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1/*
2 * drivers/extcon/extcon.c - External Connector (extcon) framework.
3 *
4 * External connector (extcon) class driver
5 *
6 * Copyright (C) 2015 Samsung Electronics
7 * Author: Chanwoo Choi <cw00.choi@samsung.com>
8 *
9 * Copyright (C) 2012 Samsung Electronics
10 * Author: Donggeun Kim <dg77.kim@samsung.com>
11 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
12 *
13 * based on android/drivers/switch/switch_class.c
14 * Copyright (C) 2008 Google, Inc.
15 * Author: Mike Lockwood <lockwood@android.com>
16 *
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.
20 *
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.
25 */
26
27#include <linux/module.h>
28#include <linux/types.h>
29#include <linux/init.h>
30#include <linux/device.h>
31#include <linux/fs.h>
32#include <linux/err.h>
33#include <linux/extcon.h>
34#include <linux/of.h>
35#include <linux/slab.h>
36#include <linux/sysfs.h>
37
38#define SUPPORTED_CABLE_MAX 32
39#define CABLE_NAME_MAX 30
40
41static const char *extcon_name[] = {
42 [EXTCON_NONE] = "NONE",
43
44 /* USB external connector */
45 [EXTCON_USB] = "USB",
46 [EXTCON_USB_HOST] = "USB-HOST",
47
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",
55
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",
65
66 /* Display external connector */
67 [EXTCON_DISP_HDMI] = "HDMI",
68 [EXTCON_DISP_MHL] = "MHL",
69 [EXTCON_DISP_DVI] = "DVI",
70 [EXTCON_DISP_VGA] = "VGA",
71
72 /* Miscellaneous external connector */
73 [EXTCON_DOCK] = "DOCK",
74 [EXTCON_JIG] = "JIG",
75 [EXTCON_MECHANICAL] = "MECHANICAL",
76
77 NULL,
78};
79
80static struct class *extcon_class;
81#if defined(CONFIG_ANDROID)
82static struct class_compat *switch_class;
83#endif /* CONFIG_ANDROID */
84
85static LIST_HEAD(extcon_dev_list);
86static DEFINE_MUTEX(extcon_dev_list_lock);
87
88/**
89 * check_mutually_exclusive - Check if new_state violates mutually_exclusive
90 * condition.
91 * @edev: the extcon device
92 * @new_state: new cable attach status for @edev
93 *
94 * Returns 0 if nothing violates. Returns the index + 1 for the first
95 * violated condition.
96 */
97static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
98{
99 int i = 0;
100
101 if (!edev->mutually_exclusive)
102 return 0;
103
104 for (i = 0; edev->mutually_exclusive[i]; i++) {
105 int weight;
106 u32 correspondants = new_state & edev->mutually_exclusive[i];
107
108 /* calculate the total number of bits set */
109 weight = hweight32(correspondants);
110 if (weight > 1)
111 return i + 1;
112 }
113
114 return 0;
115}
116
117static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
118{
119 int i;
120
121 /* Find the the index of extcon cable in edev->supported_cable */
122 for (i = 0; i < edev->max_supported; i++) {
123 if (edev->supported_cable[i] == id)
124 return i;
125 }
126
127 return -EINVAL;
128}
129
130static int find_cable_id_by_name(struct extcon_dev *edev, const char *name)
131{
132 int id = -EINVAL;
133 int i = 0;
134
135 /* Find the id of extcon cable */
136 while (extcon_name[i]) {
137 if (!strncmp(extcon_name[i], name, CABLE_NAME_MAX)) {
138 id = i;
139 break;
140 }
141 i++;
142 }
143
144 return id;
145}
146
147static int find_cable_index_by_name(struct extcon_dev *edev, const char *name)
148{
149 int id;
150
151 if (edev->max_supported == 0)
152 return -EINVAL;
153
154 /* Find the the number of extcon cable */
155 id = find_cable_id_by_name(edev, name);
156 if (id < 0)
157 return id;
158
159 return find_cable_index_by_id(edev, id);
160}
161
162static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
163{
164 if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
165 *attached = ((new >> idx) & 0x1) ? true : false;
166 return true;
167 }
168
169 return false;
170}
171
172static ssize_t state_show(struct device *dev, struct device_attribute *attr,
173 char *buf)
174{
175 int i, count = 0;
176 struct extcon_dev *edev = dev_get_drvdata(dev);
177
178 if (edev->max_supported == 0)
179 return sprintf(buf, "%u\n", edev->state);
180
181 for (i = 0; i < edev->max_supported; i++) {
182 count += sprintf(buf + count, "%s=%d\n",
183 extcon_name[edev->supported_cable[i]],
184 !!(edev->state & (1 << i)));
185 }
186
187 return count;
188}
189
190static ssize_t state_store(struct device *dev, struct device_attribute *attr,
191 const char *buf, size_t count)
192{
193 u32 state;
194 ssize_t ret = 0;
195 struct extcon_dev *edev = dev_get_drvdata(dev);
196
197 ret = sscanf(buf, "0x%x", &state);
198 if (ret == 0)
199 ret = -EINVAL;
200 else
201 ret = extcon_set_state(edev, state);
202
203 if (ret < 0)
204 return ret;
205
206 return count;
207}
208static DEVICE_ATTR_RW(state);
209
210static ssize_t name_show(struct device *dev, struct device_attribute *attr,
211 char *buf)
212{
213 struct extcon_dev *edev = dev_get_drvdata(dev);
214
215 return sprintf(buf, "%s\n", edev->name);
216}
217static DEVICE_ATTR_RO(name);
218
219static ssize_t cable_name_show(struct device *dev,
220 struct device_attribute *attr, char *buf)
221{
222 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
223 attr_name);
224 int i = cable->cable_index;
225
226 return sprintf(buf, "%s\n",
227 extcon_name[cable->edev->supported_cable[i]]);
228}
229
230static ssize_t cable_state_show(struct device *dev,
231 struct device_attribute *attr, char *buf)
232{
233 struct extcon_cable *cable = container_of(attr, struct extcon_cable,
234 attr_state);
235
236 int i = cable->cable_index;
237
238 return sprintf(buf, "%d\n",
239 extcon_get_cable_state_(cable->edev,
240 cable->edev->supported_cable[i]));
241}
242
243/**
244 * extcon_update_state() - Update the cable attach states of the extcon device
245 * only for the masked bits.
246 * @edev: the extcon device
247 * @mask: the bit mask to designate updated bits.
248 * @state: new cable attach status for @edev
249 *
250 * Changing the state sends uevent with environment variable containing
251 * the name of extcon device (envp[0]) and the state output (envp[1]).
252 * Tizen uses this format for extcon device to get events from ports.
253 * Android uses this format as well.
254 *
255 * Note that the notifier provides which bits are changed in the state
256 * variable with the val parameter (second) to the callback.
257 */
258int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
259{
260 char name_buf[120];
261 char state_buf[120];
262 char *prop_buf;
263 char *envp[3];
264 int env_offset = 0;
265 int length;
266 int index;
267 unsigned long flags;
268 bool attached;
269
270 if (!edev)
271 return -EINVAL;
272
273 spin_lock_irqsave(&edev->lock, flags);
274
275 if (edev->state != ((edev->state & ~mask) | (state & mask))) {
276 u32 old_state;
277
278 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
279 (state & mask))) {
280 spin_unlock_irqrestore(&edev->lock, flags);
281 return -EPERM;
282 }
283
284 old_state = edev->state;
285 edev->state &= ~mask;
286 edev->state |= state & mask;
287
288 for (index = 0; index < edev->max_supported; index++) {
289 if (is_extcon_changed(old_state, edev->state, index,
290 &attached))
291 raw_notifier_call_chain(&edev->nh[index],
292 attached, edev);
293 }
294
295 /* This could be in interrupt handler */
296 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
297 if (prop_buf) {
298 length = name_show(&edev->dev, NULL, prop_buf);
299 if (length > 0) {
300 if (prop_buf[length - 1] == '\n')
301 prop_buf[length - 1] = 0;
302 snprintf(name_buf, sizeof(name_buf),
303 "NAME=%s", prop_buf);
304 envp[env_offset++] = name_buf;
305 }
306 length = state_show(&edev->dev, NULL, prop_buf);
307 if (length > 0) {
308 if (prop_buf[length - 1] == '\n')
309 prop_buf[length - 1] = 0;
310 snprintf(state_buf, sizeof(state_buf),
311 "STATE=%s", prop_buf);
312 envp[env_offset++] = state_buf;
313 }
314 envp[env_offset] = NULL;
315 /* Unlock early before uevent */
316 spin_unlock_irqrestore(&edev->lock, flags);
317
318 kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
319 free_page((unsigned long)prop_buf);
320 } else {
321 /* Unlock early before uevent */
322 spin_unlock_irqrestore(&edev->lock, flags);
323
324 dev_err(&edev->dev, "out of memory in extcon_set_state\n");
325 kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
326 }
327 } else {
328 /* No changes */
329 spin_unlock_irqrestore(&edev->lock, flags);
330 }
331
332 return 0;
333}
334EXPORT_SYMBOL_GPL(extcon_update_state);
335
336/**
337 * extcon_set_state() - Set the cable attach states of the extcon device.
338 * @edev: the extcon device
339 * @state: new cable attach status for @edev
340 *
341 * Note that notifier provides which bits are changed in the state
342 * variable with the val parameter (second) to the callback.
343 */
344int extcon_set_state(struct extcon_dev *edev, u32 state)
345{
346 if (!edev)
347 return -EINVAL;
348
349 return extcon_update_state(edev, 0xffffffff, state);
350}
351EXPORT_SYMBOL_GPL(extcon_set_state);
352
353/**
354 * extcon_get_cable_state_() - Get the status of a specific cable.
355 * @edev: the extcon device that has the cable.
356 * @id: the unique id of each external connector in extcon enumeration.
357 */
358int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
359{
360 int index;
361
362 if (!edev)
363 return -EINVAL;
364
365 index = find_cable_index_by_id(edev, id);
366 if (index < 0)
367 return index;
368
369 if (edev->max_supported && edev->max_supported <= index)
370 return -EINVAL;
371
372 return !!(edev->state & (1 << index));
373}
374EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
375
376/**
377 * extcon_get_cable_state() - Get the status of a specific cable.
378 * @edev: the extcon device that has the cable.
379 * @cable_name: cable name.
380 *
381 * Note that this is slower than extcon_get_cable_state_.
382 */
383int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
384{
385 int id;
386
387 id = find_cable_id_by_name(edev, cable_name);
388 if (id < 0)
389 return id;
390
391 return extcon_get_cable_state_(edev, id);
392}
393EXPORT_SYMBOL_GPL(extcon_get_cable_state);
394
395/**
396 * extcon_set_cable_state_() - Set the status of a specific cable.
397 * @edev: the extcon device that has the cable.
398 * @id: the unique id of each external connector
399 * in extcon enumeration.
400 * @state: the new cable status. The default semantics is
401 * true: attached / false: detached.
402 */
403int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
404 bool cable_state)
405{
406 u32 state;
407 int index;
408
409 if (!edev)
410 return -EINVAL;
411
412 index = find_cable_index_by_id(edev, id);
413 if (index < 0)
414 return index;
415
416 if (edev->max_supported && edev->max_supported <= index)
417 return -EINVAL;
418
419 state = cable_state ? (1 << index) : 0;
420 return extcon_update_state(edev, 1 << index, state);
421}
422EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
423
424/**
425 * extcon_set_cable_state() - Set the status of a specific cable.
426 * @edev: the extcon device that has the cable.
427 * @cable_name: cable name.
428 * @cable_state: the new cable status. The default semantics is
429 * true: attached / false: detached.
430 *
431 * Note that this is slower than extcon_set_cable_state_.
432 */
433int extcon_set_cable_state(struct extcon_dev *edev,
434 const char *cable_name, bool cable_state)
435{
436 int id;
437
438 id = find_cable_id_by_name(edev, cable_name);
439 if (id < 0)
440 return id;
441
442 return extcon_set_cable_state_(edev, id, cable_state);
443}
444EXPORT_SYMBOL_GPL(extcon_set_cable_state);
445
446/**
447 * extcon_get_extcon_dev() - Get the extcon device instance from the name
448 * @extcon_name: The extcon name provided with extcon_dev_register()
449 */
450struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
451{
452 struct extcon_dev *sd;
453
454 if (!extcon_name)
455 return ERR_PTR(-EINVAL);
456
457 mutex_lock(&extcon_dev_list_lock);
458 list_for_each_entry(sd, &extcon_dev_list, entry) {
459 if (!strcmp(sd->name, extcon_name))
460 goto out;
461 }
462 sd = NULL;
463out:
464 mutex_unlock(&extcon_dev_list_lock);
465 return sd;
466}
467EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
468
469/**
470 * extcon_register_interest() - Register a notifier for a state change of a
471 * specific cable, not an entier set of cables of a
472 * extcon device.
473 * @obj: an empty extcon_specific_cable_nb object to be returned.
474 * @extcon_name: the name of extcon device.
475 * if NULL, extcon_register_interest will register
476 * every cable with the target cable_name given.
477 * @cable_name: the target cable name.
478 * @nb: the notifier block to get notified.
479 *
480 * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
481 * the struct for you.
482 *
483 * extcon_register_interest is a helper function for those who want to get
484 * notification for a single specific cable's status change. If a user wants
485 * to get notification for any changes of all cables of a extcon device,
486 * he/she should use the general extcon_register_notifier().
487 *
488 * Note that the second parameter given to the callback of nb (val) is
489 * "old_state", not the current state. The current state can be retrieved
490 * by looking at the third pameter (edev pointer)'s state value.
491 */
492int extcon_register_interest(struct extcon_specific_cable_nb *obj,
493 const char *extcon_name, const char *cable_name,
494 struct notifier_block *nb)
495{
496 unsigned long flags;
497 int ret;
498
499 if (!obj || !cable_name || !nb)
500 return -EINVAL;
501
502 if (extcon_name) {
503 obj->edev = extcon_get_extcon_dev(extcon_name);
504 if (!obj->edev)
505 return -ENODEV;
506
507 obj->cable_index = find_cable_index_by_name(obj->edev,
508 cable_name);
509 if (obj->cable_index < 0)
510 return obj->cable_index;
511
512 obj->user_nb = nb;
513
514 spin_lock_irqsave(&obj->edev->lock, flags);
515 ret = raw_notifier_chain_register(
516 &obj->edev->nh[obj->cable_index],
517 obj->user_nb);
518 spin_unlock_irqrestore(&obj->edev->lock, flags);
519 } else {
520 struct class_dev_iter iter;
521 struct extcon_dev *extd;
522 struct device *dev;
523
524 if (!extcon_class)
525 return -ENODEV;
526 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
527 while ((dev = class_dev_iter_next(&iter))) {
528 extd = dev_get_drvdata(dev);
529
530 if (find_cable_index_by_name(extd, cable_name) < 0)
531 continue;
532
533 class_dev_iter_exit(&iter);
534 return extcon_register_interest(obj, extd->name,
535 cable_name, nb);
536 }
537
538 ret = -ENODEV;
539 }
540
541 return ret;
542}
543EXPORT_SYMBOL_GPL(extcon_register_interest);
544
545/**
546 * extcon_unregister_interest() - Unregister the notifier registered by
547 * extcon_register_interest().
548 * @obj: the extcon_specific_cable_nb object returned by
549 * extcon_register_interest().
550 */
551int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
552{
553 unsigned long flags;
554 int ret;
555
556 if (!obj)
557 return -EINVAL;
558
559 spin_lock_irqsave(&obj->edev->lock, flags);
560 ret = raw_notifier_chain_unregister(
561 &obj->edev->nh[obj->cable_index], obj->user_nb);
562 spin_unlock_irqrestore(&obj->edev->lock, flags);
563
564 return ret;
565}
566EXPORT_SYMBOL_GPL(extcon_unregister_interest);
567
568/**
569 * extcon_register_notifier() - Register a notifiee to get notified by
570 * any attach status changes from the extcon.
571 * @edev: the extcon device that has the external connecotr.
572 * @id: the unique id of each external connector in extcon enumeration.
573 * @nb: a notifier block to be registered.
574 *
575 * Note that the second parameter given to the callback of nb (val) is
576 * "old_state", not the current state. The current state can be retrieved
577 * by looking at the third pameter (edev pointer)'s state value.
578 */
579int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
580 struct notifier_block *nb)
581{
582 unsigned long flags;
583 int ret, idx;
584
585 if (!edev || !nb)
586 return -EINVAL;
587
588 idx = find_cable_index_by_id(edev, id);
589
590 spin_lock_irqsave(&edev->lock, flags);
591 ret = raw_notifier_chain_register(&edev->nh[idx], nb);
592 spin_unlock_irqrestore(&edev->lock, flags);
593
594 return ret;
595}
596EXPORT_SYMBOL_GPL(extcon_register_notifier);
597
598/**
599 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
600 * @edev: the extcon device that has the external connecotr.
601 * @id: the unique id of each external connector in extcon enumeration.
602 * @nb: a notifier block to be registered.
603 */
604int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
605 struct notifier_block *nb)
606{
607 unsigned long flags;
608 int ret, idx;
609
610 if (!edev || !nb)
611 return -EINVAL;
612
613 idx = find_cable_index_by_id(edev, id);
614
615 spin_lock_irqsave(&edev->lock, flags);
616 ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
617 spin_unlock_irqrestore(&edev->lock, flags);
618
619 return ret;
620}
621EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
622
623static struct attribute *extcon_attrs[] = {
624 &dev_attr_state.attr,
625 &dev_attr_name.attr,
626 NULL,
627};
628ATTRIBUTE_GROUPS(extcon);
629
630static int create_extcon_class(void)
631{
632 if (!extcon_class) {
633 extcon_class = class_create(THIS_MODULE, "extcon");
634 if (IS_ERR(extcon_class))
635 return PTR_ERR(extcon_class);
636 extcon_class->dev_groups = extcon_groups;
637
638#if defined(CONFIG_ANDROID)
639 switch_class = class_compat_register("switch");
640 if (WARN(!switch_class, "cannot allocate"))
641 return -ENOMEM;
642#endif /* CONFIG_ANDROID */
643 }
644
645 return 0;
646}
647
648static void extcon_dev_release(struct device *dev)
649{
650}
651
652static const char *muex_name = "mutually_exclusive";
653static void dummy_sysfs_dev_release(struct device *dev)
654{
655}
656
657/*
658 * extcon_dev_allocate() - Allocate the memory of extcon device.
659 * @supported_cable: Array of supported extcon ending with EXTCON_NONE.
660 * If supported_cable is NULL, cable name related APIs
661 * are disabled.
662 *
663 * This function allocates the memory for extcon device without allocating
664 * memory in each extcon provider driver and initialize default setting for
665 * extcon device.
666 *
667 * Return the pointer of extcon device if success or ERR_PTR(err) if fail
668 */
669struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
670{
671 struct extcon_dev *edev;
672
673 if (!supported_cable)
674 return ERR_PTR(-EINVAL);
675
676 edev = kzalloc(sizeof(*edev), GFP_KERNEL);
677 if (!edev)
678 return ERR_PTR(-ENOMEM);
679
680 edev->max_supported = 0;
681 edev->supported_cable = supported_cable;
682
683 return edev;
684}
685
686/*
687 * extcon_dev_free() - Free the memory of extcon device.
688 * @edev: the extcon device to free
689 */
690void extcon_dev_free(struct extcon_dev *edev)
691{
692 kfree(edev);
693}
694EXPORT_SYMBOL_GPL(extcon_dev_free);
695
696static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
697{
698 struct extcon_dev **r = res;
699
700 if (WARN_ON(!r || !*r))
701 return 0;
702
703 return *r == data;
704}
705
706static void devm_extcon_dev_release(struct device *dev, void *res)
707{
708 extcon_dev_free(*(struct extcon_dev **)res);
709}
710
711/**
712 * devm_extcon_dev_allocate - Allocate managed extcon device
713 * @dev: device owning the extcon device being created
714 * @supported_cable: Array of supported extcon ending with EXTCON_NONE.
715 * If supported_cable is NULL, cable name related APIs
716 * are disabled.
717 *
718 * This function manages automatically the memory of extcon device using device
719 * resource management and simplify the control of freeing the memory of extcon
720 * device.
721 *
722 * Returns the pointer memory of allocated extcon_dev if success
723 * or ERR_PTR(err) if fail
724 */
725struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
726 const unsigned int *supported_cable)
727{
728 struct extcon_dev **ptr, *edev;
729
730 ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
731 if (!ptr)
732 return ERR_PTR(-ENOMEM);
733
734 edev = extcon_dev_allocate(supported_cable);
735 if (IS_ERR(edev)) {
736 devres_free(ptr);
737 return edev;
738 }
739
740 edev->dev.parent = dev;
741
742 *ptr = edev;
743 devres_add(dev, ptr);
744
745 return edev;
746}
747EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
748
749void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
750{
751 WARN_ON(devres_release(dev, devm_extcon_dev_release,
752 devm_extcon_dev_match, edev));
753}
754EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
755
756/**
757 * extcon_dev_register() - Register a new extcon device
758 * @edev : the new extcon device (should be allocated before calling)
759 *
760 * Among the members of edev struct, please set the "user initializing data"
761 * in any case and set the "optional callbacks" if required. However, please
762 * do not set the values of "internal data", which are initialized by
763 * this function.
764 */
765int extcon_dev_register(struct extcon_dev *edev)
766{
767 int ret, index = 0;
768 static atomic_t edev_no = ATOMIC_INIT(-1);
769
770 if (!extcon_class) {
771 ret = create_extcon_class();
772 if (ret < 0)
773 return ret;
774 }
775
776 if (!edev || !edev->supported_cable)
777 return -EINVAL;
778
779 for (; edev->supported_cable[index] != EXTCON_NONE; index++);
780
781 edev->max_supported = index;
782 if (index > SUPPORTED_CABLE_MAX) {
783 dev_err(&edev->dev,
784 "exceed the maximum number of supported cables\n");
785 return -EINVAL;
786 }
787
788 edev->dev.class = extcon_class;
789 edev->dev.release = extcon_dev_release;
790
791 edev->name = dev_name(edev->dev.parent);
792 if (IS_ERR_OR_NULL(edev->name)) {
793 dev_err(&edev->dev,
794 "extcon device name is null\n");
795 return -EINVAL;
796 }
797 dev_set_name(&edev->dev, "extcon%lu",
798 (unsigned long)atomic_inc_return(&edev_no));
799
800 if (edev->max_supported) {
801 char buf[10];
802 char *str;
803 struct extcon_cable *cable;
804
805 edev->cables = kzalloc(sizeof(struct extcon_cable) *
806 edev->max_supported, GFP_KERNEL);
807 if (!edev->cables) {
808 ret = -ENOMEM;
809 goto err_sysfs_alloc;
810 }
811 for (index = 0; index < edev->max_supported; index++) {
812 cable = &edev->cables[index];
813
814 snprintf(buf, 10, "cable.%d", index);
815 str = kzalloc(sizeof(char) * (strlen(buf) + 1),
816 GFP_KERNEL);
817 if (!str) {
818 for (index--; index >= 0; index--) {
819 cable = &edev->cables[index];
820 kfree(cable->attr_g.name);
821 }
822 ret = -ENOMEM;
823
824 goto err_alloc_cables;
825 }
826 strcpy(str, buf);
827
828 cable->edev = edev;
829 cable->cable_index = index;
830 cable->attrs[0] = &cable->attr_name.attr;
831 cable->attrs[1] = &cable->attr_state.attr;
832 cable->attrs[2] = NULL;
833 cable->attr_g.name = str;
834 cable->attr_g.attrs = cable->attrs;
835
836 sysfs_attr_init(&cable->attr_name.attr);
837 cable->attr_name.attr.name = "name";
838 cable->attr_name.attr.mode = 0444;
839 cable->attr_name.show = cable_name_show;
840
841 sysfs_attr_init(&cable->attr_state.attr);
842 cable->attr_state.attr.name = "state";
843 cable->attr_state.attr.mode = 0444;
844 cable->attr_state.show = cable_state_show;
845 }
846 }
847
848 if (edev->max_supported && edev->mutually_exclusive) {
849 char buf[80];
850 char *name;
851
852 /* Count the size of mutually_exclusive array */
853 for (index = 0; edev->mutually_exclusive[index]; index++)
854 ;
855
856 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
857 (index + 1), GFP_KERNEL);
858 if (!edev->attrs_muex) {
859 ret = -ENOMEM;
860 goto err_muex;
861 }
862
863 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
864 index, GFP_KERNEL);
865 if (!edev->d_attrs_muex) {
866 ret = -ENOMEM;
867 kfree(edev->attrs_muex);
868 goto err_muex;
869 }
870
871 for (index = 0; edev->mutually_exclusive[index]; index++) {
872 sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
873 name = kzalloc(sizeof(char) * (strlen(buf) + 1),
874 GFP_KERNEL);
875 if (!name) {
876 for (index--; index >= 0; index--) {
877 kfree(edev->d_attrs_muex[index].attr.
878 name);
879 }
880 kfree(edev->d_attrs_muex);
881 kfree(edev->attrs_muex);
882 ret = -ENOMEM;
883 goto err_muex;
884 }
885 strcpy(name, buf);
886 sysfs_attr_init(&edev->d_attrs_muex[index].attr);
887 edev->d_attrs_muex[index].attr.name = name;
888 edev->d_attrs_muex[index].attr.mode = 0000;
889 edev->attrs_muex[index] = &edev->d_attrs_muex[index]
890 .attr;
891 }
892 edev->attr_g_muex.name = muex_name;
893 edev->attr_g_muex.attrs = edev->attrs_muex;
894
895 }
896
897 if (edev->max_supported) {
898 edev->extcon_dev_type.groups =
899 kzalloc(sizeof(struct attribute_group *) *
900 (edev->max_supported + 2), GFP_KERNEL);
901 if (!edev->extcon_dev_type.groups) {
902 ret = -ENOMEM;
903 goto err_alloc_groups;
904 }
905
906 edev->extcon_dev_type.name = dev_name(&edev->dev);
907 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
908
909 for (index = 0; index < edev->max_supported; index++)
910 edev->extcon_dev_type.groups[index] =
911 &edev->cables[index].attr_g;
912 if (edev->mutually_exclusive)
913 edev->extcon_dev_type.groups[index] =
914 &edev->attr_g_muex;
915
916 edev->dev.type = &edev->extcon_dev_type;
917 }
918
919 ret = device_register(&edev->dev);
920 if (ret) {
921 put_device(&edev->dev);
922 goto err_dev;
923 }
924#if defined(CONFIG_ANDROID)
925 if (switch_class)
926 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
927#endif /* CONFIG_ANDROID */
928
929 spin_lock_init(&edev->lock);
930
931 edev->nh = devm_kzalloc(&edev->dev,
932 sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
933 if (!edev->nh) {
934 ret = -ENOMEM;
935 goto err_dev;
936 }
937
938 for (index = 0; index < edev->max_supported; index++)
939 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
940
941 dev_set_drvdata(&edev->dev, edev);
942 edev->state = 0;
943
944 mutex_lock(&extcon_dev_list_lock);
945 list_add(&edev->entry, &extcon_dev_list);
946 mutex_unlock(&extcon_dev_list_lock);
947
948 return 0;
949
950err_dev:
951 if (edev->max_supported)
952 kfree(edev->extcon_dev_type.groups);
953err_alloc_groups:
954 if (edev->max_supported && edev->mutually_exclusive) {
955 for (index = 0; edev->mutually_exclusive[index]; index++)
956 kfree(edev->d_attrs_muex[index].attr.name);
957 kfree(edev->d_attrs_muex);
958 kfree(edev->attrs_muex);
959 }
960err_muex:
961 for (index = 0; index < edev->max_supported; index++)
962 kfree(edev->cables[index].attr_g.name);
963err_alloc_cables:
964 if (edev->max_supported)
965 kfree(edev->cables);
966err_sysfs_alloc:
967 return ret;
968}
969EXPORT_SYMBOL_GPL(extcon_dev_register);
970
971/**
972 * extcon_dev_unregister() - Unregister the extcon device.
973 * @edev: the extcon device instance to be unregistered.
974 *
975 * Note that this does not call kfree(edev) because edev was not allocated
976 * by this class.
977 */
978void extcon_dev_unregister(struct extcon_dev *edev)
979{
980 int index;
981
982 if (!edev)
983 return;
984
985 mutex_lock(&extcon_dev_list_lock);
986 list_del(&edev->entry);
987 mutex_unlock(&extcon_dev_list_lock);
988
989 if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
990 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
991 dev_name(&edev->dev));
992 return;
993 }
994
995 device_unregister(&edev->dev);
996
997 if (edev->mutually_exclusive && edev->max_supported) {
998 for (index = 0; edev->mutually_exclusive[index];
999 index++)
1000 kfree(edev->d_attrs_muex[index].attr.name);
1001 kfree(edev->d_attrs_muex);
1002 kfree(edev->attrs_muex);
1003 }
1004
1005 for (index = 0; index < edev->max_supported; index++)
1006 kfree(edev->cables[index].attr_g.name);
1007
1008 if (edev->max_supported) {
1009 kfree(edev->extcon_dev_type.groups);
1010 kfree(edev->cables);
1011 }
1012
1013#if defined(CONFIG_ANDROID)
1014 if (switch_class)
1015 class_compat_remove_link(switch_class, &edev->dev, NULL);
1016#endif
1017 put_device(&edev->dev);
1018}
1019EXPORT_SYMBOL_GPL(extcon_dev_unregister);
1020
1021static void devm_extcon_dev_unreg(struct device *dev, void *res)
1022{
1023 extcon_dev_unregister(*(struct extcon_dev **)res);
1024}
1025
1026/**
1027 * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
1028 * @dev: device to allocate extcon device
1029 * @edev: the new extcon device to register
1030 *
1031 * Managed extcon_dev_register() function. If extcon device is attached with
1032 * this function, that extcon device is automatically unregistered on driver
1033 * detach. Internally this function calls extcon_dev_register() function.
1034 * To get more information, refer that function.
1035 *
1036 * If extcon device is registered with this function and the device needs to be
1037 * unregistered separately, devm_extcon_dev_unregister() should be used.
1038 *
1039 * Returns 0 if success or negaive error number if failure.
1040 */
1041int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
1042{
1043 struct extcon_dev **ptr;
1044 int ret;
1045
1046 ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
1047 if (!ptr)
1048 return -ENOMEM;
1049
1050 ret = extcon_dev_register(edev);
1051 if (ret) {
1052 devres_free(ptr);
1053 return ret;
1054 }
1055
1056 *ptr = edev;
1057 devres_add(dev, ptr);
1058
1059 return 0;
1060}
1061EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
1062
1063/**
1064 * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
1065 * @dev: device the extcon belongs to
1066 * @edev: the extcon device to unregister
1067 *
1068 * Unregister extcon device that is registered with devm_extcon_dev_register()
1069 * function.
1070 */
1071void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
1072{
1073 WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
1074 devm_extcon_dev_match, edev));
1075}
1076EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1077
1078#ifdef CONFIG_OF
1079/*
1080 * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1081 * @dev - instance to the given device
1082 * @index - index into list of extcon_dev
1083 *
1084 * return the instance of extcon device
1085 */
1086struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1087{
1088 struct device_node *node;
1089 struct extcon_dev *edev;
1090
1091 if (!dev)
1092 return ERR_PTR(-EINVAL);
1093
1094 if (!dev->of_node) {
1095 dev_err(dev, "device does not have a device node entry\n");
1096 return ERR_PTR(-EINVAL);
1097 }
1098
1099 node = of_parse_phandle(dev->of_node, "extcon", index);
1100 if (!node) {
1101 dev_err(dev, "failed to get phandle in %s node\n",
1102 dev->of_node->full_name);
1103 return ERR_PTR(-ENODEV);
1104 }
1105
1106 mutex_lock(&extcon_dev_list_lock);
1107 list_for_each_entry(edev, &extcon_dev_list, entry) {
1108 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1109 mutex_unlock(&extcon_dev_list_lock);
1110 return edev;
1111 }
1112 }
1113 mutex_unlock(&extcon_dev_list_lock);
1114
1115 return ERR_PTR(-EPROBE_DEFER);
1116}
1117#else
1118struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1119{
1120 return ERR_PTR(-ENOSYS);
1121}
1122#endif /* CONFIG_OF */
1123EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1124
1125/**
1126 * extcon_get_edev_name() - Get the name of the extcon device.
1127 * @edev: the extcon device
1128 */
1129const char *extcon_get_edev_name(struct extcon_dev *edev)
1130{
1131 return !edev ? NULL : edev->name;
1132}
1133
1134static int __init extcon_class_init(void)
1135{
1136 return create_extcon_class();
1137}
1138module_init(extcon_class_init);
1139
1140static void __exit extcon_class_exit(void)
1141{
1142#if defined(CONFIG_ANDROID)
1143 class_compat_unregister(switch_class);
1144#endif
1145 class_destroy(extcon_class);
1146}
1147module_exit(extcon_class_exit);
1148
1149MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1150MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1151MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1152MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1153MODULE_DESCRIPTION("External connector (extcon) class driver");
1154MODULE_LICENSE("GPL");