drivers/phy/freescale/phy-fsl-imx8mq-usb.c

// SPDX-License-Identifier: GPL-2.0+
/* Copyright (c) 2017 NXP. */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

#define PHY_CTRL0			0x0
#define PHY_CTRL0_REF_SSP_EN		BIT(2)
#define PHY_CTRL0_FSEL_MASK		GENMASK(10, 5)
#define PHY_CTRL0_FSEL_24M		0x2a

#define PHY_CTRL1			0x4
#define PHY_CTRL1_RESET			BIT(0)
#define PHY_CTRL1_COMMONONN		BIT(1)
#define PHY_CTRL1_ATERESET		BIT(3)
#define PHY_CTRL1_VDATSRCENB0		BIT(19)
#define PHY_CTRL1_VDATDETENB0		BIT(20)

#define PHY_CTRL2			0x8
#define PHY_CTRL2_TXENABLEN0		BIT(8)
#define PHY_CTRL2_OTG_DISABLE		BIT(9)

#define PHY_CTRL3			0xc
#define PHY_CTRL3_COMPDISTUNE_MASK	GENMASK(2, 0)
#define PHY_CTRL3_TXPREEMP_TUNE_MASK	GENMASK(16, 15)
#define PHY_CTRL3_TXRISE_TUNE_MASK	GENMASK(21, 20)
#define PHY_CTRL3_TXVREF_TUNE_MASK	GENMASK(25, 22)
#define PHY_CTRL3_TX_VBOOST_LEVEL_MASK	GENMASK(31, 29)

#define PHY_CTRL4			0x10
#define PHY_CTRL4_PCS_TX_DEEMPH_3P5DB_MASK	GENMASK(20, 15)

#define PHY_CTRL5			0x14
#define PHY_CTRL5_DMPWD_OVERRIDE_SEL	BIT(23)
#define PHY_CTRL5_DMPWD_OVERRIDE	BIT(22)
#define PHY_CTRL5_DPPWD_OVERRIDE_SEL	BIT(21)
#define PHY_CTRL5_DPPWD_OVERRIDE	BIT(20)
#define PHY_CTRL5_PCS_TX_SWING_FULL_MASK	GENMASK(6, 0)

#define PHY_CTRL6			0x18
#define PHY_CTRL6_ALT_CLK_EN		BIT(1)
#define PHY_CTRL6_ALT_CLK_SEL		BIT(0)

#define PHY_TUNE_DEFAULT		0xffffffff

struct imx8mq_usb_phy {
	struct phy *phy;
	struct clk *clk;
	void __iomem *base;
	struct regulator *vbus;
	u32 pcs_tx_swing_full;
	u32 pcs_tx_deemph_3p5db;
	u32 tx_vref_tune;
	u32 tx_rise_tune;
	u32 tx_preemp_amp_tune;
	u32 tx_vboost_level;
	u32 comp_dis_tune;
};

static u32 phy_tx_vref_tune_from_property(u32 percent)
{
	percent = clamp(percent, 94U, 124U);

	return DIV_ROUND_CLOSEST(percent - 94U, 2);
}

static u32 phy_tx_rise_tune_from_property(u32 percent)
{
	switch (percent) {
	case 0 ... 98:
		return 3;
	case 99:
		return 2;
	case 100 ... 101:
		return 1;
	default:
		return 0;
	}
}

static u32 phy_tx_preemp_amp_tune_from_property(u32 microamp)
{
	microamp = min(microamp, 1800U);

	return microamp / 600;
}

static u32 phy_tx_vboost_level_from_property(u32 microvolt)
{
	switch (microvolt) {
	case 0 ... 960:
		return 0;
	case 961 ... 1160:
		return 2;
	default:
		return 3;
	}
}

static u32 phy_pcs_tx_deemph_3p5db_from_property(u32 decibel)
{
	return min(decibel, 36U);
}

static u32 phy_comp_dis_tune_from_property(u32 percent)
{
	switch (percent) {
	case 0 ... 92:
		return 0;
	case 93 ... 95:
		return 1;
	case 96 ... 97:
		return 2;
	case 98 ... 102:
		return 3;
	case 103 ... 105:
		return 4;
	case 106 ... 109:
		return 5;
	case 110 ... 113:
		return 6;
	default:
		return 7;
	}
}
static u32 phy_pcs_tx_swing_full_from_property(u32 percent)
{
	percent = min(percent, 100U);

	return (percent * 127) / 100;
}

static void imx8m_get_phy_tuning_data(struct imx8mq_usb_phy *imx_phy)
{
	struct device *dev = imx_phy->phy->dev.parent;

	if (device_property_read_u32(dev, "fsl,phy-tx-vref-tune-percent",
				     &imx_phy->tx_vref_tune))
		imx_phy->tx_vref_tune = PHY_TUNE_DEFAULT;
	else
		imx_phy->tx_vref_tune =
			phy_tx_vref_tune_from_property(imx_phy->tx_vref_tune);

	if (device_property_read_u32(dev, "fsl,phy-tx-rise-tune-percent",
				     &imx_phy->tx_rise_tune))
		imx_phy->tx_rise_tune = PHY_TUNE_DEFAULT;
	else
		imx_phy->tx_rise_tune =
			phy_tx_rise_tune_from_property(imx_phy->tx_rise_tune);

	if (device_property_read_u32(dev, "fsl,phy-tx-preemp-amp-tune-microamp",
				     &imx_phy->tx_preemp_amp_tune))
		imx_phy->tx_preemp_amp_tune = PHY_TUNE_DEFAULT;
	else
		imx_phy->tx_preemp_amp_tune =
			phy_tx_preemp_amp_tune_from_property(imx_phy->tx_preemp_amp_tune);

	if (device_property_read_u32(dev, "fsl,phy-tx-vboost-level-microvolt",
				     &imx_phy->tx_vboost_level))
		imx_phy->tx_vboost_level = PHY_TUNE_DEFAULT;
	else
		imx_phy->tx_vboost_level =
			phy_tx_vboost_level_from_property(imx_phy->tx_vboost_level);

	if (device_property_read_u32(dev, "fsl,phy-comp-dis-tune-percent",
				     &imx_phy->comp_dis_tune))
		imx_phy->comp_dis_tune = PHY_TUNE_DEFAULT;
	else
		imx_phy->comp_dis_tune =
			phy_comp_dis_tune_from_property(imx_phy->comp_dis_tune);

	if (device_property_read_u32(dev, "fsl,pcs-tx-deemph-3p5db-attenuation-db",
				     &imx_phy->pcs_tx_deemph_3p5db))
		imx_phy->pcs_tx_deemph_3p5db = PHY_TUNE_DEFAULT;
	else
		imx_phy->pcs_tx_deemph_3p5db =
			phy_pcs_tx_deemph_3p5db_from_property(imx_phy->pcs_tx_deemph_3p5db);

	if (device_property_read_u32(dev, "fsl,phy-pcs-tx-swing-full-percent",
				     &imx_phy->pcs_tx_swing_full))
		imx_phy->pcs_tx_swing_full = PHY_TUNE_DEFAULT;
	else
		imx_phy->pcs_tx_swing_full =
			phy_pcs_tx_swing_full_from_property(imx_phy->pcs_tx_swing_full);
}

static void imx8m_phy_tune(struct imx8mq_usb_phy *imx_phy)
{
	u32 value;

	/* PHY tuning */
	if (imx_phy->pcs_tx_deemph_3p5db != PHY_TUNE_DEFAULT) {
		value = readl(imx_phy->base + PHY_CTRL4);
		value &= ~PHY_CTRL4_PCS_TX_DEEMPH_3P5DB_MASK;
		value |= FIELD_PREP(PHY_CTRL4_PCS_TX_DEEMPH_3P5DB_MASK,
				   imx_phy->pcs_tx_deemph_3p5db);
		writel(value, imx_phy->base + PHY_CTRL4);
	}

	if (imx_phy->pcs_tx_swing_full != PHY_TUNE_DEFAULT) {
		value = readl(imx_phy->base + PHY_CTRL5);
		value |= FIELD_PREP(PHY_CTRL5_PCS_TX_SWING_FULL_MASK,
				   imx_phy->pcs_tx_swing_full);
		writel(value, imx_phy->base + PHY_CTRL5);
	}

	if ((imx_phy->tx_vref_tune & imx_phy->tx_rise_tune &
	     imx_phy->tx_preemp_amp_tune & imx_phy->comp_dis_tune &
	     imx_phy->tx_vboost_level) == PHY_TUNE_DEFAULT)
		/* If all are the default values, no need update. */
		return;

	value = readl(imx_phy->base + PHY_CTRL3);

	if (imx_phy->tx_vref_tune != PHY_TUNE_DEFAULT) {
		value &= ~PHY_CTRL3_TXVREF_TUNE_MASK;
		value |= FIELD_PREP(PHY_CTRL3_TXVREF_TUNE_MASK,
				   imx_phy->tx_vref_tune);
	}

	if (imx_phy->tx_rise_tune != PHY_TUNE_DEFAULT) {
		value &= ~PHY_CTRL3_TXRISE_TUNE_MASK;
		value |= FIELD_PREP(PHY_CTRL3_TXRISE_TUNE_MASK,
				    imx_phy->tx_rise_tune);
	}

	if (imx_phy->tx_preemp_amp_tune != PHY_TUNE_DEFAULT) {
		value &= ~PHY_CTRL3_TXPREEMP_TUNE_MASK;
		value |= FIELD_PREP(PHY_CTRL3_TXPREEMP_TUNE_MASK,
				imx_phy->tx_preemp_amp_tune);
	}

	if (imx_phy->comp_dis_tune != PHY_TUNE_DEFAULT) {
		value &= ~PHY_CTRL3_COMPDISTUNE_MASK;
		value |= FIELD_PREP(PHY_CTRL3_COMPDISTUNE_MASK,
				    imx_phy->comp_dis_tune);
	}

	if (imx_phy->tx_vboost_level != PHY_TUNE_DEFAULT) {
		value &= ~PHY_CTRL3_TX_VBOOST_LEVEL_MASK;
		value |= FIELD_PREP(PHY_CTRL3_TX_VBOOST_LEVEL_MASK,
				    imx_phy->tx_vboost_level);
	}

	writel(value, imx_phy->base + PHY_CTRL3);
}

static int imx8mq_usb_phy_init(struct phy *phy)
{
	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
	u32 value;

	value = readl(imx_phy->base + PHY_CTRL1);
	value &= ~(PHY_CTRL1_VDATSRCENB0 | PHY_CTRL1_VDATDETENB0 |
		   PHY_CTRL1_COMMONONN);
	value |= PHY_CTRL1_RESET | PHY_CTRL1_ATERESET;
	writel(value, imx_phy->base + PHY_CTRL1);

	value = readl(imx_phy->base + PHY_CTRL0);
	value |= PHY_CTRL0_REF_SSP_EN;
	writel(value, imx_phy->base + PHY_CTRL0);

	value = readl(imx_phy->base + PHY_CTRL2);
	value |= PHY_CTRL2_TXENABLEN0;
	writel(value, imx_phy->base + PHY_CTRL2);

	value = readl(imx_phy->base + PHY_CTRL1);
	value &= ~(PHY_CTRL1_RESET | PHY_CTRL1_ATERESET);
	writel(value, imx_phy->base + PHY_CTRL1);

	return 0;
}

static int imx8mp_usb_phy_init(struct phy *phy)
{
	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
	u32 value;

	/* USB3.0 PHY signal fsel for 24M ref */
	value = readl(imx_phy->base + PHY_CTRL0);
	value &= ~PHY_CTRL0_FSEL_MASK;
	value |= FIELD_PREP(PHY_CTRL0_FSEL_MASK, PHY_CTRL0_FSEL_24M);
	writel(value, imx_phy->base + PHY_CTRL0);

	/* Disable alt_clk_en and use internal MPLL clocks */
	value = readl(imx_phy->base + PHY_CTRL6);
	value &= ~(PHY_CTRL6_ALT_CLK_SEL | PHY_CTRL6_ALT_CLK_EN);
	writel(value, imx_phy->base + PHY_CTRL6);

	value = readl(imx_phy->base + PHY_CTRL1);
	value &= ~(PHY_CTRL1_VDATSRCENB0 | PHY_CTRL1_VDATDETENB0);
	value |= PHY_CTRL1_RESET | PHY_CTRL1_ATERESET;
	writel(value, imx_phy->base + PHY_CTRL1);

	value = readl(imx_phy->base + PHY_CTRL0);
	value |= PHY_CTRL0_REF_SSP_EN;
	writel(value, imx_phy->base + PHY_CTRL0);

	value = readl(imx_phy->base + PHY_CTRL2);
	value |= PHY_CTRL2_TXENABLEN0 | PHY_CTRL2_OTG_DISABLE;
	writel(value, imx_phy->base + PHY_CTRL2);

	udelay(10);

	value = readl(imx_phy->base + PHY_CTRL1);
	value &= ~(PHY_CTRL1_RESET | PHY_CTRL1_ATERESET);
	writel(value, imx_phy->base + PHY_CTRL1);

	imx8m_phy_tune(imx_phy);

	return 0;
}

static int imx8mq_phy_power_on(struct phy *phy)
{
	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
	int ret;

	ret = regulator_enable(imx_phy->vbus);
	if (ret)
		return ret;

	return clk_prepare_enable(imx_phy->clk);
}

static int imx8mq_phy_power_off(struct phy *phy)
{
	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);

	clk_disable_unprepare(imx_phy->clk);
	regulator_disable(imx_phy->vbus);

	return 0;
}

static const struct phy_ops imx8mq_usb_phy_ops = {
	.init		= imx8mq_usb_phy_init,
	.power_on	= imx8mq_phy_power_on,
	.power_off	= imx8mq_phy_power_off,
	.owner		= THIS_MODULE,
};

static const struct phy_ops imx8mp_usb_phy_ops = {
	.init		= imx8mp_usb_phy_init,
	.power_on	= imx8mq_phy_power_on,
	.power_off	= imx8mq_phy_power_off,
	.owner		= THIS_MODULE,
};

static const struct of_device_id imx8mq_usb_phy_of_match[] = {
	{.compatible = "fsl,imx8mq-usb-phy",
	 .data = &imx8mq_usb_phy_ops,},
	{.compatible = "fsl,imx8mp-usb-phy",
	 .data = &imx8mp_usb_phy_ops,},
	{ }
};
MODULE_DEVICE_TABLE(of, imx8mq_usb_phy_of_match);

static int imx8mq_usb_phy_probe(struct platform_device *pdev)
{
	struct phy_provider *phy_provider;
	struct device *dev = &pdev->dev;
	struct imx8mq_usb_phy *imx_phy;
	const struct phy_ops *phy_ops;

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

	imx_phy->clk = devm_clk_get(dev, "phy");
	if (IS_ERR(imx_phy->clk)) {
		dev_err(dev, "failed to get imx8mq usb phy clock\n");
		return PTR_ERR(imx_phy->clk);
	}

	imx_phy->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(imx_phy->base))
		return PTR_ERR(imx_phy->base);

	phy_ops = of_device_get_match_data(dev);
	if (!phy_ops)
		return -EINVAL;

	imx_phy->phy = devm_phy_create(dev, NULL, phy_ops);
	if (IS_ERR(imx_phy->phy))
		return PTR_ERR(imx_phy->phy);

	imx_phy->vbus = devm_regulator_get(dev, "vbus");
	if (IS_ERR(imx_phy->vbus))
		return dev_err_probe(dev, PTR_ERR(imx_phy->vbus), "failed to get vbus\n");

	phy_set_drvdata(imx_phy->phy, imx_phy);

	imx8m_get_phy_tuning_data(imx_phy);

	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);

	return PTR_ERR_OR_ZERO(phy_provider);
}

static struct platform_driver imx8mq_usb_phy_driver = {
	.probe	= imx8mq_usb_phy_probe,
	.driver = {
		.name	= "imx8mq-usb-phy",
		.of_match_table	= imx8mq_usb_phy_of_match,
	}
};
module_platform_driver(imx8mq_usb_phy_driver);

MODULE_DESCRIPTION("FSL IMX8MQ USB PHY driver");
MODULE_LICENSE("GPL");