1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014 STMicroelectronics
4 *
5 * STMicroelectronics Generic PHY driver for STiH407 USB2.
6 *
7 * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
8 */
9#include <linux/platform_device.h>
10#include <linux/io.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/of_platform.h>
15#include <linux/clk.h>
16#include <linux/regmap.h>
17#include <linux/reset.h>
18#include <linux/mfd/syscon.h>
19#include <linux/phy/phy.h>
20
21#define PHYPARAM_REG	1
22#define PHYCTRL_REG	2
23
24/* Default PHY_SEL and REFCLKSEL configuration */
25#define STIH407_USB_PICOPHY_CTRL_PORT_CONF	0x6
26#define STIH407_USB_PICOPHY_CTRL_PORT_MASK	0x1f
27
28/* ports parameters overriding */
29#define STIH407_USB_PICOPHY_PARAM_DEF		0x39a4dc
30#define STIH407_USB_PICOPHY_PARAM_MASK		0xffffffff
31
32struct stih407_usb2_picophy {
33	struct phy *phy;
34	struct regmap *regmap;
35	struct device *dev;
36	struct reset_control *rstc;
37	struct reset_control *rstport;
38	int ctrl;
39	int param;
40};
41
42static int stih407_usb2_pico_ctrl(struct stih407_usb2_picophy *phy_dev)
43{
44	reset_control_deassert(phy_dev->rstc);
45
46	return regmap_update_bits(phy_dev->regmap, phy_dev->ctrl,
47				  STIH407_USB_PICOPHY_CTRL_PORT_MASK,
48				  STIH407_USB_PICOPHY_CTRL_PORT_CONF);
49}
50
51static int stih407_usb2_init_port(struct phy *phy)
52{
53	int ret;
54	struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
55
56	stih407_usb2_pico_ctrl(phy_dev);
57
58	ret = regmap_update_bits(phy_dev->regmap,
59				 phy_dev->param,
60				 STIH407_USB_PICOPHY_PARAM_MASK,
61				 STIH407_USB_PICOPHY_PARAM_DEF);
62	if (ret)
63		return ret;
64
65	return reset_control_deassert(phy_dev->rstport);
66}
67
68static int stih407_usb2_exit_port(struct phy *phy)
69{
70	struct stih407_usb2_picophy *phy_dev = phy_get_drvdata(phy);
71
72	/*
73	 * Only port reset is asserted, phy global reset is kept untouched
74	 * as other ports may still be active. When all ports are in reset
75	 * state, assumption is made that power will be cut off on the phy, in
76	 * case of suspend for instance. Theoretically, asserting individual
77	 * reset (like here) or global reset should be equivalent.
78	 */
79	return reset_control_assert(phy_dev->rstport);
80}
81
82static const struct phy_ops stih407_usb2_picophy_data = {
83	.init = stih407_usb2_init_port,
84	.exit = stih407_usb2_exit_port,
85	.owner = THIS_MODULE,
86};
87
88static int stih407_usb2_picophy_probe(struct platform_device *pdev)
89{
90	struct stih407_usb2_picophy *phy_dev;
91	struct device *dev = &pdev->dev;
92	struct device_node *np = dev->of_node;
93	struct phy_provider *phy_provider;
94	struct phy *phy;
95	int ret;
96
97	phy_dev = devm_kzalloc(dev, sizeof(*phy_dev), GFP_KERNEL);
98	if (!phy_dev)
99		return -ENOMEM;
100
101	phy_dev->dev = dev;
102	dev_set_drvdata(dev, phy_dev);
103
104	phy_dev->rstc = devm_reset_control_get_shared(dev, "global");
105	if (IS_ERR(phy_dev->rstc)) {
106		dev_err(dev, "failed to ctrl picoPHY reset\n");
107		return PTR_ERR(phy_dev->rstc);
108	}
109
110	phy_dev->rstport = devm_reset_control_get_exclusive(dev, "port");
111	if (IS_ERR(phy_dev->rstport)) {
112		dev_err(dev, "failed to ctrl picoPHY reset\n");
113		return PTR_ERR(phy_dev->rstport);
114	}
115
116	/* Reset port by default: only deassert it in phy init */
117	reset_control_assert(phy_dev->rstport);
118
119	phy_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
120	if (IS_ERR(phy_dev->regmap)) {
121		dev_err(dev, "No syscfg phandle specified\n");
122		return PTR_ERR(phy_dev->regmap);
123	}
124
125	ret = of_property_read_u32_index(np, "st,syscfg", PHYPARAM_REG,
126					&phy_dev->param);
127	if (ret) {
128		dev_err(dev, "can't get phyparam offset (%d)\n", ret);
129		return ret;
130	}
131
132	ret = of_property_read_u32_index(np, "st,syscfg", PHYCTRL_REG,
133					&phy_dev->ctrl);
134	if (ret) {
135		dev_err(dev, "can't get phyctrl offset (%d)\n", ret);
136		return ret;
137	}
138
139	phy = devm_phy_create(dev, NULL, &stih407_usb2_picophy_data);
140	if (IS_ERR(phy)) {
141		dev_err(dev, "failed to create Display Port PHY\n");
142		return PTR_ERR(phy);
143	}
144
145	phy_dev->phy = phy;
146	phy_set_drvdata(phy, phy_dev);
147
148	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
149	if (IS_ERR(phy_provider))
150		return PTR_ERR(phy_provider);
151
152	dev_info(dev, "STiH407 USB Generic picoPHY driver probed!");
153
154	return 0;
155}
156
157static const struct of_device_id stih407_usb2_picophy_of_match[] = {
158	{ .compatible = "st,stih407-usb2-phy" },
159	{ /*sentinel */ },
160};
161
162MODULE_DEVICE_TABLE(of, stih407_usb2_picophy_of_match);
163
164static struct platform_driver stih407_usb2_picophy_driver = {
165	.probe = stih407_usb2_picophy_probe,
166	.driver = {
167		   .name = "stih407-usb-genphy",
168		   .of_match_table = stih407_usb2_picophy_of_match,
169		   }
170};
171
172module_platform_driver(stih407_usb2_picophy_driver);
173
174MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
175MODULE_DESCRIPTION("STMicroelectronics Generic picoPHY driver for STiH407");
176MODULE_LICENSE("GPL v2");
177