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 const 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, NULL, &ops);
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		.of_match_table = bcm_kona_usb2_dt_ids,
147	},
148};
149
150module_platform_driver(bcm_kona_usb2_driver);
151
152MODULE_ALIAS("platform:bcm-kona-usb2");
153MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
154MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
155MODULE_LICENSE("GPL v2");
156