drivers/gpu/drm/stm/dw_mipi_dsi-stm.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) STMicroelectronics SA 2017
  *
  * Authors: Philippe Cornu <philippe.cornu@st.com>
  *          Yannick Fertre <yannick.fertre@st.com>
  */

 #include <linux/clk.h>
 #include <linux/iopoll.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>

 #include <video/mipi_display.h>

 #include <drm/bridge/dw_mipi_dsi.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_print.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

 /* Sleep & timeout for regulator on/off, pll lock/unlock & fifo empty */
 #define SLEEP_US	1000
 #define TIMEOUT_US	200000

 struct dw_mipi_dsi_stm {
 	void __iomem *base;
 	struct clk *pllref_clk;
 	struct dw_mipi_dsi *dsi;
 	u32 hw_version;
 	int lane_min_kbps;
 	int lane_max_kbps;
 	struct regulator *vdd_supply;
 };

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

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

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

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

 static inline void dsi_update_bits(struct dw_mipi_dsi_stm *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(enum mipi_dsi_pixel_format 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:
 		DRM_DEBUG_DRIVER("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 dw_mipi_dsi_stm *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 dw_mipi_dsi_phy_init(void *priv_data)
 {
 	struct dw_mipi_dsi_stm *dsi = priv_data;
 	u32 val;
 	int ret;

 	/* Enable the regulator */
 	dsi_set(dsi, DSI_WRPCR, WRPCR_REGEN | WRPCR_BGREN);
 	ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_RRS,
 				 SLEEP_US, TIMEOUT_US);
 	if (ret)
 		DRM_DEBUG_DRIVER("!TIMEOUT! waiting REGU, let's continue\n");

 	/* 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,
 				 SLEEP_US, TIMEOUT_US);
 	if (ret)
 		DRM_DEBUG_DRIVER("!TIMEOUT! waiting PLL, let's continue\n");

 	return 0;
 }

 static void dw_mipi_dsi_phy_power_on(void *priv_data)
 {
 	struct dw_mipi_dsi_stm *dsi = priv_data;

 	DRM_DEBUG_DRIVER("\n");

 	/* Enable the DSI wrapper */
 	dsi_set(dsi, DSI_WCR, WCR_DSIEN);
 }

 static void dw_mipi_dsi_phy_power_off(void *priv_data)
 {
 	struct dw_mipi_dsi_stm *dsi = priv_data;

 	DRM_DEBUG_DRIVER("\n");

 	/* Disable the DSI wrapper */
 	dsi_clear(dsi, DSI_WCR, WCR_DSIEN);
 }

 static int
 dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct drm_display_mode *mode,
 			  unsigned long mode_flags, u32 lanes, u32 format,
 			  unsigned int *lane_mbps)
 {
 	struct dw_mipi_dsi_stm *dsi = priv_data;
 	unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz;
 	int ret, bpp;
 	u32 val;

 	/* Update lane capabilities according to hw 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 = (unsigned int)(clk_get_rate(dsi->pllref_clk) / 1000);

 	/* Compute requested pll out */
 	bpp = mipi_dsi_pixel_format_to_bpp(format);
 	pll_out_khz = mode->clock * bpp / lanes;

 	/* Add 20% to pll out to be higher than pixel bw (burst mode only) */
 	if (mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
 		pll_out_khz = (pll_out_khz * 12) / 10;

 	if (pll_out_khz > dsi->lane_max_kbps) {
 		pll_out_khz = dsi->lane_max_kbps;
 		DRM_WARN("Warning max phy mbps is used\n");
 	}
 	if (pll_out_khz < dsi->lane_min_kbps) {
 		pll_out_khz = dsi->lane_min_kbps;
 		DRM_WARN("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)
 		DRM_WARN("Warning dsi_pll_get_params(): bad params\n");

 	/* 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;

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

 	return 0;
 }

 static int
 dw_mipi_dsi_phy_get_timing(void *priv_data, unsigned int lane_mbps,
 			   struct dw_mipi_dsi_dphy_timing *timing)
 {
 	timing->clk_hs2lp = 0x40;
 	timing->clk_lp2hs = 0x40;
 	timing->data_hs2lp = 0x40;
 	timing->data_lp2hs = 0x40;

 	return 0;
 }

 static const struct dw_mipi_dsi_phy_ops dw_mipi_dsi_stm_phy_ops = {
 	.init = dw_mipi_dsi_phy_init,
 	.power_on = dw_mipi_dsi_phy_power_on,
 	.power_off = dw_mipi_dsi_phy_power_off,
 	.get_lane_mbps = dw_mipi_dsi_get_lane_mbps,
 	.get_timing = dw_mipi_dsi_phy_get_timing,
 };

 static struct dw_mipi_dsi_plat_data dw_mipi_dsi_stm_plat_data = {
 	.max_data_lanes = 2,
 	.phy_ops = &dw_mipi_dsi_stm_phy_ops,
 };

 static const struct of_device_id dw_mipi_dsi_stm_dt_ids[] = {
 	{ .compatible = "st,stm32-dsi", .data = &dw_mipi_dsi_stm_plat_data, },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, dw_mipi_dsi_stm_dt_ids);

 static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct dw_mipi_dsi_stm *dsi;
 	struct clk *pclk;
 	struct resource *res;
 	int ret;

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

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dsi->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(dsi->base)) {
 		ret = PTR_ERR(dsi->base);
 		DRM_ERROR("Unable to get dsi registers %d\n", ret);
 		return ret;
 	}

 	dsi->vdd_supply = devm_regulator_get(dev, "phy-dsi");
 	if (IS_ERR(dsi->vdd_supply)) {
 		ret = PTR_ERR(dsi->vdd_supply);
 		if (ret != -EPROBE_DEFER)
 			DRM_ERROR("Failed to request regulator: %d\n", ret);
 		return ret;
 	}

 	ret = regulator_enable(dsi->vdd_supply);
 	if (ret) {
 		DRM_ERROR("Failed to enable regulator: %d\n", ret);
 		return ret;
 	}

 	dsi->pllref_clk = devm_clk_get(dev, "ref");
 	if (IS_ERR(dsi->pllref_clk)) {
 		ret = PTR_ERR(dsi->pllref_clk);
 		if (ret != -EPROBE_DEFER)
 			DRM_ERROR("Unable to get pll reference clock: %d\n",
 				  ret);
 		goto err_clk_get;
 	}

 	ret = clk_prepare_enable(dsi->pllref_clk);
 	if (ret) {
 		DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
 		goto err_clk_get;
 	}

 	pclk = devm_clk_get(dev, "pclk");
 	if (IS_ERR(pclk)) {
 		ret = PTR_ERR(pclk);
 		DRM_ERROR("Unable to get peripheral clock: %d\n", ret);
 		goto err_dsi_probe;
 	}

 	ret = clk_prepare_enable(pclk);
 	if (ret) {
 		DRM_ERROR("%s: Failed to enable peripheral clk\n", __func__);
 		goto err_dsi_probe;
 	}

 	dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
 	clk_disable_unprepare(pclk);

 	if (dsi->hw_version != HWVER_130 && dsi->hw_version != HWVER_131) {
 		ret = -ENODEV;
 		DRM_ERROR("bad dsi hardware version\n");
 		goto err_dsi_probe;
 	}

 	dw_mipi_dsi_stm_plat_data.base = dsi->base;
 	dw_mipi_dsi_stm_plat_data.priv_data = dsi;

 	platform_set_drvdata(pdev, dsi);

 	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
 	if (IS_ERR(dsi->dsi)) {
 		ret = PTR_ERR(dsi->dsi);
 		DRM_ERROR("Failed to initialize mipi dsi host: %d\n", ret);
 		goto err_dsi_probe;
 	}

 	return 0;

 err_dsi_probe:
 	clk_disable_unprepare(dsi->pllref_clk);
 err_clk_get:
 	regulator_disable(dsi->vdd_supply);

 	return ret;
 }

 static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
 {
 	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);

 	dw_mipi_dsi_remove(dsi->dsi);
 	clk_disable_unprepare(dsi->pllref_clk);
 	regulator_disable(dsi->vdd_supply);

 	return 0;
 }

 static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
 {
 	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;

 	DRM_DEBUG_DRIVER("\n");

 	clk_disable_unprepare(dsi->pllref_clk);
 	regulator_disable(dsi->vdd_supply);

 	return 0;
 }

 static int __maybe_unused dw_mipi_dsi_stm_resume(struct device *dev)
 {
 	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
 	int ret;

 	DRM_DEBUG_DRIVER("\n");

 	ret = regulator_enable(dsi->vdd_supply);
 	if (ret) {
 		DRM_ERROR("Failed to enable regulator: %d\n", ret);
 		return ret;
 	}

 	ret = clk_prepare_enable(dsi->pllref_clk);
 	if (ret) {
 		regulator_disable(dsi->vdd_supply);
 		DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
 		return ret;
 	}

 	return 0;
 }

 static const struct dev_pm_ops dw_mipi_dsi_stm_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(dw_mipi_dsi_stm_suspend,
 				dw_mipi_dsi_stm_resume)
 };

 static struct platform_driver dw_mipi_dsi_stm_driver = {
 	.probe		= dw_mipi_dsi_stm_probe,
 	.remove		= dw_mipi_dsi_stm_remove,
 	.driver		= {
 		.of_match_table = dw_mipi_dsi_stm_dt_ids,
 		.name	= "stm32-display-dsi",
 		.pm = &dw_mipi_dsi_stm_pm_ops,
 	},
 };

 module_platform_driver(dw_mipi_dsi_stm_driver);

 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
 MODULE_DESCRIPTION("STMicroelectronics DW MIPI DSI host controller driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) STMicroelectronics SA 2017
	*
	* Authors: Philippe Cornu <philippe.cornu@st.com>
	* Yannick Fertre <yannick.fertre@st.com>
	*/

	#include <linux/clk.h>
	#include <linux/iopoll.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/consumer.h>

	#include <video/mipi_display.h>

	#include <drm/bridge/dw_mipi_dsi.h>
	#include <drm/drm_mipi_dsi.h>
	#include <drm/drm_print.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

	/* Sleep & timeout for regulator on/off, pll lock/unlock & fifo empty */
	#define SLEEP_US 1000
	#define TIMEOUT_US 200000

	struct dw_mipi_dsi_stm {
	void __iomem *base;
	struct clk *pllref_clk;
	struct dw_mipi_dsi *dsi;
	u32 hw_version;
	int lane_min_kbps;
	int lane_max_kbps;
	struct regulator *vdd_supply;
	};

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

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

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

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

	static inline void dsi_update_bits(struct dw_mipi_dsi_stm *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(enum mipi_dsi_pixel_format 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:
	DRM_DEBUG_DRIVER("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 dw_mipi_dsi_stm *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 dw_mipi_dsi_phy_init(void *priv_data)
	{
	struct dw_mipi_dsi_stm *dsi = priv_data;
	u32 val;
	int ret;

	/* Enable the regulator */
	dsi_set(dsi, DSI_WRPCR, WRPCR_REGEN \| WRPCR_BGREN);
	ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_RRS,
	SLEEP_US, TIMEOUT_US);
	if (ret)
	DRM_DEBUG_DRIVER("!TIMEOUT! waiting REGU, let's continue\n");

	/* 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,
	SLEEP_US, TIMEOUT_US);
	if (ret)
	DRM_DEBUG_DRIVER("!TIMEOUT! waiting PLL, let's continue\n");

	return 0;
	}

	static void dw_mipi_dsi_phy_power_on(void *priv_data)
	{
	struct dw_mipi_dsi_stm *dsi = priv_data;

	DRM_DEBUG_DRIVER("\n");

	/* Enable the DSI wrapper */
	dsi_set(dsi, DSI_WCR, WCR_DSIEN);
	}

	static void dw_mipi_dsi_phy_power_off(void *priv_data)
	{
	struct dw_mipi_dsi_stm *dsi = priv_data;

	DRM_DEBUG_DRIVER("\n");

	/* Disable the DSI wrapper */
	dsi_clear(dsi, DSI_WCR, WCR_DSIEN);
	}

	static int
	dw_mipi_dsi_get_lane_mbps(void priv_data, const struct drm_display_mode mode,
	unsigned long mode_flags, u32 lanes, u32 format,
	unsigned int *lane_mbps)
	{
	struct dw_mipi_dsi_stm *dsi = priv_data;
	unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz;
	int ret, bpp;
	u32 val;

	/* Update lane capabilities according to hw 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 = (unsigned int)(clk_get_rate(dsi->pllref_clk) / 1000);

	/* Compute requested pll out */
	bpp = mipi_dsi_pixel_format_to_bpp(format);
	pll_out_khz = mode->clock * bpp / lanes;

	/* Add 20% to pll out to be higher than pixel bw (burst mode only) */
	if (mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
	pll_out_khz = (pll_out_khz * 12) / 10;

	if (pll_out_khz > dsi->lane_max_kbps) {
	pll_out_khz = dsi->lane_max_kbps;
	DRM_WARN("Warning max phy mbps is used\n");
	}
	if (pll_out_khz < dsi->lane_min_kbps) {
	pll_out_khz = dsi->lane_min_kbps;
	DRM_WARN("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)
	DRM_WARN("Warning dsi_pll_get_params(): bad params\n");

	/* 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;

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

	return 0;
	}

	static int
	dw_mipi_dsi_phy_get_timing(void *priv_data, unsigned int lane_mbps,
	struct dw_mipi_dsi_dphy_timing *timing)
	{
	timing->clk_hs2lp = 0x40;
	timing->clk_lp2hs = 0x40;
	timing->data_hs2lp = 0x40;
	timing->data_lp2hs = 0x40;

	return 0;
	}

	static const struct dw_mipi_dsi_phy_ops dw_mipi_dsi_stm_phy_ops = {
	.init = dw_mipi_dsi_phy_init,
	.power_on = dw_mipi_dsi_phy_power_on,
	.power_off = dw_mipi_dsi_phy_power_off,
	.get_lane_mbps = dw_mipi_dsi_get_lane_mbps,
	.get_timing = dw_mipi_dsi_phy_get_timing,
	};

	static struct dw_mipi_dsi_plat_data dw_mipi_dsi_stm_plat_data = {
	.max_data_lanes = 2,
	.phy_ops = &dw_mipi_dsi_stm_phy_ops,
	};

	static const struct of_device_id dw_mipi_dsi_stm_dt_ids[] = {
	{ .compatible = "st,stm32-dsi", .data = &dw_mipi_dsi_stm_plat_data, },
	{ },
	};
	MODULE_DEVICE_TABLE(of, dw_mipi_dsi_stm_dt_ids);

	static int dw_mipi_dsi_stm_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct dw_mipi_dsi_stm *dsi;
	struct clk *pclk;
	struct resource *res;
	int ret;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	dsi->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(dsi->base)) {
	ret = PTR_ERR(dsi->base);
	DRM_ERROR("Unable to get dsi registers %d\n", ret);
	return ret;
	}

	dsi->vdd_supply = devm_regulator_get(dev, "phy-dsi");
	if (IS_ERR(dsi->vdd_supply)) {
	ret = PTR_ERR(dsi->vdd_supply);
	if (ret != -EPROBE_DEFER)
	DRM_ERROR("Failed to request regulator: %d\n", ret);
	return ret;
	}

	ret = regulator_enable(dsi->vdd_supply);
	if (ret) {
	DRM_ERROR("Failed to enable regulator: %d\n", ret);
	return ret;
	}

	dsi->pllref_clk = devm_clk_get(dev, "ref");
	if (IS_ERR(dsi->pllref_clk)) {
	ret = PTR_ERR(dsi->pllref_clk);
	if (ret != -EPROBE_DEFER)
	DRM_ERROR("Unable to get pll reference clock: %d\n",
	ret);
	goto err_clk_get;
	}

	ret = clk_prepare_enable(dsi->pllref_clk);
	if (ret) {
	DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
	goto err_clk_get;
	}

	pclk = devm_clk_get(dev, "pclk");
	if (IS_ERR(pclk)) {
	ret = PTR_ERR(pclk);
	DRM_ERROR("Unable to get peripheral clock: %d\n", ret);
	goto err_dsi_probe;
	}

	ret = clk_prepare_enable(pclk);
	if (ret) {
	DRM_ERROR("%s: Failed to enable peripheral clk\n", __func__);
	goto err_dsi_probe;
	}

	dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
	clk_disable_unprepare(pclk);

	if (dsi->hw_version != HWVER_130 && dsi->hw_version != HWVER_131) {
	ret = -ENODEV;
	DRM_ERROR("bad dsi hardware version\n");
	goto err_dsi_probe;
	}

	dw_mipi_dsi_stm_plat_data.base = dsi->base;
	dw_mipi_dsi_stm_plat_data.priv_data = dsi;

	platform_set_drvdata(pdev, dsi);

	dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data);
	if (IS_ERR(dsi->dsi)) {
	ret = PTR_ERR(dsi->dsi);
	DRM_ERROR("Failed to initialize mipi dsi host: %d\n", ret);
	goto err_dsi_probe;
	}

	return 0;

	err_dsi_probe:
	clk_disable_unprepare(dsi->pllref_clk);
	err_clk_get:
	regulator_disable(dsi->vdd_supply);

	return ret;
	}

	static int dw_mipi_dsi_stm_remove(struct platform_device *pdev)
	{
	struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev);

	dw_mipi_dsi_remove(dsi->dsi);
	clk_disable_unprepare(dsi->pllref_clk);
	regulator_disable(dsi->vdd_supply);

	return 0;
	}

	static int __maybe_unused dw_mipi_dsi_stm_suspend(struct device *dev)
	{
	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;

	DRM_DEBUG_DRIVER("\n");

	clk_disable_unprepare(dsi->pllref_clk);
	regulator_disable(dsi->vdd_supply);

	return 0;
	}

	static int __maybe_unused dw_mipi_dsi_stm_resume(struct device *dev)
	{
	struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data;
	int ret;

	DRM_DEBUG_DRIVER("\n");

	ret = regulator_enable(dsi->vdd_supply);
	if (ret) {
	DRM_ERROR("Failed to enable regulator: %d\n", ret);
	return ret;
	}

	ret = clk_prepare_enable(dsi->pllref_clk);
	if (ret) {
	regulator_disable(dsi->vdd_supply);
	DRM_ERROR("Failed to enable pllref_clk: %d\n", ret);
	return ret;
	}

	return 0;
	}

	static const struct dev_pm_ops dw_mipi_dsi_stm_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(dw_mipi_dsi_stm_suspend,
	dw_mipi_dsi_stm_resume)
	};

	static struct platform_driver dw_mipi_dsi_stm_driver = {
	.probe = dw_mipi_dsi_stm_probe,
	.remove = dw_mipi_dsi_stm_remove,
	.driver = {
	.of_match_table = dw_mipi_dsi_stm_dt_ids,
	.name = "stm32-display-dsi",
	.pm = &dw_mipi_dsi_stm_pm_ops,
	},
	};

	module_platform_driver(dw_mipi_dsi_stm_driver);

	MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
	MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
	MODULE_DESCRIPTION("STMicroelectronics DW MIPI DSI host controller driver");
	MODULE_LICENSE("GPL v2");