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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