1 /*
2  * Copyright (C) 2017 John Crispin <john@phrozen.org>
3  *
4  * Based on code from
5  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/mfd/syscon.h>
23 #include <linux/module.h>
24 #include <linux/mutex.h>
25 #include <linux/of_platform.h>
26 #include <linux/phy/phy.h>
27 #include <linux/platform_device.h>
28 #include <linux/regmap.h>
29 #include <linux/reset.h>
30 
31 #define RT_SYSC_REG_SYSCFG1		0x014
32 #define RT_SYSC_REG_CLKCFG1		0x030
33 #define RT_SYSC_REG_USB_PHY_CFG		0x05c
34 
35 #define OFS_U2_PHY_AC0			0x800
36 #define OFS_U2_PHY_AC1			0x804
37 #define OFS_U2_PHY_AC2			0x808
38 #define OFS_U2_PHY_ACR0			0x810
39 #define OFS_U2_PHY_ACR1			0x814
40 #define OFS_U2_PHY_ACR2			0x818
41 #define OFS_U2_PHY_ACR3			0x81C
42 #define OFS_U2_PHY_ACR4			0x820
43 #define OFS_U2_PHY_AMON0		0x824
44 #define OFS_U2_PHY_DCR0			0x860
45 #define OFS_U2_PHY_DCR1			0x864
46 #define OFS_U2_PHY_DTM0			0x868
47 #define OFS_U2_PHY_DTM1			0x86C
48 
49 #define RT_RSTCTRL_UDEV			BIT(25)
50 #define RT_RSTCTRL_UHST			BIT(22)
51 #define RT_SYSCFG1_USB0_HOST_MODE	BIT(10)
52 
53 #define MT7620_CLKCFG1_UPHY0_CLK_EN	BIT(25)
54 #define MT7620_CLKCFG1_UPHY1_CLK_EN	BIT(22)
55 #define RT_CLKCFG1_UPHY1_CLK_EN		BIT(20)
56 #define RT_CLKCFG1_UPHY0_CLK_EN		BIT(18)
57 
58 #define USB_PHY_UTMI_8B60M		BIT(1)
59 #define UDEV_WAKEUP			BIT(0)
60 
61 struct ralink_usb_phy {
62 	struct reset_control	*rstdev;
63 	struct reset_control	*rsthost;
64 	u32			clk;
65 	struct phy		*phy;
66 	void __iomem		*base;
67 	struct regmap		*sysctl;
68 };
69 
70 static void u2_phy_w32(struct ralink_usb_phy *phy, u32 val, u32 reg)
71 {
72 	writel(val, phy->base + reg);
73 }
74 
75 static u32 u2_phy_r32(struct ralink_usb_phy *phy, u32 reg)
76 {
77 	return readl(phy->base + reg);
78 }
79 
80 static void ralink_usb_phy_init(struct ralink_usb_phy *phy)
81 {
82 	u2_phy_r32(phy, OFS_U2_PHY_AC2);
83 	u2_phy_r32(phy, OFS_U2_PHY_ACR0);
84 	u2_phy_r32(phy, OFS_U2_PHY_DCR0);
85 
86 	u2_phy_w32(phy, 0x00ffff02, OFS_U2_PHY_DCR0);
87 	u2_phy_r32(phy, OFS_U2_PHY_DCR0);
88 	u2_phy_w32(phy, 0x00555502, OFS_U2_PHY_DCR0);
89 	u2_phy_r32(phy, OFS_U2_PHY_DCR0);
90 	u2_phy_w32(phy, 0x00aaaa02, OFS_U2_PHY_DCR0);
91 	u2_phy_r32(phy, OFS_U2_PHY_DCR0);
92 	u2_phy_w32(phy, 0x00000402, OFS_U2_PHY_DCR0);
93 	u2_phy_r32(phy, OFS_U2_PHY_DCR0);
94 	u2_phy_w32(phy, 0x0048086a, OFS_U2_PHY_AC0);
95 	u2_phy_w32(phy, 0x4400001c, OFS_U2_PHY_AC1);
96 	u2_phy_w32(phy, 0xc0200000, OFS_U2_PHY_ACR3);
97 	u2_phy_w32(phy, 0x02000000, OFS_U2_PHY_DTM0);
98 }
99 
100 static int ralink_usb_phy_power_on(struct phy *_phy)
101 {
102 	struct ralink_usb_phy *phy = phy_get_drvdata(_phy);
103 	u32 t;
104 
105 	/* enable the phy */
106 	regmap_update_bits(phy->sysctl, RT_SYSC_REG_CLKCFG1,
107 			   phy->clk, phy->clk);
108 
109 	/* setup host mode */
110 	regmap_update_bits(phy->sysctl, RT_SYSC_REG_SYSCFG1,
111 			   RT_SYSCFG1_USB0_HOST_MODE,
112 			   RT_SYSCFG1_USB0_HOST_MODE);
113 
114 	/* deassert the reset lines */
115 	reset_control_deassert(phy->rsthost);
116 	reset_control_deassert(phy->rstdev);
117 
118 	/*
119 	 * The SDK kernel had a delay of 100ms. however on device
120 	 * testing showed that 10ms is enough
121 	 */
122 	mdelay(10);
123 
124 	if (phy->base)
125 		ralink_usb_phy_init(phy);
126 
127 	/* print some status info */
128 	regmap_read(phy->sysctl, RT_SYSC_REG_USB_PHY_CFG, &t);
129 	dev_info(&phy->phy->dev, "remote usb device wakeup %s\n",
130 		(t & UDEV_WAKEUP) ? ("enabled") : ("disabled"));
131 	if (t & USB_PHY_UTMI_8B60M)
132 		dev_info(&phy->phy->dev, "UTMI 8bit 60MHz\n");
133 	else
134 		dev_info(&phy->phy->dev, "UTMI 16bit 30MHz\n");
135 
136 	return 0;
137 }
138 
139 static int ralink_usb_phy_power_off(struct phy *_phy)
140 {
141 	struct ralink_usb_phy *phy = phy_get_drvdata(_phy);
142 
143 	/* disable the phy */
144 	regmap_update_bits(phy->sysctl, RT_SYSC_REG_CLKCFG1,
145 			   phy->clk, 0);
146 
147 	/* assert the reset lines */
148 	reset_control_assert(phy->rstdev);
149 	reset_control_assert(phy->rsthost);
150 
151 	return 0;
152 }
153 
154 static struct phy_ops ralink_usb_phy_ops = {
155 	.power_on	= ralink_usb_phy_power_on,
156 	.power_off	= ralink_usb_phy_power_off,
157 	.owner		= THIS_MODULE,
158 };
159 
160 static const struct of_device_id ralink_usb_phy_of_match[] = {
161 	{
162 		.compatible = "ralink,rt3352-usbphy",
163 		.data = (void *)(uintptr_t)(RT_CLKCFG1_UPHY1_CLK_EN |
164 					    RT_CLKCFG1_UPHY0_CLK_EN)
165 	},
166 	{
167 		.compatible = "mediatek,mt7620-usbphy",
168 		.data = (void *)(uintptr_t)(MT7620_CLKCFG1_UPHY1_CLK_EN |
169 					    MT7620_CLKCFG1_UPHY0_CLK_EN)
170 	},
171 	{
172 		.compatible = "mediatek,mt7628-usbphy",
173 		.data = (void *)(uintptr_t)(MT7620_CLKCFG1_UPHY1_CLK_EN |
174 					    MT7620_CLKCFG1_UPHY0_CLK_EN) },
175 	{ },
176 };
177 MODULE_DEVICE_TABLE(of, ralink_usb_phy_of_match);
178 
179 static int ralink_usb_phy_probe(struct platform_device *pdev)
180 {
181 	struct device *dev = &pdev->dev;
182 	struct resource *res;
183 	struct phy_provider *phy_provider;
184 	const struct of_device_id *match;
185 	struct ralink_usb_phy *phy;
186 
187 	match = of_match_device(ralink_usb_phy_of_match, &pdev->dev);
188 	if (!match)
189 		return -ENODEV;
190 
191 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
192 	if (!phy)
193 		return -ENOMEM;
194 
195 	phy->clk = (uintptr_t)match->data;
196 	phy->base = NULL;
197 
198 	phy->sysctl = syscon_regmap_lookup_by_phandle(dev->of_node, "ralink,sysctl");
199 	if (IS_ERR(phy->sysctl)) {
200 		dev_err(dev, "failed to get sysctl registers\n");
201 		return PTR_ERR(phy->sysctl);
202 	}
203 
204 	/* The MT7628 and MT7688 require extra setup of PHY registers. */
205 	if (of_device_is_compatible(dev->of_node, "mediatek,mt7628-usbphy")) {
206 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
207 		phy->base = devm_ioremap_resource(&pdev->dev, res);
208 		if (IS_ERR(phy->base)) {
209 			dev_err(dev, "failed to remap register memory\n");
210 			return PTR_ERR(phy->base);
211 		}
212 	}
213 
214 	phy->rsthost = devm_reset_control_get(&pdev->dev, "host");
215 	if (IS_ERR(phy->rsthost)) {
216 		dev_err(dev, "host reset is missing\n");
217 		return PTR_ERR(phy->rsthost);
218 	}
219 
220 	phy->rstdev = devm_reset_control_get(&pdev->dev, "device");
221 	if (IS_ERR(phy->rstdev)) {
222 		dev_err(dev, "device reset is missing\n");
223 		return PTR_ERR(phy->rstdev);
224 	}
225 
226 	phy->phy = devm_phy_create(dev, NULL, &ralink_usb_phy_ops);
227 	if (IS_ERR(phy->phy)) {
228 		dev_err(dev, "failed to create PHY\n");
229 		return PTR_ERR(phy->phy);
230 	}
231 	phy_set_drvdata(phy->phy, phy);
232 
233 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
234 
235 	return PTR_ERR_OR_ZERO(phy_provider);
236 }
237 
238 static struct platform_driver ralink_usb_phy_driver = {
239 	.probe	= ralink_usb_phy_probe,
240 	.driver = {
241 		.of_match_table	= ralink_usb_phy_of_match,
242 		.name  = "ralink-usb-phy",
243 	}
244 };
245 module_platform_driver(ralink_usb_phy_driver);
246 
247 MODULE_DESCRIPTION("Ralink USB phy driver");
248 MODULE_AUTHOR("John Crispin <john@phrozen.org>");
249 MODULE_LICENSE("GPL v2");
250