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/mod_devicetable.h>
8 #include <linux/module.h>
9 #include <linux/phy/phy.h>
10 #include <linux/regmap.h>
11 #include <linux/reset.h>
12 #include <linux/platform_device.h>
13 #include <linux/bitfield.h>
14 #include <dt-bindings/phy/phy.h>
15
16 #define MESON_PCIE_REG0 0x00
17 #define MESON_PCIE_COMMON_CLK BIT(4)
18 #define MESON_PCIE_PORT_SEL GENMASK(3, 2)
19 #define MESON_PCIE_CLK BIT(1)
20 #define MESON_PCIE_POWERDOWN BIT(0)
21
22 #define MESON_PCIE_TWO_X1 FIELD_PREP(MESON_PCIE_PORT_SEL, 0x3)
23 #define MESON_PCIE_COMMON_REF_CLK FIELD_PREP(MESON_PCIE_COMMON_CLK, 0x1)
24 #define MESON_PCIE_PHY_INIT (MESON_PCIE_TWO_X1 | \
25 MESON_PCIE_COMMON_REF_CLK)
26 #define MESON_PCIE_RESET_DELAY 500
27
28 struct phy_axg_pcie_priv {
29 struct phy *phy;
30 struct phy *analog;
31 struct regmap *regmap;
32 struct reset_control *reset;
33 };
34
35 static const struct regmap_config phy_axg_pcie_regmap_conf = {
36 .reg_bits = 8,
37 .val_bits = 32,
38 .reg_stride = 4,
39 .max_register = MESON_PCIE_REG0,
40 };
41
phy_axg_pcie_power_on(struct phy * phy)42 static int phy_axg_pcie_power_on(struct phy *phy)
43 {
44 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
45 int ret;
46
47 ret = phy_power_on(priv->analog);
48 if (ret != 0)
49 return ret;
50
51 regmap_update_bits(priv->regmap, MESON_PCIE_REG0,
52 MESON_PCIE_POWERDOWN, 0);
53 return 0;
54 }
55
phy_axg_pcie_power_off(struct phy * phy)56 static int phy_axg_pcie_power_off(struct phy *phy)
57 {
58 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
59 int ret;
60
61 ret = phy_power_off(priv->analog);
62 if (ret != 0)
63 return ret;
64
65 regmap_update_bits(priv->regmap, MESON_PCIE_REG0,
66 MESON_PCIE_POWERDOWN, 1);
67 return 0;
68 }
69
phy_axg_pcie_init(struct phy * phy)70 static int phy_axg_pcie_init(struct phy *phy)
71 {
72 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
73 int ret;
74
75 ret = phy_init(priv->analog);
76 if (ret != 0)
77 return ret;
78
79 regmap_write(priv->regmap, MESON_PCIE_REG0, MESON_PCIE_PHY_INIT);
80 return reset_control_reset(priv->reset);
81 }
82
phy_axg_pcie_exit(struct phy * phy)83 static int phy_axg_pcie_exit(struct phy *phy)
84 {
85 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
86 int ret;
87
88 ret = phy_exit(priv->analog);
89 if (ret != 0)
90 return ret;
91
92 return reset_control_reset(priv->reset);
93 }
94
phy_axg_pcie_reset(struct phy * phy)95 static int phy_axg_pcie_reset(struct phy *phy)
96 {
97 struct phy_axg_pcie_priv *priv = phy_get_drvdata(phy);
98 int ret = 0;
99
100 ret = phy_reset(priv->analog);
101 if (ret != 0)
102 goto out;
103
104 ret = reset_control_assert(priv->reset);
105 if (ret != 0)
106 goto out;
107 udelay(MESON_PCIE_RESET_DELAY);
108
109 ret = reset_control_deassert(priv->reset);
110 if (ret != 0)
111 goto out;
112 udelay(MESON_PCIE_RESET_DELAY);
113
114 out:
115 return ret;
116 }
117
118 static const struct phy_ops phy_axg_pcie_ops = {
119 .init = phy_axg_pcie_init,
120 .exit = phy_axg_pcie_exit,
121 .power_on = phy_axg_pcie_power_on,
122 .power_off = phy_axg_pcie_power_off,
123 .reset = phy_axg_pcie_reset,
124 .owner = THIS_MODULE,
125 };
126
phy_axg_pcie_probe(struct platform_device * pdev)127 static int phy_axg_pcie_probe(struct platform_device *pdev)
128 {
129 struct phy_provider *pphy;
130 struct device *dev = &pdev->dev;
131 struct phy_axg_pcie_priv *priv;
132 struct device_node *np = dev->of_node;
133 void __iomem *base;
134 int ret;
135
136 priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
137 if (!priv)
138 return -ENOMEM;
139
140 priv->phy = devm_phy_create(dev, np, &phy_axg_pcie_ops);
141 if (IS_ERR(priv->phy)) {
142 ret = PTR_ERR(priv->phy);
143 if (ret != -EPROBE_DEFER)
144 dev_err(dev, "failed to create PHY\n");
145 return ret;
146 }
147
148 base = devm_platform_ioremap_resource(pdev, 0);
149 if (IS_ERR(base))
150 return PTR_ERR(base);
151
152 priv->regmap = devm_regmap_init_mmio(dev, base,
153 &phy_axg_pcie_regmap_conf);
154 if (IS_ERR(priv->regmap))
155 return PTR_ERR(priv->regmap);
156
157 priv->reset = devm_reset_control_array_get_exclusive(dev);
158 if (IS_ERR(priv->reset))
159 return PTR_ERR(priv->reset);
160
161 priv->analog = devm_phy_get(dev, "analog");
162 if (IS_ERR(priv->analog))
163 return PTR_ERR(priv->analog);
164
165 phy_set_drvdata(priv->phy, priv);
166 dev_set_drvdata(dev, priv);
167 pphy = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
168
169 return PTR_ERR_OR_ZERO(pphy);
170 }
171
172 static const struct of_device_id phy_axg_pcie_of_match[] = {
173 {
174 .compatible = "amlogic,axg-pcie-phy",
175 },
176 { },
177 };
178 MODULE_DEVICE_TABLE(of, phy_axg_pcie_of_match);
179
180 static struct platform_driver phy_axg_pcie_driver = {
181 .probe = phy_axg_pcie_probe,
182 .driver = {
183 .name = "phy-axg-pcie",
184 .of_match_table = phy_axg_pcie_of_match,
185 },
186 };
187 module_platform_driver(phy_axg_pcie_driver);
188
189 MODULE_AUTHOR("Remi Pommarel <repk@triplefau.lt>");
190 MODULE_DESCRIPTION("Amlogic AXG PCIE PHY driver");
191 MODULE_LICENSE("GPL v2");
192