[PATCH v19 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

[Ulrich Hecht <uli-qwV78thtvt0@public.gmane.org>]

From: Jitao Shi <jitao.shi-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

This patch adds drm_bridge driver for parade DSI to eDP bridge chip.

Signed-off-by: Jitao Shi <jitao.shi-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
Reviewed-by: Daniel Kurtz <djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo-ZGY8ohtN/8qB+jHODAdFcQ@public.gmane.org>
[uli: followed API changes, removed FW update feature]
Signed-off-by: Ulrich Hecht <uli-qwV78thtvt0@public.gmane.org>
---

Changes since v18:
 - followed DRM API changes
 - use DEVICE_ATTR_RO()
 - remove firmware update code
 - add SPDX identifier

Changes since v17:
 - remove some unused head files.
 - add macros for ps8640 pages.
 - remove ddc_i2c client
 - add mipi_dsi_device_register_full
 - remove the manufacturer from the name and i2c_device_id
 
Changes since v16:
 - Disable ps8640 DSI MCS Function.
 - Rename gpios name more clearly.
 - Tune the ps8640 power on sequence.

Changes since v15:
 - Drop drm_connector_(un)register calls from parade ps8640.
   The main DRM driver mtk_drm_drv now calls
   drm_connector_register_all() after drm_dev_register() in the
   mtk_drm_bind() function. That function should iterate over all
   connectors and call drm_connector_register() for each of them.
   So, remove drm_connector_(un)register calls from parade ps8640.

Changes since v14:
 - update copyright info.
 - change bridge_to_ps8640 and connector_to_ps8640 to inline function.
 - fix some coding style.
 - use sizeof as array counter.
 - use drm_get_edid when read edid.
 - add mutex when firmware updating. 

Changes since v13:
 - add const on data, ps8640_write_bytes(struct i2c_client *client, const u8 *data, u16 data_len)
 - fix PAGE2_SW_REST tyro.
 - move the buf[3] init to entrance of the function.

Changes since v12:
 - fix hw_chip_id build warning

Changes since v11:
 - Remove depends on I2C, add DRM depends
 - Reuse ps8640_write_bytes() in ps8640_write_byte()
 - Use timer check for polling like the routines in <linux/iopoll.h>
 - Fix no drm_connector_unregister/drm_connector_cleanup when ps8640_bridge_attach fail
 - Check the ps8640 hardware id in ps8640_validate_firmware
 - Remove fw_version check
 - Move ps8640_validate_firmware before ps8640_enter_bl
 - Add ddc_i2c unregister when probe fail and ps8640_remove


 drivers/gpu/drm/bridge/Kconfig         |  12 +
 drivers/gpu/drm/bridge/Makefile        |   1 +
 drivers/gpu/drm/bridge/parade-ps8640.c | 672 +++++++++++++++++++++++++++++++++
 3 files changed, 685 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/parade-ps8640.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 1cc9f50..61c6415 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -82,6 +82,18 @@ config DRM_PARADE_PS8622
 	---help---
 	  Parade eDP-LVDS bridge chip driver.
 
+config DRM_PARADE_PS8640
+	tristate "Parade PS8640 MIPI DSI to eDP Converter"
+	depends on DRM
+	depends on OF
+	select DRM_KMS_HELPER
+	select DRM_MIPI_DSI
+	select DRM_PANEL
+	help
+	  Choose this option if you have PS8640 for display
+	  The PS8640 is a high-performance and low-power
+	  MIPI DSI to eDP converter
+
 config DRM_SIL_SII8620
 	tristate "Silicon Image SII8620 HDMI/MHL bridge"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 4934fcf..14660ab 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
 obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
 obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
+obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o
 obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o
 obj-$(CONFIG_DRM_SII902X) += sii902x.o
 obj-$(CONFIG_DRM_SII9234) += sii9234.o
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
new file mode 100644
index 0000000..d645dc8
--- /dev/null
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -0,0 +1,672 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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/delay.h>
+#include <linux/err.h>
+#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <asm/unaligned.h>
+#include <drm/drm_panel.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+#define PAGE1_VSTART		0x6b
+#define PAGE2_SPI_CFG3		0x82
+#define I2C_TO_SPI_RESET	0x20
+#define PAGE2_ROMADD_BYTE1	0x8e
+#define PAGE2_ROMADD_BYTE2	0x8f
+#define PAGE2_SWSPI_WDATA	0x90
+#define PAGE2_SWSPI_RDATA	0x91
+#define PAGE2_SWSPI_LEN		0x92
+#define PAGE2_SWSPI_CTL		0x93
+#define TRIGGER_NO_READBACK	0x05
+#define TRIGGER_READBACK	0x01
+#define PAGE2_SPI_STATUS	0x9e
+#define SPI_READY		0x0c
+#define PAGE2_GPIO_L		0xa6
+#define PAGE2_GPIO_H		0xa7
+#define PS_GPIO9		BIT(1)
+#define PAGE2_IROM_CTRL		0xb0
+#define IROM_ENABLE		0xc0
+#define IROM_DISABLE		0x80
+#define PAGE2_SW_RESET		0xbc
+#define SPI_SW_RESET		BIT(7)
+#define MPU_SW_RESET		BIT(6)
+#define PAGE2_ENCTLSPI_WR	0xda
+#define PAGE2_I2C_BYPASS	0xea
+#define I2C_BYPASS_EN		0xd0
+#define PAGE2_MCS_EN		0xf3
+#define MCS_EN			BIT(0)
+#define PAGE3_SET_ADD		0xfe
+#define PAGE3_SET_VAL		0xff
+#define VDO_CTL_ADD		0x13
+#define VDO_DIS			0x18
+#define VDO_EN			0x1c
+#define PAGE4_REV_L		0xf0
+#define PAGE4_REV_H		0xf1
+#define PAGE4_CHIP_L		0xf2
+#define PAGE4_CHIP_H		0xf3
+
+#define PAGE0_DP_CNTL	0
+#define PAGE1_VDO_BDG	1
+#define PAGE2_TOP_CNTL	2
+#define PAGE3_DSI_CNTL1	3
+#define PAGE4_MIPI_PHY	4
+#define PAGE5_VPLL	5
+#define PAGE6_DSI_CNTL2	6
+#define PAGE7_SPI_CNTL	7
+#define MAX_DEVS		0x8
+
+struct ps8640_info {
+	u8 family_id;
+	u8 variant_id;
+	u16 version;
+};
+
+struct ps8640 {
+	struct drm_connector connector;
+	struct drm_bridge bridge;
+	struct edid *edid;
+	struct mipi_dsi_device *dsi;
+	struct i2c_client *page[MAX_DEVS];
+	struct regulator_bulk_data supplies[2];
+	struct drm_panel *panel;
+	struct gpio_desc *gpio_reset;
+	struct gpio_desc *gpio_power_down;
+	struct gpio_desc *gpio_mode_sel;
+	bool enabled;
+
+	/* firmware file info */
+	struct ps8640_info info;
+	bool in_fw_update;
+	/* for firmware update protect */
+	struct mutex fw_mutex;
+};
+
+static const u8 enc_ctrl_code[6] = { 0xaa, 0x55, 0x50, 0x41, 0x52, 0x44 };
+static const u8 hw_chip_id[4] = { 0x00, 0x0a, 0x00, 0x30 };
+
+static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
+{
+	return container_of(e, struct ps8640, bridge);
+}
+
+static inline struct ps8640 *connector_to_ps8640(struct drm_connector *e)
+{
+	return container_of(e, struct ps8640, connector);
+}
+
+static int ps8640_read(struct i2c_client *client, u8 reg, u8 *data,
+		       u16 data_len)
+{
+	int ret;
+	struct i2c_msg msgs[] = {
+		{
+		 .addr = client->addr,
+		 .flags = 0,
+		 .len = 1,
+		 .buf = &reg,
+		},
+		{
+		 .addr = client->addr,
+		 .flags = I2C_M_RD,
+		 .len = data_len,
+		 .buf = data,
+		}
+	};
+
+	ret = i2c_transfer(client->adapter, msgs, 2);
+
+	if (ret == 2)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_write_bytes(struct i2c_client *client, const u8 *data,
+			      u16 data_len)
+{
+	int ret;
+	struct i2c_msg msg;
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = data_len;
+	msg.buf = (u8 *)data;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret == 1)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int ps8640_write_byte(struct i2c_client *client, u8 reg,  u8 data)
+{
+	u8 buf[] = { reg, data };
+
+	return ps8640_write_bytes(client, buf, sizeof(buf));
+}
+
+static void ps8640_get_mcu_fw_version(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[PAGE5_VPLL];
+	u8 fw_ver[2];
+
+	ps8640_read(client, 0x4, fw_ver, sizeof(fw_ver));
+	ps_bridge->info.version = (fw_ver[0] << 8) | fw_ver[1];
+
+	DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", fw_ver[0], fw_ver[1]);
+}
+
+static int ps8640_bridge_unmute(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[PAGE3_DSI_CNTL1];
+	u8 vdo_ctrl_buf[3] = { PAGE3_SET_ADD, VDO_CTL_ADD, VDO_EN };
+
+	return ps8640_write_bytes(client, vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
+}
+
+static int ps8640_bridge_mute(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[PAGE3_DSI_CNTL1];
+	u8 vdo_ctrl_buf[3] = { PAGE3_SET_ADD, VDO_CTL_ADD, VDO_DIS };
+
+	return ps8640_write_bytes(client, vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
+}
+
+static void ps8640_pre_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct i2c_client *client = ps_bridge->page[PAGE2_TOP_CNTL];
+	struct i2c_client *page1 = ps_bridge->page[PAGE1_VDO_BDG];
+	int err;
+	u8 set_vdo_done, mcs_en, vstart;
+	ktime_t timeout;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (ps_bridge->enabled)
+		return;
+
+	err = drm_panel_prepare(ps_bridge->panel);
+	if (err < 0) {
+		DRM_ERROR("failed to prepare panel: %d\n", err);
+		return;
+	}
+
+	err = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),
+				    ps_bridge->supplies);
+	if (err < 0) {
+		DRM_ERROR("cannot enable regulators %d\n", err);
+		goto err_panel_unprepare;
+	}
+
+	gpiod_set_value(ps_bridge->gpio_power_down, 1);
+	gpiod_set_value(ps_bridge->gpio_reset, 0);
+	usleep_range(2000, 2500);
+	gpiod_set_value(ps_bridge->gpio_reset, 1);
+
+	/*
+	 * Wait for the ps8640 embed mcu ready
+	 * First wait 200ms and then check the mcu ready flag every 20ms
+	 */
+	msleep(200);
+
+	timeout = ktime_add_ms(ktime_get(), 200);
+	for (;;) {
+		err = ps8640_read(client, PAGE2_GPIO_H, &set_vdo_done, 1);
+		if (err < 0) {
+			DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", err);
+			goto err_regulators_disable;
+		}
+		if ((set_vdo_done & PS_GPIO9) == PS_GPIO9)
+			break;
+		if (ktime_compare(ktime_get(), timeout) > 0)
+			break;
+		msleep(20);
+	}
+
+	msleep(50);
+
+	ps8640_read(page1, PAGE1_VSTART, &vstart, 1);
+	DRM_INFO("PS8640 PAGE1.0x6B = 0x%x\n", vstart);
+
+	/**
+	 * The Manufacturer Command Set (MCS) is a device dependent interface
+	 * intended for factory programming of the display module default
+	 * parameters. Once the display module is configured, the MCS shall be
+	 * disabled by the manufacturer. Once disabled, all MCS commands are
+	 * ignored by the display interface.
+	 */
+	ps8640_read(client, PAGE2_MCS_EN, &mcs_en, 1);
+	ps8640_write_byte(client, PAGE2_MCS_EN, mcs_en & ~MCS_EN);
+
+	if (ps_bridge->info.version == 0)
+		ps8640_get_mcu_fw_version(ps_bridge);
+
+	err = ps8640_bridge_unmute(ps_bridge);
+	if (err)
+		DRM_ERROR("failed to enable unmutevideo: %d\n", err);
+	/* Switch access edp panel's edid through i2c */
+	ps8640_write_byte(client, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
+	ps_bridge->enabled = true;
+
+	return;
+
+err_regulators_disable:
+	regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
+			       ps_bridge->supplies);
+err_panel_unprepare:
+	drm_panel_unprepare(ps_bridge->panel);
+}
+
+static void ps8640_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = drm_panel_enable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to enable panel: %d\n", err);
+}
+
+static void ps8640_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	err = drm_panel_disable(ps_bridge->panel);
+	if (err < 0)
+		DRM_ERROR("failed to disable panel: %d\n", err);
+}
+
+static void ps8640_post_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int err;
+
+	if (ps_bridge->in_fw_update)
+		return;
+
+	if (!ps_bridge->enabled)
+		return;
+
+	ps_bridge->enabled = false;
+
+	err = ps8640_bridge_mute(ps_bridge);
+	if (err < 0)
+		DRM_ERROR("failed to unmutevideo: %d\n", err);
+
+	gpiod_set_value(ps_bridge->gpio_reset, 0);
+	gpiod_set_value(ps_bridge->gpio_power_down, 0);
+	err = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
+				     ps_bridge->supplies);
+	if (err < 0)
+		DRM_ERROR("cannot disable regulators %d\n", err);
+
+	err = drm_panel_unprepare(ps_bridge->panel);
+	if (err)
+		DRM_ERROR("failed to unprepare panel: %d\n", err);
+}
+
+static int ps8640_get_modes(struct drm_connector *connector)
+{
+	struct ps8640 *ps_bridge = connector_to_ps8640(connector);
+	struct edid *edid;
+	int num_modes = 0;
+	bool power_off;
+
+	if (ps_bridge->edid)
+		return drm_add_edid_modes(connector, ps_bridge->edid);
+
+	power_off = !ps_bridge->enabled;
+	ps8640_pre_enable(&ps_bridge->bridge);
+
+	edid = drm_get_edid(connector, ps_bridge->page[0]->adapter);
+	if (!edid)
+		goto out;
+
+	ps_bridge->edid = edid;
+	drm_connector_update_edid_property(connector, ps_bridge->edid);
+	num_modes = drm_add_edid_modes(connector, ps_bridge->edid);
+
+out:
+	if (power_off)
+		ps8640_post_disable(&ps_bridge->bridge);
+
+	return num_modes;
+}
+
+static const struct drm_connector_helper_funcs ps8640_connector_helper_funcs = {
+	.get_modes = ps8640_get_modes,
+};
+
+static enum drm_connector_status ps8640_detect(struct drm_connector *connector,
+					       bool force)
+{
+	return connector_status_connected;
+}
+
+static const struct drm_connector_funcs ps8640_connector_funcs = {
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ps8640_detect,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+int ps8640_bridge_attach(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct device *dev = &ps_bridge->page[0]->dev;
+	struct device_node *in_ep, *dsi_node = NULL;
+	struct mipi_dsi_device *dsi;
+	struct mipi_dsi_host *host = NULL;
+	int ret;
+	const struct mipi_dsi_device_info info = { .type = "ps8640",
+						   .channel = 0,
+						   .node = NULL,
+						 };
+
+	ret = drm_connector_init(bridge->dev, &ps_bridge->connector,
+				 &ps8640_connector_funcs,
+				 DRM_MODE_CONNECTOR_eDP);
+
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector with drm: %d\n", ret);
+		return ret;
+	}
+
+	drm_connector_helper_add(&ps_bridge->connector,
+				 &ps8640_connector_helper_funcs);
+
+	ps_bridge->connector.dpms = DRM_MODE_DPMS_ON;
+	drm_connector_attach_encoder(&ps_bridge->connector,
+					  bridge->encoder);
+
+	if (ps_bridge->panel)
+		drm_panel_attach(ps_bridge->panel, &ps_bridge->connector);
+
+	/* port@0 is ps8640 dsi input port */
+	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
+	if (in_ep) {
+		dsi_node = of_graph_get_remote_port_parent(in_ep);
+		of_node_put(in_ep);
+	}
+
+	if (dsi_node) {
+		host = of_find_mipi_dsi_host_by_node(dsi_node);
+		of_node_put(dsi_node);
+		if (!host) {
+			ret = -ENODEV;
+			goto err;
+		}
+	}
+
+	dsi = mipi_dsi_device_register_full(host, &info);
+	if (IS_ERR(dsi)) {
+		dev_err(dev, "failed to create dsi device\n");
+		ret = PTR_ERR(dsi);
+		goto err;
+	}
+
+	ps_bridge->dsi = dsi;
+
+	dsi->host = host;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+				     MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = 4;
+	ret = mipi_dsi_attach(dsi);
+	if (ret)
+		goto err_dsi_attach;
+
+	return 0;
+
+err_dsi_attach:
+	mipi_dsi_device_unregister(dsi);
+err:
+	if (ps_bridge->panel)
+		drm_panel_detach(ps_bridge->panel);
+	drm_connector_cleanup(&ps_bridge->connector);
+	return ret;
+}
+
+static const struct drm_bridge_funcs ps8640_bridge_funcs = {
+	.attach = ps8640_bridge_attach,
+	.disable = ps8640_disable,
+	.post_disable = ps8640_post_disable,
+	.pre_enable = ps8640_pre_enable,
+	.enable = ps8640_enable,
+};
+
+/* Firmware Version is returned as Major.Minor */
+static ssize_t fw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "%u.%u\n", info->version >> 8,
+			 info->version & 0xff);
+}
+
+/* Hardware Version is returned as FamilyID.VariantID */
+static ssize_t hw_version_show(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	struct ps8640_info *info = &ps_bridge->info;
+
+	return scnprintf(buf, PAGE_SIZE, "ps%u.%u\n", info->family_id,
+			 info->variant_id);
+}
+
+static DEVICE_ATTR_RO(fw_version);
+static DEVICE_ATTR_RO(hw_version);
+
+static struct attribute *ps8640_attrs[] = {
+	&dev_attr_fw_version.attr,
+	&dev_attr_hw_version.attr,
+	NULL
+};
+
+static const struct attribute_group ps8640_attr_group = {
+	.attrs = ps8640_attrs,
+};
+
+static void ps8640_remove_sysfs_group(void *data)
+{
+	struct ps8640 *ps_bridge = data;
+
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+}
+
+static int ps8640_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct ps8640 *ps_bridge;
+	struct device_node *np = dev->of_node;
+	struct device_node *port, *out_ep;
+	struct device_node *panel_node = NULL;
+	int ret;
+	u32 i;
+
+	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
+	if (!ps_bridge)
+		return -ENOMEM;
+
+	/* port@1 is ps8640 output port */
+	port = of_graph_get_port_by_id(np, 1);
+	if (port) {
+		out_ep = of_get_child_by_name(port, "endpoint");
+		of_node_put(port);
+		if (out_ep) {
+			panel_node = of_graph_get_remote_port_parent(out_ep);
+			of_node_put(out_ep);
+		}
+	}
+	if (panel_node) {
+		ps_bridge->panel = of_drm_find_panel(panel_node);
+		of_node_put(panel_node);
+		if (!ps_bridge->panel)
+			return -EPROBE_DEFER;
+	}
+
+	mutex_init(&ps_bridge->fw_mutex);
+	ps_bridge->supplies[0].supply = "vdd33";
+	ps_bridge->supplies[1].supply = "vdd12";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
+				      ps_bridge->supplies);
+	if (ret) {
+		dev_info(dev, "failed to get regulators: %d\n", ret);
+		return ret;
+	}
+
+	ps_bridge->gpio_mode_sel = devm_gpiod_get_optional(&client->dev,
+							     "mode-sel",
+							     GPIOD_OUT_HIGH);
+	if (IS_ERR(ps_bridge->gpio_mode_sel)) {
+		ret = PTR_ERR(ps_bridge->gpio_mode_sel);
+		dev_err(dev, "cannot get mode-sel %d\n", ret);
+		return ret;
+	}
+
+	ps_bridge->gpio_power_down = devm_gpiod_get(&client->dev, "sleep",
+					       GPIOD_OUT_LOW);
+	if (IS_ERR(ps_bridge->gpio_power_down)) {
+		ret = PTR_ERR(ps_bridge->gpio_power_down);
+		dev_err(dev, "cannot get sleep: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Request the reset pin low to avoid the bridge being
+	 * initialized prematurely
+	 */
+	ps_bridge->gpio_reset = devm_gpiod_get(&client->dev, "reset",
+					       GPIOD_OUT_LOW);
+	if (IS_ERR(ps_bridge->gpio_reset)) {
+		ret = PTR_ERR(ps_bridge->gpio_reset);
+		dev_err(dev, "cannot get reset: %d\n", ret);
+		return ret;
+	}
+
+	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
+	ps_bridge->bridge.of_node = dev->of_node;
+
+	ps_bridge->page[0] = client;
+
+	/*
+	 * ps8640 uses multiple addresses, use dummy devices for them
+	 * page[0]: for DP control
+	 * page[1]: for VIDEO Bridge
+	 * page[2]: for control top
+	 * page[3]: for DSI Link Control1
+	 * page[4]: for MIPI Phy
+	 * page[5]: for VPLL
+	 * page[6]: for DSI Link Control2
+	 * page[7]: for spi rom mapping
+	 */
+	for (i = 1; i < MAX_DEVS; i++) {
+		ps_bridge->page[i] = i2c_new_dummy(client->adapter,
+						   client->addr + i);
+		if (!ps_bridge->page[i]) {
+			dev_err(dev, "failed i2c dummy device, address%02x\n",
+				client->addr + i);
+			ret = -EBUSY;
+			goto exit_dummy;
+		}
+	}
+	i2c_set_clientdata(client, ps_bridge);
+
+	ret = sysfs_create_group(&client->dev.kobj, &ps8640_attr_group);
+	if (ret) {
+		dev_err(dev, "failed to create sysfs entries: %d\n", ret);
+		goto exit_dummy;
+	}
+
+	ret = devm_add_action(dev, ps8640_remove_sysfs_group, ps_bridge);
+	if (ret) {
+		dev_err(dev, "failed to add sysfs cleanup action: %d\n", ret);
+		goto exit_remove_sysfs;
+	}
+
+	drm_bridge_add(&ps_bridge->bridge);
+	return 0;
+
+exit_remove_sysfs:
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+exit_dummy:
+	while (--i)
+		i2c_unregister_device(ps_bridge->page[i]);
+	return ret;
+}
+
+static int ps8640_remove(struct i2c_client *client)
+{
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+	int i = MAX_DEVS;
+
+	drm_bridge_remove(&ps_bridge->bridge);
+	sysfs_remove_group(&ps_bridge->page[0]->dev.kobj, &ps8640_attr_group);
+	while (--i)
+		i2c_unregister_device(ps_bridge->page[i]);
+
+	return 0;
+}
+
+static const struct i2c_device_id ps8640_i2c_table[] = {
+	{ "ps8640", 0 },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(i2c, ps8640_i2c_table);
+
+static const struct of_device_id ps8640_match[] = {
+	{ .compatible = "parade,ps8640" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, ps8640_match);
+
+static struct i2c_driver ps8640_driver = {
+	.id_table = ps8640_i2c_table,
+	.probe = ps8640_probe,
+	.remove = ps8640_remove,
+	.driver = {
+		.name = "ps8640",
+		.of_match_table = ps8640_match,
+	},
+};
+module_i2c_driver(ps8640_driver);
+
+MODULE_AUTHOR("Jitao Shi <jitao.shi-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>");
+MODULE_AUTHOR("CK Hu <ck.hu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>");
+MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4