[go: nahoru, domu]
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
33struct 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
43static 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
52static 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
69static 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
83static 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
89static 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
158static const struct of_device_id stih407_usb2_picophy_of_match[] = {
159	{ .compatible = "st,stih407-usb2-phy" },
160	{ /*sentinel */ },
161};
162
163MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
164
165static 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
173module_platform_driver(stih407_usb2_picophy_driver);
174
175MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
176MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
177MODULE_LICENSE("GPL v2");
178