drivers/extcon/extcon.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * drivers/extcon/extcon.c - External Connector (extcon) framework.
   4  *
   5  * Copyright (C) 2015 Samsung Electronics
   6  * Author: Chanwoo Choi <cw00.choi@samsung.com>
   7  *
   8  * Copyright (C) 2012 Samsung Electronics
   9  * Author: Donggeun Kim <dg77.kim@samsung.com>
  10  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
  11  *
  12  * based on android/drivers/switch/switch_class.c
  13  * Copyright (C) 2008 Google, Inc.
  14  * Author: Mike Lockwood <lockwood@android.com>
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/types.h>
  19 #include <linux/init.h>
  20 #include <linux/device.h>
  21 #include <linux/fs.h>
  22 #include <linux/err.h>
  23 #include <linux/of.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysfs.h>
  26
  27 #include "extcon.h"
  28
  29 #define SUPPORTED_CABLE_MAX     32
  30
  31 static const struct __extcon_info {
  32         unsigned int type;
  33         unsigned int id;
  34         const char *name;
  35
  36 } extcon_info[] = {
  37         [EXTCON_NONE] = {
  38                 .type = EXTCON_TYPE_MISC,
  39                 .id = EXTCON_NONE,
  40                 .name = "NONE",
  41         },
  42
  43         /* USB external connector */
  44         [EXTCON_USB] = {
  45                 .type = EXTCON_TYPE_USB,
  46                 .id = EXTCON_USB,
  47                 .name = "USB",
  48         },
  49         [EXTCON_USB_HOST] = {
  50                 .type = EXTCON_TYPE_USB,
  51                 .id = EXTCON_USB_HOST,
  52                 .name = "USB-HOST",
  53         },
  54
  55         /* Charging external connector */
  56         [EXTCON_CHG_USB_SDP] = {
  57                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  58                 .id = EXTCON_CHG_USB_SDP,
  59                 .name = "SDP",
  60         },
  61         [EXTCON_CHG_USB_DCP] = {
  62                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  63                 .id = EXTCON_CHG_USB_DCP,
  64                 .name = "DCP",
  65         },
  66         [EXTCON_CHG_USB_CDP] = {
  67                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  68                 .id = EXTCON_CHG_USB_CDP,
  69                 .name = "CDP",
  70         },
  71         [EXTCON_CHG_USB_ACA] = {
  72                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  73                 .id = EXTCON_CHG_USB_ACA,
  74                 .name = "ACA",
  75         },
  76         [EXTCON_CHG_USB_FAST] = {
  77                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  78                 .id = EXTCON_CHG_USB_FAST,
  79                 .name = "FAST-CHARGER",
  80         },
  81         [EXTCON_CHG_USB_SLOW] = {
  82                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  83                 .id = EXTCON_CHG_USB_SLOW,
  84                 .name = "SLOW-CHARGER",
  85         },
  86         [EXTCON_CHG_WPT] = {
  87                 .type = EXTCON_TYPE_CHG,
  88                 .id = EXTCON_CHG_WPT,
  89                 .name = "WPT",
  90         },
  91         [EXTCON_CHG_USB_PD] = {
  92                 .type = EXTCON_TYPE_CHG | EXTCON_TYPE_USB,
  93                 .id = EXTCON_CHG_USB_PD,
  94                 .name = "PD",
  95         },
  96
  97         /* Jack external connector */
  98         [EXTCON_JACK_MICROPHONE] = {
  99                 .type = EXTCON_TYPE_JACK,
 100                 .id = EXTCON_JACK_MICROPHONE,
 101                 .name = "MICROPHONE",
 102         },
 103         [EXTCON_JACK_HEADPHONE] = {
 104                 .type = EXTCON_TYPE_JACK,
 105                 .id = EXTCON_JACK_HEADPHONE,
 106                 .name = "HEADPHONE",
 107         },
 108         [EXTCON_JACK_LINE_IN] = {
 109                 .type = EXTCON_TYPE_JACK,
 110                 .id = EXTCON_JACK_LINE_IN,
 111                 .name = "LINE-IN",
 112         },
 113         [EXTCON_JACK_LINE_OUT] = {
 114                 .type = EXTCON_TYPE_JACK,
 115                 .id = EXTCON_JACK_LINE_OUT,
 116                 .name = "LINE-OUT",
 117         },
 118         [EXTCON_JACK_VIDEO_IN] = {
 119                 .type = EXTCON_TYPE_JACK,
 120                 .id = EXTCON_JACK_VIDEO_IN,
 121                 .name = "VIDEO-IN",
 122         },
 123         [EXTCON_JACK_VIDEO_OUT] = {
 124                 .type = EXTCON_TYPE_JACK,
 125                 .id = EXTCON_JACK_VIDEO_OUT,
 126                 .name = "VIDEO-OUT",
 127         },
 128         [EXTCON_JACK_SPDIF_IN] = {
 129                 .type = EXTCON_TYPE_JACK,
 130                 .id = EXTCON_JACK_SPDIF_IN,
 131                 .name = "SPDIF-IN",
 132         },
 133         [EXTCON_JACK_SPDIF_OUT] = {
 134                 .type = EXTCON_TYPE_JACK,
 135                 .id = EXTCON_JACK_SPDIF_OUT,
 136                 .name = "SPDIF-OUT",
 137         },
 138
 139         /* Display external connector */
 140         [EXTCON_DISP_HDMI] = {
 141                 .type = EXTCON_TYPE_DISP,
 142                 .id = EXTCON_DISP_HDMI,
 143                 .name = "HDMI",
 144         },
 145         [EXTCON_DISP_MHL] = {
 146                 .type = EXTCON_TYPE_DISP,
 147                 .id = EXTCON_DISP_MHL,
 148                 .name = "MHL",
 149         },
 150         [EXTCON_DISP_DVI] = {
 151                 .type = EXTCON_TYPE_DISP,
 152                 .id = EXTCON_DISP_DVI,
 153                 .name = "DVI",
 154         },
 155         [EXTCON_DISP_VGA] = {
 156                 .type = EXTCON_TYPE_DISP,
 157                 .id = EXTCON_DISP_VGA,
 158                 .name = "VGA",
 159         },
 160         [EXTCON_DISP_DP] = {
 161                 .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
 162                 .id = EXTCON_DISP_DP,
 163                 .name = "DP",
 164         },
 165         [EXTCON_DISP_HMD] = {
 166                 .type = EXTCON_TYPE_DISP | EXTCON_TYPE_USB,
 167                 .id = EXTCON_DISP_HMD,
 168                 .name = "HMD",
 169         },
 170
 171         /* Miscellaneous external connector */
 172         [EXTCON_DOCK] = {
 173                 .type = EXTCON_TYPE_MISC,
 174                 .id = EXTCON_DOCK,
 175                 .name = "DOCK",
 176         },
 177         [EXTCON_JIG] = {
 178                 .type = EXTCON_TYPE_MISC,
 179                 .id = EXTCON_JIG,
 180                 .name = "JIG",
 181         },
 182         [EXTCON_MECHANICAL] = {
 183                 .type = EXTCON_TYPE_MISC,
 184                 .id = EXTCON_MECHANICAL,
 185                 .name = "MECHANICAL",
 186         },
 187
 188         { /* sentinel */ }
 189 };
 190
 191 /**
 192  * struct extcon_cable - An internal data for an external connector.
 193  * @edev:               the extcon device
 194  * @cable_index:        the index of this cable in the edev
 195  * @attr_g:             the attribute group for the cable
 196  * @attr_name:          "name" sysfs entry
 197  * @attr_state:         "state" sysfs entry
 198  * @attrs:              the array pointing to attr_name and attr_state for attr_g
 199  */
 200 struct extcon_cable {
 201         struct extcon_dev *edev;
 202         int cable_index;
 203
 204         struct attribute_group attr_g;
 205         struct device_attribute attr_name;
 206         struct device_attribute attr_state;
 207
 208         struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
 209
 210         union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
 211         union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
 212         union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
 213         union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];
 214
 215         unsigned long usb_bits[BITS_TO_LONGS(EXTCON_PROP_USB_CNT)];
 216         unsigned long chg_bits[BITS_TO_LONGS(EXTCON_PROP_CHG_CNT)];
 217         unsigned long jack_bits[BITS_TO_LONGS(EXTCON_PROP_JACK_CNT)];
 218         unsigned long disp_bits[BITS_TO_LONGS(EXTCON_PROP_DISP_CNT)];
 219 };
 220
 221 static struct class *extcon_class;
 222
 223 static LIST_HEAD(extcon_dev_list);
 224 static DEFINE_MUTEX(extcon_dev_list_lock);
 225
 226 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
 227 {
 228         int i = 0;
 229
 230         if (!edev->mutually_exclusive)
 231                 return 0;
 232
 233         for (i = 0; edev->mutually_exclusive[i]; i++) {
 234                 int weight;
 235                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 236
 237                 /* calculate the total number of bits set */
 238                 weight = hweight32(correspondants);
 239                 if (weight > 1)
 240                         return i + 1;
 241         }
 242
 243         return 0;
 244 }
 245
 246 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 247 {
 248         int i;
 249
 250         /* Find the the index of extcon cable in edev->supported_cable */
 251         for (i = 0; i < edev->max_supported; i++) {
 252                 if (edev->supported_cable[i] == id)
 253                         return i;
 254         }
 255
 256         return -EINVAL;
 257 }
 258
 259 static int get_extcon_type(unsigned int prop)
 260 {
 261         switch (prop) {
 262         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 263                 return EXTCON_TYPE_USB;
 264         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 265                 return EXTCON_TYPE_CHG;
 266         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 267                 return EXTCON_TYPE_JACK;
 268         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 269                 return EXTCON_TYPE_DISP;
 270         default:
 271                 return -EINVAL;
 272         }
 273 }
 274
 275 static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
 276 {
 277         return !!(edev->state & BIT(index));
 278 }
 279
 280 static bool is_extcon_changed(struct extcon_dev *edev, int index,
 281                                 bool new_state)
 282 {
 283         int state = !!(edev->state & BIT(index));
 284         return (state != new_state);
 285 }
 286
 287 static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
 288 {
 289         int type;
 290
 291         /* Check whether the property is supported or not. */
 292         type = get_extcon_type(prop);
 293         if (type < 0)
 294                 return false;
 295
 296         /* Check whether a specific extcon id supports the property or not. */
 297         return !!(extcon_info[id].type & type);
 298 }
 299
 300 static int is_extcon_property_capability(struct extcon_dev *edev,
 301                                 unsigned int id, int index,unsigned int prop)
 302 {
 303         struct extcon_cable *cable;
 304         int type, ret;
 305
 306         /* Check whether the property is supported or not. */
 307         type = get_extcon_type(prop);
 308         if (type < 0)
 309                 return type;
 310
 311         cable = &edev->cables[index];
 312
 313         switch (type) {
 314         case EXTCON_TYPE_USB:
 315                 ret = test_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
 316                 break;
 317         case EXTCON_TYPE_CHG:
 318                 ret = test_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
 319                 break;
 320         case EXTCON_TYPE_JACK:
 321                 ret = test_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
 322                 break;
 323         case EXTCON_TYPE_DISP:
 324                 ret = test_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
 325                 break;
 326         default:
 327                 ret = -EINVAL;
 328         }
 329
 330         return ret;
 331 }
 332
 333 static void init_property(struct extcon_dev *edev, unsigned int id, int index)
 334 {
 335         unsigned int type = extcon_info[id].type;
 336         struct extcon_cable *cable = &edev->cables[index];
 337
 338         if (EXTCON_TYPE_USB & type)
 339                 memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
 340         if (EXTCON_TYPE_CHG & type)
 341                 memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
 342         if (EXTCON_TYPE_JACK & type)
 343                 memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
 344         if (EXTCON_TYPE_DISP & type)
 345                 memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
 346 }
 347
 348 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 349                           char *buf)
 350 {
 351         int i, count = 0;
 352         struct extcon_dev *edev = dev_get_drvdata(dev);
 353
 354         if (edev->max_supported == 0)
 355                 return sprintf(buf, "%u\n", edev->state);
 356
 357         for (i = 0; i < edev->max_supported; i++) {
 358                 count += sprintf(buf + count, "%s=%d\n",
 359                                 extcon_info[edev->supported_cable[i]].name,
 360                                  !!(edev->state & BIT(i)));
 361         }
 362
 363         return count;
 364 }
 365 static DEVICE_ATTR_RO(state);
 366
 367 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 368                 char *buf)
 369 {
 370         struct extcon_dev *edev = dev_get_drvdata(dev);
 371
 372         return sprintf(buf, "%s\n", edev->name);
 373 }
 374 static DEVICE_ATTR_RO(name);
 375
 376 static ssize_t cable_name_show(struct device *dev,
 377                                struct device_attribute *attr, char *buf)
 378 {
 379         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 380                                                   attr_name);
 381         int i = cable->cable_index;
 382
 383         return sprintf(buf, "%s\n",
 384                         extcon_info[cable->edev->supported_cable[i]].name);
 385 }
 386
 387 static ssize_t cable_state_show(struct device *dev,
 388                                 struct device_attribute *attr, char *buf)
 389 {
 390         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 391                                                   attr_state);
 392
 393         int i = cable->cable_index;
 394
 395         return sprintf(buf, "%d\n",
 396                 extcon_get_state(cable->edev, cable->edev->supported_cable[i]));
 397 }
 398
 399 /**
 400  * extcon_sync() - Synchronize the state for an external connector.
 401  * @edev:       the extcon device
 402  * @id:         the unique id indicating an external connector
 403  *
 404  * Note that this function send a notification in order to synchronize
 405  * the state and property of an external connector.
 406  *
 407  * Returns 0 if success or error number if fail.
 408  */
 409 int extcon_sync(struct extcon_dev *edev, unsigned int id)
 410 {
 411         char name_buf[120];
 412         char state_buf[120];
 413         char *prop_buf;
 414         char *envp[3];
 415         int env_offset = 0;
 416         int length;
 417         int index;
 418         int state;
 419         unsigned long flags;
 420
 421         if (!edev)
 422                 return -EINVAL;
 423
 424         index = find_cable_index_by_id(edev, id);
 425         if (index < 0)
 426                 return index;
 427
 428         spin_lock_irqsave(&edev->lock, flags);
 429         state = !!(edev->state & BIT(index));
 430         spin_unlock_irqrestore(&edev->lock, flags);
 431
 432         /*
 433          * Call functions in a raw notifier chain for the specific one
 434          * external connector.
 435          */
 436         raw_notifier_call_chain(&edev->nh[index], state, edev);
 437
 438         /*
 439          * Call functions in a raw notifier chain for the all supported
 440          * external connectors.
 441          */
 442         raw_notifier_call_chain(&edev->nh_all, state, edev);
 443
 444         spin_lock_irqsave(&edev->lock, flags);
 445         /* This could be in interrupt handler */
 446         prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 447         if (!prop_buf) {
 448                 /* Unlock early before uevent */
 449                 spin_unlock_irqrestore(&edev->lock, flags);
 450
 451                 dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 452                 kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 453
 454                 return -ENOMEM;
 455         }
 456
 457         length = name_show(&edev->dev, NULL, prop_buf);
 458         if (length > 0) {
 459                 if (prop_buf[length - 1] == '\n')
 460                         prop_buf[length - 1] = 0;
 461                 snprintf(name_buf, sizeof(name_buf), "NAME=%s", prop_buf);
 462                 envp[env_offset++] = name_buf;
 463         }
 464
 465         length = state_show(&edev->dev, NULL, prop_buf);
 466         if (length > 0) {
 467                 if (prop_buf[length - 1] == '\n')
 468                         prop_buf[length - 1] = 0;
 469                 snprintf(state_buf, sizeof(state_buf), "STATE=%s", prop_buf);
 470                 envp[env_offset++] = state_buf;
 471         }
 472         envp[env_offset] = NULL;
 473
 474         /* Unlock early before uevent */
 475         spin_unlock_irqrestore(&edev->lock, flags);
 476         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 477         free_page((unsigned long)prop_buf);
 478
 479         return 0;
 480 }
 481 EXPORT_SYMBOL_GPL(extcon_sync);
 482
 483 /**
 484  * extcon_get_state() - Get the state of an external connector.
 485  * @edev:       the extcon device
 486  * @id:         the unique id indicating an external connector
 487  *
 488  * Returns 0 if success or error number if fail.
 489  */
 490 int extcon_get_state(struct extcon_dev *edev, const unsigned int id)
 491 {
 492         int index, state;
 493         unsigned long flags;
 494
 495         if (!edev)
 496                 return -EINVAL;
 497
 498         index = find_cable_index_by_id(edev, id);
 499         if (index < 0)
 500                 return index;
 501
 502         spin_lock_irqsave(&edev->lock, flags);
 503         state = is_extcon_attached(edev, index);
 504         spin_unlock_irqrestore(&edev->lock, flags);
 505
 506         return state;
 507 }
 508 EXPORT_SYMBOL_GPL(extcon_get_state);
 509
 510 /**
 511  * extcon_set_state() - Set the state of an external connector.
 512  * @edev:       the extcon device
 513  * @id:         the unique id indicating an external connector
 514  * @state:      the new state of an external connector.
 515  *              the default semantics is true: attached / false: detached.
 516  *
 517  * Note that this function set the state of an external connector without
 518  * a notification. To synchronize the state of an external connector,
 519  * have to use extcon_set_state_sync() and extcon_sync().
 520  *
 521  * Returns 0 if success or error number if fail.
 522  */
 523 int extcon_set_state(struct extcon_dev *edev, unsigned int id, bool state)
 524 {
 525         unsigned long flags;
 526         int index, ret = 0;
 527
 528         if (!edev)
 529                 return -EINVAL;
 530
 531         index = find_cable_index_by_id(edev, id);
 532         if (index < 0)
 533                 return index;
 534
 535         spin_lock_irqsave(&edev->lock, flags);
 536
 537         /* Check whether the external connector's state is changed. */
 538         if (!is_extcon_changed(edev, index, state))
 539                 goto out;
 540
 541         if (check_mutually_exclusive(edev,
 542                 (edev->state & ~BIT(index)) | (state & BIT(index)))) {
 543                 ret = -EPERM;
 544                 goto out;
 545         }
 546
 547         /*
 548          * Initialize the value of extcon property before setting
 549          * the detached state for an external connector.
 550          */
 551         if (!state)
 552                 init_property(edev, id, index);
 553
 554         /* Update the state for an external connector. */
 555         if (state)
 556                 edev->state |= BIT(index);
 557         else
 558                 edev->state &= ~(BIT(index));
 559 out:
 560         spin_unlock_irqrestore(&edev->lock, flags);
 561
 562         return ret;
 563 }
 564 EXPORT_SYMBOL_GPL(extcon_set_state);
 565
 566 /**
 567  * extcon_set_state_sync() - Set the state of an external connector with sync.
 568  * @edev:       the extcon device
 569  * @id:         the unique id indicating an external connector
 570  * @state:      the new state of external connector.
 571  *              the default semantics is true: attached / false: detached.
 572  *
 573  * Note that this function set the state of external connector
 574  * and synchronize the state by sending a notification.
 575  *
 576  * Returns 0 if success or error number if fail.
 577  */
 578 int extcon_set_state_sync(struct extcon_dev *edev, unsigned int id, bool state)
 579 {
 580         int ret;
 581
 582         ret = extcon_set_state(edev, id, state);
 583         if (ret < 0)
 584                 return ret;
 585
 586         return extcon_sync(edev, id);
 587 }
 588 EXPORT_SYMBOL_GPL(extcon_set_state_sync);
 589
 590 /**
 591  * extcon_get_property() - Get the property value of an external connector.
 592  * @edev:       the extcon device
 593  * @id:         the unique id indicating an external connector
 594  * @prop:       the property id indicating an extcon property
 595  * @prop_val:   the pointer which store the value of extcon property
 596  *
 597  * Note that when getting the property value of external connector,
 598  * the external connector should be attached. If detached state, function
 599  * return 0 without property value. Also, the each property should be
 600  * included in the list of supported properties according to extcon type.
 601  *
 602  * Returns 0 if success or error number if fail.
 603  */
 604 int extcon_get_property(struct extcon_dev *edev, unsigned int id,
 605                                 unsigned int prop,
 606                                 union extcon_property_value *prop_val)
 607 {
 608         struct extcon_cable *cable;
 609         unsigned long flags;
 610         int index, ret = 0;
 611
 612         *prop_val = (union extcon_property_value){0};
 613
 614         if (!edev)
 615                 return -EINVAL;
 616
 617         /* Check whether the property is supported or not */
 618         if (!is_extcon_property_supported(id, prop))
 619                 return -EINVAL;
 620
 621         /* Find the cable index of external connector by using id */
 622         index = find_cable_index_by_id(edev, id);
 623         if (index < 0)
 624                 return index;
 625
 626         spin_lock_irqsave(&edev->lock, flags);
 627
 628         /* Check whether the property is available or not. */
 629         if (!is_extcon_property_capability(edev, id, index, prop)) {
 630                 spin_unlock_irqrestore(&edev->lock, flags);
 631                 return -EPERM;
 632         }
 633
 634         /*
 635          * Check whether the external connector is attached.
 636          * If external connector is detached, the user can not
 637          * get the property value.
 638          */
 639         if (!is_extcon_attached(edev, index)) {
 640                 spin_unlock_irqrestore(&edev->lock, flags);
 641                 return 0;
 642         }
 643
 644         cable = &edev->cables[index];
 645
 646         /* Get the property value according to extcon type */
 647         switch (prop) {
 648         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 649                 *prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
 650                 break;
 651         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 652                 *prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
 653                 break;
 654         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 655                 *prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
 656                 break;
 657         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 658                 *prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
 659                 break;
 660         default:
 661                 ret = -EINVAL;
 662                 break;
 663         }
 664
 665         spin_unlock_irqrestore(&edev->lock, flags);
 666
 667         return ret;
 668 }
 669 EXPORT_SYMBOL_GPL(extcon_get_property);
 670
 671 /**
 672  * extcon_set_property() - Set the property value of an external connector.
 673  * @edev:       the extcon device
 674  * @id:         the unique id indicating an external connector
 675  * @prop:       the property id indicating an extcon property
 676  * @prop_val:   the pointer including the new value of extcon property
 677  *
 678  * Note that each property should be included in the list of supported
 679  * properties according to the extcon type.
 680  *
 681  * Returns 0 if success or error number if fail.
 682  */
 683 int extcon_set_property(struct extcon_dev *edev, unsigned int id,
 684                                 unsigned int prop,
 685                                 union extcon_property_value prop_val)
 686 {
 687         struct extcon_cable *cable;
 688         unsigned long flags;
 689         int index, ret = 0;
 690
 691         if (!edev)
 692                 return -EINVAL;
 693
 694         /* Check whether the property is supported or not */
 695         if (!is_extcon_property_supported(id, prop))
 696                 return -EINVAL;
 697
 698         /* Find the cable index of external connector by using id */
 699         index = find_cable_index_by_id(edev, id);
 700         if (index < 0)
 701                 return index;
 702
 703         spin_lock_irqsave(&edev->lock, flags);
 704
 705         /* Check whether the property is available or not. */
 706         if (!is_extcon_property_capability(edev, id, index, prop)) {
 707                 spin_unlock_irqrestore(&edev->lock, flags);
 708                 return -EPERM;
 709         }
 710
 711         cable = &edev->cables[index];
 712
 713         /* Set the property value according to extcon type */
 714         switch (prop) {
 715         case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
 716                 cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
 717                 break;
 718         case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
 719                 cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
 720                 break;
 721         case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
 722                 cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
 723                 break;
 724         case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
 725                 cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
 726                 break;
 727         default:
 728                 ret = -EINVAL;
 729                 break;
 730         }
 731
 732         spin_unlock_irqrestore(&edev->lock, flags);
 733
 734         return ret;
 735 }
 736 EXPORT_SYMBOL_GPL(extcon_set_property);
 737
 738 /**
 739  * extcon_set_property_sync() - Set property of an external connector with sync.
 740  * @edev:       the extcon device
 741  * @id:         the unique id indicating an external connector
 742  * @prop:       the property id indicating an extcon property
 743  * @prop_val:   the pointer including the new value of extcon property
 744  *
 745  * Note that when setting the property value of external connector,
 746  * the external connector should be attached. The each property should
 747  * be included in the list of supported properties according to extcon type.
 748  *
 749  * Returns 0 if success or error number if fail.
 750  */
 751 int extcon_set_property_sync(struct extcon_dev *edev, unsigned int id,
 752                                 unsigned int prop,
 753                                 union extcon_property_value prop_val)
 754 {
 755         int ret;
 756
 757         ret = extcon_set_property(edev, id, prop, prop_val);
 758         if (ret < 0)
 759                 return ret;
 760
 761         return extcon_sync(edev, id);
 762 }
 763 EXPORT_SYMBOL_GPL(extcon_set_property_sync);
 764
 765 /**
 766  * extcon_get_property_capability() - Get the capability of the property
 767  *                                      for an external connector.
 768  * @edev:       the extcon device
 769  * @id:         the unique id indicating an external connector
 770  * @prop:       the property id indicating an extcon property
 771  *
 772  * Returns 1 if the property is available or 0 if not available.
 773  */
 774 int extcon_get_property_capability(struct extcon_dev *edev, unsigned int id,
 775                                         unsigned int prop)
 776 {
 777         int index;
 778
 779         if (!edev)
 780                 return -EINVAL;
 781
 782         /* Check whether the property is supported or not */
 783         if (!is_extcon_property_supported(id, prop))
 784                 return -EINVAL;
 785
 786         /* Find the cable index of external connector by using id */
 787         index = find_cable_index_by_id(edev, id);
 788         if (index < 0)
 789                 return index;
 790
 791         return is_extcon_property_capability(edev, id, index, prop);
 792 }
 793 EXPORT_SYMBOL_GPL(extcon_get_property_capability);
 794
 795 /**
 796  * extcon_set_property_capability() - Set the capability of the property
 797  *                                      for an external connector.
 798  * @edev:       the extcon device
 799  * @id:         the unique id indicating an external connector
 800  * @prop:       the property id indicating an extcon property
 801  *
 802  * Note that this function set the capability of the property
 803  * for an external connector in order to mark the bit in capability
 804  * bitmap which mean the available state of the property.
 805  *
 806  * Returns 0 if success or error number if fail.
 807  */
 808 int extcon_set_property_capability(struct extcon_dev *edev, unsigned int id,
 809                                         unsigned int prop)
 810 {
 811         struct extcon_cable *cable;
 812         int index, type, ret = 0;
 813
 814         if (!edev)
 815                 return -EINVAL;
 816
 817         /* Check whether the property is supported or not. */
 818         if (!is_extcon_property_supported(id, prop))
 819                 return -EINVAL;
 820
 821         /* Find the cable index of external connector by using id. */
 822         index = find_cable_index_by_id(edev, id);
 823         if (index < 0)
 824                 return index;
 825
 826         type = get_extcon_type(prop);
 827         if (type < 0)
 828                 return type;
 829
 830         cable = &edev->cables[index];
 831
 832         switch (type) {
 833         case EXTCON_TYPE_USB:
 834                 __set_bit(prop - EXTCON_PROP_USB_MIN, cable->usb_bits);
 835                 break;
 836         case EXTCON_TYPE_CHG:
 837                 __set_bit(prop - EXTCON_PROP_CHG_MIN, cable->chg_bits);
 838                 break;
 839         case EXTCON_TYPE_JACK:
 840                 __set_bit(prop - EXTCON_PROP_JACK_MIN, cable->jack_bits);
 841                 break;
 842         case EXTCON_TYPE_DISP:
 843                 __set_bit(prop - EXTCON_PROP_DISP_MIN, cable->disp_bits);
 844                 break;
 845         default:
 846                 ret = -EINVAL;
 847         }
 848
 849         return ret;
 850 }
 851 EXPORT_SYMBOL_GPL(extcon_set_property_capability);
 852
 853 /**
 854  * extcon_get_extcon_dev() - Get the extcon device instance from the name.
 855  * @extcon_name:        the extcon name provided with extcon_dev_register()
 856  *
 857  * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
 858  * NOTE: This function returns -EPROBE_DEFER so it may only be called from
 859  * probe() functions.
 860  */
 861 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 862 {
 863         struct extcon_dev *sd;
 864
 865         if (!extcon_name)
 866                 return ERR_PTR(-EINVAL);
 867
 868         mutex_lock(&extcon_dev_list_lock);
 869         list_for_each_entry(sd, &extcon_dev_list, entry) {
 870                 if (!strcmp(sd->name, extcon_name))
 871                         goto out;
 872         }
 873         sd = ERR_PTR(-EPROBE_DEFER);
 874 out:
 875         mutex_unlock(&extcon_dev_list_lock);
 876         return sd;
 877 }
 878 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 879
 880 /**
 881  * extcon_register_notifier() - Register a notifier block to get notified by
 882  *                              any state changes from the extcon.
 883  * @edev:       the extcon device
 884  * @id:         the unique id indicating an external connector
 885  * @nb:         a notifier block to be registered
 886  *
 887  * Note that the second parameter given to the callback of nb (val) is
 888  * the current state of an external connector and the third pameter
 889  * is the pointer of extcon device.
 890  *
 891  * Returns 0 if success or error number if fail.
 892  */
 893 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 894                              struct notifier_block *nb)
 895 {
 896         unsigned long flags;
 897         int ret, idx;
 898
 899         if (!edev || !nb)
 900                 return -EINVAL;
 901
 902         idx = find_cable_index_by_id(edev, id);
 903         if (idx < 0)
 904                 return idx;
 905
 906         spin_lock_irqsave(&edev->lock, flags);
 907         ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 908         spin_unlock_irqrestore(&edev->lock, flags);
 909
 910         return ret;
 911 }
 912 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 913
 914 /**
 915  * extcon_unregister_notifier() - Unregister a notifier block from the extcon.
 916  * @edev:       the extcon device
 917  * @id:         the unique id indicating an external connector
 918  * @nb:         a notifier block to be registered
 919  *
 920  * Returns 0 if success or error number if fail.
 921  */
 922 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 923                                 struct notifier_block *nb)
 924 {
 925         unsigned long flags;
 926         int ret, idx;
 927
 928         if (!edev || !nb)
 929                 return -EINVAL;
 930
 931         idx = find_cable_index_by_id(edev, id);
 932         if (idx < 0)
 933                 return idx;
 934
 935         spin_lock_irqsave(&edev->lock, flags);
 936         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 937         spin_unlock_irqrestore(&edev->lock, flags);
 938
 939         return ret;
 940 }
 941 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 942
 943 /**
 944  * extcon_register_notifier_all() - Register a notifier block for all connectors.
 945  * @edev:       the extcon device
 946  * @nb:         a notifier block to be registered
 947  *
 948  * Note that this function registers a notifier block in order to receive
 949  * the state change of all supported external connectors from extcon device.
 950  * And the second parameter given to the callback of nb (val) is
 951  * the current state and the third pameter is the pointer of extcon device.
 952  *
 953  * Returns 0 if success or error number if fail.
 954  */
 955 int extcon_register_notifier_all(struct extcon_dev *edev,
 956                                 struct notifier_block *nb)
 957 {
 958         unsigned long flags;
 959         int ret;
 960
 961         if (!edev || !nb)
 962                 return -EINVAL;
 963
 964         spin_lock_irqsave(&edev->lock, flags);
 965         ret = raw_notifier_chain_register(&edev->nh_all, nb);
 966         spin_unlock_irqrestore(&edev->lock, flags);
 967
 968         return ret;
 969 }
 970 EXPORT_SYMBOL_GPL(extcon_register_notifier_all);
 971
 972 /**
 973  * extcon_unregister_notifier_all() - Unregister a notifier block from extcon.
 974  * @edev:       the extcon device
 975  * @nb:         a notifier block to be registered
 976  *
 977  * Returns 0 if success or error number if fail.
 978  */
 979 int extcon_unregister_notifier_all(struct extcon_dev *edev,
 980                                 struct notifier_block *nb)
 981 {
 982         unsigned long flags;
 983         int ret;
 984
 985         if (!edev || !nb)
 986                 return -EINVAL;
 987
 988         spin_lock_irqsave(&edev->lock, flags);
 989         ret = raw_notifier_chain_unregister(&edev->nh_all, nb);
 990         spin_unlock_irqrestore(&edev->lock, flags);
 991
 992         return ret;
 993 }
 994 EXPORT_SYMBOL_GPL(extcon_unregister_notifier_all);
 995
 996 static struct attribute *extcon_attrs[] = {
 997         &dev_attr_state.attr,
 998         &dev_attr_name.attr,
 999         NULL,
1000 };
1001 ATTRIBUTE_GROUPS(extcon);
1002
1003 static int create_extcon_class(void)
1004 {
1005         if (!extcon_class) {
1006                 extcon_class = class_create(THIS_MODULE, "extcon");
1007                 if (IS_ERR(extcon_class))
1008                         return PTR_ERR(extcon_class);
1009                 extcon_class->dev_groups = extcon_groups;
1010         }
1011
1012         return 0;
1013 }
1014
1015 static void extcon_dev_release(struct device *dev)
1016 {
1017 }
1018
1019 static const char *muex_name = "mutually_exclusive";
1020 static void dummy_sysfs_dev_release(struct device *dev)
1021 {
1022 }
1023
1024 /*
1025  * extcon_dev_allocate() - Allocate the memory of extcon device.
1026  * @supported_cable:    the array of the supported external connectors
1027  *                      ending with EXTCON_NONE.
1028  *
1029  * Note that this function allocates the memory for extcon device
1030  * and initialize default setting for the extcon device.
1031  *
1032  * Returns the pointer memory of allocated extcon_dev if success
1033  * or ERR_PTR(err) if fail.
1034  */
1035 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
1036 {
1037         struct extcon_dev *edev;
1038
1039         if (!supported_cable)
1040                 return ERR_PTR(-EINVAL);
1041
1042         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
1043         if (!edev)
1044                 return ERR_PTR(-ENOMEM);
1045
1046         edev->max_supported = 0;
1047         edev->supported_cable = supported_cable;
1048
1049         return edev;
1050 }
1051
1052 /*
1053  * extcon_dev_free() - Free the memory of extcon device.
1054  * @edev:       the extcon device
1055  */
1056 void extcon_dev_free(struct extcon_dev *edev)
1057 {
1058         kfree(edev);
1059 }
1060 EXPORT_SYMBOL_GPL(extcon_dev_free);
1061
1062 /**
1063  * extcon_dev_register() - Register an new extcon device
1064  * @edev:       the extcon device to be registered
1065  *
1066  * Among the members of edev struct, please set the "user initializing data"
1067  * do not set the values of "internal data", which are initialized by
1068  * this function.
1069  *
1070  * Note that before calling this funciton, have to allocate the memory
1071  * of an extcon device by using the extcon_dev_allocate(). And the extcon
1072  * dev should include the supported_cable information.
1073  *
1074  * Returns 0 if success or error number if fail.
1075  */
1076 int extcon_dev_register(struct extcon_dev *edev)
1077 {
1078         int ret, index = 0;
1079         static atomic_t edev_no = ATOMIC_INIT(-1);
1080
1081         if (!extcon_class) {
1082                 ret = create_extcon_class();
1083                 if (ret < 0)
1084                         return ret;
1085         }
1086
1087         if (!edev || !edev->supported_cable)
1088                 return -EINVAL;
1089
1090         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
1091
1092         edev->max_supported = index;
1093         if (index > SUPPORTED_CABLE_MAX) {
1094                 dev_err(&edev->dev,
1095                         "exceed the maximum number of supported cables\n");
1096                 return -EINVAL;
1097         }
1098
1099         edev->dev.class = extcon_class;
1100         edev->dev.release = extcon_dev_release;
1101
1102         edev->name = dev_name(edev->dev.parent);
1103         if (IS_ERR_OR_NULL(edev->name)) {
1104                 dev_err(&edev->dev,
1105                         "extcon device name is null\n");
1106                 return -EINVAL;
1107         }
1108         dev_set_name(&edev->dev, "extcon%lu",
1109                         (unsigned long)atomic_inc_return(&edev_no));
1110
1111         if (edev->max_supported) {
1112                 char *str;
1113                 struct extcon_cable *cable;
1114
1115                 edev->cables = kcalloc(edev->max_supported,
1116                                        sizeof(struct extcon_cable),
1117                                        GFP_KERNEL);
1118                 if (!edev->cables) {
1119                         ret = -ENOMEM;
1120                         goto err_sysfs_alloc;
1121                 }
1122                 for (index = 0; index < edev->max_supported; index++) {
1123                         cable = &edev->cables[index];
1124
1125                         str = kasprintf(GFP_KERNEL, "cable.%d", index);
1126                         if (!str) {
1127                                 for (index--; index >= 0; index--) {
1128                                         cable = &edev->cables[index];
1129                                         kfree(cable->attr_g.name);
1130                                 }
1131                                 ret = -ENOMEM;
1132
1133                                 goto err_alloc_cables;
1134                         }
1135
1136                         cable->edev = edev;
1137                         cable->cable_index = index;
1138                         cable->attrs[0] = &cable->attr_name.attr;
1139                         cable->attrs[1] = &cable->attr_state.attr;
1140                         cable->attrs[2] = NULL;
1141                         cable->attr_g.name = str;
1142                         cable->attr_g.attrs = cable->attrs;
1143
1144                         sysfs_attr_init(&cable->attr_name.attr);
1145                         cable->attr_name.attr.name = "name";
1146                         cable->attr_name.attr.mode = 0444;
1147                         cable->attr_name.show = cable_name_show;
1148
1149                         sysfs_attr_init(&cable->attr_state.attr);
1150                         cable->attr_state.attr.name = "state";
1151                         cable->attr_state.attr.mode = 0444;
1152                         cable->attr_state.show = cable_state_show;
1153                 }
1154         }
1155
1156         if (edev->max_supported && edev->mutually_exclusive) {
1157                 char *name;
1158
1159                 /* Count the size of mutually_exclusive array */
1160                 for (index = 0; edev->mutually_exclusive[index]; index++)
1161                         ;
1162
1163                 edev->attrs_muex = kcalloc(index + 1,
1164                                            sizeof(struct attribute *),
1165                                            GFP_KERNEL);
1166                 if (!edev->attrs_muex) {
1167                         ret = -ENOMEM;
1168                         goto err_muex;
1169                 }
1170
1171                 edev->d_attrs_muex = kcalloc(index,
1172                                              sizeof(struct device_attribute),
1173                                              GFP_KERNEL);
1174                 if (!edev->d_attrs_muex) {
1175                         ret = -ENOMEM;
1176                         kfree(edev->attrs_muex);
1177                         goto err_muex;
1178                 }
1179
1180                 for (index = 0; edev->mutually_exclusive[index]; index++) {
1181                         name = kasprintf(GFP_KERNEL, "0x%x",
1182                                          edev->mutually_exclusive[index]);
1183                         if (!name) {
1184                                 for (index--; index >= 0; index--) {
1185                                         kfree(edev->d_attrs_muex[index].attr.
1186                                               name);
1187                                 }
1188                                 kfree(edev->d_attrs_muex);
1189                                 kfree(edev->attrs_muex);
1190                                 ret = -ENOMEM;
1191                                 goto err_muex;
1192                         }
1193                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
1194                         edev->d_attrs_muex[index].attr.name = name;
1195                         edev->d_attrs_muex[index].attr.mode = 0000;
1196                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
1197                                                         .attr;
1198                 }
1199                 edev->attr_g_muex.name = muex_name;
1200                 edev->attr_g_muex.attrs = edev->attrs_muex;
1201
1202         }
1203
1204         if (edev->max_supported) {
1205                 edev->extcon_dev_type.groups =
1206                         kcalloc(edev->max_supported + 2,
1207                                 sizeof(struct attribute_group *),
1208                                 GFP_KERNEL);
1209                 if (!edev->extcon_dev_type.groups) {
1210                         ret = -ENOMEM;
1211                         goto err_alloc_groups;
1212                 }
1213
1214                 edev->extcon_dev_type.name = dev_name(&edev->dev);
1215                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
1216
1217                 for (index = 0; index < edev->max_supported; index++)
1218                         edev->extcon_dev_type.groups[index] =
1219                                 &edev->cables[index].attr_g;
1220                 if (edev->mutually_exclusive)
1221                         edev->extcon_dev_type.groups[index] =
1222                                 &edev->attr_g_muex;
1223
1224                 edev->dev.type = &edev->extcon_dev_type;
1225         }
1226
1227         spin_lock_init(&edev->lock);
1228         if (edev->max_supported) {
1229                 edev->nh = kcalloc(edev->max_supported, sizeof(*edev->nh),
1230                                 GFP_KERNEL);
1231                 if (!edev->nh) {
1232                         ret = -ENOMEM;
1233                         goto err_alloc_nh;
1234                 }
1235         }
1236
1237         for (index = 0; index < edev->max_supported; index++)
1238                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
1239
1240         RAW_INIT_NOTIFIER_HEAD(&edev->nh_all);
1241
1242         dev_set_drvdata(&edev->dev, edev);
1243         edev->state = 0;
1244
1245         ret = device_register(&edev->dev);
1246         if (ret) {
1247                 put_device(&edev->dev);
1248                 goto err_dev;
1249         }
1250
1251         mutex_lock(&extcon_dev_list_lock);
1252         list_add(&edev->entry, &extcon_dev_list);
1253         mutex_unlock(&extcon_dev_list_lock);
1254
1255         return 0;
1256
1257 err_dev:
1258         if (edev->max_supported)
1259                 kfree(edev->nh);
1260 err_alloc_nh:
1261         if (edev->max_supported)
1262                 kfree(edev->extcon_dev_type.groups);
1263 err_alloc_groups:
1264         if (edev->max_supported && edev->mutually_exclusive) {
1265                 for (index = 0; edev->mutually_exclusive[index]; index++)
1266                         kfree(edev->d_attrs_muex[index].attr.name);
1267                 kfree(edev->d_attrs_muex);
1268                 kfree(edev->attrs_muex);
1269         }
1270 err_muex:
1271         for (index = 0; index < edev->max_supported; index++)
1272                 kfree(edev->cables[index].attr_g.name);
1273 err_alloc_cables:
1274         if (edev->max_supported)
1275                 kfree(edev->cables);
1276 err_sysfs_alloc:
1277         return ret;
1278 }
1279 EXPORT_SYMBOL_GPL(extcon_dev_register);
1280
1281 /**
1282  * extcon_dev_unregister() - Unregister the extcon device.
1283  * @edev:       the extcon device to be unregistered.
1284  *
1285  * Note that this does not call kfree(edev) because edev was not allocated
1286  * by this class.
1287  */
1288 void extcon_dev_unregister(struct extcon_dev *edev)
1289 {
1290         int index;
1291
1292         if (!edev)
1293                 return;
1294
1295         mutex_lock(&extcon_dev_list_lock);
1296         list_del(&edev->entry);
1297         mutex_unlock(&extcon_dev_list_lock);
1298
1299         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
1300                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
1301                                 dev_name(&edev->dev));
1302                 return;
1303         }
1304
1305         device_unregister(&edev->dev);
1306
1307         if (edev->mutually_exclusive && edev->max_supported) {
1308                 for (index = 0; edev->mutually_exclusive[index];
1309                                 index++)
1310                         kfree(edev->d_attrs_muex[index].attr.name);
1311                 kfree(edev->d_attrs_muex);
1312                 kfree(edev->attrs_muex);
1313         }
1314
1315         for (index = 0; index < edev->max_supported; index++)
1316                 kfree(edev->cables[index].attr_g.name);
1317
1318         if (edev->max_supported) {
1319                 kfree(edev->extcon_dev_type.groups);
1320                 kfree(edev->cables);
1321                 kfree(edev->nh);
1322         }
1323
1324         put_device(&edev->dev);
1325 }
1326 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
1327
1328 #ifdef CONFIG_OF
1329
1330 /*
1331  * extcon_find_edev_by_node - Find the extcon device from devicetree.
1332  * @node        : OF node identifying edev
1333  *
1334  * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
1335  */
1336 struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
1337 {
1338         struct extcon_dev *edev;
1339
1340         mutex_lock(&extcon_dev_list_lock);
1341         list_for_each_entry(edev, &extcon_dev_list, entry)
1342                 if (edev->dev.parent && edev->dev.parent->of_node == node)
1343                         goto out;
1344         edev = ERR_PTR(-EPROBE_DEFER);
1345 out:
1346         mutex_unlock(&extcon_dev_list_lock);
1347
1348         return edev;
1349 }
1350
1351 /*
1352  * extcon_get_edev_by_phandle - Get the extcon device from devicetree.
1353  * @dev         : the instance to the given device
1354  * @index       : the index into list of extcon_dev
1355  *
1356  * Return the pointer of extcon device if success or ERR_PTR(err) if fail.
1357  */
1358 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1359 {
1360         struct device_node *node;
1361         struct extcon_dev *edev;
1362
1363         if (!dev)
1364                 return ERR_PTR(-EINVAL);
1365
1366         if (!dev->of_node) {
1367                 dev_dbg(dev, "device does not have a device node entry\n");
1368                 return ERR_PTR(-EINVAL);
1369         }
1370
1371         node = of_parse_phandle(dev->of_node, "extcon", index);
1372         if (!node) {
1373                 dev_dbg(dev, "failed to get phandle in %pOF node\n",
1374                         dev->of_node);
1375                 return ERR_PTR(-ENODEV);
1376         }
1377
1378         edev = extcon_find_edev_by_node(node);
1379         of_node_put(node);
1380
1381         return edev;
1382 }
1383
1384 #else
1385
1386 struct extcon_dev *extcon_find_edev_by_node(struct device_node *node)
1387 {
1388         return ERR_PTR(-ENOSYS);
1389 }
1390
1391 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1392 {
1393         return ERR_PTR(-ENOSYS);
1394 }
1395
1396 #endif /* CONFIG_OF */
1397
1398 EXPORT_SYMBOL_GPL(extcon_find_edev_by_node);
1399 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1400
1401 /**
1402  * extcon_get_edev_name() - Get the name of the extcon device.
1403  * @edev:       the extcon device
1404  */
1405 const char *extcon_get_edev_name(struct extcon_dev *edev)
1406 {
1407         return !edev ? NULL : edev->name;
1408 }
1409 EXPORT_SYMBOL_GPL(extcon_get_edev_name);
1410
1411 static int __init extcon_class_init(void)
1412 {
1413         return create_extcon_class();
1414 }
1415 module_init(extcon_class_init);
1416
1417 static void __exit extcon_class_exit(void)
1418 {
1419         class_destroy(extcon_class);
1420 }
1421 module_exit(extcon_class_exit);
1422
1423 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1424 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1425 MODULE_DESCRIPTION("External Connector (extcon) framework");
1426 MODULE_LICENSE("GPL v2");