xref: /openbmc/linux/drivers/usb/misc/usb3503.c (revision 089a49b6)
1 /*
2  * Driver for SMSC USB3503 USB 2.0 hub controller driver
3  *
4  * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 
21 #include <linux/i2c.h>
22 #include <linux/gpio.h>
23 #include <linux/delay.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/of_gpio.h>
27 #include <linux/platform_device.h>
28 #include <linux/platform_data/usb3503.h>
29 #include <linux/regmap.h>
30 
31 #define USB3503_VIDL		0x00
32 #define USB3503_VIDM		0x01
33 #define USB3503_PIDL		0x02
34 #define USB3503_PIDM		0x03
35 #define USB3503_DIDL		0x04
36 #define USB3503_DIDM		0x05
37 
38 #define USB3503_CFG1		0x06
39 #define USB3503_SELF_BUS_PWR	(1 << 7)
40 
41 #define USB3503_CFG2		0x07
42 #define USB3503_CFG3		0x08
43 #define USB3503_NRD		0x09
44 
45 #define USB3503_PDS		0x0a
46 
47 #define USB3503_SP_ILOCK	0xe7
48 #define USB3503_SPILOCK_CONNECT	(1 << 1)
49 #define USB3503_SPILOCK_CONFIG	(1 << 0)
50 
51 #define USB3503_CFGP		0xee
52 #define USB3503_CLKSUSP		(1 << 7)
53 
54 #define USB3503_RESET		0xff
55 
56 struct usb3503 {
57 	enum usb3503_mode	mode;
58 	struct regmap		*regmap;
59 	struct device		*dev;
60 	u8	port_off_mask;
61 	int	gpio_intn;
62 	int	gpio_reset;
63 	int	gpio_connect;
64 };
65 
66 static int usb3503_reset(struct usb3503 *hub, int state)
67 {
68 	if (!state && gpio_is_valid(hub->gpio_connect))
69 		gpio_set_value_cansleep(hub->gpio_connect, 0);
70 
71 	if (gpio_is_valid(hub->gpio_reset))
72 		gpio_set_value_cansleep(hub->gpio_reset, state);
73 
74 	/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
75 	if (state)
76 		usleep_range(4000, 10000);
77 
78 	return 0;
79 }
80 
81 static int usb3503_connect(struct usb3503 *hub)
82 {
83 	struct device *dev = hub->dev;
84 	int err;
85 
86 	usb3503_reset(hub, 1);
87 
88 	if (hub->regmap) {
89 		/* SP_ILOCK: set connect_n, config_n for config */
90 		err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
91 			   (USB3503_SPILOCK_CONNECT
92 				 | USB3503_SPILOCK_CONFIG));
93 		if (err < 0) {
94 			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
95 			return err;
96 		}
97 
98 		/* PDS : Disable For Self Powered Operation */
99 		if (hub->port_off_mask) {
100 			err = regmap_update_bits(hub->regmap, USB3503_PDS,
101 					hub->port_off_mask,
102 					hub->port_off_mask);
103 			if (err < 0) {
104 				dev_err(dev, "PDS failed (%d)\n", err);
105 				return err;
106 			}
107 		}
108 
109 		/* CFG1 : SELF_BUS_PWR -> Self-Powerd operation */
110 		err = regmap_update_bits(hub->regmap, USB3503_CFG1,
111 					 USB3503_SELF_BUS_PWR,
112 					 USB3503_SELF_BUS_PWR);
113 		if (err < 0) {
114 			dev_err(dev, "CFG1 failed (%d)\n", err);
115 			return err;
116 		}
117 
118 		/* SP_LOCK: clear connect_n, config_n for hub connect */
119 		err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
120 					 (USB3503_SPILOCK_CONNECT
121 					  | USB3503_SPILOCK_CONFIG), 0);
122 		if (err < 0) {
123 			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
124 			return err;
125 		}
126 	}
127 
128 	if (gpio_is_valid(hub->gpio_connect))
129 		gpio_set_value_cansleep(hub->gpio_connect, 1);
130 
131 	hub->mode = USB3503_MODE_HUB;
132 	dev_info(dev, "switched to HUB mode\n");
133 
134 	return 0;
135 }
136 
137 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
138 {
139 	struct device *dev = hub->dev;
140 	int err = 0;
141 
142 	switch (mode) {
143 	case USB3503_MODE_HUB:
144 		err = usb3503_connect(hub);
145 		break;
146 
147 	case USB3503_MODE_STANDBY:
148 		usb3503_reset(hub, 0);
149 
150 		hub->mode = mode;
151 		dev_info(dev, "switched to STANDBY mode\n");
152 		break;
153 
154 	default:
155 		dev_err(dev, "unknown mode is requested\n");
156 		err = -EINVAL;
157 		break;
158 	}
159 
160 	return err;
161 }
162 
163 static const struct regmap_config usb3503_regmap_config = {
164 	.reg_bits = 8,
165 	.val_bits = 8,
166 
167 	.max_register = USB3503_RESET,
168 };
169 
170 static int usb3503_probe(struct usb3503 *hub)
171 {
172 	struct device *dev = hub->dev;
173 	struct usb3503_platform_data *pdata = dev_get_platdata(dev);
174 	struct device_node *np = dev->of_node;
175 	int err;
176 	u32 mode = USB3503_MODE_HUB;
177 	const u32 *property;
178 	int len;
179 
180 	if (pdata) {
181 		hub->port_off_mask	= pdata->port_off_mask;
182 		hub->gpio_intn		= pdata->gpio_intn;
183 		hub->gpio_connect	= pdata->gpio_connect;
184 		hub->gpio_reset		= pdata->gpio_reset;
185 		hub->mode		= pdata->initial_mode;
186 	} else if (np) {
187 		hub->port_off_mask = 0;
188 
189 		property = of_get_property(np, "disabled-ports", &len);
190 		if (property && (len / sizeof(u32)) > 0) {
191 			int i;
192 			for (i = 0; i < len / sizeof(u32); i++) {
193 				u32 port = be32_to_cpu(property[i]);
194 				if ((1 <= port) && (port <= 3))
195 					hub->port_off_mask |= (1 << port);
196 			}
197 		}
198 
199 		hub->gpio_intn	= of_get_named_gpio(np, "intn-gpios", 0);
200 		if (hub->gpio_intn == -EPROBE_DEFER)
201 			return -EPROBE_DEFER;
202 		hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0);
203 		if (hub->gpio_connect == -EPROBE_DEFER)
204 			return -EPROBE_DEFER;
205 		hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
206 		if (hub->gpio_reset == -EPROBE_DEFER)
207 			return -EPROBE_DEFER;
208 		of_property_read_u32(np, "initial-mode", &mode);
209 		hub->mode = mode;
210 	}
211 
212 	if (hub->port_off_mask && !hub->regmap)
213 		dev_err(dev, "Ports disabled with no control interface\n");
214 
215 	if (gpio_is_valid(hub->gpio_intn)) {
216 		err = devm_gpio_request_one(dev, hub->gpio_intn,
217 				GPIOF_OUT_INIT_HIGH, "usb3503 intn");
218 		if (err) {
219 			dev_err(dev,
220 				"unable to request GPIO %d as connect pin (%d)\n",
221 				hub->gpio_intn, err);
222 			return err;
223 		}
224 	}
225 
226 	if (gpio_is_valid(hub->gpio_connect)) {
227 		err = devm_gpio_request_one(dev, hub->gpio_connect,
228 				GPIOF_OUT_INIT_LOW, "usb3503 connect");
229 		if (err) {
230 			dev_err(dev,
231 				"unable to request GPIO %d as connect pin (%d)\n",
232 				hub->gpio_connect, err);
233 			return err;
234 		}
235 	}
236 
237 	if (gpio_is_valid(hub->gpio_reset)) {
238 		err = devm_gpio_request_one(dev, hub->gpio_reset,
239 				GPIOF_OUT_INIT_LOW, "usb3503 reset");
240 		if (err) {
241 			dev_err(dev,
242 				"unable to request GPIO %d as reset pin (%d)\n",
243 				hub->gpio_reset, err);
244 			return err;
245 		}
246 	}
247 
248 	usb3503_switch_mode(hub, hub->mode);
249 
250 	dev_info(dev, "%s: probed in %s mode\n", __func__,
251 			(hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
252 
253 	return 0;
254 }
255 
256 static int usb3503_i2c_probe(struct i2c_client *i2c,
257 			     const struct i2c_device_id *id)
258 {
259 	struct usb3503 *hub;
260 	int err;
261 
262 	hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
263 	if (!hub) {
264 		dev_err(&i2c->dev, "private data alloc fail\n");
265 		return -ENOMEM;
266 	}
267 
268 	i2c_set_clientdata(i2c, hub);
269 	hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
270 	if (IS_ERR(hub->regmap)) {
271 		err = PTR_ERR(hub->regmap);
272 		dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
273 		return err;
274 	}
275 	hub->dev = &i2c->dev;
276 
277 	return usb3503_probe(hub);
278 }
279 
280 static int usb3503_platform_probe(struct platform_device *pdev)
281 {
282 	struct usb3503 *hub;
283 
284 	hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
285 	if (!hub) {
286 		dev_err(&pdev->dev, "private data alloc fail\n");
287 		return -ENOMEM;
288 	}
289 	hub->dev = &pdev->dev;
290 
291 	return usb3503_probe(hub);
292 }
293 
294 static const struct i2c_device_id usb3503_id[] = {
295 	{ USB3503_I2C_NAME, 0 },
296 	{ }
297 };
298 MODULE_DEVICE_TABLE(i2c, usb3503_id);
299 
300 #ifdef CONFIG_OF
301 static const struct of_device_id usb3503_of_match[] = {
302 	{ .compatible = "smsc,usb3503", },
303 	{ .compatible = "smsc,usb3503a", },
304 	{},
305 };
306 MODULE_DEVICE_TABLE(of, usb3503_of_match);
307 #endif
308 
309 static struct i2c_driver usb3503_i2c_driver = {
310 	.driver = {
311 		.name = USB3503_I2C_NAME,
312 		.of_match_table = of_match_ptr(usb3503_of_match),
313 	},
314 	.probe		= usb3503_i2c_probe,
315 	.id_table	= usb3503_id,
316 };
317 
318 static struct platform_driver usb3503_platform_driver = {
319 	.driver = {
320 		.name = USB3503_I2C_NAME,
321 		.of_match_table = of_match_ptr(usb3503_of_match),
322 		.owner = THIS_MODULE,
323 	},
324 	.probe		= usb3503_platform_probe,
325 };
326 
327 static int __init usb3503_init(void)
328 {
329 	int err;
330 
331 	err = i2c_register_driver(THIS_MODULE, &usb3503_i2c_driver);
332 	if (err != 0)
333 		pr_err("usb3503: Failed to register I2C driver: %d\n", err);
334 
335 	err = platform_driver_register(&usb3503_platform_driver);
336 	if (err != 0)
337 		pr_err("usb3503: Failed to register platform driver: %d\n",
338 		       err);
339 
340 	return 0;
341 }
342 module_init(usb3503_init);
343 
344 static void __exit usb3503_exit(void)
345 {
346 	platform_driver_unregister(&usb3503_platform_driver);
347 	i2c_del_driver(&usb3503_i2c_driver);
348 }
349 module_exit(usb3503_exit);
350 
351 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
352 MODULE_DESCRIPTION("USB3503 USB HUB driver");
353 MODULE_LICENSE("GPL");
354