linux/drivers/gpu/drm/tegra/dsi.c

/*
 * Copyright (C) 2013 NVIDIA Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/host1x.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset.h>

#include <linux/regulator/consumer.h>

#include <drm/drm_mipi_dsi.h>
#include <drm/drm_panel.h>

#include <video/mipi_display.h>

#include "dc.h"
#include "drm.h"
#include "dsi.h"
#include "mipi-phy.h"

#define DSI_VIDEO_FIFO_DEPTH (1920 / 4)
#define DSI_HOST_FIFO_DEPTH 64

struct tegra_dsi {
	struct host1x_client client;
	struct tegra_output output;
	struct device *dev;

	void __iomem *regs;

	struct reset_control *rst;
	struct clk *clk_parent;
	struct clk *clk_lp;
	struct clk *clk;

	struct drm_info_list *debugfs_files;
	struct drm_minor *minor;
	struct dentry *debugfs;

	enum mipi_dsi_pixel_format format;
	unsigned int lanes;

	struct tegra_mipi_device *mipi;
	struct mipi_dsi_host host;

	struct regulator *vdd;
};

static inline struct tegra_dsi *
host1x_client_to_dsi(struct host1x_client *client)
{
	return container_of(client, struct tegra_dsi, client);
}

static inline struct tegra_dsi *host_to_tegra(struct mipi_dsi_host *host)
{
	return container_of(host, struct tegra_dsi, host);
}

static inline struct tegra_dsi *to_dsi(struct tegra_output *output)
{
	return container_of(output, struct tegra_dsi, output);
}

static inline unsigned long tegra_dsi_readl(struct tegra_dsi *dsi,
					    unsigned long reg)
{
	return readl(dsi->regs + (reg << 2));
}

static inline void tegra_dsi_writel(struct tegra_dsi *dsi, unsigned long value,
				    unsigned long reg)
{
	writel(value, dsi->regs + (reg << 2));
}

static int tegra_dsi_show_regs(struct seq_file *s, void *data)
{
	struct drm_info_node *node = s->private;
	struct tegra_dsi *dsi = node->info_ent->data;

#define DUMP_REG(name)						\
	seq_printf(s, "%-32s %#05x %08lx\n", #name, name,	\
		   tegra_dsi_readl(dsi, name))

	DUMP_REG(DSI_INCR_SYNCPT);
	DUMP_REG(DSI_INCR_SYNCPT_CONTROL);
	DUMP_REG(DSI_INCR_SYNCPT_ERROR);
	DUMP_REG(DSI_CTXSW);
	DUMP_REG(DSI_RD_DATA);
	DUMP_REG(DSI_WR_DATA);
	DUMP_REG(DSI_POWER_CONTROL);
	DUMP_REG(DSI_INT_ENABLE);
	DUMP_REG(DSI_INT_STATUS);
	DUMP_REG(DSI_INT_MASK);
	DUMP_REG(DSI_HOST_CONTROL);
	DUMP_REG(DSI_CONTROL);
	DUMP_REG(DSI_SOL_DELAY);
	DUMP_REG(DSI_MAX_THRESHOLD);
	DUMP_REG(DSI_TRIGGER);
	DUMP_REG(DSI_TX_CRC);
	DUMP_REG(DSI_STATUS);

	DUMP_REG(DSI_INIT_SEQ_CONTROL);
	DUMP_REG(DSI_INIT_SEQ_DATA_0);
	DUMP_REG(DSI_INIT_SEQ_DATA_1);
	DUMP_REG(DSI_INIT_SEQ_DATA_2);
	DUMP_REG(DSI_INIT_SEQ_DATA_3);
	DUMP_REG(DSI_INIT_SEQ_DATA_4);
	DUMP_REG(DSI_INIT_SEQ_DATA_5);
	DUMP_REG(DSI_INIT_SEQ_DATA_6);
	DUMP_REG(DSI_INIT_SEQ_DATA_7);

	DUMP_REG(DSI_PKT_SEQ_0_LO);
	DUMP_REG(DSI_PKT_SEQ_0_HI);
	DUMP_REG(DSI_PKT_SEQ_1_LO);
	DUMP_REG(DSI_PKT_SEQ_1_HI);
	DUMP_REG(DSI_PKT_SEQ_2_LO);
	DUMP_REG(DSI_PKT_SEQ_2_HI);
	DUMP_REG(DSI_PKT_SEQ_3_LO);
	DUMP_REG(DSI_PKT_SEQ_3_HI);
	DUMP_REG(DSI_PKT_SEQ_4_LO);
	DUMP_REG(DSI_PKT_SEQ_4_HI);
	DUMP_REG(DSI_PKT_SEQ_5_LO);
	DUMP_REG(DSI_PKT_SEQ_5_HI);

	DUMP_REG(DSI_DCS_CMDS);

	DUMP_REG(DSI_PKT_LEN_0_1);
	DUMP_REG(DSI_PKT_LEN_2_3);
	DUMP_REG(DSI_PKT_LEN_4_5);
	DUMP_REG(DSI_PKT_LEN_6_7);

	DUMP_REG(DSI_PHY_TIMING_0);
	DUMP_REG(DSI_PHY_TIMING_1);
	DUMP_REG(DSI_PHY_TIMING_2);
	DUMP_REG(DSI_BTA_TIMING);

	DUMP_REG(DSI_TIMEOUT_0);
	DUMP_REG(DSI_TIMEOUT_1);
	DUMP_REG(DSI_TO_TALLY);

	DUMP_REG(DSI_PAD_CONTROL_0);
	DUMP_REG(DSI_PAD_CONTROL_CD);
	DUMP_REG(DSI_PAD_CD_STATUS);
	DUMP_REG(DSI_VIDEO_MODE_CONTROL);
	DUMP_REG(DSI_PAD_CONTROL_1);
	DUMP_REG(DSI_PAD_CONTROL_2);
	DUMP_REG(DSI_PAD_CONTROL_3);
	DUMP_REG(DSI_PAD_CONTROL_4);

	DUMP_REG(DSI_GANGED_MODE_CONTROL);
	DUMP_REG(DSI_GANGED_MODE_START);
	DUMP_REG(DSI_GANGED_MODE_SIZE);

	DUMP_REG(DSI_RAW_DATA_BYTE_COUNT);
	DUMP_REG(DSI_ULTRA_LOW_POWER_CONTROL);

	DUMP_REG(DSI_INIT_SEQ_DATA_8);
	DUMP_REG(DSI_INIT_SEQ_DATA_9);
	DUMP_REG(DSI_INIT_SEQ_DATA_10);
	DUMP_REG(DSI_INIT_SEQ_DATA_11);
	DUMP_REG(DSI_INIT_SEQ_DATA_12);
	DUMP_REG(DSI_INIT_SEQ_DATA_13);
	DUMP_REG(DSI_INIT_SEQ_DATA_14);
	DUMP_REG(DSI_INIT_SEQ_DATA_15);

#undef DUMP_REG

	return 0;
}

static struct drm_info_list debugfs_files[] = {
	{ "regs", tegra_dsi_show_regs, 0, NULL },
};

static int tegra_dsi_debugfs_init(struct tegra_dsi *dsi,
				  struct drm_minor *minor)
{
	const char *name = dev_name(dsi->dev);
	unsigned int i;
	int err;

	dsi->debugfs = debugfs_create_dir(name, minor->debugfs_root);
	if (!dsi->debugfs)
		return -ENOMEM;

	dsi->debugfs_files = kmemdup(debugfs_files, sizeof(debugfs_files),
				     GFP_KERNEL);
	if (!dsi->debugfs_files) {
		err = -ENOMEM;
		goto remove;
	}

	for (i = 0; i < ARRAY_SIZE(debugfs_files); i++)
		dsi->debugfs_files[i].data = dsi;

	err = drm_debugfs_create_files(dsi->debugfs_files,
				       ARRAY_SIZE(debugfs_files),
				       dsi->debugfs, minor);
	if (err < 0)
		goto free;

	dsi->minor = minor;

	return 0;

free:
	kfree(dsi->debugfs_files);
	dsi->debugfs_files = NULL;
remove:
	debugfs_remove(dsi->debugfs);
	dsi->debugfs = NULL;

	return err;
}

static int tegra_dsi_debugfs_exit(struct tegra_dsi *dsi)
{
	drm_debugfs_remove_files(dsi->debugfs_files, ARRAY_SIZE(debugfs_files),
				 dsi->minor);
	dsi->minor = NULL;

	kfree(dsi->debugfs_files);
	dsi->debugfs_files = NULL;

	debugfs_remove(dsi->debugfs);
	dsi->debugfs = NULL;

	return 0;
}

#define PKT_ID0(id)	((((id) & 0x3f) <<  3) | (1 <<  9))
#define PKT_LEN0(len)	(((len) & 0x07) <<  0)
#define PKT_ID1(id)	((((id) & 0x3f) << 13) | (1 << 19))
#define PKT_LEN1(len)	(((len) & 0x07) << 10)
#define PKT_ID2(id)	((((id) & 0x3f) << 23) | (1 << 29))
#define PKT_LEN2(len)	(((len) & 0x07) << 20)

#define PKT_LP		(1 << 30)
#define NUM_PKT_SEQ	12

/* non-burst mode with sync-end */
static const u32 pkt_seq_vnb_syne[NUM_PKT_SEQ] = {
	[ 0] = PKT_ID0(MIPI_DSI_V_SYNC_START) | PKT_LEN0(0) |
	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
	       PKT_LP,
	[ 1] = 0,
	[ 2] = PKT_ID0(MIPI_DSI_V_SYNC_END) | PKT_LEN0(0) |
	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
	       PKT_LP,
	[ 3] = 0,
	[ 4] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
	       PKT_LP,
	[ 5] = 0,
	[ 6] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0),
	[ 7] = PKT_ID0(MIPI_DSI_BLANKING_PACKET) | PKT_LEN0(2) |
	       PKT_ID1(MIPI_DSI_PACKED_PIXEL_STREAM_24) | PKT_LEN1(3) |
	       PKT_ID2(MIPI_DSI_BLANKING_PACKET) | PKT_LEN2(4),
	[ 8] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
	       PKT_LP,
	[ 9] = 0,
	[10] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0),
	[11] = PKT_ID0(MIPI_DSI_BLANKING_PACKET) | PKT_LEN0(2) |
	       PKT_ID1(MIPI_DSI_PACKED_PIXEL_STREAM_24) | PKT_LEN1(3) |
	       PKT_ID2(MIPI_DSI_BLANKING_PACKET) | PKT_LEN2(4),
};

static int tegra_dsi_set_phy_timing(struct tegra_dsi *dsi)
{
	struct mipi_dphy_timing timing;
	unsigned long value, period;
	long rate;
	int err;

	rate = clk_get_rate(dsi->clk);
	if (rate < 0)
		return rate;

	period = DIV_ROUND_CLOSEST(1000000000UL, rate * 2);

	err = mipi_dphy_timing_get_default(&timing, period);
	if (err < 0)
		return err;

	err = mipi_dphy_timing_validate(&timing, period);
	if (err < 0) {
		dev_err(dsi->dev, "failed to validate D-PHY timing: %d\n", err);
		return err;
	}

	/*
	 * The D-PHY timing fields below are expressed in byte-clock cycles,
	 * so multiply the period by 8.
	 */
	period *= 8;

	value = DSI_TIMING_FIELD(timing.hsexit, period, 1) << 24 |
		DSI_TIMING_FIELD(timing.hstrail, period, 0) << 16 |
		DSI_TIMING_FIELD(timing.hszero, period, 3) << 8 |
		DSI_TIMING_FIELD(timing.hsprepare, period, 1);
	tegra_dsi_writel(dsi, value, DSI_PHY_TIMING_0);

	value = DSI_TIMING_FIELD(timing.clktrail, period, 1) << 24 |
		DSI_TIMING_FIELD(timing.clkpost, period, 1) << 16 |
		DSI_TIMING_FIELD(timing.clkzero, period, 1) << 8 |
		DSI_TIMING_FIELD(timing.lpx, period, 1);
	tegra_dsi_writel(dsi, value, DSI_PHY_TIMING_1);

	value = DSI_TIMING_FIELD(timing.clkprepare, period, 1) << 16 |
		DSI_TIMING_FIELD(timing.clkpre, period, 1) << 8 |
		DSI_TIMING_FIELD(0xff * period, period, 0) << 0;
	tegra_dsi_writel(dsi, value, DSI_PHY_TIMING_2);

	value = DSI_TIMING_FIELD(timing.taget, period, 1) << 16 |
		DSI_TIMING_FIELD(timing.tasure, period, 1) << 8 |
		DSI_TIMING_FIELD(timing.tago, period, 1);
	tegra_dsi_writel(dsi, value, DSI_BTA_TIMING);

	return 0;
}

static int tegra_dsi_get_muldiv(enum mipi_dsi_pixel_format format,
				unsigned int *mulp, unsigned int *divp)
{
	switch (format) {
	case MIPI_DSI_FMT_RGB666_PACKED:
	case MIPI_DSI_FMT_RGB888:
		*mulp = 3;
		*divp = 1;
		break;

	case MIPI_DSI_FMT_RGB565:
		*mulp = 2;
		*divp = 1;
		break;

	case MIPI_DSI_FMT_RGB666:
		*mulp = 9;
		*divp = 4;
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static int tegra_dsi_get_format(enum mipi_dsi_pixel_format format,
				enum tegra_dsi_format *fmt)
{
	switch (format) {
	case MIPI_DSI_FMT_RGB888:
		*fmt = TEGRA_DSI_FORMAT_24P;
		break;

	case MIPI_DSI_FMT_RGB666:
		*fmt = TEGRA_DSI_FORMAT_18NP;
		break;

	case MIPI_DSI_FMT_RGB666_PACKED:
		*fmt = TEGRA_DSI_FORMAT_18P;
		break;

	case MIPI_DSI_FMT_RGB565:
		*fmt = TEGRA_DSI_FORMAT_16P;
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static int tegra_output_dsi_enable(struct tegra_output *output)
{
	struct tegra_dc *dc = to_tegra_dc(output->encoder.crtc);
	struct drm_display_mode *mode = &dc->base.mode;
	unsigned int hact, hsw, hbp, hfp, i, mul, div;
	struct tegra_dsi *dsi = to_dsi(output);
	/* FIXME: don't hardcode this */
	const u32 *pkt_seq = pkt_seq_vnb_syne;
	enum tegra_dsi_format format;
	unsigned long value;
	int err;

	err = tegra_dsi_get_muldiv(dsi->format, &mul, &div);
	if (err < 0)
		return err;

	err = tegra_dsi_get_format(dsi->format, &format);
	if (err < 0)
		return err;

	err = clk_enable(dsi->clk);
	if (err < 0)
		return err;

	reset_control_deassert(dsi->rst);

	value = DSI_CONTROL_CHANNEL(0) | DSI_CONTROL_FORMAT(format) |
		DSI_CONTROL_LANES(dsi->lanes - 1) |
		DSI_CONTROL_SOURCE(dc->pipe);
	tegra_dsi_writel(dsi, value, DSI_CONTROL);

	tegra_dsi_writel(dsi, DSI_VIDEO_FIFO_DEPTH, DSI_MAX_THRESHOLD);

	value = DSI_HOST_CONTROL_HS | DSI_HOST_CONTROL_CS |
		DSI_HOST_CONTROL_ECC;
	tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);

	value = tegra_dsi_readl(dsi, DSI_CONTROL);
	value |= DSI_CONTROL_HS_CLK_CTRL;
	value &= ~DSI_CONTROL_TX_TRIG(3);
	value &= ~DSI_CONTROL_DCS_ENABLE;
	value |= DSI_CONTROL_VIDEO_ENABLE;
	value &= ~DSI_CONTROL_HOST_ENABLE;
	tegra_dsi_writel(dsi, value, DSI_CONTROL);

	err = tegra_dsi_set_phy_timing(dsi);
	if (err < 0)
		return err;

	for (i = 0; i < NUM_PKT_SEQ; i++)
		tegra_dsi_writel(dsi, pkt_seq[i], DSI_PKT_SEQ_0_LO + i);

	/* horizontal active pixels */
	hact = mode->hdisplay * mul / div;

	/* horizontal sync width */
	hsw = (mode->hsync_end - mode->hsync_start) * mul / div;
	hsw -= 10;

	/* horizontal back porch */
	hbp = (mode->htotal - mode->hsync_end) * mul / div;
	hbp -= 14;

	/* horizontal front porch */
	hfp = (mode->hsync_start  - mode->hdisplay) * mul / div;
	hfp -= 8;

	tegra_dsi_writel(dsi, hsw << 16 | 0, DSI_PKT_LEN_0_1);
	tegra_dsi_writel(dsi, hact << 16 | hbp, DSI_PKT_LEN_2_3);
	tegra_dsi_writel(dsi, hfp, DSI_PKT_LEN_4_5);
	tegra_dsi_writel(dsi, 0x0f0f << 16, DSI_PKT_LEN_6_7);

	/* set SOL delay */
	tegra_dsi_writel(dsi, 8 * mul / div, DSI_SOL_DELAY);

	/* enable display controller */
	value = tegra_dc_readl(dc, DC_DISP_DISP_WIN_OPTIONS);
	value |= DSI_ENABLE;
	tegra_dc_writel(dc, value, DC_DISP_DISP_WIN_OPTIONS);

	value = tegra_dc_readl(dc, DC_CMD_DISPLAY_COMMAND);
	value &= ~DISP_CTRL_MODE_MASK;
	value |= DISP_CTRL_MODE_C_DISPLAY;
	tegra_dc_writel(dc, value, DC_CMD_DISPLAY_COMMAND);

	value = tegra_dc_readl(dc, DC_CMD_DISPLAY_POWER_CONTROL);
	value |= PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
		 PW4_ENABLE | PM0_ENABLE | PM1_ENABLE;
	tegra_dc_writel(dc, value, DC_CMD_DISPLAY_POWER_CONTROL);

	tegra_dc_writel(dc, GENERAL_ACT_REQ << 8, DC_CMD_STATE_CONTROL);
	tegra_dc_writel(dc, GENERAL_ACT_REQ, DC_CMD_STATE_CONTROL);

	/* enable DSI controller */
	value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
	value |= DSI_POWER_CONTROL_ENABLE;
	tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);

	return 0;
}

static int tegra_output_dsi_disable(struct tegra_output *output)
{
	struct tegra_dc *dc = to_tegra_dc(output->encoder.crtc);
	struct tegra_dsi *dsi = to_dsi(output);
	unsigned long value;

	/* disable DSI controller */
	value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
	value &= DSI_POWER_CONTROL_ENABLE;
	tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);

	/*
	 * The following accesses registers of the display controller, so make
	 * sure it's only executed when the output is attached to one.
	 */
	if (dc) {
		value = tegra_dc_readl(dc, DC_CMD_DISPLAY_POWER_CONTROL);
		value &= ~(PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
			   PW4_ENABLE | PM0_ENABLE | PM1_ENABLE);
		tegra_dc_writel(dc, value, DC_CMD_DISPLAY_POWER_CONTROL);

		value = tegra_dc_readl(dc, DC_CMD_DISPLAY_COMMAND);
		value &= ~DISP_CTRL_MODE_MASK;
		tegra_dc_writel(dc, value, DC_CMD_DISPLAY_COMMAND);

		value = tegra_dc_readl(dc, DC_DISP_DISP_WIN_OPTIONS);
		value &= ~DSI_ENABLE;
		tegra_dc_writel(dc, value, DC_DISP_DISP_WIN_OPTIONS);

		tegra_dc_writel(dc, GENERAL_ACT_REQ << 8, DC_CMD_STATE_CONTROL);
		tegra_dc_writel(dc, GENERAL_ACT_REQ, DC_CMD_STATE_CONTROL);
	}

	clk_disable(dsi->clk);

	return 0;
}

static int tegra_output_dsi_setup_clock(struct tegra_output *output,
					struct clk *clk, unsigned long pclk)
{
	struct tegra_dc *dc = to_tegra_dc(output->encoder.crtc);
	struct drm_display_mode *mode = &dc->base.mode;
	unsigned int timeout, mul, div, vrefresh;
	struct tegra_dsi *dsi = to_dsi(output);
	unsigned long bclk, plld, value;
	struct clk *base;
	int err;

	err = tegra_dsi_get_muldiv(dsi->format, &mul, &div);
	if (err < 0)
		return err;

	vrefresh = drm_mode_vrefresh(mode);

	pclk = mode->htotal * mode->vtotal * vrefresh;
	bclk = (pclk * mul) / (div * dsi->lanes);
	plld = DIV_ROUND_UP(bclk * 8, 1000000);
	pclk = (plld * 1000000) / 2;

	err = clk_set_parent(clk, dsi->clk_parent);
	if (err < 0) {
		dev_err(dsi->dev, "failed to set parent clock: %d\n", err);
		return err;
	}

	base = clk_get_parent(dsi->clk_parent);

	/*
	 * This assumes that the parent clock is pll_d_out0 or pll_d2_out
	 * respectively, each of which divides the base pll_d by 2.
	 */
	err = clk_set_rate(base, pclk * 2);
	if (err < 0) {
		dev_err(dsi->dev, "failed to set base clock rate to %lu Hz\n",
			pclk * 2);
		return err;
	}

	/*
	 * XXX: Move the below somewhere else so that we don't need to have
	 * access to the vrefresh in this function?
	 */

	/* one frame high-speed transmission timeout */
	timeout = (bclk / vrefresh) / 512;
	value = DSI_TIMEOUT_LRX(0x2000) | DSI_TIMEOUT_HTX(timeout);
	tegra_dsi_writel(dsi, value, DSI_TIMEOUT_0);

	/* 2 ms peripheral timeout for panel */
	timeout = 2 * bclk / 512 * 1000;
	value = DSI_TIMEOUT_PR(timeout) | DSI_TIMEOUT_TA(0x2000);
	tegra_dsi_writel(dsi, value, DSI_TIMEOUT_1);

	value = DSI_TALLY_TA(0) | DSI_TALLY_LRX(0) | DSI_TALLY_HTX(0);
	tegra_dsi_writel(dsi, value, DSI_TO_TALLY);

	return 0;
}

static int tegra_output_dsi_check_mode(struct tegra_output *output,
				       struct drm_display_mode *mode,
				       enum drm_mode_status *status)
{
	/*
	 * FIXME: For now, always assume that the mode is okay.
	 */

	*status = MODE_OK;

	return 0;
}

static const struct tegra_output_ops dsi_ops = {
	.enable = tegra_output_dsi_enable,
	.disable = tegra_output_dsi_disable,
	.setup_clock = tegra_output_dsi_setup_clock,
	.check_mode = tegra_output_dsi_check_mode,
};

static int tegra_dsi_pad_enable(struct tegra_dsi *dsi)
{
	unsigned long value;

	value = DSI_PAD_CONTROL_VS1_PULLDN(0) | DSI_PAD_CONTROL_VS1_PDIO(0);
	tegra_dsi_writel(dsi, value, DSI_PAD_CONTROL_0);

	return 0;
}

static int tegra_dsi_pad_calibrate(struct tegra_dsi *dsi)
{
	unsigned long value;

	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_0);
	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_1);
	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_2);
	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_3);
	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_4);

	/* start calibration */
	tegra_dsi_pad_enable(dsi);

	value = DSI_PAD_SLEW_UP(0x7) | DSI_PAD_SLEW_DN(0x7) |
		DSI_PAD_LP_UP(0x1) | DSI_PAD_LP_DN(0x1) |
		DSI_PAD_OUT_CLK(0x0);
	tegra_dsi_writel(dsi, value, DSI_PAD_CONTROL_2);

	return tegra_mipi_calibrate(dsi->mipi);
}

static int tegra_dsi_init(struct host1x_client *client)
{
	struct tegra_drm *tegra = dev_get_drvdata(client->parent);
	struct tegra_dsi *dsi = host1x_client_to_dsi(client);
	int err;

	dsi->output.type = TEGRA_OUTPUT_DSI;
	dsi->output.dev = client->dev;
	dsi->output.ops = &dsi_ops;

	err = tegra_output_init(tegra->drm, &dsi->output);
	if (err < 0) {
		dev_err(client->dev, "output setup failed: %d\n", err);
		return err;
	}

	if (IS_ENABLED(CONFIG_DEBUG_FS)) {
		err = tegra_dsi_debugfs_init(dsi, tegra->drm->primary);
		if (err < 0)
			dev_err(dsi->dev, "debugfs setup failed: %d\n", err);
	}

	err = tegra_dsi_pad_calibrate(dsi);
	if (err < 0) {
		dev_err(dsi->dev, "MIPI calibration failed: %d\n", err);
		return err;
	}

	return 0;
}

static int tegra_dsi_exit(struct host1x_client *client)
{
	struct tegra_dsi *dsi = host1x_client_to_dsi(client);
	int err;

	if (IS_ENABLED(CONFIG_DEBUG_FS)) {
		err = tegra_dsi_debugfs_exit(dsi);
		if (err < 0)
			dev_err(dsi->dev, "debugfs cleanup failed: %d\n", err);
	}

	err = tegra_output_disable(&dsi->output);
	if (err < 0) {
		dev_err(client->dev, "output failed to disable: %d\n", err);
		return err;
	}

	err = tegra_output_exit(&dsi->output);
	if (err < 0) {
		dev_err(client->dev, "output cleanup failed: %d\n", err);
		return err;
	}

	return 0;
}

static const struct host1x_client_ops dsi_client_ops = {
	.init = tegra_dsi_init,
	.exit = tegra_dsi_exit,
};

static int tegra_dsi_setup_clocks(struct tegra_dsi *dsi)
{
	struct clk *parent;
	int err;

	parent = clk_get_parent(dsi->clk);
	if (!parent)
		return -EINVAL;

	err = clk_set_parent(parent, dsi->clk_parent);
	if (err < 0)
		return err;

	return 0;
}

static int tegra_dsi_host_attach(struct mipi_dsi_host *host,
				 struct mipi_dsi_device *device)
{
	struct tegra_dsi *dsi = host_to_tegra(host);
	struct tegra_output *output = &dsi->output;

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

	output->panel = of_drm_find_panel(device->dev.of_node);
	if (output->panel) {
		if (output->connector.dev)
			drm_helper_hpd_irq_event(output->connector.dev);
	}

	return 0;
}

static int tegra_dsi_host_detach(struct mipi_dsi_host *host,
				 struct mipi_dsi_device *device)
{
	struct tegra_dsi *dsi = host_to_tegra(host);
	struct tegra_output *output = &dsi->output;

	if (output->panel && &device->dev == output->panel->dev) {
		if (output->connector.dev)
			drm_helper_hpd_irq_event(output->connector.dev);

		output->panel = NULL;
	}

	return 0;
}

static const struct mipi_dsi_host_ops tegra_dsi_host_ops = {
	.attach = tegra_dsi_host_attach,
	.detach = tegra_dsi_host_detach,
};

static int tegra_dsi_probe(struct platform_device *pdev)
{
	struct tegra_dsi *dsi;
	struct resource *regs;
	int err;

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

	dsi->output.dev = dsi->dev = &pdev->dev;

	err = tegra_output_probe(&dsi->output);
	if (err < 0)
		return err;

	/*
	 * Assume these values by default. When a DSI peripheral driver
	 * attaches to the DSI host, the parameters will be taken from
	 * the attached device.
	 */
	dsi->format = MIPI_DSI_FMT_RGB888;
	dsi->lanes = 4;

	dsi->rst = devm_reset_control_get(&pdev->dev, "dsi");
	if (IS_ERR(dsi->rst))
		return PTR_ERR(dsi->rst);

	dsi->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(dsi->clk)) {
		dev_err(&pdev->dev, "cannot get DSI clock\n");
		return PTR_ERR(dsi->clk);
	}

	err = clk_prepare_enable(dsi->clk);
	if (err < 0) {
		dev_err(&pdev->dev, "cannot enable DSI clock\n");
		return err;
	}

	dsi->clk_lp = devm_clk_get(&pdev->dev, "lp");
	if (IS_ERR(dsi->clk_lp)) {
		dev_err(&pdev->dev, "cannot get low-power clock\n");
		return PTR_ERR(dsi->clk_lp);
	}

	err = clk_prepare_enable(dsi->clk_lp);
	if (err < 0) {
		dev_err(&pdev->dev, "cannot enable low-power clock\n");
		return err;
	}

	dsi->clk_parent = devm_clk_get(&pdev->dev, "parent");
	if (IS_ERR(dsi->clk_parent)) {
		dev_err(&pdev->dev, "cannot get parent clock\n");
		return PTR_ERR(dsi->clk_parent);
	}

	err = clk_prepare_enable(dsi->clk_parent);
	if (err < 0) {
		dev_err(&pdev->dev, "cannot enable parent clock\n");
		return err;
	}

	dsi->vdd = devm_regulator_get(&pdev->dev, "avdd-dsi-csi");
	if (IS_ERR(dsi->vdd)) {
		dev_err(&pdev->dev, "cannot get VDD supply\n");
		return PTR_ERR(dsi->vdd);
	}

	err = regulator_enable(dsi->vdd);
	if (err < 0) {
		dev_err(&pdev->dev, "cannot enable VDD supply\n");
		return err;
	}

	err = tegra_dsi_setup_clocks(dsi);
	if (err < 0) {
		dev_err(&pdev->dev, "cannot setup clocks\n");
		return err;
	}

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	dsi->regs = devm_ioremap_resource(&pdev->dev, regs);
	if (IS_ERR(dsi->regs))
		return PTR_ERR(dsi->regs);

	dsi->mipi = tegra_mipi_request(&pdev->dev);
	if (IS_ERR(dsi->mipi))
		return PTR_ERR(dsi->mipi);

	dsi->host.ops = &tegra_dsi_host_ops;
	dsi->host.dev = &pdev->dev;

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

	INIT_LIST_HEAD(&dsi->client.list);
	dsi->client.ops = &dsi_client_ops;
	dsi->client.dev = &pdev->dev;

	err = host1x_client_register(&dsi->client);
	if (err < 0) {
		dev_err(&pdev->dev, "failed to register host1x client: %d\n",
			err);
		return err;
	}

	platform_set_drvdata(pdev, dsi);

	return 0;
}

static int tegra_dsi_remove(struct platform_device *pdev)
{
	struct tegra_dsi *dsi = platform_get_drvdata(pdev);
	int err;

	err = host1x_client_unregister(&dsi->client);
	if (err < 0) {
		dev_err(&pdev->dev, "failed to unregister host1x client: %d\n",
			err);
		return err;
	}

	mipi_dsi_host_unregister(&dsi->host);
	tegra_mipi_free(dsi->mipi);

	regulator_disable(dsi->vdd);
	clk_disable_unprepare(dsi->clk_parent);
	clk_disable_unprepare(dsi->clk_lp);
	clk_disable_unprepare(dsi->clk);

	err = tegra_output_remove(&dsi->output);
	if (err < 0) {
		dev_err(&pdev->dev, "failed to remove output: %d\n", err);
		return err;
	}

	return 0;
}

static const struct of_device_id tegra_dsi_of_match[] = {
	{ .compatible = "nvidia,tegra114-dsi", },
	{ },
};

struct platform_driver tegra_dsi_driver = {
	.driver = {
		.name = "tegra-dsi",
		.of_match_table = tegra_dsi_of_match,
	},
	.probe = tegra_dsi_probe,
	.remove = tegra_dsi_remove,
};