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
lpc18xx_usb_otg_phy_init(struct phy * phy)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
lpc18xx_usb_otg_phy_exit(struct phy * phy)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
lpc18xx_usb_otg_phy_power_on(struct phy * phy)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 ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
64 LPC18XX_CREG_CREG0_USB0PHY, 0);
65 if (ret) {
66 clk_disable(lpc->clk);
67 return ret;
68 }
69
70 return 0;
71 }
72
lpc18xx_usb_otg_phy_power_off(struct phy * phy)73 static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
74 {
75 struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
76 int ret;
77
78 ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
79 LPC18XX_CREG_CREG0_USB0PHY,
80 LPC18XX_CREG_CREG0_USB0PHY);
81 if (ret)
82 return ret;
83
84 clk_disable(lpc->clk);
85
86 return 0;
87 }
88
89 static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
90 .init = lpc18xx_usb_otg_phy_init,
91 .exit = lpc18xx_usb_otg_phy_exit,
92 .power_on = lpc18xx_usb_otg_phy_power_on,
93 .power_off = lpc18xx_usb_otg_phy_power_off,
94 .owner = THIS_MODULE,
95 };
96
lpc18xx_usb_otg_phy_probe(struct platform_device * pdev)97 static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
98 {
99 struct phy_provider *phy_provider;
100 struct lpc18xx_usb_otg_phy *lpc;
101
102 lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
103 if (!lpc)
104 return -ENOMEM;
105
106 lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
107 if (IS_ERR(lpc->reg)) {
108 dev_err(&pdev->dev, "failed to get syscon\n");
109 return PTR_ERR(lpc->reg);
110 }
111
112 lpc->clk = devm_clk_get(&pdev->dev, NULL);
113 if (IS_ERR(lpc->clk)) {
114 dev_err(&pdev->dev, "failed to get clock\n");
115 return PTR_ERR(lpc->clk);
116 }
117
118 lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
119 if (IS_ERR(lpc->phy)) {
120 dev_err(&pdev->dev, "failed to create PHY\n");
121 return PTR_ERR(lpc->phy);
122 }
123
124 phy_set_drvdata(lpc->phy, lpc);
125
126 phy_provider = devm_of_phy_provider_register(&pdev->dev,
127 of_phy_simple_xlate);
128
129 return PTR_ERR_OR_ZERO(phy_provider);
130 }
131
132 static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
133 { .compatible = "nxp,lpc1850-usb-otg-phy" },
134 { }
135 };
136 MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
137
138 static struct platform_driver lpc18xx_usb_otg_phy_driver = {
139 .probe = lpc18xx_usb_otg_phy_probe,
140 .driver = {
141 .name = "lpc18xx-usb-otg-phy",
142 .of_match_table = lpc18xx_usb_otg_phy_match,
143 },
144 };
145 module_platform_driver(lpc18xx_usb_otg_phy_driver);
146
147 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
148 MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
149 MODULE_LICENSE("GPL v2");
150
