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 = 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 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 133                            const char *buf, size_t count)
 134 {
 135         u32 state;
 136         ssize_t ret = 0;
 137         struct extcon_dev *edev = dev_get_drvdata(dev);
 138
 139         ret = sscanf(buf, "0x%x", &state);
 140         if (ret == 0)
 141                 ret = -EINVAL;
 142         else
 143                 ret = extcon_set_state(edev, state);
 144
 145         if (ret < 0)
 146                 return ret;
 147
 148         return count;
 149 }
 150 static DEVICE_ATTR_RW(state);
 151
 152 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 153                 char *buf)
 154 {
 155         struct extcon_dev *edev = 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 static DEVICE_ATTR_RO(name);
 167
 168 static ssize_t cable_name_show(struct device *dev,
 169                                struct device_attribute *attr, char *buf)
 170 {
 171         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 172                                                   attr_name);
 173
 174         return sprintf(buf, "%s\n",
 175                        cable->edev->supported_cable[cable->cable_index]);
 176 }
 177
 178 static ssize_t cable_state_show(struct device *dev,
 179                                 struct device_attribute *attr, char *buf)
 180 {
 181         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 182                                                   attr_state);
 183
 184         return sprintf(buf, "%d\n",
 185                        extcon_get_cable_state_(cable->edev,
 186                                                cable->cable_index));
 187 }
 188
 189 /**
 190  * extcon_update_state() - Update the cable attach states of the extcon device
 191  *                         only for the masked bits.
 192  * @edev:       the extcon device
 193  * @mask:       the bit mask to designate updated bits.
 194  * @state:      new cable attach status for @edev
 195  *
 196  * Changing the state sends uevent with environment variable containing
 197  * the name of extcon device (envp[0]) and the state output (envp[1]).
 198  * Tizen uses this format for extcon device to get events from ports.
 199  * Android uses this format as well.
 200  *
 201  * Note that the notifier provides which bits are changed in the state
 202  * variable with the val parameter (second) to the callback.
 203  */
 204 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 205 {
 206         char name_buf[120];
 207         char state_buf[120];
 208         char *prop_buf;
 209         char *envp[3];
 210         int env_offset = 0;
 211         int length;
 212         unsigned long flags;
 213
 214         spin_lock_irqsave(&edev->lock, flags);
 215
 216         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 217                 u32 old_state = edev->state;
 218
 219                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 220                                                    (state & mask))) {
 221                         spin_unlock_irqrestore(&edev->lock, flags);
 222                         return -EPERM;
 223                 }
 224
 225                 edev->state &= ~mask;
 226                 edev->state |= state & mask;
 227
 228                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 229                 /* This could be in interrupt handler */
 230                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 231                 if (prop_buf) {
 232                         length = name_show(&edev->dev, NULL, prop_buf);
 233                         if (length > 0) {
 234                                 if (prop_buf[length - 1] == '\n')
 235                                         prop_buf[length - 1] = 0;
 236                                 snprintf(name_buf, sizeof(name_buf),
 237                                         "NAME=%s", prop_buf);
 238                                 envp[env_offset++] = name_buf;
 239                         }
 240                         length = state_show(&edev->dev, NULL, prop_buf);
 241                         if (length > 0) {
 242                                 if (prop_buf[length - 1] == '\n')
 243                                         prop_buf[length - 1] = 0;
 244                                 snprintf(state_buf, sizeof(state_buf),
 245                                         "STATE=%s", prop_buf);
 246                                 envp[env_offset++] = state_buf;
 247                         }
 248                         envp[env_offset] = NULL;
 249                         /* Unlock early before uevent */
 250                         spin_unlock_irqrestore(&edev->lock, flags);
 251
 252                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 253                         free_page((unsigned long)prop_buf);
 254                 } else {
 255                         /* Unlock early before uevent */
 256                         spin_unlock_irqrestore(&edev->lock, flags);
 257
 258                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 259                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 260                 }
 261         } else {
 262                 /* No changes */
 263                 spin_unlock_irqrestore(&edev->lock, flags);
 264         }
 265
 266         return 0;
 267 }
 268 EXPORT_SYMBOL_GPL(extcon_update_state);
 269
 270 /**
 271  * extcon_set_state() - Set the cable attach states of the extcon device.
 272  * @edev:       the extcon device
 273  * @state:      new cable attach status for @edev
 274  *
 275  * Note that notifier provides which bits are changed in the state
 276  * variable with the val parameter (second) to the callback.
 277  */
 278 int extcon_set_state(struct extcon_dev *edev, u32 state)
 279 {
 280         return extcon_update_state(edev, 0xffffffff, state);
 281 }
 282 EXPORT_SYMBOL_GPL(extcon_set_state);
 283
 284 /**
 285  * extcon_find_cable_index() - Get the cable index based on the cable name.
 286  * @edev:       the extcon device that has the cable.
 287  * @cable_name: cable name to be searched.
 288  *
 289  * Note that accessing a cable state based on cable_index is faster than
 290  * cable_name because using cable_name induces a loop with strncmp().
 291  * Thus, when get/set_cable_state is repeatedly used, using cable_index
 292  * is recommended.
 293  */
 294 int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 295 {
 296         int i;
 297
 298         if (edev->supported_cable) {
 299                 for (i = 0; edev->supported_cable[i]; i++) {
 300                         if (!strncmp(edev->supported_cable[i],
 301                                 cable_name, CABLE_NAME_MAX))
 302                                 return i;
 303                 }
 304         }
 305
 306         return -EINVAL;
 307 }
 308 EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 309
 310 /**
 311  * extcon_get_cable_state_() - Get the status of a specific cable.
 312  * @edev:       the extcon device that has the cable.
 313  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 314  */
 315 int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 316 {
 317         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 318                 return -EINVAL;
 319
 320         return !!(edev->state & (1 << index));
 321 }
 322 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 323
 324 /**
 325  * extcon_get_cable_state() - Get the status of a specific cable.
 326  * @edev:       the extcon device that has the cable.
 327  * @cable_name: cable name.
 328  *
 329  * Note that this is slower than extcon_get_cable_state_.
 330  */
 331 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 332 {
 333         return extcon_get_cable_state_(edev, extcon_find_cable_index
 334                                                 (edev, cable_name));
 335 }
 336 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 337
 338 /**
 339  * extcon_set_cable_state_() - Set the status of a specific cable.
 340  * @edev:               the extcon device that has the cable.
 341  * @index:              cable index that can be retrieved by
 342  *                      extcon_find_cable_index().
 343  * @cable_state:        the new cable status. The default semantics is
 344  *                      true: attached / false: detached.
 345  */
 346 int extcon_set_cable_state_(struct extcon_dev *edev,
 347                         int index, bool cable_state)
 348 {
 349         u32 state;
 350
 351         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 352                 return -EINVAL;
 353
 354         state = cable_state ? (1 << index) : 0;
 355         return extcon_update_state(edev, 1 << index, state);
 356 }
 357 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 358
 359 /**
 360  * extcon_set_cable_state() - Set the status of a specific cable.
 361  * @edev:               the extcon device that has the cable.
 362  * @cable_name:         cable name.
 363  * @cable_state:        the new cable status. The default semantics is
 364  *                      true: attached / false: detached.
 365  *
 366  * Note that this is slower than extcon_set_cable_state_.
 367  */
 368 int extcon_set_cable_state(struct extcon_dev *edev,
 369                         const char *cable_name, bool cable_state)
 370 {
 371         return extcon_set_cable_state_(edev, extcon_find_cable_index
 372                                         (edev, cable_name), cable_state);
 373 }
 374 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 375
 376 /**
 377  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 378  * @extcon_name:        The extcon name provided with extcon_dev_register()
 379  */
 380 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 381 {
 382         struct extcon_dev *sd;
 383
 384         mutex_lock(&extcon_dev_list_lock);
 385         list_for_each_entry(sd, &extcon_dev_list, entry) {
 386                 if (!strcmp(sd->name, extcon_name))
 387                         goto out;
 388         }
 389         sd = NULL;
 390 out:
 391         mutex_unlock(&extcon_dev_list_lock);
 392         return sd;
 393 }
 394 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 395
 396 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 397                            void *ptr)
 398 {
 399         struct extcon_specific_cable_nb *obj = container_of(nb,
 400                         struct extcon_specific_cable_nb, internal_nb);
 401         struct extcon_dev *edev = ptr;
 402
 403         if ((val & (1 << obj->cable_index)) !=
 404             (edev->state & (1 << obj->cable_index))) {
 405                 bool cable_state = true;
 406
 407                 obj->previous_value = val;
 408
 409                 if (val & (1 << obj->cable_index))
 410                         cable_state = false;
 411
 412                 return obj->user_nb->notifier_call(obj->user_nb,
 413                                 cable_state, ptr);
 414         }
 415
 416         return NOTIFY_OK;
 417 }
 418
 419 /**
 420  * extcon_register_interest() - Register a notifier for a state change of a
 421  *                              specific cable, not an entier set of cables of a
 422  *                              extcon device.
 423  * @obj:                an empty extcon_specific_cable_nb object to be returned.
 424  * @extcon_name:        the name of extcon device.
 425  *                      if NULL, extcon_register_interest will register
 426  *                      every cable with the target cable_name given.
 427  * @cable_name:         the target cable name.
 428  * @nb:                 the notifier block to get notified.
 429  *
 430  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 431  * the struct for you.
 432  *
 433  * extcon_register_interest is a helper function for those who want to get
 434  * notification for a single specific cable's status change. If a user wants
 435  * to get notification for any changes of all cables of a extcon device,
 436  * he/she should use the general extcon_register_notifier().
 437  *
 438  * Note that the second parameter given to the callback of nb (val) is
 439  * "old_state", not the current state. The current state can be retrieved
 440  * by looking at the third pameter (edev pointer)'s state value.
 441  */
 442 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 443                              const char *extcon_name, const char *cable_name,
 444                              struct notifier_block *nb)
 445 {
 446         if (!obj || !cable_name || !nb)
 447                 return -EINVAL;
 448
 449         if (extcon_name) {
 450                 obj->edev = extcon_get_extcon_dev(extcon_name);
 451                 if (!obj->edev)
 452                         return -ENODEV;
 453
 454                 obj->cable_index = extcon_find_cable_index(obj->edev,
 455                                                           cable_name);
 456                 if (obj->cable_index < 0)
 457                         return obj->cable_index;
 458
 459                 obj->user_nb = nb;
 460
 461                 obj->internal_nb.notifier_call = _call_per_cable;
 462
 463                 return raw_notifier_chain_register(&obj->edev->nh,
 464                                                   &obj->internal_nb);
 465         } else {
 466                 struct class_dev_iter iter;
 467                 struct extcon_dev *extd;
 468                 struct device *dev;
 469
 470                 if (!extcon_class)
 471                         return -ENODEV;
 472                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 473                 while ((dev = class_dev_iter_next(&iter))) {
 474                         extd = dev_get_drvdata(dev);
 475
 476                         if (extcon_find_cable_index(extd, cable_name) < 0)
 477                                 continue;
 478
 479                         class_dev_iter_exit(&iter);
 480                         return extcon_register_interest(obj, extd->name,
 481                                                 cable_name, nb);
 482                 }
 483
 484                 return -ENODEV;
 485         }
 486 }
 487 EXPORT_SYMBOL_GPL(extcon_register_interest);
 488
 489 /**
 490  * extcon_unregister_interest() - Unregister the notifier registered by
 491  *                                extcon_register_interest().
 492  * @obj:        the extcon_specific_cable_nb object returned by
 493  *              extcon_register_interest().
 494  */
 495 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 496 {
 497         if (!obj)
 498                 return -EINVAL;
 499
 500         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 501 }
 502 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 503
 504 /**
 505  * extcon_register_notifier() - Register a notifiee to get notified by
 506  *                              any attach status changes from the extcon.
 507  * @edev:       the extcon device.
 508  * @nb:         a notifier block to be registered.
 509  *
 510  * Note that the second parameter given to the callback of nb (val) is
 511  * "old_state", not the current state. The current state can be retrieved
 512  * by looking at the third pameter (edev pointer)'s state value.
 513  */
 514 int extcon_register_notifier(struct extcon_dev *edev,
 515                         struct notifier_block *nb)
 516 {
 517         return raw_notifier_chain_register(&edev->nh, nb);
 518 }
 519 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 520
 521 /**
 522  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 523  * @edev:       the extcon device.
 524  * @nb:         a registered notifier block to be unregistered.
 525  */
 526 int extcon_unregister_notifier(struct extcon_dev *edev,
 527                         struct notifier_block *nb)
 528 {
 529         return raw_notifier_chain_unregister(&edev->nh, nb);
 530 }
 531 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 532
 533 static struct attribute *extcon_attrs[] = {
 534         &dev_attr_state.attr,
 535         &dev_attr_name.attr,
 536         NULL,
 537 };
 538 ATTRIBUTE_GROUPS(extcon);
 539
 540 static int create_extcon_class(void)
 541 {
 542         if (!extcon_class) {
 543                 extcon_class = class_create(THIS_MODULE, "extcon");
 544                 if (IS_ERR(extcon_class))
 545                         return PTR_ERR(extcon_class);
 546                 extcon_class->dev_groups = extcon_groups;
 547
 548 #if defined(CONFIG_ANDROID)
 549                 switch_class = class_compat_register("switch");
 550                 if (WARN(!switch_class, "cannot allocate"))
 551                         return -ENOMEM;
 552 #endif /* CONFIG_ANDROID */
 553         }
 554
 555         return 0;
 556 }
 557
 558 static void extcon_dev_release(struct device *dev)
 559 {
 560 }
 561
 562 static const char *muex_name = "mutually_exclusive";
 563 static void dummy_sysfs_dev_release(struct device *dev)
 564 {
 565 }
 566
 567 /**
 568  * extcon_dev_register() - Register a new extcon device
 569  * @edev        : the new extcon device (should be allocated before calling)
 570  *
 571  * Among the members of edev struct, please set the "user initializing data"
 572  * in any case and set the "optional callbacks" if required. However, please
 573  * do not set the values of "internal data", which are initialized by
 574  * this function.
 575  */
 576 int extcon_dev_register(struct extcon_dev *edev)
 577 {
 578         int ret, index = 0;
 579
 580         if (!extcon_class) {
 581                 ret = create_extcon_class();
 582                 if (ret < 0)
 583                         return ret;
 584         }
 585
 586         if (edev->supported_cable) {
 587                 /* Get size of array */
 588                 for (index = 0; edev->supported_cable[index]; index++)
 589                         ;
 590                 edev->max_supported = index;
 591         } else {
 592                 edev->max_supported = 0;
 593         }
 594
 595         if (index > SUPPORTED_CABLE_MAX) {
 596                 dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 597                 return -EINVAL;
 598         }
 599
 600         edev->dev.class = extcon_class;
 601         edev->dev.release = extcon_dev_release;
 602
 603         edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
 604         if (IS_ERR_OR_NULL(edev->name)) {
 605                 dev_err(&edev->dev,
 606                         "extcon device name is null\n");
 607                 return -EINVAL;
 608         }
 609         dev_set_name(&edev->dev, "%s", edev->name);
 610
 611         if (edev->max_supported) {
 612                 char buf[10];
 613                 char *str;
 614                 struct extcon_cable *cable;
 615
 616                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 617                                        edev->max_supported, GFP_KERNEL);
 618                 if (!edev->cables) {
 619                         ret = -ENOMEM;
 620                         goto err_sysfs_alloc;
 621                 }
 622                 for (index = 0; index < edev->max_supported; index++) {
 623                         cable = &edev->cables[index];
 624
 625                         snprintf(buf, 10, "cable.%d", index);
 626                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 627                                       GFP_KERNEL);
 628                         if (!str) {
 629                                 for (index--; index >= 0; index--) {
 630                                         cable = &edev->cables[index];
 631                                         kfree(cable->attr_g.name);
 632                                 }
 633                                 ret = -ENOMEM;
 634
 635                                 goto err_alloc_cables;
 636                         }
 637                         strcpy(str, buf);
 638
 639                         cable->edev = edev;
 640                         cable->cable_index = index;
 641                         cable->attrs[0] = &cable->attr_name.attr;
 642                         cable->attrs[1] = &cable->attr_state.attr;
 643                         cable->attrs[2] = NULL;
 644                         cable->attr_g.name = str;
 645                         cable->attr_g.attrs = cable->attrs;
 646
 647                         sysfs_attr_init(&cable->attr_name.attr);
 648                         cable->attr_name.attr.name = "name";
 649                         cable->attr_name.attr.mode = 0444;
 650                         cable->attr_name.show = cable_name_show;
 651
 652                         sysfs_attr_init(&cable->attr_state.attr);
 653                         cable->attr_state.attr.name = "state";
 654                         cable->attr_state.attr.mode = 0444;
 655                         cable->attr_state.show = cable_state_show;
 656                 }
 657         }
 658
 659         if (edev->max_supported && edev->mutually_exclusive) {
 660                 char buf[80];
 661                 char *name;
 662
 663                 /* Count the size of mutually_exclusive array */
 664                 for (index = 0; edev->mutually_exclusive[index]; index++)
 665                         ;
 666
 667                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 668                                            (index + 1), GFP_KERNEL);
 669                 if (!edev->attrs_muex) {
 670                         ret = -ENOMEM;
 671                         goto err_muex;
 672                 }
 673
 674                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 675                                              index, GFP_KERNEL);
 676                 if (!edev->d_attrs_muex) {
 677                         ret = -ENOMEM;
 678                         kfree(edev->attrs_muex);
 679                         goto err_muex;
 680                 }
 681
 682                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 683                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 684                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 685                                        GFP_KERNEL);
 686                         if (!name) {
 687                                 for (index--; index >= 0; index--) {
 688                                         kfree(edev->d_attrs_muex[index].attr.
 689                                               name);
 690                                 }
 691                                 kfree(edev->d_attrs_muex);
 692                                 kfree(edev->attrs_muex);
 693                                 ret = -ENOMEM;
 694                                 goto err_muex;
 695                         }
 696                         strcpy(name, buf);
 697                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 698                         edev->d_attrs_muex[index].attr.name = name;
 699                         edev->d_attrs_muex[index].attr.mode = 0000;
 700                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 701                                                         .attr;
 702                 }
 703                 edev->attr_g_muex.name = muex_name;
 704                 edev->attr_g_muex.attrs = edev->attrs_muex;
 705
 706         }
 707
 708         if (edev->max_supported) {
 709                 edev->extcon_dev_type.groups =
 710                         kzalloc(sizeof(struct attribute_group *) *
 711                                 (edev->max_supported + 2), GFP_KERNEL);
 712                 if (!edev->extcon_dev_type.groups) {
 713                         ret = -ENOMEM;
 714                         goto err_alloc_groups;
 715                 }
 716
 717                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 718                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 719
 720                 for (index = 0; index < edev->max_supported; index++)
 721                         edev->extcon_dev_type.groups[index] =
 722                                 &edev->cables[index].attr_g;
 723                 if (edev->mutually_exclusive)
 724                         edev->extcon_dev_type.groups[index] =
 725                                 &edev->attr_g_muex;
 726
 727                 edev->dev.type = &edev->extcon_dev_type;
 728         }
 729
 730         ret = device_register(&edev->dev);
 731         if (ret) {
 732                 put_device(&edev->dev);
 733                 goto err_dev;
 734         }
 735 #if defined(CONFIG_ANDROID)
 736         if (switch_class)
 737                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 738 #endif /* CONFIG_ANDROID */
 739
 740         spin_lock_init(&edev->lock);
 741
 742         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 743
 744         dev_set_drvdata(&edev->dev, edev);
 745         edev->state = 0;
 746
 747         mutex_lock(&extcon_dev_list_lock);
 748         list_add(&edev->entry, &extcon_dev_list);
 749         mutex_unlock(&extcon_dev_list_lock);
 750
 751         return 0;
 752
 753 err_dev:
 754         if (edev->max_supported)
 755                 kfree(edev->extcon_dev_type.groups);
 756 err_alloc_groups:
 757         if (edev->max_supported && edev->mutually_exclusive) {
 758                 for (index = 0; edev->mutually_exclusive[index]; index++)
 759                         kfree(edev->d_attrs_muex[index].attr.name);
 760                 kfree(edev->d_attrs_muex);
 761                 kfree(edev->attrs_muex);
 762         }
 763 err_muex:
 764         for (index = 0; index < edev->max_supported; index++)
 765                 kfree(edev->cables[index].attr_g.name);
 766 err_alloc_cables:
 767         if (edev->max_supported)
 768                 kfree(edev->cables);
 769 err_sysfs_alloc:
 770         return ret;
 771 }
 772 EXPORT_SYMBOL_GPL(extcon_dev_register);
 773
 774 /**
 775  * extcon_dev_unregister() - Unregister the extcon device.
 776  * @edev:       the extcon device instance to be unregistered.
 777  *
 778  * Note that this does not call kfree(edev) because edev was not allocated
 779  * by this class.
 780  */
 781 void extcon_dev_unregister(struct extcon_dev *edev)
 782 {
 783         int index;
 784
 785         mutex_lock(&extcon_dev_list_lock);
 786         list_del(&edev->entry);
 787         mutex_unlock(&extcon_dev_list_lock);
 788
 789         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 790                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 791                                 dev_name(&edev->dev));
 792                 return;
 793         }
 794
 795         device_unregister(&edev->dev);
 796
 797         if (edev->mutually_exclusive && edev->max_supported) {
 798                 for (index = 0; edev->mutually_exclusive[index];
 799                                 index++)
 800                         kfree(edev->d_attrs_muex[index].attr.name);
 801                 kfree(edev->d_attrs_muex);
 802                 kfree(edev->attrs_muex);
 803         }
 804
 805         for (index = 0; index < edev->max_supported; index++)
 806                 kfree(edev->cables[index].attr_g.name);
 807
 808         if (edev->max_supported) {
 809                 kfree(edev->extcon_dev_type.groups);
 810                 kfree(edev->cables);
 811         }
 812
 813 #if defined(CONFIG_ANDROID)
 814         if (switch_class)
 815                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 816 #endif
 817         put_device(&edev->dev);
 818 }
 819 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 820
 821 static int __init extcon_class_init(void)
 822 {
 823         return create_extcon_class();
 824 }
 825 module_init(extcon_class_init);
 826
 827 static void __exit extcon_class_exit(void)
 828 {
 829 #if defined(CONFIG_ANDROID)
 830         class_compat_unregister(switch_class);
 831 #endif
 832         class_destroy(extcon_class);
 833 }
 834 module_exit(extcon_class_exit);
 835
 836 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 837 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 838 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 839 MODULE_DESCRIPTION("External connector (extcon) class driver");
 840 MODULE_LICENSE("GPL");