Merge branch 'linux-5.3' of git://github.com/skeggsb/linux into drm-fixes
[platform/kernel/linux-rpi.git] / drivers / phy / phy-lpc18xx-usb-otg.c
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
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
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
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
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
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");