1 /*
2 * Copyright (C) 2014 STMicroelectronics
3 *
4 * STMicroelectronics Generic PHY driver for STiH407 USB2.
5 *
6 * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2, as
10 * published by the Free Software Foundation.
11 *
12 */
13 #include <linux/platform_device.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_platform.h>
19 #include <linux/clk.h>
20 #include <linux/regmap.h>
21 #include <linux/reset.h>
22 #include <linux/mfd/syscon.h>
23 #include <linux/phy/phy.h>
24
25 /* Default PHY_SEL and REFCLKSEL configuration */
26 #define STIH407_USB_PICOPHY_CTRL_PORT_CONF 0x6
27 #define STIH407_USB_PICOPHY_CTRL_PORT_MASK 0x1f
28
29 /* ports parameters overriding */
30 #define STIH407_USB_PICOPHY_PARAM_DEF 0x39a4dc
31 #define STIH407_USB_PICOPHY_PARAM_MASK 0xffffffff
32
33 struct stih407_usb2_picophy {
34 struct phy *phy;
35 struct regmap *regmap;
36 struct device *dev;
37 struct reset_control *rstc;
38 struct reset_control *rstport;
39 int ctrl;
40 int param;
41 };
42
stih407_usb2_pico_ctrl(struct stih407_usb2_picophy * phy_dev)43 static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
44 {
45 reset_control_deassert(phy_dev->rstc);
46
47 return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
48 STIH407_USB_PICOPHY_CTRL_PORT_MASK,
49 STIH407_USB_PICOPHY_CTRL_PORT_CONF);
50 }
51
stih407_usb2_init_port(struct phy * phy)52 static int stih407_usb2_init_port(struct phy *phy)
53 {
54 int ret;
55 struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
56
57 stih407_usb2_pico_ctrl(phy_dev);
58
59 ret = regmap_update_bits(phy_dev->regmap,
60 phy_dev->param,
61 STIH407_USB_PICOPHY_PARAM_MASK,
62 STIH407_USB_PICOPHY_PARAM_DEF);
63 if (ret)
64 return ret;
65
66 return reset_control_deassert(phy_dev->rstport);
67 }
68
stih407_usb2_exit_port(struct phy * phy)69 static int stih407_usb2_exit_port(struct phy *phy)
70 {
71 struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
72
73 /*
74 * Only port reset is asserted, phy global reset is kept untouched
75 * as other ports may still be active. When all ports are in reset
76 * state, assumption is made that power will be cut off on the phy, in
77 * case of suspend for instance. Theoretically, asserting individual
78 * reset (like here) or global reset should be equivalent.
79 */
80 return reset_control_assert(phy_dev->rstport);
81 }
82
83 static const struct phy_ops stih407_usb2_picophy_data = {
84 .init = stih407_usb2_init_port,
85 .exit = stih407_usb2_exit_port,
86 .owner = THIS_MODULE,
87 };
88
stih407_usb2_picophy_probe(struct platform_device * pdev)89 static int stih407_usb2_picophy_probe(struct platform_device *pdev)
90 {
91 struct stih407_usb2_picophy *phy_dev;
92 struct device *dev = &pdev->dev;
93 struct device_node *np = dev->of_node;
94 struct phy_provider *phy_provider;
95 struct phy *phy;
96 struct resource *res;
97
98 phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
99 if (!phy_dev)
100 return -ENOMEM;
101
102 phy_dev->dev = dev;
103 dev_set_drvdata(dev, phy_dev);
104
105 phy_dev->rstc = devm_reset_control_get(dev, "global");
106 if (IS_ERR(phy_dev->rstc)) {
107 dev_err(dev, "failed to ctrl picoPHY reset\n");
108 return PTR_ERR(phy_dev->rstc);
109 }
110
111 phy_dev->rstport = devm_reset_control_get(dev, "port");
112 if (IS_ERR(phy_dev->rstport)) {
113 dev_err(dev, "failed to ctrl picoPHY reset\n");
114 return PTR_ERR(phy_dev->rstport);
115 }
116
117 /* Reset port by default: only deassert it in phy init */
118 reset_control_assert(phy_dev->rstport);
119
120 phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
121 if (IS_ERR(phy_dev->regmap)) {
122 dev_err(dev, "No syscfg phandle specified\n");
123 return PTR_ERR(phy_dev->regmap);
124 }
125
126 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");
127 if (!res) {
128 dev_err(dev, "No ctrl reg found\n");
129 return -ENXIO;
130 }
131 phy_dev->ctrl = res->start;
132
133 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "param");
134 if (!res) {
135 dev_err(dev, "No param reg found\n");
136 return -ENXIO;
137 }
138 phy_dev->param = res->start;
139
140 phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data, NULL);
141 if (IS_ERR(phy)) {
142 dev_err(dev, "failed to create Display Port PHY\n");
143 return PTR_ERR(phy);
144 }
145
146 phy_dev->phy = phy;
147 phy_set_drvdata(phy, phy_dev);
148
149 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
150 if (IS_ERR(phy_provider))
151 return PTR_ERR(phy_provider);
152
153 dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");
154
155 return 0;
156 }
157
158 static const struct of_device_id stih407_usb2_picophy_of_match[] = {
159 { .compatible = "st,stih407-usb2-phy" },
160 { /*sentinel */ },
161 };
162
163 MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
164
165 static struct platform_driver stih407_usb2_picophy_driver = {
166 .probe = stih407_usb2_picophy_probe,
167 .driver = {
168 .name = "stih407-usb-genphy",
169 .of_match_table = stih407_usb2_picophy_of_match,
170 }
171 };
172
173 module_platform_driver(stih407_usb2_picophy_driver);
174
175 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
176 MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
177 MODULE_LICENSE("GPL v2");
178