1/*
  2 * phy-bcm-kona-usb2.c - Broadcom Kona USB2 Phy Driver
  3 *
  4 * Copyright (C) 2013 Linaro Limited
  5 * Matt Porter <mporter@linaro.org>
  6 *
  7 * This software is licensed under the terms of the GNU General Public
  8 * License version 2, as published by the Free Software Foundation, and
  9 * may be copied, distributed, and modified under those terms.
 10 *
 11 * This program is distributed in the hope that it will be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 * GNU General Public License for more details.
 15 */
 16
 17#include <linux/clk.h>
 18#include <linux/delay.h>
 19#include <linux/err.h>
 20#include <linux/io.h>
 21#include <linux/module.h>
 22#include <linux/of.h>
 23#include <linux/phy/phy.h>
 24#include <linux/platform_device.h>
 25
 26#define OTGCTL			(0)
 27#define OTGCTL_OTGSTAT2		BIT(31)
 28#define OTGCTL_OTGSTAT1		BIT(30)
 29#define OTGCTL_PRST_N_SW	BIT(11)
 30#define OTGCTL_HRESET_N		BIT(10)
 31#define OTGCTL_UTMI_LINE_STATE1	BIT(9)
 32#define OTGCTL_UTMI_LINE_STATE0	BIT(8)
 33
 34#define P1CTL			(8)
 35#define P1CTL_SOFT_RESET	BIT(1)
 36#define P1CTL_NON_DRIVING	BIT(0)
 37
 38struct bcm_kona_usb {
 39	void __iomem *regs;
 40};
 41
 42static void bcm_kona_usb_phy_power(struct bcm_kona_usb *phy, int on)
 43{
 44	u32 val;
 45
 46	val = readl(phy->regs + OTGCTL);
 47	if (on) {
 48		/* Configure and power PHY */
 49		val &= ~(OTGCTL_OTGSTAT2 | OTGCTL_OTGSTAT1 |
 50			 OTGCTL_UTMI_LINE_STATE1 | OTGCTL_UTMI_LINE_STATE0);
 51		val |= OTGCTL_PRST_N_SW | OTGCTL_HRESET_N;
 52	} else {
 53		val &= ~(OTGCTL_PRST_N_SW | OTGCTL_HRESET_N);
 54	}
 55	writel(val, phy->regs + OTGCTL);
 56}
 57
 58static int bcm_kona_usb_phy_init(struct phy *gphy)
 59{
 60	struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
 61	u32 val;
 62
 63	/* Soft reset PHY */
 64	val = readl(phy->regs + P1CTL);
 65	val &= ~P1CTL_NON_DRIVING;
 66	val |= P1CTL_SOFT_RESET;
 67	writel(val, phy->regs + P1CTL);
 68	writel(val & ~P1CTL_SOFT_RESET, phy->regs + P1CTL);
 69	/* Reset needs to be asserted for 2ms */
 70	mdelay(2);
 71	writel(val | P1CTL_SOFT_RESET, phy->regs + P1CTL);
 72
 73	return 0;
 74}
 75
 76static int bcm_kona_usb_phy_power_on(struct phy *gphy)
 77{
 78	struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
 79
 80	bcm_kona_usb_phy_power(phy, 1);
 81
 82	return 0;
 83}
 84
 85static int bcm_kona_usb_phy_power_off(struct phy *gphy)
 86{
 87	struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
 88
 89	bcm_kona_usb_phy_power(phy, 0);
 90
 91	return 0;
 92}
 93
 94static struct phy_ops ops = {
 95	.init		= bcm_kona_usb_phy_init,
 96	.power_on	= bcm_kona_usb_phy_power_on,
 97	.power_off	= bcm_kona_usb_phy_power_off,
 98	.owner		= THIS_MODULE,
 99};
100
101static int bcm_kona_usb2_probe(struct platform_device *pdev)
102{
103	struct device *dev = &pdev->dev;
104	struct bcm_kona_usb *phy;
105	struct resource *res;
106	struct phy *gphy;
107	struct phy_provider *phy_provider;
108
109	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
110	if (!phy)
111		return -ENOMEM;
112
113	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
114	phy->regs = devm_ioremap_resource(&pdev->dev, res);
115	if (IS_ERR(phy->regs))
116		return PTR_ERR(phy->regs);
117
118	platform_set_drvdata(pdev, phy);
119
120	gphy = devm_phy_create(dev, &ops, NULL);
121	if (IS_ERR(gphy))
122		return PTR_ERR(gphy);
123
124	/* The Kona PHY supports an 8-bit wide UTMI interface */
125	phy_set_bus_width(gphy, 8);
126
127	phy_set_drvdata(gphy, phy);
128
129	phy_provider = devm_of_phy_provider_register(dev,
130			of_phy_simple_xlate);
131
132	return PTR_ERR_OR_ZERO(phy_provider);
133}
134
135static const struct of_device_id bcm_kona_usb2_dt_ids[] = {
136	{ .compatible = "brcm,kona-usb2-phy" },
137	{ /* sentinel */ }
138};
139
140MODULE_DEVICE_TABLE(of, bcm_kona_usb2_dt_ids);
141
142static struct platform_driver bcm_kona_usb2_driver = {
143	.probe		= bcm_kona_usb2_probe,
144	.driver		= {
145		.name	= "bcm-kona-usb2",
146		.owner	= THIS_MODULE,
147		.of_match_table = bcm_kona_usb2_dt_ids,
148	},
149};
150
151module_platform_driver(bcm_kona_usb2_driver);
152
153MODULE_ALIAS("platform:bcm-kona-usb2");
154MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
155MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
156MODULE_LICENSE("GPL v2");