mtk_dsi.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015 MediaTek Inc.
 */

#include <linux/clk.h>
#include <linux/component.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>

#include <video/mipi_display.h>
#include <video/videomode.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#include "mtk_drm_ddp_comp.h"

#define DSI_START		0x00

#define DSI_INTEN		0x08

#define DSI_INTSTA		0x0c
#define LPRX_RD_RDY_INT_FLAG		BIT(0)
#define CMD_DONE_INT_FLAG		BIT(1)
#define TE_RDY_INT_FLAG			BIT(2)
#define VM_DONE_INT_FLAG		BIT(3)
#define EXT_TE_RDY_INT_FLAG		BIT(4)
#define DSI_BUSY			BIT(31)

#define DSI_CON_CTRL		0x10
#define DSI_RESET			BIT(0)
#define DSI_EN				BIT(1)

#define DSI_MODE_CTRL		0x14
#define MODE				(3)
#define CMD_MODE			0
#define SYNC_PULSE_MODE			1
#define SYNC_EVENT_MODE			2
#define BURST_MODE			3
#define FRM_MODE			BIT(16)
#define MIX_MODE			BIT(17)

#define DSI_TXRX_CTRL		0x18
#define VC_NUM				BIT(1)
#define LANE_NUM			(0xf << 2)
#define DIS_EOT				BIT(6)
#define NULL_EN				BIT(7)
#define TE_FREERUN			BIT(8)
#define EXT_TE_EN			BIT(9)
#define EXT_TE_EDGE			BIT(10)
#define MAX_RTN_SIZE			(0xf << 12)
#define HSTX_CKLP_EN			BIT(16)

#define DSI_PSCTRL		0x1c
#define DSI_PS_WC			0x3fff
#define DSI_PS_SEL			(3 << 16)
#define PACKED_PS_16BIT_RGB565		(0 << 16)
#define LOOSELY_PS_18BIT_RGB666		(1 << 16)
#define PACKED_PS_18BIT_RGB666		(2 << 16)
#define PACKED_PS_24BIT_RGB888		(3 << 16)

#define DSI_VSA_NL		0x20
#define DSI_VBP_NL		0x24
#define DSI_VFP_NL		0x28
#define DSI_VACT_NL		0x2C
#define DSI_SIZE_CON		0x38
#define DSI_HSA_WC		0x50
#define DSI_HBP_WC		0x54
#define DSI_HFP_WC		0x58

#define DSI_CMDQ_SIZE		0x60
#define CMDQ_SIZE			0x3f

#define DSI_HSTX_CKL_WC		0x64

#define DSI_RX_DATA0		0x74
#define DSI_RX_DATA1		0x78
#define DSI_RX_DATA2		0x7c
#define DSI_RX_DATA3		0x80

#define DSI_RACK		0x84
#define RACK				BIT(0)

#define DSI_PHY_LCCON		0x104
#define LC_HS_TX_EN			BIT(0)
#define LC_ULPM_EN			BIT(1)
#define LC_WAKEUP_EN			BIT(2)

#define DSI_PHY_LD0CON		0x108
#define LD0_HS_TX_EN			BIT(0)
#define LD0_ULPM_EN			BIT(1)
#define LD0_WAKEUP_EN			BIT(2)

#define DSI_PHY_TIMECON0	0x110
#define LPX				(0xff << 0)
#define HS_PREP				(0xff << 8)
#define HS_ZERO				(0xff << 16)
#define HS_TRAIL			(0xff << 24)

#define DSI_PHY_TIMECON1	0x114
#define TA_GO				(0xff << 0)
#define TA_SURE				(0xff << 8)
#define TA_GET				(0xff << 16)
#define DA_HS_EXIT			(0xff << 24)

#define DSI_PHY_TIMECON2	0x118
#define CONT_DET			(0xff << 0)
#define CLK_ZERO			(0xff << 16)
#define CLK_TRAIL			(0xff << 24)

#define DSI_PHY_TIMECON3	0x11c
#define CLK_HS_PREP			(0xff << 0)
#define CLK_HS_POST			(0xff << 8)
#define CLK_HS_EXIT			(0xff << 16)

#define DSI_VM_CMD_CON		0x130
#define VM_CMD_EN			BIT(0)
#define TS_VFP_EN			BIT(5)

#define DSI_SHADOW_DEBUG	0x190U
#define FORCE_COMMIT			BIT(0)
#define BYPASS_SHADOW			BIT(1)

#define CONFIG				(0xff << 0)
#define SHORT_PACKET			0
#define LONG_PACKET			2
#define BTA				BIT(2)
#define DATA_ID				(0xff << 8)
#define DATA_0				(0xff << 16)
#define DATA_1				(0xff << 24)

#define T_LPX		5
#define T_HS_PREP	6
#define T_HS_TRAIL	8
#define T_HS_EXIT	7
#define T_HS_ZERO	10

#define NS_TO_CYCLE(n, c)    ((n) / (c) + (((n) % (c)) ? 1 : 0))

#define MTK_DSI_HOST_IS_READ(type) \
	((type == MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM) || \
	(type == MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM) || \
	(type == MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM) || \
	(type == MIPI_DSI_DCS_READ))

struct phy;

struct mtk_dsi_driver_data {
	const u32 reg_cmdq_off;
	bool has_shadow_ctl;
	bool has_size_ctl;
};

struct mtk_dsi {
	struct mtk_ddp_comp ddp_comp;
	struct device *dev;
	struct mipi_dsi_host host;
	struct drm_encoder encoder;
	struct drm_connector conn;
	struct drm_panel *panel;
	struct drm_bridge *bridge;
	struct phy *phy;

	void __iomem *regs;

	struct clk *engine_clk;
	struct clk *digital_clk;
	struct clk *hs_clk;

	u32 data_rate;

	unsigned long mode_flags;
	enum mipi_dsi_pixel_format format;
	unsigned int lanes;
	struct videomode vm;
	int refcount;
	bool enabled;
	u32 irq_data;
	wait_queue_head_t irq_wait_queue;
	const struct mtk_dsi_driver_data *driver_data;
};

static inline struct mtk_dsi *encoder_to_dsi(struct drm_encoder *e)
{
	return container_of(e, struct mtk_dsi, encoder);
}

static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
{
	return container_of(c, struct mtk_dsi, conn);
}

static inline struct mtk_dsi *host_to_dsi(struct mipi_dsi_host *h)
{
	return container_of(h, struct mtk_dsi, host);
}

static void mtk_dsi_mask(struct mtk_dsi *dsi, u32 offset, u32 mask, u32 data)
{
	u32 temp = readl(dsi->regs + offset);

	writel((temp & ~mask) | (data & mask), dsi->regs + offset);
}

static void mtk_dsi_phy_timconfig(struct mtk_dsi *dsi)
{
	u32 timcon0, timcon1, timcon2, timcon3;
	u32 ui, cycle_time;

	ui = 1000 / dsi->data_rate + 0x01;
	cycle_time = 8000 / dsi->data_rate + 0x01;

	timcon0 = T_LPX | T_HS_PREP << 8 | T_HS_ZERO << 16 | T_HS_TRAIL << 24;
	timcon1 = 4 * T_LPX | (3 * T_LPX / 2) << 8 | 5 * T_LPX << 16 |
		  T_HS_EXIT << 24;
	timcon2 = ((NS_TO_CYCLE(0x64, cycle_time) + 0xa) << 24) |
		  (NS_TO_CYCLE(0x150, cycle_time) << 16);
	timcon3 = NS_TO_CYCLE(0x40, cycle_time) | (2 * T_LPX) << 16 |
		  NS_TO_CYCLE(80 + 52 * ui, cycle_time) << 8;

	writel(timcon0, dsi->regs + DSI_PHY_TIMECON0);
	writel(timcon1, dsi->regs + DSI_PHY_TIMECON1);
	writel(timcon2, dsi->regs + DSI_PHY_TIMECON2);
	writel(timcon3, dsi->regs + DSI_PHY_TIMECON3);
}

static void mtk_dsi_enable(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_CON_CTRL, DSI_EN, DSI_EN);
}

static void mtk_dsi_disable(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_CON_CTRL, DSI_EN, 0);
}

static void mtk_dsi_reset_engine(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_CON_CTRL, DSI_RESET, DSI_RESET);
	mtk_dsi_mask(dsi, DSI_CON_CTRL, DSI_RESET, 0);
}

static void mtk_dsi_clk_ulp_mode_enter(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_PHY_LCCON, LC_HS_TX_EN, 0);
	mtk_dsi_mask(dsi, DSI_PHY_LCCON, LC_ULPM_EN, 0);
}

static void mtk_dsi_clk_ulp_mode_leave(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_PHY_LCCON, LC_ULPM_EN, 0);
	mtk_dsi_mask(dsi, DSI_PHY_LCCON, LC_WAKEUP_EN, LC_WAKEUP_EN);
	mtk_dsi_mask(dsi, DSI_PHY_LCCON, LC_WAKEUP_EN, 0);
}

static void mtk_dsi_lane0_ulp_mode_enter(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_PHY_LD0CON, LD0_HS_TX_EN, 0);
	mtk_dsi_mask(dsi, DSI_PHY_LD0CON, LD0_ULPM_EN, 0);
}

static void mtk_dsi_lane0_ulp_mode_leave(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_PHY_LD0CON, LD0_ULPM_EN, 0);
	mtk_dsi_mask(dsi, DSI_PHY_LD0CON, LD0_WAKEUP_EN, LD0_WAKEUP_EN);
	mtk_dsi_mask(dsi, DSI_PHY_LD0CON, LD0_WAKEUP_EN, 0);
}

static bool mtk_dsi_clk_hs_state(struct mtk_dsi *dsi)
{
	u32 tmp_reg1;

	tmp_reg1 = readl(dsi->regs + DSI_PHY_LCCON);
	return ((tmp_reg1 & LC_HS_TX_EN) == 1) ? true : false;
}

static void mtk_dsi_clk_hs_mode(struct mtk_dsi *dsi, bool enter)
{
	if (enter && !mtk_dsi_clk_hs_state(dsi))
		mtk_dsi_mask(dsi, DSI_PHY_LCCON, LC_HS_TX_EN, LC_HS_TX_EN);
	else if (!enter && mtk_dsi_clk_hs_state(dsi))
		mtk_dsi_mask(dsi, DSI_PHY_LCCON, LC_HS_TX_EN, 0);
}

static void mtk_dsi_set_mode(struct mtk_dsi *dsi)
{
	u32 vid_mode = CMD_MODE;

	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
			vid_mode = BURST_MODE;
		else if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
			vid_mode = SYNC_PULSE_MODE;
		else
			vid_mode = SYNC_EVENT_MODE;
	}

	writel(vid_mode, dsi->regs + DSI_MODE_CTRL);
}

static void mtk_dsi_set_vm_cmd(struct mtk_dsi *dsi)
{
	mtk_dsi_mask(dsi, DSI_VM_CMD_CON, VM_CMD_EN, VM_CMD_EN);
	mtk_dsi_mask(dsi, DSI_VM_CMD_CON, TS_VFP_EN, TS_VFP_EN);
}

static void mtk_dsi_ps_control_vact(struct mtk_dsi *dsi)
{
	struct videomode *vm = &dsi->vm;
	u32 dsi_buf_bpp, ps_wc;
	u32 ps_bpp_mode;

	if (dsi->format == MIPI_DSI_FMT_RGB565)
		dsi_buf_bpp = 2;
	else
		dsi_buf_bpp = 3;

	ps_wc = vm->hactive * dsi_buf_bpp;
	ps_bpp_mode = ps_wc;

	switch (dsi->format) {
	case MIPI_DSI_FMT_RGB888:
		ps_bpp_mode |= PACKED_PS_24BIT_RGB888;
		break;
	case MIPI_DSI_FMT_RGB666:
		ps_bpp_mode |= PACKED_PS_18BIT_RGB666;
		break;
	case MIPI_DSI_FMT_RGB666_PACKED:
		ps_bpp_mode |= LOOSELY_PS_18BIT_RGB666;
		break;
	case MIPI_DSI_FMT_RGB565:
		ps_bpp_mode |= PACKED_PS_16BIT_RGB565;
		break;
	}

	writel(vm->vactive, dsi->regs + DSI_VACT_NL);
	writel(ps_bpp_mode, dsi->regs + DSI_PSCTRL);
	writel(ps_wc, dsi->regs + DSI_HSTX_CKL_WC);
}

static void mtk_dsi_rxtx_control(struct mtk_dsi *dsi)
{
	u32 tmp_reg;

	switch (dsi->lanes) {
	case 1:
		tmp_reg = 1 << 2;
		break;
	case 2:
		tmp_reg = 3 << 2;
		break;
	case 3:
		tmp_reg = 7 << 2;
		break;
	case 4:
		tmp_reg = 0xf << 2;
		break;
	default:
		tmp_reg = 0xf << 2;
		break;
	}

	tmp_reg |= (dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) << 6;
	tmp_reg |= (dsi->mode_flags & MIPI_DSI_MODE_EOT_PACKET) >> 3;

	writel(tmp_reg, dsi->regs + DSI_TXRX_CTRL);
}

static void mtk_dsi_ps_control(struct mtk_dsi *dsi)
{
	u32 dsi_tmp_buf_bpp;
	u32 tmp_reg;

	switch (dsi->format) {
	case MIPI_DSI_FMT_RGB888:
		tmp_reg = PACKED_PS_24BIT_RGB888;
		dsi_tmp_buf_bpp = 3;
		break;
	case MIPI_DSI_FMT_RGB666:
		tmp_reg = LOOSELY_PS_18BIT_RGB666;
		dsi_tmp_buf_bpp = 3;
		break;
	case MIPI_DSI_FMT_RGB666_PACKED:
		tmp_reg = PACKED_PS_18BIT_RGB666;
		dsi_tmp_buf_bpp = 3;
		break;
	case MIPI_DSI_FMT_RGB565:
		tmp_reg = PACKED_PS_16BIT_RGB565;
		dsi_tmp_buf_bpp = 2;
		break;
	default:
		tmp_reg = PACKED_PS_24BIT_RGB888;
		dsi_tmp_buf_bpp = 3;
		break;
	}

	tmp_reg += dsi->vm.hactive * dsi_tmp_buf_bpp & DSI_PS_WC;
	writel(tmp_reg, dsi->regs + DSI_PSCTRL);
}

static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
{
	u32 horizontal_sync_active_byte;
	u32 horizontal_backporch_byte;
	u32 horizontal_frontporch_byte;
	u32 dsi_tmp_buf_bpp;

	struct videomode *vm = &dsi->vm;

	if (dsi->format == MIPI_DSI_FMT_RGB565)
		dsi_tmp_buf_bpp = 2;
	else
		dsi_tmp_buf_bpp = 3;

	writel(vm->vsync_len, dsi->regs + DSI_VSA_NL);
	writel(vm->vback_porch, dsi->regs + DSI_VBP_NL);
	writel(vm->vfront_porch, dsi->regs + DSI_VFP_NL);
	writel(vm->vactive, dsi->regs + DSI_VACT_NL);

	if (dsi->driver_data->has_size_ctl)
		writel(vm->vactive << 16 | vm->hactive,
		       dsi->regs + DSI_SIZE_CON);

	horizontal_sync_active_byte = (vm->hsync_len * dsi_tmp_buf_bpp - 10);

	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
		horizontal_backporch_byte =
			(vm->hback_porch * dsi_tmp_buf_bpp - 10);
	else
		horizontal_backporch_byte = ((vm->hback_porch + vm->hsync_len) *
			dsi_tmp_buf_bpp - 10);

	horizontal_frontporch_byte = (vm->hfront_porch * dsi_tmp_buf_bpp - 12);

	writel(horizontal_sync_active_byte, dsi->regs + DSI_HSA_WC);
	writel(horizontal_backporch_byte, dsi->regs + DSI_HBP_WC);
	writel(horizontal_frontporch_byte, dsi->regs + DSI_HFP_WC);

	mtk_dsi_ps_control(dsi);
}

static void mtk_dsi_start(struct mtk_dsi *dsi)
{
	writel(0, dsi->regs + DSI_START);
	writel(1, dsi->regs + DSI_START);
}

static void mtk_dsi_stop(struct mtk_dsi *dsi)
{
	writel(0, dsi->regs + DSI_START);
}

static void mtk_dsi_set_cmd_mode(struct mtk_dsi *dsi)
{
	writel(CMD_MODE, dsi->regs + DSI_MODE_CTRL);
}

static void mtk_dsi_set_interrupt_enable(struct mtk_dsi *dsi)
{
	u32 inten = LPRX_RD_RDY_INT_FLAG | CMD_DONE_INT_FLAG | VM_DONE_INT_FLAG;

	writel(inten, dsi->regs + DSI_INTEN);
}

static void mtk_dsi_irq_data_set(struct mtk_dsi *dsi, u32 irq_bit)
{
	dsi->irq_data |= irq_bit;
}

static void mtk_dsi_irq_data_clear(struct mtk_dsi *dsi, u32 irq_bit)
{
	dsi->irq_data &= ~irq_bit;
}

static s32 mtk_dsi_wait_for_irq_done(struct mtk_dsi *dsi, u32 irq_flag,
				     unsigned int timeout)
{
	s32 ret = 0;
	unsigned long jiffies = msecs_to_jiffies(timeout);

	ret = wait_event_interruptible_timeout(dsi->irq_wait_queue,
					       dsi->irq_data & irq_flag,
					       jiffies);
	if (ret == 0) {
		DRM_WARN("Wait DSI IRQ(0x%08x) Timeout\n", irq_flag);

		mtk_dsi_enable(dsi);
		mtk_dsi_reset_engine(dsi);
	}

	return ret;
}

static irqreturn_t mtk_dsi_irq(int irq, void *dev_id)
{
	struct mtk_dsi *dsi = dev_id;
	u32 status, tmp;
	u32 flag = LPRX_RD_RDY_INT_FLAG | CMD_DONE_INT_FLAG | VM_DONE_INT_FLAG;

	status = readl(dsi->regs + DSI_INTSTA) & flag;

	if (status) {
		do {
			mtk_dsi_mask(dsi, DSI_RACK, RACK, RACK);
			tmp = readl(dsi->regs + DSI_INTSTA);
		} while (tmp & DSI_BUSY);

		mtk_dsi_mask(dsi, DSI_INTSTA, status, 0);
		mtk_dsi_irq_data_set(dsi, status);
		wake_up_interruptible(&dsi->irq_wait_queue);
	}

	return IRQ_HANDLED;
}

static s32 mtk_dsi_switch_to_cmd_mode(struct mtk_dsi *dsi, u8 irq_flag, u32 t)
{
	mtk_dsi_irq_data_clear(dsi, irq_flag);
	mtk_dsi_set_cmd_mode(dsi);

	if (!mtk_dsi_wait_for_irq_done(dsi, irq_flag, t)) {
		DRM_ERROR("failed to switch cmd mode\n");
		return -ETIME;
	} else {
		return 0;
	}
}

static int mtk_dsi_poweron(struct mtk_dsi *dsi)
{
	struct device *dev = dsi->host.dev;
	int ret;
	u64 pixel_clock, total_bits;
	u32 htotal, htotal_bits, bit_per_pixel, overhead_cycles, overhead_bits;

	if (++dsi->refcount != 1)
		return 0;

	switch (dsi->format) {
	case MIPI_DSI_FMT_RGB565:
		bit_per_pixel = 16;
		break;
	case MIPI_DSI_FMT_RGB666_PACKED:
		bit_per_pixel = 18;
		break;
	case MIPI_DSI_FMT_RGB666:
	case MIPI_DSI_FMT_RGB888:
	default:
		bit_per_pixel = 24;
		break;
	}

	/**
	 * htotal_time = htotal * byte_per_pixel / num_lanes
	 * overhead_time = lpx + hs_prepare + hs_zero + hs_trail + hs_exit
	 * mipi_ratio = (htotal_time + overhead_time) / htotal_time
	 * data_rate = pixel_clock * bit_per_pixel * mipi_ratio / num_lanes;
	 */
	pixel_clock = dsi->vm.pixelclock;
	htotal = dsi->vm.hactive + dsi->vm.hback_porch + dsi->vm.hfront_porch +
			dsi->vm.hsync_len;
	htotal_bits = htotal * bit_per_pixel;

	overhead_cycles = T_LPX + T_HS_PREP + T_HS_ZERO + T_HS_TRAIL +
			T_HS_EXIT;
	overhead_bits = overhead_cycles * dsi->lanes * 8;
	total_bits = htotal_bits + overhead_bits;

	dsi->data_rate = DIV_ROUND_UP_ULL(pixel_clock * total_bits,
					  htotal * dsi->lanes);

	ret = clk_set_rate(dsi->hs_clk, dsi->data_rate);
	if (ret < 0) {
		dev_err(dev, "Failed to set data rate: %d\n", ret);
		goto err_refcount;
	}

	phy_power_on(dsi->phy);

	ret = clk_prepare_enable(dsi->engine_clk);
	if (ret < 0) {
		dev_err(dev, "Failed to enable engine clock: %d\n", ret);
		goto err_phy_power_off;
	}

	ret = clk_prepare_enable(dsi->digital_clk);
	if (ret < 0) {
		dev_err(dev, "Failed to enable digital clock: %d\n", ret);
		goto err_disable_engine_clk;
	}

	mtk_dsi_enable(dsi);

	if (dsi->driver_data->has_shadow_ctl)
		writel(FORCE_COMMIT | BYPASS_SHADOW,
		       dsi->regs + DSI_SHADOW_DEBUG);

	mtk_dsi_reset_engine(dsi);
	mtk_dsi_phy_timconfig(dsi);

	mtk_dsi_rxtx_control(dsi);
	mtk_dsi_ps_control_vact(dsi);
	mtk_dsi_set_vm_cmd(dsi);
	mtk_dsi_config_vdo_timing(dsi);
	mtk_dsi_set_interrupt_enable(dsi);

	mtk_dsi_clk_ulp_mode_leave(dsi);
	mtk_dsi_lane0_ulp_mode_leave(dsi);
	mtk_dsi_clk_hs_mode(dsi, 0);

	if (dsi->panel) {
		if (drm_panel_prepare(dsi->panel)) {
			DRM_ERROR("failed to prepare the panel\n");
			goto err_disable_digital_clk;
		}
	}

	return 0;
err_disable_digital_clk:
	clk_disable_unprepare(dsi->digital_clk);
err_disable_engine_clk:
	clk_disable_unprepare(dsi->engine_clk);
err_phy_power_off:
	phy_power_off(dsi->phy);
err_refcount:
	dsi->refcount--;
	return ret;
}

static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
{
	if (WARN_ON(dsi->refcount == 0))
		return;

	if (--dsi->refcount != 0)
		return;

	/*
	 * mtk_dsi_stop() and mtk_dsi_start() is asymmetric, since
	 * mtk_dsi_stop() should be called after mtk_drm_crtc_atomic_disable(),
	 * which needs irq for vblank, and mtk_dsi_stop() will disable irq.
	 * mtk_dsi_start() needs to be called in mtk_output_dsi_enable(),
	 * after dsi is fully set.
	 */
	mtk_dsi_stop(dsi);

	if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) {
		if (dsi->panel) {
			if (drm_panel_unprepare(dsi->panel)) {
				DRM_ERROR("failed to unprepare the panel\n");
				return;
			}
		}
	}

	mtk_dsi_reset_engine(dsi);
	mtk_dsi_lane0_ulp_mode_enter(dsi);
	mtk_dsi_clk_ulp_mode_enter(dsi);

	mtk_dsi_disable(dsi);

	clk_disable_unprepare(dsi->engine_clk);
	clk_disable_unprepare(dsi->digital_clk);

	phy_power_off(dsi->phy);
}

static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
{
	int ret;

	if (dsi->enabled)
		return;

	ret = mtk_dsi_poweron(dsi);
	if (ret < 0) {
		DRM_ERROR("failed to power on dsi\n");
		return;
	}

	mtk_dsi_set_mode(dsi);
	mtk_dsi_clk_hs_mode(dsi, 1);

	mtk_dsi_start(dsi);

	if (dsi->panel) {
		if (drm_panel_enable(dsi->panel)) {
			DRM_ERROR("failed to enable the panel\n");
			goto err_dsi_power_off;
		}
	}

	dsi->enabled = true;

	return;
err_dsi_power_off:
	mtk_dsi_stop(dsi);
	mtk_dsi_poweroff(dsi);
}

static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
{
	if (!dsi->enabled)
		return;

	if (dsi->panel) {
		if (drm_panel_disable(dsi->panel)) {
			DRM_ERROR("failed to disable the panel\n");
			return;
		}
	}

	mtk_dsi_poweroff(dsi);

	dsi->enabled = false;
}

static void mtk_dsi_encoder_destroy(struct drm_encoder *encoder)
{
	drm_encoder_cleanup(encoder);
}

static const struct drm_encoder_funcs mtk_dsi_encoder_funcs = {
	.destroy = mtk_dsi_encoder_destroy,
};

static bool mtk_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
				       const struct drm_display_mode *mode,
				       struct drm_display_mode *adjusted_mode)
{
	return true;
}

static void mtk_dsi_encoder_mode_set(struct drm_encoder *encoder,
				     struct drm_display_mode *mode,
				     struct drm_display_mode *adjusted)
{
	struct mtk_dsi *dsi = encoder_to_dsi(encoder);

	drm_display_mode_to_videomode(adjusted, &dsi->vm);
}

static void mtk_dsi_encoder_disable(struct drm_encoder *encoder)
{
	struct mtk_dsi *dsi = encoder_to_dsi(encoder);

	mtk_output_dsi_disable(dsi);
}

static void mtk_dsi_encoder_enable(struct drm_encoder *encoder)
{
	struct mtk_dsi *dsi = encoder_to_dsi(encoder);

	mtk_output_dsi_enable(dsi);
}

static int mtk_dsi_connector_get_modes(struct drm_connector *connector)
{
	struct mtk_dsi *dsi = connector_to_dsi(connector);

	return drm_panel_get_modes(dsi->panel);
}

static const struct drm_encoder_helper_funcs mtk_dsi_encoder_helper_funcs = {
	.mode_fixup = mtk_dsi_encoder_mode_fixup,
	.mode_set = mtk_dsi_encoder_mode_set,
	.disable = mtk_dsi_encoder_disable,
	.enable = mtk_dsi_encoder_enable,
};

static const struct drm_connector_funcs mtk_dsi_connector_funcs = {
	.fill_modes = drm_helper_probe_single_connector_modes,
	.destroy = drm_connector_cleanup,
	.reset = drm_atomic_helper_connector_reset,
	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static const struct drm_connector_helper_funcs
	mtk_dsi_connector_helper_funcs = {
	.get_modes = mtk_dsi_connector_get_modes,
};

static int mtk_dsi_create_connector(struct drm_device *drm, struct mtk_dsi *dsi)
{
	int ret;

	ret = drm_connector_init(drm, &dsi->conn, &mtk_dsi_connector_funcs,
				 DRM_MODE_CONNECTOR_DSI);
	if (ret) {
		DRM_ERROR("Failed to connector init to drm\n");
		return ret;
	}

	drm_connector_helper_add(&dsi->conn, &mtk_dsi_connector_helper_funcs);

	dsi->conn.dpms = DRM_MODE_DPMS_OFF;
	drm_connector_attach_encoder(&dsi->conn, &dsi->encoder);

	if (dsi->panel) {
		ret = drm_panel_attach(dsi->panel, &dsi->conn);
		if (ret) {
			DRM_ERROR("Failed to attach panel to drm\n");
			goto err_connector_cleanup;
		}
	}

	return 0;

err_connector_cleanup:
	drm_connector_cleanup(&dsi->conn);
	return ret;
}

static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi)
{
	int ret;

	ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
			       DRM_MODE_ENCODER_DSI, NULL);
	if (ret) {
		DRM_ERROR("Failed to encoder init to drm\n");
		return ret;
	}
	drm_encoder_helper_add(&dsi->encoder, &mtk_dsi_encoder_helper_funcs);

	/*
	 * Currently display data paths are statically assigned to a crtc each.
	 * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
	 */
	dsi->encoder.possible_crtcs = 1;

	/* If there's a bridge, attach to it and let it create the connector */
	if (dsi->bridge) {
		ret = drm_bridge_attach(&dsi->encoder, dsi->bridge, NULL);
		if (ret) {
			DRM_ERROR("Failed to attach bridge to drm\n");
			goto err_encoder_cleanup;
		}
	} else {
		/* Otherwise create our own connector and attach to a panel */
		ret = mtk_dsi_create_connector(drm, dsi);
		if (ret)
			goto err_encoder_cleanup;
	}

	return 0;

err_encoder_cleanup:
	drm_encoder_cleanup(&dsi->encoder);
	return ret;
}

static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi)
{
	drm_encoder_cleanup(&dsi->encoder);
	/* Skip connector cleanup if creation was delegated to the bridge */
	if (dsi->conn.dev)
		drm_connector_cleanup(&dsi->conn);
	if (dsi->panel)
		drm_panel_detach(dsi->panel);
}

static void mtk_dsi_ddp_start(struct mtk_ddp_comp *comp)
{
	struct mtk_dsi *dsi = container_of(comp, struct mtk_dsi, ddp_comp);

	mtk_dsi_poweron(dsi);
}

static void mtk_dsi_ddp_stop(struct mtk_ddp_comp *comp)
{
	struct mtk_dsi *dsi = container_of(comp, struct mtk_dsi, ddp_comp);

	mtk_dsi_poweroff(dsi);
}

static const struct mtk_ddp_comp_funcs mtk_dsi_funcs = {
	.start = mtk_dsi_ddp_start,
	.stop = mtk_dsi_ddp_stop,
};

static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
			       struct mipi_dsi_device *device)
{
	struct mtk_dsi *dsi = host_to_dsi(host);

	dsi->lanes = device->lanes;
	dsi->format = device->format;
	dsi->mode_flags = device->mode_flags;

	if (dsi->conn.dev)
		drm_helper_hpd_irq_event(dsi->conn.dev);

	return 0;
}

static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
			       struct mipi_dsi_device *device)
{
	struct mtk_dsi *dsi = host_to_dsi(host);

	if (dsi->conn.dev)
		drm_helper_hpd_irq_event(dsi->conn.dev);

	return 0;
}

static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi)
{
	int ret;
	u32 val;

	ret = readl_poll_timeout(dsi->regs + DSI_INTSTA, val, !(val & DSI_BUSY),
				 4, 2000000);
	if (ret) {
		DRM_WARN("polling dsi wait not busy timeout!\n");

		mtk_dsi_enable(dsi);
		mtk_dsi_reset_engine(dsi);
	}
}

static u32 mtk_dsi_recv_cnt(u8 type, u8 *read_data)
{
	switch (type) {
	case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_1BYTE:
	case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_1BYTE:
		return 1;
	case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_2BYTE:
	case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_2BYTE:
		return 2;
	case MIPI_DSI_RX_GENERIC_LONG_READ_RESPONSE:
	case MIPI_DSI_RX_DCS_LONG_READ_RESPONSE:
		return read_data[1] + read_data[2] * 16;
	case MIPI_DSI_RX_ACKNOWLEDGE_AND_ERROR_REPORT:
		DRM_INFO("type is 0x02, try again\n");
		break;
	default:
		DRM_INFO("type(0x%x) not recognized\n", type);
		break;
	}

	return 0;
}

static void mtk_dsi_cmdq(struct mtk_dsi *dsi, const struct mipi_dsi_msg *msg)
{
	const char *tx_buf = msg->tx_buf;
	u8 config, cmdq_size, cmdq_off, type = msg->type;
	u32 reg_val, cmdq_mask, i;
	u32 reg_cmdq_off = dsi->driver_data->reg_cmdq_off;

	if (MTK_DSI_HOST_IS_READ(type))
		config = BTA;
	else
		config = (msg->tx_len > 2) ? LONG_PACKET : SHORT_PACKET;

	if (msg->tx_len > 2) {
		cmdq_size = 1 + (msg->tx_len + 3) / 4;
		cmdq_off = 4;
		cmdq_mask = CONFIG | DATA_ID | DATA_0 | DATA_1;
		reg_val = (msg->tx_len << 16) | (type << 8) | config;
	} else {
		cmdq_size = 1;
		cmdq_off = 2;
		cmdq_mask = CONFIG | DATA_ID;
		reg_val = (type << 8) | config;
	}

	for (i = 0; i < msg->tx_len; i++)
		mtk_dsi_mask(dsi, (reg_cmdq_off + cmdq_off + i) & (~0x3U),
			     (0xffUL << (((i + cmdq_off) & 3U) * 8U)),
			     tx_buf[i] << (((i + cmdq_off) & 3U) * 8U));

	mtk_dsi_mask(dsi, reg_cmdq_off, cmdq_mask, reg_val);
	mtk_dsi_mask(dsi, DSI_CMDQ_SIZE, CMDQ_SIZE, cmdq_size);
}

static ssize_t mtk_dsi_host_send_cmd(struct mtk_dsi *dsi,
				     const struct mipi_dsi_msg *msg, u8 flag)
{
	mtk_dsi_wait_for_idle(dsi);
	mtk_dsi_irq_data_clear(dsi, flag);
	mtk_dsi_cmdq(dsi, msg);
	mtk_dsi_start(dsi);

	if (!mtk_dsi_wait_for_irq_done(dsi, flag, 2000))
		return -ETIME;
	else
		return 0;
}

static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
				     const struct mipi_dsi_msg *msg)
{
	struct mtk_dsi *dsi = host_to_dsi(host);
	u32 recv_cnt, i;
	u8 read_data[16];
	void *src_addr;
	u8 irq_flag = CMD_DONE_INT_FLAG;

	if (readl(dsi->regs + DSI_MODE_CTRL) & MODE) {
		DRM_ERROR("dsi engine is not command mode\n");
		return -EINVAL;
	}

	if (MTK_DSI_HOST_IS_READ(msg->type))
		irq_flag |= LPRX_RD_RDY_INT_FLAG;

	if (mtk_dsi_host_send_cmd(dsi, msg, irq_flag) < 0)
		return -ETIME;

	if (!MTK_DSI_HOST_IS_READ(msg->type))
		return 0;

	if (!msg->rx_buf) {
		DRM_ERROR("dsi receive buffer size may be NULL\n");
		return -EINVAL;
	}

	for (i = 0; i < 16; i++)
		*(read_data + i) = readb(dsi->regs + DSI_RX_DATA0 + i);

	recv_cnt = mtk_dsi_recv_cnt(read_data[0], read_data);

	if (recv_cnt > 2)
		src_addr = &read_data[4];
	else
		src_addr = &read_data[1];

	if (recv_cnt > 10)
		recv_cnt = 10;

	if (recv_cnt > msg->rx_len)
		recv_cnt = msg->rx_len;

	if (recv_cnt)
		memcpy(msg->rx_buf, src_addr, recv_cnt);

	DRM_INFO("dsi get %d byte data from the panel address(0x%x)\n",
		 recv_cnt, *((u8 *)(msg->tx_buf)));

	return recv_cnt;
}

static const struct mipi_dsi_host_ops mtk_dsi_ops = {
	.attach = mtk_dsi_host_attach,
	.detach = mtk_dsi_host_detach,
	.transfer = mtk_dsi_host_transfer,
};

static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
{
	int ret;
	struct drm_device *drm = data;
	struct mtk_dsi *dsi = dev_get_drvdata(dev);

	ret = mtk_ddp_comp_register(drm, &dsi->ddp_comp);
	if (ret < 0) {
		dev_err(dev, "Failed to register component %pOF: %d\n",
			dev->of_node, ret);
		return ret;
	}

	ret = mtk_dsi_create_conn_enc(drm, dsi);
	if (ret) {
		DRM_ERROR("Encoder create failed with %d\n", ret);
		goto err_unregister;
	}

	return 0;

err_unregister:
	mtk_ddp_comp_unregister(drm, &dsi->ddp_comp);
	return ret;
}

static void mtk_dsi_unbind(struct device *dev, struct device *master,
			   void *data)
{
	struct drm_device *drm = data;
	struct mtk_dsi *dsi = dev_get_drvdata(dev);

	mtk_dsi_destroy_conn_enc(dsi);
	mtk_ddp_comp_unregister(drm, &dsi->ddp_comp);
}

static const struct component_ops mtk_dsi_component_ops = {
	.bind = mtk_dsi_bind,
	.unbind = mtk_dsi_unbind,
};

static int mtk_dsi_probe(struct platform_device *pdev)
{
	struct mtk_dsi *dsi;
	struct device *dev = &pdev->dev;
	struct resource *regs;
	int irq_num;
	int comp_id;
	int ret;

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

	dsi->host.ops = &mtk_dsi_ops;
	dsi->host.dev = dev;
	ret = mipi_dsi_host_register(&dsi->host);
	if (ret < 0) {
		dev_err(dev, "failed to register DSI host: %d\n", ret);
		return ret;
	}

	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
					  &dsi->panel, &dsi->bridge);
	if (ret)
		goto err_unregister_host;

	dsi->driver_data = of_device_get_match_data(dev);

	dsi->engine_clk = devm_clk_get(dev, "engine");
	if (IS_ERR(dsi->engine_clk)) {
		ret = PTR_ERR(dsi->engine_clk);
		dev_err(dev, "Failed to get engine clock: %d\n", ret);
		goto err_unregister_host;
	}

	dsi->digital_clk = devm_clk_get(dev, "digital");
	if (IS_ERR(dsi->digital_clk)) {
		ret = PTR_ERR(dsi->digital_clk);
		dev_err(dev, "Failed to get digital clock: %d\n", ret);
		goto err_unregister_host;
	}

	dsi->hs_clk = devm_clk_get(dev, "hs");
	if (IS_ERR(dsi->hs_clk)) {
		ret = PTR_ERR(dsi->hs_clk);
		dev_err(dev, "Failed to get hs clock: %d\n", ret);
		goto err_unregister_host;
	}

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	dsi->regs = devm_ioremap_resource(dev, regs);
	if (IS_ERR(dsi->regs)) {
		ret = PTR_ERR(dsi->regs);
		dev_err(dev, "Failed to ioremap memory: %d\n", ret);
		goto err_unregister_host;
	}

	dsi->phy = devm_phy_get(dev, "dphy");
	if (IS_ERR(dsi->phy)) {
		ret = PTR_ERR(dsi->phy);
		dev_err(dev, "Failed to get MIPI-DPHY: %d\n", ret);
		goto err_unregister_host;
	}

	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DSI);
	if (comp_id < 0) {
		dev_err(dev, "Failed to identify by alias: %d\n", comp_id);
		ret = comp_id;
		goto err_unregister_host;
	}

	ret = mtk_ddp_comp_init(dev, dev->of_node, &dsi->ddp_comp, comp_id,
				&mtk_dsi_funcs);
	if (ret) {
		dev_err(dev, "Failed to initialize component: %d\n", ret);
		goto err_unregister_host;
	}

	irq_num = platform_get_irq(pdev, 0);
	if (irq_num < 0) {
		dev_err(&pdev->dev, "failed to get dsi irq_num: %d\n", irq_num);
		ret = irq_num;
		goto err_unregister_host;
	}

	irq_set_status_flags(irq_num, IRQ_TYPE_LEVEL_LOW);
	ret = devm_request_irq(&pdev->dev, irq_num, mtk_dsi_irq,
			       IRQF_TRIGGER_LOW, dev_name(&pdev->dev), dsi);
	if (ret) {
		dev_err(&pdev->dev, "failed to request mediatek dsi irq\n");
		goto err_unregister_host;
	}

	init_waitqueue_head(&dsi->irq_wait_queue);

	platform_set_drvdata(pdev, dsi);

	ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
	if (ret) {
		dev_err(&pdev->dev, "failed to add component: %d\n", ret);
		goto err_unregister_host;
	}

	return 0;

err_unregister_host:
	mipi_dsi_host_unregister(&dsi->host);
	return ret;
}

static int mtk_dsi_remove(struct platform_device *pdev)
{
	struct mtk_dsi *dsi = platform_get_drvdata(pdev);

	mtk_output_dsi_disable(dsi);
	component_del(&pdev->dev, &mtk_dsi_component_ops);
	mipi_dsi_host_unregister(&dsi->host);

	return 0;
}

static const struct mtk_dsi_driver_data mt8173_dsi_driver_data = {
	.reg_cmdq_off = 0x200,
};

static const struct mtk_dsi_driver_data mt2701_dsi_driver_data = {
	.reg_cmdq_off = 0x180,
};

static const struct of_device_id mtk_dsi_of_match[] = {
	{ .compatible = "mediatek,mt2701-dsi",
	  .data = &mt2701_dsi_driver_data },
	{ .compatible = "mediatek,mt8173-dsi",
	  .data = &mt8173_dsi_driver_data },
	{ },
};

struct platform_driver mtk_dsi_driver = {
	.probe = mtk_dsi_probe,
	.remove = mtk_dsi_remove,
	.driver = {
		.name = "mtk-dsi",
		.of_match_table = mtk_dsi_of_match,
	},
};