1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * StarFive JH7110 USB 2.0 PHY driver
4  *
5  * Copyright (C) 2023 StarFive Technology Co., Ltd.
6  * Author: Minda Chen <minda.chen@starfivetech.com>
7  */
8 
9 #include <linux/bits.h>
10 #include <linux/clk.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/phy/phy.h>
15 #include <linux/platform_device.h>
16 #include <linux/usb/of.h>
17 
18 #define USB_125M_CLK_RATE		125000000
19 #define USB_LS_KEEPALIVE_OFF		0x4
20 #define USB_LS_KEEPALIVE_ENABLE		BIT(4)
21 
22 struct jh7110_usb2_phy {
23 	struct phy *phy;
24 	void __iomem *regs;
25 	struct clk *usb_125m_clk;
26 	struct clk *app_125m;
27 	enum phy_mode mode;
28 };
29 
30 static void usb2_set_ls_keepalive(struct jh7110_usb2_phy *phy, bool set)
31 {
32 	unsigned int val;
33 
34 	/* Host mode enable the LS speed keep-alive signal */
35 	val = readl(phy->regs + USB_LS_KEEPALIVE_OFF);
36 	if (set)
37 		val |= USB_LS_KEEPALIVE_ENABLE;
38 	else
39 		val &= ~USB_LS_KEEPALIVE_ENABLE;
40 
41 	writel(val, phy->regs + USB_LS_KEEPALIVE_OFF);
42 }
43 
44 static int usb2_phy_set_mode(struct phy *_phy,
45 			     enum phy_mode mode, int submode)
46 {
47 	struct jh7110_usb2_phy *phy = phy_get_drvdata(_phy);
48 
49 	switch (mode) {
50 	case PHY_MODE_USB_HOST:
51 	case PHY_MODE_USB_DEVICE:
52 	case PHY_MODE_USB_OTG:
53 		break;
54 	default:
55 		return -EINVAL;
56 	}
57 
58 	if (mode != phy->mode) {
59 		dev_dbg(&_phy->dev, "Changing phy to %d\n", mode);
60 		phy->mode = mode;
61 		usb2_set_ls_keepalive(phy, (mode != PHY_MODE_USB_DEVICE));
62 	}
63 
64 	return 0;
65 }
66 
67 static int jh7110_usb2_phy_init(struct phy *_phy)
68 {
69 	struct jh7110_usb2_phy *phy = phy_get_drvdata(_phy);
70 	int ret;
71 
72 	ret = clk_set_rate(phy->usb_125m_clk, USB_125M_CLK_RATE);
73 	if (ret)
74 		return ret;
75 
76 	ret = clk_prepare_enable(phy->app_125m);
77 	if (ret)
78 		return ret;
79 
80 	return 0;
81 }
82 
83 static int jh7110_usb2_phy_exit(struct phy *_phy)
84 {
85 	struct jh7110_usb2_phy *phy = phy_get_drvdata(_phy);
86 
87 	clk_disable_unprepare(phy->app_125m);
88 
89 	return 0;
90 }
91 
92 static const struct phy_ops jh7110_usb2_phy_ops = {
93 	.init		= jh7110_usb2_phy_init,
94 	.exit		= jh7110_usb2_phy_exit,
95 	.set_mode	= usb2_phy_set_mode,
96 	.owner		= THIS_MODULE,
97 };
98 
99 static int jh7110_usb_phy_probe(struct platform_device *pdev)
100 {
101 	struct jh7110_usb2_phy *phy;
102 	struct device *dev = &pdev->dev;
103 	struct phy_provider *phy_provider;
104 
105 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
106 	if (!phy)
107 		return -ENOMEM;
108 
109 	phy->usb_125m_clk = devm_clk_get(dev, "125m");
110 	if (IS_ERR(phy->usb_125m_clk))
111 		return dev_err_probe(dev, PTR_ERR(phy->usb_125m_clk),
112 			"Failed to get 125m clock\n");
113 
114 	phy->app_125m = devm_clk_get(dev, "app_125m");
115 	if (IS_ERR(phy->app_125m))
116 		return dev_err_probe(dev, PTR_ERR(phy->app_125m),
117 			"Failed to get app 125m clock\n");
118 
119 	phy->regs = devm_platform_ioremap_resource(pdev, 0);
120 	if (IS_ERR(phy->regs))
121 		return dev_err_probe(dev, PTR_ERR(phy->regs),
122 			"Failed to map phy base\n");
123 
124 	phy->phy = devm_phy_create(dev, NULL, &jh7110_usb2_phy_ops);
125 	if (IS_ERR(phy->phy))
126 		return dev_err_probe(dev, PTR_ERR(phy->phy),
127 			"Failed to create phy\n");
128 
129 	phy_set_drvdata(phy->phy, phy);
130 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
131 
132 	return PTR_ERR_OR_ZERO(phy_provider);
133 }
134 
135 static const struct of_device_id jh7110_usb_phy_of_match[] = {
136 	{ .compatible = "starfive,jh7110-usb-phy" },
137 	{ /* sentinel */ },
138 };
139 MODULE_DEVICE_TABLE(of, jh7110_usb_phy_of_match);
140 
141 static struct platform_driver jh7110_usb_phy_driver = {
142 	.probe	= jh7110_usb_phy_probe,
143 	.driver = {
144 		.of_match_table	= jh7110_usb_phy_of_match,
145 		.name  = "jh7110-usb-phy",
146 	}
147 };
148 module_platform_driver(jh7110_usb_phy_driver);
149 
150 MODULE_DESCRIPTION("StarFive JH7110 USB 2.0 PHY driver");
151 MODULE_AUTHOR("Minda Chen <minda.chen@starfivetech.com>");
152 MODULE_LICENSE("GPL");
153