1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Renesas R-Car Gen3 PCIe PHY driver
4 *
5 * Copyright (C) 2018 Cogent Embedded, Inc.
6 */
7
8#include <linux/clk.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/phy/phy.h>
13#include <linux/of_device.h>
14#include <linux/platform_device.h>
15#include <linux/spinlock.h>
16
17#define PHY_CTRL		0x4000		/* R8A77980 only */
18
19/* PHY control register (PHY_CTRL) */
20#define PHY_CTRL_PHY_PWDN	BIT(2)
21
22struct rcar_gen3_phy {
23	struct phy *phy;
24	spinlock_t lock;
25	void __iomem *base;
26};
27
28static void rcar_gen3_phy_pcie_modify_reg(struct phy *p, unsigned int reg,
29					  u32 clear, u32 set)
30{
31	struct rcar_gen3_phy *phy = phy_get_drvdata(p);
32	void __iomem *base = phy->base;
33	unsigned long flags;
34	u32 value;
35
36	spin_lock_irqsave(&phy->lock, flags);
37
38	value = readl(base + reg);
39	value &= ~clear;
40	value |= set;
41	writel(value, base + reg);
42
43	spin_unlock_irqrestore(&phy->lock, flags);
44}
45
46static int r8a77980_phy_pcie_power_on(struct phy *p)
47{
48	/* Power on the PCIe PHY */
49	rcar_gen3_phy_pcie_modify_reg(p, PHY_CTRL, PHY_CTRL_PHY_PWDN, 0);
50
51	return 0;
52}
53
54static int r8a77980_phy_pcie_power_off(struct phy *p)
55{
56	/* Power off the PCIe PHY */
57	rcar_gen3_phy_pcie_modify_reg(p, PHY_CTRL, 0, PHY_CTRL_PHY_PWDN);
58
59	return 0;
60}
61
62static const struct phy_ops r8a77980_phy_pcie_ops = {
63	.power_on	= r8a77980_phy_pcie_power_on,
64	.power_off	= r8a77980_phy_pcie_power_off,
65	.owner		= THIS_MODULE,
66};
67
68static const struct of_device_id rcar_gen3_phy_pcie_match_table[] = {
69	{ .compatible = "renesas,r8a77980-pcie-phy" },
70	{ }
71};
72MODULE_DEVICE_TABLE(of, rcar_gen3_phy_pcie_match_table);
73
74static int rcar_gen3_phy_pcie_probe(struct platform_device *pdev)
75{
76	struct device *dev = &pdev->dev;
77	struct phy_provider *provider;
78	struct rcar_gen3_phy *phy;
79	struct resource *res;
80	void __iomem *base;
81	int error;
82
83	if (!dev->of_node) {
84		dev_err(dev,
85			"This driver must only be instantiated from the device tree\n");
86		return -EINVAL;
87	}
88
89	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
90	base = devm_ioremap_resource(dev, res);
91	if (IS_ERR(base))
92		return PTR_ERR(base);
93
94	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
95	if (!phy)
96		return -ENOMEM;
97
98	spin_lock_init(&phy->lock);
99
100	phy->base = base;
101
102	/*
103	 * devm_phy_create() will call pm_runtime_enable(&phy->dev);
104	 * And then, phy-core will manage runtime PM for this device.
105	 */
106	pm_runtime_enable(dev);
107
108	phy->phy = devm_phy_create(dev, NULL, &r8a77980_phy_pcie_ops);
109	if (IS_ERR(phy->phy)) {
110		dev_err(dev, "Failed to create PCIe PHY\n");
111		error = PTR_ERR(phy->phy);
112		goto error;
113	}
114	phy_set_drvdata(phy->phy, phy);
115
116	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
117	if (IS_ERR(provider)) {
118		dev_err(dev, "Failed to register PHY provider\n");
119		error = PTR_ERR(provider);
120		goto error;
121	}
122
123	return 0;
124
125error:
126	pm_runtime_disable(dev);
127
128	return error;
129}
130
131static int rcar_gen3_phy_pcie_remove(struct platform_device *pdev)
132{
133	pm_runtime_disable(&pdev->dev);
134
135	return 0;
136};
137
138static struct platform_driver rcar_gen3_phy_driver = {
139	.driver = {
140		.name		= "phy_rcar_gen3_pcie",
141		.of_match_table	= rcar_gen3_phy_pcie_match_table,
142	},
143	.probe	= rcar_gen3_phy_pcie_probe,
144	.remove = rcar_gen3_phy_pcie_remove,
145};
146
147module_platform_driver(rcar_gen3_phy_driver);
148
149MODULE_LICENSE("GPL v2");
150MODULE_DESCRIPTION("Renesas R-Car Gen3 PCIe PHY");
151MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
152