drivers/gpu/drm/bridge/ps8622.c - kernel/msm-4.19 - Gitiles

 /*
  * Parade PS8622 eDP/LVDS bridge driver
  *
  * Copyright (C) 2014 Google, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * 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/backlight.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/fb.h>
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_graph.h>
 #include <linux/pm.h>
 #include <linux/regulator/consumer.h>

 #include <drm/drm_panel.h>

 #include "drmP.h"
 #include "drm_crtc.h"
 #include "drm_crtc_helper.h"
 #include "drm_atomic_helper.h"

 /* Brightness scale on the Parade chip */
 #define PS8622_MAX_BRIGHTNESS 0xff

 /* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
 #define PS8622_POWER_RISE_T1_MIN_US 10
 #define PS8622_POWER_RISE_T1_MAX_US 10000
 #define PS8622_RST_HIGH_T2_MIN_US 3000
 #define PS8622_RST_HIGH_T2_MAX_US 30000
 #define PS8622_PWMO_END_T12_MS 200
 #define PS8622_POWER_FALL_T16_MAX_US 10000
 #define PS8622_POWER_OFF_T17_MS 500

 #if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
 	(PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
 #error "T2.min + T1.max must be less than T2.max + T1.min"
 #endif

 struct ps8622_bridge {
 	struct drm_connector connector;
 	struct i2c_client *client;
 	struct drm_bridge bridge;
 	struct drm_panel *panel;
 	struct regulator *v12;
 	struct backlight_device *bl;

 	struct gpio_desc *gpio_slp;
 	struct gpio_desc *gpio_rst;

 	u32 max_lane_count;
 	u32 lane_count;

 	bool enabled;
 };

 static inline struct ps8622_bridge *
 		bridge_to_ps8622(struct drm_bridge *bridge)
 {
 	return container_of(bridge, struct ps8622_bridge, bridge);
 }

 static inline struct ps8622_bridge *
 		connector_to_ps8622(struct drm_connector *connector)
 {
 	return container_of(connector, struct ps8622_bridge, connector);
 }

 static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
 {
 	int ret;
 	struct i2c_adapter *adap = client->adapter;
 	struct i2c_msg msg;
 	u8 data[] = {reg, val};

 	msg.addr = client->addr + page;
 	msg.flags = 0;
 	msg.len = sizeof(data);
 	msg.buf = data;

 	ret = i2c_transfer(adap, &msg, 1);
 	if (ret != 1)
 		pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
 			client->addr + page, reg, val, ret);
 	return !(ret == 1);
 }

 static int ps8622_send_config(struct ps8622_bridge *ps8622)
 {
 	struct i2c_client *cl = ps8622->client;
 	int err = 0;

 	/* HPD low */
 	err = ps8622_set(cl, 0x02, 0xa1, 0x01);
 	if (err)
 		goto error;

 	/* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
 	err = ps8622_set(cl, 0x04, 0x14, 0x01);
 	if (err)
 		goto error;

 	/* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
 	err = ps8622_set(cl, 0x04, 0xe3, 0x20);
 	if (err)
 		goto error;

 	/* [7] RCO SS enable */
 	err = ps8622_set(cl, 0x04, 0xe2, 0x80);
 	if (err)
 		goto error;

 	/* RPHY Setting
 	 * [3:2] CDR tune wait cycle before measure for fine tune
 	 * b00: 1us b01: 0.5us b10:2us, b11: 4us
 	 */
 	err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
 	if (err)
 		goto error;

 	/* [3] RFD always on */
 	err = ps8622_set(cl, 0x04, 0x89, 0x08);
 	if (err)
 		goto error;

 	/* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
 	err = ps8622_set(cl, 0x04, 0x71, 0x2d);
 	if (err)
 		goto error;

 	/* 2.7G CDR settings: NOF=40LSB for HBR CDR  setting */
 	err = ps8622_set(cl, 0x04, 0x7d, 0x07);
 	if (err)
 		goto error;

 	/* [1:0] Fmin=+4bands */
 	err = ps8622_set(cl, 0x04, 0x7b, 0x00);
 	if (err)
 		goto error;

 	/* [7:5] DCO_FTRNG=+-40% */
 	err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
 	if (err)
 		goto error;

 	/* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
 	err = ps8622_set(cl, 0x04, 0xc0, 0x12);
 	if (err)
 		goto error;

 	/* Gitune=-37% */
 	err = ps8622_set(cl, 0x04, 0xc1, 0x92);
 	if (err)
 		goto error;

 	/* Fbstep=100% */
 	err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
 	if (err)
 		goto error;

 	/* [7] LOS signal disable */
 	err = ps8622_set(cl, 0x04, 0x32, 0x80);
 	if (err)
 		goto error;

 	/* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
 	err = ps8622_set(cl, 0x04, 0x00, 0xb0);
 	if (err)
 		goto error;

 	/* [7:6] Right-bar GPIO output strength is 8mA */
 	err = ps8622_set(cl, 0x04, 0x15, 0x40);
 	if (err)
 		goto error;

 	/* EQ Training State Machine Setting, RCO calibration start */
 	err = ps8622_set(cl, 0x04, 0x54, 0x10);
 	if (err)
 		goto error;

 	/* Logic, needs more than 10 I2C command */
 	/* [4:0] MAX_LANE_COUNT set to max supported lanes */
 	err = ps8622_set(cl, 0x01, 0x02, 0x80 | ps8622->max_lane_count);
 	if (err)
 		goto error;

 	/* [4:0] LANE_COUNT_SET set to chosen lane count */
 	err = ps8622_set(cl, 0x01, 0x21, 0x80 | ps8622->lane_count);
 	if (err)
 		goto error;

 	err = ps8622_set(cl, 0x00, 0x52, 0x20);
 	if (err)
 		goto error;

 	/* HPD CP toggle enable */
 	err = ps8622_set(cl, 0x00, 0xf1, 0x03);
 	if (err)
 		goto error;

 	err = ps8622_set(cl, 0x00, 0x62, 0x41);
 	if (err)
 		goto error;

 	/* Counter number, add 1ms counter delay */
 	err = ps8622_set(cl, 0x00, 0xf6, 0x01);
 	if (err)
 		goto error;

 	/* [6]PWM function control by DPCD0040f[7], default is PWM block */
 	err = ps8622_set(cl, 0x00, 0x77, 0x06);
 	if (err)
 		goto error;

 	/* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
 	err = ps8622_set(cl, 0x00, 0x4c, 0x04);
 	if (err)
 		goto error;

 	/* DPCD00400='h00, Parade OUI ='h001cf8 */
 	err = ps8622_set(cl, 0x01, 0xc0, 0x00);
 	if (err)
 		goto error;

 	/* DPCD00401='h1c */
 	err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
 	if (err)
 		goto error;

 	/* DPCD00402='hf8 */
 	err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
 	if (err)
 		goto error;

 	/* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
 	err = ps8622_set(cl, 0x01, 0xc3, 0x44);
 	if (err)
 		goto error;

 	/* DPCD404 */
 	err = ps8622_set(cl, 0x01, 0xc4, 0x32);
 	if (err)
 		goto error;

 	/* DPCD405 */
 	err = ps8622_set(cl, 0x01, 0xc5, 0x53);
 	if (err)
 		goto error;

 	/* DPCD406 */
 	err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
 	if (err)
 		goto error;

 	/* DPCD407 */
 	err = ps8622_set(cl, 0x01, 0xc7, 0x56);
 	if (err)
 		goto error;

 	/* DPCD408 */
 	err = ps8622_set(cl, 0x01, 0xc8, 0x35);
 	if (err)
 		goto error;

 	/* DPCD40A, Initial Code major revision '01' */
 	err = ps8622_set(cl, 0x01, 0xca, 0x01);
 	if (err)
 		goto error;

 	/* DPCD40B, Initial Code minor revision '05' */
 	err = ps8622_set(cl, 0x01, 0xcb, 0x05);
 	if (err)
 		goto error;


 	if (ps8622->bl) {
 		/* DPCD720, internal PWM */
 		err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
 		if (err)
 			goto error;

 		/* FFh for 100% brightness, 0h for 0% brightness */
 		err = ps8622_set(cl, 0x01, 0xa7,
 				ps8622->bl->props.brightness);
 		if (err)
 			goto error;
 	} else {
 		/* DPCD720, external PWM */
 		err = ps8622_set(cl, 0x01, 0xa5, 0x80);
 		if (err)
 			goto error;
 	}

 	/* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
 	err = ps8622_set(cl, 0x01, 0xcc, 0x13);
 	if (err)
 		goto error;

 	/* Enable SSC set by register */
 	err = ps8622_set(cl, 0x02, 0xb1, 0x20);
 	if (err)
 		goto error;

 	/* Set SSC enabled and +/-1% central spreading */
 	err = ps8622_set(cl, 0x04, 0x10, 0x16);
 	if (err)
 		goto error;

 	/* Logic end */
 	/* MPU Clock source: LC => RCO */
 	err = ps8622_set(cl, 0x04, 0x59, 0x60);
 	if (err)
 		goto error;

 	/* LC -> RCO */
 	err = ps8622_set(cl, 0x04, 0x54, 0x14);
 	if (err)
 		goto error;

 	/* HPD high */
 	err = ps8622_set(cl, 0x02, 0xa1, 0x91);

 error:
 	return err ? -EIO : 0;
 }

 static int ps8622_backlight_update(struct backlight_device *bl)
 {
 	struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
 	int ret, brightness = bl->props.brightness;

 	if (bl->props.power != FB_BLANK_UNBLANK ||
 	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
 		brightness = 0;

 	if (!ps8622->enabled)
 		return -EINVAL;

 	ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);

 	return ret;
 }

 static const struct backlight_ops ps8622_backlight_ops = {
 	.update_status	= ps8622_backlight_update,
 };

 static void ps8622_pre_enable(struct drm_bridge *bridge)
 {
 	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
 	int ret;

 	if (ps8622->enabled)
 		return;

 	gpiod_set_value(ps8622->gpio_rst, 0);

 	if (ps8622->v12) {
 		ret = regulator_enable(ps8622->v12);
 		if (ret)
 			DRM_ERROR("fails to enable ps8622->v12");
 	}

 	if (drm_panel_prepare(ps8622->panel)) {
 		DRM_ERROR("failed to prepare panel\n");
 		return;
 	}

 	gpiod_set_value(ps8622->gpio_slp, 1);

 	/*
 	 * T1 is the range of time that it takes for the power to rise after we
 	 * enable the lcd/ps8622 fet. T2 is the range of time in which the
 	 * data sheet specifies we should deassert the reset pin.
 	 *
 	 * If it takes T1.max for the power to rise, we need to wait atleast
 	 * T2.min before deasserting the reset pin. If it takes T1.min for the
 	 * power to rise, we need to wait at most T2.max before deasserting the
 	 * reset pin.
 	 */
 	usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
 		     PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);

 	gpiod_set_value(ps8622->gpio_rst, 1);

 	/* wait 20ms after RST high */
 	usleep_range(20000, 30000);

 	ret = ps8622_send_config(ps8622);
 	if (ret) {
 		DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
 		return;
 	}

 	ps8622->enabled = true;
 }

 static void ps8622_enable(struct drm_bridge *bridge)
 {
 	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);

 	if (drm_panel_enable(ps8622->panel)) {
 		DRM_ERROR("failed to enable panel\n");
 		return;
 	}
 }

 static void ps8622_disable(struct drm_bridge *bridge)
 {
 	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);

 	if (drm_panel_disable(ps8622->panel)) {
 		DRM_ERROR("failed to disable panel\n");
 		return;
 	}
 	msleep(PS8622_PWMO_END_T12_MS);
 }

 static void ps8622_post_disable(struct drm_bridge *bridge)
 {
 	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);

 	if (!ps8622->enabled)
 		return;

 	ps8622->enabled = false;

 	/*
 	 * This doesn't matter if the regulators are turned off, but something
 	 * else might keep them on. In that case, we want to assert the slp gpio
 	 * to lower power.
 	 */
 	gpiod_set_value(ps8622->gpio_slp, 0);

 	if (drm_panel_unprepare(ps8622->panel)) {
 		DRM_ERROR("failed to unprepare panel\n");
 		return;
 	}

 	if (ps8622->v12)
 		regulator_disable(ps8622->v12);

 	/*
 	 * Sleep for at least the amount of time that it takes the power rail to
 	 * fall to prevent asserting the rst gpio from doing anything.
 	 */
 	usleep_range(PS8622_POWER_FALL_T16_MAX_US,
 		     2 * PS8622_POWER_FALL_T16_MAX_US);
 	gpiod_set_value(ps8622->gpio_rst, 0);

 	msleep(PS8622_POWER_OFF_T17_MS);
 }

 static int ps8622_get_modes(struct drm_connector *connector)
 {
 	struct ps8622_bridge *ps8622;

 	ps8622 = connector_to_ps8622(connector);

 	return drm_panel_get_modes(ps8622->panel);
 }

 static struct drm_encoder *ps8622_best_encoder(struct drm_connector *connector)
 {
 	struct ps8622_bridge *ps8622;

 	ps8622 = connector_to_ps8622(connector);

 	return ps8622->bridge.encoder;
 }

 static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
 	.get_modes = ps8622_get_modes,
 	.best_encoder = ps8622_best_encoder,
 };

 static enum drm_connector_status ps8622_detect(struct drm_connector *connector,
 								bool force)
 {
 	return connector_status_connected;
 }

 static void ps8622_connector_destroy(struct drm_connector *connector)
 {
 	drm_connector_cleanup(connector);
 }

 static const struct drm_connector_funcs ps8622_connector_funcs = {
 	.dpms = drm_atomic_helper_connector_dpms,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.detect = ps8622_detect,
 	.destroy = ps8622_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 ps8622_attach(struct drm_bridge *bridge)
 {
 	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
 	int ret;

 	if (!bridge->encoder) {
 		DRM_ERROR("Parent encoder object not found");
 		return -ENODEV;
 	}

 	ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
 	ret = drm_connector_init(bridge->dev, &ps8622->connector,
 			&ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
 	if (ret) {
 		DRM_ERROR("Failed to initialize connector with drm\n");
 		return ret;
 	}
 	drm_connector_helper_add(&ps8622->connector,
 					&ps8622_connector_helper_funcs);
 	drm_connector_register(&ps8622->connector);
 	drm_mode_connector_attach_encoder(&ps8622->connector,
 							bridge->encoder);

 	if (ps8622->panel)
 		drm_panel_attach(ps8622->panel, &ps8622->connector);

 	drm_helper_hpd_irq_event(ps8622->connector.dev);

 	return ret;
 }

 static const struct drm_bridge_funcs ps8622_bridge_funcs = {
 	.pre_enable = ps8622_pre_enable,
 	.enable = ps8622_enable,
 	.disable = ps8622_disable,
 	.post_disable = ps8622_post_disable,
 	.attach = ps8622_attach,
 };

 static const struct of_device_id ps8622_devices[] = {
 	{.compatible = "parade,ps8622",},
 	{.compatible = "parade,ps8625",},
 	{}
 };
 MODULE_DEVICE_TABLE(of, ps8622_devices);

 static int ps8622_probe(struct i2c_client *client,
 					const struct i2c_device_id *id)
 {
 	struct device *dev = &client->dev;
 	struct device_node *endpoint, *panel_node;
 	struct ps8622_bridge *ps8622;
 	int ret;

 	ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
 	if (!ps8622)
 		return -ENOMEM;

 	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
 	if (endpoint) {
 		panel_node = of_graph_get_remote_port_parent(endpoint);
 		if (panel_node) {
 			ps8622->panel = of_drm_find_panel(panel_node);
 			of_node_put(panel_node);
 			if (!ps8622->panel)
 				return -EPROBE_DEFER;
 		}
 	}

 	ps8622->client = client;

 	ps8622->v12 = devm_regulator_get(dev, "vdd12");
 	if (IS_ERR(ps8622->v12)) {
 		dev_info(dev, "no 1.2v regulator found for PS8622\n");
 		ps8622->v12 = NULL;
 	}

 	ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
 	if (IS_ERR(ps8622->gpio_slp)) {
 		ret = PTR_ERR(ps8622->gpio_slp);
 		dev_err(dev, "cannot get gpio_slp %d\n", ret);
 		return ret;
 	}

 	/*
 	 * Assert the reset pin high to avoid the bridge being
 	 * initialized prematurely
 	 */
 	ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(ps8622->gpio_rst)) {
 		ret = PTR_ERR(ps8622->gpio_rst);
 		dev_err(dev, "cannot get gpio_rst %d\n", ret);
 		return ret;
 	}

 	ps8622->max_lane_count = id->driver_data;

 	if (of_property_read_u32(dev->of_node, "lane-count",
 						&ps8622->lane_count)) {
 		ps8622->lane_count = ps8622->max_lane_count;
 	} else if (ps8622->lane_count > ps8622->max_lane_count) {
 		dev_info(dev, "lane-count property is too high,"
 						"using max_lane_count\n");
 		ps8622->lane_count = ps8622->max_lane_count;
 	}

 	if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
 		ps8622->bl = backlight_device_register("ps8622-backlight",
 				dev, ps8622, &ps8622_backlight_ops,
 				NULL);
 		if (IS_ERR(ps8622->bl)) {
 			DRM_ERROR("failed to register backlight\n");
 			ret = PTR_ERR(ps8622->bl);
 			ps8622->bl = NULL;
 			return ret;
 		}
 		ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
 		ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
 	}

 	ps8622->bridge.funcs = &ps8622_bridge_funcs;
 	ps8622->bridge.of_node = dev->of_node;
 	ret = drm_bridge_add(&ps8622->bridge);
 	if (ret) {
 		DRM_ERROR("Failed to add bridge\n");
 		return ret;
 	}

 	i2c_set_clientdata(client, ps8622);

 	return 0;
 }

 static int ps8622_remove(struct i2c_client *client)
 {
 	struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);

 	if (ps8622->bl)
 		backlight_device_unregister(ps8622->bl);

 	drm_bridge_remove(&ps8622->bridge);

 	return 0;
 }

 static const struct i2c_device_id ps8622_i2c_table[] = {
 	/* Device type, max_lane_count */
 	{"ps8622", 1},
 	{"ps8625", 2},
 	{},
 };
 MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);

 static struct i2c_driver ps8622_driver = {
 	.id_table	= ps8622_i2c_table,
 	.probe		= ps8622_probe,
 	.remove		= ps8622_remove,
 	.driver		= {
 		.name	= "ps8622",
 		.owner	= THIS_MODULE,
 		.of_match_table = ps8622_devices,
 	},
 };
 module_i2c_driver(ps8622_driver);

 MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
 MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Parade PS8622 eDP/LVDS bridge driver
	*
	* Copyright (C) 2014 Google, Inc.
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* 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/backlight.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/fb.h>
	#include <linux/gpio.h>
	#include <linux/gpio/consumer.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/of_graph.h>
	#include <linux/pm.h>
	#include <linux/regulator/consumer.h>

	#include <drm/drm_panel.h>

	#include "drmP.h"
	#include "drm_crtc.h"
	#include "drm_crtc_helper.h"
	#include "drm_atomic_helper.h"

	/* Brightness scale on the Parade chip */
	#define PS8622_MAX_BRIGHTNESS 0xff

	/* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
	#define PS8622_POWER_RISE_T1_MIN_US 10
	#define PS8622_POWER_RISE_T1_MAX_US 10000
	#define PS8622_RST_HIGH_T2_MIN_US 3000
	#define PS8622_RST_HIGH_T2_MAX_US 30000
	#define PS8622_PWMO_END_T12_MS 200
	#define PS8622_POWER_FALL_T16_MAX_US 10000
	#define PS8622_POWER_OFF_T17_MS 500

	#if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
	(PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
	#error "T2.min + T1.max must be less than T2.max + T1.min"
	#endif

	struct ps8622_bridge {
	struct drm_connector connector;
	struct i2c_client *client;
	struct drm_bridge bridge;
	struct drm_panel *panel;
	struct regulator *v12;
	struct backlight_device *bl;

	struct gpio_desc *gpio_slp;
	struct gpio_desc *gpio_rst;

	u32 max_lane_count;
	u32 lane_count;

	bool enabled;
	};

	static inline struct ps8622_bridge *
	bridge_to_ps8622(struct drm_bridge *bridge)
	{
	return container_of(bridge, struct ps8622_bridge, bridge);
	}

	static inline struct ps8622_bridge *
	connector_to_ps8622(struct drm_connector *connector)
	{
	return container_of(connector, struct ps8622_bridge, connector);
	}

	static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
	{
	int ret;
	struct i2c_adapter *adap = client->adapter;
	struct i2c_msg msg;
	u8 data[] = {reg, val};

	msg.addr = client->addr + page;
	msg.flags = 0;
	msg.len = sizeof(data);
	msg.buf = data;

	ret = i2c_transfer(adap, &msg, 1);
	if (ret != 1)
	pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
	client->addr + page, reg, val, ret);
	return !(ret == 1);
	}

	static int ps8622_send_config(struct ps8622_bridge *ps8622)
	{
	struct i2c_client *cl = ps8622->client;
	int err = 0;

	/* HPD low */
	err = ps8622_set(cl, 0x02, 0xa1, 0x01);
	if (err)
	goto error;

	/* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
	err = ps8622_set(cl, 0x04, 0x14, 0x01);
	if (err)
	goto error;

	/* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
	err = ps8622_set(cl, 0x04, 0xe3, 0x20);
	if (err)
	goto error;

	/* [7] RCO SS enable */
	err = ps8622_set(cl, 0x04, 0xe2, 0x80);
	if (err)
	goto error;

	/* RPHY Setting
	* [3:2] CDR tune wait cycle before measure for fine tune
	* b00: 1us b01: 0.5us b10:2us, b11: 4us
	*/
	err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
	if (err)
	goto error;

	/* [3] RFD always on */
	err = ps8622_set(cl, 0x04, 0x89, 0x08);
	if (err)
	goto error;

	/* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
	err = ps8622_set(cl, 0x04, 0x71, 0x2d);
	if (err)
	goto error;

	/* 2.7G CDR settings: NOF=40LSB for HBR CDR setting */
	err = ps8622_set(cl, 0x04, 0x7d, 0x07);
	if (err)
	goto error;

	/* [1:0] Fmin=+4bands */
	err = ps8622_set(cl, 0x04, 0x7b, 0x00);
	if (err)
	goto error;

	/* [7:5] DCO_FTRNG=+-40% */
	err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
	if (err)
	goto error;

	/* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
	err = ps8622_set(cl, 0x04, 0xc0, 0x12);
	if (err)
	goto error;

	/* Gitune=-37% */
	err = ps8622_set(cl, 0x04, 0xc1, 0x92);
	if (err)
	goto error;

	/* Fbstep=100% */
	err = ps8622_set(cl, 0x04, 0xc2, 0x1c);
	if (err)
	goto error;

	/* [7] LOS signal disable */
	err = ps8622_set(cl, 0x04, 0x32, 0x80);
	if (err)
	goto error;

	/* RPIO Setting: [7:4] LVDS driver bias current : 75% (250mV swing) */
	err = ps8622_set(cl, 0x04, 0x00, 0xb0);
	if (err)
	goto error;

	/* [7:6] Right-bar GPIO output strength is 8mA */
	err = ps8622_set(cl, 0x04, 0x15, 0x40);
	if (err)
	goto error;

	/* EQ Training State Machine Setting, RCO calibration start */
	err = ps8622_set(cl, 0x04, 0x54, 0x10);
	if (err)
	goto error;

	/* Logic, needs more than 10 I2C command */
	/* [4:0] MAX_LANE_COUNT set to max supported lanes */
	err = ps8622_set(cl, 0x01, 0x02, 0x80 \| ps8622->max_lane_count);
	if (err)
	goto error;

	/* [4:0] LANE_COUNT_SET set to chosen lane count */
	err = ps8622_set(cl, 0x01, 0x21, 0x80 \| ps8622->lane_count);
	if (err)
	goto error;

	err = ps8622_set(cl, 0x00, 0x52, 0x20);
	if (err)
	goto error;

	/* HPD CP toggle enable */
	err = ps8622_set(cl, 0x00, 0xf1, 0x03);
	if (err)
	goto error;

	err = ps8622_set(cl, 0x00, 0x62, 0x41);
	if (err)
	goto error;

	/* Counter number, add 1ms counter delay */
	err = ps8622_set(cl, 0x00, 0xf6, 0x01);
	if (err)
	goto error;

	/* [6]PWM function control by DPCD0040f[7], default is PWM block */
	err = ps8622_set(cl, 0x00, 0x77, 0x06);
	if (err)
	goto error;

	/* 04h Adjust VTotal toleranceto fix the 30Hz no display issue */
	err = ps8622_set(cl, 0x00, 0x4c, 0x04);
	if (err)
	goto error;

	/* DPCD00400='h00, Parade OUI ='h001cf8 */
	err = ps8622_set(cl, 0x01, 0xc0, 0x00);
	if (err)
	goto error;

	/* DPCD00401='h1c */
	err = ps8622_set(cl, 0x01, 0xc1, 0x1c);
	if (err)
	goto error;

	/* DPCD00402='hf8 */
	err = ps8622_set(cl, 0x01, 0xc2, 0xf8);
	if (err)
	goto error;

	/* DPCD403~408 = ASCII code, D2SLV5='h4432534c5635 */
	err = ps8622_set(cl, 0x01, 0xc3, 0x44);
	if (err)
	goto error;

	/* DPCD404 */
	err = ps8622_set(cl, 0x01, 0xc4, 0x32);
	if (err)
	goto error;

	/* DPCD405 */
	err = ps8622_set(cl, 0x01, 0xc5, 0x53);
	if (err)
	goto error;

	/* DPCD406 */
	err = ps8622_set(cl, 0x01, 0xc6, 0x4c);
	if (err)
	goto error;

	/* DPCD407 */
	err = ps8622_set(cl, 0x01, 0xc7, 0x56);
	if (err)
	goto error;

	/* DPCD408 */
	err = ps8622_set(cl, 0x01, 0xc8, 0x35);
	if (err)
	goto error;

	/* DPCD40A, Initial Code major revision '01' */
	err = ps8622_set(cl, 0x01, 0xca, 0x01);
	if (err)
	goto error;

	/* DPCD40B, Initial Code minor revision '05' */
	err = ps8622_set(cl, 0x01, 0xcb, 0x05);
	if (err)
	goto error;


	if (ps8622->bl) {
	/* DPCD720, internal PWM */
	err = ps8622_set(cl, 0x01, 0xa5, 0xa0);
	if (err)
	goto error;

	/* FFh for 100% brightness, 0h for 0% brightness */
	err = ps8622_set(cl, 0x01, 0xa7,
	ps8622->bl->props.brightness);
	if (err)
	goto error;
	} else {
	/* DPCD720, external PWM */
	err = ps8622_set(cl, 0x01, 0xa5, 0x80);
	if (err)
	goto error;
	}

	/* Set LVDS output as 6bit-VESA mapping, single LVDS channel */
	err = ps8622_set(cl, 0x01, 0xcc, 0x13);
	if (err)
	goto error;

	/* Enable SSC set by register */
	err = ps8622_set(cl, 0x02, 0xb1, 0x20);
	if (err)
	goto error;

	/* Set SSC enabled and +/-1% central spreading */
	err = ps8622_set(cl, 0x04, 0x10, 0x16);
	if (err)
	goto error;

	/* Logic end */
	/* MPU Clock source: LC => RCO */
	err = ps8622_set(cl, 0x04, 0x59, 0x60);
	if (err)
	goto error;

	/* LC -> RCO */
	err = ps8622_set(cl, 0x04, 0x54, 0x14);
	if (err)
	goto error;

	/* HPD high */
	err = ps8622_set(cl, 0x02, 0xa1, 0x91);

	error:
	return err ? -EIO : 0;
	}

	static int ps8622_backlight_update(struct backlight_device *bl)
	{
	struct ps8622_bridge *ps8622 = dev_get_drvdata(&bl->dev);
	int ret, brightness = bl->props.brightness;

	if (bl->props.power != FB_BLANK_UNBLANK \|\|
	bl->props.state & (BL_CORE_SUSPENDED \| BL_CORE_FBBLANK))
	brightness = 0;

	if (!ps8622->enabled)
	return -EINVAL;

	ret = ps8622_set(ps8622->client, 0x01, 0xa7, brightness);

	return ret;
	}

	static const struct backlight_ops ps8622_backlight_ops = {
	.update_status = ps8622_backlight_update,
	};

	static void ps8622_pre_enable(struct drm_bridge *bridge)
	{
	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
	int ret;

	if (ps8622->enabled)
	return;

	gpiod_set_value(ps8622->gpio_rst, 0);

	if (ps8622->v12) {
	ret = regulator_enable(ps8622->v12);
	if (ret)
	DRM_ERROR("fails to enable ps8622->v12");
	}

	if (drm_panel_prepare(ps8622->panel)) {
	DRM_ERROR("failed to prepare panel\n");
	return;
	}

	gpiod_set_value(ps8622->gpio_slp, 1);

	/*
	* T1 is the range of time that it takes for the power to rise after we
	* enable the lcd/ps8622 fet. T2 is the range of time in which the
	* data sheet specifies we should deassert the reset pin.
	*
	* If it takes T1.max for the power to rise, we need to wait atleast
	* T2.min before deasserting the reset pin. If it takes T1.min for the
	* power to rise, we need to wait at most T2.max before deasserting the
	* reset pin.
	*/
	usleep_range(PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US,
	PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US);

	gpiod_set_value(ps8622->gpio_rst, 1);

	/* wait 20ms after RST high */
	usleep_range(20000, 30000);

	ret = ps8622_send_config(ps8622);
	if (ret) {
	DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
	return;
	}

	ps8622->enabled = true;
	}

	static void ps8622_enable(struct drm_bridge *bridge)
	{
	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);

	if (drm_panel_enable(ps8622->panel)) {
	DRM_ERROR("failed to enable panel\n");
	return;
	}
	}

	static void ps8622_disable(struct drm_bridge *bridge)
	{
	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);

	if (drm_panel_disable(ps8622->panel)) {
	DRM_ERROR("failed to disable panel\n");
	return;
	}
	msleep(PS8622_PWMO_END_T12_MS);
	}

	static void ps8622_post_disable(struct drm_bridge *bridge)
	{
	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);

	if (!ps8622->enabled)
	return;

	ps8622->enabled = false;

	/*
	* This doesn't matter if the regulators are turned off, but something
	* else might keep them on. In that case, we want to assert the slp gpio
	* to lower power.
	*/
	gpiod_set_value(ps8622->gpio_slp, 0);

	if (drm_panel_unprepare(ps8622->panel)) {
	DRM_ERROR("failed to unprepare panel\n");
	return;
	}

	if (ps8622->v12)
	regulator_disable(ps8622->v12);

	/*
	* Sleep for at least the amount of time that it takes the power rail to
	* fall to prevent asserting the rst gpio from doing anything.
	*/
	usleep_range(PS8622_POWER_FALL_T16_MAX_US,
	2 * PS8622_POWER_FALL_T16_MAX_US);
	gpiod_set_value(ps8622->gpio_rst, 0);

	msleep(PS8622_POWER_OFF_T17_MS);
	}

	static int ps8622_get_modes(struct drm_connector *connector)
	{
	struct ps8622_bridge *ps8622;

	ps8622 = connector_to_ps8622(connector);

	return drm_panel_get_modes(ps8622->panel);
	}

	static struct drm_encoder ps8622_best_encoder(struct drm_connector connector)
	{
	struct ps8622_bridge *ps8622;

	ps8622 = connector_to_ps8622(connector);

	return ps8622->bridge.encoder;
	}

	static const struct drm_connector_helper_funcs ps8622_connector_helper_funcs = {
	.get_modes = ps8622_get_modes,
	.best_encoder = ps8622_best_encoder,
	};

	static enum drm_connector_status ps8622_detect(struct drm_connector *connector,
	bool force)
	{
	return connector_status_connected;
	}

	static void ps8622_connector_destroy(struct drm_connector *connector)
	{
	drm_connector_cleanup(connector);
	}

	static const struct drm_connector_funcs ps8622_connector_funcs = {
	.dpms = drm_atomic_helper_connector_dpms,
	.fill_modes = drm_helper_probe_single_connector_modes,
	.detect = ps8622_detect,
	.destroy = ps8622_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 ps8622_attach(struct drm_bridge *bridge)
	{
	struct ps8622_bridge *ps8622 = bridge_to_ps8622(bridge);
	int ret;

	if (!bridge->encoder) {
	DRM_ERROR("Parent encoder object not found");
	return -ENODEV;
	}

	ps8622->connector.polled = DRM_CONNECTOR_POLL_HPD;
	ret = drm_connector_init(bridge->dev, &ps8622->connector,
	&ps8622_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
	if (ret) {
	DRM_ERROR("Failed to initialize connector with drm\n");
	return ret;
	}
	drm_connector_helper_add(&ps8622->connector,
	&ps8622_connector_helper_funcs);
	drm_connector_register(&ps8622->connector);
	drm_mode_connector_attach_encoder(&ps8622->connector,
	bridge->encoder);

	if (ps8622->panel)
	drm_panel_attach(ps8622->panel, &ps8622->connector);

	drm_helper_hpd_irq_event(ps8622->connector.dev);

	return ret;
	}

	static const struct drm_bridge_funcs ps8622_bridge_funcs = {
	.pre_enable = ps8622_pre_enable,
	.enable = ps8622_enable,
	.disable = ps8622_disable,
	.post_disable = ps8622_post_disable,
	.attach = ps8622_attach,
	};

	static const struct of_device_id ps8622_devices[] = {
	{.compatible = "parade,ps8622",},
	{.compatible = "parade,ps8625",},
	{}
	};
	MODULE_DEVICE_TABLE(of, ps8622_devices);

	static int ps8622_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct device *dev = &client->dev;
	struct device_node endpoint, panel_node;
	struct ps8622_bridge *ps8622;
	int ret;

	ps8622 = devm_kzalloc(dev, sizeof(*ps8622), GFP_KERNEL);
	if (!ps8622)
	return -ENOMEM;

	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
	if (endpoint) {
	panel_node = of_graph_get_remote_port_parent(endpoint);
	if (panel_node) {
	ps8622->panel = of_drm_find_panel(panel_node);
	of_node_put(panel_node);
	if (!ps8622->panel)
	return -EPROBE_DEFER;
	}
	}

	ps8622->client = client;

	ps8622->v12 = devm_regulator_get(dev, "vdd12");
	if (IS_ERR(ps8622->v12)) {
	dev_info(dev, "no 1.2v regulator found for PS8622\n");
	ps8622->v12 = NULL;
	}

	ps8622->gpio_slp = devm_gpiod_get(dev, "sleep", GPIOD_OUT_HIGH);
	if (IS_ERR(ps8622->gpio_slp)) {
	ret = PTR_ERR(ps8622->gpio_slp);
	dev_err(dev, "cannot get gpio_slp %d\n", ret);
	return ret;
	}

	/*
	* Assert the reset pin high to avoid the bridge being
	* initialized prematurely
	*/
	ps8622->gpio_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(ps8622->gpio_rst)) {
	ret = PTR_ERR(ps8622->gpio_rst);
	dev_err(dev, "cannot get gpio_rst %d\n", ret);
	return ret;
	}

	ps8622->max_lane_count = id->driver_data;

	if (of_property_read_u32(dev->of_node, "lane-count",
	&ps8622->lane_count)) {
	ps8622->lane_count = ps8622->max_lane_count;
	} else if (ps8622->lane_count > ps8622->max_lane_count) {
	dev_info(dev, "lane-count property is too high,"
	"using max_lane_count\n");
	ps8622->lane_count = ps8622->max_lane_count;
	}

	if (!of_find_property(dev->of_node, "use-external-pwm", NULL)) {
	ps8622->bl = backlight_device_register("ps8622-backlight",
	dev, ps8622, &ps8622_backlight_ops,
	NULL);
	if (IS_ERR(ps8622->bl)) {
	DRM_ERROR("failed to register backlight\n");
	ret = PTR_ERR(ps8622->bl);
	ps8622->bl = NULL;
	return ret;
	}
	ps8622->bl->props.max_brightness = PS8622_MAX_BRIGHTNESS;
	ps8622->bl->props.brightness = PS8622_MAX_BRIGHTNESS;
	}

	ps8622->bridge.funcs = &ps8622_bridge_funcs;
	ps8622->bridge.of_node = dev->of_node;
	ret = drm_bridge_add(&ps8622->bridge);
	if (ret) {
	DRM_ERROR("Failed to add bridge\n");
	return ret;
	}

	i2c_set_clientdata(client, ps8622);

	return 0;
	}

	static int ps8622_remove(struct i2c_client *client)
	{
	struct ps8622_bridge *ps8622 = i2c_get_clientdata(client);

	if (ps8622->bl)
	backlight_device_unregister(ps8622->bl);

	drm_bridge_remove(&ps8622->bridge);

	return 0;
	}

	static const struct i2c_device_id ps8622_i2c_table[] = {
	/* Device type, max_lane_count */
	{"ps8622", 1},
	{"ps8625", 2},
	{},
	};
	MODULE_DEVICE_TABLE(i2c, ps8622_i2c_table);

	static struct i2c_driver ps8622_driver = {
	.id_table = ps8622_i2c_table,
	.probe = ps8622_probe,
	.remove = ps8622_remove,
	.driver = {
	.name = "ps8622",
	.owner = THIS_MODULE,
	.of_match_table = ps8622_devices,
	},
	};
	module_i2c_driver(ps8622_driver);

	MODULE_AUTHOR("Vincent Palatin <vpalatin@chromium.org>");
	MODULE_DESCRIPTION("Parade ps8622/ps8625 eDP-LVDS converter driver");
	MODULE_LICENSE("GPL v2");