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_USB]            = "USB",
  43         [EXTCON_USB_HOST]       = "USB-Host",
  44         [EXTCON_TA]             = "TA",
  45         [EXTCON_FAST_CHARGER]   = "Fast-charger",
  46         [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  47         [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  48         [EXTCON_LINE_IN]        = "Line-in",
  49         [EXTCON_LINE_OUT]       = "Line-out",
  50         [EXTCON_MICROPHONE]     = "Microphone",
  51         [EXTCON_HEADPHONE]      = "Headphone",
  52         [EXTCON_HDMI]           = "HDMI",
  53         [EXTCON_MHL]            = "MHL",
  54         [EXTCON_DVI]            = "DVI",
  55         [EXTCON_VGA]            = "VGA",
  56         [EXTCON_SPDIF_IN]       = "SPDIF-in",
  57         [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  58         [EXTCON_VIDEO_IN]       = "Video-in",
  59         [EXTCON_VIDEO_OUT]      = "Video-out",
  60         [EXTCON_DOCK]           = "Dock",
  61         [EXTCON_JIG]            = "JIG",
  62         [EXTCON_MECHANICAL]     = "Mechanical",
  63         NULL,
  64 };
  65
  66 static struct class *extcon_class;
  67 #if defined(CONFIG_ANDROID)
  68 static struct class_compat *switch_class;
  69 #endif /* CONFIG_ANDROID */
  70
  71 static LIST_HEAD(extcon_dev_list);
  72 static DEFINE_MUTEX(extcon_dev_list_lock);
  73
  74 /**
  75  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  76  *                            condition.
  77  * @edev:       the extcon device
  78  * @new_state:  new cable attach status for @edev
  79  *
  80  * Returns 0 if nothing violates. Returns the index + 1 for the first
  81  * violated condition.
  82  */
  83 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  84 {
  85         int i = 0;
  86
  87         if (!edev->mutually_exclusive)
  88                 return 0;
  89
  90         for (i = 0; edev->mutually_exclusive[i]; i++) {
  91                 int weight;
  92                 u32 correspondants = new_state & edev->mutually_exclusive[i];
  93
  94                 /* calculate the total number of bits set */
  95                 weight = hweight32(correspondants);
  96                 if (weight > 1)
  97                         return i + 1;
  98         }
  99
 100         return 0;
 101 }
 102
 103 static int find_cable_index_by_id(struct extcon_dev *edev, const enum extcon id)
 104 {
 105         int i;
 106
 107         /* Find the the index of extcon cable in edev->supported_cable */
 108         for (i = 0; i < edev->max_supported; i++) {
 109                 if (edev->supported_cable[i] == id)
 110                         return i;
 111         }
 112
 113         return -EINVAL;
 114 }
 115
 116 static int find_cable_index_by_name(struct extcon_dev *edev, const char *name)
 117 {
 118         enum extcon id = EXTCON_NONE;
 119         int i;
 120
 121         if (edev->max_supported == 0)
 122                 return -EINVAL;
 123
 124         /* Find the the number of extcon cable */
 125         for (i = 0; i < EXTCON_END; i++) {
 126                 if (!extcon_name[i])
 127                         continue;
 128                 if (!strncmp(extcon_name[i], name, CABLE_NAME_MAX)) {
 129                         id = i;
 130                         break;
 131                 }
 132         }
 133
 134         if (id == EXTCON_NONE)
 135                 return -EINVAL;
 136
 137         return find_cable_index_by_id(edev, id);
 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->print_state) {
 147                 int ret = edev->print_state(edev, buf);
 148
 149                 if (ret >= 0)
 150                         return ret;
 151                 /* Use default if failed */
 152         }
 153
 154         if (edev->max_supported == 0)
 155                 return sprintf(buf, "%u\n", edev->state);
 156
 157         for (i = 0; i < edev->max_supported; i++) {
 158                 count += sprintf(buf + count, "%s=%d\n",
 159                                 extcon_name[edev->supported_cable[i]],
 160                                  !!(edev->state & (1 << i)));
 161         }
 162
 163         return count;
 164 }
 165
 166 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 167                            const char *buf, size_t count)
 168 {
 169         u32 state;
 170         ssize_t ret = 0;
 171         struct extcon_dev *edev = dev_get_drvdata(dev);
 172
 173         ret = sscanf(buf, "0x%x", &state);
 174         if (ret == 0)
 175                 ret = -EINVAL;
 176         else
 177                 ret = extcon_set_state(edev, state);
 178
 179         if (ret < 0)
 180                 return ret;
 181
 182         return count;
 183 }
 184 static DEVICE_ATTR_RW(state);
 185
 186 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 187                 char *buf)
 188 {
 189         struct extcon_dev *edev = dev_get_drvdata(dev);
 190
 191         /* Optional callback given by the user */
 192         if (edev->print_name) {
 193                 int ret = edev->print_name(edev, buf);
 194
 195                 if (ret >= 0)
 196                         return ret;
 197         }
 198
 199         return sprintf(buf, "%s\n", edev->name);
 200 }
 201 static DEVICE_ATTR_RO(name);
 202
 203 static ssize_t cable_name_show(struct device *dev,
 204                                struct device_attribute *attr, char *buf)
 205 {
 206         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 207                                                   attr_name);
 208         int i = cable->cable_index;
 209
 210         return sprintf(buf, "%s\n",
 211                         extcon_name[cable->edev->supported_cable[i]]);
 212 }
 213
 214 static ssize_t cable_state_show(struct device *dev,
 215                                 struct device_attribute *attr, char *buf)
 216 {
 217         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 218                                                   attr_state);
 219
 220         return sprintf(buf, "%d\n",
 221                        extcon_get_cable_state_(cable->edev,
 222                                                cable->cable_index));
 223 }
 224
 225 /**
 226  * extcon_update_state() - Update the cable attach states of the extcon device
 227  *                         only for the masked bits.
 228  * @edev:       the extcon device
 229  * @mask:       the bit mask to designate updated bits.
 230  * @state:      new cable attach status for @edev
 231  *
 232  * Changing the state sends uevent with environment variable containing
 233  * the name of extcon device (envp[0]) and the state output (envp[1]).
 234  * Tizen uses this format for extcon device to get events from ports.
 235  * Android uses this format as well.
 236  *
 237  * Note that the notifier provides which bits are changed in the state
 238  * variable with the val parameter (second) to the callback.
 239  */
 240 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 241 {
 242         char name_buf[120];
 243         char state_buf[120];
 244         char *prop_buf;
 245         char *envp[3];
 246         int env_offset = 0;
 247         int length;
 248         unsigned long flags;
 249
 250         spin_lock_irqsave(&edev->lock, flags);
 251
 252         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 253                 u32 old_state = edev->state;
 254
 255                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 256                                                    (state & mask))) {
 257                         spin_unlock_irqrestore(&edev->lock, flags);
 258                         return -EPERM;
 259                 }
 260
 261                 edev->state &= ~mask;
 262                 edev->state |= state & mask;
 263
 264                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 265                 /* This could be in interrupt handler */
 266                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 267                 if (prop_buf) {
 268                         length = name_show(&edev->dev, NULL, prop_buf);
 269                         if (length > 0) {
 270                                 if (prop_buf[length - 1] == '\n')
 271                                         prop_buf[length - 1] = 0;
 272                                 snprintf(name_buf, sizeof(name_buf),
 273                                         "NAME=%s", prop_buf);
 274                                 envp[env_offset++] = name_buf;
 275                         }
 276                         length = state_show(&edev->dev, NULL, prop_buf);
 277                         if (length > 0) {
 278                                 if (prop_buf[length - 1] == '\n')
 279                                         prop_buf[length - 1] = 0;
 280                                 snprintf(state_buf, sizeof(state_buf),
 281                                         "STATE=%s", prop_buf);
 282                                 envp[env_offset++] = state_buf;
 283                         }
 284                         envp[env_offset] = NULL;
 285                         /* Unlock early before uevent */
 286                         spin_unlock_irqrestore(&edev->lock, flags);
 287
 288                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 289                         free_page((unsigned long)prop_buf);
 290                 } else {
 291                         /* Unlock early before uevent */
 292                         spin_unlock_irqrestore(&edev->lock, flags);
 293
 294                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 295                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 296                 }
 297         } else {
 298                 /* No changes */
 299                 spin_unlock_irqrestore(&edev->lock, flags);
 300         }
 301
 302         return 0;
 303 }
 304 EXPORT_SYMBOL_GPL(extcon_update_state);
 305
 306 /**
 307  * extcon_set_state() - Set the cable attach states of the extcon device.
 308  * @edev:       the extcon device
 309  * @state:      new cable attach status for @edev
 310  *
 311  * Note that notifier provides which bits are changed in the state
 312  * variable with the val parameter (second) to the callback.
 313  */
 314 int extcon_set_state(struct extcon_dev *edev, u32 state)
 315 {
 316         return extcon_update_state(edev, 0xffffffff, state);
 317 }
 318 EXPORT_SYMBOL_GPL(extcon_set_state);
 319
 320 /**
 321  * extcon_get_cable_state_() - Get the status of a specific cable.
 322  * @edev:       the extcon device that has the cable.
 323  * @id:         the unique id of each external connector in extcon enumeration.
 324  */
 325 int extcon_get_cable_state_(struct extcon_dev *edev, const enum extcon id)
 326 {
 327         int index;
 328
 329         index = find_cable_index_by_id(edev, id);
 330         if (index < 0)
 331                 return index;
 332
 333         if (edev->max_supported && edev->max_supported <= index)
 334                 return -EINVAL;
 335
 336         return !!(edev->state & (1 << index));
 337 }
 338 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 339
 340 /**
 341  * extcon_get_cable_state() - Get the status of a specific cable.
 342  * @edev:       the extcon device that has the cable.
 343  * @cable_name: cable name.
 344  *
 345  * Note that this is slower than extcon_get_cable_state_.
 346  */
 347 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 348 {
 349         return extcon_get_cable_state_(edev, find_cable_index_by_name
 350                                                 (edev, cable_name));
 351 }
 352 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 353
 354 /**
 355  * extcon_set_cable_state_() - Set the status of a specific cable.
 356  * @edev:               the extcon device that has the cable.
 357  * @id:                 the unique id of each external connector
 358  *                      in extcon enumeration.
 359  * @state:              the new cable status. The default semantics is
 360  *                      true: attached / false: detached.
 361  */
 362 int extcon_set_cable_state_(struct extcon_dev *edev, enum extcon id,
 363                                 bool cable_state)
 364 {
 365         u32 state;
 366         int index;
 367
 368         index = find_cable_index_by_id(edev, id);
 369         if (index < 0)
 370                 return index;
 371
 372         if (edev->max_supported && edev->max_supported <= index)
 373                 return -EINVAL;
 374
 375         state = cable_state ? (1 << index) : 0;
 376         return extcon_update_state(edev, 1 << index, state);
 377 }
 378 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 379
 380 /**
 381  * extcon_set_cable_state() - Set the status of a specific cable.
 382  * @edev:               the extcon device that has the cable.
 383  * @cable_name:         cable name.
 384  * @cable_state:        the new cable status. The default semantics is
 385  *                      true: attached / false: detached.
 386  *
 387  * Note that this is slower than extcon_set_cable_state_.
 388  */
 389 int extcon_set_cable_state(struct extcon_dev *edev,
 390                         const char *cable_name, bool cable_state)
 391 {
 392         return extcon_set_cable_state_(edev, find_cable_index_by_name
 393                                         (edev, cable_name), cable_state);
 394 }
 395 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 396
 397 /**
 398  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 399  * @extcon_name:        The extcon name provided with extcon_dev_register()
 400  */
 401 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 402 {
 403         struct extcon_dev *sd;
 404
 405         mutex_lock(&extcon_dev_list_lock);
 406         list_for_each_entry(sd, &extcon_dev_list, entry) {
 407                 if (!strcmp(sd->name, extcon_name))
 408                         goto out;
 409         }
 410         sd = NULL;
 411 out:
 412         mutex_unlock(&extcon_dev_list_lock);
 413         return sd;
 414 }
 415 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 416
 417 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 418                            void *ptr)
 419 {
 420         struct extcon_specific_cable_nb *obj = container_of(nb,
 421                         struct extcon_specific_cable_nb, internal_nb);
 422         struct extcon_dev *edev = ptr;
 423
 424         if ((val & (1 << obj->cable_index)) !=
 425             (edev->state & (1 << obj->cable_index))) {
 426                 bool cable_state = true;
 427
 428                 obj->previous_value = val;
 429
 430                 if (val & (1 << obj->cable_index))
 431                         cable_state = false;
 432
 433                 return obj->user_nb->notifier_call(obj->user_nb,
 434                                 cable_state, ptr);
 435         }
 436
 437         return NOTIFY_OK;
 438 }
 439
 440 /**
 441  * extcon_register_interest() - Register a notifier for a state change of a
 442  *                              specific cable, not an entier set of cables of a
 443  *                              extcon device.
 444  * @obj:                an empty extcon_specific_cable_nb object to be returned.
 445  * @extcon_name:        the name of extcon device.
 446  *                      if NULL, extcon_register_interest will register
 447  *                      every cable with the target cable_name given.
 448  * @cable_name:         the target cable name.
 449  * @nb:                 the notifier block to get notified.
 450  *
 451  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 452  * the struct for you.
 453  *
 454  * extcon_register_interest is a helper function for those who want to get
 455  * notification for a single specific cable's status change. If a user wants
 456  * to get notification for any changes of all cables of a extcon device,
 457  * he/she should use the general extcon_register_notifier().
 458  *
 459  * Note that the second parameter given to the callback of nb (val) is
 460  * "old_state", not the current state. The current state can be retrieved
 461  * by looking at the third pameter (edev pointer)'s state value.
 462  */
 463 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 464                              const char *extcon_name, const char *cable_name,
 465                              struct notifier_block *nb)
 466 {
 467         unsigned long flags;
 468         int ret;
 469
 470         if (!obj || !cable_name || !nb)
 471                 return -EINVAL;
 472
 473         if (extcon_name) {
 474                 obj->edev = extcon_get_extcon_dev(extcon_name);
 475                 if (!obj->edev)
 476                         return -ENODEV;
 477
 478                 obj->cable_index = find_cable_index_by_name(obj->edev,
 479                                                         cable_name);
 480                 if (obj->cable_index < 0)
 481                         return obj->cable_index;
 482
 483                 obj->user_nb = nb;
 484
 485                 obj->internal_nb.notifier_call = _call_per_cable;
 486
 487                 spin_lock_irqsave(&obj->edev->lock, flags);
 488                 ret = raw_notifier_chain_register(&obj->edev->nh,
 489                                                   &obj->internal_nb);
 490                 spin_unlock_irqrestore(&obj->edev->lock, flags);
 491         } else {
 492                 struct class_dev_iter iter;
 493                 struct extcon_dev *extd;
 494                 struct device *dev;
 495
 496                 if (!extcon_class)
 497                         return -ENODEV;
 498                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 499                 while ((dev = class_dev_iter_next(&iter))) {
 500                         extd = dev_get_drvdata(dev);
 501
 502                         if (find_cable_index_by_name(extd, cable_name) < 0)
 503                                 continue;
 504
 505                         class_dev_iter_exit(&iter);
 506                         return extcon_register_interest(obj, extd->name,
 507                                                 cable_name, nb);
 508                 }
 509
 510                 ret = -ENODEV;
 511         }
 512
 513         return ret;
 514 }
 515 EXPORT_SYMBOL_GPL(extcon_register_interest);
 516
 517 /**
 518  * extcon_unregister_interest() - Unregister the notifier registered by
 519  *                                extcon_register_interest().
 520  * @obj:        the extcon_specific_cable_nb object returned by
 521  *              extcon_register_interest().
 522  */
 523 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 524 {
 525         unsigned long flags;
 526         int ret;
 527
 528         if (!obj)
 529                 return -EINVAL;
 530
 531         spin_lock_irqsave(&obj->edev->lock, flags);
 532         ret = raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 533         spin_unlock_irqrestore(&obj->edev->lock, flags);
 534
 535         return ret;
 536 }
 537 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 538
 539 /**
 540  * extcon_register_notifier() - Register a notifiee to get notified by
 541  *                              any attach status changes from the extcon.
 542  * @edev:       the extcon device.
 543  * @nb:         a notifier block to be registered.
 544  *
 545  * Note that the second parameter given to the callback of nb (val) is
 546  * "old_state", not the current state. The current state can be retrieved
 547  * by looking at the third pameter (edev pointer)'s state value.
 548  */
 549 int extcon_register_notifier(struct extcon_dev *edev,
 550                         struct notifier_block *nb)
 551 {
 552         unsigned long flags;
 553         int ret;
 554
 555         spin_lock_irqsave(&edev->lock, flags);
 556         ret = raw_notifier_chain_register(&edev->nh, nb);
 557         spin_unlock_irqrestore(&edev->lock, flags);
 558
 559         return ret;
 560 }
 561 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 562
 563 /**
 564  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 565  * @edev:       the extcon device.
 566  * @nb:         a registered notifier block to be unregistered.
 567  */
 568 int extcon_unregister_notifier(struct extcon_dev *edev,
 569                         struct notifier_block *nb)
 570 {
 571         unsigned long flags;
 572         int ret;
 573
 574         spin_lock_irqsave(&edev->lock, flags);
 575         ret = raw_notifier_chain_unregister(&edev->nh, nb);
 576         spin_unlock_irqrestore(&edev->lock, flags);
 577
 578         return ret;
 579 }
 580 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 581
 582 static struct attribute *extcon_attrs[] = {
 583         &dev_attr_state.attr,
 584         &dev_attr_name.attr,
 585         NULL,
 586 };
 587 ATTRIBUTE_GROUPS(extcon);
 588
 589 static int create_extcon_class(void)
 590 {
 591         if (!extcon_class) {
 592                 extcon_class = class_create(THIS_MODULE, "extcon");
 593                 if (IS_ERR(extcon_class))
 594                         return PTR_ERR(extcon_class);
 595                 extcon_class->dev_groups = extcon_groups;
 596
 597 #if defined(CONFIG_ANDROID)
 598                 switch_class = class_compat_register("switch");
 599                 if (WARN(!switch_class, "cannot allocate"))
 600                         return -ENOMEM;
 601 #endif /* CONFIG_ANDROID */
 602         }
 603
 604         return 0;
 605 }
 606
 607 static void extcon_dev_release(struct device *dev)
 608 {
 609 }
 610
 611 static const char *muex_name = "mutually_exclusive";
 612 static void dummy_sysfs_dev_release(struct device *dev)
 613 {
 614 }
 615
 616 /*
 617  * extcon_dev_allocate() - Allocate the memory of extcon device.
 618  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 619  *                      If supported_cable is NULL, cable name related APIs
 620  *                      are disabled.
 621  *
 622  * This function allocates the memory for extcon device without allocating
 623  * memory in each extcon provider driver and initialize default setting for
 624  * extcon device.
 625  *
 626  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 627  */
 628 struct extcon_dev *extcon_dev_allocate(const enum extcon *supported_cable)
 629 {
 630         struct extcon_dev *edev;
 631
 632         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 633         if (!edev)
 634                 return ERR_PTR(-ENOMEM);
 635
 636         edev->max_supported = 0;
 637         edev->supported_cable = supported_cable;
 638
 639         return edev;
 640 }
 641
 642 /*
 643  * extcon_dev_free() - Free the memory of extcon device.
 644  * @edev:       the extcon device to free
 645  */
 646 void extcon_dev_free(struct extcon_dev *edev)
 647 {
 648         kfree(edev);
 649 }
 650 EXPORT_SYMBOL_GPL(extcon_dev_free);
 651
 652 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 653 {
 654         struct extcon_dev **r = res;
 655
 656         if (WARN_ON(!r || !*r))
 657                 return 0;
 658
 659         return *r == data;
 660 }
 661
 662 static void devm_extcon_dev_release(struct device *dev, void *res)
 663 {
 664         extcon_dev_free(*(struct extcon_dev **)res);
 665 }
 666
 667 /**
 668  * devm_extcon_dev_allocate - Allocate managed extcon device
 669  * @dev:                device owning the extcon device being created
 670  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 671  *                      If supported_cable is NULL, cable name related APIs
 672  *                      are disabled.
 673  *
 674  * This function manages automatically the memory of extcon device using device
 675  * resource management and simplify the control of freeing the memory of extcon
 676  * device.
 677  *
 678  * Returns the pointer memory of allocated extcon_dev if success
 679  * or ERR_PTR(err) if fail
 680  */
 681 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 682                                         const enum extcon *supported_cable)
 683 {
 684         struct extcon_dev **ptr, *edev;
 685
 686         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 687         if (!ptr)
 688                 return ERR_PTR(-ENOMEM);
 689
 690         edev = extcon_dev_allocate(supported_cable);
 691         if (IS_ERR(edev)) {
 692                 devres_free(ptr);
 693                 return edev;
 694         }
 695
 696         edev->dev.parent = dev;
 697
 698         *ptr = edev;
 699         devres_add(dev, ptr);
 700
 701         return edev;
 702 }
 703 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 704
 705 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 706 {
 707         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 708                                devm_extcon_dev_match, edev));
 709 }
 710 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 711
 712 /**
 713  * extcon_dev_register() - Register a new extcon device
 714  * @edev        : the new extcon device (should be allocated before calling)
 715  *
 716  * Among the members of edev struct, please set the "user initializing data"
 717  * in any case and set the "optional callbacks" if required. However, please
 718  * do not set the values of "internal data", which are initialized by
 719  * this function.
 720  */
 721 int extcon_dev_register(struct extcon_dev *edev)
 722 {
 723         int ret, index = 0;
 724         static atomic_t edev_no = ATOMIC_INIT(-1);
 725
 726         if (!extcon_class) {
 727                 ret = create_extcon_class();
 728                 if (ret < 0)
 729                         return ret;
 730         }
 731
 732         if (!edev->supported_cable)
 733                 return -EINVAL;
 734
 735         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 736
 737         edev->max_supported = index;
 738         if (index > SUPPORTED_CABLE_MAX) {
 739                 dev_err(&edev->dev,
 740                         "exceed the maximum number of supported cables\n");
 741                 return -EINVAL;
 742         }
 743
 744         edev->dev.class = extcon_class;
 745         edev->dev.release = extcon_dev_release;
 746
 747         edev->name = dev_name(edev->dev.parent);
 748         if (IS_ERR_OR_NULL(edev->name)) {
 749                 dev_err(&edev->dev,
 750                         "extcon device name is null\n");
 751                 return -EINVAL;
 752         }
 753         dev_set_name(&edev->dev, "extcon%lu",
 754                         (unsigned long)atomic_inc_return(&edev_no));
 755
 756         if (edev->max_supported) {
 757                 char buf[10];
 758                 char *str;
 759                 struct extcon_cable *cable;
 760
 761                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 762                                        edev->max_supported, GFP_KERNEL);
 763                 if (!edev->cables) {
 764                         ret = -ENOMEM;
 765                         goto err_sysfs_alloc;
 766                 }
 767                 for (index = 0; index < edev->max_supported; index++) {
 768                         cable = &edev->cables[index];
 769
 770                         snprintf(buf, 10, "cable.%d", index);
 771                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 772                                       GFP_KERNEL);
 773                         if (!str) {
 774                                 for (index--; index >= 0; index--) {
 775                                         cable = &edev->cables[index];
 776                                         kfree(cable->attr_g.name);
 777                                 }
 778                                 ret = -ENOMEM;
 779
 780                                 goto err_alloc_cables;
 781                         }
 782                         strcpy(str, buf);
 783
 784                         cable->edev = edev;
 785                         cable->cable_index = index;
 786                         cable->attrs[0] = &cable->attr_name.attr;
 787                         cable->attrs[1] = &cable->attr_state.attr;
 788                         cable->attrs[2] = NULL;
 789                         cable->attr_g.name = str;
 790                         cable->attr_g.attrs = cable->attrs;
 791
 792                         sysfs_attr_init(&cable->attr_name.attr);
 793                         cable->attr_name.attr.name = "name";
 794                         cable->attr_name.attr.mode = 0444;
 795                         cable->attr_name.show = cable_name_show;
 796
 797                         sysfs_attr_init(&cable->attr_state.attr);
 798                         cable->attr_state.attr.name = "state";
 799                         cable->attr_state.attr.mode = 0444;
 800                         cable->attr_state.show = cable_state_show;
 801                 }
 802         }
 803
 804         if (edev->max_supported && edev->mutually_exclusive) {
 805                 char buf[80];
 806                 char *name;
 807
 808                 /* Count the size of mutually_exclusive array */
 809                 for (index = 0; edev->mutually_exclusive[index]; index++)
 810                         ;
 811
 812                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 813                                            (index + 1), GFP_KERNEL);
 814                 if (!edev->attrs_muex) {
 815                         ret = -ENOMEM;
 816                         goto err_muex;
 817                 }
 818
 819                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 820                                              index, GFP_KERNEL);
 821                 if (!edev->d_attrs_muex) {
 822                         ret = -ENOMEM;
 823                         kfree(edev->attrs_muex);
 824                         goto err_muex;
 825                 }
 826
 827                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 828                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 829                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 830                                        GFP_KERNEL);
 831                         if (!name) {
 832                                 for (index--; index >= 0; index--) {
 833                                         kfree(edev->d_attrs_muex[index].attr.
 834                                               name);
 835                                 }
 836                                 kfree(edev->d_attrs_muex);
 837                                 kfree(edev->attrs_muex);
 838                                 ret = -ENOMEM;
 839                                 goto err_muex;
 840                         }
 841                         strcpy(name, buf);
 842                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 843                         edev->d_attrs_muex[index].attr.name = name;
 844                         edev->d_attrs_muex[index].attr.mode = 0000;
 845                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 846                                                         .attr;
 847                 }
 848                 edev->attr_g_muex.name = muex_name;
 849                 edev->attr_g_muex.attrs = edev->attrs_muex;
 850
 851         }
 852
 853         if (edev->max_supported) {
 854                 edev->extcon_dev_type.groups =
 855                         kzalloc(sizeof(struct attribute_group *) *
 856                                 (edev->max_supported + 2), GFP_KERNEL);
 857                 if (!edev->extcon_dev_type.groups) {
 858                         ret = -ENOMEM;
 859                         goto err_alloc_groups;
 860                 }
 861
 862                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 863                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 864
 865                 for (index = 0; index < edev->max_supported; index++)
 866                         edev->extcon_dev_type.groups[index] =
 867                                 &edev->cables[index].attr_g;
 868                 if (edev->mutually_exclusive)
 869                         edev->extcon_dev_type.groups[index] =
 870                                 &edev->attr_g_muex;
 871
 872                 edev->dev.type = &edev->extcon_dev_type;
 873         }
 874
 875         ret = device_register(&edev->dev);
 876         if (ret) {
 877                 put_device(&edev->dev);
 878                 goto err_dev;
 879         }
 880 #if defined(CONFIG_ANDROID)
 881         if (switch_class)
 882                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 883 #endif /* CONFIG_ANDROID */
 884
 885         spin_lock_init(&edev->lock);
 886
 887         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 888
 889         dev_set_drvdata(&edev->dev, edev);
 890         edev->state = 0;
 891
 892         mutex_lock(&extcon_dev_list_lock);
 893         list_add(&edev->entry, &extcon_dev_list);
 894         mutex_unlock(&extcon_dev_list_lock);
 895
 896         return 0;
 897
 898 err_dev:
 899         if (edev->max_supported)
 900                 kfree(edev->extcon_dev_type.groups);
 901 err_alloc_groups:
 902         if (edev->max_supported && edev->mutually_exclusive) {
 903                 for (index = 0; edev->mutually_exclusive[index]; index++)
 904                         kfree(edev->d_attrs_muex[index].attr.name);
 905                 kfree(edev->d_attrs_muex);
 906                 kfree(edev->attrs_muex);
 907         }
 908 err_muex:
 909         for (index = 0; index < edev->max_supported; index++)
 910                 kfree(edev->cables[index].attr_g.name);
 911 err_alloc_cables:
 912         if (edev->max_supported)
 913                 kfree(edev->cables);
 914 err_sysfs_alloc:
 915         return ret;
 916 }
 917 EXPORT_SYMBOL_GPL(extcon_dev_register);
 918
 919 /**
 920  * extcon_dev_unregister() - Unregister the extcon device.
 921  * @edev:       the extcon device instance to be unregistered.
 922  *
 923  * Note that this does not call kfree(edev) because edev was not allocated
 924  * by this class.
 925  */
 926 void extcon_dev_unregister(struct extcon_dev *edev)
 927 {
 928         int index;
 929
 930         mutex_lock(&extcon_dev_list_lock);
 931         list_del(&edev->entry);
 932         mutex_unlock(&extcon_dev_list_lock);
 933
 934         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 935                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 936                                 dev_name(&edev->dev));
 937                 return;
 938         }
 939
 940         device_unregister(&edev->dev);
 941
 942         if (edev->mutually_exclusive && edev->max_supported) {
 943                 for (index = 0; edev->mutually_exclusive[index];
 944                                 index++)
 945                         kfree(edev->d_attrs_muex[index].attr.name);
 946                 kfree(edev->d_attrs_muex);
 947                 kfree(edev->attrs_muex);
 948         }
 949
 950         for (index = 0; index < edev->max_supported; index++)
 951                 kfree(edev->cables[index].attr_g.name);
 952
 953         if (edev->max_supported) {
 954                 kfree(edev->extcon_dev_type.groups);
 955                 kfree(edev->cables);
 956         }
 957
 958 #if defined(CONFIG_ANDROID)
 959         if (switch_class)
 960                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 961 #endif
 962         put_device(&edev->dev);
 963 }
 964 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 965
 966 static void devm_extcon_dev_unreg(struct device *dev, void *res)
 967 {
 968         extcon_dev_unregister(*(struct extcon_dev **)res);
 969 }
 970
 971 /**
 972  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
 973  * @dev:        device to allocate extcon device
 974  * @edev:       the new extcon device to register
 975  *
 976  * Managed extcon_dev_register() function. If extcon device is attached with
 977  * this function, that extcon device is automatically unregistered on driver
 978  * detach. Internally this function calls extcon_dev_register() function.
 979  * To get more information, refer that function.
 980  *
 981  * If extcon device is registered with this function and the device needs to be
 982  * unregistered separately, devm_extcon_dev_unregister() should be used.
 983  *
 984  * Returns 0 if success or negaive error number if failure.
 985  */
 986 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
 987 {
 988         struct extcon_dev **ptr;
 989         int ret;
 990
 991         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
 992         if (!ptr)
 993                 return -ENOMEM;
 994
 995         ret = extcon_dev_register(edev);
 996         if (ret) {
 997                 devres_free(ptr);
 998                 return ret;
 999         }
1000
1001         *ptr = edev;
1002         devres_add(dev, ptr);
1003
1004         return 0;
1005 }
1006 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
1007
1008 /**
1009  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
1010  * @dev:        device the extcon belongs to
1011  * @edev:       the extcon device to unregister
1012  *
1013  * Unregister extcon device that is registered with devm_extcon_dev_register()
1014  * function.
1015  */
1016 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
1017 {
1018         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
1019                                devm_extcon_dev_match, edev));
1020 }
1021 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1022
1023 #ifdef CONFIG_OF
1024 /*
1025  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1026  * @dev - instance to the given device
1027  * @index - index into list of extcon_dev
1028  *
1029  * return the instance of extcon device
1030  */
1031 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1032 {
1033         struct device_node *node;
1034         struct extcon_dev *edev;
1035
1036         if (!dev->of_node) {
1037                 dev_err(dev, "device does not have a device node entry\n");
1038                 return ERR_PTR(-EINVAL);
1039         }
1040
1041         node = of_parse_phandle(dev->of_node, "extcon", index);
1042         if (!node) {
1043                 dev_err(dev, "failed to get phandle in %s node\n",
1044                         dev->of_node->full_name);
1045                 return ERR_PTR(-ENODEV);
1046         }
1047
1048         mutex_lock(&extcon_dev_list_lock);
1049         list_for_each_entry(edev, &extcon_dev_list, entry) {
1050                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1051                         mutex_unlock(&extcon_dev_list_lock);
1052                         return edev;
1053                 }
1054         }
1055         mutex_unlock(&extcon_dev_list_lock);
1056
1057         return ERR_PTR(-EPROBE_DEFER);
1058 }
1059 #else
1060 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1061 {
1062         return ERR_PTR(-ENOSYS);
1063 }
1064 #endif /* CONFIG_OF */
1065 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1066
1067 /**
1068  * extcon_get_edev_name() - Get the name of the extcon device.
1069  * @edev:       the extcon device
1070  */
1071 const char *extcon_get_edev_name(struct extcon_dev *edev)
1072 {
1073         return !edev ? NULL : edev->name;
1074 }
1075
1076 static int __init extcon_class_init(void)
1077 {
1078         return create_extcon_class();
1079 }
1080 module_init(extcon_class_init);
1081
1082 static void __exit extcon_class_exit(void)
1083 {
1084 #if defined(CONFIG_ANDROID)
1085         class_compat_unregister(switch_class);
1086 #endif
1087         class_destroy(extcon_class);
1088 }
1089 module_exit(extcon_class_exit);
1090
1091 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1092 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1093 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1094 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1095 MODULE_DESCRIPTION("External connector (extcon) class driver");
1096 MODULE_LICENSE("GPL");