drivers/extcon/extcon-class.c

   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/slab.h>
  33 #include <linux/sysfs.h>
  34
  35 /*
  36  * extcon_cable_name suggests the standard cable names for commonly used
  37  * cable types.
  38  *
  39  * However, please do not use extcon_cable_name directly for extcon_dev
  40  * struct's supported_cable pointer unless your device really supports
  41  * every single port-type of the following cable names. Please choose cable
  42  * names that are actually used in your extcon device.
  43  */
  44 const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
  45         [EXTCON_USB]            = "USB",
  46         [EXTCON_USB_HOST]       = "USB-Host",
  47         [EXTCON_TA]             = "TA",
  48         [EXTCON_FAST_CHARGER]   = "Fast-charger",
  49         [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  50         [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  51         [EXTCON_HDMI]           = "HDMI",
  52         [EXTCON_MHL]            = "MHL",
  53         [EXTCON_DVI]            = "DVI",
  54         [EXTCON_VGA]            = "VGA",
  55         [EXTCON_DOCK]           = "Dock",
  56         [EXTCON_LINE_IN]        = "Line-in",
  57         [EXTCON_LINE_OUT]       = "Line-out",
  58         [EXTCON_MIC_IN]         = "Microphone",
  59         [EXTCON_HEADPHONE_OUT]  = "Headphone",
  60         [EXTCON_SPDIF_IN]       = "SPDIF-in",
  61         [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  62         [EXTCON_VIDEO_IN]       = "Video-in",
  63         [EXTCON_VIDEO_OUT]      = "Video-out",
  64         [EXTCON_MECHANICAL]     = "Mechanical",
  65 };
  66
  67 static struct class *extcon_class;
  68 #if defined(CONFIG_ANDROID)
  69 static struct class_compat *switch_class;
  70 #endif /* CONFIG_ANDROID */
  71
  72 static LIST_HEAD(extcon_dev_list);
  73 static DEFINE_MUTEX(extcon_dev_list_lock);
  74
  75 /**
  76  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  77  *                          condition.
  78  * @edev:       the extcon device
  79  * @new_state:  new cable attach status for @edev
  80  *
  81  * Returns 0 if nothing violates. Returns the index + 1 for the first
  82  * violated condition.
  83  */
  84 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  85 {
  86         int i = 0;
  87
  88         if (!edev->mutually_exclusive)
  89                 return 0;
  90
  91         for (i = 0; edev->mutually_exclusive[i]; i++) {
  92                 int weight;
  93                 u32 correspondants = new_state & edev->mutually_exclusive[i];
  94
  95                 /* calculate the total number of bits set */
  96                 weight = hweight32(correspondants);
  97                 if (weight > 1)
  98                         return i + 1;
  99         }
 100
 101         return 0;
 102 }
 103
 104 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 105                           char *buf)
 106 {
 107         int i, count = 0;
 108         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 109
 110         if (edev->print_state) {
 111                 int ret = edev->print_state(edev, buf);
 112
 113                 if (ret >= 0)
 114                         return ret;
 115                 /* Use default if failed */
 116         }
 117
 118         if (edev->max_supported == 0)
 119                 return sprintf(buf, "%u\n", edev->state);
 120
 121         for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
 122                 if (!edev->supported_cable[i])
 123                         break;
 124                 count += sprintf(buf + count, "%s=%d\n",
 125                                  edev->supported_cable[i],
 126                                  !!(edev->state & (1 << i)));
 127         }
 128
 129         return count;
 130 }
 131
 132 int extcon_set_state(struct extcon_dev *edev, u32 state);
 133 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 134                            const char *buf, size_t count)
 135 {
 136         u32 state;
 137         ssize_t ret = 0;
 138         struct extcon_dev *edev = (struct extcon_dev *) 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 }
 151 static DEVICE_ATTR_RW(state);
 152
 153 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 154                 char *buf)
 155 {
 156         struct extcon_dev *edev = (struct extcon_dev *) 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                 if (ret >= 0)
 162                         return ret;
 163         }
 164
 165         return sprintf(buf, "%s\n", dev_name(edev->dev));
 166 }
 167 static DEVICE_ATTR_RO(name);
 168
 169 static ssize_t cable_name_show(struct device *dev,
 170                                struct device_attribute *attr, char *buf)
 171 {
 172         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 173                                                   attr_name);
 174
 175         return sprintf(buf, "%s\n",
 176                        cable->edev->supported_cable[cable->cable_index]);
 177 }
 178
 179 static ssize_t cable_state_show(struct device *dev,
 180                                 struct device_attribute *attr, char *buf)
 181 {
 182         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 183                                                   attr_state);
 184
 185         return sprintf(buf, "%d\n",
 186                        extcon_get_cable_state_(cable->edev,
 187                                                cable->cable_index));
 188 }
 189
 190 /**
 191  * extcon_update_state() - Update the cable attach states of the extcon device
 192  *                      only for the masked bits.
 193  * @edev:       the extcon device
 194  * @mask:       the bit mask to designate updated bits.
 195  * @state:      new cable attach status for @edev
 196  *
 197  * Changing the state sends uevent with environment variable containing
 198  * the name of extcon device (envp[0]) and the state output (envp[1]).
 199  * Tizen uses this format for extcon device to get events from ports.
 200  * Android uses this format as well.
 201  *
 202  * Note that the notifier provides which bits are changed in the state
 203  * variable with the val parameter (second) to the callback.
 204  */
 205 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 206 {
 207         char name_buf[120];
 208         char state_buf[120];
 209         char *prop_buf;
 210         char *envp[3];
 211         int env_offset = 0;
 212         int length;
 213         unsigned long flags;
 214
 215         spin_lock_irqsave(&edev->lock, flags);
 216
 217         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 218                 u32 old_state = edev->state;
 219
 220                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 221                                                    (state & mask))) {
 222                         spin_unlock_irqrestore(&edev->lock, flags);
 223                         return -EPERM;
 224                 }
 225
 226                 edev->state &= ~mask;
 227                 edev->state |= state & mask;
 228
 229                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 230
 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 }
 270 EXPORT_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  */
 280 int extcon_set_state(struct extcon_dev *edev, u32 state)
 281 {
 282         return extcon_update_state(edev, 0xffffffff, state);
 283 }
 284 EXPORT_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  */
 296 int 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 }
 310 EXPORT_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  */
 317 int 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 }
 324 EXPORT_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  */
 333 int 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 }
 338 EXPORT_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 extcon_find_cable_index().
 344  * @cable_state:        the new cable status. The default semantics is
 345  *                      true: attached / false: detached.
 346  */
 347 int extcon_set_cable_state_(struct extcon_dev *edev,
 348                         int index, bool cable_state)
 349 {
 350         u32 state;
 351
 352         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 353                 return -EINVAL;
 354
 355         state = cable_state ? (1 << index) : 0;
 356         return extcon_update_state(edev, 1 << index, state);
 357 }
 358 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 359
 360 /**
 361  * extcon_set_cable_state() - Set the status of a specific cable.
 362  * @edev:       the extcon device that has the cable.
 363  * @cable_name: cable name.
 364  * @cable_state:        the new cable status. The default semantics is
 365  *                      true: attached / false: detached.
 366  *
 367  * Note that this is slower than extcon_set_cable_state_.
 368  */
 369 int extcon_set_cable_state(struct extcon_dev *edev,
 370                         const char *cable_name, bool cable_state)
 371 {
 372         return extcon_set_cable_state_(edev, extcon_find_cable_index
 373                                         (edev, cable_name), cable_state);
 374 }
 375 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 376
 377 /**
 378  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 379  * @extcon_name:        The extcon name provided with extcon_dev_register()
 380  */
 381 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 382 {
 383         struct extcon_dev *sd;
 384
 385         mutex_lock(&extcon_dev_list_lock);
 386         list_for_each_entry(sd, &extcon_dev_list, entry) {
 387                 if (!strcmp(sd->name, extcon_name))
 388                         goto out;
 389         }
 390         sd = NULL;
 391 out:
 392         mutex_unlock(&extcon_dev_list_lock);
 393         return sd;
 394 }
 395 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 396
 397 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 398                            void *ptr)
 399 {
 400         struct extcon_specific_cable_nb *obj = container_of(nb,
 401                         struct extcon_specific_cable_nb, internal_nb);
 402         struct extcon_dev *edev = ptr;
 403
 404         if ((val & (1 << obj->cable_index)) !=
 405             (edev->state & (1 << obj->cable_index))) {
 406                 bool cable_state = true;
 407
 408                 obj->previous_value = val;
 409
 410                 if (val & (1 << obj->cable_index))
 411                         cable_state = false;
 412
 413                 return obj->user_nb->notifier_call(obj->user_nb,
 414                                 cable_state, ptr);
 415         }
 416
 417         return NOTIFY_OK;
 418 }
 419
 420 /**
 421  * extcon_register_interest() - Register a notifier for a state change of a
 422  *                            specific cable, not an entier set of cables of a
 423  *                            extcon device.
 424  * @obj:        an empty extcon_specific_cable_nb object to be returned.
 425  * @extcon_name:        the name of extcon device.
 426  *                      if NULL, extcon_register_interest will register
 427  *                      every cable with the target cable_name given.
 428  * @cable_name:         the target cable name.
 429  * @nb:         the notifier block to get notified.
 430  *
 431  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 432  * the struct for you.
 433  *
 434  * extcon_register_interest is a helper function for those who want to get
 435  * notification for a single specific cable's status change. If a user wants
 436  * to get notification for any changes of all cables of a extcon device,
 437  * he/she should use the general extcon_register_notifier().
 438  *
 439  * Note that the second parameter given to the callback of nb (val) is
 440  * "old_state", not the current state. The current state can be retrieved
 441  * by looking at the third pameter (edev pointer)'s state value.
 442  */
 443 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 444                              const char *extcon_name, const char *cable_name,
 445                              struct notifier_block *nb)
 446 {
 447         if (!obj || !cable_name || !nb)
 448                 return -EINVAL;
 449
 450         if (extcon_name) {
 451                 obj->edev = extcon_get_extcon_dev(extcon_name);
 452                 if (!obj->edev)
 453                         return -ENODEV;
 454
 455                 obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
 456                 if (obj->cable_index < 0)
 457                         return obj->cable_index;
 458
 459                 obj->user_nb = nb;
 460
 461                 obj->internal_nb.notifier_call = _call_per_cable;
 462
 463                 return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
 464         } else {
 465                 struct class_dev_iter iter;
 466                 struct extcon_dev *extd;
 467                 struct device *dev;
 468
 469                 if (!extcon_class)
 470                         return -ENODEV;
 471                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 472                 while ((dev = class_dev_iter_next(&iter))) {
 473                         extd = (struct extcon_dev *)dev_get_drvdata(dev);
 474
 475                         if (extcon_find_cable_index(extd, cable_name) < 0)
 476                                 continue;
 477
 478                         class_dev_iter_exit(&iter);
 479                         return extcon_register_interest(obj, extd->name,
 480                                                 cable_name, nb);
 481                 }
 482
 483                 return -ENODEV;
 484         }
 485 }
 486 EXPORT_SYMBOL_GPL(extcon_register_interest);
 487
 488 /**
 489  * extcon_unregister_interest() - Unregister the notifier registered by
 490  *                              extcon_register_interest().
 491  * @obj:        the extcon_specific_cable_nb object returned by
 492  *              extcon_register_interest().
 493  */
 494 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 495 {
 496         if (!obj)
 497                 return -EINVAL;
 498
 499         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 500 }
 501 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 502
 503 /**
 504  * extcon_register_notifier() - Register a notifiee to get notified by
 505  *                            any attach status changes from the extcon.
 506  * @edev:       the extcon device.
 507  * @nb:         a notifier block to be registered.
 508  *
 509  * Note that the second parameter given to the callback of nb (val) is
 510  * "old_state", not the current state. The current state can be retrieved
 511  * by looking at the third pameter (edev pointer)'s state value.
 512  */
 513 int extcon_register_notifier(struct extcon_dev *edev,
 514                         struct notifier_block *nb)
 515 {
 516         return raw_notifier_chain_register(&edev->nh, nb);
 517 }
 518 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 519
 520 /**
 521  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 522  * @edev:       the extcon device.
 523  * @nb:         a registered notifier block to be unregistered.
 524  */
 525 int extcon_unregister_notifier(struct extcon_dev *edev,
 526                         struct notifier_block *nb)
 527 {
 528         return raw_notifier_chain_unregister(&edev->nh, nb);
 529 }
 530 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 531
 532 static struct attribute *extcon_attrs[] = {
 533         &dev_attr_state.attr,
 534         &dev_attr_name.attr,
 535         NULL,
 536 };
 537 ATTRIBUTE_GROUPS(extcon);
 538
 539 static int create_extcon_class(void)
 540 {
 541         if (!extcon_class) {
 542                 extcon_class = class_create(THIS_MODULE, "extcon");
 543                 if (IS_ERR(extcon_class))
 544                         return PTR_ERR(extcon_class);
 545                 extcon_class->dev_groups = extcon_groups;
 546
 547 #if defined(CONFIG_ANDROID)
 548                 switch_class = class_compat_register("switch");
 549                 if (WARN(!switch_class, "cannot allocate"))
 550                         return -ENOMEM;
 551 #endif /* CONFIG_ANDROID */
 552         }
 553
 554         return 0;
 555 }
 556
 557 static void extcon_dev_release(struct device *dev)
 558 {
 559         kfree(dev);
 560 }
 561
 562 static const char *muex_name = "mutually_exclusive";
 563 static void dummy_sysfs_dev_release(struct device *dev)
 564 {
 565 }
 566
 567 /**
 568  * extcon_dev_register() - Register a new extcon device
 569  * @edev        : the new extcon device (should be allocated before calling)
 570  * @dev         : the parent device for this extcon device.
 571  *
 572  * Among the members of edev struct, please set the "user initializing data"
 573  * in any case and set the "optional callbacks" if required. However, please
 574  * do not set the values of "internal data", which are initialized by
 575  * this function.
 576  */
 577 int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
 578 {
 579         int ret, index = 0;
 580
 581         if (!extcon_class) {
 582                 ret = create_extcon_class();
 583                 if (ret < 0)
 584                         return ret;
 585         }
 586
 587         if (edev->supported_cable) {
 588                 /* Get size of array */
 589                 for (index = 0; edev->supported_cable[index]; index++)
 590                         ;
 591                 edev->max_supported = index;
 592         } else {
 593                 edev->max_supported = 0;
 594         }
 595
 596         if (index > SUPPORTED_CABLE_MAX) {
 597                 dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 598                 return -EINVAL;
 599         }
 600
 601         edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 602         if (!edev->dev)
 603                 return -ENOMEM;
 604         edev->dev->parent = dev;
 605         edev->dev->class = extcon_class;
 606         edev->dev->release = extcon_dev_release;
 607
 608         edev->name = edev->name ? edev->name : dev_name(dev);
 609         dev_set_name(edev->dev, "%s", edev->name);
 610
 611         if (edev->max_supported) {
 612                 char buf[10];
 613                 char *str;
 614                 struct extcon_cable *cable;
 615
 616                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 617                                        edev->max_supported, GFP_KERNEL);
 618                 if (!edev->cables) {
 619                         ret = -ENOMEM;
 620                         goto err_sysfs_alloc;
 621                 }
 622                 for (index = 0; index < edev->max_supported; index++) {
 623                         cable = &edev->cables[index];
 624
 625                         snprintf(buf, 10, "cable.%d", index);
 626                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 627                                       GFP_KERNEL);
 628                         if (!str) {
 629                                 for (index--; index >= 0; index--) {
 630                                         cable = &edev->cables[index];
 631                                         kfree(cable->attr_g.name);
 632                                 }
 633                                 ret = -ENOMEM;
 634
 635                                 goto err_alloc_cables;
 636                         }
 637                         strcpy(str, buf);
 638
 639                         cable->edev = edev;
 640                         cable->cable_index = index;
 641                         cable->attrs[0] = &cable->attr_name.attr;
 642                         cable->attrs[1] = &cable->attr_state.attr;
 643                         cable->attrs[2] = NULL;
 644                         cable->attr_g.name = str;
 645                         cable->attr_g.attrs = cable->attrs;
 646
 647                         sysfs_attr_init(&cable->attr_name.attr);
 648                         cable->attr_name.attr.name = "name";
 649                         cable->attr_name.attr.mode = 0444;
 650                         cable->attr_name.show = cable_name_show;
 651
 652                         sysfs_attr_init(&cable->attr_state.attr);
 653                         cable->attr_state.attr.name = "state";
 654                         cable->attr_state.attr.mode = 0444;
 655                         cable->attr_state.show = cable_state_show;
 656                 }
 657         }
 658
 659         if (edev->max_supported && edev->mutually_exclusive) {
 660                 char buf[80];
 661                 char *name;
 662
 663                 /* Count the size of mutually_exclusive array */
 664                 for (index = 0; edev->mutually_exclusive[index]; index++)
 665                         ;
 666
 667                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 668                                            (index + 1), GFP_KERNEL);
 669                 if (!edev->attrs_muex) {
 670                         ret = -ENOMEM;
 671                         goto err_muex;
 672                 }
 673
 674                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 675                                              index, GFP_KERNEL);
 676                 if (!edev->d_attrs_muex) {
 677                         ret = -ENOMEM;
 678                         kfree(edev->attrs_muex);
 679                         goto err_muex;
 680                 }
 681
 682                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 683                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 684                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 685                                        GFP_KERNEL);
 686                         if (!name) {
 687                                 for (index--; index >= 0; index--) {
 688                                         kfree(edev->d_attrs_muex[index].attr.
 689                                               name);
 690                                 }
 691                                 kfree(edev->d_attrs_muex);
 692                                 kfree(edev->attrs_muex);
 693                                 ret = -ENOMEM;
 694                                 goto err_muex;
 695                         }
 696                         strcpy(name, buf);
 697                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 698                         edev->d_attrs_muex[index].attr.name = name;
 699                         edev->d_attrs_muex[index].attr.mode = 0000;
 700                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 701                                                         .attr;
 702                 }
 703                 edev->attr_g_muex.name = muex_name;
 704                 edev->attr_g_muex.attrs = edev->attrs_muex;
 705
 706         }
 707
 708         if (edev->max_supported) {
 709                 edev->extcon_dev_type.groups =
 710                         kzalloc(sizeof(struct attribute_group *) *
 711                                 (edev->max_supported + 2), GFP_KERNEL);
 712                 if (!edev->extcon_dev_type.groups) {
 713                         ret = -ENOMEM;
 714                         goto err_alloc_groups;
 715                 }
 716
 717                 edev->extcon_dev_type.name = dev_name(edev->dev);
 718                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 719
 720                 for (index = 0; index < edev->max_supported; index++)
 721                         edev->extcon_dev_type.groups[index] =
 722                                 &edev->cables[index].attr_g;
 723                 if (edev->mutually_exclusive)
 724                         edev->extcon_dev_type.groups[index] =
 725                                 &edev->attr_g_muex;
 726
 727                 edev->dev->type = &edev->extcon_dev_type;
 728         }
 729
 730         ret = device_register(edev->dev);
 731         if (ret) {
 732                 put_device(edev->dev);
 733                 goto err_dev;
 734         }
 735 #if defined(CONFIG_ANDROID)
 736         if (switch_class)
 737                 ret = class_compat_create_link(switch_class, edev->dev,
 738                                                NULL);
 739 #endif /* CONFIG_ANDROID */
 740
 741         spin_lock_init(&edev->lock);
 742
 743         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 744
 745         dev_set_drvdata(edev->dev, edev);
 746         edev->state = 0;
 747
 748         mutex_lock(&extcon_dev_list_lock);
 749         list_add(&edev->entry, &extcon_dev_list);
 750         mutex_unlock(&extcon_dev_list_lock);
 751
 752         return 0;
 753
 754 err_dev:
 755         if (edev->max_supported)
 756                 kfree(edev->extcon_dev_type.groups);
 757 err_alloc_groups:
 758         if (edev->max_supported && edev->mutually_exclusive) {
 759                 for (index = 0; edev->mutually_exclusive[index]; index++)
 760                         kfree(edev->d_attrs_muex[index].attr.name);
 761                 kfree(edev->d_attrs_muex);
 762                 kfree(edev->attrs_muex);
 763         }
 764 err_muex:
 765         for (index = 0; index < edev->max_supported; index++)
 766                 kfree(edev->cables[index].attr_g.name);
 767 err_alloc_cables:
 768         if (edev->max_supported)
 769                 kfree(edev->cables);
 770 err_sysfs_alloc:
 771         kfree(edev->dev);
 772         return ret;
 773 }
 774 EXPORT_SYMBOL_GPL(extcon_dev_register);
 775
 776 /**
 777  * extcon_dev_unregister() - Unregister the extcon device.
 778  * @edev:       the extcon device instance to be unregistered.
 779  *
 780  * Note that this does not call kfree(edev) because edev was not allocated
 781  * by this class.
 782  */
 783 void extcon_dev_unregister(struct extcon_dev *edev)
 784 {
 785         int index;
 786
 787         mutex_lock(&extcon_dev_list_lock);
 788         list_del(&edev->entry);
 789         mutex_unlock(&extcon_dev_list_lock);
 790
 791         if (IS_ERR_OR_NULL(get_device(edev->dev))) {
 792                 dev_err(edev->dev, "Failed to unregister extcon_dev (%s)\n",
 793                                 dev_name(edev->dev));
 794                 return;
 795         }
 796
 797         if (edev->mutually_exclusive && edev->max_supported) {
 798                 for (index = 0; edev->mutually_exclusive[index];
 799                                 index++)
 800                         kfree(edev->d_attrs_muex[index].attr.name);
 801                 kfree(edev->d_attrs_muex);
 802                 kfree(edev->attrs_muex);
 803         }
 804
 805         for (index = 0; index < edev->max_supported; index++)
 806                 kfree(edev->cables[index].attr_g.name);
 807
 808         if (edev->max_supported) {
 809                 kfree(edev->extcon_dev_type.groups);
 810                 kfree(edev->cables);
 811         }
 812
 813 #if defined(CONFIG_ANDROID)
 814         if (switch_class)
 815                 class_compat_remove_link(switch_class, edev->dev, NULL);
 816 #endif
 817         device_unregister(edev->dev);
 818         put_device(edev->dev);
 819 }
 820 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 821
 822 static int __init extcon_class_init(void)
 823 {
 824         return create_extcon_class();
 825 }
 826 module_init(extcon_class_init);
 827
 828 static void __exit extcon_class_exit(void)
 829 {
 830 #if defined(CONFIG_ANDROID)
 831         class_compat_unregister(switch_class);
 832 #endif
 833         class_destroy(extcon_class);
 834 }
 835 module_exit(extcon_class_exit);
 836
 837 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 838 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 839 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 840 MODULE_DESCRIPTION("External connector (extcon) class driver");
 841 MODULE_LICENSE("GPL");