xref: /openbmc/linux/drivers/usb/phy/phy.c (revision a9d85efb)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * phy.c -- USB phy handling
4  *
5  * Copyright (C) 2004-2013 Texas Instruments
6  */
7 #include <linux/kernel.h>
8 #include <linux/export.h>
9 #include <linux/err.h>
10 #include <linux/device.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/of.h>
14 
15 #include <linux/usb/phy.h>
16 
17 /* Default current range by charger type. */
18 #define DEFAULT_SDP_CUR_MIN	2
19 #define DEFAULT_SDP_CUR_MAX	500
20 #define DEFAULT_SDP_CUR_MIN_SS	150
21 #define DEFAULT_SDP_CUR_MAX_SS	900
22 #define DEFAULT_DCP_CUR_MIN	500
23 #define DEFAULT_DCP_CUR_MAX	5000
24 #define DEFAULT_CDP_CUR_MIN	1500
25 #define DEFAULT_CDP_CUR_MAX	5000
26 #define DEFAULT_ACA_CUR_MIN	1500
27 #define DEFAULT_ACA_CUR_MAX	5000
28 
29 static LIST_HEAD(phy_list);
30 static DEFINE_SPINLOCK(phy_lock);
31 
32 struct phy_devm {
33 	struct usb_phy *phy;
34 	struct notifier_block *nb;
35 };
36 
37 static const char *const usb_chger_type[] = {
38 	[UNKNOWN_TYPE]			= "USB_CHARGER_UNKNOWN_TYPE",
39 	[SDP_TYPE]			= "USB_CHARGER_SDP_TYPE",
40 	[CDP_TYPE]			= "USB_CHARGER_CDP_TYPE",
41 	[DCP_TYPE]			= "USB_CHARGER_DCP_TYPE",
42 	[ACA_TYPE]			= "USB_CHARGER_ACA_TYPE",
43 };
44 
45 static const char *const usb_chger_state[] = {
46 	[USB_CHARGER_DEFAULT]	= "USB_CHARGER_DEFAULT",
47 	[USB_CHARGER_PRESENT]	= "USB_CHARGER_PRESENT",
48 	[USB_CHARGER_ABSENT]	= "USB_CHARGER_ABSENT",
49 };
50 
51 static struct usb_phy *__usb_find_phy(struct list_head *list,
52 	enum usb_phy_type type)
53 {
54 	struct usb_phy  *phy = NULL;
55 
56 	list_for_each_entry(phy, list, head) {
57 		if (phy->type != type)
58 			continue;
59 
60 		return phy;
61 	}
62 
63 	return ERR_PTR(-ENODEV);
64 }
65 
66 static struct usb_phy *__of_usb_find_phy(struct device_node *node)
67 {
68 	struct usb_phy  *phy;
69 
70 	if (!of_device_is_available(node))
71 		return ERR_PTR(-ENODEV);
72 
73 	list_for_each_entry(phy, &phy_list, head) {
74 		if (node != phy->dev->of_node)
75 			continue;
76 
77 		return phy;
78 	}
79 
80 	return ERR_PTR(-EPROBE_DEFER);
81 }
82 
83 static struct usb_phy *__device_to_usb_phy(struct device *dev)
84 {
85 	struct usb_phy *usb_phy;
86 
87 	list_for_each_entry(usb_phy, &phy_list, head) {
88 		if (usb_phy->dev == dev)
89 			return usb_phy;
90 	}
91 
92 	return NULL;
93 }
94 
95 static void usb_phy_set_default_current(struct usb_phy *usb_phy)
96 {
97 	usb_phy->chg_cur.sdp_min = DEFAULT_SDP_CUR_MIN;
98 	usb_phy->chg_cur.sdp_max = DEFAULT_SDP_CUR_MAX;
99 	usb_phy->chg_cur.dcp_min = DEFAULT_DCP_CUR_MIN;
100 	usb_phy->chg_cur.dcp_max = DEFAULT_DCP_CUR_MAX;
101 	usb_phy->chg_cur.cdp_min = DEFAULT_CDP_CUR_MIN;
102 	usb_phy->chg_cur.cdp_max = DEFAULT_CDP_CUR_MAX;
103 	usb_phy->chg_cur.aca_min = DEFAULT_ACA_CUR_MIN;
104 	usb_phy->chg_cur.aca_max = DEFAULT_ACA_CUR_MAX;
105 }
106 
107 /**
108  * usb_phy_notify_charger_work - notify the USB charger state
109  * @work: the charger work to notify the USB charger state
110  *
111  * This work can be issued when USB charger state has been changed or
112  * USB charger current has been changed, then we can notify the current
113  * what can be drawn to power user and the charger state to userspace.
114  *
115  * If we get the charger type from extcon subsystem, we can notify the
116  * charger state to power user automatically by usb_phy_get_charger_type()
117  * issuing from extcon subsystem.
118  *
119  * If we get the charger type from ->charger_detect() instead of extcon
120  * subsystem, the usb phy driver should issue usb_phy_set_charger_state()
121  * to set charger state when the charger state has been changed.
122  */
123 static void usb_phy_notify_charger_work(struct work_struct *work)
124 {
125 	struct usb_phy *usb_phy = container_of(work, struct usb_phy, chg_work);
126 	unsigned int min, max;
127 
128 	switch (usb_phy->chg_state) {
129 	case USB_CHARGER_PRESENT:
130 		usb_phy_get_charger_current(usb_phy, &min, &max);
131 
132 		atomic_notifier_call_chain(&usb_phy->notifier, max, usb_phy);
133 		break;
134 	case USB_CHARGER_ABSENT:
135 		usb_phy_set_default_current(usb_phy);
136 
137 		atomic_notifier_call_chain(&usb_phy->notifier, 0, usb_phy);
138 		break;
139 	default:
140 		dev_warn(usb_phy->dev, "Unknown USB charger state: %d\n",
141 			 usb_phy->chg_state);
142 		return;
143 	}
144 
145 	kobject_uevent(&usb_phy->dev->kobj, KOBJ_CHANGE);
146 }
147 
148 static int usb_phy_uevent(struct device *dev, struct kobj_uevent_env *env)
149 {
150 	struct usb_phy *usb_phy;
151 	char uchger_state[50] = { 0 };
152 	char uchger_type[50] = { 0 };
153 	unsigned long flags;
154 
155 	spin_lock_irqsave(&phy_lock, flags);
156 	usb_phy = __device_to_usb_phy(dev);
157 	spin_unlock_irqrestore(&phy_lock, flags);
158 
159 	if (!usb_phy)
160 		return -ENODEV;
161 
162 	snprintf(uchger_state, ARRAY_SIZE(uchger_state),
163 		 "USB_CHARGER_STATE=%s", usb_chger_state[usb_phy->chg_state]);
164 
165 	snprintf(uchger_type, ARRAY_SIZE(uchger_type),
166 		 "USB_CHARGER_TYPE=%s", usb_chger_type[usb_phy->chg_type]);
167 
168 	if (add_uevent_var(env, uchger_state))
169 		return -ENOMEM;
170 
171 	if (add_uevent_var(env, uchger_type))
172 		return -ENOMEM;
173 
174 	return 0;
175 }
176 
177 static void __usb_phy_get_charger_type(struct usb_phy *usb_phy)
178 {
179 	if (extcon_get_state(usb_phy->edev, EXTCON_CHG_USB_SDP) > 0) {
180 		usb_phy->chg_type = SDP_TYPE;
181 		usb_phy->chg_state = USB_CHARGER_PRESENT;
182 	} else if (extcon_get_state(usb_phy->edev, EXTCON_CHG_USB_CDP) > 0) {
183 		usb_phy->chg_type = CDP_TYPE;
184 		usb_phy->chg_state = USB_CHARGER_PRESENT;
185 	} else if (extcon_get_state(usb_phy->edev, EXTCON_CHG_USB_DCP) > 0) {
186 		usb_phy->chg_type = DCP_TYPE;
187 		usb_phy->chg_state = USB_CHARGER_PRESENT;
188 	} else if (extcon_get_state(usb_phy->edev, EXTCON_CHG_USB_ACA) > 0) {
189 		usb_phy->chg_type = ACA_TYPE;
190 		usb_phy->chg_state = USB_CHARGER_PRESENT;
191 	} else {
192 		usb_phy->chg_type = UNKNOWN_TYPE;
193 		usb_phy->chg_state = USB_CHARGER_ABSENT;
194 	}
195 
196 	schedule_work(&usb_phy->chg_work);
197 }
198 
199 /**
200  * usb_phy_get_charger_type - get charger type from extcon subsystem
201  * @nb: the notifier block to determine charger type
202  * @state: the cable state
203  * @data: private data
204  *
205  * Determin the charger type from extcon subsystem which also means the
206  * charger state has been chaned, then we should notify this event.
207  */
208 static int usb_phy_get_charger_type(struct notifier_block *nb,
209 				    unsigned long state, void *data)
210 {
211 	struct usb_phy *usb_phy = container_of(nb, struct usb_phy, type_nb);
212 
213 	__usb_phy_get_charger_type(usb_phy);
214 	return NOTIFY_OK;
215 }
216 
217 /**
218  * usb_phy_set_charger_current - set the USB charger current
219  * @usb_phy: the USB phy to be used
220  * @mA: the current need to be set
221  *
222  * Usually we only change the charger default current when USB finished the
223  * enumeration as one SDP charger. As one SDP charger, usb_phy_set_power()
224  * will issue this function to change charger current when after setting USB
225  * configuration, or suspend/resume USB. For other type charger, we should
226  * use the default charger current and we do not suggest to issue this function
227  * to change the charger current.
228  *
229  * When USB charger current has been changed, we need to notify the power users.
230  */
231 void usb_phy_set_charger_current(struct usb_phy *usb_phy, unsigned int mA)
232 {
233 	switch (usb_phy->chg_type) {
234 	case SDP_TYPE:
235 		if (usb_phy->chg_cur.sdp_max == mA)
236 			return;
237 
238 		usb_phy->chg_cur.sdp_max = (mA > DEFAULT_SDP_CUR_MAX_SS) ?
239 			DEFAULT_SDP_CUR_MAX_SS : mA;
240 		break;
241 	case DCP_TYPE:
242 		if (usb_phy->chg_cur.dcp_max == mA)
243 			return;
244 
245 		usb_phy->chg_cur.dcp_max = (mA > DEFAULT_DCP_CUR_MAX) ?
246 			DEFAULT_DCP_CUR_MAX : mA;
247 		break;
248 	case CDP_TYPE:
249 		if (usb_phy->chg_cur.cdp_max == mA)
250 			return;
251 
252 		usb_phy->chg_cur.cdp_max = (mA > DEFAULT_CDP_CUR_MAX) ?
253 			DEFAULT_CDP_CUR_MAX : mA;
254 		break;
255 	case ACA_TYPE:
256 		if (usb_phy->chg_cur.aca_max == mA)
257 			return;
258 
259 		usb_phy->chg_cur.aca_max = (mA > DEFAULT_ACA_CUR_MAX) ?
260 			DEFAULT_ACA_CUR_MAX : mA;
261 		break;
262 	default:
263 		return;
264 	}
265 
266 	schedule_work(&usb_phy->chg_work);
267 }
268 EXPORT_SYMBOL_GPL(usb_phy_set_charger_current);
269 
270 /**
271  * usb_phy_get_charger_current - get the USB charger current
272  * @usb_phy: the USB phy to be used
273  * @min: the minimum current
274  * @max: the maximum current
275  *
276  * Usually we will notify the maximum current to power user, but for some
277  * special case, power user also need the minimum current value. Then the
278  * power user can issue this function to get the suitable current.
279  */
280 void usb_phy_get_charger_current(struct usb_phy *usb_phy,
281 				 unsigned int *min, unsigned int *max)
282 {
283 	switch (usb_phy->chg_type) {
284 	case SDP_TYPE:
285 		*min = usb_phy->chg_cur.sdp_min;
286 		*max = usb_phy->chg_cur.sdp_max;
287 		break;
288 	case DCP_TYPE:
289 		*min = usb_phy->chg_cur.dcp_min;
290 		*max = usb_phy->chg_cur.dcp_max;
291 		break;
292 	case CDP_TYPE:
293 		*min = usb_phy->chg_cur.cdp_min;
294 		*max = usb_phy->chg_cur.cdp_max;
295 		break;
296 	case ACA_TYPE:
297 		*min = usb_phy->chg_cur.aca_min;
298 		*max = usb_phy->chg_cur.aca_max;
299 		break;
300 	default:
301 		*min = 0;
302 		*max = 0;
303 		break;
304 	}
305 }
306 EXPORT_SYMBOL_GPL(usb_phy_get_charger_current);
307 
308 /**
309  * usb_phy_set_charger_state - set the USB charger state
310  * @usb_phy: the USB phy to be used
311  * @state: the new state need to be set for charger
312  *
313  * The usb phy driver can issue this function when the usb phy driver
314  * detected the charger state has been changed, in this case the charger
315  * type should be get from ->charger_detect().
316  */
317 void usb_phy_set_charger_state(struct usb_phy *usb_phy,
318 			       enum usb_charger_state state)
319 {
320 	if (usb_phy->chg_state == state || !usb_phy->charger_detect)
321 		return;
322 
323 	usb_phy->chg_state = state;
324 	if (usb_phy->chg_state == USB_CHARGER_PRESENT)
325 		usb_phy->chg_type = usb_phy->charger_detect(usb_phy);
326 	else
327 		usb_phy->chg_type = UNKNOWN_TYPE;
328 
329 	schedule_work(&usb_phy->chg_work);
330 }
331 EXPORT_SYMBOL_GPL(usb_phy_set_charger_state);
332 
333 static void devm_usb_phy_release(struct device *dev, void *res)
334 {
335 	struct usb_phy *phy = *(struct usb_phy **)res;
336 
337 	usb_put_phy(phy);
338 }
339 
340 static void devm_usb_phy_release2(struct device *dev, void *_res)
341 {
342 	struct phy_devm *res = _res;
343 
344 	if (res->nb)
345 		usb_unregister_notifier(res->phy, res->nb);
346 	usb_put_phy(res->phy);
347 }
348 
349 static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
350 {
351 	struct usb_phy **phy = res;
352 
353 	return *phy == match_data;
354 }
355 
356 static void usb_charger_init(struct usb_phy *usb_phy)
357 {
358 	usb_phy->chg_type = UNKNOWN_TYPE;
359 	usb_phy->chg_state = USB_CHARGER_DEFAULT;
360 	usb_phy_set_default_current(usb_phy);
361 	INIT_WORK(&usb_phy->chg_work, usb_phy_notify_charger_work);
362 }
363 
364 static int usb_add_extcon(struct usb_phy *x)
365 {
366 	int ret;
367 
368 	if (of_property_read_bool(x->dev->of_node, "extcon")) {
369 		x->edev = extcon_get_edev_by_phandle(x->dev, 0);
370 		if (IS_ERR(x->edev))
371 			return PTR_ERR(x->edev);
372 
373 		x->id_edev = extcon_get_edev_by_phandle(x->dev, 1);
374 		if (IS_ERR(x->id_edev)) {
375 			x->id_edev = NULL;
376 			dev_info(x->dev, "No separate ID extcon device\n");
377 		}
378 
379 		if (x->vbus_nb.notifier_call) {
380 			ret = devm_extcon_register_notifier(x->dev, x->edev,
381 							    EXTCON_USB,
382 							    &x->vbus_nb);
383 			if (ret < 0) {
384 				dev_err(x->dev,
385 					"register VBUS notifier failed\n");
386 				return ret;
387 			}
388 		} else {
389 			x->type_nb.notifier_call = usb_phy_get_charger_type;
390 
391 			ret = devm_extcon_register_notifier(x->dev, x->edev,
392 							    EXTCON_CHG_USB_SDP,
393 							    &x->type_nb);
394 			if (ret) {
395 				dev_err(x->dev,
396 					"register extcon USB SDP failed.\n");
397 				return ret;
398 			}
399 
400 			ret = devm_extcon_register_notifier(x->dev, x->edev,
401 							    EXTCON_CHG_USB_CDP,
402 							    &x->type_nb);
403 			if (ret) {
404 				dev_err(x->dev,
405 					"register extcon USB CDP failed.\n");
406 				return ret;
407 			}
408 
409 			ret = devm_extcon_register_notifier(x->dev, x->edev,
410 							    EXTCON_CHG_USB_DCP,
411 							    &x->type_nb);
412 			if (ret) {
413 				dev_err(x->dev,
414 					"register extcon USB DCP failed.\n");
415 				return ret;
416 			}
417 
418 			ret = devm_extcon_register_notifier(x->dev, x->edev,
419 							    EXTCON_CHG_USB_ACA,
420 							    &x->type_nb);
421 			if (ret) {
422 				dev_err(x->dev,
423 					"register extcon USB ACA failed.\n");
424 				return ret;
425 			}
426 		}
427 
428 		if (x->id_nb.notifier_call) {
429 			struct extcon_dev *id_ext;
430 
431 			if (x->id_edev)
432 				id_ext = x->id_edev;
433 			else
434 				id_ext = x->edev;
435 
436 			ret = devm_extcon_register_notifier(x->dev, id_ext,
437 							    EXTCON_USB_HOST,
438 							    &x->id_nb);
439 			if (ret < 0) {
440 				dev_err(x->dev,
441 					"register ID notifier failed\n");
442 				return ret;
443 			}
444 		}
445 	}
446 
447 	if (x->type_nb.notifier_call)
448 		__usb_phy_get_charger_type(x);
449 
450 	return 0;
451 }
452 
453 /**
454  * devm_usb_get_phy - find the USB PHY
455  * @dev: device that requests this phy
456  * @type: the type of the phy the controller requires
457  *
458  * Gets the phy using usb_get_phy(), and associates a device with it using
459  * devres. On driver detach, release function is invoked on the devres data,
460  * then, devres data is freed.
461  *
462  * For use by USB host and peripheral drivers.
463  */
464 struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type)
465 {
466 	struct usb_phy **ptr, *phy;
467 
468 	ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
469 	if (!ptr)
470 		return ERR_PTR(-ENOMEM);
471 
472 	phy = usb_get_phy(type);
473 	if (!IS_ERR(phy)) {
474 		*ptr = phy;
475 		devres_add(dev, ptr);
476 	} else
477 		devres_free(ptr);
478 
479 	return phy;
480 }
481 EXPORT_SYMBOL_GPL(devm_usb_get_phy);
482 
483 /**
484  * usb_get_phy - find the USB PHY
485  * @type: the type of the phy the controller requires
486  *
487  * Returns the phy driver, after getting a refcount to it; or
488  * -ENODEV if there is no such phy.  The caller is responsible for
489  * calling usb_put_phy() to release that count.
490  *
491  * For use by USB host and peripheral drivers.
492  */
493 struct usb_phy *usb_get_phy(enum usb_phy_type type)
494 {
495 	struct usb_phy	*phy = NULL;
496 	unsigned long	flags;
497 
498 	spin_lock_irqsave(&phy_lock, flags);
499 
500 	phy = __usb_find_phy(&phy_list, type);
501 	if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
502 		pr_debug("PHY: unable to find transceiver of type %s\n",
503 			usb_phy_type_string(type));
504 		if (!IS_ERR(phy))
505 			phy = ERR_PTR(-ENODEV);
506 
507 		goto err0;
508 	}
509 
510 	get_device(phy->dev);
511 
512 err0:
513 	spin_unlock_irqrestore(&phy_lock, flags);
514 
515 	return phy;
516 }
517 EXPORT_SYMBOL_GPL(usb_get_phy);
518 
519 /**
520  * devm_usb_get_phy_by_node - find the USB PHY by device_node
521  * @dev: device that requests this phy
522  * @node: the device_node for the phy device.
523  * @nb: a notifier_block to register with the phy.
524  *
525  * Returns the phy driver associated with the given device_node,
526  * after getting a refcount to it, -ENODEV if there is no such phy or
527  * -EPROBE_DEFER if the device is not yet loaded. While at that, it
528  * also associates the device with
529  * the phy using devres. On driver detach, release function is invoked
530  * on the devres data, then, devres data is freed.
531  *
532  * For use by peripheral drivers for devices related to a phy,
533  * such as a charger.
534  */
535 struct  usb_phy *devm_usb_get_phy_by_node(struct device *dev,
536 					  struct device_node *node,
537 					  struct notifier_block *nb)
538 {
539 	struct usb_phy	*phy = ERR_PTR(-ENOMEM);
540 	struct phy_devm	*ptr;
541 	unsigned long	flags;
542 
543 	ptr = devres_alloc(devm_usb_phy_release2, sizeof(*ptr), GFP_KERNEL);
544 	if (!ptr) {
545 		dev_dbg(dev, "failed to allocate memory for devres\n");
546 		goto err0;
547 	}
548 
549 	spin_lock_irqsave(&phy_lock, flags);
550 
551 	phy = __of_usb_find_phy(node);
552 	if (IS_ERR(phy)) {
553 		devres_free(ptr);
554 		goto err1;
555 	}
556 
557 	if (!try_module_get(phy->dev->driver->owner)) {
558 		phy = ERR_PTR(-ENODEV);
559 		devres_free(ptr);
560 		goto err1;
561 	}
562 	if (nb)
563 		usb_register_notifier(phy, nb);
564 	ptr->phy = phy;
565 	ptr->nb = nb;
566 	devres_add(dev, ptr);
567 
568 	get_device(phy->dev);
569 
570 err1:
571 	spin_unlock_irqrestore(&phy_lock, flags);
572 
573 err0:
574 
575 	return phy;
576 }
577 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_node);
578 
579 /**
580  * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
581  * @dev: device that requests this phy
582  * @phandle: name of the property holding the phy phandle value
583  * @index: the index of the phy
584  *
585  * Returns the phy driver associated with the given phandle value,
586  * after getting a refcount to it, -ENODEV if there is no such phy or
587  * -EPROBE_DEFER if there is a phandle to the phy, but the device is
588  * not yet loaded. While at that, it also associates the device with
589  * the phy using devres. On driver detach, release function is invoked
590  * on the devres data, then, devres data is freed.
591  *
592  * For use by USB host and peripheral drivers.
593  */
594 struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
595 	const char *phandle, u8 index)
596 {
597 	struct device_node *node;
598 	struct usb_phy	*phy;
599 
600 	if (!dev->of_node) {
601 		dev_dbg(dev, "device does not have a device node entry\n");
602 		return ERR_PTR(-EINVAL);
603 	}
604 
605 	node = of_parse_phandle(dev->of_node, phandle, index);
606 	if (!node) {
607 		dev_dbg(dev, "failed to get %s phandle in %pOF node\n", phandle,
608 			dev->of_node);
609 		return ERR_PTR(-ENODEV);
610 	}
611 	phy = devm_usb_get_phy_by_node(dev, node, NULL);
612 	of_node_put(node);
613 	return phy;
614 }
615 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_phandle);
616 
617 /**
618  * devm_usb_put_phy - release the USB PHY
619  * @dev: device that wants to release this phy
620  * @phy: the phy returned by devm_usb_get_phy()
621  *
622  * destroys the devres associated with this phy and invokes usb_put_phy
623  * to release the phy.
624  *
625  * For use by USB host and peripheral drivers.
626  */
627 void devm_usb_put_phy(struct device *dev, struct usb_phy *phy)
628 {
629 	int r;
630 
631 	r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy);
632 	dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n");
633 }
634 EXPORT_SYMBOL_GPL(devm_usb_put_phy);
635 
636 /**
637  * usb_put_phy - release the USB PHY
638  * @x: the phy returned by usb_get_phy()
639  *
640  * Releases a refcount the caller received from usb_get_phy().
641  *
642  * For use by USB host and peripheral drivers.
643  */
644 void usb_put_phy(struct usb_phy *x)
645 {
646 	if (x) {
647 		struct module *owner = x->dev->driver->owner;
648 
649 		put_device(x->dev);
650 		module_put(owner);
651 	}
652 }
653 EXPORT_SYMBOL_GPL(usb_put_phy);
654 
655 /**
656  * usb_add_phy: declare the USB PHY
657  * @x: the USB phy to be used; or NULL
658  * @type: the type of this PHY
659  *
660  * This call is exclusively for use by phy drivers, which
661  * coordinate the activities of drivers for host and peripheral
662  * controllers, and in some cases for VBUS current regulation.
663  */
664 int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
665 {
666 	int		ret = 0;
667 	unsigned long	flags;
668 	struct usb_phy	*phy;
669 
670 	if (x->type != USB_PHY_TYPE_UNDEFINED) {
671 		dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
672 		return -EINVAL;
673 	}
674 
675 	usb_charger_init(x);
676 	ret = usb_add_extcon(x);
677 	if (ret)
678 		return ret;
679 
680 	ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
681 
682 	spin_lock_irqsave(&phy_lock, flags);
683 
684 	list_for_each_entry(phy, &phy_list, head) {
685 		if (phy->type == type) {
686 			ret = -EBUSY;
687 			dev_err(x->dev, "transceiver type %s already exists\n",
688 						usb_phy_type_string(type));
689 			goto out;
690 		}
691 	}
692 
693 	x->type = type;
694 	list_add_tail(&x->head, &phy_list);
695 
696 out:
697 	spin_unlock_irqrestore(&phy_lock, flags);
698 	return ret;
699 }
700 EXPORT_SYMBOL_GPL(usb_add_phy);
701 
702 static struct device_type usb_phy_dev_type = {
703 	.name = "usb_phy",
704 	.uevent = usb_phy_uevent,
705 };
706 
707 /**
708  * usb_add_phy_dev - declare the USB PHY
709  * @x: the USB phy to be used; or NULL
710  *
711  * This call is exclusively for use by phy drivers, which
712  * coordinate the activities of drivers for host and peripheral
713  * controllers, and in some cases for VBUS current regulation.
714  */
715 int usb_add_phy_dev(struct usb_phy *x)
716 {
717 	unsigned long flags;
718 	int ret;
719 
720 	if (!x->dev) {
721 		dev_err(x->dev, "no device provided for PHY\n");
722 		return -EINVAL;
723 	}
724 
725 	usb_charger_init(x);
726 	ret = usb_add_extcon(x);
727 	if (ret)
728 		return ret;
729 
730 	x->dev->type = &usb_phy_dev_type;
731 
732 	ATOMIC_INIT_NOTIFIER_HEAD(&x->notifier);
733 
734 	spin_lock_irqsave(&phy_lock, flags);
735 	list_add_tail(&x->head, &phy_list);
736 	spin_unlock_irqrestore(&phy_lock, flags);
737 
738 	return 0;
739 }
740 EXPORT_SYMBOL_GPL(usb_add_phy_dev);
741 
742 /**
743  * usb_remove_phy - remove the OTG PHY
744  * @x: the USB OTG PHY to be removed;
745  *
746  * This reverts the effects of usb_add_phy
747  */
748 void usb_remove_phy(struct usb_phy *x)
749 {
750 	unsigned long	flags;
751 
752 	spin_lock_irqsave(&phy_lock, flags);
753 	if (x)
754 		list_del(&x->head);
755 	spin_unlock_irqrestore(&phy_lock, flags);
756 }
757 EXPORT_SYMBOL_GPL(usb_remove_phy);
758 
759 /**
760  * usb_phy_set_event - set event to phy event
761  * @x: the phy returned by usb_get_phy();
762  * @event: event to set
763  *
764  * This sets event to phy event
765  */
766 void usb_phy_set_event(struct usb_phy *x, unsigned long event)
767 {
768 	x->last_event = event;
769 }
770 EXPORT_SYMBOL_GPL(usb_phy_set_event);
771