drivers/gpu/drm/bridge/sii902x.c - third_party/linux - Git at Google

 /*
  * Copyright (C) 2016 Atmel
  *		      Bo Shen <voice.shen@atmel.com>
  *
  * Authors:	      Bo Shen <voice.shen@atmel.com>
  *		      Boris Brezillon <boris.brezillon@free-electrons.com>
  *		      Wu, Songjun <Songjun.Wu@atmel.com>
  *
  *
  * Copyright (C) 2010-2011 Freescale Semiconductor, Inc. All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/regmap.h>

 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_edid.h>

 #define SII902X_TPI_VIDEO_DATA			0x0

 #define SII902X_TPI_PIXEL_REPETITION		0x8
 #define SII902X_TPI_AVI_PIXEL_REP_BUS_24BIT     BIT(5)
 #define SII902X_TPI_AVI_PIXEL_REP_RISING_EDGE   BIT(4)
 #define SII902X_TPI_AVI_PIXEL_REP_4X		3
 #define SII902X_TPI_AVI_PIXEL_REP_2X		1
 #define SII902X_TPI_AVI_PIXEL_REP_NONE		0
 #define SII902X_TPI_CLK_RATIO_HALF		(0 << 6)
 #define SII902X_TPI_CLK_RATIO_1X		(1 << 6)
 #define SII902X_TPI_CLK_RATIO_2X		(2 << 6)
 #define SII902X_TPI_CLK_RATIO_4X		(3 << 6)

 #define SII902X_TPI_AVI_IN_FORMAT		0x9
 #define SII902X_TPI_AVI_INPUT_BITMODE_12BIT	BIT(7)
 #define SII902X_TPI_AVI_INPUT_DITHER		BIT(6)
 #define SII902X_TPI_AVI_INPUT_RANGE_LIMITED	(2 << 2)
 #define SII902X_TPI_AVI_INPUT_RANGE_FULL	(1 << 2)
 #define SII902X_TPI_AVI_INPUT_RANGE_AUTO	(0 << 2)
 #define SII902X_TPI_AVI_INPUT_COLORSPACE_BLACK	(3 << 0)
 #define SII902X_TPI_AVI_INPUT_COLORSPACE_YUV422	(2 << 0)
 #define SII902X_TPI_AVI_INPUT_COLORSPACE_YUV444	(1 << 0)
 #define SII902X_TPI_AVI_INPUT_COLORSPACE_RGB	(0 << 0)

 #define SII902X_TPI_AVI_INFOFRAME		0x0c

 #define SII902X_SYS_CTRL_DATA			0x1a
 #define SII902X_SYS_CTRL_PWR_DWN		BIT(4)
 #define SII902X_SYS_CTRL_AV_MUTE		BIT(3)
 #define SII902X_SYS_CTRL_DDC_BUS_REQ		BIT(2)
 #define SII902X_SYS_CTRL_DDC_BUS_GRTD		BIT(1)
 #define SII902X_SYS_CTRL_OUTPUT_MODE		BIT(0)
 #define SII902X_SYS_CTRL_OUTPUT_HDMI		1
 #define SII902X_SYS_CTRL_OUTPUT_DVI		0

 #define SII902X_REG_CHIPID(n)			(0x1b + (n))

 #define SII902X_PWR_STATE_CTRL			0x1e
 #define SII902X_AVI_POWER_STATE_MSK		GENMASK(1, 0)
 #define SII902X_AVI_POWER_STATE_D(l)		((l) & SII902X_AVI_POWER_STATE_MSK)

 #define SII902X_INT_ENABLE			0x3c
 #define SII902X_INT_STATUS			0x3d
 #define SII902X_HOTPLUG_EVENT			BIT(0)
 #define SII902X_PLUGGED_STATUS			BIT(2)

 #define SII902X_REG_TPI_RQB			0xc7

 #define SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS	500

 struct sii902x {
 	struct i2c_client *i2c;
 	struct regmap *regmap;
 	struct drm_bridge bridge;
 	struct drm_connector connector;
 	struct gpio_desc *reset_gpio;
 };

 static inline struct sii902x *bridge_to_sii902x(struct drm_bridge *bridge)
 {
 	return container_of(bridge, struct sii902x, bridge);
 }

 static inline struct sii902x *connector_to_sii902x(struct drm_connector *con)
 {
 	return container_of(con, struct sii902x, connector);
 }

 static void sii902x_reset(struct sii902x *sii902x)
 {
 	if (!sii902x->reset_gpio)
 		return;

 	gpiod_set_value(sii902x->reset_gpio, 1);

 	/* The datasheet says treset-min = 100us. Make it 150us to be sure. */
 	usleep_range(150, 200);

 	gpiod_set_value(sii902x->reset_gpio, 0);
 }

 static enum drm_connector_status
 sii902x_connector_detect(struct drm_connector *connector, bool force)
 {
 	struct sii902x *sii902x = connector_to_sii902x(connector);
 	unsigned int status;

 	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);

 	return (status & SII902X_PLUGGED_STATUS) ?
 	       connector_status_connected : connector_status_disconnected;
 }

 static const struct drm_connector_funcs sii902x_connector_funcs = {
 	.detect = sii902x_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.destroy = drm_connector_cleanup,
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };

 static int sii902x_get_modes(struct drm_connector *connector)
 {
 	struct sii902x *sii902x = connector_to_sii902x(connector);
 	struct regmap *regmap = sii902x->regmap;
 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 	struct device *dev = &sii902x->i2c->dev;
 	unsigned long timeout;
 	unsigned int retries;
 	unsigned int status;
 	struct edid *edid;
 	int num = 0;
 	int ret;

 	ret = regmap_update_bits(regmap, SII902X_SYS_CTRL_DATA,
 				 SII902X_SYS_CTRL_DDC_BUS_REQ,
 				 SII902X_SYS_CTRL_DDC_BUS_REQ);
 	if (ret)
 		return ret;

 	timeout = jiffies +
 		  msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
 	do {
 		ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA, &status);
 		if (ret)
 			return ret;
 	} while (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
 		 time_before(jiffies, timeout));

 	if (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
 		dev_err(dev, "failed to acquire the i2c bus\n");
 		return -ETIMEDOUT;
 	}

 	ret = regmap_write(regmap, SII902X_SYS_CTRL_DATA, status);
 	if (ret)
 		return ret;

 	edid = drm_get_edid(connector, sii902x->i2c->adapter);
 	drm_mode_connector_update_edid_property(connector, edid);
 	if (edid) {
 		num = drm_add_edid_modes(connector, edid);
 		kfree(edid);
 	}

 	ret = drm_display_info_set_bus_formats(&connector->display_info,
 					       &bus_format, 1);
 	if (ret)
 		return ret;

 	/*
 	 * Sometimes the I2C bus can stall after failure to use the
 	 * EDID channel. Retry a few times to see if things clear
 	 * up, else continue anyway.
 	 */
 	retries = 5;
 	do {
 		ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA,
 				  &status);
 		retries--;
 	} while (ret && retries);
 	if (ret)
 		dev_err(dev, "failed to read status (%d)\n", ret);

 	ret = regmap_update_bits(regmap, SII902X_SYS_CTRL_DATA,
 				 SII902X_SYS_CTRL_DDC_BUS_REQ |
 				 SII902X_SYS_CTRL_DDC_BUS_GRTD, 0);
 	if (ret)
 		return ret;

 	timeout = jiffies +
 		  msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
 	do {
 		ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA, &status);
 		if (ret)
 			return ret;
 	} while (status & (SII902X_SYS_CTRL_DDC_BUS_REQ |
 			   SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
 		 time_before(jiffies, timeout));

 	if (status & (SII902X_SYS_CTRL_DDC_BUS_REQ |
 		      SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
 		dev_err(dev, "failed to release the i2c bus\n");
 		return -ETIMEDOUT;
 	}

 	return num;
 }

 static enum drm_mode_status sii902x_mode_valid(struct drm_connector *connector,
 					       struct drm_display_mode *mode)
 {
 	/* TODO: check mode */

 	return MODE_OK;
 }

 static const struct drm_connector_helper_funcs sii902x_connector_helper_funcs = {
 	.get_modes = sii902x_get_modes,
 	.mode_valid = sii902x_mode_valid,
 };

 static void sii902x_bridge_disable(struct drm_bridge *bridge)
 {
 	struct sii902x *sii902x = bridge_to_sii902x(bridge);

 	regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
 			   SII902X_SYS_CTRL_PWR_DWN,
 			   SII902X_SYS_CTRL_PWR_DWN);
 }

 static void sii902x_bridge_enable(struct drm_bridge *bridge)
 {
 	struct sii902x *sii902x = bridge_to_sii902x(bridge);

 	regmap_update_bits(sii902x->regmap, SII902X_PWR_STATE_CTRL,
 			   SII902X_AVI_POWER_STATE_MSK,
 			   SII902X_AVI_POWER_STATE_D(0));
 	regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
 			   SII902X_SYS_CTRL_PWR_DWN, 0);
 }

 static void sii902x_bridge_mode_set(struct drm_bridge *bridge,
 				    struct drm_display_mode *mode,
 				    struct drm_display_mode *adj)
 {
 	struct sii902x *sii902x = bridge_to_sii902x(bridge);
 	struct regmap *regmap = sii902x->regmap;
 	u8 buf[HDMI_INFOFRAME_SIZE(AVI)];
 	struct hdmi_avi_infoframe frame;
 	int ret;

 	buf[0] = adj->clock;
 	buf[1] = adj->clock >> 8;
 	buf[2] = adj->vrefresh;
 	buf[3] = 0x00;
 	buf[4] = adj->hdisplay;
 	buf[5] = adj->hdisplay >> 8;
 	buf[6] = adj->vdisplay;
 	buf[7] = adj->vdisplay >> 8;
 	buf[8] = SII902X_TPI_CLK_RATIO_1X | SII902X_TPI_AVI_PIXEL_REP_NONE |
 		 SII902X_TPI_AVI_PIXEL_REP_BUS_24BIT;
 	buf[9] = SII902X_TPI_AVI_INPUT_RANGE_AUTO |
 		 SII902X_TPI_AVI_INPUT_COLORSPACE_RGB;

 	ret = regmap_bulk_write(regmap, SII902X_TPI_VIDEO_DATA, buf, 10);
 	if (ret)
 		return;

 	ret = drm_hdmi_avi_infoframe_from_display_mode(&frame, adj, false);
 	if (ret < 0) {
 		DRM_ERROR("couldn't fill AVI infoframe\n");
 		return;
 	}

 	ret = hdmi_avi_infoframe_pack(&frame, buf, sizeof(buf));
 	if (ret < 0) {
 		DRM_ERROR("failed to pack AVI infoframe: %d\n", ret);
 		return;
 	}

 	/* Do not send the infoframe header, but keep the CRC field. */
 	regmap_bulk_write(regmap, SII902X_TPI_AVI_INFOFRAME,
 			  buf + HDMI_INFOFRAME_HEADER_SIZE - 1,
 			  HDMI_AVI_INFOFRAME_SIZE + 1);
 }

 static int sii902x_bridge_attach(struct drm_bridge *bridge)
 {
 	struct sii902x *sii902x = bridge_to_sii902x(bridge);
 	struct drm_device *drm = bridge->dev;
 	int ret;

 	drm_connector_helper_add(&sii902x->connector,
 				 &sii902x_connector_helper_funcs);

 	if (!drm_core_check_feature(drm, DRIVER_ATOMIC)) {
 		dev_err(&sii902x->i2c->dev,
 			"sii902x driver is only compatible with DRM devices supporting atomic updates\n");
 		return -ENOTSUPP;
 	}

 	ret = drm_connector_init(drm, &sii902x->connector,
 				 &sii902x_connector_funcs,
 				 DRM_MODE_CONNECTOR_HDMIA);
 	if (ret)
 		return ret;

 	if (sii902x->i2c->irq > 0)
 		sii902x->connector.polled = DRM_CONNECTOR_POLL_HPD;
 	else
 		sii902x->connector.polled = DRM_CONNECTOR_POLL_CONNECT;

 	drm_mode_connector_attach_encoder(&sii902x->connector, bridge->encoder);

 	return 0;
 }

 static const struct drm_bridge_funcs sii902x_bridge_funcs = {
 	.attach = sii902x_bridge_attach,
 	.mode_set = sii902x_bridge_mode_set,
 	.disable = sii902x_bridge_disable,
 	.enable = sii902x_bridge_enable,
 };

 static const struct regmap_range sii902x_volatile_ranges[] = {
 	{ .range_min = 0, .range_max = 0xff },
 };

 static const struct regmap_access_table sii902x_volatile_table = {
 	.yes_ranges = sii902x_volatile_ranges,
 	.n_yes_ranges = ARRAY_SIZE(sii902x_volatile_ranges),
 };

 static const struct regmap_config sii902x_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.volatile_table = &sii902x_volatile_table,
 	.cache_type = REGCACHE_NONE,
 };

 static irqreturn_t sii902x_interrupt(int irq, void *data)
 {
 	struct sii902x *sii902x = data;
 	unsigned int status = 0;

 	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);
 	regmap_write(sii902x->regmap, SII902X_INT_STATUS, status);

 	if ((status & SII902X_HOTPLUG_EVENT) && sii902x->bridge.dev)
 		drm_helper_hpd_irq_event(sii902x->bridge.dev);

 	return IRQ_HANDLED;
 }

 static int sii902x_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct device *dev = &client->dev;
 	unsigned int status = 0;
 	struct sii902x *sii902x;
 	u8 chipid[4];
 	int ret;

 	sii902x = devm_kzalloc(dev, sizeof(*sii902x), GFP_KERNEL);
 	if (!sii902x)
 		return -ENOMEM;

 	sii902x->i2c = client;
 	sii902x->regmap = devm_regmap_init_i2c(client, &sii902x_regmap_config);
 	if (IS_ERR(sii902x->regmap))
 		return PTR_ERR(sii902x->regmap);

 	sii902x->reset_gpio = devm_gpiod_get_optional(dev, "reset",
 						      GPIOD_OUT_LOW);
 	if (IS_ERR(sii902x->reset_gpio)) {
 		dev_err(dev, "Failed to retrieve/request reset gpio: %ld\n",
 			PTR_ERR(sii902x->reset_gpio));
 		return PTR_ERR(sii902x->reset_gpio);
 	}

 	sii902x_reset(sii902x);

 	ret = regmap_write(sii902x->regmap, SII902X_REG_TPI_RQB, 0x0);
 	if (ret)
 		return ret;

 	ret = regmap_bulk_read(sii902x->regmap, SII902X_REG_CHIPID(0),
 			       &chipid, 4);
 	if (ret) {
 		dev_err(dev, "regmap_read failed %d\n", ret);
 		return ret;
 	}

 	if (chipid[0] != 0xb0) {
 		dev_err(dev, "Invalid chipid: %02x (expecting 0xb0)\n",
 			chipid[0]);
 		return -EINVAL;
 	}

 	/* Clear all pending interrupts */
 	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);
 	regmap_write(sii902x->regmap, SII902X_INT_STATUS, status);

 	if (client->irq > 0) {
 		regmap_write(sii902x->regmap, SII902X_INT_ENABLE,
 			     SII902X_HOTPLUG_EVENT);

 		ret = devm_request_threaded_irq(dev, client->irq, NULL,
 						sii902x_interrupt,
 						IRQF_ONESHOT, dev_name(dev),
 						sii902x);
 		if (ret)
 			return ret;
 	}

 	sii902x->bridge.funcs = &sii902x_bridge_funcs;
 	sii902x->bridge.of_node = dev->of_node;
 	drm_bridge_add(&sii902x->bridge);

 	i2c_set_clientdata(client, sii902x);

 	return 0;
 }

 static int sii902x_remove(struct i2c_client *client)

 {
 	struct sii902x *sii902x = i2c_get_clientdata(client);

 	drm_bridge_remove(&sii902x->bridge);

 	return 0;
 }

 static const struct of_device_id sii902x_dt_ids[] = {
 	{ .compatible = "sil,sii9022", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sii902x_dt_ids);

 static const struct i2c_device_id sii902x_i2c_ids[] = {
 	{ "sii9022", 0 },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, sii902x_i2c_ids);

 static struct i2c_driver sii902x_driver = {
 	.probe = sii902x_probe,
 	.remove = sii902x_remove,
 	.driver = {
 		.name = "sii902x",
 		.of_match_table = sii902x_dt_ids,
 	},
 	.id_table = sii902x_i2c_ids,
 };
 module_i2c_driver(sii902x_driver);

 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 MODULE_DESCRIPTION("SII902x RGB -> HDMI bridges");
 MODULE_LICENSE("GPL");
	/*
	* Copyright (C) 2016 Atmel
	* Bo Shen <voice.shen@atmel.com>
	*
	* Authors: Bo Shen <voice.shen@atmel.com>
	* Boris Brezillon <boris.brezillon@free-electrons.com>
	* Wu, Songjun <Songjun.Wu@atmel.com>
	*
	*
	* Copyright (C) 2010-2011 Freescale Semiconductor, Inc. All Rights Reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/gpio/consumer.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/regmap.h>

	#include <drm/drmP.h>
	#include <drm/drm_atomic_helper.h>
	#include <drm/drm_crtc_helper.h>
	#include <drm/drm_edid.h>

	#define SII902X_TPI_VIDEO_DATA 0x0

	#define SII902X_TPI_PIXEL_REPETITION 0x8
	#define SII902X_TPI_AVI_PIXEL_REP_BUS_24BIT BIT(5)
	#define SII902X_TPI_AVI_PIXEL_REP_RISING_EDGE BIT(4)
	#define SII902X_TPI_AVI_PIXEL_REP_4X 3
	#define SII902X_TPI_AVI_PIXEL_REP_2X 1
	#define SII902X_TPI_AVI_PIXEL_REP_NONE 0
	#define SII902X_TPI_CLK_RATIO_HALF (0 << 6)
	#define SII902X_TPI_CLK_RATIO_1X (1 << 6)
	#define SII902X_TPI_CLK_RATIO_2X (2 << 6)
	#define SII902X_TPI_CLK_RATIO_4X (3 << 6)

	#define SII902X_TPI_AVI_IN_FORMAT 0x9
	#define SII902X_TPI_AVI_INPUT_BITMODE_12BIT BIT(7)
	#define SII902X_TPI_AVI_INPUT_DITHER BIT(6)
	#define SII902X_TPI_AVI_INPUT_RANGE_LIMITED (2 << 2)
	#define SII902X_TPI_AVI_INPUT_RANGE_FULL (1 << 2)
	#define SII902X_TPI_AVI_INPUT_RANGE_AUTO (0 << 2)
	#define SII902X_TPI_AVI_INPUT_COLORSPACE_BLACK (3 << 0)
	#define SII902X_TPI_AVI_INPUT_COLORSPACE_YUV422 (2 << 0)
	#define SII902X_TPI_AVI_INPUT_COLORSPACE_YUV444 (1 << 0)
	#define SII902X_TPI_AVI_INPUT_COLORSPACE_RGB (0 << 0)

	#define SII902X_TPI_AVI_INFOFRAME 0x0c

	#define SII902X_SYS_CTRL_DATA 0x1a
	#define SII902X_SYS_CTRL_PWR_DWN BIT(4)
	#define SII902X_SYS_CTRL_AV_MUTE BIT(3)
	#define SII902X_SYS_CTRL_DDC_BUS_REQ BIT(2)
	#define SII902X_SYS_CTRL_DDC_BUS_GRTD BIT(1)
	#define SII902X_SYS_CTRL_OUTPUT_MODE BIT(0)
	#define SII902X_SYS_CTRL_OUTPUT_HDMI 1
	#define SII902X_SYS_CTRL_OUTPUT_DVI 0

	#define SII902X_REG_CHIPID(n) (0x1b + (n))

	#define SII902X_PWR_STATE_CTRL 0x1e
	#define SII902X_AVI_POWER_STATE_MSK GENMASK(1, 0)
	#define SII902X_AVI_POWER_STATE_D(l) ((l) & SII902X_AVI_POWER_STATE_MSK)

	#define SII902X_INT_ENABLE 0x3c
	#define SII902X_INT_STATUS 0x3d
	#define SII902X_HOTPLUG_EVENT BIT(0)
	#define SII902X_PLUGGED_STATUS BIT(2)

	#define SII902X_REG_TPI_RQB 0xc7

	#define SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS 500

	struct sii902x {
	struct i2c_client *i2c;
	struct regmap *regmap;
	struct drm_bridge bridge;
	struct drm_connector connector;
	struct gpio_desc *reset_gpio;
	};

	static inline struct sii902x bridge_to_sii902x(struct drm_bridge bridge)
	{
	return container_of(bridge, struct sii902x, bridge);
	}

	static inline struct sii902x connector_to_sii902x(struct drm_connector con)
	{
	return container_of(con, struct sii902x, connector);
	}

	static void sii902x_reset(struct sii902x *sii902x)
	{
	if (!sii902x->reset_gpio)
	return;

	gpiod_set_value(sii902x->reset_gpio, 1);

	/* The datasheet says treset-min = 100us. Make it 150us to be sure. */
	usleep_range(150, 200);

	gpiod_set_value(sii902x->reset_gpio, 0);
	}

	static enum drm_connector_status
	sii902x_connector_detect(struct drm_connector *connector, bool force)
	{
	struct sii902x *sii902x = connector_to_sii902x(connector);
	unsigned int status;

	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);

	return (status & SII902X_PLUGGED_STATUS) ?
	connector_status_connected : connector_status_disconnected;
	}

	static const struct drm_connector_funcs sii902x_connector_funcs = {
	.detect = sii902x_connector_detect,
	.fill_modes = drm_helper_probe_single_connector_modes,
	.destroy = drm_connector_cleanup,
	.reset = drm_atomic_helper_connector_reset,
	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
	};

	static int sii902x_get_modes(struct drm_connector *connector)
	{
	struct sii902x *sii902x = connector_to_sii902x(connector);
	struct regmap *regmap = sii902x->regmap;
	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
	struct device *dev = &sii902x->i2c->dev;
	unsigned long timeout;
	unsigned int retries;
	unsigned int status;
	struct edid *edid;
	int num = 0;
	int ret;

	ret = regmap_update_bits(regmap, SII902X_SYS_CTRL_DATA,
	SII902X_SYS_CTRL_DDC_BUS_REQ,
	SII902X_SYS_CTRL_DDC_BUS_REQ);
	if (ret)
	return ret;

	timeout = jiffies +
	msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
	do {
	ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA, &status);
	if (ret)
	return ret;
	} while (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
	time_before(jiffies, timeout));

	if (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
	dev_err(dev, "failed to acquire the i2c bus\n");
	return -ETIMEDOUT;
	}

	ret = regmap_write(regmap, SII902X_SYS_CTRL_DATA, status);
	if (ret)
	return ret;

	edid = drm_get_edid(connector, sii902x->i2c->adapter);
	drm_mode_connector_update_edid_property(connector, edid);
	if (edid) {
	num = drm_add_edid_modes(connector, edid);
	kfree(edid);
	}

	ret = drm_display_info_set_bus_formats(&connector->display_info,
	&bus_format, 1);
	if (ret)
	return ret;

	/*
	* Sometimes the I2C bus can stall after failure to use the
	* EDID channel. Retry a few times to see if things clear
	* up, else continue anyway.
	*/
	retries = 5;
	do {
	ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA,
	&status);
	retries--;
	} while (ret && retries);
	if (ret)
	dev_err(dev, "failed to read status (%d)\n", ret);

	ret = regmap_update_bits(regmap, SII902X_SYS_CTRL_DATA,
	SII902X_SYS_CTRL_DDC_BUS_REQ \|
	SII902X_SYS_CTRL_DDC_BUS_GRTD, 0);
	if (ret)
	return ret;

	timeout = jiffies +
	msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
	do {
	ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA, &status);
	if (ret)
	return ret;
	} while (status & (SII902X_SYS_CTRL_DDC_BUS_REQ \|
	SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
	time_before(jiffies, timeout));

	if (status & (SII902X_SYS_CTRL_DDC_BUS_REQ \|
	SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
	dev_err(dev, "failed to release the i2c bus\n");
	return -ETIMEDOUT;
	}

	return num;
	}

	static enum drm_mode_status sii902x_mode_valid(struct drm_connector *connector,
	struct drm_display_mode *mode)
	{
	/* TODO: check mode */

	return MODE_OK;
	}

	static const struct drm_connector_helper_funcs sii902x_connector_helper_funcs = {
	.get_modes = sii902x_get_modes,
	.mode_valid = sii902x_mode_valid,
	};

	static void sii902x_bridge_disable(struct drm_bridge *bridge)
	{
	struct sii902x *sii902x = bridge_to_sii902x(bridge);

	regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
	SII902X_SYS_CTRL_PWR_DWN,
	SII902X_SYS_CTRL_PWR_DWN);
	}

	static void sii902x_bridge_enable(struct drm_bridge *bridge)
	{
	struct sii902x *sii902x = bridge_to_sii902x(bridge);

	regmap_update_bits(sii902x->regmap, SII902X_PWR_STATE_CTRL,
	SII902X_AVI_POWER_STATE_MSK,
	SII902X_AVI_POWER_STATE_D(0));
	regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
	SII902X_SYS_CTRL_PWR_DWN, 0);
	}

	static void sii902x_bridge_mode_set(struct drm_bridge *bridge,
	struct drm_display_mode *mode,
	struct drm_display_mode *adj)
	{
	struct sii902x *sii902x = bridge_to_sii902x(bridge);
	struct regmap *regmap = sii902x->regmap;
	u8 buf[HDMI_INFOFRAME_SIZE(AVI)];
	struct hdmi_avi_infoframe frame;
	int ret;

	buf[0] = adj->clock;
	buf[1] = adj->clock >> 8;
	buf[2] = adj->vrefresh;
	buf[3] = 0x00;
	buf[4] = adj->hdisplay;
	buf[5] = adj->hdisplay >> 8;
	buf[6] = adj->vdisplay;
	buf[7] = adj->vdisplay >> 8;
	buf[8] = SII902X_TPI_CLK_RATIO_1X \| SII902X_TPI_AVI_PIXEL_REP_NONE \|
	SII902X_TPI_AVI_PIXEL_REP_BUS_24BIT;
	buf[9] = SII902X_TPI_AVI_INPUT_RANGE_AUTO \|
	SII902X_TPI_AVI_INPUT_COLORSPACE_RGB;

	ret = regmap_bulk_write(regmap, SII902X_TPI_VIDEO_DATA, buf, 10);
	if (ret)
	return;

	ret = drm_hdmi_avi_infoframe_from_display_mode(&frame, adj, false);
	if (ret < 0) {
	DRM_ERROR("couldn't fill AVI infoframe\n");
	return;
	}

	ret = hdmi_avi_infoframe_pack(&frame, buf, sizeof(buf));
	if (ret < 0) {
	DRM_ERROR("failed to pack AVI infoframe: %d\n", ret);
	return;
	}

	/* Do not send the infoframe header, but keep the CRC field. */
	regmap_bulk_write(regmap, SII902X_TPI_AVI_INFOFRAME,
	buf + HDMI_INFOFRAME_HEADER_SIZE - 1,
	HDMI_AVI_INFOFRAME_SIZE + 1);
	}

	static int sii902x_bridge_attach(struct drm_bridge *bridge)
	{
	struct sii902x *sii902x = bridge_to_sii902x(bridge);
	struct drm_device *drm = bridge->dev;
	int ret;

	drm_connector_helper_add(&sii902x->connector,
	&sii902x_connector_helper_funcs);

	if (!drm_core_check_feature(drm, DRIVER_ATOMIC)) {
	dev_err(&sii902x->i2c->dev,
	"sii902x driver is only compatible with DRM devices supporting atomic updates\n");
	return -ENOTSUPP;
	}

	ret = drm_connector_init(drm, &sii902x->connector,
	&sii902x_connector_funcs,
	DRM_MODE_CONNECTOR_HDMIA);
	if (ret)
	return ret;

	if (sii902x->i2c->irq > 0)
	sii902x->connector.polled = DRM_CONNECTOR_POLL_HPD;
	else
	sii902x->connector.polled = DRM_CONNECTOR_POLL_CONNECT;

	drm_mode_connector_attach_encoder(&sii902x->connector, bridge->encoder);

	return 0;
	}

	static const struct drm_bridge_funcs sii902x_bridge_funcs = {
	.attach = sii902x_bridge_attach,
	.mode_set = sii902x_bridge_mode_set,
	.disable = sii902x_bridge_disable,
	.enable = sii902x_bridge_enable,
	};

	static const struct regmap_range sii902x_volatile_ranges[] = {
	{ .range_min = 0, .range_max = 0xff },
	};

	static const struct regmap_access_table sii902x_volatile_table = {
	.yes_ranges = sii902x_volatile_ranges,
	.n_yes_ranges = ARRAY_SIZE(sii902x_volatile_ranges),
	};

	static const struct regmap_config sii902x_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.volatile_table = &sii902x_volatile_table,
	.cache_type = REGCACHE_NONE,
	};

	static irqreturn_t sii902x_interrupt(int irq, void *data)
	{
	struct sii902x *sii902x = data;
	unsigned int status = 0;

	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);
	regmap_write(sii902x->regmap, SII902X_INT_STATUS, status);

	if ((status & SII902X_HOTPLUG_EVENT) && sii902x->bridge.dev)
	drm_helper_hpd_irq_event(sii902x->bridge.dev);

	return IRQ_HANDLED;
	}

	static int sii902x_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct device *dev = &client->dev;
	unsigned int status = 0;
	struct sii902x *sii902x;
	u8 chipid[4];
	int ret;

	sii902x = devm_kzalloc(dev, sizeof(*sii902x), GFP_KERNEL);
	if (!sii902x)
	return -ENOMEM;

	sii902x->i2c = client;
	sii902x->regmap = devm_regmap_init_i2c(client, &sii902x_regmap_config);
	if (IS_ERR(sii902x->regmap))
	return PTR_ERR(sii902x->regmap);

	sii902x->reset_gpio = devm_gpiod_get_optional(dev, "reset",
	GPIOD_OUT_LOW);
	if (IS_ERR(sii902x->reset_gpio)) {
	dev_err(dev, "Failed to retrieve/request reset gpio: %ld\n",
	PTR_ERR(sii902x->reset_gpio));
	return PTR_ERR(sii902x->reset_gpio);
	}

	sii902x_reset(sii902x);

	ret = regmap_write(sii902x->regmap, SII902X_REG_TPI_RQB, 0x0);
	if (ret)
	return ret;

	ret = regmap_bulk_read(sii902x->regmap, SII902X_REG_CHIPID(0),
	&chipid, 4);
	if (ret) {
	dev_err(dev, "regmap_read failed %d\n", ret);
	return ret;
	}

	if (chipid[0] != 0xb0) {
	dev_err(dev, "Invalid chipid: %02x (expecting 0xb0)\n",
	chipid[0]);
	return -EINVAL;
	}

	/* Clear all pending interrupts */
	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);
	regmap_write(sii902x->regmap, SII902X_INT_STATUS, status);

	if (client->irq > 0) {
	regmap_write(sii902x->regmap, SII902X_INT_ENABLE,
	SII902X_HOTPLUG_EVENT);

	ret = devm_request_threaded_irq(dev, client->irq, NULL,
	sii902x_interrupt,
	IRQF_ONESHOT, dev_name(dev),
	sii902x);
	if (ret)
	return ret;
	}

	sii902x->bridge.funcs = &sii902x_bridge_funcs;
	sii902x->bridge.of_node = dev->of_node;
	drm_bridge_add(&sii902x->bridge);

	i2c_set_clientdata(client, sii902x);

	return 0;
	}

	static int sii902x_remove(struct i2c_client *client)

	{
	struct sii902x *sii902x = i2c_get_clientdata(client);

	drm_bridge_remove(&sii902x->bridge);

	return 0;
	}

	static const struct of_device_id sii902x_dt_ids[] = {
	{ .compatible = "sil,sii9022", },
	{ }
	};
	MODULE_DEVICE_TABLE(of, sii902x_dt_ids);

	static const struct i2c_device_id sii902x_i2c_ids[] = {
	{ "sii9022", 0 },
	{ },
	};
	MODULE_DEVICE_TABLE(i2c, sii902x_i2c_ids);

	static struct i2c_driver sii902x_driver = {
	.probe = sii902x_probe,
	.remove = sii902x_remove,
	.driver = {
	.name = "sii902x",
	.of_match_table = sii902x_dt_ids,
	},
	.id_table = sii902x_i2c_ids,
	};
	module_i2c_driver(sii902x_driver);

	MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
	MODULE_DESCRIPTION("SII902x RGB -> HDMI bridges");
	MODULE_LICENSE("GPL");