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  1/*
  2 *  drivers/extcon/extcon_class.c
  3 *
  4 *  External connector (extcon) class driver
  5 *
  6 * Copyright (C) 2012 Samsung Electronics
  7 * Author: Donggeun Kim <dg77.kim@samsung.com>
  8 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
  9 *
 10 * based on android/drivers/switch/switch_class.c
 11 * Copyright (C) 2008 Google, Inc.
 12 * Author: Mike Lockwood <lockwood@android.com>
 13 *
 14 * This software is licensed under the terms of the GNU General Public
 15 * License version 2, as published by the Free Software Foundation, and
 16 * may be copied, distributed, and modified under those terms.
 17 *
 18 * This program is distributed in the hope that it will be useful,
 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 21 * GNU General Public License for more details.
 22 *
 23*/
 24
 25#include <linux/module.h>
 26#include <linux/types.h>
 27#include <linux/init.h>
 28#include <linux/device.h>
 29#include <linux/fs.h>
 30#include <linux/err.h>
 31#include <linux/extcon.h>
 32#include <linux/slab.h>
 33#include <linux/sysfs.h>
 34#include <linux/of.h>
 35
 36/*
 37 * extcon_cable_name suggests the standard cable names for commonly used
 38 * cable types.
 39 *
 40 * However, please do not use extcon_cable_name directly for extcon_dev
 41 * struct's supported_cable pointer unless your device really supports
 42 * every single port-type of the following cable names. Please choose cable
 43 * names that are actually used in your extcon device.
 44 */
 45const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
 46	[EXTCON_USB]		= "USB",
 47	[EXTCON_USB_HOST]	= "USB-Host",
 48	[EXTCON_TA]		= "TA",
 49	[EXTCON_FAST_CHARGER]	= "Fast-charger",
 50	[EXTCON_SLOW_CHARGER]	= "Slow-charger",
 51	[EXTCON_CHARGE_DOWNSTREAM]	= "Charge-downstream",
 52	[EXTCON_HDMI]		= "HDMI",
 53	[EXTCON_MHL]		= "MHL",
 54	[EXTCON_DVI]		= "DVI",
 55	[EXTCON_VGA]		= "VGA",
 56	[EXTCON_DOCK]		= "Dock",
 57	[EXTCON_LINE_IN]	= "Line-in",
 58	[EXTCON_LINE_OUT]	= "Line-out",
 59	[EXTCON_MIC_IN]		= "Microphone",
 60	[EXTCON_HEADPHONE_OUT]	= "Headphone",
 61	[EXTCON_SPDIF_IN]	= "SPDIF-in",
 62	[EXTCON_SPDIF_OUT]	= "SPDIF-out",
 63	[EXTCON_VIDEO_IN]	= "Video-in",
 64	[EXTCON_VIDEO_OUT]	= "Video-out",
 65	[EXTCON_MECHANICAL]	= "Mechanical",
 66};
 67
 68static struct class *extcon_class;
 69#if defined(CONFIG_ANDROID)
 70static struct class_compat *switch_class;
 71#endif /* CONFIG_ANDROID */
 72
 73static LIST_HEAD(extcon_dev_list);
 74static DEFINE_MUTEX(extcon_dev_list_lock);
 75
 76/**
 77 * check_mutually_exclusive - Check if new_state violates mutually_exclusive
 78 *			      condition.
 79 * @edev:	the extcon device
 80 * @new_state:	new cable attach status for @edev
 81 *
 82 * Returns 0 if nothing violates. Returns the index + 1 for the first
 83 * violated condition.
 84 */
 85static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
 86{
 87	int i = 0;
 88
 89	if (!edev->mutually_exclusive)
 90		return 0;
 91
 92	for (i = 0; edev->mutually_exclusive[i]; i++) {
 93		int weight;
 94		u32 correspondants = new_state & edev->mutually_exclusive[i];
 95
 96		/* calculate the total number of bits set */
 97		weight = hweight32(correspondants);
 98		if (weight > 1)
 99			return i + 1;
100	}
101
102	return 0;
103}
104
105static ssize_t state_show(struct device *dev, struct device_attribute *attr,
106			  char *buf)
107{
108	int i, count = 0;
109	struct extcon_dev *edev = dev_get_drvdata(dev);
110
111	if (edev->print_state) {
112		int ret = edev->print_state(edev, buf);
113
114		if (ret >= 0)
115			return ret;
116		/* Use default if failed */
117	}
118
119	if (edev->max_supported == 0)
120		return sprintf(buf, "%u\n", edev->state);
121
122	for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
123		if (!edev->supported_cable[i])
124			break;
125		count += sprintf(buf + count, "%s=%d\n",
126				 edev->supported_cable[i],
127				 !!(edev->state & (1 << i)));
128	}
129
130	return count;
131}
132
133static ssize_t state_store(struct device *dev, struct device_attribute *attr,
134			   const char *buf, size_t count)
135{
136	u32 state;
137	ssize_t ret = 0;
138	struct extcon_dev *edev = dev_get_drvdata(dev);
139
140	ret = sscanf(buf, "0x%x", &state);
141	if (ret == 0)
142		ret = -EINVAL;
143	else
144		ret = extcon_set_state(edev, state);
145
146	if (ret < 0)
147		return ret;
148
149	return count;
150}
151static DEVICE_ATTR_RW(state);
152
153static ssize_t name_show(struct device *dev, struct device_attribute *attr,
154		char *buf)
155{
156	struct extcon_dev *edev = dev_get_drvdata(dev);
157
158	/* Optional callback given by the user */
159	if (edev->print_name) {
160		int ret = edev->print_name(edev, buf);
161		if (ret >= 0)
162			return ret;
163	}
164
165	return sprintf(buf, "%s\n", dev_name(&edev->dev));
166}
167static DEVICE_ATTR_RO(name);
168
169static ssize_t cable_name_show(struct device *dev,
170			       struct device_attribute *attr, char *buf)
171{
172	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
173						  attr_name);
174
175	return sprintf(buf, "%s\n",
176		       cable->edev->supported_cable[cable->cable_index]);
177}
178
179static ssize_t cable_state_show(struct device *dev,
180				struct device_attribute *attr, char *buf)
181{
182	struct extcon_cable *cable = container_of(attr, struct extcon_cable,
183						  attr_state);
184
185	return sprintf(buf, "%d\n",
186		       extcon_get_cable_state_(cable->edev,
187					       cable->cable_index));
188}
189
190/**
191 * extcon_update_state() - Update the cable attach states of the extcon device
192 *			   only for the masked bits.
193 * @edev:	the extcon device
194 * @mask:	the bit mask to designate updated bits.
195 * @state:	new cable attach status for @edev
196 *
197 * Changing the state sends uevent with environment variable containing
198 * the name of extcon device (envp[0]) and the state output (envp[1]).
199 * Tizen uses this format for extcon device to get events from ports.
200 * Android uses this format as well.
201 *
202 * Note that the notifier provides which bits are changed in the state
203 * variable with the val parameter (second) to the callback.
204 */
205int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
206{
207	char name_buf[120];
208	char state_buf[120];
209	char *prop_buf;
210	char *envp[3];
211	int env_offset = 0;
212	int length;
213	unsigned long flags;
214
215	spin_lock_irqsave(&edev->lock, flags);
216
217	if (edev->state != ((edev->state & ~mask) | (state & mask))) {
218		u32 old_state = edev->state;
219
220		if (check_mutually_exclusive(edev, (edev->state & ~mask) |
221						   (state & mask))) {
222			spin_unlock_irqrestore(&edev->lock, flags);
223			return -EPERM;
224		}
225
226		edev->state &= ~mask;
227		edev->state |= state & mask;
228
229		raw_notifier_call_chain(&edev->nh, old_state, edev);
230		/* This could be in interrupt handler */
231		prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
232		if (prop_buf) {
233			length = name_show(&edev->dev, NULL, prop_buf);
234			if (length > 0) {
235				if (prop_buf[length - 1] == '\n')
236					prop_buf[length - 1] = 0;
237				snprintf(name_buf, sizeof(name_buf),
238					"NAME=%s", prop_buf);
239				envp[env_offset++] = name_buf;
240			}
241			length = state_show(&edev->dev, NULL, prop_buf);
242			if (length > 0) {
243				if (prop_buf[length - 1] == '\n')
244					prop_buf[length - 1] = 0;
245				snprintf(state_buf, sizeof(state_buf),
246					"STATE=%s", prop_buf);
247				envp[env_offset++] = state_buf;
248			}
249			envp[env_offset] = NULL;
250			/* Unlock early before uevent */
251			spin_unlock_irqrestore(&edev->lock, flags);
252
253			kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
254			free_page((unsigned long)prop_buf);
255		} else {
256			/* Unlock early before uevent */
257			spin_unlock_irqrestore(&edev->lock, flags);
258
259			dev_err(&edev->dev, "out of memory in extcon_set_state\n");
260			kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
261		}
262	} else {
263		/* No changes */
264		spin_unlock_irqrestore(&edev->lock, flags);
265	}
266
267	return 0;
268}
269EXPORT_SYMBOL_GPL(extcon_update_state);
270
271/**
272 * extcon_set_state() - Set the cable attach states of the extcon device.
273 * @edev:	the extcon device
274 * @state:	new cable attach status for @edev
275 *
276 * Note that notifier provides which bits are changed in the state
277 * variable with the val parameter (second) to the callback.
278 */
279int extcon_set_state(struct extcon_dev *edev, u32 state)
280{
281	return extcon_update_state(edev, 0xffffffff, state);
282}
283EXPORT_SYMBOL_GPL(extcon_set_state);
284
285/**
286 * extcon_find_cable_index() - Get the cable index based on the cable name.
287 * @edev:	the extcon device that has the cable.
288 * @cable_name:	cable name to be searched.
289 *
290 * Note that accessing a cable state based on cable_index is faster than
291 * cable_name because using cable_name induces a loop with strncmp().
292 * Thus, when get/set_cable_state is repeatedly used, using cable_index
293 * is recommended.
294 */
295int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
296{
297	int i;
298
299	if (edev->supported_cable) {
300		for (i = 0; edev->supported_cable[i]; i++) {
301			if (!strncmp(edev->supported_cable[i],
302				cable_name, CABLE_NAME_MAX))
303				return i;
304		}
305	}
306
307	return -EINVAL;
308}
309EXPORT_SYMBOL_GPL(extcon_find_cable_index);
310
311/**
312 * extcon_get_cable_state_() - Get the status of a specific cable.
313 * @edev:	the extcon device that has the cable.
314 * @index:	cable index that can be retrieved by extcon_find_cable_index().
315 */
316int extcon_get_cable_state_(struct extcon_dev *edev, int index)
317{
318	if (index < 0 || (edev->max_supported && edev->max_supported <= index))
319		return -EINVAL;
320
321	return !!(edev->state & (1 << index));
322}
323EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
324
325/**
326 * extcon_get_cable_state() - Get the status of a specific cable.
327 * @edev:	the extcon device that has the cable.
328 * @cable_name:	cable name.
329 *
330 * Note that this is slower than extcon_get_cable_state_.
331 */
332int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
333{
334	return extcon_get_cable_state_(edev, extcon_find_cable_index
335						(edev, cable_name));
336}
337EXPORT_SYMBOL_GPL(extcon_get_cable_state);
338
339/**
340 * extcon_set_cable_state_() - Set the status of a specific cable.
341 * @edev:		the extcon device that has the cable.
342 * @index:		cable index that can be retrieved by
343 *			extcon_find_cable_index().
344 * @cable_state:	the new cable status. The default semantics is
345 *			true: attached / false: detached.
346 */
347int extcon_set_cable_state_(struct extcon_dev *edev,
348			int index, bool cable_state)
349{
350	u32 state;
351
352	if (index < 0 || (edev->max_supported && edev->max_supported <= index))
353		return -EINVAL;
354
355	state = cable_state ? (1 << index) : 0;
356	return extcon_update_state(edev, 1 << index, state);
357}
358EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
359
360/**
361 * extcon_set_cable_state() - Set the status of a specific cable.
362 * @edev:		the extcon device that has the cable.
363 * @cable_name:		cable name.
364 * @cable_state:	the new cable status. The default semantics is
365 *			true: attached / false: detached.
366 *
367 * Note that this is slower than extcon_set_cable_state_.
368 */
369int extcon_set_cable_state(struct extcon_dev *edev,
370			const char *cable_name, bool cable_state)
371{
372	return extcon_set_cable_state_(edev, extcon_find_cable_index
373					(edev, cable_name), cable_state);
374}
375EXPORT_SYMBOL_GPL(extcon_set_cable_state);
376
377/**
378 * extcon_get_extcon_dev() - Get the extcon device instance from the name
379 * @extcon_name:	The extcon name provided with extcon_dev_register()
380 */
381struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
382{
383	struct extcon_dev *sd;
384
385	mutex_lock(&extcon_dev_list_lock);
386	list_for_each_entry(sd, &extcon_dev_list, entry) {
387		if (!strcmp(sd->name, extcon_name))
388			goto out;
389	}
390	sd = NULL;
391out:
392	mutex_unlock(&extcon_dev_list_lock);
393	return sd;
394}
395EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
396
397static int _call_per_cable(struct notifier_block *nb, unsigned long val,
398			   void *ptr)
399{
400	struct extcon_specific_cable_nb *obj = container_of(nb,
401			struct extcon_specific_cable_nb, internal_nb);
402	struct extcon_dev *edev = ptr;
403
404	if ((val & (1 << obj->cable_index)) !=
405	    (edev->state & (1 << obj->cable_index))) {
406		bool cable_state = true;
407
408		obj->previous_value = val;
409
410		if (val & (1 << obj->cable_index))
411			cable_state = false;
412
413		return obj->user_nb->notifier_call(obj->user_nb,
414				cable_state, ptr);
415	}
416
417	return NOTIFY_OK;
418}
419
420/**
421 * extcon_register_interest() - Register a notifier for a state change of a
422 *				specific cable, not an entier set of cables of a
423 *				extcon device.
424 * @obj:		an empty extcon_specific_cable_nb object to be returned.
425 * @extcon_name:	the name of extcon device.
426 *			if NULL, extcon_register_interest will register
427 *			every cable with the target cable_name given.
428 * @cable_name:		the target cable name.
429 * @nb:			the notifier block to get notified.
430 *
431 * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
432 * the struct for you.
433 *
434 * extcon_register_interest is a helper function for those who want to get
435 * notification for a single specific cable's status change. If a user wants
436 * to get notification for any changes of all cables of a extcon device,
437 * he/she should use the general extcon_register_notifier().
438 *
439 * Note that the second parameter given to the callback of nb (val) is
440 * "old_state", not the current state. The current state can be retrieved
441 * by looking at the third pameter (edev pointer)'s state value.
442 */
443int extcon_register_interest(struct extcon_specific_cable_nb *obj,
444			     const char *extcon_name, const char *cable_name,
445			     struct notifier_block *nb)
446{
447	if (!obj || !cable_name || !nb)
448		return -EINVAL;
449
450	if (extcon_name) {
451		obj->edev = extcon_get_extcon_dev(extcon_name);
452		if (!obj->edev)
453			return -ENODEV;
454
455		obj->cable_index = extcon_find_cable_index(obj->edev,
456							  cable_name);
457		if (obj->cable_index < 0)
458			return obj->cable_index;
459
460		obj->user_nb = nb;
461
462		obj->internal_nb.notifier_call = _call_per_cable;
463
464		return raw_notifier_chain_register(&obj->edev->nh,
465						  &obj->internal_nb);
466	} else {
467		struct class_dev_iter iter;
468		struct extcon_dev *extd;
469		struct device *dev;
470
471		if (!extcon_class)
472			return -ENODEV;
473		class_dev_iter_init(&iter, extcon_class, NULL, NULL);
474		while ((dev = class_dev_iter_next(&iter))) {
475			extd = dev_get_drvdata(dev);
476
477			if (extcon_find_cable_index(extd, cable_name) < 0)
478				continue;
479
480			class_dev_iter_exit(&iter);
481			return extcon_register_interest(obj, extd->name,
482						cable_name, nb);
483		}
484
485		return -ENODEV;
486	}
487}
488EXPORT_SYMBOL_GPL(extcon_register_interest);
489
490/**
491 * extcon_unregister_interest() - Unregister the notifier registered by
492 *				  extcon_register_interest().
493 * @obj:	the extcon_specific_cable_nb object returned by
494 *		extcon_register_interest().
495 */
496int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
497{
498	if (!obj)
499		return -EINVAL;
500
501	return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
502}
503EXPORT_SYMBOL_GPL(extcon_unregister_interest);
504
505/**
506 * extcon_register_notifier() - Register a notifiee to get notified by
507 *				any attach status changes from the extcon.
508 * @edev:	the extcon device.
509 * @nb:		a notifier block to be registered.
510 *
511 * Note that the second parameter given to the callback of nb (val) is
512 * "old_state", not the current state. The current state can be retrieved
513 * by looking at the third pameter (edev pointer)'s state value.
514 */
515int extcon_register_notifier(struct extcon_dev *edev,
516			struct notifier_block *nb)
517{
518	return raw_notifier_chain_register(&edev->nh, nb);
519}
520EXPORT_SYMBOL_GPL(extcon_register_notifier);
521
522/**
523 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
524 * @edev:	the extcon device.
525 * @nb:		a registered notifier block to be unregistered.
526 */
527int extcon_unregister_notifier(struct extcon_dev *edev,
528			struct notifier_block *nb)
529{
530	return raw_notifier_chain_unregister(&edev->nh, nb);
531}
532EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
533
534static struct attribute *extcon_attrs[] = {
535	&dev_attr_state.attr,
536	&dev_attr_name.attr,
537	NULL,
538};
539ATTRIBUTE_GROUPS(extcon);
540
541static int create_extcon_class(void)
542{
543	if (!extcon_class) {
544		extcon_class = class_create(THIS_MODULE, "extcon");
545		if (IS_ERR(extcon_class))
546			return PTR_ERR(extcon_class);
547		extcon_class->dev_groups = extcon_groups;
548
549#if defined(CONFIG_ANDROID)
550		switch_class = class_compat_register("switch");
551		if (WARN(!switch_class, "cannot allocate"))
552			return -ENOMEM;
553#endif /* CONFIG_ANDROID */
554	}
555
556	return 0;
557}
558
559static void extcon_dev_release(struct device *dev)
560{
561}
562
563static const char *muex_name = "mutually_exclusive";
564static void dummy_sysfs_dev_release(struct device *dev)
565{
566}
567
568/**
569 * extcon_dev_register() - Register a new extcon device
570 * @edev	: the new extcon device (should be allocated before calling)
571 *
572 * Among the members of edev struct, please set the "user initializing data"
573 * in any case and set the "optional callbacks" if required. However, please
574 * do not set the values of "internal data", which are initialized by
575 * this function.
576 */
577int extcon_dev_register(struct extcon_dev *edev)
578{
579	int ret, index = 0;
580
581	if (!extcon_class) {
582		ret = create_extcon_class();
583		if (ret < 0)
584			return ret;
585	}
586
587	if (edev->supported_cable) {
588		/* Get size of array */
589		for (index = 0; edev->supported_cable[index]; index++)
590			;
591		edev->max_supported = index;
592	} else {
593		edev->max_supported = 0;
594	}
595
596	if (index > SUPPORTED_CABLE_MAX) {
597		dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
598		return -EINVAL;
599	}
600
601	edev->dev.class = extcon_class;
602	edev->dev.release = extcon_dev_release;
603
604	edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
605	if (IS_ERR_OR_NULL(edev->name)) {
606		dev_err(&edev->dev,
607			"extcon device name is null\n");
608		return -EINVAL;
609	}
610	dev_set_name(&edev->dev, "%s", edev->name);
611
612	if (edev->max_supported) {
613		char buf[10];
614		char *str;
615		struct extcon_cable *cable;
616
617		edev->cables = kzalloc(sizeof(struct extcon_cable) *
618				       edev->max_supported, GFP_KERNEL);
619		if (!edev->cables) {
620			ret = -ENOMEM;
621			goto err_sysfs_alloc;
622		}
623		for (index = 0; index < edev->max_supported; index++) {
624			cable = &edev->cables[index];
625
626			snprintf(buf, 10, "cable.%d", index);
627			str = kzalloc(sizeof(char) * (strlen(buf) + 1),
628				      GFP_KERNEL);
629			if (!str) {
630				for (index--; index >= 0; index--) {
631					cable = &edev->cables[index];
632					kfree(cable->attr_g.name);
633				}
634				ret = -ENOMEM;
635
636				goto err_alloc_cables;
637			}
638			strcpy(str, buf);
639
640			cable->edev = edev;
641			cable->cable_index = index;
642			cable->attrs[0] = &cable->attr_name.attr;
643			cable->attrs[1] = &cable->attr_state.attr;
644			cable->attrs[2] = NULL;
645			cable->attr_g.name = str;
646			cable->attr_g.attrs = cable->attrs;
647
648			sysfs_attr_init(&cable->attr_name.attr);
649			cable->attr_name.attr.name = "name";
650			cable->attr_name.attr.mode = 0444;
651			cable->attr_name.show = cable_name_show;
652
653			sysfs_attr_init(&cable->attr_state.attr);
654			cable->attr_state.attr.name = "state";
655			cable->attr_state.attr.mode = 0444;
656			cable->attr_state.show = cable_state_show;
657		}
658	}
659
660	if (edev->max_supported && edev->mutually_exclusive) {
661		char buf[80];
662		char *name;
663
664		/* Count the size of mutually_exclusive array */
665		for (index = 0; edev->mutually_exclusive[index]; index++)
666			;
667
668		edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
669					   (index + 1), GFP_KERNEL);
670		if (!edev->attrs_muex) {
671			ret = -ENOMEM;
672			goto err_muex;
673		}
674
675		edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
676					     index, GFP_KERNEL);
677		if (!edev->d_attrs_muex) {
678			ret = -ENOMEM;
679			kfree(edev->attrs_muex);
680			goto err_muex;
681		}
682
683		for (index = 0; edev->mutually_exclusive[index]; index++) {
684			sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
685			name = kzalloc(sizeof(char) * (strlen(buf) + 1),
686				       GFP_KERNEL);
687			if (!name) {
688				for (index--; index >= 0; index--) {
689					kfree(edev->d_attrs_muex[index].attr.
690					      name);
691				}
692				kfree(edev->d_attrs_muex);
693				kfree(edev->attrs_muex);
694				ret = -ENOMEM;
695				goto err_muex;
696			}
697			strcpy(name, buf);
698			sysfs_attr_init(&edev->d_attrs_muex[index].attr);
699			edev->d_attrs_muex[index].attr.name = name;
700			edev->d_attrs_muex[index].attr.mode = 0000;
701			edev->attrs_muex[index] = &edev->d_attrs_muex[index]
702							.attr;
703		}
704		edev->attr_g_muex.name = muex_name;
705		edev->attr_g_muex.attrs = edev->attrs_muex;
706
707	}
708
709	if (edev->max_supported) {
710		edev->extcon_dev_type.groups =
711			kzalloc(sizeof(struct attribute_group *) *
712				(edev->max_supported + 2), GFP_KERNEL);
713		if (!edev->extcon_dev_type.groups) {
714			ret = -ENOMEM;
715			goto err_alloc_groups;
716		}
717
718		edev->extcon_dev_type.name = dev_name(&edev->dev);
719		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
720
721		for (index = 0; index < edev->max_supported; index++)
722			edev->extcon_dev_type.groups[index] =
723				&edev->cables[index].attr_g;
724		if (edev->mutually_exclusive)
725			edev->extcon_dev_type.groups[index] =
726				&edev->attr_g_muex;
727
728		edev->dev.type = &edev->extcon_dev_type;
729	}
730
731	ret = device_register(&edev->dev);
732	if (ret) {
733		put_device(&edev->dev);
734		goto err_dev;
735	}
736#if defined(CONFIG_ANDROID)
737	if (switch_class)
738		ret = class_compat_create_link(switch_class, &edev->dev, NULL);
739#endif /* CONFIG_ANDROID */
740
741	spin_lock_init(&edev->lock);
742
743	RAW_INIT_NOTIFIER_HEAD(&edev->nh);
744
745	dev_set_drvdata(&edev->dev, edev);
746	edev->state = 0;
747
748	mutex_lock(&extcon_dev_list_lock);
749	list_add(&edev->entry, &extcon_dev_list);
750	mutex_unlock(&extcon_dev_list_lock);
751
752	return 0;
753
754err_dev:
755	if (edev->max_supported)
756		kfree(edev->extcon_dev_type.groups);
757err_alloc_groups:
758	if (edev->max_supported && edev->mutually_exclusive) {
759		for (index = 0; edev->mutually_exclusive[index]; index++)
760			kfree(edev->d_attrs_muex[index].attr.name);
761		kfree(edev->d_attrs_muex);
762		kfree(edev->attrs_muex);
763	}
764err_muex:
765	for (index = 0; index < edev->max_supported; index++)
766		kfree(edev->cables[index].attr_g.name);
767err_alloc_cables:
768	if (edev->max_supported)
769		kfree(edev->cables);
770err_sysfs_alloc:
771	return ret;
772}
773EXPORT_SYMBOL_GPL(extcon_dev_register);
774
775/**
776 * extcon_dev_unregister() - Unregister the extcon device.
777 * @edev:	the extcon device instance to be unregistered.
778 *
779 * Note that this does not call kfree(edev) because edev was not allocated
780 * by this class.
781 */
782void extcon_dev_unregister(struct extcon_dev *edev)
783{
784	int index;
785
786	mutex_lock(&extcon_dev_list_lock);
787	list_del(&edev->entry);
788	mutex_unlock(&extcon_dev_list_lock);
789
790	if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
791		dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
792				dev_name(&edev->dev));
793		return;
794	}
795
796	device_unregister(&edev->dev);
797
798	if (edev->mutually_exclusive && edev->max_supported) {
799		for (index = 0; edev->mutually_exclusive[index];
800				index++)
801			kfree(edev->d_attrs_muex[index].attr.name);
802		kfree(edev->d_attrs_muex);
803		kfree(edev->attrs_muex);
804	}
805
806	for (index = 0; index < edev->max_supported; index++)
807		kfree(edev->cables[index].attr_g.name);
808
809	if (edev->max_supported) {
810		kfree(edev->extcon_dev_type.groups);
811		kfree(edev->cables);
812	}
813
814#if defined(CONFIG_ANDROID)
815	if (switch_class)
816		class_compat_remove_link(switch_class, &edev->dev, NULL);
817#endif
818	put_device(&edev->dev);
819}
820EXPORT_SYMBOL_GPL(extcon_dev_unregister);
821
822#ifdef CONFIG_OF
823/*
824 * extcon_get_edev_by_phandle - Get the extcon device from devicetree
825 * @dev - instance to the given device
826 * @index - index into list of extcon_dev
827 *
828 * return the instance of extcon device
829 */
830struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
831{
832	struct device_node *node;
833	struct extcon_dev *edev;
834
835	if (!dev->of_node) {
836		dev_err(dev, "device does not have a device node entry\n");
837		return ERR_PTR(-EINVAL);
838	}
839
840	node = of_parse_phandle(dev->of_node, "extcon", index);
841	if (!node) {
842		dev_err(dev, "failed to get phandle in %s node\n",
843			dev->of_node->full_name);
844		return ERR_PTR(-ENODEV);
845	}
846
847	edev = extcon_get_extcon_dev(node->name);
848	if (!edev) {
849		dev_err(dev, "unable to get extcon device : %s\n", node->name);
850		return ERR_PTR(-ENODEV);
851	}
852
853	return edev;
854}
855#else
856struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
857{
858	return ERR_PTR(-ENOSYS);
859}
860#endif /* CONFIG_OF */
861EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
862
863static int __init extcon_class_init(void)
864{
865	return create_extcon_class();
866}
867module_init(extcon_class_init);
868
869static void __exit extcon_class_exit(void)
870{
871#if defined(CONFIG_ANDROID)
872	class_compat_unregister(switch_class);
873#endif
874	class_destroy(extcon_class);
875}
876module_exit(extcon_class_exit);
877
878MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
879MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
880MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
881MODULE_DESCRIPTION("External connector (extcon) class driver");
882MODULE_LICENSE("GPL");