xref: /linux/drivers/phy/phy-core.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
1 /*
2  * phy-core.c  --  Generic Phy framework.
3  *
4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5  *
6  * Author: Kishon Vijay Abraham I <kishon@ti.com>
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/export.h>
16 #include <linux/module.h>
17 #include <linux/err.h>
18 #include <linux/device.h>
19 #include <linux/slab.h>
20 #include <linux/of.h>
21 #include <linux/phy/phy.h>
22 #include <linux/idr.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/regulator/consumer.h>
25 
26 static struct class *phy_class;
27 static DEFINE_MUTEX(phy_provider_mutex);
28 static LIST_HEAD(phy_provider_list);
29 static DEFINE_IDA(phy_ida);
30 
31 static void devm_phy_release(struct device *dev, void *res)
32 {
33 	struct phy *phy = *(struct phy **)res;
34 
35 	phy_put(phy);
36 }
37 
38 static void devm_phy_provider_release(struct device *dev, void *res)
39 {
40 	struct phy_provider *phy_provider = *(struct phy_provider **)res;
41 
42 	of_phy_provider_unregister(phy_provider);
43 }
44 
45 static void devm_phy_consume(struct device *dev, void *res)
46 {
47 	struct phy *phy = *(struct phy **)res;
48 
49 	phy_destroy(phy);
50 }
51 
52 static int devm_phy_match(struct device *dev, void *res, void *match_data)
53 {
54 	return res == match_data;
55 }
56 
57 static struct phy *phy_lookup(struct device *device, const char *port)
58 {
59 	unsigned int count;
60 	struct phy *phy;
61 	struct device *dev;
62 	struct phy_consumer *consumers;
63 	struct class_dev_iter iter;
64 
65 	class_dev_iter_init(&iter, phy_class, NULL, NULL);
66 	while ((dev = class_dev_iter_next(&iter))) {
67 		phy = to_phy(dev);
68 
69 		if (!phy->init_data)
70 			continue;
71 		count = phy->init_data->num_consumers;
72 		consumers = phy->init_data->consumers;
73 		while (count--) {
74 			if (!strcmp(consumers->dev_name, dev_name(device)) &&
75 					!strcmp(consumers->port, port)) {
76 				class_dev_iter_exit(&iter);
77 				return phy;
78 			}
79 			consumers++;
80 		}
81 	}
82 
83 	class_dev_iter_exit(&iter);
84 	return ERR_PTR(-ENODEV);
85 }
86 
87 static struct phy_provider *of_phy_provider_lookup(struct device_node *node)
88 {
89 	struct phy_provider *phy_provider;
90 	struct device_node *child;
91 
92 	list_for_each_entry(phy_provider, &phy_provider_list, list) {
93 		if (phy_provider->dev->of_node == node)
94 			return phy_provider;
95 
96 		for_each_child_of_node(phy_provider->dev->of_node, child)
97 			if (child == node)
98 				return phy_provider;
99 	}
100 
101 	return ERR_PTR(-EPROBE_DEFER);
102 }
103 
104 int phy_pm_runtime_get(struct phy *phy)
105 {
106 	int ret;
107 
108 	if (!pm_runtime_enabled(&phy->dev))
109 		return -ENOTSUPP;
110 
111 	ret = pm_runtime_get(&phy->dev);
112 	if (ret < 0 && ret != -EINPROGRESS)
113 		pm_runtime_put_noidle(&phy->dev);
114 
115 	return ret;
116 }
117 EXPORT_SYMBOL_GPL(phy_pm_runtime_get);
118 
119 int phy_pm_runtime_get_sync(struct phy *phy)
120 {
121 	int ret;
122 
123 	if (!pm_runtime_enabled(&phy->dev))
124 		return -ENOTSUPP;
125 
126 	ret = pm_runtime_get_sync(&phy->dev);
127 	if (ret < 0)
128 		pm_runtime_put_sync(&phy->dev);
129 
130 	return ret;
131 }
132 EXPORT_SYMBOL_GPL(phy_pm_runtime_get_sync);
133 
134 int phy_pm_runtime_put(struct phy *phy)
135 {
136 	if (!pm_runtime_enabled(&phy->dev))
137 		return -ENOTSUPP;
138 
139 	return pm_runtime_put(&phy->dev);
140 }
141 EXPORT_SYMBOL_GPL(phy_pm_runtime_put);
142 
143 int phy_pm_runtime_put_sync(struct phy *phy)
144 {
145 	if (!pm_runtime_enabled(&phy->dev))
146 		return -ENOTSUPP;
147 
148 	return pm_runtime_put_sync(&phy->dev);
149 }
150 EXPORT_SYMBOL_GPL(phy_pm_runtime_put_sync);
151 
152 void phy_pm_runtime_allow(struct phy *phy)
153 {
154 	if (!pm_runtime_enabled(&phy->dev))
155 		return;
156 
157 	pm_runtime_allow(&phy->dev);
158 }
159 EXPORT_SYMBOL_GPL(phy_pm_runtime_allow);
160 
161 void phy_pm_runtime_forbid(struct phy *phy)
162 {
163 	if (!pm_runtime_enabled(&phy->dev))
164 		return;
165 
166 	pm_runtime_forbid(&phy->dev);
167 }
168 EXPORT_SYMBOL_GPL(phy_pm_runtime_forbid);
169 
170 int phy_init(struct phy *phy)
171 {
172 	int ret;
173 
174 	if (!phy)
175 		return 0;
176 
177 	ret = phy_pm_runtime_get_sync(phy);
178 	if (ret < 0 && ret != -ENOTSUPP)
179 		return ret;
180 
181 	mutex_lock(&phy->mutex);
182 	if (phy->init_count == 0 && phy->ops->init) {
183 		ret = phy->ops->init(phy);
184 		if (ret < 0) {
185 			dev_err(&phy->dev, "phy init failed --> %d\n", ret);
186 			goto out;
187 		}
188 	} else {
189 		ret = 0; /* Override possible ret == -ENOTSUPP */
190 	}
191 	++phy->init_count;
192 
193 out:
194 	mutex_unlock(&phy->mutex);
195 	phy_pm_runtime_put(phy);
196 	return ret;
197 }
198 EXPORT_SYMBOL_GPL(phy_init);
199 
200 int phy_exit(struct phy *phy)
201 {
202 	int ret;
203 
204 	if (!phy)
205 		return 0;
206 
207 	ret = phy_pm_runtime_get_sync(phy);
208 	if (ret < 0 && ret != -ENOTSUPP)
209 		return ret;
210 
211 	mutex_lock(&phy->mutex);
212 	if (phy->init_count == 1 && phy->ops->exit) {
213 		ret = phy->ops->exit(phy);
214 		if (ret < 0) {
215 			dev_err(&phy->dev, "phy exit failed --> %d\n", ret);
216 			goto out;
217 		}
218 	}
219 	--phy->init_count;
220 
221 out:
222 	mutex_unlock(&phy->mutex);
223 	phy_pm_runtime_put(phy);
224 	return ret;
225 }
226 EXPORT_SYMBOL_GPL(phy_exit);
227 
228 int phy_power_on(struct phy *phy)
229 {
230 	int ret;
231 
232 	if (!phy)
233 		return 0;
234 
235 	if (phy->pwr) {
236 		ret = regulator_enable(phy->pwr);
237 		if (ret)
238 			return ret;
239 	}
240 
241 	ret = phy_pm_runtime_get_sync(phy);
242 	if (ret < 0 && ret != -ENOTSUPP)
243 		return ret;
244 
245 	mutex_lock(&phy->mutex);
246 	if (phy->power_count == 0 && phy->ops->power_on) {
247 		ret = phy->ops->power_on(phy);
248 		if (ret < 0) {
249 			dev_err(&phy->dev, "phy poweron failed --> %d\n", ret);
250 			goto out;
251 		}
252 	} else {
253 		ret = 0; /* Override possible ret == -ENOTSUPP */
254 	}
255 	++phy->power_count;
256 	mutex_unlock(&phy->mutex);
257 	return 0;
258 
259 out:
260 	mutex_unlock(&phy->mutex);
261 	phy_pm_runtime_put_sync(phy);
262 	if (phy->pwr)
263 		regulator_disable(phy->pwr);
264 
265 	return ret;
266 }
267 EXPORT_SYMBOL_GPL(phy_power_on);
268 
269 int phy_power_off(struct phy *phy)
270 {
271 	int ret;
272 
273 	if (!phy)
274 		return 0;
275 
276 	mutex_lock(&phy->mutex);
277 	if (phy->power_count == 1 && phy->ops->power_off) {
278 		ret =  phy->ops->power_off(phy);
279 		if (ret < 0) {
280 			dev_err(&phy->dev, "phy poweroff failed --> %d\n", ret);
281 			mutex_unlock(&phy->mutex);
282 			return ret;
283 		}
284 	}
285 	--phy->power_count;
286 	mutex_unlock(&phy->mutex);
287 	phy_pm_runtime_put(phy);
288 
289 	if (phy->pwr)
290 		regulator_disable(phy->pwr);
291 
292 	return 0;
293 }
294 EXPORT_SYMBOL_GPL(phy_power_off);
295 
296 /**
297  * _of_phy_get() - lookup and obtain a reference to a phy by phandle
298  * @np: device_node for which to get the phy
299  * @index: the index of the phy
300  *
301  * Returns the phy associated with the given phandle value,
302  * after getting a refcount to it or -ENODEV if there is no such phy or
303  * -EPROBE_DEFER if there is a phandle to the phy, but the device is
304  * not yet loaded. This function uses of_xlate call back function provided
305  * while registering the phy_provider to find the phy instance.
306  */
307 static struct phy *_of_phy_get(struct device_node *np, int index)
308 {
309 	int ret;
310 	struct phy_provider *phy_provider;
311 	struct phy *phy = NULL;
312 	struct of_phandle_args args;
313 
314 	ret = of_parse_phandle_with_args(np, "phys", "#phy-cells",
315 		index, &args);
316 	if (ret)
317 		return ERR_PTR(-ENODEV);
318 
319 	mutex_lock(&phy_provider_mutex);
320 	phy_provider = of_phy_provider_lookup(args.np);
321 	if (IS_ERR(phy_provider) || !try_module_get(phy_provider->owner)) {
322 		phy = ERR_PTR(-EPROBE_DEFER);
323 		goto err0;
324 	}
325 
326 	phy = phy_provider->of_xlate(phy_provider->dev, &args);
327 	module_put(phy_provider->owner);
328 
329 err0:
330 	mutex_unlock(&phy_provider_mutex);
331 	of_node_put(args.np);
332 
333 	return phy;
334 }
335 
336 /**
337  * of_phy_get() - lookup and obtain a reference to a phy using a device_node.
338  * @np: device_node for which to get the phy
339  * @con_id: name of the phy from device's point of view
340  *
341  * Returns the phy driver, after getting a refcount to it; or
342  * -ENODEV if there is no such phy. The caller is responsible for
343  * calling phy_put() to release that count.
344  */
345 struct phy *of_phy_get(struct device_node *np, const char *con_id)
346 {
347 	struct phy *phy = NULL;
348 	int index = 0;
349 
350 	if (con_id)
351 		index = of_property_match_string(np, "phy-names", con_id);
352 
353 	phy = _of_phy_get(np, index);
354 	if (IS_ERR(phy))
355 		return phy;
356 
357 	if (!try_module_get(phy->ops->owner))
358 		return ERR_PTR(-EPROBE_DEFER);
359 
360 	get_device(&phy->dev);
361 
362 	return phy;
363 }
364 EXPORT_SYMBOL_GPL(of_phy_get);
365 
366 /**
367  * phy_put() - release the PHY
368  * @phy: the phy returned by phy_get()
369  *
370  * Releases a refcount the caller received from phy_get().
371  */
372 void phy_put(struct phy *phy)
373 {
374 	if (!phy || IS_ERR(phy))
375 		return;
376 
377 	module_put(phy->ops->owner);
378 	put_device(&phy->dev);
379 }
380 EXPORT_SYMBOL_GPL(phy_put);
381 
382 /**
383  * devm_phy_put() - release the PHY
384  * @dev: device that wants to release this phy
385  * @phy: the phy returned by devm_phy_get()
386  *
387  * destroys the devres associated with this phy and invokes phy_put
388  * to release the phy.
389  */
390 void devm_phy_put(struct device *dev, struct phy *phy)
391 {
392 	int r;
393 
394 	if (!phy)
395 		return;
396 
397 	r = devres_destroy(dev, devm_phy_release, devm_phy_match, phy);
398 	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
399 }
400 EXPORT_SYMBOL_GPL(devm_phy_put);
401 
402 /**
403  * of_phy_simple_xlate() - returns the phy instance from phy provider
404  * @dev: the PHY provider device
405  * @args: of_phandle_args (not used here)
406  *
407  * Intended to be used by phy provider for the common case where #phy-cells is
408  * 0. For other cases where #phy-cells is greater than '0', the phy provider
409  * should provide a custom of_xlate function that reads the *args* and returns
410  * the appropriate phy.
411  */
412 struct phy *of_phy_simple_xlate(struct device *dev, struct of_phandle_args
413 	*args)
414 {
415 	struct phy *phy;
416 	struct class_dev_iter iter;
417 	struct device_node *node = dev->of_node;
418 	struct device_node *child;
419 
420 	class_dev_iter_init(&iter, phy_class, NULL, NULL);
421 	while ((dev = class_dev_iter_next(&iter))) {
422 		phy = to_phy(dev);
423 		if (node != phy->dev.of_node) {
424 			for_each_child_of_node(node, child) {
425 				if (child == phy->dev.of_node)
426 					goto phy_found;
427 			}
428 			continue;
429 		}
430 
431 phy_found:
432 		class_dev_iter_exit(&iter);
433 		return phy;
434 	}
435 
436 	class_dev_iter_exit(&iter);
437 	return ERR_PTR(-ENODEV);
438 }
439 EXPORT_SYMBOL_GPL(of_phy_simple_xlate);
440 
441 /**
442  * phy_get() - lookup and obtain a reference to a phy.
443  * @dev: device that requests this phy
444  * @string: the phy name as given in the dt data or the name of the controller
445  * port for non-dt case
446  *
447  * Returns the phy driver, after getting a refcount to it; or
448  * -ENODEV if there is no such phy.  The caller is responsible for
449  * calling phy_put() to release that count.
450  */
451 struct phy *phy_get(struct device *dev, const char *string)
452 {
453 	int index = 0;
454 	struct phy *phy;
455 
456 	if (string == NULL) {
457 		dev_WARN(dev, "missing string\n");
458 		return ERR_PTR(-EINVAL);
459 	}
460 
461 	if (dev->of_node) {
462 		index = of_property_match_string(dev->of_node, "phy-names",
463 			string);
464 		phy = _of_phy_get(dev->of_node, index);
465 	} else {
466 		phy = phy_lookup(dev, string);
467 	}
468 	if (IS_ERR(phy))
469 		return phy;
470 
471 	if (!try_module_get(phy->ops->owner))
472 		return ERR_PTR(-EPROBE_DEFER);
473 
474 	get_device(&phy->dev);
475 
476 	return phy;
477 }
478 EXPORT_SYMBOL_GPL(phy_get);
479 
480 /**
481  * phy_optional_get() - lookup and obtain a reference to an optional phy.
482  * @dev: device that requests this phy
483  * @string: the phy name as given in the dt data or the name of the controller
484  * port for non-dt case
485  *
486  * Returns the phy driver, after getting a refcount to it; or
487  * NULL if there is no such phy.  The caller is responsible for
488  * calling phy_put() to release that count.
489  */
490 struct phy *phy_optional_get(struct device *dev, const char *string)
491 {
492 	struct phy *phy = phy_get(dev, string);
493 
494 	if (PTR_ERR(phy) == -ENODEV)
495 		phy = NULL;
496 
497 	return phy;
498 }
499 EXPORT_SYMBOL_GPL(phy_optional_get);
500 
501 /**
502  * devm_phy_get() - lookup and obtain a reference to a phy.
503  * @dev: device that requests this phy
504  * @string: the phy name as given in the dt data or phy device name
505  * for non-dt case
506  *
507  * Gets the phy using phy_get(), and associates a device with it using
508  * devres. On driver detach, release function is invoked on the devres data,
509  * then, devres data is freed.
510  */
511 struct phy *devm_phy_get(struct device *dev, const char *string)
512 {
513 	struct phy **ptr, *phy;
514 
515 	ptr = devres_alloc(devm_phy_release, sizeof(*ptr), GFP_KERNEL);
516 	if (!ptr)
517 		return ERR_PTR(-ENOMEM);
518 
519 	phy = phy_get(dev, string);
520 	if (!IS_ERR(phy)) {
521 		*ptr = phy;
522 		devres_add(dev, ptr);
523 	} else {
524 		devres_free(ptr);
525 	}
526 
527 	return phy;
528 }
529 EXPORT_SYMBOL_GPL(devm_phy_get);
530 
531 /**
532  * devm_phy_optional_get() - lookup and obtain a reference to an optional phy.
533  * @dev: device that requests this phy
534  * @string: the phy name as given in the dt data or phy device name
535  * for non-dt case
536  *
537  * Gets the phy using phy_get(), and associates a device with it using
538  * devres. On driver detach, release function is invoked on the devres
539  * data, then, devres data is freed. This differs to devm_phy_get() in
540  * that if the phy does not exist, it is not considered an error and
541  * -ENODEV will not be returned. Instead the NULL phy is returned,
542  * which can be passed to all other phy consumer calls.
543  */
544 struct phy *devm_phy_optional_get(struct device *dev, const char *string)
545 {
546 	struct phy *phy = devm_phy_get(dev, string);
547 
548 	if (PTR_ERR(phy) == -ENODEV)
549 		phy = NULL;
550 
551 	return phy;
552 }
553 EXPORT_SYMBOL_GPL(devm_phy_optional_get);
554 
555 /**
556  * devm_of_phy_get() - lookup and obtain a reference to a phy.
557  * @dev: device that requests this phy
558  * @np: node containing the phy
559  * @con_id: name of the phy from device's point of view
560  *
561  * Gets the phy using of_phy_get(), and associates a device with it using
562  * devres. On driver detach, release function is invoked on the devres data,
563  * then, devres data is freed.
564  */
565 struct phy *devm_of_phy_get(struct device *dev, struct device_node *np,
566 			    const char *con_id)
567 {
568 	struct phy **ptr, *phy;
569 
570 	ptr = devres_alloc(devm_phy_release, sizeof(*ptr), GFP_KERNEL);
571 	if (!ptr)
572 		return ERR_PTR(-ENOMEM);
573 
574 	phy = of_phy_get(np, con_id);
575 	if (!IS_ERR(phy)) {
576 		*ptr = phy;
577 		devres_add(dev, ptr);
578 	} else {
579 		devres_free(ptr);
580 	}
581 
582 	return phy;
583 }
584 EXPORT_SYMBOL_GPL(devm_of_phy_get);
585 
586 /**
587  * phy_create() - create a new phy
588  * @dev: device that is creating the new phy
589  * @node: device node of the phy
590  * @ops: function pointers for performing phy operations
591  * @init_data: contains the list of PHY consumers or NULL
592  *
593  * Called to create a phy using phy framework.
594  */
595 struct phy *phy_create(struct device *dev, struct device_node *node,
596 		       const struct phy_ops *ops,
597 		       struct phy_init_data *init_data)
598 {
599 	int ret;
600 	int id;
601 	struct phy *phy;
602 
603 	if (WARN_ON(!dev))
604 		return ERR_PTR(-EINVAL);
605 
606 	phy = kzalloc(sizeof(*phy), GFP_KERNEL);
607 	if (!phy)
608 		return ERR_PTR(-ENOMEM);
609 
610 	id = ida_simple_get(&phy_ida, 0, 0, GFP_KERNEL);
611 	if (id < 0) {
612 		dev_err(dev, "unable to get id\n");
613 		ret = id;
614 		goto free_phy;
615 	}
616 
617 	/* phy-supply */
618 	phy->pwr = regulator_get_optional(dev, "phy");
619 	if (IS_ERR(phy->pwr)) {
620 		if (PTR_ERR(phy->pwr) == -EPROBE_DEFER) {
621 			ret = -EPROBE_DEFER;
622 			goto free_ida;
623 		}
624 		phy->pwr = NULL;
625 	}
626 
627 	device_initialize(&phy->dev);
628 	mutex_init(&phy->mutex);
629 
630 	phy->dev.class = phy_class;
631 	phy->dev.parent = dev;
632 	phy->dev.of_node = node ?: dev->of_node;
633 	phy->id = id;
634 	phy->ops = ops;
635 	phy->init_data = init_data;
636 
637 	ret = dev_set_name(&phy->dev, "phy-%s.%d", dev_name(dev), id);
638 	if (ret)
639 		goto put_dev;
640 
641 	ret = device_add(&phy->dev);
642 	if (ret)
643 		goto put_dev;
644 
645 	if (pm_runtime_enabled(dev)) {
646 		pm_runtime_enable(&phy->dev);
647 		pm_runtime_no_callbacks(&phy->dev);
648 	}
649 
650 	return phy;
651 
652 put_dev:
653 	put_device(&phy->dev);  /* calls phy_release() which frees resources */
654 	return ERR_PTR(ret);
655 
656 free_ida:
657 	ida_simple_remove(&phy_ida, phy->id);
658 
659 free_phy:
660 	kfree(phy);
661 	return ERR_PTR(ret);
662 }
663 EXPORT_SYMBOL_GPL(phy_create);
664 
665 /**
666  * devm_phy_create() - create a new phy
667  * @dev: device that is creating the new phy
668  * @node: device node of the phy
669  * @ops: function pointers for performing phy operations
670  * @init_data: contains the list of PHY consumers or NULL
671  *
672  * Creates a new PHY device adding it to the PHY class.
673  * While at that, it also associates the device with the phy using devres.
674  * On driver detach, release function is invoked on the devres data,
675  * then, devres data is freed.
676  */
677 struct phy *devm_phy_create(struct device *dev, struct device_node *node,
678 			    const struct phy_ops *ops,
679 			    struct phy_init_data *init_data)
680 {
681 	struct phy **ptr, *phy;
682 
683 	ptr = devres_alloc(devm_phy_consume, sizeof(*ptr), GFP_KERNEL);
684 	if (!ptr)
685 		return ERR_PTR(-ENOMEM);
686 
687 	phy = phy_create(dev, node, ops, init_data);
688 	if (!IS_ERR(phy)) {
689 		*ptr = phy;
690 		devres_add(dev, ptr);
691 	} else {
692 		devres_free(ptr);
693 	}
694 
695 	return phy;
696 }
697 EXPORT_SYMBOL_GPL(devm_phy_create);
698 
699 /**
700  * phy_destroy() - destroy the phy
701  * @phy: the phy to be destroyed
702  *
703  * Called to destroy the phy.
704  */
705 void phy_destroy(struct phy *phy)
706 {
707 	pm_runtime_disable(&phy->dev);
708 	device_unregister(&phy->dev);
709 }
710 EXPORT_SYMBOL_GPL(phy_destroy);
711 
712 /**
713  * devm_phy_destroy() - destroy the PHY
714  * @dev: device that wants to release this phy
715  * @phy: the phy returned by devm_phy_get()
716  *
717  * destroys the devres associated with this phy and invokes phy_destroy
718  * to destroy the phy.
719  */
720 void devm_phy_destroy(struct device *dev, struct phy *phy)
721 {
722 	int r;
723 
724 	r = devres_destroy(dev, devm_phy_consume, devm_phy_match, phy);
725 	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
726 }
727 EXPORT_SYMBOL_GPL(devm_phy_destroy);
728 
729 /**
730  * __of_phy_provider_register() - create/register phy provider with the framework
731  * @dev: struct device of the phy provider
732  * @owner: the module owner containing of_xlate
733  * @of_xlate: function pointer to obtain phy instance from phy provider
734  *
735  * Creates struct phy_provider from dev and of_xlate function pointer.
736  * This is used in the case of dt boot for finding the phy instance from
737  * phy provider.
738  */
739 struct phy_provider *__of_phy_provider_register(struct device *dev,
740 	struct module *owner, struct phy * (*of_xlate)(struct device *dev,
741 	struct of_phandle_args *args))
742 {
743 	struct phy_provider *phy_provider;
744 
745 	phy_provider = kzalloc(sizeof(*phy_provider), GFP_KERNEL);
746 	if (!phy_provider)
747 		return ERR_PTR(-ENOMEM);
748 
749 	phy_provider->dev = dev;
750 	phy_provider->owner = owner;
751 	phy_provider->of_xlate = of_xlate;
752 
753 	mutex_lock(&phy_provider_mutex);
754 	list_add_tail(&phy_provider->list, &phy_provider_list);
755 	mutex_unlock(&phy_provider_mutex);
756 
757 	return phy_provider;
758 }
759 EXPORT_SYMBOL_GPL(__of_phy_provider_register);
760 
761 /**
762  * __devm_of_phy_provider_register() - create/register phy provider with the
763  * framework
764  * @dev: struct device of the phy provider
765  * @owner: the module owner containing of_xlate
766  * @of_xlate: function pointer to obtain phy instance from phy provider
767  *
768  * Creates struct phy_provider from dev and of_xlate function pointer.
769  * This is used in the case of dt boot for finding the phy instance from
770  * phy provider. While at that, it also associates the device with the
771  * phy provider using devres. On driver detach, release function is invoked
772  * on the devres data, then, devres data is freed.
773  */
774 struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
775 	struct module *owner, struct phy * (*of_xlate)(struct device *dev,
776 	struct of_phandle_args *args))
777 {
778 	struct phy_provider **ptr, *phy_provider;
779 
780 	ptr = devres_alloc(devm_phy_provider_release, sizeof(*ptr), GFP_KERNEL);
781 	if (!ptr)
782 		return ERR_PTR(-ENOMEM);
783 
784 	phy_provider = __of_phy_provider_register(dev, owner, of_xlate);
785 	if (!IS_ERR(phy_provider)) {
786 		*ptr = phy_provider;
787 		devres_add(dev, ptr);
788 	} else {
789 		devres_free(ptr);
790 	}
791 
792 	return phy_provider;
793 }
794 EXPORT_SYMBOL_GPL(__devm_of_phy_provider_register);
795 
796 /**
797  * of_phy_provider_unregister() - unregister phy provider from the framework
798  * @phy_provider: phy provider returned by of_phy_provider_register()
799  *
800  * Removes the phy_provider created using of_phy_provider_register().
801  */
802 void of_phy_provider_unregister(struct phy_provider *phy_provider)
803 {
804 	if (IS_ERR(phy_provider))
805 		return;
806 
807 	mutex_lock(&phy_provider_mutex);
808 	list_del(&phy_provider->list);
809 	kfree(phy_provider);
810 	mutex_unlock(&phy_provider_mutex);
811 }
812 EXPORT_SYMBOL_GPL(of_phy_provider_unregister);
813 
814 /**
815  * devm_of_phy_provider_unregister() - remove phy provider from the framework
816  * @dev: struct device of the phy provider
817  *
818  * destroys the devres associated with this phy provider and invokes
819  * of_phy_provider_unregister to unregister the phy provider.
820  */
821 void devm_of_phy_provider_unregister(struct device *dev,
822 	struct phy_provider *phy_provider) {
823 	int r;
824 
825 	r = devres_destroy(dev, devm_phy_provider_release, devm_phy_match,
826 		phy_provider);
827 	dev_WARN_ONCE(dev, r, "couldn't find PHY provider device resource\n");
828 }
829 EXPORT_SYMBOL_GPL(devm_of_phy_provider_unregister);
830 
831 /**
832  * phy_release() - release the phy
833  * @dev: the dev member within phy
834  *
835  * When the last reference to the device is removed, it is called
836  * from the embedded kobject as release method.
837  */
838 static void phy_release(struct device *dev)
839 {
840 	struct phy *phy;
841 
842 	phy = to_phy(dev);
843 	dev_vdbg(dev, "releasing '%s'\n", dev_name(dev));
844 	regulator_put(phy->pwr);
845 	ida_simple_remove(&phy_ida, phy->id);
846 	kfree(phy);
847 }
848 
849 static int __init phy_core_init(void)
850 {
851 	phy_class = class_create(THIS_MODULE, "phy");
852 	if (IS_ERR(phy_class)) {
853 		pr_err("failed to create phy class --> %ld\n",
854 			PTR_ERR(phy_class));
855 		return PTR_ERR(phy_class);
856 	}
857 
858 	phy_class->dev_release = phy_release;
859 
860 	return 0;
861 }
862 module_init(phy_core_init);
863 
864 static void __exit phy_core_exit(void)
865 {
866 	class_destroy(phy_class);
867 }
868 module_exit(phy_core_exit);
869 
870 MODULE_DESCRIPTION("Generic PHY Framework");
871 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
872 MODULE_LICENSE("GPL v2");
873