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 
38 struct bcm_kona_usb {
39 	void __iomem *regs;
40 };
41 
42 static 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 
58 static 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 
76 static 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 
85 static 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 
94 static 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 
101 static 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 
135 static const struct of_device_id bcm_kona_usb2_dt_ids[] = {
136 	{ .compatible = "brcm,kona-usb2-phy" },
137 	{ /* sentinel */ }
138 };
139 
140 MODULE_DEVICE_TABLE(of, bcm_kona_usb2_dt_ids);
141 
142 static 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 
150 module_platform_driver(bcm_kona_usb2_driver);
151 
152 MODULE_ALIAS("platform:bcm-kona-usb2");
153 MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
154 MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
155 MODULE_LICENSE("GPL v2");
156