linux/linux-5.4.31/drivers/phy/renesas/phy-rcar-gen3-pcie.c

152 lines
3.3 KiB
C

// 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>");