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 #include <linux/of.h>
  35
  36 /*
  37  * extcon_cable_name suggests the standard cable names for commonly used
  38  * cable types.
  39  *
  40  * However, please do not use extcon_cable_name directly for extcon_dev
  41  * struct's supported_cable pointer unless your device really supports
  42  * every single port-type of the following cable names. Please choose cable
  43  * names that are actually used in your extcon device.
  44  */
  45 const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
  46         [EXTCON_USB]            = "USB",
  47         [EXTCON_USB_HOST]       = "USB-Host",
  48         [EXTCON_TA]             = "TA",
  49         [EXTCON_FAST_CHARGER]   = "Fast-charger",
  50         [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  51         [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  52         [EXTCON_HDMI]           = "HDMI",
  53         [EXTCON_MHL]            = "MHL",
  54         [EXTCON_DVI]            = "DVI",
  55         [EXTCON_VGA]            = "VGA",
  56         [EXTCON_DOCK]           = "Dock",
  57         [EXTCON_LINE_IN]        = "Line-in",
  58         [EXTCON_LINE_OUT]       = "Line-out",
  59         [EXTCON_MIC_IN]         = "Microphone",
  60         [EXTCON_HEADPHONE_OUT]  = "Headphone",
  61         [EXTCON_SPDIF_IN]       = "SPDIF-in",
  62         [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  63         [EXTCON_VIDEO_IN]       = "Video-in",
  64         [EXTCON_VIDEO_OUT]      = "Video-out",
  65         [EXTCON_MECHANICAL]     = "Mechanical",
  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 weight;
  94                 u32 correspondants = new_state & edev->mutually_exclusive[i];
  95
  96                 /* calculate the total number of bits set */
  97                 weight = hweight32(correspondants);
  98                 if (weight > 1)
  99                         return i + 1;
 100         }
 101
 102         return 0;
 103 }
 104
 105 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 106                           char *buf)
 107 {
 108         int i, count = 0;
 109         struct extcon_dev *edev = dev_get_drvdata(dev);
 110
 111         if (edev->print_state) {
 112                 int ret = edev->print_state(edev, buf);
 113
 114                 if (ret >= 0)
 115                         return ret;
 116                 /* Use default if failed */
 117         }
 118
 119         if (edev->max_supported == 0)
 120                 return sprintf(buf, "%u\n", edev->state);
 121
 122         for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
 123                 if (!edev->supported_cable[i])
 124                         break;
 125                 count += sprintf(buf + count, "%s=%d\n",
 126                                  edev->supported_cable[i],
 127                                  !!(edev->state & (1 << i)));
 128         }
 129
 130         return count;
 131 }
 132
 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 = 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 = 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                 /* This could be in interrupt handler */
 231                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 232                 if (prop_buf) {
 233                         length = name_show(&edev->dev, NULL, prop_buf);
 234                         if (length > 0) {
 235                                 if (prop_buf[length - 1] == '\n')
 236                                         prop_buf[length - 1] = 0;
 237                                 snprintf(name_buf, sizeof(name_buf),
 238                                         "NAME=%s", prop_buf);
 239                                 envp[env_offset++] = name_buf;
 240                         }
 241                         length = state_show(&edev->dev, NULL, prop_buf);
 242                         if (length > 0) {
 243                                 if (prop_buf[length - 1] == '\n')
 244                                         prop_buf[length - 1] = 0;
 245                                 snprintf(state_buf, sizeof(state_buf),
 246                                         "STATE=%s", prop_buf);
 247                                 envp[env_offset++] = state_buf;
 248                         }
 249                         envp[env_offset] = NULL;
 250                         /* Unlock early before uevent */
 251                         spin_unlock_irqrestore(&edev->lock, flags);
 252
 253                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 254                         free_page((unsigned long)prop_buf);
 255                 } else {
 256                         /* Unlock early before uevent */
 257                         spin_unlock_irqrestore(&edev->lock, flags);
 258
 259                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 260                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 261                 }
 262         } else {
 263                 /* No changes */
 264                 spin_unlock_irqrestore(&edev->lock, flags);
 265         }
 266
 267         return 0;
 268 }
 269 EXPORT_SYMBOL_GPL(extcon_update_state);
 270
 271 /**
 272  * extcon_set_state() - Set the cable attach states of the extcon device.
 273  * @edev:       the extcon device
 274  * @state:      new cable attach status for @edev
 275  *
 276  * Note that notifier provides which bits are changed in the state
 277  * variable with the val parameter (second) to the callback.
 278  */
 279 int extcon_set_state(struct extcon_dev *edev, u32 state)
 280 {
 281         return extcon_update_state(edev, 0xffffffff, state);
 282 }
 283 EXPORT_SYMBOL_GPL(extcon_set_state);
 284
 285 /**
 286  * extcon_find_cable_index() - Get the cable index based on the cable name.
 287  * @edev:       the extcon device that has the cable.
 288  * @cable_name: cable name to be searched.
 289  *
 290  * Note that accessing a cable state based on cable_index is faster than
 291  * cable_name because using cable_name induces a loop with strncmp().
 292  * Thus, when get/set_cable_state is repeatedly used, using cable_index
 293  * is recommended.
 294  */
 295 int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 296 {
 297         int i;
 298
 299         if (edev->supported_cable) {
 300                 for (i = 0; edev->supported_cable[i]; i++) {
 301                         if (!strncmp(edev->supported_cable[i],
 302                                 cable_name, CABLE_NAME_MAX))
 303                                 return i;
 304                 }
 305         }
 306
 307         return -EINVAL;
 308 }
 309 EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 310
 311 /**
 312  * extcon_get_cable_state_() - Get the status of a specific cable.
 313  * @edev:       the extcon device that has the cable.
 314  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 315  */
 316 int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 317 {
 318         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 319                 return -EINVAL;
 320
 321         return !!(edev->state & (1 << index));
 322 }
 323 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 324
 325 /**
 326  * extcon_get_cable_state() - Get the status of a specific cable.
 327  * @edev:       the extcon device that has the cable.
 328  * @cable_name: cable name.
 329  *
 330  * Note that this is slower than extcon_get_cable_state_.
 331  */
 332 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 333 {
 334         return extcon_get_cable_state_(edev, extcon_find_cable_index
 335                                                 (edev, cable_name));
 336 }
 337 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 338
 339 /**
 340  * extcon_set_cable_state_() - Set the status of a specific cable.
 341  * @edev:               the extcon device that has the cable.
 342  * @index:              cable index that can be retrieved by
 343  *                      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,
 456                                                           cable_name);
 457                 if (obj->cable_index < 0)
 458                         return obj->cable_index;
 459
 460                 obj->user_nb = nb;
 461
 462                 obj->internal_nb.notifier_call = _call_per_cable;
 463
 464                 return raw_notifier_chain_register(&obj->edev->nh,
 465                                                   &obj->internal_nb);
 466         } else {
 467                 struct class_dev_iter iter;
 468                 struct extcon_dev *extd;
 469                 struct device *dev;
 470
 471                 if (!extcon_class)
 472                         return -ENODEV;
 473                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 474                 while ((dev = class_dev_iter_next(&iter))) {
 475                         extd = dev_get_drvdata(dev);
 476
 477                         if (extcon_find_cable_index(extd, cable_name) < 0)
 478                                 continue;
 479
 480                         class_dev_iter_exit(&iter);
 481                         return extcon_register_interest(obj, extd->name,
 482                                                 cable_name, nb);
 483                 }
 484
 485                 return -ENODEV;
 486         }
 487 }
 488 EXPORT_SYMBOL_GPL(extcon_register_interest);
 489
 490 /**
 491  * extcon_unregister_interest() - Unregister the notifier registered by
 492  *                                extcon_register_interest().
 493  * @obj:        the extcon_specific_cable_nb object returned by
 494  *              extcon_register_interest().
 495  */
 496 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 497 {
 498         if (!obj)
 499                 return -EINVAL;
 500
 501         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 502 }
 503 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 504
 505 /**
 506  * extcon_register_notifier() - Register a notifiee to get notified by
 507  *                              any attach status changes from the extcon.
 508  * @edev:       the extcon device.
 509  * @nb:         a notifier block to be registered.
 510  *
 511  * Note that the second parameter given to the callback of nb (val) is
 512  * "old_state", not the current state. The current state can be retrieved
 513  * by looking at the third pameter (edev pointer)'s state value.
 514  */
 515 int extcon_register_notifier(struct extcon_dev *edev,
 516                         struct notifier_block *nb)
 517 {
 518         return raw_notifier_chain_register(&edev->nh, nb);
 519 }
 520 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 521
 522 /**
 523  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 524  * @edev:       the extcon device.
 525  * @nb:         a registered notifier block to be unregistered.
 526  */
 527 int extcon_unregister_notifier(struct extcon_dev *edev,
 528                         struct notifier_block *nb)
 529 {
 530         return raw_notifier_chain_unregister(&edev->nh, nb);
 531 }
 532 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 533
 534 static struct attribute *extcon_attrs[] = {
 535         &dev_attr_state.attr,
 536         &dev_attr_name.attr,
 537         NULL,
 538 };
 539 ATTRIBUTE_GROUPS(extcon);
 540
 541 static int create_extcon_class(void)
 542 {
 543         if (!extcon_class) {
 544                 extcon_class = class_create(THIS_MODULE, "extcon");
 545                 if (IS_ERR(extcon_class))
 546                         return PTR_ERR(extcon_class);
 547                 extcon_class->dev_groups = extcon_groups;
 548
 549 #if defined(CONFIG_ANDROID)
 550                 switch_class = class_compat_register("switch");
 551                 if (WARN(!switch_class, "cannot allocate"))
 552                         return -ENOMEM;
 553 #endif /* CONFIG_ANDROID */
 554         }
 555
 556         return 0;
 557 }
 558
 559 static void extcon_dev_release(struct device *dev)
 560 {
 561 }
 562
 563 static const char *muex_name = "mutually_exclusive";
 564 static void dummy_sysfs_dev_release(struct device *dev)
 565 {
 566 }
 567
 568 /**
 569  * extcon_dev_register() - Register a new extcon device
 570  * @edev        : the new extcon device (should be allocated before calling)
 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)
 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.class = extcon_class;
 602         edev->dev.release = extcon_dev_release;
 603
 604         edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
 605         if (IS_ERR_OR_NULL(edev->name)) {
 606                 dev_err(&edev->dev,
 607                         "extcon device name is null\n");
 608                 return -EINVAL;
 609         }
 610         dev_set_name(&edev->dev, "%s", edev->name);
 611
 612         if (edev->max_supported) {
 613                 char buf[10];
 614                 char *str;
 615                 struct extcon_cable *cable;
 616
 617                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 618                                        edev->max_supported, GFP_KERNEL);
 619                 if (!edev->cables) {
 620                         ret = -ENOMEM;
 621                         goto err_sysfs_alloc;
 622                 }
 623                 for (index = 0; index < edev->max_supported; index++) {
 624                         cable = &edev->cables[index];
 625
 626                         snprintf(buf, 10, "cable.%d", index);
 627                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 628                                       GFP_KERNEL);
 629                         if (!str) {
 630                                 for (index--; index >= 0; index--) {
 631                                         cable = &edev->cables[index];
 632                                         kfree(cable->attr_g.name);
 633                                 }
 634                                 ret = -ENOMEM;
 635
 636                                 goto err_alloc_cables;
 637                         }
 638                         strcpy(str, buf);
 639
 640                         cable->edev = edev;
 641                         cable->cable_index = index;
 642                         cable->attrs[0] = &cable->attr_name.attr;
 643                         cable->attrs[1] = &cable->attr_state.attr;
 644                         cable->attrs[2] = NULL;
 645                         cable->attr_g.name = str;
 646                         cable->attr_g.attrs = cable->attrs;
 647
 648                         sysfs_attr_init(&cable->attr_name.attr);
 649                         cable->attr_name.attr.name = "name";
 650                         cable->attr_name.attr.mode = 0444;
 651                         cable->attr_name.show = cable_name_show;
 652
 653                         sysfs_attr_init(&cable->attr_state.attr);
 654                         cable->attr_state.attr.name = "state";
 655                         cable->attr_state.attr.mode = 0444;
 656                         cable->attr_state.show = cable_state_show;
 657                 }
 658         }
 659
 660         if (edev->max_supported && edev->mutually_exclusive) {
 661                 char buf[80];
 662                 char *name;
 663
 664                 /* Count the size of mutually_exclusive array */
 665                 for (index = 0; edev->mutually_exclusive[index]; index++)
 666                         ;
 667
 668                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 669                                            (index + 1), GFP_KERNEL);
 670                 if (!edev->attrs_muex) {
 671                         ret = -ENOMEM;
 672                         goto err_muex;
 673                 }
 674
 675                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 676                                              index, GFP_KERNEL);
 677                 if (!edev->d_attrs_muex) {
 678                         ret = -ENOMEM;
 679                         kfree(edev->attrs_muex);
 680                         goto err_muex;
 681                 }
 682
 683                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 684                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 685                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 686                                        GFP_KERNEL);
 687                         if (!name) {
 688                                 for (index--; index >= 0; index--) {
 689                                         kfree(edev->d_attrs_muex[index].attr.
 690                                               name);
 691                                 }
 692                                 kfree(edev->d_attrs_muex);
 693                                 kfree(edev->attrs_muex);
 694                                 ret = -ENOMEM;
 695                                 goto err_muex;
 696                         }
 697                         strcpy(name, buf);
 698                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 699                         edev->d_attrs_muex[index].attr.name = name;
 700                         edev->d_attrs_muex[index].attr.mode = 0000;
 701                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 702                                                         .attr;
 703                 }
 704                 edev->attr_g_muex.name = muex_name;
 705                 edev->attr_g_muex.attrs = edev->attrs_muex;
 706
 707         }
 708
 709         if (edev->max_supported) {
 710                 edev->extcon_dev_type.groups =
 711                         kzalloc(sizeof(struct attribute_group *) *
 712                                 (edev->max_supported + 2), GFP_KERNEL);
 713                 if (!edev->extcon_dev_type.groups) {
 714                         ret = -ENOMEM;
 715                         goto err_alloc_groups;
 716                 }
 717
 718                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 719                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 720
 721                 for (index = 0; index < edev->max_supported; index++)
 722                         edev->extcon_dev_type.groups[index] =
 723                                 &edev->cables[index].attr_g;
 724                 if (edev->mutually_exclusive)
 725                         edev->extcon_dev_type.groups[index] =
 726                                 &edev->attr_g_muex;
 727
 728                 edev->dev.type = &edev->extcon_dev_type;
 729         }
 730
 731         ret = device_register(&edev->dev);
 732         if (ret) {
 733                 put_device(&edev->dev);
 734                 goto err_dev;
 735         }
 736 #if defined(CONFIG_ANDROID)
 737         if (switch_class)
 738                 ret = class_compat_create_link(switch_class, &edev->dev, 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         return ret;
 772 }
 773 EXPORT_SYMBOL_GPL(extcon_dev_register);
 774
 775 /**
 776  * extcon_dev_unregister() - Unregister the extcon device.
 777  * @edev:       the extcon device instance to be unregistered.
 778  *
 779  * Note that this does not call kfree(edev) because edev was not allocated
 780  * by this class.
 781  */
 782 void extcon_dev_unregister(struct extcon_dev *edev)
 783 {
 784         int index;
 785
 786         mutex_lock(&extcon_dev_list_lock);
 787         list_del(&edev->entry);
 788         mutex_unlock(&extcon_dev_list_lock);
 789
 790         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 791                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 792                                 dev_name(&edev->dev));
 793                 return;
 794         }
 795
 796         device_unregister(&edev->dev);
 797
 798         if (edev->mutually_exclusive && edev->max_supported) {
 799                 for (index = 0; edev->mutually_exclusive[index];
 800                                 index++)
 801                         kfree(edev->d_attrs_muex[index].attr.name);
 802                 kfree(edev->d_attrs_muex);
 803                 kfree(edev->attrs_muex);
 804         }
 805
 806         for (index = 0; index < edev->max_supported; index++)
 807                 kfree(edev->cables[index].attr_g.name);
 808
 809         if (edev->max_supported) {
 810                 kfree(edev->extcon_dev_type.groups);
 811                 kfree(edev->cables);
 812         }
 813
 814 #if defined(CONFIG_ANDROID)
 815         if (switch_class)
 816                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 817 #endif
 818         put_device(&edev->dev);
 819 }
 820 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 821
 822 #ifdef CONFIG_OF
 823 /*
 824  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
 825  * @dev - instance to the given device
 826  * @index - index into list of extcon_dev
 827  *
 828  * return the instance of extcon device
 829  */
 830 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 831 {
 832         struct device_node *node;
 833         struct extcon_dev *edev;
 834
 835         if (!dev->of_node) {
 836                 dev_err(dev, "device does not have a device node entry\n");
 837                 return ERR_PTR(-EINVAL);
 838         }
 839
 840         node = of_parse_phandle(dev->of_node, "extcon", index);
 841         if (!node) {
 842                 dev_err(dev, "failed to get phandle in %s node\n",
 843                         dev->of_node->full_name);
 844                 return ERR_PTR(-ENODEV);
 845         }
 846
 847         edev = extcon_get_extcon_dev(node->name);
 848         if (!edev) {
 849                 dev_err(dev, "unable to get extcon device : %s\n", node->name);
 850                 return ERR_PTR(-ENODEV);
 851         }
 852
 853         return edev;
 854 }
 855 #else
 856 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 857 {
 858         return ERR_PTR(-ENOSYS);
 859 }
 860 #endif /* CONFIG_OF */
 861 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
 862
 863 static int __init extcon_class_init(void)
 864 {
 865         return create_extcon_class();
 866 }
 867 module_init(extcon_class_init);
 868
 869 static void __exit extcon_class_exit(void)
 870 {
 871 #if defined(CONFIG_ANDROID)
 872         class_compat_unregister(switch_class);
 873 #endif
 874         class_destroy(extcon_class);
 875 }
 876 module_exit(extcon_class_exit);
 877
 878 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 879 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 880 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 881 MODULE_DESCRIPTION("External connector (extcon) class driver");
 882 MODULE_LICENSE("GPL");