drivers/extcon/extcon.c

   1 /*
   2  *  drivers/extcon/extcon.c - External Connector (extcon) framework.
   3  *
   4  *  External connector (extcon) class driver
   5  *
   6  * Copyright (C) 2015 Samsung Electronics
   7  * Author: Chanwoo Choi <cw00.choi@samsung.com>
   8  *
   9  * Copyright (C) 2012 Samsung Electronics
  10  * Author: Donggeun Kim <dg77.kim@samsung.com>
  11  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
  12  *
  13  * based on android/drivers/switch/switch_class.c
  14  * Copyright (C) 2008 Google, Inc.
  15  * Author: Mike Lockwood <lockwood@android.com>
  16  *
  17  * This software is licensed under the terms of the GNU General Public
  18  * License version 2, as published by the Free Software Foundation, and
  19  * may be copied, distributed, and modified under those terms.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/types.h>
  29 #include <linux/init.h>
  30 #include <linux/device.h>
  31 #include <linux/fs.h>
  32 #include <linux/err.h>
  33 #include <linux/extcon.h>
  34 #include <linux/of.h>
  35 #include <linux/slab.h>
  36 #include <linux/sysfs.h>
  37
  38 #define SUPPORTED_CABLE_MAX     32
  39 #define CABLE_NAME_MAX          30
  40
  41 static const char *extcon_name[] =  {
  42         [EXTCON_NONE]                   = "NONE",
  43
  44         /* USB external connector */
  45         [EXTCON_USB]                    = "USB",
  46         [EXTCON_USB_HOST]               = "USB-HOST",
  47
  48         /* Charging external connector */
  49         [EXTCON_CHG_USB_SDP]            = "SDP",
  50         [EXTCON_CHG_USB_DCP]            = "DCP",
  51         [EXTCON_CHG_USB_CDP]            = "CDP",
  52         [EXTCON_CHG_USB_ACA]            = "ACA",
  53         [EXTCON_CHG_USB_FAST]           = "FAST-CHARGER",
  54         [EXTCON_CHG_USB_SLOW]           = "SLOW-CHARGER",
  55
  56         /* Jack external connector */
  57         [EXTCON_JACK_MICROPHONE]        = "MICROPHONE",
  58         [EXTCON_JACK_HEADPHONE]         = "HEADPHONE",
  59         [EXTCON_JACK_LINE_IN]           = "LINE-IN",
  60         [EXTCON_JACK_LINE_OUT]          = "LINE-OUT",
  61         [EXTCON_JACK_VIDEO_IN]          = "VIDEO-IN",
  62         [EXTCON_JACK_VIDEO_OUT]         = "VIDEO-OUT",
  63         [EXTCON_JACK_SPDIF_IN]          = "SPDIF-IN",
  64         [EXTCON_JACK_SPDIF_OUT]         = "SPDIF-OUT",
  65
  66         /* Display external connector */
  67         [EXTCON_DISP_HDMI]              = "HDMI",
  68         [EXTCON_DISP_MHL]               = "MHL",
  69         [EXTCON_DISP_DVI]               = "DVI",
  70         [EXTCON_DISP_VGA]               = "VGA",
  71
  72         /* Miscellaneous external connector */
  73         [EXTCON_DOCK]                   = "DOCK",
  74         [EXTCON_JIG]                    = "JIG",
  75         [EXTCON_MECHANICAL]             = "MECHANICAL",
  76
  77         NULL,
  78 };
  79
  80 /**
  81  * struct extcon_cable - An internal data for each cable of extcon device.
  82  * @edev:               The extcon device
  83  * @cable_index:        Index of this cable in the edev
  84  * @attr_g:             Attribute group for the cable
  85  * @attr_name:          "name" sysfs entry
  86  * @attr_state:         "state" sysfs entry
  87  * @attrs:              Array pointing to attr_name and attr_state for attr_g
  88  */
  89 struct extcon_cable {
  90         struct extcon_dev *edev;
  91         int cable_index;
  92
  93         struct attribute_group attr_g;
  94         struct device_attribute attr_name;
  95         struct device_attribute attr_state;
  96
  97         struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
  98 };
  99
 100 static struct class *extcon_class;
 101 #if defined(CONFIG_ANDROID)
 102 static struct class_compat *switch_class;
 103 #endif /* CONFIG_ANDROID */
 104
 105 static LIST_HEAD(extcon_dev_list);
 106 static DEFINE_MUTEX(extcon_dev_list_lock);
 107
 108 /**
 109  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
 110  *                            condition.
 111  * @edev:       the extcon device
 112  * @new_state:  new cable attach status for @edev
 113  *
 114  * Returns 0 if nothing violates. Returns the index + 1 for the first
 115  * violated condition.
 116  */
 117 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
 118 {
 119         int i = 0;
 120
 121         if (!edev->mutually_exclusive)
 122                 return 0;
 123
 124         for (i = 0; edev->mutually_exclusive[i]; i++) {
 125                 int weight;
 126                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 127
 128                 /* calculate the total number of bits set */
 129                 weight = hweight32(correspondants);
 130                 if (weight > 1)
 131                         return i + 1;
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 138 {
 139         int i;
 140
 141         /* Find the the index of extcon cable in edev->supported_cable */
 142         for (i = 0; i < edev->max_supported; i++) {
 143                 if (edev->supported_cable[i] == id)
 144                         return i;
 145         }
 146
 147         return -EINVAL;
 148 }
 149
 150 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 151 {
 152         if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
 153                 *attached = ((new >> idx) & 0x1) ? true : false;
 154                 return true;
 155         }
 156
 157         return false;
 158 }
 159
 160 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 161                           char *buf)
 162 {
 163         int i, count = 0;
 164         struct extcon_dev *edev = dev_get_drvdata(dev);
 165
 166         if (edev->max_supported == 0)
 167                 return sprintf(buf, "%u\n", edev->state);
 168
 169         for (i = 0; i < edev->max_supported; i++) {
 170                 count += sprintf(buf + count, "%s=%d\n",
 171                                 extcon_name[edev->supported_cable[i]],
 172                                  !!(edev->state & (1 << i)));
 173         }
 174
 175         return count;
 176 }
 177
 178 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 179                            const char *buf, size_t count)
 180 {
 181         u32 state;
 182         ssize_t ret = 0;
 183         struct extcon_dev *edev = dev_get_drvdata(dev);
 184
 185         ret = sscanf(buf, "0x%x", &state);
 186         if (ret == 0)
 187                 ret = -EINVAL;
 188         else
 189                 ret = extcon_set_state(edev, state);
 190
 191         if (ret < 0)
 192                 return ret;
 193
 194         return count;
 195 }
 196 static DEVICE_ATTR_RW(state);
 197
 198 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 199                 char *buf)
 200 {
 201         struct extcon_dev *edev = dev_get_drvdata(dev);
 202
 203         return sprintf(buf, "%s\n", edev->name);
 204 }
 205 static DEVICE_ATTR_RO(name);
 206
 207 static ssize_t cable_name_show(struct device *dev,
 208                                struct device_attribute *attr, char *buf)
 209 {
 210         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 211                                                   attr_name);
 212         int i = cable->cable_index;
 213
 214         return sprintf(buf, "%s\n",
 215                         extcon_name[cable->edev->supported_cable[i]]);
 216 }
 217
 218 static ssize_t cable_state_show(struct device *dev,
 219                                 struct device_attribute *attr, char *buf)
 220 {
 221         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 222                                                   attr_state);
 223
 224         int i = cable->cable_index;
 225
 226         return sprintf(buf, "%d\n",
 227                        extcon_get_cable_state_(cable->edev,
 228                                                cable->edev->supported_cable[i]));
 229 }
 230
 231 /**
 232  * extcon_update_state() - Update the cable attach states of the extcon device
 233  *                         only for the masked bits.
 234  * @edev:       the extcon device
 235  * @mask:       the bit mask to designate updated bits.
 236  * @state:      new cable attach status for @edev
 237  *
 238  * Changing the state sends uevent with environment variable containing
 239  * the name of extcon device (envp[0]) and the state output (envp[1]).
 240  * Tizen uses this format for extcon device to get events from ports.
 241  * Android uses this format as well.
 242  *
 243  * Note that the notifier provides which bits are changed in the state
 244  * variable with the val parameter (second) to the callback.
 245  */
 246 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 247 {
 248         char name_buf[120];
 249         char state_buf[120];
 250         char *prop_buf;
 251         char *envp[3];
 252         int env_offset = 0;
 253         int length;
 254         int index;
 255         unsigned long flags;
 256         bool attached;
 257
 258         if (!edev)
 259                 return -EINVAL;
 260
 261         spin_lock_irqsave(&edev->lock, flags);
 262
 263         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 264                 u32 old_state;
 265
 266                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 267                                                    (state & mask))) {
 268                         spin_unlock_irqrestore(&edev->lock, flags);
 269                         return -EPERM;
 270                 }
 271
 272                 old_state = edev->state;
 273                 edev->state &= ~mask;
 274                 edev->state |= state & mask;
 275
 276                 for (index = 0; index < edev->max_supported; index++) {
 277                         if (is_extcon_changed(old_state, edev->state, index,
 278                                               &attached))
 279                                 raw_notifier_call_chain(&edev->nh[index],
 280                                                         attached, edev);
 281                 }
 282
 283                 /* This could be in interrupt handler */
 284                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 285                 if (prop_buf) {
 286                         length = name_show(&edev->dev, NULL, prop_buf);
 287                         if (length > 0) {
 288                                 if (prop_buf[length - 1] == '\n')
 289                                         prop_buf[length - 1] = 0;
 290                                 snprintf(name_buf, sizeof(name_buf),
 291                                         "NAME=%s", prop_buf);
 292                                 envp[env_offset++] = name_buf;
 293                         }
 294                         length = state_show(&edev->dev, NULL, prop_buf);
 295                         if (length > 0) {
 296                                 if (prop_buf[length - 1] == '\n')
 297                                         prop_buf[length - 1] = 0;
 298                                 snprintf(state_buf, sizeof(state_buf),
 299                                         "STATE=%s", prop_buf);
 300                                 envp[env_offset++] = state_buf;
 301                         }
 302                         envp[env_offset] = NULL;
 303                         /* Unlock early before uevent */
 304                         spin_unlock_irqrestore(&edev->lock, flags);
 305
 306                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 307                         free_page((unsigned long)prop_buf);
 308                 } else {
 309                         /* Unlock early before uevent */
 310                         spin_unlock_irqrestore(&edev->lock, flags);
 311
 312                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 313                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 314                 }
 315         } else {
 316                 /* No changes */
 317                 spin_unlock_irqrestore(&edev->lock, flags);
 318         }
 319
 320         return 0;
 321 }
 322 EXPORT_SYMBOL_GPL(extcon_update_state);
 323
 324 /**
 325  * extcon_set_state() - Set the cable attach states of the extcon device.
 326  * @edev:       the extcon device
 327  * @state:      new cable attach status for @edev
 328  *
 329  * Note that notifier provides which bits are changed in the state
 330  * variable with the val parameter (second) to the callback.
 331  */
 332 int extcon_set_state(struct extcon_dev *edev, u32 state)
 333 {
 334         if (!edev)
 335                 return -EINVAL;
 336
 337         return extcon_update_state(edev, 0xffffffff, state);
 338 }
 339 EXPORT_SYMBOL_GPL(extcon_set_state);
 340
 341 /**
 342  * extcon_get_cable_state_() - Get the status of a specific cable.
 343  * @edev:       the extcon device that has the cable.
 344  * @id:         the unique id of each external connector in extcon enumeration.
 345  */
 346 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 347 {
 348         int index;
 349
 350         if (!edev)
 351                 return -EINVAL;
 352
 353         index = find_cable_index_by_id(edev, id);
 354         if (index < 0)
 355                 return index;
 356
 357         if (edev->max_supported && edev->max_supported <= index)
 358                 return -EINVAL;
 359
 360         return !!(edev->state & (1 << index));
 361 }
 362 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 363
 364 /**
 365  * extcon_set_cable_state_() - Set the status of a specific cable.
 366  * @edev:               the extcon device that has the cable.
 367  * @id:                 the unique id of each external connector
 368  *                      in extcon enumeration.
 369  * @state:              the new cable status. The default semantics is
 370  *                      true: attached / false: detached.
 371  */
 372 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 373                                 bool cable_state)
 374 {
 375         u32 state;
 376         int index;
 377
 378         if (!edev)
 379                 return -EINVAL;
 380
 381         index = find_cable_index_by_id(edev, id);
 382         if (index < 0)
 383                 return index;
 384
 385         if (edev->max_supported && edev->max_supported <= index)
 386                 return -EINVAL;
 387
 388         state = cable_state ? (1 << index) : 0;
 389         return extcon_update_state(edev, 1 << index, state);
 390 }
 391 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 392
 393 /**
 394  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 395  * @extcon_name:        The extcon name provided with extcon_dev_register()
 396  */
 397 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 398 {
 399         struct extcon_dev *sd;
 400
 401         if (!extcon_name)
 402                 return ERR_PTR(-EINVAL);
 403
 404         mutex_lock(&extcon_dev_list_lock);
 405         list_for_each_entry(sd, &extcon_dev_list, entry) {
 406                 if (!strcmp(sd->name, extcon_name))
 407                         goto out;
 408         }
 409         sd = NULL;
 410 out:
 411         mutex_unlock(&extcon_dev_list_lock);
 412         return sd;
 413 }
 414 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 415
 416 /**
 417  * extcon_register_notifier() - Register a notifiee to get notified by
 418  *                              any attach status changes from the extcon.
 419  * @edev:       the extcon device that has the external connecotr.
 420  * @id:         the unique id of each external connector in extcon enumeration.
 421  * @nb:         a notifier block to be registered.
 422  *
 423  * Note that the second parameter given to the callback of nb (val) is
 424  * "old_state", not the current state. The current state can be retrieved
 425  * by looking at the third pameter (edev pointer)'s state value.
 426  */
 427 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 428                              struct notifier_block *nb)
 429 {
 430         unsigned long flags;
 431         int ret, idx;
 432
 433         if (!nb)
 434                 return -EINVAL;
 435
 436         if (edev) {
 437                 idx = find_cable_index_by_id(edev, id);
 438                 if (idx < 0)
 439                         return idx;
 440
 441                 spin_lock_irqsave(&edev->lock, flags);
 442                 ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 443                 spin_unlock_irqrestore(&edev->lock, flags);
 444         } else {
 445                 struct extcon_dev *extd;
 446
 447                 mutex_lock(&extcon_dev_list_lock);
 448                 list_for_each_entry(extd, &extcon_dev_list, entry) {
 449                         idx = find_cable_index_by_id(extd, id);
 450                         if (idx >= 0)
 451                                 break;
 452                 }
 453                 mutex_unlock(&extcon_dev_list_lock);
 454
 455                 if (idx >= 0) {
 456                         edev = extd;
 457                         return extcon_register_notifier(extd, id, nb);
 458                 } else {
 459                         ret = -ENODEV;
 460                 }
 461         }
 462
 463         return ret;
 464 }
 465 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 466
 467 /**
 468  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 469  * @edev:       the extcon device that has the external connecotr.
 470  * @id:         the unique id of each external connector in extcon enumeration.
 471  * @nb:         a notifier block to be registered.
 472  */
 473 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 474                                 struct notifier_block *nb)
 475 {
 476         unsigned long flags;
 477         int ret, idx;
 478
 479         if (!edev || !nb)
 480                 return -EINVAL;
 481
 482         idx = find_cable_index_by_id(edev, id);
 483         if (idx < 0)
 484                 return idx;
 485
 486         spin_lock_irqsave(&edev->lock, flags);
 487         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 488         spin_unlock_irqrestore(&edev->lock, flags);
 489
 490         return ret;
 491 }
 492 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 493
 494 static struct attribute *extcon_attrs[] = {
 495         &dev_attr_state.attr,
 496         &dev_attr_name.attr,
 497         NULL,
 498 };
 499 ATTRIBUTE_GROUPS(extcon);
 500
 501 static int create_extcon_class(void)
 502 {
 503         if (!extcon_class) {
 504                 extcon_class = class_create(THIS_MODULE, "extcon");
 505                 if (IS_ERR(extcon_class))
 506                         return PTR_ERR(extcon_class);
 507                 extcon_class->dev_groups = extcon_groups;
 508
 509 #if defined(CONFIG_ANDROID)
 510                 switch_class = class_compat_register("switch");
 511                 if (WARN(!switch_class, "cannot allocate"))
 512                         return -ENOMEM;
 513 #endif /* CONFIG_ANDROID */
 514         }
 515
 516         return 0;
 517 }
 518
 519 static void extcon_dev_release(struct device *dev)
 520 {
 521 }
 522
 523 static const char *muex_name = "mutually_exclusive";
 524 static void dummy_sysfs_dev_release(struct device *dev)
 525 {
 526 }
 527
 528 /*
 529  * extcon_dev_allocate() - Allocate the memory of extcon device.
 530  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 531  *                      If supported_cable is NULL, cable name related APIs
 532  *                      are disabled.
 533  *
 534  * This function allocates the memory for extcon device without allocating
 535  * memory in each extcon provider driver and initialize default setting for
 536  * extcon device.
 537  *
 538  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 539  */
 540 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 541 {
 542         struct extcon_dev *edev;
 543
 544         if (!supported_cable)
 545                 return ERR_PTR(-EINVAL);
 546
 547         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 548         if (!edev)
 549                 return ERR_PTR(-ENOMEM);
 550
 551         edev->max_supported = 0;
 552         edev->supported_cable = supported_cable;
 553
 554         return edev;
 555 }
 556
 557 /*
 558  * extcon_dev_free() - Free the memory of extcon device.
 559  * @edev:       the extcon device to free
 560  */
 561 void extcon_dev_free(struct extcon_dev *edev)
 562 {
 563         kfree(edev);
 564 }
 565 EXPORT_SYMBOL_GPL(extcon_dev_free);
 566
 567 /**
 568  * extcon_dev_register() - Register a new extcon device
 569  * @edev        : the new extcon device (should be allocated before calling)
 570  *
 571  * Among the members of edev struct, please set the "user initializing data"
 572  * in any case and set the "optional callbacks" if required. However, please
 573  * do not set the values of "internal data", which are initialized by
 574  * this function.
 575  */
 576 int extcon_dev_register(struct extcon_dev *edev)
 577 {
 578         int ret, index = 0;
 579         static atomic_t edev_no = ATOMIC_INIT(-1);
 580
 581         if (!extcon_class) {
 582                 ret = create_extcon_class();
 583                 if (ret < 0)
 584                         return ret;
 585         }
 586
 587         if (!edev || !edev->supported_cable)
 588                 return -EINVAL;
 589
 590         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 591
 592         edev->max_supported = index;
 593         if (index > SUPPORTED_CABLE_MAX) {
 594                 dev_err(&edev->dev,
 595                         "exceed the maximum number of supported cables\n");
 596                 return -EINVAL;
 597         }
 598
 599         edev->dev.class = extcon_class;
 600         edev->dev.release = extcon_dev_release;
 601
 602         edev->name = dev_name(edev->dev.parent);
 603         if (IS_ERR_OR_NULL(edev->name)) {
 604                 dev_err(&edev->dev,
 605                         "extcon device name is null\n");
 606                 return -EINVAL;
 607         }
 608         dev_set_name(&edev->dev, "extcon%lu",
 609                         (unsigned long)atomic_inc_return(&edev_no));
 610
 611         if (edev->max_supported) {
 612                 char buf[10];
 613                 char *str;
 614                 struct extcon_cable *cable;
 615
 616                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 617                                        edev->max_supported, GFP_KERNEL);
 618                 if (!edev->cables) {
 619                         ret = -ENOMEM;
 620                         goto err_sysfs_alloc;
 621                 }
 622                 for (index = 0; index < edev->max_supported; index++) {
 623                         cable = &edev->cables[index];
 624
 625                         snprintf(buf, 10, "cable.%d", index);
 626                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 627                                       GFP_KERNEL);
 628                         if (!str) {
 629                                 for (index--; index >= 0; index--) {
 630                                         cable = &edev->cables[index];
 631                                         kfree(cable->attr_g.name);
 632                                 }
 633                                 ret = -ENOMEM;
 634
 635                                 goto err_alloc_cables;
 636                         }
 637                         strcpy(str, buf);
 638
 639                         cable->edev = edev;
 640                         cable->cable_index = index;
 641                         cable->attrs[0] = &cable->attr_name.attr;
 642                         cable->attrs[1] = &cable->attr_state.attr;
 643                         cable->attrs[2] = NULL;
 644                         cable->attr_g.name = str;
 645                         cable->attr_g.attrs = cable->attrs;
 646
 647                         sysfs_attr_init(&cable->attr_name.attr);
 648                         cable->attr_name.attr.name = "name";
 649                         cable->attr_name.attr.mode = 0444;
 650                         cable->attr_name.show = cable_name_show;
 651
 652                         sysfs_attr_init(&cable->attr_state.attr);
 653                         cable->attr_state.attr.name = "state";
 654                         cable->attr_state.attr.mode = 0444;
 655                         cable->attr_state.show = cable_state_show;
 656                 }
 657         }
 658
 659         if (edev->max_supported && edev->mutually_exclusive) {
 660                 char buf[80];
 661                 char *name;
 662
 663                 /* Count the size of mutually_exclusive array */
 664                 for (index = 0; edev->mutually_exclusive[index]; index++)
 665                         ;
 666
 667                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 668                                            (index + 1), GFP_KERNEL);
 669                 if (!edev->attrs_muex) {
 670                         ret = -ENOMEM;
 671                         goto err_muex;
 672                 }
 673
 674                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 675                                              index, GFP_KERNEL);
 676                 if (!edev->d_attrs_muex) {
 677                         ret = -ENOMEM;
 678                         kfree(edev->attrs_muex);
 679                         goto err_muex;
 680                 }
 681
 682                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 683                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 684                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 685                                        GFP_KERNEL);
 686                         if (!name) {
 687                                 for (index--; index >= 0; index--) {
 688                                         kfree(edev->d_attrs_muex[index].attr.
 689                                               name);
 690                                 }
 691                                 kfree(edev->d_attrs_muex);
 692                                 kfree(edev->attrs_muex);
 693                                 ret = -ENOMEM;
 694                                 goto err_muex;
 695                         }
 696                         strcpy(name, buf);
 697                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 698                         edev->d_attrs_muex[index].attr.name = name;
 699                         edev->d_attrs_muex[index].attr.mode = 0000;
 700                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 701                                                         .attr;
 702                 }
 703                 edev->attr_g_muex.name = muex_name;
 704                 edev->attr_g_muex.attrs = edev->attrs_muex;
 705
 706         }
 707
 708         if (edev->max_supported) {
 709                 edev->extcon_dev_type.groups =
 710                         kzalloc(sizeof(struct attribute_group *) *
 711                                 (edev->max_supported + 2), GFP_KERNEL);
 712                 if (!edev->extcon_dev_type.groups) {
 713                         ret = -ENOMEM;
 714                         goto err_alloc_groups;
 715                 }
 716
 717                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 718                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 719
 720                 for (index = 0; index < edev->max_supported; index++)
 721                         edev->extcon_dev_type.groups[index] =
 722                                 &edev->cables[index].attr_g;
 723                 if (edev->mutually_exclusive)
 724                         edev->extcon_dev_type.groups[index] =
 725                                 &edev->attr_g_muex;
 726
 727                 edev->dev.type = &edev->extcon_dev_type;
 728         }
 729
 730         ret = device_register(&edev->dev);
 731         if (ret) {
 732                 put_device(&edev->dev);
 733                 goto err_dev;
 734         }
 735 #if defined(CONFIG_ANDROID)
 736         if (switch_class)
 737                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 738 #endif /* CONFIG_ANDROID */
 739
 740         spin_lock_init(&edev->lock);
 741
 742         edev->nh = devm_kzalloc(&edev->dev,
 743                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 744         if (!edev->nh) {
 745                 ret = -ENOMEM;
 746                 goto err_dev;
 747         }
 748
 749         for (index = 0; index < edev->max_supported; index++)
 750                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 751
 752         dev_set_drvdata(&edev->dev, edev);
 753         edev->state = 0;
 754
 755         mutex_lock(&extcon_dev_list_lock);
 756         list_add(&edev->entry, &extcon_dev_list);
 757         mutex_unlock(&extcon_dev_list_lock);
 758
 759         return 0;
 760
 761 err_dev:
 762         if (edev->max_supported)
 763                 kfree(edev->extcon_dev_type.groups);
 764 err_alloc_groups:
 765         if (edev->max_supported && edev->mutually_exclusive) {
 766                 for (index = 0; edev->mutually_exclusive[index]; index++)
 767                         kfree(edev->d_attrs_muex[index].attr.name);
 768                 kfree(edev->d_attrs_muex);
 769                 kfree(edev->attrs_muex);
 770         }
 771 err_muex:
 772         for (index = 0; index < edev->max_supported; index++)
 773                 kfree(edev->cables[index].attr_g.name);
 774 err_alloc_cables:
 775         if (edev->max_supported)
 776                 kfree(edev->cables);
 777 err_sysfs_alloc:
 778         return ret;
 779 }
 780 EXPORT_SYMBOL_GPL(extcon_dev_register);
 781
 782 /**
 783  * extcon_dev_unregister() - Unregister the extcon device.
 784  * @edev:       the extcon device instance to be unregistered.
 785  *
 786  * Note that this does not call kfree(edev) because edev was not allocated
 787  * by this class.
 788  */
 789 void extcon_dev_unregister(struct extcon_dev *edev)
 790 {
 791         int index;
 792
 793         if (!edev)
 794                 return;
 795
 796         mutex_lock(&extcon_dev_list_lock);
 797         list_del(&edev->entry);
 798         mutex_unlock(&extcon_dev_list_lock);
 799
 800         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 801                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 802                                 dev_name(&edev->dev));
 803                 return;
 804         }
 805
 806         device_unregister(&edev->dev);
 807
 808         if (edev->mutually_exclusive && edev->max_supported) {
 809                 for (index = 0; edev->mutually_exclusive[index];
 810                                 index++)
 811                         kfree(edev->d_attrs_muex[index].attr.name);
 812                 kfree(edev->d_attrs_muex);
 813                 kfree(edev->attrs_muex);
 814         }
 815
 816         for (index = 0; index < edev->max_supported; index++)
 817                 kfree(edev->cables[index].attr_g.name);
 818
 819         if (edev->max_supported) {
 820                 kfree(edev->extcon_dev_type.groups);
 821                 kfree(edev->cables);
 822         }
 823
 824 #if defined(CONFIG_ANDROID)
 825         if (switch_class)
 826                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 827 #endif
 828         put_device(&edev->dev);
 829 }
 830 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 831
 832 #ifdef CONFIG_OF
 833 /*
 834  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
 835  * @dev - instance to the given device
 836  * @index - index into list of extcon_dev
 837  *
 838  * return the instance of extcon device
 839  */
 840 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 841 {
 842         struct device_node *node;
 843         struct extcon_dev *edev;
 844
 845         if (!dev)
 846                 return ERR_PTR(-EINVAL);
 847
 848         if (!dev->of_node) {
 849                 dev_err(dev, "device does not have a device node entry\n");
 850                 return ERR_PTR(-EINVAL);
 851         }
 852
 853         node = of_parse_phandle(dev->of_node, "extcon", index);
 854         if (!node) {
 855                 dev_err(dev, "failed to get phandle in %s node\n",
 856                         dev->of_node->full_name);
 857                 return ERR_PTR(-ENODEV);
 858         }
 859
 860         mutex_lock(&extcon_dev_list_lock);
 861         list_for_each_entry(edev, &extcon_dev_list, entry) {
 862                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
 863                         mutex_unlock(&extcon_dev_list_lock);
 864                         of_node_put(node);
 865                         return edev;
 866                 }
 867         }
 868         mutex_unlock(&extcon_dev_list_lock);
 869         of_node_put(node);
 870
 871         return ERR_PTR(-EPROBE_DEFER);
 872 }
 873 #else
 874 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 875 {
 876         return ERR_PTR(-ENOSYS);
 877 }
 878 #endif /* CONFIG_OF */
 879 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
 880
 881 /**
 882  * extcon_get_edev_name() - Get the name of the extcon device.
 883  * @edev:       the extcon device
 884  */
 885 const char *extcon_get_edev_name(struct extcon_dev *edev)
 886 {
 887         return !edev ? NULL : edev->name;
 888 }
 889
 890 static int __init extcon_class_init(void)
 891 {
 892         return create_extcon_class();
 893 }
 894 module_init(extcon_class_init);
 895
 896 static void __exit extcon_class_exit(void)
 897 {
 898 #if defined(CONFIG_ANDROID)
 899         class_compat_unregister(switch_class);
 900 #endif
 901         class_destroy(extcon_class);
 902 }
 903 module_exit(extcon_class_exit);
 904
 905 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
 906 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 907 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 908 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 909 MODULE_DESCRIPTION("External connector (extcon) class driver");
 910 MODULE_LICENSE("GPL");