GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / phy / phy-lpc18xx-usb-otg.c
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");