drivers/video/stm32/stm32_dsi.c - platform/external/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2019 STMicroelectronics - All Rights Reserved
  * Author(s): Philippe Cornu <philippe.cornu@st.com> for STMicroelectronics.
  *	      Yannick Fertre <yannick.fertre@st.com> for STMicroelectronics.
  *
  * This MIPI DSI controller driver is based on the Linux Kernel driver from
  * drivers/gpu/drm/stm/dw_mipi_dsi-stm.c.
  */

 #include <common.h>
 #include <clk.h>
 #include <dm.h>
 #include <dsi_host.h>
 #include <mipi_dsi.h>
 #include <panel.h>
 #include <reset.h>
 #include <video.h>
 #include <video_bridge.h>
 #include <asm/io.h>
 #include <asm/arch/gpio.h>
 #include <dm/device-internal.h>
 #include <dm/device_compat.h>
 #include <dm/lists.h>
 #include <linux/iopoll.h>
 #include <power/regulator.h>

 #define HWVER_130			0x31333000	/* IP version 1.30 */
 #define HWVER_131			0x31333100	/* IP version 1.31 */

 /* DSI digital registers & bit definitions */
 #define DSI_VERSION			0x00
 #define VERSION				GENMASK(31, 8)

 /*
  * DSI wrapper registers & bit definitions
  * Note: registers are named as in the Reference Manual
  */
 #define DSI_WCFGR	0x0400		/* Wrapper ConFiGuration Reg */
 #define WCFGR_DSIM	BIT(0)		/* DSI Mode */
 #define WCFGR_COLMUX	GENMASK(3, 1)	/* COLor MUltipleXing */

 #define DSI_WCR		0x0404		/* Wrapper Control Reg */
 #define WCR_DSIEN	BIT(3)		/* DSI ENable */

 #define DSI_WISR	0x040C		/* Wrapper Interrupt and Status Reg */
 #define WISR_PLLLS	BIT(8)		/* PLL Lock Status */
 #define WISR_RRS	BIT(12)		/* Regulator Ready Status */

 #define DSI_WPCR0	0x0418		/* Wrapper Phy Conf Reg 0 */
 #define WPCR0_UIX4	GENMASK(5, 0)	/* Unit Interval X 4 */
 #define WPCR0_TDDL	BIT(16)		/* Turn Disable Data Lanes */

 #define DSI_WRPCR	0x0430		/* Wrapper Regulator & Pll Ctrl Reg */
 #define WRPCR_PLLEN	BIT(0)		/* PLL ENable */
 #define WRPCR_NDIV	GENMASK(8, 2)	/* pll loop DIVision Factor */
 #define WRPCR_IDF	GENMASK(14, 11)	/* pll Input Division Factor */
 #define WRPCR_ODF	GENMASK(17, 16)	/* pll Output Division Factor */
 #define WRPCR_REGEN	BIT(24)		/* REGulator ENable */
 #define WRPCR_BGREN	BIT(28)		/* BandGap Reference ENable */
 #define IDF_MIN		1
 #define IDF_MAX		7
 #define NDIV_MIN	10
 #define NDIV_MAX	125
 #define ODF_MIN		1
 #define ODF_MAX		8

 /* dsi color format coding according to the datasheet */
 enum dsi_color {
 	DSI_RGB565_CONF1,
 	DSI_RGB565_CONF2,
 	DSI_RGB565_CONF3,
 	DSI_RGB666_CONF1,
 	DSI_RGB666_CONF2,
 	DSI_RGB888,
 };

 #define LANE_MIN_KBPS	31250
 #define LANE_MAX_KBPS	500000

 /* Timeout for regulator on/off, pll lock/unlock & fifo empty */
 #define TIMEOUT_US	200000

 struct stm32_dsi_priv {
 	struct mipi_dsi_device device;
 	void __iomem *base;
 	struct udevice *panel;
 	u32 pllref_clk;
 	u32 hw_version;
 	int lane_min_kbps;
 	int lane_max_kbps;
 	struct udevice *vdd_reg;
 	struct udevice *dsi_host;
 };

 static inline void dsi_write(struct stm32_dsi_priv *dsi, u32 reg, u32 val)
 {
 	writel(val, dsi->base + reg);
 }

 static inline u32 dsi_read(struct stm32_dsi_priv *dsi, u32 reg)
 {
 	return readl(dsi->base + reg);
 }

 static inline void dsi_set(struct stm32_dsi_priv *dsi, u32 reg, u32 mask)
 {
 	dsi_write(dsi, reg, dsi_read(dsi, reg) | mask);
 }

 static inline void dsi_clear(struct stm32_dsi_priv *dsi, u32 reg, u32 mask)
 {
 	dsi_write(dsi, reg, dsi_read(dsi, reg) & ~mask);
 }

 static inline void dsi_update_bits(struct stm32_dsi_priv *dsi, u32 reg,
 				   u32 mask, u32 val)
 {
 	dsi_write(dsi, reg, (dsi_read(dsi, reg) & ~mask) | val);
 }

 static enum dsi_color dsi_color_from_mipi(u32 fmt)
 {
 	switch (fmt) {
 	case MIPI_DSI_FMT_RGB888:
 		return DSI_RGB888;
 	case MIPI_DSI_FMT_RGB666:
 		return DSI_RGB666_CONF2;
 	case MIPI_DSI_FMT_RGB666_PACKED:
 		return DSI_RGB666_CONF1;
 	case MIPI_DSI_FMT_RGB565:
 		return DSI_RGB565_CONF1;
 	default:
 		pr_err("MIPI color invalid, so we use rgb888\n");
 	}
 	return DSI_RGB888;
 }

 static int dsi_pll_get_clkout_khz(int clkin_khz, int idf, int ndiv, int odf)
 {
 	int divisor = idf * odf;

 	/* prevent from division by 0 */
 	if (!divisor)
 		return 0;

 	return DIV_ROUND_CLOSEST(clkin_khz * ndiv, divisor);
 }

 static int dsi_pll_get_params(struct stm32_dsi_priv *dsi,
 			      int clkin_khz, int clkout_khz,
 			      int *idf, int *ndiv, int *odf)
 {
 	int i, o, n, n_min, n_max;
 	int fvco_min, fvco_max, delta, best_delta; /* all in khz */

 	/* Early checks preventing division by 0 & odd results */
 	if (clkin_khz <= 0 || clkout_khz <= 0)
 		return -EINVAL;

 	fvco_min = dsi->lane_min_kbps * 2 * ODF_MAX;
 	fvco_max = dsi->lane_max_kbps * 2 * ODF_MIN;

 	best_delta = 1000000; /* big started value (1000000khz) */

 	for (i = IDF_MIN; i <= IDF_MAX; i++) {
 		/* Compute ndiv range according to Fvco */
 		n_min = ((fvco_min * i) / (2 * clkin_khz)) + 1;
 		n_max = (fvco_max * i) / (2 * clkin_khz);

 		/* No need to continue idf loop if we reach ndiv max */
 		if (n_min >= NDIV_MAX)
 			break;

 		/* Clamp ndiv to valid values */
 		if (n_min < NDIV_MIN)
 			n_min = NDIV_MIN;
 		if (n_max > NDIV_MAX)
 			n_max = NDIV_MAX;

 		for (o = ODF_MIN; o <= ODF_MAX; o *= 2) {
 			n = DIV_ROUND_CLOSEST(i * o * clkout_khz, clkin_khz);
 			/* Check ndiv according to vco range */
 			if (n < n_min || n > n_max)
 				continue;
 			/* Check if new delta is better & saves parameters */
 			delta = dsi_pll_get_clkout_khz(clkin_khz, i, n, o) -
 				clkout_khz;
 			if (delta < 0)
 				delta = -delta;
 			if (delta < best_delta) {
 				*idf = i;
 				*ndiv = n;
 				*odf = o;
 				best_delta = delta;
 			}
 			/* fast return in case of "perfect result" */
 			if (!delta)
 				return 0;
 		}
 	}

 	return 0;
 }

 static int dsi_phy_init(void *priv_data)
 {
 	struct mipi_dsi_device *device = priv_data;
 	struct udevice *dev = device->dev;
 	struct stm32_dsi_priv *dsi = dev_get_priv(dev);
 	u32 val;
 	int ret;

 	debug("Initialize DSI physical layer\n");

 	/* Enable the regulator */
 	dsi_set(dsi, DSI_WRPCR, WRPCR_REGEN | WRPCR_BGREN);
 	ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_RRS,
 				 TIMEOUT_US);
 	if (ret) {
 		debug("!TIMEOUT! waiting REGU\n");
 		return ret;
 	}

 	/* Enable the DSI PLL & wait for its lock */
 	dsi_set(dsi, DSI_WRPCR, WRPCR_PLLEN);
 	ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_PLLLS,
 				 TIMEOUT_US);
 	if (ret) {
 		debug("!TIMEOUT! waiting PLL\n");
 		return ret;
 	}

 	return 0;
 }

 static void dsi_phy_post_set_mode(void *priv_data, unsigned long mode_flags)
 {
 	struct mipi_dsi_device *device = priv_data;
 	struct udevice *dev = device->dev;
 	struct stm32_dsi_priv *dsi = dev_get_priv(dev);

 	debug("Set mode %p enable %ld\n", dsi,
 	      mode_flags & MIPI_DSI_MODE_VIDEO);

 	if (!dsi)
 		return;

 	/*
 	 * DSI wrapper must be enabled in video mode & disabled in command mode.
 	 * If wrapper is enabled in command mode, the display controller
 	 * register access will hang.
 	 */

 	if (mode_flags & MIPI_DSI_MODE_VIDEO)
 		dsi_set(dsi, DSI_WCR, WCR_DSIEN);
 	else
 		dsi_clear(dsi, DSI_WCR, WCR_DSIEN);
 }

 static int dsi_get_lane_mbps(void *priv_data, struct display_timing *timings,
 			     u32 lanes, u32 format, unsigned int *lane_mbps)
 {
 	struct mipi_dsi_device *device = priv_data;
 	struct udevice *dev = device->dev;
 	struct stm32_dsi_priv *dsi = dev_get_priv(dev);
 	int idf, ndiv, odf, pll_in_khz, pll_out_khz;
 	int ret, bpp;
 	u32 val;

 	/* Update lane capabilities according to hw version */
 	dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
 	dsi->lane_min_kbps = LANE_MIN_KBPS;
 	dsi->lane_max_kbps = LANE_MAX_KBPS;
 	if (dsi->hw_version == HWVER_131) {
 		dsi->lane_min_kbps *= 2;
 		dsi->lane_max_kbps *= 2;
 	}

 	pll_in_khz = dsi->pllref_clk / 1000;

 	/* Compute requested pll out */
 	bpp = mipi_dsi_pixel_format_to_bpp(format);
 	pll_out_khz = (timings->pixelclock.typ / 1000) * bpp / lanes;
 	/* Add 20% to pll out to be higher than pixel bw (burst mode only) */
 	pll_out_khz = (pll_out_khz * 12) / 10;
 	if (pll_out_khz > dsi->lane_max_kbps) {
 		pll_out_khz = dsi->lane_max_kbps;
 		dev_warn(dev, "Warning max phy mbps is used\n");
 	}
 	if (pll_out_khz < dsi->lane_min_kbps) {
 		pll_out_khz = dsi->lane_min_kbps;
 		dev_warn(dev, "Warning min phy mbps is used\n");
 	}

 	/* Compute best pll parameters */
 	idf = 0;
 	ndiv = 0;
 	odf = 0;
 	ret = dsi_pll_get_params(dsi, pll_in_khz, pll_out_khz,
 				 &idf, &ndiv, &odf);
 	if (ret) {
 		dev_err(dev, "Warning dsi_pll_get_params(): bad params\n");
 		return ret;
 	}

 	/* Get the adjusted pll out value */
 	pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);

 	/* Set the PLL division factors */
 	dsi_update_bits(dsi, DSI_WRPCR,	WRPCR_NDIV | WRPCR_IDF | WRPCR_ODF,
 			(ndiv << 2) | (idf << 11) | ((ffs(odf) - 1) << 16));

 	/* Compute uix4 & set the bit period in high-speed mode */
 	val = 4000000 / pll_out_khz;
 	dsi_update_bits(dsi, DSI_WPCR0, WPCR0_UIX4, val);

 	/* Select video mode by resetting DSIM bit */
 	dsi_clear(dsi, DSI_WCFGR, WCFGR_DSIM);

 	/* Select the color coding */
 	dsi_update_bits(dsi, DSI_WCFGR, WCFGR_COLMUX,
 			dsi_color_from_mipi(format) << 1);

 	*lane_mbps = pll_out_khz / 1000;

 	debug("pll_in %ukHz pll_out %ukHz lane_mbps %uMHz\n",
 	      pll_in_khz, pll_out_khz, *lane_mbps);

 	return 0;
 }

 static const struct mipi_dsi_phy_ops dsi_stm_phy_ops = {
 	.init = dsi_phy_init,
 	.get_lane_mbps = dsi_get_lane_mbps,
 	.post_set_mode = dsi_phy_post_set_mode,
 };

 static int stm32_dsi_attach(struct udevice *dev)
 {
 	struct stm32_dsi_priv *priv = dev_get_priv(dev);
 	struct mipi_dsi_device *device = &priv->device;
 	struct mipi_dsi_panel_plat *mplat;
 	struct display_timing timings;
 	int ret;

 	ret = uclass_first_device(UCLASS_PANEL, &priv->panel);
 	if (ret) {
 		dev_err(dev, "panel device error %d\n", ret);
 		return ret;
 	}

 	mplat = dev_get_platdata(priv->panel);
 	mplat->device = &priv->device;

 	ret = panel_get_display_timing(priv->panel, &timings);
 	if (ret) {
 		ret = fdtdec_decode_display_timing(gd->fdt_blob,
 						   dev_of_offset(priv->panel),
 						   0, &timings);
 		if (ret) {
 			dev_err(dev, "decode display timing error %d\n", ret);
 			return ret;
 		}
 	}

 	ret = uclass_get_device(UCLASS_DSI_HOST, 0, &priv->dsi_host);
 	if (ret) {
 		dev_err(dev, "No video dsi host detected %d\n", ret);
 		return ret;
 	}

 	ret = dsi_host_init(priv->dsi_host, device, &timings, 2,
 			    &dsi_stm_phy_ops);
 	if (ret) {
 		dev_err(dev, "failed to initialize mipi dsi host\n");
 		return ret;
 	}

 	return 0;
 }

 static int stm32_dsi_set_backlight(struct udevice *dev, int percent)
 {
 	struct stm32_dsi_priv *priv = dev_get_priv(dev);
 	int ret;

 	ret = panel_enable_backlight(priv->panel);
 	if (ret) {
 		dev_err(dev, "panel %s enable backlight error %d\n",
 			priv->panel->name, ret);
 		return ret;
 	}

 	ret = dsi_host_enable(priv->dsi_host);
 	if (ret) {
 		dev_err(dev, "failed to enable mipi dsi host\n");
 		return ret;
 	}

 	return 0;
 }

 static int stm32_dsi_bind(struct udevice *dev)
 {
 	int ret;

 	ret = device_bind_driver_to_node(dev, "dw_mipi_dsi", "dsihost",
 					 dev_ofnode(dev), NULL);
 	if (ret)
 		return ret;

 	return dm_scan_fdt_dev(dev);
 }

 static int stm32_dsi_probe(struct udevice *dev)
 {
 	struct stm32_dsi_priv *priv = dev_get_priv(dev);
 	struct mipi_dsi_device *device = &priv->device;
 	struct reset_ctl rst;
 	struct clk clk;
 	int ret;

 	device->dev = dev;

 	priv->base = (void *)dev_read_addr(dev);
 	if ((fdt_addr_t)priv->base == FDT_ADDR_T_NONE) {
 		dev_err(dev, "dsi dt register address error\n");
 		return -EINVAL;
 	}

 	if (IS_ENABLED(CONFIG_DM_REGULATOR)) {
 		ret =  device_get_supply_regulator(dev, "phy-dsi-supply",
 						   &priv->vdd_reg);
 		if (ret && ret != -ENOENT) {
 			dev_err(dev, "Warning: cannot get phy dsi supply\n");
 			return -ENODEV;
 		}

 		if (ret != -ENOENT) {
 			ret = regulator_set_enable(priv->vdd_reg, true);
 			if (ret)
 				return ret;
 		}
 	}

 	ret = clk_get_by_name(device->dev, "pclk", &clk);
 	if (ret) {
 		dev_err(dev, "peripheral clock get error %d\n", ret);
 		goto err_reg;
 	}

 	ret = clk_enable(&clk);
 	if (ret) {
 		dev_err(dev, "peripheral clock enable error %d\n", ret);
 		goto err_reg;
 	}

 	ret = clk_get_by_name(dev, "ref", &clk);
 	if (ret) {
 		dev_err(dev, "pll reference clock get error %d\n", ret);
 		goto err_clk;
 	}

 	priv->pllref_clk = (unsigned int)clk_get_rate(&clk);

 	ret = reset_get_by_index(device->dev, 0, &rst);
 	if (ret) {
 		dev_err(dev, "missing dsi hardware reset\n");
 		goto err_clk;
 	}

 	/* Reset */
 	reset_deassert(&rst);

 	return 0;
 err_clk:
 	clk_disable(&clk);
 err_reg:
 	if (IS_ENABLED(CONFIG_DM_REGULATOR))
 		regulator_set_enable(priv->vdd_reg, false);

 	return ret;
 }

 struct video_bridge_ops stm32_dsi_ops = {
 	.attach = stm32_dsi_attach,
 	.set_backlight = stm32_dsi_set_backlight,
 };

 static const struct udevice_id stm32_dsi_ids[] = {
 	{ .compatible = "st,stm32-dsi"},
 	{ }
 };

 U_BOOT_DRIVER(stm32_dsi) = {
 	.name				= "stm32-display-dsi",
 	.id				= UCLASS_VIDEO_BRIDGE,
 	.of_match			= stm32_dsi_ids,
 	.bind				= stm32_dsi_bind,
 	.probe				= stm32_dsi_probe,
 	.ops				= &stm32_dsi_ops,
 	.priv_auto_alloc_size		= sizeof(struct stm32_dsi_priv),
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (C) 2019 STMicroelectronics - All Rights Reserved
	* Author(s): Philippe Cornu <philippe.cornu@st.com> for STMicroelectronics.
	* Yannick Fertre <yannick.fertre@st.com> for STMicroelectronics.
	*
	* This MIPI DSI controller driver is based on the Linux Kernel driver from
	* drivers/gpu/drm/stm/dw_mipi_dsi-stm.c.
	*/

	#include <common.h>
	#include <clk.h>
	#include <dm.h>
	#include <dsi_host.h>
	#include <mipi_dsi.h>
	#include <panel.h>
	#include <reset.h>
	#include <video.h>
	#include <video_bridge.h>
	#include <asm/io.h>
	#include <asm/arch/gpio.h>
	#include <dm/device-internal.h>
	#include <dm/device_compat.h>
	#include <dm/lists.h>
	#include <linux/iopoll.h>
	#include <power/regulator.h>

	#define HWVER_130 0x31333000 /* IP version 1.30 */
	#define HWVER_131 0x31333100 /* IP version 1.31 */

	/* DSI digital registers & bit definitions */
	#define DSI_VERSION 0x00
	#define VERSION GENMASK(31, 8)

	/*
	* DSI wrapper registers & bit definitions
	* Note: registers are named as in the Reference Manual
	*/
	#define DSI_WCFGR 0x0400 /* Wrapper ConFiGuration Reg */
	#define WCFGR_DSIM BIT(0) /* DSI Mode */
	#define WCFGR_COLMUX GENMASK(3, 1) /* COLor MUltipleXing */

	#define DSI_WCR 0x0404 /* Wrapper Control Reg */
	#define WCR_DSIEN BIT(3) /* DSI ENable */

	#define DSI_WISR 0x040C /* Wrapper Interrupt and Status Reg */
	#define WISR_PLLLS BIT(8) /* PLL Lock Status */
	#define WISR_RRS BIT(12) /* Regulator Ready Status */

	#define DSI_WPCR0 0x0418 /* Wrapper Phy Conf Reg 0 */
	#define WPCR0_UIX4 GENMASK(5, 0) /* Unit Interval X 4 */
	#define WPCR0_TDDL BIT(16) /* Turn Disable Data Lanes */

	#define DSI_WRPCR 0x0430 /* Wrapper Regulator & Pll Ctrl Reg */
	#define WRPCR_PLLEN BIT(0) /* PLL ENable */
	#define WRPCR_NDIV GENMASK(8, 2) /* pll loop DIVision Factor */
	#define WRPCR_IDF GENMASK(14, 11) /* pll Input Division Factor */
	#define WRPCR_ODF GENMASK(17, 16) /* pll Output Division Factor */
	#define WRPCR_REGEN BIT(24) /* REGulator ENable */
	#define WRPCR_BGREN BIT(28) /* BandGap Reference ENable */
	#define IDF_MIN 1
	#define IDF_MAX 7
	#define NDIV_MIN 10
	#define NDIV_MAX 125
	#define ODF_MIN 1
	#define ODF_MAX 8

	/* dsi color format coding according to the datasheet */
	enum dsi_color {
	DSI_RGB565_CONF1,
	DSI_RGB565_CONF2,
	DSI_RGB565_CONF3,
	DSI_RGB666_CONF1,
	DSI_RGB666_CONF2,
	DSI_RGB888,
	};

	#define LANE_MIN_KBPS 31250
	#define LANE_MAX_KBPS 500000

	/* Timeout for regulator on/off, pll lock/unlock & fifo empty */
	#define TIMEOUT_US 200000

	struct stm32_dsi_priv {
	struct mipi_dsi_device device;
	void __iomem *base;
	struct udevice *panel;
	u32 pllref_clk;
	u32 hw_version;
	int lane_min_kbps;
	int lane_max_kbps;
	struct udevice *vdd_reg;
	struct udevice *dsi_host;
	};

	static inline void dsi_write(struct stm32_dsi_priv *dsi, u32 reg, u32 val)
	{
	writel(val, dsi->base + reg);
	}

	static inline u32 dsi_read(struct stm32_dsi_priv *dsi, u32 reg)
	{
	return readl(dsi->base + reg);
	}

	static inline void dsi_set(struct stm32_dsi_priv *dsi, u32 reg, u32 mask)
	{
	dsi_write(dsi, reg, dsi_read(dsi, reg) \| mask);
	}

	static inline void dsi_clear(struct stm32_dsi_priv *dsi, u32 reg, u32 mask)
	{
	dsi_write(dsi, reg, dsi_read(dsi, reg) & ~mask);
	}

	static inline void dsi_update_bits(struct stm32_dsi_priv *dsi, u32 reg,
	u32 mask, u32 val)
	{
	dsi_write(dsi, reg, (dsi_read(dsi, reg) & ~mask) \| val);
	}

	static enum dsi_color dsi_color_from_mipi(u32 fmt)
	{
	switch (fmt) {
	case MIPI_DSI_FMT_RGB888:
	return DSI_RGB888;
	case MIPI_DSI_FMT_RGB666:
	return DSI_RGB666_CONF2;
	case MIPI_DSI_FMT_RGB666_PACKED:
	return DSI_RGB666_CONF1;
	case MIPI_DSI_FMT_RGB565:
	return DSI_RGB565_CONF1;
	default:
	pr_err("MIPI color invalid, so we use rgb888\n");
	}
	return DSI_RGB888;
	}

	static int dsi_pll_get_clkout_khz(int clkin_khz, int idf, int ndiv, int odf)
	{
	int divisor = idf * odf;

	/* prevent from division by 0 */
	if (!divisor)
	return 0;

	return DIV_ROUND_CLOSEST(clkin_khz * ndiv, divisor);
	}

	static int dsi_pll_get_params(struct stm32_dsi_priv *dsi,
	int clkin_khz, int clkout_khz,
	int idf, int ndiv, int *odf)
	{
	int i, o, n, n_min, n_max;
	int fvco_min, fvco_max, delta, best_delta; /* all in khz */

	/* Early checks preventing division by 0 & odd results */
	if (clkin_khz <= 0 \|\| clkout_khz <= 0)
	return -EINVAL;

	fvco_min = dsi->lane_min_kbps * 2 * ODF_MAX;
	fvco_max = dsi->lane_max_kbps * 2 * ODF_MIN;

	best_delta = 1000000; /* big started value (1000000khz) */

	for (i = IDF_MIN; i <= IDF_MAX; i++) {
	/* Compute ndiv range according to Fvco */
	n_min = ((fvco_min * i) / (2 * clkin_khz)) + 1;
	n_max = (fvco_max * i) / (2 * clkin_khz);

	/* No need to continue idf loop if we reach ndiv max */
	if (n_min >= NDIV_MAX)
	break;

	/* Clamp ndiv to valid values */
	if (n_min < NDIV_MIN)
	n_min = NDIV_MIN;
	if (n_max > NDIV_MAX)
	n_max = NDIV_MAX;

	for (o = ODF_MIN; o <= ODF_MAX; o *= 2) {
	n = DIV_ROUND_CLOSEST(i * o * clkout_khz, clkin_khz);
	/* Check ndiv according to vco range */
	if (n < n_min \|\| n > n_max)
	continue;
	/* Check if new delta is better & saves parameters */
	delta = dsi_pll_get_clkout_khz(clkin_khz, i, n, o) -
	clkout_khz;
	if (delta < 0)
	delta = -delta;
	if (delta < best_delta) {
	*idf = i;
	*ndiv = n;
	*odf = o;
	best_delta = delta;
	}
	/* fast return in case of "perfect result" */
	if (!delta)
	return 0;
	}
	}

	return 0;
	}

	static int dsi_phy_init(void *priv_data)
	{
	struct mipi_dsi_device *device = priv_data;
	struct udevice *dev = device->dev;
	struct stm32_dsi_priv *dsi = dev_get_priv(dev);
	u32 val;
	int ret;

	debug("Initialize DSI physical layer\n");

	/* Enable the regulator */
	dsi_set(dsi, DSI_WRPCR, WRPCR_REGEN \| WRPCR_BGREN);
	ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_RRS,
	TIMEOUT_US);
	if (ret) {
	debug("!TIMEOUT! waiting REGU\n");
	return ret;
	}

	/* Enable the DSI PLL & wait for its lock */
	dsi_set(dsi, DSI_WRPCR, WRPCR_PLLEN);
	ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_PLLLS,
	TIMEOUT_US);
	if (ret) {
	debug("!TIMEOUT! waiting PLL\n");
	return ret;
	}

	return 0;
	}

	static void dsi_phy_post_set_mode(void *priv_data, unsigned long mode_flags)
	{
	struct mipi_dsi_device *device = priv_data;
	struct udevice *dev = device->dev;
	struct stm32_dsi_priv *dsi = dev_get_priv(dev);

	debug("Set mode %p enable %ld\n", dsi,
	mode_flags & MIPI_DSI_MODE_VIDEO);

	if (!dsi)
	return;

	/*
	* DSI wrapper must be enabled in video mode & disabled in command mode.
	* If wrapper is enabled in command mode, the display controller
	* register access will hang.
	*/

	if (mode_flags & MIPI_DSI_MODE_VIDEO)
	dsi_set(dsi, DSI_WCR, WCR_DSIEN);
	else
	dsi_clear(dsi, DSI_WCR, WCR_DSIEN);
	}

	static int dsi_get_lane_mbps(void priv_data, struct display_timing timings,
	u32 lanes, u32 format, unsigned int *lane_mbps)
	{
	struct mipi_dsi_device *device = priv_data;
	struct udevice *dev = device->dev;
	struct stm32_dsi_priv *dsi = dev_get_priv(dev);
	int idf, ndiv, odf, pll_in_khz, pll_out_khz;
	int ret, bpp;
	u32 val;

	/* Update lane capabilities according to hw version */
	dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
	dsi->lane_min_kbps = LANE_MIN_KBPS;
	dsi->lane_max_kbps = LANE_MAX_KBPS;
	if (dsi->hw_version == HWVER_131) {
	dsi->lane_min_kbps *= 2;
	dsi->lane_max_kbps *= 2;
	}

	pll_in_khz = dsi->pllref_clk / 1000;

	/* Compute requested pll out */
	bpp = mipi_dsi_pixel_format_to_bpp(format);
	pll_out_khz = (timings->pixelclock.typ / 1000) * bpp / lanes;
	/* Add 20% to pll out to be higher than pixel bw (burst mode only) */
	pll_out_khz = (pll_out_khz * 12) / 10;
	if (pll_out_khz > dsi->lane_max_kbps) {
	pll_out_khz = dsi->lane_max_kbps;
	dev_warn(dev, "Warning max phy mbps is used\n");
	}
	if (pll_out_khz < dsi->lane_min_kbps) {
	pll_out_khz = dsi->lane_min_kbps;
	dev_warn(dev, "Warning min phy mbps is used\n");
	}

	/* Compute best pll parameters */
	idf = 0;
	ndiv = 0;
	odf = 0;
	ret = dsi_pll_get_params(dsi, pll_in_khz, pll_out_khz,
	&idf, &ndiv, &odf);
	if (ret) {
	dev_err(dev, "Warning dsi_pll_get_params(): bad params\n");
	return ret;
	}

	/* Get the adjusted pll out value */
	pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf);

	/* Set the PLL division factors */
	dsi_update_bits(dsi, DSI_WRPCR, WRPCR_NDIV \| WRPCR_IDF \| WRPCR_ODF,
	(ndiv << 2) \| (idf << 11) \| ((ffs(odf) - 1) << 16));

	/* Compute uix4 & set the bit period in high-speed mode */
	val = 4000000 / pll_out_khz;
	dsi_update_bits(dsi, DSI_WPCR0, WPCR0_UIX4, val);

	/* Select video mode by resetting DSIM bit */
	dsi_clear(dsi, DSI_WCFGR, WCFGR_DSIM);

	/* Select the color coding */
	dsi_update_bits(dsi, DSI_WCFGR, WCFGR_COLMUX,
	dsi_color_from_mipi(format) << 1);

	*lane_mbps = pll_out_khz / 1000;

	debug("pll_in %ukHz pll_out %ukHz lane_mbps %uMHz\n",
	pll_in_khz, pll_out_khz, *lane_mbps);

	return 0;
	}

	static const struct mipi_dsi_phy_ops dsi_stm_phy_ops = {
	.init = dsi_phy_init,
	.get_lane_mbps = dsi_get_lane_mbps,
	.post_set_mode = dsi_phy_post_set_mode,
	};

	static int stm32_dsi_attach(struct udevice *dev)
	{
	struct stm32_dsi_priv *priv = dev_get_priv(dev);
	struct mipi_dsi_device *device = &priv->device;
	struct mipi_dsi_panel_plat *mplat;
	struct display_timing timings;
	int ret;

	ret = uclass_first_device(UCLASS_PANEL, &priv->panel);
	if (ret) {
	dev_err(dev, "panel device error %d\n", ret);
	return ret;
	}

	mplat = dev_get_platdata(priv->panel);
	mplat->device = &priv->device;

	ret = panel_get_display_timing(priv->panel, &timings);
	if (ret) {
	ret = fdtdec_decode_display_timing(gd->fdt_blob,
	dev_of_offset(priv->panel),
	0, &timings);
	if (ret) {
	dev_err(dev, "decode display timing error %d\n", ret);
	return ret;
	}
	}

	ret = uclass_get_device(UCLASS_DSI_HOST, 0, &priv->dsi_host);
	if (ret) {
	dev_err(dev, "No video dsi host detected %d\n", ret);
	return ret;
	}

	ret = dsi_host_init(priv->dsi_host, device, &timings, 2,
	&dsi_stm_phy_ops);
	if (ret) {
	dev_err(dev, "failed to initialize mipi dsi host\n");
	return ret;
	}

	return 0;
	}

	static int stm32_dsi_set_backlight(struct udevice *dev, int percent)
	{
	struct stm32_dsi_priv *priv = dev_get_priv(dev);
	int ret;

	ret = panel_enable_backlight(priv->panel);
	if (ret) {
	dev_err(dev, "panel %s enable backlight error %d\n",
	priv->panel->name, ret);
	return ret;
	}

	ret = dsi_host_enable(priv->dsi_host);
	if (ret) {
	dev_err(dev, "failed to enable mipi dsi host\n");
	return ret;
	}

	return 0;
	}

	static int stm32_dsi_bind(struct udevice *dev)
	{
	int ret;

	ret = device_bind_driver_to_node(dev, "dw_mipi_dsi", "dsihost",
	dev_ofnode(dev), NULL);
	if (ret)
	return ret;

	return dm_scan_fdt_dev(dev);
	}

	static int stm32_dsi_probe(struct udevice *dev)
	{
	struct stm32_dsi_priv *priv = dev_get_priv(dev);
	struct mipi_dsi_device *device = &priv->device;
	struct reset_ctl rst;
	struct clk clk;
	int ret;

	device->dev = dev;

	priv->base = (void *)dev_read_addr(dev);
	if ((fdt_addr_t)priv->base == FDT_ADDR_T_NONE) {
	dev_err(dev, "dsi dt register address error\n");
	return -EINVAL;
	}

	if (IS_ENABLED(CONFIG_DM_REGULATOR)) {
	ret = device_get_supply_regulator(dev, "phy-dsi-supply",
	&priv->vdd_reg);
	if (ret && ret != -ENOENT) {
	dev_err(dev, "Warning: cannot get phy dsi supply\n");
	return -ENODEV;
	}

	if (ret != -ENOENT) {
	ret = regulator_set_enable(priv->vdd_reg, true);
	if (ret)
	return ret;
	}
	}

	ret = clk_get_by_name(device->dev, "pclk", &clk);
	if (ret) {
	dev_err(dev, "peripheral clock get error %d\n", ret);
	goto err_reg;
	}

	ret = clk_enable(&clk);
	if (ret) {
	dev_err(dev, "peripheral clock enable error %d\n", ret);
	goto err_reg;
	}

	ret = clk_get_by_name(dev, "ref", &clk);
	if (ret) {
	dev_err(dev, "pll reference clock get error %d\n", ret);
	goto err_clk;
	}

	priv->pllref_clk = (unsigned int)clk_get_rate(&clk);

	ret = reset_get_by_index(device->dev, 0, &rst);
	if (ret) {
	dev_err(dev, "missing dsi hardware reset\n");
	goto err_clk;
	}

	/* Reset */
	reset_deassert(&rst);

	return 0;
	err_clk:
	clk_disable(&clk);
	err_reg:
	if (IS_ENABLED(CONFIG_DM_REGULATOR))
	regulator_set_enable(priv->vdd_reg, false);

	return ret;
	}

	struct video_bridge_ops stm32_dsi_ops = {
	.attach = stm32_dsi_attach,
	.set_backlight = stm32_dsi_set_backlight,
	};

	static const struct udevice_id stm32_dsi_ids[] = {
	{ .compatible = "st,stm32-dsi"},
	{ }
	};

	U_BOOT_DRIVER(stm32_dsi) = {
	.name = "stm32-display-dsi",
	.id = UCLASS_VIDEO_BRIDGE,
	.of_match = stm32_dsi_ids,
	.bind = stm32_dsi_bind,
	.probe = stm32_dsi_probe,
	.ops = &stm32_dsi_ops,
	.priv_auto_alloc_size = sizeof(struct stm32_dsi_priv),
	};