phy: Renesas R-Car gen3 PCIe PHY driver

	help

	  Support for USB PHY found on Renesas R-Car generation 2 SoCs.

config PHY_RCAR_GEN3_PCIE

	tristate "Renesas R-Car generation 3 PCIe PHY driver"

	depends on ARCH_RENESAS

	select GENERIC_PHY

	help

	  Support for the PCIe PHY found on Renesas R-Car generation 3 SoCs.

config PHY_RCAR_GEN3_USB2

	tristate "Renesas R-Car generation 3 USB 2.0 PHY driver"

	depends on ARCH_RENESAS

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

obj-$(CONFIG_PHY_RCAR_GEN3_PCIE)	+= phy-rcar-gen3-pcie.o

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

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

// SPDX-License-Identifier: GPL-2.0

/*

 * Renesas R-Car Gen3 PCIe PHY driver

 *

 * Copyright (C) 2018 Cogent Embedded, Inc.

 */

#include <linux/clk.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/phy/phy.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

#include <linux/spinlock.h>

#define PHY_CTRL		0x4000		/* R8A77980 only */

/* PHY control register (PHY_CTRL) */

#define PHY_CTRL_PHY_PWDN	BIT(2)

struct rcar_gen3_phy {

	struct phy *phy;

	spinlock_t lock;

	void __iomem *base;

};

static void rcar_gen3_phy_pcie_modify_reg(struct phy *p, unsigned int reg,

					  u32 clear, u32 set)

{

	struct rcar_gen3_phy *phy = phy_get_drvdata(p);

	void __iomem *base = phy->base;

	unsigned long flags;

	u32 value;

	spin_lock_irqsave(&phy->lock, flags);

	value = readl(base + reg);

	value &= ~clear;

	value |= set;

	writel(value, base + reg);

	spin_unlock_irqrestore(&phy->lock, flags);

}

static int r8a77980_phy_pcie_power_on(struct phy *p)

{

	/* Power on the PCIe PHY */

	rcar_gen3_phy_pcie_modify_reg(p, PHY_CTRL, PHY_CTRL_PHY_PWDN, 0);

	return 0;

}

static int r8a77980_phy_pcie_power_off(struct phy *p)

{

	/* Power off the PCIe PHY */

	rcar_gen3_phy_pcie_modify_reg(p, PHY_CTRL, 0, PHY_CTRL_PHY_PWDN);

	return 0;

}

static const struct phy_ops r8a77980_phy_pcie_ops = {

	.power_on	= r8a77980_phy_pcie_power_on,

	.power_off	= r8a77980_phy_pcie_power_off,

	.owner		= THIS_MODULE,

};

static const struct of_device_id rcar_gen3_phy_pcie_match_table[] = {

	{ .compatible = "renesas,r8a77980-pcie-phy" },

	{ }

};

MODULE_DEVICE_TABLE(of, rcar_gen3_phy_pcie_match_table);

static int rcar_gen3_phy_pcie_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct phy_provider *provider;

	struct rcar_gen3_phy *phy;

	struct resource *res;

	void __iomem *base;

	int error;

	if (!dev->of_node) {

		dev_err(dev,

			"This driver must only be instantiated from the device tree\n");

		return -EINVAL;

	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	base = devm_ioremap_resource(dev, res);

	if (IS_ERR(base))

		return PTR_ERR(base);

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

	if (!phy)

		return -ENOMEM;

	spin_lock_init(&phy->lock);

	phy->base = base;

	/*

	 * 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);

	phy->phy = devm_phy_create(dev, NULL, &r8a77980_phy_pcie_ops);

	if (IS_ERR(phy->phy)) {

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

		error = PTR_ERR(phy->phy);

		goto error;

	}

	phy_set_drvdata(phy->phy, phy);

	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);

	if (IS_ERR(provider)) {

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

		error = PTR_ERR(provider);

		goto error;

	}

	return 0;

error:

	pm_runtime_disable(dev);

	return error;

}

static int rcar_gen3_phy_pcie_remove(struct platform_device *pdev)

{

	pm_runtime_disable(&pdev->dev);

	return 0;

};

static struct platform_driver rcar_gen3_phy_driver = {

	.driver = {

		.name		= "phy_rcar_gen3_pcie",

		.of_match_table	= rcar_gen3_phy_pcie_match_table,

	},

	.probe	= rcar_gen3_phy_pcie_probe,

	.remove = rcar_gen3_phy_pcie_remove,

};

module_platform_driver(rcar_gen3_phy_driver);

MODULE_LICENSE("GPL v2");

MODULE_DESCRIPTION("Renesas R-Car Gen3 PCIe PHY");

MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");