drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi2.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2024, Fuzhou Rockchip Electronics Co., Ltd
 *
 * Modified by Heiko Stuebner <heiko.stuebner@cherry.de>
 * This generic Synopsys DesignWare MIPI DSI2 host driver is based on the
 * Rockchip version from rockchip/dw-mipi-dsi2.c converted to use bridge APIs.
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/export.h>
#include <linux/iopoll.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>

#include <video/mipi_display.h>

#include <drm/bridge/dw_mipi_dsi2.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>

#define DSI2_PWR_UP			0x000c
#define RESET				0
#define POWER_UP			BIT(0)
#define CMD_TX_MODE(x)			FIELD_PREP(BIT(24), x)
#define DSI2_SOFT_RESET			0x0010
#define SYS_RSTN			BIT(2)
#define PHY_RSTN			BIT(1)
#define IPI_RSTN			BIT(0)
#define INT_ST_MAIN			0x0014
#define DSI2_MODE_CTRL			0x0018
#define DSI2_MODE_STATUS		0x001c
#define DSI2_CORE_STATUS		0x0020
#define PRI_RD_DATA_AVAIL		BIT(26)
#define PRI_FIFOS_NOT_EMPTY		BIT(25)
#define PRI_BUSY			BIT(24)
#define CRI_RD_DATA_AVAIL		BIT(18)
#define CRT_FIFOS_NOT_EMPTY		BIT(17)
#define CRI_BUSY			BIT(16)
#define IPI_FIFOS_NOT_EMPTY		BIT(9)
#define IPI_BUSY			BIT(8)
#define CORE_FIFOS_NOT_EMPTY		BIT(1)
#define CORE_BUSY			BIT(0)
#define MANUAL_MODE_CFG			0x0024
#define MANUAL_MODE_EN			BIT(0)
#define DSI2_TIMEOUT_HSTX_CFG		0x0048
#define TO_HSTX(x)			FIELD_PREP(GENMASK(15, 0), x)
#define DSI2_TIMEOUT_HSTXRDY_CFG	0x004c
#define TO_HSTXRDY(x)			FIELD_PREP(GENMASK(15, 0), x)
#define DSI2_TIMEOUT_LPRX_CFG		0x0050
#define TO_LPRXRDY(x)			FIELD_PREP(GENMASK(15, 0), x)
#define DSI2_TIMEOUT_LPTXRDY_CFG	0x0054
#define TO_LPTXRDY(x)			FIELD_PREP(GENMASK(15, 0), x)
#define DSI2_TIMEOUT_LPTXTRIG_CFG	0x0058
#define TO_LPTXTRIG(x)			FIELD_PREP(GENMASK(15, 0), x)
#define DSI2_TIMEOUT_LPTXULPS_CFG	0x005c
#define TO_LPTXULPS(x)			FIELD_PREP(GENMASK(15, 0), x)
#define DSI2_TIMEOUT_BTA_CFG		0x60
#define TO_BTA(x)			FIELD_PREP(GENMASK(15, 0), x)

#define DSI2_PHY_MODE_CFG		0x0100
#define PPI_WIDTH(x)			FIELD_PREP(GENMASK(9, 8), x)
#define PHY_LANES(x)			FIELD_PREP(GENMASK(5, 4), (x) - 1)
#define PHY_TYPE(x)			FIELD_PREP(BIT(0), x)
#define DSI2_PHY_CLK_CFG		0X0104
#define PHY_LPTX_CLK_DIV(x)		FIELD_PREP(GENMASK(12, 8), x)
#define CLK_TYPE_MASK			BIT(0)
#define NON_CONTINUOUS_CLK		BIT(0)
#define CONTINUOUS_CLK			0
#define DSI2_PHY_LP2HS_MAN_CFG		0x010c
#define PHY_LP2HS_TIME(x)		FIELD_PREP(GENMASK(28, 0), x)
#define DSI2_PHY_HS2LP_MAN_CFG		0x0114
#define PHY_HS2LP_TIME(x)		FIELD_PREP(GENMASK(28, 0), x)
#define DSI2_PHY_MAX_RD_T_MAN_CFG	0x011c
#define PHY_MAX_RD_TIME(x)		FIELD_PREP(GENMASK(26, 0), x)
#define DSI2_PHY_ESC_CMD_T_MAN_CFG	0x0124
#define PHY_ESC_CMD_TIME(x)		FIELD_PREP(GENMASK(28, 0), x)
#define DSI2_PHY_ESC_BYTE_T_MAN_CFG	0x012c
#define PHY_ESC_BYTE_TIME(x)		FIELD_PREP(GENMASK(28, 0), x)

#define DSI2_PHY_IPI_RATIO_MAN_CFG	0x0134
#define PHY_IPI_RATIO(x)		FIELD_PREP(GENMASK(21, 0), x)
#define DSI2_PHY_SYS_RATIO_MAN_CFG	0x013C
#define PHY_SYS_RATIO(x)		FIELD_PREP(GENMASK(16, 0), x)

#define DSI2_DSI_GENERAL_CFG		0x0200
#define BTA_EN				BIT(1)
#define EOTP_TX_EN			BIT(0)
#define DSI2_DSI_VCID_CFG		0x0204
#define TX_VCID(x)			FIELD_PREP(GENMASK(1, 0), x)
#define DSI2_DSI_SCRAMBLING_CFG		0x0208
#define SCRAMBLING_SEED(x)		FIELD_PREP(GENMASK(31, 16), x)
#define SCRAMBLING_EN			BIT(0)
#define DSI2_DSI_VID_TX_CFG		0x020c
#define LPDT_DISPLAY_CMD_EN		BIT(20)
#define BLK_VFP_HS_EN			BIT(14)
#define BLK_VBP_HS_EN			BIT(13)
#define BLK_VSA_HS_EN			BIT(12)
#define BLK_HFP_HS_EN			BIT(6)
#define BLK_HBP_HS_EN			BIT(5)
#define BLK_HSA_HS_EN			BIT(4)
#define VID_MODE_TYPE(x)		FIELD_PREP(GENMASK(1, 0), x)
#define DSI2_CRI_TX_HDR			0x02c0
#define CMD_TX_MODE(x)			FIELD_PREP(BIT(24), x)
#define DSI2_CRI_TX_PLD			0x02c4
#define DSI2_CRI_RX_HDR			0x02c8
#define DSI2_CRI_RX_PLD			0x02cc

#define DSI2_IPI_COLOR_MAN_CFG		0x0300
#define IPI_DEPTH(x)			FIELD_PREP(GENMASK(7, 4), x)
#define IPI_DEPTH_5_6_5_BITS		0x02
#define IPI_DEPTH_6_BITS		0x03
#define IPI_DEPTH_8_BITS		0x05
#define IPI_DEPTH_10_BITS		0x06
#define IPI_FORMAT(x)			FIELD_PREP(GENMASK(3, 0), x)
#define IPI_FORMAT_RGB			0x0
#define IPI_FORMAT_DSC			0x0b
#define DSI2_IPI_VID_HSA_MAN_CFG	0x0304
#define VID_HSA_TIME(x)			FIELD_PREP(GENMASK(29, 0), x)
#define DSI2_IPI_VID_HBP_MAN_CFG	0x030c
#define VID_HBP_TIME(x)			FIELD_PREP(GENMASK(29, 0), x)
#define DSI2_IPI_VID_HACT_MAN_CFG	0x0314
#define VID_HACT_TIME(x)		FIELD_PREP(GENMASK(29, 0), x)
#define DSI2_IPI_VID_HLINE_MAN_CFG	0x031c
#define VID_HLINE_TIME(x)		FIELD_PREP(GENMASK(29, 0), x)
#define DSI2_IPI_VID_VSA_MAN_CFG	0x0324
#define VID_VSA_LINES(x)		FIELD_PREP(GENMASK(9, 0), x)
#define DSI2_IPI_VID_VBP_MAN_CFG	0X032C
#define VID_VBP_LINES(x)		FIELD_PREP(GENMASK(9, 0), x)
#define DSI2_IPI_VID_VACT_MAN_CFG	0X0334
#define VID_VACT_LINES(x)		FIELD_PREP(GENMASK(13, 0), x)
#define DSI2_IPI_VID_VFP_MAN_CFG	0X033C
#define VID_VFP_LINES(x)		FIELD_PREP(GENMASK(9, 0), x)
#define DSI2_IPI_PIX_PKT_CFG		0x0344
#define MAX_PIX_PKT(x)			FIELD_PREP(GENMASK(15, 0), x)

#define DSI2_INT_ST_PHY			0x0400
#define DSI2_INT_MASK_PHY		0x0404
#define DSI2_INT_ST_TO			0x0410
#define DSI2_INT_MASK_TO		0x0414
#define DSI2_INT_ST_ACK			0x0420
#define DSI2_INT_MASK_ACK		0x0424
#define DSI2_INT_ST_IPI			0x0430
#define DSI2_INT_MASK_IPI		0x0434
#define DSI2_INT_ST_FIFO		0x0440
#define DSI2_INT_MASK_FIFO		0x0444
#define DSI2_INT_ST_PRI			0x0450
#define DSI2_INT_MASK_PRI		0x0454
#define DSI2_INT_ST_CRI			0x0460
#define DSI2_INT_MASK_CRI		0x0464
#define DSI2_INT_FORCE_CRI		0x0468
#define DSI2_MAX_REGISGER		DSI2_INT_FORCE_CRI

#define MODE_STATUS_TIMEOUT_US		10000
#define CMD_PKT_STATUS_TIMEOUT_US	20000

enum vid_mode_type {
	VID_MODE_TYPE_NON_BURST_SYNC_PULSES,
	VID_MODE_TYPE_NON_BURST_SYNC_EVENTS,
	VID_MODE_TYPE_BURST,
};

enum mode_ctrl {
	IDLE_MODE,
	AUTOCALC_MODE,
	COMMAND_MODE,
	VIDEO_MODE,
	DATA_STREAM_MODE,
	VIDEO_TEST_MODE,
	DATA_STREAM_TEST_MODE,
};

enum ppi_width {
	PPI_WIDTH_8_BITS,
	PPI_WIDTH_16_BITS,
	PPI_WIDTH_32_BITS,
};

struct cmd_header {
	u8 cmd_type;
	u8 delay;
	u8 payload_length;
};

struct dw_mipi_dsi2 {
	struct drm_bridge bridge;
	struct mipi_dsi_host dsi_host;
	struct drm_bridge *panel_bridge;
	struct device *dev;
	struct regmap *regmap;
	struct clk *pclk;
	struct clk *sys_clk;

	unsigned int lane_mbps; /* per lane */
	u32 channel;
	u32 lanes;
	u32 format;
	unsigned long mode_flags;

	struct drm_display_mode mode;
	const struct dw_mipi_dsi2_plat_data *plat_data;
};

static inline struct dw_mipi_dsi2 *host_to_dsi2(struct mipi_dsi_host *host)
{
	return container_of(host, struct dw_mipi_dsi2, dsi_host);
}

static inline struct dw_mipi_dsi2 *bridge_to_dsi2(struct drm_bridge *bridge)
{
	return container_of(bridge, struct dw_mipi_dsi2, bridge);
}

static int cri_fifos_wait_avail(struct dw_mipi_dsi2 *dsi2)
{
	u32 sts, mask;
	int ret;

	mask = CRI_BUSY | CRT_FIFOS_NOT_EMPTY;
	ret = regmap_read_poll_timeout(dsi2->regmap, DSI2_CORE_STATUS, sts,
				       !(sts & mask), 0, CMD_PKT_STATUS_TIMEOUT_US);
	if (ret < 0) {
		dev_err(dsi2->dev, "command interface is busy\n");
		return ret;
	}

	return 0;
}

static void dw_mipi_dsi2_set_vid_mode(struct dw_mipi_dsi2 *dsi2)
{
	u32 val = 0, mode;
	int ret;

	if (dsi2->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HFP)
		val |= BLK_HFP_HS_EN;

	if (dsi2->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HBP)
		val |= BLK_HBP_HS_EN;

	if (dsi2->mode_flags & MIPI_DSI_MODE_VIDEO_NO_HSA)
		val |= BLK_HSA_HS_EN;

	if (dsi2->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
		val |= VID_MODE_TYPE_BURST;
	else if (dsi2->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
		val |= VID_MODE_TYPE_NON_BURST_SYNC_PULSES;
	else
		val |= VID_MODE_TYPE_NON_BURST_SYNC_EVENTS;

	regmap_write(dsi2->regmap, DSI2_DSI_VID_TX_CFG, val);

	regmap_write(dsi2->regmap, DSI2_MODE_CTRL, VIDEO_MODE);
	ret = regmap_read_poll_timeout(dsi2->regmap, DSI2_MODE_STATUS,
				       mode, mode & VIDEO_MODE,
				       1000, MODE_STATUS_TIMEOUT_US);
	if (ret < 0)
		dev_err(dsi2->dev, "failed to enter video mode\n");
}

static void dw_mipi_dsi2_set_data_stream_mode(struct dw_mipi_dsi2 *dsi2)
{
	u32 mode;
	int ret;

	regmap_write(dsi2->regmap, DSI2_MODE_CTRL, DATA_STREAM_MODE);
	ret = regmap_read_poll_timeout(dsi2->regmap, DSI2_MODE_STATUS,
				       mode, mode & DATA_STREAM_MODE,
				       1000, MODE_STATUS_TIMEOUT_US);
	if (ret < 0)
		dev_err(dsi2->dev, "failed to enter data stream mode\n");
}

static void dw_mipi_dsi2_set_cmd_mode(struct dw_mipi_dsi2 *dsi2)
{
	u32 mode;
	int ret;

	regmap_write(dsi2->regmap, DSI2_MODE_CTRL, COMMAND_MODE);
	ret = regmap_read_poll_timeout(dsi2->regmap, DSI2_MODE_STATUS,
				       mode, mode & COMMAND_MODE,
				       1000, MODE_STATUS_TIMEOUT_US);
	if (ret < 0)
		dev_err(dsi2->dev, "failed to enter data stream mode\n");
}

static void dw_mipi_dsi2_host_softrst(struct dw_mipi_dsi2 *dsi2)
{
	regmap_write(dsi2->regmap, DSI2_SOFT_RESET, 0x0);
	usleep_range(50, 100);
	regmap_write(dsi2->regmap, DSI2_SOFT_RESET,
		     SYS_RSTN | PHY_RSTN | IPI_RSTN);
}

static void dw_mipi_dsi2_phy_clk_mode_cfg(struct dw_mipi_dsi2 *dsi2)
{
	u32 sys_clk, esc_clk_div;
	u32 val = 0;

	/*
	 * clk_type should be NON_CONTINUOUS_CLK before
	 * initial deskew calibration be sent.
	 */
	val |= NON_CONTINUOUS_CLK;

	/* The maximum value of the escape clock frequency is 20MHz */
	sys_clk = clk_get_rate(dsi2->sys_clk) / USEC_PER_SEC;
	esc_clk_div = DIV_ROUND_UP(sys_clk, 20 * 2);
	val |= PHY_LPTX_CLK_DIV(esc_clk_div);

	regmap_write(dsi2->regmap, DSI2_PHY_CLK_CFG, val);
}

static void dw_mipi_dsi2_phy_ratio_cfg(struct dw_mipi_dsi2 *dsi2)
{
	struct drm_display_mode *mode = &dsi2->mode;
	u64 sys_clk = clk_get_rate(dsi2->sys_clk);
	u64 pixel_clk, ipi_clk, phy_hsclk;
	u64 tmp;

	/*
	 * in DPHY mode, the phy_hstx_clk is exactly 1/16 the Lane high-speed
	 * data rate; In CPHY mode, the phy_hstx_clk is exactly 1/7 the trio
	 * high speed symbol rate.
	 */
	phy_hsclk = DIV_ROUND_CLOSEST_ULL(dsi2->lane_mbps * USEC_PER_SEC, 16);

	/* IPI_RATIO_MAN_CFG = PHY_HSTX_CLK / IPI_CLK */
	pixel_clk = mode->crtc_clock * MSEC_PER_SEC;
	ipi_clk = pixel_clk / 4;

	tmp = DIV_ROUND_CLOSEST_ULL(phy_hsclk << 16, ipi_clk);
	regmap_write(dsi2->regmap, DSI2_PHY_IPI_RATIO_MAN_CFG,
		     PHY_IPI_RATIO(tmp));

	/*
	 * SYS_RATIO_MAN_CFG = MIPI_DCPHY_HSCLK_Freq / MIPI_DCPHY_HSCLK_Freq
	 */
	tmp = DIV_ROUND_CLOSEST_ULL(phy_hsclk << 16, sys_clk);
	regmap_write(dsi2->regmap, DSI2_PHY_SYS_RATIO_MAN_CFG,
		     PHY_SYS_RATIO(tmp));
}

static void dw_mipi_dsi2_lp2hs_or_hs2lp_cfg(struct dw_mipi_dsi2 *dsi2)
{
	const struct dw_mipi_dsi2_phy_ops *phy_ops = dsi2->plat_data->phy_ops;
	struct dw_mipi_dsi2_phy_timing timing;
	int ret;

	ret = phy_ops->get_timing(dsi2->plat_data->priv_data,
				  dsi2->lane_mbps, &timing);
	if (ret)
		dev_err(dsi2->dev, "Retrieving phy timings failed\n");

	regmap_write(dsi2->regmap, DSI2_PHY_LP2HS_MAN_CFG, PHY_LP2HS_TIME(timing.data_lp2hs));
	regmap_write(dsi2->regmap, DSI2_PHY_HS2LP_MAN_CFG, PHY_HS2LP_TIME(timing.data_hs2lp));
}

static void dw_mipi_dsi2_phy_init(struct dw_mipi_dsi2 *dsi2)
{
	const struct dw_mipi_dsi2_phy_ops *phy_ops = dsi2->plat_data->phy_ops;
	struct dw_mipi_dsi2_phy_iface iface;
	u32 val = 0;

	phy_ops->get_interface(dsi2->plat_data->priv_data, &iface);

	switch (iface.ppi_width) {
	case 8:
		val |= PPI_WIDTH(PPI_WIDTH_8_BITS);
		break;
	case 16:
		val |= PPI_WIDTH(PPI_WIDTH_16_BITS);
		break;
	case 32:
		val |= PPI_WIDTH(PPI_WIDTH_32_BITS);
		break;
	default:
		/* Caught in probe */
		break;
	}

	val |= PHY_LANES(dsi2->lanes);
	val |= PHY_TYPE(DW_MIPI_DSI2_DPHY);
	regmap_write(dsi2->regmap, DSI2_PHY_MODE_CFG, val);

	dw_mipi_dsi2_phy_clk_mode_cfg(dsi2);
	dw_mipi_dsi2_phy_ratio_cfg(dsi2);
	dw_mipi_dsi2_lp2hs_or_hs2lp_cfg(dsi2);

	/* phy configuration 8 - 10 */
}

static void dw_mipi_dsi2_tx_option_set(struct dw_mipi_dsi2 *dsi2)
{
	u32 val;

	val = BTA_EN | EOTP_TX_EN;

	if (dsi2->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
		val &= ~EOTP_TX_EN;

	regmap_write(dsi2->regmap, DSI2_DSI_GENERAL_CFG, val);
	regmap_write(dsi2->regmap, DSI2_DSI_VCID_CFG, TX_VCID(dsi2->channel));
}

static void dw_mipi_dsi2_ipi_color_coding_cfg(struct dw_mipi_dsi2 *dsi2)
{
	u32 val, color_depth;

	switch (dsi2->format) {
	case MIPI_DSI_FMT_RGB666:
	case MIPI_DSI_FMT_RGB666_PACKED:
		color_depth = IPI_DEPTH_6_BITS;
		break;
	case MIPI_DSI_FMT_RGB565:
		color_depth = IPI_DEPTH_5_6_5_BITS;
		break;
	case MIPI_DSI_FMT_RGB888:
	default:
		color_depth = IPI_DEPTH_8_BITS;
		break;
	}

	val = IPI_DEPTH(color_depth) |
	      IPI_FORMAT(IPI_FORMAT_RGB);
	regmap_write(dsi2->regmap, DSI2_IPI_COLOR_MAN_CFG, val);
}

static void dw_mipi_dsi2_vertical_timing_config(struct dw_mipi_dsi2 *dsi2,
						const struct drm_display_mode *mode)
{
	u32 vactive, vsa, vfp, vbp;

	vactive = mode->vdisplay;
	vsa = mode->vsync_end - mode->vsync_start;
	vfp = mode->vsync_start - mode->vdisplay;
	vbp = mode->vtotal - mode->vsync_end;

	regmap_write(dsi2->regmap, DSI2_IPI_VID_VSA_MAN_CFG, VID_VSA_LINES(vsa));
	regmap_write(dsi2->regmap, DSI2_IPI_VID_VBP_MAN_CFG, VID_VBP_LINES(vbp));
	regmap_write(dsi2->regmap, DSI2_IPI_VID_VACT_MAN_CFG, VID_VACT_LINES(vactive));
	regmap_write(dsi2->regmap, DSI2_IPI_VID_VFP_MAN_CFG, VID_VFP_LINES(vfp));
}

static void dw_mipi_dsi2_ipi_set(struct dw_mipi_dsi2 *dsi2)
{
	struct drm_display_mode *mode = &dsi2->mode;
	u32 hline, hsa, hbp, hact;
	u64 hline_time, hsa_time, hbp_time, hact_time, tmp;
	u64 pixel_clk, phy_hs_clk;
	u16 val;

	val = mode->hdisplay;

	regmap_write(dsi2->regmap, DSI2_IPI_PIX_PKT_CFG, MAX_PIX_PKT(val));

	dw_mipi_dsi2_ipi_color_coding_cfg(dsi2);

	/*
	 * if the controller is intended to operate in data stream mode,
	 * no more steps are required.
	 */
	if (!(dsi2->mode_flags & MIPI_DSI_MODE_VIDEO))
		return;

	hact = mode->hdisplay;
	hsa = mode->hsync_end - mode->hsync_start;
	hbp = mode->htotal - mode->hsync_end;
	hline = mode->htotal;

	pixel_clk = mode->crtc_clock * MSEC_PER_SEC;

	phy_hs_clk = DIV_ROUND_CLOSEST_ULL(dsi2->lane_mbps * USEC_PER_SEC, 16);

	tmp = hsa * phy_hs_clk;
	hsa_time = DIV_ROUND_CLOSEST_ULL(tmp << 16, pixel_clk);
	regmap_write(dsi2->regmap, DSI2_IPI_VID_HSA_MAN_CFG, VID_HSA_TIME(hsa_time));

	tmp = hbp * phy_hs_clk;
	hbp_time = DIV_ROUND_CLOSEST_ULL(tmp << 16, pixel_clk);
	regmap_write(dsi2->regmap, DSI2_IPI_VID_HBP_MAN_CFG, VID_HBP_TIME(hbp_time));

	tmp = hact * phy_hs_clk;
	hact_time = DIV_ROUND_CLOSEST_ULL(tmp << 16, pixel_clk);
	regmap_write(dsi2->regmap, DSI2_IPI_VID_HACT_MAN_CFG, VID_HACT_TIME(hact_time));

	tmp = hline * phy_hs_clk;
	hline_time = DIV_ROUND_CLOSEST_ULL(tmp << 16, pixel_clk);
	regmap_write(dsi2->regmap, DSI2_IPI_VID_HLINE_MAN_CFG, VID_HLINE_TIME(hline_time));

	dw_mipi_dsi2_vertical_timing_config(dsi2, mode);
}

static void
dw_mipi_dsi2_work_mode(struct dw_mipi_dsi2 *dsi2, u32 mode)
{
	/*
	 * select controller work in Manual mode
	 * Manual: MANUAL_MODE_EN
	 * Automatic: 0
	 */
	regmap_write(dsi2->regmap, MANUAL_MODE_CFG, mode);
}

static int dw_mipi_dsi2_host_attach(struct mipi_dsi_host *host,
				    struct mipi_dsi_device *device)
{
	struct dw_mipi_dsi2 *dsi2 = host_to_dsi2(host);
	const struct dw_mipi_dsi2_plat_data *pdata = dsi2->plat_data;
	struct drm_bridge *bridge;
	int ret;

	if (device->lanes > dsi2->plat_data->max_data_lanes) {
		dev_err(dsi2->dev, "the number of data lanes(%u) is too many\n",
			device->lanes);
		return -EINVAL;
	}

	dsi2->lanes = device->lanes;
	dsi2->channel = device->channel;
	dsi2->format = device->format;
	dsi2->mode_flags = device->mode_flags;

	bridge = devm_drm_of_get_bridge(dsi2->dev, dsi2->dev->of_node, 1, 0);
	if (IS_ERR(bridge))
		return PTR_ERR(bridge);

	bridge->pre_enable_prev_first = true;
	dsi2->panel_bridge = bridge;

	drm_bridge_add(&dsi2->bridge);

	if (pdata->host_ops && pdata->host_ops->attach) {
		ret = pdata->host_ops->attach(pdata->priv_data, device);
		if (ret < 0)
			return ret;
	}

	return 0;
}

static int dw_mipi_dsi2_host_detach(struct mipi_dsi_host *host,
				    struct mipi_dsi_device *device)
{
	struct dw_mipi_dsi2 *dsi2 = host_to_dsi2(host);
	const struct dw_mipi_dsi2_plat_data *pdata = dsi2->plat_data;
	int ret;

	if (pdata->host_ops && pdata->host_ops->detach) {
		ret = pdata->host_ops->detach(pdata->priv_data, device);
		if (ret < 0)
			return ret;
	}

	drm_bridge_remove(&dsi2->bridge);

	drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);

	return 0;
}

static int dw_mipi_dsi2_gen_pkt_hdr_write(struct dw_mipi_dsi2 *dsi2,
					  u32 hdr_val, bool lpm)
{
	int ret;

	regmap_write(dsi2->regmap, DSI2_CRI_TX_HDR, hdr_val | CMD_TX_MODE(lpm));

	ret = cri_fifos_wait_avail(dsi2);
	if (ret) {
		dev_err(dsi2->dev, "failed to write command header\n");
		return ret;
	}

	return 0;
}

static int dw_mipi_dsi2_write(struct dw_mipi_dsi2 *dsi2,
			      const struct mipi_dsi_packet *packet, bool lpm)
{
	const u8 *tx_buf = packet->payload;
	int len = packet->payload_length, pld_data_bytes = sizeof(u32);
	__le32 word;

	/* Send payload */
	while (len) {
		if (len < pld_data_bytes) {
			word = 0;
			memcpy(&word, tx_buf, len);
			regmap_write(dsi2->regmap, DSI2_CRI_TX_PLD, le32_to_cpu(word));
			len = 0;
		} else {
			memcpy(&word, tx_buf, pld_data_bytes);
			regmap_write(dsi2->regmap, DSI2_CRI_TX_PLD, le32_to_cpu(word));
			tx_buf += pld_data_bytes;
			len -= pld_data_bytes;
		}
	}

	word = 0;
	memcpy(&word, packet->header, sizeof(packet->header));
	return dw_mipi_dsi2_gen_pkt_hdr_write(dsi2, le32_to_cpu(word), lpm);
}

static int dw_mipi_dsi2_read(struct dw_mipi_dsi2 *dsi2,
			     const struct mipi_dsi_msg *msg)
{
	u8 *payload = msg->rx_buf;
	int i, j, ret, len = msg->rx_len;
	u8 data_type;
	u16 wc;
	u32 val;

	ret = regmap_read_poll_timeout(dsi2->regmap, DSI2_CORE_STATUS,
				       val, val & CRI_RD_DATA_AVAIL,
				       100, CMD_PKT_STATUS_TIMEOUT_US);
	if (ret) {
		dev_err(dsi2->dev, "CRI has no available read data\n");
		return ret;
	}

	regmap_read(dsi2->regmap, DSI2_CRI_RX_HDR, &val);
	data_type = val & 0x3f;

	if (mipi_dsi_packet_format_is_short(data_type)) {
		for (i = 0; i < len && i < 2; i++)
			payload[i] = (val >> (8 * (i + 1))) & 0xff;

		return 0;
	}

	wc = (val >> 8) & 0xffff;
	/* Receive payload */
	for (i = 0; i < len && i < wc; i += 4) {
		regmap_read(dsi2->regmap, DSI2_CRI_RX_PLD, &val);
		for (j = 0; j < 4 && j + i < len && j + i < wc; j++)
			payload[i + j] = val >> (8 * j);
	}

	return 0;
}

static ssize_t dw_mipi_dsi2_host_transfer(struct mipi_dsi_host *host,
					  const struct mipi_dsi_msg *msg)
{
	struct dw_mipi_dsi2 *dsi2 = host_to_dsi2(host);
	bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
	struct mipi_dsi_packet packet;
	int ret, nb_bytes;

	regmap_update_bits(dsi2->regmap, DSI2_DSI_VID_TX_CFG,
			   LPDT_DISPLAY_CMD_EN,
			   lpm ? LPDT_DISPLAY_CMD_EN : 0);

	/* create a packet to the DSI protocol */
	ret = mipi_dsi_create_packet(&packet, msg);
	if (ret) {
		dev_err(dsi2->dev, "failed to create packet: %d\n", ret);
		return ret;
	}

	ret = cri_fifos_wait_avail(dsi2);
	if (ret)
		return ret;

	ret = dw_mipi_dsi2_write(dsi2, &packet, lpm);
	if (ret)
		return ret;

	if (msg->rx_buf && msg->rx_len) {
		ret = dw_mipi_dsi2_read(dsi2, msg);
		if (ret < 0)
			return ret;
		nb_bytes = msg->rx_len;
	} else {
		nb_bytes = packet.size;
	}

	return nb_bytes;
}

static const struct mipi_dsi_host_ops dw_mipi_dsi2_host_ops = {
	.attach = dw_mipi_dsi2_host_attach,
	.detach = dw_mipi_dsi2_host_detach,
	.transfer = dw_mipi_dsi2_host_transfer,
};

static u32 *
dw_mipi_dsi2_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
					      struct drm_bridge_state *bridge_state,
					      struct drm_crtc_state *crtc_state,
					      struct drm_connector_state *conn_state,
					      u32 output_fmt,
					      unsigned int *num_input_fmts)
{
	struct dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);
	const struct dw_mipi_dsi2_plat_data *pdata = dsi2->plat_data;
	u32 *input_fmts;

	if (pdata->get_input_bus_fmts)
		return pdata->get_input_bus_fmts(pdata->priv_data,
						 bridge, bridge_state,
						 crtc_state, conn_state,
						 output_fmt, num_input_fmts);

	/* Fall back to MEDIA_BUS_FMT_FIXED as the only input format. */
	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
	if (!input_fmts)
		return NULL;
	input_fmts[0] = MEDIA_BUS_FMT_FIXED;
	*num_input_fmts = 1;

	return input_fmts;
}

static int dw_mipi_dsi2_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 dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);
	const struct dw_mipi_dsi2_plat_data *pdata = dsi2->plat_data;
	bool ret;

	bridge_state->input_bus_cfg.flags =
		DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;

	if (pdata->mode_fixup) {
		ret = pdata->mode_fixup(pdata->priv_data, &crtc_state->mode,
					&crtc_state->adjusted_mode);
		if (!ret) {
			DRM_DEBUG_DRIVER("failed to fixup mode " DRM_MODE_FMT "\n",
					 DRM_MODE_ARG(&crtc_state->mode));
			return -EINVAL;
		}
	}

	return 0;
}

static void dw_mipi_dsi2_bridge_post_atomic_disable(struct drm_bridge *bridge,
						    struct drm_atomic_state *state)
{
	struct dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);
	const struct dw_mipi_dsi2_phy_ops *phy_ops = dsi2->plat_data->phy_ops;

	regmap_write(dsi2->regmap, DSI2_IPI_PIX_PKT_CFG, 0);

	/*
	 * Switch to command mode before panel-bridge post_disable &
	 * panel unprepare.
	 * Note: panel-bridge disable & panel disable has been called
	 * before by the drm framework.
	 */
	dw_mipi_dsi2_set_cmd_mode(dsi2);

	regmap_write(dsi2->regmap, DSI2_PWR_UP, RESET);

	if (phy_ops->power_off)
		phy_ops->power_off(dsi2->plat_data->priv_data);

	clk_disable_unprepare(dsi2->sys_clk);
	clk_disable_unprepare(dsi2->pclk);
	pm_runtime_put(dsi2->dev);
}

static unsigned int dw_mipi_dsi2_get_lanes(struct dw_mipi_dsi2 *dsi2)
{
	/* single-dsi, so no other instance to consider */
	return dsi2->lanes;
}

static void dw_mipi_dsi2_mode_set(struct dw_mipi_dsi2 *dsi2,
				  const struct drm_display_mode *adjusted_mode)
{
	const struct dw_mipi_dsi2_phy_ops *phy_ops = dsi2->plat_data->phy_ops;
	void *priv_data = dsi2->plat_data->priv_data;
	u32 lanes = dw_mipi_dsi2_get_lanes(dsi2);
	int ret;

	clk_prepare_enable(dsi2->pclk);
	clk_prepare_enable(dsi2->sys_clk);

	ret = phy_ops->get_lane_mbps(priv_data, adjusted_mode, dsi2->mode_flags,
				     lanes, dsi2->format, &dsi2->lane_mbps);
	if (ret)
		DRM_DEBUG_DRIVER("Phy get_lane_mbps() failed\n");

	pm_runtime_get_sync(dsi2->dev);

	dw_mipi_dsi2_host_softrst(dsi2);
	regmap_write(dsi2->regmap, DSI2_PWR_UP, RESET);

	dw_mipi_dsi2_work_mode(dsi2, MANUAL_MODE_EN);
	dw_mipi_dsi2_phy_init(dsi2);

	if (phy_ops->power_on)
		phy_ops->power_on(dsi2->plat_data->priv_data);

	dw_mipi_dsi2_tx_option_set(dsi2);

	/*
	 * initial deskew calibration is send after phy_power_on,
	 * then we can configure clk_type.
	 */

	regmap_update_bits(dsi2->regmap, DSI2_PHY_CLK_CFG, CLK_TYPE_MASK,
			   dsi2->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS ? NON_CONTINUOUS_CLK :
									      CONTINUOUS_CLK);

	regmap_write(dsi2->regmap, DSI2_PWR_UP, POWER_UP);
	dw_mipi_dsi2_set_cmd_mode(dsi2);

	dw_mipi_dsi2_ipi_set(dsi2);
}

static void dw_mipi_dsi2_bridge_atomic_pre_enable(struct drm_bridge *bridge,
						  struct drm_atomic_state *state)
{
	struct dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);

	/* Power up the dsi ctl into a command mode */
	dw_mipi_dsi2_mode_set(dsi2, &dsi2->mode);
}

static void dw_mipi_dsi2_bridge_mode_set(struct drm_bridge *bridge,
					 const struct drm_display_mode *mode,
					 const struct drm_display_mode *adjusted_mode)
{
	struct dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);

	/* Store the display mode for later use in pre_enable callback */
	drm_mode_copy(&dsi2->mode, adjusted_mode);
}

static void dw_mipi_dsi2_bridge_atomic_enable(struct drm_bridge *bridge,
					      struct drm_atomic_state *state)
{
	struct dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);

	/* Switch to video mode for panel-bridge enable & panel enable */
	if (dsi2->mode_flags & MIPI_DSI_MODE_VIDEO)
		dw_mipi_dsi2_set_vid_mode(dsi2);
	else
		dw_mipi_dsi2_set_data_stream_mode(dsi2);
}

static enum drm_mode_status
dw_mipi_dsi2_bridge_mode_valid(struct drm_bridge *bridge,
			       const struct drm_display_info *info,
			       const struct drm_display_mode *mode)
{
	struct dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);
	const struct dw_mipi_dsi2_plat_data *pdata = dsi2->plat_data;
	enum drm_mode_status mode_status = MODE_OK;

	if (pdata->mode_valid)
		mode_status = pdata->mode_valid(pdata->priv_data, mode,
						dsi2->mode_flags,
						dw_mipi_dsi2_get_lanes(dsi2),
						dsi2->format);

	return mode_status;
}

static int dw_mipi_dsi2_bridge_attach(struct drm_bridge *bridge,
				      struct drm_encoder *encoder,
				      enum drm_bridge_attach_flags flags)
{
	struct dw_mipi_dsi2 *dsi2 = bridge_to_dsi2(bridge);

	/* Set the encoder type as caller does not know it */
	encoder->encoder_type = DRM_MODE_ENCODER_DSI;

	/* Attach the panel-bridge to the dsi bridge */
	return drm_bridge_attach(encoder, dsi2->panel_bridge, bridge,
				 flags);
}

static const struct drm_bridge_funcs dw_mipi_dsi2_bridge_funcs = {
	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
	.atomic_get_input_bus_fmts = dw_mipi_dsi2_bridge_atomic_get_input_bus_fmts,
	.atomic_check		= dw_mipi_dsi2_bridge_atomic_check,
	.atomic_reset		= drm_atomic_helper_bridge_reset,
	.atomic_pre_enable	= dw_mipi_dsi2_bridge_atomic_pre_enable,
	.atomic_enable		= dw_mipi_dsi2_bridge_atomic_enable,
	.atomic_post_disable	= dw_mipi_dsi2_bridge_post_atomic_disable,
	.mode_set		= dw_mipi_dsi2_bridge_mode_set,
	.mode_valid		= dw_mipi_dsi2_bridge_mode_valid,
	.attach			= dw_mipi_dsi2_bridge_attach,
};

static const struct regmap_config dw_mipi_dsi2_regmap_config = {
	.name = "dsi2-host",
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.fast_io = true,
};

static struct dw_mipi_dsi2 *
__dw_mipi_dsi2_probe(struct platform_device *pdev,
		     const struct dw_mipi_dsi2_plat_data *plat_data)
{
	struct device *dev = &pdev->dev;
	struct reset_control *apb_rst;
	struct dw_mipi_dsi2 *dsi2;
	int ret;

	dsi2 = devm_drm_bridge_alloc(dev, struct dw_mipi_dsi2, bridge,
				     &dw_mipi_dsi2_bridge_funcs);
	if (IS_ERR(dsi2))
		return ERR_CAST(dsi2);

	dsi2->dev = dev;
	dsi2->plat_data = plat_data;

	if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps ||
	    !plat_data->phy_ops->get_timing)
		return dev_err_ptr_probe(dev, -ENODEV, "Phy not properly configured\n");

	if (!plat_data->regmap) {
		void __iomem *base = devm_platform_ioremap_resource(pdev, 0);

		if (IS_ERR(base))
			return dev_err_cast_probe(dev, base, "failed to registers\n");

		dsi2->regmap = devm_regmap_init_mmio(dev, base,
						     &dw_mipi_dsi2_regmap_config);
		if (IS_ERR(dsi2->regmap))
			return dev_err_cast_probe(dev, dsi2->regmap, "failed to init regmap\n");
	} else {
		dsi2->regmap = plat_data->regmap;
	}

	dsi2->pclk = devm_clk_get(dev, "pclk");
	if (IS_ERR(dsi2->pclk))
		return dev_err_cast_probe(dev, dsi2->pclk, "Unable to get pclk\n");

	dsi2->sys_clk = devm_clk_get(dev, "sys");
	if (IS_ERR(dsi2->sys_clk))
		return dev_err_cast_probe(dev, dsi2->sys_clk, "Unable to get sys_clk\n");

	/*
	 * Note that the reset was not defined in the initial device tree, so
	 * we have to be prepared for it not being found.
	 */
	apb_rst = devm_reset_control_get_optional_exclusive(dev, "apb");
	if (IS_ERR(apb_rst))
		return dev_err_cast_probe(dev, apb_rst, "Unable to get reset control\n");

	if (apb_rst) {
		ret = clk_prepare_enable(dsi2->pclk);
		if (ret) {
			dev_err(dev, "%s: Failed to enable pclk\n", __func__);
			return ERR_PTR(ret);
		}

		reset_control_assert(apb_rst);
		usleep_range(10, 20);
		reset_control_deassert(apb_rst);

		clk_disable_unprepare(dsi2->pclk);
	}

	devm_pm_runtime_enable(dev);

	dsi2->dsi_host.ops = &dw_mipi_dsi2_host_ops;
	dsi2->dsi_host.dev = dev;
	ret = mipi_dsi_host_register(&dsi2->dsi_host);
	if (ret) {
		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
		pm_runtime_disable(dev);
		return ERR_PTR(ret);
	}

	dsi2->bridge.driver_private = dsi2;
	dsi2->bridge.of_node = pdev->dev.of_node;

	return dsi2;
}

static void __dw_mipi_dsi2_remove(struct dw_mipi_dsi2 *dsi2)
{
	mipi_dsi_host_unregister(&dsi2->dsi_host);
}

/*
 * Probe/remove API, used to create the bridge instance.
 */
struct dw_mipi_dsi2 *
dw_mipi_dsi2_probe(struct platform_device *pdev,
		   const struct dw_mipi_dsi2_plat_data *plat_data)
{
	return __dw_mipi_dsi2_probe(pdev, plat_data);
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi2_probe);

void dw_mipi_dsi2_remove(struct dw_mipi_dsi2 *dsi2)
{
	__dw_mipi_dsi2_remove(dsi2);
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi2_remove);

/*
 * Bind/unbind API, used from platforms based on the component framework
 * to attach the bridge to an encoder.
 */
int dw_mipi_dsi2_bind(struct dw_mipi_dsi2 *dsi2, struct drm_encoder *encoder)
{
	return drm_bridge_attach(encoder, &dsi2->bridge, NULL, 0);
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi2_bind);

void dw_mipi_dsi2_unbind(struct dw_mipi_dsi2 *dsi2)
{
}
EXPORT_SYMBOL_GPL(dw_mipi_dsi2_unbind);

MODULE_AUTHOR("Guochun Huang <hero.huang@rock-chips.com>");
MODULE_AUTHOR("Heiko Stuebner <heiko.stuebner@cherry.de>");
MODULE_DESCRIPTION("DW MIPI DSI2 host controller driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:dw-mipi-dsi2");