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
22struct 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
30static 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
44static 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
67static 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
83static 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
92static 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
99static 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
135static const struct of_device_id jh7110_usb_phy_of_match[] = {
136	{ .compatible = "starfive,jh7110-usb-phy" },
137	{ /* sentinel */ },
138};
139MODULE_DEVICE_TABLE(of, jh7110_usb_phy_of_match);
140
141static 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};
148module_platform_driver(jh7110_usb_phy_driver);
149
150MODULE_DESCRIPTION("StarFive JH7110 USB 2.0 PHY driver");
151MODULE_AUTHOR("Minda Chen <minda.chen@starfivetech.com>");
152MODULE_LICENSE("GPL");
153