+	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
+
+	/* Power off all modules except configuration registers access */
+	anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
+			 SP_HDCP_PD | SP_AUDIO_PD | SP_VIDEO_PD | SP_LINK_PD);
+	if (anx6345->panel)
+		drm_panel_disable(anx6345->panel);
+}
+
+static void anx6345_bridge_mode_set(struct drm_bridge *bridge,
+				    struct drm_display_mode *mode,
+				    struct drm_display_mode *adjusted_mode)
+{
+	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
+
+	if (WARN_ON(!anx6345->powered))
+		return;
+}
+
+static void anx6345_bridge_enable(struct drm_bridge *bridge)
+{
+	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
+	int err;
+
+	if (anx6345->panel)
+		drm_panel_enable(anx6345->panel);
+
+	err = anx6345_start(anx6345);
+	if (err) {
+		DRM_ERROR("Failed to initialize: %d\n", err);
+		return;
+	}
+
+	err = anx6345_config_dp_output(anx6345);
+	if (err)
+		DRM_ERROR("Failed to enable DP output: %d\n", err);
+}
+
+static const struct drm_bridge_funcs anx6345_bridge_funcs = {
+	.attach = anx6345_bridge_attach,
+	.mode_fixup = anx6345_bridge_mode_fixup,
+	.disable = anx6345_bridge_disable,
+	.mode_set = anx6345_bridge_mode_set,
+	.enable = anx6345_bridge_enable,
+};
+
+static void unregister_i2c_dummy_clients(struct anx6345 *anx6345)
+{
+	unsigned int i;
+
+	for (i = 1; i < ARRAY_SIZE(anx6345->i2c_clients); i++)
+		if (anx6345->i2c_clients[i] &&
+		    anx6345->i2c_clients[i]->addr != anx6345->client->addr)
+			i2c_unregister_device(anx6345->i2c_clients[i]);
+}
+
+static const struct regmap_config anx6345_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+};
+
+static const u16 anx6345_chipid_list[] = {
+	0x6345,
+};
+
+static int anx6345_i2c_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id)
+{
+	struct anx6345 *anx6345;
+	struct anx6345_platform_data *pdata;
+	unsigned int i, idl, idh, version;
+	bool found = false;
+	int err;
+
+	anx6345 = devm_kzalloc(&client->dev, sizeof(*anx6345), GFP_KERNEL);
+	if (!anx6345)
+		return -ENOMEM;
+
+	pdata = &anx6345->pdata;
+
+	mutex_init(&anx6345->lock);
+
+	anx6345->bridge.of_node = client->dev.of_node;
+
+	anx6345->client = client;
+	i2c_set_clientdata(client, anx6345);
+
+	err = drm_of_find_panel_or_bridge(client->dev.of_node, 1, 0,
+					  &anx6345->panel, NULL);
+	if (err == -EPROBE_DEFER)
+		return err;
+
+	if (err)
+		DRM_DEBUG("No panel found\n");
+
+	err = anx6345_init_pdata(anx6345);
+	if (err) {
+		DRM_ERROR("Failed to initialize pdata: %d\n", err);
+		return err;
+	}
+
+	/* Map slave addresses of ANX6345 */
+	for (i = 0; i < I2C_NUM_ADDRESSES; i++) {
+		if (anx6345_i2c_addresses[i] >> 1 != client->addr)
+			anx6345->i2c_clients[i] = i2c_new_dummy(client->adapter,
+						anx6345_i2c_addresses[i] >> 1);
+		else
+			anx6345->i2c_clients[i] = client;
+
+		if (!anx6345->i2c_clients[i]) {
+			err = -ENOMEM;
+			DRM_ERROR("Failed to reserve I2C bus %02x\n",
+				  anx6345_i2c_addresses[i]);
+			goto err_unregister_i2c;
+		}
+
+		anx6345->map[i] = devm_regmap_init_i2c(anx6345->i2c_clients[i],
+						       &anx6345_regmap_config);
+		if (IS_ERR(anx6345->map[i])) {
+			err = PTR_ERR(anx6345->map[i]);
+			DRM_ERROR("Failed regmap initialization %02x\n",
+				  anx6345_i2c_addresses[i]);
+			goto err_unregister_i2c;
+		}
+	}
+
+	/* Look for supported chip ID */
+	anx6345_poweron(anx6345);
+
+	err = regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_IDL_REG,
+			  &idl);
+	if (err)
+		goto err_poweroff;
+
+	err = regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_IDH_REG,
+			  &idh);
+	if (err)
+		goto err_poweroff;
+
+	anx6345->chipid = (u8)idl | ((u8)idh << 8);
+
+	err = regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_VERSION_REG,
+			  &version);
+	if (err)
+		goto err_poweroff;
+
+	for (i = 0; i < ARRAY_SIZE(anx6345_chipid_list); i++) {
+		if (anx6345->chipid == anx6345_chipid_list[i]) {
+			DRM_INFO("Found ANX%x (ver. %d) eDP Transmitter\n",
+				 anx6345->chipid, version);
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		DRM_ERROR("ANX%x (ver. %d) not supported by this driver\n",
+			  anx6345->chipid, version);
+		err = -ENODEV;
+		goto err_poweroff;
+	}
+
+	anx6345->bridge.funcs = &anx6345_bridge_funcs;
+
+	drm_bridge_add(&anx6345->bridge);
+
+	return 0;
+
+err_poweroff:
+	anx6345_poweroff(anx6345);
+
+err_unregister_i2c:
+	unregister_i2c_dummy_clients(anx6345);
+	return err;
+}
+
+static int anx6345_i2c_remove(struct i2c_client *client)
+{
+	struct anx6345 *anx6345 = i2c_get_clientdata(client);
+
+	drm_bridge_remove(&anx6345->bridge);
+
+	unregister_i2c_dummy_clients(anx6345);
+
+	kfree(anx6345->edid);
+
+	return 0;
+}
+
+static const struct i2c_device_id anx6345_id[] = {
+	{ "anx6345", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, anx6345_id);
+
+static const struct of_device_id anx6345_match_table[] = {
+	{ .compatible = "analogix,anx6345", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, anx6345_match_table);
+
+static struct i2c_driver anx6345_driver = {
+	.driver = {
+		   .name = "anx6345",
+		   .of_match_table = of_match_ptr(anx6345_match_table),
+		  },
+	.probe = anx6345_i2c_probe,
+	.remove = anx6345_i2c_remove,
+	.id_table = anx6345_id,
+};
+module_i2c_driver(anx6345_driver);
+
+MODULE_DESCRIPTION("ANX6345 eDP Transmitter driver");
+MODULE_AUTHOR("Icenowy Zheng <[e-mail]>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
index 9cb30962032e..53b0e73d6a24 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
@@ -117,7 +117,7 @@  ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg)
 	else	/* For non-zero-sized set the length field. */
 		ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
 
-	if ((msg->request & DP_AUX_I2C_READ) == 0) {
+	if ((msg->size > 0) && ((msg->request & DP_AUX_I2C_READ) == 0)) {
 		/* When WRITE | MOT write values to data buffer */
 		err = regmap_bulk_write(map_dptx,
 					SP_DP_BUF_DATA0_REG, buffer,
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
index c2ca854613a0..b29a0b3bc23c 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
@@ -75,7 +75,11 @@ 
 #define SP_CHA_STA			BIT(2)
 /* Bits for DP System Control Register 3 */
 #define SP_HPD_STATUS			BIT(6)
+#define SP_HPD_FORCE			BIT(5)
+#define SP_HPD_CTRL			BIT(4)
 #define SP_STRM_VALID			BIT(2)
+#define SP_STRM_FORCE			BIT(1)
+#define SP_STRM_CTRL			BIT(0)
 /* Bits for DP System Control Register 4 */
 #define SP_ENHANCED_MODE		BIT(3)
 
@@ -120,6 +124,9 @@ 
 #define SP_LINK_BW_SET_MASK		0x1f
 #define SP_INITIAL_SLIM_M_AUD_SEL	BIT(5)
 
+/* DP Lane Count Setting Register */
+#define SP_DP_LANE_COUNT_SET_REG	0xa1
+
 /* DP Training Pattern Set Register */
 #define SP_DP_TRAINING_PATTERN_SET_REG	0xa2
 
@@ -133,6 +140,7 @@ 
 
 /* DP Link Training Control Register */
 #define SP_DP_LT_CTRL_REG		0xa8
+#define SP_DP_LT_INPROGRESS		0x80
 #define SP_LT_ERROR_TYPE_MASK		0x70
 #  define SP_LT_NO_ERROR		0x00
 #  define SP_LT_AUX_WRITE_ERROR		0x01
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h b/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h
index 7d683573e970..480c98a225b1 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-txcommon.h
@@ -183,6 +183,9 @@ 
 #define SP_VBIT				BIT(1)
 #define SP_AUDIO_LAYOUT			BIT(0)
 
+/* Analog Debug Register 1 */
+#define SP_ANALOG_DEBUG1_REG		0xdc
+
 /* Analog Debug Register 2 */
 #define SP_ANALOG_DEBUG2_REG		0xdd
 #define SP_FORCE_SW_OFF_BYPASS		0x20