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_gen_xceiv.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_gen_xceiv	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		.owner  = THIS_MODULE,
127		.of_match_table = keystone_usbphy_ids,
128	},
129};
130
131module_platform_driver(keystone_usbphy_driver);
132
133MODULE_ALIAS("platform:keystone-usbphy");
134MODULE_AUTHOR("Texas Instruments Inc.");
135MODULE_DESCRIPTION("Keystone USB phy driver");
136MODULE_LICENSE("GPL v2");