2 * drivers/extcon/extcon.c - External Connector (extcon) framework.
4 * External connector (extcon) class driver
6 * Copyright (C) 2015 Samsung Electronics
7 * Author: Chanwoo Choi <cw00.choi@samsung.com>
9 * Copyright (C) 2012 Samsung Electronics
10 * Author: Donggeun Kim <dg77.kim@samsung.com>
11 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
13 * based on android/drivers/switch/switch_class.c
14 * Copyright (C) 2008 Google, Inc.
15 * Author: Mike Lockwood <lockwood@android.com>
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.
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.
27 #include <linux/module.h>
28 #include <linux/types.h>
29 #include <linux/init.h>
30 #include <linux/device.h>
32 #include <linux/err.h>
33 #include <linux/extcon.h>
35 #include <linux/slab.h>
36 #include <linux/sysfs.h>
38 #define SUPPORTED_CABLE_MAX 32
39 #define CABLE_NAME_MAX 30
41 static const char *extcon_name[] = {
42 [EXTCON_NONE] = "NONE",
44 /* USB external connector */
46 [EXTCON_USB_HOST] = "USB-HOST",
48 /* Charging external connector */
49 [EXTCON_CHG_USB_SDP] = "SDP",
50 [EXTCON_CHG_USB_DCP] = "DCP",
51 [EXTCON_CHG_USB_CDP] = "CDP",
52 [EXTCON_CHG_USB_ACA] = "ACA",
53 [EXTCON_CHG_USB_FAST] = "FAST-CHARGER",
54 [EXTCON_CHG_USB_SLOW] = "SLOW-CHARGER",
56 /* Jack external connector */
57 [EXTCON_JACK_MICROPHONE] = "MICROPHONE",
58 [EXTCON_JACK_HEADPHONE] = "HEADPHONE",
59 [EXTCON_JACK_LINE_IN] = "LINE-IN",
60 [EXTCON_JACK_LINE_OUT] = "LINE-OUT",
61 [EXTCON_JACK_VIDEO_IN] = "VIDEO-IN",
62 [EXTCON_JACK_VIDEO_OUT] = "VIDEO-OUT",
63 [EXTCON_JACK_SPDIF_IN] = "SPDIF-IN",
64 [EXTCON_JACK_SPDIF_OUT] = "SPDIF-OUT",
66 /* Display external connector */
67 [EXTCON_DISP_HDMI] = "HDMI",
68 [EXTCON_DISP_MHL] = "MHL",
69 [EXTCON_DISP_DVI] = "DVI",
70 [EXTCON_DISP_VGA] = "VGA",
72 /* Miscellaneous external connector */
73 [EXTCON_DOCK] = "DOCK",
75 [EXTCON_MECHANICAL] = "MECHANICAL",
81 * struct extcon_cable - An internal data for each cable of extcon device.
82 * @edev: The extcon device
83 * @cable_index: Index of this cable in the edev
84 * @attr_g: Attribute group for the cable
85 * @attr_name: "name" sysfs entry
86 * @attr_state: "state" sysfs entry
87 * @attrs: Array pointing to attr_name and attr_state for attr_g
90 struct extcon_dev *edev;
93 struct attribute_group attr_g;
94 struct device_attribute attr_name;
95 struct device_attribute attr_state;
97 struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
100 static struct class *extcon_class;
101 #if defined(CONFIG_ANDROID)
102 static struct class_compat *switch_class;
103 #endif /* CONFIG_ANDROID */
105 static LIST_HEAD(extcon_dev_list);
106 static DEFINE_MUTEX(extcon_dev_list_lock);
109 * check_mutually_exclusive - Check if new_state violates mutually_exclusive
111 * @edev: the extcon device
112 * @new_state: new cable attach status for @edev
114 * Returns 0 if nothing violates. Returns the index + 1 for the first
115 * violated condition.
117 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
121 if (!edev->mutually_exclusive)
124 for (i = 0; edev->mutually_exclusive[i]; i++) {
126 u32 correspondants = new_state & edev->mutually_exclusive[i];
128 /* calculate the total number of bits set */
129 weight = hweight32(correspondants);
137 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
141 /* Find the the index of extcon cable in edev->supported_cable */
142 for (i = 0; i < edev->max_supported; i++) {
143 if (edev->supported_cable[i] == id)
150 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
152 if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
153 *attached = ((new >> idx) & 0x1) ? true : false;
160 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
164 struct extcon_dev *edev = dev_get_drvdata(dev);
166 if (edev->max_supported == 0)
167 return sprintf(buf, "%u\n", edev->state);
169 for (i = 0; i < edev->max_supported; i++) {
170 count += sprintf(buf + count, "%s=%d\n",
171 extcon_name[edev->supported_cable[i]],
172 !!(edev->state & (1 << i)));
178 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
179 const char *buf, size_t count)
183 struct extcon_dev *edev = dev_get_drvdata(dev);
185 ret = sscanf(buf, "0x%x", &state);
189 ret = extcon_set_state(edev, state);
196 static DEVICE_ATTR_RW(state);
198 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
201 struct extcon_dev *edev = dev_get_drvdata(dev);
203 return sprintf(buf, "%s\n", edev->name);
205 static DEVICE_ATTR_RO(name);
207 static ssize_t cable_name_show(struct device *dev,
208 struct device_attribute *attr, char *buf)
210 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
212 int i = cable->cable_index;
214 return sprintf(buf, "%s\n",
215 extcon_name[cable->edev->supported_cable[i]]);
218 static ssize_t cable_state_show(struct device *dev,
219 struct device_attribute *attr, char *buf)
221 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
224 int i = cable->cable_index;
226 return sprintf(buf, "%d\n",
227 extcon_get_cable_state_(cable->edev,
228 cable->edev->supported_cable[i]));
232 * extcon_update_state() - Update the cable attach states of the extcon device
233 * only for the masked bits.
234 * @edev: the extcon device
235 * @mask: the bit mask to designate updated bits.
236 * @state: new cable attach status for @edev
238 * Changing the state sends uevent with environment variable containing
239 * the name of extcon device (envp[0]) and the state output (envp[1]).
240 * Tizen uses this format for extcon device to get events from ports.
241 * Android uses this format as well.
243 * Note that the notifier provides which bits are changed in the state
244 * variable with the val parameter (second) to the callback.
246 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
261 spin_lock_irqsave(&edev->lock, flags);
263 if (edev->state != ((edev->state & ~mask) | (state & mask))) {
266 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
268 spin_unlock_irqrestore(&edev->lock, flags);
272 old_state = edev->state;
273 edev->state &= ~mask;
274 edev->state |= state & mask;
276 for (index = 0; index < edev->max_supported; index++) {
277 if (is_extcon_changed(old_state, edev->state, index,
279 raw_notifier_call_chain(&edev->nh[index],
283 /* This could be in interrupt handler */
284 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
286 length = name_show(&edev->dev, NULL, prop_buf);
288 if (prop_buf[length - 1] == '\n')
289 prop_buf[length - 1] = 0;
290 snprintf(name_buf, sizeof(name_buf),
291 "NAME=%s", prop_buf);
292 envp[env_offset++] = name_buf;
294 length = state_show(&edev->dev, NULL, prop_buf);
296 if (prop_buf[length - 1] == '\n')
297 prop_buf[length - 1] = 0;
298 snprintf(state_buf, sizeof(state_buf),
299 "STATE=%s", prop_buf);
300 envp[env_offset++] = state_buf;
302 envp[env_offset] = NULL;
303 /* Unlock early before uevent */
304 spin_unlock_irqrestore(&edev->lock, flags);
306 kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
307 free_page((unsigned long)prop_buf);
309 /* Unlock early before uevent */
310 spin_unlock_irqrestore(&edev->lock, flags);
312 dev_err(&edev->dev, "out of memory in extcon_set_state\n");
313 kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
317 spin_unlock_irqrestore(&edev->lock, flags);
322 EXPORT_SYMBOL_GPL(extcon_update_state);
325 * extcon_set_state() - Set the cable attach states of the extcon device.
326 * @edev: the extcon device
327 * @state: new cable attach status for @edev
329 * Note that notifier provides which bits are changed in the state
330 * variable with the val parameter (second) to the callback.
332 int extcon_set_state(struct extcon_dev *edev, u32 state)
337 return extcon_update_state(edev, 0xffffffff, state);
339 EXPORT_SYMBOL_GPL(extcon_set_state);
342 * extcon_get_cable_state_() - Get the status of a specific cable.
343 * @edev: the extcon device that has the cable.
344 * @id: the unique id of each external connector in extcon enumeration.
346 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
353 index = find_cable_index_by_id(edev, id);
357 if (edev->max_supported && edev->max_supported <= index)
360 return !!(edev->state & (1 << index));
362 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
365 * extcon_set_cable_state_() - Set the status of a specific cable.
366 * @edev: the extcon device that has the cable.
367 * @id: the unique id of each external connector
368 * in extcon enumeration.
369 * @state: the new cable status. The default semantics is
370 * true: attached / false: detached.
372 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
381 index = find_cable_index_by_id(edev, id);
385 if (edev->max_supported && edev->max_supported <= index)
388 state = cable_state ? (1 << index) : 0;
389 return extcon_update_state(edev, 1 << index, state);
391 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
394 * extcon_get_extcon_dev() - Get the extcon device instance from the name
395 * @extcon_name: The extcon name provided with extcon_dev_register()
397 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
399 struct extcon_dev *sd;
402 return ERR_PTR(-EINVAL);
404 mutex_lock(&extcon_dev_list_lock);
405 list_for_each_entry(sd, &extcon_dev_list, entry) {
406 if (!strcmp(sd->name, extcon_name))
411 mutex_unlock(&extcon_dev_list_lock);
414 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
417 * extcon_register_notifier() - Register a notifiee to get notified by
418 * any attach status changes from the extcon.
419 * @edev: the extcon device that has the external connecotr.
420 * @id: the unique id of each external connector in extcon enumeration.
421 * @nb: a notifier block to be registered.
423 * Note that the second parameter given to the callback of nb (val) is
424 * "old_state", not the current state. The current state can be retrieved
425 * by looking at the third pameter (edev pointer)'s state value.
427 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
428 struct notifier_block *nb)
437 idx = find_cable_index_by_id(edev, id);
441 spin_lock_irqsave(&edev->lock, flags);
442 ret = raw_notifier_chain_register(&edev->nh[idx], nb);
443 spin_unlock_irqrestore(&edev->lock, flags);
445 struct extcon_dev *extd;
447 mutex_lock(&extcon_dev_list_lock);
448 list_for_each_entry(extd, &extcon_dev_list, entry) {
449 idx = find_cable_index_by_id(extd, id);
453 mutex_unlock(&extcon_dev_list_lock);
457 return extcon_register_notifier(extd, id, nb);
465 EXPORT_SYMBOL_GPL(extcon_register_notifier);
468 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
469 * @edev: the extcon device that has the external connecotr.
470 * @id: the unique id of each external connector in extcon enumeration.
471 * @nb: a notifier block to be registered.
473 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
474 struct notifier_block *nb)
482 idx = find_cable_index_by_id(edev, id);
486 spin_lock_irqsave(&edev->lock, flags);
487 ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
488 spin_unlock_irqrestore(&edev->lock, flags);
492 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
494 static struct attribute *extcon_attrs[] = {
495 &dev_attr_state.attr,
499 ATTRIBUTE_GROUPS(extcon);
501 static int create_extcon_class(void)
504 extcon_class = class_create(THIS_MODULE, "extcon");
505 if (IS_ERR(extcon_class))
506 return PTR_ERR(extcon_class);
507 extcon_class->dev_groups = extcon_groups;
509 #if defined(CONFIG_ANDROID)
510 switch_class = class_compat_register("switch");
511 if (WARN(!switch_class, "cannot allocate"))
513 #endif /* CONFIG_ANDROID */
519 static void extcon_dev_release(struct device *dev)
523 static const char *muex_name = "mutually_exclusive";
524 static void dummy_sysfs_dev_release(struct device *dev)
529 * extcon_dev_allocate() - Allocate the memory of extcon device.
530 * @supported_cable: Array of supported extcon ending with EXTCON_NONE.
531 * If supported_cable is NULL, cable name related APIs
534 * This function allocates the memory for extcon device without allocating
535 * memory in each extcon provider driver and initialize default setting for
538 * Return the pointer of extcon device if success or ERR_PTR(err) if fail
540 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
542 struct extcon_dev *edev;
544 if (!supported_cable)
545 return ERR_PTR(-EINVAL);
547 edev = kzalloc(sizeof(*edev), GFP_KERNEL);
549 return ERR_PTR(-ENOMEM);
551 edev->max_supported = 0;
552 edev->supported_cable = supported_cable;
558 * extcon_dev_free() - Free the memory of extcon device.
559 * @edev: the extcon device to free
561 void extcon_dev_free(struct extcon_dev *edev)
565 EXPORT_SYMBOL_GPL(extcon_dev_free);
568 * extcon_dev_register() - Register a new extcon device
569 * @edev : the new extcon device (should be allocated before calling)
571 * Among the members of edev struct, please set the "user initializing data"
572 * in any case and set the "optional callbacks" if required. However, please
573 * do not set the values of "internal data", which are initialized by
576 int extcon_dev_register(struct extcon_dev *edev)
579 static atomic_t edev_no = ATOMIC_INIT(-1);
582 ret = create_extcon_class();
587 if (!edev || !edev->supported_cable)
590 for (; edev->supported_cable[index] != EXTCON_NONE; index++);
592 edev->max_supported = index;
593 if (index > SUPPORTED_CABLE_MAX) {
595 "exceed the maximum number of supported cables\n");
599 edev->dev.class = extcon_class;
600 edev->dev.release = extcon_dev_release;
602 edev->name = dev_name(edev->dev.parent);
603 if (IS_ERR_OR_NULL(edev->name)) {
605 "extcon device name is null\n");
608 dev_set_name(&edev->dev, "extcon%lu",
609 (unsigned long)atomic_inc_return(&edev_no));
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, NULL);
738 #endif /* CONFIG_ANDROID */
740 spin_lock_init(&edev->lock);
742 edev->nh = devm_kzalloc(&edev->dev,
743 sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
749 for (index = 0; index < edev->max_supported; index++)
750 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
752 dev_set_drvdata(&edev->dev, edev);
755 mutex_lock(&extcon_dev_list_lock);
756 list_add(&edev->entry, &extcon_dev_list);
757 mutex_unlock(&extcon_dev_list_lock);
762 if (edev->max_supported)
763 kfree(edev->extcon_dev_type.groups);
765 if (edev->max_supported && edev->mutually_exclusive) {
766 for (index = 0; edev->mutually_exclusive[index]; index++)
767 kfree(edev->d_attrs_muex[index].attr.name);
768 kfree(edev->d_attrs_muex);
769 kfree(edev->attrs_muex);
772 for (index = 0; index < edev->max_supported; index++)
773 kfree(edev->cables[index].attr_g.name);
775 if (edev->max_supported)
780 EXPORT_SYMBOL_GPL(extcon_dev_register);
783 * extcon_dev_unregister() - Unregister the extcon device.
784 * @edev: the extcon device instance to be unregistered.
786 * Note that this does not call kfree(edev) because edev was not allocated
789 void extcon_dev_unregister(struct extcon_dev *edev)
796 mutex_lock(&extcon_dev_list_lock);
797 list_del(&edev->entry);
798 mutex_unlock(&extcon_dev_list_lock);
800 if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
801 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
802 dev_name(&edev->dev));
806 device_unregister(&edev->dev);
808 if (edev->mutually_exclusive && edev->max_supported) {
809 for (index = 0; edev->mutually_exclusive[index];
811 kfree(edev->d_attrs_muex[index].attr.name);
812 kfree(edev->d_attrs_muex);
813 kfree(edev->attrs_muex);
816 for (index = 0; index < edev->max_supported; index++)
817 kfree(edev->cables[index].attr_g.name);
819 if (edev->max_supported) {
820 kfree(edev->extcon_dev_type.groups);
824 #if defined(CONFIG_ANDROID)
826 class_compat_remove_link(switch_class, &edev->dev, NULL);
828 put_device(&edev->dev);
830 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
834 * extcon_get_edev_by_phandle - Get the extcon device from devicetree
835 * @dev - instance to the given device
836 * @index - index into list of extcon_dev
838 * return the instance of extcon device
840 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
842 struct device_node *node;
843 struct extcon_dev *edev;
846 return ERR_PTR(-EINVAL);
849 dev_err(dev, "device does not have a device node entry\n");
850 return ERR_PTR(-EINVAL);
853 node = of_parse_phandle(dev->of_node, "extcon", index);
855 dev_err(dev, "failed to get phandle in %s node\n",
856 dev->of_node->full_name);
857 return ERR_PTR(-ENODEV);
860 mutex_lock(&extcon_dev_list_lock);
861 list_for_each_entry(edev, &extcon_dev_list, entry) {
862 if (edev->dev.parent && edev->dev.parent->of_node == node) {
863 mutex_unlock(&extcon_dev_list_lock);
868 mutex_unlock(&extcon_dev_list_lock);
871 return ERR_PTR(-EPROBE_DEFER);
874 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
876 return ERR_PTR(-ENOSYS);
878 #endif /* CONFIG_OF */
879 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
882 * extcon_get_edev_name() - Get the name of the extcon device.
883 * @edev: the extcon device
885 const char *extcon_get_edev_name(struct extcon_dev *edev)
887 return !edev ? NULL : edev->name;
890 static int __init extcon_class_init(void)
892 return create_extcon_class();
894 module_init(extcon_class_init);
896 static void __exit extcon_class_exit(void)
898 #if defined(CONFIG_ANDROID)
899 class_compat_unregister(switch_class);
901 class_destroy(extcon_class);
903 module_exit(extcon_class_exit);
905 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
906 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
907 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
908 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
909 MODULE_DESCRIPTION("External connector (extcon) class driver");
910 MODULE_LICENSE("GPL");