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