1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Amlogic AXG PCIE PHY driver
4 *
5 * Copyright (C) 2020 Remi Pommarel <repk@triplefau.lt>
6 */
7 #include <linux/module.h>
8 #include <linux/phy/phy.h>
9 #include <linux/regmap.h>
10 #include <linux/reset.h>
11 #include <linux/platform_device.h>
12 #include <linux/bitfield.h>
13 #include <dt-bindings/phy/phy.h>
14
15 #define MESON_PCIE_REG0 0x00
16 #define MESON_PCIE_COMMON_CLK BIT(4)
17 #define MESON_PCIE_PORT_SEL GENMASK(3, 2)
18 #define MESON_PCIE_CLK BIT(1)
19 #define MESON_PCIE_POWERDOWN BIT(0)
20
21 #define MESON_PCIE_TWO_X1 FIELD_PREP(MESON_PCIE_PORT_SEL, 0x3)
22 #define MESON_PCIE_COMMON_REF_CLK FIELD_PREP(MESON_PCIE_COMMON_CLK, 0x1)
23 #define MESON_PCIE_PHY_INIT (MESON_PCIE_TWO_X1 | \
24 MESON_PCIE_COMMON_REF_CLK)
25 #define MESON_PCIE_RESET_DELAY 500
26
27 struct phy_axg_pcie_priv {
28 struct phy *phy;
29 struct phy *analog;
30 struct regmap *regmap;
31 struct reset_control *reset;
32 };
33
34 static const struct regmap_config phy_axg_pcie_regmap_conf = {
35 .reg_bits = 8,
36 .val_bits = 32,
37 .reg_stride = 4,
38 .max_register = MESON_PCIE_REG0,
39 };
40
phy_axg_pcie_power_on(struct phy * phy)41 static int phy_axg_pcie_power_on(struct phy *phy)
42 {
43 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
44 int ret;
45
46 ret = phy_power_on(priv->analog);
47 if (ret != 0)
48 return ret;
49
50 regmap_update_bits(priv->regmap, MESON_PCIE_REG0,
51 MESON_PCIE_POWERDOWN, 0);
52 return 0;
53 }
54
phy_axg_pcie_power_off(struct phy * phy)55 static int phy_axg_pcie_power_off(struct phy *phy)
56 {
57 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
58 int ret;
59
60 ret = phy_power_off(priv->analog);
61 if (ret != 0)
62 return ret;
63
64 regmap_update_bits(priv->regmap, MESON_PCIE_REG0,
65 MESON_PCIE_POWERDOWN, 1);
66 return 0;
67 }
68
phy_axg_pcie_init(struct phy * phy)69 static int phy_axg_pcie_init(struct phy *phy)
70 {
71 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
72 int ret;
73
74 ret = phy_init(priv->analog);
75 if (ret != 0)
76 return ret;
77
78 regmap_write(priv->regmap, MESON_PCIE_REG0, MESON_PCIE_PHY_INIT);
79 return reset_control_reset(priv->reset);
80 }
81
phy_axg_pcie_exit(struct phy * phy)82 static int phy_axg_pcie_exit(struct phy *phy)
83 {
84 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
85 int ret;
86
87 ret = phy_exit(priv->analog);
88 if (ret != 0)
89 return ret;
90
91 return reset_control_reset(priv->reset);
92 }
93
phy_axg_pcie_reset(struct phy * phy)94 static int phy_axg_pcie_reset(struct phy *phy)
95 {
96 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
97 int ret = 0;
98
99 ret = phy_reset(priv->analog);
100 if (ret != 0)
101 goto out;
102
103 ret = reset_control_assert(priv->reset);
104 if (ret != 0)
105 goto out;
106 udelay(MESON_PCIE_RESET_DELAY);
107
108 ret = reset_control_deassert(priv->reset);
109 if (ret != 0)
110 goto out;
111 udelay(MESON_PCIE_RESET_DELAY);
112
113 out:
114 return ret;
115 }
116
117 static const struct phy_ops phy_axg_pcie_ops = {
118 .init = phy_axg_pcie_init,
119 .exit = phy_axg_pcie_exit,
120 .power_on = phy_axg_pcie_power_on,
121 .power_off = phy_axg_pcie_power_off,
122 .reset = phy_axg_pcie_reset,
123 .owner = THIS_MODULE,
124 };
125
phy_axg_pcie_probe(struct platform_device * pdev)126 static int phy_axg_pcie_probe(struct platform_device *pdev)
127 {
128 struct phy_provider *pphy;
129 struct device *dev = &pdev->dev;
130 struct phy_axg_pcie_priv *priv;
131 struct device_node *np = dev->of_node;
132 void __iomem *base;
133 int ret;
134
135 priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
136 if (!priv)
137 return -ENOMEM;
138
139 priv->phy = devm_phy_create(dev, np, &phy_axg_pcie_ops);
140 if (IS_ERR(priv->phy)) {
141 ret = PTR_ERR(priv->phy);
142 if (ret != -EPROBE_DEFER)
143 dev_err(dev, "failed to create PHY\n");
144 return ret;
145 }
146
147 base = devm_platform_ioremap_resource(pdev, 0);
148 if (IS_ERR(base))
149 return PTR_ERR(base);
150
151 priv->regmap = devm_regmap_init_mmio(dev, base,
152 &phy_axg_pcie_regmap_conf);
153 if (IS_ERR(priv->regmap))
154 return PTR_ERR(priv->regmap);
155
156 priv->reset = devm_reset_control_array_get_exclusive(dev);
157 if (IS_ERR(priv->reset))
158 return PTR_ERR(priv->reset);
159
160 priv->analog = devm_phy_get(dev, "analog");
161 if (IS_ERR(priv->analog))
162 return PTR_ERR(priv->analog);
163
164 phy_set_drvdata(priv->phy, priv);
165 dev_set_drvdata(dev, priv);
166 pphy = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
167
168 return PTR_ERR_OR_ZERO(pphy);
169 }
170
171 static const struct of_device_id phy_axg_pcie_of_match[] = {
172 {
173 .compatible = "amlogic,axg-pcie-phy",
174 },
175 { },
176 };
177 MODULE_DEVICE_TABLE(of, phy_axg_pcie_of_match);
178
179 static struct platform_driver phy_axg_pcie_driver = {
180 .probe = phy_axg_pcie_probe,
181 .driver = {
182 .name = "phy-axg-pcie",
183 .of_match_table = phy_axg_pcie_of_match,
184 },
185 };
186 module_platform_driver(phy_axg_pcie_driver);
187
188 MODULE_AUTHOR("Remi Pommarel <repk@triplefau.lt>");
189 MODULE_DESCRIPTION("Amlogic AXG PCIE PHY driver");
190 MODULE_LICENSE("GPL v2");
191