1/*
2 * phy-keystone - USB PHY, talking to dwc3 controller in Keystone.
3 *
4 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * Author: WingMan Kwok <w-kwok2@ti.com>
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 */
18
19#include <linux/module.h>
20#include <linux/platform_device.h>
21#include <linux/usb/usb_phy_generic.h>
22#include <linux/io.h>
23#include <linux/of.h>
24
25#include "phy-generic.h"
26
27/* USB PHY control register offsets */
28#define USB_PHY_CTL_UTMI		0x0000
29#define USB_PHY_CTL_PIPE		0x0004
30#define USB_PHY_CTL_PARAM_1		0x0008
31#define USB_PHY_CTL_PARAM_2		0x000c
32#define USB_PHY_CTL_CLOCK		0x0010
33#define USB_PHY_CTL_PLL			0x0014
34
35#define PHY_REF_SSP_EN			BIT(29)
36
37struct keystone_usbphy {
38	struct usb_phy_generic	usb_phy_gen;
39	void __iomem			*phy_ctrl;
40};
41
42static inline u32 keystone_usbphy_readl(void __iomem *base, u32 offset)
43{
44	return readl(base + offset);
45}
46
47static inline void keystone_usbphy_writel(void __iomem *base,
48					  u32 offset, u32 value)
49{
50	writel(value, base + offset);
51}
52
53static int keystone_usbphy_init(struct usb_phy *phy)
54{
55	struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
56	u32 val;
57
58	val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
59	keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
60				val | PHY_REF_SSP_EN);
61	return 0;
62}
63
64static void keystone_usbphy_shutdown(struct usb_phy *phy)
65{
66	struct keystone_usbphy *k_phy = dev_get_drvdata(phy->dev);
67	u32 val;
68
69	val  = keystone_usbphy_readl(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK);
70	keystone_usbphy_writel(k_phy->phy_ctrl, USB_PHY_CTL_CLOCK,
71				val &= ~PHY_REF_SSP_EN);
72}
73
74static int keystone_usbphy_probe(struct platform_device *pdev)
75{
76	struct device		*dev = &pdev->dev;
77	struct keystone_usbphy	*k_phy;
78	struct resource		*res;
79	int ret;
80
81	k_phy = devm_kzalloc(dev, sizeof(*k_phy), GFP_KERNEL);
82	if (!k_phy)
83		return -ENOMEM;
84
85	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
86	k_phy->phy_ctrl = devm_ioremap_resource(dev, res);
87	if (IS_ERR(k_phy->phy_ctrl))
88		return PTR_ERR(k_phy->phy_ctrl);
89
90	ret = usb_phy_gen_create_phy(dev, &k_phy->usb_phy_gen, NULL);
91	if (ret)
92		return ret;
93
94	k_phy->usb_phy_gen.phy.init = keystone_usbphy_init;
95	k_phy->usb_phy_gen.phy.shutdown = keystone_usbphy_shutdown;
96
97	platform_set_drvdata(pdev, k_phy);
98
99	ret = usb_add_phy_dev(&k_phy->usb_phy_gen.phy);
100	if (ret)
101		return ret;
102
103	return 0;
104}
105
106static int keystone_usbphy_remove(struct platform_device *pdev)
107{
108	struct keystone_usbphy *k_phy = platform_get_drvdata(pdev);
109
110	usb_remove_phy(&k_phy->usb_phy_gen.phy);
111
112	return 0;
113}
114
115static const struct of_device_id keystone_usbphy_ids[] = {
116	{ .compatible = "ti,keystone-usbphy" },
117	{ }
118};
119MODULE_DEVICE_TABLE(of, keystone_usbphy_ids);
120
121static struct platform_driver keystone_usbphy_driver = {
122	.probe          = keystone_usbphy_probe,
123	.remove         = keystone_usbphy_remove,
124	.driver         = {
125		.name   = "keystone-usbphy",
126		.of_match_table = keystone_usbphy_ids,
127	},
128};
129
130module_platform_driver(keystone_usbphy_driver);
131
132MODULE_ALIAS("platform:keystone-usbphy");
133MODULE_AUTHOR("Texas Instruments Inc.");
134MODULE_DESCRIPTION("Keystone USB phy driver");
135MODULE_LICENSE("GPL v2");
136