xref: /linux/drivers/extcon/extcon.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  *  drivers/extcon/extcon.c - External Connector (extcon) framework.
3  *
4  *  External connector (extcon) class driver
5  *
6  * Copyright (C) 2015 Samsung Electronics
7  * Author: Chanwoo Choi <cw00.choi@samsung.com>
8  *
9  * Copyright (C) 2012 Samsung Electronics
10  * Author: Donggeun Kim <dg77.kim@samsung.com>
11  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
12  *
13  * based on android/drivers/switch/switch_class.c
14  * Copyright (C) 2008 Google, Inc.
15  * Author: Mike Lockwood <lockwood@android.com>
16  *
17  * This software is licensed under the terms of the GNU General Public
18  * License version 2, as published by the Free Software Foundation, and
19  * may be copied, distributed, and modified under those terms.
20  *
21  * This program is distributed in the hope that it will be useful,
22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24  * GNU General Public License for more details.
25  */
26 
27 #include <linux/module.h>
28 #include <linux/types.h>
29 #include <linux/init.h>
30 #include <linux/device.h>
31 #include <linux/fs.h>
32 #include <linux/err.h>
33 #include <linux/of.h>
34 #include <linux/slab.h>
35 #include <linux/sysfs.h>
36 
37 #include "extcon.h"
38 
39 #define SUPPORTED_CABLE_MAX	32
40 #define CABLE_NAME_MAX		30
41 
42 struct __extcon_info {
43 	unsigned int type;
44 	unsigned int id;
45 	const char *name;
46 
47 } extcon_info[] = {
48 	[EXTCON_NONE] = {
49 		.type = EXTCON_TYPE_MISC,
50 		.id = EXTCON_NONE,
51 		.name = "NONE",
52 	},
53 
54 	/* USB external connector */
55 	[EXTCON_USB] = {
56 		.type = EXTCON_TYPE_USB,
57 		.id = EXTCON_USB,
58 		.name = "USB",
59 	},
60 	[EXTCON_USB_HOST] = {
61 		.type = EXTCON_TYPE_USB,
62 		.id = EXTCON_USB_HOST,
63 		.name = "USB-HOST",
64 	},
65 
66 	/* Charging external connector */
67 	[EXTCON_CHG_USB_SDP] = {
68 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
69 		.id = EXTCON_CHG_USB_SDP,
70 		.name = "SDP",
71 	},
72 	[EXTCON_CHG_USB_DCP] = {
73 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
74 		.id = EXTCON_CHG_USB_DCP,
75 		.name = "DCP",
76 	},
77 	[EXTCON_CHG_USB_CDP] = {
78 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
79 		.id = EXTCON_CHG_USB_CDP,
80 		.name = "CDP",
81 	},
82 	[EXTCON_CHG_USB_ACA] = {
83 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
84 		.id = EXTCON_CHG_USB_ACA,
85 		.name = "ACA",
86 	},
87 	[EXTCON_CHG_USB_FAST] = {
88 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
89 		.id = EXTCON_CHG_USB_FAST,
90 		.name = "FAST-CHARGER",
91 	},
92 	[EXTCON_CHG_USB_SLOW] = {
93 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
94 		.id = EXTCON_CHG_USB_SLOW,
95 		.name = "SLOW-CHARGER",
96 	},
97 	[EXTCON_CHG_WPT] = {
98 		.type = EXTCON_TYPE_CHG,
99 		.id = EXTCON_CHG_WPT,
100 		.name = "WPT",
101 	},
102 	[EXTCON_CHG_USB_PD] = {
103 		.type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
104 		.id = EXTCON_CHG_USB_PD,
105 		.name = "PD",
106 	},
107 
108 	/* Jack external connector */
109 	[EXTCON_JACK_MICROPHONE] = {
110 		.type = EXTCON_TYPE_JACK,
111 		.id = EXTCON_JACK_MICROPHONE,
112 		.name = "MICROPHONE",
113 	},
114 	[EXTCON_JACK_HEADPHONE] = {
115 		.type = EXTCON_TYPE_JACK,
116 		.id = EXTCON_JACK_HEADPHONE,
117 		.name = "HEADPHONE",
118 	},
119 	[EXTCON_JACK_LINE_IN] = {
120 		.type = EXTCON_TYPE_JACK,
121 		.id = EXTCON_JACK_LINE_IN,
122 		.name = "LINE-IN",
123 	},
124 	[EXTCON_JACK_LINE_OUT] = {
125 		.type = EXTCON_TYPE_JACK,
126 		.id = EXTCON_JACK_LINE_OUT,
127 		.name = "LINE-OUT",
128 	},
129 	[EXTCON_JACK_VIDEO_IN] = {
130 		.type = EXTCON_TYPE_JACK,
131 		.id = EXTCON_JACK_VIDEO_IN,
132 		.name = "VIDEO-IN",
133 	},
134 	[EXTCON_JACK_VIDEO_OUT] = {
135 		.type = EXTCON_TYPE_JACK,
136 		.id = EXTCON_JACK_VIDEO_OUT,
137 		.name = "VIDEO-OUT",
138 	},
139 	[EXTCON_JACK_SPDIF_IN] = {
140 		.type = EXTCON_TYPE_JACK,
141 		.id = EXTCON_JACK_SPDIF_IN,
142 		.name = "SPDIF-IN",
143 	},
144 	[EXTCON_JACK_SPDIF_OUT] = {
145 		.type = EXTCON_TYPE_JACK,
146 		.id = EXTCON_JACK_SPDIF_OUT,
147 		.name = "SPDIF-OUT",
148 	},
149 
150 	/* Display external connector */
151 	[EXTCON_DISP_HDMI] = {
152 		.type = EXTCON_TYPE_DISP,
153 		.id = EXTCON_DISP_HDMI,
154 		.name = "HDMI",
155 	},
156 	[EXTCON_DISP_MHL] = {
157 		.type = EXTCON_TYPE_DISP,
158 		.id = EXTCON_DISP_MHL,
159 		.name = "MHL",
160 	},
161 	[EXTCON_DISP_DVI] = {
162 		.type = EXTCON_TYPE_DISP,
163 		.id = EXTCON_DISP_DVI,
164 		.name = "DVI",
165 	},
166 	[EXTCON_DISP_VGA] = {
167 		.type = EXTCON_TYPE_DISP,
168 		.id = EXTCON_DISP_VGA,
169 		.name = "VGA",
170 	},
171 	[EXTCON_DISP_DP] = {
172 		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
173 		.id = EXTCON_DISP_DP,
174 		.name = "DP",
175 	},
176 	[EXTCON_DISP_HMD] = {
177 		.type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
178 		.id = EXTCON_DISP_HMD,
179 		.name = "HMD",
180 	},
181 
182 	/* Miscellaneous external connector */
183 	[EXTCON_DOCK] = {
184 		.type = EXTCON_TYPE_MISC,
185 		.id = EXTCON_DOCK,
186 		.name = "DOCK",
187 	},
188 	[EXTCON_JIG] = {
189 		.type = EXTCON_TYPE_MISC,
190 		.id = EXTCON_JIG,
191 		.name = "JIG",
192 	},
193 	[EXTCON_MECHANICAL] = {
194 		.type = EXTCON_TYPE_MISC,
195 		.id = EXTCON_MECHANICAL,
196 		.name = "MECHANICAL",
197 	},
198 
199 	{ /* sentinel */ }
200 };
201 
202 /**
203  * struct extcon_cable - An internal data for each cable of extcon device.
204  * @edev:		The extcon device
205  * @cable_index:	Index of this cable in the edev
206  * @attr_g:		Attribute group for the cable
207  * @attr_name:		"name" sysfs entry
208  * @attr_state:		"state" sysfs entry
209  * @attrs:		Array pointing to attr_name and attr_state for attr_g
210  */
211 struct extcon_cable {
212 	struct extcon_dev *edev;
213 	int cable_index;
214 
215 	struct attribute_group attr_g;
216 	struct device_attribute attr_name;
217 	struct device_attribute attr_state;
218 
219 	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
220 
221 	union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
222 	union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
223 	union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
224 	union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];
225 
226 	unsigned long usb_bits[BITS_TO_LONGS(EXTCON_PROP_USB_CNT)];
227 	unsigned long chg_bits[BITS_TO_LONGS(EXTCON_PROP_CHG_CNT)];
228 	unsigned long jack_bits[BITS_TO_LONGS(EXTCON_PROP_JACK_CNT)];
229 	unsigned long disp_bits[BITS_TO_LONGS(EXTCON_PROP_DISP_CNT)];
230 };
231 
232 static struct class *extcon_class;
233 #if defined(CONFIG_ANDROID)
234 static struct class_compat *switch_class;
235 #endif /* CONFIG_ANDROID */
236 
237 static LIST_HEAD(extcon_dev_list);
238 static DEFINE_MUTEX(extcon_dev_list_lock);
239 
240 /**
241  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
242  *			      condition.
243  * @edev:	the extcon device
244  * @new_state:	new cable attach status for @edev
245  *
246  * Returns 0 if nothing violates. Returns the index + 1 for the first
247  * violated condition.
248  */
249 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
250 {
251 	int i = 0;
252 
253 	if (!edev->mutually_exclusive)
254 		return 0;
255 
256 	for (i = 0; edev->mutually_exclusive[i]; i++) {
257 		int weight;
258 		u32 correspondants = new_state & edev->mutually_exclusive[i];
259 
260 		/* calculate the total number of bits set */
261 		weight = hweight32(correspondants);
262 		if (weight > 1)
263 			return i + 1;
264 	}
265 
266 	return 0;
267 }
268 
269 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
270 {
271 	int i;
272 
273 	/* Find the the index of extcon cable in edev->supported_cable */
274 	for (i = 0; i < edev->max_supported; i++) {
275 		if (edev->supported_cable[i] == id)
276 			return i;
277 	}
278 
279 	return -EINVAL;
280 }
281 
282 static int get_extcon_type(unsigned int prop)
283 {
284 	switch (prop) {
285 	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
286 		return EXTCON_TYPE_USB;
287 	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
288 		return EXTCON_TYPE_CHG;
289 	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
290 		return EXTCON_TYPE_JACK;
291 	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
292 		return EXTCON_TYPE_DISP;
293 	default:
294 		return -EINVAL;
295 	}
296 }
297 
298 static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
299 {
300 	return !!(edev->state & BIT(index));
301 }
302 
303 static bool is_extcon_changed(struct extcon_dev *edev, int index,
304 				bool new_state)
305 {
306 	int state = !!(edev->state & BIT(index));
307 	return (state != new_state);
308 }
309 
310 static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
311 {
312 	int type;
313 
314 	/* Check whether the property is supported or not. */
315 	type = get_extcon_type(prop);
316 	if (type < 0)
317 		return false;
318 
319 	/* Check whether a specific extcon id supports the property or not. */
320 	return !!(extcon_info[id].type & type);
321 }
322 
323 static int is_extcon_property_capability(struct extcon_dev *edev,
324 				unsigned int id, int index,unsigned int prop)
325 {
326 	struct extcon_cable *cable;
327 	int type, ret;
328 
329 	/* Check whether the property is supported or not. */
330 	type = get_extcon_type(prop);
331 	if (type < 0)
332 		return type;
333 
334 	cable = &edev->cables[index];
335 
336 	switch (type) {
337 	case EXTCON_TYPE_USB:
338 		ret = test_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
339 		break;
340 	case EXTCON_TYPE_CHG:
341 		ret = test_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
342 		break;
343 	case EXTCON_TYPE_JACK:
344 		ret = test_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
345 		break;
346 	case EXTCON_TYPE_DISP:
347 		ret = test_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
348 		break;
349 	default:
350 		ret = -EINVAL;
351 	}
352 
353 	return ret;
354 }
355 
356 static void init_property(struct extcon_dev *edev, unsigned int id, int index)
357 {
358 	unsigned int type = extcon_info[id].type;
359 	struct extcon_cable *cable = &edev->cables[index];
360 
361 	if (EXTCON_TYPE_USB & type)
362 		memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
363 	if (EXTCON_TYPE_CHG & type)
364 		memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
365 	if (EXTCON_TYPE_JACK & type)
366 		memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
367 	if (EXTCON_TYPE_DISP & type)
368 		memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
369 }
370 
371 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
372 			  char *buf)
373 {
374 	int i, count = 0;
375 	struct extcon_dev *edev = dev_get_drvdata(dev);
376 
377 	if (edev->max_supported == 0)
378 		return sprintf(buf, "%u\n", edev->state);
379 
380 	for (i = 0; i < edev->max_supported; i++) {
381 		count += sprintf(buf + count, "%s=%d\n",
382 				extcon_info[edev->supported_cable[i]].name,
383 				 !!(edev->state & (1 << i)));
384 	}
385 
386 	return count;
387 }
388 static DEVICE_ATTR_RO(state);
389 
390 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
391 		char *buf)
392 {
393 	struct extcon_dev *edev = dev_get_drvdata(dev);
394 
395 	return sprintf(buf, "%s\n", edev->name);
396 }
397 static DEVICE_ATTR_RO(name);
398 
399 static ssize_t cable_name_show(struct device *dev,
400 			       struct device_attribute *attr, char *buf)
401 {
402 	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
403 						  attr_name);
404 	int i = cable->cable_index;
405 
406 	return sprintf(buf, "%s\n",
407 			extcon_info[cable->edev->supported_cable[i]].name);
408 }
409 
410 static ssize_t cable_state_show(struct device *dev,
411 				struct device_attribute *attr, char *buf)
412 {
413 	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
414 						  attr_state);
415 
416 	int i = cable->cable_index;
417 
418 	return sprintf(buf, "%d\n",
419 		extcon_get_state(cable->edev, cable->edev->supported_cable[i]));
420 }
421 
422 /**
423  * extcon_sync()	- Synchronize the states for both the attached/detached
424  * @edev:		the extcon device that has the cable.
425  *
426  * This function send a notification to synchronize the all states of a
427  * specific external connector
428  */
429 int extcon_sync(struct extcon_dev *edev, unsigned int id)
430 {
431 	char name_buf[120];
432 	char state_buf[120];
433 	char *prop_buf;
434 	char *envp[3];
435 	int env_offset = 0;
436 	int length;
437 	int index;
438 	int state;
439 	unsigned long flags;
440 
441 	if (!edev)
442 		return -EINVAL;
443 
444 	index = find_cable_index_by_id(edev, id);
445 	if (index < 0)
446 		return index;
447 
448 	spin_lock_irqsave(&edev->lock, flags);
449 
450 	state = !!(edev->state & BIT(index));
451 	raw_notifier_call_chain(&edev->nh[index], state, edev);
452 
453 	/* This could be in interrupt handler */
454 	prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
455 	if (!prop_buf) {
456 		/* Unlock early before uevent */
457 		spin_unlock_irqrestore(&edev->lock, flags);
458 
459 		dev_err(&edev->dev, "out of memory in extcon_set_state\n");
460 		kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
461 
462 		return -ENOMEM;
463 	}
464 
465 	length = name_show(&edev->dev, NULL, prop_buf);
466 	if (length > 0) {
467 		if (prop_buf[length - 1] == '\n')
468 			prop_buf[length - 1] = 0;
469 		snprintf(name_buf, sizeof(name_buf), "NAME=%s", prop_buf);
470 		envp[env_offset++] = name_buf;
471 	}
472 
473 	length = state_show(&edev->dev, NULL, prop_buf);
474 	if (length > 0) {
475 		if (prop_buf[length - 1] == '\n')
476 			prop_buf[length - 1] = 0;
477 		snprintf(state_buf, sizeof(state_buf), "STATE=%s", prop_buf);
478 		envp[env_offset++] = state_buf;
479 	}
480 	envp[env_offset] = NULL;
481 
482 	/* Unlock early before uevent */
483 	spin_unlock_irqrestore(&edev->lock, flags);
484 	kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
485 	free_page((unsigned long)prop_buf);
486 
487 	return 0;
488 }
489 EXPORT_SYMBOL_GPL(extcon_sync);
490 
491 /**
492  * extcon_get_state() - Get the state of a external connector.
493  * @edev:	the extcon device that has the cable.
494  * @id:		the unique id of each external connector in extcon enumeration.
495  */
496 int extcon_get_state(struct extcon_dev *edev, const unsigned int id)
497 {
498 	int index, state;
499 	unsigned long flags;
500 
501 	if (!edev)
502 		return -EINVAL;
503 
504 	index = find_cable_index_by_id(edev, id);
505 	if (index < 0)
506 		return index;
507 
508 	spin_lock_irqsave(&edev->lock, flags);
509 	state = is_extcon_attached(edev, index);
510 	spin_unlock_irqrestore(&edev->lock, flags);
511 
512 	return state;
513 }
514 EXPORT_SYMBOL_GPL(extcon_get_state);
515 
516 /**
517  * extcon_set_state() - Set the state of a external connector.
518  *			without a notification.
519  * @edev:		the extcon device that has the cable.
520  * @id:			the unique id of each external connector
521  *			in extcon enumeration.
522  * @state:		the new cable status. The default semantics is
523  *			true: attached / false: detached.
524  *
525  * This function only set the state of a external connector without
526  * a notification. To synchronize the data of a external connector,
527  * use extcon_set_state_sync() and extcon_sync().
528  */
529 int extcon_set_state(struct extcon_dev *edev, unsigned int id,
530 				bool cable_state)
531 {
532 	unsigned long flags;
533 	int index, ret = 0;
534 
535 	if (!edev)
536 		return -EINVAL;
537 
538 	index = find_cable_index_by_id(edev, id);
539 	if (index < 0)
540 		return index;
541 
542 	spin_lock_irqsave(&edev->lock, flags);
543 
544 	/* Check whether the external connector's state is changed. */
545 	if (!is_extcon_changed(edev, index, cable_state))
546 		goto out;
547 
548 	if (check_mutually_exclusive(edev,
549 		(edev->state & ~BIT(index)) | (cable_state & BIT(index)))) {
550 		ret = -EPERM;
551 		goto out;
552 	}
553 
554 	/*
555 	 * Initialize the value of extcon property before setting
556 	 * the detached state for an external connector.
557 	 */
558 	if (!cable_state)
559 		init_property(edev, id, index);
560 
561 	/* Update the state for a external connector. */
562 	if (cable_state)
563 		edev->state |= BIT(index);
564 	else
565 		edev->state &= ~(BIT(index));
566 out:
567 	spin_unlock_irqrestore(&edev->lock, flags);
568 
569 	return ret;
570 }
571 EXPORT_SYMBOL_GPL(extcon_set_state);
572 
573 /**
574  * extcon_set_state_sync() - Set the state of a external connector
575  *			with a notification.
576  * @edev:		the extcon device that has the cable.
577  * @id:			the unique id of each external connector
578  *			in extcon enumeration.
579  * @state:		the new cable status. The default semantics is
580  *			true: attached / false: detached.
581  *
582  * This function set the state of external connector and synchronize the data
583  * by usning a notification.
584  */
585 int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id,
586 				bool cable_state)
587 {
588 	int ret, index;
589 	unsigned long flags;
590 
591 	index = find_cable_index_by_id(edev, id);
592 	if (index < 0)
593 		return index;
594 
595 	/* Check whether the external connector's state is changed. */
596 	spin_lock_irqsave(&edev->lock, flags);
597 	ret = is_extcon_changed(edev, index, cable_state);
598 	spin_unlock_irqrestore(&edev->lock, flags);
599 	if (!ret)
600 		return 0;
601 
602 	ret = extcon_set_state(edev, id, cable_state);
603 	if (ret < 0)
604 		return ret;
605 
606 	return extcon_sync(edev, id);
607 }
608 EXPORT_SYMBOL_GPL(extcon_set_state_sync);
609 
610 /**
611  * extcon_get_property() - Get the property value of a specific cable.
612  * @edev:		the extcon device that has the cable.
613  * @id:			the unique id of each external connector
614  *			in extcon enumeration.
615  * @prop:		the property id among enum extcon_property.
616  * @prop_val:		the pointer which store the value of property.
617  *
618  * When getting the property value of external connector, the external connector
619  * should be attached. If detached state, function just return 0 without
620  * property value. Also, the each property should be included in the list of
621  * supported properties according to the type of external connectors.
622  *
623  * Returns 0 if success or error number if fail
624  */
625 int extcon_get_property(struct extcon_dev *edev, unsigned int id,
626 				unsigned int prop,
627 				union extcon_property_value *prop_val)
628 {
629 	struct extcon_cable *cable;
630 	unsigned long flags;
631 	int index, ret = 0;
632 
633 	*prop_val = (union extcon_property_value)(0);
634 
635 	if (!edev)
636 		return -EINVAL;
637 
638 	/* Check whether the property is supported or not */
639 	if (!is_extcon_property_supported(id, prop))
640 		return -EINVAL;
641 
642 	/* Find the cable index of external connector by using id */
643 	index = find_cable_index_by_id(edev, id);
644 	if (index < 0)
645 		return index;
646 
647 	spin_lock_irqsave(&edev->lock, flags);
648 
649 	/* Check whether the property is available or not. */
650 	if (!is_extcon_property_capability(edev, id, index, prop)) {
651 		spin_unlock_irqrestore(&edev->lock, flags);
652 		return -EPERM;
653 	}
654 
655 	/*
656 	 * Check whether the external connector is attached.
657 	 * If external connector is detached, the user can not
658 	 * get the property value.
659 	 */
660 	if (!is_extcon_attached(edev, index)) {
661 		spin_unlock_irqrestore(&edev->lock, flags);
662 		return 0;
663 	}
664 
665 	cable = &edev->cables[index];
666 
667 	/* Get the property value according to extcon type */
668 	switch (prop) {
669 	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
670 		*prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
671 		break;
672 	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
673 		*prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
674 		break;
675 	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
676 		*prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
677 		break;
678 	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
679 		*prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
680 		break;
681 	default:
682 		ret = -EINVAL;
683 		break;
684 	}
685 
686 	spin_unlock_irqrestore(&edev->lock, flags);
687 
688 	return ret;
689 }
690 EXPORT_SYMBOL_GPL(extcon_get_property);
691 
692 /**
693  * extcon_set_property() - Set the property value of a specific cable.
694  * @edev:		the extcon device that has the cable.
695  * @id:			the unique id of each external connector
696  *			in extcon enumeration.
697  * @prop:		the property id among enum extcon_property.
698  * @prop_val:		the pointer including the new value of property.
699  *
700  * The each property should be included in the list of supported properties
701  * according to the type of external connectors.
702  *
703  * Returns 0 if success or error number if fail
704  */
705 int extcon_set_property(struct extcon_dev *edev, unsigned int id,
706 				unsigned int prop,
707 				union extcon_property_value prop_val)
708 {
709 	struct extcon_cable *cable;
710 	unsigned long flags;
711 	int index, ret = 0;
712 
713 	if (!edev)
714 		return -EINVAL;
715 
716 	/* Check whether the property is supported or not */
717 	if (!is_extcon_property_supported(id, prop))
718 		return -EINVAL;
719 
720 	/* Find the cable index of external connector by using id */
721 	index = find_cable_index_by_id(edev, id);
722 	if (index < 0)
723 		return index;
724 
725 	spin_lock_irqsave(&edev->lock, flags);
726 
727 	/* Check whether the property is available or not. */
728 	if (!is_extcon_property_capability(edev, id, index, prop)) {
729 		spin_unlock_irqrestore(&edev->lock, flags);
730 		return -EPERM;
731 	}
732 
733 	cable = &edev->cables[index];
734 
735 	/* Set the property value according to extcon type */
736 	switch (prop) {
737 	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
738 		cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
739 		break;
740 	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
741 		cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
742 		break;
743 	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
744 		cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
745 		break;
746 	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
747 		cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
748 		break;
749 	default:
750 		ret = -EINVAL;
751 		break;
752 	}
753 
754 	spin_unlock_irqrestore(&edev->lock, flags);
755 
756 	return ret;
757 }
758 EXPORT_SYMBOL_GPL(extcon_set_property);
759 
760 /**
761  * extcon_set_property_sync() - Set the property value of a specific cable
762 			with a notification.
763  * @prop_val:		the pointer including the new value of property.
764  *
765  * When setting the property value of external connector, the external connector
766  * should be attached. The each property should be included in the list of
767  * supported properties according to the type of external connectors.
768  *
769  * Returns 0 if success or error number if fail
770  */
771 int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
772 				unsigned int prop,
773 				union extcon_property_value prop_val)
774 {
775 	int ret;
776 
777 	ret = extcon_set_property(edev, id, prop, prop_val);
778 	if (ret < 0)
779 		return ret;
780 
781 	return extcon_sync(edev, id);
782 }
783 EXPORT_SYMBOL_GPL(extcon_set_property_sync);
784 
785 /**
786  * extcon_get_property_capability() - Get the capability of property
787  *			of an external connector.
788  * @edev:		the extcon device that has the cable.
789  * @id:			the unique id of each external connector
790  *			in extcon enumeration.
791  * @prop:		the property id among enum extcon_property.
792  *
793  * Returns 1 if the property is available or 0 if not available.
794  */
795 int extcon_get_property_capability(struct extcon_dev *edev, unsigned int id,
796 					unsigned int prop)
797 {
798 	int index;
799 
800 	if (!edev)
801 		return -EINVAL;
802 
803 	/* Check whether the property is supported or not */
804 	if (!is_extcon_property_supported(id, prop))
805 		return -EINVAL;
806 
807 	/* Find the cable index of external connector by using id */
808 	index = find_cable_index_by_id(edev, id);
809 	if (index < 0)
810 		return index;
811 
812 	return is_extcon_property_capability(edev, id, index, prop);
813 }
814 EXPORT_SYMBOL_GPL(extcon_get_property_capability);
815 
816 /**
817  * extcon_set_property_capability() - Set the capability of a property
818  *			of an external connector.
819  * @edev:		the extcon device that has the cable.
820  * @id:			the unique id of each external connector
821  *			in extcon enumeration.
822  * @prop:		the property id among enum extcon_property.
823  *
824  * This function set the capability of a property for an external connector
825  * to mark the bit in capability bitmap which mean the available state of
826  * a property.
827  *
828  * Returns 0 if success or error number if fail
829  */
830 int extcon_set_property_capability(struct extcon_dev *edev, unsigned int id,
831 					unsigned int prop)
832 {
833 	struct extcon_cable *cable;
834 	int index, type, ret = 0;
835 
836 	if (!edev)
837 		return -EINVAL;
838 
839 	/* Check whether the property is supported or not. */
840 	if (!is_extcon_property_supported(id, prop))
841 		return -EINVAL;
842 
843 	/* Find the cable index of external connector by using id. */
844 	index = find_cable_index_by_id(edev, id);
845 	if (index < 0)
846 		return index;
847 
848 	type = get_extcon_type(prop);
849 	if (type < 0)
850 		return type;
851 
852 	cable = &edev->cables[index];
853 
854 	switch (type) {
855 	case EXTCON_TYPE_USB:
856 		__set_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
857 		break;
858 	case EXTCON_TYPE_CHG:
859 		__set_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
860 		break;
861 	case EXTCON_TYPE_JACK:
862 		__set_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
863 		break;
864 	case EXTCON_TYPE_DISP:
865 		__set_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
866 		break;
867 	default:
868 		ret = -EINVAL;
869 	}
870 
871 	return ret;
872 }
873 EXPORT_SYMBOL_GPL(extcon_set_property_capability);
874 
875 /**
876  * extcon_get_extcon_dev() - Get the extcon device instance from the name
877  * @extcon_name:	The extcon name provided with extcon_dev_register()
878  */
879 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
880 {
881 	struct extcon_dev *sd;
882 
883 	if (!extcon_name)
884 		return ERR_PTR(-EINVAL);
885 
886 	mutex_lock(&extcon_dev_list_lock);
887 	list_for_each_entry(sd, &extcon_dev_list, entry) {
888 		if (!strcmp(sd->name, extcon_name))
889 			goto out;
890 	}
891 	sd = NULL;
892 out:
893 	mutex_unlock(&extcon_dev_list_lock);
894 	return sd;
895 }
896 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
897 
898 /**
899  * extcon_register_notifier() - Register a notifiee to get notified by
900  *				any attach status changes from the extcon.
901  * @edev:	the extcon device that has the external connecotr.
902  * @id:		the unique id of each external connector in extcon enumeration.
903  * @nb:		a notifier block to be registered.
904  *
905  * Note that the second parameter given to the callback of nb (val) is
906  * "old_state", not the current state. The current state can be retrieved
907  * by looking at the third pameter (edev pointer)'s state value.
908  */
909 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
910 			     struct notifier_block *nb)
911 {
912 	unsigned long flags;
913 	int ret, idx = -EINVAL;
914 
915 	if (!edev || !nb)
916 		return -EINVAL;
917 
918 	idx = find_cable_index_by_id(edev, id);
919 	if (idx < 0)
920 		return idx;
921 
922 	spin_lock_irqsave(&edev->lock, flags);
923 	ret = raw_notifier_chain_register(&edev->nh[idx], nb);
924 	spin_unlock_irqrestore(&edev->lock, flags);
925 
926 	return ret;
927 }
928 EXPORT_SYMBOL_GPL(extcon_register_notifier);
929 
930 /**
931  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
932  * @edev:	the extcon device that has the external connecotr.
933  * @id:		the unique id of each external connector in extcon enumeration.
934  * @nb:		a notifier block to be registered.
935  */
936 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
937 				struct notifier_block *nb)
938 {
939 	unsigned long flags;
940 	int ret, idx;
941 
942 	if (!edev || !nb)
943 		return -EINVAL;
944 
945 	idx = find_cable_index_by_id(edev, id);
946 	if (idx < 0)
947 		return idx;
948 
949 	spin_lock_irqsave(&edev->lock, flags);
950 	ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
951 	spin_unlock_irqrestore(&edev->lock, flags);
952 
953 	return ret;
954 }
955 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
956 
957 static struct attribute *extcon_attrs[] = {
958 	&dev_attr_state.attr,
959 	&dev_attr_name.attr,
960 	NULL,
961 };
962 ATTRIBUTE_GROUPS(extcon);
963 
964 static int create_extcon_class(void)
965 {
966 	if (!extcon_class) {
967 		extcon_class = class_create(THIS_MODULE, "extcon");
968 		if (IS_ERR(extcon_class))
969 			return PTR_ERR(extcon_class);
970 		extcon_class->dev_groups = extcon_groups;
971 
972 #if defined(CONFIG_ANDROID)
973 		switch_class = class_compat_register("switch");
974 		if (WARN(!switch_class, "cannot allocate"))
975 			return -ENOMEM;
976 #endif /* CONFIG_ANDROID */
977 	}
978 
979 	return 0;
980 }
981 
982 static void extcon_dev_release(struct device *dev)
983 {
984 }
985 
986 static const char *muex_name = "mutually_exclusive";
987 static void dummy_sysfs_dev_release(struct device *dev)
988 {
989 }
990 
991 /*
992  * extcon_dev_allocate() - Allocate the memory of extcon device.
993  * @supported_cable:	Array of supported extcon ending with EXTCON_NONE.
994  *			If supported_cable is NULL, cable name related APIs
995  *			are disabled.
996  *
997  * This function allocates the memory for extcon device without allocating
998  * memory in each extcon provider driver and initialize default setting for
999  * extcon device.
1000  *
1001  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
1002  */
1003 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
1004 {
1005 	struct extcon_dev *edev;
1006 
1007 	if (!supported_cable)
1008 		return ERR_PTR(-EINVAL);
1009 
1010 	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
1011 	if (!edev)
1012 		return ERR_PTR(-ENOMEM);
1013 
1014 	edev->max_supported = 0;
1015 	edev->supported_cable = supported_cable;
1016 
1017 	return edev;
1018 }
1019 
1020 /*
1021  * extcon_dev_free() - Free the memory of extcon device.
1022  * @edev:	the extcon device to free
1023  */
1024 void extcon_dev_free(struct extcon_dev *edev)
1025 {
1026 	kfree(edev);
1027 }
1028 EXPORT_SYMBOL_GPL(extcon_dev_free);
1029 
1030 /**
1031  * extcon_dev_register() - Register a new extcon device
1032  * @edev	: the new extcon device (should be allocated before calling)
1033  *
1034  * Among the members of edev struct, please set the "user initializing data"
1035  * in any case and set the "optional callbacks" if required. However, please
1036  * do not set the values of "internal data", which are initialized by
1037  * this function.
1038  */
1039 int extcon_dev_register(struct extcon_dev *edev)
1040 {
1041 	int ret, index = 0;
1042 	static atomic_t edev_no = ATOMIC_INIT(-1);
1043 
1044 	if (!extcon_class) {
1045 		ret = create_extcon_class();
1046 		if (ret < 0)
1047 			return ret;
1048 	}
1049 
1050 	if (!edev || !edev->supported_cable)
1051 		return -EINVAL;
1052 
1053 	for (; edev->supported_cable[index] != EXTCON_NONE; index++);
1054 
1055 	edev->max_supported = index;
1056 	if (index > SUPPORTED_CABLE_MAX) {
1057 		dev_err(&edev->dev,
1058 			"exceed the maximum number of supported cables\n");
1059 		return -EINVAL;
1060 	}
1061 
1062 	edev->dev.class = extcon_class;
1063 	edev->dev.release = extcon_dev_release;
1064 
1065 	edev->name = dev_name(edev->dev.parent);
1066 	if (IS_ERR_OR_NULL(edev->name)) {
1067 		dev_err(&edev->dev,
1068 			"extcon device name is null\n");
1069 		return -EINVAL;
1070 	}
1071 	dev_set_name(&edev->dev, "extcon%lu",
1072 			(unsigned long)atomic_inc_return(&edev_no));
1073 
1074 	if (edev->max_supported) {
1075 		char buf[10];
1076 		char *str;
1077 		struct extcon_cable *cable;
1078 
1079 		edev->cables = kzalloc(sizeof(struct extcon_cable) *
1080 				       edev->max_supported, GFP_KERNEL);
1081 		if (!edev->cables) {
1082 			ret = -ENOMEM;
1083 			goto err_sysfs_alloc;
1084 		}
1085 		for (index = 0; index < edev->max_supported; index++) {
1086 			cable = &edev->cables[index];
1087 
1088 			snprintf(buf, 10, "cable.%d", index);
1089 			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
1090 				      GFP_KERNEL);
1091 			if (!str) {
1092 				for (index--; index >= 0; index--) {
1093 					cable = &edev->cables[index];
1094 					kfree(cable->attr_g.name);
1095 				}
1096 				ret = -ENOMEM;
1097 
1098 				goto err_alloc_cables;
1099 			}
1100 			strcpy(str, buf);
1101 
1102 			cable->edev = edev;
1103 			cable->cable_index = index;
1104 			cable->attrs[0] = &cable->attr_name.attr;
1105 			cable->attrs[1] = &cable->attr_state.attr;
1106 			cable->attrs[2] = NULL;
1107 			cable->attr_g.name = str;
1108 			cable->attr_g.attrs = cable->attrs;
1109 
1110 			sysfs_attr_init(&cable->attr_name.attr);
1111 			cable->attr_name.attr.name = "name";
1112 			cable->attr_name.attr.mode = 0444;
1113 			cable->attr_name.show = cable_name_show;
1114 
1115 			sysfs_attr_init(&cable->attr_state.attr);
1116 			cable->attr_state.attr.name = "state";
1117 			cable->attr_state.attr.mode = 0444;
1118 			cable->attr_state.show = cable_state_show;
1119 		}
1120 	}
1121 
1122 	if (edev->max_supported && edev->mutually_exclusive) {
1123 		char buf[80];
1124 		char *name;
1125 
1126 		/* Count the size of mutually_exclusive array */
1127 		for (index = 0; edev->mutually_exclusive[index]; index++)
1128 			;
1129 
1130 		edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
1131 					   (index + 1), GFP_KERNEL);
1132 		if (!edev->attrs_muex) {
1133 			ret = -ENOMEM;
1134 			goto err_muex;
1135 		}
1136 
1137 		edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
1138 					     index, GFP_KERNEL);
1139 		if (!edev->d_attrs_muex) {
1140 			ret = -ENOMEM;
1141 			kfree(edev->attrs_muex);
1142 			goto err_muex;
1143 		}
1144 
1145 		for (index = 0; edev->mutually_exclusive[index]; index++) {
1146 			sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
1147 			name = kzalloc(sizeof(char) * (strlen(buf) + 1),
1148 				       GFP_KERNEL);
1149 			if (!name) {
1150 				for (index--; index >= 0; index--) {
1151 					kfree(edev->d_attrs_muex[index].attr.
1152 					      name);
1153 				}
1154 				kfree(edev->d_attrs_muex);
1155 				kfree(edev->attrs_muex);
1156 				ret = -ENOMEM;
1157 				goto err_muex;
1158 			}
1159 			strcpy(name, buf);
1160 			sysfs_attr_init(&edev->d_attrs_muex[index].attr);
1161 			edev->d_attrs_muex[index].attr.name = name;
1162 			edev->d_attrs_muex[index].attr.mode = 0000;
1163 			edev->attrs_muex[index] = &edev->d_attrs_muex[index]
1164 							.attr;
1165 		}
1166 		edev->attr_g_muex.name = muex_name;
1167 		edev->attr_g_muex.attrs = edev->attrs_muex;
1168 
1169 	}
1170 
1171 	if (edev->max_supported) {
1172 		edev->extcon_dev_type.groups =
1173 			kzalloc(sizeof(struct attribute_group *) *
1174 				(edev->max_supported + 2), GFP_KERNEL);
1175 		if (!edev->extcon_dev_type.groups) {
1176 			ret = -ENOMEM;
1177 			goto err_alloc_groups;
1178 		}
1179 
1180 		edev->extcon_dev_type.name = dev_name(&edev->dev);
1181 		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
1182 
1183 		for (index = 0; index < edev->max_supported; index++)
1184 			edev->extcon_dev_type.groups[index] =
1185 				&edev->cables[index].attr_g;
1186 		if (edev->mutually_exclusive)
1187 			edev->extcon_dev_type.groups[index] =
1188 				&edev->attr_g_muex;
1189 
1190 		edev->dev.type = &edev->extcon_dev_type;
1191 	}
1192 
1193 	ret = device_register(&edev->dev);
1194 	if (ret) {
1195 		put_device(&edev->dev);
1196 		goto err_dev;
1197 	}
1198 #if defined(CONFIG_ANDROID)
1199 	if (switch_class)
1200 		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
1201 #endif /* CONFIG_ANDROID */
1202 
1203 	spin_lock_init(&edev->lock);
1204 
1205 	edev->nh = devm_kzalloc(&edev->dev,
1206 			sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
1207 	if (!edev->nh) {
1208 		ret = -ENOMEM;
1209 		goto err_dev;
1210 	}
1211 
1212 	for (index = 0; index < edev->max_supported; index++)
1213 		RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
1214 
1215 	dev_set_drvdata(&edev->dev, edev);
1216 	edev->state = 0;
1217 
1218 	mutex_lock(&extcon_dev_list_lock);
1219 	list_add(&edev->entry, &extcon_dev_list);
1220 	mutex_unlock(&extcon_dev_list_lock);
1221 
1222 	return 0;
1223 
1224 err_dev:
1225 	if (edev->max_supported)
1226 		kfree(edev->extcon_dev_type.groups);
1227 err_alloc_groups:
1228 	if (edev->max_supported && edev->mutually_exclusive) {
1229 		for (index = 0; edev->mutually_exclusive[index]; index++)
1230 			kfree(edev->d_attrs_muex[index].attr.name);
1231 		kfree(edev->d_attrs_muex);
1232 		kfree(edev->attrs_muex);
1233 	}
1234 err_muex:
1235 	for (index = 0; index < edev->max_supported; index++)
1236 		kfree(edev->cables[index].attr_g.name);
1237 err_alloc_cables:
1238 	if (edev->max_supported)
1239 		kfree(edev->cables);
1240 err_sysfs_alloc:
1241 	return ret;
1242 }
1243 EXPORT_SYMBOL_GPL(extcon_dev_register);
1244 
1245 /**
1246  * extcon_dev_unregister() - Unregister the extcon device.
1247  * @edev:	the extcon device instance to be unregistered.
1248  *
1249  * Note that this does not call kfree(edev) because edev was not allocated
1250  * by this class.
1251  */
1252 void extcon_dev_unregister(struct extcon_dev *edev)
1253 {
1254 	int index;
1255 
1256 	if (!edev)
1257 		return;
1258 
1259 	mutex_lock(&extcon_dev_list_lock);
1260 	list_del(&edev->entry);
1261 	mutex_unlock(&extcon_dev_list_lock);
1262 
1263 	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
1264 		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
1265 				dev_name(&edev->dev));
1266 		return;
1267 	}
1268 
1269 	device_unregister(&edev->dev);
1270 
1271 	if (edev->mutually_exclusive && edev->max_supported) {
1272 		for (index = 0; edev->mutually_exclusive[index];
1273 				index++)
1274 			kfree(edev->d_attrs_muex[index].attr.name);
1275 		kfree(edev->d_attrs_muex);
1276 		kfree(edev->attrs_muex);
1277 	}
1278 
1279 	for (index = 0; index < edev->max_supported; index++)
1280 		kfree(edev->cables[index].attr_g.name);
1281 
1282 	if (edev->max_supported) {
1283 		kfree(edev->extcon_dev_type.groups);
1284 		kfree(edev->cables);
1285 	}
1286 
1287 #if defined(CONFIG_ANDROID)
1288 	if (switch_class)
1289 		class_compat_remove_link(switch_class, &edev->dev, NULL);
1290 #endif
1291 	put_device(&edev->dev);
1292 }
1293 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
1294 
1295 #ifdef CONFIG_OF
1296 /*
1297  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1298  * @dev - instance to the given device
1299  * @index - index into list of extcon_dev
1300  *
1301  * return the instance of extcon device
1302  */
1303 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1304 {
1305 	struct device_node *node;
1306 	struct extcon_dev *edev;
1307 
1308 	if (!dev)
1309 		return ERR_PTR(-EINVAL);
1310 
1311 	if (!dev->of_node) {
1312 		dev_dbg(dev, "device does not have a device node entry\n");
1313 		return ERR_PTR(-EINVAL);
1314 	}
1315 
1316 	node = of_parse_phandle(dev->of_node, "extcon", index);
1317 	if (!node) {
1318 		dev_dbg(dev, "failed to get phandle in %s node\n",
1319 			dev->of_node->full_name);
1320 		return ERR_PTR(-ENODEV);
1321 	}
1322 
1323 	mutex_lock(&extcon_dev_list_lock);
1324 	list_for_each_entry(edev, &extcon_dev_list, entry) {
1325 		if (edev->dev.parent && edev->dev.parent->of_node == node) {
1326 			mutex_unlock(&extcon_dev_list_lock);
1327 			of_node_put(node);
1328 			return edev;
1329 		}
1330 	}
1331 	mutex_unlock(&extcon_dev_list_lock);
1332 	of_node_put(node);
1333 
1334 	return ERR_PTR(-EPROBE_DEFER);
1335 }
1336 #else
1337 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1338 {
1339 	return ERR_PTR(-ENOSYS);
1340 }
1341 #endif /* CONFIG_OF */
1342 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1343 
1344 /**
1345  * extcon_get_edev_name() - Get the name of the extcon device.
1346  * @edev:	the extcon device
1347  */
1348 const char *extcon_get_edev_name(struct extcon_dev *edev)
1349 {
1350 	return !edev ? NULL : edev->name;
1351 }
1352 
1353 static int __init extcon_class_init(void)
1354 {
1355 	return create_extcon_class();
1356 }
1357 module_init(extcon_class_init);
1358 
1359 static void __exit extcon_class_exit(void)
1360 {
1361 #if defined(CONFIG_ANDROID)
1362 	class_compat_unregister(switch_class);
1363 #endif
1364 	class_destroy(extcon_class);
1365 }
1366 module_exit(extcon_class_exit);
1367 
1368 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1369 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1370 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1371 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1372 MODULE_DESCRIPTION("External connector (extcon) class driver");
1373 MODULE_LICENSE("GPL");
1374