1 /*
2  * Allwinner sun4i USB phy driver
3  *
4  * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
5  *
6  * Based on code from
7  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
8  *
9  * Modelled after: Samsung S5P/EXYNOS SoC series MIPI CSIS/DSIM DPHY driver
10  * Copyright (C) 2013 Samsung Electronics Co., Ltd.
11  * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  */
23 
24 #include <linux/clk.h>
25 #include <linux/err.h>
26 #include <linux/io.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/mutex.h>
30 #include <linux/of.h>
31 #include <linux/of_address.h>
32 #include <linux/phy/phy.h>
33 #include <linux/platform_device.h>
34 #include <linux/regulator/consumer.h>
35 #include <linux/reset.h>
36 
37 #define REG_ISCR			0x00
38 #define REG_PHYCTL			0x04
39 #define REG_PHYBIST			0x08
40 #define REG_PHYTUNE			0x0c
41 
42 #define PHYCTL_DATA			BIT(7)
43 
44 #define SUNXI_AHB_ICHR8_EN		BIT(10)
45 #define SUNXI_AHB_INCR4_BURST_EN	BIT(9)
46 #define SUNXI_AHB_INCRX_ALIGN_EN	BIT(8)
47 #define SUNXI_ULPI_BYPASS_EN		BIT(0)
48 
49 /* Common Control Bits for Both PHYs */
50 #define PHY_PLL_BW			0x03
51 #define PHY_RES45_CAL_EN		0x0c
52 
53 /* Private Control Bits for Each PHY */
54 #define PHY_TX_AMPLITUDE_TUNE		0x20
55 #define PHY_TX_SLEWRATE_TUNE		0x22
56 #define PHY_VBUSVALID_TH_SEL		0x25
57 #define PHY_PULLUP_RES_SEL		0x27
58 #define PHY_OTG_FUNC_EN			0x28
59 #define PHY_VBUS_DET_EN			0x29
60 #define PHY_DISCON_TH_SEL		0x2a
61 
62 #define MAX_PHYS			3
63 
64 struct sun4i_usb_phy_data {
65 	void __iomem *base;
66 	struct mutex mutex;
67 	int num_phys;
68 	u32 disc_thresh;
69 	struct sun4i_usb_phy {
70 		struct phy *phy;
71 		void __iomem *pmu;
72 		struct regulator *vbus;
73 		struct reset_control *reset;
74 		struct clk *clk;
75 		int index;
76 	} phys[MAX_PHYS];
77 };
78 
79 #define to_sun4i_usb_phy_data(phy) \
80 	container_of((phy), struct sun4i_usb_phy_data, phys[(phy)->index])
81 
sun4i_usb_phy_write(struct sun4i_usb_phy * phy,u32 addr,u32 data,int len)82 static void sun4i_usb_phy_write(struct sun4i_usb_phy *phy, u32 addr, u32 data,
83 				int len)
84 {
85 	struct sun4i_usb_phy_data *phy_data = to_sun4i_usb_phy_data(phy);
86 	u32 temp, usbc_bit = BIT(phy->index * 2);
87 	int i;
88 
89 	mutex_lock(&phy_data->mutex);
90 
91 	for (i = 0; i < len; i++) {
92 		temp = readl(phy_data->base + REG_PHYCTL);
93 
94 		/* clear the address portion */
95 		temp &= ~(0xff << 8);
96 
97 		/* set the address */
98 		temp |= ((addr + i) << 8);
99 		writel(temp, phy_data->base + REG_PHYCTL);
100 
101 		/* set the data bit and clear usbc bit*/
102 		temp = readb(phy_data->base + REG_PHYCTL);
103 		if (data & 0x1)
104 			temp |= PHYCTL_DATA;
105 		else
106 			temp &= ~PHYCTL_DATA;
107 		temp &= ~usbc_bit;
108 		writeb(temp, phy_data->base + REG_PHYCTL);
109 
110 		/* pulse usbc_bit */
111 		temp = readb(phy_data->base + REG_PHYCTL);
112 		temp |= usbc_bit;
113 		writeb(temp, phy_data->base + REG_PHYCTL);
114 
115 		temp = readb(phy_data->base + REG_PHYCTL);
116 		temp &= ~usbc_bit;
117 		writeb(temp, phy_data->base + REG_PHYCTL);
118 
119 		data >>= 1;
120 	}
121 	mutex_unlock(&phy_data->mutex);
122 }
123 
sun4i_usb_phy_passby(struct sun4i_usb_phy * phy,int enable)124 static void sun4i_usb_phy_passby(struct sun4i_usb_phy *phy, int enable)
125 {
126 	u32 bits, reg_value;
127 
128 	if (!phy->pmu)
129 		return;
130 
131 	bits = SUNXI_AHB_ICHR8_EN | SUNXI_AHB_INCR4_BURST_EN |
132 		SUNXI_AHB_INCRX_ALIGN_EN | SUNXI_ULPI_BYPASS_EN;
133 
134 	reg_value = readl(phy->pmu);
135 
136 	if (enable)
137 		reg_value |= bits;
138 	else
139 		reg_value &= ~bits;
140 
141 	writel(reg_value, phy->pmu);
142 }
143 
sun4i_usb_phy_init(struct phy * _phy)144 static int sun4i_usb_phy_init(struct phy *_phy)
145 {
146 	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
147 	struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
148 	int ret;
149 
150 	ret = clk_prepare_enable(phy->clk);
151 	if (ret)
152 		return ret;
153 
154 	ret = reset_control_deassert(phy->reset);
155 	if (ret) {
156 		clk_disable_unprepare(phy->clk);
157 		return ret;
158 	}
159 
160 	/* Enable USB 45 Ohm resistor calibration */
161 	if (phy->index == 0)
162 		sun4i_usb_phy_write(phy, PHY_RES45_CAL_EN, 0x01, 1);
163 
164 	/* Adjust PHY's magnitude and rate */
165 	sun4i_usb_phy_write(phy, PHY_TX_AMPLITUDE_TUNE, 0x14, 5);
166 
167 	/* Disconnect threshold adjustment */
168 	sun4i_usb_phy_write(phy, PHY_DISCON_TH_SEL, data->disc_thresh, 2);
169 
170 	sun4i_usb_phy_passby(phy, 1);
171 
172 	return 0;
173 }
174 
sun4i_usb_phy_exit(struct phy * _phy)175 static int sun4i_usb_phy_exit(struct phy *_phy)
176 {
177 	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
178 
179 	sun4i_usb_phy_passby(phy, 0);
180 	reset_control_assert(phy->reset);
181 	clk_disable_unprepare(phy->clk);
182 
183 	return 0;
184 }
185 
sun4i_usb_phy_power_on(struct phy * _phy)186 static int sun4i_usb_phy_power_on(struct phy *_phy)
187 {
188 	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
189 	int ret = 0;
190 
191 	if (phy->vbus)
192 		ret = regulator_enable(phy->vbus);
193 
194 	return ret;
195 }
196 
sun4i_usb_phy_power_off(struct phy * _phy)197 static int sun4i_usb_phy_power_off(struct phy *_phy)
198 {
199 	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
200 
201 	if (phy->vbus)
202 		regulator_disable(phy->vbus);
203 
204 	return 0;
205 }
206 
207 static struct phy_ops sun4i_usb_phy_ops = {
208 	.init		= sun4i_usb_phy_init,
209 	.exit		= sun4i_usb_phy_exit,
210 	.power_on	= sun4i_usb_phy_power_on,
211 	.power_off	= sun4i_usb_phy_power_off,
212 	.owner		= THIS_MODULE,
213 };
214 
sun4i_usb_phy_xlate(struct device * dev,struct of_phandle_args * args)215 static struct phy *sun4i_usb_phy_xlate(struct device *dev,
216 					struct of_phandle_args *args)
217 {
218 	struct sun4i_usb_phy_data *data = dev_get_drvdata(dev);
219 
220 	if (args->args[0] >= data->num_phys)
221 		return ERR_PTR(-ENODEV);
222 
223 	return data->phys[args->args[0]].phy;
224 }
225 
sun4i_usb_phy_probe(struct platform_device * pdev)226 static int sun4i_usb_phy_probe(struct platform_device *pdev)
227 {
228 	struct sun4i_usb_phy_data *data;
229 	struct device *dev = &pdev->dev;
230 	struct device_node *np = dev->of_node;
231 	struct phy_provider *phy_provider;
232 	bool dedicated_clocks;
233 	struct resource *res;
234 	int i;
235 
236 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
237 	if (!data)
238 		return -ENOMEM;
239 
240 	mutex_init(&data->mutex);
241 
242 	if (of_device_is_compatible(np, "allwinner,sun5i-a13-usb-phy"))
243 		data->num_phys = 2;
244 	else
245 		data->num_phys = 3;
246 
247 	if (of_device_is_compatible(np, "allwinner,sun4i-a10-usb-phy") ||
248 	    of_device_is_compatible(np, "allwinner,sun6i-a31-usb-phy"))
249 		data->disc_thresh = 3;
250 	else
251 		data->disc_thresh = 2;
252 
253 	if (of_device_is_compatible(np, "allwinner,sun6i-a31-usb-phy"))
254 		dedicated_clocks = true;
255 	else
256 		dedicated_clocks = false;
257 
258 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy_ctrl");
259 	data->base = devm_ioremap_resource(dev, res);
260 	if (IS_ERR(data->base))
261 		return PTR_ERR(data->base);
262 
263 	for (i = 0; i < data->num_phys; i++) {
264 		struct sun4i_usb_phy *phy = data->phys + i;
265 		char name[16];
266 
267 		snprintf(name, sizeof(name), "usb%d_vbus", i);
268 		phy->vbus = devm_regulator_get_optional(dev, name);
269 		if (IS_ERR(phy->vbus)) {
270 			if (PTR_ERR(phy->vbus) == -EPROBE_DEFER)
271 				return -EPROBE_DEFER;
272 			phy->vbus = NULL;
273 		}
274 
275 		if (dedicated_clocks)
276 			snprintf(name, sizeof(name), "usb%d_phy", i);
277 		else
278 			strlcpy(name, "usb_phy", sizeof(name));
279 
280 		phy->clk = devm_clk_get(dev, name);
281 		if (IS_ERR(phy->clk)) {
282 			dev_err(dev, "failed to get clock %s\n", name);
283 			return PTR_ERR(phy->clk);
284 		}
285 
286 		snprintf(name, sizeof(name), "usb%d_reset", i);
287 		phy->reset = devm_reset_control_get(dev, name);
288 		if (IS_ERR(phy->reset)) {
289 			dev_err(dev, "failed to get reset %s\n", name);
290 			return PTR_ERR(phy->reset);
291 		}
292 
293 		if (i) { /* No pmu for usbc0 */
294 			snprintf(name, sizeof(name), "pmu%d", i);
295 			res = platform_get_resource_byname(pdev,
296 							IORESOURCE_MEM, name);
297 			phy->pmu = devm_ioremap_resource(dev, res);
298 			if (IS_ERR(phy->pmu))
299 				return PTR_ERR(phy->pmu);
300 		}
301 
302 		phy->phy = devm_phy_create(dev, NULL, &sun4i_usb_phy_ops);
303 		if (IS_ERR(phy->phy)) {
304 			dev_err(dev, "failed to create PHY %d\n", i);
305 			return PTR_ERR(phy->phy);
306 		}
307 
308 		phy->index = i;
309 		phy_set_drvdata(phy->phy, &data->phys[i]);
310 	}
311 
312 	dev_set_drvdata(dev, data);
313 	phy_provider = devm_of_phy_provider_register(dev, sun4i_usb_phy_xlate);
314 
315 	return PTR_ERR_OR_ZERO(phy_provider);
316 }
317 
318 static const struct of_device_id sun4i_usb_phy_of_match[] = {
319 	{ .compatible = "allwinner,sun4i-a10-usb-phy" },
320 	{ .compatible = "allwinner,sun5i-a13-usb-phy" },
321 	{ .compatible = "allwinner,sun6i-a31-usb-phy" },
322 	{ .compatible = "allwinner,sun7i-a20-usb-phy" },
323 	{ },
324 };
325 MODULE_DEVICE_TABLE(of, sun4i_usb_phy_of_match);
326 
327 static struct platform_driver sun4i_usb_phy_driver = {
328 	.probe	= sun4i_usb_phy_probe,
329 	.driver = {
330 		.of_match_table	= sun4i_usb_phy_of_match,
331 		.name  = "sun4i-usb-phy",
332 	}
333 };
334 module_platform_driver(sun4i_usb_phy_driver);
335 
336 MODULE_DESCRIPTION("Allwinner sun4i USB phy driver");
337 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
338 MODULE_LICENSE("GPL v2");
339