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         [EXTCON_CHG_USB_PD] = {
 103                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
 104                 .id = EXTCON_CHG_USB_PD,
 105                 .name = "PD",
 106         },
 107
 108         /* Jack external connector */
 109         [EXTCON_JACK_MICROPHONE] = {
 110                 .type = EXTCON_TYPE_JACK,
 111                 .id = EXTCON_JACK_MICROPHONE,
 112                 .name = "MICROPHONE",
 113         },
 114         [EXTCON_JACK_HEADPHONE] = {
 115                 .type = EXTCON_TYPE_JACK,
 116                 .id = EXTCON_JACK_HEADPHONE,
 117                 .name = "HEADPHONE",
 118         },
 119         [EXTCON_JACK_LINE_IN] = {
 120                 .type = EXTCON_TYPE_JACK,
 121                 .id = EXTCON_JACK_LINE_IN,
 122                 .name = "LINE-IN",
 123         },
 124         [EXTCON_JACK_LINE_OUT] = {
 125                 .type = EXTCON_TYPE_JACK,
 126                 .id = EXTCON_JACK_LINE_OUT,
 127                 .name = "LINE-OUT",
 128         },
 129         [EXTCON_JACK_VIDEO_IN] = {
 130                 .type = EXTCON_TYPE_JACK,
 131                 .id = EXTCON_JACK_VIDEO_IN,
 132                 .name = "VIDEO-IN",
 133         },
 134         [EXTCON_JACK_VIDEO_OUT] = {
 135                 .type = EXTCON_TYPE_JACK,
 136                 .id = EXTCON_JACK_VIDEO_OUT,
 137                 .name = "VIDEO-OUT",
 138         },
 139         [EXTCON_JACK_SPDIF_IN] = {
 140                 .type = EXTCON_TYPE_JACK,
 141                 .id = EXTCON_JACK_SPDIF_IN,
 142                 .name = "SPDIF-IN",
 143         },
 144         [EXTCON_JACK_SPDIF_OUT] = {
 145                 .type = EXTCON_TYPE_JACK,
 146                 .id = EXTCON_JACK_SPDIF_OUT,
 147                 .name = "SPDIF-OUT",
 148         },
 149
 150         /* Display external connector */
 151         [EXTCON_DISP_HDMI] = {
 152                 .type = EXTCON_TYPE_DISP,
 153                 .id = EXTCON_DISP_HDMI,
 154                 .name = "HDMI",
 155         },
 156         [EXTCON_DISP_MHL] = {
 157                 .type = EXTCON_TYPE_DISP,
 158                 .id = EXTCON_DISP_MHL,
 159                 .name = "MHL",
 160         },
 161         [EXTCON_DISP_DVI] = {
 162                 .type = EXTCON_TYPE_DISP,
 163                 .id = EXTCON_DISP_DVI,
 164                 .name = "DVI",
 165         },
 166         [EXTCON_DISP_VGA] = {
 167                 .type = EXTCON_TYPE_DISP,
 168                 .id = EXTCON_DISP_VGA,
 169                 .name = "VGA",
 170         },
 171         [EXTCON_DISP_DP] = {
 172                 .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
 173                 .id = EXTCON_DISP_DP,
 174                 .name = "DP",
 175         },
 176         [EXTCON_DISP_HMD] = {
 177                 .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
 178                 .id = EXTCON_DISP_HMD,
 179                 .name = "HMD",
 180         },
 181
 182         /* Miscellaneous external connector */
 183         [EXTCON_DOCK] = {
 184                 .type = EXTCON_TYPE_MISC,
 185                 .id = EXTCON_DOCK,
 186                 .name = "DOCK",
 187         },
 188         [EXTCON_JIG] = {
 189                 .type = EXTCON_TYPE_MISC,
 190                 .id = EXTCON_JIG,
 191                 .name = "JIG",
 192         },
 193         [EXTCON_MECHANICAL] = {
 194                 .type = EXTCON_TYPE_MISC,
 195                 .id = EXTCON_MECHANICAL,
 196                 .name = "MECHANICAL",
 197         },
 198
 199         { /* sentinel */ }
 200 };
 201
 202 /**
 203  * struct extcon_cable - An internal data for each cable of extcon device.
 204  * @edev:               The extcon device
 205  * @cable_index:        Index of this cable in the edev
 206  * @attr_g:             Attribute group for the cable
 207  * @attr_name:          "name" sysfs entry
 208  * @attr_state:         "state" sysfs entry
 209  * @attrs:              Array pointing to attr_name and attr_state for attr_g
 210  */
 211 struct extcon_cable {
 212         struct extcon_dev *edev;
 213         int cable_index;
 214
 215         struct attribute_group attr_g;
 216         struct device_attribute attr_name;
 217         struct device_attribute attr_state;
 218
 219         struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
 220
 221         union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
 222         union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
 223         union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
 224         union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];
 225
 226         unsigned long usb_bits[BITS_TO_LONGS(EXTCON_PROP_USB_CNT)];
 227         unsigned long chg_bits[BITS_TO_LONGS(EXTCON_PROP_CHG_CNT)];
 228         unsigned long jack_bits[BITS_TO_LONGS(EXTCON_PROP_JACK_CNT)];
 229         unsigned long disp_bits[BITS_TO_LONGS(EXTCON_PROP_DISP_CNT)];
 230 };
 231
 232 static struct class *extcon_class;
 233 #if defined(CONFIG_ANDROID)
 234 static struct class_compat *switch_class;
 235 #endif /* CONFIG_ANDROID */
 236
 237 static LIST_HEAD(extcon_dev_list);
 238 static DEFINE_MUTEX(extcon_dev_list_lock);
 239
 240 /**
 241  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
 242  *                            condition.
 243  * @edev:       the extcon device
 244  * @new_state:  new cable attach status for @edev
 245  *
 246  * Returns 0 if nothing violates. Returns the index + 1 for the first
 247  * violated condition.
 248  */
 249 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
 250 {
 251         int i = 0;
 252
 253         if (!edev->mutually_exclusive)
 254                 return 0;
 255
 256         for (i = 0; edev->mutually_exclusive[i]; i++) {
 257                 int weight;
 258                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 259
 260                 /* calculate the total number of bits set */
 261                 weight = hweight32(correspondants);
 262                 if (weight > 1)
 263                         return i + 1;
 264         }
 265
 266         return 0;
 267 }
 268
 269 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 270 {
 271         int i;
 272
 273         /* Find the the index of extcon cable in edev->supported_cable */
 274         for (i = 0; i < edev->max_supported; i++) {
 275                 if (edev->supported_cable[i] == id)
 276                         return i;
 277         }
 278
 279         return -EINVAL;
 280 }
 281
 282 static int get_extcon_type(unsigned int prop)
 283 {
 284         switch (prop) {
 285         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 286                 return EXTCON_TYPE_USB;
 287         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 288                 return EXTCON_TYPE_CHG;
 289         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 290                 return EXTCON_TYPE_JACK;
 291         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 292                 return EXTCON_TYPE_DISP;
 293         default:
 294                 return -EINVAL;
 295         }
 296 }
 297
 298 static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
 299 {
 300         return !!(edev->state & BIT(index));
 301 }
 302
 303 static bool is_extcon_changed(struct extcon_dev *edev, int index,
 304                                 bool new_state)
 305 {
 306         int state = !!(edev->state & BIT(index));
 307         return (state != new_state);
 308 }
 309
 310 static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
 311 {
 312         int type;
 313
 314         /* Check whether the property is supported or not. */
 315         type = get_extcon_type(prop);
 316         if (type < 0)
 317                 return false;
 318
 319         /* Check whether a specific extcon id supports the property or not. */
 320         return !!(extcon_info[id].type & type);
 321 }
 322
 323 static int is_extcon_property_capability(struct extcon_dev *edev,
 324                                 unsigned int id, int index,unsigned int prop)
 325 {
 326         struct extcon_cable *cable;
 327         int type, ret;
 328
 329         /* Check whether the property is supported or not. */
 330         type = get_extcon_type(prop);
 331         if (type < 0)
 332                 return type;
 333
 334         cable = &edev->cables[index];
 335
 336         switch (type) {
 337         case EXTCON_TYPE_USB:
 338                 ret = test_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
 339                 break;
 340         case EXTCON_TYPE_CHG:
 341                 ret = test_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
 342                 break;
 343         case EXTCON_TYPE_JACK:
 344                 ret = test_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
 345                 break;
 346         case EXTCON_TYPE_DISP:
 347                 ret = test_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
 348                 break;
 349         default:
 350                 ret = -EINVAL;
 351         }
 352
 353         return ret;
 354 }
 355
 356 static void init_property(struct extcon_dev *edev, unsigned int id, int index)
 357 {
 358         unsigned int type = extcon_info[id].type;
 359         struct extcon_cable *cable = &edev->cables[index];
 360
 361         if (EXTCON_TYPE_USB & type)
 362                 memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
 363         if (EXTCON_TYPE_CHG & type)
 364                 memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
 365         if (EXTCON_TYPE_JACK & type)
 366                 memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
 367         if (EXTCON_TYPE_DISP & type)
 368                 memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
 369 }
 370
 371 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 372                           char *buf)
 373 {
 374         int i, count = 0;
 375         struct extcon_dev *edev = dev_get_drvdata(dev);
 376
 377         if (edev->max_supported == 0)
 378                 return sprintf(buf, "%u\n", edev->state);
 379
 380         for (i = 0; i < edev->max_supported; i++) {
 381                 count += sprintf(buf + count, "%s=%d\n",
 382                                 extcon_info[edev->supported_cable[i]].name,
 383                                  !!(edev->state & (1 << i)));
 384         }
 385
 386         return count;
 387 }
 388 static DEVICE_ATTR_RO(state);
 389
 390 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 391                 char *buf)
 392 {
 393         struct extcon_dev *edev = dev_get_drvdata(dev);
 394
 395         return sprintf(buf, "%s\n", edev->name);
 396 }
 397 static DEVICE_ATTR_RO(name);
 398
 399 static ssize_t cable_name_show(struct device *dev,
 400                                struct device_attribute *attr, char *buf)
 401 {
 402         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 403                                                   attr_name);
 404         int i = cable->cable_index;
 405
 406         return sprintf(buf, "%s\n",
 407                         extcon_info[cable->edev->supported_cable[i]].name);
 408 }
 409
 410 static ssize_t cable_state_show(struct device *dev,
 411                                 struct device_attribute *attr, char *buf)
 412 {
 413         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 414                                                   attr_state);
 415
 416         int i = cable->cable_index;
 417
 418         return sprintf(buf, "%d\n",
 419                 extcon_get_state(cable->edev, cable->edev->supported_cable[i]));
 420 }
 421
 422 /**
 423  * extcon_sync()        - Synchronize the states for both the attached/detached
 424  * @edev:               the extcon device that has the cable.
 425  *
 426  * This function send a notification to synchronize the all states of a
 427  * specific external connector
 428  */
 429 int extcon_sync(struct extcon_dev *edev, unsigned int id)
 430 {
 431         char name_buf[120];
 432         char state_buf[120];
 433         char *prop_buf;
 434         char *envp[3];
 435         int env_offset = 0;
 436         int length;
 437         int index;
 438         int state;
 439         unsigned long flags;
 440
 441         if (!edev)
 442                 return -EINVAL;
 443
 444         index = find_cable_index_by_id(edev, id);
 445         if (index < 0)
 446                 return index;
 447
 448         spin_lock_irqsave(&edev->lock, flags);
 449
 450         state = !!(edev->state & BIT(index));
 451
 452         /*
 453          * Call functions in a raw notifier chain for the specific one
 454          * external connector.
 455          */
 456         raw_notifier_call_chain(&edev->nh[index], state, edev);
 457
 458         /*
 459          * Call functions in a raw notifier chain for the all supported
 460          * external connectors.
 461          */
 462         raw_notifier_call_chain(&edev->nh_all, state, edev);
 463
 464         /* This could be in interrupt handler */
 465         prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 466         if (!prop_buf) {
 467                 /* Unlock early before uevent */
 468                 spin_unlock_irqrestore(&edev->lock, flags);
 469
 470                 dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 471                 kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 472
 473                 return -ENOMEM;
 474         }
 475
 476         length = name_show(&edev->dev, NULL, prop_buf);
 477         if (length > 0) {
 478                 if (prop_buf[length - 1] == '\n')
 479                         prop_buf[length - 1] = 0;
 480                 snprintf(name_buf, sizeof(name_buf), "NAME=%s", prop_buf);
 481                 envp[env_offset++] = name_buf;
 482         }
 483
 484         length = state_show(&edev->dev, NULL, prop_buf);
 485         if (length > 0) {
 486                 if (prop_buf[length - 1] == '\n')
 487                         prop_buf[length - 1] = 0;
 488                 snprintf(state_buf, sizeof(state_buf), "STATE=%s", prop_buf);
 489                 envp[env_offset++] = state_buf;
 490         }
 491         envp[env_offset] = NULL;
 492
 493         /* Unlock early before uevent */
 494         spin_unlock_irqrestore(&edev->lock, flags);
 495         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 496         free_page((unsigned long)prop_buf);
 497
 498         return 0;
 499 }
 500 EXPORT_SYMBOL_GPL(extcon_sync);
 501
 502 /**
 503  * extcon_get_state() - Get the state of a external connector.
 504  * @edev:       the extcon device that has the cable.
 505  * @id:         the unique id of each external connector in extcon enumeration.
 506  */
 507 int extcon_get_state(struct extcon_dev *edev, const unsigned int id)
 508 {
 509         int index, state;
 510         unsigned long flags;
 511
 512         if (!edev)
 513                 return -EINVAL;
 514
 515         index = find_cable_index_by_id(edev, id);
 516         if (index < 0)
 517                 return index;
 518
 519         spin_lock_irqsave(&edev->lock, flags);
 520         state = is_extcon_attached(edev, index);
 521         spin_unlock_irqrestore(&edev->lock, flags);
 522
 523         return state;
 524 }
 525 EXPORT_SYMBOL_GPL(extcon_get_state);
 526
 527 /**
 528  * extcon_set_state() - Set the state of a external connector.
 529  *                      without a notification.
 530  * @edev:               the extcon device that has the cable.
 531  * @id:                 the unique id of each external connector
 532  *                      in extcon enumeration.
 533  * @state:              the new cable status. The default semantics is
 534  *                      true: attached / false: detached.
 535  *
 536  * This function only set the state of a external connector without
 537  * a notification. To synchronize the data of a external connector,
 538  * use extcon_set_state_sync() and extcon_sync().
 539  */
 540 int extcon_set_state(struct extcon_dev *edev, unsigned int id,
 541                                 bool cable_state)
 542 {
 543         unsigned long flags;
 544         int index, ret = 0;
 545
 546         if (!edev)
 547                 return -EINVAL;
 548
 549         index = find_cable_index_by_id(edev, id);
 550         if (index < 0)
 551                 return index;
 552
 553         spin_lock_irqsave(&edev->lock, flags);
 554
 555         /* Check whether the external connector's state is changed. */
 556         if (!is_extcon_changed(edev, index, cable_state))
 557                 goto out;
 558
 559         if (check_mutually_exclusive(edev,
 560                 (edev->state & ~BIT(index)) | (cable_state & BIT(index)))) {
 561                 ret = -EPERM;
 562                 goto out;
 563         }
 564
 565         /*
 566          * Initialize the value of extcon property before setting
 567          * the detached state for an external connector.
 568          */
 569         if (!cable_state)
 570                 init_property(edev, id, index);
 571
 572         /* Update the state for a external connector. */
 573         if (cable_state)
 574                 edev->state |= BIT(index);
 575         else
 576                 edev->state &= ~(BIT(index));
 577 out:
 578         spin_unlock_irqrestore(&edev->lock, flags);
 579
 580         return ret;
 581 }
 582 EXPORT_SYMBOL_GPL(extcon_set_state);
 583
 584 /**
 585  * extcon_set_state_sync() - Set the state of a external connector
 586  *                      with a notification.
 587  * @edev:               the extcon device that has the cable.
 588  * @id:                 the unique id of each external connector
 589  *                      in extcon enumeration.
 590  * @state:              the new cable status. The default semantics is
 591  *                      true: attached / false: detached.
 592  *
 593  * This function set the state of external connector and synchronize the data
 594  * by usning a notification.
 595  */
 596 int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id,
 597                                 bool cable_state)
 598 {
 599         int ret, index;
 600         unsigned long flags;
 601
 602         index = find_cable_index_by_id(edev, id);
 603         if (index < 0)
 604                 return index;
 605
 606         /* Check whether the external connector's state is changed. */
 607         spin_lock_irqsave(&edev->lock, flags);
 608         ret = is_extcon_changed(edev, index, cable_state);
 609         spin_unlock_irqrestore(&edev->lock, flags);
 610         if (!ret)
 611                 return 0;
 612
 613         ret = extcon_set_state(edev, id, cable_state);
 614         if (ret < 0)
 615                 return ret;
 616
 617         return extcon_sync(edev, id);
 618 }
 619 EXPORT_SYMBOL_GPL(extcon_set_state_sync);
 620
 621 /**
 622  * extcon_get_property() - Get the property value of a specific cable.
 623  * @edev:               the extcon device that has the cable.
 624  * @id:                 the unique id of each external connector
 625  *                      in extcon enumeration.
 626  * @prop:               the property id among enum extcon_property.
 627  * @prop_val:           the pointer which store the value of property.
 628  *
 629  * When getting the property value of external connector, the external connector
 630  * should be attached. If detached state, function just return 0 without
 631  * property value. Also, the each property should be included in the list of
 632  * supported properties according to the type of external connectors.
 633  *
 634  * Returns 0 if success or error number if fail
 635  */
 636 int extcon_get_property(struct extcon_dev *edev, unsigned int id,
 637                                 unsigned int prop,
 638                                 union extcon_property_value *prop_val)
 639 {
 640         struct extcon_cable *cable;
 641         unsigned long flags;
 642         int index, ret = 0;
 643
 644         *prop_val = (union extcon_property_value)(0);
 645
 646         if (!edev)
 647                 return -EINVAL;
 648
 649         /* Check whether the property is supported or not */
 650         if (!is_extcon_property_supported(id, prop))
 651                 return -EINVAL;
 652
 653         /* Find the cable index of external connector by using id */
 654         index = find_cable_index_by_id(edev, id);
 655         if (index < 0)
 656                 return index;
 657
 658         spin_lock_irqsave(&edev->lock, flags);
 659
 660         /* Check whether the property is available or not. */
 661         if (!is_extcon_property_capability(edev, id, index, prop)) {
 662                 spin_unlock_irqrestore(&edev->lock, flags);
 663                 return -EPERM;
 664         }
 665
 666         /*
 667          * Check whether the external connector is attached.
 668          * If external connector is detached, the user can not
 669          * get the property value.
 670          */
 671         if (!is_extcon_attached(edev, index)) {
 672                 spin_unlock_irqrestore(&edev->lock, flags);
 673                 return 0;
 674         }
 675
 676         cable = &edev->cables[index];
 677
 678         /* Get the property value according to extcon type */
 679         switch (prop) {
 680         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 681                 *prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
 682                 break;
 683         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 684                 *prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
 685                 break;
 686         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 687                 *prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
 688                 break;
 689         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 690                 *prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
 691                 break;
 692         default:
 693                 ret = -EINVAL;
 694                 break;
 695         }
 696
 697         spin_unlock_irqrestore(&edev->lock, flags);
 698
 699         return ret;
 700 }
 701 EXPORT_SYMBOL_GPL(extcon_get_property);
 702
 703 /**
 704  * extcon_set_property() - Set the property value of a specific cable.
 705  * @edev:               the extcon device that has the cable.
 706  * @id:                 the unique id of each external connector
 707  *                      in extcon enumeration.
 708  * @prop:               the property id among enum extcon_property.
 709  * @prop_val:           the pointer including the new value of property.
 710  *
 711  * The each property should be included in the list of supported properties
 712  * according to the type of external connectors.
 713  *
 714  * Returns 0 if success or error number if fail
 715  */
 716 int extcon_set_property(struct extcon_dev *edev, unsigned int id,
 717                                 unsigned int prop,
 718                                 union extcon_property_value prop_val)
 719 {
 720         struct extcon_cable *cable;
 721         unsigned long flags;
 722         int index, ret = 0;
 723
 724         if (!edev)
 725                 return -EINVAL;
 726
 727         /* Check whether the property is supported or not */
 728         if (!is_extcon_property_supported(id, prop))
 729                 return -EINVAL;
 730
 731         /* Find the cable index of external connector by using id */
 732         index = find_cable_index_by_id(edev, id);
 733         if (index < 0)
 734                 return index;
 735
 736         spin_lock_irqsave(&edev->lock, flags);
 737
 738         /* Check whether the property is available or not. */
 739         if (!is_extcon_property_capability(edev, id, index, prop)) {
 740                 spin_unlock_irqrestore(&edev->lock, flags);
 741                 return -EPERM;
 742         }
 743
 744         cable = &edev->cables[index];
 745
 746         /* Set the property value according to extcon type */
 747         switch (prop) {
 748         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 749                 cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
 750                 break;
 751         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 752                 cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
 753                 break;
 754         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 755                 cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
 756                 break;
 757         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 758                 cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
 759                 break;
 760         default:
 761                 ret = -EINVAL;
 762                 break;
 763         }
 764
 765         spin_unlock_irqrestore(&edev->lock, flags);
 766
 767         return ret;
 768 }
 769 EXPORT_SYMBOL_GPL(extcon_set_property);
 770
 771 /**
 772  * extcon_set_property_sync() - Set the property value of a specific cable
 773                         with a notification.
 774  * @prop_val:           the pointer including the new value of property.
 775  *
 776  * When setting the property value of external connector, the external connector
 777  * should be attached. The each property should be included in the list of
 778  * supported properties according to the type of external connectors.
 779  *
 780  * Returns 0 if success or error number if fail
 781  */
 782 int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
 783                                 unsigned int prop,
 784                                 union extcon_property_value prop_val)
 785 {
 786         int ret;
 787
 788         ret = extcon_set_property(edev, id, prop, prop_val);
 789         if (ret < 0)
 790                 return ret;
 791
 792         return extcon_sync(edev, id);
 793 }
 794 EXPORT_SYMBOL_GPL(extcon_set_property_sync);
 795
 796 /**
 797  * extcon_get_property_capability() - Get the capability of property
 798  *                      of an external connector.
 799  * @edev:               the extcon device that has the cable.
 800  * @id:                 the unique id of each external connector
 801  *                      in extcon enumeration.
 802  * @prop:               the property id among enum extcon_property.
 803  *
 804  * Returns 1 if the property is available or 0 if not available.
 805  */
 806 int extcon_get_property_capability(struct extcon_dev *edev, unsigned int id,
 807                                         unsigned int prop)
 808 {
 809         int index;
 810
 811         if (!edev)
 812                 return -EINVAL;
 813
 814         /* Check whether the property is supported or not */
 815         if (!is_extcon_property_supported(id, prop))
 816                 return -EINVAL;
 817
 818         /* Find the cable index of external connector by using id */
 819         index = find_cable_index_by_id(edev, id);
 820         if (index < 0)
 821                 return index;
 822
 823         return is_extcon_property_capability(edev, id, index, prop);
 824 }
 825 EXPORT_SYMBOL_GPL(extcon_get_property_capability);
 826
 827 /**
 828  * extcon_set_property_capability() - Set the capability of a property
 829  *                      of an external connector.
 830  * @edev:               the extcon device that has the cable.
 831  * @id:                 the unique id of each external connector
 832  *                      in extcon enumeration.
 833  * @prop:               the property id among enum extcon_property.
 834  *
 835  * This function set the capability of a property for an external connector
 836  * to mark the bit in capability bitmap which mean the available state of
 837  * a property.
 838  *
 839  * Returns 0 if success or error number if fail
 840  */
 841 int extcon_set_property_capability(struct extcon_dev *edev, unsigned int id,
 842                                         unsigned int prop)
 843 {
 844         struct extcon_cable *cable;
 845         int index, type, ret = 0;
 846
 847         if (!edev)
 848                 return -EINVAL;
 849
 850         /* Check whether the property is supported or not. */
 851         if (!is_extcon_property_supported(id, prop))
 852                 return -EINVAL;
 853
 854         /* Find the cable index of external connector by using id. */
 855         index = find_cable_index_by_id(edev, id);
 856         if (index < 0)
 857                 return index;
 858
 859         type = get_extcon_type(prop);
 860         if (type < 0)
 861                 return type;
 862
 863         cable = &edev->cables[index];
 864
 865         switch (type) {
 866         case EXTCON_TYPE_USB:
 867                 __set_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
 868                 break;
 869         case EXTCON_TYPE_CHG:
 870                 __set_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
 871                 break;
 872         case EXTCON_TYPE_JACK:
 873                 __set_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
 874                 break;
 875         case EXTCON_TYPE_DISP:
 876                 __set_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
 877                 break;
 878         default:
 879                 ret = -EINVAL;
 880         }
 881
 882         return ret;
 883 }
 884 EXPORT_SYMBOL_GPL(extcon_set_property_capability);
 885
 886 /**
 887  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 888  * @extcon_name:        The extcon name provided with extcon_dev_register()
 889  */
 890 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 891 {
 892         struct extcon_dev *sd;
 893
 894         if (!extcon_name)
 895                 return ERR_PTR(-EINVAL);
 896
 897         mutex_lock(&extcon_dev_list_lock);
 898         list_for_each_entry(sd, &extcon_dev_list, entry) {
 899                 if (!strcmp(sd->name, extcon_name))
 900                         goto out;
 901         }
 902         sd = NULL;
 903 out:
 904         mutex_unlock(&extcon_dev_list_lock);
 905         return sd;
 906 }
 907 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 908
 909 /**
 910  * extcon_register_notifier() - Register a notifiee to get notified by
 911  *                              any attach status changes from the extcon.
 912  * @edev:       the extcon device that has the external connecotr.
 913  * @id:         the unique id of each external connector in extcon enumeration.
 914  * @nb:         a notifier block to be registered.
 915  *
 916  * Note that the second parameter given to the callback of nb (val) is
 917  * "old_state", not the current state. The current state can be retrieved
 918  * by looking at the third pameter (edev pointer)'s state value.
 919  */
 920 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 921                              struct notifier_block *nb)
 922 {
 923         unsigned long flags;
 924         int ret, idx = -EINVAL;
 925
 926         if (!edev || !nb)
 927                 return -EINVAL;
 928
 929         idx = find_cable_index_by_id(edev, id);
 930         if (idx < 0)
 931                 return idx;
 932
 933         spin_lock_irqsave(&edev->lock, flags);
 934         ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 935         spin_unlock_irqrestore(&edev->lock, flags);
 936
 937         return ret;
 938 }
 939 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 940
 941 /**
 942  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 943  * @edev:       the extcon device that has the external connecotr.
 944  * @id:         the unique id of each external connector in extcon enumeration.
 945  * @nb:         a notifier block to be registered.
 946  */
 947 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 948                                 struct notifier_block *nb)
 949 {
 950         unsigned long flags;
 951         int ret, idx;
 952
 953         if (!edev || !nb)
 954                 return -EINVAL;
 955
 956         idx = find_cable_index_by_id(edev, id);
 957         if (idx < 0)
 958                 return idx;
 959
 960         spin_lock_irqsave(&edev->lock, flags);
 961         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 962         spin_unlock_irqrestore(&edev->lock, flags);
 963
 964         return ret;
 965 }
 966 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 967
 968 /**
 969  * extcon_register_notifier_all() - Register a notifier block for all connectors
 970  * @edev:       the extcon device that has the external connecotr.
 971  * @nb:         a notifier block to be registered.
 972  *
 973  * This fucntion registers a notifier block in order to receive the state
 974  * change of all supported external connectors from extcon device.
 975  * And The second parameter given to the callback of nb (val) is
 976  * the current state and third parameter is the edev pointer.
 977  *
 978  * Returns 0 if success or error number if fail
 979  */
 980 int extcon_register_notifier_all(struct extcon_dev *edev,
 981                                 struct notifier_block *nb)
 982 {
 983         unsigned long flags;
 984         int ret;
 985
 986         if (!edev || !nb)
 987                 return -EINVAL;
 988
 989         spin_lock_irqsave(&edev->lock, flags);
 990         ret = raw_notifier_chain_register(&edev->nh_all, nb);
 991         spin_unlock_irqrestore(&edev->lock, flags);
 992
 993         return ret;
 994 }
 995 EXPORT_SYMBOL_GPL(extcon_register_notifier_all);
 996
 997 /**
 998  * extcon_unregister_notifier_all() - Unregister a notifier block from extcon.
 999  * @edev:       the extcon device that has the external connecotr.
1000  * @nb:         a notifier block to be registered.
1001  *
1002  * Returns 0 if success or error number if fail
1003  */
1004 int extcon_unregister_notifier_all(struct extcon_dev *edev,
1005                                 struct notifier_block *nb)
1006 {
1007         unsigned long flags;
1008         int ret;
1009
1010         if (!edev || !nb)
1011                 return -EINVAL;
1012
1013         spin_lock_irqsave(&edev->lock, flags);
1014         ret = raw_notifier_chain_unregister(&edev->nh_all, nb);
1015         spin_unlock_irqrestore(&edev->lock, flags);
1016
1017         return ret;
1018 }
1019 EXPORT_SYMBOL_GPL(extcon_unregister_notifier_all);
1020
1021 static struct attribute *extcon_attrs[] = {
1022         &dev_attr_state.attr,
1023         &dev_attr_name.attr,
1024         NULL,
1025 };
1026 ATTRIBUTE_GROUPS(extcon);
1027
1028 static int create_extcon_class(void)
1029 {
1030         if (!extcon_class) {
1031                 extcon_class = class_create(THIS_MODULE, "extcon");
1032                 if (IS_ERR(extcon_class))
1033                         return PTR_ERR(extcon_class);
1034                 extcon_class->dev_groups = extcon_groups;
1035
1036 #if defined(CONFIG_ANDROID)
1037                 switch_class = class_compat_register("switch");
1038                 if (WARN(!switch_class, "cannot allocate"))
1039                         return -ENOMEM;
1040 #endif /* CONFIG_ANDROID */
1041         }
1042
1043         return 0;
1044 }
1045
1046 static void extcon_dev_release(struct device *dev)
1047 {
1048 }
1049
1050 static const char *muex_name = "mutually_exclusive";
1051 static void dummy_sysfs_dev_release(struct device *dev)
1052 {
1053 }
1054
1055 /*
1056  * extcon_dev_allocate() - Allocate the memory of extcon device.
1057  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
1058  *                      If supported_cable is NULL, cable name related APIs
1059  *                      are disabled.
1060  *
1061  * This function allocates the memory for extcon device without allocating
1062  * memory in each extcon provider driver and initialize default setting for
1063  * extcon device.
1064  *
1065  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
1066  */
1067 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
1068 {
1069         struct extcon_dev *edev;
1070
1071         if (!supported_cable)
1072                 return ERR_PTR(-EINVAL);
1073
1074         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
1075         if (!edev)
1076                 return ERR_PTR(-ENOMEM);
1077
1078         edev->max_supported = 0;
1079         edev->supported_cable = supported_cable;
1080
1081         return edev;
1082 }
1083
1084 /*
1085  * extcon_dev_free() - Free the memory of extcon device.
1086  * @edev:       the extcon device to free
1087  */
1088 void extcon_dev_free(struct extcon_dev *edev)
1089 {
1090         kfree(edev);
1091 }
1092 EXPORT_SYMBOL_GPL(extcon_dev_free);
1093
1094 /**
1095  * extcon_dev_register() - Register a new extcon device
1096  * @edev        : the new extcon device (should be allocated before calling)
1097  *
1098  * Among the members of edev struct, please set the "user initializing data"
1099  * in any case and set the "optional callbacks" if required. However, please
1100  * do not set the values of "internal data", which are initialized by
1101  * this function.
1102  */
1103 int extcon_dev_register(struct extcon_dev *edev)
1104 {
1105         int ret, index = 0;
1106         static atomic_t edev_no = ATOMIC_INIT(-1);
1107
1108         if (!extcon_class) {
1109                 ret = create_extcon_class();
1110                 if (ret < 0)
1111                         return ret;
1112         }
1113
1114         if (!edev || !edev->supported_cable)
1115                 return -EINVAL;
1116
1117         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
1118
1119         edev->max_supported = index;
1120         if (index > SUPPORTED_CABLE_MAX) {
1121                 dev_err(&edev->dev,
1122                         "exceed the maximum number of supported cables\n");
1123                 return -EINVAL;
1124         }
1125
1126         edev->dev.class = extcon_class;
1127         edev->dev.release = extcon_dev_release;
1128
1129         edev->name = dev_name(edev->dev.parent);
1130         if (IS_ERR_OR_NULL(edev->name)) {
1131                 dev_err(&edev->dev,
1132                         "extcon device name is null\n");
1133                 return -EINVAL;
1134         }
1135         dev_set_name(&edev->dev, "extcon%lu",
1136                         (unsigned long)atomic_inc_return(&edev_no));
1137
1138         if (edev->max_supported) {
1139                 char buf[10];
1140                 char *str;
1141                 struct extcon_cable *cable;
1142
1143                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
1144                                        edev->max_supported, GFP_KERNEL);
1145                 if (!edev->cables) {
1146                         ret = -ENOMEM;
1147                         goto err_sysfs_alloc;
1148                 }
1149                 for (index = 0; index < edev->max_supported; index++) {
1150                         cable = &edev->cables[index];
1151
1152                         snprintf(buf, 10, "cable.%d", index);
1153                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
1154                                       GFP_KERNEL);
1155                         if (!str) {
1156                                 for (index--; index >= 0; index--) {
1157                                         cable = &edev->cables[index];
1158                                         kfree(cable->attr_g.name);
1159                                 }
1160                                 ret = -ENOMEM;
1161
1162                                 goto err_alloc_cables;
1163                         }
1164                         strcpy(str, buf);
1165
1166                         cable->edev = edev;
1167                         cable->cable_index = index;
1168                         cable->attrs[0] = &cable->attr_name.attr;
1169                         cable->attrs[1] = &cable->attr_state.attr;
1170                         cable->attrs[2] = NULL;
1171                         cable->attr_g.name = str;
1172                         cable->attr_g.attrs = cable->attrs;
1173
1174                         sysfs_attr_init(&cable->attr_name.attr);
1175                         cable->attr_name.attr.name = "name";
1176                         cable->attr_name.attr.mode = 0444;
1177                         cable->attr_name.show = cable_name_show;
1178
1179                         sysfs_attr_init(&cable->attr_state.attr);
1180                         cable->attr_state.attr.name = "state";
1181                         cable->attr_state.attr.mode = 0444;
1182                         cable->attr_state.show = cable_state_show;
1183                 }
1184         }
1185
1186         if (edev->max_supported && edev->mutually_exclusive) {
1187                 char buf[80];
1188                 char *name;
1189
1190                 /* Count the size of mutually_exclusive array */
1191                 for (index = 0; edev->mutually_exclusive[index]; index++)
1192                         ;
1193
1194                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
1195                                            (index + 1), GFP_KERNEL);
1196                 if (!edev->attrs_muex) {
1197                         ret = -ENOMEM;
1198                         goto err_muex;
1199                 }
1200
1201                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
1202                                              index, GFP_KERNEL);
1203                 if (!edev->d_attrs_muex) {
1204                         ret = -ENOMEM;
1205                         kfree(edev->attrs_muex);
1206                         goto err_muex;
1207                 }
1208
1209                 for (index = 0; edev->mutually_exclusive[index]; index++) {
1210                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
1211                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
1212                                        GFP_KERNEL);
1213                         if (!name) {
1214                                 for (index--; index >= 0; index--) {
1215                                         kfree(edev->d_attrs_muex[index].attr.
1216                                               name);
1217                                 }
1218                                 kfree(edev->d_attrs_muex);
1219                                 kfree(edev->attrs_muex);
1220                                 ret = -ENOMEM;
1221                                 goto err_muex;
1222                         }
1223                         strcpy(name, buf);
1224                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
1225                         edev->d_attrs_muex[index].attr.name = name;
1226                         edev->d_attrs_muex[index].attr.mode = 0000;
1227                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
1228                                                         .attr;
1229                 }
1230                 edev->attr_g_muex.name = muex_name;
1231                 edev->attr_g_muex.attrs = edev->attrs_muex;
1232
1233         }
1234
1235         if (edev->max_supported) {
1236                 edev->extcon_dev_type.groups =
1237                         kzalloc(sizeof(struct attribute_group *) *
1238                                 (edev->max_supported + 2), GFP_KERNEL);
1239                 if (!edev->extcon_dev_type.groups) {
1240                         ret = -ENOMEM;
1241                         goto err_alloc_groups;
1242                 }
1243
1244                 edev->extcon_dev_type.name = dev_name(&edev->dev);
1245                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
1246
1247                 for (index = 0; index < edev->max_supported; index++)
1248                         edev->extcon_dev_type.groups[index] =
1249                                 &edev->cables[index].attr_g;
1250                 if (edev->mutually_exclusive)
1251                         edev->extcon_dev_type.groups[index] =
1252                                 &edev->attr_g_muex;
1253
1254                 edev->dev.type = &edev->extcon_dev_type;
1255         }
1256
1257         ret = device_register(&edev->dev);
1258         if (ret) {
1259                 put_device(&edev->dev);
1260                 goto err_dev;
1261         }
1262 #if defined(CONFIG_ANDROID)
1263         if (switch_class)
1264                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
1265 #endif /* CONFIG_ANDROID */
1266
1267         spin_lock_init(&edev->lock);
1268
1269         edev->nh = devm_kzalloc(&edev->dev,
1270                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
1271         if (!edev->nh) {
1272                 ret = -ENOMEM;
1273                 goto err_dev;
1274         }
1275
1276         for (index = 0; index < edev->max_supported; index++)
1277                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
1278
1279         RAW_INIT_NOTIFIER_HEAD(&edev->nh_all);
1280
1281         dev_set_drvdata(&edev->dev, edev);
1282         edev->state = 0;
1283
1284         mutex_lock(&extcon_dev_list_lock);
1285         list_add(&edev->entry, &extcon_dev_list);
1286         mutex_unlock(&extcon_dev_list_lock);
1287
1288         return 0;
1289
1290 err_dev:
1291         if (edev->max_supported)
1292                 kfree(edev->extcon_dev_type.groups);
1293 err_alloc_groups:
1294         if (edev->max_supported && edev->mutually_exclusive) {
1295                 for (index = 0; edev->mutually_exclusive[index]; index++)
1296                         kfree(edev->d_attrs_muex[index].attr.name);
1297                 kfree(edev->d_attrs_muex);
1298                 kfree(edev->attrs_muex);
1299         }
1300 err_muex:
1301         for (index = 0; index < edev->max_supported; index++)
1302                 kfree(edev->cables[index].attr_g.name);
1303 err_alloc_cables:
1304         if (edev->max_supported)
1305                 kfree(edev->cables);
1306 err_sysfs_alloc:
1307         return ret;
1308 }
1309 EXPORT_SYMBOL_GPL(extcon_dev_register);
1310
1311 /**
1312  * extcon_dev_unregister() - Unregister the extcon device.
1313  * @edev:       the extcon device instance to be unregistered.
1314  *
1315  * Note that this does not call kfree(edev) because edev was not allocated
1316  * by this class.
1317  */
1318 void extcon_dev_unregister(struct extcon_dev *edev)
1319 {
1320         int index;
1321
1322         if (!edev)
1323                 return;
1324
1325         mutex_lock(&extcon_dev_list_lock);
1326         list_del(&edev->entry);
1327         mutex_unlock(&extcon_dev_list_lock);
1328
1329         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
1330                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
1331                                 dev_name(&edev->dev));
1332                 return;
1333         }
1334
1335         device_unregister(&edev->dev);
1336
1337         if (edev->mutually_exclusive && edev->max_supported) {
1338                 for (index = 0; edev->mutually_exclusive[index];
1339                                 index++)
1340                         kfree(edev->d_attrs_muex[index].attr.name);
1341                 kfree(edev->d_attrs_muex);
1342                 kfree(edev->attrs_muex);
1343         }
1344
1345         for (index = 0; index < edev->max_supported; index++)
1346                 kfree(edev->cables[index].attr_g.name);
1347
1348         if (edev->max_supported) {
1349                 kfree(edev->extcon_dev_type.groups);
1350                 kfree(edev->cables);
1351         }
1352
1353 #if defined(CONFIG_ANDROID)
1354         if (switch_class)
1355                 class_compat_remove_link(switch_class, &edev->dev, NULL);
1356 #endif
1357         put_device(&edev->dev);
1358 }
1359 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
1360
1361 #ifdef CONFIG_OF
1362 /*
1363  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1364  * @dev - instance to the given device
1365  * @index - index into list of extcon_dev
1366  *
1367  * return the instance of extcon device
1368  */
1369 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1370 {
1371         struct device_node *node;
1372         struct extcon_dev *edev;
1373
1374         if (!dev)
1375                 return ERR_PTR(-EINVAL);
1376
1377         if (!dev->of_node) {
1378                 dev_dbg(dev, "device does not have a device node entry\n");
1379                 return ERR_PTR(-EINVAL);
1380         }
1381
1382         node = of_parse_phandle(dev->of_node, "extcon", index);
1383         if (!node) {
1384                 dev_dbg(dev, "failed to get phandle in %s node\n",
1385                         dev->of_node->full_name);
1386                 return ERR_PTR(-ENODEV);
1387         }
1388
1389         mutex_lock(&extcon_dev_list_lock);
1390         list_for_each_entry(edev, &extcon_dev_list, entry) {
1391                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1392                         mutex_unlock(&extcon_dev_list_lock);
1393                         of_node_put(node);
1394                         return edev;
1395                 }
1396         }
1397         mutex_unlock(&extcon_dev_list_lock);
1398         of_node_put(node);
1399
1400         return ERR_PTR(-EPROBE_DEFER);
1401 }
1402 #else
1403 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1404 {
1405         return ERR_PTR(-ENOSYS);
1406 }
1407 #endif /* CONFIG_OF */
1408 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1409
1410 /**
1411  * extcon_get_edev_name() - Get the name of the extcon device.
1412  * @edev:       the extcon device
1413  */
1414 const char *extcon_get_edev_name(struct extcon_dev *edev)
1415 {
1416         return !edev ? NULL : edev->name;
1417 }
1418
1419 static int __init extcon_class_init(void)
1420 {
1421         return create_extcon_class();
1422 }
1423 module_init(extcon_class_init);
1424
1425 static void __exit extcon_class_exit(void)
1426 {
1427 #if defined(CONFIG_ANDROID)
1428         class_compat_unregister(switch_class);
1429 #endif
1430         class_destroy(extcon_class);
1431 }
1432 module_exit(extcon_class_exit);
1433
1434 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1435 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1436 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1437 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1438 MODULE_DESCRIPTION("External connector (extcon) class driver");
1439 MODULE_LICENSE("GPL");