// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2009-2018, Linux Foundation. All rights reserved.
 * Copyright (c) 2018-2020, Linaro Limited
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/slab.h>

/* PHY register and bit definitions */
#define PHY_CTRL_COMMON0		0x078
#define SIDDQ				BIT(2)
#define PHY_IRQ_CMD			0x0d0
#define PHY_INTR_MASK0			0x0d4
#define PHY_INTR_CLEAR0			0x0dc
#define DPDM_MASK			0x1e
#define DP_1_0				BIT(4)
#define DP_0_1				BIT(3)
#define DM_1_0				BIT(2)
#define DM_0_1				BIT(1)

enum hsphy_voltage {
	VOL_NONE,
	VOL_MIN,
	VOL_MAX,
	VOL_NUM,
};

enum hsphy_vreg {
	VDD,
	VDDA_1P8,
	VDDA_3P3,
	VREG_NUM,
};

struct hsphy_init_seq {
	int offset;
	int val;
	int delay;
};

struct hsphy_data {
	const struct hsphy_init_seq *init_seq;
	unsigned int init_seq_num;
};

struct hsphy_priv {
	void __iomem *base;
	struct clk_bulk_data *clks;
	int num_clks;
	struct reset_control *phy_reset;
	struct reset_control *por_reset;
	struct regulator_bulk_data vregs[VREG_NUM];
	const struct hsphy_data *data;
	enum phy_mode mode;
};

static int qcom_snps_hsphy_set_mode(struct phy *phy, enum phy_mode mode,
				    int submode)
{
	struct hsphy_priv *priv = phy_get_drvdata(phy);

	priv->mode = PHY_MODE_INVALID;

	if (mode > 0)
		priv->mode = mode;

	return 0;
}

static void qcom_snps_hsphy_enable_hv_interrupts(struct hsphy_priv *priv)
{
	u32 val;

	/* Clear any existing interrupts before enabling the interrupts */
	val = readb(priv->base + PHY_INTR_CLEAR0);
	val |= DPDM_MASK;
	writeb(val, priv->base + PHY_INTR_CLEAR0);

	writeb(0x0, priv->base + PHY_IRQ_CMD);
	usleep_range(200, 220);
	writeb(0x1, priv->base + PHY_IRQ_CMD);

	/* Make sure the interrupts are cleared */
	usleep_range(200, 220);

	val = readb(priv->base + PHY_INTR_MASK0);
	switch (priv->mode) {
	case PHY_MODE_USB_HOST_HS:
	case PHY_MODE_USB_HOST_FS:
	case PHY_MODE_USB_DEVICE_HS:
	case PHY_MODE_USB_DEVICE_FS:
		val |= DP_1_0 | DM_0_1;
		break;
	case PHY_MODE_USB_HOST_LS:
	case PHY_MODE_USB_DEVICE_LS:
		val |= DP_0_1 | DM_1_0;
		break;
	default:
		/* No device connected */
		val |= DP_0_1 | DM_0_1;
		break;
	}
	writeb(val, priv->base + PHY_INTR_MASK0);
}

static void qcom_snps_hsphy_disable_hv_interrupts(struct hsphy_priv *priv)
{
	u32 val;

	val = readb(priv->base + PHY_INTR_MASK0);
	val &= ~DPDM_MASK;
	writeb(val, priv->base + PHY_INTR_MASK0);

	/* Clear any pending interrupts */
	val = readb(priv->base + PHY_INTR_CLEAR0);
	val |= DPDM_MASK;
	writeb(val, priv->base + PHY_INTR_CLEAR0);

	writeb(0x0, priv->base + PHY_IRQ_CMD);
	usleep_range(200, 220);

	writeb(0x1, priv->base + PHY_IRQ_CMD);
	usleep_range(200, 220);
}

static void qcom_snps_hsphy_enter_retention(struct hsphy_priv *priv)
{
	u32 val;

	val = readb(priv->base + PHY_CTRL_COMMON0);
	val |= SIDDQ;
	writeb(val, priv->base + PHY_CTRL_COMMON0);
}

static void qcom_snps_hsphy_exit_retention(struct hsphy_priv *priv)
{
	u32 val;

	val = readb(priv->base + PHY_CTRL_COMMON0);
	val &= ~SIDDQ;
	writeb(val, priv->base + PHY_CTRL_COMMON0);
}

static int qcom_snps_hsphy_power_on(struct phy *phy)
{
	struct hsphy_priv *priv = phy_get_drvdata(phy);
	int ret;

	ret = regulator_bulk_enable(VREG_NUM, priv->vregs);
	if (ret)
		return ret;
	ret = clk_bulk_prepare_enable(priv->num_clks, priv->clks);
	if (ret)
		goto err_disable_regulator;
	qcom_snps_hsphy_disable_hv_interrupts(priv);
	qcom_snps_hsphy_exit_retention(priv);

	return 0;

err_disable_regulator:
	regulator_bulk_disable(VREG_NUM, priv->vregs);

	return ret;
}

static int qcom_snps_hsphy_power_off(struct phy *phy)
{
	struct hsphy_priv *priv = phy_get_drvdata(phy);

	qcom_snps_hsphy_enter_retention(priv);
	qcom_snps_hsphy_enable_hv_interrupts(priv);
	clk_bulk_disable_unprepare(priv->num_clks, priv->clks);
	regulator_bulk_disable(VREG_NUM, priv->vregs);

	return 0;
}

static int qcom_snps_hsphy_reset(struct hsphy_priv *priv)
{
	int ret;

	ret = reset_control_assert(priv->phy_reset);
	if (ret)
		return ret;

	usleep_range(10, 15);

	ret = reset_control_deassert(priv->phy_reset);
	if (ret)
		return ret;

	usleep_range(80, 100);

	return 0;
}

static void qcom_snps_hsphy_init_sequence(struct hsphy_priv *priv)
{
	const struct hsphy_data *data = priv->data;
	const struct hsphy_init_seq *seq;
	int i;

	/* Device match data is optional. */
	if (!data)
		return;

	seq = data->init_seq;

	for (i = 0; i < data->init_seq_num; i++, seq++) {
		writeb(seq->val, priv->base + seq->offset);
		if (seq->delay)
			usleep_range(seq->delay, seq->delay + 10);
	}
}

static int qcom_snps_hsphy_por_reset(struct hsphy_priv *priv)
{
	int ret;

	ret = reset_control_assert(priv->por_reset);
	if (ret)
		return ret;

	/*
	 * The Femto PHY is POR reset in the following scenarios.
	 *
	 * 1. After overriding the parameter registers.
	 * 2. Low power mode exit from PHY retention.
	 *
	 * Ensure that SIDDQ is cleared before bringing the PHY
	 * out of reset.
	 */
	qcom_snps_hsphy_exit_retention(priv);

	/*
	 * As per databook, 10 usec delay is required between
	 * PHY POR assert and de-assert.
	 */
	usleep_range(10, 20);
	ret = reset_control_deassert(priv->por_reset);
	if (ret)
		return ret;

	/*
	 * As per databook, it takes 75 usec for PHY to stabilize
	 * after the reset.
	 */
	usleep_range(80, 100);

	return 0;
}

static int qcom_snps_hsphy_init(struct phy *phy)
{
	struct hsphy_priv *priv = phy_get_drvdata(phy);
	int ret;

	ret = qcom_snps_hsphy_reset(priv);
	if (ret)
		return ret;

	qcom_snps_hsphy_init_sequence(priv);

	ret = qcom_snps_hsphy_por_reset(priv);
	if (ret)
		return ret;

	return 0;
}

static const struct phy_ops qcom_snps_hsphy_ops = {
	.init = qcom_snps_hsphy_init,
	.power_on = qcom_snps_hsphy_power_on,
	.power_off = qcom_snps_hsphy_power_off,
	.set_mode = qcom_snps_hsphy_set_mode,
	.owner = THIS_MODULE,
};

static const char * const qcom_snps_hsphy_clks[] = {
	"ref",
	"ahb",
	"sleep",
};

static int qcom_snps_hsphy_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct phy_provider *provider;
	struct hsphy_priv *priv;
	struct phy *phy;
	int ret;
	int i;

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

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

	priv->num_clks = ARRAY_SIZE(qcom_snps_hsphy_clks);
	priv->clks = devm_kcalloc(dev, priv->num_clks, sizeof(*priv->clks),
				  GFP_KERNEL);
	if (!priv->clks)
		return -ENOMEM;

	for (i = 0; i < priv->num_clks; i++)
		priv->clks[i].id = qcom_snps_hsphy_clks[i];

	ret = devm_clk_bulk_get(dev, priv->num_clks, priv->clks);
	if (ret)
		return ret;

	priv->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
	if (IS_ERR(priv->phy_reset))
		return PTR_ERR(priv->phy_reset);

	priv->por_reset = devm_reset_control_get_exclusive(dev, "por");
	if (IS_ERR(priv->por_reset))
		return PTR_ERR(priv->por_reset);

	priv->vregs[VDD].supply = "vdd";
	priv->vregs[VDDA_1P8].supply = "vdda1p8";
	priv->vregs[VDDA_3P3].supply = "vdda3p3";

	ret = devm_regulator_bulk_get(dev, VREG_NUM, priv->vregs);
	if (ret)
		return ret;

	/* Get device match data */
	priv->data = device_get_match_data(dev);

	phy = devm_phy_create(dev, dev->of_node, &qcom_snps_hsphy_ops);
	if (IS_ERR(phy))
		return PTR_ERR(phy);

	phy_set_drvdata(phy, priv);

	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
	if (IS_ERR(provider))
		return PTR_ERR(provider);

	ret = regulator_set_load(priv->vregs[VDDA_1P8].consumer, 19000);
	if (ret < 0)
		return ret;

	ret = regulator_set_load(priv->vregs[VDDA_3P3].consumer, 16000);
	if (ret < 0)
		goto unset_1p8_load;

	return 0;

unset_1p8_load:
	regulator_set_load(priv->vregs[VDDA_1P8].consumer, 0);

	return ret;
}

/*
 * The macro is used to define an initialization sequence.  Each tuple
 * is meant to program 'value' into phy register at 'offset' with 'delay'
 * in us followed.
 */
#define HSPHY_INIT_CFG(o, v, d)	{ .offset = o, .val = v, .delay = d, }

static const struct hsphy_init_seq init_seq_femtophy[] = {
	HSPHY_INIT_CFG(0xc0, 0x01, 0),
	HSPHY_INIT_CFG(0xe8, 0x0d, 0),
	HSPHY_INIT_CFG(0x74, 0x12, 0),
	HSPHY_INIT_CFG(0x98, 0x63, 0),
	HSPHY_INIT_CFG(0x9c, 0x03, 0),
	HSPHY_INIT_CFG(0xa0, 0x1d, 0),
	HSPHY_INIT_CFG(0xa4, 0x03, 0),
	HSPHY_INIT_CFG(0x8c, 0x23, 0),
	HSPHY_INIT_CFG(0x78, 0x08, 0),
	HSPHY_INIT_CFG(0x7c, 0xdc, 0),
	HSPHY_INIT_CFG(0x90, 0xe0, 20),
	HSPHY_INIT_CFG(0x74, 0x10, 0),
	HSPHY_INIT_CFG(0x90, 0x60, 0),
};

static const struct hsphy_data hsphy_data_femtophy = {
	.init_seq = init_seq_femtophy,
	.init_seq_num = ARRAY_SIZE(init_seq_femtophy),
};

static const struct of_device_id qcom_snps_hsphy_match[] = {
	{ .compatible = "qcom,usb-hs-28nm-femtophy", .data = &hsphy_data_femtophy, },
	{ },
};
MODULE_DEVICE_TABLE(of, qcom_snps_hsphy_match);

static struct platform_driver qcom_snps_hsphy_driver = {
	.probe = qcom_snps_hsphy_probe,
	.driver	= {
		.name = "qcom,usb-hs-28nm-phy",
		.of_match_table = qcom_snps_hsphy_match,
	},
};
module_platform_driver(qcom_snps_hsphy_driver);

MODULE_DESCRIPTION("Qualcomm 28nm Hi-Speed USB PHY driver");
MODULE_LICENSE("GPL v2");