drivers/extcon/extcon.c

   1 /*
   2  *  drivers/extcon/extcon.c - External Connector (extcon) framework.
   3  *
   4  *  External connector (extcon) class driver
   5  *
   6  * Copyright (C) 2015 Samsung Electronics
   7  * Author: Chanwoo Choi <cw00.choi@samsung.com>
   8  *
   9  * Copyright (C) 2012 Samsung Electronics
  10  * Author: Donggeun Kim <dg77.kim@samsung.com>
  11  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
  12  *
  13  * based on android/drivers/switch/switch_class.c
  14  * Copyright (C) 2008 Google, Inc.
  15  * Author: Mike Lockwood <lockwood@android.com>
  16  *
  17  * This software is licensed under the terms of the GNU General Public
  18  * License version 2, as published by the Free Software Foundation, and
  19  * may be copied, distributed, and modified under those terms.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/types.h>
  29 #include <linux/init.h>
  30 #include <linux/device.h>
  31 #include <linux/fs.h>
  32 #include <linux/err.h>
  33 #include <linux/extcon.h>
  34 #include <linux/of.h>
  35 #include <linux/slab.h>
  36 #include <linux/sysfs.h>
  37
  38 #define SUPPORTED_CABLE_MAX     32
  39 #define CABLE_NAME_MAX          30
  40
  41 struct __extcon_info {
  42         unsigned int type;
  43         unsigned int id;
  44         const char *name;
  45
  46 } extcon_info[] = {
  47         [EXTCON_NONE] = {
  48                 .type = EXTCON_TYPE_MISC,
  49                 .id = EXTCON_NONE,
  50                 .name = "NONE",
  51         },
  52
  53         /* USB external connector */
  54         [EXTCON_USB] = {
  55                 .type = EXTCON_TYPE_USB,
  56                 .id = EXTCON_USB,
  57                 .name = "USB",
  58         },
  59         [EXTCON_USB_HOST] = {
  60                 .type = EXTCON_TYPE_USB,
  61                 .id = EXTCON_USB_HOST,
  62                 .name = "USB_HOST",
  63         },
  64
  65         /* Charging external connector */
  66         [EXTCON_CHG_USB_SDP] = {
  67                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  68                 .id = EXTCON_CHG_USB_SDP,
  69                 .name = "SDP",
  70         },
  71         [EXTCON_CHG_USB_DCP] = {
  72                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  73                 .id = EXTCON_CHG_USB_DCP,
  74                 .name = "DCP",
  75         },
  76         [EXTCON_CHG_USB_CDP] = {
  77                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  78                 .id = EXTCON_CHG_USB_CDP,
  79                 .name = "CDP",
  80         },
  81         [EXTCON_CHG_USB_ACA] = {
  82                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  83                 .id = EXTCON_CHG_USB_ACA,
  84                 .name = "ACA",
  85         },
  86         [EXTCON_CHG_USB_FAST] = {
  87                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  88                 .id = EXTCON_CHG_USB_FAST,
  89                 .name = "FAST-CHARGER",
  90         },
  91         [EXTCON_CHG_USB_SLOW] = {
  92                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  93                 .id = EXTCON_CHG_USB_SLOW,
  94                 .name = "SLOW-CHARGER",
  95         },
  96         [EXTCON_CHG_WPT] = {
  97                 .type = EXTCON_TYPE_CHG,
  98                 .id = EXTCON_CHG_WPT,
  99                 .name = "WPT",
 100         },
 101
 102         /* Jack external connector */
 103         [EXTCON_JACK_MICROPHONE] = {
 104                 .type = EXTCON_TYPE_JACK,
 105                 .id = EXTCON_JACK_MICROPHONE,
 106                 .name = "MICROPHONE",
 107         },
 108         [EXTCON_JACK_HEADPHONE] = {
 109                 .type = EXTCON_TYPE_JACK,
 110                 .id = EXTCON_JACK_HEADPHONE,
 111                 .name = "HEADPHONE",
 112         },
 113         [EXTCON_JACK_LINE_IN] = {
 114                 .type = EXTCON_TYPE_JACK,
 115                 .id = EXTCON_JACK_LINE_IN,
 116                 .name = "LINE-IN",
 117         },
 118         [EXTCON_JACK_LINE_OUT] = {
 119                 .type = EXTCON_TYPE_JACK,
 120                 .id = EXTCON_JACK_LINE_OUT,
 121                 .name = "LINE-OUT",
 122         },
 123         [EXTCON_JACK_VIDEO_IN] = {
 124                 .type = EXTCON_TYPE_JACK,
 125                 .id = EXTCON_JACK_VIDEO_IN,
 126                 .name = "VIDEO-IN",
 127         },
 128         [EXTCON_JACK_VIDEO_OUT] = {
 129                 .type = EXTCON_TYPE_JACK,
 130                 .id = EXTCON_JACK_VIDEO_OUT,
 131                 .name = "VIDEO-OUT",
 132         },
 133         [EXTCON_JACK_SPDIF_IN] = {
 134                 .type = EXTCON_TYPE_JACK,
 135                 .id = EXTCON_JACK_SPDIF_IN,
 136                 .name = "SPDIF-IN",
 137         },
 138         [EXTCON_JACK_SPDIF_OUT] = {
 139                 .type = EXTCON_TYPE_JACK,
 140                 .id = EXTCON_JACK_SPDIF_OUT,
 141                 .name = "SPDIF-OUT",
 142         },
 143
 144         /* Display external connector */
 145         [EXTCON_DISP_HDMI] = {
 146                 .type = EXTCON_TYPE_DISP,
 147                 .id = EXTCON_DISP_HDMI,
 148                 .name = "HDMI",
 149         },
 150         [EXTCON_DISP_MHL] = {
 151                 .type = EXTCON_TYPE_DISP,
 152                 .id = EXTCON_DISP_MHL,
 153                 .name = "MHL",
 154         },
 155         [EXTCON_DISP_DVI] = {
 156                 .type = EXTCON_TYPE_DISP,
 157                 .id = EXTCON_DISP_DVI,
 158                 .name = "DVI",
 159         },
 160         [EXTCON_DISP_VGA] = {
 161                 .type = EXTCON_TYPE_DISP,
 162                 .id = EXTCON_DISP_VGA,
 163                 .name = "VGA",
 164         },
 165         [EXTCON_DISP_DP] = {
 166                 .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
 167                 .id = EXTCON_DISP_DP,
 168                 .name = "DP",
 169         },
 170         [EXTCON_DISP_HMD] = {
 171                 .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
 172                 .id = EXTCON_DISP_HMD,
 173                 .name = "HMD",
 174         },
 175
 176         /* Miscellaneous external connector */
 177         [EXTCON_DOCK] = {
 178                 .type = EXTCON_TYPE_MISC,
 179                 .id = EXTCON_DOCK,
 180                 .name = "DOCK",
 181         },
 182         [EXTCON_JIG] = {
 183                 .type = EXTCON_TYPE_MISC,
 184                 .id = EXTCON_JIG,
 185                 .name = "JIG",
 186         },
 187         [EXTCON_MECHANICAL] = {
 188                 .type = EXTCON_TYPE_MISC,
 189                 .id = EXTCON_MECHANICAL,
 190                 .name = "MECHANICAL",
 191         },
 192
 193         { /* sentinel */ }
 194 };
 195
 196 /**
 197  * struct extcon_cable - An internal data for each cable of extcon device.
 198  * @edev:               The extcon device
 199  * @cable_index:        Index of this cable in the edev
 200  * @attr_g:             Attribute group for the cable
 201  * @attr_name:          "name" sysfs entry
 202  * @attr_state:         "state" sysfs entry
 203  * @attrs:              Array pointing to attr_name and attr_state for attr_g
 204  */
 205 struct extcon_cable {
 206         struct extcon_dev *edev;
 207         int cable_index;
 208
 209         struct attribute_group attr_g;
 210         struct device_attribute attr_name;
 211         struct device_attribute attr_state;
 212
 213         struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
 214
 215         union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
 216         union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
 217         union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
 218         union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];
 219
 220         unsigned long usb_bits[BITS_TO_LONGS(EXTCON_PROP_USB_CNT)];
 221         unsigned long chg_bits[BITS_TO_LONGS(EXTCON_PROP_CHG_CNT)];
 222         unsigned long jack_bits[BITS_TO_LONGS(EXTCON_PROP_JACK_CNT)];
 223         unsigned long disp_bits[BITS_TO_LONGS(EXTCON_PROP_DISP_CNT)];
 224 };
 225
 226 static struct class *extcon_class;
 227 #if defined(CONFIG_ANDROID)
 228 static struct class_compat *switch_class;
 229 #endif /* CONFIG_ANDROID */
 230
 231 static LIST_HEAD(extcon_dev_list);
 232 static DEFINE_MUTEX(extcon_dev_list_lock);
 233
 234 /**
 235  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
 236  *                            condition.
 237  * @edev:       the extcon device
 238  * @new_state:  new cable attach status for @edev
 239  *
 240  * Returns 0 if nothing violates. Returns the index + 1 for the first
 241  * violated condition.
 242  */
 243 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
 244 {
 245         int i = 0;
 246
 247         if (!edev->mutually_exclusive)
 248                 return 0;
 249
 250         for (i = 0; edev->mutually_exclusive[i]; i++) {
 251                 int weight;
 252                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 253
 254                 /* calculate the total number of bits set */
 255                 weight = hweight32(correspondants);
 256                 if (weight > 1)
 257                         return i + 1;
 258         }
 259
 260         return 0;
 261 }
 262
 263 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 264 {
 265         int i;
 266
 267         /* Find the the index of extcon cable in edev->supported_cable */
 268         for (i = 0; i < edev->max_supported; i++) {
 269                 if (edev->supported_cable[i] == id)
 270                         return i;
 271         }
 272
 273         return -EINVAL;
 274 }
 275
 276 static int get_extcon_type(unsigned int prop)
 277 {
 278         switch (prop) {
 279         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 280                 return EXTCON_TYPE_USB;
 281         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 282                 return EXTCON_TYPE_CHG;
 283         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 284                 return EXTCON_TYPE_JACK;
 285         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 286                 return EXTCON_TYPE_DISP;
 287         default:
 288                 return -EINVAL;
 289         }
 290 }
 291
 292 static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
 293 {
 294         return !!(edev->state & BIT(index));
 295 }
 296
 297 static bool is_extcon_changed(struct extcon_dev *edev, int index,
 298                                 bool new_state)
 299 {
 300         int state = !!(edev->state & BIT(index));
 301         return (state != new_state);
 302 }
 303
 304 static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
 305 {
 306         int type;
 307
 308         /* Check whether the property is supported or not. */
 309         type = get_extcon_type(prop);
 310         if (type < 0)
 311                 return false;
 312
 313         /* Check whether a specific extcon id supports the property or not. */
 314         return !!(extcon_info[id].type & type);
 315 }
 316
 317 static int is_extcon_property_capability(struct extcon_dev *edev,
 318                                 unsigned int id, int index,unsigned int prop)
 319 {
 320         struct extcon_cable *cable;
 321         int type, ret;
 322
 323         /* Check whether the property is supported or not. */
 324         type = get_extcon_type(prop);
 325         if (type < 0)
 326                 return type;
 327
 328         cable = &edev->cables[index];
 329
 330         switch (type) {
 331         case EXTCON_TYPE_USB:
 332                 ret = test_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
 333                 break;
 334         case EXTCON_TYPE_CHG:
 335                 ret = test_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
 336                 break;
 337         case EXTCON_TYPE_JACK:
 338                 ret = test_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
 339                 break;
 340         case EXTCON_TYPE_DISP:
 341                 ret = test_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
 342                 break;
 343         default:
 344                 ret = -EINVAL;
 345         }
 346
 347         return ret;
 348 }
 349
 350 static void init_property(struct extcon_dev *edev, unsigned int id, int index)
 351 {
 352         unsigned int type = extcon_info[id].type;
 353         struct extcon_cable *cable = &edev->cables[index];
 354
 355         if (EXTCON_TYPE_USB & type)
 356                 memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
 357         if (EXTCON_TYPE_CHG & type)
 358                 memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
 359         if (EXTCON_TYPE_JACK & type)
 360                 memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
 361         if (EXTCON_TYPE_DISP & type)
 362                 memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
 363 }
 364
 365 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 366                           char *buf)
 367 {
 368         int i, count = 0;
 369         struct extcon_dev *edev = dev_get_drvdata(dev);
 370
 371         if (edev->max_supported == 0)
 372                 return sprintf(buf, "%u\n", edev->state);
 373
 374         for (i = 0; i < edev->max_supported; i++) {
 375                 count += sprintf(buf + count, "%s=%d\n",
 376                                 extcon_info[edev->supported_cable[i]].name,
 377                                  !!(edev->state & (1 << i)));
 378         }
 379
 380         return count;
 381 }
 382 static DEVICE_ATTR_RO(state);
 383
 384 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 385                 char *buf)
 386 {
 387         struct extcon_dev *edev = dev_get_drvdata(dev);
 388
 389         return sprintf(buf, "%s\n", edev->name);
 390 }
 391 static DEVICE_ATTR_RO(name);
 392
 393 static ssize_t cable_name_show(struct device *dev,
 394                                struct device_attribute *attr, char *buf)
 395 {
 396         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 397                                                   attr_name);
 398         int i = cable->cable_index;
 399
 400         return sprintf(buf, "%s\n",
 401                         extcon_info[cable->edev->supported_cable[i]].name);
 402 }
 403
 404 static ssize_t cable_state_show(struct device *dev,
 405                                 struct device_attribute *attr, char *buf)
 406 {
 407         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 408                                                   attr_state);
 409
 410         int i = cable->cable_index;
 411
 412         return sprintf(buf, "%d\n",
 413                 extcon_get_state(cable->edev, cable->edev->supported_cable[i]));
 414 }
 415
 416 /**
 417  * extcon_sync()        - Synchronize the states for both the attached/detached
 418  * @edev:               the extcon device that has the cable.
 419  *
 420  * This function send a notification to synchronize the all states of a
 421  * specific external connector
 422  */
 423 int extcon_sync(struct extcon_dev *edev, unsigned int id)
 424 {
 425         char name_buf[120];
 426         char state_buf[120];
 427         char *prop_buf;
 428         char *envp[3];
 429         int env_offset = 0;
 430         int length;
 431         int index;
 432         int state;
 433         unsigned long flags;
 434
 435         if (!edev)
 436                 return -EINVAL;
 437
 438         index = find_cable_index_by_id(edev, id);
 439         if (index < 0)
 440                 return index;
 441
 442         spin_lock_irqsave(&edev->lock, flags);
 443
 444         state = !!(edev->state & BIT(index));
 445         raw_notifier_call_chain(&edev->nh[index], state, edev);
 446
 447         /* This could be in interrupt handler */
 448         prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 449         if (!prop_buf) {
 450                 /* Unlock early before uevent */
 451                 spin_unlock_irqrestore(&edev->lock, flags);
 452
 453                 dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 454                 kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 455
 456                 return 0;
 457         }
 458
 459         length = name_show(&edev->dev, NULL, prop_buf);
 460         if (length > 0) {
 461                 if (prop_buf[length - 1] == '\n')
 462                         prop_buf[length - 1] = 0;
 463                 snprintf(name_buf, sizeof(name_buf), "NAME=%s", prop_buf);
 464                 envp[env_offset++] = name_buf;
 465         }
 466
 467         length = state_show(&edev->dev, NULL, prop_buf);
 468         if (length > 0) {
 469                 if (prop_buf[length - 1] == '\n')
 470                         prop_buf[length - 1] = 0;
 471                 snprintf(state_buf, sizeof(state_buf), "STATE=%s", prop_buf);
 472                 envp[env_offset++] = state_buf;
 473         }
 474         envp[env_offset] = NULL;
 475
 476         /* Unlock early before uevent */
 477         spin_unlock_irqrestore(&edev->lock, flags);
 478         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 479         free_page((unsigned long)prop_buf);
 480
 481         return 0;
 482 }
 483 EXPORT_SYMBOL_GPL(extcon_sync);
 484
 485 /**
 486  * extcon_get_state() - Get the state of a external connector.
 487  * @edev:       the extcon device that has the cable.
 488  * @id:         the unique id of each external connector in extcon enumeration.
 489  */
 490 int extcon_get_state(struct extcon_dev *edev, const unsigned int id)
 491 {
 492         int index, state;
 493         unsigned long flags;
 494
 495         if (!edev)
 496                 return -EINVAL;
 497
 498         index = find_cable_index_by_id(edev, id);
 499         if (index < 0)
 500                 return index;
 501
 502         spin_lock_irqsave(&edev->lock, flags);
 503         state = is_extcon_attached(edev, index);
 504         spin_unlock_irqrestore(&edev->lock, flags);
 505
 506         return state;
 507 }
 508 EXPORT_SYMBOL_GPL(extcon_get_state);
 509
 510 /**
 511  * extcon_set_state() - Set the state of a external connector.
 512  *                      without a notification.
 513  * @edev:               the extcon device that has the cable.
 514  * @id:                 the unique id of each external connector
 515  *                      in extcon enumeration.
 516  * @state:              the new cable status. The default semantics is
 517  *                      true: attached / false: detached.
 518  *
 519  * This function only set the state of a external connector without
 520  * a notification. To synchronize the data of a external connector,
 521  * use extcon_set_state_sync() and extcon_sync().
 522  */
 523 int extcon_set_state(struct extcon_dev *edev, unsigned int id,
 524                                 bool cable_state)
 525 {
 526         unsigned long flags;
 527         int index, ret = 0;
 528
 529         if (!edev)
 530                 return -EINVAL;
 531
 532         index = find_cable_index_by_id(edev, id);
 533         if (index < 0)
 534                 return index;
 535
 536         spin_lock_irqsave(&edev->lock, flags);
 537
 538         /* Check whether the external connector's state is changed. */
 539         if (!is_extcon_changed(edev, index, cable_state))
 540                 goto out;
 541
 542         if (check_mutually_exclusive(edev,
 543                 (edev->state & ~BIT(index)) | (cable_state & BIT(index)))) {
 544                 ret = -EPERM;
 545                 goto out;
 546         }
 547
 548         /*
 549          * Initialize the value of extcon property before setting
 550          * the detached state for an external connector.
 551          */
 552         if (!cable_state)
 553                 init_property(edev, id, index);
 554
 555         /* Update the state for a external connector. */
 556         if (cable_state)
 557                 edev->state |= BIT(index);
 558         else
 559                 edev->state &= ~(BIT(index));
 560 out:
 561         spin_unlock_irqrestore(&edev->lock, flags);
 562
 563         return ret;
 564 }
 565 EXPORT_SYMBOL_GPL(extcon_set_state);
 566
 567 /**
 568  * extcon_set_state_sync() - Set the state of a external connector
 569  *                      with a notification.
 570  * @edev:               the extcon device that has the cable.
 571  * @id:                 the unique id of each external connector
 572  *                      in extcon enumeration.
 573  * @state:              the new cable status. The default semantics is
 574  *                      true: attached / false: detached.
 575  *
 576  * This function set the state of external connector and synchronize the data
 577  * by usning a notification.
 578  */
 579 int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id,
 580                                 bool cable_state)
 581 {
 582         int ret, index;
 583         unsigned long flags;
 584
 585         index = find_cable_index_by_id(edev, id);
 586         if (index < 0)
 587                 return index;
 588
 589         /* Check whether the external connector's state is changed. */
 590         spin_lock_irqsave(&edev->lock, flags);
 591         ret = is_extcon_changed(edev, index, cable_state);
 592         spin_unlock_irqrestore(&edev->lock, flags);
 593         if (!ret)
 594                 return 0;
 595
 596         ret = extcon_set_state(edev, id, cable_state);
 597         if (ret < 0)
 598                 return ret;
 599
 600         return extcon_sync(edev, id);
 601 }
 602 EXPORT_SYMBOL_GPL(extcon_set_state_sync);
 603
 604 /**
 605  * extcon_get_property() - Get the property value of a specific cable.
 606  * @edev:               the extcon device that has the cable.
 607  * @id:                 the unique id of each external connector
 608  *                      in extcon enumeration.
 609  * @prop:               the property id among enum extcon_property.
 610  * @prop_val:           the pointer which store the value of property.
 611  *
 612  * When getting the property value of external connector, the external connector
 613  * should be attached. If detached state, function just return 0 without
 614  * property value. Also, the each property should be included in the list of
 615  * supported properties according to the type of external connectors.
 616  *
 617  * Returns 0 if success or error number if fail
 618  */
 619 int extcon_get_property(struct extcon_dev *edev, unsigned int id,
 620                                 unsigned int prop,
 621                                 union extcon_property_value *prop_val)
 622 {
 623         struct extcon_cable *cable;
 624         unsigned long flags;
 625         int index, ret = 0;
 626
 627         *prop_val = (union extcon_property_value)(0);
 628
 629         if (!edev)
 630                 return -EINVAL;
 631
 632         /* Check whether the property is supported or not */
 633         if (!is_extcon_property_supported(id, prop))
 634                 return -EINVAL;
 635
 636         /* Find the cable index of external connector by using id */
 637         index = find_cable_index_by_id(edev, id);
 638         if (index < 0)
 639                 return index;
 640
 641         spin_lock_irqsave(&edev->lock, flags);
 642
 643         /* Check whether the property is available or not. */
 644         if (!is_extcon_property_capability(edev, id, index, prop)) {
 645                 spin_unlock_irqrestore(&edev->lock, flags);
 646                 return -EPERM;
 647         }
 648
 649         /*
 650          * Check whether the external connector is attached.
 651          * If external connector is detached, the user can not
 652          * get the property value.
 653          */
 654         if (!is_extcon_attached(edev, index)) {
 655                 spin_unlock_irqrestore(&edev->lock, flags);
 656                 return 0;
 657         }
 658
 659         cable = &edev->cables[index];
 660
 661         /* Get the property value according to extcon type */
 662         switch (prop) {
 663         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 664                 *prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
 665                 break;
 666         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 667                 *prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
 668                 break;
 669         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 670                 *prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
 671                 break;
 672         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 673                 *prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
 674                 break;
 675         default:
 676                 ret = -EINVAL;
 677                 break;
 678         }
 679
 680         spin_unlock_irqrestore(&edev->lock, flags);
 681
 682         return ret;
 683 }
 684 EXPORT_SYMBOL_GPL(extcon_get_property);
 685
 686 /**
 687  * extcon_set_property() - Set the property value of a specific cable.
 688  * @edev:               the extcon device that has the cable.
 689  * @id:                 the unique id of each external connector
 690  *                      in extcon enumeration.
 691  * @prop:               the property id among enum extcon_property.
 692  * @prop_val:           the pointer including the new value of property.
 693  *
 694  * The each property should be included in the list of supported properties
 695  * according to the type of external connectors.
 696  *
 697  * Returns 0 if success or error number if fail
 698  */
 699 int extcon_set_property(struct extcon_dev *edev, unsigned int id,
 700                                 unsigned int prop,
 701                                 union extcon_property_value prop_val)
 702 {
 703         struct extcon_cable *cable;
 704         unsigned long flags;
 705         int index, ret = 0;
 706
 707         if (!edev)
 708                 return -EINVAL;
 709
 710         /* Check whether the property is supported or not */
 711         if (!is_extcon_property_supported(id, prop))
 712                 return -EINVAL;
 713
 714         /* Find the cable index of external connector by using id */
 715         index = find_cable_index_by_id(edev, id);
 716         if (index < 0)
 717                 return index;
 718
 719         spin_lock_irqsave(&edev->lock, flags);
 720
 721         /* Check whether the property is available or not. */
 722         if (!is_extcon_property_capability(edev, id, index, prop)) {
 723                 spin_unlock_irqrestore(&edev->lock, flags);
 724                 return -EPERM;
 725         }
 726
 727         cable = &edev->cables[index];
 728
 729         /* Set the property value according to extcon type */
 730         switch (prop) {
 731         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 732                 cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
 733                 break;
 734         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 735                 cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
 736                 break;
 737         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 738                 cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
 739                 break;
 740         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 741                 cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
 742                 break;
 743         default:
 744                 ret = -EINVAL;
 745                 break;
 746         }
 747
 748         spin_unlock_irqrestore(&edev->lock, flags);
 749
 750         return ret;
 751 }
 752 EXPORT_SYMBOL_GPL(extcon_set_property);
 753
 754 /**
 755  * extcon_set_property_sync() - Set the property value of a specific cable
 756                         with a notification.
 757  * @prop_val:           the pointer including the new value of property.
 758  *
 759  * When setting the property value of external connector, the external connector
 760  * should be attached. The each property should be included in the list of
 761  * supported properties according to the type of external connectors.
 762  *
 763  * Returns 0 if success or error number if fail
 764  */
 765 int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
 766                                 unsigned int prop,
 767                                 union extcon_property_value prop_val)
 768 {
 769         int ret;
 770
 771         ret = extcon_set_property(edev, id, prop, prop_val);
 772         if (ret < 0)
 773                 return ret;
 774
 775         return extcon_sync(edev, id);
 776 }
 777 EXPORT_SYMBOL_GPL(extcon_set_property_sync);
 778
 779 /**
 780  * extcon_get_property_capability() - Get the capability of property
 781  *                      of an external connector.
 782  * @edev:               the extcon device that has the cable.
 783  * @id:                 the unique id of each external connector
 784  *                      in extcon enumeration.
 785  * @prop:               the property id among enum extcon_property.
 786  *
 787  * Returns 1 if the property is available or 0 if not available.
 788  */
 789 int extcon_get_property_capability(struct extcon_dev *edev, unsigned int id,
 790                                         unsigned int prop)
 791 {
 792         int index;
 793
 794         if (!edev)
 795                 return -EINVAL;
 796
 797         /* Check whether the property is supported or not */
 798         if (!is_extcon_property_supported(id, prop))
 799                 return -EINVAL;
 800
 801         /* Find the cable index of external connector by using id */
 802         index = find_cable_index_by_id(edev, id);
 803         if (index < 0)
 804                 return index;
 805
 806         return is_extcon_property_capability(edev, id, index, prop);
 807 }
 808 EXPORT_SYMBOL_GPL(extcon_get_property_capability);
 809
 810 /**
 811  * extcon_set_property_capability() - Set the capability of a property
 812  *                      of an external connector.
 813  * @edev:               the extcon device that has the cable.
 814  * @id:                 the unique id of each external connector
 815  *                      in extcon enumeration.
 816  * @prop:               the property id among enum extcon_property.
 817  *
 818  * This function set the capability of a property for an external connector
 819  * to mark the bit in capability bitmap which mean the available state of
 820  * a property.
 821  *
 822  * Returns 0 if success or error number if fail
 823  */
 824 int extcon_set_property_capability(struct extcon_dev *edev, unsigned int id,
 825                                         unsigned int prop)
 826 {
 827         struct extcon_cable *cable;
 828         int index, type, ret = 0;
 829
 830         if (!edev)
 831                 return -EINVAL;
 832
 833         /* Check whether the property is supported or not. */
 834         if (!is_extcon_property_supported(id, prop))
 835                 return -EINVAL;
 836
 837         /* Find the cable index of external connector by using id. */
 838         index = find_cable_index_by_id(edev, id);
 839         if (index < 0)
 840                 return index;
 841
 842         type = get_extcon_type(prop);
 843         if (type < 0)
 844                 return type;
 845
 846         cable = &edev->cables[index];
 847
 848         switch (type) {
 849         case EXTCON_TYPE_USB:
 850                 __set_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
 851                 break;
 852         case EXTCON_TYPE_CHG:
 853                 __set_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
 854                 break;
 855         case EXTCON_TYPE_JACK:
 856                 __set_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
 857                 break;
 858         case EXTCON_TYPE_DISP:
 859                 __set_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
 860                 break;
 861         default:
 862                 ret = -EINVAL;
 863         }
 864
 865         return ret;
 866 }
 867 EXPORT_SYMBOL_GPL(extcon_set_property_capability);
 868
 869 /**
 870  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 871  * @extcon_name:        The extcon name provided with extcon_dev_register()
 872  */
 873 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 874 {
 875         struct extcon_dev *sd;
 876
 877         if (!extcon_name)
 878                 return ERR_PTR(-EINVAL);
 879
 880         mutex_lock(&extcon_dev_list_lock);
 881         list_for_each_entry(sd, &extcon_dev_list, entry) {
 882                 if (!strcmp(sd->name, extcon_name))
 883                         goto out;
 884         }
 885         sd = NULL;
 886 out:
 887         mutex_unlock(&extcon_dev_list_lock);
 888         return sd;
 889 }
 890 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 891
 892 /**
 893  * extcon_register_notifier() - Register a notifiee to get notified by
 894  *                              any attach status changes from the extcon.
 895  * @edev:       the extcon device that has the external connecotr.
 896  * @id:         the unique id of each external connector in extcon enumeration.
 897  * @nb:         a notifier block to be registered.
 898  *
 899  * Note that the second parameter given to the callback of nb (val) is
 900  * "old_state", not the current state. The current state can be retrieved
 901  * by looking at the third pameter (edev pointer)'s state value.
 902  */
 903 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 904                              struct notifier_block *nb)
 905 {
 906         unsigned long flags;
 907         int ret, idx = -EINVAL;
 908
 909         if (!nb)
 910                 return -EINVAL;
 911
 912         if (edev) {
 913                 idx = find_cable_index_by_id(edev, id);
 914                 if (idx < 0)
 915                         return idx;
 916
 917                 spin_lock_irqsave(&edev->lock, flags);
 918                 ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 919                 spin_unlock_irqrestore(&edev->lock, flags);
 920         } else {
 921                 struct extcon_dev *extd;
 922
 923                 mutex_lock(&extcon_dev_list_lock);
 924                 list_for_each_entry(extd, &extcon_dev_list, entry) {
 925                         idx = find_cable_index_by_id(extd, id);
 926                         if (idx >= 0)
 927                                 break;
 928                 }
 929                 mutex_unlock(&extcon_dev_list_lock);
 930
 931                 if (idx >= 0) {
 932                         edev = extd;
 933                         return extcon_register_notifier(extd, id, nb);
 934                 } else {
 935                         ret = -ENODEV;
 936                 }
 937         }
 938
 939         return ret;
 940 }
 941 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 942
 943 /**
 944  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 945  * @edev:       the extcon device that has the external connecotr.
 946  * @id:         the unique id of each external connector in extcon enumeration.
 947  * @nb:         a notifier block to be registered.
 948  */
 949 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 950                                 struct notifier_block *nb)
 951 {
 952         unsigned long flags;
 953         int ret, idx;
 954
 955         if (!edev || !nb)
 956                 return -EINVAL;
 957
 958         idx = find_cable_index_by_id(edev, id);
 959         if (idx < 0)
 960                 return idx;
 961
 962         spin_lock_irqsave(&edev->lock, flags);
 963         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 964         spin_unlock_irqrestore(&edev->lock, flags);
 965
 966         return ret;
 967 }
 968 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 969
 970 static struct attribute *extcon_attrs[] = {
 971         &dev_attr_state.attr,
 972         &dev_attr_name.attr,
 973         NULL,
 974 };
 975 ATTRIBUTE_GROUPS(extcon);
 976
 977 static int create_extcon_class(void)
 978 {
 979         if (!extcon_class) {
 980                 extcon_class = class_create(THIS_MODULE, "extcon");
 981                 if (IS_ERR(extcon_class))
 982                         return PTR_ERR(extcon_class);
 983                 extcon_class->dev_groups = extcon_groups;
 984
 985 #if defined(CONFIG_ANDROID)
 986                 switch_class = class_compat_register("switch");
 987                 if (WARN(!switch_class, "cannot allocate"))
 988                         return -ENOMEM;
 989 #endif /* CONFIG_ANDROID */
 990         }
 991
 992         return 0;
 993 }
 994
 995 static void extcon_dev_release(struct device *dev)
 996 {
 997 }
 998
 999 static const char *muex_name = "mutually_exclusive";
1000 static void dummy_sysfs_dev_release(struct device *dev)
1001 {
1002 }
1003
1004 /*
1005  * extcon_dev_allocate() - Allocate the memory of extcon device.
1006  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
1007  *                      If supported_cable is NULL, cable name related APIs
1008  *                      are disabled.
1009  *
1010  * This function allocates the memory for extcon device without allocating
1011  * memory in each extcon provider driver and initialize default setting for
1012  * extcon device.
1013  *
1014  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
1015  */
1016 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
1017 {
1018         struct extcon_dev *edev;
1019
1020         if (!supported_cable)
1021                 return ERR_PTR(-EINVAL);
1022
1023         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
1024         if (!edev)
1025                 return ERR_PTR(-ENOMEM);
1026
1027         edev->max_supported = 0;
1028         edev->supported_cable = supported_cable;
1029
1030         return edev;
1031 }
1032
1033 /*
1034  * extcon_dev_free() - Free the memory of extcon device.
1035  * @edev:       the extcon device to free
1036  */
1037 void extcon_dev_free(struct extcon_dev *edev)
1038 {
1039         kfree(edev);
1040 }
1041 EXPORT_SYMBOL_GPL(extcon_dev_free);
1042
1043 /**
1044  * extcon_dev_register() - Register a new extcon device
1045  * @edev        : the new extcon device (should be allocated before calling)
1046  *
1047  * Among the members of edev struct, please set the "user initializing data"
1048  * in any case and set the "optional callbacks" if required. However, please
1049  * do not set the values of "internal data", which are initialized by
1050  * this function.
1051  */
1052 int extcon_dev_register(struct extcon_dev *edev)
1053 {
1054         int ret, index = 0;
1055         static atomic_t edev_no = ATOMIC_INIT(-1);
1056
1057         if (!extcon_class) {
1058                 ret = create_extcon_class();
1059                 if (ret < 0)
1060                         return ret;
1061         }
1062
1063         if (!edev || !edev->supported_cable)
1064                 return -EINVAL;
1065
1066         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
1067
1068         edev->max_supported = index;
1069         if (index > SUPPORTED_CABLE_MAX) {
1070                 dev_err(&edev->dev,
1071                         "exceed the maximum number of supported cables\n");
1072                 return -EINVAL;
1073         }
1074
1075         edev->dev.class = extcon_class;
1076         edev->dev.release = extcon_dev_release;
1077
1078         edev->name = dev_name(edev->dev.parent);
1079         if (IS_ERR_OR_NULL(edev->name)) {
1080                 dev_err(&edev->dev,
1081                         "extcon device name is null\n");
1082                 return -EINVAL;
1083         }
1084         dev_set_name(&edev->dev, "extcon%lu",
1085                         (unsigned long)atomic_inc_return(&edev_no));
1086
1087         if (edev->max_supported) {
1088                 char buf[10];
1089                 char *str;
1090                 struct extcon_cable *cable;
1091
1092                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
1093                                        edev->max_supported, GFP_KERNEL);
1094                 if (!edev->cables) {
1095                         ret = -ENOMEM;
1096                         goto err_sysfs_alloc;
1097                 }
1098                 for (index = 0; index < edev->max_supported; index++) {
1099                         cable = &edev->cables[index];
1100
1101                         snprintf(buf, 10, "cable.%d", index);
1102                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
1103                                       GFP_KERNEL);
1104                         if (!str) {
1105                                 for (index--; index >= 0; index--) {
1106                                         cable = &edev->cables[index];
1107                                         kfree(cable->attr_g.name);
1108                                 }
1109                                 ret = -ENOMEM;
1110
1111                                 goto err_alloc_cables;
1112                         }
1113                         strcpy(str, buf);
1114
1115                         cable->edev = edev;
1116                         cable->cable_index = index;
1117                         cable->attrs[0] = &cable->attr_name.attr;
1118                         cable->attrs[1] = &cable->attr_state.attr;
1119                         cable->attrs[2] = NULL;
1120                         cable->attr_g.name = str;
1121                         cable->attr_g.attrs = cable->attrs;
1122
1123                         sysfs_attr_init(&cable->attr_name.attr);
1124                         cable->attr_name.attr.name = "name";
1125                         cable->attr_name.attr.mode = 0444;
1126                         cable->attr_name.show = cable_name_show;
1127
1128                         sysfs_attr_init(&cable->attr_state.attr);
1129                         cable->attr_state.attr.name = "state";
1130                         cable->attr_state.attr.mode = 0444;
1131                         cable->attr_state.show = cable_state_show;
1132                 }
1133         }
1134
1135         if (edev->max_supported && edev->mutually_exclusive) {
1136                 char buf[80];
1137                 char *name;
1138
1139                 /* Count the size of mutually_exclusive array */
1140                 for (index = 0; edev->mutually_exclusive[index]; index++)
1141                         ;
1142
1143                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
1144                                            (index + 1), GFP_KERNEL);
1145                 if (!edev->attrs_muex) {
1146                         ret = -ENOMEM;
1147                         goto err_muex;
1148                 }
1149
1150                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
1151                                              index, GFP_KERNEL);
1152                 if (!edev->d_attrs_muex) {
1153                         ret = -ENOMEM;
1154                         kfree(edev->attrs_muex);
1155                         goto err_muex;
1156                 }
1157
1158                 for (index = 0; edev->mutually_exclusive[index]; index++) {
1159                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
1160                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
1161                                        GFP_KERNEL);
1162                         if (!name) {
1163                                 for (index--; index >= 0; index--) {
1164                                         kfree(edev->d_attrs_muex[index].attr.
1165                                               name);
1166                                 }
1167                                 kfree(edev->d_attrs_muex);
1168                                 kfree(edev->attrs_muex);
1169                                 ret = -ENOMEM;
1170                                 goto err_muex;
1171                         }
1172                         strcpy(name, buf);
1173                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
1174                         edev->d_attrs_muex[index].attr.name = name;
1175                         edev->d_attrs_muex[index].attr.mode = 0000;
1176                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
1177                                                         .attr;
1178                 }
1179                 edev->attr_g_muex.name = muex_name;
1180                 edev->attr_g_muex.attrs = edev->attrs_muex;
1181
1182         }
1183
1184         if (edev->max_supported) {
1185                 edev->extcon_dev_type.groups =
1186                         kzalloc(sizeof(struct attribute_group *) *
1187                                 (edev->max_supported + 2), GFP_KERNEL);
1188                 if (!edev->extcon_dev_type.groups) {
1189                         ret = -ENOMEM;
1190                         goto err_alloc_groups;
1191                 }
1192
1193                 edev->extcon_dev_type.name = dev_name(&edev->dev);
1194                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
1195
1196                 for (index = 0; index < edev->max_supported; index++)
1197                         edev->extcon_dev_type.groups[index] =
1198                                 &edev->cables[index].attr_g;
1199                 if (edev->mutually_exclusive)
1200                         edev->extcon_dev_type.groups[index] =
1201                                 &edev->attr_g_muex;
1202
1203                 edev->dev.type = &edev->extcon_dev_type;
1204         }
1205
1206         ret = device_register(&edev->dev);
1207         if (ret) {
1208                 put_device(&edev->dev);
1209                 goto err_dev;
1210         }
1211 #if defined(CONFIG_ANDROID)
1212         if (switch_class)
1213                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
1214 #endif /* CONFIG_ANDROID */
1215
1216         spin_lock_init(&edev->lock);
1217
1218         edev->nh = devm_kzalloc(&edev->dev,
1219                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
1220         if (!edev->nh) {
1221                 ret = -ENOMEM;
1222                 goto err_dev;
1223         }
1224
1225         for (index = 0; index < edev->max_supported; index++)
1226                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
1227
1228         dev_set_drvdata(&edev->dev, edev);
1229         edev->state = 0;
1230
1231         mutex_lock(&extcon_dev_list_lock);
1232         list_add(&edev->entry, &extcon_dev_list);
1233         mutex_unlock(&extcon_dev_list_lock);
1234
1235         return 0;
1236
1237 err_dev:
1238         if (edev->max_supported)
1239                 kfree(edev->extcon_dev_type.groups);
1240 err_alloc_groups:
1241         if (edev->max_supported && edev->mutually_exclusive) {
1242                 for (index = 0; edev->mutually_exclusive[index]; index++)
1243                         kfree(edev->d_attrs_muex[index].attr.name);
1244                 kfree(edev->d_attrs_muex);
1245                 kfree(edev->attrs_muex);
1246         }
1247 err_muex:
1248         for (index = 0; index < edev->max_supported; index++)
1249                 kfree(edev->cables[index].attr_g.name);
1250 err_alloc_cables:
1251         if (edev->max_supported)
1252                 kfree(edev->cables);
1253 err_sysfs_alloc:
1254         return ret;
1255 }
1256 EXPORT_SYMBOL_GPL(extcon_dev_register);
1257
1258 /**
1259  * extcon_dev_unregister() - Unregister the extcon device.
1260  * @edev:       the extcon device instance to be unregistered.
1261  *
1262  * Note that this does not call kfree(edev) because edev was not allocated
1263  * by this class.
1264  */
1265 void extcon_dev_unregister(struct extcon_dev *edev)
1266 {
1267         int index;
1268
1269         if (!edev)
1270                 return;
1271
1272         mutex_lock(&extcon_dev_list_lock);
1273         list_del(&edev->entry);
1274         mutex_unlock(&extcon_dev_list_lock);
1275
1276         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
1277                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
1278                                 dev_name(&edev->dev));
1279                 return;
1280         }
1281
1282         device_unregister(&edev->dev);
1283
1284         if (edev->mutually_exclusive && edev->max_supported) {
1285                 for (index = 0; edev->mutually_exclusive[index];
1286                                 index++)
1287                         kfree(edev->d_attrs_muex[index].attr.name);
1288                 kfree(edev->d_attrs_muex);
1289                 kfree(edev->attrs_muex);
1290         }
1291
1292         for (index = 0; index < edev->max_supported; index++)
1293                 kfree(edev->cables[index].attr_g.name);
1294
1295         if (edev->max_supported) {
1296                 kfree(edev->extcon_dev_type.groups);
1297                 kfree(edev->cables);
1298         }
1299
1300 #if defined(CONFIG_ANDROID)
1301         if (switch_class)
1302                 class_compat_remove_link(switch_class, &edev->dev, NULL);
1303 #endif
1304         put_device(&edev->dev);
1305 }
1306 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
1307
1308 #ifdef CONFIG_OF
1309 /*
1310  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1311  * @dev - instance to the given device
1312  * @index - index into list of extcon_dev
1313  *
1314  * return the instance of extcon device
1315  */
1316 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1317 {
1318         struct device_node *node;
1319         struct extcon_dev *edev;
1320
1321         if (!dev)
1322                 return ERR_PTR(-EINVAL);
1323
1324         if (!dev->of_node) {
1325                 dev_dbg(dev, "device does not have a device node entry\n");
1326                 return ERR_PTR(-EINVAL);
1327         }
1328
1329         node = of_parse_phandle(dev->of_node, "extcon", index);
1330         if (!node) {
1331                 dev_dbg(dev, "failed to get phandle in %s node\n",
1332                         dev->of_node->full_name);
1333                 return ERR_PTR(-ENODEV);
1334         }
1335
1336         mutex_lock(&extcon_dev_list_lock);
1337         list_for_each_entry(edev, &extcon_dev_list, entry) {
1338                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1339                         mutex_unlock(&extcon_dev_list_lock);
1340                         of_node_put(node);
1341                         return edev;
1342                 }
1343         }
1344         mutex_unlock(&extcon_dev_list_lock);
1345         of_node_put(node);
1346
1347         return ERR_PTR(-EPROBE_DEFER);
1348 }
1349 #else
1350 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1351 {
1352         return ERR_PTR(-ENOSYS);
1353 }
1354 #endif /* CONFIG_OF */
1355 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1356
1357 /**
1358  * extcon_get_edev_name() - Get the name of the extcon device.
1359  * @edev:       the extcon device
1360  */
1361 const char *extcon_get_edev_name(struct extcon_dev *edev)
1362 {
1363         return !edev ? NULL : edev->name;
1364 }
1365
1366 static int __init extcon_class_init(void)
1367 {
1368         return create_extcon_class();
1369 }
1370 module_init(extcon_class_init);
1371
1372 static void __exit extcon_class_exit(void)
1373 {
1374 #if defined(CONFIG_ANDROID)
1375         class_compat_unregister(switch_class);
1376 #endif
1377         class_destroy(extcon_class);
1378 }
1379 module_exit(extcon_class_exit);
1380
1381 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1382 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1383 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1384 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1385 MODULE_DESCRIPTION("External connector (extcon) class driver");
1386 MODULE_LICENSE("GPL");