xref: /openbmc/linux/drivers/usb/misc/usb3503.c (revision d7a3d85e)
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/clk.h>
22 #include <linux/i2c.h>
23 #include <linux/gpio.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/module.h>
27 #include <linux/of_gpio.h>
28 #include <linux/platform_device.h>
29 #include <linux/platform_data/usb3503.h>
30 #include <linux/regmap.h>
31 
32 #define USB3503_VIDL		0x00
33 #define USB3503_VIDM		0x01
34 #define USB3503_PIDL		0x02
35 #define USB3503_PIDM		0x03
36 #define USB3503_DIDL		0x04
37 #define USB3503_DIDM		0x05
38 
39 #define USB3503_CFG1		0x06
40 #define USB3503_SELF_BUS_PWR	(1 << 7)
41 
42 #define USB3503_CFG2		0x07
43 #define USB3503_CFG3		0x08
44 #define USB3503_NRD		0x09
45 
46 #define USB3503_PDS		0x0a
47 
48 #define USB3503_SP_ILOCK	0xe7
49 #define USB3503_SPILOCK_CONNECT	(1 << 1)
50 #define USB3503_SPILOCK_CONFIG	(1 << 0)
51 
52 #define USB3503_CFGP		0xee
53 #define USB3503_CLKSUSP		(1 << 7)
54 
55 #define USB3503_RESET		0xff
56 
57 struct usb3503 {
58 	enum usb3503_mode	mode;
59 	struct regmap		*regmap;
60 	struct device		*dev;
61 	struct clk		*clk;
62 	u8	port_off_mask;
63 	int	gpio_intn;
64 	int	gpio_reset;
65 	int	gpio_connect;
66 	bool	secondary_ref_clk;
67 };
68 
69 static int usb3503_reset(struct usb3503 *hub, int state)
70 {
71 	if (!state && gpio_is_valid(hub->gpio_connect))
72 		gpio_set_value_cansleep(hub->gpio_connect, 0);
73 
74 	if (gpio_is_valid(hub->gpio_reset))
75 		gpio_set_value_cansleep(hub->gpio_reset, state);
76 
77 	/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
78 	if (state)
79 		usleep_range(4000, 10000);
80 
81 	return 0;
82 }
83 
84 static int usb3503_connect(struct usb3503 *hub)
85 {
86 	struct device *dev = hub->dev;
87 	int err;
88 
89 	usb3503_reset(hub, 1);
90 
91 	if (hub->regmap) {
92 		/* SP_ILOCK: set connect_n, config_n for config */
93 		err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
94 			   (USB3503_SPILOCK_CONNECT
95 				 | USB3503_SPILOCK_CONFIG));
96 		if (err < 0) {
97 			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
98 			return err;
99 		}
100 
101 		/* PDS : Set the ports which are disabled in self-powered mode. */
102 		if (hub->port_off_mask) {
103 			err = regmap_update_bits(hub->regmap, USB3503_PDS,
104 					hub->port_off_mask,
105 					hub->port_off_mask);
106 			if (err < 0) {
107 				dev_err(dev, "PDS failed (%d)\n", err);
108 				return err;
109 			}
110 		}
111 
112 		/* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */
113 		err = regmap_update_bits(hub->regmap, USB3503_CFG1,
114 					 USB3503_SELF_BUS_PWR,
115 					 USB3503_SELF_BUS_PWR);
116 		if (err < 0) {
117 			dev_err(dev, "CFG1 failed (%d)\n", err);
118 			return err;
119 		}
120 
121 		/* SP_LOCK: clear connect_n, config_n for hub connect */
122 		err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
123 					 (USB3503_SPILOCK_CONNECT
124 					  | USB3503_SPILOCK_CONFIG), 0);
125 		if (err < 0) {
126 			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
127 			return err;
128 		}
129 	}
130 
131 	if (gpio_is_valid(hub->gpio_connect))
132 		gpio_set_value_cansleep(hub->gpio_connect, 1);
133 
134 	hub->mode = USB3503_MODE_HUB;
135 	dev_info(dev, "switched to HUB mode\n");
136 
137 	return 0;
138 }
139 
140 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
141 {
142 	struct device *dev = hub->dev;
143 	int err = 0;
144 
145 	switch (mode) {
146 	case USB3503_MODE_HUB:
147 		err = usb3503_connect(hub);
148 		break;
149 
150 	case USB3503_MODE_STANDBY:
151 		usb3503_reset(hub, 0);
152 		dev_info(dev, "switched to STANDBY mode\n");
153 		break;
154 
155 	default:
156 		dev_err(dev, "unknown mode is requested\n");
157 		err = -EINVAL;
158 		break;
159 	}
160 
161 	return err;
162 }
163 
164 static const struct regmap_config usb3503_regmap_config = {
165 	.reg_bits = 8,
166 	.val_bits = 8,
167 
168 	.max_register = USB3503_RESET,
169 };
170 
171 static int usb3503_probe(struct usb3503 *hub)
172 {
173 	struct device *dev = hub->dev;
174 	struct usb3503_platform_data *pdata = dev_get_platdata(dev);
175 	struct device_node *np = dev->of_node;
176 	int err;
177 	u32 mode = USB3503_MODE_HUB;
178 	const u32 *property;
179 	int len;
180 
181 	if (pdata) {
182 		hub->port_off_mask	= pdata->port_off_mask;
183 		hub->gpio_intn		= pdata->gpio_intn;
184 		hub->gpio_connect	= pdata->gpio_connect;
185 		hub->gpio_reset		= pdata->gpio_reset;
186 		hub->mode		= pdata->initial_mode;
187 	} else if (np) {
188 		struct clk *clk;
189 		u32 rate = 0;
190 		hub->port_off_mask = 0;
191 
192 		if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
193 			switch (rate) {
194 			case 38400000:
195 			case 26000000:
196 			case 19200000:
197 			case 12000000:
198 				hub->secondary_ref_clk = 0;
199 				break;
200 			case 24000000:
201 			case 27000000:
202 			case 25000000:
203 			case 50000000:
204 				hub->secondary_ref_clk = 1;
205 				break;
206 			default:
207 				dev_err(dev,
208 					"unsupported reference clock rate (%d)\n",
209 					(int) rate);
210 				return -EINVAL;
211 			}
212 		}
213 
214 		clk = devm_clk_get(dev, "refclk");
215 		if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) {
216 			dev_err(dev, "unable to request refclk (%ld)\n",
217 					PTR_ERR(clk));
218 			return PTR_ERR(clk);
219 		}
220 
221 		if (!IS_ERR(clk)) {
222 			hub->clk = clk;
223 
224 			if (rate != 0) {
225 				err = clk_set_rate(hub->clk, rate);
226 				if (err) {
227 					dev_err(dev,
228 						"unable to set reference clock rate to %d\n",
229 						(int) rate);
230 					return err;
231 				}
232 			}
233 
234 			err = clk_prepare_enable(hub->clk);
235 			if (err) {
236 				dev_err(dev,
237 					"unable to enable reference clock\n");
238 				return err;
239 			}
240 		}
241 
242 		property = of_get_property(np, "disabled-ports", &len);
243 		if (property && (len / sizeof(u32)) > 0) {
244 			int i;
245 			for (i = 0; i < len / sizeof(u32); i++) {
246 				u32 port = be32_to_cpu(property[i]);
247 				if ((1 <= port) && (port <= 3))
248 					hub->port_off_mask |= (1 << port);
249 			}
250 		}
251 
252 		hub->gpio_intn	= of_get_named_gpio(np, "intn-gpios", 0);
253 		if (hub->gpio_intn == -EPROBE_DEFER)
254 			return -EPROBE_DEFER;
255 		hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0);
256 		if (hub->gpio_connect == -EPROBE_DEFER)
257 			return -EPROBE_DEFER;
258 		hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
259 		if (hub->gpio_reset == -EPROBE_DEFER)
260 			return -EPROBE_DEFER;
261 		of_property_read_u32(np, "initial-mode", &mode);
262 		hub->mode = mode;
263 	}
264 
265 	if (hub->port_off_mask && !hub->regmap)
266 		dev_err(dev, "Ports disabled with no control interface\n");
267 
268 	if (gpio_is_valid(hub->gpio_intn)) {
269 		int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW :
270 						   GPIOF_OUT_INIT_HIGH;
271 		err = devm_gpio_request_one(dev, hub->gpio_intn, val,
272 					    "usb3503 intn");
273 		if (err) {
274 			dev_err(dev,
275 				"unable to request GPIO %d as interrupt pin (%d)\n",
276 				hub->gpio_intn, err);
277 			return err;
278 		}
279 	}
280 
281 	if (gpio_is_valid(hub->gpio_connect)) {
282 		err = devm_gpio_request_one(dev, hub->gpio_connect,
283 				GPIOF_OUT_INIT_LOW, "usb3503 connect");
284 		if (err) {
285 			dev_err(dev,
286 				"unable to request GPIO %d as connect pin (%d)\n",
287 				hub->gpio_connect, err);
288 			return err;
289 		}
290 	}
291 
292 	if (gpio_is_valid(hub->gpio_reset)) {
293 		err = devm_gpio_request_one(dev, hub->gpio_reset,
294 				GPIOF_OUT_INIT_LOW, "usb3503 reset");
295 		if (err) {
296 			dev_err(dev,
297 				"unable to request GPIO %d as reset pin (%d)\n",
298 				hub->gpio_reset, err);
299 			return err;
300 		}
301 	}
302 
303 	usb3503_switch_mode(hub, hub->mode);
304 
305 	dev_info(dev, "%s: probed in %s mode\n", __func__,
306 			(hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");
307 
308 	return 0;
309 }
310 
311 static int usb3503_i2c_probe(struct i2c_client *i2c,
312 			     const struct i2c_device_id *id)
313 {
314 	struct usb3503 *hub;
315 	int err;
316 
317 	hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
318 	if (!hub)
319 		return -ENOMEM;
320 
321 	i2c_set_clientdata(i2c, hub);
322 	hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
323 	if (IS_ERR(hub->regmap)) {
324 		err = PTR_ERR(hub->regmap);
325 		dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
326 		return err;
327 	}
328 	hub->dev = &i2c->dev;
329 
330 	return usb3503_probe(hub);
331 }
332 
333 static int usb3503_platform_probe(struct platform_device *pdev)
334 {
335 	struct usb3503 *hub;
336 
337 	hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
338 	if (!hub)
339 		return -ENOMEM;
340 	hub->dev = &pdev->dev;
341 
342 	return usb3503_probe(hub);
343 }
344 
345 #ifdef CONFIG_PM_SLEEP
346 static int usb3503_i2c_suspend(struct device *dev)
347 {
348 	struct i2c_client *client = to_i2c_client(dev);
349 	struct usb3503 *hub = i2c_get_clientdata(client);
350 
351 	usb3503_switch_mode(hub, USB3503_MODE_STANDBY);
352 
353 	if (hub->clk)
354 		clk_disable_unprepare(hub->clk);
355 
356 	return 0;
357 }
358 
359 static int usb3503_i2c_resume(struct device *dev)
360 {
361 	struct i2c_client *client = to_i2c_client(dev);
362 	struct usb3503 *hub = i2c_get_clientdata(client);
363 
364 	if (hub->clk)
365 		clk_prepare_enable(hub->clk);
366 
367 	usb3503_switch_mode(hub, hub->mode);
368 
369 	return 0;
370 }
371 #endif
372 
373 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
374 		usb3503_i2c_resume);
375 
376 static const struct i2c_device_id usb3503_id[] = {
377 	{ USB3503_I2C_NAME, 0 },
378 	{ }
379 };
380 MODULE_DEVICE_TABLE(i2c, usb3503_id);
381 
382 #ifdef CONFIG_OF
383 static const struct of_device_id usb3503_of_match[] = {
384 	{ .compatible = "smsc,usb3503", },
385 	{ .compatible = "smsc,usb3503a", },
386 	{},
387 };
388 MODULE_DEVICE_TABLE(of, usb3503_of_match);
389 #endif
390 
391 static struct i2c_driver usb3503_i2c_driver = {
392 	.driver = {
393 		.name = USB3503_I2C_NAME,
394 		.pm = &usb3503_i2c_pm_ops,
395 		.of_match_table = of_match_ptr(usb3503_of_match),
396 	},
397 	.probe		= usb3503_i2c_probe,
398 	.id_table	= usb3503_id,
399 };
400 
401 static struct platform_driver usb3503_platform_driver = {
402 	.driver = {
403 		.name = USB3503_I2C_NAME,
404 		.of_match_table = of_match_ptr(usb3503_of_match),
405 	},
406 	.probe		= usb3503_platform_probe,
407 };
408 
409 static int __init usb3503_init(void)
410 {
411 	int err;
412 
413 	err = i2c_register_driver(THIS_MODULE, &usb3503_i2c_driver);
414 	if (err != 0)
415 		pr_err("usb3503: Failed to register I2C driver: %d\n", err);
416 
417 	err = platform_driver_register(&usb3503_platform_driver);
418 	if (err != 0)
419 		pr_err("usb3503: Failed to register platform driver: %d\n",
420 		       err);
421 
422 	return 0;
423 }
424 module_init(usb3503_init);
425 
426 static void __exit usb3503_exit(void)
427 {
428 	platform_driver_unregister(&usb3503_platform_driver);
429 	i2c_del_driver(&usb3503_i2c_driver);
430 }
431 module_exit(usb3503_exit);
432 
433 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
434 MODULE_DESCRIPTION("USB3503 USB HUB driver");
435 MODULE_LICENSE("GPL");
436