linux/drivers/extcon/extcon-class.c
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   1/*
   2 *  drivers/extcon/extcon_class.c
   3 *
   4 *  External connector (extcon) class driver
   5 *
   6 * Copyright (C) 2012 Samsung Electronics
   7 * Author: Donggeun Kim <dg77.kim@samsung.com>
   8 * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
   9 *
  10 * based on android/drivers/switch/switch_class.c
  11 * Copyright (C) 2008 Google, Inc.
  12 * Author: Mike Lockwood <lockwood@android.com>
  13 *
  14 * This software is licensed under the terms of the GNU General Public
  15 * License version 2, as published by the Free Software Foundation, and
  16 * may be copied, distributed, and modified under those terms.
  17 *
  18 * This program is distributed in the hope that it will be useful,
  19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 * GNU General Public License for more details.
  22 *
  23*/
  24
  25#include <linux/module.h>
  26#include <linux/types.h>
  27#include <linux/init.h>
  28#include <linux/device.h>
  29#include <linux/fs.h>
  30#include <linux/err.h>
  31#include <linux/extcon.h>
  32#include <linux/slab.h>
  33#include <linux/sysfs.h>
  34
  35/*
  36 * extcon_cable_name suggests the standard cable names for commonly used
  37 * cable types.
  38 *
  39 * However, please do not use extcon_cable_name directly for extcon_dev
  40 * struct's supported_cable pointer unless your device really supports
  41 * every single port-type of the following cable names. Please choose cable
  42 * names that are actually used in your extcon device.
  43 */
  44const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
  45        [EXTCON_USB]            = "USB",
  46        [EXTCON_USB_HOST]       = "USB-Host",
  47        [EXTCON_TA]             = "TA",
  48        [EXTCON_FAST_CHARGER]   = "Fast-charger",
  49        [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  50        [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  51        [EXTCON_HDMI]           = "HDMI",
  52        [EXTCON_MHL]            = "MHL",
  53        [EXTCON_DVI]            = "DVI",
  54        [EXTCON_VGA]            = "VGA",
  55        [EXTCON_DOCK]           = "Dock",
  56        [EXTCON_LINE_IN]        = "Line-in",
  57        [EXTCON_LINE_OUT]       = "Line-out",
  58        [EXTCON_MIC_IN]         = "Microphone",
  59        [EXTCON_HEADPHONE_OUT]  = "Headphone",
  60        [EXTCON_SPDIF_IN]       = "SPDIF-in",
  61        [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  62        [EXTCON_VIDEO_IN]       = "Video-in",
  63        [EXTCON_VIDEO_OUT]      = "Video-out",
  64        [EXTCON_MECHANICAL]     = "Mechanical",
  65};
  66
  67static struct class *extcon_class;
  68#if defined(CONFIG_ANDROID)
  69static struct class_compat *switch_class;
  70#endif /* CONFIG_ANDROID */
  71
  72static LIST_HEAD(extcon_dev_list);
  73static DEFINE_MUTEX(extcon_dev_list_lock);
  74
  75/**
  76 * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  77 *                          condition.
  78 * @edev:       the extcon device
  79 * @new_state:  new cable attach status for @edev
  80 *
  81 * Returns 0 if nothing violates. Returns the index + 1 for the first
  82 * violated condition.
  83 */
  84static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  85{
  86        int i = 0;
  87
  88        if (!edev->mutually_exclusive)
  89                return 0;
  90
  91        for (i = 0; edev->mutually_exclusive[i]; i++) {
  92                int weight;
  93                u32 correspondants = new_state & edev->mutually_exclusive[i];
  94
  95                /* calculate the total number of bits set */
  96                weight = hweight32(correspondants);
  97                if (weight > 1)
  98                        return i + 1;
  99        }
 100
 101        return 0;
 102}
 103
 104static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 105                          char *buf)
 106{
 107        int i, count = 0;
 108        struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 109
 110        if (edev->print_state) {
 111                int ret = edev->print_state(edev, buf);
 112
 113                if (ret >= 0)
 114                        return ret;
 115                /* Use default if failed */
 116        }
 117
 118        if (edev->max_supported == 0)
 119                return sprintf(buf, "%u\n", edev->state);
 120
 121        for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
 122                if (!edev->supported_cable[i])
 123                        break;
 124                count += sprintf(buf + count, "%s=%d\n",
 125                                 edev->supported_cable[i],
 126                                 !!(edev->state & (1 << i)));
 127        }
 128
 129        return count;
 130}
 131
 132int extcon_set_state(struct extcon_dev *edev, u32 state);
 133static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 134                           const char *buf, size_t count)
 135{
 136        u32 state;
 137        ssize_t ret = 0;
 138        struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 139
 140        ret = sscanf(buf, "0x%x", &state);
 141        if (ret == 0)
 142                ret = -EINVAL;
 143        else
 144                ret = extcon_set_state(edev, state);
 145
 146        if (ret < 0)
 147                return ret;
 148
 149        return count;
 150}
 151static DEVICE_ATTR_RW(state);
 152
 153static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 154                char *buf)
 155{
 156        struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 157
 158        /* Optional callback given by the user */
 159        if (edev->print_name) {
 160                int ret = edev->print_name(edev, buf);
 161                if (ret >= 0)
 162                        return ret;
 163        }
 164
 165        return sprintf(buf, "%s\n", dev_name(edev->dev));
 166}
 167static DEVICE_ATTR_RO(name);
 168
 169static ssize_t cable_name_show(struct device *dev,
 170                               struct device_attribute *attr, char *buf)
 171{
 172        struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 173                                                  attr_name);
 174
 175        return sprintf(buf, "%s\n",
 176                       cable->edev->supported_cable[cable->cable_index]);
 177}
 178
 179static ssize_t cable_state_show(struct device *dev,
 180                                struct device_attribute *attr, char *buf)
 181{
 182        struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 183                                                  attr_state);
 184
 185        return sprintf(buf, "%d\n",
 186                       extcon_get_cable_state_(cable->edev,
 187                                               cable->cable_index));
 188}
 189
 190/**
 191 * extcon_update_state() - Update the cable attach states of the extcon device
 192 *                      only for the masked bits.
 193 * @edev:       the extcon device
 194 * @mask:       the bit mask to designate updated bits.
 195 * @state:      new cable attach status for @edev
 196 *
 197 * Changing the state sends uevent with environment variable containing
 198 * the name of extcon device (envp[0]) and the state output (envp[1]).
 199 * Tizen uses this format for extcon device to get events from ports.
 200 * Android uses this format as well.
 201 *
 202 * Note that the notifier provides which bits are changed in the state
 203 * variable with the val parameter (second) to the callback.
 204 */
 205int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 206{
 207        char name_buf[120];
 208        char state_buf[120];
 209        char *prop_buf;
 210        char *envp[3];
 211        int env_offset = 0;
 212        int length;
 213        unsigned long flags;
 214
 215        spin_lock_irqsave(&edev->lock, flags);
 216
 217        if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 218                u32 old_state = edev->state;
 219
 220                if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 221                                                   (state & mask))) {
 222                        spin_unlock_irqrestore(&edev->lock, flags);
 223                        return -EPERM;
 224                }
 225
 226                edev->state &= ~mask;
 227                edev->state |= state & mask;
 228
 229                raw_notifier_call_chain(&edev->nh, old_state, edev);
 230
 231                /* This could be in interrupt handler */
 232                prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 233                if (prop_buf) {
 234                        length = name_show(edev->dev, NULL, prop_buf);
 235                        if (length > 0) {
 236                                if (prop_buf[length - 1] == '\n')
 237                                        prop_buf[length - 1] = 0;
 238                                snprintf(name_buf, sizeof(name_buf),
 239                                        "NAME=%s", prop_buf);
 240                                envp[env_offset++] = name_buf;
 241                        }
 242                        length = state_show(edev->dev, NULL, prop_buf);
 243                        if (length > 0) {
 244                                if (prop_buf[length - 1] == '\n')
 245                                        prop_buf[length - 1] = 0;
 246                                snprintf(state_buf, sizeof(state_buf),
 247                                        "STATE=%s", prop_buf);
 248                                envp[env_offset++] = state_buf;
 249                        }
 250                        envp[env_offset] = NULL;
 251                        /* Unlock early before uevent */
 252                        spin_unlock_irqrestore(&edev->lock, flags);
 253
 254                        kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp);
 255                        free_page((unsigned long)prop_buf);
 256                } else {
 257                        /* Unlock early before uevent */
 258                        spin_unlock_irqrestore(&edev->lock, flags);
 259
 260                        dev_err(edev->dev, "out of memory in extcon_set_state\n");
 261                        kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE);
 262                }
 263        } else {
 264                /* No changes */
 265                spin_unlock_irqrestore(&edev->lock, flags);
 266        }
 267
 268        return 0;
 269}
 270EXPORT_SYMBOL_GPL(extcon_update_state);
 271
 272/**
 273 * extcon_set_state() - Set the cable attach states of the extcon device.
 274 * @edev:       the extcon device
 275 * @state:      new cable attach status for @edev
 276 *
 277 * Note that notifier provides which bits are changed in the state
 278 * variable with the val parameter (second) to the callback.
 279 */
 280int extcon_set_state(struct extcon_dev *edev, u32 state)
 281{
 282        return extcon_update_state(edev, 0xffffffff, state);
 283}
 284EXPORT_SYMBOL_GPL(extcon_set_state);
 285
 286/**
 287 * extcon_find_cable_index() - Get the cable index based on the cable name.
 288 * @edev:       the extcon device that has the cable.
 289 * @cable_name: cable name to be searched.
 290 *
 291 * Note that accessing a cable state based on cable_index is faster than
 292 * cable_name because using cable_name induces a loop with strncmp().
 293 * Thus, when get/set_cable_state is repeatedly used, using cable_index
 294 * is recommended.
 295 */
 296int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 297{
 298        int i;
 299
 300        if (edev->supported_cable) {
 301                for (i = 0; edev->supported_cable[i]; i++) {
 302                        if (!strncmp(edev->supported_cable[i],
 303                                cable_name, CABLE_NAME_MAX))
 304                                return i;
 305                }
 306        }
 307
 308        return -EINVAL;
 309}
 310EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 311
 312/**
 313 * extcon_get_cable_state_() - Get the status of a specific cable.
 314 * @edev:       the extcon device that has the cable.
 315 * @index:      cable index that can be retrieved by extcon_find_cable_index().
 316 */
 317int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 318{
 319        if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 320                return -EINVAL;
 321
 322        return !!(edev->state & (1 << index));
 323}
 324EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 325
 326/**
 327 * extcon_get_cable_state() - Get the status of a specific cable.
 328 * @edev:       the extcon device that has the cable.
 329 * @cable_name: cable name.
 330 *
 331 * Note that this is slower than extcon_get_cable_state_.
 332 */
 333int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 334{
 335        return extcon_get_cable_state_(edev, extcon_find_cable_index
 336                                                (edev, cable_name));
 337}
 338EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 339
 340/**
 341 * extcon_set_cable_state_() - Set the status of a specific cable.
 342 * @edev:       the extcon device that has the cable.
 343 * @index:      cable index that can be retrieved by extcon_find_cable_index().
 344 * @cable_state:        the new cable status. The default semantics is
 345 *                      true: attached / false: detached.
 346 */
 347int extcon_set_cable_state_(struct extcon_dev *edev,
 348                        int index, bool cable_state)
 349{
 350        u32 state;
 351
 352        if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 353                return -EINVAL;
 354
 355        state = cable_state ? (1 << index) : 0;
 356        return extcon_update_state(edev, 1 << index, state);
 357}
 358EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 359
 360/**
 361 * extcon_set_cable_state() - Set the status of a specific cable.
 362 * @edev:       the extcon device that has the cable.
 363 * @cable_name: cable name.
 364 * @cable_state:        the new cable status. The default semantics is
 365 *                      true: attached / false: detached.
 366 *
 367 * Note that this is slower than extcon_set_cable_state_.
 368 */
 369int extcon_set_cable_state(struct extcon_dev *edev,
 370                        const char *cable_name, bool cable_state)
 371{
 372        return extcon_set_cable_state_(edev, extcon_find_cable_index
 373                                        (edev, cable_name), cable_state);
 374}
 375EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 376
 377/**
 378 * extcon_get_extcon_dev() - Get the extcon device instance from the name
 379 * @extcon_name:        The extcon name provided with extcon_dev_register()
 380 */
 381struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 382{
 383        struct extcon_dev *sd;
 384
 385        mutex_lock(&extcon_dev_list_lock);
 386        list_for_each_entry(sd, &extcon_dev_list, entry) {
 387                if (!strcmp(sd->name, extcon_name))
 388                        goto out;
 389        }
 390        sd = NULL;
 391out:
 392        mutex_unlock(&extcon_dev_list_lock);
 393        return sd;
 394}
 395EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 396
 397static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 398                           void *ptr)
 399{
 400        struct extcon_specific_cable_nb *obj = container_of(nb,
 401                        struct extcon_specific_cable_nb, internal_nb);
 402        struct extcon_dev *edev = ptr;
 403
 404        if ((val & (1 << obj->cable_index)) !=
 405            (edev->state & (1 << obj->cable_index))) {
 406                bool cable_state = true;
 407
 408                obj->previous_value = val;
 409
 410                if (val & (1 << obj->cable_index))
 411                        cable_state = false;
 412
 413                return obj->user_nb->notifier_call(obj->user_nb,
 414                                cable_state, ptr);
 415        }
 416
 417        return NOTIFY_OK;
 418}
 419
 420/**
 421 * extcon_register_interest() - Register a notifier for a state change of a
 422 *                            specific cable, not an entier set of cables of a
 423 *                            extcon device.
 424 * @obj:        an empty extcon_specific_cable_nb object to be returned.
 425 * @extcon_name:        the name of extcon device.
 426 *                      if NULL, extcon_register_interest will register
 427 *                      every cable with the target cable_name given.
 428 * @cable_name:         the target cable name.
 429 * @nb:         the notifier block to get notified.
 430 *
 431 * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 432 * the struct for you.
 433 *
 434 * extcon_register_interest is a helper function for those who want to get
 435 * notification for a single specific cable's status change. If a user wants
 436 * to get notification for any changes of all cables of a extcon device,
 437 * he/she should use the general extcon_register_notifier().
 438 *
 439 * Note that the second parameter given to the callback of nb (val) is
 440 * "old_state", not the current state. The current state can be retrieved
 441 * by looking at the third pameter (edev pointer)'s state value.
 442 */
 443int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 444                             const char *extcon_name, const char *cable_name,
 445                             struct notifier_block *nb)
 446{
 447        if (!obj || !cable_name || !nb)
 448                return -EINVAL;
 449
 450        if (extcon_name) {
 451                obj->edev = extcon_get_extcon_dev(extcon_name);
 452                if (!obj->edev)
 453                        return -ENODEV;
 454
 455                obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
 456                if (obj->cable_index < 0)
 457                        return obj->cable_index;
 458
 459                obj->user_nb = nb;
 460
 461                obj->internal_nb.notifier_call = _call_per_cable;
 462
 463                return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
 464        } else {
 465                struct class_dev_iter iter;
 466                struct extcon_dev *extd;
 467                struct device *dev;
 468
 469                if (!extcon_class)
 470                        return -ENODEV;
 471                class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 472                while ((dev = class_dev_iter_next(&iter))) {
 473                        extd = (struct extcon_dev *)dev_get_drvdata(dev);
 474
 475                        if (extcon_find_cable_index(extd, cable_name) < 0)
 476                                continue;
 477
 478                        class_dev_iter_exit(&iter);
 479                        return extcon_register_interest(obj, extd->name,
 480                                                cable_name, nb);
 481                }
 482
 483                return -ENODEV;
 484        }
 485}
 486EXPORT_SYMBOL_GPL(extcon_register_interest);
 487
 488/**
 489 * extcon_unregister_interest() - Unregister the notifier registered by
 490 *                              extcon_register_interest().
 491 * @obj:        the extcon_specific_cable_nb object returned by
 492 *              extcon_register_interest().
 493 */
 494int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 495{
 496        if (!obj)
 497                return -EINVAL;
 498
 499        return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 500}
 501EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 502
 503/**
 504 * extcon_register_notifier() - Register a notifiee to get notified by
 505 *                            any attach status changes from the extcon.
 506 * @edev:       the extcon device.
 507 * @nb:         a notifier block to be registered.
 508 *
 509 * Note that the second parameter given to the callback of nb (val) is
 510 * "old_state", not the current state. The current state can be retrieved
 511 * by looking at the third pameter (edev pointer)'s state value.
 512 */
 513int extcon_register_notifier(struct extcon_dev *edev,
 514                        struct notifier_block *nb)
 515{
 516        return raw_notifier_chain_register(&edev->nh, nb);
 517}
 518EXPORT_SYMBOL_GPL(extcon_register_notifier);
 519
 520/**
 521 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 522 * @edev:       the extcon device.
 523 * @nb:         a registered notifier block to be unregistered.
 524 */
 525int extcon_unregister_notifier(struct extcon_dev *edev,
 526                        struct notifier_block *nb)
 527{
 528        return raw_notifier_chain_unregister(&edev->nh, nb);
 529}
 530EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 531
 532static struct attribute *extcon_attrs[] = {
 533        &dev_attr_state.attr,
 534        &dev_attr_name.attr,
 535        NULL,
 536};
 537ATTRIBUTE_GROUPS(extcon);
 538
 539static int create_extcon_class(void)
 540{
 541        if (!extcon_class) {
 542                extcon_class = class_create(THIS_MODULE, "extcon");
 543                if (IS_ERR(extcon_class))
 544                        return PTR_ERR(extcon_class);
 545                extcon_class->dev_groups = extcon_groups;
 546
 547#if defined(CONFIG_ANDROID)
 548                switch_class = class_compat_register("switch");
 549                if (WARN(!switch_class, "cannot allocate"))
 550                        return -ENOMEM;
 551#endif /* CONFIG_ANDROID */
 552        }
 553
 554        return 0;
 555}
 556
 557static void extcon_dev_release(struct device *dev)
 558{
 559        kfree(dev);
 560}
 561
 562static const char *muex_name = "mutually_exclusive";
 563static void dummy_sysfs_dev_release(struct device *dev)
 564{
 565}
 566
 567/**
 568 * extcon_dev_register() - Register a new extcon device
 569 * @edev        : the new extcon device (should be allocated before calling)
 570 * @dev         : the parent device for this extcon device.
 571 *
 572 * Among the members of edev struct, please set the "user initializing data"
 573 * in any case and set the "optional callbacks" if required. However, please
 574 * do not set the values of "internal data", which are initialized by
 575 * this function.
 576 */
 577int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
 578{
 579        int ret, index = 0;
 580
 581        if (!extcon_class) {
 582                ret = create_extcon_class();
 583                if (ret < 0)
 584                        return ret;
 585        }
 586
 587        if (edev->supported_cable) {
 588                /* Get size of array */
 589                for (index = 0; edev->supported_cable[index]; index++)
 590                        ;
 591                edev->max_supported = index;
 592        } else {
 593                edev->max_supported = 0;
 594        }
 595
 596        if (index > SUPPORTED_CABLE_MAX) {
 597                dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 598                return -EINVAL;
 599        }
 600
 601        edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 602        if (!edev->dev)
 603                return -ENOMEM;
 604        edev->dev->parent = dev;
 605        edev->dev->class = extcon_class;
 606        edev->dev->release = extcon_dev_release;
 607
 608        edev->name = edev->name ? edev->name : dev_name(dev);
 609        dev_set_name(edev->dev, "%s", edev->name);
 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,
 738                                               NULL);
 739#endif /* CONFIG_ANDROID */
 740
 741        spin_lock_init(&edev->lock);
 742
 743        RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 744
 745        dev_set_drvdata(edev->dev, edev);
 746        edev->state = 0;
 747
 748        mutex_lock(&extcon_dev_list_lock);
 749        list_add(&edev->entry, &extcon_dev_list);
 750        mutex_unlock(&extcon_dev_list_lock);
 751
 752        return 0;
 753
 754err_dev:
 755        if (edev->max_supported)
 756                kfree(edev->extcon_dev_type.groups);
 757err_alloc_groups:
 758        if (edev->max_supported && edev->mutually_exclusive) {
 759                for (index = 0; edev->mutually_exclusive[index]; index++)
 760                        kfree(edev->d_attrs_muex[index].attr.name);
 761                kfree(edev->d_attrs_muex);
 762                kfree(edev->attrs_muex);
 763        }
 764err_muex:
 765        for (index = 0; index < edev->max_supported; index++)
 766                kfree(edev->cables[index].attr_g.name);
 767err_alloc_cables:
 768        if (edev->max_supported)
 769                kfree(edev->cables);
 770err_sysfs_alloc:
 771        kfree(edev->dev);
 772        return ret;
 773}
 774EXPORT_SYMBOL_GPL(extcon_dev_register);
 775
 776/**
 777 * extcon_dev_unregister() - Unregister the extcon device.
 778 * @edev:       the extcon device instance to be unregistered.
 779 *
 780 * Note that this does not call kfree(edev) because edev was not allocated
 781 * by this class.
 782 */
 783void extcon_dev_unregister(struct extcon_dev *edev)
 784{
 785        int index;
 786
 787        mutex_lock(&extcon_dev_list_lock);
 788        list_del(&edev->entry);
 789        mutex_unlock(&extcon_dev_list_lock);
 790
 791        if (IS_ERR_OR_NULL(get_device(edev->dev))) {
 792                dev_err(edev->dev, "Failed to unregister extcon_dev (%s)\n",
 793                                dev_name(edev->dev));
 794                return;
 795        }
 796
 797        if (edev->mutually_exclusive && edev->max_supported) {
 798                for (index = 0; edev->mutually_exclusive[index];
 799                                index++)
 800                        kfree(edev->d_attrs_muex[index].attr.name);
 801                kfree(edev->d_attrs_muex);
 802                kfree(edev->attrs_muex);
 803        }
 804
 805        for (index = 0; index < edev->max_supported; index++)
 806                kfree(edev->cables[index].attr_g.name);
 807
 808        if (edev->max_supported) {
 809                kfree(edev->extcon_dev_type.groups);
 810                kfree(edev->cables);
 811        }
 812
 813#if defined(CONFIG_ANDROID)
 814        if (switch_class)
 815                class_compat_remove_link(switch_class, edev->dev, NULL);
 816#endif
 817        device_unregister(edev->dev);
 818        put_device(edev->dev);
 819}
 820EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 821
 822static int __init extcon_class_init(void)
 823{
 824        return create_extcon_class();
 825}
 826module_init(extcon_class_init);
 827
 828static void __exit extcon_class_exit(void)
 829{
 830#if defined(CONFIG_ANDROID)
 831        class_compat_unregister(switch_class);
 832#endif
 833        class_destroy(extcon_class);
 834}
 835module_exit(extcon_class_exit);
 836
 837MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 838MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 839MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 840MODULE_DESCRIPTION("External connector (extcon) class driver");
 841MODULE_LICENSE("GPL");
 842
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