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 static struct class *extcon_class;
  81 #if defined(CONFIG_ANDROID)
  82 static struct class_compat *switch_class;
  83 #endif /* CONFIG_ANDROID */
  84
  85 static LIST_HEAD(extcon_dev_list);
  86 static DEFINE_MUTEX(extcon_dev_list_lock);
  87
  88 /**
  89  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  90  *                            condition.
  91  * @edev:       the extcon device
  92  * @new_state:  new cable attach status for @edev
  93  *
  94  * Returns 0 if nothing violates. Returns the index + 1 for the first
  95  * violated condition.
  96  */
  97 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  98 {
  99         int i = 0;
 100
 101         if (!edev->mutually_exclusive)
 102                 return 0;
 103
 104         for (i = 0; edev->mutually_exclusive[i]; i++) {
 105                 int weight;
 106                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 107
 108                 /* calculate the total number of bits set */
 109                 weight = hweight32(correspondants);
 110                 if (weight > 1)
 111                         return i + 1;
 112         }
 113
 114         return 0;
 115 }
 116
 117 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 118 {
 119         int i;
 120
 121         /* Find the the index of extcon cable in edev->supported_cable */
 122         for (i = 0; i < edev->max_supported; i++) {
 123                 if (edev->supported_cable[i] == id)
 124                         return i;
 125         }
 126
 127         return -EINVAL;
 128 }
 129
 130 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 131 {
 132         if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
 133                 *attached = ((new >> idx) & 0x1) ? true : false;
 134                 return true;
 135         }
 136
 137         return false;
 138 }
 139
 140 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 141                           char *buf)
 142 {
 143         int i, count = 0;
 144         struct extcon_dev *edev = dev_get_drvdata(dev);
 145
 146         if (edev->max_supported == 0)
 147                 return sprintf(buf, "%u\n", edev->state);
 148
 149         for (i = 0; i < edev->max_supported; i++) {
 150                 count += sprintf(buf + count, "%s=%d\n",
 151                                 extcon_name[edev->supported_cable[i]],
 152                                  !!(edev->state & (1 << i)));
 153         }
 154
 155         return count;
 156 }
 157
 158 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 159                            const char *buf, size_t count)
 160 {
 161         u32 state;
 162         ssize_t ret = 0;
 163         struct extcon_dev *edev = dev_get_drvdata(dev);
 164
 165         ret = sscanf(buf, "0x%x", &state);
 166         if (ret == 0)
 167                 ret = -EINVAL;
 168         else
 169                 ret = extcon_set_state(edev, state);
 170
 171         if (ret < 0)
 172                 return ret;
 173
 174         return count;
 175 }
 176 static DEVICE_ATTR_RW(state);
 177
 178 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 179                 char *buf)
 180 {
 181         struct extcon_dev *edev = dev_get_drvdata(dev);
 182
 183         return sprintf(buf, "%s\n", edev->name);
 184 }
 185 static DEVICE_ATTR_RO(name);
 186
 187 static ssize_t cable_name_show(struct device *dev,
 188                                struct device_attribute *attr, char *buf)
 189 {
 190         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 191                                                   attr_name);
 192         int i = cable->cable_index;
 193
 194         return sprintf(buf, "%s\n",
 195                         extcon_name[cable->edev->supported_cable[i]]);
 196 }
 197
 198 static ssize_t cable_state_show(struct device *dev,
 199                                 struct device_attribute *attr, char *buf)
 200 {
 201         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 202                                                   attr_state);
 203
 204         int i = cable->cable_index;
 205
 206         return sprintf(buf, "%d\n",
 207                        extcon_get_cable_state_(cable->edev,
 208                                                cable->edev->supported_cable[i]));
 209 }
 210
 211 /**
 212  * extcon_update_state() - Update the cable attach states of the extcon device
 213  *                         only for the masked bits.
 214  * @edev:       the extcon device
 215  * @mask:       the bit mask to designate updated bits.
 216  * @state:      new cable attach status for @edev
 217  *
 218  * Changing the state sends uevent with environment variable containing
 219  * the name of extcon device (envp[0]) and the state output (envp[1]).
 220  * Tizen uses this format for extcon device to get events from ports.
 221  * Android uses this format as well.
 222  *
 223  * Note that the notifier provides which bits are changed in the state
 224  * variable with the val parameter (second) to the callback.
 225  */
 226 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 227 {
 228         char name_buf[120];
 229         char state_buf[120];
 230         char *prop_buf;
 231         char *envp[3];
 232         int env_offset = 0;
 233         int length;
 234         int index;
 235         unsigned long flags;
 236         bool attached;
 237
 238         if (!edev)
 239                 return -EINVAL;
 240
 241         spin_lock_irqsave(&edev->lock, flags);
 242
 243         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 244                 u32 old_state;
 245
 246                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 247                                                    (state & mask))) {
 248                         spin_unlock_irqrestore(&edev->lock, flags);
 249                         return -EPERM;
 250                 }
 251
 252                 old_state = edev->state;
 253                 edev->state &= ~mask;
 254                 edev->state |= state & mask;
 255
 256                 for (index = 0; index < edev->max_supported; index++) {
 257                         if (is_extcon_changed(old_state, edev->state, index,
 258                                               &attached))
 259                                 raw_notifier_call_chain(&edev->nh[index],
 260                                                         attached, edev);
 261                 }
 262
 263                 /* This could be in interrupt handler */
 264                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 265                 if (prop_buf) {
 266                         length = name_show(&edev->dev, NULL, prop_buf);
 267                         if (length > 0) {
 268                                 if (prop_buf[length - 1] == '\n')
 269                                         prop_buf[length - 1] = 0;
 270                                 snprintf(name_buf, sizeof(name_buf),
 271                                         "NAME=%s", prop_buf);
 272                                 envp[env_offset++] = name_buf;
 273                         }
 274                         length = state_show(&edev->dev, NULL, prop_buf);
 275                         if (length > 0) {
 276                                 if (prop_buf[length - 1] == '\n')
 277                                         prop_buf[length - 1] = 0;
 278                                 snprintf(state_buf, sizeof(state_buf),
 279                                         "STATE=%s", prop_buf);
 280                                 envp[env_offset++] = state_buf;
 281                         }
 282                         envp[env_offset] = NULL;
 283                         /* Unlock early before uevent */
 284                         spin_unlock_irqrestore(&edev->lock, flags);
 285
 286                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 287                         free_page((unsigned long)prop_buf);
 288                 } else {
 289                         /* Unlock early before uevent */
 290                         spin_unlock_irqrestore(&edev->lock, flags);
 291
 292                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 293                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 294                 }
 295         } else {
 296                 /* No changes */
 297                 spin_unlock_irqrestore(&edev->lock, flags);
 298         }
 299
 300         return 0;
 301 }
 302 EXPORT_SYMBOL_GPL(extcon_update_state);
 303
 304 /**
 305  * extcon_set_state() - Set the cable attach states of the extcon device.
 306  * @edev:       the extcon device
 307  * @state:      new cable attach status for @edev
 308  *
 309  * Note that notifier provides which bits are changed in the state
 310  * variable with the val parameter (second) to the callback.
 311  */
 312 int extcon_set_state(struct extcon_dev *edev, u32 state)
 313 {
 314         if (!edev)
 315                 return -EINVAL;
 316
 317         return extcon_update_state(edev, 0xffffffff, state);
 318 }
 319 EXPORT_SYMBOL_GPL(extcon_set_state);
 320
 321 /**
 322  * extcon_get_cable_state_() - Get the status of a specific cable.
 323  * @edev:       the extcon device that has the cable.
 324  * @id:         the unique id of each external connector in extcon enumeration.
 325  */
 326 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 327 {
 328         int index;
 329
 330         if (!edev)
 331                 return -EINVAL;
 332
 333         index = find_cable_index_by_id(edev, id);
 334         if (index < 0)
 335                 return index;
 336
 337         if (edev->max_supported && edev->max_supported <= index)
 338                 return -EINVAL;
 339
 340         return !!(edev->state & (1 << index));
 341 }
 342 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 343
 344 /**
 345  * extcon_set_cable_state_() - Set the status of a specific cable.
 346  * @edev:               the extcon device that has the cable.
 347  * @id:                 the unique id of each external connector
 348  *                      in extcon enumeration.
 349  * @state:              the new cable status. The default semantics is
 350  *                      true: attached / false: detached.
 351  */
 352 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 353                                 bool cable_state)
 354 {
 355         u32 state;
 356         int index;
 357
 358         if (!edev)
 359                 return -EINVAL;
 360
 361         index = find_cable_index_by_id(edev, id);
 362         if (index < 0)
 363                 return index;
 364
 365         if (edev->max_supported && edev->max_supported <= index)
 366                 return -EINVAL;
 367
 368         state = cable_state ? (1 << index) : 0;
 369         return extcon_update_state(edev, 1 << index, state);
 370 }
 371 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 372
 373 /**
 374  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 375  * @extcon_name:        The extcon name provided with extcon_dev_register()
 376  */
 377 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 378 {
 379         struct extcon_dev *sd;
 380
 381         if (!extcon_name)
 382                 return ERR_PTR(-EINVAL);
 383
 384         mutex_lock(&extcon_dev_list_lock);
 385         list_for_each_entry(sd, &extcon_dev_list, entry) {
 386                 if (!strcmp(sd->name, extcon_name))
 387                         goto out;
 388         }
 389         sd = NULL;
 390 out:
 391         mutex_unlock(&extcon_dev_list_lock);
 392         return sd;
 393 }
 394 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 395
 396 /**
 397  * extcon_register_notifier() - Register a notifiee to get notified by
 398  *                              any attach status changes from the extcon.
 399  * @edev:       the extcon device that has the external connecotr.
 400  * @id:         the unique id of each external connector in extcon enumeration.
 401  * @nb:         a notifier block to be registered.
 402  *
 403  * Note that the second parameter given to the callback of nb (val) is
 404  * "old_state", not the current state. The current state can be retrieved
 405  * by looking at the third pameter (edev pointer)'s state value.
 406  */
 407 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 408                              struct notifier_block *nb)
 409 {
 410         unsigned long flags;
 411         int ret, idx;
 412
 413         if (!nb)
 414                 return -EINVAL;
 415
 416         if (edev) {
 417                 idx = find_cable_index_by_id(edev, id);
 418
 419                 spin_lock_irqsave(&edev->lock, flags);
 420                 ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 421                 spin_unlock_irqrestore(&edev->lock, flags);
 422         } else {
 423                 struct extcon_dev *extd;
 424
 425                 mutex_lock(&extcon_dev_list_lock);
 426                 list_for_each_entry(extd, &extcon_dev_list, entry) {
 427                         idx = find_cable_index_by_id(extd, id);
 428                         if (idx >= 0)
 429                                 break;
 430                 }
 431                 mutex_unlock(&extcon_dev_list_lock);
 432
 433                 if (idx >= 0) {
 434                         edev = extd;
 435                         return extcon_register_notifier(extd, id, nb);
 436                 } else {
 437                         ret = -ENODEV;
 438                 }
 439         }
 440
 441         return ret;
 442 }
 443 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 444
 445 /**
 446  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 447  * @edev:       the extcon device that has the external connecotr.
 448  * @id:         the unique id of each external connector in extcon enumeration.
 449  * @nb:         a notifier block to be registered.
 450  */
 451 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 452                                 struct notifier_block *nb)
 453 {
 454         unsigned long flags;
 455         int ret, idx;
 456
 457         if (!edev || !nb)
 458                 return -EINVAL;
 459
 460         idx = find_cable_index_by_id(edev, id);
 461
 462         spin_lock_irqsave(&edev->lock, flags);
 463         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 464         spin_unlock_irqrestore(&edev->lock, flags);
 465
 466         return ret;
 467 }
 468 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 469
 470 static struct attribute *extcon_attrs[] = {
 471         &dev_attr_state.attr,
 472         &dev_attr_name.attr,
 473         NULL,
 474 };
 475 ATTRIBUTE_GROUPS(extcon);
 476
 477 static int create_extcon_class(void)
 478 {
 479         if (!extcon_class) {
 480                 extcon_class = class_create(THIS_MODULE, "extcon");
 481                 if (IS_ERR(extcon_class))
 482                         return PTR_ERR(extcon_class);
 483                 extcon_class->dev_groups = extcon_groups;
 484
 485 #if defined(CONFIG_ANDROID) && !defined(CONFIG_SWITCH)
 486                 switch_class = class_compat_register("switch");
 487                 if (WARN(!switch_class, "cannot allocate"))
 488                         return -ENOMEM;
 489 #endif /* CONFIG_ANDROID */
 490         }
 491
 492         return 0;
 493 }
 494
 495 static void extcon_dev_release(struct device *dev)
 496 {
 497 }
 498
 499 static const char *muex_name = "mutually_exclusive";
 500 static void dummy_sysfs_dev_release(struct device *dev)
 501 {
 502 }
 503
 504 /*
 505  * extcon_dev_allocate() - Allocate the memory of extcon device.
 506  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 507  *                      If supported_cable is NULL, cable name related APIs
 508  *                      are disabled.
 509  *
 510  * This function allocates the memory for extcon device without allocating
 511  * memory in each extcon provider driver and initialize default setting for
 512  * extcon device.
 513  *
 514  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 515  */
 516 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 517 {
 518         struct extcon_dev *edev;
 519
 520         if (!supported_cable)
 521                 return ERR_PTR(-EINVAL);
 522
 523         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 524         if (!edev)
 525                 return ERR_PTR(-ENOMEM);
 526
 527         edev->max_supported = 0;
 528         edev->supported_cable = supported_cable;
 529
 530         return edev;
 531 }
 532
 533 /*
 534  * extcon_dev_free() - Free the memory of extcon device.
 535  * @edev:       the extcon device to free
 536  */
 537 void extcon_dev_free(struct extcon_dev *edev)
 538 {
 539         kfree(edev);
 540 }
 541 EXPORT_SYMBOL_GPL(extcon_dev_free);
 542
 543 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 544 {
 545         struct extcon_dev **r = res;
 546
 547         if (WARN_ON(!r || !*r))
 548                 return 0;
 549
 550         return *r == data;
 551 }
 552
 553 static void devm_extcon_dev_release(struct device *dev, void *res)
 554 {
 555         extcon_dev_free(*(struct extcon_dev **)res);
 556 }
 557
 558 /**
 559  * devm_extcon_dev_allocate - Allocate managed extcon device
 560  * @dev:                device owning the extcon device being created
 561  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 562  *                      If supported_cable is NULL, cable name related APIs
 563  *                      are disabled.
 564  *
 565  * This function manages automatically the memory of extcon device using device
 566  * resource management and simplify the control of freeing the memory of extcon
 567  * device.
 568  *
 569  * Returns the pointer memory of allocated extcon_dev if success
 570  * or ERR_PTR(err) if fail
 571  */
 572 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 573                                         const unsigned int *supported_cable)
 574 {
 575         struct extcon_dev **ptr, *edev;
 576
 577         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 578         if (!ptr)
 579                 return ERR_PTR(-ENOMEM);
 580
 581         edev = extcon_dev_allocate(supported_cable);
 582         if (IS_ERR(edev)) {
 583                 devres_free(ptr);
 584                 return edev;
 585         }
 586
 587         edev->dev.parent = dev;
 588
 589         *ptr = edev;
 590         devres_add(dev, ptr);
 591
 592         return edev;
 593 }
 594 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 595
 596 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 597 {
 598         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 599                                devm_extcon_dev_match, edev));
 600 }
 601 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 602
 603 /**
 604  * extcon_dev_register() - Register a new extcon device
 605  * @edev        : the new extcon device (should be allocated before calling)
 606  *
 607  * Among the members of edev struct, please set the "user initializing data"
 608  * in any case and set the "optional callbacks" if required. However, please
 609  * do not set the values of "internal data", which are initialized by
 610  * this function.
 611  */
 612 int extcon_dev_register(struct extcon_dev *edev)
 613 {
 614         int ret, index = 0;
 615         static atomic_t edev_no = ATOMIC_INIT(-1);
 616
 617         if (!extcon_class) {
 618                 ret = create_extcon_class();
 619                 if (ret < 0)
 620                         return ret;
 621         }
 622
 623         if (!edev || !edev->supported_cable)
 624                 return -EINVAL;
 625
 626         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 627
 628         edev->max_supported = index;
 629         if (index > SUPPORTED_CABLE_MAX) {
 630                 dev_err(&edev->dev,
 631                         "exceed the maximum number of supported cables\n");
 632                 return -EINVAL;
 633         }
 634
 635         edev->dev.class = extcon_class;
 636         edev->dev.release = extcon_dev_release;
 637
 638         edev->name = dev_name(edev->dev.parent);
 639         if (IS_ERR_OR_NULL(edev->name)) {
 640                 dev_err(&edev->dev,
 641                         "extcon device name is null\n");
 642                 return -EINVAL;
 643         }
 644         dev_set_name(&edev->dev, "extcon%lu",
 645                         (unsigned long)atomic_inc_return(&edev_no));
 646
 647         if (edev->max_supported) {
 648                 char buf[10];
 649                 char *str;
 650                 struct extcon_cable *cable;
 651
 652                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 653                                        edev->max_supported, GFP_KERNEL);
 654                 if (!edev->cables) {
 655                         ret = -ENOMEM;
 656                         goto err_sysfs_alloc;
 657                 }
 658                 for (index = 0; index < edev->max_supported; index++) {
 659                         cable = &edev->cables[index];
 660
 661                         snprintf(buf, 10, "cable.%d", index);
 662                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 663                                       GFP_KERNEL);
 664                         if (!str) {
 665                                 for (index--; index >= 0; index--) {
 666                                         cable = &edev->cables[index];
 667                                         kfree(cable->attr_g.name);
 668                                 }
 669                                 ret = -ENOMEM;
 670
 671                                 goto err_alloc_cables;
 672                         }
 673                         strcpy(str, buf);
 674
 675                         cable->edev = edev;
 676                         cable->cable_index = index;
 677                         cable->attrs[0] = &cable->attr_name.attr;
 678                         cable->attrs[1] = &cable->attr_state.attr;
 679                         cable->attrs[2] = NULL;
 680                         cable->attr_g.name = str;
 681                         cable->attr_g.attrs = cable->attrs;
 682
 683                         sysfs_attr_init(&cable->attr_name.attr);
 684                         cable->attr_name.attr.name = "name";
 685                         cable->attr_name.attr.mode = 0444;
 686                         cable->attr_name.show = cable_name_show;
 687
 688                         sysfs_attr_init(&cable->attr_state.attr);
 689                         cable->attr_state.attr.name = "state";
 690                         cable->attr_state.attr.mode = 0444;
 691                         cable->attr_state.show = cable_state_show;
 692                 }
 693         }
 694
 695         if (edev->max_supported && edev->mutually_exclusive) {
 696                 char buf[80];
 697                 char *name;
 698
 699                 /* Count the size of mutually_exclusive array */
 700                 for (index = 0; edev->mutually_exclusive[index]; index++)
 701                         ;
 702
 703                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 704                                            (index + 1), GFP_KERNEL);
 705                 if (!edev->attrs_muex) {
 706                         ret = -ENOMEM;
 707                         goto err_muex;
 708                 }
 709
 710                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 711                                              index, GFP_KERNEL);
 712                 if (!edev->d_attrs_muex) {
 713                         ret = -ENOMEM;
 714                         kfree(edev->attrs_muex);
 715                         goto err_muex;
 716                 }
 717
 718                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 719                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 720                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 721                                        GFP_KERNEL);
 722                         if (!name) {
 723                                 for (index--; index >= 0; index--) {
 724                                         kfree(edev->d_attrs_muex[index].attr.
 725                                               name);
 726                                 }
 727                                 kfree(edev->d_attrs_muex);
 728                                 kfree(edev->attrs_muex);
 729                                 ret = -ENOMEM;
 730                                 goto err_muex;
 731                         }
 732                         strcpy(name, buf);
 733                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 734                         edev->d_attrs_muex[index].attr.name = name;
 735                         edev->d_attrs_muex[index].attr.mode = 0000;
 736                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 737                                                         .attr;
 738                 }
 739                 edev->attr_g_muex.name = muex_name;
 740                 edev->attr_g_muex.attrs = edev->attrs_muex;
 741
 742         }
 743
 744         if (edev->max_supported) {
 745                 edev->extcon_dev_type.groups =
 746                         kzalloc(sizeof(struct attribute_group *) *
 747                                 (edev->max_supported + 2), GFP_KERNEL);
 748                 if (!edev->extcon_dev_type.groups) {
 749                         ret = -ENOMEM;
 750                         goto err_alloc_groups;
 751                 }
 752
 753                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 754                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 755
 756                 for (index = 0; index < edev->max_supported; index++)
 757                         edev->extcon_dev_type.groups[index] =
 758                                 &edev->cables[index].attr_g;
 759                 if (edev->mutually_exclusive)
 760                         edev->extcon_dev_type.groups[index] =
 761                                 &edev->attr_g_muex;
 762
 763                 edev->dev.type = &edev->extcon_dev_type;
 764         }
 765
 766         ret = device_register(&edev->dev);
 767         if (ret) {
 768                 put_device(&edev->dev);
 769                 goto err_dev;
 770         }
 771 #if defined(CONFIG_ANDROID)
 772         if (switch_class)
 773                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 774 #endif /* CONFIG_ANDROID */
 775
 776         spin_lock_init(&edev->lock);
 777
 778         edev->nh = devm_kzalloc(&edev->dev,
 779                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 780         if (!edev->nh) {
 781                 ret = -ENOMEM;
 782                 goto err_dev;
 783         }
 784
 785         for (index = 0; index < edev->max_supported; index++)
 786                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 787
 788         dev_set_drvdata(&edev->dev, edev);
 789         edev->state = 0;
 790
 791         mutex_lock(&extcon_dev_list_lock);
 792         list_add(&edev->entry, &extcon_dev_list);
 793         mutex_unlock(&extcon_dev_list_lock);
 794
 795         return 0;
 796
 797 err_dev:
 798         if (edev->max_supported)
 799                 kfree(edev->extcon_dev_type.groups);
 800 err_alloc_groups:
 801         if (edev->max_supported && edev->mutually_exclusive) {
 802                 for (index = 0; edev->mutually_exclusive[index]; index++)
 803                         kfree(edev->d_attrs_muex[index].attr.name);
 804                 kfree(edev->d_attrs_muex);
 805                 kfree(edev->attrs_muex);
 806         }
 807 err_muex:
 808         for (index = 0; index < edev->max_supported; index++)
 809                 kfree(edev->cables[index].attr_g.name);
 810 err_alloc_cables:
 811         if (edev->max_supported)
 812                 kfree(edev->cables);
 813 err_sysfs_alloc:
 814         return ret;
 815 }
 816 EXPORT_SYMBOL_GPL(extcon_dev_register);
 817
 818 /**
 819  * extcon_dev_unregister() - Unregister the extcon device.
 820  * @edev:       the extcon device instance to be unregistered.
 821  *
 822  * Note that this does not call kfree(edev) because edev was not allocated
 823  * by this class.
 824  */
 825 void extcon_dev_unregister(struct extcon_dev *edev)
 826 {
 827         int index;
 828
 829         if (!edev)
 830                 return;
 831
 832         mutex_lock(&extcon_dev_list_lock);
 833         list_del(&edev->entry);
 834         mutex_unlock(&extcon_dev_list_lock);
 835
 836         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 837                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 838                                 dev_name(&edev->dev));
 839                 return;
 840         }
 841
 842         device_unregister(&edev->dev);
 843
 844         if (edev->mutually_exclusive && edev->max_supported) {
 845                 for (index = 0; edev->mutually_exclusive[index];
 846                                 index++)
 847                         kfree(edev->d_attrs_muex[index].attr.name);
 848                 kfree(edev->d_attrs_muex);
 849                 kfree(edev->attrs_muex);
 850         }
 851
 852         for (index = 0; index < edev->max_supported; index++)
 853                 kfree(edev->cables[index].attr_g.name);
 854
 855         if (edev->max_supported) {
 856                 kfree(edev->extcon_dev_type.groups);
 857                 kfree(edev->cables);
 858         }
 859
 860 #if defined(CONFIG_ANDROID)
 861         if (switch_class)
 862                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 863 #endif
 864         put_device(&edev->dev);
 865 }
 866 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 867
 868 static void devm_extcon_dev_unreg(struct device *dev, void *res)
 869 {
 870         extcon_dev_unregister(*(struct extcon_dev **)res);
 871 }
 872
 873 /**
 874  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
 875  * @dev:        device to allocate extcon device
 876  * @edev:       the new extcon device to register
 877  *
 878  * Managed extcon_dev_register() function. If extcon device is attached with
 879  * this function, that extcon device is automatically unregistered on driver
 880  * detach. Internally this function calls extcon_dev_register() function.
 881  * To get more information, refer that function.
 882  *
 883  * If extcon device is registered with this function and the device needs to be
 884  * unregistered separately, devm_extcon_dev_unregister() should be used.
 885  *
 886  * Returns 0 if success or negaive error number if failure.
 887  */
 888 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
 889 {
 890         struct extcon_dev **ptr;
 891         int ret;
 892
 893         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
 894         if (!ptr)
 895                 return -ENOMEM;
 896
 897         ret = extcon_dev_register(edev);
 898         if (ret) {
 899                 devres_free(ptr);
 900                 return ret;
 901         }
 902
 903         *ptr = edev;
 904         devres_add(dev, ptr);
 905
 906         return 0;
 907 }
 908 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
 909
 910 /**
 911  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
 912  * @dev:        device the extcon belongs to
 913  * @edev:       the extcon device to unregister
 914  *
 915  * Unregister extcon device that is registered with devm_extcon_dev_register()
 916  * function.
 917  */
 918 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
 919 {
 920         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
 921                                devm_extcon_dev_match, edev));
 922 }
 923 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
 924
 925 #ifdef CONFIG_OF
 926 /*
 927  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
 928  * @dev - instance to the given device
 929  * @index - index into list of extcon_dev
 930  *
 931  * return the instance of extcon device
 932  */
 933 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 934 {
 935         struct device_node *node;
 936         struct extcon_dev *edev;
 937
 938         if (!dev)
 939                 return ERR_PTR(-EINVAL);
 940
 941         if (!dev->of_node) {
 942                 dev_err(dev, "device does not have a device node entry\n");
 943                 return ERR_PTR(-EINVAL);
 944         }
 945
 946         node = of_parse_phandle(dev->of_node, "extcon", index);
 947         if (!node) {
 948                 dev_err(dev, "failed to get phandle in %s node\n",
 949                         dev->of_node->full_name);
 950                 return ERR_PTR(-ENODEV);
 951         }
 952
 953         mutex_lock(&extcon_dev_list_lock);
 954         list_for_each_entry(edev, &extcon_dev_list, entry) {
 955                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
 956                         mutex_unlock(&extcon_dev_list_lock);
 957                         return edev;
 958                 }
 959         }
 960         mutex_unlock(&extcon_dev_list_lock);
 961
 962         return ERR_PTR(-EPROBE_DEFER);
 963 }
 964 #else
 965 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 966 {
 967         return ERR_PTR(-ENOSYS);
 968 }
 969 #endif /* CONFIG_OF */
 970 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
 971
 972 /**
 973  * extcon_get_edev_name() - Get the name of the extcon device.
 974  * @edev:       the extcon device
 975  */
 976 const char *extcon_get_edev_name(struct extcon_dev *edev)
 977 {
 978         return !edev ? NULL : edev->name;
 979 }
 980
 981 static int __init extcon_class_init(void)
 982 {
 983         return create_extcon_class();
 984 }
 985 module_init(extcon_class_init);
 986
 987 static void __exit extcon_class_exit(void)
 988 {
 989 #if defined(CONFIG_ANDROID)
 990         class_compat_unregister(switch_class);
 991 #endif
 992         class_destroy(extcon_class);
 993 }
 994 module_exit(extcon_class_exit);
 995
 996 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
 997 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 998 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 999 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1000 MODULE_DESCRIPTION("External connector (extcon) class driver");
1001 MODULE_LICENSE("GPL");