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
  34 /*
  35  * extcon_cable_name suggests the standard cable names for commonly used
  36  * cable types.
  37  *
  38  * However, please do not use extcon_cable_name directly for extcon_dev
  39  * struct's supported_cable pointer unless your device really supports
  40  * every single port-type of the following cable names. Please choose cable
  41  * names that are actually used in your extcon device.
  42  */
  43 const char *extcon_cable_name[] = {
  44         [EXTCON_USB]            = "USB",
  45         [EXTCON_USB_HOST]       = "USB-Host",
  46         [EXTCON_TA]             = "TA",
  47         [EXTCON_FAST_CHARGER]   = "Fast-charger",
  48         [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  49         [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  50         [EXTCON_HDMI]           = "HDMI",
  51         [EXTCON_MHL]            = "MHL",
  52         [EXTCON_DVI]            = "DVI",
  53         [EXTCON_VGA]            = "VGA",
  54         [EXTCON_DOCK]           = "Dock",
  55         [EXTCON_LINE_IN]        = "Line-in",
  56         [EXTCON_LINE_OUT]       = "Line-out",
  57         [EXTCON_MIC_IN]         = "Microphone",
  58         [EXTCON_HEADPHONE_OUT]  = "Headphone",
  59         [EXTCON_SPDIF_IN]       = "SPDIF-in",
  60         [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  61         [EXTCON_VIDEO_IN]       = "Video-in",
  62         [EXTCON_VIDEO_OUT]      = "Video-out",
  63         [EXTCON_MECHANICAL]     = "Mechanical",
  64
  65         NULL,
  66 };
  67
  68 static struct class *extcon_class;
  69 #if defined(CONFIG_ANDROID)
  70 static struct class_compat *switch_class;
  71 #endif /* CONFIG_ANDROID */
  72
  73 static LIST_HEAD(extcon_dev_list);
  74 static DEFINE_MUTEX(extcon_dev_list_lock);
  75
  76 /**
  77  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  78  *                          condition.
  79  * @edev:       the extcon device
  80  * @new_state:  new cable attach status for @edev
  81  *
  82  * Returns 0 if nothing violates. Returns the index + 1 for the first
  83  * violated condition.
  84  */
  85 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  86 {
  87         int i = 0;
  88
  89         if (!edev->mutually_exclusive)
  90                 return 0;
  91
  92         for (i = 0; edev->mutually_exclusive[i]; i++) {
  93                 int count = 0, j;
  94                 u32 correspondants = new_state & edev->mutually_exclusive[i];
  95                 u32 exp = 1;
  96
  97                 for (j = 0; j < 32; j++) {
  98                         if (exp & correspondants)
  99                                 count++;
 100                         if (count > 1)
 101                                 return i + 1;
 102                         exp <<= 1;
 103                 }
 104         }
 105
 106         return 0;
 107 }
 108
 109 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 110                           char *buf)
 111 {
 112         int i, count = 0;
 113         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 114
 115         if (edev->print_state) {
 116                 int ret = edev->print_state(edev, buf);
 117
 118                 if (ret >= 0)
 119                         return ret;
 120                 /* Use default if failed */
 121         }
 122
 123         if (edev->max_supported == 0)
 124                 return sprintf(buf, "%u\n", edev->state);
 125
 126         for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
 127                 if (!edev->supported_cable[i])
 128                         break;
 129                 count += sprintf(buf + count, "%s=%d\n",
 130                                  edev->supported_cable[i],
 131                                  !!(edev->state & (1 << i)));
 132         }
 133
 134         return count;
 135 }
 136
 137 int extcon_set_state(struct extcon_dev *edev, u32 state);
 138 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 139                            const char *buf, size_t count)
 140 {
 141         u32 state;
 142         ssize_t ret = 0;
 143         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 144
 145         ret = sscanf(buf, "0x%x", &state);
 146         if (ret == 0)
 147                 ret = -EINVAL;
 148         else
 149                 ret = extcon_set_state(edev, state);
 150
 151         if (ret < 0)
 152                 return ret;
 153
 154         return count;
 155 }
 156
 157 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 158                 char *buf)
 159 {
 160         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 161
 162         /* Optional callback given by the user */
 163         if (edev->print_name) {
 164                 int ret = edev->print_name(edev, buf);
 165                 if (ret >= 0)
 166                         return ret;
 167         }
 168
 169         return sprintf(buf, "%s\n", dev_name(edev->dev));
 170 }
 171
 172 static ssize_t cable_name_show(struct device *dev,
 173                                struct device_attribute *attr, char *buf)
 174 {
 175         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 176                                                   attr_name);
 177
 178         return sprintf(buf, "%s\n",
 179                        cable->edev->supported_cable[cable->cable_index]);
 180 }
 181
 182 static ssize_t cable_state_show(struct device *dev,
 183                                 struct device_attribute *attr, char *buf)
 184 {
 185         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 186                                                   attr_state);
 187
 188         return sprintf(buf, "%d\n",
 189                        extcon_get_cable_state_(cable->edev,
 190                                                cable->cable_index));
 191 }
 192
 193 static ssize_t cable_state_store(struct device *dev,
 194                                  struct device_attribute *attr, const char *buf,
 195                                  size_t count)
 196 {
 197         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 198                                                   attr_state);
 199         int ret, state;
 200
 201         ret = sscanf(buf, "%d", &state);
 202         if (ret == 0)
 203                 ret = -EINVAL;
 204         else
 205                 ret = extcon_set_cable_state_(cable->edev, cable->cable_index,
 206                                               state);
 207
 208         if (ret < 0)
 209                 return ret;
 210         return count;
 211 }
 212
 213 /**
 214  * extcon_update_state() - Update the cable attach states of the extcon device
 215  *                      only for the masked bits.
 216  * @edev:       the extcon device
 217  * @mask:       the bit mask to designate updated bits.
 218  * @state:      new cable attach status for @edev
 219  *
 220  * Changing the state sends uevent with environment variable containing
 221  * the name of extcon device (envp[0]) and the state output (envp[1]).
 222  * Tizen uses this format for extcon device to get events from ports.
 223  * Android uses this format as well.
 224  *
 225  * Note that the notifier provides which bits are changed in the state
 226  * variable with the val parameter (second) to the callback.
 227  */
 228 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 229 {
 230         char name_buf[120];
 231         char state_buf[120];
 232         char *prop_buf;
 233         char *envp[3];
 234         int env_offset = 0;
 235         int length;
 236         unsigned long flags;
 237
 238         spin_lock_irqsave(&edev->lock, flags);
 239
 240         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 241                 u32 old_state = edev->state;
 242
 243                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 244                                                    (state & mask))) {
 245                         spin_unlock_irqrestore(&edev->lock, flags);
 246                         return -EPERM;
 247                 }
 248
 249                 edev->state &= ~mask;
 250                 edev->state |= state & mask;
 251
 252                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 253
 254                 /* This could be in interrupt handler */
 255                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 256                 if (prop_buf) {
 257                         length = name_show(edev->dev, NULL, prop_buf);
 258                         if (length > 0) {
 259                                 if (prop_buf[length - 1] == '\n')
 260                                         prop_buf[length - 1] = 0;
 261                                 snprintf(name_buf, sizeof(name_buf),
 262                                         "NAME=%s", prop_buf);
 263                                 envp[env_offset++] = name_buf;
 264                         }
 265                         length = state_show(edev->dev, NULL, prop_buf);
 266                         if (length > 0) {
 267                                 if (prop_buf[length - 1] == '\n')
 268                                         prop_buf[length - 1] = 0;
 269                                 snprintf(state_buf, sizeof(state_buf),
 270                                         "STATE=%s", prop_buf);
 271                                 envp[env_offset++] = state_buf;
 272                         }
 273                         envp[env_offset] = NULL;
 274                         /* Unlock early before uevent */
 275                         spin_unlock_irqrestore(&edev->lock, flags);
 276
 277                         kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp);
 278                         free_page((unsigned long)prop_buf);
 279                 } else {
 280                         /* Unlock early before uevent */
 281                         spin_unlock_irqrestore(&edev->lock, flags);
 282
 283                         dev_err(edev->dev, "out of memory in extcon_set_state\n");
 284                         kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE);
 285                 }
 286         } else {
 287                 /* No changes */
 288                 spin_unlock_irqrestore(&edev->lock, flags);
 289         }
 290
 291         return 0;
 292 }
 293 EXPORT_SYMBOL_GPL(extcon_update_state);
 294
 295 /**
 296  * extcon_set_state() - Set the cable attach states of the extcon device.
 297  * @edev:       the extcon device
 298  * @state:      new cable attach status for @edev
 299  *
 300  * Note that notifier provides which bits are changed in the state
 301  * variable with the val parameter (second) to the callback.
 302  */
 303 int extcon_set_state(struct extcon_dev *edev, u32 state)
 304 {
 305         return extcon_update_state(edev, 0xffffffff, state);
 306 }
 307 EXPORT_SYMBOL_GPL(extcon_set_state);
 308
 309 /**
 310  * extcon_find_cable_index() - Get the cable index based on the cable name.
 311  * @edev:       the extcon device that has the cable.
 312  * @cable_name: cable name to be searched.
 313  *
 314  * Note that accessing a cable state based on cable_index is faster than
 315  * cable_name because using cable_name induces a loop with strncmp().
 316  * Thus, when get/set_cable_state is repeatedly used, using cable_index
 317  * is recommended.
 318  */
 319 int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 320 {
 321         int i;
 322
 323         if (edev->supported_cable) {
 324                 for (i = 0; edev->supported_cable[i]; i++) {
 325                         if (!strncmp(edev->supported_cable[i],
 326                                 cable_name, CABLE_NAME_MAX))
 327                                 return i;
 328                 }
 329         }
 330
 331         return -EINVAL;
 332 }
 333 EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 334
 335 /**
 336  * extcon_get_cable_state_() - Get the status of a specific cable.
 337  * @edev:       the extcon device that has the cable.
 338  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 339  */
 340 int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 341 {
 342         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 343                 return -EINVAL;
 344
 345         return !!(edev->state & (1 << index));
 346 }
 347 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 348
 349 /**
 350  * extcon_get_cable_state() - Get the status of a specific cable.
 351  * @edev:       the extcon device that has the cable.
 352  * @cable_name: cable name.
 353  *
 354  * Note that this is slower than extcon_get_cable_state_.
 355  */
 356 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 357 {
 358         return extcon_get_cable_state_(edev, extcon_find_cable_index
 359                                                 (edev, cable_name));
 360 }
 361 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 362
 363 /**
 364  * extcon_get_cable_state_() - Set the status of a specific cable.
 365  * @edev:       the extcon device that has the cable.
 366  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 367  * @cable_state:        the new cable status. The default semantics is
 368  *                      true: attached / false: detached.
 369  */
 370 int extcon_set_cable_state_(struct extcon_dev *edev,
 371                         int index, bool cable_state)
 372 {
 373         u32 state;
 374
 375         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 376                 return -EINVAL;
 377
 378         state = cable_state ? (1 << index) : 0;
 379         return extcon_update_state(edev, 1 << index, state);
 380 }
 381 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 382
 383 /**
 384  * extcon_get_cable_state() - Set the status of a specific cable.
 385  * @edev:       the extcon device that has the cable.
 386  * @cable_name: cable name.
 387  * @cable_state:        the new cable status. The default semantics is
 388  *                      true: attached / false: detached.
 389  *
 390  * Note that this is slower than extcon_set_cable_state_.
 391  */
 392 int extcon_set_cable_state(struct extcon_dev *edev,
 393                         const char *cable_name, bool cable_state)
 394 {
 395         return extcon_set_cable_state_(edev, extcon_find_cable_index
 396                                         (edev, cable_name), cable_state);
 397 }
 398 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 399
 400 /**
 401  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 402  * @extcon_name:        The extcon name provided with extcon_dev_register()
 403  */
 404 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 405 {
 406         struct extcon_dev *sd;
 407
 408         mutex_lock(&extcon_dev_list_lock);
 409         list_for_each_entry(sd, &extcon_dev_list, entry) {
 410                 if (!strcmp(sd->name, extcon_name))
 411                         goto out;
 412         }
 413         sd = NULL;
 414 out:
 415         mutex_unlock(&extcon_dev_list_lock);
 416         return sd;
 417 }
 418 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 419
 420 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 421                            void *ptr)
 422 {
 423         struct extcon_specific_cable_nb *obj = container_of(nb,
 424                         struct extcon_specific_cable_nb, internal_nb);
 425         struct extcon_dev *edev = ptr;
 426
 427         if ((val & (1 << obj->cable_index)) !=
 428             (edev->state & (1 << obj->cable_index))) {
 429                 bool cable_state = true;
 430
 431                 obj->previous_value = val;
 432
 433                 if (val & (1 << obj->cable_index))
 434                         cable_state = false;
 435
 436                 return obj->user_nb->notifier_call(obj->user_nb,
 437                                 cable_state, ptr);
 438         }
 439
 440         return NOTIFY_OK;
 441 }
 442
 443 /**
 444  * extcon_register_interest() - Register a notifier for a state change of a
 445  *                            specific cable, not a entier set of cables of a
 446  *                            extcon device.
 447  * @obj:        an empty extcon_specific_cable_nb object to be returned.
 448  * @extcon_name:        the name of extcon device.
 449  * @cable_name:         the target cable name.
 450  * @nb:         the notifier block to get notified.
 451  *
 452  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 453  * the struct for you.
 454  *
 455  * extcon_register_interest is a helper function for those who want to get
 456  * notification for a single specific cable's status change. If a user wants
 457  * to get notification for any changes of all cables of a extcon device,
 458  * he/she should use the general extcon_register_notifier().
 459  *
 460  * Note that the second parameter given to the callback of nb (val) is
 461  * "old_state", not the current state. The current state can be retrieved
 462  * by looking at the third pameter (edev pointer)'s state value.
 463  */
 464 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 465                              const char *extcon_name, const char *cable_name,
 466                              struct notifier_block *nb)
 467 {
 468         if (!obj || !extcon_name || !cable_name || !nb)
 469                 return -EINVAL;
 470
 471         obj->edev = extcon_get_extcon_dev(extcon_name);
 472         if (!obj->edev)
 473                 return -ENODEV;
 474
 475         obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
 476         if (obj->cable_index < 0)
 477                 return -ENODEV;
 478
 479         obj->user_nb = nb;
 480
 481         obj->internal_nb.notifier_call = _call_per_cable;
 482
 483         return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
 484 }
 485
 486 /**
 487  * extcon_unregister_interest() - Unregister the notifier registered by
 488  *                              extcon_register_interest().
 489  * @obj:        the extcon_specific_cable_nb object returned by
 490  *              extcon_register_interest().
 491  */
 492 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 493 {
 494         if (!obj)
 495                 return -EINVAL;
 496
 497         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 498 }
 499
 500 /**
 501  * extcon_register_notifier() - Register a notifee to get notified by
 502  *                            any attach status changes from the extcon.
 503  * @edev:       the extcon device.
 504  * @nb:         a notifier block to be registered.
 505  *
 506  * Note that the second parameter given to the callback of nb (val) is
 507  * "old_state", not the current state. The current state can be retrieved
 508  * by looking at the third pameter (edev pointer)'s state value.
 509  */
 510 int extcon_register_notifier(struct extcon_dev *edev,
 511                         struct notifier_block *nb)
 512 {
 513         return raw_notifier_chain_register(&edev->nh, nb);
 514 }
 515 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 516
 517 /**
 518  * extcon_unregister_notifier() - Unregister a notifee from the extcon device.
 519  * @edev:       the extcon device.
 520  * @nb:         a registered notifier block to be unregistered.
 521  */
 522 int extcon_unregister_notifier(struct extcon_dev *edev,
 523                         struct notifier_block *nb)
 524 {
 525         return raw_notifier_chain_unregister(&edev->nh, nb);
 526 }
 527 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 528
 529 static struct device_attribute extcon_attrs[] = {
 530         __ATTR(state, S_IRUGO | S_IWUSR, state_show, state_store),
 531         __ATTR_RO(name),
 532         __ATTR_NULL,
 533 };
 534
 535 static int create_extcon_class(void)
 536 {
 537         if (!extcon_class) {
 538                 extcon_class = class_create(THIS_MODULE, "extcon");
 539                 if (IS_ERR(extcon_class))
 540                         return PTR_ERR(extcon_class);
 541                 extcon_class->dev_attrs = extcon_attrs;
 542
 543 #if defined(CONFIG_ANDROID)
 544                 switch_class = class_compat_register("switch");
 545                 if (WARN(!switch_class, "cannot allocate"))
 546                         return -ENOMEM;
 547 #endif /* CONFIG_ANDROID */
 548         }
 549
 550         return 0;
 551 }
 552
 553 static void extcon_cleanup(struct extcon_dev *edev, bool skip)
 554 {
 555         mutex_lock(&extcon_dev_list_lock);
 556         list_del(&edev->entry);
 557         mutex_unlock(&extcon_dev_list_lock);
 558
 559         if (!skip && get_device(edev->dev)) {
 560                 int index;
 561
 562                 if (edev->mutually_exclusive && edev->max_supported) {
 563                         for (index = 0; edev->mutually_exclusive[index];
 564                              index++)
 565                                 kfree(edev->d_attrs_muex[index].attr.name);
 566                         kfree(edev->d_attrs_muex);
 567                         kfree(edev->attrs_muex);
 568                 }
 569
 570                 for (index = 0; index < edev->max_supported; index++)
 571                         kfree(edev->cables[index].attr_g.name);
 572
 573                 if (edev->max_supported) {
 574                         kfree(edev->extcon_dev_type.groups);
 575                         kfree(edev->cables);
 576                 }
 577
 578                 device_unregister(edev->dev);
 579                 put_device(edev->dev);
 580         }
 581
 582         kfree(edev->dev);
 583 }
 584
 585 static void extcon_dev_release(struct device *dev)
 586 {
 587         struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 588
 589         extcon_cleanup(edev, true);
 590 }
 591
 592 static const char *muex_name = "mutually_exclusive";
 593 static void dummy_sysfs_dev_release(struct device *dev)
 594 {
 595 }
 596
 597 /**
 598  * extcon_dev_register() - Register a new extcon device
 599  * @edev        : the new extcon device (should be allocated before calling)
 600  * @dev         : the parent device for this extcon device.
 601  *
 602  * Among the members of edev struct, please set the "user initializing data"
 603  * in any case and set the "optional callbacks" if required. However, please
 604  * do not set the values of "internal data", which are initialized by
 605  * this function.
 606  */
 607 int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
 608 {
 609         int ret, index = 0;
 610
 611         if (!extcon_class) {
 612                 ret = create_extcon_class();
 613                 if (ret < 0)
 614                         return ret;
 615         }
 616
 617         if (edev->supported_cable) {
 618                 /* Get size of array */
 619                 for (index = 0; edev->supported_cable[index]; index++)
 620                         ;
 621                 edev->max_supported = index;
 622         } else {
 623                 edev->max_supported = 0;
 624         }
 625
 626         if (index > SUPPORTED_CABLE_MAX) {
 627                 dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 628                 return -EINVAL;
 629         }
 630
 631         edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 632         if (!edev->dev)
 633                 return -ENOMEM;
 634         edev->dev->parent = dev;
 635         edev->dev->class = extcon_class;
 636         edev->dev->release = extcon_dev_release;
 637
 638         dev_set_name(edev->dev, edev->name ? edev->name : dev_name(dev));
 639
 640         if (edev->max_supported) {
 641                 char buf[10];
 642                 char *str;
 643                 struct extcon_cable *cable;
 644
 645                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 646                                        edev->max_supported, GFP_KERNEL);
 647                 if (!edev->cables) {
 648                         ret = -ENOMEM;
 649                         goto err_sysfs_alloc;
 650                 }
 651                 for (index = 0; index < edev->max_supported; index++) {
 652                         cable = &edev->cables[index];
 653
 654                         snprintf(buf, 10, "cable.%d", index);
 655                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 656                                       GFP_KERNEL);
 657                         if (!str) {
 658                                 for (index--; index >= 0; index--) {
 659                                         cable = &edev->cables[index];
 660                                         kfree(cable->attr_g.name);
 661                                 }
 662                                 ret = -ENOMEM;
 663
 664                                 goto err_alloc_cables;
 665                         }
 666                         strcpy(str, buf);
 667
 668                         cable->edev = edev;
 669                         cable->cable_index = index;
 670                         cable->attrs[0] = &cable->attr_name.attr;
 671                         cable->attrs[1] = &cable->attr_state.attr;
 672                         cable->attrs[2] = NULL;
 673                         cable->attr_g.name = str;
 674                         cable->attr_g.attrs = cable->attrs;
 675
 676                         cable->attr_name.attr.name = "name";
 677                         cable->attr_name.attr.mode = 0444;
 678                         cable->attr_name.show = cable_name_show;
 679
 680                         cable->attr_state.attr.name = "state";
 681                         cable->attr_state.attr.mode = 0644;
 682                         cable->attr_state.show = cable_state_show;
 683                         cable->attr_state.store = cable_state_store;
 684                 }
 685         }
 686
 687         if (edev->max_supported && edev->mutually_exclusive) {
 688                 char buf[80];
 689                 char *name;
 690
 691                 /* Count the size of mutually_exclusive array */
 692                 for (index = 0; edev->mutually_exclusive[index]; index++)
 693                         ;
 694
 695                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 696                                            (index + 1), GFP_KERNEL);
 697                 if (!edev->attrs_muex) {
 698                         ret = -ENOMEM;
 699                         goto err_muex;
 700                 }
 701
 702                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 703                                              index, GFP_KERNEL);
 704                 if (!edev->d_attrs_muex) {
 705                         ret = -ENOMEM;
 706                         kfree(edev->attrs_muex);
 707                         goto err_muex;
 708                 }
 709
 710                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 711                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 712                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 713                                        GFP_KERNEL);
 714                         if (!name) {
 715                                 for (index--; index >= 0; index--) {
 716                                         kfree(edev->d_attrs_muex[index].attr.
 717                                               name);
 718                                 }
 719                                 kfree(edev->d_attrs_muex);
 720                                 kfree(edev->attrs_muex);
 721                                 ret = -ENOMEM;
 722                                 goto err_muex;
 723                         }
 724                         strcpy(name, buf);
 725                         edev->d_attrs_muex[index].attr.name = name;
 726                         edev->d_attrs_muex[index].attr.mode = 0000;
 727                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 728                                                         .attr;
 729                 }
 730                 edev->attr_g_muex.name = muex_name;
 731                 edev->attr_g_muex.attrs = edev->attrs_muex;
 732
 733         }
 734
 735         if (edev->max_supported) {
 736                 edev->extcon_dev_type.groups =
 737                         kzalloc(sizeof(struct attribute_group *) *
 738                                 (edev->max_supported + 2), GFP_KERNEL);
 739                 if (!edev->extcon_dev_type.groups) {
 740                         ret = -ENOMEM;
 741                         goto err_alloc_groups;
 742                 }
 743
 744                 edev->extcon_dev_type.name = dev_name(edev->dev);
 745                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 746
 747                 for (index = 0; index < edev->max_supported; index++)
 748                         edev->extcon_dev_type.groups[index] =
 749                                 &edev->cables[index].attr_g;
 750                 if (edev->mutually_exclusive)
 751                         edev->extcon_dev_type.groups[index] =
 752                                 &edev->attr_g_muex;
 753
 754                 edev->dev->type = &edev->extcon_dev_type;
 755         }
 756
 757         ret = device_register(edev->dev);
 758         if (ret) {
 759                 put_device(edev->dev);
 760                 goto err_dev;
 761         }
 762 #if defined(CONFIG_ANDROID)
 763         if (switch_class)
 764                 ret = class_compat_create_link(switch_class, edev->dev,
 765                                                NULL);
 766 #endif /* CONFIG_ANDROID */
 767
 768         spin_lock_init(&edev->lock);
 769
 770         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 771
 772         dev_set_drvdata(edev->dev, edev);
 773         edev->state = 0;
 774
 775         mutex_lock(&extcon_dev_list_lock);
 776         list_add(&edev->entry, &extcon_dev_list);
 777         mutex_unlock(&extcon_dev_list_lock);
 778
 779         return 0;
 780
 781 err_dev:
 782         if (edev->max_supported)
 783                 kfree(edev->extcon_dev_type.groups);
 784 err_alloc_groups:
 785         if (edev->max_supported && edev->mutually_exclusive) {
 786                 for (index = 0; edev->mutually_exclusive[index]; index++)
 787                         kfree(edev->d_attrs_muex[index].attr.name);
 788                 kfree(edev->d_attrs_muex);
 789                 kfree(edev->attrs_muex);
 790         }
 791 err_muex:
 792         for (index = 0; index < edev->max_supported; index++)
 793                 kfree(edev->cables[index].attr_g.name);
 794 err_alloc_cables:
 795         if (edev->max_supported)
 796                 kfree(edev->cables);
 797 err_sysfs_alloc:
 798         kfree(edev->dev);
 799         return ret;
 800 }
 801 EXPORT_SYMBOL_GPL(extcon_dev_register);
 802
 803 /**
 804  * extcon_dev_unregister() - Unregister the extcon device.
 805  * @edev:       the extcon device instance to be unregitered.
 806  *
 807  * Note that this does not call kfree(edev) because edev was not allocated
 808  * by this class.
 809  */
 810 void extcon_dev_unregister(struct extcon_dev *edev)
 811 {
 812         extcon_cleanup(edev, false);
 813 }
 814 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 815
 816 static int __init extcon_class_init(void)
 817 {
 818         return create_extcon_class();
 819 }
 820 module_init(extcon_class_init);
 821
 822 static void __exit extcon_class_exit(void)
 823 {
 824         class_destroy(extcon_class);
 825 }
 826 module_exit(extcon_class_exit);
 827
 828 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 829 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 830 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 831 MODULE_DESCRIPTION("External connector (extcon) class driver");
 832 MODULE_LICENSE("GPL");