1 /*
2  * PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
3  *
4  * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/err.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/phy/phy.h>
18 #include <linux/platform_device.h>
19 #include <linux/regmap.h>
20 
21 /* USB OTG PHY register offset and bit in CREG */
22 #define LPC18XX_CREG_CREG0		0x004
23 #define LPC18XX_CREG_CREG0_USB0PHY	BIT(5)
24 
25 struct lpc18xx_usb_otg_phy {
26 	struct phy *phy;
27 	struct clk *clk;
28 	struct regmap *reg;
29 };
30 
31 static int lpc18xx_usb_otg_phy_init(struct phy *phy)
32 {
33 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
34 	int ret;
35 
36 	/* The PHY must be clocked at 480 MHz */
37 	ret = clk_set_rate(lpc->clk, 480000000);
38 	if (ret)
39 		return ret;
40 
41 	return clk_prepare(lpc->clk);
42 }
43 
44 static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
45 {
46 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
47 
48 	clk_unprepare(lpc->clk);
49 
50 	return 0;
51 }
52 
53 static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
54 {
55 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
56 	int ret;
57 
58 	ret = clk_enable(lpc->clk);
59 	if (ret)
60 		return ret;
61 
62 	/* The bit in CREG is cleared to enable the PHY */
63 	return regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
64 				  LPC18XX_CREG_CREG0_USB0PHY, 0);
65 }
66 
67 static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
68 {
69 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
70 	int ret;
71 
72 	ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
73 				 LPC18XX_CREG_CREG0_USB0PHY,
74 				 LPC18XX_CREG_CREG0_USB0PHY);
75 	if (ret)
76 		return ret;
77 
78 	clk_disable(lpc->clk);
79 
80 	return 0;
81 }
82 
83 static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
84 	.init		= lpc18xx_usb_otg_phy_init,
85 	.exit		= lpc18xx_usb_otg_phy_exit,
86 	.power_on	= lpc18xx_usb_otg_phy_power_on,
87 	.power_off	= lpc18xx_usb_otg_phy_power_off,
88 	.owner		= THIS_MODULE,
89 };
90 
91 static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
92 {
93 	struct phy_provider *phy_provider;
94 	struct lpc18xx_usb_otg_phy *lpc;
95 
96 	lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
97 	if (!lpc)
98 		return -ENOMEM;
99 
100 	lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
101 	if (IS_ERR(lpc->reg)) {
102 		dev_err(&pdev->dev, "failed to get syscon\n");
103 		return PTR_ERR(lpc->reg);
104 	}
105 
106 	lpc->clk = devm_clk_get(&pdev->dev, NULL);
107 	if (IS_ERR(lpc->clk)) {
108 		dev_err(&pdev->dev, "failed to get clock\n");
109 		return PTR_ERR(lpc->clk);
110 	}
111 
112 	lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
113 	if (IS_ERR(lpc->phy)) {
114 		dev_err(&pdev->dev, "failed to create PHY\n");
115 		return PTR_ERR(lpc->phy);
116 	}
117 
118 	phy_set_drvdata(lpc->phy, lpc);
119 
120 	phy_provider = devm_of_phy_provider_register(&pdev->dev,
121 						     of_phy_simple_xlate);
122 
123 	return PTR_ERR_OR_ZERO(phy_provider);
124 }
125 
126 static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
127 	{ .compatible = "nxp,lpc1850-usb-otg-phy" },
128 	{ }
129 };
130 MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
131 
132 static struct platform_driver lpc18xx_usb_otg_phy_driver = {
133 	.probe		= lpc18xx_usb_otg_phy_probe,
134 	.driver		= {
135 		.name	= "lpc18xx-usb-otg-phy",
136 		.of_match_table = lpc18xx_usb_otg_phy_match,
137 	},
138 };
139 module_platform_driver(lpc18xx_usb_otg_phy_driver);
140 
141 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
142 MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
143 MODULE_LICENSE("GPL v2");
144