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