xref: /openbmc/linux/drivers/phy/phy-core.c (revision 4eb5928d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * phy-core.c  --  Generic Phy framework.
4  *
5  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
6  *
7  * Author: Kishon Vijay Abraham I <kishon@ti.com>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/export.h>
12 #include <linux/module.h>
13 #include <linux/err.h>
14 #include <linux/device.h>
15 #include <linux/slab.h>
16 #include <linux/of.h>
17 #include <linux/phy/phy.h>
18 #include <linux/idr.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/regulator/consumer.h>
21 
22 static struct class *phy_class;
23 static DEFINE_MUTEX(phy_provider_mutex);
24 static LIST_HEAD(phy_provider_list);
25 static LIST_HEAD(phys);
26 static DEFINE_IDA(phy_ida);
27 
28 static void devm_phy_release(struct device *dev, void *res)
29 {
30 	struct phy *phy = *(struct phy **)res;
31 
32 	phy_put(dev, phy);
33 }
34 
35 static void devm_phy_provider_release(struct device *dev, void *res)
36 {
37 	struct phy_provider *phy_provider = *(struct phy_provider **)res;
38 
39 	of_phy_provider_unregister(phy_provider);
40 }
41 
42 static void devm_phy_consume(struct device *dev, void *res)
43 {
44 	struct phy *phy = *(struct phy **)res;
45 
46 	phy_destroy(phy);
47 }
48 
49 static int devm_phy_match(struct device *dev, void *res, void *match_data)
50 {
51 	struct phy **phy = res;
52 
53 	return *phy == match_data;
54 }
55 
56 /**
57  * phy_create_lookup() - allocate and register PHY/device association
58  * @phy: the phy of the association
59  * @con_id: connection ID string on device
60  * @dev_id: the device of the association
61  *
62  * Creates and registers phy_lookup entry.
63  */
64 int phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id)
65 {
66 	struct phy_lookup *pl;
67 
68 	if (!phy || !dev_id || !con_id)
69 		return -EINVAL;
70 
71 	pl = kzalloc(sizeof(*pl), GFP_KERNEL);
72 	if (!pl)
73 		return -ENOMEM;
74 
75 	pl->dev_id = dev_id;
76 	pl->con_id = con_id;
77 	pl->phy = phy;
78 
79 	mutex_lock(&phy_provider_mutex);
80 	list_add_tail(&pl->node, &phys);
81 	mutex_unlock(&phy_provider_mutex);
82 
83 	return 0;
84 }
85 EXPORT_SYMBOL_GPL(phy_create_lookup);
86 
87 /**
88  * phy_remove_lookup() - find and remove PHY/device association
89  * @phy: the phy of the association
90  * @con_id: connection ID string on device
91  * @dev_id: the device of the association
92  *
93  * Finds and unregisters phy_lookup entry that was created with
94  * phy_create_lookup().
95  */
96 void phy_remove_lookup(struct phy *phy, const char *con_id, const char *dev_id)
97 {
98 	struct phy_lookup *pl;
99 
100 	if (!phy || !dev_id || !con_id)
101 		return;
102 
103 	mutex_lock(&phy_provider_mutex);
104 	list_for_each_entry(pl, &phys, node)
105 		if (pl->phy == phy && !strcmp(pl->dev_id, dev_id) &&
106 		    !strcmp(pl->con_id, con_id)) {
107 			list_del(&pl->node);
108 			kfree(pl);
109 			break;
110 		}
111 	mutex_unlock(&phy_provider_mutex);
112 }
113 EXPORT_SYMBOL_GPL(phy_remove_lookup);
114 
115 static struct phy *phy_find(struct device *dev, const char *con_id)
116 {
117 	const char *dev_id = dev_name(dev);
118 	struct phy_lookup *p, *pl = NULL;
119 
120 	mutex_lock(&phy_provider_mutex);
121 	list_for_each_entry(p, &phys, node)
122 		if (!strcmp(p->dev_id, dev_id) && !strcmp(p->con_id, con_id)) {
123 			pl = p;
124 			break;
125 		}
126 	mutex_unlock(&phy_provider_mutex);
127 
128 	return pl ? pl->phy : ERR_PTR(-ENODEV);
129 }
130 
131 static struct phy_provider *of_phy_provider_lookup(struct device_node *node)
132 {
133 	struct phy_provider *phy_provider;
134 	struct device_node *child;
135 
136 	list_for_each_entry(phy_provider, &phy_provider_list, list) {
137 		if (phy_provider->dev->of_node == node)
138 			return phy_provider;
139 
140 		for_each_child_of_node(phy_provider->children, child)
141 			if (child == node)
142 				return phy_provider;
143 	}
144 
145 	return ERR_PTR(-EPROBE_DEFER);
146 }
147 
148 int phy_pm_runtime_get(struct phy *phy)
149 {
150 	int ret;
151 
152 	if (!phy)
153 		return 0;
154 
155 	if (!pm_runtime_enabled(&phy->dev))
156 		return -ENOTSUPP;
157 
158 	ret = pm_runtime_get(&phy->dev);
159 	if (ret < 0 && ret != -EINPROGRESS)
160 		pm_runtime_put_noidle(&phy->dev);
161 
162 	return ret;
163 }
164 EXPORT_SYMBOL_GPL(phy_pm_runtime_get);
165 
166 int phy_pm_runtime_get_sync(struct phy *phy)
167 {
168 	int ret;
169 
170 	if (!phy)
171 		return 0;
172 
173 	if (!pm_runtime_enabled(&phy->dev))
174 		return -ENOTSUPP;
175 
176 	ret = pm_runtime_get_sync(&phy->dev);
177 	if (ret < 0)
178 		pm_runtime_put_sync(&phy->dev);
179 
180 	return ret;
181 }
182 EXPORT_SYMBOL_GPL(phy_pm_runtime_get_sync);
183 
184 int phy_pm_runtime_put(struct phy *phy)
185 {
186 	if (!phy)
187 		return 0;
188 
189 	if (!pm_runtime_enabled(&phy->dev))
190 		return -ENOTSUPP;
191 
192 	return pm_runtime_put(&phy->dev);
193 }
194 EXPORT_SYMBOL_GPL(phy_pm_runtime_put);
195 
196 int phy_pm_runtime_put_sync(struct phy *phy)
197 {
198 	if (!phy)
199 		return 0;
200 
201 	if (!pm_runtime_enabled(&phy->dev))
202 		return -ENOTSUPP;
203 
204 	return pm_runtime_put_sync(&phy->dev);
205 }
206 EXPORT_SYMBOL_GPL(phy_pm_runtime_put_sync);
207 
208 void phy_pm_runtime_allow(struct phy *phy)
209 {
210 	if (!phy)
211 		return;
212 
213 	if (!pm_runtime_enabled(&phy->dev))
214 		return;
215 
216 	pm_runtime_allow(&phy->dev);
217 }
218 EXPORT_SYMBOL_GPL(phy_pm_runtime_allow);
219 
220 void phy_pm_runtime_forbid(struct phy *phy)
221 {
222 	if (!phy)
223 		return;
224 
225 	if (!pm_runtime_enabled(&phy->dev))
226 		return;
227 
228 	pm_runtime_forbid(&phy->dev);
229 }
230 EXPORT_SYMBOL_GPL(phy_pm_runtime_forbid);
231 
232 int phy_init(struct phy *phy)
233 {
234 	int ret;
235 
236 	if (!phy)
237 		return 0;
238 
239 	ret = phy_pm_runtime_get_sync(phy);
240 	if (ret < 0 && ret != -ENOTSUPP)
241 		return ret;
242 	ret = 0; /* Override possible ret == -ENOTSUPP */
243 
244 	mutex_lock(&phy->mutex);
245 	if (phy->init_count == 0 && phy->ops->init) {
246 		ret = phy->ops->init(phy);
247 		if (ret < 0) {
248 			dev_err(&phy->dev, "phy init failed --> %d\n", ret);
249 			goto out;
250 		}
251 	}
252 	++phy->init_count;
253 
254 out:
255 	mutex_unlock(&phy->mutex);
256 	phy_pm_runtime_put(phy);
257 	return ret;
258 }
259 EXPORT_SYMBOL_GPL(phy_init);
260 
261 int phy_exit(struct phy *phy)
262 {
263 	int ret;
264 
265 	if (!phy)
266 		return 0;
267 
268 	ret = phy_pm_runtime_get_sync(phy);
269 	if (ret < 0 && ret != -ENOTSUPP)
270 		return ret;
271 	ret = 0; /* Override possible ret == -ENOTSUPP */
272 
273 	mutex_lock(&phy->mutex);
274 	if (phy->init_count == 1 && phy->ops->exit) {
275 		ret = phy->ops->exit(phy);
276 		if (ret < 0) {
277 			dev_err(&phy->dev, "phy exit failed --> %d\n", ret);
278 			goto out;
279 		}
280 	}
281 	--phy->init_count;
282 
283 out:
284 	mutex_unlock(&phy->mutex);
285 	phy_pm_runtime_put(phy);
286 	return ret;
287 }
288 EXPORT_SYMBOL_GPL(phy_exit);
289 
290 int phy_power_on(struct phy *phy)
291 {
292 	int ret = 0;
293 
294 	if (!phy)
295 		goto out;
296 
297 	if (phy->pwr) {
298 		ret = regulator_enable(phy->pwr);
299 		if (ret)
300 			goto out;
301 	}
302 
303 	ret = phy_pm_runtime_get_sync(phy);
304 	if (ret < 0 && ret != -ENOTSUPP)
305 		goto err_pm_sync;
306 
307 	ret = 0; /* Override possible ret == -ENOTSUPP */
308 
309 	mutex_lock(&phy->mutex);
310 	if (phy->power_count == 0 && phy->ops->power_on) {
311 		ret = phy->ops->power_on(phy);
312 		if (ret < 0) {
313 			dev_err(&phy->dev, "phy poweron failed --> %d\n", ret);
314 			goto err_pwr_on;
315 		}
316 	}
317 	++phy->power_count;
318 	mutex_unlock(&phy->mutex);
319 	return 0;
320 
321 err_pwr_on:
322 	mutex_unlock(&phy->mutex);
323 	phy_pm_runtime_put_sync(phy);
324 err_pm_sync:
325 	if (phy->pwr)
326 		regulator_disable(phy->pwr);
327 out:
328 	return ret;
329 }
330 EXPORT_SYMBOL_GPL(phy_power_on);
331 
332 int phy_power_off(struct phy *phy)
333 {
334 	int ret;
335 
336 	if (!phy)
337 		return 0;
338 
339 	mutex_lock(&phy->mutex);
340 	if (phy->power_count == 1 && phy->ops->power_off) {
341 		ret =  phy->ops->power_off(phy);
342 		if (ret < 0) {
343 			dev_err(&phy->dev, "phy poweroff failed --> %d\n", ret);
344 			mutex_unlock(&phy->mutex);
345 			return ret;
346 		}
347 	}
348 	--phy->power_count;
349 	mutex_unlock(&phy->mutex);
350 	phy_pm_runtime_put(phy);
351 
352 	if (phy->pwr)
353 		regulator_disable(phy->pwr);
354 
355 	return 0;
356 }
357 EXPORT_SYMBOL_GPL(phy_power_off);
358 
359 int phy_set_mode_ext(struct phy *phy, enum phy_mode mode, int submode)
360 {
361 	int ret;
362 
363 	if (!phy || !phy->ops->set_mode)
364 		return 0;
365 
366 	mutex_lock(&phy->mutex);
367 	ret = phy->ops->set_mode(phy, mode, submode);
368 	if (!ret)
369 		phy->attrs.mode = mode;
370 	mutex_unlock(&phy->mutex);
371 
372 	return ret;
373 }
374 EXPORT_SYMBOL_GPL(phy_set_mode_ext);
375 
376 int phy_reset(struct phy *phy)
377 {
378 	int ret;
379 
380 	if (!phy || !phy->ops->reset)
381 		return 0;
382 
383 	ret = phy_pm_runtime_get_sync(phy);
384 	if (ret < 0 && ret != -ENOTSUPP)
385 		return ret;
386 
387 	mutex_lock(&phy->mutex);
388 	ret = phy->ops->reset(phy);
389 	mutex_unlock(&phy->mutex);
390 
391 	phy_pm_runtime_put(phy);
392 
393 	return ret;
394 }
395 EXPORT_SYMBOL_GPL(phy_reset);
396 
397 /**
398  * phy_calibrate() - Tunes the phy hw parameters for current configuration
399  * @phy: the phy returned by phy_get()
400  *
401  * Used to calibrate phy hardware, typically by adjusting some parameters in
402  * runtime, which are otherwise lost after host controller reset and cannot
403  * be applied in phy_init() or phy_power_on().
404  *
405  * Returns: 0 if successful, an negative error code otherwise
406  */
407 int phy_calibrate(struct phy *phy)
408 {
409 	int ret;
410 
411 	if (!phy || !phy->ops->calibrate)
412 		return 0;
413 
414 	mutex_lock(&phy->mutex);
415 	ret = phy->ops->calibrate(phy);
416 	mutex_unlock(&phy->mutex);
417 
418 	return ret;
419 }
420 EXPORT_SYMBOL_GPL(phy_calibrate);
421 
422 /**
423  * phy_configure() - Changes the phy parameters
424  * @phy: the phy returned by phy_get()
425  * @opts: New configuration to apply
426  *
427  * Used to change the PHY parameters. phy_init() must have been called
428  * on the phy. The configuration will be applied on the current phy
429  * mode, that can be changed using phy_set_mode().
430  *
431  * Returns: 0 if successful, an negative error code otherwise
432  */
433 int phy_configure(struct phy *phy, union phy_configure_opts *opts)
434 {
435 	int ret;
436 
437 	if (!phy)
438 		return -EINVAL;
439 
440 	if (!phy->ops->configure)
441 		return -EOPNOTSUPP;
442 
443 	mutex_lock(&phy->mutex);
444 	ret = phy->ops->configure(phy, opts);
445 	mutex_unlock(&phy->mutex);
446 
447 	return ret;
448 }
449 EXPORT_SYMBOL_GPL(phy_configure);
450 
451 /**
452  * phy_validate() - Checks the phy parameters
453  * @phy: the phy returned by phy_get()
454  * @mode: phy_mode the configuration is applicable to.
455  * @submode: PHY submode the configuration is applicable to.
456  * @opts: Configuration to check
457  *
458  * Used to check that the current set of parameters can be handled by
459  * the phy. Implementations are free to tune the parameters passed as
460  * arguments if needed by some implementation detail or
461  * constraints. It will not change any actual configuration of the
462  * PHY, so calling it as many times as deemed fit will have no side
463  * effect.
464  *
465  * Returns: 0 if successful, an negative error code otherwise
466  */
467 int phy_validate(struct phy *phy, enum phy_mode mode, int submode,
468 		 union phy_configure_opts *opts)
469 {
470 	int ret;
471 
472 	if (!phy)
473 		return -EINVAL;
474 
475 	if (!phy->ops->validate)
476 		return -EOPNOTSUPP;
477 
478 	mutex_lock(&phy->mutex);
479 	ret = phy->ops->validate(phy, mode, submode, opts);
480 	mutex_unlock(&phy->mutex);
481 
482 	return ret;
483 }
484 EXPORT_SYMBOL_GPL(phy_validate);
485 
486 /**
487  * _of_phy_get() - lookup and obtain a reference to a phy by phandle
488  * @np: device_node for which to get the phy
489  * @index: the index of the phy
490  *
491  * Returns the phy associated with the given phandle value,
492  * after getting a refcount to it or -ENODEV if there is no such phy or
493  * -EPROBE_DEFER if there is a phandle to the phy, but the device is
494  * not yet loaded. This function uses of_xlate call back function provided
495  * while registering the phy_provider to find the phy instance.
496  */
497 static struct phy *_of_phy_get(struct device_node *np, int index)
498 {
499 	int ret;
500 	struct phy_provider *phy_provider;
501 	struct phy *phy = NULL;
502 	struct of_phandle_args args;
503 
504 	ret = of_parse_phandle_with_args(np, "phys", "#phy-cells",
505 		index, &args);
506 	if (ret)
507 		return ERR_PTR(-ENODEV);
508 
509 	/* This phy type handled by the usb-phy subsystem for now */
510 	if (of_device_is_compatible(args.np, "usb-nop-xceiv"))
511 		return ERR_PTR(-ENODEV);
512 
513 	mutex_lock(&phy_provider_mutex);
514 	phy_provider = of_phy_provider_lookup(args.np);
515 	if (IS_ERR(phy_provider) || !try_module_get(phy_provider->owner)) {
516 		phy = ERR_PTR(-EPROBE_DEFER);
517 		goto out_unlock;
518 	}
519 
520 	if (!of_device_is_available(args.np)) {
521 		dev_warn(phy_provider->dev, "Requested PHY is disabled\n");
522 		phy = ERR_PTR(-ENODEV);
523 		goto out_put_module;
524 	}
525 
526 	phy = phy_provider->of_xlate(phy_provider->dev, &args);
527 
528 out_put_module:
529 	module_put(phy_provider->owner);
530 
531 out_unlock:
532 	mutex_unlock(&phy_provider_mutex);
533 	of_node_put(args.np);
534 
535 	return phy;
536 }
537 
538 /**
539  * of_phy_get() - lookup and obtain a reference to a phy using a device_node.
540  * @np: device_node for which to get the phy
541  * @con_id: name of the phy from device's point of view
542  *
543  * Returns the phy driver, after getting a refcount to it; or
544  * -ENODEV if there is no such phy. The caller is responsible for
545  * calling phy_put() to release that count.
546  */
547 struct phy *of_phy_get(struct device_node *np, const char *con_id)
548 {
549 	struct phy *phy = NULL;
550 	int index = 0;
551 
552 	if (con_id)
553 		index = of_property_match_string(np, "phy-names", con_id);
554 
555 	phy = _of_phy_get(np, index);
556 	if (IS_ERR(phy))
557 		return phy;
558 
559 	if (!try_module_get(phy->ops->owner))
560 		return ERR_PTR(-EPROBE_DEFER);
561 
562 	get_device(&phy->dev);
563 
564 	return phy;
565 }
566 EXPORT_SYMBOL_GPL(of_phy_get);
567 
568 /**
569  * of_phy_put() - release the PHY
570  * @phy: the phy returned by of_phy_get()
571  *
572  * Releases a refcount the caller received from of_phy_get().
573  */
574 void of_phy_put(struct phy *phy)
575 {
576 	if (!phy || IS_ERR(phy))
577 		return;
578 
579 	mutex_lock(&phy->mutex);
580 	if (phy->ops->release)
581 		phy->ops->release(phy);
582 	mutex_unlock(&phy->mutex);
583 
584 	module_put(phy->ops->owner);
585 	put_device(&phy->dev);
586 }
587 EXPORT_SYMBOL_GPL(of_phy_put);
588 
589 /**
590  * phy_put() - release the PHY
591  * @dev: device that wants to release this phy
592  * @phy: the phy returned by phy_get()
593  *
594  * Releases a refcount the caller received from phy_get().
595  */
596 void phy_put(struct device *dev, struct phy *phy)
597 {
598 	device_link_remove(dev, &phy->dev);
599 	of_phy_put(phy);
600 }
601 EXPORT_SYMBOL_GPL(phy_put);
602 
603 /**
604  * devm_phy_put() - release the PHY
605  * @dev: device that wants to release this phy
606  * @phy: the phy returned by devm_phy_get()
607  *
608  * destroys the devres associated with this phy and invokes phy_put
609  * to release the phy.
610  */
611 void devm_phy_put(struct device *dev, struct phy *phy)
612 {
613 	int r;
614 
615 	if (!phy)
616 		return;
617 
618 	r = devres_destroy(dev, devm_phy_release, devm_phy_match, phy);
619 	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
620 }
621 EXPORT_SYMBOL_GPL(devm_phy_put);
622 
623 /**
624  * of_phy_simple_xlate() - returns the phy instance from phy provider
625  * @dev: the PHY provider device
626  * @args: of_phandle_args (not used here)
627  *
628  * Intended to be used by phy provider for the common case where #phy-cells is
629  * 0. For other cases where #phy-cells is greater than '0', the phy provider
630  * should provide a custom of_xlate function that reads the *args* and returns
631  * the appropriate phy.
632  */
633 struct phy *of_phy_simple_xlate(struct device *dev, struct of_phandle_args
634 	*args)
635 {
636 	struct phy *phy;
637 	struct class_dev_iter iter;
638 
639 	class_dev_iter_init(&iter, phy_class, NULL, NULL);
640 	while ((dev = class_dev_iter_next(&iter))) {
641 		phy = to_phy(dev);
642 		if (args->np != phy->dev.of_node)
643 			continue;
644 
645 		class_dev_iter_exit(&iter);
646 		return phy;
647 	}
648 
649 	class_dev_iter_exit(&iter);
650 	return ERR_PTR(-ENODEV);
651 }
652 EXPORT_SYMBOL_GPL(of_phy_simple_xlate);
653 
654 /**
655  * phy_get() - lookup and obtain a reference to a phy.
656  * @dev: device that requests this phy
657  * @string: the phy name as given in the dt data or the name of the controller
658  * port for non-dt case
659  *
660  * Returns the phy driver, after getting a refcount to it; or
661  * -ENODEV if there is no such phy.  The caller is responsible for
662  * calling phy_put() to release that count.
663  */
664 struct phy *phy_get(struct device *dev, const char *string)
665 {
666 	int index = 0;
667 	struct phy *phy;
668 	struct device_link *link;
669 
670 	if (string == NULL) {
671 		dev_WARN(dev, "missing string\n");
672 		return ERR_PTR(-EINVAL);
673 	}
674 
675 	if (dev->of_node) {
676 		index = of_property_match_string(dev->of_node, "phy-names",
677 			string);
678 		phy = _of_phy_get(dev->of_node, index);
679 	} else {
680 		phy = phy_find(dev, string);
681 	}
682 	if (IS_ERR(phy))
683 		return phy;
684 
685 	if (!try_module_get(phy->ops->owner))
686 		return ERR_PTR(-EPROBE_DEFER);
687 
688 	get_device(&phy->dev);
689 
690 	link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
691 	if (!link)
692 		dev_dbg(dev, "failed to create device link to %s\n",
693 			dev_name(phy->dev.parent));
694 
695 	return phy;
696 }
697 EXPORT_SYMBOL_GPL(phy_get);
698 
699 /**
700  * phy_optional_get() - lookup and obtain a reference to an optional phy.
701  * @dev: device that requests this phy
702  * @string: the phy name as given in the dt data or the name of the controller
703  * port for non-dt case
704  *
705  * Returns the phy driver, after getting a refcount to it; or
706  * NULL if there is no such phy.  The caller is responsible for
707  * calling phy_put() to release that count.
708  */
709 struct phy *phy_optional_get(struct device *dev, const char *string)
710 {
711 	struct phy *phy = phy_get(dev, string);
712 
713 	if (PTR_ERR(phy) == -ENODEV)
714 		phy = NULL;
715 
716 	return phy;
717 }
718 EXPORT_SYMBOL_GPL(phy_optional_get);
719 
720 /**
721  * devm_phy_get() - lookup and obtain a reference to a phy.
722  * @dev: device that requests this phy
723  * @string: the phy name as given in the dt data or phy device name
724  * for non-dt case
725  *
726  * Gets the phy using phy_get(), and associates a device with it using
727  * devres. On driver detach, release function is invoked on the devres data,
728  * then, devres data is freed.
729  */
730 struct phy *devm_phy_get(struct device *dev, const char *string)
731 {
732 	struct phy **ptr, *phy;
733 
734 	ptr = devres_alloc(devm_phy_release, sizeof(*ptr), GFP_KERNEL);
735 	if (!ptr)
736 		return ERR_PTR(-ENOMEM);
737 
738 	phy = phy_get(dev, string);
739 	if (!IS_ERR(phy)) {
740 		*ptr = phy;
741 		devres_add(dev, ptr);
742 	} else {
743 		devres_free(ptr);
744 	}
745 
746 	return phy;
747 }
748 EXPORT_SYMBOL_GPL(devm_phy_get);
749 
750 /**
751  * devm_phy_optional_get() - lookup and obtain a reference to an optional phy.
752  * @dev: device that requests this phy
753  * @string: the phy name as given in the dt data or phy device name
754  * for non-dt case
755  *
756  * Gets the phy using phy_get(), and associates a device with it using
757  * devres. On driver detach, release function is invoked on the devres
758  * data, then, devres data is freed. This differs to devm_phy_get() in
759  * that if the phy does not exist, it is not considered an error and
760  * -ENODEV will not be returned. Instead the NULL phy is returned,
761  * which can be passed to all other phy consumer calls.
762  */
763 struct phy *devm_phy_optional_get(struct device *dev, const char *string)
764 {
765 	struct phy *phy = devm_phy_get(dev, string);
766 
767 	if (PTR_ERR(phy) == -ENODEV)
768 		phy = NULL;
769 
770 	return phy;
771 }
772 EXPORT_SYMBOL_GPL(devm_phy_optional_get);
773 
774 /**
775  * devm_of_phy_get() - lookup and obtain a reference to a phy.
776  * @dev: device that requests this phy
777  * @np: node containing the phy
778  * @con_id: name of the phy from device's point of view
779  *
780  * Gets the phy using of_phy_get(), and associates a device with it using
781  * devres. On driver detach, release function is invoked on the devres data,
782  * then, devres data is freed.
783  */
784 struct phy *devm_of_phy_get(struct device *dev, struct device_node *np,
785 			    const char *con_id)
786 {
787 	struct phy **ptr, *phy;
788 	struct device_link *link;
789 
790 	ptr = devres_alloc(devm_phy_release, sizeof(*ptr), GFP_KERNEL);
791 	if (!ptr)
792 		return ERR_PTR(-ENOMEM);
793 
794 	phy = of_phy_get(np, con_id);
795 	if (!IS_ERR(phy)) {
796 		*ptr = phy;
797 		devres_add(dev, ptr);
798 	} else {
799 		devres_free(ptr);
800 		return phy;
801 	}
802 
803 	link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
804 	if (!link)
805 		dev_dbg(dev, "failed to create device link to %s\n",
806 			dev_name(phy->dev.parent));
807 
808 	return phy;
809 }
810 EXPORT_SYMBOL_GPL(devm_of_phy_get);
811 
812 /**
813  * devm_of_phy_get_by_index() - lookup and obtain a reference to a phy by index.
814  * @dev: device that requests this phy
815  * @np: node containing the phy
816  * @index: index of the phy
817  *
818  * Gets the phy using _of_phy_get(), then gets a refcount to it,
819  * and associates a device with it using devres. On driver detach,
820  * release function is invoked on the devres data,
821  * then, devres data is freed.
822  *
823  */
824 struct phy *devm_of_phy_get_by_index(struct device *dev, struct device_node *np,
825 				     int index)
826 {
827 	struct phy **ptr, *phy;
828 	struct device_link *link;
829 
830 	ptr = devres_alloc(devm_phy_release, sizeof(*ptr), GFP_KERNEL);
831 	if (!ptr)
832 		return ERR_PTR(-ENOMEM);
833 
834 	phy = _of_phy_get(np, index);
835 	if (IS_ERR(phy)) {
836 		devres_free(ptr);
837 		return phy;
838 	}
839 
840 	if (!try_module_get(phy->ops->owner)) {
841 		devres_free(ptr);
842 		return ERR_PTR(-EPROBE_DEFER);
843 	}
844 
845 	get_device(&phy->dev);
846 
847 	*ptr = phy;
848 	devres_add(dev, ptr);
849 
850 	link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
851 	if (!link)
852 		dev_dbg(dev, "failed to create device link to %s\n",
853 			dev_name(phy->dev.parent));
854 
855 	return phy;
856 }
857 EXPORT_SYMBOL_GPL(devm_of_phy_get_by_index);
858 
859 /**
860  * phy_create() - create a new phy
861  * @dev: device that is creating the new phy
862  * @node: device node of the phy
863  * @ops: function pointers for performing phy operations
864  *
865  * Called to create a phy using phy framework.
866  */
867 struct phy *phy_create(struct device *dev, struct device_node *node,
868 		       const struct phy_ops *ops)
869 {
870 	int ret;
871 	int id;
872 	struct phy *phy;
873 
874 	if (WARN_ON(!dev))
875 		return ERR_PTR(-EINVAL);
876 
877 	phy = kzalloc(sizeof(*phy), GFP_KERNEL);
878 	if (!phy)
879 		return ERR_PTR(-ENOMEM);
880 
881 	id = ida_simple_get(&phy_ida, 0, 0, GFP_KERNEL);
882 	if (id < 0) {
883 		dev_err(dev, "unable to get id\n");
884 		ret = id;
885 		goto free_phy;
886 	}
887 
888 	device_initialize(&phy->dev);
889 	mutex_init(&phy->mutex);
890 
891 	phy->dev.class = phy_class;
892 	phy->dev.parent = dev;
893 	phy->dev.of_node = node ?: dev->of_node;
894 	phy->id = id;
895 	phy->ops = ops;
896 
897 	ret = dev_set_name(&phy->dev, "phy-%s.%d", dev_name(dev), id);
898 	if (ret)
899 		goto put_dev;
900 
901 	/* phy-supply */
902 	phy->pwr = regulator_get_optional(&phy->dev, "phy");
903 	if (IS_ERR(phy->pwr)) {
904 		ret = PTR_ERR(phy->pwr);
905 		if (ret == -EPROBE_DEFER)
906 			goto put_dev;
907 
908 		phy->pwr = NULL;
909 	}
910 
911 	ret = device_add(&phy->dev);
912 	if (ret)
913 		goto put_dev;
914 
915 	if (pm_runtime_enabled(dev)) {
916 		pm_runtime_enable(&phy->dev);
917 		pm_runtime_no_callbacks(&phy->dev);
918 	}
919 
920 	return phy;
921 
922 put_dev:
923 	put_device(&phy->dev);  /* calls phy_release() which frees resources */
924 	return ERR_PTR(ret);
925 
926 free_phy:
927 	kfree(phy);
928 	return ERR_PTR(ret);
929 }
930 EXPORT_SYMBOL_GPL(phy_create);
931 
932 /**
933  * devm_phy_create() - create a new phy
934  * @dev: device that is creating the new phy
935  * @node: device node of the phy
936  * @ops: function pointers for performing phy operations
937  *
938  * Creates a new PHY device adding it to the PHY class.
939  * While at that, it also associates the device with the phy using devres.
940  * On driver detach, release function is invoked on the devres data,
941  * then, devres data is freed.
942  */
943 struct phy *devm_phy_create(struct device *dev, struct device_node *node,
944 			    const struct phy_ops *ops)
945 {
946 	struct phy **ptr, *phy;
947 
948 	ptr = devres_alloc(devm_phy_consume, sizeof(*ptr), GFP_KERNEL);
949 	if (!ptr)
950 		return ERR_PTR(-ENOMEM);
951 
952 	phy = phy_create(dev, node, ops);
953 	if (!IS_ERR(phy)) {
954 		*ptr = phy;
955 		devres_add(dev, ptr);
956 	} else {
957 		devres_free(ptr);
958 	}
959 
960 	return phy;
961 }
962 EXPORT_SYMBOL_GPL(devm_phy_create);
963 
964 /**
965  * phy_destroy() - destroy the phy
966  * @phy: the phy to be destroyed
967  *
968  * Called to destroy the phy.
969  */
970 void phy_destroy(struct phy *phy)
971 {
972 	pm_runtime_disable(&phy->dev);
973 	device_unregister(&phy->dev);
974 }
975 EXPORT_SYMBOL_GPL(phy_destroy);
976 
977 /**
978  * devm_phy_destroy() - destroy the PHY
979  * @dev: device that wants to release this phy
980  * @phy: the phy returned by devm_phy_get()
981  *
982  * destroys the devres associated with this phy and invokes phy_destroy
983  * to destroy the phy.
984  */
985 void devm_phy_destroy(struct device *dev, struct phy *phy)
986 {
987 	int r;
988 
989 	r = devres_destroy(dev, devm_phy_consume, devm_phy_match, phy);
990 	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
991 }
992 EXPORT_SYMBOL_GPL(devm_phy_destroy);
993 
994 /**
995  * __of_phy_provider_register() - create/register phy provider with the framework
996  * @dev: struct device of the phy provider
997  * @children: device node containing children (if different from dev->of_node)
998  * @owner: the module owner containing of_xlate
999  * @of_xlate: function pointer to obtain phy instance from phy provider
1000  *
1001  * Creates struct phy_provider from dev and of_xlate function pointer.
1002  * This is used in the case of dt boot for finding the phy instance from
1003  * phy provider.
1004  *
1005  * If the PHY provider doesn't nest children directly but uses a separate
1006  * child node to contain the individual children, the @children parameter
1007  * can be used to override the default. If NULL, the default (dev->of_node)
1008  * will be used. If non-NULL, the device node must be a child (or further
1009  * descendant) of dev->of_node. Otherwise an ERR_PTR()-encoded -EINVAL
1010  * error code is returned.
1011  */
1012 struct phy_provider *__of_phy_provider_register(struct device *dev,
1013 	struct device_node *children, struct module *owner,
1014 	struct phy * (*of_xlate)(struct device *dev,
1015 				 struct of_phandle_args *args))
1016 {
1017 	struct phy_provider *phy_provider;
1018 
1019 	/*
1020 	 * If specified, the device node containing the children must itself
1021 	 * be the provider's device node or a child (or further descendant)
1022 	 * thereof.
1023 	 */
1024 	if (children) {
1025 		struct device_node *parent = of_node_get(children), *next;
1026 
1027 		while (parent) {
1028 			if (parent == dev->of_node)
1029 				break;
1030 
1031 			next = of_get_parent(parent);
1032 			of_node_put(parent);
1033 			parent = next;
1034 		}
1035 
1036 		if (!parent)
1037 			return ERR_PTR(-EINVAL);
1038 
1039 		of_node_put(parent);
1040 	} else {
1041 		children = dev->of_node;
1042 	}
1043 
1044 	phy_provider = kzalloc(sizeof(*phy_provider), GFP_KERNEL);
1045 	if (!phy_provider)
1046 		return ERR_PTR(-ENOMEM);
1047 
1048 	phy_provider->dev = dev;
1049 	phy_provider->children = of_node_get(children);
1050 	phy_provider->owner = owner;
1051 	phy_provider->of_xlate = of_xlate;
1052 
1053 	mutex_lock(&phy_provider_mutex);
1054 	list_add_tail(&phy_provider->list, &phy_provider_list);
1055 	mutex_unlock(&phy_provider_mutex);
1056 
1057 	return phy_provider;
1058 }
1059 EXPORT_SYMBOL_GPL(__of_phy_provider_register);
1060 
1061 /**
1062  * __devm_of_phy_provider_register() - create/register phy provider with the
1063  * framework
1064  * @dev: struct device of the phy provider
1065  * @children: device node containing children (if different from dev->of_node)
1066  * @owner: the module owner containing of_xlate
1067  * @of_xlate: function pointer to obtain phy instance from phy provider
1068  *
1069  * Creates struct phy_provider from dev and of_xlate function pointer.
1070  * This is used in the case of dt boot for finding the phy instance from
1071  * phy provider. While at that, it also associates the device with the
1072  * phy provider using devres. On driver detach, release function is invoked
1073  * on the devres data, then, devres data is freed.
1074  */
1075 struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
1076 	struct device_node *children, struct module *owner,
1077 	struct phy * (*of_xlate)(struct device *dev,
1078 				 struct of_phandle_args *args))
1079 {
1080 	struct phy_provider **ptr, *phy_provider;
1081 
1082 	ptr = devres_alloc(devm_phy_provider_release, sizeof(*ptr), GFP_KERNEL);
1083 	if (!ptr)
1084 		return ERR_PTR(-ENOMEM);
1085 
1086 	phy_provider = __of_phy_provider_register(dev, children, owner,
1087 						  of_xlate);
1088 	if (!IS_ERR(phy_provider)) {
1089 		*ptr = phy_provider;
1090 		devres_add(dev, ptr);
1091 	} else {
1092 		devres_free(ptr);
1093 	}
1094 
1095 	return phy_provider;
1096 }
1097 EXPORT_SYMBOL_GPL(__devm_of_phy_provider_register);
1098 
1099 /**
1100  * of_phy_provider_unregister() - unregister phy provider from the framework
1101  * @phy_provider: phy provider returned by of_phy_provider_register()
1102  *
1103  * Removes the phy_provider created using of_phy_provider_register().
1104  */
1105 void of_phy_provider_unregister(struct phy_provider *phy_provider)
1106 {
1107 	if (IS_ERR(phy_provider))
1108 		return;
1109 
1110 	mutex_lock(&phy_provider_mutex);
1111 	list_del(&phy_provider->list);
1112 	of_node_put(phy_provider->children);
1113 	kfree(phy_provider);
1114 	mutex_unlock(&phy_provider_mutex);
1115 }
1116 EXPORT_SYMBOL_GPL(of_phy_provider_unregister);
1117 
1118 /**
1119  * devm_of_phy_provider_unregister() - remove phy provider from the framework
1120  * @dev: struct device of the phy provider
1121  * @phy_provider: phy provider returned by of_phy_provider_register()
1122  *
1123  * destroys the devres associated with this phy provider and invokes
1124  * of_phy_provider_unregister to unregister the phy provider.
1125  */
1126 void devm_of_phy_provider_unregister(struct device *dev,
1127 	struct phy_provider *phy_provider)
1128 {
1129 	int r;
1130 
1131 	r = devres_destroy(dev, devm_phy_provider_release, devm_phy_match,
1132 		phy_provider);
1133 	dev_WARN_ONCE(dev, r, "couldn't find PHY provider device resource\n");
1134 }
1135 EXPORT_SYMBOL_GPL(devm_of_phy_provider_unregister);
1136 
1137 /**
1138  * phy_release() - release the phy
1139  * @dev: the dev member within phy
1140  *
1141  * When the last reference to the device is removed, it is called
1142  * from the embedded kobject as release method.
1143  */
1144 static void phy_release(struct device *dev)
1145 {
1146 	struct phy *phy;
1147 
1148 	phy = to_phy(dev);
1149 	dev_vdbg(dev, "releasing '%s'\n", dev_name(dev));
1150 	regulator_put(phy->pwr);
1151 	ida_simple_remove(&phy_ida, phy->id);
1152 	kfree(phy);
1153 }
1154 
1155 static int __init phy_core_init(void)
1156 {
1157 	phy_class = class_create(THIS_MODULE, "phy");
1158 	if (IS_ERR(phy_class)) {
1159 		pr_err("failed to create phy class --> %ld\n",
1160 			PTR_ERR(phy_class));
1161 		return PTR_ERR(phy_class);
1162 	}
1163 
1164 	phy_class->dev_release = phy_release;
1165 
1166 	return 0;
1167 }
1168 device_initcall(phy_core_init);
1169