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>
32 #include <linux/slab.h>
33 #include <linux/sysfs.h>
36 * extcon_cable_name suggests the standard cable names for commonly used
39 * However, please do not use extcon_cable_name directly for extcon_dev
40 * struct's supported_cable pointer unless your device really supports
41 * every single port-type of the following cable names. Please choose cable
42 * names that are actually used in your extcon device.
44 const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
46 [EXTCON_USB_HOST] = "USB-Host",
48 [EXTCON_FAST_CHARGER] = "Fast-charger",
49 [EXTCON_SLOW_CHARGER] = "Slow-charger",
50 [EXTCON_CHARGE_DOWNSTREAM] = "Charge-downstream",
51 [EXTCON_HDMI] = "HDMI",
55 [EXTCON_DOCK] = "Dock",
56 [EXTCON_LINE_IN] = "Line-in",
57 [EXTCON_LINE_OUT] = "Line-out",
58 [EXTCON_MIC_IN] = "Microphone",
59 [EXTCON_HEADPHONE_OUT] = "Headphone",
60 [EXTCON_SPDIF_IN] = "SPDIF-in",
61 [EXTCON_SPDIF_OUT] = "SPDIF-out",
62 [EXTCON_VIDEO_IN] = "Video-in",
63 [EXTCON_VIDEO_OUT] = "Video-out",
64 [EXTCON_MECHANICAL] = "Mechanical",
67 static struct class *extcon_class;
68 #if defined(CONFIG_ANDROID)
69 static struct class_compat *switch_class;
70 #endif /* CONFIG_ANDROID */
72 static LIST_HEAD(extcon_dev_list);
73 static DEFINE_MUTEX(extcon_dev_list_lock);
76 * check_mutually_exclusive - Check if new_state violates mutually_exclusive
78 * @edev: the extcon device
79 * @new_state: new cable attach status for @edev
81 * Returns 0 if nothing violates. Returns the index + 1 for the first
84 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
88 if (!edev->mutually_exclusive)
91 for (i = 0; edev->mutually_exclusive[i]; i++) {
93 u32 correspondants = new_state & edev->mutually_exclusive[i];
95 /* calculate the total number of bits set */
96 weight = hweight32(correspondants);
104 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
108 struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
110 if (edev->print_state) {
111 int ret = edev->print_state(edev, buf);
115 /* Use default if failed */
118 if (edev->max_supported == 0)
119 return sprintf(buf, "%u\n", edev->state);
121 for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
122 if (!edev->supported_cable[i])
124 count += sprintf(buf + count, "%s=%d\n",
125 edev->supported_cable[i],
126 !!(edev->state & (1 << i)));
132 int extcon_set_state(struct extcon_dev *edev, u32 state);
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 = (struct extcon_dev *) 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 = (struct extcon_dev *) dev_get_drvdata(dev);
158 /* Optional callback given by the user */
159 if (edev->print_name) {
160 int ret = edev->print_name(edev, buf);
165 return sprintf(buf, "%s\n", dev_name(edev->dev));
167 static DEVICE_ATTR_RO(name);
169 static ssize_t cable_name_show(struct device *dev,
170 struct device_attribute *attr, char *buf)
172 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
175 return sprintf(buf, "%s\n",
176 cable->edev->supported_cable[cable->cable_index]);
179 static ssize_t cable_state_show(struct device *dev,
180 struct device_attribute *attr, char *buf)
182 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
185 return sprintf(buf, "%d\n",
186 extcon_get_cable_state_(cable->edev,
187 cable->cable_index));
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
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.
202 * Note that the notifier provides which bits are changed in the state
203 * variable with the val parameter (second) to the callback.
205 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
215 spin_lock_irqsave(&edev->lock, flags);
217 if (edev->state != ((edev->state & ~mask) | (state & mask))) {
218 u32 old_state = edev->state;
220 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
222 spin_unlock_irqrestore(&edev->lock, flags);
226 edev->state &= ~mask;
227 edev->state |= state & mask;
229 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 extcon_find_cable_index().
344 * @cable_state: the new cable status. The default semantics is
345 * true: attached / false: detached.
347 int extcon_set_cable_state_(struct extcon_dev *edev,
348 int index, bool cable_state)
352 if (index < 0 || (edev->max_supported && edev->max_supported <= index))
355 state = cable_state ? (1 << index) : 0;
356 return extcon_update_state(edev, 1 << index, state);
358 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
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.
367 * Note that this is slower than extcon_set_cable_state_.
369 int extcon_set_cable_state(struct extcon_dev *edev,
370 const char *cable_name, bool cable_state)
372 return extcon_set_cable_state_(edev, extcon_find_cable_index
373 (edev, cable_name), cable_state);
375 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
378 * extcon_get_extcon_dev() - Get the extcon device instance from the name
379 * @extcon_name: The extcon name provided with extcon_dev_register()
381 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
383 struct extcon_dev *sd;
385 mutex_lock(&extcon_dev_list_lock);
386 list_for_each_entry(sd, &extcon_dev_list, entry) {
387 if (!strcmp(sd->name, extcon_name))
392 mutex_unlock(&extcon_dev_list_lock);
395 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
397 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
400 struct extcon_specific_cable_nb *obj = container_of(nb,
401 struct extcon_specific_cable_nb, internal_nb);
402 struct extcon_dev *edev = ptr;
404 if ((val & (1 << obj->cable_index)) !=
405 (edev->state & (1 << obj->cable_index))) {
406 bool cable_state = true;
408 obj->previous_value = val;
410 if (val & (1 << obj->cable_index))
413 return obj->user_nb->notifier_call(obj->user_nb,
421 * extcon_register_interest() - Register a notifier for a state change of a
422 * specific cable, not an entier set of cables of a
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.
431 * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
432 * the struct for you.
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().
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.
443 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
444 const char *extcon_name, const char *cable_name,
445 struct notifier_block *nb)
447 if (!obj || !cable_name || !nb)
451 obj->edev = extcon_get_extcon_dev(extcon_name);
455 obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
456 if (obj->cable_index < 0)
457 return obj->cable_index;
461 obj->internal_nb.notifier_call = _call_per_cable;
463 return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
465 struct class_dev_iter iter;
466 struct extcon_dev *extd;
471 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
472 while ((dev = class_dev_iter_next(&iter))) {
473 extd = (struct extcon_dev *)dev_get_drvdata(dev);
475 if (extcon_find_cable_index(extd, cable_name) < 0)
478 class_dev_iter_exit(&iter);
479 return extcon_register_interest(obj, extd->name,
486 EXPORT_SYMBOL_GPL(extcon_register_interest);
489 * extcon_unregister_interest() - Unregister the notifier registered by
490 * extcon_register_interest().
491 * @obj: the extcon_specific_cable_nb object returned by
492 * extcon_register_interest().
494 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
499 return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
501 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
504 * extcon_register_notifier() - Register a notifiee to get notified by
505 * any attach status changes from the extcon.
506 * @edev: the extcon device.
507 * @nb: a notifier block to be registered.
509 * Note that the second parameter given to the callback of nb (val) is
510 * "old_state", not the current state. The current state can be retrieved
511 * by looking at the third pameter (edev pointer)'s state value.
513 int extcon_register_notifier(struct extcon_dev *edev,
514 struct notifier_block *nb)
516 return raw_notifier_chain_register(&edev->nh, nb);
518 EXPORT_SYMBOL_GPL(extcon_register_notifier);
521 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
522 * @edev: the extcon device.
523 * @nb: a registered notifier block to be unregistered.
525 int extcon_unregister_notifier(struct extcon_dev *edev,
526 struct notifier_block *nb)
528 return raw_notifier_chain_unregister(&edev->nh, nb);
530 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
532 static struct attribute *extcon_attrs[] = {
533 &dev_attr_state.attr,
537 ATTRIBUTE_GROUPS(extcon);
539 static int create_extcon_class(void)
542 extcon_class = class_create(THIS_MODULE, "extcon");
543 if (IS_ERR(extcon_class))
544 return PTR_ERR(extcon_class);
545 extcon_class->dev_groups = extcon_groups;
547 #if defined(CONFIG_ANDROID)
548 switch_class = class_compat_register("switch");
549 if (WARN(!switch_class, "cannot allocate"))
551 #endif /* CONFIG_ANDROID */
557 static void extcon_dev_release(struct device *dev)
562 static const char *muex_name = "mutually_exclusive";
563 static void dummy_sysfs_dev_release(struct device *dev)
568 * extcon_dev_register() - Register a new extcon device
569 * @edev : the new extcon device (should be allocated before calling)
570 * @dev : the parent device for this extcon device.
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
577 int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
582 ret = create_extcon_class();
587 if (edev->supported_cable) {
588 /* Get size of array */
589 for (index = 0; edev->supported_cable[index]; index++)
591 edev->max_supported = index;
593 edev->max_supported = 0;
596 if (index > SUPPORTED_CABLE_MAX) {
597 dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
601 edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
604 edev->dev->parent = dev;
605 edev->dev->class = extcon_class;
606 edev->dev->release = extcon_dev_release;
608 edev->name = edev->name ? edev->name : dev_name(dev);
609 dev_set_name(edev->dev, "%s", edev->name);
611 if (edev->max_supported) {
614 struct extcon_cable *cable;
616 edev->cables = kzalloc(sizeof(struct extcon_cable) *
617 edev->max_supported, GFP_KERNEL);
620 goto err_sysfs_alloc;
622 for (index = 0; index < edev->max_supported; index++) {
623 cable = &edev->cables[index];
625 snprintf(buf, 10, "cable.%d", index);
626 str = kzalloc(sizeof(char) * (strlen(buf) + 1),
629 for (index--; index >= 0; index--) {
630 cable = &edev->cables[index];
631 kfree(cable->attr_g.name);
635 goto err_alloc_cables;
640 cable->cable_index = index;
641 cable->attrs[0] = &cable->attr_name.attr;
642 cable->attrs[1] = &cable->attr_state.attr;
643 cable->attrs[2] = NULL;
644 cable->attr_g.name = str;
645 cable->attr_g.attrs = cable->attrs;
647 sysfs_attr_init(&cable->attr_name.attr);
648 cable->attr_name.attr.name = "name";
649 cable->attr_name.attr.mode = 0444;
650 cable->attr_name.show = cable_name_show;
652 sysfs_attr_init(&cable->attr_state.attr);
653 cable->attr_state.attr.name = "state";
654 cable->attr_state.attr.mode = 0444;
655 cable->attr_state.show = cable_state_show;
659 if (edev->max_supported && edev->mutually_exclusive) {
663 /* Count the size of mutually_exclusive array */
664 for (index = 0; edev->mutually_exclusive[index]; index++)
667 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
668 (index + 1), GFP_KERNEL);
669 if (!edev->attrs_muex) {
674 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
676 if (!edev->d_attrs_muex) {
678 kfree(edev->attrs_muex);
682 for (index = 0; edev->mutually_exclusive[index]; index++) {
683 sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
684 name = kzalloc(sizeof(char) * (strlen(buf) + 1),
687 for (index--; index >= 0; index--) {
688 kfree(edev->d_attrs_muex[index].attr.
691 kfree(edev->d_attrs_muex);
692 kfree(edev->attrs_muex);
697 sysfs_attr_init(&edev->d_attrs_muex[index].attr);
698 edev->d_attrs_muex[index].attr.name = name;
699 edev->d_attrs_muex[index].attr.mode = 0000;
700 edev->attrs_muex[index] = &edev->d_attrs_muex[index]
703 edev->attr_g_muex.name = muex_name;
704 edev->attr_g_muex.attrs = edev->attrs_muex;
708 if (edev->max_supported) {
709 edev->extcon_dev_type.groups =
710 kzalloc(sizeof(struct attribute_group *) *
711 (edev->max_supported + 2), GFP_KERNEL);
712 if (!edev->extcon_dev_type.groups) {
714 goto err_alloc_groups;
717 edev->extcon_dev_type.name = dev_name(edev->dev);
718 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
720 for (index = 0; index < edev->max_supported; index++)
721 edev->extcon_dev_type.groups[index] =
722 &edev->cables[index].attr_g;
723 if (edev->mutually_exclusive)
724 edev->extcon_dev_type.groups[index] =
727 edev->dev->type = &edev->extcon_dev_type;
730 ret = device_register(edev->dev);
732 put_device(edev->dev);
735 #if defined(CONFIG_ANDROID)
737 ret = class_compat_create_link(switch_class, edev->dev,
739 #endif /* CONFIG_ANDROID */
741 spin_lock_init(&edev->lock);
743 RAW_INIT_NOTIFIER_HEAD(&edev->nh);
745 dev_set_drvdata(edev->dev, edev);
748 mutex_lock(&extcon_dev_list_lock);
749 list_add(&edev->entry, &extcon_dev_list);
750 mutex_unlock(&extcon_dev_list_lock);
755 if (edev->max_supported)
756 kfree(edev->extcon_dev_type.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);
765 for (index = 0; index < edev->max_supported; index++)
766 kfree(edev->cables[index].attr_g.name);
768 if (edev->max_supported)
774 EXPORT_SYMBOL_GPL(extcon_dev_register);
777 * extcon_dev_unregister() - Unregister the extcon device.
778 * @edev: the extcon device instance to be unregistered.
780 * Note that this does not call kfree(edev) because edev was not allocated
783 void extcon_dev_unregister(struct extcon_dev *edev)
787 mutex_lock(&extcon_dev_list_lock);
788 list_del(&edev->entry);
789 mutex_unlock(&extcon_dev_list_lock);
791 if (IS_ERR_OR_NULL(get_device(edev->dev))) {
792 dev_err(edev->dev, "Failed to unregister extcon_dev (%s)\n",
793 dev_name(edev->dev));
797 if (edev->mutually_exclusive && edev->max_supported) {
798 for (index = 0; edev->mutually_exclusive[index];
800 kfree(edev->d_attrs_muex[index].attr.name);
801 kfree(edev->d_attrs_muex);
802 kfree(edev->attrs_muex);
805 for (index = 0; index < edev->max_supported; index++)
806 kfree(edev->cables[index].attr_g.name);
808 if (edev->max_supported) {
809 kfree(edev->extcon_dev_type.groups);
813 #if defined(CONFIG_ANDROID)
815 class_compat_remove_link(switch_class, edev->dev, NULL);
817 device_unregister(edev->dev);
818 put_device(edev->dev);
820 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
822 static int __init extcon_class_init(void)
824 return create_extcon_class();
826 module_init(extcon_class_init);
828 static void __exit extcon_class_exit(void)
830 #if defined(CONFIG_ANDROID)
831 class_compat_unregister(switch_class);
833 class_destroy(extcon_class);
835 module_exit(extcon_class_exit);
837 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
838 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
839 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
840 MODULE_DESCRIPTION("External connector (extcon) class driver");
841 MODULE_LICENSE("GPL");