drm/bridge: synopsys: Add DW DPTX Controller support library

The DW DP TX Controller is compliant with the DisplayPort Specification
Version 1.4 with the following features:

* DisplayPort 1.4a
* Main Link: 1/2/4 lanes
* Main Link Support 1.62Gbps, 2.7Gbps, 5.4Gbps and 8.1Gbps
* AUX channel 1Mbps
* Single Stream Transport(SST)
* Multistream Transport (MST)
* Type-C support (alternate mode)
* HDCP 2.2, HDCP 1.3
* Supports up to 8/10 bits per color component
* Supports RBG, YCbCr4:4:4, YCbCr4:2:2, YCbCr4:2:0
* Pixel clock up to 594MHz
* I2S, SPDIF audio interface

Add library with common helpers to make it can be shared with
other SoC.

Signed-off-by: Andy Yan <[e-mail]>
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Tested-by: Sebastian Reichel <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Baryshkov <[e-mail]>

drivers/gpu/drm/bridge/synopsys/Kconfig

···
 # SPDX-License-Identifier: GPL-2.0-only
+config DRM_DW_DP
+	tristate
+	select DRM_DISPLAY_HELPER
+	select DRM_DISPLAY_DP_HELPER
+	select DRM_KMS_HELPER
+	select REGMAP_MMIO
+
 config DRM_DW_HDMI
 	tristate
 	select DRM_DISPLAY_HDMI_HELPER

drivers/gpu/drm/bridge/synopsys/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_DRM_DW_DP) += dw-dp.o
 obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
 obj-$(CONFIG_DRM_DW_HDMI_GP_AUDIO) += dw-hdmi-gp-audio.o

drivers/gpu/drm/bridge/synopsys/dw-dp.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Synopsys DesignWare Cores DisplayPort Transmitter Controller
+ *
+ * Copyright (c) 2025 Rockchip Electronics Co., Ltd.
+ *
+ * Author: Andy Yan <[e-mail]>
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/media-bus-format.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/phy/phy.h>
+#include <linux/unaligned.h>
+
+#include <drm/bridge/dw_dp.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
+#include <drm/display/drm_dp_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_of.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#define DW_DP_VERSION_NUMBER			0x0000
+#define DW_DP_VERSION_TYPE			0x0004
+#define DW_DP_ID				0x0008
+
+#define DW_DP_CONFIG_REG1			0x0100
+#define DW_DP_CONFIG_REG2			0x0104
+#define DW_DP_CONFIG_REG3			0x0108
+
+#define DW_DP_CCTL				0x0200
+#define FORCE_HPD				BIT(4)
+#define DEFAULT_FAST_LINK_TRAIN_EN		BIT(2)
+#define ENHANCE_FRAMING_EN			BIT(1)
+#define SCRAMBLE_DIS				BIT(0)
+#define DW_DP_SOFT_RESET_CTRL			0x0204
+#define VIDEO_RESET				BIT(5)
+#define AUX_RESET				BIT(4)
+#define AUDIO_SAMPLER_RESET			BIT(3)
+#define HDCP_MODULE_RESET			BIT(2)
+#define PHY_SOFT_RESET				BIT(1)
+#define CONTROLLER_RESET			BIT(0)
+
+#define DW_DP_VSAMPLE_CTRL			0x0300
+#define PIXEL_MODE_SELECT			GENMASK(22, 21)
+#define VIDEO_MAPPING				GENMASK(20, 16)
+#define VIDEO_STREAM_ENABLE			BIT(5)
+
+#define DW_DP_VSAMPLE_STUFF_CTRL1		0x0304
+
+#define DW_DP_VSAMPLE_STUFF_CTRL2		0x0308
+
+#define DW_DP_VINPUT_POLARITY_CTRL		0x030c
+#define DE_IN_POLARITY				BIT(2)
+#define HSYNC_IN_POLARITY			BIT(1)
+#define VSYNC_IN_POLARITY			BIT(0)
+
+#define DW_DP_VIDEO_CONFIG1			0x0310
+#define HACTIVE					GENMASK(31, 16)
+#define HBLANK					GENMASK(15, 2)
+#define I_P					BIT(1)
+#define R_V_BLANK_IN_OSC			BIT(0)
+
+#define DW_DP_VIDEO_CONFIG2			0x0314
+#define VBLANK					GENMASK(31, 16)
+#define VACTIVE					GENMASK(15, 0)
+
+#define DW_DP_VIDEO_CONFIG3			0x0318
+#define H_SYNC_WIDTH				GENMASK(31, 16)
+#define H_FRONT_PORCH				GENMASK(15, 0)
+
+#define DW_DP_VIDEO_CONFIG4			0x031c
+#define V_SYNC_WIDTH				GENMASK(31, 16)
+#define V_FRONT_PORCH				GENMASK(15, 0)
+
+#define DW_DP_VIDEO_CONFIG5			0x0320
+#define INIT_THRESHOLD_HI			GENMASK(22, 21)
+#define AVERAGE_BYTES_PER_TU_FRAC		GENMASK(19, 16)
+#define INIT_THRESHOLD				GENMASK(13, 7)
+#define AVERAGE_BYTES_PER_TU			GENMASK(6, 0)
+
+#define DW_DP_VIDEO_MSA1			0x0324
+#define VSTART					GENMASK(31, 16)
+#define HSTART					GENMASK(15, 0)
+
+#define DW_DP_VIDEO_MSA2			0x0328
+#define MISC0					GENMASK(31, 24)
+
+#define DW_DP_VIDEO_MSA3			0x032c
+#define MISC1					GENMASK(31, 24)
+
+#define DW_DP_VIDEO_HBLANK_INTERVAL		0x0330
+#define HBLANK_INTERVAL_EN			BIT(16)
+#define HBLANK_INTERVAL				GENMASK(15, 0)
+
+#define DW_DP_AUD_CONFIG1			0x0400
+#define AUDIO_TIMESTAMP_VERSION_NUM		GENMASK(29, 24)
+#define AUDIO_PACKET_ID				GENMASK(23, 16)
+#define AUDIO_MUTE				BIT(15)
+#define NUM_CHANNELS				GENMASK(14, 12)
+#define HBR_MODE_ENABLE				BIT(10)
+#define AUDIO_DATA_WIDTH			GENMASK(9, 5)
+#define AUDIO_DATA_IN_EN			GENMASK(4, 1)
+#define AUDIO_INF_SELECT			BIT(0)
+
+#define DW_DP_SDP_VERTICAL_CTRL			0x0500
+#define EN_VERTICAL_SDP				BIT(2)
+#define EN_AUDIO_STREAM_SDP			BIT(1)
+#define EN_AUDIO_TIMESTAMP_SDP			BIT(0)
+#define DW_DP_SDP_HORIZONTAL_CTRL		0x0504
+#define EN_HORIZONTAL_SDP			BIT(2)
+#define DW_DP_SDP_STATUS_REGISTER		0x0508
+#define DW_DP_SDP_MANUAL_CTRL			0x050c
+#define DW_DP_SDP_STATUS_EN			0x0510
+
+#define DW_DP_SDP_REGISTER_BANK			0x0600
+#define SDP_REGS				GENMASK(31, 0)
+
+#define DW_DP_PHYIF_CTRL			0x0a00
+#define PHY_WIDTH				BIT(25)
+#define PHY_POWERDOWN				GENMASK(20, 17)
+#define PHY_BUSY				GENMASK(15, 12)
+#define SSC_DIS					BIT(16)
+#define XMIT_ENABLE				GENMASK(11, 8)
+#define PHY_LANES				GENMASK(7, 6)
+#define PHY_RATE				GENMASK(5, 4)
+#define TPS_SEL					GENMASK(3, 0)
+
+#define DW_DP_PHY_TX_EQ				0x0a04
+#define DW_DP_CUSTOMPAT0			0x0a08
+#define DW_DP_CUSTOMPAT1			0x0a0c
+#define DW_DP_CUSTOMPAT2			0x0a10
+#define DW_DP_HBR2_COMPLIANCE_SCRAMBLER_RESET	0x0a14
+#define DW_DP_PHYIF_PWRDOWN_CTRL		0x0a18
+
+#define DW_DP_AUX_CMD				0x0b00
+#define AUX_CMD_TYPE				GENMASK(31, 28)
+#define AUX_ADDR				GENMASK(27, 8)
+#define I2C_ADDR_ONLY				BIT(4)
+#define AUX_LEN_REQ				GENMASK(3, 0)
+
+#define DW_DP_AUX_STATUS			0x0b04
+#define AUX_TIMEOUT				BIT(17)
+#define AUX_BYTES_READ				GENMASK(23, 19)
+#define AUX_STATUS				GENMASK(7, 4)
+
+#define DW_DP_AUX_DATA0				0x0b08
+#define DW_DP_AUX_DATA1				0x0b0c
+#define DW_DP_AUX_DATA2				0x0b10
+#define DW_DP_AUX_DATA3				0x0b14
+
+#define DW_DP_GENERAL_INTERRUPT			0x0d00
+#define VIDEO_FIFO_OVERFLOW_STREAM0		BIT(6)
+#define AUDIO_FIFO_OVERFLOW_STREAM0		BIT(5)
+#define SDP_EVENT_STREAM0			BIT(4)
+#define AUX_CMD_INVALID				BIT(3)
+#define HDCP_EVENT				BIT(2)
+#define AUX_REPLY_EVENT				BIT(1)
+#define HPD_EVENT				BIT(0)
+
+#define DW_DP_GENERAL_INTERRUPT_ENABLE		0x0d04
+#define HDCP_EVENT_EN				BIT(2)
+#define AUX_REPLY_EVENT_EN			BIT(1)
+#define HPD_EVENT_EN				BIT(0)
+
+#define DW_DP_HPD_STATUS			0x0d08
+#define HPD_STATE				GENMASK(11, 9)
+#define HPD_STATUS				BIT(8)
+#define HPD_HOT_UNPLUG				BIT(2)
+#define HPD_HOT_PLUG				BIT(1)
+#define HPD_IRQ					BIT(0)
+
+#define DW_DP_HPD_INTERRUPT_ENABLE		0x0d0c
+#define HPD_UNPLUG_ERR_EN			BIT(3)
+#define HPD_UNPLUG_EN				BIT(2)
+#define HPD_PLUG_EN				BIT(1)
+#define HPD_IRQ_EN				BIT(0)
+
+#define DW_DP_HDCP_CFG				0x0e00
+#define DPCD12PLUS				BIT(7)
+#define CP_IRQ					BIT(6)
+#define BYPENCRYPTION				BIT(5)
+#define HDCP_LOCK				BIT(4)
+#define ENCRYPTIONDISABLE			BIT(3)
+#define ENABLE_HDCP_13				BIT(2)
+#define ENABLE_HDCP				BIT(1)
+
+#define DW_DP_HDCP_OBS				0x0e04
+#define HDCP22_RE_AUTHENTICATION_REQ		BIT(31)
+#define HDCP22_AUTHENTICATION_FAILED		BIT(30)
+#define HDCP22_AUTHENTICATION_SUCCESS		BIT(29)
+#define HDCP22_CAPABLE_SINK			BIT(28)
+#define HDCP22_SINK_CAP_CHECK_COMPLETE		BIT(27)
+#define HDCP22_STATE				GENMASK(26, 24)
+#define HDCP22_BOOTED				BIT(23)
+#define HDCP13_BSTATUS				GENMASK(22, 19)
+#define REPEATER				BIT(18)
+#define HDCP_CAPABLE				BIT(17)
+#define STATEE					GENMASK(16, 14)
+#define STATEOEG				GENMASK(13, 11)
+#define STATER					GENMASK(10, 8)
+#define STATEA					GENMASK(7, 4)
+#define SUBSTATEA				GENMASK(3, 1)
+#define HDCPENGAGED				BIT(0)
+
+#define DW_DP_HDCP_APIINTCLR			0x0e08
+#define DW_DP_HDCP_APIINTSTAT			0x0e0c
+#define DW_DP_HDCP_APIINTMSK			0x0e10
+#define HDCP22_GPIOINT				BIT(8)
+#define HDCP_ENGAGED				BIT(7)
+#define HDCP_FAILED				BIT(6)
+#define KSVSHA1CALCDONEINT			BIT(5)
+#define AUXRESPNACK7TIMES			BIT(4)
+#define AUXRESPTIMEOUT				BIT(3)
+#define AUXRESPDEFER7TIMES			BIT(2)
+#define KSVACCESSINT				BIT(0)
+
+#define DW_DP_HDCP_KSVMEMCTRL			0x0e18
+#define KSVSHA1STATUS				BIT(4)
+#define KSVMEMACCESS				BIT(1)
+#define KSVMEMREQUEST				BIT(0)
+
+#define DW_DP_HDCP_REG_BKSV0			0x3600
+#define DW_DP_HDCP_REG_BKSV1			0x3604
+#define DW_DP_HDCP_REG_ANCONF			0x3608
+#define AN_BYPASS				BIT(0)
+
+#define DW_DP_HDCP_REG_AN0			0x360c
+#define DW_DP_HDCP_REG_AN1			0x3610
+#define DW_DP_HDCP_REG_RMLCTL			0x3614
+#define ODPK_DECRYPT_ENABLE			BIT(0)
+
+#define DW_DP_HDCP_REG_RMLSTS			0x3618
+#define IDPK_WR_OK_STS				BIT(6)
+#define	IDPK_DATA_INDEX				GENMASK(5, 0)
+#define DW_DP_HDCP_REG_SEED			0x361c
+#define DW_DP_HDCP_REG_DPK0			0x3620
+#define DW_DP_HDCP_REG_DPK1			0x3624
+#define DW_DP_HDCP22_GPIOSTS			0x3628
+#define DW_DP_HDCP22_GPIOCHNGSTS		0x362c
+#define DW_DP_HDCP_REG_DPK_CRC			0x3630
+
+#define DW_DP_MAX_REGISTER			DW_DP_HDCP_REG_DPK_CRC
+
+#define SDP_REG_BANK_SIZE			16
+
+struct dw_dp_link_caps {
+	bool enhanced_framing;
+	bool tps3_supported;
+	bool tps4_supported;
+	bool fast_training;
+	bool channel_coding;
+	bool ssc;
+};
+
+struct dw_dp_link_train_set {
+	unsigned int voltage_swing[4];
+	unsigned int pre_emphasis[4];
+	bool voltage_max_reached[4];
+	bool pre_max_reached[4];
+};
+
+struct dw_dp_link_train {
+	struct dw_dp_link_train_set adjust;
+	bool clock_recovered;
+	bool channel_equalized;
+};
+
+struct dw_dp_link {
+	u8 dpcd[DP_RECEIVER_CAP_SIZE];
+	unsigned char revision;
+	unsigned int rate;
+	unsigned int lanes;
+	u8 sink_count;
+	u8 vsc_sdp_supported;
+	struct dw_dp_link_caps caps;
+	struct dw_dp_link_train train;
+	struct drm_dp_desc desc;
+};
+
+struct dw_dp_bridge_state {
+	struct drm_bridge_state base;
+	struct drm_display_mode mode;
+	u8 video_mapping;
+	u8 color_format;
+	u8 bpc;
+	u8 bpp;
+};
+
+struct dw_dp_sdp {
+	struct dp_sdp base;
+	unsigned long flags;
+};
+
+struct dw_dp_hotplug {
+	bool long_hpd;
+};
+
+struct dw_dp {
+	struct drm_bridge bridge;
+	struct device *dev;
+	struct regmap *regmap;
+	struct phy *phy;
+	struct clk *apb_clk;
+	struct clk *aux_clk;
+	struct clk *i2s_clk;
+	struct clk *spdif_clk;
+	struct clk *hdcp_clk;
+	struct reset_control *rstc;
+	struct completion complete;
+	int irq;
+	struct work_struct hpd_work;
+	struct dw_dp_hotplug hotplug;
+	/* Serialize hpd status access */
+	struct mutex irq_lock;
+
+	struct drm_dp_aux aux;
+
+	struct dw_dp_link link;
+	struct dw_dp_plat_data plat_data;
+	u8 pixel_mode;
+
+	DECLARE_BITMAP(sdp_reg_bank, SDP_REG_BANK_SIZE);
+};
+
+enum {
+	DW_DP_RGB_6BIT,
+	DW_DP_RGB_8BIT,
+	DW_DP_RGB_10BIT,
+	DW_DP_RGB_12BIT,
+	DW_DP_RGB_16BIT,
+	DW_DP_YCBCR444_8BIT,
+	DW_DP_YCBCR444_10BIT,
+	DW_DP_YCBCR444_12BIT,
+	DW_DP_YCBCR444_16BIT,
+	DW_DP_YCBCR422_8BIT,
+	DW_DP_YCBCR422_10BIT,
+	DW_DP_YCBCR422_12BIT,
+	DW_DP_YCBCR422_16BIT,
+	DW_DP_YCBCR420_8BIT,
+	DW_DP_YCBCR420_10BIT,
+	DW_DP_YCBCR420_12BIT,
+	DW_DP_YCBCR420_16BIT,
+};
+
+enum {
+	DW_DP_MP_SINGLE_PIXEL,
+	DW_DP_MP_DUAL_PIXEL,
+	DW_DP_MP_QUAD_PIXEL,
+};
+
+enum {
+	DW_DP_SDP_VERTICAL_INTERVAL = BIT(0),
+	DW_DP_SDP_HORIZONTAL_INTERVAL = BIT(1),
+};
+
+enum {
+	DW_DP_HPD_STATE_IDLE,
+	DW_DP_HPD_STATE_UNPLUG,
+	DP_DP_HPD_STATE_TIMEOUT = 4,
+	DW_DP_HPD_STATE_PLUG = 7
+};
+
+enum {
+	DW_DP_PHY_PATTERN_NONE,
+	DW_DP_PHY_PATTERN_TPS_1,
+	DW_DP_PHY_PATTERN_TPS_2,
+	DW_DP_PHY_PATTERN_TPS_3,
+	DW_DP_PHY_PATTERN_TPS_4,
+	DW_DP_PHY_PATTERN_SERM,
+	DW_DP_PHY_PATTERN_PBRS7,
+	DW_DP_PHY_PATTERN_CUSTOM_80BIT,
+	DW_DP_PHY_PATTERN_CP2520_1,
+	DW_DP_PHY_PATTERN_CP2520_2,
+};
+
+struct dw_dp_output_format {
+	u32 bus_format;
+	u32 color_format;
+	u8 video_mapping;
+	u8 bpc;
+	u8 bpp;
+};
+
+#define to_dw_dp_bridge_state(s) container_of(s, struct dw_dp_bridge_state, base)
+
+static const struct dw_dp_output_format dw_dp_output_formats[] = {
+	{ MEDIA_BUS_FMT_RGB101010_1X30, DRM_COLOR_FORMAT_RGB444, DW_DP_RGB_10BIT, 10, 30 },
+	{ MEDIA_BUS_FMT_RGB888_1X24, DRM_COLOR_FORMAT_RGB444, DW_DP_RGB_8BIT, 8, 24 },
+	{ MEDIA_BUS_FMT_YUV10_1X30, DRM_COLOR_FORMAT_YCBCR444, DW_DP_YCBCR444_10BIT, 10, 30 },
+	{ MEDIA_BUS_FMT_YUV8_1X24, DRM_COLOR_FORMAT_YCBCR444, DW_DP_YCBCR444_8BIT, 8, 24},
+	{ MEDIA_BUS_FMT_YUYV10_1X20, DRM_COLOR_FORMAT_YCBCR422, DW_DP_YCBCR422_10BIT, 10, 20 },
+	{ MEDIA_BUS_FMT_YUYV8_1X16, DRM_COLOR_FORMAT_YCBCR422, DW_DP_YCBCR422_8BIT, 8, 16 },
+	{ MEDIA_BUS_FMT_UYYVYY10_0_5X30, DRM_COLOR_FORMAT_YCBCR420, DW_DP_YCBCR420_10BIT, 10, 15 },
+	{ MEDIA_BUS_FMT_UYYVYY8_0_5X24, DRM_COLOR_FORMAT_YCBCR420, DW_DP_YCBCR420_8BIT, 8, 12 },
+	{ MEDIA_BUS_FMT_RGB666_1X24_CPADHI, DRM_COLOR_FORMAT_RGB444, DW_DP_RGB_6BIT, 6, 18 },
+};
+
+static const struct dw_dp_output_format *dw_dp_get_output_format(u32 bus_format)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(dw_dp_output_formats); i++)
+		if (dw_dp_output_formats[i].bus_format == bus_format)
+			return &dw_dp_output_formats[i];
+
+	return NULL;
+}
+
+static inline struct dw_dp *bridge_to_dp(struct drm_bridge *b)
+{
+	return container_of(b, struct dw_dp, bridge);
+}
+
+static struct dw_dp_bridge_state *dw_dp_get_bridge_state(struct dw_dp *dp)
+{
+	struct dw_dp_bridge_state *dw_bridge_state;
+	struct drm_bridge_state *state;
+
+	state = drm_priv_to_bridge_state(dp->bridge.base.state);
+	if (!state)
+		return  NULL;
+
+	dw_bridge_state = to_dw_dp_bridge_state(state);
+	if (!dw_bridge_state)
+		return NULL;
+
+	return dw_bridge_state;
+}
+
+static inline void dw_dp_phy_set_pattern(struct dw_dp *dp, u32 pattern)
+{
+	regmap_update_bits(dp->regmap, DW_DP_PHYIF_CTRL, TPS_SEL,
+			   FIELD_PREP(TPS_SEL, pattern));
+}
+
+static void dw_dp_phy_xmit_enable(struct dw_dp *dp, u32 lanes)
+{
+	u32 xmit_enable;
+
+	switch (lanes) {
+	case 4:
+	case 2:
+	case 1:
+		xmit_enable = GENMASK(lanes - 1, 0);
+		break;
+	case 0:
+	default:
+		xmit_enable = 0;
+		break;
+	}
+
+	regmap_update_bits(dp->regmap, DW_DP_PHYIF_CTRL, XMIT_ENABLE,
+			   FIELD_PREP(XMIT_ENABLE, xmit_enable));
+}
+
+static bool dw_dp_bandwidth_ok(struct dw_dp *dp,
+			       const struct drm_display_mode *mode, u32 bpp,
+			       unsigned int lanes, unsigned int rate)
+{
+	u32 max_bw, req_bw;
+
+	req_bw = mode->clock * bpp / 8;
+	max_bw = lanes * rate;
+	if (req_bw > max_bw)
+		return false;
+
+	return true;
+}
+
+static bool dw_dp_hpd_detect(struct dw_dp *dp)
+{
+	u32 value;
+
+	regmap_read(dp->regmap, DW_DP_HPD_STATUS, &value);
+
+	return FIELD_GET(HPD_STATE, value) == DW_DP_HPD_STATE_PLUG;
+}
+
+static void dw_dp_link_caps_reset(struct dw_dp_link_caps *caps)
+{
+	caps->enhanced_framing = false;
+	caps->tps3_supported = false;
+	caps->tps4_supported = false;
+	caps->fast_training = false;
+	caps->channel_coding = false;
+}
+
+static void dw_dp_link_reset(struct dw_dp_link *link)
+{
+	link->vsc_sdp_supported = 0;
+	link->sink_count = 0;
+	link->revision = 0;
+	link->rate = 0;
+	link->lanes = 0;
+
+	dw_dp_link_caps_reset(&link->caps);
+	memset(link->dpcd, 0, sizeof(link->dpcd));
+}
+
+static int dw_dp_link_parse(struct dw_dp *dp, struct drm_connector *connector)
+{
+	struct dw_dp_link *link = &dp->link;
+	int ret;
+
+	dw_dp_link_reset(link);
+
+	ret = drm_dp_read_dpcd_caps(&dp->aux, link->dpcd);
+	if (ret < 0)
+		return ret;
+
+	drm_dp_read_desc(&dp->aux, &link->desc, drm_dp_is_branch(link->dpcd));
+
+	if (drm_dp_read_sink_count_cap(connector, link->dpcd, &link->desc)) {
+		ret = drm_dp_read_sink_count(&dp->aux);
+		if (ret < 0)
+			return ret;
+
+		link->sink_count = ret;
+
+		/* Dongle connected, but no display */
+		if (!link->sink_count)
+			return -ENODEV;
+	}
+
+	link->vsc_sdp_supported = drm_dp_vsc_sdp_supported(&dp->aux, link->dpcd);
+
+	link->revision = link->dpcd[DP_DPCD_REV];
+	link->rate = min_t(u32, min(dp->plat_data.max_link_rate,
+				    dp->phy->attrs.max_link_rate * 100),
+			   drm_dp_max_link_rate(link->dpcd));
+	link->lanes = min_t(u8, phy_get_bus_width(dp->phy),
+			    drm_dp_max_lane_count(link->dpcd));
+
+	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(link->dpcd);
+	link->caps.tps3_supported = drm_dp_tps3_supported(link->dpcd);
+	link->caps.tps4_supported = drm_dp_tps4_supported(link->dpcd);
+	link->caps.fast_training = drm_dp_fast_training_cap(link->dpcd);
+	link->caps.channel_coding = drm_dp_channel_coding_supported(link->dpcd);
+	link->caps.ssc = !!(link->dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5);
+
+	return 0;
+}
+
+static int dw_dp_link_train_update_vs_emph(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	struct dw_dp_link_train_set *train_set = &link->train.adjust;
+	unsigned int lanes = dp->link.lanes;
+	union phy_configure_opts phy_cfg;
+	unsigned int *vs, *pe;
+	int i, ret;
+	u8 buf[4];
+
+	vs = train_set->voltage_swing;
+	pe = train_set->pre_emphasis;
+
+	for (i = 0; i < lanes; i++) {
+		phy_cfg.dp.voltage[i] = vs[i];
+		phy_cfg.dp.pre[i] = pe[i];
+	}
+
+	phy_cfg.dp.set_lanes = false;
+	phy_cfg.dp.set_rate = false;
+	phy_cfg.dp.set_voltages = true;
+
+	ret = phy_configure(dp->phy, &phy_cfg);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < lanes; i++) {
+		buf[i] = (vs[i] << DP_TRAIN_VOLTAGE_SWING_SHIFT) |
+			 (pe[i] << DP_TRAIN_PRE_EMPHASIS_SHIFT);
+		if (train_set->voltage_max_reached[i])
+			buf[i] |= DP_TRAIN_MAX_SWING_REACHED;
+		if (train_set->pre_max_reached[i])
+			buf[i] |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
+	}
+
+	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, buf, lanes);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int dw_dp_phy_configure(struct dw_dp *dp, unsigned int rate,
+			       unsigned int lanes, bool ssc)
+{
+	union phy_configure_opts phy_cfg;
+	int ret;
+
+	/* Move PHY to P3 */
+	regmap_update_bits(dp->regmap, DW_DP_PHYIF_CTRL, PHY_POWERDOWN,
+			   FIELD_PREP(PHY_POWERDOWN, 0x3));
+
+	phy_cfg.dp.lanes = lanes;
+	phy_cfg.dp.link_rate = rate / 100;
+	phy_cfg.dp.ssc = ssc;
+	phy_cfg.dp.set_lanes = true;
+	phy_cfg.dp.set_rate = true;
+	phy_cfg.dp.set_voltages = false;
+	ret = phy_configure(dp->phy, &phy_cfg);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(dp->regmap, DW_DP_PHYIF_CTRL, PHY_LANES,
+			   FIELD_PREP(PHY_LANES, lanes / 2));
+
+	/* Move PHY to P0 */
+	regmap_update_bits(dp->regmap, DW_DP_PHYIF_CTRL, PHY_POWERDOWN,
+			   FIELD_PREP(PHY_POWERDOWN, 0x0));
+
+	dw_dp_phy_xmit_enable(dp, lanes);
+
+	return 0;
+}
+
+static int dw_dp_link_configure(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	u8 buf[2];
+	int ret;
+
+	ret = dw_dp_phy_configure(dp, link->rate, link->lanes, link->caps.ssc);
+	if (ret)
+		return ret;
+
+	buf[0] = drm_dp_link_rate_to_bw_code(link->rate);
+	buf[1] = link->lanes;
+
+	if (link->caps.enhanced_framing) {
+		buf[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
+		regmap_update_bits(dp->regmap, DW_DP_CCTL, ENHANCE_FRAMING_EN,
+				   FIELD_PREP(ENHANCE_FRAMING_EN, 1));
+	} else {
+		regmap_update_bits(dp->regmap, DW_DP_CCTL, ENHANCE_FRAMING_EN,
+				   FIELD_PREP(ENHANCE_FRAMING_EN, 0));
+	}
+
+	ret = drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	buf[0] = link->caps.ssc ? DP_SPREAD_AMP_0_5 : 0;
+	buf[1] = link->caps.channel_coding ? DP_SET_ANSI_8B10B : 0;
+
+	ret = drm_dp_dpcd_write(&dp->aux, DP_DOWNSPREAD_CTRL, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void dw_dp_link_train_init(struct dw_dp_link_train *train)
+{
+	struct dw_dp_link_train_set *adj = &train->adjust;
+	unsigned int i;
+
+	for (i = 0; i < 4; i++) {
+		adj->voltage_swing[i] = 0;
+		adj->pre_emphasis[i] = 0;
+		adj->voltage_max_reached[i] = false;
+		adj->pre_max_reached[i] = false;
+	}
+
+	train->clock_recovered = false;
+	train->channel_equalized = false;
+}
+
+static bool dw_dp_link_train_valid(const struct dw_dp_link_train *train)
+{
+	return train->clock_recovered && train->channel_equalized;
+}
+
+static int dw_dp_link_train_set_pattern(struct dw_dp *dp, u32 pattern)
+{
+	u8 buf = 0;
+	int ret;
+
+	if (pattern && pattern != DP_TRAINING_PATTERN_4) {
+		buf |= DP_LINK_SCRAMBLING_DISABLE;
+
+		regmap_update_bits(dp->regmap, DW_DP_CCTL, SCRAMBLE_DIS,
+				   FIELD_PREP(SCRAMBLE_DIS, 1));
+	} else {
+		regmap_update_bits(dp->regmap, DW_DP_CCTL, SCRAMBLE_DIS,
+				   FIELD_PREP(SCRAMBLE_DIS, 0));
+	}
+
+	switch (pattern) {
+	case DP_TRAINING_PATTERN_DISABLE:
+		dw_dp_phy_set_pattern(dp, DW_DP_PHY_PATTERN_NONE);
+		break;
+	case DP_TRAINING_PATTERN_1:
+		dw_dp_phy_set_pattern(dp, DW_DP_PHY_PATTERN_TPS_1);
+		break;
+	case DP_TRAINING_PATTERN_2:
+		dw_dp_phy_set_pattern(dp, DW_DP_PHY_PATTERN_TPS_2);
+		break;
+	case DP_TRAINING_PATTERN_3:
+		dw_dp_phy_set_pattern(dp, DW_DP_PHY_PATTERN_TPS_3);
+		break;
+	case DP_TRAINING_PATTERN_4:
+		dw_dp_phy_set_pattern(dp, DW_DP_PHY_PATTERN_TPS_4);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
+				 buf | pattern);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static u8 dw_dp_voltage_max(u8 preemph)
+{
+	switch (preemph & DP_TRAIN_PRE_EMPHASIS_MASK) {
+	case DP_TRAIN_PRE_EMPH_LEVEL_0:
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
+	case DP_TRAIN_PRE_EMPH_LEVEL_1:
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
+	case DP_TRAIN_PRE_EMPH_LEVEL_2:
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_1;
+	case DP_TRAIN_PRE_EMPH_LEVEL_3:
+	default:
+		return DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
+	}
+}
+
+static bool dw_dp_link_get_adjustments(struct dw_dp_link *link,
+				       u8 status[DP_LINK_STATUS_SIZE])
+{
+	struct dw_dp_link_train_set *adj = &link->train.adjust;
+	unsigned int i;
+	bool changed = false;
+	u8 v = 0;
+	u8 p = 0;
+
+	for (i = 0; i < link->lanes; i++) {
+		v = drm_dp_get_adjust_request_voltage(status, i);
+		v >>= DP_TRAIN_VOLTAGE_SWING_SHIFT;
+		p = drm_dp_get_adjust_request_pre_emphasis(status, i);
+		p >>= DP_TRAIN_PRE_EMPHASIS_SHIFT;
+
+		if (v != adj->voltage_swing[i] || p != adj->pre_emphasis[i])
+			changed = true;
+
+		if (p >=  (DP_TRAIN_PRE_EMPH_LEVEL_3 >> DP_TRAIN_PRE_EMPHASIS_SHIFT)) {
+			adj->pre_emphasis[i] = DP_TRAIN_PRE_EMPH_LEVEL_3 >>
+					       DP_TRAIN_PRE_EMPHASIS_SHIFT;
+			adj->pre_max_reached[i] = true;
+		} else {
+			adj->pre_emphasis[i] = p;
+			adj->pre_max_reached[i] = false;
+		}
+
+		v = min(v, dw_dp_voltage_max(p));
+		if (v >= (DP_TRAIN_VOLTAGE_SWING_LEVEL_3 >> DP_TRAIN_VOLTAGE_SWING_SHIFT)) {
+			adj->voltage_swing[i] = DP_TRAIN_VOLTAGE_SWING_LEVEL_3 >>
+						DP_TRAIN_VOLTAGE_SWING_SHIFT;
+			adj->voltage_max_reached[i] = true;
+		} else {
+			adj->voltage_swing[i] = v;
+			adj->voltage_max_reached[i] = false;
+		}
+	}
+
+	return changed;
+}
+
+static int dw_dp_link_clock_recovery(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	u8 status[DP_LINK_STATUS_SIZE];
+	unsigned int tries = 0;
+	int ret;
+	bool adj_changed;
+
+	ret = dw_dp_link_train_set_pattern(dp, DP_TRAINING_PATTERN_1);
+	if (ret)
+		return ret;
+
+	for (;;) {
+		ret = dw_dp_link_train_update_vs_emph(dp);
+		if (ret)
+			return ret;
+
+		drm_dp_link_train_clock_recovery_delay(&dp->aux, link->dpcd);
+
+		ret = drm_dp_dpcd_read_link_status(&dp->aux, status);
+		if (ret < 0) {
+			dev_err(dp->dev, "failed to read link status: %d\n", ret);
+			return ret;
+		}
+
+		if (drm_dp_clock_recovery_ok(status, link->lanes)) {
+			link->train.clock_recovered = true;
+			break;
+		}
+
+		/*
+		 * According to DP spec 1.4, if current ADJ is the same
+		 * with previous REQ, we need to retry 5 times.
+		 */
+		adj_changed = dw_dp_link_get_adjustments(link, status);
+		if (!adj_changed)
+			tries++;
+		else
+			tries = 0;
+
+		if (tries == 5)
+			break;
+	}
+
+	return 0;
+}
+
+static int dw_dp_link_channel_equalization(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	u8 status[DP_LINK_STATUS_SIZE], pattern;
+	unsigned int tries;
+	int ret;
+
+	if (link->caps.tps4_supported)
+		pattern = DP_TRAINING_PATTERN_4;
+	else if (link->caps.tps3_supported)
+		pattern = DP_TRAINING_PATTERN_3;
+	else
+		pattern = DP_TRAINING_PATTERN_2;
+	ret = dw_dp_link_train_set_pattern(dp, pattern);
+	if (ret)
+		return ret;
+
+	for (tries = 1; tries < 5; tries++) {
+		ret = dw_dp_link_train_update_vs_emph(dp);
+		if (ret)
+			return ret;
+
+		drm_dp_link_train_channel_eq_delay(&dp->aux, link->dpcd);
+
+		ret = drm_dp_dpcd_read_link_status(&dp->aux, status);
+		if (ret < 0)
+			return ret;
+
+		if (!drm_dp_clock_recovery_ok(status, link->lanes)) {
+			dev_err(dp->dev, "clock recovery lost while equalizing channel\n");
+			link->train.clock_recovered = false;
+			break;
+		}
+
+		if (drm_dp_channel_eq_ok(status, link->lanes)) {
+			link->train.channel_equalized = true;
+			break;
+		}
+
+		dw_dp_link_get_adjustments(link, status);
+	}
+
+	return 0;
+}
+
+static int dw_dp_link_downgrade(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	struct dw_dp_bridge_state *state;
+
+	state = dw_dp_get_bridge_state(dp);
+
+	switch (link->rate) {
+	case 162000:
+		return -EINVAL;
+	case 270000:
+		link->rate = 162000;
+		break;
+	case 540000:
+		link->rate = 270000;
+		break;
+	case 810000:
+		link->rate = 540000;
+		break;
+	}
+
+	if (!dw_dp_bandwidth_ok(dp, &state->mode, state->bpp, link->lanes,
+				link->rate))
+		return -E2BIG;
+
+	return 0;
+}
+
+static int dw_dp_link_train_full(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	int ret;
+
+retry:
+	dw_dp_link_train_init(&link->train);
+
+	dev_dbg(dp->dev, "full-training link: %u lane%s at %u MHz\n",
+		link->lanes, (link->lanes > 1) ? "s" : "", link->rate / 100);
+
+	ret = dw_dp_link_configure(dp);
+	if (ret < 0) {
+		dev_err(dp->dev, "failed to configure DP link: %d\n", ret);
+		return ret;
+	}
+
+	ret = dw_dp_link_clock_recovery(dp);
+	if (ret < 0) {
+		dev_err(dp->dev, "clock recovery failed: %d\n", ret);
+		goto out;
+	}
+
+	if (!link->train.clock_recovered) {
+		dev_err(dp->dev, "clock recovery failed, downgrading link\n");
+
+		ret = dw_dp_link_downgrade(dp);
+		if (ret < 0)
+			goto out;
+		else
+			goto retry;
+	}
+
+	dev_dbg(dp->dev, "clock recovery succeeded\n");
+
+	ret = dw_dp_link_channel_equalization(dp);
+	if (ret < 0) {
+		dev_err(dp->dev, "channel equalization failed: %d\n", ret);
+		goto out;
+	}
+
+	if (!link->train.channel_equalized) {
+		dev_err(dp->dev, "channel equalization failed, downgrading link\n");
+
+		ret = dw_dp_link_downgrade(dp);
+		if (ret < 0)
+			goto out;
+		else
+			goto retry;
+	}
+
+	dev_dbg(dp->dev, "channel equalization succeeded\n");
+
+out:
+	dw_dp_link_train_set_pattern(dp, DP_TRAINING_PATTERN_DISABLE);
+	return ret;
+}
+
+static int dw_dp_link_train_fast(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	int ret;
+	u8 status[DP_LINK_STATUS_SIZE];
+	u8 pattern;
+
+	dw_dp_link_train_init(&link->train);
+
+	dev_dbg(dp->dev, "fast-training link: %u lane%s at %u MHz\n",
+		link->lanes, (link->lanes > 1) ? "s" : "", link->rate / 100);
+
+	ret = dw_dp_link_configure(dp);
+	if (ret < 0) {
+		dev_err(dp->dev, "failed to configure DP link: %d\n", ret);
+		return ret;
+	}
+
+	ret = dw_dp_link_train_set_pattern(dp, DP_TRAINING_PATTERN_1);
+	if (ret)
+		goto out;
+
+	usleep_range(500, 1000);
+
+	if (link->caps.tps4_supported)
+		pattern = DP_TRAINING_PATTERN_4;
+	else if (link->caps.tps3_supported)
+		pattern = DP_TRAINING_PATTERN_3;
+	else
+		pattern = DP_TRAINING_PATTERN_2;
+	ret = dw_dp_link_train_set_pattern(dp, pattern);
+	if (ret)
+		goto out;
+
+	usleep_range(500, 1000);
+
+	ret = drm_dp_dpcd_read_link_status(&dp->aux, status);
+	if (ret < 0) {
+		dev_err(dp->dev, "failed to read link status: %d\n", ret);
+		goto out;
+	}
+
+	if (!drm_dp_clock_recovery_ok(status, link->lanes)) {
+		dev_err(dp->dev, "clock recovery failed\n");
+		ret = -EIO;
+		goto out;
+	}
+
+	if (!drm_dp_channel_eq_ok(status, link->lanes)) {
+		dev_err(dp->dev, "channel equalization failed\n");
+		ret = -EIO;
+		goto out;
+	}
+
+out:
+	dw_dp_link_train_set_pattern(dp, DP_TRAINING_PATTERN_DISABLE);
+	return ret;
+}
+
+static int dw_dp_link_train(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	int ret;
+
+	if (link->caps.fast_training) {
+		if (dw_dp_link_train_valid(&link->train)) {
+			ret = dw_dp_link_train_fast(dp);
+			if (ret < 0)
+				dev_err(dp->dev, "fast link training failed: %d\n", ret);
+			else
+				return 0;
+		}
+	}
+
+	ret = dw_dp_link_train_full(dp);
+	if (ret < 0) {
+		dev_err(dp->dev, "full link training failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int dw_dp_send_sdp(struct dw_dp *dp, struct dw_dp_sdp *sdp)
+{
+	const u8 *payload = sdp->base.db;
+	u32 reg;
+	int i, nr;
+
+	nr = find_first_zero_bit(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
+	if (nr < SDP_REG_BANK_SIZE)
+		set_bit(nr, dp->sdp_reg_bank);
+	else
+		return -EBUSY;
+
+	reg = DW_DP_SDP_REGISTER_BANK + nr * 9 * 4;
+
+	/* SDP header */
+	regmap_write(dp->regmap, reg, get_unaligned_le32(&sdp->base.sdp_header));
+
+	/* SDP data payload */
+	for (i = 1; i < 9; i++, payload += 4)
+		regmap_write(dp->regmap, reg + i * 4,
+			     FIELD_PREP(SDP_REGS, get_unaligned_le32(payload)));
+
+	if (sdp->flags & DW_DP_SDP_VERTICAL_INTERVAL)
+		regmap_update_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL,
+				   EN_VERTICAL_SDP << nr,
+				   EN_VERTICAL_SDP << nr);
+
+	if (sdp->flags & DW_DP_SDP_HORIZONTAL_INTERVAL)
+		regmap_update_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL,
+				   EN_HORIZONTAL_SDP << nr,
+				   EN_HORIZONTAL_SDP << nr);
+
+	return 0;
+}
+
+static int dw_dp_send_vsc_sdp(struct dw_dp *dp)
+{
+	struct dw_dp_bridge_state *state;
+	struct dw_dp_sdp sdp = {};
+	struct drm_dp_vsc_sdp vsc = {};
+
+	state = dw_dp_get_bridge_state(dp);
+	if (!state)
+		return -EINVAL;
+
+	vsc.bpc = state->bpc;
+
+	vsc.sdp_type = DP_SDP_VSC;
+	vsc.revision = 0x5;
+	vsc.length = 0x13;
+	vsc.content_type = DP_CONTENT_TYPE_NOT_DEFINED;
+
+	sdp.flags = DW_DP_SDP_VERTICAL_INTERVAL;
+
+	switch (state->color_format) {
+	case DRM_COLOR_FORMAT_YCBCR444:
+		vsc.pixelformat = DP_PIXELFORMAT_YUV444;
+		break;
+	case DRM_COLOR_FORMAT_YCBCR420:
+		vsc.pixelformat = DP_PIXELFORMAT_YUV420;
+		break;
+	case DRM_COLOR_FORMAT_YCBCR422:
+		vsc.pixelformat = DP_PIXELFORMAT_YUV422;
+		break;
+	case DRM_COLOR_FORMAT_RGB444:
+	default:
+		vsc.pixelformat = DP_PIXELFORMAT_RGB;
+		break;
+	}
+
+	if (state->color_format == DRM_COLOR_FORMAT_RGB444) {
+		vsc.colorimetry = DP_COLORIMETRY_DEFAULT;
+		vsc.dynamic_range = DP_DYNAMIC_RANGE_VESA;
+	} else {
+		vsc.colorimetry = DP_COLORIMETRY_BT709_YCC;
+		vsc.dynamic_range = DP_DYNAMIC_RANGE_CTA;
+	}
+
+	drm_dp_vsc_sdp_pack(&vsc, &sdp.base);
+
+	return dw_dp_send_sdp(dp, &sdp);
+}
+
+static int dw_dp_video_set_pixel_mode(struct dw_dp *dp)
+{
+	switch (dp->pixel_mode) {
+	case DW_DP_MP_SINGLE_PIXEL:
+	case DW_DP_MP_DUAL_PIXEL:
+	case DW_DP_MP_QUAD_PIXEL:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(dp->regmap, DW_DP_VSAMPLE_CTRL, PIXEL_MODE_SELECT,
+			   FIELD_PREP(PIXEL_MODE_SELECT, dp->pixel_mode));
+
+	return 0;
+}
+
+static bool dw_dp_video_need_vsc_sdp(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	struct dw_dp_bridge_state *state;
+
+	state = dw_dp_get_bridge_state(dp);
+	if (!state)
+		return -EINVAL;
+
+	if (!link->vsc_sdp_supported)
+		return false;
+
+	if (state->color_format == DRM_COLOR_FORMAT_YCBCR420)
+		return true;
+
+	return false;
+}
+
+static int dw_dp_video_set_msa(struct dw_dp *dp, u8 color_format, u8 bpc,
+			       u16 vstart, u16 hstart)
+{
+	u16 misc = 0;
+
+	if (dw_dp_video_need_vsc_sdp(dp))
+		misc |= DP_MSA_MISC_COLOR_VSC_SDP;
+
+	switch (color_format) {
+	case DRM_COLOR_FORMAT_RGB444:
+		misc |= DP_MSA_MISC_COLOR_RGB;
+		break;
+	case DRM_COLOR_FORMAT_YCBCR444:
+		misc |= DP_MSA_MISC_COLOR_YCBCR_444_BT709;
+		break;
+	case DRM_COLOR_FORMAT_YCBCR422:
+		misc |= DP_MSA_MISC_COLOR_YCBCR_422_BT709;
+		break;
+	case DRM_COLOR_FORMAT_YCBCR420:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (bpc) {
+	case 6:
+		misc |= DP_MSA_MISC_6_BPC;
+		break;
+	case 8:
+		misc |= DP_MSA_MISC_8_BPC;
+		break;
+	case 10:
+		misc |= DP_MSA_MISC_10_BPC;
+		break;
+	case 12:
+		misc |= DP_MSA_MISC_12_BPC;
+		break;
+	case 16:
+		misc |= DP_MSA_MISC_16_BPC;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_write(dp->regmap, DW_DP_VIDEO_MSA1,
+		     FIELD_PREP(VSTART, vstart) | FIELD_PREP(HSTART, hstart));
+	regmap_write(dp->regmap, DW_DP_VIDEO_MSA2, FIELD_PREP(MISC0, misc));
+	regmap_write(dp->regmap, DW_DP_VIDEO_MSA3, FIELD_PREP(MISC1, misc >> 8));
+
+	return 0;
+}
+
+static void dw_dp_video_disable(struct dw_dp *dp)
+{
+	regmap_update_bits(dp->regmap, DW_DP_VSAMPLE_CTRL, VIDEO_STREAM_ENABLE,
+			   FIELD_PREP(VIDEO_STREAM_ENABLE, 0));
+}
+
+static int dw_dp_video_enable(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	struct dw_dp_bridge_state *state;
+	struct drm_display_mode *mode;
+	u8 color_format, bpc, bpp;
+	u8 init_threshold, vic;
+	u32 hstart, hactive, hblank, h_sync_width, h_front_porch;
+	u32 vstart, vactive, vblank, v_sync_width, v_front_porch;
+	u32 peak_stream_bandwidth, link_bandwidth;
+	u32 average_bytes_per_tu, average_bytes_per_tu_frac;
+	u32 ts, hblank_interval;
+	u32 value;
+	int ret;
+
+	state = dw_dp_get_bridge_state(dp);
+	if (!state)
+		return -EINVAL;
+
+	bpc = state->bpc;
+	bpp = state->bpp;
+	color_format = state->color_format;
+	mode = &state->mode;
+
+	vstart = mode->vtotal - mode->vsync_start;
+	hstart = mode->htotal - mode->hsync_start;
+
+	ret = dw_dp_video_set_pixel_mode(dp);
+	if (ret)
+		return ret;
+
+	ret = dw_dp_video_set_msa(dp, color_format, bpc, vstart, hstart);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(dp->regmap, DW_DP_VSAMPLE_CTRL, VIDEO_MAPPING,
+			   FIELD_PREP(VIDEO_MAPPING, state->video_mapping));
+
+	/* Configure DW_DP_VINPUT_POLARITY_CTRL register */
+	value = 0;
+	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
+		value |= FIELD_PREP(HSYNC_IN_POLARITY, 1);
+	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+		value |= FIELD_PREP(VSYNC_IN_POLARITY, 1);
+	regmap_write(dp->regmap, DW_DP_VINPUT_POLARITY_CTRL, value);
+
+	/* Configure DW_DP_VIDEO_CONFIG1 register */
+	hactive = mode->hdisplay;
+	hblank = mode->htotal - mode->hdisplay;
+	value = FIELD_PREP(HACTIVE, hactive) | FIELD_PREP(HBLANK, hblank);
+	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+		value |= FIELD_PREP(I_P, 1);
+	vic = drm_match_cea_mode(mode);
+	if (vic == 5 || vic == 6 || vic == 7 ||
+	    vic == 10 || vic == 11 || vic == 20 ||
+	    vic == 21 || vic == 22 || vic == 39 ||
+	    vic == 25 || vic == 26 || vic == 40 ||
+	    vic == 44 || vic == 45 || vic == 46 ||
+	    vic == 50 || vic == 51 || vic == 54 ||
+	    vic == 55 || vic == 58 || vic  == 59)
+		value |= R_V_BLANK_IN_OSC;
+	regmap_write(dp->regmap, DW_DP_VIDEO_CONFIG1, value);
+
+	/* Configure DW_DP_VIDEO_CONFIG2 register */
+	vblank = mode->vtotal - mode->vdisplay;
+	vactive = mode->vdisplay;
+	regmap_write(dp->regmap, DW_DP_VIDEO_CONFIG2,
+		     FIELD_PREP(VBLANK, vblank) | FIELD_PREP(VACTIVE, vactive));
+
+	/* Configure DW_DP_VIDEO_CONFIG3 register */
+	h_sync_width = mode->hsync_end - mode->hsync_start;
+	h_front_porch = mode->hsync_start - mode->hdisplay;
+	regmap_write(dp->regmap, DW_DP_VIDEO_CONFIG3,
+		     FIELD_PREP(H_SYNC_WIDTH, h_sync_width) |
+		     FIELD_PREP(H_FRONT_PORCH, h_front_porch));
+
+	/* Configure DW_DP_VIDEO_CONFIG4 register */
+	v_sync_width = mode->vsync_end - mode->vsync_start;
+	v_front_porch = mode->vsync_start - mode->vdisplay;
+	regmap_write(dp->regmap, DW_DP_VIDEO_CONFIG4,
+		     FIELD_PREP(V_SYNC_WIDTH, v_sync_width) |
+		     FIELD_PREP(V_FRONT_PORCH, v_front_porch));
+
+	/* Configure DW_DP_VIDEO_CONFIG5 register */
+	peak_stream_bandwidth = mode->clock * bpp / 8;
+	link_bandwidth = (link->rate / 1000) * link->lanes;
+	ts = peak_stream_bandwidth * 64 / link_bandwidth;
+	average_bytes_per_tu = ts / 1000;
+	average_bytes_per_tu_frac = ts / 100 - average_bytes_per_tu * 10;
+	if (dp->pixel_mode == DW_DP_MP_SINGLE_PIXEL) {
+		if (average_bytes_per_tu < 6)
+			init_threshold = 32;
+		else if (hblank <= 80 && color_format != DRM_COLOR_FORMAT_YCBCR420)
+			init_threshold = 12;
+		else if (hblank <= 40 && color_format == DRM_COLOR_FORMAT_YCBCR420)
+			init_threshold = 3;
+		else
+			init_threshold = 16;
+	} else {
+		u32 t1 = 0, t2 = 0, t3 = 0;
+
+		switch (bpc) {
+		case 6:
+			t1 = (4 * 1000 / 9) * link->lanes;
+			break;
+		case 8:
+			if (color_format == DRM_COLOR_FORMAT_YCBCR422) {
+				t1 = (1000 / 2) * link->lanes;
+			} else {
+				if (dp->pixel_mode == DW_DP_MP_DUAL_PIXEL)
+					t1 = (1000 / 3) * link->lanes;
+				else
+					t1 = (3000 / 16) * link->lanes;
+			}
+			break;
+		case 10:
+			if (color_format == DRM_COLOR_FORMAT_YCBCR422)
+				t1 = (2000 / 5) * link->lanes;
+			else
+				t1 = (4000 / 15) * link->lanes;
+			break;
+		case 12:
+			if (color_format == DRM_COLOR_FORMAT_YCBCR422) {
+				if (dp->pixel_mode == DW_DP_MP_DUAL_PIXEL)
+					t1 = (1000 / 6) * link->lanes;
+				else
+					t1 = (1000 / 3) * link->lanes;
+			} else {
+				t1 = (2000 / 9) * link->lanes;
+			}
+			break;
+		case 16:
+			if (color_format != DRM_COLOR_FORMAT_YCBCR422 &&
+			    dp->pixel_mode == DW_DP_MP_DUAL_PIXEL)
+				t1 = (1000 / 6) * link->lanes;
+			else
+				t1 = (1000 / 4) * link->lanes;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		if (color_format == DRM_COLOR_FORMAT_YCBCR420)
+			t2 = (link->rate / 4) * 1000 / (mode->clock / 2);
+		else
+			t2 = (link->rate / 4) * 1000 / mode->clock;
+
+		if (average_bytes_per_tu_frac)
+			t3 = average_bytes_per_tu + 1;
+		else
+			t3 = average_bytes_per_tu;
+		init_threshold = t1 * t2 * t3 / (1000 * 1000);
+		if (init_threshold <= 16 || average_bytes_per_tu < 10)
+			init_threshold = 40;
+	}
+
+	regmap_write(dp->regmap, DW_DP_VIDEO_CONFIG5,
+		     FIELD_PREP(INIT_THRESHOLD_HI, init_threshold >> 6) |
+		     FIELD_PREP(AVERAGE_BYTES_PER_TU_FRAC, average_bytes_per_tu_frac) |
+		     FIELD_PREP(INIT_THRESHOLD, init_threshold) |
+		     FIELD_PREP(AVERAGE_BYTES_PER_TU, average_bytes_per_tu));
+
+	/* Configure DW_DP_VIDEO_HBLANK_INTERVAL register */
+	hblank_interval = hblank * (link->rate / 4) / mode->clock;
+	regmap_write(dp->regmap, DW_DP_VIDEO_HBLANK_INTERVAL,
+		     FIELD_PREP(HBLANK_INTERVAL_EN, 1) |
+		     FIELD_PREP(HBLANK_INTERVAL, hblank_interval));
+
+	/* Video stream enable */
+	regmap_update_bits(dp->regmap, DW_DP_VSAMPLE_CTRL, VIDEO_STREAM_ENABLE,
+			   FIELD_PREP(VIDEO_STREAM_ENABLE, 1));
+
+	if (dw_dp_video_need_vsc_sdp(dp))
+		dw_dp_send_vsc_sdp(dp);
+
+	return 0;
+}
+
+static void dw_dp_hpd_init(struct dw_dp *dp)
+{
+	/* Enable all HPD interrupts */
+	regmap_update_bits(dp->regmap, DW_DP_HPD_INTERRUPT_ENABLE,
+			   HPD_UNPLUG_EN | HPD_PLUG_EN | HPD_IRQ_EN,
+			   FIELD_PREP(HPD_UNPLUG_EN, 1) |
+			   FIELD_PREP(HPD_PLUG_EN, 1) |
+			   FIELD_PREP(HPD_IRQ_EN, 1));
+
+	/* Enable all top-level interrupts */
+	regmap_update_bits(dp->regmap, DW_DP_GENERAL_INTERRUPT_ENABLE,
+			   HPD_EVENT_EN, FIELD_PREP(HPD_EVENT_EN, 1));
+}
+
+static void dw_dp_aux_init(struct dw_dp *dp)
+{
+	regmap_update_bits(dp->regmap, DW_DP_GENERAL_INTERRUPT_ENABLE,
+			   AUX_REPLY_EVENT_EN, FIELD_PREP(AUX_REPLY_EVENT_EN, 1));
+}
+
+static void dw_dp_init_hw(struct dw_dp *dp)
+{
+	regmap_update_bits(dp->regmap, DW_DP_CCTL, DEFAULT_FAST_LINK_TRAIN_EN,
+			   FIELD_PREP(DEFAULT_FAST_LINK_TRAIN_EN, 0));
+
+	dw_dp_hpd_init(dp);
+	dw_dp_aux_init(dp);
+}
+
+static int dw_dp_aux_write_data(struct dw_dp *dp, const u8 *buffer, size_t size)
+{
+	size_t i, j;
+
+	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
+		size_t num = min_t(size_t, size - i * 4, 4);
+		u32 value = 0;
+
+		for (j = 0; j < num; j++)
+			value |= buffer[i * 4 + j] << (j * 8);
+
+		regmap_write(dp->regmap, DW_DP_AUX_DATA0 + i * 4, value);
+	}
+
+	return size;
+}
+
+static int dw_dp_aux_read_data(struct dw_dp *dp, u8 *buffer, size_t size)
+{
+	size_t i, j;
+
+	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
+		size_t num = min_t(size_t, size - i * 4, 4);
+		u32 value;
+
+		regmap_read(dp->regmap, DW_DP_AUX_DATA0 + i * 4, &value);
+
+		for (j = 0; j < num; j++)
+			buffer[i * 4 + j] = value >> (j * 8);
+	}
+
+	return size;
+}
+
+static ssize_t dw_dp_aux_transfer(struct drm_dp_aux *aux,
+				  struct drm_dp_aux_msg *msg)
+{
+	struct dw_dp *dp = container_of(aux, struct dw_dp, aux);
+	unsigned long timeout = msecs_to_jiffies(10);
+	u32 status, value;
+	ssize_t ret = 0;
+
+	if (WARN_ON(msg->size > 16))
+		return -E2BIG;
+
+	switch (msg->request & ~DP_AUX_I2C_MOT) {
+	case DP_AUX_NATIVE_WRITE:
+	case DP_AUX_I2C_WRITE:
+	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
+		ret = dw_dp_aux_write_data(dp, msg->buffer, msg->size);
+		if (ret < 0)
+			return ret;
+		break;
+	case DP_AUX_NATIVE_READ:
+	case DP_AUX_I2C_READ:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (msg->size > 0)
+		value = FIELD_PREP(AUX_LEN_REQ, msg->size - 1);
+	else
+		value = FIELD_PREP(I2C_ADDR_ONLY, 1);
+	value |= FIELD_PREP(AUX_CMD_TYPE, msg->request);
+	value |= FIELD_PREP(AUX_ADDR, msg->address);
+	regmap_write(dp->regmap, DW_DP_AUX_CMD, value);
+
+	status = wait_for_completion_timeout(&dp->complete, timeout);
+	if (!status) {
+		dev_err(dp->dev, "timeout waiting for AUX reply\n");
+		return -ETIMEDOUT;
+	}
+
+	regmap_read(dp->regmap, DW_DP_AUX_STATUS, &value);
+	if (value & AUX_TIMEOUT)
+		return -ETIMEDOUT;
+
+	msg->reply = FIELD_GET(AUX_STATUS, value);
+
+	if (msg->size > 0 && msg->reply == DP_AUX_NATIVE_REPLY_ACK) {
+		if (msg->request & DP_AUX_I2C_READ) {
+			size_t count = FIELD_GET(AUX_BYTES_READ, value) - 1;
+
+			if (count != msg->size)
+				return -EBUSY;
+
+			ret = dw_dp_aux_read_data(dp, msg->buffer, count);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Limits for the video timing for DP:
+ * 1. the hfp should be 2 pixels aligned;
+ * 2. the minimum hsync should be 9 pixel;
+ * 3. the minimum hbp should be 16 pixel;
+ */
+static int dw_dp_bridge_atomic_check(struct drm_bridge *bridge,
+				     struct drm_bridge_state *bridge_state,
+				     struct drm_crtc_state *crtc_state,
+				     struct drm_connector_state *conn_state)
+{
+	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
+	struct dw_dp *dp = bridge_to_dp(bridge);
+	struct dw_dp_bridge_state *state;
+	const struct dw_dp_output_format *fmt;
+	struct drm_display_mode *mode;
+	int min_hbp = 16;
+	int min_hsync = 9;
+
+	state = to_dw_dp_bridge_state(bridge_state);
+	mode = &state->mode;
+
+	fmt = dw_dp_get_output_format(bridge_state->output_bus_cfg.format);
+	if (!fmt)
+		return -EINVAL;
+
+	state->video_mapping = fmt->video_mapping;
+	state->color_format = fmt->color_format;
+	state->bpc = fmt->bpc;
+	state->bpp = fmt->bpp;
+
+	if ((adjusted_mode->hsync_start - adjusted_mode->hdisplay) & 0x1) {
+		adjusted_mode->hsync_start += 1;
+		dev_warn(dp->dev, "hfp is not 2 pixeel aligned, fixup to aligned hfp\n");
+	}
+
+	if (adjusted_mode->hsync_end - adjusted_mode->hsync_start < min_hsync) {
+		adjusted_mode->hsync_end = adjusted_mode->hsync_start + min_hsync;
+		dev_warn(dp->dev, "hsync is too narrow, fixup to min hsync:%d\n", min_hsync);
+	}
+
+	if (adjusted_mode->htotal - adjusted_mode->hsync_end < min_hbp) {
+		adjusted_mode->htotal = adjusted_mode->hsync_end + min_hbp;
+		dev_warn(dp->dev, "hbp is too narrow, fixup to min hbp:%d\n", min_hbp);
+	}
+
+	drm_mode_copy(mode, adjusted_mode);
+
+	return 0;
+}
+
+static enum drm_mode_status dw_dp_bridge_mode_valid(struct drm_bridge *bridge,
+						    const struct drm_display_info *info,
+						    const struct drm_display_mode *mode)
+{
+	struct dw_dp *dp = bridge_to_dp(bridge);
+	struct dw_dp_link *link = &dp->link;
+	u32 min_bpp;
+
+	if (info->color_formats & DRM_COLOR_FORMAT_YCBCR420 &&
+	    link->vsc_sdp_supported &&
+	    (drm_mode_is_420_only(info, mode) || drm_mode_is_420_also(info, mode)))
+		min_bpp = 12;
+	else if (info->color_formats & DRM_COLOR_FORMAT_YCBCR422)
+		min_bpp = 16;
+	else if (info->color_formats & DRM_COLOR_FORMAT_RGB444)
+		min_bpp = 18;
+	else
+		min_bpp = 24;
+
+	if (!link->vsc_sdp_supported &&
+	    drm_mode_is_420_only(info, mode))
+		return MODE_NO_420;
+
+	if (!dw_dp_bandwidth_ok(dp, mode, min_bpp, link->lanes, link->rate))
+		return MODE_CLOCK_HIGH;
+
+	return MODE_OK;
+}
+
+static bool dw_dp_needs_link_retrain(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+	u8 link_status[DP_LINK_STATUS_SIZE];
+
+	if (!dw_dp_link_train_valid(&link->train))
+		return false;
+
+	if (drm_dp_dpcd_read_link_status(&dp->aux, link_status) < 0)
+		return false;
+
+	/* Retrain if Channel EQ or CR not ok */
+	return !drm_dp_channel_eq_ok(link_status, dp->link.lanes);
+}
+
+static void dw_dp_link_disable(struct dw_dp *dp)
+{
+	struct dw_dp_link *link = &dp->link;
+
+	if (dw_dp_hpd_detect(dp))
+		drm_dp_link_power_down(&dp->aux, dp->link.revision);
+
+	dw_dp_phy_xmit_enable(dp, 0);
+
+	phy_power_off(dp->phy);
+
+	link->train.clock_recovered = false;
+	link->train.channel_equalized = false;
+}
+
+static int dw_dp_link_enable(struct dw_dp *dp)
+{
+	int ret;
+
+	ret = phy_power_on(dp->phy);
+	if (ret)
+		return ret;
+
+	ret = drm_dp_link_power_up(&dp->aux, dp->link.revision);
+	if (ret < 0)
+		return ret;
+
+	ret = dw_dp_link_train(dp);
+
+	return ret;
+}
+
+static void dw_dp_bridge_atomic_enable(struct drm_bridge *bridge,
+				       struct drm_atomic_state *state)
+{
+	struct dw_dp *dp = bridge_to_dp(bridge);
+	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
+	int ret;
+
+	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
+	if (!connector) {
+		dev_err(dp->dev, "failed to get connector\n");
+		return;
+	}
+
+	conn_state = drm_atomic_get_new_connector_state(state, connector);
+	if (!conn_state) {
+		dev_err(dp->dev, "failed to get connector state\n");
+		return;
+	}
+
+	set_bit(0, dp->sdp_reg_bank);
+
+	ret = dw_dp_link_enable(dp);
+	if (ret < 0) {
+		dev_err(dp->dev, "failed to enable link: %d\n", ret);
+		return;
+	}
+
+	ret = dw_dp_video_enable(dp);
+	if (ret < 0) {
+		dev_err(dp->dev, "failed to enable video: %d\n", ret);
+		return;
+	}
+}
+
+static void dw_dp_reset(struct dw_dp *dp)
+{
+	int val;
+
+	disable_irq(dp->irq);
+	regmap_update_bits(dp->regmap, DW_DP_SOFT_RESET_CTRL, CONTROLLER_RESET,
+			   FIELD_PREP(CONTROLLER_RESET, 1));
+	usleep_range(10, 20);
+	regmap_update_bits(dp->regmap, DW_DP_SOFT_RESET_CTRL, CONTROLLER_RESET,
+			   FIELD_PREP(CONTROLLER_RESET, 0));
+
+	dw_dp_init_hw(dp);
+	regmap_read_poll_timeout(dp->regmap, DW_DP_HPD_STATUS, val,
+				 FIELD_GET(HPD_HOT_PLUG, val), 200, 200000);
+	regmap_write(dp->regmap, DW_DP_HPD_STATUS, HPD_HOT_PLUG);
+	enable_irq(dp->irq);
+}
+
+static void dw_dp_bridge_atomic_disable(struct drm_bridge *bridge,
+					struct drm_atomic_state *state)
+{
+	struct dw_dp *dp = bridge_to_dp(bridge);
+
+	dw_dp_video_disable(dp);
+	dw_dp_link_disable(dp);
+	bitmap_zero(dp->sdp_reg_bank, SDP_REG_BANK_SIZE);
+	dw_dp_reset(dp);
+}
+
+static bool dw_dp_hpd_detect_link(struct dw_dp *dp, struct drm_connector *connector)
+{
+	int ret;
+
+	ret = phy_power_on(dp->phy);
+	if (ret < 0)
+		return false;
+	ret = dw_dp_link_parse(dp, connector);
+	phy_power_off(dp->phy);
+
+	return !ret;
+}
+
+static enum drm_connector_status dw_dp_bridge_detect(struct drm_bridge *bridge,
+						     struct drm_connector *connector)
+{
+	struct dw_dp *dp = bridge_to_dp(bridge);
+
+	if (!dw_dp_hpd_detect(dp))
+		return connector_status_disconnected;
+
+	if (!dw_dp_hpd_detect_link(dp, connector))
+		return connector_status_disconnected;
+
+	return connector_status_connected;
+}
+
+static const struct drm_edid *dw_dp_bridge_edid_read(struct drm_bridge *bridge,
+						     struct drm_connector *connector)
+{
+	struct dw_dp *dp = bridge_to_dp(bridge);
+	const struct drm_edid *edid;
+	int ret;
+
+	ret = phy_power_on(dp->phy);
+	if (ret)
+		return NULL;
+
+	edid = drm_edid_read_ddc(connector, &dp->aux.ddc);
+
+	phy_power_off(dp->phy);
+
+	return edid;
+}
+
+static u32 *dw_dp_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
+						    struct drm_bridge_state *bridge_state,
+						    struct drm_crtc_state *crtc_state,
+						    struct drm_connector_state *conn_state,
+						    unsigned int *num_output_fmts)
+{
+	struct dw_dp *dp = bridge_to_dp(bridge);
+	struct dw_dp_link *link = &dp->link;
+	struct drm_display_info *di = &conn_state->connector->display_info;
+	struct drm_display_mode mode = crtc_state->mode;
+	const struct dw_dp_output_format *fmt;
+	u32 i, j = 0;
+	u32 *output_fmts;
+
+	*num_output_fmts = 0;
+
+	output_fmts = kcalloc(ARRAY_SIZE(dw_dp_output_formats), sizeof(*output_fmts), GFP_KERNEL);
+	if (!output_fmts)
+		return NULL;
+
+	for (i = 0; i < ARRAY_SIZE(dw_dp_output_formats); i++) {
+		fmt = &dw_dp_output_formats[i];
+
+		if (fmt->bpc > conn_state->max_bpc)
+			continue;
+
+		if (!(fmt->color_format & di->color_formats))
+			continue;
+
+		if (fmt->color_format == DRM_COLOR_FORMAT_YCBCR420 &&
+		    !link->vsc_sdp_supported)
+			continue;
+
+		if (fmt->color_format != DRM_COLOR_FORMAT_YCBCR420 &&
+		    drm_mode_is_420_only(di, &mode))
+			continue;
+
+		if (!dw_dp_bandwidth_ok(dp, &mode, fmt->bpp, link->lanes, link->rate))
+			continue;
+
+		output_fmts[j++] = fmt->bus_format;
+	}
+
+	*num_output_fmts = j;
+
+	return output_fmts;
+}
+
+static struct drm_bridge_state *dw_dp_bridge_atomic_duplicate_state(struct drm_bridge *bridge)
+{
+	struct dw_dp_bridge_state *state;
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return NULL;
+
+	__drm_atomic_helper_bridge_duplicate_state(bridge, &state->base);
+
+	return &state->base;
+}
+
+static const struct drm_bridge_funcs dw_dp_bridge_funcs = {
+	.atomic_duplicate_state = dw_dp_bridge_atomic_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_get_input_bus_fmts = drm_atomic_helper_bridge_propagate_bus_fmt,
+	.atomic_get_output_bus_fmts = dw_dp_bridge_atomic_get_output_bus_fmts,
+	.atomic_check = dw_dp_bridge_atomic_check,
+	.mode_valid = dw_dp_bridge_mode_valid,
+	.atomic_enable = dw_dp_bridge_atomic_enable,
+	.atomic_disable = dw_dp_bridge_atomic_disable,
+	.detect = dw_dp_bridge_detect,
+	.edid_read = dw_dp_bridge_edid_read,
+};
+
+static int dw_dp_link_retrain(struct dw_dp *dp)
+{
+	struct drm_device *dev = dp->bridge.dev;
+	struct drm_modeset_acquire_ctx ctx;
+	int ret;
+
+	if (!dw_dp_needs_link_retrain(dp))
+		return 0;
+
+	dev_dbg(dp->dev, "Retraining link\n");
+
+	drm_modeset_acquire_init(&ctx, 0);
+	for (;;) {
+		ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
+		if (ret != -EDEADLK)
+			break;
+
+		drm_modeset_backoff(&ctx);
+	}
+
+	if (!ret)
+		ret = dw_dp_link_train(dp);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	return ret;
+}
+
+static void dw_dp_hpd_work(struct work_struct *work)
+{
+	struct dw_dp *dp = container_of(work, struct dw_dp, hpd_work);
+	bool long_hpd;
+	int ret;
+
+	mutex_lock(&dp->irq_lock);
+	long_hpd = dp->hotplug.long_hpd;
+	mutex_unlock(&dp->irq_lock);
+
+	dev_dbg(dp->dev, "[drm] Get hpd irq - %s\n", long_hpd ? "long" : "short");
+
+	if (!long_hpd) {
+		if (dw_dp_needs_link_retrain(dp)) {
+			ret = dw_dp_link_retrain(dp);
+			if (ret)
+				dev_warn(dp->dev, "Retrain link failed\n");
+		}
+	} else {
+		drm_helper_hpd_irq_event(dp->bridge.dev);
+	}
+}
+
+static void dw_dp_handle_hpd_event(struct dw_dp *dp)
+{
+	u32 value;
+
+	mutex_lock(&dp->irq_lock);
+	regmap_read(dp->regmap, DW_DP_HPD_STATUS, &value);
+
+	if (value & HPD_IRQ) {
+		dev_dbg(dp->dev, "IRQ from the HPD\n");
+		dp->hotplug.long_hpd = false;
+		regmap_write(dp->regmap, DW_DP_HPD_STATUS, HPD_IRQ);
+	}
+
+	if (value & HPD_HOT_PLUG) {
+		dev_dbg(dp->dev, "Hot plug detected\n");
+		dp->hotplug.long_hpd = true;
+		regmap_write(dp->regmap, DW_DP_HPD_STATUS, HPD_HOT_PLUG);
+	}
+
+	if (value & HPD_HOT_UNPLUG) {
+		dev_dbg(dp->dev, "Unplug detected\n");
+		dp->hotplug.long_hpd = true;
+		regmap_write(dp->regmap, DW_DP_HPD_STATUS, HPD_HOT_UNPLUG);
+	}
+	mutex_unlock(&dp->irq_lock);
+
+	schedule_work(&dp->hpd_work);
+}
+
+static irqreturn_t dw_dp_irq(int irq, void *data)
+{
+	struct dw_dp *dp = data;
+	u32 value;
+
+	regmap_read(dp->regmap, DW_DP_GENERAL_INTERRUPT, &value);
+	if (!value)
+		return IRQ_NONE;
+
+	if (value & HPD_EVENT)
+		dw_dp_handle_hpd_event(dp);
+
+	if (value & AUX_REPLY_EVENT) {
+		regmap_write(dp->regmap, DW_DP_GENERAL_INTERRUPT, AUX_REPLY_EVENT);
+		complete(&dp->complete);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static const struct regmap_range dw_dp_readable_ranges[] = {
+	regmap_reg_range(DW_DP_VERSION_NUMBER, DW_DP_ID),
+	regmap_reg_range(DW_DP_CONFIG_REG1, DW_DP_CONFIG_REG3),
+	regmap_reg_range(DW_DP_CCTL, DW_DP_SOFT_RESET_CTRL),
+	regmap_reg_range(DW_DP_VSAMPLE_CTRL, DW_DP_VIDEO_HBLANK_INTERVAL),
+	regmap_reg_range(DW_DP_AUD_CONFIG1, DW_DP_AUD_CONFIG1),
+	regmap_reg_range(DW_DP_SDP_VERTICAL_CTRL, DW_DP_SDP_STATUS_EN),
+	regmap_reg_range(DW_DP_PHYIF_CTRL, DW_DP_PHYIF_PWRDOWN_CTRL),
+	regmap_reg_range(DW_DP_AUX_CMD, DW_DP_AUX_DATA3),
+	regmap_reg_range(DW_DP_GENERAL_INTERRUPT, DW_DP_HPD_INTERRUPT_ENABLE),
+};
+
+static const struct regmap_access_table dw_dp_readable_table = {
+	.yes_ranges     = dw_dp_readable_ranges,
+	.n_yes_ranges   = ARRAY_SIZE(dw_dp_readable_ranges),
+};
+
+static const struct regmap_config dw_dp_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.fast_io = true,
+	.max_register = DW_DP_MAX_REGISTER,
+	.rd_table = &dw_dp_readable_table,
+};
+
+static void dw_dp_phy_exit(void *data)
+{
+	struct dw_dp *dp = data;
+
+	phy_exit(dp->phy);
+}
+
+struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
+			 const struct dw_dp_plat_data *plat_data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct dw_dp *dp;
+	struct drm_bridge *bridge;
+	void __iomem *res;
+	int ret;
+
+	dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
+	if (!dp)
+		return ERR_PTR(-ENOMEM);
+
+	dp = devm_drm_bridge_alloc(dev, struct dw_dp, bridge, &dw_dp_bridge_funcs);
+	if (IS_ERR(dp))
+		return ERR_CAST(dp);
+
+	dp->dev = dev;
+	dp->pixel_mode = DW_DP_MP_QUAD_PIXEL;
+
+	dp->plat_data.max_link_rate = plat_data->max_link_rate;
+	bridge = &dp->bridge;
+	mutex_init(&dp->irq_lock);
+	INIT_WORK(&dp->hpd_work, dw_dp_hpd_work);
+	init_completion(&dp->complete);
+
+	res = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(res))
+		return ERR_CAST(res);
+
+	dp->regmap = devm_regmap_init_mmio(dev, res, &dw_dp_regmap_config);
+	if (IS_ERR(dp->regmap)) {
+		dev_err_probe(dev, PTR_ERR(dp->regmap), "failed to create regmap\n");
+		return ERR_CAST(dp->regmap);
+	}
+
+	dp->phy = devm_of_phy_get(dev, dev->of_node, NULL);
+	if (IS_ERR(dp->phy)) {
+		dev_err_probe(dev, PTR_ERR(dp->phy), "failed to get phy\n");
+		return ERR_CAST(dp->phy);
+	}
+
+	dp->apb_clk = devm_clk_get_enabled(dev, "apb");
+	if (IS_ERR(dp->apb_clk)) {
+		dev_err_probe(dev, PTR_ERR(dp->apb_clk), "failed to get apb clock\n");
+		return ERR_CAST(dp->apb_clk);
+	}
+
+	dp->aux_clk = devm_clk_get_enabled(dev, "aux");
+	if (IS_ERR(dp->aux_clk)) {
+		dev_err_probe(dev, PTR_ERR(dp->aux_clk), "failed to get aux clock\n");
+		return ERR_CAST(dp->aux_clk);
+	}
+
+	dp->i2s_clk = devm_clk_get(dev, "i2s");
+	if (IS_ERR(dp->i2s_clk)) {
+		dev_err_probe(dev, PTR_ERR(dp->i2s_clk), "failed to get i2s clock\n");
+		return ERR_CAST(dp->i2s_clk);
+	}
+
+	dp->spdif_clk = devm_clk_get(dev, "spdif");
+	if (IS_ERR(dp->spdif_clk)) {
+		dev_err_probe(dev, PTR_ERR(dp->spdif_clk), "failed to get spdif clock\n");
+		return ERR_CAST(dp->spdif_clk);
+	}
+
+	dp->hdcp_clk = devm_clk_get(dev, "hdcp");
+	if (IS_ERR(dp->hdcp_clk)) {
+		dev_err_probe(dev, PTR_ERR(dp->hdcp_clk), "failed to get hdcp clock\n");
+		return ERR_CAST(dp->hdcp_clk);
+	}
+
+	dp->rstc = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(dp->rstc)) {
+		dev_err_probe(dev, PTR_ERR(dp->rstc), "failed to get reset control\n");
+		return ERR_CAST(dp->rstc);
+	}
+
+	bridge->of_node = dev->of_node;
+	bridge->ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
+	bridge->type = DRM_MODE_CONNECTOR_DisplayPort;
+	bridge->ycbcr_420_allowed = true;
+
+	dp->aux.dev = dev;
+	dp->aux.drm_dev = encoder->dev;
+	dp->aux.name = dev_name(dev);
+	dp->aux.transfer = dw_dp_aux_transfer;
+	ret = drm_dp_aux_register(&dp->aux);
+	if (ret) {
+		dev_err_probe(dev, ret, "Aux register failed\n");
+		return ERR_PTR(ret);
+	}
+
+	ret = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	if (ret)
+		dev_err_probe(dev, ret, "Failed to attach bridge\n");
+
+	dw_dp_init_hw(dp);
+
+	ret = phy_init(dp->phy);
+	if (ret) {
+		dev_err_probe(dev, ret, "phy init failed\n");
+		return ERR_PTR(ret);
+	}
+
+	ret = devm_add_action_or_reset(dev, dw_dp_phy_exit, dp);
+	if (ret)
+		return ERR_PTR(ret);
+
+	dp->irq = platform_get_irq(pdev, 0);
+	if (dp->irq < 0)
+		return ERR_PTR(ret);
+
+	ret = devm_request_threaded_irq(dev, dp->irq, NULL, dw_dp_irq,
+					IRQF_ONESHOT, dev_name(dev), dp);
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to request irq\n");
+		return ERR_PTR(ret);
+	}
+
+	return dp;
+}
+EXPORT_SYMBOL_GPL(dw_dp_bind);
+
+MODULE_AUTHOR("Andy Yan <[e-mail]>");
+MODULE_DESCRIPTION("DW DP Core Library");
+MODULE_LICENSE("GPL");

include/drm/bridge/dw_dp.h

···
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2025 Rockchip Electronics Co., Ltd.
+ */
+
+#ifndef __DW_DP__
+#define __DW_DP__
+
+#include <linux/device.h>
+
+struct drm_encoder;
+struct dw_dp;
+
+struct dw_dp_plat_data {
+	u32 max_link_rate;
+};
+
+struct dw_dp *dw_dp_bind(struct device *dev, struct drm_encoder *encoder,
+			 const struct dw_dp_plat_data *plat_data);
+#endif /* __DW_DP__ */