xref: /linux/drivers/extcon/extcon.c (revision 75a6faf617d107bdbc74d36ccf89f2280b96ac26)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * drivers/extcon/extcon.c - External Connector (extcon) framework.
4  *
5  * Copyright (C) 2015 Samsung Electronics
6  * Author: Chanwoo Choi <cw00.choi@samsung.com>
7  *
8  * Copyright (C) 2012 Samsung Electronics
9  * Author: Donggeun Kim <dg77.kim@samsung.com>
10  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
11  *
12  * based on android/drivers/switch/switch_class.c
13  * Copyright (C) 2008 Google, Inc.
14  * Author: Mike Lockwood <lockwood@android.com>
15  */
16 
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/init.h>
20 #include <linux/device.h>
21 #include <linux/fs.h>
22 #include <linux/err.h>
23 #include <linux/of.h>
24 #include <linux/slab.h>
25 #include <linux/sysfs.h>
26 
27 #include "extcon.h"
28 
29 #define SUPPORTED_CABLE_MAX	32
30 
31 static const struct __extcon_info {
32 	unsigned int type;
33 	unsigned int id;
34 	const char *name;
35 
36 } extcon_info[] = {
37 	[EXTCON_NONE] = {
38 		.type = EXTCON_TYPE_MISC,
39 		.id = EXTCON_NONE,
40 		.name = "NONE",
41 	},
42 
43 	/* USB external connector */
44 	[EXTCON_USB] = {
45 		.type = EXTCON_TYPE_USB,
46 		.id = EXTCON_USB,
47 		.name = "USB",
48 	},
49 	[EXTCON_USB_HOST] = {
50 		.type = EXTCON_TYPE_USB,
51 		.id = EXTCON_USB_HOST,
52 		.name = "USB-HOST",
53 	},
54 
55 	/* Charging external connector */
56 	[EXTCON_CHG_USB_SDP] = {
57 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
58 		.id = EXTCON_CHG_USB_SDP,
59 		.name = "SDP",
60 	},
61 	[EXTCON_CHG_USB_DCP] = {
62 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
63 		.id = EXTCON_CHG_USB_DCP,
64 		.name = "DCP",
65 	},
66 	[EXTCON_CHG_USB_CDP] = {
67 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
68 		.id = EXTCON_CHG_USB_CDP,
69 		.name = "CDP",
70 	},
71 	[EXTCON_CHG_USB_ACA] = {
72 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
73 		.id = EXTCON_CHG_USB_ACA,
74 		.name = "ACA",
75 	},
76 	[EXTCON_CHG_USB_FAST] = {
77 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
78 		.id = EXTCON_CHG_USB_FAST,
79 		.name = "FAST-CHARGER",
80 	},
81 	[EXTCON_CHG_USB_SLOW] = {
82 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
83 		.id = EXTCON_CHG_USB_SLOW,
84 		.name = "SLOW-CHARGER",
85 	},
86 	[EXTCON_CHG_WPT] = {
87 		.type = EXTCON_TYPE_CHG,
88 		.id = EXTCON_CHG_WPT,
89 		.name = "WPT",
90 	},
91 	[EXTCON_CHG_USB_PD] = {
92 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
93 		.id = EXTCON_CHG_USB_PD,
94 		.name = "PD",
95 	},
96 
97 	/* Jack external connector */
98 	[EXTCON_JACK_MICROPHONE] = {
99 		.type = EXTCON_TYPE_JACK,
100 		.id = EXTCON_JACK_MICROPHONE,
101 		.name = "MICROPHONE",
102 	},
103 	[EXTCON_JACK_HEADPHONE] = {
104 		.type = EXTCON_TYPE_JACK,
105 		.id = EXTCON_JACK_HEADPHONE,
106 		.name = "HEADPHONE",
107 	},
108 	[EXTCON_JACK_LINE_IN] = {
109 		.type = EXTCON_TYPE_JACK,
110 		.id = EXTCON_JACK_LINE_IN,
111 		.name = "LINE-IN",
112 	},
113 	[EXTCON_JACK_LINE_OUT] = {
114 		.type = EXTCON_TYPE_JACK,
115 		.id = EXTCON_JACK_LINE_OUT,
116 		.name = "LINE-OUT",
117 	},
118 	[EXTCON_JACK_VIDEO_IN] = {
119 		.type = EXTCON_TYPE_JACK,
120 		.id = EXTCON_JACK_VIDEO_IN,
121 		.name = "VIDEO-IN",
122 	},
123 	[EXTCON_JACK_VIDEO_OUT] = {
124 		.type = EXTCON_TYPE_JACK,
125 		.id = EXTCON_JACK_VIDEO_OUT,
126 		.name = "VIDEO-OUT",
127 	},
128 	[EXTCON_JACK_SPDIF_IN] = {
129 		.type = EXTCON_TYPE_JACK,
130 		.id = EXTCON_JACK_SPDIF_IN,
131 		.name = "SPDIF-IN",
132 	},
133 	[EXTCON_JACK_SPDIF_OUT] = {
134 		.type = EXTCON_TYPE_JACK,
135 		.id = EXTCON_JACK_SPDIF_OUT,
136 		.name = "SPDIF-OUT",
137 	},
138 
139 	/* Display external connector */
140 	[EXTCON_DISP_HDMI] = {
141 		.type = EXTCON_TYPE_DISP,
142 		.id = EXTCON_DISP_HDMI,
143 		.name = "HDMI",
144 	},
145 	[EXTCON_DISP_MHL] = {
146 		.type = EXTCON_TYPE_DISP,
147 		.id = EXTCON_DISP_MHL,
148 		.name = "MHL",
149 	},
150 	[EXTCON_DISP_DVI] = {
151 		.type = EXTCON_TYPE_DISP,
152 		.id = EXTCON_DISP_DVI,
153 		.name = "DVI",
154 	},
155 	[EXTCON_DISP_VGA] = {
156 		.type = EXTCON_TYPE_DISP,
157 		.id = EXTCON_DISP_VGA,
158 		.name = "VGA",
159 	},
160 	[EXTCON_DISP_DP] = {
161 		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
162 		.id = EXTCON_DISP_DP,
163 		.name = "DP",
164 	},
165 	[EXTCON_DISP_HMD] = {
166 		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
167 		.id = EXTCON_DISP_HMD,
168 		.name = "HMD",
169 	},
170 
171 	/* Miscellaneous external connector */
172 	[EXTCON_DOCK] = {
173 		.type = EXTCON_TYPE_MISC,
174 		.id = EXTCON_DOCK,
175 		.name = "DOCK",
176 	},
177 	[EXTCON_JIG] = {
178 		.type = EXTCON_TYPE_MISC,
179 		.id = EXTCON_JIG,
180 		.name = "JIG",
181 	},
182 	[EXTCON_MECHANICAL] = {
183 		.type = EXTCON_TYPE_MISC,
184 		.id = EXTCON_MECHANICAL,
185 		.name = "MECHANICAL",
186 	},
187 
188 	{ /* sentinel */ }
189 };
190 
191 /**
192  * struct extcon_cable - An internal data for an external connector.
193  * @edev:		the extcon device
194  * @cable_index:	the index of this cable in the edev
195  * @attr_g:		the attribute group for the cable
196  * @attr_name:		"name" sysfs entry
197  * @attr_state:		"state" sysfs entry
198  * @attrs:		the array pointing to attr_name and attr_state for attr_g
199  */
200 struct extcon_cable {
201 	struct extcon_dev *edev;
202 	int cable_index;
203 
204 	struct attribute_group attr_g;
205 	struct device_attribute attr_name;
206 	struct device_attribute attr_state;
207 
208 	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
209 
210 	union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
211 	union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
212 	union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
213 	union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];
214 
215 	unsigned long usb_bits[BITS_TO_LONGS(EXTCON_PROP_USB_CNT)];
216 	unsigned long chg_bits[BITS_TO_LONGS(EXTCON_PROP_CHG_CNT)];
217 	unsigned long jack_bits[BITS_TO_LONGS(EXTCON_PROP_JACK_CNT)];
218 	unsigned long disp_bits[BITS_TO_LONGS(EXTCON_PROP_DISP_CNT)];
219 };
220 
221 static struct class *extcon_class;
222 
223 static LIST_HEAD(extcon_dev_list);
224 static DEFINE_MUTEX(extcon_dev_list_lock);
225 
226 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
227 {
228 	int i = 0;
229 
230 	if (!edev->mutually_exclusive)
231 		return 0;
232 
233 	for (i = 0; edev->mutually_exclusive[i]; i++) {
234 		int weight;
235 		u32 correspondants = new_state & edev->mutually_exclusive[i];
236 
237 		/* calculate the total number of bits set */
238 		weight = hweight32(correspondants);
239 		if (weight > 1)
240 			return i + 1;
241 	}
242 
243 	return 0;
244 }
245 
246 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
247 {
248 	int i;
249 
250 	/* Find the the index of extcon cable in edev->supported_cable */
251 	for (i = 0; i < edev->max_supported; i++) {
252 		if (edev->supported_cable[i] == id)
253 			return i;
254 	}
255 
256 	return -EINVAL;
257 }
258 
259 static int get_extcon_type(unsigned int prop)
260 {
261 	switch (prop) {
262 	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
263 		return EXTCON_TYPE_USB;
264 	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
265 		return EXTCON_TYPE_CHG;
266 	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
267 		return EXTCON_TYPE_JACK;
268 	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
269 		return EXTCON_TYPE_DISP;
270 	default:
271 		return -EINVAL;
272 	}
273 }
274 
275 static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
276 {
277 	return !!(edev->state & BIT(index));
278 }
279 
280 static bool is_extcon_changed(struct extcon_dev *edev, int index,
281 				bool new_state)
282 {
283 	int state = !!(edev->state & BIT(index));
284 	return (state != new_state);
285 }
286 
287 static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
288 {
289 	int type;
290 
291 	/* Check whether the property is supported or not. */
292 	type = get_extcon_type(prop);
293 	if (type < 0)
294 		return false;
295 
296 	/* Check whether a specific extcon id supports the property or not. */
297 	return !!(extcon_info[id].type & type);
298 }
299 
300 static int is_extcon_property_capability(struct extcon_dev *edev,
301 				unsigned int id, int index,unsigned int prop)
302 {
303 	struct extcon_cable *cable;
304 	int type, ret;
305 
306 	/* Check whether the property is supported or not. */
307 	type = get_extcon_type(prop);
308 	if (type < 0)
309 		return type;
310 
311 	cable = &edev->cables[index];
312 
313 	switch (type) {
314 	case EXTCON_TYPE_USB:
315 		ret = test_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
316 		break;
317 	case EXTCON_TYPE_CHG:
318 		ret = test_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
319 		break;
320 	case EXTCON_TYPE_JACK:
321 		ret = test_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
322 		break;
323 	case EXTCON_TYPE_DISP:
324 		ret = test_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
325 		break;
326 	default:
327 		ret = -EINVAL;
328 	}
329 
330 	return ret;
331 }
332 
333 static void init_property(struct extcon_dev *edev, unsigned int id, int index)
334 {
335 	unsigned int type = extcon_info[id].type;
336 	struct extcon_cable *cable = &edev->cables[index];
337 
338 	if (EXTCON_TYPE_USB & type)
339 		memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
340 	if (EXTCON_TYPE_CHG & type)
341 		memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
342 	if (EXTCON_TYPE_JACK & type)
343 		memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
344 	if (EXTCON_TYPE_DISP & type)
345 		memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
346 }
347 
348 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
349 			  char *buf)
350 {
351 	int i, count = 0;
352 	struct extcon_dev *edev = dev_get_drvdata(dev);
353 
354 	if (edev->max_supported == 0)
355 		return sprintf(buf, "%u\n", edev->state);
356 
357 	for (i = 0; i < edev->max_supported; i++) {
358 		count += sprintf(buf + count, "%s=%d\n",
359 				extcon_info[edev->supported_cable[i]].name,
360 				 !!(edev->state & BIT(i)));
361 	}
362 
363 	return count;
364 }
365 static DEVICE_ATTR_RO(state);
366 
367 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
368 		char *buf)
369 {
370 	struct extcon_dev *edev = dev_get_drvdata(dev);
371 
372 	return sprintf(buf, "%s\n", edev->name);
373 }
374 static DEVICE_ATTR_RO(name);
375 
376 static ssize_t cable_name_show(struct device *dev,
377 			       struct device_attribute *attr, char *buf)
378 {
379 	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
380 						  attr_name);
381 	int i = cable->cable_index;
382 
383 	return sprintf(buf, "%s\n",
384 			extcon_info[cable->edev->supported_cable[i]].name);
385 }
386 
387 static ssize_t cable_state_show(struct device *dev,
388 				struct device_attribute *attr, char *buf)
389 {
390 	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
391 						  attr_state);
392 
393 	int i = cable->cable_index;
394 
395 	return sprintf(buf, "%d\n",
396 		extcon_get_state(cable->edev, cable->edev->supported_cable[i]));
397 }
398 
399 /**
400  * extcon_sync() - Synchronize the state for an external connector.
401  * @edev:	the extcon device
402  *
403  * Note that this function send a notification in order to synchronize
404  * the state and property of an external connector.
405  *
406  * Returns 0 if success or error number if fail.
407  */
408 int extcon_sync(struct extcon_dev *edev, unsigned int id)
409 {
410 	char name_buf[120];
411 	char state_buf[120];
412 	char *prop_buf;
413 	char *envp[3];
414 	int env_offset = 0;
415 	int length;
416 	int index;
417 	int state;
418 	unsigned long flags;
419 
420 	if (!edev)
421 		return -EINVAL;
422 
423 	index = find_cable_index_by_id(edev, id);
424 	if (index < 0)
425 		return index;
426 
427 	spin_lock_irqsave(&edev->lock, flags);
428 	state = !!(edev->state & BIT(index));
429 	spin_unlock_irqrestore(&edev->lock, flags);
430 
431 	/*
432 	 * Call functions in a raw notifier chain for the specific one
433 	 * external connector.
434 	 */
435 	raw_notifier_call_chain(&edev->nh[index], state, edev);
436 
437 	/*
438 	 * Call functions in a raw notifier chain for the all supported
439 	 * external connectors.
440 	 */
441 	raw_notifier_call_chain(&edev->nh_all, state, edev);
442 
443 	spin_lock_irqsave(&edev->lock, flags);
444 	/* This could be in interrupt handler */
445 	prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
446 	if (!prop_buf) {
447 		/* Unlock early before uevent */
448 		spin_unlock_irqrestore(&edev->lock, flags);
449 
450 		dev_err(&edev->dev, "out of memory in extcon_set_state\n");
451 		kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
452 
453 		return -ENOMEM;
454 	}
455 
456 	length = name_show(&edev->dev, NULL, prop_buf);
457 	if (length > 0) {
458 		if (prop_buf[length - 1] == '\n')
459 			prop_buf[length - 1] = 0;
460 		snprintf(name_buf, sizeof(name_buf), "NAME=%s", prop_buf);
461 		envp[env_offset++] = name_buf;
462 	}
463 
464 	length = state_show(&edev->dev, NULL, prop_buf);
465 	if (length > 0) {
466 		if (prop_buf[length - 1] == '\n')
467 			prop_buf[length - 1] = 0;
468 		snprintf(state_buf, sizeof(state_buf), "STATE=%s", prop_buf);
469 		envp[env_offset++] = state_buf;
470 	}
471 	envp[env_offset] = NULL;
472 
473 	/* Unlock early before uevent */
474 	spin_unlock_irqrestore(&edev->lock, flags);
475 	kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
476 	free_page((unsigned long)prop_buf);
477 
478 	return 0;
479 }
480 EXPORT_SYMBOL_GPL(extcon_sync);
481 
482 /**
483  * extcon_get_state() - Get the state of an external connector.
484  * @edev:	the extcon device
485  * @id:		the unique id indicating an external connector
486  *
487  * Returns 0 if success or error number if fail.
488  */
489 int extcon_get_state(struct extcon_dev *edev, const unsigned int id)
490 {
491 	int index, state;
492 	unsigned long flags;
493 
494 	if (!edev)
495 		return -EINVAL;
496 
497 	index = find_cable_index_by_id(edev, id);
498 	if (index < 0)
499 		return index;
500 
501 	spin_lock_irqsave(&edev->lock, flags);
502 	state = is_extcon_attached(edev, index);
503 	spin_unlock_irqrestore(&edev->lock, flags);
504 
505 	return state;
506 }
507 EXPORT_SYMBOL_GPL(extcon_get_state);
508 
509 /**
510  * extcon_set_state() - Set the state of an external connector.
511  * @edev:	the extcon device
512  * @id:		the unique id indicating an external connector
513  * @state:	the new state of an external connector.
514  *		the default semantics is true: attached / false: detached.
515  *
516  * Note that this function set the state of an external connector without
517  * a notification. To synchronize the state of an external connector,
518  * have to use extcon_set_state_sync() and extcon_sync().
519  *
520  * Returns 0 if success or error number if fail.
521  */
522 int extcon_set_state(struct extcon_dev *edev, unsigned int id, bool state)
523 {
524 	unsigned long flags;
525 	int index, ret = 0;
526 
527 	if (!edev)
528 		return -EINVAL;
529 
530 	index = find_cable_index_by_id(edev, id);
531 	if (index < 0)
532 		return index;
533 
534 	spin_lock_irqsave(&edev->lock, flags);
535 
536 	/* Check whether the external connector's state is changed. */
537 	if (!is_extcon_changed(edev, index, state))
538 		goto out;
539 
540 	if (check_mutually_exclusive(edev,
541 		(edev->state & ~BIT(index)) | (state & BIT(index)))) {
542 		ret = -EPERM;
543 		goto out;
544 	}
545 
546 	/*
547 	 * Initialize the value of extcon property before setting
548 	 * the detached state for an external connector.
549 	 */
550 	if (!state)
551 		init_property(edev, id, index);
552 
553 	/* Update the state for an external connector. */
554 	if (state)
555 		edev->state |= BIT(index);
556 	else
557 		edev->state &= ~(BIT(index));
558 out:
559 	spin_unlock_irqrestore(&edev->lock, flags);
560 
561 	return ret;
562 }
563 EXPORT_SYMBOL_GPL(extcon_set_state);
564 
565 /**
566  * extcon_set_state_sync() - Set the state of an external connector with sync.
567  * @edev:	the extcon device
568  * @id:		the unique id indicating an external connector
569  * @state:	the new state of external connector.
570  *		the default semantics is true: attached / false: detached.
571  *
572  * Note that this function set the state of external connector
573  * and synchronize the state by sending a notification.
574  *
575  * Returns 0 if success or error number if fail.
576  */
577 int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id, bool state)
578 {
579 	int ret, index;
580 	unsigned long flags;
581 
582 	index = find_cable_index_by_id(edev, id);
583 	if (index < 0)
584 		return index;
585 
586 	/* Check whether the external connector's state is changed. */
587 	spin_lock_irqsave(&edev->lock, flags);
588 	ret = is_extcon_changed(edev, index, state);
589 	spin_unlock_irqrestore(&edev->lock, flags);
590 	if (!ret)
591 		return 0;
592 
593 	ret = extcon_set_state(edev, id, state);
594 	if (ret < 0)
595 		return ret;
596 
597 	return extcon_sync(edev, id);
598 }
599 EXPORT_SYMBOL_GPL(extcon_set_state_sync);
600 
601 /**
602  * extcon_get_property() - Get the property value of an external connector.
603  * @edev:	the extcon device
604  * @id:		the unique id indicating an external connector
605  * @prop:	the property id indicating an extcon property
606  * @prop_val:	the pointer which store the value of extcon property
607  *
608  * Note that when getting the property value of external connector,
609  * the external connector should be attached. If detached state, function
610  * return 0 without property value. Also, the each property should be
611  * included in the list of supported properties according to extcon type.
612  *
613  * Returns 0 if success or error number if fail.
614  */
615 int extcon_get_property(struct extcon_dev *edev, unsigned int id,
616 				unsigned int prop,
617 				union extcon_property_value *prop_val)
618 {
619 	struct extcon_cable *cable;
620 	unsigned long flags;
621 	int index, ret = 0;
622 
623 	*prop_val = (union extcon_property_value){0};
624 
625 	if (!edev)
626 		return -EINVAL;
627 
628 	/* Check whether the property is supported or not */
629 	if (!is_extcon_property_supported(id, prop))
630 		return -EINVAL;
631 
632 	/* Find the cable index of external connector by using id */
633 	index = find_cable_index_by_id(edev, id);
634 	if (index < 0)
635 		return index;
636 
637 	spin_lock_irqsave(&edev->lock, flags);
638 
639 	/* Check whether the property is available or not. */
640 	if (!is_extcon_property_capability(edev, id, index, prop)) {
641 		spin_unlock_irqrestore(&edev->lock, flags);
642 		return -EPERM;
643 	}
644 
645 	/*
646 	 * Check whether the external connector is attached.
647 	 * If external connector is detached, the user can not
648 	 * get the property value.
649 	 */
650 	if (!is_extcon_attached(edev, index)) {
651 		spin_unlock_irqrestore(&edev->lock, flags);
652 		return 0;
653 	}
654 
655 	cable = &edev->cables[index];
656 
657 	/* Get the property value according to extcon type */
658 	switch (prop) {
659 	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
660 		*prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
661 		break;
662 	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
663 		*prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
664 		break;
665 	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
666 		*prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
667 		break;
668 	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
669 		*prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
670 		break;
671 	default:
672 		ret = -EINVAL;
673 		break;
674 	}
675 
676 	spin_unlock_irqrestore(&edev->lock, flags);
677 
678 	return ret;
679 }
680 EXPORT_SYMBOL_GPL(extcon_get_property);
681 
682 /**
683  * extcon_set_property() - Set the property value of an external connector.
684  * @edev:	the extcon device
685  * @id:		the unique id indicating an external connector
686  * @prop:	the property id indicating an extcon property
687  * @prop_val:	the pointer including the new value of extcon property
688  *
689  * Note that each property should be included in the list of supported
690  * properties according to the extcon type.
691  *
692  * Returns 0 if success or error number if fail.
693  */
694 int extcon_set_property(struct extcon_dev *edev, unsigned int id,
695 				unsigned int prop,
696 				union extcon_property_value prop_val)
697 {
698 	struct extcon_cable *cable;
699 	unsigned long flags;
700 	int index, ret = 0;
701 
702 	if (!edev)
703 		return -EINVAL;
704 
705 	/* Check whether the property is supported or not */
706 	if (!is_extcon_property_supported(id, prop))
707 		return -EINVAL;
708 
709 	/* Find the cable index of external connector by using id */
710 	index = find_cable_index_by_id(edev, id);
711 	if (index < 0)
712 		return index;
713 
714 	spin_lock_irqsave(&edev->lock, flags);
715 
716 	/* Check whether the property is available or not. */
717 	if (!is_extcon_property_capability(edev, id, index, prop)) {
718 		spin_unlock_irqrestore(&edev->lock, flags);
719 		return -EPERM;
720 	}
721 
722 	cable = &edev->cables[index];
723 
724 	/* Set the property value according to extcon type */
725 	switch (prop) {
726 	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
727 		cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
728 		break;
729 	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
730 		cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
731 		break;
732 	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
733 		cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
734 		break;
735 	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
736 		cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
737 		break;
738 	default:
739 		ret = -EINVAL;
740 		break;
741 	}
742 
743 	spin_unlock_irqrestore(&edev->lock, flags);
744 
745 	return ret;
746 }
747 EXPORT_SYMBOL_GPL(extcon_set_property);
748 
749 /**
750  * extcon_set_property_sync() - Set property of an external connector with sync.
751  * @prop_val:	the pointer including the new value of extcon property
752  *
753  * Note that when setting the property value of external connector,
754  * the external connector should be attached. The each property should
755  * be included in the list of supported properties according to extcon type.
756  *
757  * Returns 0 if success or error number if fail.
758  */
759 int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
760 				unsigned int prop,
761 				union extcon_property_value prop_val)
762 {
763 	int ret;
764 
765 	ret = extcon_set_property(edev, id, prop, prop_val);
766 	if (ret < 0)
767 		return ret;
768 
769 	return extcon_sync(edev, id);
770 }
771 EXPORT_SYMBOL_GPL(extcon_set_property_sync);
772 
773 /**
774  * extcon_get_property_capability() - Get the capability of the property
775  *					for an external connector.
776  * @edev:	the extcon device
777  * @id:		the unique id indicating an external connector
778  * @prop:	the property id indicating an extcon property
779  *
780  * Returns 1 if the property is available or 0 if not available.
781  */
782 int extcon_get_property_capability(struct extcon_dev *edev, unsigned int id,
783 					unsigned int prop)
784 {
785 	int index;
786 
787 	if (!edev)
788 		return -EINVAL;
789 
790 	/* Check whether the property is supported or not */
791 	if (!is_extcon_property_supported(id, prop))
792 		return -EINVAL;
793 
794 	/* Find the cable index of external connector by using id */
795 	index = find_cable_index_by_id(edev, id);
796 	if (index < 0)
797 		return index;
798 
799 	return is_extcon_property_capability(edev, id, index, prop);
800 }
801 EXPORT_SYMBOL_GPL(extcon_get_property_capability);
802 
803 /**
804  * extcon_set_property_capability() - Set the capability of the property
805  *					for an external connector.
806  * @edev:	the extcon device
807  * @id:		the unique id indicating an external connector
808  * @prop:	the property id indicating an extcon property
809  *
810  * Note that this function set the capability of the property
811  * for an external connector in order to mark the bit in capability
812  * bitmap which mean the available state of the property.
813  *
814  * Returns 0 if success or error number if fail.
815  */
816 int extcon_set_property_capability(struct extcon_dev *edev, unsigned int id,
817 					unsigned int prop)
818 {
819 	struct extcon_cable *cable;
820 	int index, type, ret = 0;
821 
822 	if (!edev)
823 		return -EINVAL;
824 
825 	/* Check whether the property is supported or not. */
826 	if (!is_extcon_property_supported(id, prop))
827 		return -EINVAL;
828 
829 	/* Find the cable index of external connector by using id. */
830 	index = find_cable_index_by_id(edev, id);
831 	if (index < 0)
832 		return index;
833 
834 	type = get_extcon_type(prop);
835 	if (type < 0)
836 		return type;
837 
838 	cable = &edev->cables[index];
839 
840 	switch (type) {
841 	case EXTCON_TYPE_USB:
842 		__set_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
843 		break;
844 	case EXTCON_TYPE_CHG:
845 		__set_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
846 		break;
847 	case EXTCON_TYPE_JACK:
848 		__set_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
849 		break;
850 	case EXTCON_TYPE_DISP:
851 		__set_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
852 		break;
853 	default:
854 		ret = -EINVAL;
855 	}
856 
857 	return ret;
858 }
859 EXPORT_SYMBOL_GPL(extcon_set_property_capability);
860 
861 /**
862  * extcon_get_extcon_dev() - Get the extcon device instance from the name.
863  * @extcon_name:	the extcon name provided with extcon_dev_register()
864  *
865  * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
866  */
867 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
868 {
869 	struct extcon_dev *sd;
870 
871 	if (!extcon_name)
872 		return ERR_PTR(-EINVAL);
873 
874 	mutex_lock(&extcon_dev_list_lock);
875 	list_for_each_entry(sd, &extcon_dev_list, entry) {
876 		if (!strcmp(sd->name, extcon_name))
877 			goto out;
878 	}
879 	sd = NULL;
880 out:
881 	mutex_unlock(&extcon_dev_list_lock);
882 	return sd;
883 }
884 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
885 
886 /**
887  * extcon_register_notifier() - Register a notifier block to get notified by
888  *				any state changes from the extcon.
889  * @edev:	the extcon device
890  * @id:		the unique id indicating an external connector
891  * @nb:		a notifier block to be registered
892  *
893  * Note that the second parameter given to the callback of nb (val) is
894  * the current state of an external connector and the third pameter
895  * is the pointer of extcon device.
896  *
897  * Returns 0 if success or error number if fail.
898  */
899 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
900 			     struct notifier_block *nb)
901 {
902 	unsigned long flags;
903 	int ret, idx = -EINVAL;
904 
905 	if (!edev || !nb)
906 		return -EINVAL;
907 
908 	idx = find_cable_index_by_id(edev, id);
909 	if (idx < 0)
910 		return idx;
911 
912 	spin_lock_irqsave(&edev->lock, flags);
913 	ret = raw_notifier_chain_register(&edev->nh[idx], nb);
914 	spin_unlock_irqrestore(&edev->lock, flags);
915 
916 	return ret;
917 }
918 EXPORT_SYMBOL_GPL(extcon_register_notifier);
919 
920 /**
921  * extcon_unregister_notifier() - Unregister a notifier block from the extcon.
922  * @edev:	the extcon device
923  * @id:		the unique id indicating an external connector
924  * @nb:		a notifier block to be registered
925  *
926  * Returns 0 if success or error number if fail.
927  */
928 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
929 				struct notifier_block *nb)
930 {
931 	unsigned long flags;
932 	int ret, idx;
933 
934 	if (!edev || !nb)
935 		return -EINVAL;
936 
937 	idx = find_cable_index_by_id(edev, id);
938 	if (idx < 0)
939 		return idx;
940 
941 	spin_lock_irqsave(&edev->lock, flags);
942 	ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
943 	spin_unlock_irqrestore(&edev->lock, flags);
944 
945 	return ret;
946 }
947 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
948 
949 /**
950  * extcon_register_notifier_all() - Register a notifier block for all connectors.
951  * @edev:	the extcon device
952  * @nb:		a notifier block to be registered
953  *
954  * Note that this function registers a notifier block in order to receive
955  * the state change of all supported external connectors from extcon device.
956  * And the second parameter given to the callback of nb (val) is
957  * the current state and the third pameter is the pointer of extcon device.
958  *
959  * Returns 0 if success or error number if fail.
960  */
961 int extcon_register_notifier_all(struct extcon_dev *edev,
962 				struct notifier_block *nb)
963 {
964 	unsigned long flags;
965 	int ret;
966 
967 	if (!edev || !nb)
968 		return -EINVAL;
969 
970 	spin_lock_irqsave(&edev->lock, flags);
971 	ret = raw_notifier_chain_register(&edev->nh_all, nb);
972 	spin_unlock_irqrestore(&edev->lock, flags);
973 
974 	return ret;
975 }
976 EXPORT_SYMBOL_GPL(extcon_register_notifier_all);
977 
978 /**
979  * extcon_unregister_notifier_all() - Unregister a notifier block from extcon.
980  * @edev:	the extcon device
981  * @nb:		a notifier block to be registered
982  *
983  * Returns 0 if success or error number if fail.
984  */
985 int extcon_unregister_notifier_all(struct extcon_dev *edev,
986 				struct notifier_block *nb)
987 {
988 	unsigned long flags;
989 	int ret;
990 
991 	if (!edev || !nb)
992 		return -EINVAL;
993 
994 	spin_lock_irqsave(&edev->lock, flags);
995 	ret = raw_notifier_chain_unregister(&edev->nh_all, nb);
996 	spin_unlock_irqrestore(&edev->lock, flags);
997 
998 	return ret;
999 }
1000 EXPORT_SYMBOL_GPL(extcon_unregister_notifier_all);
1001 
1002 static struct attribute *extcon_attrs[] = {
1003 	&dev_attr_state.attr,
1004 	&dev_attr_name.attr,
1005 	NULL,
1006 };
1007 ATTRIBUTE_GROUPS(extcon);
1008 
1009 static int create_extcon_class(void)
1010 {
1011 	if (!extcon_class) {
1012 		extcon_class = class_create(THIS_MODULE, "extcon");
1013 		if (IS_ERR(extcon_class))
1014 			return PTR_ERR(extcon_class);
1015 		extcon_class->dev_groups = extcon_groups;
1016 	}
1017 
1018 	return 0;
1019 }
1020 
1021 static void extcon_dev_release(struct device *dev)
1022 {
1023 }
1024 
1025 static const char *muex_name = "mutually_exclusive";
1026 static void dummy_sysfs_dev_release(struct device *dev)
1027 {
1028 }
1029 
1030 /*
1031  * extcon_dev_allocate() - Allocate the memory of extcon device.
1032  * @supported_cable:	the array of the supported external connectors
1033  *			ending with EXTCON_NONE.
1034  *
1035  * Note that this function allocates the memory for extcon device
1036  * and initialize default setting for the extcon device.
1037  *
1038  * Returns the pointer memory of allocated extcon_dev if success
1039  * or ERR_PTR(err) if fail.
1040  */
1041 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
1042 {
1043 	struct extcon_dev *edev;
1044 
1045 	if (!supported_cable)
1046 		return ERR_PTR(-EINVAL);
1047 
1048 	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
1049 	if (!edev)
1050 		return ERR_PTR(-ENOMEM);
1051 
1052 	edev->max_supported = 0;
1053 	edev->supported_cable = supported_cable;
1054 
1055 	return edev;
1056 }
1057 
1058 /*
1059  * extcon_dev_free() - Free the memory of extcon device.
1060  * @edev:	the extcon device
1061  */
1062 void extcon_dev_free(struct extcon_dev *edev)
1063 {
1064 	kfree(edev);
1065 }
1066 EXPORT_SYMBOL_GPL(extcon_dev_free);
1067 
1068 /**
1069  * extcon_dev_register() - Register an new extcon device
1070  * @edev:	the extcon device to be registered
1071  *
1072  * Among the members of edev struct, please set the "user initializing data"
1073  * do not set the values of "internal data", which are initialized by
1074  * this function.
1075  *
1076  * Note that before calling this funciton, have to allocate the memory
1077  * of an extcon device by using the extcon_dev_allocate(). And the extcon
1078  * dev should include the supported_cable information.
1079  *
1080  * Returns 0 if success or error number if fail.
1081  */
1082 int extcon_dev_register(struct extcon_dev *edev)
1083 {
1084 	int ret, index = 0;
1085 	static atomic_t edev_no = ATOMIC_INIT(-1);
1086 
1087 	if (!extcon_class) {
1088 		ret = create_extcon_class();
1089 		if (ret < 0)
1090 			return ret;
1091 	}
1092 
1093 	if (!edev || !edev->supported_cable)
1094 		return -EINVAL;
1095 
1096 	for (; edev->supported_cable[index] != EXTCON_NONE; index++);
1097 
1098 	edev->max_supported = index;
1099 	if (index > SUPPORTED_CABLE_MAX) {
1100 		dev_err(&edev->dev,
1101 			"exceed the maximum number of supported cables\n");
1102 		return -EINVAL;
1103 	}
1104 
1105 	edev->dev.class = extcon_class;
1106 	edev->dev.release = extcon_dev_release;
1107 
1108 	edev->name = dev_name(edev->dev.parent);
1109 	if (IS_ERR_OR_NULL(edev->name)) {
1110 		dev_err(&edev->dev,
1111 			"extcon device name is null\n");
1112 		return -EINVAL;
1113 	}
1114 	dev_set_name(&edev->dev, "extcon%lu",
1115 			(unsigned long)atomic_inc_return(&edev_no));
1116 
1117 	if (edev->max_supported) {
1118 		char *str;
1119 		struct extcon_cable *cable;
1120 
1121 		edev->cables = kcalloc(edev->max_supported,
1122 				       sizeof(struct extcon_cable),
1123 				       GFP_KERNEL);
1124 		if (!edev->cables) {
1125 			ret = -ENOMEM;
1126 			goto err_sysfs_alloc;
1127 		}
1128 		for (index = 0; index < edev->max_supported; index++) {
1129 			cable = &edev->cables[index];
1130 
1131 			str = kasprintf(GFP_KERNEL, "cable.%d", index);
1132 			if (!str) {
1133 				for (index--; index >= 0; index--) {
1134 					cable = &edev->cables[index];
1135 					kfree(cable->attr_g.name);
1136 				}
1137 				ret = -ENOMEM;
1138 
1139 				goto err_alloc_cables;
1140 			}
1141 
1142 			cable->edev = edev;
1143 			cable->cable_index = index;
1144 			cable->attrs[0] = &cable->attr_name.attr;
1145 			cable->attrs[1] = &cable->attr_state.attr;
1146 			cable->attrs[2] = NULL;
1147 			cable->attr_g.name = str;
1148 			cable->attr_g.attrs = cable->attrs;
1149 
1150 			sysfs_attr_init(&cable->attr_name.attr);
1151 			cable->attr_name.attr.name = "name";
1152 			cable->attr_name.attr.mode = 0444;
1153 			cable->attr_name.show = cable_name_show;
1154 
1155 			sysfs_attr_init(&cable->attr_state.attr);
1156 			cable->attr_state.attr.name = "state";
1157 			cable->attr_state.attr.mode = 0444;
1158 			cable->attr_state.show = cable_state_show;
1159 		}
1160 	}
1161 
1162 	if (edev->max_supported && edev->mutually_exclusive) {
1163 		char *name;
1164 
1165 		/* Count the size of mutually_exclusive array */
1166 		for (index = 0; edev->mutually_exclusive[index]; index++)
1167 			;
1168 
1169 		edev->attrs_muex = kcalloc(index + 1,
1170 					   sizeof(struct attribute *),
1171 					   GFP_KERNEL);
1172 		if (!edev->attrs_muex) {
1173 			ret = -ENOMEM;
1174 			goto err_muex;
1175 		}
1176 
1177 		edev->d_attrs_muex = kcalloc(index,
1178 					     sizeof(struct device_attribute),
1179 					     GFP_KERNEL);
1180 		if (!edev->d_attrs_muex) {
1181 			ret = -ENOMEM;
1182 			kfree(edev->attrs_muex);
1183 			goto err_muex;
1184 		}
1185 
1186 		for (index = 0; edev->mutually_exclusive[index]; index++) {
1187 			name = kasprintf(GFP_KERNEL, "0x%x",
1188 					 edev->mutually_exclusive[index]);
1189 			if (!name) {
1190 				for (index--; index >= 0; index--) {
1191 					kfree(edev->d_attrs_muex[index].attr.
1192 					      name);
1193 				}
1194 				kfree(edev->d_attrs_muex);
1195 				kfree(edev->attrs_muex);
1196 				ret = -ENOMEM;
1197 				goto err_muex;
1198 			}
1199 			sysfs_attr_init(&edev->d_attrs_muex[index].attr);
1200 			edev->d_attrs_muex[index].attr.name = name;
1201 			edev->d_attrs_muex[index].attr.mode = 0000;
1202 			edev->attrs_muex[index] = &edev->d_attrs_muex[index]
1203 							.attr;
1204 		}
1205 		edev->attr_g_muex.name = muex_name;
1206 		edev->attr_g_muex.attrs = edev->attrs_muex;
1207 
1208 	}
1209 
1210 	if (edev->max_supported) {
1211 		edev->extcon_dev_type.groups =
1212 			kcalloc(edev->max_supported + 2,
1213 				sizeof(struct attribute_group *),
1214 				GFP_KERNEL);
1215 		if (!edev->extcon_dev_type.groups) {
1216 			ret = -ENOMEM;
1217 			goto err_alloc_groups;
1218 		}
1219 
1220 		edev->extcon_dev_type.name = dev_name(&edev->dev);
1221 		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
1222 
1223 		for (index = 0; index < edev->max_supported; index++)
1224 			edev->extcon_dev_type.groups[index] =
1225 				&edev->cables[index].attr_g;
1226 		if (edev->mutually_exclusive)
1227 			edev->extcon_dev_type.groups[index] =
1228 				&edev->attr_g_muex;
1229 
1230 		edev->dev.type = &edev->extcon_dev_type;
1231 	}
1232 
1233 	ret = device_register(&edev->dev);
1234 	if (ret) {
1235 		put_device(&edev->dev);
1236 		goto err_dev;
1237 	}
1238 
1239 	spin_lock_init(&edev->lock);
1240 	edev->nh = devm_kcalloc(&edev->dev, edev->max_supported,
1241 				sizeof(*edev->nh), GFP_KERNEL);
1242 	if (!edev->nh) {
1243 		ret = -ENOMEM;
1244 		goto err_dev;
1245 	}
1246 
1247 	for (index = 0; index < edev->max_supported; index++)
1248 		RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
1249 
1250 	RAW_INIT_NOTIFIER_HEAD(&edev->nh_all);
1251 
1252 	dev_set_drvdata(&edev->dev, edev);
1253 	edev->state = 0;
1254 
1255 	mutex_lock(&extcon_dev_list_lock);
1256 	list_add(&edev->entry, &extcon_dev_list);
1257 	mutex_unlock(&extcon_dev_list_lock);
1258 
1259 	return 0;
1260 
1261 err_dev:
1262 	if (edev->max_supported)
1263 		kfree(edev->extcon_dev_type.groups);
1264 err_alloc_groups:
1265 	if (edev->max_supported && edev->mutually_exclusive) {
1266 		for (index = 0; edev->mutually_exclusive[index]; index++)
1267 			kfree(edev->d_attrs_muex[index].attr.name);
1268 		kfree(edev->d_attrs_muex);
1269 		kfree(edev->attrs_muex);
1270 	}
1271 err_muex:
1272 	for (index = 0; index < edev->max_supported; index++)
1273 		kfree(edev->cables[index].attr_g.name);
1274 err_alloc_cables:
1275 	if (edev->max_supported)
1276 		kfree(edev->cables);
1277 err_sysfs_alloc:
1278 	return ret;
1279 }
1280 EXPORT_SYMBOL_GPL(extcon_dev_register);
1281 
1282 /**
1283  * extcon_dev_unregister() - Unregister the extcon device.
1284  * @edev:	the extcon device to be unregistered.
1285  *
1286  * Note that this does not call kfree(edev) because edev was not allocated
1287  * by this class.
1288  */
1289 void extcon_dev_unregister(struct extcon_dev *edev)
1290 {
1291 	int index;
1292 
1293 	if (!edev)
1294 		return;
1295 
1296 	mutex_lock(&extcon_dev_list_lock);
1297 	list_del(&edev->entry);
1298 	mutex_unlock(&extcon_dev_list_lock);
1299 
1300 	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
1301 		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
1302 				dev_name(&edev->dev));
1303 		return;
1304 	}
1305 
1306 	device_unregister(&edev->dev);
1307 
1308 	if (edev->mutually_exclusive && edev->max_supported) {
1309 		for (index = 0; edev->mutually_exclusive[index];
1310 				index++)
1311 			kfree(edev->d_attrs_muex[index].attr.name);
1312 		kfree(edev->d_attrs_muex);
1313 		kfree(edev->attrs_muex);
1314 	}
1315 
1316 	for (index = 0; index < edev->max_supported; index++)
1317 		kfree(edev->cables[index].attr_g.name);
1318 
1319 	if (edev->max_supported) {
1320 		kfree(edev->extcon_dev_type.groups);
1321 		kfree(edev->cables);
1322 	}
1323 
1324 	put_device(&edev->dev);
1325 }
1326 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
1327 
1328 #ifdef CONFIG_OF
1329 
1330 /*
1331  * extcon_find_edev_by_node - Find the extcon device from devicetree.
1332  * @node	: OF node identifying edev
1333  *
1334  * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
1335  */
1336 struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
1337 {
1338 	struct extcon_dev *edev;
1339 
1340 	mutex_lock(&extcon_dev_list_lock);
1341 	list_for_each_entry(edev, &extcon_dev_list, entry)
1342 		if (edev->dev.parent && edev->dev.parent->of_node == node)
1343 			goto out;
1344 	edev = ERR_PTR(-EPROBE_DEFER);
1345 out:
1346 	mutex_unlock(&extcon_dev_list_lock);
1347 
1348 	return edev;
1349 }
1350 
1351 /*
1352  * extcon_get_edev_by_phandle - Get the extcon device from devicetree.
1353  * @dev		: the instance to the given device
1354  * @index	: the index into list of extcon_dev
1355  *
1356  * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
1357  */
1358 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1359 {
1360 	struct device_node *node;
1361 	struct extcon_dev *edev;
1362 
1363 	if (!dev)
1364 		return ERR_PTR(-EINVAL);
1365 
1366 	if (!dev->of_node) {
1367 		dev_dbg(dev, "device does not have a device node entry\n");
1368 		return ERR_PTR(-EINVAL);
1369 	}
1370 
1371 	node = of_parse_phandle(dev->of_node, "extcon", index);
1372 	if (!node) {
1373 		dev_dbg(dev, "failed to get phandle in %pOF node\n",
1374 			dev->of_node);
1375 		return ERR_PTR(-ENODEV);
1376 	}
1377 
1378 	edev = extcon_find_edev_by_node(node);
1379 	of_node_put(node);
1380 
1381 	return edev;
1382 }
1383 
1384 #else
1385 
1386 struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
1387 {
1388 	return ERR_PTR(-ENOSYS);
1389 }
1390 
1391 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1392 {
1393 	return ERR_PTR(-ENOSYS);
1394 }
1395 
1396 #endif /* CONFIG_OF */
1397 
1398 EXPORT_SYMBOL_GPL(extcon_find_edev_by_node);
1399 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1400 
1401 /**
1402  * extcon_get_edev_name() - Get the name of the extcon device.
1403  * @edev:	the extcon device
1404  */
1405 const char *extcon_get_edev_name(struct extcon_dev *edev)
1406 {
1407 	return !edev ? NULL : edev->name;
1408 }
1409 
1410 static int __init extcon_class_init(void)
1411 {
1412 	return create_extcon_class();
1413 }
1414 module_init(extcon_class_init);
1415 
1416 static void __exit extcon_class_exit(void)
1417 {
1418 	class_destroy(extcon_class);
1419 }
1420 module_exit(extcon_class_exit);
1421 
1422 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1423 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1424 MODULE_DESCRIPTION("External Connector (extcon) framework");
1425 MODULE_LICENSE("GPL v2");
1426