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-rw-r--r--drivers/extcon/extcon.c1066
1 files changed, 1066 insertions, 0 deletions
diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
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index 000000000000..4c9f165e4a04
--- /dev/null
+++ b/drivers/extcon/extcon.c
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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/of.h>
33#include <linux/slab.h>
34#include <linux/sysfs.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
162 if (ret >= 0)
163 return ret;
164 }
165
166 return sprintf(buf, "%s\n", dev_name(&edev->dev));
167}
168static DEVICE_ATTR_RO(name);
169
170static ssize_t cable_name_show(struct device *dev,
171 struct device_attribute *attr, char *buf)
172{
173 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
174 attr_name);
175
176 return sprintf(buf, "%s\n",
177 cable->edev->supported_cable[cable->cable_index]);
178}
179
180static ssize_t cable_state_show(struct device *dev,
181 struct device_attribute *attr, char *buf)
182{
183 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
184 attr_state);
185
186 return sprintf(buf, "%d\n",
187 extcon_get_cable_state_(cable->edev,
188 cable->cable_index));
189}
190
191/**
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
197 *
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.
202 *
203 * Note that the notifier provides which bits are changed in the state
204 * variable with the val parameter (second) to the callback.
205 */
206int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
207{
208 char name_buf[120];
209 char state_buf[120];
210 char *prop_buf;
211 char *envp[3];
212 int env_offset = 0;
213 int length;
214 unsigned long flags;
215
216 spin_lock_irqsave(&edev->lock, flags);
217
218 if (edev->state != ((edev->state & ~mask) | (state & mask))) {
219 u32 old_state = edev->state;
220
221 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
222 (state & mask))) {
223 spin_unlock_irqrestore(&edev->lock, flags);
224 return -EPERM;
225 }
226
227 edev->state &= ~mask;
228 edev->state |= state & mask;
229
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);
233 if (prop_buf) {
234 length = name_show(&edev->dev, NULL, prop_buf);
235 if (length > 0) {
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;
241 }
242 length = state_show(&edev->dev, NULL, prop_buf);
243 if (length > 0) {
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;
249 }
250 envp[env_offset] = NULL;
251 /* Unlock early before uevent */
252 spin_unlock_irqrestore(&edev->lock, flags);
253
254 kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
255 free_page((unsigned long)prop_buf);
256 } else {
257 /* Unlock early before uevent */
258 spin_unlock_irqrestore(&edev->lock, flags);
259
260 dev_err(&edev->dev, "out of memory in extcon_set_state\n");
261 kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
262 }
263 } else {
264 /* No changes */
265 spin_unlock_irqrestore(&edev->lock, flags);
266 }
267
268 return 0;
269}
270EXPORT_SYMBOL_GPL(extcon_update_state);
271
272/**
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
276 *
277 * Note that notifier provides which bits are changed in the state
278 * variable with the val parameter (second) to the callback.
279 */
280int extcon_set_state(struct extcon_dev *edev, u32 state)
281{
282 return extcon_update_state(edev, 0xffffffff, state);
283}
284EXPORT_SYMBOL_GPL(extcon_set_state);
285
286/**
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.
290 *
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
294 * is recommended.
295 */
296int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
297{
298 int i;
299
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))
304 return i;
305 }
306 }
307
308 return -EINVAL;
309}
310EXPORT_SYMBOL_GPL(extcon_find_cable_index);
311
312/**
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().
316 */
317int extcon_get_cable_state_(struct extcon_dev *edev, int index)
318{
319 if (index < 0 || (edev->max_supported && edev->max_supported <= index))
320 return -EINVAL;
321
322 return !!(edev->state & (1 << index));
323}
324EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
325
326/**
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.
330 *
331 * Note that this is slower than extcon_get_cable_state_.
332 */
333int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
334{
335 return extcon_get_cable_state_(edev, extcon_find_cable_index
336 (edev, cable_name));
337}
338EXPORT_SYMBOL_GPL(extcon_get_cable_state);
339
340/**
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.
347 */
348int extcon_set_cable_state_(struct extcon_dev *edev,
349 int index, bool cable_state)
350{
351 u32 state;
352
353 if (index < 0 || (edev->max_supported && edev->max_supported <= index))
354 return -EINVAL;
355
356 state = cable_state ? (1 << index) : 0;
357 return extcon_update_state(edev, 1 << index, state);
358}
359EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
360
361/**
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.
367 *
368 * Note that this is slower than extcon_set_cable_state_.
369 */
370int extcon_set_cable_state(struct extcon_dev *edev,
371 const char *cable_name, bool cable_state)
372{
373 return extcon_set_cable_state_(edev, extcon_find_cable_index
374 (edev, cable_name), cable_state);
375}
376EXPORT_SYMBOL_GPL(extcon_set_cable_state);
377
378/**
379 * extcon_get_extcon_dev() - Get the extcon device instance from the name
380 * @extcon_name: The extcon name provided with extcon_dev_register()
381 */
382struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
383{
384 struct extcon_dev *sd;
385
386 mutex_lock(&extcon_dev_list_lock);
387 list_for_each_entry(sd, &extcon_dev_list, entry) {
388 if (!strcmp(sd->name, extcon_name))
389 goto out;
390 }
391 sd = NULL;
392out:
393 mutex_unlock(&extcon_dev_list_lock);
394 return sd;
395}
396EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
397
398static int _call_per_cable(struct notifier_block *nb, unsigned long val,
399 void *ptr)
400{
401 struct extcon_specific_cable_nb *obj = container_of(nb,
402 struct extcon_specific_cable_nb, internal_nb);
403 struct extcon_dev *edev = ptr;
404
405 if ((val & (1 << obj->cable_index)) !=
406 (edev->state & (1 << obj->cable_index))) {
407 bool cable_state = true;
408
409 obj->previous_value = val;
410
411 if (val & (1 << obj->cable_index))
412 cable_state = false;
413
414 return obj->user_nb->notifier_call(obj->user_nb,
415 cable_state, ptr);
416 }
417
418 return NOTIFY_OK;
419}
420
421/**
422 * extcon_register_interest() - Register a notifier for a state change of a
423 * specific cable, not an entier set of cables of a
424 * extcon device.
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.
431 *
432 * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
433 * the struct for you.
434 *
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().
439 *
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.
443 */
444int extcon_register_interest(struct extcon_specific_cable_nb *obj,
445 const char *extcon_name, const char *cable_name,
446 struct notifier_block *nb)
447{
448 unsigned long flags;
449 int ret;
450
451 if (!obj || !cable_name || !nb)
452 return -EINVAL;
453
454 if (extcon_name) {
455 obj->edev = extcon_get_extcon_dev(extcon_name);
456 if (!obj->edev)
457 return -ENODEV;
458
459 obj->cable_index = extcon_find_cable_index(obj->edev,
460 cable_name);
461 if (obj->cable_index < 0)
462 return obj->cable_index;
463
464 obj->user_nb = nb;
465
466 obj->internal_nb.notifier_call = _call_per_cable;
467
468 spin_lock_irqsave(&obj->edev->lock, flags);
469 ret = raw_notifier_chain_register(&obj->edev->nh,
470 &obj->internal_nb);
471 spin_unlock_irqrestore(&obj->edev->lock, flags);
472 return ret;
473 } else {
474 struct class_dev_iter iter;
475 struct extcon_dev *extd;
476 struct device *dev;
477
478 if (!extcon_class)
479 return -ENODEV;
480 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
481 while ((dev = class_dev_iter_next(&iter))) {
482 extd = dev_get_drvdata(dev);
483
484 if (extcon_find_cable_index(extd, cable_name) < 0)
485 continue;
486
487 class_dev_iter_exit(&iter);
488 return extcon_register_interest(obj, extd->name,
489 cable_name, nb);
490 }
491
492 return -ENODEV;
493 }
494}
495EXPORT_SYMBOL_GPL(extcon_register_interest);
496
497/**
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().
502 */
503int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
504{
505 unsigned long flags;
506 int ret;
507
508 if (!obj)
509 return -EINVAL;
510
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);
514
515 return ret;
516}
517EXPORT_SYMBOL_GPL(extcon_unregister_interest);
518
519/**
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.
524 *
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.
528 */
529int extcon_register_notifier(struct extcon_dev *edev,
530 struct notifier_block *nb)
531{
532 unsigned long flags;
533 int ret;
534
535 spin_lock_irqsave(&edev->lock, flags);
536 ret = raw_notifier_chain_register(&edev->nh, nb);
537 spin_unlock_irqrestore(&edev->lock, flags);
538
539 return ret;
540}
541EXPORT_SYMBOL_GPL(extcon_register_notifier);
542
543/**
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.
547 */
548int extcon_unregister_notifier(struct extcon_dev *edev,
549 struct notifier_block *nb)
550{
551 unsigned long flags;
552 int ret;
553
554 spin_lock_irqsave(&edev->lock, flags);
555 ret = raw_notifier_chain_unregister(&edev->nh, nb);
556 spin_unlock_irqrestore(&edev->lock, flags);
557
558 return ret;
559}
560EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
561
562static struct attribute *extcon_attrs[] = {
563 &dev_attr_state.attr,
564 &dev_attr_name.attr,
565 NULL,
566};
567ATTRIBUTE_GROUPS(extcon);
568
569static int create_extcon_class(void)
570{
571 if (!extcon_class) {
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;
576
577#if defined(CONFIG_ANDROID)
578 switch_class = class_compat_register("switch");
579 if (WARN(!switch_class, "cannot allocate"))
580 return -ENOMEM;
581#endif /* CONFIG_ANDROID */
582 }
583
584 return 0;
585}
586
587static void extcon_dev_release(struct device *dev)
588{
589}
590
591static const char *muex_name = "mutually_exclusive";
592static void dummy_sysfs_dev_release(struct device *dev)
593{
594}
595
596/*
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
600 * are disabled.
601 *
602 * This function allocates the memory for extcon device without allocating
603 * memory in each extcon provider driver and initialize default setting for
604 * extcon device.
605 *
606 * Return the pointer of extcon device if success or ERR_PTR(err) if fail
607 */
608struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
609{
610 struct extcon_dev *edev;
611
612 edev = kzalloc(sizeof(*edev), GFP_KERNEL);
613 if (!edev)
614 return ERR_PTR(-ENOMEM);
615
616 edev->max_supported = 0;
617 edev->supported_cable = supported_cable;
618
619 return edev;
620}
621
622/*
623 * extcon_dev_free() - Free the memory of extcon device.
624 * @edev: the extcon device to free
625 */
626void extcon_dev_free(struct extcon_dev *edev)
627{
628 kfree(edev);
629}
630EXPORT_SYMBOL_GPL(extcon_dev_free);
631
632static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
633{
634 struct extcon_dev **r = res;
635
636 if (WARN_ON(!r || !*r))
637 return 0;
638
639 return *r == data;
640}
641
642static void devm_extcon_dev_release(struct device *dev, void *res)
643{
644 extcon_dev_free(*(struct extcon_dev **)res);
645}
646
647/**
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
652 * are disabled.
653 *
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
656 * device.
657 *
658 * Returns the pointer memory of allocated extcon_dev if success
659 * or ERR_PTR(err) if fail
660 */
661struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
662 const char **supported_cable)
663{
664 struct extcon_dev **ptr, *edev;
665
666 ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
667 if (!ptr)
668 return ERR_PTR(-ENOMEM);
669
670 edev = extcon_dev_allocate(supported_cable);
671 if (IS_ERR(edev)) {
672 devres_free(ptr);
673 return edev;
674 }
675
676 edev->dev.parent = dev;
677
678 *ptr = edev;
679 devres_add(dev, ptr);
680
681 return edev;
682}
683EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
684
685void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
686{
687 WARN_ON(devres_release(dev, devm_extcon_dev_release,
688 devm_extcon_dev_match, edev));
689}
690EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
691
692/**
693 * extcon_dev_register() - Register a new extcon device
694 * @edev : the new extcon device (should be allocated before calling)
695 *
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
699 * this function.
700 */
701int extcon_dev_register(struct extcon_dev *edev)
702{
703 int ret, index = 0;
704
705 if (!extcon_class) {
706 ret = create_extcon_class();
707 if (ret < 0)
708 return ret;
709 }
710
711 if (edev->supported_cable) {
712 /* Get size of array */
713 for (index = 0; edev->supported_cable[index]; index++)
714 ;
715 edev->max_supported = index;
716 } else {
717 edev->max_supported = 0;
718 }
719
720 if (index > SUPPORTED_CABLE_MAX) {
721 dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
722 return -EINVAL;
723 }
724
725 edev->dev.class = extcon_class;
726 edev->dev.release = extcon_dev_release;
727
728 edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
729 if (IS_ERR_OR_NULL(edev->name)) {
730 dev_err(&edev->dev,
731 "extcon device name is null\n");
732 return -EINVAL;
733 }
734 dev_set_name(&edev->dev, "%s", edev->name);
735
736 if (edev->max_supported) {
737 char buf[10];
738 char *str;
739 struct extcon_cable *cable;
740
741 edev->cables = kzalloc(sizeof(struct extcon_cable) *
742 edev->max_supported, GFP_KERNEL);
743 if (!edev->cables) {
744 ret = -ENOMEM;
745 goto err_sysfs_alloc;
746 }
747 for (index = 0; index < edev->max_supported; index++) {
748 cable = &edev->cables[index];
749
750 snprintf(buf, 10, "cable.%d", index);
751 str = kzalloc(sizeof(char) * (strlen(buf) + 1),
752 GFP_KERNEL);
753 if (!str) {
754 for (index--; index >= 0; index--) {
755 cable = &edev->cables[index];
756 kfree(cable->attr_g.name);
757 }
758 ret = -ENOMEM;
759
760 goto err_alloc_cables;
761 }
762 strcpy(str, buf);
763
764 cable->edev = edev;
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;
771
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;
776
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;
781 }
782 }
783
784 if (edev->max_supported && edev->mutually_exclusive) {
785 char buf[80];
786 char *name;
787
788 /* Count the size of mutually_exclusive array */
789 for (index = 0; edev->mutually_exclusive[index]; index++)
790 ;
791
792 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
793 (index + 1), GFP_KERNEL);
794 if (!edev->attrs_muex) {
795 ret = -ENOMEM;
796 goto err_muex;
797 }
798
799 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
800 index, GFP_KERNEL);
801 if (!edev->d_attrs_muex) {
802 ret = -ENOMEM;
803 kfree(edev->attrs_muex);
804 goto err_muex;
805 }
806
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),
810 GFP_KERNEL);
811 if (!name) {
812 for (index--; index >= 0; index--) {
813 kfree(edev->d_attrs_muex[index].attr.
814 name);
815 }
816 kfree(edev->d_attrs_muex);
817 kfree(edev->attrs_muex);
818 ret = -ENOMEM;
819 goto err_muex;
820 }
821 strcpy(name, buf);
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]
826 .attr;
827 }
828 edev->attr_g_muex.name = muex_name;
829 edev->attr_g_muex.attrs = edev->attrs_muex;
830
831 }
832
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) {
838 ret = -ENOMEM;
839 goto err_alloc_groups;
840 }
841
842 edev->extcon_dev_type.name = dev_name(&edev->dev);
843 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
844
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] =
850 &edev->attr_g_muex;
851
852 edev->dev.type = &edev->extcon_dev_type;
853 }
854
855 ret = device_register(&edev->dev);
856 if (ret) {
857 put_device(&edev->dev);
858 goto err_dev;
859 }
860#if defined(CONFIG_ANDROID)
861 if (switch_class)
862 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
863#endif /* CONFIG_ANDROID */
864
865 spin_lock_init(&edev->lock);
866
867 RAW_INIT_NOTIFIER_HEAD(&edev->nh);
868
869 dev_set_drvdata(&edev->dev, edev);
870 edev->state = 0;
871
872 mutex_lock(&extcon_dev_list_lock);
873 list_add(&edev->entry, &extcon_dev_list);
874 mutex_unlock(&extcon_dev_list_lock);
875
876 return 0;
877
878err_dev:
879 if (edev->max_supported)
880 kfree(edev->extcon_dev_type.groups);
881err_alloc_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);
887 }
888err_muex:
889 for (index = 0; index < edev->max_supported; index++)
890 kfree(edev->cables[index].attr_g.name);
891err_alloc_cables:
892 if (edev->max_supported)
893 kfree(edev->cables);
894err_sysfs_alloc:
895 return ret;
896}
897EXPORT_SYMBOL_GPL(extcon_dev_register);
898
899/**
900 * extcon_dev_unregister() - Unregister the extcon device.
901 * @edev: the extcon device instance to be unregistered.
902 *
903 * Note that this does not call kfree(edev) because edev was not allocated
904 * by this class.
905 */
906void extcon_dev_unregister(struct extcon_dev *edev)
907{
908 int index;
909
910 mutex_lock(&extcon_dev_list_lock);
911 list_del(&edev->entry);
912 mutex_unlock(&extcon_dev_list_lock);
913
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));
917 return;
918 }
919
920 device_unregister(&edev->dev);
921
922 if (edev->mutually_exclusive && edev->max_supported) {
923 for (index = 0; edev->mutually_exclusive[index];
924 index++)
925 kfree(edev->d_attrs_muex[index].attr.name);
926 kfree(edev->d_attrs_muex);
927 kfree(edev->attrs_muex);
928 }
929
930 for (index = 0; index < edev->max_supported; index++)
931 kfree(edev->cables[index].attr_g.name);
932
933 if (edev->max_supported) {
934 kfree(edev->extcon_dev_type.groups);
935 kfree(edev->cables);
936 }
937
938#if defined(CONFIG_ANDROID)
939 if (switch_class)
940 class_compat_remove_link(switch_class, &edev->dev, NULL);
941#endif
942 put_device(&edev->dev);
943}
944EXPORT_SYMBOL_GPL(extcon_dev_unregister);
945
946static void devm_extcon_dev_unreg(struct device *dev, void *res)
947{
948 extcon_dev_unregister(*(struct extcon_dev **)res);
949}
950
951/**
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
955 *
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.
960 *
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.
963 *
964 * Returns 0 if success or negaive error number if failure.
965 */
966int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
967{
968 struct extcon_dev **ptr;
969 int ret;
970
971 ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
972 if (!ptr)
973 return -ENOMEM;
974
975 ret = extcon_dev_register(edev);
976 if (ret) {
977 devres_free(ptr);
978 return ret;
979 }
980
981 *ptr = edev;
982 devres_add(dev, ptr);
983
984 return 0;
985}
986EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
987
988/**
989 * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
990 * @dev: device the extcon belongs to
991 * @edev: the extcon device to unregister
992 *
993 * Unregister extcon device that is registered with devm_extcon_dev_register()
994 * function.
995 */
996void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
997{
998 WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
999 devm_extcon_dev_match, edev));
1000}
1001EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1002
1003#ifdef CONFIG_OF
1004/*
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
1008 *
1009 * return the instance of extcon device
1010 */
1011struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1012{
1013 struct device_node *node;
1014 struct extcon_dev *edev;
1015
1016 if (!dev->of_node) {
1017 dev_err(dev, "device does not have a device node entry\n");
1018 return ERR_PTR(-EINVAL);
1019 }
1020
1021 node = of_parse_phandle(dev->of_node, "extcon", index);
1022 if (!node) {
1023 dev_err(dev, "failed to get phandle in %s node\n",
1024 dev->of_node->full_name);
1025 return ERR_PTR(-ENODEV);
1026 }
1027
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);
1032 return edev;
1033 }
1034 }
1035 mutex_unlock(&extcon_dev_list_lock);
1036
1037 return ERR_PTR(-EPROBE_DEFER);
1038}
1039#else
1040struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1041{
1042 return ERR_PTR(-ENOSYS);
1043}
1044#endif /* CONFIG_OF */
1045EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1046
1047static int __init extcon_class_init(void)
1048{
1049 return create_extcon_class();
1050}
1051module_init(extcon_class_init);
1052
1053static void __exit extcon_class_exit(void)
1054{
1055#if defined(CONFIG_ANDROID)
1056 class_compat_unregister(switch_class);
1057#endif
1058 class_destroy(extcon_class);
1059}
1060module_exit(extcon_class_exit);
1061
1062MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1063MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1064MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1065MODULE_DESCRIPTION("External connector (extcon) class driver");
1066MODULE_LICENSE("GPL");
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-20 11:19:57 -0400