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}
 151
 152static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 153                char *buf)
 154{
 155        struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev);
 156
 157        /* Optional callback given by the user */
 158        if (edev->print_name) {
 159                int ret = edev->print_name(edev, buf);
 160                if (ret >= 0)
 161                        return ret;
 162        }
 163
 164        return sprintf(buf, "%s\n", dev_name(edev->dev));
 165}
 166
 167static ssize_t cable_name_show(struct device *dev,
 168                               struct device_attribute *attr, char *buf)
 169{
 170        struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 171                                                  attr_name);
 172
 173        return sprintf(buf, "%s\n",
 174                       cable->edev->supported_cable[cable->cable_index]);
 175}
 176
 177static ssize_t cable_state_show(struct device *dev,
 178                                struct device_attribute *attr, char *buf)
 179{
 180        struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 181                                                  attr_state);
 182
 183        return sprintf(buf, "%d\n",
 184                       extcon_get_cable_state_(cable->edev,
 185                                               cable->cable_index));
 186}
 187
 188static ssize_t cable_state_store(struct device *dev,
 189                                 struct device_attribute *attr, const char *buf,
 190                                 size_t count)
 191{
 192        struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 193                                                  attr_state);
 194        int ret, state;
 195
 196        ret = sscanf(buf, "%d", &state);
 197        if (ret == 0)
 198                ret = -EINVAL;
 199        else
 200                ret = extcon_set_cable_state_(cable->edev, cable->cable_index,
 201                                              state);
 202
 203        if (ret < 0)
 204                return ret;
 205        return count;
 206}
 207
 208/**
 209 * extcon_update_state() - Update the cable attach states of the extcon device
 210 *                      only for the masked bits.
 211 * @edev:       the extcon device
 212 * @mask:       the bit mask to designate updated bits.
 213 * @state:      new cable attach status for @edev
 214 *
 215 * Changing the state sends uevent with environment variable containing
 216 * the name of extcon device (envp[0]) and the state output (envp[1]).
 217 * Tizen uses this format for extcon device to get events from ports.
 218 * Android uses this format as well.
 219 *
 220 * Note that the notifier provides which bits are changed in the state
 221 * variable with the val parameter (second) to the callback.
 222 */
 223int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 224{
 225        char name_buf[120];
 226        char state_buf[120];
 227        char *prop_buf;
 228        char *envp[3];
 229        int env_offset = 0;
 230        int length;
 231        unsigned long flags;
 232
 233        spin_lock_irqsave(&edev->lock, flags);
 234
 235        if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 236                u32 old_state = edev->state;
 237
 238                if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 239                                                   (state & mask))) {
 240                        spin_unlock_irqrestore(&edev->lock, flags);
 241                        return -EPERM;
 242                }
 243
 244                edev->state &= ~mask;
 245                edev->state |= state & mask;
 246
 247                raw_notifier_call_chain(&edev->nh, old_state, edev);
 248
 249                /* This could be in interrupt handler */
 250                prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 251                if (prop_buf) {
 252                        length = name_show(edev->dev, NULL, prop_buf);
 253                        if (length > 0) {
 254                                if (prop_buf[length - 1] == '\n')
 255                                        prop_buf[length - 1] = 0;
 256                                snprintf(name_buf, sizeof(name_buf),
 257                                        "NAME=%s", prop_buf);
 258                                envp[env_offset++] = name_buf;
 259                        }
 260                        length = state_show(edev->dev, NULL, prop_buf);
 261                        if (length > 0) {
 262                                if (prop_buf[length - 1] == '\n')
 263                                        prop_buf[length - 1] = 0;
 264                                snprintf(state_buf, sizeof(state_buf),
 265                                        "STATE=%s", prop_buf);
 266                                envp[env_offset++] = state_buf;
 267                        }
 268                        envp[env_offset] = NULL;
 269                        /* Unlock early before uevent */
 270                        spin_unlock_irqrestore(&edev->lock, flags);
 271
 272                        kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp);
 273                        free_page((unsigned long)prop_buf);
 274                } else {
 275                        /* Unlock early before uevent */
 276                        spin_unlock_irqrestore(&edev->lock, flags);
 277
 278                        dev_err(edev->dev, "out of memory in extcon_set_state\n");
 279                        kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE);
 280                }
 281        } else {
 282                /* No changes */
 283                spin_unlock_irqrestore(&edev->lock, flags);
 284        }
 285
 286        return 0;
 287}
 288EXPORT_SYMBOL_GPL(extcon_update_state);
 289
 290/**
 291 * extcon_set_state() - Set the cable attach states of the extcon device.
 292 * @edev:       the extcon device
 293 * @state:      new cable attach status for @edev
 294 *
 295 * Note that notifier provides which bits are changed in the state
 296 * variable with the val parameter (second) to the callback.
 297 */
 298int extcon_set_state(struct extcon_dev *edev, u32 state)
 299{
 300        return extcon_update_state(edev, 0xffffffff, state);
 301}
 302EXPORT_SYMBOL_GPL(extcon_set_state);
 303
 304/**
 305 * extcon_find_cable_index() - Get the cable index based on the cable name.
 306 * @edev:       the extcon device that has the cable.
 307 * @cable_name: cable name to be searched.
 308 *
 309 * Note that accessing a cable state based on cable_index is faster than
 310 * cable_name because using cable_name induces a loop with strncmp().
 311 * Thus, when get/set_cable_state is repeatedly used, using cable_index
 312 * is recommended.
 313 */
 314int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 315{
 316        int i;
 317
 318        if (edev->supported_cable) {
 319                for (i = 0; edev->supported_cable[i]; i++) {
 320                        if (!strncmp(edev->supported_cable[i],
 321                                cable_name, CABLE_NAME_MAX))
 322                                return i;
 323                }
 324        }
 325
 326        return -EINVAL;
 327}
 328EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 329
 330/**
 331 * extcon_get_cable_state_() - Get the status of a specific cable.
 332 * @edev:       the extcon device that has the cable.
 333 * @index:      cable index that can be retrieved by extcon_find_cable_index().
 334 */
 335int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 336{
 337        if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 338                return -EINVAL;
 339
 340        return !!(edev->state & (1 << index));
 341}
 342EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 343
 344/**
 345 * extcon_get_cable_state() - Get the status of a specific cable.
 346 * @edev:       the extcon device that has the cable.
 347 * @cable_name: cable name.
 348 *
 349 * Note that this is slower than extcon_get_cable_state_.
 350 */
 351int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 352{
 353        return extcon_get_cable_state_(edev, extcon_find_cable_index
 354                                                (edev, cable_name));
 355}
 356EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 357
 358/**
 359 * extcon_set_cable_state_() - Set the status of a specific cable.
 360 * @edev:       the extcon device that has the cable.
 361 * @index:      cable index that can be retrieved by extcon_find_cable_index().
 362 * @cable_state:        the new cable status. The default semantics is
 363 *                      true: attached / false: detached.
 364 */
 365int extcon_set_cable_state_(struct extcon_dev *edev,
 366                        int index, bool cable_state)
 367{
 368        u32 state;
 369
 370        if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 371                return -EINVAL;
 372
 373        state = cable_state ? (1 << index) : 0;
 374        return extcon_update_state(edev, 1 << index, state);
 375}
 376EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 377
 378/**
 379 * extcon_set_cable_state() - Set the status of a specific cable.
 380 * @edev:       the extcon device that has the cable.
 381 * @cable_name: cable name.
 382 * @cable_state:        the new cable status. The default semantics is
 383 *                      true: attached / false: detached.
 384 *
 385 * Note that this is slower than extcon_set_cable_state_.
 386 */
 387int extcon_set_cable_state(struct extcon_dev *edev,
 388                        const char *cable_name, bool cable_state)
 389{
 390        return extcon_set_cable_state_(edev, extcon_find_cable_index
 391                                        (edev, cable_name), cable_state);
 392}
 393EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 394
 395/**
 396 * extcon_get_extcon_dev() - Get the extcon device instance from the name
 397 * @extcon_name:        The extcon name provided with extcon_dev_register()
 398 */
 399struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 400{
 401        struct extcon_dev *sd;
 402
 403        mutex_lock(&extcon_dev_list_lock);
 404        list_for_each_entry(sd, &extcon_dev_list, entry) {
 405                if (!strcmp(sd->name, extcon_name))
 406                        goto out;
 407        }
 408        sd = NULL;
 409out:
 410        mutex_unlock(&extcon_dev_list_lock);
 411        return sd;
 412}
 413EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 414
 415static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 416                           void *ptr)
 417{
 418        struct extcon_specific_cable_nb *obj = container_of(nb,
 419                        struct extcon_specific_cable_nb, internal_nb);
 420        struct extcon_dev *edev = ptr;
 421
 422        if ((val & (1 << obj->cable_index)) !=
 423            (edev->state & (1 << obj->cable_index))) {
 424                bool cable_state = true;
 425
 426                obj->previous_value = val;
 427
 428                if (val & (1 << obj->cable_index))
 429                        cable_state = false;
 430
 431                return obj->user_nb->notifier_call(obj->user_nb,
 432                                cable_state, ptr);
 433        }
 434
 435        return NOTIFY_OK;
 436}
 437
 438/**
 439 * extcon_register_interest() - Register a notifier for a state change of a
 440 *                            specific cable, not an entier set of cables of a
 441 *                            extcon device.
 442 * @obj:        an empty extcon_specific_cable_nb object to be returned.
 443 * @extcon_name:        the name of extcon device.
 444 *                      if NULL, extcon_register_interest will register
 445 *                      every cable with the target cable_name given.
 446 * @cable_name:         the target cable name.
 447 * @nb:         the notifier block to get notified.
 448 *
 449 * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 450 * the struct for you.
 451 *
 452 * extcon_register_interest is a helper function for those who want to get
 453 * notification for a single specific cable's status change. If a user wants
 454 * to get notification for any changes of all cables of a extcon device,
 455 * he/she should use the general extcon_register_notifier().
 456 *
 457 * Note that the second parameter given to the callback of nb (val) is
 458 * "old_state", not the current state. The current state can be retrieved
 459 * by looking at the third pameter (edev pointer)'s state value.
 460 */
 461int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 462                             const char *extcon_name, const char *cable_name,
 463                             struct notifier_block *nb)
 464{
 465        if (!obj || !cable_name || !nb)
 466                return -EINVAL;
 467
 468        if (extcon_name) {
 469                obj->edev = extcon_get_extcon_dev(extcon_name);
 470                if (!obj->edev)
 471                        return -ENODEV;
 472
 473                obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
 474                if (obj->cable_index < 0)
 475                        return obj->cable_index;
 476
 477                obj->user_nb = nb;
 478
 479                obj->internal_nb.notifier_call = _call_per_cable;
 480
 481                return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb);
 482        } else {
 483                struct class_dev_iter iter;
 484                struct extcon_dev *extd;
 485                struct device *dev;
 486
 487                if (!extcon_class)
 488                        return -ENODEV;
 489                class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 490                while ((dev = class_dev_iter_next(&iter))) {
 491                        extd = (struct extcon_dev *)dev_get_drvdata(dev);
 492
 493                        if (extcon_find_cable_index(extd, cable_name) < 0)
 494                                continue;
 495
 496                        class_dev_iter_exit(&iter);
 497                        return extcon_register_interest(obj, extd->name,
 498                                                cable_name, nb);
 499                }
 500
 501                return -ENODEV;
 502        }
 503}
 504
 505/**
 506 * extcon_unregister_interest() - Unregister the notifier registered by
 507 *                              extcon_register_interest().
 508 * @obj:        the extcon_specific_cable_nb object returned by
 509 *              extcon_register_interest().
 510 */
 511int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 512{
 513        if (!obj)
 514                return -EINVAL;
 515
 516        return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 517}
 518
 519/**
 520 * extcon_register_notifier() - Register a notifiee to get notified by
 521 *                            any attach status changes from the extcon.
 522 * @edev:       the extcon device.
 523 * @nb:         a notifier block to be registered.
 524 *
 525 * Note that the second parameter given to the callback of nb (val) is
 526 * "old_state", not the current state. The current state can be retrieved
 527 * by looking at the third pameter (edev pointer)'s state value.
 528 */
 529int extcon_register_notifier(struct extcon_dev *edev,
 530                        struct notifier_block *nb)
 531{
 532        return raw_notifier_chain_register(&edev->nh, nb);
 533}
 534EXPORT_SYMBOL_GPL(extcon_register_notifier);
 535
 536/**
 537 * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 538 * @edev:       the extcon device.
 539 * @nb:         a registered notifier block to be unregistered.
 540 */
 541int extcon_unregister_notifier(struct extcon_dev *edev,
 542                        struct notifier_block *nb)
 543{
 544        return raw_notifier_chain_unregister(&edev->nh, nb);
 545}
 546EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 547
 548static struct device_attribute extcon_attrs[] = {
 549        __ATTR(state, S_IRUGO | S_IWUSR, state_show, state_store),
 550        __ATTR_RO(name),
 551        __ATTR_NULL,
 552};
 553
 554static int create_extcon_class(void)
 555{
 556        if (!extcon_class) {
 557                extcon_class = class_create(THIS_MODULE, "extcon");
 558                if (IS_ERR(extcon_class))
 559                        return PTR_ERR(extcon_class);
 560                extcon_class->dev_attrs = extcon_attrs;
 561
 562#if defined(CONFIG_ANDROID)
 563                switch_class = class_compat_register("switch");
 564                if (WARN(!switch_class, "cannot allocate"))
 565                        return -ENOMEM;
 566#endif /* CONFIG_ANDROID */
 567        }
 568
 569        return 0;
 570}
 571
 572static void extcon_dev_release(struct device *dev)
 573{
 574        kfree(dev);
 575}
 576
 577static const char *muex_name = "mutually_exclusive";
 578static void dummy_sysfs_dev_release(struct device *dev)
 579{
 580}
 581
 582/**
 583 * extcon_dev_register() - Register a new extcon device
 584 * @edev        : the new extcon device (should be allocated before calling)
 585 * @dev         : the parent device for this extcon device.
 586 *
 587 * Among the members of edev struct, please set the "user initializing data"
 588 * in any case and set the "optional callbacks" if required. However, please
 589 * do not set the values of "internal data", which are initialized by
 590 * this function.
 591 */
 592int extcon_dev_register(struct extcon_dev *edev, struct device *dev)
 593{
 594        int ret, index = 0;
 595
 596        if (!extcon_class) {
 597                ret = create_extcon_class();
 598                if (ret < 0)
 599                        return ret;
 600        }
 601
 602        if (edev->supported_cable) {
 603                /* Get size of array */
 604                for (index = 0; edev->supported_cable[index]; index++)
 605                        ;
 606                edev->max_supported = index;
 607        } else {
 608                edev->max_supported = 0;
 609        }
 610
 611        if (index > SUPPORTED_CABLE_MAX) {
 612                dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 613                return -EINVAL;
 614        }
 615
 616        edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
 617        if (!edev->dev)
 618                return -ENOMEM;
 619        edev->dev->parent = dev;
 620        edev->dev->class = extcon_class;
 621        edev->dev->release = extcon_dev_release;
 622
 623        dev_set_name(edev->dev, edev->name ? edev->name : dev_name(dev));
 624
 625        if (edev->max_supported) {
 626                char buf[10];
 627                char *str;
 628                struct extcon_cable *cable;
 629
 630                edev->cables = kzalloc(sizeof(struct extcon_cable) *
 631                                       edev->max_supported, GFP_KERNEL);
 632                if (!edev->cables) {
 633                        ret = -ENOMEM;
 634                        goto err_sysfs_alloc;
 635                }
 636                for (index = 0; index < edev->max_supported; index++) {
 637                        cable = &edev->cables[index];
 638
 639                        snprintf(buf, 10, "cable.%d", index);
 640                        str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 641                                      GFP_KERNEL);
 642                        if (!str) {
 643                                for (index--; index >= 0; index--) {
 644                                        cable = &edev->cables[index];
 645                                        kfree(cable->attr_g.name);
 646                                }
 647                                ret = -ENOMEM;
 648
 649                                goto err_alloc_cables;
 650                        }
 651                        strcpy(str, buf);
 652
 653                        cable->edev = edev;
 654                        cable->cable_index = index;
 655                        cable->attrs[0] = &cable->attr_name.attr;
 656                        cable->attrs[1] = &cable->attr_state.attr;
 657                        cable->attrs[2] = NULL;
 658                        cable->attr_g.name = str;
 659                        cable->attr_g.attrs = cable->attrs;
 660
 661                        sysfs_attr_init(&cable->attr_name.attr);
 662                        cable->attr_name.attr.name = "name";
 663                        cable->attr_name.attr.mode = 0444;
 664                        cable->attr_name.show = cable_name_show;
 665
 666                        sysfs_attr_init(&cable->attr_state.attr);
 667                        cable->attr_state.attr.name = "state";
 668                        cable->attr_state.attr.mode = 0644;
 669                        cable->attr_state.show = cable_state_show;
 670                        cable->attr_state.store = cable_state_store;
 671                }
 672        }
 673
 674        if (edev->max_supported && edev->mutually_exclusive) {
 675                char buf[80];
 676                char *name;
 677
 678                /* Count the size of mutually_exclusive array */
 679                for (index = 0; edev->mutually_exclusive[index]; index++)
 680                        ;
 681
 682                edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 683                                           (index + 1), GFP_KERNEL);
 684                if (!edev->attrs_muex) {
 685                        ret = -ENOMEM;
 686                        goto err_muex;
 687                }
 688
 689                edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 690                                             index, GFP_KERNEL);
 691                if (!edev->d_attrs_muex) {
 692                        ret = -ENOMEM;
 693                        kfree(edev->attrs_muex);
 694                        goto err_muex;
 695                }
 696
 697                for (index = 0; edev->mutually_exclusive[index]; index++) {
 698                        sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 699                        name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 700                                       GFP_KERNEL);
 701                        if (!name) {
 702                                for (index--; index >= 0; index--) {
 703                                        kfree(edev->d_attrs_muex[index].attr.
 704                                              name);
 705                                }
 706                                kfree(edev->d_attrs_muex);
 707                                kfree(edev->attrs_muex);
 708                                ret = -ENOMEM;
 709                                goto err_muex;
 710                        }
 711                        strcpy(name, buf);
 712                        sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 713                        edev->d_attrs_muex[index].attr.name = name;
 714                        edev->d_attrs_muex[index].attr.mode = 0000;
 715                        edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 716                                                        .attr;
 717                }
 718                edev->attr_g_muex.name = muex_name;
 719                edev->attr_g_muex.attrs = edev->attrs_muex;
 720
 721        }
 722
 723        if (edev->max_supported) {
 724                edev->extcon_dev_type.groups =
 725                        kzalloc(sizeof(struct attribute_group *) *
 726                                (edev->max_supported + 2), GFP_KERNEL);
 727                if (!edev->extcon_dev_type.groups) {
 728                        ret = -ENOMEM;
 729                        goto err_alloc_groups;
 730                }
 731
 732                edev->extcon_dev_type.name = dev_name(edev->dev);
 733                edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 734
 735                for (index = 0; index < edev->max_supported; index++)
 736                        edev->extcon_dev_type.groups[index] =
 737                                &edev->cables[index].attr_g;
 738                if (edev->mutually_exclusive)
 739                        edev->extcon_dev_type.groups[index] =
 740                                &edev->attr_g_muex;
 741
 742                edev->dev->type = &edev->extcon_dev_type;
 743        }
 744
 745        ret = device_register(edev->dev);
 746        if (ret) {
 747                put_device(edev->dev);
 748                goto err_dev;
 749        }
 750#if defined(CONFIG_ANDROID)
 751        if (switch_class)
 752                ret = class_compat_create_link(switch_class, edev->dev,
 753                                               NULL);
 754#endif /* CONFIG_ANDROID */
 755
 756        spin_lock_init(&edev->lock);
 757
 758        RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 759
 760        dev_set_drvdata(edev->dev, edev);
 761        edev->state = 0;
 762
 763        mutex_lock(&extcon_dev_list_lock);
 764        list_add(&edev->entry, &extcon_dev_list);
 765        mutex_unlock(&extcon_dev_list_lock);
 766
 767        return 0;
 768
 769err_dev:
 770        if (edev->max_supported)
 771                kfree(edev->extcon_dev_type.groups);
 772err_alloc_groups:
 773        if (edev->max_supported && edev->mutually_exclusive) {
 774                for (index = 0; edev->mutually_exclusive[index]; index++)
 775                        kfree(edev->d_attrs_muex[index].attr.name);
 776                kfree(edev->d_attrs_muex);
 777                kfree(edev->attrs_muex);
 778        }
 779err_muex:
 780        for (index = 0; index < edev->max_supported; index++)
 781                kfree(edev->cables[index].attr_g.name);
 782err_alloc_cables:
 783        if (edev->max_supported)
 784                kfree(edev->cables);
 785err_sysfs_alloc:
 786        kfree(edev->dev);
 787        return ret;
 788}
 789EXPORT_SYMBOL_GPL(extcon_dev_register);
 790
 791/**
 792 * extcon_dev_unregister() - Unregister the extcon device.
 793 * @edev:       the extcon device instance to be unregistered.
 794 *
 795 * Note that this does not call kfree(edev) because edev was not allocated
 796 * by this class.
 797 */
 798void extcon_dev_unregister(struct extcon_dev *edev)
 799{
 800        int index;
 801
 802        mutex_lock(&extcon_dev_list_lock);
 803        list_del(&edev->entry);
 804        mutex_unlock(&extcon_dev_list_lock);
 805
 806        if (IS_ERR_OR_NULL(get_device(edev->dev))) {
 807                dev_err(edev->dev, "Failed to unregister extcon_dev (%s)\n",
 808                                dev_name(edev->dev));
 809                return;
 810        }
 811
 812        if (edev->mutually_exclusive && edev->max_supported) {
 813                for (index = 0; edev->mutually_exclusive[index];
 814                                index++)
 815                        kfree(edev->d_attrs_muex[index].attr.name);
 816                kfree(edev->d_attrs_muex);
 817                kfree(edev->attrs_muex);
 818        }
 819
 820        for (index = 0; index < edev->max_supported; index++)
 821                kfree(edev->cables[index].attr_g.name);
 822
 823        if (edev->max_supported) {
 824                kfree(edev->extcon_dev_type.groups);
 825                kfree(edev->cables);
 826        }
 827
 828#if defined(CONFIG_ANDROID)
 829        if (switch_class)
 830                class_compat_remove_link(switch_class, edev->dev, NULL);
 831#endif
 832        device_unregister(edev->dev);
 833        put_device(edev->dev);
 834}
 835EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 836
 837static int __init extcon_class_init(void)
 838{
 839        return create_extcon_class();
 840}
 841module_init(extcon_class_init);
 842
 843static void __exit extcon_class_exit(void)
 844{
 845#if defined(CONFIG_ANDROID)
 846        class_compat_unregister(switch_class);
 847#endif
 848        class_destroy(extcon_class);
 849}
 850module_exit(extcon_class_exit);
 851
 852MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 853MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 854MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 855MODULE_DESCRIPTION("External connector (extcon) class driver");
 856MODULE_LICENSE("GPL");
 857
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