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