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