[linux.git] / drivers / phy / phy-pistachio-usb.c

/*
 * IMG Pistachio USB PHY driver
 *
 * Copyright (C) 2015 Google, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#include <dt-bindings/phy/phy-pistachio-usb.h>

#define USB_PHY_CONTROL1				0x04
#define USB_PHY_CONTROL1_FSEL_SHIFT			2
#define USB_PHY_CONTROL1_FSEL_MASK			0x7

#define USB_PHY_STRAP_CONTROL				0x10
#define USB_PHY_STRAP_CONTROL_REFCLK_SHIFT		4
#define USB_PHY_STRAP_CONTROL_REFCLK_MASK		0x3

#define USB_PHY_STATUS					0x14
#define USB_PHY_STATUS_RX_PHY_CLK			BIT(9)
#define USB_PHY_STATUS_RX_UTMI_CLK			BIT(8)
#define USB_PHY_STATUS_VBUS_FAULT			BIT(7)

struct pistachio_usb_phy {
	struct device *dev;
	struct regmap *cr_top;
	struct clk *phy_clk;
	unsigned int refclk;
};

static const unsigned long fsel_rate_map[] = {
	9600000,
	10000000,
	12000000,
	19200000,
	20000000,
	24000000,
	0,
	50000000,
};

static int pistachio_usb_phy_power_on(struct phy *phy)
{
	struct pistachio_usb_phy *p_phy = phy_get_drvdata(phy);
	unsigned long timeout, rate;
	unsigned int i;
	int ret;

	ret = clk_prepare_enable(p_phy->phy_clk);
	if (ret < 0) {
		dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret);
		return ret;
	}

	regmap_update_bits(p_phy->cr_top, USB_PHY_STRAP_CONTROL,
			   USB_PHY_STRAP_CONTROL_REFCLK_MASK <<
			   USB_PHY_STRAP_CONTROL_REFCLK_SHIFT,
			   p_phy->refclk << USB_PHY_STRAP_CONTROL_REFCLK_SHIFT);

	rate = clk_get_rate(p_phy->phy_clk);
	if (p_phy->refclk == REFCLK_XO_CRYSTAL && rate != 12000000) {
		dev_err(p_phy->dev, "Unsupported rate for XO crystal: %ld\n",
			rate);
		ret = -EINVAL;
		goto disable_clk;
	}

	for (i = 0; i < ARRAY_SIZE(fsel_rate_map); i++) {
		if (rate == fsel_rate_map[i])
			break;
	}
	if (i == ARRAY_SIZE(fsel_rate_map)) {
		dev_err(p_phy->dev, "Unsupported clock rate: %lu\n", rate);
		ret = -EINVAL;
		goto disable_clk;
	}

	regmap_update_bits(p_phy->cr_top, USB_PHY_CONTROL1,
			   USB_PHY_CONTROL1_FSEL_MASK <<
			   USB_PHY_CONTROL1_FSEL_SHIFT,
			   i << USB_PHY_CONTROL1_FSEL_SHIFT);

	timeout = jiffies + msecs_to_jiffies(200);
	while (time_before(jiffies, timeout)) {
		unsigned int val;

		regmap_read(p_phy->cr_top, USB_PHY_STATUS, &val);
		if (val & USB_PHY_STATUS_VBUS_FAULT) {
			dev_err(p_phy->dev, "VBUS fault detected\n");
			ret = -EIO;
			goto disable_clk;
		}
		if ((val & USB_PHY_STATUS_RX_PHY_CLK) &&
		    (val & USB_PHY_STATUS_RX_UTMI_CLK))
			return 0;
		usleep_range(1000, 1500);
	}

	dev_err(p_phy->dev, "Timed out waiting for PHY to power on\n");
	ret = -ETIMEDOUT;

disable_clk:
	clk_disable_unprepare(p_phy->phy_clk);
	return ret;
}

static int pistachio_usb_phy_power_off(struct phy *phy)
{
	struct pistachio_usb_phy *p_phy = phy_get_drvdata(phy);

	clk_disable_unprepare(p_phy->phy_clk);

	return 0;
}

static const struct phy_ops pistachio_usb_phy_ops = {
	.power_on = pistachio_usb_phy_power_on,
	.power_off = pistachio_usb_phy_power_off,
	.owner = THIS_MODULE,
};

static int pistachio_usb_phy_probe(struct platform_device *pdev)
{
	struct pistachio_usb_phy *p_phy;
	struct phy_provider *provider;
	struct phy *phy;
	int ret;

	p_phy = devm_kzalloc(&pdev->dev, sizeof(*p_phy), GFP_KERNEL);
	if (!p_phy)
		return -ENOMEM;
	p_phy->dev = &pdev->dev;
	platform_set_drvdata(pdev, p_phy);

	p_phy->cr_top = syscon_regmap_lookup_by_phandle(p_phy->dev->of_node,
							"img,cr-top");
	if (IS_ERR(p_phy->cr_top)) {
		dev_err(p_phy->dev, "Failed to get CR_TOP registers: %ld\n",
			PTR_ERR(p_phy->cr_top));
		return PTR_ERR(p_phy->cr_top);
	}

	p_phy->phy_clk = devm_clk_get(p_phy->dev, "usb_phy");
	if (IS_ERR(p_phy->phy_clk)) {
		dev_err(p_phy->dev, "Failed to get usb_phy clock: %ld\n",
			PTR_ERR(p_phy->phy_clk));
		return PTR_ERR(p_phy->phy_clk);
	}

	ret = of_property_read_u32(p_phy->dev->of_node, "img,refclk",
				   &p_phy->refclk);
	if (ret < 0) {
		dev_err(p_phy->dev, "No reference clock selector specified\n");
		return ret;
	}

	phy = devm_phy_create(p_phy->dev, NULL, &pistachio_usb_phy_ops);
	if (IS_ERR(phy)) {
		dev_err(p_phy->dev, "Failed to create PHY: %ld\n",
			PTR_ERR(phy));
		return PTR_ERR(phy);
	}
	phy_set_drvdata(phy, p_phy);

	provider = devm_of_phy_provider_register(p_phy->dev,
						 of_phy_simple_xlate);
	if (IS_ERR(provider)) {
		dev_err(p_phy->dev, "Failed to register PHY provider: %ld\n",
			PTR_ERR(provider));
		return PTR_ERR(provider);
	}

	return 0;
}

static const struct of_device_id pistachio_usb_phy_of_match[] = {
	{ .compatible = "img,pistachio-usb-phy", },
	{ },
};
MODULE_DEVICE_TABLE(of, pistachio_usb_phy_of_match);

static struct platform_driver pistachio_usb_phy_driver = {
	.probe		= pistachio_usb_phy_probe,
	.driver		= {
		.name	= "pistachio-usb-phy",
		.of_match_table = pistachio_usb_phy_of_match,
	},
};
module_platform_driver(pistachio_usb_phy_driver);

MODULE_AUTHOR("Andrew Bresticker <[email protected]>");
MODULE_DESCRIPTION("IMG Pistachio USB2.0 PHY driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
57991eba AB	1	/*
	2	* IMG Pistachio USB PHY driver
	3	*
	4	* Copyright (C) 2015 Google, Inc.
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/clk.h>
	12	#include <linux/delay.h>
	13	#include <linux/io.h>
	14	#include <linux/kernel.h>
	15	#include <linux/mfd/syscon.h>
	16	#include <linux/module.h>
	17	#include <linux/of.h>
	18	#include <linux/phy/phy.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/regmap.h>
	21
	22	#include <dt-bindings/phy/phy-pistachio-usb.h>
	23
	24	#define USB_PHY_CONTROL1 0x04
	25	#define USB_PHY_CONTROL1_FSEL_SHIFT 2
	26	#define USB_PHY_CONTROL1_FSEL_MASK 0x7
	27
	28	#define USB_PHY_STRAP_CONTROL 0x10
	29	#define USB_PHY_STRAP_CONTROL_REFCLK_SHIFT 4
	30	#define USB_PHY_STRAP_CONTROL_REFCLK_MASK 0x3
	31
	32	#define USB_PHY_STATUS 0x14
	33	#define USB_PHY_STATUS_RX_PHY_CLK BIT(9)
	34	#define USB_PHY_STATUS_RX_UTMI_CLK BIT(8)
	35	#define USB_PHY_STATUS_VBUS_FAULT BIT(7)
	36
	37	struct pistachio_usb_phy {
	38	struct device *dev;
	39	struct regmap *cr_top;
	40	struct clk *phy_clk;
	41	unsigned int refclk;
	42	};
	43
	44	static const unsigned long fsel_rate_map[] = {
	45	9600000,
	46	10000000,
	47	12000000,
	48	19200000,
	49	20000000,
	50	24000000,
	51	0,
	52	50000000,
	53	};
	54
	55	static int pistachio_usb_phy_power_on(struct phy *phy)
	56	{
	57	struct pistachio_usb_phy *p_phy = phy_get_drvdata(phy);
	58	unsigned long timeout, rate;
	59	unsigned int i;
	60	int ret;
	61
	62	ret = clk_prepare_enable(p_phy->phy_clk);
	63	if (ret < 0) {
	64	dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret);
65	return ret;
66	}
67
68	regmap_update_bits(p_phy->cr_top, USB_PHY_STRAP_CONTROL,
69	USB_PHY_STRAP_CONTROL_REFCLK_MASK <<
70	USB_PHY_STRAP_CONTROL_REFCLK_SHIFT,
71	p_phy->refclk << USB_PHY_STRAP_CONTROL_REFCLK_SHIFT);
72
73	rate = clk_get_rate(p_phy->phy_clk);
74	if (p_phy->refclk == REFCLK_XO_CRYSTAL && rate != 12000000) {
75	dev_err(p_phy->dev, "Unsupported rate for XO crystal: %ld\n",
76	rate);
77	ret = -EINVAL;
78	goto disable_clk;
79	}
80
81	for (i = 0; i < ARRAY_SIZE(fsel_rate_map); i++) {
82	if (rate == fsel_rate_map[i])
83	break;
84	}
85	if (i == ARRAY_SIZE(fsel_rate_map)) {
86	dev_err(p_phy->dev, "Unsupported clock rate: %lu\n", rate);
87	ret = -EINVAL;
88	goto disable_clk;
89	}
90
91	regmap_update_bits(p_phy->cr_top, USB_PHY_CONTROL1,
92	USB_PHY_CONTROL1_FSEL_MASK <<
93	USB_PHY_CONTROL1_FSEL_SHIFT,
94	i << USB_PHY_CONTROL1_FSEL_SHIFT);
95
96	timeout = jiffies + msecs_to_jiffies(200);
97	while (time_before(jiffies, timeout)) {
98	unsigned int val;
99
100	regmap_read(p_phy->cr_top, USB_PHY_STATUS, &val);
101	if (val & USB_PHY_STATUS_VBUS_FAULT) {
102	dev_err(p_phy->dev, "VBUS fault detected\n");
103	ret = -EIO;
104	goto disable_clk;
105	}
106	if ((val & USB_PHY_STATUS_RX_PHY_CLK) &&
107	(val & USB_PHY_STATUS_RX_UTMI_CLK))
108	return 0;
109	usleep_range(1000, 1500);
110	}
111
112	dev_err(p_phy->dev, "Timed out waiting for PHY to power on\n");
113	ret = -ETIMEDOUT;
114
115	disable_clk:
116	clk_disable_unprepare(p_phy->phy_clk);
117	return ret;
118	}
119
120	static int pistachio_usb_phy_power_off(struct phy *phy)
121	{
122	struct pistachio_usb_phy *p_phy = phy_get_drvdata(phy);
123
124	clk_disable_unprepare(p_phy->phy_clk);
125
126	return 0;
127	}
128
129	static const struct phy_ops pistachio_usb_phy_ops = {
130	.power_on = pistachio_usb_phy_power_on,
131	.power_off = pistachio_usb_phy_power_off,
132	.owner = THIS_MODULE,
133	};
134
135	static int pistachio_usb_phy_probe(struct platform_device *pdev)
136	{
137	struct pistachio_usb_phy *p_phy;
138	struct phy_provider *provider;
139	struct phy *phy;
140	int ret;
141
142	p_phy = devm_kzalloc(&pdev->dev, sizeof(*p_phy), GFP_KERNEL);
143	if (!p_phy)
144	return -ENOMEM;
145	p_phy->dev = &pdev->dev;
146	platform_set_drvdata(pdev, p_phy);
147
148	p_phy->cr_top = syscon_regmap_lookup_by_phandle(p_phy->dev->of_node,
149	"img,cr-top");
150	if (IS_ERR(p_phy->cr_top)) {
151	dev_err(p_phy->dev, "Failed to get CR_TOP registers: %ld\n",
152	PTR_ERR(p_phy->cr_top));
153	return PTR_ERR(p_phy->cr_top);
154	}
155
156	p_phy->phy_clk = devm_clk_get(p_phy->dev, "usb_phy");
157	if (IS_ERR(p_phy->phy_clk)) {
158	dev_err(p_phy->dev, "Failed to get usb_phy clock: %ld\n",
159	PTR_ERR(p_phy->phy_clk));
160	return PTR_ERR(p_phy->phy_clk);
161	}
162
163	ret = of_property_read_u32(p_phy->dev->of_node, "img,refclk",
164	&p_phy->refclk);
165	if (ret < 0) {
166	dev_err(p_phy->dev, "No reference clock selector specified\n");
167	return ret;
168	}
169
170	phy = devm_phy_create(p_phy->dev, NULL, &pistachio_usb_phy_ops);
171	if (IS_ERR(phy)) {
172	dev_err(p_phy->dev, "Failed to create PHY: %ld\n",
173	PTR_ERR(phy));
174	return PTR_ERR(phy);
175	}
176	phy_set_drvdata(phy, p_phy);
177
178	provider = devm_of_phy_provider_register(p_phy->dev,
179	of_phy_simple_xlate);
180	if (IS_ERR(provider)) {
181	dev_err(p_phy->dev, "Failed to register PHY provider: %ld\n",
182	PTR_ERR(provider));
183	return PTR_ERR(provider);
184	}
185
186	return 0;
187	}
188
189	static const struct of_device_id pistachio_usb_phy_of_match[] = {
190	{ .compatible = "img,pistachio-usb-phy", },
191	{ },
192	};
193	MODULE_DEVICE_TABLE(of, pistachio_usb_phy_of_match);
194
195	static struct platform_driver pistachio_usb_phy_driver = {
196	.probe = pistachio_usb_phy_probe,
197	.driver = {
198	.name = "pistachio-usb-phy",
199	.of_match_table = pistachio_usb_phy_of_match,
200	},
201	};
202	module_platform_driver(pistachio_usb_phy_driver);
203
204	MODULE_AUTHOR("Andrew Bresticker <[email protected]>");
205	MODULE_DESCRIPTION("IMG Pistachio USB2.0 PHY driver");
206	MODULE_LICENSE("GPL v2");