xref: /openbmc/linux/drivers/usb/phy/phy-keystone.c (revision 2a598d0b)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * phy-keystone - USB PHY, talking to dwc3 controller in Keystone.
4  *
5  * Copyright (C) 2013 Texas Instruments Incorporated - https://www.ti.com
6  *
7  * Author: WingMan Kwok <w-kwok2@ti.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/usb/usb_phy_generic.h>
13 #include <linux/io.h>
14 #include <linux/of.h>
15 
16 #include "phy-generic.h"
17 
18 /* USB PHY control register offsets */
19 #define USB_PHY_CTL_UTMI		0x0000
20 #define USB_PHY_CTL_PIPE		0x0004
21 #define USB_PHY_CTL_PARAM_1		0x0008
22 #define USB_PHY_CTL_PARAM_2		0x000c
23 #define USB_PHY_CTL_CLOCK		0x0010
24 #define USB_PHY_CTL_PLL			0x0014
25 
26 #define PHY_REF_SSP_EN			BIT(29)
27 
28 struct keystone_usbphy {
29 	struct usb_phy_generic	usb_phy_gen;
30 	void __iomem			*phy_ctrl;
31 };
32 
33 static inline u32 keystone_usbphy_readl(void __iomem *base, u32 offset)
34 {
35 	return readl(base + offset);
36 }
37 
38 static inline void keystone_usbphy_writel(void __iomem *base,
39 					  u32 offset, u32 value)
40 {
41 	writel(value, base + offset);
42 }
43 
44 static int keystone_usbphy_init(struct usb_phy *phy)
45 {
46 	struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
47 	u32 val;
48 
49 	val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
50 	keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
51 				val | PHY_REF_SSP_EN);
52 	return 0;
53 }
54 
55 static void keystone_usbphy_shutdown(struct usb_phy *phy)
56 {
57 	struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
58 	u32 val;
59 
60 	val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
61 	keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
62 				val & ~PHY_REF_SSP_EN);
63 }
64 
65 static int keystone_usbphy_probe(struct platform_device *pdev)
66 {
67 	struct device		*dev = &pdev->dev;
68 	struct keystone_usbphy	*k_phy;
69 	int ret;
70 
71 	k_phy = devm_kzalloc(dev, sizeof(*k_phy), GFP_KERNEL);
72 	if (!k_phy)
73 		return -ENOMEM;
74 
75 	k_phy->phy_ctrl = devm_platform_ioremap_resource(pdev, 0);
76 	if (IS_ERR(k_phy->phy_ctrl))
77 		return PTR_ERR(k_phy->phy_ctrl);
78 
79 	ret = usb_phy_gen_create_phy(dev, &k_phy->usb_phy_gen);
80 	if (ret)
81 		return ret;
82 
83 	k_phy->usb_phy_gen.phy.init = keystone_usbphy_init;
84 	k_phy->usb_phy_gen.phy.shutdown = keystone_usbphy_shutdown;
85 
86 	platform_set_drvdata(pdev, k_phy);
87 
88 	return usb_add_phy_dev(&k_phy->usb_phy_gen.phy);
89 }
90 
91 static void keystone_usbphy_remove(struct platform_device *pdev)
92 {
93 	struct keystone_usbphy *k_phy = platform_get_drvdata(pdev);
94 
95 	usb_remove_phy(&k_phy->usb_phy_gen.phy);
96 }
97 
98 static const struct of_device_id keystone_usbphy_ids[] = {
99 	{ .compatible = "ti,keystone-usbphy" },
100 	{ }
101 };
102 MODULE_DEVICE_TABLE(of, keystone_usbphy_ids);
103 
104 static struct platform_driver keystone_usbphy_driver = {
105 	.probe          = keystone_usbphy_probe,
106 	.remove_new     = keystone_usbphy_remove,
107 	.driver         = {
108 		.name   = "keystone-usbphy",
109 		.of_match_table = keystone_usbphy_ids,
110 	},
111 };
112 
113 module_platform_driver(keystone_usbphy_driver);
114 
115 MODULE_ALIAS("platform:keystone-usbphy");
116 MODULE_AUTHOR("Texas Instruments Inc.");
117 MODULE_DESCRIPTION("Keystone USB phy driver");
118 MODULE_LICENSE("GPL v2");
119