tc358768.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  Copyright (C) 2020 Texas Instruments Incorporated - https://www.ti.com
 *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/media-bus-format.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/units.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <video/mipi_display.h>
#include <video/videomode.h>

/* Global (16-bit addressable) */
#define TC358768_CHIPID			0x0000
#define TC358768_SYSCTL			0x0002
#define TC358768_CONFCTL		0x0004
#define TC358768_VSDLY			0x0006
#define TC358768_DATAFMT		0x0008
#define TC358768_GPIOEN			0x000E
#define TC358768_GPIODIR		0x0010
#define TC358768_GPIOIN			0x0012
#define TC358768_GPIOOUT		0x0014
#define TC358768_PLLCTL0		0x0016
#define TC358768_PLLCTL1		0x0018
#define TC358768_CMDBYTE		0x0022
#define TC358768_PP_MISC		0x0032
#define TC358768_DSITX_DT		0x0050
#define TC358768_FIFOSTATUS		0x00F8

/* Debug (16-bit addressable) */
#define TC358768_VBUFCTRL		0x00E0
#define TC358768_DBG_WIDTH		0x00E2
#define TC358768_DBG_VBLANK		0x00E4
#define TC358768_DBG_DATA		0x00E8

/* TX PHY (32-bit addressable) */
#define TC358768_CLW_DPHYCONTTX		0x0100
#define TC358768_D0W_DPHYCONTTX		0x0104
#define TC358768_D1W_DPHYCONTTX		0x0108
#define TC358768_D2W_DPHYCONTTX		0x010C
#define TC358768_D3W_DPHYCONTTX		0x0110
#define TC358768_CLW_CNTRL		0x0140
#define TC358768_D0W_CNTRL		0x0144
#define TC358768_D1W_CNTRL		0x0148
#define TC358768_D2W_CNTRL		0x014C
#define TC358768_D3W_CNTRL		0x0150

/* TX PPI (32-bit addressable) */
#define TC358768_STARTCNTRL		0x0204
#define TC358768_DSITXSTATUS		0x0208
#define TC358768_LINEINITCNT		0x0210
#define TC358768_LPTXTIMECNT		0x0214
#define TC358768_TCLK_HEADERCNT		0x0218
#define TC358768_TCLK_TRAILCNT		0x021C
#define TC358768_THS_HEADERCNT		0x0220
#define TC358768_TWAKEUP		0x0224
#define TC358768_TCLK_POSTCNT		0x0228
#define TC358768_THS_TRAILCNT		0x022C
#define TC358768_HSTXVREGCNT		0x0230
#define TC358768_HSTXVREGEN		0x0234
#define TC358768_TXOPTIONCNTRL		0x0238
#define TC358768_BTACNTRL1		0x023C

/* TX CTRL (32-bit addressable) */
#define TC358768_DSI_CONTROL		0x040C
#define TC358768_DSI_STATUS		0x0410
#define TC358768_DSI_INT		0x0414
#define TC358768_DSI_INT_ENA		0x0418
#define TC358768_DSICMD_RDFIFO		0x0430
#define TC358768_DSI_ACKERR		0x0434
#define TC358768_DSI_ACKERR_INTENA	0x0438
#define TC358768_DSI_ACKERR_HALT	0x043c
#define TC358768_DSI_RXERR		0x0440
#define TC358768_DSI_RXERR_INTENA	0x0444
#define TC358768_DSI_RXERR_HALT		0x0448
#define TC358768_DSI_ERR		0x044C
#define TC358768_DSI_ERR_INTENA		0x0450
#define TC358768_DSI_ERR_HALT		0x0454
#define TC358768_DSI_CONFW		0x0500
#define TC358768_DSI_LPCMD		0x0500
#define TC358768_DSI_RESET		0x0504
#define TC358768_DSI_INT_CLR		0x050C
#define TC358768_DSI_START		0x0518

/* DSITX CTRL (16-bit addressable) */
#define TC358768_DSICMD_TX		0x0600
#define TC358768_DSICMD_TYPE		0x0602
#define TC358768_DSICMD_WC		0x0604
#define TC358768_DSICMD_WD0		0x0610
#define TC358768_DSICMD_WD1		0x0612
#define TC358768_DSICMD_WD2		0x0614
#define TC358768_DSICMD_WD3		0x0616
#define TC358768_DSI_EVENT		0x0620
#define TC358768_DSI_VSW		0x0622
#define TC358768_DSI_VBPR		0x0624
#define TC358768_DSI_VACT		0x0626
#define TC358768_DSI_HSW		0x0628
#define TC358768_DSI_HBPR		0x062A
#define TC358768_DSI_HACT		0x062C

/* TC358768_DSI_CONTROL (0x040C) register */
#define TC358768_DSI_CONTROL_DIS_MODE	BIT(15)
#define TC358768_DSI_CONTROL_TXMD	BIT(7)
#define TC358768_DSI_CONTROL_HSCKMD	BIT(5)
#define TC358768_DSI_CONTROL_EOTDIS	BIT(0)

/* TC358768_DSI_CONFW (0x0500) register */
#define TC358768_DSI_CONFW_MODE_SET	(5 << 29)
#define TC358768_DSI_CONFW_MODE_CLR	(6 << 29)
#define TC358768_DSI_CONFW_ADDR_DSI_CONTROL	(0x3 << 24)

static const char * const tc358768_supplies[] = {
	"vddc", "vddmipi", "vddio"
};

struct tc358768_dsi_output {
	struct mipi_dsi_device *dev;
	struct drm_panel *panel;
	struct drm_bridge *bridge;
};

struct tc358768_priv {
	struct device *dev;
	struct regmap *regmap;
	struct gpio_desc *reset_gpio;
	struct regulator_bulk_data supplies[ARRAY_SIZE(tc358768_supplies)];
	struct clk *refclk;
	int enabled;
	int error;

	struct mipi_dsi_host dsi_host;
	struct drm_bridge bridge;
	struct tc358768_dsi_output output;

	u32 pd_lines; /* number of Parallel Port Input Data Lines */
	u32 dsi_lanes; /* number of DSI Lanes */
	u32 dsi_bpp; /* number of Bits Per Pixel over DSI */

	/* Parameters for PLL programming */
	u32 fbd;	/* PLL feedback divider */
	u32 prd;	/* PLL input divider */
	u32 frs;	/* PLL Freqency range for HSCK (post divider) */

	u32 dsiclk;	/* pll_clk / 2 */
	u32 pclk;	/* incoming pclk rate */
};

static inline struct tc358768_priv *dsi_host_to_tc358768(struct mipi_dsi_host
							 *host)
{
	return container_of(host, struct tc358768_priv, dsi_host);
}

static inline struct tc358768_priv *bridge_to_tc358768(struct drm_bridge
						       *bridge)
{
	return container_of(bridge, struct tc358768_priv, bridge);
}

static int tc358768_clear_error(struct tc358768_priv *priv)
{
	int ret = priv->error;

	priv->error = 0;
	return ret;
}

static void tc358768_write(struct tc358768_priv *priv, u32 reg, u32 val)
{
	/* work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
	int tmpval = val;
	size_t count = 2;

	if (priv->error)
		return;

	/* 16-bit register? */
	if (reg < 0x100 || reg >= 0x600)
		count = 1;

	priv->error = regmap_bulk_write(priv->regmap, reg, &tmpval, count);
}

static void tc358768_read(struct tc358768_priv *priv, u32 reg, u32 *val)
{
	size_t count = 2;

	if (priv->error)
		return;

	/* 16-bit register? */
	if (reg < 0x100 || reg >= 0x600) {
		*val = 0;
		count = 1;
	}

	priv->error = regmap_bulk_read(priv->regmap, reg, val, count);
}

static void tc358768_update_bits(struct tc358768_priv *priv, u32 reg, u32 mask,
				 u32 val)
{
	u32 tmp, orig;

	tc358768_read(priv, reg, &orig);

	if (priv->error)
		return;

	tmp = orig & ~mask;
	tmp |= val & mask;
	if (tmp != orig)
		tc358768_write(priv, reg, tmp);
}

static int tc358768_sw_reset(struct tc358768_priv *priv)
{
	/* Assert Reset */
	tc358768_write(priv, TC358768_SYSCTL, 1);
	/* Release Reset, Exit Sleep */
	tc358768_write(priv, TC358768_SYSCTL, 0);

	return tc358768_clear_error(priv);
}

static void tc358768_hw_enable(struct tc358768_priv *priv)
{
	int ret;

	if (priv->enabled)
		return;

	ret = clk_prepare_enable(priv->refclk);
	if (ret < 0)
		dev_err(priv->dev, "error enabling refclk (%d)\n", ret);

	ret = regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
	if (ret < 0)
		dev_err(priv->dev, "error enabling regulators (%d)\n", ret);

	if (priv->reset_gpio)
		usleep_range(200, 300);

	/*
	 * The RESX is active low (GPIO_ACTIVE_LOW).
	 * DEASSERT (value = 0) the reset_gpio to enable the chip
	 */
	gpiod_set_value_cansleep(priv->reset_gpio, 0);

	/* wait for encoder clocks to stabilize */
	usleep_range(1000, 2000);

	priv->enabled = true;
}

static void tc358768_hw_disable(struct tc358768_priv *priv)
{
	int ret;

	if (!priv->enabled)
		return;

	/*
	 * The RESX is active low (GPIO_ACTIVE_LOW).
	 * ASSERT (value = 1) the reset_gpio to disable the chip
	 */
	gpiod_set_value_cansleep(priv->reset_gpio, 1);

	ret = regulator_bulk_disable(ARRAY_SIZE(priv->supplies),
				     priv->supplies);
	if (ret < 0)
		dev_err(priv->dev, "error disabling regulators (%d)\n", ret);

	clk_disable_unprepare(priv->refclk);

	priv->enabled = false;
}

static u32 tc358768_pll_to_pclk(struct tc358768_priv *priv, u32 pll_clk)
{
	return (u32)div_u64((u64)pll_clk * priv->dsi_lanes, priv->dsi_bpp);
}

static u32 tc358768_pclk_to_pll(struct tc358768_priv *priv, u32 pclk)
{
	return (u32)div_u64((u64)pclk * priv->dsi_bpp, priv->dsi_lanes);
}

static int tc358768_calc_pll(struct tc358768_priv *priv,
			     const struct drm_display_mode *mode,
			     bool verify_only)
{
	static const u32 frs_limits[] = {
		1000000000,
		500000000,
		250000000,
		125000000,
		62500000
	};
	unsigned long refclk;
	u32 prd, target_pll, i, max_pll, min_pll;
	u32 frs, best_diff, best_pll, best_prd, best_fbd;

	target_pll = tc358768_pclk_to_pll(priv, mode->clock * 1000);

	/* pll_clk = RefClk * FBD / PRD * (1 / (2^FRS)) */

	for (i = 0; i < ARRAY_SIZE(frs_limits); i++)
		if (target_pll >= frs_limits[i])
			break;

	if (i == ARRAY_SIZE(frs_limits) || i == 0)
		return -EINVAL;

	frs = i - 1;
	max_pll = frs_limits[i - 1];
	min_pll = frs_limits[i];

	refclk = clk_get_rate(priv->refclk);

	best_diff = UINT_MAX;
	best_pll = 0;
	best_prd = 0;
	best_fbd = 0;

	for (prd = 1; prd <= 16; ++prd) {
		u32 divisor = prd * (1 << frs);
		u32 fbd;

		for (fbd = 1; fbd <= 512; ++fbd) {
			u32 pll, diff, pll_in;

			pll = (u32)div_u64((u64)refclk * fbd, divisor);

			if (pll >= max_pll || pll < min_pll)
				continue;

			pll_in = (u32)div_u64((u64)refclk, prd);
			if (pll_in < 4000000)
				continue;

			diff = max(pll, target_pll) - min(pll, target_pll);

			if (diff < best_diff) {
				best_diff = diff;
				best_pll = pll;
				best_prd = prd;
				best_fbd = fbd;

				if (best_diff == 0)
					goto found;
			}
		}
	}

	if (best_diff == UINT_MAX) {
		dev_err(priv->dev, "could not find suitable PLL setup\n");
		return -EINVAL;
	}

found:
	if (verify_only)
		return 0;

	priv->fbd = best_fbd;
	priv->prd = best_prd;
	priv->frs = frs;
	priv->dsiclk = best_pll / 2;
	priv->pclk = mode->clock * 1000;

	return 0;
}

static int tc358768_dsi_host_attach(struct mipi_dsi_host *host,
				    struct mipi_dsi_device *dev)
{
	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
	struct drm_bridge *bridge;
	struct drm_panel *panel;
	struct device_node *ep;
	int ret;

	if (dev->lanes > 4) {
		dev_err(priv->dev, "unsupported number of data lanes(%u)\n",
			dev->lanes);
		return -EINVAL;
	}

	/*
	 * tc358768 supports both Video and Pulse mode, but the driver only
	 * implements Video (event) mode currently
	 */
	if (!(dev->mode_flags & MIPI_DSI_MODE_VIDEO)) {
		dev_err(priv->dev, "Only MIPI_DSI_MODE_VIDEO is supported\n");
		return -ENOTSUPP;
	}

	/*
	 * tc358768 supports RGB888, RGB666, RGB666_PACKED and RGB565, but only
	 * RGB888 is verified.
	 */
	if (dev->format != MIPI_DSI_FMT_RGB888) {
		dev_warn(priv->dev, "Only MIPI_DSI_FMT_RGB888 tested!\n");
		return -ENOTSUPP;
	}

	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0, &panel,
					  &bridge);
	if (ret)
		return ret;

	if (panel) {
		bridge = drm_panel_bridge_add_typed(panel,
						    DRM_MODE_CONNECTOR_DSI);
		if (IS_ERR(bridge))
			return PTR_ERR(bridge);
	}

	priv->output.dev = dev;
	priv->output.bridge = bridge;
	priv->output.panel = panel;

	priv->dsi_lanes = dev->lanes;
	priv->dsi_bpp = mipi_dsi_pixel_format_to_bpp(dev->format);

	/* get input ep (port0/endpoint0) */
	ret = -EINVAL;
	ep = of_graph_get_endpoint_by_regs(host->dev->of_node, 0, 0);
	if (ep) {
		ret = of_property_read_u32(ep, "data-lines", &priv->pd_lines);

		of_node_put(ep);
	}

	if (ret)
		priv->pd_lines = priv->dsi_bpp;

	drm_bridge_add(&priv->bridge);

	return 0;
}

static int tc358768_dsi_host_detach(struct mipi_dsi_host *host,
				    struct mipi_dsi_device *dev)
{
	struct tc358768_priv *priv = dsi_host_to_tc358768(host);

	drm_bridge_remove(&priv->bridge);
	if (priv->output.panel)
		drm_panel_bridge_remove(priv->output.bridge);

	return 0;
}

static ssize_t tc358768_dsi_host_transfer(struct mipi_dsi_host *host,
					  const struct mipi_dsi_msg *msg)
{
	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
	struct mipi_dsi_packet packet;
	int ret;

	if (!priv->enabled) {
		dev_err(priv->dev, "Bridge is not enabled\n");
		return -ENODEV;
	}

	if (msg->rx_len) {
		dev_warn(priv->dev, "MIPI rx is not supported\n");
		return -ENOTSUPP;
	}

	if (msg->tx_len > 8) {
		dev_warn(priv->dev, "Maximum 8 byte MIPI tx is supported\n");
		return -ENOTSUPP;
	}

	ret = mipi_dsi_create_packet(&packet, msg);
	if (ret)
		return ret;

	if (mipi_dsi_packet_format_is_short(msg->type)) {
		tc358768_write(priv, TC358768_DSICMD_TYPE,
			       (0x10 << 8) | (packet.header[0] & 0x3f));
		tc358768_write(priv, TC358768_DSICMD_WC, 0);
		tc358768_write(priv, TC358768_DSICMD_WD0,
			       (packet.header[2] << 8) | packet.header[1]);
	} else {
		int i;

		tc358768_write(priv, TC358768_DSICMD_TYPE,
			       (0x40 << 8) | (packet.header[0] & 0x3f));
		tc358768_write(priv, TC358768_DSICMD_WC, packet.payload_length);
		for (i = 0; i < packet.payload_length; i += 2) {
			u16 val = packet.payload[i];

			if (i + 1 < packet.payload_length)
				val |= packet.payload[i + 1] << 8;

			tc358768_write(priv, TC358768_DSICMD_WD0 + i, val);
		}
	}

	/* start transfer */
	tc358768_write(priv, TC358768_DSICMD_TX, 1);

	ret = tc358768_clear_error(priv);
	if (ret)
		dev_warn(priv->dev, "Software disable failed: %d\n", ret);
	else
		ret = packet.size;

	return ret;
}

static const struct mipi_dsi_host_ops tc358768_dsi_host_ops = {
	.attach = tc358768_dsi_host_attach,
	.detach = tc358768_dsi_host_detach,
	.transfer = tc358768_dsi_host_transfer,
};

static int tc358768_bridge_attach(struct drm_bridge *bridge,
				  enum drm_bridge_attach_flags flags)
{
	struct tc358768_priv *priv = bridge_to_tc358768(bridge);

	if (!drm_core_check_feature(bridge->dev, DRIVER_ATOMIC)) {
		dev_err(priv->dev, "needs atomic updates support\n");
		return -ENOTSUPP;
	}

	return drm_bridge_attach(bridge->encoder, priv->output.bridge, bridge,
				 flags);
}

static enum drm_mode_status
tc358768_bridge_mode_valid(struct drm_bridge *bridge,
			   const struct drm_display_info *info,
			   const struct drm_display_mode *mode)
{
	struct tc358768_priv *priv = bridge_to_tc358768(bridge);

	if (tc358768_calc_pll(priv, mode, true))
		return MODE_CLOCK_RANGE;

	return MODE_OK;
}

static void tc358768_bridge_disable(struct drm_bridge *bridge)
{
	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
	int ret;

	/* set FrmStop */
	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(15), BIT(15));

	/* wait at least for one frame */
	msleep(50);

	/* clear PP_en */
	tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), 0);

	/* set RstPtr */
	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(14), BIT(14));

	ret = tc358768_clear_error(priv);
	if (ret)
		dev_warn(priv->dev, "Software disable failed: %d\n", ret);
}

static void tc358768_bridge_post_disable(struct drm_bridge *bridge)
{
	struct tc358768_priv *priv = bridge_to_tc358768(bridge);

	tc358768_hw_disable(priv);
}

static int tc358768_setup_pll(struct tc358768_priv *priv,
			      const struct drm_display_mode *mode)
{
	u32 fbd, prd, frs;
	int ret;

	ret = tc358768_calc_pll(priv, mode, false);
	if (ret) {
		dev_err(priv->dev, "PLL calculation failed: %d\n", ret);
		return ret;
	}

	fbd = priv->fbd;
	prd = priv->prd;
	frs = priv->frs;

	dev_dbg(priv->dev, "PLL: refclk %lu, fbd %u, prd %u, frs %u\n",
		clk_get_rate(priv->refclk), fbd, prd, frs);
	dev_dbg(priv->dev, "PLL: pll_clk: %u, DSIClk %u, HSByteClk %u\n",
		priv->dsiclk * 2, priv->dsiclk, priv->dsiclk / 4);
	dev_dbg(priv->dev, "PLL: pclk %u (panel: %u)\n",
		tc358768_pll_to_pclk(priv, priv->dsiclk * 2),
		mode->clock * 1000);

	/* PRD[15:12] FBD[8:0] */
	tc358768_write(priv, TC358768_PLLCTL0, ((prd - 1) << 12) | (fbd - 1));

	/* FRS[11:10] LBWS[9:8] CKEN[4] RESETB[1] EN[0] */
	tc358768_write(priv, TC358768_PLLCTL1,
		       (frs << 10) | (0x2 << 8) | BIT(1) | BIT(0));

	/* wait for lock */
	usleep_range(1000, 2000);

	/* FRS[11:10] LBWS[9:8] CKEN[4] PLL_CKEN[4] RESETB[1] EN[0] */
	tc358768_write(priv, TC358768_PLLCTL1,
		       (frs << 10) | (0x2 << 8) | BIT(4) | BIT(1) | BIT(0));

	return tc358768_clear_error(priv);
}

static u32 tc358768_ns_to_cnt(u32 ns, u32 period_ps)
{
	return DIV_ROUND_UP(ns * 1000, period_ps);
}

static u32 tc358768_ps_to_ns(u32 ps)
{
	return ps / 1000;
}

static u32 tc358768_dpi_to_ns(u32 val, u32 pclk)
{
	return (u32)div_u64((u64)val * NANO, pclk);
}

/* Convert value in DPI pixel clock units to DSI byte count */
static u32 tc358768_dpi_to_dsi_bytes(struct tc358768_priv *priv, u32 val)
{
	u64 m = (u64)val * priv->dsiclk / 4 * priv->dsi_lanes;
	u64 n = priv->pclk;

	return (u32)div_u64(m + n - 1, n);
}

static u32 tc358768_dsi_bytes_to_ns(struct tc358768_priv *priv, u32 val)
{
	u64 m = (u64)val * NANO;
	u64 n = priv->dsiclk / 4 * priv->dsi_lanes;

	return (u32)div_u64(m, n);
}

static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
{
	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
	struct mipi_dsi_device *dsi_dev = priv->output.dev;
	unsigned long mode_flags = dsi_dev->mode_flags;
	u32 val, val2, lptxcnt, hact, data_type;
	s32 raw_val;
	const struct drm_display_mode *mode;
	u32 hsbyteclk_ps, dsiclk_ps, ui_ps;
	u32 dsiclk, hsbyteclk;
	int ret, i;
	struct videomode vm;
	struct device *dev = priv->dev;
	/* In pixelclock units */
	u32 dpi_htot, dpi_data_start;
	/* In byte units */
	u32 dsi_dpi_htot, dsi_dpi_data_start;
	u32 dsi_hsw, dsi_hbp, dsi_hact, dsi_hfp;
	const u32 dsi_hss = 4; /* HSS is a short packet (4 bytes) */
	/* In hsbyteclk units */
	u32 dsi_vsdly;
	const u32 internal_dly = 40;

	if (mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
		dev_warn_once(dev, "Non-continuous mode unimplemented, falling back to continuous\n");
		mode_flags &= ~MIPI_DSI_CLOCK_NON_CONTINUOUS;
	}

	tc358768_hw_enable(priv);

	ret = tc358768_sw_reset(priv);
	if (ret) {
		dev_err(dev, "Software reset failed: %d\n", ret);
		tc358768_hw_disable(priv);
		return;
	}

	mode = &bridge->encoder->crtc->state->adjusted_mode;
	ret = tc358768_setup_pll(priv, mode);
	if (ret) {
		dev_err(dev, "PLL setup failed: %d\n", ret);
		tc358768_hw_disable(priv);
		return;
	}

	drm_display_mode_to_videomode(mode, &vm);

	dsiclk = priv->dsiclk;
	hsbyteclk = dsiclk / 4;

	/* Data Format Control Register */
	val = BIT(2) | BIT(1) | BIT(0); /* rdswap_en | dsitx_en | txdt_en */
	switch (dsi_dev->format) {
	case MIPI_DSI_FMT_RGB888:
		val |= (0x3 << 4);
		hact = vm.hactive * 3;
		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_24;
		break;
	case MIPI_DSI_FMT_RGB666:
		val |= (0x4 << 4);
		hact = vm.hactive * 3;
		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_18;
		break;

	case MIPI_DSI_FMT_RGB666_PACKED:
		val |= (0x4 << 4) | BIT(3);
		hact = vm.hactive * 18 / 8;
		data_type = MIPI_DSI_PIXEL_STREAM_3BYTE_18;
		break;

	case MIPI_DSI_FMT_RGB565:
		val |= (0x5 << 4);
		hact = vm.hactive * 2;
		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_16;
		break;
	default:
		dev_err(dev, "Invalid data format (%u)\n",
			dsi_dev->format);
		tc358768_hw_disable(priv);
		return;
	}

	/*
	 * There are three important things to make TC358768 work correctly,
	 * which are not trivial to manage:
	 *
	 * 1. Keep the DPI line-time and the DSI line-time as close to each
	 *    other as possible.
	 * 2. TC358768 goes to LP mode after each line's active area. The DSI
	 *    HFP period has to be long enough for entering and exiting LP mode.
	 *    But it is not clear how to calculate this.
	 * 3. VSDly (video start delay) has to be long enough to ensure that the
	 *    DSI TX does not start transmitting until we have started receiving
	 *    pixel data from the DPI input. It is not clear how to calculate
	 *    this either.
	 */

	dpi_htot = vm.hactive + vm.hfront_porch + vm.hsync_len + vm.hback_porch;
	dpi_data_start = vm.hsync_len + vm.hback_porch;

	dev_dbg(dev, "dpi horiz timing (pclk): %u + %u + %u + %u = %u\n",
		vm.hsync_len, vm.hback_porch, vm.hactive, vm.hfront_porch,
		dpi_htot);

	dev_dbg(dev, "dpi horiz timing (ns): %u + %u + %u + %u = %u\n",
		tc358768_dpi_to_ns(vm.hsync_len, vm.pixelclock),
		tc358768_dpi_to_ns(vm.hback_porch, vm.pixelclock),
		tc358768_dpi_to_ns(vm.hactive, vm.pixelclock),
		tc358768_dpi_to_ns(vm.hfront_porch, vm.pixelclock),
		tc358768_dpi_to_ns(dpi_htot, vm.pixelclock));

	dev_dbg(dev, "dpi data start (ns): %u + %u = %u\n",
		tc358768_dpi_to_ns(vm.hsync_len, vm.pixelclock),
		tc358768_dpi_to_ns(vm.hback_porch, vm.pixelclock),
		tc358768_dpi_to_ns(dpi_data_start, vm.pixelclock));

	dsi_dpi_htot = tc358768_dpi_to_dsi_bytes(priv, dpi_htot);
	dsi_dpi_data_start = tc358768_dpi_to_dsi_bytes(priv, dpi_data_start);

	if (dsi_dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
		dsi_hsw = tc358768_dpi_to_dsi_bytes(priv, vm.hsync_len);
		dsi_hbp = tc358768_dpi_to_dsi_bytes(priv, vm.hback_porch);
	} else {
		/* HBP is included in HSW in event mode */
		dsi_hbp = 0;
		dsi_hsw = tc358768_dpi_to_dsi_bytes(priv,
						    vm.hsync_len +
						    vm.hback_porch);

		/*
		 * The pixel packet includes the actual pixel data, and:
		 * DSI packet header = 4 bytes
		 * DCS code = 1 byte
		 * DSI packet footer = 2 bytes
		 */
		dsi_hact = hact + 4 + 1 + 2;

		dsi_hfp = dsi_dpi_htot - dsi_hact - dsi_hsw - dsi_hss;

		/*
		 * Here we should check if HFP is long enough for entering LP
		 * and exiting LP, but it's not clear how to calculate that.
		 * Instead, this is a naive algorithm that just adjusts the HFP
		 * and HSW so that HFP is (at least) roughly 2/3 of the total
		 * blanking time.
		 */
		if (dsi_hfp < (dsi_hfp + dsi_hsw + dsi_hss) * 2 / 3) {
			u32 old_hfp = dsi_hfp;
			u32 old_hsw = dsi_hsw;
			u32 tot = dsi_hfp + dsi_hsw + dsi_hss;

			dsi_hsw = tot / 3;

			/*
			 * Seems like sometimes HSW has to be divisible by num-lanes, but
			 * not always...
			 */
			dsi_hsw = roundup(dsi_hsw, priv->dsi_lanes);

			dsi_hfp = dsi_dpi_htot - dsi_hact - dsi_hsw - dsi_hss;

			dev_dbg(dev,
				"hfp too short, adjusting dsi hfp and dsi hsw from %u, %u to %u, %u\n",
				old_hfp, old_hsw, dsi_hfp, dsi_hsw);
		}

		dev_dbg(dev,
			"dsi horiz timing (bytes): %u, %u + %u + %u + %u = %u\n",
			dsi_hss, dsi_hsw, dsi_hbp, dsi_hact, dsi_hfp,
			dsi_hss + dsi_hsw + dsi_hbp + dsi_hact + dsi_hfp);

		dev_dbg(dev, "dsi horiz timing (ns): %u + %u + %u + %u + %u = %u\n",
			tc358768_dsi_bytes_to_ns(priv, dsi_hss),
			tc358768_dsi_bytes_to_ns(priv, dsi_hsw),
			tc358768_dsi_bytes_to_ns(priv, dsi_hbp),
			tc358768_dsi_bytes_to_ns(priv, dsi_hact),
			tc358768_dsi_bytes_to_ns(priv, dsi_hfp),
			tc358768_dsi_bytes_to_ns(priv, dsi_hss + dsi_hsw +
						 dsi_hbp + dsi_hact + dsi_hfp));
	}

	/* VSDly calculation */

	/* Start with the HW internal delay */
	dsi_vsdly = internal_dly;

	/* Convert to byte units as the other variables are in byte units */
	dsi_vsdly *= priv->dsi_lanes;

	/* Do we need more delay, in addition to the internal? */
	if (dsi_dpi_data_start > dsi_vsdly + dsi_hss + dsi_hsw + dsi_hbp) {
		dsi_vsdly = dsi_dpi_data_start - dsi_hss - dsi_hsw - dsi_hbp;
		dsi_vsdly = roundup(dsi_vsdly, priv->dsi_lanes);
	}

	dev_dbg(dev, "dsi data start (bytes) %u + %u + %u + %u = %u\n",
		dsi_vsdly, dsi_hss, dsi_hsw, dsi_hbp,
		dsi_vsdly + dsi_hss + dsi_hsw + dsi_hbp);

	dev_dbg(dev, "dsi data start (ns) %u + %u + %u + %u = %u\n",
		tc358768_dsi_bytes_to_ns(priv, dsi_vsdly),
		tc358768_dsi_bytes_to_ns(priv, dsi_hss),
		tc358768_dsi_bytes_to_ns(priv, dsi_hsw),
		tc358768_dsi_bytes_to_ns(priv, dsi_hbp),
		tc358768_dsi_bytes_to_ns(priv, dsi_vsdly + dsi_hss + dsi_hsw + dsi_hbp));

	/* Convert back to hsbyteclk */
	dsi_vsdly /= priv->dsi_lanes;

	/*
	 * The docs say that there is an internal delay of 40 cycles.
	 * However, we get underflows if we follow that rule. If we
	 * instead ignore the internal delay, things work. So either
	 * the docs are wrong or the calculations are wrong.
	 *
	 * As a temporary fix, add the internal delay here, to counter
	 * the subtraction when writing the register.
	 */
	dsi_vsdly += internal_dly;

	/* Clamp to the register max */
	if (dsi_vsdly - internal_dly > 0x3ff) {
		dev_warn(dev, "VSDly too high, underflows likely\n");
		dsi_vsdly = 0x3ff + internal_dly;
	}

	/* VSDly[9:0] */
	tc358768_write(priv, TC358768_VSDLY, dsi_vsdly - internal_dly);

	tc358768_write(priv, TC358768_DATAFMT, val);
	tc358768_write(priv, TC358768_DSITX_DT, data_type);

	/* Enable D-PHY (HiZ->LP11) */
	tc358768_write(priv, TC358768_CLW_CNTRL, 0x0000);
	/* Enable lanes */
	for (i = 0; i < dsi_dev->lanes; i++)
		tc358768_write(priv, TC358768_D0W_CNTRL + i * 4, 0x0000);

	/* DSI Timings */
	hsbyteclk_ps = (u32)div_u64(PICO, hsbyteclk);
	dsiclk_ps = (u32)div_u64(PICO, dsiclk);
	ui_ps = dsiclk_ps / 2;
	dev_dbg(dev, "dsiclk: %u ps, ui %u ps, hsbyteclk %u ps\n", dsiclk_ps,
		ui_ps, hsbyteclk_ps);

	/* LP11 > 100us for D-PHY Rx Init */
	val = tc358768_ns_to_cnt(100 * 1000, hsbyteclk_ps) - 1;
	dev_dbg(dev, "LINEINITCNT: %u\n", val);
	tc358768_write(priv, TC358768_LINEINITCNT, val);

	/* LPTimeCnt > 50ns */
	val = tc358768_ns_to_cnt(50, hsbyteclk_ps) - 1;
	lptxcnt = val;
	dev_dbg(dev, "LPTXTIMECNT: %u\n", val);
	tc358768_write(priv, TC358768_LPTXTIMECNT, val);

	/* 38ns < TCLK_PREPARE < 95ns */
	val = tc358768_ns_to_cnt(65, hsbyteclk_ps) - 1;
	dev_dbg(dev, "TCLK_PREPARECNT %u\n", val);
	/* TCLK_PREPARE + TCLK_ZERO > 300ns */
	val2 = tc358768_ns_to_cnt(300 - tc358768_ps_to_ns(2 * ui_ps),
				  hsbyteclk_ps) - 2;
	dev_dbg(dev, "TCLK_ZEROCNT %u\n", val2);
	val |= val2 << 8;
	tc358768_write(priv, TC358768_TCLK_HEADERCNT, val);

	/* TCLK_TRAIL > 60ns AND TEOT <= 105 ns + 12*UI */
	raw_val = tc358768_ns_to_cnt(60 + tc358768_ps_to_ns(2 * ui_ps), hsbyteclk_ps) - 5;
	val = clamp(raw_val, 0, 127);
	dev_dbg(dev, "TCLK_TRAILCNT: %u\n", val);
	tc358768_write(priv, TC358768_TCLK_TRAILCNT, val);

	/* 40ns + 4*UI < THS_PREPARE < 85ns + 6*UI */
	val = 50 + tc358768_ps_to_ns(4 * ui_ps);
	val = tc358768_ns_to_cnt(val, hsbyteclk_ps) - 1;
	dev_dbg(dev, "THS_PREPARECNT %u\n", val);
	/* THS_PREPARE + THS_ZERO > 145ns + 10*UI */
	raw_val = tc358768_ns_to_cnt(145 - tc358768_ps_to_ns(3 * ui_ps), hsbyteclk_ps) - 10;
	val2 = clamp(raw_val, 0, 127);
	dev_dbg(dev, "THS_ZEROCNT %u\n", val2);
	val |= val2 << 8;
	tc358768_write(priv, TC358768_THS_HEADERCNT, val);

	/* TWAKEUP > 1ms in lptxcnt steps */
	val = tc358768_ns_to_cnt(1020000, hsbyteclk_ps);
	val = val / (lptxcnt + 1) - 1;
	dev_dbg(dev, "TWAKEUP: %u\n", val);
	tc358768_write(priv, TC358768_TWAKEUP, val);

	/* TCLK_POSTCNT > 60ns + 52*UI */
	val = tc358768_ns_to_cnt(60 + tc358768_ps_to_ns(52 * ui_ps),
				 hsbyteclk_ps) - 3;
	dev_dbg(dev, "TCLK_POSTCNT: %u\n", val);
	tc358768_write(priv, TC358768_TCLK_POSTCNT, val);

	/* max(60ns + 4*UI, 8*UI) < THS_TRAILCNT < 105ns + 12*UI */
	raw_val = tc358768_ns_to_cnt(60 + tc358768_ps_to_ns(18 * ui_ps),
				     hsbyteclk_ps) - 4;
	val = clamp(raw_val, 0, 15);
	dev_dbg(dev, "THS_TRAILCNT: %u\n", val);
	tc358768_write(priv, TC358768_THS_TRAILCNT, val);

	val = BIT(0);
	for (i = 0; i < dsi_dev->lanes; i++)
		val |= BIT(i + 1);
	tc358768_write(priv, TC358768_HSTXVREGEN, val);

	tc358768_write(priv, TC358768_TXOPTIONCNTRL,
		       (mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) ? 0 : BIT(0));

	/* TXTAGOCNT[26:16] RXTASURECNT[10:0] */
	val = tc358768_ps_to_ns((lptxcnt + 1) * hsbyteclk_ps * 4);
	val = tc358768_ns_to_cnt(val, hsbyteclk_ps) / 4 - 1;
	dev_dbg(dev, "TXTAGOCNT: %u\n", val);
	val2 = tc358768_ns_to_cnt(tc358768_ps_to_ns((lptxcnt + 1) * hsbyteclk_ps),
				  hsbyteclk_ps) - 2;
	dev_dbg(dev, "RXTASURECNT: %u\n", val2);
	val = val << 16 | val2;
	tc358768_write(priv, TC358768_BTACNTRL1, val);

	/* START[0] */
	tc358768_write(priv, TC358768_STARTCNTRL, 1);

	if (dsi_dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
		/* Set pulse mode */
		tc358768_write(priv, TC358768_DSI_EVENT, 0);

		/* vact */
		tc358768_write(priv, TC358768_DSI_VACT, vm.vactive);

		/* vsw */
		tc358768_write(priv, TC358768_DSI_VSW, vm.vsync_len);

		/* vbp */
		tc358768_write(priv, TC358768_DSI_VBPR, vm.vback_porch);