1 /*
2 * phy.c -- USB phy handling
3 *
4 * Copyright (C) 2004-2013 Texas Instruments
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 #include <linux/kernel.h>
12 #include <linux/export.h>
13 #include <linux/err.h>
14 #include <linux/device.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/of.h>
18
19 #include <linux/usb/phy.h>
20
21 static LIST_HEAD(phy_list);
22 static LIST_HEAD(phy_bind_list);
23 static DEFINE_SPINLOCK(phy_lock);
24
25 struct phy_devm {
26 struct usb_phy *phy;
27 struct notifier_block *nb;
28 };
29
__usb_find_phy(struct list_head * list,enum usb_phy_type type)30 static struct usb_phy *__usb_find_phy(struct list_head *list,
31 enum usb_phy_type type)
32 {
33 struct usb_phy *phy = NULL;
34
35 list_for_each_entry(phy, list, head) {
36 if (phy->type != type)
37 continue;
38
39 return phy;
40 }
41
42 return ERR_PTR(-ENODEV);
43 }
44
__usb_find_phy_dev(struct device * dev,struct list_head * list,u8 index)45 static struct usb_phy *__usb_find_phy_dev(struct device *dev,
46 struct list_head *list, u8 index)
47 {
48 struct usb_phy_bind *phy_bind = NULL;
49
50 list_for_each_entry(phy_bind, list, list) {
51 if (!(strcmp(phy_bind->dev_name, dev_name(dev))) &&
52 phy_bind->index == index) {
53 if (phy_bind->phy)
54 return phy_bind->phy;
55 else
56 return ERR_PTR(-EPROBE_DEFER);
57 }
58 }
59
60 return ERR_PTR(-ENODEV);
61 }
62
__of_usb_find_phy(struct device_node * node)63 static struct usb_phy *__of_usb_find_phy(struct device_node *node)
64 {
65 struct usb_phy *phy;
66
67 if (!of_device_is_available(node))
68 return ERR_PTR(-ENODEV);
69
70 list_for_each_entry(phy, &phy_list, head) {
71 if (node != phy->dev->of_node)
72 continue;
73
74 return phy;
75 }
76
77 return ERR_PTR(-EPROBE_DEFER);
78 }
79
devm_usb_phy_release(struct device * dev,void * res)80 static void devm_usb_phy_release(struct device *dev, void *res)
81 {
82 struct usb_phy *phy = *(struct usb_phy **)res;
83
84 usb_put_phy(phy);
85 }
86
devm_usb_phy_release2(struct device * dev,void * _res)87 static void devm_usb_phy_release2(struct device *dev, void *_res)
88 {
89 struct phy_devm *res = _res;
90
91 if (res->nb)
92 usb_unregister_notifier(res->phy, res->nb);
93 usb_put_phy(res->phy);
94 }
95
devm_usb_phy_match(struct device * dev,void * res,void * match_data)96 static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
97 {
98 struct usb_phy **phy = res;
99
100 return *phy == match_data;
101 }
102
103 /**
104 * devm_usb_get_phy - find the USB PHY
105 * @dev - device that requests this phy
106 * @type - the type of the phy the controller requires
107 *
108 * Gets the phy using usb_get_phy(), and associates a device with it using
109 * devres. On driver detach, release function is invoked on the devres data,
110 * then, devres data is freed.
111 *
112 * For use by USB host and peripheral drivers.
113 */
devm_usb_get_phy(struct device * dev,enum usb_phy_type type)114 struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
115 {
116 struct usb_phy **ptr, *phy;
117
118 ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
119 if (!ptr)
120 return ERR_PTR(-ENOMEM);
121
122 phy = usb_get_phy(type);
123 if (!IS_ERR(phy)) {
124 *ptr = phy;
125 devres_add(dev, ptr);
126 } else
127 devres_free(ptr);
128
129 return phy;
130 }
131 EXPORT_SYMBOL_GPL(devm_usb_get_phy);
132
133 /**
134 * usb_get_phy - find the USB PHY
135 * @type - the type of the phy the controller requires
136 *
137 * Returns the phy driver, after getting a refcount to it; or
138 * -ENODEV if there is no such phy. The caller is responsible for
139 * calling usb_put_phy() to release that count.
140 *
141 * For use by USB host and peripheral drivers.
142 */
usb_get_phy(enum usb_phy_type type)143 struct usb_phy *usb_get_phy(enum usb_phy_type type)
144 {
145 struct usb_phy *phy = NULL;
146 unsigned long flags;
147
148 spin_lock_irqsave(&phy_lock, flags);
149
150 phy = __usb_find_phy(&phy_list, type);
151 if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
152 pr_debug("PHY: unable to find transceiver of type %s\n",
153 usb_phy_type_string(type));
154 if (!IS_ERR(phy))
155 phy = ERR_PTR(-ENODEV);
156
157 goto err0;
158 }
159
160 get_device(phy->dev);
161
162 err0:
163 spin_unlock_irqrestore(&phy_lock, flags);
164
165 return phy;
166 }
167 EXPORT_SYMBOL_GPL(usb_get_phy);
168
169 /**
170 * devm_usb_get_phy_by_node - find the USB PHY by device_node
171 * @dev - device that requests this phy
172 * @node - the device_node for the phy device.
173 * @nb - a notifier_block to register with the phy.
174 *
175 * Returns the phy driver associated with the given device_node,
176 * after getting a refcount to it, -ENODEV if there is no such phy or
177 * -EPROBE_DEFER if the device is not yet loaded. While at that, it
178 * also associates the device with
179 * the phy using devres. On driver detach, release function is invoked
180 * on the devres data, then, devres data is freed.
181 *
182 * For use by peripheral drivers for devices related to a phy,
183 * such as a charger.
184 */
devm_usb_get_phy_by_node(struct device * dev,struct device_node * node,struct notifier_block * nb)185 struct usb_phy *devm_usb_get_phy_by_node(struct device *dev,
186 struct device_node *node,
187 struct notifier_block *nb)
188 {
189 struct usb_phy *phy = ERR_PTR(-ENOMEM);
190 struct phy_devm *ptr;
191 unsigned long flags;
192
193 ptr = devres_alloc(devm_usb_phy_release2, sizeof(*ptr), GFP_KERNEL);
194 if (!ptr) {
195 dev_dbg(dev, "failed to allocate memory for devres\n");
196 goto err0;
197 }
198
199 spin_lock_irqsave(&phy_lock, flags);
200
201 phy = __of_usb_find_phy(node);
202 if (IS_ERR(phy)) {
203 devres_free(ptr);
204 goto err1;
205 }
206
207 if (!try_module_get(phy->dev->driver->owner)) {
208 phy = ERR_PTR(-ENODEV);
209 devres_free(ptr);
210 goto err1;
211 }
212 if (nb)
213 usb_register_notifier(phy, nb);
214 ptr->phy = phy;
215 ptr->nb = nb;
216 devres_add(dev, ptr);
217
218 get_device(phy->dev);
219
220 err1:
221 spin_unlock_irqrestore(&phy_lock, flags);
222
223 err0:
224
225 return phy;
226 }
227 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_node);
228
229 /**
230 * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
231 * @dev - device that requests this phy
232 * @phandle - name of the property holding the phy phandle value
233 * @index - the index of the phy
234 *
235 * Returns the phy driver associated with the given phandle value,
236 * after getting a refcount to it, -ENODEV if there is no such phy or
237 * -EPROBE_DEFER if there is a phandle to the phy, but the device is
238 * not yet loaded. While at that, it also associates the device with
239 * the phy using devres. On driver detach, release function is invoked
240 * on the devres data, then, devres data is freed.
241 *
242 * For use by USB host and peripheral drivers.
243 */
devm_usb_get_phy_by_phandle(struct device * dev,const char * phandle,u8 index)244 struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
245 const char *phandle, u8 index)
246 {
247 struct device_node *node;
248 struct usb_phy *phy;
249
250 if (!dev->of_node) {
251 dev_dbg(dev, "device does not have a device node entry\n");
252 return ERR_PTR(-EINVAL);
253 }
254
255 node = of_parse_phandle(dev->of_node, phandle, index);
256 if (!node) {
257 dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
258 dev->of_node->full_name);
259 return ERR_PTR(-ENODEV);
260 }
261 phy = devm_usb_get_phy_by_node(dev, node, NULL);
262 of_node_put(node);
263 return phy;
264 }
265 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_phandle);
266
267 /**
268 * usb_get_phy_dev - find the USB PHY
269 * @dev - device that requests this phy
270 * @index - the index of the phy
271 *
272 * Returns the phy driver, after getting a refcount to it; or
273 * -ENODEV if there is no such phy. The caller is responsible for
274 * calling usb_put_phy() to release that count.
275 *
276 * For use by USB host and peripheral drivers.
277 */
usb_get_phy_dev(struct device * dev,u8 index)278 struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index)
279 {
280 struct usb_phy *phy = NULL;
281 unsigned long flags;
282
283 spin_lock_irqsave(&phy_lock, flags);
284
285 phy = __usb_find_phy_dev(dev, &phy_bind_list, index);
286 if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
287 dev_dbg(dev, "unable to find transceiver\n");
288 if (!IS_ERR(phy))
289 phy = ERR_PTR(-ENODEV);
290
291 goto err0;
292 }
293
294 get_device(phy->dev);
295
296 err0:
297 spin_unlock_irqrestore(&phy_lock, flags);
298
299 return phy;
300 }
301 EXPORT_SYMBOL_GPL(usb_get_phy_dev);
302
303 /**
304 * devm_usb_get_phy_dev - find the USB PHY using device ptr and index
305 * @dev - device that requests this phy
306 * @index - the index of the phy
307 *
308 * Gets the phy using usb_get_phy_dev(), and associates a device with it using
309 * devres. On driver detach, release function is invoked on the devres data,
310 * then, devres data is freed.
311 *
312 * For use by USB host and peripheral drivers.
313 */
devm_usb_get_phy_dev(struct device * dev,u8 index)314 struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index)
315 {
316 struct usb_phy **ptr, *phy;
317
318 ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
319 if (!ptr)
320 return NULL;
321
322 phy = usb_get_phy_dev(dev, index);
323 if (!IS_ERR(phy)) {
324 *ptr = phy;
325 devres_add(dev, ptr);
326 } else
327 devres_free(ptr);
328
329 return phy;
330 }
331 EXPORT_SYMBOL_GPL(devm_usb_get_phy_dev);
332
333 /**
334 * devm_usb_put_phy - release the USB PHY
335 * @dev - device that wants to release this phy
336 * @phy - the phy returned by devm_usb_get_phy()
337 *
338 * destroys the devres associated with this phy and invokes usb_put_phy
339 * to release the phy.
340 *
341 * For use by USB host and peripheral drivers.
342 */
devm_usb_put_phy(struct device * dev,struct usb_phy * phy)343 void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
344 {
345 int r;
346
347 r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
348 dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
349 }
350 EXPORT_SYMBOL_GPL(devm_usb_put_phy);
351
352 /**
353 * usb_put_phy - release the USB PHY
354 * @x: the phy returned by usb_get_phy()
355 *
356 * Releases a refcount the caller received from usb_get_phy().
357 *
358 * For use by USB host and peripheral drivers.
359 */
usb_put_phy(struct usb_phy * x)360 void usb_put_phy(struct usb_phy *x)
361 {
362 if (x) {
363 struct module *owner = x->dev->driver->owner;
364
365 put_device(x->dev);
366 module_put(owner);
367 }
368 }
369 EXPORT_SYMBOL_GPL(usb_put_phy);
370
371 /**
372 * usb_add_phy - declare the USB PHY
373 * @x: the USB phy to be used; or NULL
374 * @type - the type of this PHY
375 *
376 * This call is exclusively for use by phy drivers, which
377 * coordinate the activities of drivers for host and peripheral
378 * controllers, and in some cases for VBUS current regulation.
379 */
usb_add_phy(struct usb_phy * x,enum usb_phy_type type)380 int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
381 {
382 int ret = 0;
383 unsigned long flags;
384 struct usb_phy *phy;
385
386 if (x->type != USB_PHY_TYPE_UNDEFINED) {
387 dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
388 return -EINVAL;
389 }
390
391 ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
392
393 spin_lock_irqsave(&phy_lock, flags);
394
395 list_for_each_entry(phy, &phy_list, head) {
396 if (phy->type == type) {
397 ret = -EBUSY;
398 dev_err(x->dev, "transceiver type %s already exists\n",
399 usb_phy_type_string(type));
400 goto out;
401 }
402 }
403
404 x->type = type;
405 list_add_tail(&x->head, &phy_list);
406
407 out:
408 spin_unlock_irqrestore(&phy_lock, flags);
409 return ret;
410 }
411 EXPORT_SYMBOL_GPL(usb_add_phy);
412
413 /**
414 * usb_add_phy_dev - declare the USB PHY
415 * @x: the USB phy to be used; or NULL
416 *
417 * This call is exclusively for use by phy drivers, which
418 * coordinate the activities of drivers for host and peripheral
419 * controllers, and in some cases for VBUS current regulation.
420 */
usb_add_phy_dev(struct usb_phy * x)421 int usb_add_phy_dev(struct usb_phy *x)
422 {
423 struct usb_phy_bind *phy_bind;
424 unsigned long flags;
425
426 if (!x->dev) {
427 dev_err(x->dev, "no device provided for PHY\n");
428 return -EINVAL;
429 }
430
431 ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
432
433 spin_lock_irqsave(&phy_lock, flags);
434 list_for_each_entry(phy_bind, &phy_bind_list, list)
435 if (!(strcmp(phy_bind->phy_dev_name, dev_name(x->dev))))
436 phy_bind->phy = x;
437
438 list_add_tail(&x->head, &phy_list);
439
440 spin_unlock_irqrestore(&phy_lock, flags);
441 return 0;
442 }
443 EXPORT_SYMBOL_GPL(usb_add_phy_dev);
444
445 /**
446 * usb_remove_phy - remove the OTG PHY
447 * @x: the USB OTG PHY to be removed;
448 *
449 * This reverts the effects of usb_add_phy
450 */
usb_remove_phy(struct usb_phy * x)451 void usb_remove_phy(struct usb_phy *x)
452 {
453 unsigned long flags;
454 struct usb_phy_bind *phy_bind;
455
456 spin_lock_irqsave(&phy_lock, flags);
457 if (x) {
458 list_for_each_entry(phy_bind, &phy_bind_list, list)
459 if (phy_bind->phy == x)
460 phy_bind->phy = NULL;
461 list_del(&x->head);
462 }
463 spin_unlock_irqrestore(&phy_lock, flags);
464 }
465 EXPORT_SYMBOL_GPL(usb_remove_phy);
466
467 /**
468 * usb_bind_phy - bind the phy and the controller that uses the phy
469 * @dev_name: the device name of the device that will bind to the phy
470 * @index: index to specify the port number
471 * @phy_dev_name: the device name of the phy
472 *
473 * Fills the phy_bind structure with the dev_name and phy_dev_name. This will
474 * be used when the phy driver registers the phy and when the controller
475 * requests this phy.
476 *
477 * To be used by platform specific initialization code.
478 */
usb_bind_phy(const char * dev_name,u8 index,const char * phy_dev_name)479 int usb_bind_phy(const char *dev_name, u8 index,
480 const char *phy_dev_name)
481 {
482 struct usb_phy_bind *phy_bind;
483 unsigned long flags;
484
485 phy_bind = kzalloc(sizeof(*phy_bind), GFP_KERNEL);
486 if (!phy_bind)
487 return -ENOMEM;
488
489 phy_bind->dev_name = dev_name;
490 phy_bind->phy_dev_name = phy_dev_name;
491 phy_bind->index = index;
492
493 spin_lock_irqsave(&phy_lock, flags);
494 list_add_tail(&phy_bind->list, &phy_bind_list);
495 spin_unlock_irqrestore(&phy_lock, flags);
496
497 return 0;
498 }
499 EXPORT_SYMBOL_GPL(usb_bind_phy);
500
501 /**
502 * usb_phy_set_event - set event to phy event
503 * @x: the phy returned by usb_get_phy();
504 *
505 * This sets event to phy event
506 */
usb_phy_set_event(struct usb_phy * x,unsigned long event)507 void usb_phy_set_event(struct usb_phy *x, unsigned long event)
508 {
509 x->last_event = event;
510 }
511 EXPORT_SYMBOL_GPL(usb_phy_set_event);
512