summaryrefslogtreecommitdiffstats
path: root/drivers/phy/phy-stih407-usb.c
blob: 74f0fab3cd8a9df0e29dacc08e04338fbb7762e1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 * Copyright (C) 2014 STMicroelectronics
 *
 * STMicroelectronics Generic PHY driver for STiH407 USB2.
 *
 * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2, as
 * published by the Free Software Foundation.
 *
 */
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/clk.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/mfd/syscon.h>
#include <linux/phy/phy.h>

/* Default PHY_SEL and REFCLKSEL configuration */
#define STIH407_USB_PICOPHY_CTRL_PORT_CONF	0x6
#define STIH407_USB_PICOPHY_CTRL_PORT_MASK	0x1f

/* ports parameters overriding */
#define STIH407_USB_PICOPHY_PARAM_DEF		0x39a4dc
#define STIH407_USB_PICOPHY_PARAM_MASK		0xffffffff

struct stih407_usb2_picophy {
	struct phy *phy;
	struct regmap *regmap;
	struct device *dev;
	struct reset_control *rstc;
	struct reset_control *rstport;
	int ctrl;
	int param;
};

static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
{
	reset_control_deassert(phy_dev->rstc);

	return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
				  STIH407_USB_PICOPHY_CTRL_PORT_MASK,
				  STIH407_USB_PICOPHY_CTRL_PORT_CONF);
}

static int stih407_usb2_init_port(struct phy *phy)
{
	int ret;
	struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);

	stih407_usb2_pico_ctrl(phy_dev);

	ret = regmap_update_bits(phy_dev->regmap,
				 phy_dev->param,
				 STIH407_USB_PICOPHY_PARAM_MASK,
				 STIH407_USB_PICOPHY_PARAM_DEF);
	if (ret)
		return ret;

	return reset_control_deassert(phy_dev->rstport);
}

static int stih407_usb2_exit_port(struct phy *phy)
{
	struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);

	/*
	 * Only port reset is asserted, phy global reset is kept untouched
	 * as other ports may still be active. When all ports are in reset
	 * state, assumption is made that power will be cut off on the phy, in
	 * case of suspend for instance. Theoretically, asserting individual
	 * reset (like here) or global reset should be equivalent.
	 */
	return reset_control_assert(phy_dev->rstport);
}

static const struct phy_ops stih407_usb2_picophy_data = {
	.init = stih407_usb2_init_port,
	.exit = stih407_usb2_exit_port,
	.owner = THIS_MODULE,
};

static int stih407_usb2_picophy_probe(struct platform_device *pdev)
{
	struct stih407_usb2_picophy *phy_dev;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct phy_provider *phy_provider;
	struct phy *phy;
	struct resource *res;

	phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
	if (!phy_dev)
		return -ENOMEM;

	phy_dev->dev = dev;
	dev_set_drvdata(dev, phy_dev);

	phy_dev->rstc = devm_reset_control_get(dev, "global");
	if (IS_ERR(phy_dev->rstc)) {
		dev_err(dev, "failed to ctrl picoPHY reset\n");
		return PTR_ERR(phy_dev->rstc);
	}

	phy_dev->rstport = devm_reset_control_get(dev, "port");
	if (IS_ERR(phy_dev->rstport)) {
		dev_err(dev, "failed to ctrl picoPHY reset\n");
		return PTR_ERR(phy_dev->rstport);
	}

	/* Reset port by default: only deassert it in phy init */
	reset_control_assert(phy_dev->rstport);

	phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
	if (IS_ERR(phy_dev->regmap)) {
		dev_err(dev, "No syscfg phandle specified\n");
		return PTR_ERR(phy_dev->regmap);
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");
	if (!res) {
		dev_err(dev, "No ctrl reg found\n");
		return -ENXIO;
	}
	phy_dev->ctrl = res->start;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "param");
	if (!res) {
		dev_err(dev, "No param reg found\n");
		return -ENXIO;
	}
	phy_dev->param = res->start;

	phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data);
	if (IS_ERR(phy)) {
		dev_err(dev, "failed to create Display Port PHY\n");
		return PTR_ERR(phy);
	}

	phy_dev->phy = phy;
	phy_set_drvdata(phy, phy_dev);

	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
	if (IS_ERR(phy_provider))
		return PTR_ERR(phy_provider);

	dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");

	return 0;
}

static const struct of_device_id stih407_usb2_picophy_of_match[] = {
	{ .compatible = "st,stih407-usb2-phy" },
	{ /*sentinel */ },
};

MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);

static struct platform_driver stih407_usb2_picophy_driver = {
	.probe = stih407_usb2_picophy_probe,
	.driver = {
		   .name = "stih407-usb-genphy",
		   .of_match_table = stih407_usb2_picophy_of_match,
		   }
};

module_platform_driver(stih407_usb2_picophy_driver);

MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
MODULE_LICENSE("GPL v2");