2 * drivers/extcon/extcon_class.c
4 * External connector (extcon) class driver
6 * Copyright (C) 2012 Samsung Electronics
7 * Author: Donggeun Kim <dg77.kim@samsung.com>
8 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
10 * based on android/drivers/switch/switch_class.c
11 * Copyright (C) 2008 Google, Inc.
12 * Author: Mike Lockwood <lockwood@android.com>
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.
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.
25 #include <linux/module.h>
26 #include <linux/types.h>
27 #include <linux/init.h>
28 #include <linux/device.h>
30 #include <linux/err.h>
31 #include <linux/extcon.h>
33 #include <linux/slab.h>
34 #include <linux/sysfs.h>
37 * extcon_cable_name suggests the standard cable names for commonly used
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.
45 const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
47 [EXTCON_USB_HOST] = "USB-Host",
49 [EXTCON_FAST_CHARGER] = "Fast-charger",
50 [EXTCON_SLOW_CHARGER] = "Slow-charger",
51 [EXTCON_CHARGE_DOWNSTREAM] = "Charge-downstream",
52 [EXTCON_HDMI] = "HDMI",
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",
68 static struct class *extcon_class;
69 #if defined(CONFIG_ANDROID)
70 static struct class_compat *switch_class;
71 #endif /* CONFIG_ANDROID */
73 static LIST_HEAD(extcon_dev_list);
74 static DEFINE_MUTEX(extcon_dev_list_lock);
77 * check_mutually_exclusive - Check if new_state violates mutually_exclusive
79 * @edev: the extcon device
80 * @new_state: new cable attach status for @edev
82 * Returns 0 if nothing violates. Returns the index + 1 for the first
85 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
89 if (!edev->mutually_exclusive)
92 for (i = 0; edev->mutually_exclusive[i]; i++) {
94 u32 correspondants = new_state & edev->mutually_exclusive[i];
96 /* calculate the total number of bits set */
97 weight = hweight32(correspondants);
105 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
109 struct extcon_dev *edev = dev_get_drvdata(dev);
111 if (edev->print_state) {
112 int ret = edev->print_state(edev, buf);
116 /* Use default if failed */
119 if (edev->max_supported == 0)
120 return sprintf(buf, "%u\n", edev->state);
122 for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
123 if (!edev->supported_cable[i])
125 count += sprintf(buf + count, "%s=%d\n",
126 edev->supported_cable[i],
127 !!(edev->state & (1 << i)));
133 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
134 const char *buf, size_t count)
138 struct extcon_dev *edev = dev_get_drvdata(dev);
140 ret = sscanf(buf, "0x%x", &state);
144 ret = extcon_set_state(edev, state);
151 static DEVICE_ATTR_RW(state);
153 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
156 struct extcon_dev *edev = dev_get_drvdata(dev);
158 /* Optional callback given by the user */
159 if (edev->print_name) {
160 int ret = edev->print_name(edev, buf);
166 return sprintf(buf, "%s\n", dev_name(&edev->dev));
168 static DEVICE_ATTR_RO(name);
170 static ssize_t cable_name_show(struct device *dev,
171 struct device_attribute *attr, char *buf)
173 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
176 return sprintf(buf, "%s\n",
177 cable->edev->supported_cable[cable->cable_index]);
180 static ssize_t cable_state_show(struct device *dev,
181 struct device_attribute *attr, char *buf)
183 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
186 return sprintf(buf, "%d\n",
187 extcon_get_cable_state_(cable->edev,
188 cable->cable_index));
192 * extcon_update_state() - Update the cable attach states of the extcon device
193 * only for the masked bits.
194 * @edev: the extcon device
195 * @mask: the bit mask to designate updated bits.
196 * @state: new cable attach status for @edev
198 * Changing the state sends uevent with environment variable containing
199 * the name of extcon device (envp[0]) and the state output (envp[1]).
200 * Tizen uses this format for extcon device to get events from ports.
201 * Android uses this format as well.
203 * Note that the notifier provides which bits are changed in the state
204 * variable with the val parameter (second) to the callback.
206 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
216 spin_lock_irqsave(&edev->lock, flags);
218 if (edev->state != ((edev->state & ~mask) | (state & mask))) {
219 u32 old_state = edev->state;
221 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
223 spin_unlock_irqrestore(&edev->lock, flags);
227 edev->state &= ~mask;
228 edev->state |= state & mask;
230 raw_notifier_call_chain(&edev->nh, old_state, edev);
231 /* This could be in interrupt handler */
232 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
234 length = name_show(&edev->dev, NULL, prop_buf);
236 if (prop_buf[length - 1] == '\n')
237 prop_buf[length - 1] = 0;
238 snprintf(name_buf, sizeof(name_buf),
239 "NAME=%s", prop_buf);
240 envp[env_offset++] = name_buf;
242 length = state_show(&edev->dev, NULL, prop_buf);
244 if (prop_buf[length - 1] == '\n')
245 prop_buf[length - 1] = 0;
246 snprintf(state_buf, sizeof(state_buf),
247 "STATE=%s", prop_buf);
248 envp[env_offset++] = state_buf;
250 envp[env_offset] = NULL;
251 /* Unlock early before uevent */
252 spin_unlock_irqrestore(&edev->lock, flags);
254 kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
255 free_page((unsigned long)prop_buf);
257 /* Unlock early before uevent */
258 spin_unlock_irqrestore(&edev->lock, flags);
260 dev_err(&edev->dev, "out of memory in extcon_set_state\n");
261 kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
265 spin_unlock_irqrestore(&edev->lock, flags);
270 EXPORT_SYMBOL_GPL(extcon_update_state);
273 * extcon_set_state() - Set the cable attach states of the extcon device.
274 * @edev: the extcon device
275 * @state: new cable attach status for @edev
277 * Note that notifier provides which bits are changed in the state
278 * variable with the val parameter (second) to the callback.
280 int extcon_set_state(struct extcon_dev *edev, u32 state)
282 return extcon_update_state(edev, 0xffffffff, state);
284 EXPORT_SYMBOL_GPL(extcon_set_state);
287 * extcon_find_cable_index() - Get the cable index based on the cable name.
288 * @edev: the extcon device that has the cable.
289 * @cable_name: cable name to be searched.
291 * Note that accessing a cable state based on cable_index is faster than
292 * cable_name because using cable_name induces a loop with strncmp().
293 * Thus, when get/set_cable_state is repeatedly used, using cable_index
296 int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
300 if (edev->supported_cable) {
301 for (i = 0; edev->supported_cable[i]; i++) {
302 if (!strncmp(edev->supported_cable[i],
303 cable_name, CABLE_NAME_MAX))
310 EXPORT_SYMBOL_GPL(extcon_find_cable_index);
313 * extcon_get_cable_state_() - Get the status of a specific cable.
314 * @edev: the extcon device that has the cable.
315 * @index: cable index that can be retrieved by extcon_find_cable_index().
317 int extcon_get_cable_state_(struct extcon_dev *edev, int index)
319 if (index < 0 || (edev->max_supported && edev->max_supported <= index))
322 return !!(edev->state & (1 << index));
324 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
327 * extcon_get_cable_state() - Get the status of a specific cable.
328 * @edev: the extcon device that has the cable.
329 * @cable_name: cable name.
331 * Note that this is slower than extcon_get_cable_state_.
333 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
335 return extcon_get_cable_state_(edev, extcon_find_cable_index
338 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
341 * extcon_set_cable_state_() - Set the status of a specific cable.
342 * @edev: the extcon device that has the cable.
343 * @index: cable index that can be retrieved by
344 * extcon_find_cable_index().
345 * @cable_state: the new cable status. The default semantics is
346 * true: attached / false: detached.
348 int extcon_set_cable_state_(struct extcon_dev *edev,
349 int index, bool cable_state)
353 if (index < 0 || (edev->max_supported && edev->max_supported <= index))
356 state = cable_state ? (1 << index) : 0;
357 return extcon_update_state(edev, 1 << index, state);
359 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
362 * extcon_set_cable_state() - Set the status of a specific cable.
363 * @edev: the extcon device that has the cable.
364 * @cable_name: cable name.
365 * @cable_state: the new cable status. The default semantics is
366 * true: attached / false: detached.
368 * Note that this is slower than extcon_set_cable_state_.
370 int extcon_set_cable_state(struct extcon_dev *edev,
371 const char *cable_name, bool cable_state)
373 return extcon_set_cable_state_(edev, extcon_find_cable_index
374 (edev, cable_name), cable_state);
376 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
379 * extcon_get_extcon_dev() - Get the extcon device instance from the name
380 * @extcon_name: The extcon name provided with extcon_dev_register()
382 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
384 struct extcon_dev *sd;
386 mutex_lock(&extcon_dev_list_lock);
387 list_for_each_entry(sd, &extcon_dev_list, entry) {
388 if (!strcmp(sd->name, extcon_name))
393 mutex_unlock(&extcon_dev_list_lock);
396 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
398 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
401 struct extcon_specific_cable_nb *obj = container_of(nb,
402 struct extcon_specific_cable_nb, internal_nb);
403 struct extcon_dev *edev = ptr;
405 if ((val & (1 << obj->cable_index)) !=
406 (edev->state & (1 << obj->cable_index))) {
407 bool cable_state = true;
409 obj->previous_value = val;
411 if (val & (1 << obj->cable_index))
414 return obj->user_nb->notifier_call(obj->user_nb,
422 * extcon_register_interest() - Register a notifier for a state change of a
423 * specific cable, not an entier set of cables of a
425 * @obj: an empty extcon_specific_cable_nb object to be returned.
426 * @extcon_name: the name of extcon device.
427 * if NULL, extcon_register_interest will register
428 * every cable with the target cable_name given.
429 * @cable_name: the target cable name.
430 * @nb: the notifier block to get notified.
432 * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
433 * the struct for you.
435 * extcon_register_interest is a helper function for those who want to get
436 * notification for a single specific cable's status change. If a user wants
437 * to get notification for any changes of all cables of a extcon device,
438 * he/she should use the general extcon_register_notifier().
440 * Note that the second parameter given to the callback of nb (val) is
441 * "old_state", not the current state. The current state can be retrieved
442 * by looking at the third pameter (edev pointer)'s state value.
444 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
445 const char *extcon_name, const char *cable_name,
446 struct notifier_block *nb)
451 if (!obj || !cable_name || !nb)
455 obj->edev = extcon_get_extcon_dev(extcon_name);
459 obj->cable_index = extcon_find_cable_index(obj->edev,
461 if (obj->cable_index < 0)
462 return obj->cable_index;
466 obj->internal_nb.notifier_call = _call_per_cable;
468 spin_lock_irqsave(&obj->edev->lock, flags);
469 ret = raw_notifier_chain_register(&obj->edev->nh,
471 spin_unlock_irqrestore(&obj->edev->lock, flags);
474 struct class_dev_iter iter;
475 struct extcon_dev *extd;
480 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
481 while ((dev = class_dev_iter_next(&iter))) {
482 extd = dev_get_drvdata(dev);
484 if (extcon_find_cable_index(extd, cable_name) < 0)
487 class_dev_iter_exit(&iter);
488 return extcon_register_interest(obj, extd->name,
495 EXPORT_SYMBOL_GPL(extcon_register_interest);
498 * extcon_unregister_interest() - Unregister the notifier registered by
499 * extcon_register_interest().
500 * @obj: the extcon_specific_cable_nb object returned by
501 * extcon_register_interest().
503 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
511 spin_lock_irqsave(&obj->edev->lock, flags);
512 ret = raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
513 spin_unlock_irqrestore(&obj->edev->lock, flags);
517 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
520 * extcon_register_notifier() - Register a notifiee to get notified by
521 * any attach status changes from the extcon.
522 * @edev: the extcon device.
523 * @nb: a notifier block to be registered.
525 * Note that the second parameter given to the callback of nb (val) is
526 * "old_state", not the current state. The current state can be retrieved
527 * by looking at the third pameter (edev pointer)'s state value.
529 int extcon_register_notifier(struct extcon_dev *edev,
530 struct notifier_block *nb)
535 spin_lock_irqsave(&edev->lock, flags);
536 ret = raw_notifier_chain_register(&edev->nh, nb);
537 spin_unlock_irqrestore(&edev->lock, flags);
541 EXPORT_SYMBOL_GPL(extcon_register_notifier);
544 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
545 * @edev: the extcon device.
546 * @nb: a registered notifier block to be unregistered.
548 int extcon_unregister_notifier(struct extcon_dev *edev,
549 struct notifier_block *nb)
554 spin_lock_irqsave(&edev->lock, flags);
555 ret = raw_notifier_chain_unregister(&edev->nh, nb);
556 spin_unlock_irqrestore(&edev->lock, flags);
560 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
562 static struct attribute *extcon_attrs[] = {
563 &dev_attr_state.attr,
567 ATTRIBUTE_GROUPS(extcon);
569 static int create_extcon_class(void)
572 extcon_class = class_create(THIS_MODULE, "extcon");
573 if (IS_ERR(extcon_class))
574 return PTR_ERR(extcon_class);
575 extcon_class->dev_groups = extcon_groups;
577 #if defined(CONFIG_ANDROID)
578 switch_class = class_compat_register("switch");
579 if (WARN(!switch_class, "cannot allocate"))
581 #endif /* CONFIG_ANDROID */
587 static void extcon_dev_release(struct device *dev)
591 static const char *muex_name = "mutually_exclusive";
592 static void dummy_sysfs_dev_release(struct device *dev)
597 * extcon_dev_allocate() - Allocate the memory of extcon device.
598 * @supported_cable: Array of supported cable names ending with NULL.
599 * If supported_cable is NULL, cable name related APIs
602 * This function allocates the memory for extcon device without allocating
603 * memory in each extcon provider driver and initialize default setting for
606 * Return the pointer of extcon device if success or ERR_PTR(err) if fail
608 struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
610 struct extcon_dev *edev;
612 edev = kzalloc(sizeof(*edev), GFP_KERNEL);
614 return ERR_PTR(-ENOMEM);
616 edev->max_supported = 0;
617 edev->supported_cable = supported_cable;
623 * extcon_dev_free() - Free the memory of extcon device.
624 * @edev: the extcon device to free
626 void extcon_dev_free(struct extcon_dev *edev)
630 EXPORT_SYMBOL_GPL(extcon_dev_free);
632 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
634 struct extcon_dev **r = res;
636 if (WARN_ON(!r || !*r))
642 static void devm_extcon_dev_release(struct device *dev, void *res)
644 extcon_dev_free(*(struct extcon_dev **)res);
648 * devm_extcon_dev_allocate - Allocate managed extcon device
649 * @dev: device owning the extcon device being created
650 * @supported_cable: Array of supported cable names ending with NULL.
651 * If supported_cable is NULL, cable name related APIs
654 * This function manages automatically the memory of extcon device using device
655 * resource management and simplify the control of freeing the memory of extcon
658 * Returns the pointer memory of allocated extcon_dev if success
659 * or ERR_PTR(err) if fail
661 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
662 const char **supported_cable)
664 struct extcon_dev **ptr, *edev;
666 ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
668 return ERR_PTR(-ENOMEM);
670 edev = extcon_dev_allocate(supported_cable);
676 edev->dev.parent = dev;
679 devres_add(dev, ptr);
683 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
685 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
687 WARN_ON(devres_release(dev, devm_extcon_dev_release,
688 devm_extcon_dev_match, edev));
690 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
693 * extcon_dev_register() - Register a new extcon device
694 * @edev : the new extcon device (should be allocated before calling)
696 * Among the members of edev struct, please set the "user initializing data"
697 * in any case and set the "optional callbacks" if required. However, please
698 * do not set the values of "internal data", which are initialized by
701 int extcon_dev_register(struct extcon_dev *edev)
706 ret = create_extcon_class();
711 if (edev->supported_cable) {
712 /* Get size of array */
713 for (index = 0; edev->supported_cable[index]; index++)
715 edev->max_supported = index;
717 edev->max_supported = 0;
720 if (index > SUPPORTED_CABLE_MAX) {
721 dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
725 edev->dev.class = extcon_class;
726 edev->dev.release = extcon_dev_release;
728 edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
729 if (IS_ERR_OR_NULL(edev->name)) {
731 "extcon device name is null\n");
734 dev_set_name(&edev->dev, "%s", edev->name);
736 if (edev->max_supported) {
739 struct extcon_cable *cable;
741 edev->cables = kzalloc(sizeof(struct extcon_cable) *
742 edev->max_supported, GFP_KERNEL);
745 goto err_sysfs_alloc;
747 for (index = 0; index < edev->max_supported; index++) {
748 cable = &edev->cables[index];
750 snprintf(buf, 10, "cable.%d", index);
751 str = kzalloc(sizeof(char) * (strlen(buf) + 1),
754 for (index--; index >= 0; index--) {
755 cable = &edev->cables[index];
756 kfree(cable->attr_g.name);
760 goto err_alloc_cables;
765 cable->cable_index = index;
766 cable->attrs[0] = &cable->attr_name.attr;
767 cable->attrs[1] = &cable->attr_state.attr;
768 cable->attrs[2] = NULL;
769 cable->attr_g.name = str;
770 cable->attr_g.attrs = cable->attrs;
772 sysfs_attr_init(&cable->attr_name.attr);
773 cable->attr_name.attr.name = "name";
774 cable->attr_name.attr.mode = 0444;
775 cable->attr_name.show = cable_name_show;
777 sysfs_attr_init(&cable->attr_state.attr);
778 cable->attr_state.attr.name = "state";
779 cable->attr_state.attr.mode = 0444;
780 cable->attr_state.show = cable_state_show;
784 if (edev->max_supported && edev->mutually_exclusive) {
788 /* Count the size of mutually_exclusive array */
789 for (index = 0; edev->mutually_exclusive[index]; index++)
792 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
793 (index + 1), GFP_KERNEL);
794 if (!edev->attrs_muex) {
799 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
801 if (!edev->d_attrs_muex) {
803 kfree(edev->attrs_muex);
807 for (index = 0; edev->mutually_exclusive[index]; index++) {
808 sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
809 name = kzalloc(sizeof(char) * (strlen(buf) + 1),
812 for (index--; index >= 0; index--) {
813 kfree(edev->d_attrs_muex[index].attr.
816 kfree(edev->d_attrs_muex);
817 kfree(edev->attrs_muex);
822 sysfs_attr_init(&edev->d_attrs_muex[index].attr);
823 edev->d_attrs_muex[index].attr.name = name;
824 edev->d_attrs_muex[index].attr.mode = 0000;
825 edev->attrs_muex[index] = &edev->d_attrs_muex[index]
828 edev->attr_g_muex.name = muex_name;
829 edev->attr_g_muex.attrs = edev->attrs_muex;
833 if (edev->max_supported) {
834 edev->extcon_dev_type.groups =
835 kzalloc(sizeof(struct attribute_group *) *
836 (edev->max_supported + 2), GFP_KERNEL);
837 if (!edev->extcon_dev_type.groups) {
839 goto err_alloc_groups;
842 edev->extcon_dev_type.name = dev_name(&edev->dev);
843 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
845 for (index = 0; index < edev->max_supported; index++)
846 edev->extcon_dev_type.groups[index] =
847 &edev->cables[index].attr_g;
848 if (edev->mutually_exclusive)
849 edev->extcon_dev_type.groups[index] =
852 edev->dev.type = &edev->extcon_dev_type;
855 ret = device_register(&edev->dev);
857 put_device(&edev->dev);
860 #if defined(CONFIG_ANDROID)
862 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
863 #endif /* CONFIG_ANDROID */
865 spin_lock_init(&edev->lock);
867 RAW_INIT_NOTIFIER_HEAD(&edev->nh);
869 dev_set_drvdata(&edev->dev, edev);
872 mutex_lock(&extcon_dev_list_lock);
873 list_add(&edev->entry, &extcon_dev_list);
874 mutex_unlock(&extcon_dev_list_lock);
879 if (edev->max_supported)
880 kfree(edev->extcon_dev_type.groups);
882 if (edev->max_supported && edev->mutually_exclusive) {
883 for (index = 0; edev->mutually_exclusive[index]; index++)
884 kfree(edev->d_attrs_muex[index].attr.name);
885 kfree(edev->d_attrs_muex);
886 kfree(edev->attrs_muex);
889 for (index = 0; index < edev->max_supported; index++)
890 kfree(edev->cables[index].attr_g.name);
892 if (edev->max_supported)
897 EXPORT_SYMBOL_GPL(extcon_dev_register);
900 * extcon_dev_unregister() - Unregister the extcon device.
901 * @edev: the extcon device instance to be unregistered.
903 * Note that this does not call kfree(edev) because edev was not allocated
906 void extcon_dev_unregister(struct extcon_dev *edev)
910 mutex_lock(&extcon_dev_list_lock);
911 list_del(&edev->entry);
912 mutex_unlock(&extcon_dev_list_lock);
914 if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
915 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
916 dev_name(&edev->dev));
920 device_unregister(&edev->dev);
922 if (edev->mutually_exclusive && edev->max_supported) {
923 for (index = 0; edev->mutually_exclusive[index];
925 kfree(edev->d_attrs_muex[index].attr.name);
926 kfree(edev->d_attrs_muex);
927 kfree(edev->attrs_muex);
930 for (index = 0; index < edev->max_supported; index++)
931 kfree(edev->cables[index].attr_g.name);
933 if (edev->max_supported) {
934 kfree(edev->extcon_dev_type.groups);
938 #if defined(CONFIG_ANDROID)
940 class_compat_remove_link(switch_class, &edev->dev, NULL);
942 put_device(&edev->dev);
944 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
946 static void devm_extcon_dev_unreg(struct device *dev, void *res)
948 extcon_dev_unregister(*(struct extcon_dev **)res);
952 * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
953 * @dev: device to allocate extcon device
954 * @edev: the new extcon device to register
956 * Managed extcon_dev_register() function. If extcon device is attached with
957 * this function, that extcon device is automatically unregistered on driver
958 * detach. Internally this function calls extcon_dev_register() function.
959 * To get more information, refer that function.
961 * If extcon device is registered with this function and the device needs to be
962 * unregistered separately, devm_extcon_dev_unregister() should be used.
964 * Returns 0 if success or negaive error number if failure.
966 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
968 struct extcon_dev **ptr;
971 ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
975 ret = extcon_dev_register(edev);
982 devres_add(dev, ptr);
986 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
989 * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
990 * @dev: device the extcon belongs to
991 * @edev: the extcon device to unregister
993 * Unregister extcon device that is registered with devm_extcon_dev_register()
996 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
998 WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
999 devm_extcon_dev_match, edev));
1001 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1005 * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1006 * @dev - instance to the given device
1007 * @index - index into list of extcon_dev
1009 * return the instance of extcon device
1011 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1013 struct device_node *node;
1014 struct extcon_dev *edev;
1016 if (!dev->of_node) {
1017 dev_err(dev, "device does not have a device node entry\n");
1018 return ERR_PTR(-EINVAL);
1021 node = of_parse_phandle(dev->of_node, "extcon", index);
1023 dev_err(dev, "failed to get phandle in %s node\n",
1024 dev->of_node->full_name);
1025 return ERR_PTR(-ENODEV);
1028 mutex_lock(&extcon_dev_list_lock);
1029 list_for_each_entry(edev, &extcon_dev_list, entry) {
1030 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1031 mutex_unlock(&extcon_dev_list_lock);
1035 mutex_unlock(&extcon_dev_list_lock);
1037 return ERR_PTR(-EPROBE_DEFER);
1040 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1042 return ERR_PTR(-ENOSYS);
1044 #endif /* CONFIG_OF */
1045 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1047 static int __init extcon_class_init(void)
1049 return create_extcon_class();
1051 module_init(extcon_class_init);
1053 static void __exit extcon_class_exit(void)
1055 #if defined(CONFIG_ANDROID)
1056 class_compat_unregister(switch_class);
1058 class_destroy(extcon_class);
1060 module_exit(extcon_class_exit);
1062 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1063 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1064 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1065 MODULE_DESCRIPTION("External connector (extcon) class driver");
1066 MODULE_LICENSE("GPL");