// SPDX-License-Identifier: GPL-2.0
/*
 * phy-uniphier-usb3ss.c - SS-PHY driver for Socionext UniPhier USB3 controller
 * Copyright 2015-2018 Socionext Inc.
 * Author:
 *      Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
 * Contributors:
 *      Motoya Tanigawa <tanigawa.motoya@socionext.com>
 *      Masami Hiramatsu <masami.hiramatsu@linaro.org>
 */

#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/io.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/regulator/consumer.h>
#include <linux/reset.h>

#define SSPHY_TESTI		0x0
#define SSPHY_TESTO		0x4
#define TESTI_DAT_MASK		GENMASK(13, 6)
#define TESTI_ADR_MASK		GENMASK(5, 1)
#define TESTI_WR_EN		BIT(0)

#define PHY_F(regno, msb, lsb) { (regno), (msb), (lsb) }

#define CDR_CPD_TRIM	PHY_F(7, 3, 0)	/* RxPLL charge pump current */
#define CDR_CPF_TRIM	PHY_F(8, 3, 0)	/* RxPLL charge pump current 2 */
#define TX_PLL_TRIM	PHY_F(9, 3, 0)	/* TxPLL charge pump current */
#define BGAP_TRIM	PHY_F(11, 3, 0)	/* Bandgap voltage */
#define CDR_TRIM	PHY_F(13, 6, 5)	/* Clock Data Recovery setting */
#define VCO_CTRL	PHY_F(26, 7, 4)	/* VCO control */
#define VCOPLL_CTRL	PHY_F(27, 2, 0)	/* TxPLL VCO tuning */
#define VCOPLL_CM	PHY_F(28, 1, 0)	/* TxPLL voltage */

#define MAX_PHY_PARAMS	7

struct uniphier_u3ssphy_param {
	struct {
		int reg_no;
		int msb;
		int lsb;
	} field;
	u8 value;
};

struct uniphier_u3ssphy_priv {
	struct device *dev;
	void __iomem *base;
	struct clk *clk, *clk_ext, *clk_parent, *clk_parent_gio;
	struct reset_control *rst, *rst_parent, *rst_parent_gio;
	struct regulator *vbus;
	const struct uniphier_u3ssphy_soc_data *data;
};

struct uniphier_u3ssphy_soc_data {
	bool is_legacy;
	int nparams;
	const struct uniphier_u3ssphy_param param[MAX_PHY_PARAMS];
};

static void uniphier_u3ssphy_testio_write(struct uniphier_u3ssphy_priv *priv,
					  u32 data)
{
	/* need to read TESTO twice after accessing TESTI */
	writel(data, priv->base + SSPHY_TESTI);
	readl(priv->base + SSPHY_TESTO);
	readl(priv->base + SSPHY_TESTO);
}

static void uniphier_u3ssphy_set_param(struct uniphier_u3ssphy_priv *priv,
				       const struct uniphier_u3ssphy_param *p)
{
	u32 val;
	u8 field_mask = GENMASK(p->field.msb, p->field.lsb);
	u8 data;

	/* read previous data */
	val  = FIELD_PREP(TESTI_DAT_MASK, 1);
	val |= FIELD_PREP(TESTI_ADR_MASK, p->field.reg_no);
	uniphier_u3ssphy_testio_write(priv, val);
	val = readl(priv->base + SSPHY_TESTO);

	/* update value */
	val &= ~FIELD_PREP(TESTI_DAT_MASK, field_mask);
	data = field_mask & (p->value << p->field.lsb);
	val  = FIELD_PREP(TESTI_DAT_MASK, data);
	val |= FIELD_PREP(TESTI_ADR_MASK, p->field.reg_no);
	uniphier_u3ssphy_testio_write(priv, val);
	uniphier_u3ssphy_testio_write(priv, val | TESTI_WR_EN);
	uniphier_u3ssphy_testio_write(priv, val);

	/* read current data as dummy */
	val  = FIELD_PREP(TESTI_DAT_MASK, 1);
	val |= FIELD_PREP(TESTI_ADR_MASK, p->field.reg_no);
	uniphier_u3ssphy_testio_write(priv, val);
	readl(priv->base + SSPHY_TESTO);
}

static int uniphier_u3ssphy_power_on(struct phy *phy)
{
	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);
	int ret;

	ret = clk_prepare_enable(priv->clk_ext);
	if (ret)
		return ret;

	ret = clk_prepare_enable(priv->clk);
	if (ret)
		goto out_clk_ext_disable;

	ret = reset_control_deassert(priv->rst);
	if (ret)
		goto out_clk_disable;

	if (priv->vbus) {
		ret = regulator_enable(priv->vbus);
		if (ret)
			goto out_rst_assert;
	}

	return 0;

out_rst_assert:
	reset_control_assert(priv->rst);
out_clk_disable:
	clk_disable_unprepare(priv->clk);
out_clk_ext_disable:
	clk_disable_unprepare(priv->clk_ext);

	return ret;
}

static int uniphier_u3ssphy_power_off(struct phy *phy)
{
	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);

	if (priv->vbus)
		regulator_disable(priv->vbus);

	reset_control_assert(priv->rst);
	clk_disable_unprepare(priv->clk);
	clk_disable_unprepare(priv->clk_ext);

	return 0;
}

static int uniphier_u3ssphy_init(struct phy *phy)
{
	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);
	int i, ret;

	ret = clk_prepare_enable(priv->clk_parent);
	if (ret)
		return ret;

	ret = clk_prepare_enable(priv->clk_parent_gio);
	if (ret)
		goto out_clk_disable;

	ret = reset_control_deassert(priv->rst_parent);
	if (ret)
		goto out_clk_gio_disable;

	ret = reset_control_deassert(priv->rst_parent_gio);
	if (ret)
		goto out_rst_assert;

	if (priv->data->is_legacy)
		return 0;

	for (i = 0; i < priv->data->nparams; i++)
		uniphier_u3ssphy_set_param(priv, &priv->data->param[i]);

	return 0;

out_rst_assert:
	reset_control_assert(priv->rst_parent);
out_clk_gio_disable:
	clk_disable_unprepare(priv->clk_parent_gio);
out_clk_disable:
	clk_disable_unprepare(priv->clk_parent);

	return ret;
}

static int uniphier_u3ssphy_exit(struct phy *phy)
{
	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);

	reset_control_assert(priv->rst_parent_gio);
	reset_control_assert(priv->rst_parent);
	clk_disable_unprepare(priv->clk_parent_gio);
	clk_disable_unprepare(priv->clk_parent);

	return 0;
}

static const struct phy_ops uniphier_u3ssphy_ops = {
	.init           = uniphier_u3ssphy_init,
	.exit           = uniphier_u3ssphy_exit,
	.power_on       = uniphier_u3ssphy_power_on,
	.power_off      = uniphier_u3ssphy_power_off,
	.owner          = THIS_MODULE,
};

static int uniphier_u3ssphy_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct uniphier_u3ssphy_priv *priv;
	struct phy_provider *phy_provider;
	struct resource *res;
	struct phy *phy;

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

	priv->dev = dev;
	priv->data = of_device_get_match_data(dev);
	if (WARN_ON(!priv->data ||
		    priv->data->nparams > MAX_PHY_PARAMS))
		return -EINVAL;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(priv->base))
		return PTR_ERR(priv->base);

	if (!priv->data->is_legacy) {
		priv->clk = devm_clk_get(dev, "phy");
		if (IS_ERR(priv->clk))
			return PTR_ERR(priv->clk);

		priv->clk_ext = devm_clk_get_optional(dev, "phy-ext");
		if (IS_ERR(priv->clk_ext))
			return PTR_ERR(priv->clk_ext);

		priv->rst = devm_reset_control_get_shared(dev, "phy");
		if (IS_ERR(priv->rst))
			return PTR_ERR(priv->rst);
	} else {
		priv->clk_parent_gio = devm_clk_get(dev, "gio");
		if (IS_ERR(priv->clk_parent_gio))
			return PTR_ERR(priv->clk_parent_gio);

		priv->rst_parent_gio =
			devm_reset_control_get_shared(dev, "gio");
		if (IS_ERR(priv->rst_parent_gio))
			return PTR_ERR(priv->rst_parent_gio);
	}

	priv->clk_parent = devm_clk_get(dev, "link");
	if (IS_ERR(priv->clk_parent))
		return PTR_ERR(priv->clk_parent);

	priv->rst_parent = devm_reset_control_get_shared(dev, "link");
	if (IS_ERR(priv->rst_parent))
		return PTR_ERR(priv->rst_parent);

	priv->vbus = devm_regulator_get_optional(dev, "vbus");
	if (IS_ERR(priv->vbus)) {
		if (PTR_ERR(priv->vbus) == -EPROBE_DEFER)
			return PTR_ERR(priv->vbus);
		priv->vbus = NULL;
	}

	phy = devm_phy_create(dev, dev->of_node, &uniphier_u3ssphy_ops);
	if (IS_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 const struct uniphier_u3ssphy_soc_data uniphier_pro4_data = {
	.is_legacy = true,
};

static const struct uniphier_u3ssphy_soc_data uniphier_pxs2_data = {
	.is_legacy = false,
	.nparams = 7,
	.param = {
		{ CDR_CPD_TRIM, 10 },
		{ CDR_CPF_TRIM, 3 },
		{ TX_PLL_TRIM, 5 },
		{ BGAP_TRIM, 9 },
		{ CDR_TRIM, 2 },
		{ VCOPLL_CTRL, 7 },
		{ VCOPLL_CM, 1 },
	},
};

static const struct uniphier_u3ssphy_soc_data uniphier_ld20_data = {
	.is_legacy = false,
	.nparams = 3,
	.param = {
		{ CDR_CPD_TRIM, 6 },
		{ CDR_TRIM, 2 },
		{ VCO_CTRL, 5 },
	},
};

static const struct of_device_id uniphier_u3ssphy_match[] = {
	{
		.compatible = "socionext,uniphier-pro4-usb3-ssphy",
		.data = &uniphier_pro4_data,
	},
	{
		.compatible = "socionext,uniphier-pxs2-usb3-ssphy",
		.data = &uniphier_pxs2_data,
	},
	{
		.compatible = "socionext,uniphier-ld20-usb3-ssphy",
		.data = &uniphier_ld20_data,
	},
	{
		.compatible = "socionext,uniphier-pxs3-usb3-ssphy",
		.data = &uniphier_ld20_data,
	},
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, uniphier_u3ssphy_match);

static struct platform_driver uniphier_u3ssphy_driver = {
	.probe = uniphier_u3ssphy_probe,
	.driver	= {
		.name = "uniphier-usb3-ssphy",
		.of_match_table	= uniphier_u3ssphy_match,
	},
};

module_platform_driver(uniphier_u3ssphy_driver);

MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
MODULE_DESCRIPTION("UniPhier SS-PHY driver for USB3 controller");
MODULE_LICENSE("GPL v2");