1/*
2 * Rockchip usb PHY driver
3 *
4 * Copyright (C) 2014 Yunzhi Li <lyz@rock-chips.com>
5 * Copyright (C) 2014 ROCKCHIP, Inc.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/clk.h>
18#include <linux/io.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/mutex.h>
22#include <linux/of.h>
23#include <linux/of_address.h>
24#include <linux/phy/phy.h>
25#include <linux/platform_device.h>
26#include <linux/regulator/consumer.h>
27#include <linux/reset.h>
28#include <linux/regmap.h>
29#include <linux/mfd/syscon.h>
30
31/*
32 * The higher 16-bit of this register is used for write protection
33 * only if BIT(13 + 16) set to 1 the BIT(13) can be written.
34 */
35#define SIDDQ_WRITE_ENA	BIT(29)
36#define SIDDQ_ON		BIT(13)
37#define SIDDQ_OFF		(0 << 13)
38
39struct rockchip_usb_phy {
40	unsigned int	reg_offset;
41	struct regmap	*reg_base;
42	struct clk	*clk;
43	struct phy	*phy;
44};
45
46static int rockchip_usb_phy_power(struct rockchip_usb_phy *phy,
47					   bool siddq)
48{
49	return regmap_write(phy->reg_base, phy->reg_offset,
50			    SIDDQ_WRITE_ENA | (siddq ? SIDDQ_ON : SIDDQ_OFF));
51}
52
53static int rockchip_usb_phy_power_off(struct phy *_phy)
54{
55	struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
56	int ret = 0;
57
58	/* Power down usb phy analog blocks by set siddq 1 */
59	ret = rockchip_usb_phy_power(phy, 1);
60	if (ret)
61		return ret;
62
63	clk_disable_unprepare(phy->clk);
64
65	return 0;
66}
67
68static int rockchip_usb_phy_power_on(struct phy *_phy)
69{
70	struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
71	int ret = 0;
72
73	ret = clk_prepare_enable(phy->clk);
74	if (ret)
75		return ret;
76
77	/* Power up usb phy analog blocks by set siddq 0 */
78	ret = rockchip_usb_phy_power(phy, 0);
79	if (ret) {
80		clk_disable_unprepare(phy->clk);
81		return ret;
82	}
83
84	return 0;
85}
86
87static struct phy_ops ops = {
88	.power_on	= rockchip_usb_phy_power_on,
89	.power_off	= rockchip_usb_phy_power_off,
90	.owner		= THIS_MODULE,
91};
92
93static int rockchip_usb_phy_probe(struct platform_device *pdev)
94{
95	struct device *dev = &pdev->dev;
96	struct rockchip_usb_phy *rk_phy;
97	struct phy_provider *phy_provider;
98	struct device_node *child;
99	struct regmap *grf;
100	unsigned int reg_offset;
101
102	grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
103	if (IS_ERR(grf)) {
104		dev_err(&pdev->dev, "Missing rockchip,grf property\n");
105		return PTR_ERR(grf);
106	}
107
108	for_each_available_child_of_node(dev->of_node, child) {
109		rk_phy = devm_kzalloc(dev, sizeof(*rk_phy), GFP_KERNEL);
110		if (!rk_phy)
111			return -ENOMEM;
112
113		if (of_property_read_u32(child, "reg", &reg_offset)) {
114			dev_err(dev, "missing reg property in node %s\n",
115				child->name);
116			return -EINVAL;
117		}
118
119		rk_phy->reg_offset = reg_offset;
120		rk_phy->reg_base = grf;
121
122		rk_phy->clk = of_clk_get_by_name(child, "phyclk");
123		if (IS_ERR(rk_phy->clk))
124			rk_phy->clk = NULL;
125
126		rk_phy->phy = devm_phy_create(dev, child, &ops);
127		if (IS_ERR(rk_phy->phy)) {
128			dev_err(dev, "failed to create PHY\n");
129			return PTR_ERR(rk_phy->phy);
130		}
131		phy_set_drvdata(rk_phy->phy, rk_phy);
132	}
133
134	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
135	return PTR_ERR_OR_ZERO(phy_provider);
136}
137
138static const struct of_device_id rockchip_usb_phy_dt_ids[] = {
139	{ .compatible = "rockchip,rk3288-usb-phy" },
140	{}
141};
142
143MODULE_DEVICE_TABLE(of, rockchip_usb_phy_dt_ids);
144
145static struct platform_driver rockchip_usb_driver = {
146	.probe		= rockchip_usb_phy_probe,
147	.driver		= {
148		.name	= "rockchip-usb-phy",
149		.owner	= THIS_MODULE,
150		.of_match_table = rockchip_usb_phy_dt_ids,
151	},
152};
153
154module_platform_driver(rockchip_usb_driver);
155
156MODULE_AUTHOR("Yunzhi Li <lyz@rock-chips.com>");
157MODULE_DESCRIPTION("Rockchip USB 2.0 PHY driver");
158MODULE_LICENSE("GPL v2");
159