1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * phy-bcm-kona-usb2.c - Broadcom Kona USB2 Phy Driver
4  *
5  * Copyright (C) 2013 Linaro Limited
6  * Matt Porter <mporter@linaro.org>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/phy/phy.h>
16 #include <linux/platform_device.h>
17 
18 #define OTGCTL			(0)
19 #define OTGCTL_OTGSTAT2		BIT(31)
20 #define OTGCTL_OTGSTAT1		BIT(30)
21 #define OTGCTL_PRST_N_SW	BIT(11)
22 #define OTGCTL_HRESET_N		BIT(10)
23 #define OTGCTL_UTMI_LINE_STATE1	BIT(9)
24 #define OTGCTL_UTMI_LINE_STATE0	BIT(8)
25 
26 #define P1CTL			(8)
27 #define P1CTL_SOFT_RESET	BIT(1)
28 #define P1CTL_NON_DRIVING	BIT(0)
29 
30 struct bcm_kona_usb {
31 	void __iomem *regs;
32 };
33 
bcm_kona_usb_phy_power(struct bcm_kona_usb * phy,int on)34 static void bcm_kona_usb_phy_power(struct bcm_kona_usb *phy, int on)
35 {
36 	u32 val;
37 
38 	val = readl(phy->regs + OTGCTL);
39 	if (on) {
40 		/* Configure and power PHY */
41 		val &= ~(OTGCTL_OTGSTAT2 | OTGCTL_OTGSTAT1 |
42 			 OTGCTL_UTMI_LINE_STATE1 | OTGCTL_UTMI_LINE_STATE0);
43 		val |= OTGCTL_PRST_N_SW | OTGCTL_HRESET_N;
44 	} else {
45 		val &= ~(OTGCTL_PRST_N_SW | OTGCTL_HRESET_N);
46 	}
47 	writel(val, phy->regs + OTGCTL);
48 }
49 
bcm_kona_usb_phy_init(struct phy * gphy)50 static int bcm_kona_usb_phy_init(struct phy *gphy)
51 {
52 	struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
53 	u32 val;
54 
55 	/* Soft reset PHY */
56 	val = readl(phy->regs + P1CTL);
57 	val &= ~P1CTL_NON_DRIVING;
58 	val |= P1CTL_SOFT_RESET;
59 	writel(val, phy->regs + P1CTL);
60 	writel(val & ~P1CTL_SOFT_RESET, phy->regs + P1CTL);
61 	/* Reset needs to be asserted for 2ms */
62 	mdelay(2);
63 	writel(val | P1CTL_SOFT_RESET, phy->regs + P1CTL);
64 
65 	return 0;
66 }
67 
bcm_kona_usb_phy_power_on(struct phy * gphy)68 static int bcm_kona_usb_phy_power_on(struct phy *gphy)
69 {
70 	struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
71 
72 	bcm_kona_usb_phy_power(phy, 1);
73 
74 	return 0;
75 }
76 
bcm_kona_usb_phy_power_off(struct phy * gphy)77 static int bcm_kona_usb_phy_power_off(struct phy *gphy)
78 {
79 	struct bcm_kona_usb *phy = phy_get_drvdata(gphy);
80 
81 	bcm_kona_usb_phy_power(phy, 0);
82 
83 	return 0;
84 }
85 
86 static const struct phy_ops ops = {
87 	.init		= bcm_kona_usb_phy_init,
88 	.power_on	= bcm_kona_usb_phy_power_on,
89 	.power_off	= bcm_kona_usb_phy_power_off,
90 	.owner		= THIS_MODULE,
91 };
92 
bcm_kona_usb2_probe(struct platform_device * pdev)93 static int bcm_kona_usb2_probe(struct platform_device *pdev)
94 {
95 	struct device *dev = &pdev->dev;
96 	struct bcm_kona_usb *phy;
97 	struct phy *gphy;
98 	struct phy_provider *phy_provider;
99 
100 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
101 	if (!phy)
102 		return -ENOMEM;
103 
104 	phy->regs = devm_platform_ioremap_resource(pdev, 0);
105 	if (IS_ERR(phy->regs))
106 		return PTR_ERR(phy->regs);
107 
108 	platform_set_drvdata(pdev, phy);
109 
110 	gphy = devm_phy_create(dev, NULL, &ops);
111 	if (IS_ERR(gphy))
112 		return PTR_ERR(gphy);
113 
114 	/* The Kona PHY supports an 8-bit wide UTMI interface */
115 	phy_set_bus_width(gphy, 8);
116 
117 	phy_set_drvdata(gphy, phy);
118 
119 	phy_provider = devm_of_phy_provider_register(dev,
120 			of_phy_simple_xlate);
121 
122 	return PTR_ERR_OR_ZERO(phy_provider);
123 }
124 
125 static const struct of_device_id bcm_kona_usb2_dt_ids[] = {
126 	{ .compatible = "brcm,kona-usb2-phy" },
127 	{ /* sentinel */ }
128 };
129 
130 MODULE_DEVICE_TABLE(of, bcm_kona_usb2_dt_ids);
131 
132 static struct platform_driver bcm_kona_usb2_driver = {
133 	.probe		= bcm_kona_usb2_probe,
134 	.driver		= {
135 		.name	= "bcm-kona-usb2",
136 		.of_match_table = bcm_kona_usb2_dt_ids,
137 	},
138 };
139 
140 module_platform_driver(bcm_kona_usb2_driver);
141 
142 MODULE_ALIAS("platform:bcm-kona-usb2");
143 MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
144 MODULE_DESCRIPTION("BCM Kona USB 2.0 PHY driver");
145 MODULE_LICENSE("GPL v2");
146