3 files changed, 508 insertions, 0 deletions

diff --git a/drivers/phy/freescale/Kconfig b/drivers/phy/freescale/Kconfig
index f435d6406943..320630ffe3cd 100644
--- a/drivers/phy/freescale/Kconfig
+++ b/drivers/phy/freescale/Kconfig
@@ -4,3 +4,13 @@ config PHY_FSL_IMX8MQ_USB
 	depends on OF && HAS_IOMEM
 	select GENERIC_PHY
 	default ARCH_MXC && ARM64
+
+config PHY_MIXEL_MIPI_DPHY
+	tristate "Mixel MIPI DSI PHY support"
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	select REGMAP_MMIO
+	help
+	  Enable this to add support for the Mixel DSI PHY as found
+	  on NXP's i.MX8 family of SOCs.
diff --git a/drivers/phy/freescale/Makefile b/drivers/phy/freescale/Makefile
index a459a44f6ecd..1d02e3869b45 100644
--- a/drivers/phy/freescale/Makefile
+++ b/drivers/phy/freescale/Makefile
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_PHY_FSL_IMX8MQ_USB)	+= phy-fsl-imx8mq-usb.o
+obj-$(CONFIG_PHY_MIXEL_MIPI_DPHY)	+= phy-fsl-imx8-mipi-dphy.o
diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
new file mode 100644
index 000000000000..9f2c1da14f5a
--- /dev/null
+++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
@@ -0,0 +1,497 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2017,2018 NXP
+ * Copyright 2019 Purism SPC
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* DPHY registers */
+#define DPHY_PD_DPHY			0x00
+#define DPHY_M_PRG_HS_PREPARE		0x04
+#define DPHY_MC_PRG_HS_PREPARE		0x08
+#define DPHY_M_PRG_HS_ZERO		0x0c
+#define DPHY_MC_PRG_HS_ZERO		0x10
+#define DPHY_M_PRG_HS_TRAIL		0x14
+#define DPHY_MC_PRG_HS_TRAIL		0x18
+#define DPHY_PD_PLL			0x1c
+#define DPHY_TST			0x20
+#define DPHY_CN				0x24
+#define DPHY_CM				0x28
+#define DPHY_CO				0x2c
+#define DPHY_LOCK			0x30
+#define DPHY_LOCK_BYP			0x34
+#define DPHY_REG_BYPASS_PLL		0x4C
+
+#define MBPS(x) ((x) * 1000000)
+
+#define DATA_RATE_MAX_SPEED MBPS(1500)
+#define DATA_RATE_MIN_SPEED MBPS(80)
+
+#define PLL_LOCK_SLEEP 10
+#define PLL_LOCK_TIMEOUT 1000
+
+#define CN_BUF	0xcb7a89c0
+#define CO_BUF	0x63
+#define CM(x)	(				  \
+		((x) <	32) ? 0xe0 | ((x) - 16) : \
+		((x) <	64) ? 0xc0 | ((x) - 32) : \
+		((x) < 128) ? 0x80 | ((x) - 64) : \
+		((x) - 128))
+#define CN(x)	(((x) == 1) ? 0x1f : (((CN_BUF) >> ((x) - 1)) & 0x1f))
+#define CO(x)	((CO_BUF) >> (8 - (x)) & 0x03)
+
+/* PHY power on is active low */
+#define PWR_ON	0
+#define PWR_OFF	1
+
+enum mixel_dphy_devtype {
+	MIXEL_IMX8MQ,
+};
+
+struct mixel_dphy_devdata {
+	u8 reg_tx_rcal;
+	u8 reg_auto_pd_en;
+	u8 reg_rxlprp;
+	u8 reg_rxcdrp;
+	u8 reg_rxhs_settle;
+};
+
+static const struct mixel_dphy_devdata mixel_dphy_devdata[] = {
+	[MIXEL_IMX8MQ] = {
+		.reg_tx_rcal = 0x38,
+		.reg_auto_pd_en = 0x3c,
+		.reg_rxlprp = 0x40,
+		.reg_rxcdrp = 0x44,
+		.reg_rxhs_settle = 0x48,
+	},
+};
+
+struct mixel_dphy_cfg {
+	/* DPHY PLL parameters */
+	u32 cm;
+	u32 cn;
+	u32 co;
+	/* DPHY register values */
+	u8 mc_prg_hs_prepare;
+	u8 m_prg_hs_prepare;
+	u8 mc_prg_hs_zero;
+	u8 m_prg_hs_zero;
+	u8 mc_prg_hs_trail;
+	u8 m_prg_hs_trail;
+	u8 rxhs_settle;
+};
+
+struct mixel_dphy_priv {
+	struct mixel_dphy_cfg cfg;
+	struct regmap *regmap;
+	struct clk *phy_ref_clk;
+	const struct mixel_dphy_devdata *devdata;
+};
+
+static const struct regmap_config mixel_dphy_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = DPHY_REG_BYPASS_PLL,
+	.name = "mipi-dphy",
+};
+
+static int phy_write(struct phy *phy, u32 value, unsigned int reg)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = regmap_write(priv->regmap, reg, value);
+	if (ret < 0)
+		dev_err(&phy->dev, "Failed to write DPHY reg %d: %d\n", reg,
+			ret);
+	return ret;
+}
+
+/*
+ * Find a ratio close to the desired one using continued fraction
+ * approximation ending either at exact match or maximum allowed
+ * nominator, denominator.
+ */
+static void get_best_ratio(u32 *pnum, u32 *pdenom, u32 max_n, u32 max_d)
+{
+	u32 a = *pnum;
+	u32 b = *pdenom;
+	u32 c;
+	u32 n[] = {0, 1};
+	u32 d[] = {1, 0};
+	u32 whole;
+	unsigned int i = 1;
+
+	while (b) {
+		i ^= 1;
+		whole = a / b;
+		n[i] += (n[i ^ 1] * whole);
+		d[i] += (d[i ^ 1] * whole);
+		if ((n[i] > max_n) || (d[i] > max_d)) {
+			i ^= 1;
+			break;
+		}
+		c = a - (b * whole);
+		a = b;
+		b = c;
+	}
+	*pnum = n[i];
+	*pdenom = d[i];
+}
+
+static int mixel_dphy_config_from_opts(struct phy *phy,
+	       struct phy_configure_opts_mipi_dphy *dphy_opts,
+	       struct mixel_dphy_cfg *cfg)
+{
+	struct mixel_dphy_priv *priv = dev_get_drvdata(phy->dev.parent);
+	unsigned long ref_clk = clk_get_rate(priv->phy_ref_clk);
+	u32 lp_t, numerator, denominator;
+	unsigned long long tmp;
+	u32 n;
+	int i;
+
+	if (dphy_opts->hs_clk_rate > DATA_RATE_MAX_SPEED ||
+	    dphy_opts->hs_clk_rate < DATA_RATE_MIN_SPEED)
+		return -EINVAL;
+
+	numerator = dphy_opts->hs_clk_rate;
+	denominator = ref_clk;
+	get_best_ratio(&numerator, &denominator, 255, 256);
+	if (!numerator || !denominator) {
+		dev_err(&phy->dev, "Invalid %d/%d for %ld/%ld\n",
+			numerator, denominator,
+			dphy_opts->hs_clk_rate, ref_clk);
+		return -EINVAL;
+	}
+
+	while ((numerator < 16) && (denominator <= 128)) {
+		numerator <<= 1;
+		denominator <<= 1;
+	}
+	/*
+	 * CM ranges between 16 and 255
+	 * CN ranges between 1 and 32
+	 * CO is power of 2: 1, 2, 4, 8
+	 */
+	i = __ffs(denominator);
+	if (i > 3)
+		i = 3;
+	cfg->cn = denominator >> i;
+	cfg->co = 1 << i;
+	cfg->cm = numerator;
+
+	if (cfg->cm < 16 || cfg->cm > 255 ||
+	    cfg->cn < 1 || cfg->cn > 32 ||
+	    cfg->co < 1 || cfg->co > 8) {
+		dev_err(&phy->dev, "Invalid CM/CN/CO values: %u/%u/%u\n",
+			cfg->cm, cfg->cn, cfg->co);
+		dev_err(&phy->dev, "for hs_clk/ref_clk=%ld/%ld ~ %d/%d\n",
+			dphy_opts->hs_clk_rate, ref_clk,
+			numerator, denominator);
+		return -EINVAL;
+	}
+
+	dev_dbg(&phy->dev, "hs_clk/ref_clk=%ld/%ld ~ %d/%d\n",
+		dphy_opts->hs_clk_rate, ref_clk, numerator, denominator);
+
+	/* LP clock period */
+	tmp = 1000000000000LL;
+	do_div(tmp, dphy_opts->lp_clk_rate); /* ps */
+	if (tmp > ULONG_MAX)
+		return -EINVAL;
+
+	lp_t = tmp;
+	dev_dbg(&phy->dev, "LP clock %lu, period: %u ps\n",
+		dphy_opts->lp_clk_rate, lp_t);
+
+	/* hs_prepare: in lp clock periods */
+	if (2 * dphy_opts->hs_prepare > 5 * lp_t) {
+		dev_err(&phy->dev,
+			"hs_prepare (%u) > 2.5 * lp clock period (%u)\n",
+			dphy_opts->hs_prepare, lp_t);
+		return -EINVAL;
+	}
+	/* 00: lp_t, 01: 1.5 * lp_t, 10: 2 * lp_t, 11: 2.5 * lp_t */
+	if (dphy_opts->hs_prepare < lp_t) {
+		n = 0;
+	} else {
+		tmp = 2 * (dphy_opts->hs_prepare - lp_t);
+		do_div(tmp, lp_t);
+		n = tmp;
+	}
+	cfg->m_prg_hs_prepare = n;
+
+	/* clk_prepare: in lp clock periods */
+	if (2 * dphy_opts->clk_prepare > 3 * lp_t) {
+		dev_err(&phy->dev,
+			"clk_prepare (%u) > 1.5 * lp clock period (%u)\n",
+			dphy_opts->clk_prepare, lp_t);
+		return -EINVAL;
+	}
+	/* 00: lp_t, 01: 1.5 * lp_t */
+	cfg->mc_prg_hs_prepare = dphy_opts->clk_prepare > lp_t ? 1 : 0;
+
+	/* hs_zero: formula from NXP BSP */
+	n = (144 * (dphy_opts->hs_clk_rate / 1000000) - 47500) / 10000;
+	cfg->m_prg_hs_zero = n < 1 ? 1 : n;
+
+	/* clk_zero: formula from NXP BSP */
+	n = (34 * (dphy_opts->hs_clk_rate / 1000000) - 2500) / 1000;
+	cfg->mc_prg_hs_zero = n < 1 ? 1 : n;
+
+	/* clk_trail, hs_trail: formula from NXP BSP */
+	n = (103 * (dphy_opts->hs_clk_rate / 1000000) + 10000) / 10000;
+	if (n > 15)
+		n = 15;
+	if (n < 1)
+		n = 1;
+	cfg->m_prg_hs_trail = n;
+	cfg->mc_prg_hs_trail = n;
+
+	/* rxhs_settle: formula from NXP BSP */
+	if (dphy_opts->hs_clk_rate < MBPS(80))
+		cfg->rxhs_settle = 0x0d;
+	else if (dphy_opts->hs_clk_rate < MBPS(90))
+		cfg->rxhs_settle = 0x0c;
+	else if (dphy_opts->hs_clk_rate < MBPS(125))
+		cfg->rxhs_settle = 0x0b;
+	else if (dphy_opts->hs_clk_rate < MBPS(150))
+		cfg->rxhs_settle = 0x0a;
+	else if (dphy_opts->hs_clk_rate < MBPS(225))
+		cfg->rxhs_settle = 0x09;
+	else if (dphy_opts->hs_clk_rate < MBPS(500))
+		cfg->rxhs_settle = 0x08;
+	else
+		cfg->rxhs_settle = 0x07;
+
+	dev_dbg(&phy->dev, "phy_config: %u %u %u %u %u %u %u\n",
+		cfg->m_prg_hs_prepare, cfg->mc_prg_hs_prepare,
+		cfg->m_prg_hs_zero, cfg->mc_prg_hs_zero,
+		cfg->m_prg_hs_trail, cfg->mc_prg_hs_trail,
+		cfg->rxhs_settle);
+
+	return 0;
+}
+
+static void mixel_phy_set_hs_timings(struct phy *phy)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+
+	phy_write(phy, priv->cfg.m_prg_hs_prepare, DPHY_M_PRG_HS_PREPARE);
+	phy_write(phy, priv->cfg.mc_prg_hs_prepare, DPHY_MC_PRG_HS_PREPARE);
+	phy_write(phy, priv->cfg.m_prg_hs_zero, DPHY_M_PRG_HS_ZERO);
+	phy_write(phy, priv->cfg.mc_prg_hs_zero, DPHY_MC_PRG_HS_ZERO);
+	phy_write(phy, priv->cfg.m_prg_hs_trail, DPHY_M_PRG_HS_TRAIL);
+	phy_write(phy, priv->cfg.mc_prg_hs_trail, DPHY_MC_PRG_HS_TRAIL);
+	phy_write(phy, priv->cfg.rxhs_settle, priv->devdata->reg_rxhs_settle);
+}
+
+static int mixel_dphy_set_pll_params(struct phy *phy)
+{
+	struct mixel_dphy_priv *priv = dev_get_drvdata(phy->dev.parent);
+
+	if (priv->cfg.cm < 16 || priv->cfg.cm > 255 ||
+	    priv->cfg.cn < 1 || priv->cfg.cn > 32 ||
+	    priv->cfg.co < 1 || priv->cfg.co > 8) {
+		dev_err(&phy->dev, "Invalid CM/CN/CO values! (%u/%u/%u)\n",
+			priv->cfg.cm, priv->cfg.cn, priv->cfg.co);
+		return -EINVAL;
+	}
+	dev_dbg(&phy->dev, "Using CM:%u CN:%u CO:%u\n",
+		priv->cfg.cm, priv->cfg.cn, priv->cfg.co);
+	phy_write(phy, CM(priv->cfg.cm), DPHY_CM);
+	phy_write(phy, CN(priv->cfg.cn), DPHY_CN);
+	phy_write(phy, CO(priv->cfg.co), DPHY_CO);
+	return 0;
+}
+
+static int mixel_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+	struct mixel_dphy_cfg cfg = { 0 };
+	int ret;
+
+	ret = mixel_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
+	if (ret)
+		return ret;
+
+	/* Update the configuration */
+	memcpy(&priv->cfg, &cfg, sizeof(struct mixel_dphy_cfg));
+
+	phy_write(phy, 0x00, DPHY_LOCK_BYP);
+	phy_write(phy, 0x01, priv->devdata->reg_tx_rcal);
+	phy_write(phy, 0x00, priv->devdata->reg_auto_pd_en);
+	phy_write(phy, 0x02, priv->devdata->reg_rxlprp);
+	phy_write(phy, 0x02, priv->devdata->reg_rxcdrp);
+	phy_write(phy, 0x25, DPHY_TST);
+
+	mixel_phy_set_hs_timings(phy);
+	ret = mixel_dphy_set_pll_params(phy);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int mixel_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
+			       union phy_configure_opts *opts)
+{
+	struct mixel_dphy_cfg cfg = { 0 };
+
+	if (mode != PHY_MODE_MIPI_DPHY)
+		return -EINVAL;
+
+	return mixel_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
+}
+
+static int mixel_dphy_init(struct phy *phy)
+{
+	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
+	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
+
+	return 0;
+}
+
+static int mixel_dphy_exit(struct phy *phy)
+{
+	phy_write(phy, 0, DPHY_CM);
+	phy_write(phy, 0, DPHY_CN);
+	phy_write(phy, 0, DPHY_CO);
+
+	return 0;
+}
+
+static int mixel_dphy_power_on(struct phy *phy)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+	u32 locked;
+	int ret;
+
+	ret = clk_prepare_enable(priv->phy_ref_clk);
+	if (ret < 0)
+		return ret;
+
+	phy_write(phy, PWR_ON, DPHY_PD_PLL);
+	ret = regmap_read_poll_timeout(priv->regmap, DPHY_LOCK, locked,
+				       locked, PLL_LOCK_SLEEP,
+				       PLL_LOCK_TIMEOUT);
+	if (ret < 0) {
+		dev_err(&phy->dev, "Could not get DPHY lock (%d)!\n", ret);
+		goto clock_disable;
+	}
+	phy_write(phy, PWR_ON, DPHY_PD_DPHY);
+
+	return 0;
+clock_disable:
+	clk_disable_unprepare(priv->phy_ref_clk);
+	return ret;
+}
+
+static int mixel_dphy_power_off(struct phy *phy)
+{
+	struct mixel_dphy_priv *priv = phy_get_drvdata(phy);
+
+	phy_write(phy, PWR_OFF, DPHY_PD_PLL);
+	phy_write(phy, PWR_OFF, DPHY_PD_DPHY);
+
+	clk_disable_unprepare(priv->phy_ref_clk);
+
+	return 0;
+}
+
+static const struct phy_ops mixel_dphy_phy_ops = {
+	.init = mixel_dphy_init,
+	.exit = mixel_dphy_exit,
+	.power_on = mixel_dphy_power_on,
+	.power_off = mixel_dphy_power_off,
+	.configure = mixel_dphy_configure,
+	.validate = mixel_dphy_validate,
+	.owner = THIS_MODULE,
+};
+
+static const struct of_device_id mixel_dphy_of_match[] = {
+	{ .compatible = "fsl,imx8mq-mipi-dphy",
+	  .data = &mixel_dphy_devdata[MIXEL_IMX8MQ] },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mixel_dphy_of_match);
+
+static int mixel_dphy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct phy_provider *phy_provider;
+	struct mixel_dphy_priv *priv;
+	struct resource *res;
+	struct phy *phy;
+	void __iomem *base;
+
+	if (!np)
+		return -ENODEV;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->devdata = of_device_get_match_data(&pdev->dev);
+	if (!priv->devdata)
+		return -EINVAL;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+					     &mixel_dphy_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		dev_err(dev, "Couldn't create the DPHY regmap\n");
+		return PTR_ERR(priv->regmap);
+	}
+
+	priv->phy_ref_clk = devm_clk_get(&pdev->dev, "phy_ref");
+	if (IS_ERR(priv->phy_ref_clk)) {
+		dev_err(dev, "No phy_ref clock found\n");
+		return PTR_ERR(priv->phy_ref_clk);
+	}
+	dev_dbg(dev, "phy_ref clock rate: %lu\n",
+		clk_get_rate(priv->phy_ref_clk));
+
+	dev_set_drvdata(dev, priv);
+
+	phy = devm_phy_create(dev, np, &mixel_dphy_phy_ops);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "Failed to create phy %ld\n", PTR_ERR(phy));
+		return PTR_ERR(phy);
+	}
+	phy_set_drvdata(phy, priv);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static struct platform_driver mixel_dphy_driver = {
+	.probe	= mixel_dphy_probe,
+	.driver = {
+		.name = "mixel-mipi-dphy",
+		.of_match_table	= mixel_dphy_of_match,
+	}
+};
+module_platform_driver(mixel_dphy_driver);
+
+MODULE_AUTHOR("NXP Semiconductor");
+MODULE_DESCRIPTION("Mixel MIPI-DSI PHY driver");
+MODULE_LICENSE("GPL");