1/*
  2 * Copyright (C) 2014 STMicroelectronics
  3 *
  4 * STMicroelectronics PHY driver for STiH41x USB.
  5 *
  6 * Author: Maxime Coquelin <maxime.coquelin@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
 14#include <linux/platform_device.h>
 15#include <linux/io.h>
 16#include <linux/kernel.h>
 17#include <linux/module.h>
 18#include <linux/of.h>
 19#include <linux/of_platform.h>
 20#include <linux/clk.h>
 21#include <linux/phy/phy.h>
 22#include <linux/regmap.h>
 23#include <linux/mfd/syscon.h>
 24
 25#define SYSCFG332  0x80
 26#define SYSCFG2520 0x820
 27
 28/**
 29 * struct stih41x_usb_cfg - SoC specific PHY register mapping
 30 * @syscfg: Offset in syscfg registers bank
 31 * @cfg_mask: Bits mask for PHY configuration
 32 * @cfg: Static configuration value for PHY
 33 * @oscok: Notify the PHY oscillator clock is ready
 34 *	   Setting this bit enable the PHY
 35 */
 36struct stih41x_usb_cfg {
 37	u32 syscfg;
 38	u32 cfg_mask;
 39	u32 cfg;
 40	u32 oscok;
 41};
 42
 43/**
 44 * struct stih41x_usb_phy - Private data for the PHY
 45 * @dev: device for this controller
 46 * @regmap: Syscfg registers bank in which PHY is configured
 47 * @cfg: SoC specific PHY register mapping
 48 * @clk: Oscillator used by the PHY
 49 */
 50struct stih41x_usb_phy {
 51	struct device *dev;
 52	struct regmap *regmap;
 53	const struct stih41x_usb_cfg *cfg;
 54	struct clk *clk;
 55};
 56
 57static struct stih41x_usb_cfg stih415_usb_phy_cfg = {
 58	.syscfg = SYSCFG332,
 59	.cfg_mask = 0x3f,
 60	.cfg = 0x38,
 61	.oscok = BIT(6),
 62};
 63
 64static struct stih41x_usb_cfg stih416_usb_phy_cfg = {
 65	.syscfg = SYSCFG2520,
 66	.cfg_mask = 0x33f,
 67	.cfg = 0x238,
 68	.oscok = BIT(6),
 69};
 70
 71static int stih41x_usb_phy_init(struct phy *phy)
 72{
 73	struct stih41x_usb_phy *phy_dev = phy_get_drvdata(phy);
 74
 75	return regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
 76			   phy_dev->cfg->cfg_mask, phy_dev->cfg->cfg);
 77}
 78
 79static int stih41x_usb_phy_power_on(struct phy *phy)
 80{
 81	struct stih41x_usb_phy *phy_dev = phy_get_drvdata(phy);
 82	int ret;
 83
 84	ret = clk_prepare_enable(phy_dev->clk);
 85	if (ret) {
 86		dev_err(phy_dev->dev, "Failed to enable osc_phy clock\n");
 87		return ret;
 88	}
 89
 90	ret = regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
 91				 phy_dev->cfg->oscok, phy_dev->cfg->oscok);
 92	if (ret)
 93		clk_disable_unprepare(phy_dev->clk);
 94
 95	return ret;
 96}
 97
 98static int stih41x_usb_phy_power_off(struct phy *phy)
 99{
100	struct stih41x_usb_phy *phy_dev = phy_get_drvdata(phy);
101	int ret;
102
103	ret = regmap_update_bits(phy_dev->regmap, phy_dev->cfg->syscfg,
104			phy_dev->cfg->oscok, 0);
105	if (ret) {
106		dev_err(phy_dev->dev, "Failed to clear oscok bit\n");
107		return ret;
108	}
109
110	clk_disable_unprepare(phy_dev->clk);
111
112	return 0;
113}
114
115static const struct phy_ops stih41x_usb_phy_ops = {
116	.init		= stih41x_usb_phy_init,
117	.power_on	= stih41x_usb_phy_power_on,
118	.power_off	= stih41x_usb_phy_power_off,
119	.owner		= THIS_MODULE,
120};
121
122static const struct of_device_id stih41x_usb_phy_of_match[];
123
124static int stih41x_usb_phy_probe(struct platform_device *pdev)
125{
126	struct device_node *np = pdev->dev.of_node;
127	const struct of_device_id *match;
128	struct stih41x_usb_phy *phy_dev;
129	struct device *dev = &pdev->dev;
130	struct phy_provider *phy_provider;
131	struct phy *phy;
132
133	phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
134	if (!phy_dev)
135		return -ENOMEM;
136
137	match = of_match_device(stih41x_usb_phy_of_match, &pdev->dev);
138	if (!match)
139		return -ENODEV;
140
141	phy_dev->cfg = match->data;
142
143	phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
144	if (IS_ERR(phy_dev->regmap)) {
145		dev_err(dev, "No syscfg phandle specified\n");
146		return PTR_ERR(phy_dev->regmap);
147	}
148
149	phy_dev->clk = devm_clk_get(dev, "osc_phy");
150	if (IS_ERR(phy_dev->clk)) {
151		dev_err(dev, "osc_phy clk not found\n");
152		return PTR_ERR(phy_dev->clk);
153	}
154
155	phy = devm_phy_create(dev, NULL, &stih41x_usb_phy_ops);
156
157	if (IS_ERR(phy)) {
158		dev_err(dev, "failed to create phy\n");
159		return PTR_ERR(phy);
160	}
161
162	phy_dev->dev = dev;
163
164	phy_set_drvdata(phy, phy_dev);
165
166	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
167	return PTR_ERR_OR_ZERO(phy_provider);
168}
169
170static const struct of_device_id stih41x_usb_phy_of_match[] = {
171	{ .compatible = "st,stih415-usb-phy", .data = &stih415_usb_phy_cfg },
172	{ .compatible = "st,stih416-usb-phy", .data = &stih416_usb_phy_cfg },
173	{ /* sentinel */ },
174};
175MODULE_DEVICE_TABLE(of, stih41x_usb_phy_of_match);
176
177static struct platform_driver stih41x_usb_phy_driver = {
178	.probe	= stih41x_usb_phy_probe,
179	.driver = {
180		.name	= "stih41x-usb-phy",
181		.of_match_table	= stih41x_usb_phy_of_match,
182	}
183};
184module_platform_driver(stih41x_usb_phy_driver);
185
186MODULE_AUTHOR("Maxime Coquelin <maxime.coquelin@st.com>");
187MODULE_DESCRIPTION("STMicroelectronics USB PHY driver for STiH41x series");
188MODULE_LICENSE("GPL v2");