drm/bridge: add it6505 driver

This adds support for the iTE IT6505.
This device can convert DPI signal to DP output.

From: Allen Chen <allen.chen@ite.com.tw>
Tested-by: Hsin-yi Wang <hsinyi@chromium.org>
Signed-off-by: Hermes Wu <hermes.wu@ite.com.tw>
Signed-off-by: Allen Chen <allen.chen@ite.com.tw>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220114091502.333083-1-allen.chen@ite.com.tw

drivers/gpu/drm/bridge/Kconfig

@@ -75,6 +75,14 @@ config DRM_DISPLAY_CONNECTOR
 	  on ARM-based platforms. Saying Y here when this driver is not needed
 	  will not cause any issue.
 
+config DRM_ITE_IT6505
+        tristate "ITE IT6505 DisplayPort bridge"
+        depends on OF
+        select DRM_KMS_HELPER
+        select EXTCON
+        help
+          ITE IT6505 DisplayPort bridge chip driver.
+
 config DRM_LONTIUM_LT8912B
 	tristate "Lontium LT8912B DSI/HDMI bridge"
 	depends on OF

drivers/gpu/drm/bridge/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o
 obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
 obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o
 obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
+obj-$(CONFIG_DRM_ITE_IT6505) += ite-it6505.o
 obj-$(CONFIG_DRM_LONTIUM_LT8912B) += lontium-lt8912b.o
 obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o
 obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o

drivers/gpu/drm/bridge/ite-it6505.c

+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/fs.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#include <crypto/hash.h>
+
+#include <drm/dp/drm_dp_helper.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_hdcp.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+#include <sound/hdmi-codec.h>
+
+#define REG_IC_VER 0x04
+
+#define REG_RESET_CTRL 0x05
+#define VIDEO_RESET BIT(0)
+#define AUDIO_RESET BIT(1)
+#define ALL_LOGIC_RESET BIT(2)
+#define AUX_RESET BIT(3)
+#define HDCP_RESET BIT(4)
+
+#define INT_STATUS_01 0x06
+#define INT_MASK_01 0x09
+#define INT_HPD_CHANGE 0
+#define INT_RECEIVE_HPD_IRQ 1
+#define INT_SCDT_CHANGE 2
+#define INT_HDCP_FAIL 3
+#define INT_HDCP_DONE 4
+#define BIT_OFFSET(x) (((x) - INT_STATUS_01) * BITS_PER_BYTE)
+#define BIT_INT_HPD INT_HPD_CHANGE
+#define BIT_INT_HPD_IRQ INT_RECEIVE_HPD_IRQ
+#define BIT_INT_SCDT INT_SCDT_CHANGE
+#define BIT_INT_HDCP_FAIL INT_HDCP_FAIL
+#define BIT_INT_HDCP_DONE INT_HDCP_DONE
+
+#define INT_STATUS_02 0x07
+#define INT_MASK_02 0x0A
+#define INT_AUX_CMD_FAIL 0
+#define INT_HDCP_KSV_CHECK 1
+#define INT_AUDIO_FIFO_ERROR 2
+#define BIT_INT_AUX_CMD_FAIL (BIT_OFFSET(0x07) + INT_AUX_CMD_FAIL)
+#define BIT_INT_HDCP_KSV_CHECK (BIT_OFFSET(0x07) + INT_HDCP_KSV_CHECK)
+#define BIT_INT_AUDIO_FIFO_ERROR (BIT_OFFSET(0x07) + INT_AUDIO_FIFO_ERROR)
+
+#define INT_STATUS_03 0x08
+#define INT_MASK_03 0x0B
+#define INT_LINK_TRAIN_FAIL 4
+#define INT_VID_FIFO_ERROR 5
+#define INT_IO_LATCH_FIFO_OVERFLOW 7
+#define BIT_INT_LINK_TRAIN_FAIL (BIT_OFFSET(0x08) + INT_LINK_TRAIN_FAIL)
+#define BIT_INT_VID_FIFO_ERROR (BIT_OFFSET(0x08) + INT_VID_FIFO_ERROR)
+#define BIT_INT_IO_FIFO_OVERFLOW (BIT_OFFSET(0x08) + INT_IO_LATCH_FIFO_OVERFLOW)
+
+#define REG_SYSTEM_STS 0x0D
+#define INT_STS BIT(0)
+#define HPD_STS BIT(1)
+#define VIDEO_STB BIT(2)
+
+#define REG_LINK_TRAIN_STS 0x0E
+#define LINK_STATE_CR BIT(2)
+#define LINK_STATE_EQ BIT(3)
+#define LINK_STATE_NORP BIT(4)
+
+#define REG_BANK_SEL 0x0F
+#define REG_CLK_CTRL0 0x10
+#define M_PCLK_DELAY 0x03
+
+#define REG_AUX_OPT 0x11
+#define AUX_AUTO_RST BIT(0)
+#define AUX_FIX_FREQ BIT(3)
+
+#define REG_DATA_CTRL0 0x12
+#define VIDEO_LATCH_EDGE BIT(4)
+#define ENABLE_PCLK_COUNTER BIT(7)
+
+#define REG_PCLK_COUNTER_VALUE 0x13
+
+#define REG_501_FIFO_CTRL 0x15
+#define RST_501_FIFO BIT(1)
+
+#define REG_TRAIN_CTRL0 0x16
+#define FORCE_LBR BIT(0)
+#define LANE_COUNT_MASK 0x06
+#define LANE_SWAP BIT(3)
+#define SPREAD_AMP_5 BIT(4)
+#define FORCE_CR_DONE BIT(5)
+#define FORCE_EQ_DONE BIT(6)
+
+#define REG_TRAIN_CTRL1 0x17
+#define AUTO_TRAIN BIT(0)
+#define MANUAL_TRAIN BIT(1)
+#define FORCE_RETRAIN BIT(2)
+
+#define REG_AUX_CTRL 0x23
+#define CLR_EDID_FIFO BIT(0)
+#define AUX_USER_MODE BIT(1)
+#define AUX_NO_SEGMENT_WR BIT(6)
+#define AUX_EN_FIFO_READ BIT(7)
+
+#define REG_AUX_ADR_0_7 0x24
+#define REG_AUX_ADR_8_15 0x25
+#define REG_AUX_ADR_16_19 0x26
+#define REG_AUX_OUT_DATA0 0x27
+
+#define REG_AUX_CMD_REQ 0x2B
+#define AUX_BUSY BIT(5)
+
+#define REG_AUX_DATA_0_7 0x2C
+#define REG_AUX_DATA_8_15 0x2D
+#define REG_AUX_DATA_16_23 0x2E
+#define REG_AUX_DATA_24_31 0x2F
+
+#define REG_AUX_DATA_FIFO 0x2F
+
+#define REG_AUX_ERROR_STS 0x9F
+#define M_AUX_REQ_FAIL 0x03
+
+#define REG_HDCP_CTRL1 0x38
+#define HDCP_CP_ENABLE BIT(0)
+
+#define REG_HDCP_TRIGGER 0x39
+#define HDCP_TRIGGER_START  BIT(0)
+#define HDCP_TRIGGER_CPIRQ  BIT(1)
+#define HDCP_TRIGGER_KSV_DONE  BIT(4)
+#define HDCP_TRIGGER_KSV_FAIL BIT(5)
+
+#define REG_HDCP_CTRL2 0x3A
+#define HDCP_AN_SEL BIT(0)
+#define HDCP_AN_GEN BIT(1)
+#define HDCP_HW_HPDIRQ_ACT BIT(2)
+#define HDCP_EN_M0_READ BIT(5)
+
+#define REG_M0_0_7 0x4C
+#define REG_AN_0_7 0x4C
+#define REG_SP_CTRL0 0x58
+#define REG_IP_CTRL1 0x59
+#define REG_IP_CTRL2 0x5A
+
+#define REG_LINK_DRV 0x5C
+#define DRV_HS BIT(1)
+
+#define REG_DRV_LN_DATA_SEL 0x5D
+
+#define REG_AUX 0x5E
+
+#define REG_VID_BUS_CTRL0 0x60
+#define IN_DDR BIT(2)
+#define DDR_CD (0x01 << 6)
+
+#define REG_VID_BUS_CTRL1 0x61
+#define TX_FIFO_RESET BIT(1)
+
+#define REG_INPUT_CTRL 0xA0
+#define INPUT_HSYNC_POL BIT(0)
+#define INPUT_VSYNC_POL BIT(2)
+#define INPUT_INTERLACED BIT(4)
+
+#define REG_INPUT_HTOTAL 0xA1
+#define REG_INPUT_HACTIVE_START 0xA3
+#define REG_INPUT_HACTIVE_WIDTH 0xA5
+#define REG_INPUT_HFRONT_PORCH 0xA7
+#define REG_INPUT_HSYNC_WIDTH 0xA9
+#define REG_INPUT_VTOTAL 0xAB
+#define REG_INPUT_VACTIVE_START 0xAD
+#define REG_INPUT_VACTIVE_WIDTH 0xAF
+#define REG_INPUT_VFRONT_PORCH 0xB1
+#define REG_INPUT_VSYNC_WIDTH 0xB3
+
+#define REG_AUDIO_SRC_CTRL 0xB8
+#define M_AUDIO_I2S_EN 0x0F
+#define EN_I2S0 BIT(0)
+#define EN_I2S1 BIT(1)
+#define EN_I2S2 BIT(2)
+#define EN_I2S3 BIT(3)
+#define AUDIO_FIFO_RESET BIT(7)
+
+#define REG_AUDIO_FMT 0xB9
+#define REG_AUDIO_FIFO_SEL 0xBA
+
+#define REG_AUDIO_CTRL0 0xBB
+#define AUDIO_FULL_PKT BIT(4)
+#define AUDIO_16B_BOUND BIT(5)
+
+#define REG_AUDIO_CTRL1 0xBC
+#define REG_AUDIO_INPUT_FREQ 0xBE
+
+#define REG_IEC958_STS0 0xBF
+#define REG_IEC958_STS1 0xC0
+#define REG_IEC958_STS2 0xC1
+#define REG_IEC958_STS3 0xC2
+#define REG_IEC958_STS4 0xC3
+
+#define REG_HPD_IRQ_TIME 0xC9
+#define REG_AUX_DEBUG_MODE 0xCA
+#define REG_AUX_OPT2 0xCB
+#define REG_HDCP_OPT 0xCE
+#define REG_USER_DRV_PRE 0xCF
+
+#define REG_DATA_MUTE_CTRL 0xD3
+#define ENABLE_ENHANCED_FRAME BIT(0)
+#define ENABLE_AUTO_VIDEO_FIFO_RESET BIT(1)
+#define EN_VID_MUTE BIT(4)
+#define EN_AUD_MUTE BIT(5)
+
+#define REG_TIME_STMP_CTRL 0xD4
+#define EN_ENHANCE_VID_STMP BIT(0)
+#define EN_ENHANCE_AUD_STMP BIT(2)
+#define M_STAMP_STEP 0x30
+#define EN_SSC_GAT BIT(6)
+
+#define REG_INFOFRAME_CTRL 0xE8
+#define EN_AVI_PKT BIT(0)
+#define EN_AUD_PKT BIT(1)
+#define EN_MPG_PKT BIT(2)
+#define EN_GEN_PKT BIT(3)
+#define EN_VID_TIME_STMP BIT(4)
+#define EN_AUD_TIME_STMP BIT(5)
+#define EN_VID_CTRL_PKT (EN_AVI_PKT | EN_VID_TIME_STMP)
+#define EN_AUD_CTRL_PKT (EN_AUD_PKT | EN_AUD_TIME_STMP)
+
+#define REG_AUDIO_N_0_7 0xDE
+#define REG_AUDIO_N_8_15 0xDF
+#define REG_AUDIO_N_16_23 0xE0
+
+#define REG_AVI_INFO_DB1 0xE9
+#define REG_AVI_INFO_DB2 0xEA
+#define REG_AVI_INFO_DB3 0xEB
+#define REG_AVI_INFO_DB4 0xEC
+#define REG_AVI_INFO_DB5 0xED
+#define REG_AVI_INFO_SUM 0xF6
+
+#define REG_AUD_INFOFRAM_DB1 0xF7
+#define REG_AUD_INFOFRAM_DB2 0xF8
+#define REG_AUD_INFOFRAM_DB3 0xF9
+#define REG_AUD_INFOFRAM_DB4 0xFA
+#define REG_AUD_INFOFRAM_SUM 0xFB
+
+/* the following six registers are in bank1 */
+#define REG_DRV_0_DB_800_MV 0x7E
+#define REG_PRE_0_DB_800_MV 0x7F
+#define REG_PRE_3P5_DB_800_MV 0x81
+#define REG_SSC_CTRL0 0x88
+#define REG_SSC_CTRL1 0x89
+#define REG_SSC_CTRL2 0x8A
+
+#define RBR DP_LINK_BW_1_62
+#define HBR DP_LINK_BW_2_7
+#define HBR2 DP_LINK_BW_5_4
+#define HBR3 DP_LINK_BW_8_1
+
+#define DPCD_V_1_1 0x11
+#define MISC_VERB 0xF0
+#define MISC_VERC 0x70
+#define I2S_INPUT_FORMAT_STANDARD 0
+#define I2S_INPUT_FORMAT_32BIT 1
+#define I2S_INPUT_LEFT_JUSTIFIED 0
+#define I2S_INPUT_RIGHT_JUSTIFIED 1
+#define I2S_DATA_1T_DELAY 0
+#define I2S_DATA_NO_DELAY 1
+#define I2S_WS_LEFT_CHANNEL 0
+#define I2S_WS_RIGHT_CHANNEL 1
+#define I2S_DATA_MSB_FIRST 0
+#define I2S_DATA_LSB_FIRST 1
+#define WORD_LENGTH_16BIT 0
+#define WORD_LENGTH_18BIT 1
+#define WORD_LENGTH_20BIT 2
+#define WORD_LENGTH_24BIT 3
+#define DEBUGFS_DIR_NAME "it6505-debugfs"
+#define READ_BUFFER_SIZE 200
+
+/* Vendor option */
+#define HDCP_DESIRED 1
+#define MAX_LANE_COUNT 4
+#define MAX_LINK_RATE HBR
+#define AUTO_TRAIN_RETRY 3
+#define MAX_HDCP_DOWN_STREAM_COUNT 10
+#define MAX_CR_LEVEL 0x03
+#define MAX_EQ_LEVEL 0x03
+#define AUX_WAIT_TIMEOUT_MS 15
+#define AUX_FIFO_MAX_SIZE 32
+#define PIXEL_CLK_DELAY 1
+#define PIXEL_CLK_INVERSE 0
+#define ADJUST_PHASE_THRESHOLD 80000
+#define DPI_PIXEL_CLK_MAX 95000
+#define HDCP_SHA1_FIFO_LEN (MAX_HDCP_DOWN_STREAM_COUNT * 5 + 10)
+#define DEFAULT_PWR_ON 0
+#define DEFAULT_DRV_HOLD 0
+
+#define AUDIO_SELECT I2S
+#define AUDIO_TYPE LPCM
+#define AUDIO_SAMPLE_RATE SAMPLE_RATE_48K
+#define AUDIO_CHANNEL_COUNT 2
+#define I2S_INPUT_FORMAT I2S_INPUT_FORMAT_32BIT
+#define I2S_JUSTIFIED I2S_INPUT_LEFT_JUSTIFIED
+#define I2S_DATA_DELAY I2S_DATA_1T_DELAY
+#define I2S_WS_CHANNEL I2S_WS_LEFT_CHANNEL
+#define I2S_DATA_SEQUENCE I2S_DATA_MSB_FIRST
+#define AUDIO_WORD_LENGTH WORD_LENGTH_24BIT
+
+enum aux_cmd_type {
+	CMD_AUX_NATIVE_READ = 0x0,
+	CMD_AUX_NATIVE_WRITE = 0x5,
+	CMD_AUX_I2C_EDID_READ = 0xB,
+};
+
+enum aux_cmd_reply {
+	REPLY_ACK,
+	REPLY_NACK,
+	REPLY_DEFER,
+};
+
+enum link_train_status {
+	LINK_IDLE,
+	LINK_BUSY,
+	LINK_OK,
+};
+
+enum hdcp_state {
+	HDCP_AUTH_IDLE,
+	HDCP_AUTH_GOING,
+	HDCP_AUTH_DONE,
+};
+
+struct it6505_platform_data {
+	struct regulator *pwr18;
+	struct regulator *ovdd;
+	struct gpio_desc *gpiod_reset;
+};
+
+enum it6505_audio_select {
+	I2S = 0,
+	SPDIF,
+};
+
+enum it6505_audio_sample_rate {
+	SAMPLE_RATE_24K = 0x6,
+	SAMPLE_RATE_32K = 0x3,
+	SAMPLE_RATE_48K = 0x2,
+	SAMPLE_RATE_96K = 0xA,
+	SAMPLE_RATE_192K = 0xE,
+	SAMPLE_RATE_44_1K = 0x0,
+	SAMPLE_RATE_88_2K = 0x8,
+	SAMPLE_RATE_176_4K = 0xC,
+};
+
+enum it6505_audio_type {
+	LPCM = 0,
+	NLPCM,
+	DSS,
+};
+
+struct it6505_audio_data {
+	enum it6505_audio_select select;
+	enum it6505_audio_sample_rate sample_rate;
+	enum it6505_audio_type type;
+	u8 word_length;
+	u8 channel_count;
+	u8 i2s_input_format;
+	u8 i2s_justified;
+	u8 i2s_data_delay;
+	u8 i2s_ws_channel;
+	u8 i2s_data_sequence;
+};
+
+struct it6505_audio_sample_rate_map {
+	enum it6505_audio_sample_rate rate;
+	int sample_rate_value;
+};
+
+struct it6505_drm_dp_link {
+	unsigned char revision;
+	unsigned int rate;
+	unsigned int num_lanes;
+	unsigned long capabilities;
+};
+
+struct debugfs_entries {
+	char *name;
+	const struct file_operations *fops;
+};
+
+struct it6505 {
+	struct drm_dp_aux aux;
+	struct drm_bridge bridge;
+	struct i2c_client *client;
+	struct it6505_drm_dp_link link;
+	struct it6505_platform_data pdata;
+	/*
+	 * Mutex protects extcon and interrupt functions from interfering
+	 * each other.
+	 */
+	struct mutex extcon_lock;
+	struct mutex mode_lock; /* used to bridge_detect */
+	struct mutex aux_lock; /* used to aux data transfers */
+	struct regmap *regmap;
+	struct drm_display_mode source_output_mode;
+	struct drm_display_mode video_info;
+	struct notifier_block event_nb;
+	struct extcon_dev *extcon;
+	struct work_struct extcon_wq;
+	enum drm_connector_status connector_status;
+	enum link_train_status link_state;
+	struct work_struct link_works;
+	u8 dpcd[DP_RECEIVER_CAP_SIZE];
+	u8 lane_count;
+	u8 link_rate_bw_code;
+	u8 sink_count;
+	bool step_train;
+	bool branch_device;
+	bool enable_ssc;
+	bool lane_swap_disabled;
+	bool lane_swap;
+	bool powered;
+	bool hpd_state;
+	u32 afe_setting;
+	enum hdcp_state hdcp_status;
+	struct delayed_work hdcp_work;
+	struct work_struct hdcp_wait_ksv_list;
+	struct completion wait_edid_complete;
+	u8 auto_train_retry;
+	bool hdcp_desired;
+	bool is_repeater;
+	u8 hdcp_down_stream_count;
+	u8 bksvs[DRM_HDCP_KSV_LEN];
+	u8 sha1_input[HDCP_SHA1_FIFO_LEN];
+	bool enable_enhanced_frame;
+	hdmi_codec_plugged_cb plugged_cb;
+	struct device *codec_dev;
+	struct delayed_work delayed_audio;
+	struct it6505_audio_data audio;
+	struct dentry *debugfs;
+
+	/* it6505 driver hold option */
+	bool enable_drv_hold;
+};
+
+struct it6505_step_train_para {
+	u8 voltage_swing[MAX_LANE_COUNT];
+	u8 pre_emphasis[MAX_LANE_COUNT];
+};
+
+/*
+ * Vendor option afe settings for different platforms
+ * 0: without FPC cable
+ * 1: with FPC cable
+ */
+
+static const u8 afe_setting_table[][3] = {
+	{0x82, 0x00, 0x45},
+	{0x93, 0x2A, 0x85}
+};
+
+static const struct it6505_audio_sample_rate_map audio_sample_rate_map[] = {
+	{SAMPLE_RATE_24K, 24000},
+	{SAMPLE_RATE_32K, 32000},
+	{SAMPLE_RATE_48K, 48000},
+	{SAMPLE_RATE_96K, 96000},
+	{SAMPLE_RATE_192K, 192000},
+	{SAMPLE_RATE_44_1K, 44100},
+	{SAMPLE_RATE_88_2K, 88200},
+	{SAMPLE_RATE_176_4K, 176400},
+};
+
+static const struct regmap_range it6505_bridge_volatile_ranges[] = {
+	{ .range_min = 0, .range_max = 0xFF },
+};
+
+static const struct regmap_access_table it6505_bridge_volatile_table = {
+	.yes_ranges = it6505_bridge_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(it6505_bridge_volatile_ranges),
+};
+
+static const struct regmap_config it6505_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.volatile_table = &it6505_bridge_volatile_table,
+	.cache_type = REGCACHE_NONE,
+};
+
+static int it6505_read(struct it6505 *it6505, unsigned int reg_addr)
+{
+	unsigned int value;
+	int err;
+	struct device *dev = &it6505->client->dev;
+
+	err = regmap_read(it6505->regmap, reg_addr, &value);
+	if (err < 0) {
+		dev_err(dev, "read failed reg[0x%x] err: %d", reg_addr, err);
+		return err;
+	}
+
+	return value;
+}
+
+static int it6505_write(struct it6505 *it6505, unsigned int reg_addr,
+			unsigned int reg_val)
+{
+	int err;
+	struct device *dev = &it6505->client->dev;
+
+	err = regmap_write(it6505->regmap, reg_addr, reg_val);
+
+	if (err < 0) {
+		dev_err(dev, "write failed reg[0x%x] = 0x%x err = %d",
+			reg_addr, reg_val, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int it6505_set_bits(struct it6505 *it6505, unsigned int reg,
+			   unsigned int mask, unsigned int value)
+{
+	int err;
+	struct device *dev = &it6505->client->dev;
+
+	err = regmap_update_bits(it6505->regmap, reg, mask, value);
+	if (err < 0) {
+		dev_err(dev, "write reg[0x%x] = 0x%x mask = 0x%x failed err %d",
+			reg, value, mask, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static void it6505_debug_print(struct it6505 *it6505, unsigned int reg,
+			       const char *prefix)
+{
+	struct device *dev = &it6505->client->dev;
+	int val;
+
+	if (likely(!(__drm_debug & DRM_UT_DRIVER)))
+		return;
+
+	val = it6505_read(it6505, reg);
+	if (val < 0)
+		DRM_DEV_DEBUG_DRIVER(dev, "%s reg[%02x] read error (%d)",
+				     prefix, reg, val);
+	else
+		DRM_DEV_DEBUG_DRIVER(dev, "%s reg[%02x] = 0x%02x", prefix, reg,
+				     val);
+}
+
+static int it6505_dpcd_read(struct it6505 *it6505, unsigned long offset)
+{
+	u8 value;
+	int ret;
+	struct device *dev = &it6505->client->dev;
+
+	ret = drm_dp_dpcd_readb(&it6505->aux, offset, &value);
+	if (ret < 0) {
+		dev_err(dev, "DPCD read failed [0x%lx] ret: %d", offset, ret);
+		return ret;
+	}
+	return value;
+}
+
+static int it6505_dpcd_write(struct it6505 *it6505, unsigned long offset,
+			     u8 datain)
+{
+	int ret;
+	struct device *dev = &it6505->client->dev;
+
+	ret = drm_dp_dpcd_writeb(&it6505->aux, offset, datain);
+	if (ret < 0) {
+		dev_err(dev, "DPCD write failed [0x%lx] ret: %d", offset, ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int it6505_get_dpcd(struct it6505 *it6505, int offset, u8 *dpcd, int num)
+{
+	int ret;
+	struct device *dev = &it6505->client->dev;
+
+	ret = drm_dp_dpcd_read(&it6505->aux, offset, dpcd, num);
+
+	if (ret < 0)
+		return ret;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "ret = %d DPCD[0x%x] = 0x%*ph", ret, offset,
+			     num, dpcd);
+
+	return 0;
+}
+
+static void it6505_dump(struct it6505 *it6505)
+{
+	unsigned int i, j;
+	u8 regs[16];
+	struct device *dev = &it6505->client->dev;
+
+	for (i = 0; i <= 0xff; i += 16) {
+		for (j = 0; j < 16; j++)
+			regs[j] = it6505_read(it6505, i + j);
+
+		DRM_DEV_DEBUG_DRIVER(dev, "[0x%02x] = %16ph", i, regs);
+	}
+}
+
+static bool it6505_get_sink_hpd_status(struct it6505 *it6505)
+{
+	int reg_0d;
+
+	reg_0d = it6505_read(it6505, REG_SYSTEM_STS);
+
+	if (reg_0d < 0)
+		return false;
+
+	return reg_0d & HPD_STS;
+}
+
+static int it6505_read_word(struct it6505 *it6505, unsigned int reg)
+{
+	int val0, val1;
+
+	val0 = it6505_read(it6505, reg);
+	if (val0 < 0)
+		return val0;
+
+	val1 = it6505_read(it6505, reg + 1);
+	if (val1 < 0)
+		return val1;
+
+	return (val1 << 8) | val0;
+}
+
+static void it6505_calc_video_info(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	int hsync_pol, vsync_pol, interlaced;
+	int htotal, hdes, hdew, hfph, hsyncw;
+	int vtotal, vdes, vdew, vfph, vsyncw;
+	int rddata, i, pclk, sum = 0;
+
+	usleep_range(10000, 15000);
+	rddata = it6505_read(it6505, REG_INPUT_CTRL);
+	hsync_pol = rddata & INPUT_HSYNC_POL;
+	vsync_pol = (rddata & INPUT_VSYNC_POL) >> 2;
+	interlaced = (rddata & INPUT_INTERLACED) >> 4;
+
+	htotal = it6505_read_word(it6505, REG_INPUT_HTOTAL) & 0x1FFF;
+	hdes = it6505_read_word(it6505, REG_INPUT_HACTIVE_START) & 0x1FFF;
+	hdew = it6505_read_word(it6505, REG_INPUT_HACTIVE_WIDTH) & 0x1FFF;
+	hfph = it6505_read_word(it6505, REG_INPUT_HFRONT_PORCH) & 0x1FFF;
+	hsyncw = it6505_read_word(it6505, REG_INPUT_HSYNC_WIDTH) & 0x1FFF;
+
+	vtotal = it6505_read_word(it6505, REG_INPUT_VTOTAL) & 0xFFF;
+	vdes = it6505_read_word(it6505, REG_INPUT_VACTIVE_START) & 0xFFF;
+	vdew = it6505_read_word(it6505, REG_INPUT_VACTIVE_WIDTH) & 0xFFF;
+	vfph = it6505_read_word(it6505, REG_INPUT_VFRONT_PORCH) & 0xFFF;
+	vsyncw = it6505_read_word(it6505, REG_INPUT_VSYNC_WIDTH) & 0xFFF;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "hsync_pol:%d, vsync_pol:%d, interlaced:%d",
+			     hsync_pol, vsync_pol, interlaced);
+	DRM_DEV_DEBUG_DRIVER(dev, "hactive_start:%d, vactive_start:%d",
+			     hdes, vdes);
+
+	for (i = 0; i < 10; i++) {
+		it6505_set_bits(it6505, REG_DATA_CTRL0, ENABLE_PCLK_COUNTER,
+				ENABLE_PCLK_COUNTER);
+		usleep_range(10000, 15000);
+		it6505_set_bits(it6505, REG_DATA_CTRL0, ENABLE_PCLK_COUNTER,
+				0x00);
+		rddata = it6505_read_word(it6505, REG_PCLK_COUNTER_VALUE) &
+			 0xFFF;
+
+		sum += rddata;
+	}
+
+	if (sum == 0) {
+		DRM_DEV_DEBUG_DRIVER(dev, "calc video timing error");
+		return;
+	}
+
+	sum /= 10;
+	pclk = 13500 * 2048 / sum;
+	it6505->video_info.clock = pclk;
+	it6505->video_info.hdisplay = hdew;
+	it6505->video_info.hsync_start = hdew + hfph;
+	it6505->video_info.hsync_end = hdew + hfph + hsyncw;
+	it6505->video_info.htotal = htotal;
+	it6505->video_info.vdisplay = vdew;
+	it6505->video_info.vsync_start = vdew + vfph;
+	it6505->video_info.vsync_end = vdew + vfph + vsyncw;
+	it6505->video_info.vtotal = vtotal;
+
+	DRM_DEV_DEBUG_DRIVER(dev, DRM_MODE_FMT,
+			     DRM_MODE_ARG(&it6505->video_info));
+}
+
+static int it6505_drm_dp_link_probe(struct drm_dp_aux *aux,
+				    struct it6505_drm_dp_link *link)
+{
+	u8 values[3];
+	int err;
+
+	memset(link, 0, sizeof(*link));
+
+	err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values));
+	if (err < 0)
+		return err;
+
+	link->revision = values[0];
+	link->rate = drm_dp_bw_code_to_link_rate(values[1]);
+	link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
+
+	if (values[2] & DP_ENHANCED_FRAME_CAP)
+		link->capabilities = DP_ENHANCED_FRAME_CAP;
+
+	return 0;
+}
+
+static int it6505_drm_dp_link_power_up(struct drm_dp_aux *aux,
+				       struct it6505_drm_dp_link *link)
+{
+	u8 value;
+	int err;
+
+	/* DP_SET_POWER register is only available on DPCD v1.1 and later */
+	if (link->revision < DPCD_V_1_1)
+		return 0;
+
+	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
+	if (err < 0)
+		return err;
+
+	value &= ~DP_SET_POWER_MASK;
+	value |= DP_SET_POWER_D0;
+
+	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
+	if (err < 0)
+		return err;
+
+	/*
+	 * According to the DP 1.1 specification, a "Sink Device must exit the
+	 * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink
+	 * Control Field" (register 0x600).
+	 */
+	usleep_range(1000, 2000);
+
+	return 0;
+}
+
+static void it6505_clear_int(struct it6505 *it6505)
+{
+	it6505_write(it6505, INT_STATUS_01, 0xFF);
+	it6505_write(it6505, INT_STATUS_02, 0xFF);
+	it6505_write(it6505, INT_STATUS_03, 0xFF);
+}
+
+static void it6505_int_mask_enable(struct it6505 *it6505)
+{
+	it6505_write(it6505, INT_MASK_01, BIT(INT_HPD_CHANGE) |
+		     BIT(INT_RECEIVE_HPD_IRQ) | BIT(INT_SCDT_CHANGE) |
+		     BIT(INT_HDCP_FAIL) | BIT(INT_HDCP_DONE));
+
+	it6505_write(it6505, INT_MASK_02, BIT(INT_AUX_CMD_FAIL) |
+		     BIT(INT_HDCP_KSV_CHECK) | BIT(INT_AUDIO_FIFO_ERROR));
+
+	it6505_write(it6505, INT_MASK_03, BIT(INT_LINK_TRAIN_FAIL) |
+		     BIT(INT_VID_FIFO_ERROR) | BIT(INT_IO_LATCH_FIFO_OVERFLOW));
+}
+
+static void it6505_int_mask_disable(struct it6505 *it6505)
+{
+	it6505_write(it6505, INT_MASK_01, 0x00);
+	it6505_write(it6505, INT_MASK_02, 0x00);
+	it6505_write(it6505, INT_MASK_03, 0x00);
+}
+
+static void it6505_lane_termination_on(struct it6505 *it6505)
+{
+	int regcf;
+
+	regcf = it6505_read(it6505, REG_USER_DRV_PRE);
+
+	if (regcf == MISC_VERB)
+		it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL, 0x80, 0x00);
+
+	if (regcf == MISC_VERC) {
+		if (it6505->lane_swap) {
+			switch (it6505->lane_count) {
+			case 1:
+			case 2:
+				it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL,
+						0x0C, 0x08);
+				break;
+			default:
+				it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL,
+						0x0C, 0x0C);
+				break;
+			}
+		} else {
+			switch (it6505->lane_count) {
+			case 1:
+			case 2:
+				it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL,
+						0x0C, 0x04);
+				break;
+			default:
+				it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL,
+						0x0C, 0x0C);
+				break;
+			}
+		}
+	}
+}
+
+static void it6505_lane_termination_off(struct it6505 *it6505)
+{
+	int regcf;
+
+	regcf = it6505_read(it6505, REG_USER_DRV_PRE);
+
+	if (regcf == MISC_VERB)
+		it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL, 0x80, 0x80);
+
+	if (regcf == MISC_VERC)
+		it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL, 0x0C, 0x00);
+}
+
+static void it6505_lane_power_on(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_LINK_DRV, 0xF1,
+			(it6505->lane_swap ?
+				 GENMASK(7, 8 - it6505->lane_count) :
+				 GENMASK(3 + it6505->lane_count, 4)) |
+				0x01);
+}
+
+static void it6505_lane_power_off(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_LINK_DRV, 0xF0, 0x00);
+}
+
+static void it6505_lane_off(struct it6505 *it6505)
+{
+	it6505_lane_power_off(it6505);
+	it6505_lane_termination_off(it6505);
+}
+
+static void it6505_aux_termination_on(struct it6505 *it6505)
+{
+	int regcf;
+
+	regcf = it6505_read(it6505, REG_USER_DRV_PRE);
+
+	if (regcf == MISC_VERB)
+		it6505_lane_termination_on(it6505);
+
+	if (regcf == MISC_VERC)
+		it6505_set_bits(it6505, REG_DRV_LN_DATA_SEL, 0x80, 0x80);
+}
+
+static void it6505_aux_power_on(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_AUX, 0x02, 0x02);
+}
+
+static void it6505_aux_on(struct it6505 *it6505)
+{
+	it6505_aux_power_on(it6505);
+	it6505_aux_termination_on(it6505);
+}
+
+static void it6505_aux_reset(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_RESET_CTRL, AUX_RESET, AUX_RESET);
+	it6505_set_bits(it6505, REG_RESET_CTRL, AUX_RESET, 0x00);
+}
+
+static void it6505_reset_logic(struct it6505 *it6505)
+{
+	regmap_write(it6505->regmap, REG_RESET_CTRL, ALL_LOGIC_RESET);
+	usleep_range(1000, 1500);
+}
+
+static bool it6505_aux_op_finished(struct it6505 *it6505)
+{
+	int reg2b = it6505_read(it6505, REG_AUX_CMD_REQ);
+
+	if (reg2b < 0)
+		return false;
+
+	return (reg2b & AUX_BUSY) == 0;
+}
+
+static int it6505_aux_wait(struct it6505 *it6505)
+{
+	int status;
+	unsigned long timeout;
+	struct device *dev = &it6505->client->dev;
+
+	timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
+
+	while (!it6505_aux_op_finished(it6505)) {
+		if (time_after(jiffies, timeout)) {
+			dev_err(dev, "Timed out waiting AUX to finish");
+			return -ETIMEDOUT;
+		}
+		usleep_range(1000, 2000);
+	}
+
+	status = it6505_read(it6505, REG_AUX_ERROR_STS);
+	if (status < 0) {
+		dev_err(dev, "Failed to read AUX channel: %d", status);
+		return status;
+	}
+
+	return 0;
+}
+
+static ssize_t it6505_aux_operation(struct it6505 *it6505,
+				    enum aux_cmd_type cmd,
+				    unsigned int address, u8 *buffer,
+				    size_t size, enum aux_cmd_reply *reply)
+{
+	int i, ret;
+	bool aux_write_check = false;
+
+	if (!it6505_get_sink_hpd_status(it6505))
+		return -EIO;
+
+	/* set AUX user mode */
+	it6505_set_bits(it6505, REG_AUX_CTRL, AUX_USER_MODE, AUX_USER_MODE);
+
+aux_op_start:
+	if (cmd == CMD_AUX_I2C_EDID_READ) {
+		/* AUX EDID FIFO has max length of AUX_FIFO_MAX_SIZE bytes. */
+		size = min_t(size_t, size, AUX_FIFO_MAX_SIZE);
+		/* Enable AUX FIFO read back and clear FIFO */
+		it6505_set_bits(it6505, REG_AUX_CTRL,
+				AUX_EN_FIFO_READ | CLR_EDID_FIFO,
+				AUX_EN_FIFO_READ | CLR_EDID_FIFO);
+
+		it6505_set_bits(it6505, REG_AUX_CTRL,
+				AUX_EN_FIFO_READ | CLR_EDID_FIFO,
+				AUX_EN_FIFO_READ);
+	} else {
+		/* The DP AUX transmit buffer has 4 bytes. */
+		size = min_t(size_t, size, 4);
+		it6505_set_bits(it6505, REG_AUX_CTRL, AUX_NO_SEGMENT_WR,
+				AUX_NO_SEGMENT_WR);
+	}
+
+	/* Start Address[7:0] */
+	it6505_write(it6505, REG_AUX_ADR_0_7, (address >> 0) & 0xFF);
+	/* Start Address[15:8] */
+	it6505_write(it6505, REG_AUX_ADR_8_15, (address >> 8) & 0xFF);
+	/* WriteNum[3:0]+StartAdr[19:16] */
+	it6505_write(it6505, REG_AUX_ADR_16_19,
+		     ((address >> 16) & 0x0F) | ((size - 1) << 4));
+
+	if (cmd == CMD_AUX_NATIVE_WRITE)
+		regmap_bulk_write(it6505->regmap, REG_AUX_OUT_DATA0, buffer,
+				  size);
+
+	/* Aux Fire */
+	it6505_write(it6505, REG_AUX_CMD_REQ, cmd);
+
+	ret = it6505_aux_wait(it6505);
+	if (ret < 0)
+		goto aux_op_err;
+
+	ret = it6505_read(it6505, REG_AUX_ERROR_STS);
+	if (ret < 0)
+		goto aux_op_err;
+
+	switch ((ret >> 6) & 0x3) {
+	case 0:
+		*reply = REPLY_ACK;
+		break;
+	case 1:
+		*reply = REPLY_DEFER;
+		ret = -EAGAIN;
+		goto aux_op_err;
+	case 2:
+		*reply = REPLY_NACK;
+		ret = -EIO;
+		goto aux_op_err;
+	case 3:
+		ret = -ETIMEDOUT;
+		goto aux_op_err;
+	}
+
+	/* Read back Native Write data */
+	if (cmd == CMD_AUX_NATIVE_WRITE) {
+		aux_write_check = true;
+		cmd = CMD_AUX_NATIVE_READ;
+		goto aux_op_start;
+	}
+
+	if (cmd == CMD_AUX_I2C_EDID_READ) {
+		for (i = 0; i < size; i++) {
+			ret = it6505_read(it6505, REG_AUX_DATA_FIFO);
+			if (ret < 0)
+				goto aux_op_err;
+			buffer[i] = ret;
+		}
+	} else {
+		for (i = 0; i < size; i++) {
+			ret = it6505_read(it6505, REG_AUX_DATA_0_7 + i);
+			if (ret < 0)
+				goto aux_op_err;
+
+			if (aux_write_check && buffer[size - 1 - i] != ret) {
+				ret = -EINVAL;
+				goto aux_op_err;
+			}
+
+			buffer[size - 1 - i] = ret;
+		}
+	}
+
+	ret = i;
+
+aux_op_err:
+	if (cmd == CMD_AUX_I2C_EDID_READ) {
+		/* clear AUX FIFO */
+		it6505_set_bits(it6505, REG_AUX_CTRL,
+				AUX_EN_FIFO_READ | CLR_EDID_FIFO,
+				AUX_EN_FIFO_READ | CLR_EDID_FIFO);
+		it6505_set_bits(it6505, REG_AUX_CTRL,
+				AUX_EN_FIFO_READ | CLR_EDID_FIFO, 0x00);
+	}
+
+	/* Leave AUX user mode */
+	it6505_set_bits(it6505, REG_AUX_CTRL, AUX_USER_MODE, 0);
+
+	return ret;
+}
+
+static ssize_t it6505_aux_do_transfer(struct it6505 *it6505,
+				      enum aux_cmd_type cmd,
+				      unsigned int address, u8 *buffer,
+				      size_t size, enum aux_cmd_reply *reply)
+{
+	int i, ret_size, ret = 0, request_size;
+
+	mutex_lock(&it6505->aux_lock);
+	for (i = 0; i < size; i += 4) {
+		request_size = min((int)size - i, 4);
+		ret_size = it6505_aux_operation(it6505, cmd, address + i,
+						buffer + i, request_size,
+						reply);
+		if (ret_size < 0) {
+			ret = ret_size;
+			goto aux_op_err;
+		}
+
+		ret += ret_size;
+	}
+
+aux_op_err:
+	mutex_unlock(&it6505->aux_lock);
+	return ret;
+}
+
+static ssize_t it6505_aux_transfer(struct drm_dp_aux *aux,
+				   struct drm_dp_aux_msg *msg)
+{
+	struct it6505 *it6505 = container_of(aux, struct it6505, aux);
+	u8 cmd;
+	bool is_i2c = !(msg->request & DP_AUX_NATIVE_WRITE);
+	int ret;
+	enum aux_cmd_reply reply;
+
+	/* IT6505 doesn't support arbitrary I2C read / write. */
+	if (is_i2c)
+		return -EINVAL;
+
+	switch (msg->request) {
+	case DP_AUX_NATIVE_READ:
+		cmd = CMD_AUX_NATIVE_READ;
+		break;
+	case DP_AUX_NATIVE_WRITE:
+		cmd = CMD_AUX_NATIVE_WRITE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = it6505_aux_do_transfer(it6505, cmd, msg->address, msg->buffer,
+				     msg->size, &reply);
+	if (ret < 0)
+		return ret;
+
+	switch (reply) {
+	case REPLY_ACK:
+		msg->reply = DP_AUX_NATIVE_REPLY_ACK;
+		break;
+	case REPLY_NACK:
+		msg->reply = DP_AUX_NATIVE_REPLY_NACK;
+		break;
+	case REPLY_DEFER:
+		msg->reply = DP_AUX_NATIVE_REPLY_DEFER;
+		break;
+	}
+
+	return ret;
+}
+
+static int it6505_get_edid_block(void *data, u8 *buf, unsigned int block,
+				 size_t len)
+{
+	struct it6505 *it6505 = data;
+	struct device *dev = &it6505->client->dev;
+	enum aux_cmd_reply reply;
+	int offset, ret, aux_retry = 100;
+
+	it6505_aux_reset(it6505);
+	DRM_DEV_DEBUG_DRIVER(dev, "block number = %d", block);
+
+	for (offset = 0; offset < EDID_LENGTH;) {
+		ret = it6505_aux_do_transfer(it6505, CMD_AUX_I2C_EDID_READ,
+					     block * EDID_LENGTH + offset,
+					     buf + offset, 8, &reply);
+
+		if (ret < 0 && ret != -EAGAIN)
+			return ret;
+
+		switch (reply) {
+		case REPLY_ACK:
+			DRM_DEV_DEBUG_DRIVER(dev, "[0x%02x]: %8ph", offset,
+					     buf + offset);
+			offset += 8;
+			aux_retry = 100;
+			break;
+		case REPLY_NACK:
+			return -EIO;
+		case REPLY_DEFER:
+			msleep(20);
+			if (!(--aux_retry))
+				return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static void it6505_variable_config(struct it6505 *it6505)
+{
+	it6505->link_rate_bw_code = HBR;
+	it6505->lane_count = MAX_LANE_COUNT;
+	it6505->link_state = LINK_IDLE;
+	it6505->hdcp_desired = HDCP_DESIRED;
+	it6505->auto_train_retry = AUTO_TRAIN_RETRY;
+	it6505->audio.select = AUDIO_SELECT;
+	it6505->audio.sample_rate = AUDIO_SAMPLE_RATE;
+	it6505->audio.channel_count = AUDIO_CHANNEL_COUNT;
+	it6505->audio.type = AUDIO_TYPE;
+	it6505->audio.i2s_input_format = I2S_INPUT_FORMAT;
+	it6505->audio.i2s_justified = I2S_JUSTIFIED;
+	it6505->audio.i2s_data_delay = I2S_DATA_DELAY;
+	it6505->audio.i2s_ws_channel = I2S_WS_CHANNEL;
+	it6505->audio.i2s_data_sequence = I2S_DATA_SEQUENCE;
+	it6505->audio.word_length = AUDIO_WORD_LENGTH;
+	memset(it6505->sha1_input, 0, sizeof(it6505->sha1_input));
+	memset(it6505->bksvs, 0, sizeof(it6505->bksvs));
+}
+
+static int it6505_send_video_infoframe(struct it6505 *it6505,
+				       struct hdmi_avi_infoframe *frame)
+{
+	u8 buffer[HDMI_INFOFRAME_HEADER_SIZE + HDMI_AVI_INFOFRAME_SIZE];
+	int err;
+	struct device *dev = &it6505->client->dev;
+
+	err = hdmi_avi_infoframe_pack(frame, buffer, sizeof(buffer));
+	if (err < 0) {
+		dev_err(dev, "Failed to pack AVI infoframe: %d", err);
+		return err;
+	}
+
+	err = it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AVI_PKT, 0x00);
+	if (err)
+		return err;
+
+	err = regmap_bulk_write(it6505->regmap, REG_AVI_INFO_DB1,
+				buffer + HDMI_INFOFRAME_HEADER_SIZE,
+				frame->length);
+	if (err)
+		return err;
+
+	err = it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AVI_PKT,
+			      EN_AVI_PKT);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static void it6505_get_extcon_property(struct it6505 *it6505)
+{
+	int err;
+	union extcon_property_value property;
+	struct device *dev = &it6505->client->dev;
+
+	if (it6505->extcon && !it6505->lane_swap_disabled) {
+		err = extcon_get_property(it6505->extcon, EXTCON_DISP_DP,
+					  EXTCON_PROP_USB_TYPEC_POLARITY,
+					  &property);
+		if (err) {
+			dev_err(dev, "get property fail!");
+			return;
+		}
+		it6505->lane_swap = property.intval;
+	}
+}
+
+static void it6505_clk_phase_adjustment(struct it6505 *it6505,
+					const struct drm_display_mode *mode)
+{
+	int clock = mode->clock;
+
+	it6505_set_bits(it6505, REG_CLK_CTRL0, M_PCLK_DELAY,
+			clock < ADJUST_PHASE_THRESHOLD ? PIXEL_CLK_DELAY : 0);
+	it6505_set_bits(it6505, REG_DATA_CTRL0, VIDEO_LATCH_EDGE,
+			PIXEL_CLK_INVERSE << 4);
+}
+
+static void it6505_link_reset_step_train(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_TRAIN_CTRL0,
+			FORCE_CR_DONE | FORCE_EQ_DONE, 0x00);
+	it6505_dpcd_write(it6505, DP_TRAINING_PATTERN_SET,
+			  DP_TRAINING_PATTERN_DISABLE);
+}
+
+static void it6505_init(struct it6505 *it6505)
+{
+	it6505_write(it6505, REG_AUX_OPT, AUX_AUTO_RST | AUX_FIX_FREQ);
+	it6505_write(it6505, REG_AUX_CTRL, AUX_NO_SEGMENT_WR);
+	it6505_write(it6505, REG_HDCP_CTRL2, HDCP_AN_SEL | HDCP_HW_HPDIRQ_ACT);
+	it6505_write(it6505, REG_VID_BUS_CTRL0, IN_DDR | DDR_CD);
+	it6505_write(it6505, REG_VID_BUS_CTRL1, 0x01);
+	it6505_write(it6505, REG_AUDIO_CTRL0, AUDIO_16B_BOUND);
+
+	/* chip internal setting, don't modify */
+	it6505_write(it6505, REG_HPD_IRQ_TIME, 0xF5);
+	it6505_write(it6505, REG_AUX_DEBUG_MODE, 0x4D);
+	it6505_write(it6505, REG_AUX_OPT2, 0x17);
+	it6505_write(it6505, REG_HDCP_OPT, 0x60);
+	it6505_write(it6505, REG_DATA_MUTE_CTRL,
+		     EN_VID_MUTE | EN_AUD_MUTE | ENABLE_AUTO_VIDEO_FIFO_RESET);
+	it6505_write(it6505, REG_TIME_STMP_CTRL,
+		     EN_SSC_GAT | EN_ENHANCE_VID_STMP | EN_ENHANCE_AUD_STMP);
+	it6505_write(it6505, REG_INFOFRAME_CTRL, 0x00);
+	it6505_write(it6505, REG_BANK_SEL, 0x01);
+	it6505_write(it6505, REG_DRV_0_DB_800_MV,
+		     afe_setting_table[it6505->afe_setting][0]);
+	it6505_write(it6505, REG_PRE_0_DB_800_MV,
+		     afe_setting_table[it6505->afe_setting][1]);
+	it6505_write(it6505, REG_PRE_3P5_DB_800_MV,
+		     afe_setting_table[it6505->afe_setting][2]);
+	it6505_write(it6505, REG_SSC_CTRL0, 0x9E);
+	it6505_write(it6505, REG_SSC_CTRL1, 0x1C);
+	it6505_write(it6505, REG_SSC_CTRL2, 0x42);
+	it6505_write(it6505, REG_BANK_SEL, 0x00);
+}
+
+static void it6505_video_disable(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_VID_MUTE, EN_VID_MUTE);
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_VID_CTRL_PKT, 0x00);
+	it6505_set_bits(it6505, REG_RESET_CTRL, VIDEO_RESET, VIDEO_RESET);
+}
+
+static void it6505_video_reset(struct it6505 *it6505)
+{
+	it6505_link_reset_step_train(it6505);
+	it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_VID_MUTE, EN_VID_MUTE);
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_VID_CTRL_PKT, 0x00);
+	it6505_set_bits(it6505, REG_RESET_CTRL, VIDEO_RESET, VIDEO_RESET);
+	it6505_set_bits(it6505, REG_501_FIFO_CTRL, RST_501_FIFO, RST_501_FIFO);
+	it6505_set_bits(it6505, REG_501_FIFO_CTRL, RST_501_FIFO, 0x00);
+	it6505_set_bits(it6505, REG_RESET_CTRL, VIDEO_RESET, 0x00);
+}
+
+static void it6505_update_video_parameter(struct it6505 *it6505,
+					  const struct drm_display_mode *mode)
+{
+	it6505_clk_phase_adjustment(it6505, mode);
+	it6505_video_disable(it6505);
+}
+
+static bool it6505_audio_input(struct it6505 *it6505)
+{
+	int reg05, regbe;
+
+	reg05 = it6505_read(it6505, REG_RESET_CTRL);
+	it6505_set_bits(it6505, REG_RESET_CTRL, AUDIO_RESET, 0x00);
+	usleep_range(3000, 4000);
+	regbe = it6505_read(it6505, REG_AUDIO_INPUT_FREQ);
+	it6505_write(it6505, REG_RESET_CTRL, reg05);
+
+	return regbe != 0xFF;
+}
+
+static void it6505_setup_audio_channel_status(struct it6505 *it6505)
+{
+	enum it6505_audio_sample_rate sample_rate = it6505->audio.sample_rate;
+	u8 audio_word_length_map[] = { 0x02, 0x04, 0x03, 0x0B };
+
+	/* Channel Status */
+	it6505_write(it6505, REG_IEC958_STS0, it6505->audio.type << 1);
+	it6505_write(it6505, REG_IEC958_STS1, 0x00);
+	it6505_write(it6505, REG_IEC958_STS2, 0x00);
+	it6505_write(it6505, REG_IEC958_STS3, sample_rate);
+	it6505_write(it6505, REG_IEC958_STS4, (~sample_rate << 4) |
+		     audio_word_length_map[it6505->audio.word_length]);
+}
+
+static void it6505_setup_audio_format(struct it6505 *it6505)
+{
+	/* I2S MODE */
+	it6505_write(it6505, REG_AUDIO_FMT,
+		     (it6505->audio.word_length << 5) |
+		     (it6505->audio.i2s_data_sequence << 4) |
+		     (it6505->audio.i2s_ws_channel << 3) |
+		     (it6505->audio.i2s_data_delay << 2) |
+		     (it6505->audio.i2s_justified << 1) |
+		     it6505->audio.i2s_input_format);
+	if (it6505->audio.select == SPDIF) {
+		it6505_write(it6505, REG_AUDIO_FIFO_SEL, 0x00);
+		/* 0x30 = 128*FS */
+		it6505_set_bits(it6505, REG_AUX_OPT, 0xF0, 0x30);
+	} else {
+		it6505_write(it6505, REG_AUDIO_FIFO_SEL, 0xE4);
+	}
+
+	it6505_write(it6505, REG_AUDIO_CTRL0, 0x20);
+	it6505_write(it6505, REG_AUDIO_CTRL1, 0x00);
+}
+
+static void it6505_enable_audio_source(struct it6505 *it6505)
+{
+	unsigned int audio_source_count;
+
+	audio_source_count = BIT(DIV_ROUND_UP(it6505->audio.channel_count, 2))
+				 - 1;
+
+	audio_source_count |= it6505->audio.select << 4;
+
+	it6505_write(it6505, REG_AUDIO_SRC_CTRL, audio_source_count);
+}
+
+static void it6505_enable_audio_infoframe(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	u8 audio_info_ca[] = { 0x00, 0x00, 0x01, 0x03, 0x07, 0x0B, 0x0F, 0x1F };
+
+	DRM_DEV_DEBUG_DRIVER(dev, "infoframe channel_allocation:0x%02x",
+			     audio_info_ca[it6505->audio.channel_count - 1]);
+
+	it6505_write(it6505, REG_AUD_INFOFRAM_DB1, it6505->audio.channel_count
+		     - 1);
+	it6505_write(it6505, REG_AUD_INFOFRAM_DB2, 0x00);
+	it6505_write(it6505, REG_AUD_INFOFRAM_DB3,
+		     audio_info_ca[it6505->audio.channel_count - 1]);
+	it6505_write(it6505, REG_AUD_INFOFRAM_DB4, 0x00);
+	it6505_write(it6505, REG_AUD_INFOFRAM_SUM, 0x00);
+
+	/* Enable Audio InfoFrame */
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AUD_CTRL_PKT,
+			EN_AUD_CTRL_PKT);
+}
+
+static void it6505_disable_audio(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_AUD_MUTE, EN_AUD_MUTE);
+	it6505_set_bits(it6505, REG_AUDIO_SRC_CTRL, M_AUDIO_I2S_EN, 0x00);
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL, EN_AUD_CTRL_PKT, 0x00);
+	it6505_set_bits(it6505, REG_RESET_CTRL, AUDIO_RESET, AUDIO_RESET);
+}
+
+static void it6505_enable_audio(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	int regbe;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "start");
+	it6505_disable_audio(it6505);
+
+	it6505_setup_audio_channel_status(it6505);
+	it6505_setup_audio_format(it6505);
+	it6505_enable_audio_source(it6505);
+	it6505_enable_audio_infoframe(it6505);
+
+	it6505_write(it6505, REG_AUDIO_N_0_7, 0x00);
+	it6505_write(it6505, REG_AUDIO_N_8_15, 0x80);
+	it6505_write(it6505, REG_AUDIO_N_16_23, 0x00);
+
+	it6505_set_bits(it6505, REG_AUDIO_SRC_CTRL, AUDIO_FIFO_RESET,
+			AUDIO_FIFO_RESET);
+	it6505_set_bits(it6505, REG_AUDIO_SRC_CTRL, AUDIO_FIFO_RESET, 0x00);
+	it6505_set_bits(it6505, REG_RESET_CTRL, AUDIO_RESET, 0x00);
+	regbe = it6505_read(it6505, REG_AUDIO_INPUT_FREQ);
+	DRM_DEV_DEBUG_DRIVER(dev, "regbe:0x%02x audio input fs: %d.%d kHz",
+			     regbe, 6750 / regbe, (6750 % regbe) * 10 / regbe);
+	it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_AUD_MUTE, 0x00);
+}
+
+static bool it6505_use_step_train_check(struct it6505 *it6505)
+{
+	if (it6505->link.revision >= 0x12)
+		return it6505->dpcd[DP_TRAINING_AUX_RD_INTERVAL] >= 0x01;
+
+	return true;
+}
+
+static void it6505_parse_link_capabilities(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	struct it6505_drm_dp_link *link = &it6505->link;
+	int bcaps;
+
+	if (it6505->dpcd[0] == 0) {
+		it6505_aux_on(it6505);
+		it6505_get_dpcd(it6505, DP_DPCD_REV, it6505->dpcd,
+				ARRAY_SIZE(it6505->dpcd));
+	}
+
+	DRM_DEV_DEBUG_DRIVER(dev, "DPCD Rev.: %d.%d",
+			     link->revision >> 4, link->revision & 0x0F);
+
+	DRM_DEV_DEBUG_DRIVER(dev, "Sink max link rate: %d.%02d Gbps per lane",
+			     link->rate / 100000, link->rate / 1000 % 100);
+
+	it6505->link_rate_bw_code = drm_dp_link_rate_to_bw_code(link->rate);
+	DRM_DEV_DEBUG_DRIVER(dev, "link rate bw code:0x%02x",
+			     it6505->link_rate_bw_code);
+	it6505->link_rate_bw_code = min_t(int, it6505->link_rate_bw_code,
+					  MAX_LINK_RATE);
+
+	it6505->lane_count = link->num_lanes;
+	DRM_DEV_DEBUG_DRIVER(dev, "Sink support %d lanes training",
+			     it6505->lane_count);
+	it6505->lane_count = min_t(int, it6505->lane_count, MAX_LANE_COUNT);
+
+	it6505->branch_device = drm_dp_is_branch(it6505->dpcd);
+	DRM_DEV_DEBUG_DRIVER(dev, "Sink %sbranch device",
+			     it6505->branch_device ? "" : "Not ");
+
+	it6505->enable_enhanced_frame = link->capabilities;
+	DRM_DEV_DEBUG_DRIVER(dev, "Sink %sSupport Enhanced Framing",
+			     it6505->enable_enhanced_frame ? "" : "Not ");
+
+	it6505->enable_ssc = (it6505->dpcd[DP_MAX_DOWNSPREAD] &
+				DP_MAX_DOWNSPREAD_0_5);
+	DRM_DEV_DEBUG_DRIVER(dev, "Maximum Down-Spread: %s, %ssupport SSC!",
+			     it6505->enable_ssc ? "0.5" : "0",
+			     it6505->enable_ssc ? "" : "Not ");
+
+	it6505->step_train = it6505_use_step_train_check(it6505);
+	if (it6505->step_train)
+		DRM_DEV_DEBUG_DRIVER(dev, "auto train fail, will step train");
+
+	bcaps = it6505_dpcd_read(it6505, DP_AUX_HDCP_BCAPS);
+	DRM_DEV_DEBUG_DRIVER(dev, "bcaps:0x%02x", bcaps);
+	if (bcaps & DP_BCAPS_HDCP_CAPABLE) {
+		it6505->is_repeater = (bcaps & DP_BCAPS_REPEATER_PRESENT);
+		DRM_DEV_DEBUG_DRIVER(dev, "Support HDCP! Downstream is %s!",
+				     it6505->is_repeater ? "repeater" :
+				     "receiver");
+	} else {
+		DRM_DEV_DEBUG_DRIVER(dev, "Sink not support HDCP!");
+		it6505->hdcp_desired = false;
+	}
+	DRM_DEV_DEBUG_DRIVER(dev, "HDCP %s",
+			     it6505->hdcp_desired ? "desired" : "undesired");
+}
+
+static void it6505_setup_ssc(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_TRAIN_CTRL0, SPREAD_AMP_5,
+			it6505->enable_ssc ? SPREAD_AMP_5 : 0x00);
+	if (it6505->enable_ssc) {
+		it6505_write(it6505, REG_BANK_SEL, 0x01);
+		it6505_write(it6505, REG_SSC_CTRL0, 0x9E);
+		it6505_write(it6505, REG_SSC_CTRL1, 0x1C);
+		it6505_write(it6505, REG_SSC_CTRL2, 0x42);
+		it6505_write(it6505, REG_BANK_SEL, 0x00);
+		it6505_write(it6505, REG_SP_CTRL0, 0x07);
+		it6505_write(it6505, REG_IP_CTRL1, 0x29);
+		it6505_write(it6505, REG_IP_CTRL2, 0x03);
+		/* Stamp Interrupt Step */
+		it6505_set_bits(it6505, REG_TIME_STMP_CTRL, M_STAMP_STEP,
+				0x10);
+		it6505_dpcd_write(it6505, DP_DOWNSPREAD_CTRL,
+				  DP_SPREAD_AMP_0_5);
+	} else {
+		it6505_dpcd_write(it6505, DP_DOWNSPREAD_CTRL, 0x00);
+		it6505_set_bits(it6505, REG_TIME_STMP_CTRL, M_STAMP_STEP,
+				0x00);
+	}
+}
+
+static inline void it6505_link_rate_setup(struct it6505 *it6505)
+{
+	it6505_set_bits(it6505, REG_TRAIN_CTRL0, FORCE_LBR,
+			(it6505->link_rate_bw_code == RBR) ? FORCE_LBR : 0x00);
+	it6505_set_bits(it6505, REG_LINK_DRV, DRV_HS,
+			(it6505->link_rate_bw_code == RBR) ? 0x00 : DRV_HS);
+}
+
+static void it6505_lane_count_setup(struct it6505 *it6505)
+{
+	it6505_get_extcon_property(it6505);
+	it6505_set_bits(it6505, REG_TRAIN_CTRL0, LANE_SWAP,
+			it6505->lane_swap ? LANE_SWAP : 0x00);
+	it6505_set_bits(it6505, REG_TRAIN_CTRL0, LANE_COUNT_MASK,
+			(it6505->lane_count - 1) << 1);
+}
+
+static void it6505_link_training_setup(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	if (it6505->enable_enhanced_frame)
+		it6505_set_bits(it6505, REG_DATA_MUTE_CTRL,
+				ENABLE_ENHANCED_FRAME, ENABLE_ENHANCED_FRAME);
+
+	it6505_link_rate_setup(it6505);
+	it6505_lane_count_setup(it6505);
+	it6505_setup_ssc(it6505);
+	DRM_DEV_DEBUG_DRIVER(dev,
+			     "%s, %d lanes, %sable ssc, %sable enhanced frame",
+			     it6505->link_rate_bw_code != RBR ? "HBR" : "RBR",
+			     it6505->lane_count,
+			     it6505->enable_ssc ? "en" : "dis",
+			     it6505->enable_enhanced_frame ? "en" : "dis");
+}
+
+static bool it6505_link_start_auto_train(struct it6505 *it6505)
+{
+	int timeout = 500, link_training_state;
+	bool state = false;
+
+	mutex_lock(&it6505->aux_lock);
+	it6505_set_bits(it6505, REG_TRAIN_CTRL0,
+			FORCE_CR_DONE | FORCE_EQ_DONE, 0x00);
+	it6505_write(it6505, REG_TRAIN_CTRL1, FORCE_RETRAIN);
+	it6505_write(it6505, REG_TRAIN_CTRL1, AUTO_TRAIN);
+
+	while (timeout > 0) {
+		usleep_range(1000, 2000);
+		link_training_state = it6505_read(it6505, REG_LINK_TRAIN_STS);
+
+		if (link_training_state > 0 &&
+		    (link_training_state & LINK_STATE_NORP)) {
+			state = true;
+			goto unlock;
+		}
+
+		timeout--;
+	}
+unlock:
+	mutex_unlock(&it6505->aux_lock);
+
+	return state;
+}
+
+static int it6505_drm_dp_link_configure(struct it6505 *it6505)
+{
+	u8 values[2];
+	int err;
+	struct drm_dp_aux *aux = &it6505->aux;
+
+	values[0] = it6505->link_rate_bw_code;
+	values[1] = it6505->lane_count;
+
+	if (it6505->enable_enhanced_frame)
+		values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
+
+	err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static bool it6505_check_voltage_swing_max(u8 lane_voltage_swing_pre_emphasis)
+{
+	return ((lane_voltage_swing_pre_emphasis & 0x03) == MAX_CR_LEVEL);
+}
+
+static bool it6505_check_pre_emphasis_max(u8 lane_voltage_swing_pre_emphasis)
+{
+	return ((lane_voltage_swing_pre_emphasis & 0x03) == MAX_EQ_LEVEL);
+}
+
+static bool it6505_check_max_voltage_swing_reached(u8 *lane_voltage_swing,
+						   u8 lane_count)
+{
+	u8 i;
+
+	for (i = 0; i < lane_count; i++) {
+		if (lane_voltage_swing[i] & DP_TRAIN_MAX_SWING_REACHED)
+			return true;
+	}
+
+	return false;
+}
+
+static bool
+step_train_lane_voltage_para_set(struct it6505 *it6505,
+				 struct it6505_step_train_para
+				 *lane_voltage_pre_emphasis,
+				 u8 *lane_voltage_pre_emphasis_set)
+{
+	u8 *voltage_swing = lane_voltage_pre_emphasis->voltage_swing;
+	u8 *pre_emphasis = lane_voltage_pre_emphasis->pre_emphasis;
+	u8 i;
+
+	for (i = 0; i < it6505->lane_count; i++) {
+		voltage_swing[i] &= 0x03;
+		lane_voltage_pre_emphasis_set[i] = voltage_swing[i];
+		if (it6505_check_voltage_swing_max(voltage_swing[i]))
+			lane_voltage_pre_emphasis_set[i] |=
+				DP_TRAIN_MAX_SWING_REACHED;
+
+		pre_emphasis[i] &= 0x03;
+		lane_voltage_pre_emphasis_set[i] |= pre_emphasis[i]
+			<< DP_TRAIN_PRE_EMPHASIS_SHIFT;
+		if (it6505_check_pre_emphasis_max(pre_emphasis[i]))
+			lane_voltage_pre_emphasis_set[i] |=
+				DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
+		it6505_dpcd_write(it6505, DP_TRAINING_LANE0_SET + i,
+				  lane_voltage_pre_emphasis_set[i]);
+
+		if (lane_voltage_pre_emphasis_set[i] !=
+		    it6505_dpcd_read(it6505, DP_TRAINING_LANE0_SET + i))
+			return false;
+	}
+
+	return true;
+}
+
+static bool
+it6505_step_cr_train(struct it6505 *it6505,
+		     struct it6505_step_train_para *lane_voltage_pre_emphasis)
+{
+	u8 loop_count = 0, i = 0, j;
+	u8 link_status[DP_LINK_STATUS_SIZE] = { 0 };
+	u8 lane_level_config[MAX_LANE_COUNT] = { 0 };
+	int pre_emphasis_adjust = -1, voltage_swing_adjust = -1;
+	const struct drm_dp_aux *aux = &it6505->aux;
+
+	it6505_dpcd_write(it6505, DP_DOWNSPREAD_CTRL,
+			  it6505->enable_ssc ? DP_SPREAD_AMP_0_5 : 0x00);
+	it6505_dpcd_write(it6505, DP_TRAINING_PATTERN_SET,
+			  DP_TRAINING_PATTERN_1);
+
+	while (loop_count < 5 && i < 10) {
+		i++;
+		if (!step_train_lane_voltage_para_set(it6505,
+						      lane_voltage_pre_emphasis,
+						      lane_level_config))
+			continue;
+		drm_dp_link_train_clock_recovery_delay(aux, it6505->dpcd);
+		drm_dp_dpcd_read_link_status(&it6505->aux, link_status);
+
+		if (drm_dp_clock_recovery_ok(link_status, it6505->lane_count)) {
+			it6505_set_bits(it6505, REG_TRAIN_CTRL0, FORCE_CR_DONE,
+					FORCE_CR_DONE);
+			return true;
+		}
+		DRM_DEV_DEBUG_DRIVER(&it6505->client->dev, "cr not done");
+
+		if (it6505_check_max_voltage_swing_reached(lane_level_config,
+							   it6505->lane_count))
+			goto cr_train_fail;
+
+		for (j = 0; j < it6505->lane_count; j++) {
+			lane_voltage_pre_emphasis->voltage_swing[j] =
+				drm_dp_get_adjust_request_voltage(link_status,
+								  j) >>
+				DP_TRAIN_VOLTAGE_SWING_SHIFT;
+			lane_voltage_pre_emphasis->pre_emphasis[j] =
+			drm_dp_get_adjust_request_pre_emphasis(link_status,
+							       j) >>
+					DP_TRAIN_PRE_EMPHASIS_SHIFT;
+			if (voltage_swing_adjust ==
+			     lane_voltage_pre_emphasis->voltage_swing[j] &&
+			    pre_emphasis_adjust ==
+			     lane_voltage_pre_emphasis->pre_emphasis[j]) {
+				loop_count++;
+				continue;
+			}
+
+			voltage_swing_adjust =
+				lane_voltage_pre_emphasis->voltage_swing[j];
+			pre_emphasis_adjust =
+				lane_voltage_pre_emphasis->pre_emphasis[j];
+			loop_count = 0;
+
+			if (voltage_swing_adjust + pre_emphasis_adjust >
+			    MAX_EQ_LEVEL)
+				lane_voltage_pre_emphasis->voltage_swing[j] =
+					MAX_EQ_LEVEL -
+					lane_voltage_pre_emphasis
+						->pre_emphasis[j];
+		}
+	}
+
+cr_train_fail:
+	it6505_dpcd_write(it6505, DP_TRAINING_PATTERN_SET,
+			  DP_TRAINING_PATTERN_DISABLE);
+
+	return false;
+}
+
+static bool
+it6505_step_eq_train(struct it6505 *it6505,
+		     struct it6505_step_train_para *lane_voltage_pre_emphasis)
+{
+	u8 loop_count = 0, i, link_status[DP_LINK_STATUS_SIZE] = { 0 };
+	u8 lane_level_config[MAX_LANE_COUNT] = { 0 };
+	const struct drm_dp_aux *aux = &it6505->aux;
+
+	it6505_dpcd_write(it6505, DP_TRAINING_PATTERN_SET,
+			  DP_TRAINING_PATTERN_2);
+
+	while (loop_count < 6) {
+		loop_count++;
+
+		if (!step_train_lane_voltage_para_set(it6505,
+						      lane_voltage_pre_emphasis,
+						      lane_level_config))
+			continue;
+
+		drm_dp_link_train_channel_eq_delay(aux, it6505->dpcd);
+		drm_dp_dpcd_read_link_status(&it6505->aux, link_status);
+
+		if (!drm_dp_clock_recovery_ok(link_status, it6505->lane_count))
+			goto eq_train_fail;
+
+		if (drm_dp_channel_eq_ok(link_status, it6505->lane_count)) {
+			it6505_dpcd_write(it6505, DP_TRAINING_PATTERN_SET,
+					  DP_TRAINING_PATTERN_DISABLE);
+			it6505_set_bits(it6505, REG_TRAIN_CTRL0, FORCE_EQ_DONE,
+					FORCE_EQ_DONE);
+			return true;
+		}
+		DRM_DEV_DEBUG_DRIVER(&it6505->client->dev, "eq not done");
+
+		for (i = 0; i < it6505->lane_count; i++) {
+			lane_voltage_pre_emphasis->voltage_swing[i] =
+				drm_dp_get_adjust_request_voltage(link_status,
+								  i) >>
+				DP_TRAIN_VOLTAGE_SWING_SHIFT;
+			lane_voltage_pre_emphasis->pre_emphasis[i] =
+			drm_dp_get_adjust_request_pre_emphasis(link_status,
+							       i) >>
+					DP_TRAIN_PRE_EMPHASIS_SHIFT;
+
+			if (lane_voltage_pre_emphasis->voltage_swing[i] +
+				    lane_voltage_pre_emphasis->pre_emphasis[i] >
+			    MAX_EQ_LEVEL)
+				lane_voltage_pre_emphasis->voltage_swing[i] =
+					0x03 - lane_voltage_pre_emphasis
+						       ->pre_emphasis[i];
+		}
+	}
+
+eq_train_fail:
+	it6505_dpcd_write(it6505, DP_TRAINING_PATTERN_SET,
+			  DP_TRAINING_PATTERN_DISABLE);
+	return false;
+}
+
+static bool it6505_link_start_step_train(struct it6505 *it6505)
+{
+	int err;
+	struct it6505_step_train_para lane_voltage_pre_emphasis = {
+		.voltage_swing = { 0 },
+		.pre_emphasis = { 0 },
+	};
+
+	DRM_DEV_DEBUG_DRIVER(&it6505->client->dev, "start");
+	err = it6505_drm_dp_link_configure(it6505);
+
+	if (err < 0)
+		return false;
+	if (!it6505_step_cr_train(it6505, &lane_voltage_pre_emphasis))
+		return false;
+	if (!it6505_step_eq_train(it6505, &lane_voltage_pre_emphasis))
+		return false;
+	return true;
+}
+
+static bool it6505_get_video_status(struct it6505 *it6505)
+{
+	int reg_0d;
+
+	reg_0d = it6505_read(it6505, REG_SYSTEM_STS);
+
+	if (reg_0d < 0)
+		return false;
+
+	return reg_0d & VIDEO_STB;
+}
+
+static void it6505_reset_hdcp(struct it6505 *it6505)
+{
+	it6505->hdcp_status = HDCP_AUTH_IDLE;
+	/* Disable CP_Desired */
+	it6505_set_bits(it6505, REG_HDCP_CTRL1, HDCP_CP_ENABLE, 0x00);
+	it6505_set_bits(it6505, REG_RESET_CTRL, HDCP_RESET, HDCP_RESET);
+}
+
+static void it6505_start_hdcp(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "start");
+	it6505_reset_hdcp(it6505);
+	queue_delayed_work(system_wq, &it6505->hdcp_work,
+			   msecs_to_jiffies(2400));
+}
+
+static void it6505_stop_hdcp(struct it6505 *it6505)
+{
+	it6505_reset_hdcp(it6505);
+	cancel_delayed_work(&it6505->hdcp_work);
+}
+
+static bool it6505_hdcp_is_ksv_valid(u8 *ksv)
+{
+	int i, ones = 0;
+
+	/* KSV has 20 1's and 20 0's */
+	for (i = 0; i < DRM_HDCP_KSV_LEN; i++)
+		ones += hweight8(ksv[i]);
+	if (ones != 20)
+		return false;
+	return true;
+}
+
+static void it6505_hdcp_part1_auth(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	u8 hdcp_bcaps;
+
+	it6505_set_bits(it6505, REG_RESET_CTRL, HDCP_RESET, 0x00);
+	/* Disable CP_Desired */
+	it6505_set_bits(it6505, REG_HDCP_CTRL1, HDCP_CP_ENABLE, 0x00);
+
+	usleep_range(1000, 1500);
+	hdcp_bcaps = it6505_dpcd_read(it6505, DP_AUX_HDCP_BCAPS);
+	DRM_DEV_DEBUG_DRIVER(dev, "DPCD[0x68028]: 0x%02x",
+			     hdcp_bcaps);
+
+	if (!hdcp_bcaps)
+		return;
+
+	/* clear the repeater List Chk Done and fail bit */
+	it6505_set_bits(it6505, REG_HDCP_TRIGGER,
+			HDCP_TRIGGER_KSV_DONE | HDCP_TRIGGER_KSV_FAIL,
+			0x00);
+
+	/* Enable An Generator */
+	it6505_set_bits(it6505, REG_HDCP_CTRL2, HDCP_AN_GEN, HDCP_AN_GEN);
+	/* delay1ms(10);*/
+	usleep_range(10000, 15000);
+	/* Stop An Generator */
+	it6505_set_bits(it6505, REG_HDCP_CTRL2, HDCP_AN_GEN, 0x00);
+
+	it6505_set_bits(it6505, REG_HDCP_CTRL1, HDCP_CP_ENABLE, HDCP_CP_ENABLE);
+
+	it6505_set_bits(it6505, REG_HDCP_TRIGGER, HDCP_TRIGGER_START,
+			HDCP_TRIGGER_START);
+
+	it6505->hdcp_status = HDCP_AUTH_GOING;
+}
+
+static int it6505_sha1_digest(struct it6505 *it6505, u8 *sha1_input,
+			      unsigned int size, u8 *output_av)
+{
+	struct shash_desc *desc;
+	struct crypto_shash *tfm;
+	int err;
+	struct device *dev = &it6505->client->dev;
+
+	tfm = crypto_alloc_shash("sha1", 0, 0);
+	if (IS_ERR(tfm)) {
+		dev_err(dev, "crypto_alloc_shash sha1 failed");
+		return PTR_ERR(tfm);
+	}
+	desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(tfm), GFP_KERNEL);
+	if (!desc) {
+		crypto_free_shash(tfm);
+		return -ENOMEM;
+	}
+
+	desc->tfm = tfm;
+	err = crypto_shash_digest(desc, sha1_input, size, output_av);
+	if (err)
+		dev_err(dev, "crypto_shash_digest sha1 failed");
+
+	crypto_free_shash(tfm);
+	kfree(desc);
+	return err;
+}
+
+static int it6505_setup_sha1_input(struct it6505 *it6505, u8 *sha1_input)
+{
+	struct device *dev = &it6505->client->dev;
+	u8 binfo[2];
+	int down_stream_count, i, err, msg_count = 0;
+
+	err = it6505_get_dpcd(it6505, DP_AUX_HDCP_BINFO, binfo,
+			      ARRAY_SIZE(binfo));
+
+	if (err < 0) {
+		dev_err(dev, "Read binfo value Fail");
+		return err;
+	}
+
+	down_stream_count = binfo[0] & 0x7F;
+	DRM_DEV_DEBUG_DRIVER(dev, "binfo:0x%*ph", (int)ARRAY_SIZE(binfo),
+			     binfo);
+
+	if ((binfo[0] & BIT(7)) || (binfo[1] & BIT(3))) {
+		dev_err(dev, "HDCP max cascade device exceed");
+		return 0;
+	}
+
+	if (!down_stream_count ||
+	    down_stream_count > MAX_HDCP_DOWN_STREAM_COUNT) {
+		dev_err(dev, "HDCP down stream count Error %d",
+			down_stream_count);
+		return 0;
+	}
+
+	for (i = 0; i < down_stream_count; i++) {
+		err = it6505_get_dpcd(it6505, DP_AUX_HDCP_KSV_FIFO +
+				      (i % 3) * DRM_HDCP_KSV_LEN,
+				      sha1_input + msg_count,
+				      DRM_HDCP_KSV_LEN);
+
+		if (err < 0)
+			return err;
+
+		msg_count += 5;
+	}
+
+	it6505->hdcp_down_stream_count = down_stream_count;
+	sha1_input[msg_count++] = binfo[0];
+	sha1_input[msg_count++] = binfo[1];
+
+	it6505_set_bits(it6505, REG_HDCP_CTRL2, HDCP_EN_M0_READ,
+			HDCP_EN_M0_READ);
+
+	err = regmap_bulk_read(it6505->regmap, REG_M0_0_7,
+			       sha1_input + msg_count, 8);
+
+	it6505_set_bits(it6505, REG_HDCP_CTRL2, HDCP_EN_M0_READ, 0x00);
+
+	if (err < 0) {
+		dev_err(dev, " Warning, Read M value Fail");
+		return err;
+	}
+
+	msg_count += 8;
+
+	return msg_count;
+}
+
+static bool it6505_hdcp_part2_ksvlist_check(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	u8 av[5][4], bv[5][4];
+	int i, err;
+
+	i = it6505_setup_sha1_input(it6505, it6505->sha1_input);
+	if (i <= 0) {
+		dev_err(dev, "SHA-1 Input length error %d", i);
+		return false;
+	}
+
+	it6505_sha1_digest(it6505, it6505->sha1_input, i, (u8 *)av);
+
+	err = it6505_get_dpcd(it6505, DP_AUX_HDCP_V_PRIME(0), (u8 *)bv,
+			      sizeof(bv));
+
+	if (err < 0) {
+		dev_err(dev, "Read V' value Fail");
+		return false;
+	}
+
+	for (i = 0; i < 5; i++)
+		if (bv[i][3] != av[i][0] || bv[i][2] != av[i][1] ||
+		    bv[i][1] != av[i][2] || bv[i][0] != av[i][3])
+			return false;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "V' all match!!");
+	return true;
+}
+
+static void it6505_hdcp_wait_ksv_list(struct work_struct *work)
+{
+	struct it6505 *it6505 = container_of(work, struct it6505,
+					     hdcp_wait_ksv_list);
+	struct device *dev = &it6505->client->dev;
+	unsigned int timeout = 5000;
+	u8 bstatus = 0;
+	bool ksv_list_check;
+
+	timeout /= 20;
+	while (timeout > 0) {
+		if (!it6505_get_sink_hpd_status(it6505))
+			return;
+
+		bstatus = it6505_dpcd_read(it6505, DP_AUX_HDCP_BSTATUS);
+
+		if (bstatus & DP_BSTATUS_READY)
+			break;
+
+		msleep(20);
+		timeout--;
+	}
+
+	if (timeout == 0) {
+		DRM_DEV_DEBUG_DRIVER(dev, "timeout and ksv list wait failed");
+		goto timeout;
+	}
+
+	ksv_list_check = it6505_hdcp_part2_ksvlist_check(it6505);
+	DRM_DEV_DEBUG_DRIVER(dev, "ksv list ready, ksv list check %s",
+			     ksv_list_check ? "pass" : "fail");
+	if (ksv_list_check) {
+		it6505_set_bits(it6505, REG_HDCP_TRIGGER,
+				HDCP_TRIGGER_KSV_DONE, HDCP_TRIGGER_KSV_DONE);
+		return;
+	}
+timeout:
+	it6505_set_bits(it6505, REG_HDCP_TRIGGER,
+			HDCP_TRIGGER_KSV_DONE | HDCP_TRIGGER_KSV_FAIL,
+			HDCP_TRIGGER_KSV_DONE | HDCP_TRIGGER_KSV_FAIL);
+}
+
+static void it6505_hdcp_work(struct work_struct *work)
+{
+	struct it6505 *it6505 = container_of(work, struct it6505,
+					     hdcp_work.work);
+	struct device *dev = &it6505->client->dev;
+	int ret;
+	u8 link_status[DP_LINK_STATUS_SIZE] = { 0 };
+
+	DRM_DEV_DEBUG_DRIVER(dev, "start");
+
+	if (!it6505_get_sink_hpd_status(it6505))
+		return;
+
+	ret = drm_dp_dpcd_read_link_status(&it6505->aux, link_status);
+	DRM_DEV_DEBUG_DRIVER(dev, "ret: %d link_status: %*ph", ret,
+			     (int)sizeof(link_status), link_status);
+
+	if (ret < 0 || !drm_dp_channel_eq_ok(link_status, it6505->lane_count) ||
+	    !it6505_get_video_status(it6505)) {
+		DRM_DEV_DEBUG_DRIVER(dev, "link train not done or no video");
+		return;
+	}
+
+	ret = it6505_get_dpcd(it6505, DP_AUX_HDCP_BKSV, it6505->bksvs,
+			      ARRAY_SIZE(it6505->bksvs));
+	if (ret < 0) {
+		dev_err(dev, "fail to get bksv  ret: %d", ret);
+		it6505_set_bits(it6505, REG_HDCP_TRIGGER,
+				HDCP_TRIGGER_KSV_FAIL, HDCP_TRIGGER_KSV_FAIL);
+	}
+
+	DRM_DEV_DEBUG_DRIVER(dev, "bksv = 0x%*ph",
+			     (int)ARRAY_SIZE(it6505->bksvs), it6505->bksvs);
+
+	if (!it6505_hdcp_is_ksv_valid(it6505->bksvs)) {
+		dev_err(dev, "Display Port bksv not valid");
+		it6505_set_bits(it6505, REG_HDCP_TRIGGER,
+				HDCP_TRIGGER_KSV_FAIL, HDCP_TRIGGER_KSV_FAIL);
+	}
+
+	it6505_hdcp_part1_auth(it6505);
+}
+
+static void it6505_show_hdcp_info(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	int i;
+	u8 *sha1 = it6505->sha1_input;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "hdcp_status: %d is_repeater: %d",
+			     it6505->hdcp_status, it6505->is_repeater);
+	DRM_DEV_DEBUG_DRIVER(dev, "bksv = 0x%*ph",
+			     (int)ARRAY_SIZE(it6505->bksvs), it6505->bksvs);
+
+	if (it6505->is_repeater) {
+		DRM_DEV_DEBUG_DRIVER(dev, "hdcp_down_stream_count: %d",
+				     it6505->hdcp_down_stream_count);
+		DRM_DEV_DEBUG_DRIVER(dev, "sha1_input: 0x%*ph",
+				     (int)ARRAY_SIZE(it6505->sha1_input),
+				     it6505->sha1_input);
+		for (i = 0; i < it6505->hdcp_down_stream_count; i++) {
+			DRM_DEV_DEBUG_DRIVER(dev, "KSV_%d = 0x%*ph", i,
+					     DRM_HDCP_KSV_LEN, sha1);
+			sha1 += DRM_HDCP_KSV_LEN;
+		}
+		DRM_DEV_DEBUG_DRIVER(dev, "binfo: 0x%2ph M0: 0x%8ph",
+				     sha1, sha1 + 2);
+	}
+}
+
+static void it6505_stop_link_train(struct it6505 *it6505)
+{
+	it6505->link_state = LINK_IDLE;
+	cancel_work_sync(&it6505->link_works);
+	it6505_write(it6505, REG_TRAIN_CTRL1, FORCE_RETRAIN);
+}
+
+static void it6505_link_train_ok(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	it6505->link_state = LINK_OK;
+	/* disalbe mute enable avi info frame */
+	it6505_set_bits(it6505, REG_DATA_MUTE_CTRL, EN_VID_MUTE, 0x00);
+	it6505_set_bits(it6505, REG_INFOFRAME_CTRL,
+			EN_VID_CTRL_PKT, EN_VID_CTRL_PKT);
+
+	if (it6505_audio_input(it6505)) {
+		DRM_DEV_DEBUG_DRIVER(dev, "Enable audio!");
+		it6505_enable_audio(it6505);
+	}
+
+	if (it6505->hdcp_desired)
+		it6505_start_hdcp(it6505);
+}
+
+static void it6505_link_step_train_process(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	int ret, i, step_retry = 3;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "Start step train");
+
+	if (it6505->sink_count == 0) {
+		DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count:%d, force eq",
+				     it6505->sink_count);
+		it6505_set_bits(it6505,	REG_TRAIN_CTRL0, FORCE_EQ_DONE,
+				FORCE_EQ_DONE);
+		return;
+	}
+
+	if (!it6505->step_train) {
+		DRM_DEV_DEBUG_DRIVER(dev, "not support step train");
+		return;
+	}
+
+	/* step training start here */
+	for (i = 0; i < step_retry; i++) {
+		it6505_link_reset_step_train(it6505);
+		ret = it6505_link_start_step_train(it6505);
+		DRM_DEV_DEBUG_DRIVER(dev, "step train %s, retry:%d times",
+				     ret ? "pass" : "failed", i + 1);
+		if (ret) {
+			it6505_link_train_ok(it6505);
+			return;
+		}
+	}
+
+	DRM_DEV_DEBUG_DRIVER(dev, "training fail");
+	it6505->link_state = LINK_IDLE;
+	it6505_video_reset(it6505);
+}
+
+static void it6505_link_training_work(struct work_struct *work)
+{
+	struct it6505 *it6505 = container_of(work, struct it6505, link_works);
+	struct device *dev = &it6505->client->dev;
+	int ret;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count: %d",
+			     it6505->sink_count);
+
+	if (!it6505_get_sink_hpd_status(it6505))
+		return;
+
+	it6505_link_training_setup(it6505);
+	it6505_reset_hdcp(it6505);
+	it6505_aux_reset(it6505);
+
+	if (it6505->auto_train_retry < 1) {
+		it6505_link_step_train_process(it6505);
+		return;
+	}
+
+	ret = it6505_link_start_auto_train(it6505);
+	DRM_DEV_DEBUG_DRIVER(dev, "auto train %s, auto_train_retry: %d",
+			     ret ? "pass" : "failed", it6505->auto_train_retry);
+	it6505->auto_train_retry--;
+
+	if (ret) {
+		it6505_link_train_ok(it6505);
+		return;
+	}
+
+	it6505_dump(it6505);
+}
+
+static void it6505_plugged_status_to_codec(struct it6505 *it6505)
+{
+	enum drm_connector_status status = it6505->connector_status;
+
+	if (it6505->plugged_cb && it6505->codec_dev)
+		it6505->plugged_cb(it6505->codec_dev,
+				   status == connector_status_connected);
+}
+
+static int it6505_process_hpd_irq(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	int ret, dpcd_sink_count, dp_irq_vector, bstatus;
+	u8 link_status[DP_LINK_STATUS_SIZE];
+
+	if (!it6505_get_sink_hpd_status(it6505)) {
+		DRM_DEV_DEBUG_DRIVER(dev, "HPD_IRQ HPD low");
+		it6505->sink_count = 0;
+		return 0;
+	}
+
+	ret = it6505_dpcd_read(it6505, DP_SINK_COUNT);
+	if (ret < 0)
+		return ret;
+
+	dpcd_sink_count = DP_GET_SINK_COUNT(ret);
+	DRM_DEV_DEBUG_DRIVER(dev, "dpcd_sink_count: %d it6505->sink_count:%d",
+			     dpcd_sink_count, it6505->sink_count);
+
+	if (it6505->branch_device && dpcd_sink_count != it6505->sink_count) {
+		memset(it6505->dpcd, 0, sizeof(it6505->dpcd));
+		it6505->sink_count = dpcd_sink_count;
+		it6505_reset_logic(it6505);
+		it6505_int_mask_enable(it6505);
+		it6505_init(it6505);
+		return 0;
+	}
+
+	dp_irq_vector = it6505_dpcd_read(it6505, DP_DEVICE_SERVICE_IRQ_VECTOR);
+	if (dp_irq_vector < 0)
+		return dp_irq_vector;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "dp_irq_vector = 0x%02x", dp_irq_vector);
+
+	if (dp_irq_vector & DP_CP_IRQ) {
+		it6505_set_bits(it6505, REG_HDCP_TRIGGER, HDCP_TRIGGER_CPIRQ,
+				HDCP_TRIGGER_CPIRQ);
+
+		bstatus = it6505_dpcd_read(it6505, DP_AUX_HDCP_BSTATUS);
+		if (bstatus < 0)
+			return bstatus;
+
+		DRM_DEV_DEBUG_DRIVER(dev, "Bstatus = 0x%02x", bstatus);
+	}
+
+	ret = drm_dp_dpcd_read_link_status(&it6505->aux, link_status);
+	if (ret < 0) {
+		dev_err(dev, "Fail to read link status ret: %d", ret);
+		return ret;
+	}
+
+	DRM_DEV_DEBUG_DRIVER(dev, "link status = 0x%*ph",
+			     (int)ARRAY_SIZE(link_status), link_status);
+
+	if (!drm_dp_channel_eq_ok(link_status, it6505->lane_count)) {
+		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
+		it6505_video_reset(it6505);
+	}
+
+	return 0;
+}
+
+static void it6505_irq_hpd(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	it6505->hpd_state = it6505_get_sink_hpd_status(it6505);
+	DRM_DEV_DEBUG_DRIVER(dev, "hpd change interrupt, change to %s",
+			     it6505->hpd_state ? "high" : "low");
+
+	if (it6505->bridge.dev)
+		drm_helper_hpd_irq_event(it6505->bridge.dev);
+	DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count: %d",
+			     it6505->sink_count);
+
+	if (it6505->hpd_state) {
+		wait_for_completion_timeout(&it6505->wait_edid_complete,
+					    msecs_to_jiffies(6000));
+		it6505_lane_termination_on(it6505);
+		it6505_lane_power_on(it6505);
+
+		/*
+		 * for some dongle which issue HPD_irq
+		 * when sink count change from  0->1
+		 * it6505 not able to receive HPD_IRQ
+		 * if HW never go into trainig done
+		 */
+
+		if (it6505->branch_device && it6505->sink_count == 0)
+			schedule_work(&it6505->link_works);
+
+		if (!it6505_get_video_status(it6505))
+			it6505_video_reset(it6505);
+
+		it6505_calc_video_info(it6505);
+	} else {
+		memset(it6505->dpcd, 0, sizeof(it6505->dpcd));
+
+		if (it6505->hdcp_desired)
+			it6505_stop_hdcp(it6505);
+
+		it6505_video_disable(it6505);
+		it6505_disable_audio(it6505);
+		it6505_stop_link_train(it6505);
+		it6505_lane_off(it6505);
+		it6505_link_reset_step_train(it6505);
+	}
+}
+
+static void it6505_irq_hpd_irq(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "hpd_irq interrupt");
+
+	if (it6505_process_hpd_irq(it6505) < 0)
+		DRM_DEV_DEBUG_DRIVER(dev, "process hpd_irq fail!");
+}
+
+static void it6505_irq_scdt(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	bool data;
+
+	data = it6505_get_video_status(it6505);
+	DRM_DEV_DEBUG_DRIVER(dev, "video stable change interrupt, %s",
+			     data ? "stable" : "unstable");
+	it6505_calc_video_info(it6505);
+	it6505_link_reset_step_train(it6505);
+
+	if (data)
+		schedule_work(&it6505->link_works);
+}
+
+static void it6505_irq_hdcp_done(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "hdcp done interrupt");
+	it6505->hdcp_status = HDCP_AUTH_DONE;
+	it6505_show_hdcp_info(it6505);
+}
+
+static void it6505_irq_hdcp_fail(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "hdcp fail interrupt");
+	it6505->hdcp_status = HDCP_AUTH_IDLE;
+	it6505_show_hdcp_info(it6505);
+	it6505_start_hdcp(it6505);
+}
+
+static void it6505_irq_aux_cmd_fail(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "AUX PC Request Fail Interrupt");
+}
+
+static void it6505_irq_hdcp_ksv_check(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "HDCP event Interrupt");
+	schedule_work(&it6505->hdcp_wait_ksv_list);
+}
+
+static void it6505_irq_audio_fifo_error(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "audio fifo error Interrupt");
+
+	if (it6505_audio_input(it6505))
+		it6505_enable_audio(it6505);
+}
+
+static void it6505_irq_link_train_fail(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "link training fail interrupt");
+	schedule_work(&it6505->link_works);
+}
+
+static void it6505_irq_video_fifo_error(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "video fifo overflow interrupt");
+	it6505->auto_train_retry = AUTO_TRAIN_RETRY;
+	flush_work(&it6505->link_works);
+	it6505_stop_hdcp(it6505);
+	it6505_video_reset(it6505);
+}
+
+static void it6505_irq_io_latch_fifo_overflow(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "IO latch fifo overflow interrupt");
+	it6505->auto_train_retry = AUTO_TRAIN_RETRY;
+	flush_work(&it6505->link_works);
+	it6505_stop_hdcp(it6505);
+	it6505_video_reset(it6505);
+}
+
+static bool it6505_test_bit(unsigned int bit, const unsigned int *addr)
+{
+	return 1 & (addr[bit / BITS_PER_BYTE] >> (bit % BITS_PER_BYTE));
+}
+
+static irqreturn_t it6505_int_threaded_handler(int unused, void *data)
+{
+	struct it6505 *it6505 = data;
+	struct device *dev = &it6505->client->dev;
+	static const struct {
+		int bit;
+		void (*handler)(struct it6505 *it6505);
+	} irq_vec[] = {
+		{ BIT_INT_HPD, it6505_irq_hpd },
+		{ BIT_INT_HPD_IRQ, it6505_irq_hpd_irq },
+		{ BIT_INT_SCDT, it6505_irq_scdt },
+		{ BIT_INT_HDCP_FAIL, it6505_irq_hdcp_fail },
+		{ BIT_INT_HDCP_DONE, it6505_irq_hdcp_done },
+		{ BIT_INT_AUX_CMD_FAIL, it6505_irq_aux_cmd_fail },
+		{ BIT_INT_HDCP_KSV_CHECK, it6505_irq_hdcp_ksv_check },
+		{ BIT_INT_AUDIO_FIFO_ERROR, it6505_irq_audio_fifo_error },
+		{ BIT_INT_LINK_TRAIN_FAIL, it6505_irq_link_train_fail },
+		{ BIT_INT_VID_FIFO_ERROR, it6505_irq_video_fifo_error },
+		{ BIT_INT_IO_FIFO_OVERFLOW, it6505_irq_io_latch_fifo_overflow },
+	};
+	int int_status[3], i;
+
+	msleep(100);
+	mutex_lock(&it6505->extcon_lock);
+
+	if (it6505->enable_drv_hold || !it6505->powered)
+		goto unlock;
+
+	int_status[0] = it6505_read(it6505, INT_STATUS_01);
+	int_status[1] = it6505_read(it6505, INT_STATUS_02);
+	int_status[2] = it6505_read(it6505, INT_STATUS_03);
+
+	it6505_write(it6505, INT_STATUS_01, int_status[0]);
+	it6505_write(it6505, INT_STATUS_02, int_status[1]);
+	it6505_write(it6505, INT_STATUS_03, int_status[2]);
+
+	DRM_DEV_DEBUG_DRIVER(dev, "reg06 = 0x%02x", int_status[0]);
+	DRM_DEV_DEBUG_DRIVER(dev, "reg07 = 0x%02x", int_status[1]);
+	DRM_DEV_DEBUG_DRIVER(dev, "reg08 = 0x%02x", int_status[2]);
+	it6505_debug_print(it6505, REG_SYSTEM_STS, "");
+
+	if (it6505_test_bit(irq_vec[0].bit, (unsigned int *)int_status))
+		irq_vec[0].handler(it6505);
+
+	if (!it6505->hpd_state)
+		goto unlock;
+
+	for (i = 1; i < ARRAY_SIZE(irq_vec); i++) {
+		if (it6505_test_bit(irq_vec[i].bit, (unsigned int *)int_status))
+			irq_vec[i].handler(it6505);
+	}
+
+unlock:
+	mutex_unlock(&it6505->extcon_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int it6505_poweron(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	struct it6505_platform_data *pdata = &it6505->pdata;
+	int err;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "it6505 start powered on");
+
+	if (it6505->powered) {
+		DRM_DEV_DEBUG_DRIVER(dev, "it6505 already powered on");
+		return 0;
+	}
+
+	if (pdata->pwr18) {
+		err = regulator_enable(pdata->pwr18);
+		if (err) {
+			DRM_DEV_DEBUG_DRIVER(dev, "Failed to enable VDD18: %d",
+					     err);
+			return err;
+		}
+	}
+
+	if (pdata->ovdd) {
+		/* time interval between IVDD and OVDD at least be 1ms */
+		usleep_range(1000, 2000);
+		err = regulator_enable(pdata->ovdd);
+		if (err) {
+			regulator_disable(pdata->pwr18);
+			return err;
+		}
+	}
+	/* time interval between OVDD and SYSRSTN at least be 10ms */
+	if (pdata->gpiod_reset) {
+		usleep_range(10000, 20000);
+		gpiod_set_value_cansleep(pdata->gpiod_reset, 0);
+		usleep_range(1000, 2000);
+		gpiod_set_value_cansleep(pdata->gpiod_reset, 1);
+		usleep_range(10000, 20000);
+	}
+
+	it6505_reset_logic(it6505);
+	it6505_int_mask_enable(it6505);
+	it6505_init(it6505);
+	it6505_lane_off(it6505);
+
+	it6505->powered = true;
+
+	return 0;
+}
+
+static int it6505_poweroff(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	struct it6505_platform_data *pdata = &it6505->pdata;
+	int err;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "it6505 start power off");
+
+	if (!it6505->powered) {
+		DRM_DEV_DEBUG_DRIVER(dev, "power had been already off");
+		return 0;
+	}
+
+	if (pdata->gpiod_reset)
+		gpiod_set_value_cansleep(pdata->gpiod_reset, 0);
+
+	if (pdata->pwr18) {
+		err = regulator_disable(pdata->pwr18);
+		if (err)
+			return err;
+	}
+
+	if (pdata->ovdd) {
+		err = regulator_disable(pdata->ovdd);
+		if (err)
+			return err;
+	}
+
+	it6505->powered = false;
+	it6505->sink_count = 0;
+
+	return 0;
+}
+
+static enum drm_connector_status it6505_detect(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	enum drm_connector_status status = connector_status_disconnected;
+	int dp_sink_count;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count:%d powered:%d",
+			     it6505->sink_count, it6505->powered);
+
+	mutex_lock(&it6505->mode_lock);
+
+	if (!it6505->powered)
+		goto unlock;
+
+	if (it6505->enable_drv_hold) {
+		status = it6505_get_sink_hpd_status(it6505) ?
+					connector_status_connected :
+					connector_status_disconnected;
+		goto unlock;
+	}
+
+	if (it6505_get_sink_hpd_status(it6505)) {
+		it6505_aux_on(it6505);
+		it6505_drm_dp_link_probe(&it6505->aux, &it6505->link);
+		it6505_drm_dp_link_power_up(&it6505->aux, &it6505->link);
+		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
+
+		if (it6505->dpcd[0] == 0) {
+			it6505_get_dpcd(it6505, DP_DPCD_REV, it6505->dpcd,
+					ARRAY_SIZE(it6505->dpcd));
+			it6505_variable_config(it6505);
+			it6505_parse_link_capabilities(it6505);
+		}
+
+		dp_sink_count = it6505_dpcd_read(it6505, DP_SINK_COUNT);
+		it6505->sink_count = DP_GET_SINK_COUNT(dp_sink_count);
+		DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count:%d branch:%d",
+				     it6505->sink_count, it6505->branch_device);
+
+		if (it6505->branch_device) {
+			status = (it6505->sink_count != 0) ?
+				 connector_status_connected :
+				 connector_status_disconnected;
+		} else {
+			status = connector_status_connected;
+		}
+	} else {
+		it6505->sink_count = 0;
+		memset(it6505->dpcd, 0, sizeof(it6505->dpcd));
+	}
+
+unlock:
+	if (it6505->connector_status != status) {
+		it6505->connector_status = status;
+		it6505_plugged_status_to_codec(it6505);
+	}
+
+	mutex_unlock(&it6505->mode_lock);
+
+	return status;
+}
+
+static int it6505_extcon_notifier(struct notifier_block *self,
+				  unsigned long event, void *ptr)
+{
+	struct it6505 *it6505 = container_of(self, struct it6505, event_nb);
+
+	schedule_work(&it6505->extcon_wq);
+	return NOTIFY_DONE;
+}
+
+static void it6505_extcon_work(struct work_struct *work)
+{
+	struct it6505 *it6505 = container_of(work, struct it6505, extcon_wq);
+	struct device *dev = &it6505->client->dev;
+	int state = extcon_get_state(it6505->extcon, EXTCON_DISP_DP);
+	unsigned int pwroffretry = 0;
+
+	if (it6505->enable_drv_hold)
+		return;
+
+	mutex_lock(&it6505->extcon_lock);
+
+	DRM_DEV_DEBUG_DRIVER(dev, "EXTCON_DISP_DP = 0x%02x", state);
+	if (state > 0) {
+		DRM_DEV_DEBUG_DRIVER(dev, "start to power on");
+		msleep(100);
+		it6505_poweron(it6505);
+	} else {
+		DRM_DEV_DEBUG_DRIVER(dev, "start to power off");
+		while (it6505_poweroff(it6505) && pwroffretry++ < 5) {
+			DRM_DEV_DEBUG_DRIVER(dev, "power off fail %d times",
+					     pwroffretry);
+		}
+
+		drm_helper_hpd_irq_event(it6505->bridge.dev);
+		memset(it6505->dpcd, 0, sizeof(it6505->dpcd));
+		DRM_DEV_DEBUG_DRIVER(dev, "power off it6505 success!");
+	}
+
+	mutex_unlock(&it6505->extcon_lock);
+}
+
+static int it6505_use_notifier_module(struct it6505 *it6505)
+{
+	int ret;
+	struct device *dev = &it6505->client->dev;
+
+	it6505->event_nb.notifier_call = it6505_extcon_notifier;
+	INIT_WORK(&it6505->extcon_wq, it6505_extcon_work);
+	ret = devm_extcon_register_notifier(&it6505->client->dev,
+					    it6505->extcon, EXTCON_DISP_DP,
+					    &it6505->event_nb);
+	if (ret) {
+		dev_err(dev, "failed to register notifier for DP");
+		return ret;
+	}
+
+	schedule_work(&it6505->extcon_wq);
+
+	return 0;
+}
+
+static void it6505_remove_notifier_module(struct it6505 *it6505)
+{
+	if (it6505->extcon) {
+		devm_extcon_unregister_notifier(&it6505->client->dev,
+						it6505->extcon,	EXTCON_DISP_DP,
+						&it6505->event_nb);
+
+		flush_work(&it6505->extcon_wq);
+	}
+}
+
+static void __maybe_unused it6505_delayed_audio(struct work_struct *work)
+{
+	struct it6505 *it6505 = container_of(work, struct it6505,
+					     delayed_audio.work);
+
+	DRM_DEV_DEBUG_DRIVER(&it6505->client->dev, "start");
+
+	if (!it6505->powered)
+		return;
+
+	if (!it6505->enable_drv_hold)
+		it6505_enable_audio(it6505);
+}
+
+static int __maybe_unused it6505_audio_setup_hw_params(struct it6505 *it6505,
+						       struct hdmi_codec_params
+						       *params)
+{
+	struct device *dev = &it6505->client->dev;
+	int i = 0;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "%s %d Hz, %d bit, %d channels\n", __func__,
+			     params->sample_rate, params->sample_width,
+			     params->cea.channels);
+
+	if (!it6505->bridge.encoder)
+		return -ENODEV;
+
+	if (params->cea.channels <= 1 || params->cea.channels > 8) {
+		DRM_DEV_DEBUG_DRIVER(dev, "channel number: %d not support",
+				     it6505->audio.channel_count);
+		return -EINVAL;
+	}
+
+	it6505->audio.channel_count = params->cea.channels;
+
+	while (i < ARRAY_SIZE(audio_sample_rate_map) &&
+	       params->sample_rate !=
+		       audio_sample_rate_map[i].sample_rate_value) {
+		i++;
+	}
+	if (i == ARRAY_SIZE(audio_sample_rate_map)) {
+		DRM_DEV_DEBUG_DRIVER(dev, "sample rate: %d Hz not support",
+				     params->sample_rate);
+		return -EINVAL;
+	}
+	it6505->audio.sample_rate = audio_sample_rate_map[i].rate;
+
+	switch (params->sample_width) {
+	case 16:
+		it6505->audio.word_length = WORD_LENGTH_16BIT;
+		break;
+	case 18:
+		it6505->audio.word_length = WORD_LENGTH_18BIT;
+		break;
+	case 20:
+		it6505->audio.word_length = WORD_LENGTH_20BIT;
+		break;
+	case 24:
+	case 32:
+		it6505->audio.word_length = WORD_LENGTH_24BIT;
+		break;
+	default:
+		DRM_DEV_DEBUG_DRIVER(dev, "wordlength: %d bit not support",
+				     params->sample_width);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void __maybe_unused it6505_audio_shutdown(struct device *dev, void *data)
+{
+	struct it6505 *it6505 = dev_get_drvdata(dev);
+
+	if (it6505->powered)
+		it6505_disable_audio(it6505);
+}
+
+static int __maybe_unused it6505_audio_hook_plugged_cb(struct device *dev,
+						       void *data,
+						       hdmi_codec_plugged_cb fn,
+						       struct device *codec_dev)
+{
+	struct it6505 *it6505 = data;
+
+	it6505->plugged_cb = fn;
+	it6505->codec_dev = codec_dev;
+	it6505_plugged_status_to_codec(it6505);
+
+	return 0;
+}
+
+static inline struct it6505 *bridge_to_it6505(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct it6505, bridge);
+}
+
+static int it6505_bridge_attach(struct drm_bridge *bridge,
+				enum drm_bridge_attach_flags flags)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+	struct device *dev = &it6505->client->dev;
+	int ret;
+
+	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+		DRM_ERROR("DRM_BRIDGE_ATTACH_NO_CONNECTOR must be supplied");
+		return -EINVAL;
+	}
+
+	if (!bridge->encoder) {
+		dev_err(dev, "Parent encoder object not found");
+		return -ENODEV;
+	}
+
+	/* Register aux channel */
+	it6505->aux.name = "DP-AUX";
+	it6505->aux.dev = dev;
+	it6505->aux.drm_dev = bridge->dev;
+	it6505->aux.transfer = it6505_aux_transfer;
+
+	ret = drm_dp_aux_register(&it6505->aux);
+
+	if (ret < 0) {
+		dev_err(dev, "Failed to register aux: %d", ret);
+		return ret;
+	}
+
+	if (it6505->extcon) {
+		ret = it6505_use_notifier_module(it6505);
+		if (ret < 0) {
+			dev_err(dev, "use notifier module failed");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void it6505_bridge_detach(struct drm_bridge *bridge)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+
+	flush_work(&it6505->link_works);
+	it6505_remove_notifier_module(it6505);
+}
+
+static enum drm_mode_status
+it6505_bridge_mode_valid(struct drm_bridge *bridge,
+			 const struct drm_display_info *info,
+			 const struct drm_display_mode *mode)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+
+	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+		return MODE_NO_INTERLACE;
+
+	if (mode->clock > DPI_PIXEL_CLK_MAX)
+		return MODE_CLOCK_HIGH;
+
+	it6505->video_info.clock = mode->clock;
+
+	return MODE_OK;
+}
+
+static void it6505_bridge_atomic_enable(struct drm_bridge *bridge,
+					struct drm_bridge_state *old_state)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+	struct device *dev = &it6505->client->dev;
+	struct drm_atomic_state *state = old_state->base.state;
+	struct hdmi_avi_infoframe frame;
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector_state *conn_state;
+	struct drm_display_mode *mode;
+	struct drm_connector *connector;
+	int ret;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "start");
+
+	connector = drm_atomic_get_new_connector_for_encoder(state,
+							     bridge->encoder);
+
+	if (WARN_ON(!connector))
+		return;
+
+	conn_state = drm_atomic_get_new_connector_state(state, connector);
+
+	if (WARN_ON(!conn_state))
+		return;
+
+	crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
+
+	if (WARN_ON(!crtc_state))
+		return;
+
+	mode = &crtc_state->adjusted_mode;
+
+	if (WARN_ON(!mode))
+		return;
+
+	ret = drm_hdmi_avi_infoframe_from_display_mode(&frame,
+						       connector,
+						       mode);
+	if (ret)
+		dev_err(dev, "Failed to setup AVI infoframe: %d", ret);
+
+	it6505_update_video_parameter(it6505, mode);
+
+	ret = it6505_send_video_infoframe(it6505, &frame);
+
+	if (ret)
+		dev_err(dev, "Failed to send AVI infoframe: %d", ret);
+
+	it6505_int_mask_enable(it6505);
+	it6505_video_reset(it6505);
+}
+
+static void it6505_bridge_atomic_disable(struct drm_bridge *bridge,
+					 struct drm_bridge_state *old_state)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+	struct device *dev = &it6505->client->dev;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "start");
+
+	if (it6505->powered)
+		it6505_video_disable(it6505);
+}
+
+static enum drm_connector_status
+it6505_bridge_detect(struct drm_bridge *bridge)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+
+	return it6505_detect(it6505);
+}
+
+static struct edid *it6505_bridge_get_edid(struct drm_bridge *bridge,
+					   struct drm_connector *connector)
+{
+	struct it6505 *it6505 = bridge_to_it6505(bridge);
+	struct device *dev = &it6505->client->dev;
+	struct edid *edid;
+
+	edid = drm_do_get_edid(connector, it6505_get_edid_block, it6505);
+
+	if (!edid) {
+		DRM_DEV_DEBUG_DRIVER(dev, "failed to get edid!");
+		return NULL;
+	}
+
+	return edid;
+}
+
+static const struct drm_bridge_funcs it6505_bridge_funcs = {
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.attach = it6505_bridge_attach,
+	.detach = it6505_bridge_detach,
+	.mode_valid = it6505_bridge_mode_valid,
+	.atomic_enable = it6505_bridge_atomic_enable,
+	.atomic_disable = it6505_bridge_atomic_disable,
+	.detect = it6505_bridge_detect,
+	.get_edid = it6505_bridge_get_edid,
+};
+
+static __maybe_unused int it6505_bridge_resume(struct device *dev)
+{
+	struct it6505 *it6505 = dev_get_drvdata(dev);
+
+	return it6505_poweron(it6505);
+}
+
+static __maybe_unused int it6505_bridge_suspend(struct device *dev)
+{
+	struct it6505 *it6505 = dev_get_drvdata(dev);
+
+	return it6505_poweroff(it6505);
+}
+
+static SIMPLE_DEV_PM_OPS(it6505_bridge_pm_ops, it6505_bridge_suspend,
+			 it6505_bridge_resume);
+
+static int it6505_init_pdata(struct it6505 *it6505)
+{
+	struct it6505_platform_data *pdata = &it6505->pdata;
+	struct device *dev = &it6505->client->dev;
+
+	/* 1.0V digital core power regulator  */
+	pdata->pwr18 = devm_regulator_get(dev, "pwr18");
+	if (IS_ERR(pdata->pwr18)) {
+		dev_err(dev, "pwr18 regulator not found");
+		return PTR_ERR(pdata->pwr18);
+	}
+
+	pdata->ovdd = devm_regulator_get(dev, "ovdd");
+	if (IS_ERR(pdata->ovdd)) {
+		dev_err(dev, "ovdd regulator not found");
+		return PTR_ERR(pdata->ovdd);
+	}
+
+	pdata->gpiod_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(pdata->gpiod_reset)) {
+		dev_err(dev, "gpiod_reset gpio not found");
+		return PTR_ERR(pdata->gpiod_reset);
+	}
+
+	return 0;
+}
+
+static void it6505_parse_dt(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+	u32 *afe_setting = &it6505->afe_setting;
+
+	it6505->lane_swap_disabled =
+		device_property_read_bool(dev, "no-laneswap");
+
+	if (it6505->lane_swap_disabled)
+		it6505->lane_swap = false;
+
+	if (device_property_read_u32(dev, "afe-setting", afe_setting) == 0) {
+		if (*afe_setting >= ARRAY_SIZE(afe_setting_table)) {
+			dev_err(dev, "afe setting error, use default");
+			*afe_setting = 0;
+		}
+	} else {
+		*afe_setting = 0;
+	}
+	DRM_DEV_DEBUG_DRIVER(dev, "using afe_setting: %d", *afe_setting);
+}
+
+static ssize_t receive_timing_debugfs_show(struct file *file, char __user *buf,
+					   size_t len, loff_t *ppos)
+{
+	struct it6505 *it6505 = file->private_data;
+	struct drm_display_mode *vid = &it6505->video_info;
+	u8 read_buf[READ_BUFFER_SIZE];
+	u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
+	ssize_t ret, count;
+
+	if (!it6505)
+		return -ENODEV;
+
+	it6505_calc_video_info(it6505);
+	str += scnprintf(str, end - str, "---video timing---\n");
+	str += scnprintf(str, end - str, "PCLK:%d.%03dMHz\n",
+			 vid->clock / 1000, vid->clock % 1000);
+	str += scnprintf(str, end - str, "HTotal:%d\n", vid->htotal);
+	str += scnprintf(str, end - str, "HActive:%d\n", vid->hdisplay);
+	str += scnprintf(str, end - str, "HFrontPorch:%d\n",
+			 vid->hsync_start - vid->hdisplay);
+	str += scnprintf(str, end - str, "HSyncWidth:%d\n",
+			 vid->hsync_end - vid->hsync_start);
+	str += scnprintf(str, end - str, "HBackPorch:%d\n",
+			 vid->htotal - vid->hsync_end);
+	str += scnprintf(str, end - str, "VTotal:%d\n", vid->vtotal);
+	str += scnprintf(str, end - str, "VActive:%d\n", vid->vdisplay);
+	str += scnprintf(str, end - str, "VFrontPorch:%d\n",
+			 vid->vsync_start - vid->vdisplay);
+	str += scnprintf(str, end - str, "VSyncWidth:%d\n",
+			 vid->vsync_end - vid->vsync_start);
+	str += scnprintf(str, end - str, "VBackPorch:%d\n",
+			 vid->vtotal - vid->vsync_end);
+
+	count = str - read_buf;
+	ret = simple_read_from_buffer(buf, len, ppos, read_buf, count);
+
+	return ret;
+}
+
+static int force_power_on_off_debugfs_write(void *data, u64 value)
+{
+	struct it6505 *it6505 = data;
+
+	if (!it6505)
+		return -ENODEV;
+
+	if (value)
+		it6505_poweron(it6505);
+	else
+		it6505_poweroff(it6505);
+
+	return 0;
+}
+
+static int enable_drv_hold_debugfs_show(void *data, u64 *buf)
+{
+	struct it6505 *it6505 = data;
+
+	if (!it6505)
+		return -ENODEV;
+
+	*buf = it6505->enable_drv_hold;
+
+	return 0;
+}
+
+static int enable_drv_hold_debugfs_write(void *data, u64 drv_hold)
+{
+	struct it6505 *it6505 = data;
+
+	if (!it6505)
+		return -ENODEV;
+
+	it6505->enable_drv_hold = drv_hold;
+
+	if (it6505->enable_drv_hold) {
+		it6505_int_mask_disable(it6505);
+	} else {
+		it6505_clear_int(it6505);
+		it6505_int_mask_enable(it6505);
+
+		if (it6505->powered) {
+			it6505->connector_status =
+					it6505_get_sink_hpd_status(it6505) ?
+					connector_status_connected :
+					connector_status_disconnected;
+		} else {
+			it6505->connector_status =
+					connector_status_disconnected;
+		}
+	}
+
+	return 0;
+}
+
+static const struct file_operations receive_timing_fops = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read = receive_timing_debugfs_show,
+	.llseek = default_llseek,
+};
+
+DEFINE_DEBUGFS_ATTRIBUTE(fops_force_power, NULL,
+			 force_power_on_off_debugfs_write, "%llu\n");
+
+DEFINE_DEBUGFS_ATTRIBUTE(fops_enable_drv_hold, enable_drv_hold_debugfs_show,
+			 enable_drv_hold_debugfs_write, "%llu\n");
+
+static const struct debugfs_entries debugfs_entry[] = {
+	{ "receive_timing", &receive_timing_fops },
+	{ "force_power_on_off", &fops_force_power },
+	{ "enable_drv_hold", &fops_enable_drv_hold },
+	{ NULL, NULL },
+};
+
+static void debugfs_create_files(struct it6505 *it6505)
+{
+	int i = 0;
+
+	while (debugfs_entry[i].name && debugfs_entry[i].fops) {
+		debugfs_create_file(debugfs_entry[i].name, 0644,
+				    it6505->debugfs, it6505,
+				    debugfs_entry[i].fops);
+		i++;
+	}
+}
+
+static void debugfs_init(struct it6505 *it6505)
+{
+	struct device *dev = &it6505->client->dev;
+
+	it6505->debugfs = debugfs_create_dir(DEBUGFS_DIR_NAME, NULL);
+
+	if (IS_ERR(it6505->debugfs)) {
+		dev_err(dev, "failed to create debugfs root");
+		return;
+	}
+
+	debugfs_create_files(it6505);
+}
+
+static void it6505_debugfs_remove(struct it6505 *it6505)
+{
+	debugfs_remove_recursive(it6505->debugfs);
+}
+
+static void it6505_shutdown(struct i2c_client *client)
+{
+	struct it6505 *it6505 = dev_get_drvdata(&client->dev);
+
+	if (it6505->powered)
+		it6505_lane_off(it6505);
+}
+
+static int it6505_i2c_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct it6505 *it6505;
+	struct device *dev = &client->dev;
+	struct extcon_dev *extcon;
+	int err, intp_irq;
+
+	it6505 = devm_kzalloc(&client->dev, sizeof(*it6505), GFP_KERNEL);
+	if (!it6505)
+		return -ENOMEM;
+
+	mutex_init(&it6505->extcon_lock);
+	mutex_init(&it6505->mode_lock);
+	mutex_init(&it6505->aux_lock);
+
+	it6505->bridge.of_node = client->dev.of_node;
+	it6505->connector_status = connector_status_disconnected;
+	it6505->client = client;
+	i2c_set_clientdata(client, it6505);
+
+	/* get extcon device from DTS */
+	extcon = extcon_get_edev_by_phandle(dev, 0);
+	if (PTR_ERR(extcon) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	if (IS_ERR(extcon)) {
+		dev_err(dev, "can not get extcon device!");
+		return PTR_ERR(extcon);
+	}
+
+	it6505->extcon = extcon;
+
+	it6505->regmap = devm_regmap_init_i2c(client, &it6505_regmap_config);
+	if (IS_ERR(it6505->regmap)) {
+		dev_err(dev, "regmap i2c init failed");
+		err = PTR_ERR(it6505->regmap);
+		return err;
+	}
+
+	err = it6505_init_pdata(it6505);
+	if (err) {
+		dev_err(dev, "Failed to initialize pdata: %d", err);
+		return err;
+	}
+
+	it6505_parse_dt(it6505);
+
+	intp_irq = client->irq;
+
+	if (!intp_irq) {
+		dev_err(dev, "Failed to get INTP IRQ");
+		err = -ENODEV;
+		return err;
+	}
+
+	err = devm_request_threaded_irq(&client->dev, intp_irq, NULL,
+					it6505_int_threaded_handler,
+					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					"it6505-intp", it6505);
+	if (err) {
+		dev_err(dev, "Failed to request INTP threaded IRQ: %d", err);
+		return err;
+	}
+
+	INIT_WORK(&it6505->link_works, it6505_link_training_work);
+	INIT_WORK(&it6505->hdcp_wait_ksv_list, it6505_hdcp_wait_ksv_list);
+	INIT_DELAYED_WORK(&it6505->hdcp_work, it6505_hdcp_work);
+	init_completion(&it6505->wait_edid_complete);
+	memset(it6505->dpcd, 0, sizeof(it6505->dpcd));
+	it6505->powered = false;
+	it6505->enable_drv_hold = DEFAULT_DRV_HOLD;
+
+	if (DEFAULT_PWR_ON)
+		it6505_poweron(it6505);
+
+	DRM_DEV_DEBUG_DRIVER(dev, "it6505 device name: %s", dev_name(dev));
+	debugfs_init(it6505);
+
+	it6505->bridge.funcs = &it6505_bridge_funcs;
+	it6505->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
+	it6505->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID |
+			     DRM_BRIDGE_OP_HPD;
+	drm_bridge_add(&it6505->bridge);
+
+	return 0;
+}
+
+static int it6505_i2c_remove(struct i2c_client *client)
+{
+	struct it6505 *it6505 = i2c_get_clientdata(client);
+
+	drm_bridge_remove(&it6505->bridge);
+	drm_dp_aux_unregister(&it6505->aux);
+	it6505_debugfs_remove(it6505);
+	it6505_poweroff(it6505);
+
+	return 0;
+}
+
+static const struct i2c_device_id it6505_id[] = {
+	{ "it6505", 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, it6505_id);
+
+static const struct of_device_id it6505_of_match[] = {
+	{ .compatible = "ite,it6505" },
+	{ }
+};
+
+static struct i2c_driver it6505_i2c_driver = {
+	.driver = {
+		.name = "it6505",
+		.of_match_table = it6505_of_match,
+		.pm = &it6505_bridge_pm_ops,
+	},
+	.probe = it6505_i2c_probe,
+	.remove = it6505_i2c_remove,
+	.shutdown = it6505_shutdown,
+	.id_table = it6505_id,
+};
+
+module_i2c_driver(it6505_i2c_driver);
+
+MODULE_AUTHOR("Allen Chen <allen.chen@ite.com.tw>");
+MODULE_DESCRIPTION("IT6505 DisplayPort Transmitter driver");
+MODULE_LICENSE("GPL v2");