1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
4  *
5  * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/err.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/phy/phy.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16 
17 /* USB OTG PHY register offset and bit in CREG */
18 #define LPC18XX_CREG_CREG0		0x004
19 #define LPC18XX_CREG_CREG0_USB0PHY	BIT(5)
20 
21 struct lpc18xx_usb_otg_phy {
22 	struct phy *phy;
23 	struct clk *clk;
24 	struct regmap *reg;
25 };
26 
lpc18xx_usb_otg_phy_init(struct phy * phy)27 static int lpc18xx_usb_otg_phy_init(struct phy *phy)
28 {
29 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
30 	int ret;
31 
32 	/* The PHY must be clocked at 480 MHz */
33 	ret = clk_set_rate(lpc->clk, 480000000);
34 	if (ret)
35 		return ret;
36 
37 	return clk_prepare(lpc->clk);
38 }
39 
lpc18xx_usb_otg_phy_exit(struct phy * phy)40 static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
41 {
42 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
43 
44 	clk_unprepare(lpc->clk);
45 
46 	return 0;
47 }
48 
lpc18xx_usb_otg_phy_power_on(struct phy * phy)49 static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
50 {
51 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
52 	int ret;
53 
54 	ret = clk_enable(lpc->clk);
55 	if (ret)
56 		return ret;
57 
58 	/* The bit in CREG is cleared to enable the PHY */
59 	ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
60 				  LPC18XX_CREG_CREG0_USB0PHY, 0);
61 	if (ret) {
62 		clk_disable(lpc->clk);
63 		return ret;
64 	}
65 
66 	return 0;
67 }
68 
lpc18xx_usb_otg_phy_power_off(struct phy * phy)69 static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
70 {
71 	struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
72 	int ret;
73 
74 	ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
75 				 LPC18XX_CREG_CREG0_USB0PHY,
76 				 LPC18XX_CREG_CREG0_USB0PHY);
77 	if (ret)
78 		return ret;
79 
80 	clk_disable(lpc->clk);
81 
82 	return 0;
83 }
84 
85 static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
86 	.init		= lpc18xx_usb_otg_phy_init,
87 	.exit		= lpc18xx_usb_otg_phy_exit,
88 	.power_on	= lpc18xx_usb_otg_phy_power_on,
89 	.power_off	= lpc18xx_usb_otg_phy_power_off,
90 	.owner		= THIS_MODULE,
91 };
92 
lpc18xx_usb_otg_phy_probe(struct platform_device * pdev)93 static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
94 {
95 	struct phy_provider *phy_provider;
96 	struct lpc18xx_usb_otg_phy *lpc;
97 
98 	lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
99 	if (!lpc)
100 		return -ENOMEM;
101 
102 	lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
103 	if (IS_ERR(lpc->reg)) {
104 		dev_err(&pdev->dev, "failed to get syscon\n");
105 		return PTR_ERR(lpc->reg);
106 	}
107 
108 	lpc->clk = devm_clk_get(&pdev->dev, NULL);
109 	if (IS_ERR(lpc->clk)) {
110 		dev_err(&pdev->dev, "failed to get clock\n");
111 		return PTR_ERR(lpc->clk);
112 	}
113 
114 	lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
115 	if (IS_ERR(lpc->phy)) {
116 		dev_err(&pdev->dev, "failed to create PHY\n");
117 		return PTR_ERR(lpc->phy);
118 	}
119 
120 	phy_set_drvdata(lpc->phy, lpc);
121 
122 	phy_provider = devm_of_phy_provider_register(&pdev->dev,
123 						     of_phy_simple_xlate);
124 
125 	return PTR_ERR_OR_ZERO(phy_provider);
126 }
127 
128 static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
129 	{ .compatible = "nxp,lpc1850-usb-otg-phy" },
130 	{ }
131 };
132 MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
133 
134 static struct platform_driver lpc18xx_usb_otg_phy_driver = {
135 	.probe		= lpc18xx_usb_otg_phy_probe,
136 	.driver		= {
137 		.name	= "lpc18xx-usb-otg-phy",
138 		.of_match_table = lpc18xx_usb_otg_phy_match,
139 	},
140 };
141 module_platform_driver(lpc18xx_usb_otg_phy_driver);
142 
143 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
144 MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
145 MODULE_LICENSE("GPL v2");
146