phy: rcar-gen3-usb3: add support for R-Car Gen3 USB 3.0 PHY

* Renesas R-Car generation 3 USB 3.0 PHY

This file provides information on what the device node for the R-Car generation

3 USB 3.0 PHY contains.

If you want to enable spread spectrum clock (ssc), you should use USB_EXTAL

instead of USB3_CLK. However, if you don't want to these features, you don't

need this driver.

Required properties:

- compatible: "renesas,r8a7795-usb3-phy" if the device is a part of an R8A7795

	      SoC.

	      "renesas,r8a7796-usb3-phy" if the device is a part of an R8A7796

	      SoC.

	      "renesas,rcar-gen3-usb3-phy" for a generic R-Car Gen3 compatible

	      device.

	      When compatible with the generic version, nodes must list the

	      SoC-specific version corresponding to the platform first

	      followed by the generic version.

- reg: offset and length of the USB 3.0 PHY register block.

- clocks: A list of phandles and clock-specifier pairs.

- clock-names: Name of the clocks.

  - The funcional clock must be "usb3-if".

  - The usb3's external clock must be "usb3s_clk".

  - The usb2's external clock must be "usb_extal". If you want to use the ssc,

    the clock-frequency must not be 0.

- #phy-cells: see phy-bindings.txt in the same directory, must be <0>.

Optional properties:

- renesas,ssc-range: Enable/disable spread spectrum clock (ssc) by using

		     the following values as u32:

			- 0 (or the property doesn't exist): disable the ssc

			- 4980: enable the ssc as -4980 ppm

			- 4492: enable the ssc as -4492 ppm

			- 4003: enable the ssc as -4003 ppm

Example (R-Car H3):

	usb-phy@e65ee000 {

		compatible = "renesas,r8a7795-usb3-phy",

			     "renesas,rcar-gen3-usb3-phy";

		reg = <0 0xe65ee000 0 0x90>;

		clocks = <&cpg CPG_MOD 328>, <&usb3s0_clk>, <&usb_extal>;

		clock-names = "usb3-if", "usb3s_clk", "usb_extal";

	};

S:	Supported

F:	drivers/iio/adc/rcar_gyro_adc.c

RENESAS USB2 PHY DRIVER

RENESAS USB PHY DRIVER

M:	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

L:	linux-renesas-soc@vger.kernel.org

S:	Maintained

F:	drivers/phy/renesas/phy-rcar-gen3-usb2.c

F:	drivers/phy/renesas/phy-rcar-gen3-usb*.c

RESET CONTROLLER FRAMEWORK

M:	Philipp Zabel <p.zabel@pengutronix.de>

	select GENERIC_PHY

	help

	  Support for USB 2.0 PHY found on Renesas R-Car generation 3 SoCs.

config PHY_RCAR_GEN3_USB3

	tristate "Renesas R-Car generation 3 USB 3.0 PHY driver"

	depends on ARCH_RENESAS || COMPILE_TEST

	select GENERIC_PHY

	help

	  Support for USB 3.0 PHY found on Renesas R-Car generation 3 SoCs.

obj-$(CONFIG_PHY_RCAR_GEN2)		+= phy-rcar-gen2.o

obj-$(CONFIG_PHY_RCAR_GEN3_USB2)	+= phy-rcar-gen3-usb2.o

obj-$(CONFIG_PHY_RCAR_GEN3_USB3)	+= phy-rcar-gen3-usb3.o

/*

 * Renesas R-Car Gen3 for USB3.0 PHY driver

 *

 * Copyright (C) 2017 Renesas Electronics Corporation

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#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/pm_runtime.h>

#define USB30_CLKSET0		0x034

#define USB30_CLKSET1		0x036

#define USB30_SSC_SET		0x038

#define USB30_PHY_ENABLE	0x060

#define USB30_VBUS_EN		0x064

/* USB30_CLKSET0 */

#define CLKSET0_PRIVATE			0x05c0

#define CLKSET0_USB30_FSEL_USB_EXTAL	0x0002

/* USB30_CLKSET1 */

#define CLKSET1_USB30_PLL_MULTI_SHIFT		6

#define CLKSET1_USB30_PLL_MULTI_USB_EXTAL	(0x64 << \

						 CLKSET1_USB30_PLL_MULTI_SHIFT)

#define CLKSET1_PHYRESET	BIT(4)	/* 1: reset */

#define CLKSET1_REF_CLKDIV	BIT(3)	/* 1: USB_EXTAL */

#define CLKSET1_PRIVATE_2_1	BIT(1)	/* Write B'01 */

#define CLKSET1_REF_CLK_SEL	BIT(0)	/* 1: USB3S0_CLK_P */

/* USB30_SSC_SET */

#define SSC_SET_SSC_EN		BIT(12)

#define SSC_SET_RANGE_SHIFT	9

#define SSC_SET_RANGE_4980	(0x0 << SSC_SET_RANGE_SHIFT)

#define SSC_SET_RANGE_4492	(0x1 << SSC_SET_RANGE_SHIFT)

#define SSC_SET_RANGE_4003	(0x2 << SSC_SET_RANGE_SHIFT)

/* USB30_PHY_ENABLE */

#define PHY_ENABLE_RESET_EN	BIT(4)

/* USB30_VBUS_EN */

#define VBUS_EN_VBUS_EN		BIT(1)

struct rcar_gen3_usb3 {

	void __iomem *base;

	struct phy *phy;

	u32 ssc_range;

	bool usb3s_clk;

	bool usb_extal;

};

static void write_clkset1_for_usb_extal(struct rcar_gen3_usb3 *r, bool reset)

{

	u16 val = CLKSET1_USB30_PLL_MULTI_USB_EXTAL |

		  CLKSET1_REF_CLKDIV | CLKSET1_PRIVATE_2_1;

	if (reset)

		val |= CLKSET1_PHYRESET;

	writew(val, r->base + USB30_CLKSET1);

}

static void rcar_gen3_phy_usb3_enable_ssc(struct rcar_gen3_usb3 *r)

{

	u16 val = SSC_SET_SSC_EN;

	switch (r->ssc_range) {

	case 4980:

		val |= SSC_SET_RANGE_4980;

		break;

	case 4492:

		val |= SSC_SET_RANGE_4492;

		break;

	case 4003:

		val |= SSC_SET_RANGE_4003;

		break;

	default:

		dev_err(&r->phy->dev, "%s: unsupported range (%x)\n", __func__,

			r->ssc_range);

		return;

	}

	writew(val, r->base + USB30_SSC_SET);

}

static void rcar_gen3_phy_usb3_select_usb_extal(struct rcar_gen3_usb3 *r)

{

	write_clkset1_for_usb_extal(r, false);

	if (r->ssc_range)

		rcar_gen3_phy_usb3_enable_ssc(r);

	writew(CLKSET0_PRIVATE | CLKSET0_USB30_FSEL_USB_EXTAL,

	       r->base + USB30_CLKSET0);

	writew(PHY_ENABLE_RESET_EN, r->base + USB30_PHY_ENABLE);

	write_clkset1_for_usb_extal(r, true);

	usleep_range(10, 20);

	write_clkset1_for_usb_extal(r, false);

}

static int rcar_gen3_phy_usb3_init(struct phy *p)

{

	struct rcar_gen3_usb3 *r = phy_get_drvdata(p);

	dev_vdbg(&r->phy->dev, "%s: enter (%d, %d, %d)\n", __func__,

		 r->usb3s_clk, r->usb_extal, r->ssc_range);

	if (!r->usb3s_clk && r->usb_extal)

		rcar_gen3_phy_usb3_select_usb_extal(r);

	/* Enables VBUS detection anyway */

	writew(VBUS_EN_VBUS_EN, r->base + USB30_VBUS_EN);

	return 0;

}

static const struct phy_ops rcar_gen3_phy_usb3_ops = {

	.init		= rcar_gen3_phy_usb3_init,

	.owner		= THIS_MODULE,

};

static const struct of_device_id rcar_gen3_phy_usb3_match_table[] = {

	{ .compatible = "renesas,rcar-gen3-usb3-phy" },

	{ }

};

MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb3_match_table);

static int rcar_gen3_phy_usb3_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct rcar_gen3_usb3 *r;

	struct phy_provider *provider;

	struct resource *res;

	int ret = 0;

	struct clk *clk;

	if (!dev->of_node) {

		dev_err(dev, "This driver needs device tree\n");

		return -EINVAL;

	}

	r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL);

	if (!r)

		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	r->base = devm_ioremap_resource(dev, res);

	if (IS_ERR(r->base))

		return PTR_ERR(r->base);

	clk = devm_clk_get(dev, "usb3s_clk");

	if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {

		r->usb3s_clk = !!clk_get_rate(clk);

		clk_disable_unprepare(clk);

	}

	clk = devm_clk_get(dev, "usb_extal");

	if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {

		r->usb_extal = !!clk_get_rate(clk);

		clk_disable_unprepare(clk);

	}

	if (!r->usb3s_clk && !r->usb_extal) {

		dev_err(dev, "This driver needs usb3s_clk and/or usb_extal\n");

		ret = -EINVAL;

		goto error;

	}

	/*

	 * devm_phy_create() will call pm_runtime_enable(&phy->dev);

	 * And then, phy-core will manage runtime pm for this device.

	 */

	pm_runtime_enable(dev);

	r->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb3_ops);

	if (IS_ERR(r->phy)) {

		dev_err(dev, "Failed to create USB3 PHY\n");

		ret = PTR_ERR(r->phy);

		goto error;

	}

	of_property_read_u32(dev->of_node, "renesas,ssc-range", &r->ssc_range);

	platform_set_drvdata(pdev, r);

	phy_set_drvdata(r->phy, r);

	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);

	if (IS_ERR(provider)) {

		dev_err(dev, "Failed to register PHY provider\n");

		ret = PTR_ERR(provider);

		goto error;

	}

	return 0;

error:

	pm_runtime_disable(dev);

	return ret;

}

static int rcar_gen3_phy_usb3_remove(struct platform_device *pdev)

{

	pm_runtime_disable(&pdev->dev);

	return 0;

};

static struct platform_driver rcar_gen3_phy_usb3_driver = {

	.driver = {

		.name		= "phy_rcar_gen3_usb3",

		.of_match_table	= rcar_gen3_phy_usb3_match_table,

	},

	.probe	= rcar_gen3_phy_usb3_probe,

	.remove = rcar_gen3_phy_usb3_remove,

};

module_platform_driver(rcar_gen3_phy_usb3_driver);

MODULE_LICENSE("GPL v2");

MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 3.0 PHY");

MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");