drivers/extcon/extcon.c

   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
  41 static 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
  80 /**
  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
  88  */
  89 struct extcon_cable {
  90         struct extcon_dev *edev;
  91         int cable_index;
  92
  93         struct attribute_group attr_g;
  94         struct device_attribute attr_name;
  95         struct device_attribute attr_state;
  96
  97         struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
  98 };
  99
 100 static struct class *extcon_class;
 101 #if defined(CONFIG_ANDROID)
 102 static struct class_compat *switch_class;
 103 #endif /* CONFIG_ANDROID */
 104
 105 static LIST_HEAD(extcon_dev_list);
 106 static DEFINE_MUTEX(extcon_dev_list_lock);
 107
 108 /**
 109  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
 110  *                            condition.
 111  * @edev:       the extcon device
 112  * @new_state:  new cable attach status for @edev
 113  *
 114  * Returns 0 if nothing violates. Returns the index + 1 for the first
 115  * violated condition.
 116  */
 117 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
 118 {
 119         int i = 0;
 120
 121         if (!edev->mutually_exclusive)
 122                 return 0;
 123
 124         for (i = 0; edev->mutually_exclusive[i]; i++) {
 125                 int weight;
 126                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 127
 128                 /* calculate the total number of bits set */
 129                 weight = hweight32(correspondants);
 130                 if (weight > 1)
 131                         return i + 1;
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 138 {
 139         int i;
 140
 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)
 144                         return i;
 145         }
 146
 147         return -EINVAL;
 148 }
 149
 150 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 151 {
 152         if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
 153                 *attached = ((new >> idx) & 0x1) ? true : false;
 154                 return true;
 155         }
 156
 157         return false;
 158 }
 159
 160 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 161                           char *buf)
 162 {
 163         int i, count = 0;
 164         struct extcon_dev *edev = dev_get_drvdata(dev);
 165
 166         if (edev->max_supported == 0)
 167                 return sprintf(buf, "%u\n", edev->state);
 168
 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)));
 173         }
 174
 175         return count;
 176 }
 177 static DEVICE_ATTR_RO(state);
 178
 179 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 180                 char *buf)
 181 {
 182         struct extcon_dev *edev = dev_get_drvdata(dev);
 183
 184         return sprintf(buf, "%s\n", edev->name);
 185 }
 186 static DEVICE_ATTR_RO(name);
 187
 188 static ssize_t cable_name_show(struct device *dev,
 189                                struct device_attribute *attr, char *buf)
 190 {
 191         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 192                                                   attr_name);
 193         int i = cable->cable_index;
 194
 195         return sprintf(buf, "%s\n",
 196                         extcon_name[cable->edev->supported_cable[i]]);
 197 }
 198
 199 static ssize_t cable_state_show(struct device *dev,
 200                                 struct device_attribute *attr, char *buf)
 201 {
 202         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 203                                                   attr_state);
 204
 205         int i = cable->cable_index;
 206
 207         return sprintf(buf, "%d\n",
 208                        extcon_get_cable_state_(cable->edev,
 209                                                cable->edev->supported_cable[i]));
 210 }
 211
 212 /**
 213  * extcon_update_state() - Update the cable attach states of the extcon device
 214  *                         only for the masked bits.
 215  * @edev:       the extcon device
 216  * @mask:       the bit mask to designate updated bits.
 217  * @state:      new cable attach status for @edev
 218  *
 219  * Changing the state sends uevent with environment variable containing
 220  * the name of extcon device (envp[0]) and the state output (envp[1]).
 221  * Tizen uses this format for extcon device to get events from ports.
 222  * Android uses this format as well.
 223  *
 224  * Note that the notifier provides which bits are changed in the state
 225  * variable with the val parameter (second) to the callback.
 226  */
 227 static int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 228 {
 229         char name_buf[120];
 230         char state_buf[120];
 231         char *prop_buf;
 232         char *envp[3];
 233         int env_offset = 0;
 234         int length;
 235         int index;
 236         unsigned long flags;
 237         bool attached;
 238
 239         if (!edev)
 240                 return -EINVAL;
 241
 242         spin_lock_irqsave(&edev->lock, flags);
 243
 244         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 245                 u32 old_state;
 246
 247                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 248                                                    (state & mask))) {
 249                         spin_unlock_irqrestore(&edev->lock, flags);
 250                         return -EPERM;
 251                 }
 252
 253                 old_state = edev->state;
 254                 edev->state &= ~mask;
 255                 edev->state |= state & mask;
 256
 257                 for (index = 0; index < edev->max_supported; index++) {
 258                         if (is_extcon_changed(old_state, edev->state, index,
 259                                               &attached))
 260                                 raw_notifier_call_chain(&edev->nh[index],
 261                                                         attached, edev);
 262                 }
 263
 264                 /* This could be in interrupt handler */
 265                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 266                 if (prop_buf) {
 267                         length = name_show(&edev->dev, NULL, prop_buf);
 268                         if (length > 0) {
 269                                 if (prop_buf[length - 1] == '\n')
 270                                         prop_buf[length - 1] = 0;
 271                                 snprintf(name_buf, sizeof(name_buf),
 272                                         "NAME=%s", prop_buf);
 273                                 envp[env_offset++] = name_buf;
 274                         }
 275                         length = state_show(&edev->dev, NULL, prop_buf);
 276                         if (length > 0) {
 277                                 if (prop_buf[length - 1] == '\n')
 278                                         prop_buf[length - 1] = 0;
 279                                 snprintf(state_buf, sizeof(state_buf),
 280                                         "STATE=%s", prop_buf);
 281                                 envp[env_offset++] = state_buf;
 282                         }
 283                         envp[env_offset] = NULL;
 284                         /* Unlock early before uevent */
 285                         spin_unlock_irqrestore(&edev->lock, flags);
 286
 287                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 288                         free_page((unsigned long)prop_buf);
 289                 } else {
 290                         /* Unlock early before uevent */
 291                         spin_unlock_irqrestore(&edev->lock, flags);
 292
 293                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 294                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 295                 }
 296         } else {
 297                 /* No changes */
 298                 spin_unlock_irqrestore(&edev->lock, flags);
 299         }
 300
 301         return 0;
 302 }
 303
 304 /**
 305  * extcon_get_cable_state_() - Get the status of a specific cable.
 306  * @edev:       the extcon device that has the cable.
 307  * @id:         the unique id of each external connector in extcon enumeration.
 308  */
 309 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 310 {
 311         int index;
 312
 313         if (!edev)
 314                 return -EINVAL;
 315
 316         index = find_cable_index_by_id(edev, id);
 317         if (index < 0)
 318                 return index;
 319
 320         if (edev->max_supported && edev->max_supported <= index)
 321                 return -EINVAL;
 322
 323         return !!(edev->state & (1 << index));
 324 }
 325 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 326
 327 /**
 328  * extcon_set_cable_state_() - Set the status of a specific cable.
 329  * @edev:               the extcon device that has the cable.
 330  * @id:                 the unique id of each external connector
 331  *                      in extcon enumeration.
 332  * @state:              the new cable status. The default semantics is
 333  *                      true: attached / false: detached.
 334  */
 335 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 336                                 bool cable_state)
 337 {
 338         u32 state;
 339         int index;
 340
 341         if (!edev)
 342                 return -EINVAL;
 343
 344         index = find_cable_index_by_id(edev, id);
 345         if (index < 0)
 346                 return index;
 347
 348         if (edev->max_supported && edev->max_supported <= index)
 349                 return -EINVAL;
 350
 351         state = cable_state ? (1 << index) : 0;
 352         return extcon_update_state(edev, 1 << index, state);
 353 }
 354 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 355
 356 /**
 357  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 358  * @extcon_name:        The extcon name provided with extcon_dev_register()
 359  */
 360 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 361 {
 362         struct extcon_dev *sd;
 363
 364         if (!extcon_name)
 365                 return ERR_PTR(-EINVAL);
 366
 367         mutex_lock(&extcon_dev_list_lock);
 368         list_for_each_entry(sd, &extcon_dev_list, entry) {
 369                 if (!strcmp(sd->name, extcon_name))
 370                         goto out;
 371         }
 372         sd = NULL;
 373 out:
 374         mutex_unlock(&extcon_dev_list_lock);
 375         return sd;
 376 }
 377 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 378
 379 /**
 380  * extcon_register_notifier() - Register a notifiee to get notified by
 381  *                              any attach status changes from the extcon.
 382  * @edev:       the extcon device that has the external connecotr.
 383  * @id:         the unique id of each external connector in extcon enumeration.
 384  * @nb:         a notifier block to be registered.
 385  *
 386  * Note that the second parameter given to the callback of nb (val) is
 387  * "old_state", not the current state. The current state can be retrieved
 388  * by looking at the third pameter (edev pointer)'s state value.
 389  */
 390 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 391                              struct notifier_block *nb)
 392 {
 393         unsigned long flags;
 394         int ret, idx;
 395
 396         if (!nb)
 397                 return -EINVAL;
 398
 399         if (edev) {
 400                 idx = find_cable_index_by_id(edev, id);
 401                 if (idx < 0)
 402                         return idx;
 403
 404                 spin_lock_irqsave(&edev->lock, flags);
 405                 ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 406                 spin_unlock_irqrestore(&edev->lock, flags);
 407         } else {
 408                 struct extcon_dev *extd;
 409
 410                 mutex_lock(&extcon_dev_list_lock);
 411                 list_for_each_entry(extd, &extcon_dev_list, entry) {
 412                         idx = find_cable_index_by_id(extd, id);
 413                         if (idx >= 0)
 414                                 break;
 415                 }
 416                 mutex_unlock(&extcon_dev_list_lock);
 417
 418                 if (idx >= 0) {
 419                         edev = extd;
 420                         return extcon_register_notifier(extd, id, nb);
 421                 } else {
 422                         ret = -ENODEV;
 423                 }
 424         }
 425
 426         return ret;
 427 }
 428 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 429
 430 /**
 431  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 432  * @edev:       the extcon device that has the external connecotr.
 433  * @id:         the unique id of each external connector in extcon enumeration.
 434  * @nb:         a notifier block to be registered.
 435  */
 436 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 437                                 struct notifier_block *nb)
 438 {
 439         unsigned long flags;
 440         int ret, idx;
 441
 442         if (!edev || !nb)
 443                 return -EINVAL;
 444
 445         idx = find_cable_index_by_id(edev, id);
 446         if (idx < 0)
 447                 return idx;
 448
 449         spin_lock_irqsave(&edev->lock, flags);
 450         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 451         spin_unlock_irqrestore(&edev->lock, flags);
 452
 453         return ret;
 454 }
 455 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 456
 457 static struct attribute *extcon_attrs[] = {
 458         &dev_attr_state.attr,
 459         &dev_attr_name.attr,
 460         NULL,
 461 };
 462 ATTRIBUTE_GROUPS(extcon);
 463
 464 static int create_extcon_class(void)
 465 {
 466         if (!extcon_class) {
 467                 extcon_class = class_create(THIS_MODULE, "extcon");
 468                 if (IS_ERR(extcon_class))
 469                         return PTR_ERR(extcon_class);
 470                 extcon_class->dev_groups = extcon_groups;
 471
 472 #if defined(CONFIG_ANDROID) && !defined(CONFIG_SWITCH)
 473                 switch_class = class_compat_register("switch");
 474                 if (WARN(!switch_class, "cannot allocate"))
 475                         return -ENOMEM;
 476 #endif /* CONFIG_ANDROID */
 477         }
 478
 479         return 0;
 480 }
 481
 482 static void extcon_dev_release(struct device *dev)
 483 {
 484 }
 485
 486 static const char *muex_name = "mutually_exclusive";
 487 static void dummy_sysfs_dev_release(struct device *dev)
 488 {
 489 }
 490
 491 /*
 492  * extcon_dev_allocate() - Allocate the memory of extcon device.
 493  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 494  *                      If supported_cable is NULL, cable name related APIs
 495  *                      are disabled.
 496  *
 497  * This function allocates the memory for extcon device without allocating
 498  * memory in each extcon provider driver and initialize default setting for
 499  * extcon device.
 500  *
 501  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 502  */
 503 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 504 {
 505         struct extcon_dev *edev;
 506
 507         if (!supported_cable)
 508                 return ERR_PTR(-EINVAL);
 509
 510         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 511         if (!edev)
 512                 return ERR_PTR(-ENOMEM);
 513
 514         edev->max_supported = 0;
 515         edev->supported_cable = supported_cable;
 516
 517         return edev;
 518 }
 519
 520 /*
 521  * extcon_dev_free() - Free the memory of extcon device.
 522  * @edev:       the extcon device to free
 523  */
 524 void extcon_dev_free(struct extcon_dev *edev)
 525 {
 526         kfree(edev);
 527 }
 528 EXPORT_SYMBOL_GPL(extcon_dev_free);
 529
 530 /**
 531  * extcon_dev_register() - Register a new extcon device
 532  * @edev        : the new extcon device (should be allocated before calling)
 533  *
 534  * Among the members of edev struct, please set the "user initializing data"
 535  * in any case and set the "optional callbacks" if required. However, please
 536  * do not set the values of "internal data", which are initialized by
 537  * this function.
 538  */
 539 int extcon_dev_register(struct extcon_dev *edev)
 540 {
 541         int ret, index = 0;
 542         static atomic_t edev_no = ATOMIC_INIT(-1);
 543
 544         if (!extcon_class) {
 545                 ret = create_extcon_class();
 546                 if (ret < 0)
 547                         return ret;
 548         }
 549
 550         if (!edev || !edev->supported_cable)
 551                 return -EINVAL;
 552
 553         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 554
 555         edev->max_supported = index;
 556         if (index > SUPPORTED_CABLE_MAX) {
 557                 dev_err(&edev->dev,
 558                         "exceed the maximum number of supported cables\n");
 559                 return -EINVAL;
 560         }
 561
 562         edev->dev.class = extcon_class;
 563         edev->dev.release = extcon_dev_release;
 564
 565         edev->name = dev_name(edev->dev.parent);
 566         if (IS_ERR_OR_NULL(edev->name)) {
 567                 dev_err(&edev->dev,
 568                         "extcon device name is null\n");
 569                 return -EINVAL;
 570         }
 571         dev_set_name(&edev->dev, "extcon%lu",
 572                         (unsigned long)atomic_inc_return(&edev_no));
 573
 574         if (edev->max_supported) {
 575                 char buf[10];
 576                 char *str;
 577                 struct extcon_cable *cable;
 578
 579                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 580                                        edev->max_supported, GFP_KERNEL);
 581                 if (!edev->cables) {
 582                         ret = -ENOMEM;
 583                         goto err_sysfs_alloc;
 584                 }
 585                 for (index = 0; index < edev->max_supported; index++) {
 586                         cable = &edev->cables[index];
 587
 588                         snprintf(buf, 10, "cable.%d", index);
 589                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 590                                       GFP_KERNEL);
 591                         if (!str) {
 592                                 for (index--; index >= 0; index--) {
 593                                         cable = &edev->cables[index];
 594                                         kfree(cable->attr_g.name);
 595                                 }
 596                                 ret = -ENOMEM;
 597
 598                                 goto err_alloc_cables;
 599                         }
 600                         strcpy(str, buf);
 601
 602                         cable->edev = edev;
 603                         cable->cable_index = index;
 604                         cable->attrs[0] = &cable->attr_name.attr;
 605                         cable->attrs[1] = &cable->attr_state.attr;
 606                         cable->attrs[2] = NULL;
 607                         cable->attr_g.name = str;
 608                         cable->attr_g.attrs = cable->attrs;
 609
 610                         sysfs_attr_init(&cable->attr_name.attr);
 611                         cable->attr_name.attr.name = "name";
 612                         cable->attr_name.attr.mode = 0444;
 613                         cable->attr_name.show = cable_name_show;
 614
 615                         sysfs_attr_init(&cable->attr_state.attr);
 616                         cable->attr_state.attr.name = "state";
 617                         cable->attr_state.attr.mode = 0444;
 618                         cable->attr_state.show = cable_state_show;
 619                 }
 620         }
 621
 622         if (edev->max_supported && edev->mutually_exclusive) {
 623                 char buf[80];
 624                 char *name;
 625
 626                 /* Count the size of mutually_exclusive array */
 627                 for (index = 0; edev->mutually_exclusive[index]; index++)
 628                         ;
 629
 630                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 631                                            (index + 1), GFP_KERNEL);
 632                 if (!edev->attrs_muex) {
 633                         ret = -ENOMEM;
 634                         goto err_muex;
 635                 }
 636
 637                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 638                                              index, GFP_KERNEL);
 639                 if (!edev->d_attrs_muex) {
 640                         ret = -ENOMEM;
 641                         kfree(edev->attrs_muex);
 642                         goto err_muex;
 643                 }
 644
 645                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 646                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 647                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 648                                        GFP_KERNEL);
 649                         if (!name) {
 650                                 for (index--; index >= 0; index--) {
 651                                         kfree(edev->d_attrs_muex[index].attr.
 652                                               name);
 653                                 }
 654                                 kfree(edev->d_attrs_muex);
 655                                 kfree(edev->attrs_muex);
 656                                 ret = -ENOMEM;
 657                                 goto err_muex;
 658                         }
 659                         strcpy(name, buf);
 660                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 661                         edev->d_attrs_muex[index].attr.name = name;
 662                         edev->d_attrs_muex[index].attr.mode = 0000;
 663                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 664                                                         .attr;
 665                 }
 666                 edev->attr_g_muex.name = muex_name;
 667                 edev->attr_g_muex.attrs = edev->attrs_muex;
 668
 669         }
 670
 671         if (edev->max_supported) {
 672                 edev->extcon_dev_type.groups =
 673                         kzalloc(sizeof(struct attribute_group *) *
 674                                 (edev->max_supported + 2), GFP_KERNEL);
 675                 if (!edev->extcon_dev_type.groups) {
 676                         ret = -ENOMEM;
 677                         goto err_alloc_groups;
 678                 }
 679
 680                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 681                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 682
 683                 for (index = 0; index < edev->max_supported; index++)
 684                         edev->extcon_dev_type.groups[index] =
 685                                 &edev->cables[index].attr_g;
 686                 if (edev->mutually_exclusive)
 687                         edev->extcon_dev_type.groups[index] =
 688                                 &edev->attr_g_muex;
 689
 690                 edev->dev.type = &edev->extcon_dev_type;
 691         }
 692
 693         ret = device_register(&edev->dev);
 694         if (ret) {
 695                 put_device(&edev->dev);
 696                 goto err_dev;
 697         }
 698 #if defined(CONFIG_ANDROID)
 699         if (switch_class)
 700                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 701 #endif /* CONFIG_ANDROID */
 702
 703         spin_lock_init(&edev->lock);
 704
 705         edev->nh = devm_kzalloc(&edev->dev,
 706                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 707         if (!edev->nh) {
 708                 ret = -ENOMEM;
 709                 goto err_dev;
 710         }
 711
 712         for (index = 0; index < edev->max_supported; index++)
 713                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 714
 715         dev_set_drvdata(&edev->dev, edev);
 716         edev->state = 0;
 717
 718         mutex_lock(&extcon_dev_list_lock);
 719         list_add(&edev->entry, &extcon_dev_list);
 720         mutex_unlock(&extcon_dev_list_lock);
 721
 722         return 0;
 723
 724 err_dev:
 725         if (edev->max_supported)
 726                 kfree(edev->extcon_dev_type.groups);
 727 err_alloc_groups:
 728         if (edev->max_supported && edev->mutually_exclusive) {
 729                 for (index = 0; edev->mutually_exclusive[index]; index++)
 730                         kfree(edev->d_attrs_muex[index].attr.name);
 731                 kfree(edev->d_attrs_muex);
 732                 kfree(edev->attrs_muex);
 733         }
 734 err_muex:
 735         for (index = 0; index < edev->max_supported; index++)
 736                 kfree(edev->cables[index].attr_g.name);
 737 err_alloc_cables:
 738         if (edev->max_supported)
 739                 kfree(edev->cables);
 740 err_sysfs_alloc:
 741         return ret;
 742 }
 743 EXPORT_SYMBOL_GPL(extcon_dev_register);
 744
 745 /**
 746  * extcon_dev_unregister() - Unregister the extcon device.
 747  * @edev:       the extcon device instance to be unregistered.
 748  *
 749  * Note that this does not call kfree(edev) because edev was not allocated
 750  * by this class.
 751  */
 752 void extcon_dev_unregister(struct extcon_dev *edev)
 753 {
 754         int index;
 755
 756         if (!edev)
 757                 return;
 758
 759         mutex_lock(&extcon_dev_list_lock);
 760         list_del(&edev->entry);
 761         mutex_unlock(&extcon_dev_list_lock);
 762
 763         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 764                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 765                                 dev_name(&edev->dev));
 766                 return;
 767         }
 768
 769         device_unregister(&edev->dev);
 770
 771         if (edev->mutually_exclusive && edev->max_supported) {
 772                 for (index = 0; edev->mutually_exclusive[index];
 773                                 index++)
 774                         kfree(edev->d_attrs_muex[index].attr.name);
 775                 kfree(edev->d_attrs_muex);
 776                 kfree(edev->attrs_muex);
 777         }
 778
 779         for (index = 0; index < edev->max_supported; index++)
 780                 kfree(edev->cables[index].attr_g.name);
 781
 782         if (edev->max_supported) {
 783                 kfree(edev->extcon_dev_type.groups);
 784                 kfree(edev->cables);
 785         }
 786
 787 #if defined(CONFIG_ANDROID)
 788         if (switch_class)
 789                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 790 #endif
 791         put_device(&edev->dev);
 792 }
 793 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 794
 795 #ifdef CONFIG_OF
 796 /*
 797  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
 798  * @dev - instance to the given device
 799  * @index - index into list of extcon_dev
 800  *
 801  * return the instance of extcon device
 802  */
 803 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 804 {
 805         struct device_node *node;
 806         struct extcon_dev *edev;
 807
 808         if (!dev)
 809                 return ERR_PTR(-EINVAL);
 810
 811         if (!dev->of_node) {
 812                 dev_dbg(dev, "device does not have a device node entry\n");
 813                 return ERR_PTR(-EINVAL);
 814         }
 815
 816         node = of_parse_phandle(dev->of_node, "extcon", index);
 817         if (!node) {
 818                 dev_dbg(dev, "failed to get phandle in %s node\n",
 819                         dev->of_node->full_name);
 820                 return ERR_PTR(-ENODEV);
 821         }
 822
 823         mutex_lock(&extcon_dev_list_lock);
 824         list_for_each_entry(edev, &extcon_dev_list, entry) {
 825                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
 826                         mutex_unlock(&extcon_dev_list_lock);
 827                         of_node_put(node);
 828                         return edev;
 829                 }
 830         }
 831         mutex_unlock(&extcon_dev_list_lock);
 832         of_node_put(node);
 833
 834         return ERR_PTR(-EPROBE_DEFER);
 835 }
 836 #else
 837 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 838 {
 839         return ERR_PTR(-ENOSYS);
 840 }
 841 #endif /* CONFIG_OF */
 842 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
 843
 844 /**
 845  * extcon_get_edev_name() - Get the name of the extcon device.
 846  * @edev:       the extcon device
 847  */
 848 const char *extcon_get_edev_name(struct extcon_dev *edev)
 849 {
 850         return !edev ? NULL : edev->name;
 851 }
 852
 853 static int __init extcon_class_init(void)
 854 {
 855         return create_extcon_class();
 856 }
 857 module_init(extcon_class_init);
 858
 859 static void __exit extcon_class_exit(void)
 860 {
 861 #if defined(CONFIG_ANDROID)
 862         class_compat_unregister(switch_class);
 863 #endif
 864         class_destroy(extcon_class);
 865 }
 866 module_exit(extcon_class_exit);
 867
 868 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
 869 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 870 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 871 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 872 MODULE_DESCRIPTION("External connector (extcon) class driver");
 873 MODULE_LICENSE("GPL");