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 #define PHYPARAM_REG 1
26 #define PHYCTRL_REG 2
27
28 /* Default PHY_SEL and REFCLKSEL configuration */
29 #define STIH407_USB_PICOPHY_CTRL_PORT_CONF 0x6
30 #define STIH407_USB_PICOPHY_CTRL_PORT_MASK 0x1f
31
32 /* ports parameters overriding */
33 #define STIH407_USB_PICOPHY_PARAM_DEF 0x39a4dc
34 #define STIH407_USB_PICOPHY_PARAM_MASK 0xffffffff
35
36 struct stih407_usb2_picophy {
37 struct phy *phy;
38 struct regmap *regmap;
39 struct device *dev;
40 struct reset_control *rstc;
41 struct reset_control *rstport;
42 int ctrl;
43 int param;
44 };
45
stih407_usb2_pico_ctrl(struct stih407_usb2_picophy * phy_dev)46 static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
47 {
48 reset_control_deassert(phy_dev->rstc);
49
50 return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
51 STIH407_USB_PICOPHY_CTRL_PORT_MASK,
52 STIH407_USB_PICOPHY_CTRL_PORT_CONF);
53 }
54
stih407_usb2_init_port(struct phy * phy)55 static int stih407_usb2_init_port(struct phy *phy)
56 {
57 int ret;
58 struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
59
60 stih407_usb2_pico_ctrl(phy_dev);
61
62 ret = regmap_update_bits(phy_dev->regmap,
63 phy_dev->param,
64 STIH407_USB_PICOPHY_PARAM_MASK,
65 STIH407_USB_PICOPHY_PARAM_DEF);
66 if (ret)
67 return ret;
68
69 return reset_control_deassert(phy_dev->rstport);
70 }
71
stih407_usb2_exit_port(struct phy * phy)72 static int stih407_usb2_exit_port(struct phy *phy)
73 {
74 struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
75
76 /*
77 * Only port reset is asserted, phy global reset is kept untouched
78 * as other ports may still be active. When all ports are in reset
79 * state, assumption is made that power will be cut off on the phy, in
80 * case of suspend for instance. Theoretically, asserting individual
81 * reset (like here) or global reset should be equivalent.
82 */
83 return reset_control_assert(phy_dev->rstport);
84 }
85
86 static const struct phy_ops stih407_usb2_picophy_data = {
87 .init = stih407_usb2_init_port,
88 .exit = stih407_usb2_exit_port,
89 .owner = THIS_MODULE,
90 };
91
stih407_usb2_picophy_probe(struct platform_device * pdev)92 static int stih407_usb2_picophy_probe(struct platform_device *pdev)
93 {
94 struct stih407_usb2_picophy *phy_dev;
95 struct device *dev = &pdev->dev;
96 struct device_node *np = dev->of_node;
97 struct phy_provider *phy_provider;
98 struct phy *phy;
99 int ret;
100
101 phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
102 if (!phy_dev)
103 return -ENOMEM;
104
105 phy_dev->dev = dev;
106 dev_set_drvdata(dev, phy_dev);
107
108 phy_dev->rstc = devm_reset_control_get_shared(dev, "global");
109 if (IS_ERR(phy_dev->rstc)) {
110 dev_err(dev, "failed to ctrl picoPHY reset\n");
111 return PTR_ERR(phy_dev->rstc);
112 }
113
114 phy_dev->rstport = devm_reset_control_get_exclusive(dev, "port");
115 if (IS_ERR(phy_dev->rstport)) {
116 dev_err(dev, "failed to ctrl picoPHY reset\n");
117 return PTR_ERR(phy_dev->rstport);
118 }
119
120 /* Reset port by default: only deassert it in phy init */
121 reset_control_assert(phy_dev->rstport);
122
123 phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
124 if (IS_ERR(phy_dev->regmap)) {
125 dev_err(dev, "No syscfg phandle specified\n");
126 return PTR_ERR(phy_dev->regmap);
127 }
128
129 ret = of_property_read_u32_index(np, "st,syscfg", PHYPARAM_REG,
130 &phy_dev->param);
131 if (ret) {
132 dev_err(dev, "can't get phyparam offset (%d)\n", ret);
133 return ret;
134 }
135
136 ret = of_property_read_u32_index(np, "st,syscfg", PHYCTRL_REG,
137 &phy_dev->ctrl);
138 if (ret) {
139 dev_err(dev, "can't get phyctrl offset (%d)\n", ret);
140 return ret;
141 }
142
143 phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data);
144 if (IS_ERR(phy)) {
145 dev_err(dev, "failed to create Display Port PHY\n");
146 return PTR_ERR(phy);
147 }
148
149 phy_dev->phy = phy;
150 phy_set_drvdata(phy, phy_dev);
151
152 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
153 if (IS_ERR(phy_provider))
154 return PTR_ERR(phy_provider);
155
156 dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");
157
158 return 0;
159 }
160
161 static const struct of_device_id stih407_usb2_picophy_of_match[] = {
162 { .compatible = "st,stih407-usb2-phy" },
163 { /*sentinel */ },
164 };
165
166 MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
167
168 static struct platform_driver stih407_usb2_picophy_driver = {
169 .probe = stih407_usb2_picophy_probe,
170 .driver = {
171 .name = "stih407-usb-genphy",
172 .of_match_table = stih407_usb2_picophy_of_match,
173 }
174 };
175
176 module_platform_driver(stih407_usb2_picophy_driver);
177
178 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
179 MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
180 MODULE_LICENSE("GPL v2");
181
