drivers/extcon/extcon-class.c

   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/of.h>
  33 #include <linux/slab.h>
  34 #include <linux/sysfs.h>
  35 #include <linux/of.h>
  36
  37 /*
  38  * extcon_cable_name suggests the standard cable names for commonly used
  39  * cable types.
  40  *
  41  * However, please do not use extcon_cable_name directly for extcon_dev
  42  * struct's supported_cable pointer unless your device really supports
  43  * every single port-type of the following cable names. Please choose cable
  44  * names that are actually used in your extcon device.
  45  */
  46 const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
  47         [EXTCON_USB]            = "USB",
  48         [EXTCON_USB_HOST]       = "USB-Host",
  49         [EXTCON_TA]             = "TA",
  50         [EXTCON_FAST_CHARGER]   = "Fast-charger",
  51         [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  52         [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  53         [EXTCON_HDMI]           = "HDMI",
  54         [EXTCON_MHL]            = "MHL",
  55         [EXTCON_DVI]            = "DVI",
  56         [EXTCON_VGA]            = "VGA",
  57         [EXTCON_DOCK]           = "Dock",
  58         [EXTCON_LINE_IN]        = "Line-in",
  59         [EXTCON_LINE_OUT]       = "Line-out",
  60         [EXTCON_MIC_IN]         = "Microphone",
  61         [EXTCON_HEADPHONE_OUT]  = "Headphone",
  62         [EXTCON_SPDIF_IN]       = "SPDIF-in",
  63         [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  64         [EXTCON_VIDEO_IN]       = "Video-in",
  65         [EXTCON_VIDEO_OUT]      = "Video-out",
  66         [EXTCON_MECHANICAL]     = "Mechanical",
  67 };
  68
  69 static struct class *extcon_class;
  70 #if defined(CONFIG_ANDROID)
  71 static struct class_compat *switch_class;
  72 #endif /* CONFIG_ANDROID */
  73
  74 static LIST_HEAD(extcon_dev_list);
  75 static DEFINE_MUTEX(extcon_dev_list_lock);
  76
  77 /**
  78  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  79  *                            condition.
  80  * @edev:       the extcon device
  81  * @new_state:  new cable attach status for @edev
  82  *
  83  * Returns 0 if nothing violates. Returns the index + 1 for the first
  84  * violated condition.
  85  */
  86 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  87 {
  88         int i = 0;
  89
  90         if (!edev->mutually_exclusive)
  91                 return 0;
  92
  93         for (i = 0; edev->mutually_exclusive[i]; i++) {
  94                 int weight;
  95                 u32 correspondants = new_state & edev->mutually_exclusive[i];
  96
  97                 /* calculate the total number of bits set */
  98                 weight = hweight32(correspondants);
  99                 if (weight > 1)
 100                         return i + 1;
 101         }
 102
 103         return 0;
 104 }
 105
 106 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 107                           char *buf)
 108 {
 109         int i, count = 0;
 110         struct extcon_dev *edev = dev_get_drvdata(dev);
 111
 112         if (edev->print_state) {
 113                 int ret = edev->print_state(edev, buf);
 114
 115                 if (ret >= 0)
 116                         return ret;
 117                 /* Use default if failed */
 118         }
 119
 120         if (edev->max_supported == 0)
 121                 return sprintf(buf, "%u\n", edev->state);
 122
 123         for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
 124                 if (!edev->supported_cable[i])
 125                         break;
 126                 count += sprintf(buf + count, "%s=%d\n",
 127                                  edev->supported_cable[i],
 128                                  !!(edev->state & (1 << i)));
 129         }
 130
 131         return count;
 132 }
 133
 134 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 135                            const char *buf, size_t count)
 136 {
 137         u32 state;
 138         ssize_t ret = 0;
 139         struct extcon_dev *edev = dev_get_drvdata(dev);
 140
 141         ret = sscanf(buf, "0x%x", &state);
 142         if (ret == 0)
 143                 ret = -EINVAL;
 144         else
 145                 ret = extcon_set_state(edev, state);
 146
 147         if (ret < 0)
 148                 return ret;
 149
 150         return count;
 151 }
 152 static DEVICE_ATTR_RW(state);
 153
 154 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 155                 char *buf)
 156 {
 157         struct extcon_dev *edev = dev_get_drvdata(dev);
 158
 159         /* Optional callback given by the user */
 160         if (edev->print_name) {
 161                 int ret = edev->print_name(edev, buf);
 162                 if (ret >= 0)
 163                         return ret;
 164         }
 165
 166         return sprintf(buf, "%s\n", dev_name(&edev->dev));
 167 }
 168 static DEVICE_ATTR_RO(name);
 169
 170 static ssize_t cable_name_show(struct device *dev,
 171                                struct device_attribute *attr, char *buf)
 172 {
 173         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 174                                                   attr_name);
 175
 176         return sprintf(buf, "%s\n",
 177                        cable->edev->supported_cable[cable->cable_index]);
 178 }
 179
 180 static ssize_t cable_state_show(struct device *dev,
 181                                 struct device_attribute *attr, char *buf)
 182 {
 183         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 184                                                   attr_state);
 185
 186         return sprintf(buf, "%d\n",
 187                        extcon_get_cable_state_(cable->edev,
 188                                                cable->cable_index));
 189 }
 190
 191 /**
 192  * extcon_update_state() - Update the cable attach states of the extcon device
 193  *                         only for the masked bits.
 194  * @edev:       the extcon device
 195  * @mask:       the bit mask to designate updated bits.
 196  * @state:      new cable attach status for @edev
 197  *
 198  * Changing the state sends uevent with environment variable containing
 199  * the name of extcon device (envp[0]) and the state output (envp[1]).
 200  * Tizen uses this format for extcon device to get events from ports.
 201  * Android uses this format as well.
 202  *
 203  * Note that the notifier provides which bits are changed in the state
 204  * variable with the val parameter (second) to the callback.
 205  */
 206 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 207 {
 208         char name_buf[120];
 209         char state_buf[120];
 210         char *prop_buf;
 211         char *envp[3];
 212         int env_offset = 0;
 213         int length;
 214         unsigned long flags;
 215
 216         spin_lock_irqsave(&edev->lock, flags);
 217
 218         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 219                 u32 old_state = edev->state;
 220
 221                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 222                                                    (state & mask))) {
 223                         spin_unlock_irqrestore(&edev->lock, flags);
 224                         return -EPERM;
 225                 }
 226
 227                 edev->state &= ~mask;
 228                 edev->state |= state & mask;
 229
 230                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 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 }
 270 EXPORT_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  */
 280 int extcon_set_state(struct extcon_dev *edev, u32 state)
 281 {
 282         return extcon_update_state(edev, 0xffffffff, state);
 283 }
 284 EXPORT_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  */
 296 int 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 }
 310 EXPORT_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  */
 317 int 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 }
 324 EXPORT_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  */
 333 int 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 }
 338 EXPORT_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
 344  *                      extcon_find_cable_index().
 345  * @cable_state:        the new cable status. The default semantics is
 346  *                      true: attached / false: detached.
 347  */
 348 int extcon_set_cable_state_(struct extcon_dev *edev,
 349                         int index, bool cable_state)
 350 {
 351         u32 state;
 352
 353         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 354                 return -EINVAL;
 355
 356         state = cable_state ? (1 << index) : 0;
 357         return extcon_update_state(edev, 1 << index, state);
 358 }
 359 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 360
 361 /**
 362  * extcon_set_cable_state() - Set the status of a specific cable.
 363  * @edev:               the extcon device that has the cable.
 364  * @cable_name:         cable name.
 365  * @cable_state:        the new cable status. The default semantics is
 366  *                      true: attached / false: detached.
 367  *
 368  * Note that this is slower than extcon_set_cable_state_.
 369  */
 370 int extcon_set_cable_state(struct extcon_dev *edev,
 371                         const char *cable_name, bool cable_state)
 372 {
 373         return extcon_set_cable_state_(edev, extcon_find_cable_index
 374                                         (edev, cable_name), cable_state);
 375 }
 376 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 377
 378 /**
 379  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 380  * @extcon_name:        The extcon name provided with extcon_dev_register()
 381  */
 382 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 383 {
 384         struct extcon_dev *sd;
 385
 386         mutex_lock(&extcon_dev_list_lock);
 387         list_for_each_entry(sd, &extcon_dev_list, entry) {
 388                 if (!strcmp(sd->name, extcon_name))
 389                         goto out;
 390         }
 391         sd = NULL;
 392 out:
 393         mutex_unlock(&extcon_dev_list_lock);
 394         return sd;
 395 }
 396 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 397
 398 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 399                            void *ptr)
 400 {
 401         struct extcon_specific_cable_nb *obj = container_of(nb,
 402                         struct extcon_specific_cable_nb, internal_nb);
 403         struct extcon_dev *edev = ptr;
 404
 405         if ((val & (1 << obj->cable_index)) !=
 406             (edev->state & (1 << obj->cable_index))) {
 407                 bool cable_state = true;
 408
 409                 obj->previous_value = val;
 410
 411                 if (val & (1 << obj->cable_index))
 412                         cable_state = false;
 413
 414                 return obj->user_nb->notifier_call(obj->user_nb,
 415                                 cable_state, ptr);
 416         }
 417
 418         return NOTIFY_OK;
 419 }
 420
 421 /**
 422  * extcon_register_interest() - Register a notifier for a state change of a
 423  *                              specific cable, not an entier set of cables of a
 424  *                              extcon device.
 425  * @obj:                an empty extcon_specific_cable_nb object to be returned.
 426  * @extcon_name:        the name of extcon device.
 427  *                      if NULL, extcon_register_interest will register
 428  *                      every cable with the target cable_name given.
 429  * @cable_name:         the target cable name.
 430  * @nb:                 the notifier block to get notified.
 431  *
 432  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 433  * the struct for you.
 434  *
 435  * extcon_register_interest is a helper function for those who want to get
 436  * notification for a single specific cable's status change. If a user wants
 437  * to get notification for any changes of all cables of a extcon device,
 438  * he/she should use the general extcon_register_notifier().
 439  *
 440  * Note that the second parameter given to the callback of nb (val) is
 441  * "old_state", not the current state. The current state can be retrieved
 442  * by looking at the third pameter (edev pointer)'s state value.
 443  */
 444 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 445                              const char *extcon_name, const char *cable_name,
 446                              struct notifier_block *nb)
 447 {
 448         if (!obj || !cable_name || !nb)
 449                 return -EINVAL;
 450
 451         if (extcon_name) {
 452                 obj->edev = extcon_get_extcon_dev(extcon_name);
 453                 if (!obj->edev)
 454                         return -ENODEV;
 455
 456                 obj->cable_index = extcon_find_cable_index(obj->edev,
 457                                                           cable_name);
 458                 if (obj->cable_index < 0)
 459                         return obj->cable_index;
 460
 461                 obj->user_nb = nb;
 462
 463                 obj->internal_nb.notifier_call = _call_per_cable;
 464
 465                 return raw_notifier_chain_register(&obj->edev->nh,
 466                                                   &obj->internal_nb);
 467         } else {
 468                 struct class_dev_iter iter;
 469                 struct extcon_dev *extd;
 470                 struct device *dev;
 471
 472                 if (!extcon_class)
 473                         return -ENODEV;
 474                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 475                 while ((dev = class_dev_iter_next(&iter))) {
 476                         extd = dev_get_drvdata(dev);
 477
 478                         if (extcon_find_cable_index(extd, cable_name) < 0)
 479                                 continue;
 480
 481                         class_dev_iter_exit(&iter);
 482                         return extcon_register_interest(obj, extd->name,
 483                                                 cable_name, nb);
 484                 }
 485
 486                 return -ENODEV;
 487         }
 488 }
 489 EXPORT_SYMBOL_GPL(extcon_register_interest);
 490
 491 /**
 492  * extcon_unregister_interest() - Unregister the notifier registered by
 493  *                                extcon_register_interest().
 494  * @obj:        the extcon_specific_cable_nb object returned by
 495  *              extcon_register_interest().
 496  */
 497 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 498 {
 499         if (!obj)
 500                 return -EINVAL;
 501
 502         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 503 }
 504 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 505
 506 /**
 507  * extcon_register_notifier() - Register a notifiee to get notified by
 508  *                              any attach status changes from the extcon.
 509  * @edev:       the extcon device.
 510  * @nb:         a notifier block to be registered.
 511  *
 512  * Note that the second parameter given to the callback of nb (val) is
 513  * "old_state", not the current state. The current state can be retrieved
 514  * by looking at the third pameter (edev pointer)'s state value.
 515  */
 516 int extcon_register_notifier(struct extcon_dev *edev,
 517                         struct notifier_block *nb)
 518 {
 519         return raw_notifier_chain_register(&edev->nh, nb);
 520 }
 521 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 522
 523 /**
 524  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 525  * @edev:       the extcon device.
 526  * @nb:         a registered notifier block to be unregistered.
 527  */
 528 int extcon_unregister_notifier(struct extcon_dev *edev,
 529                         struct notifier_block *nb)
 530 {
 531         return raw_notifier_chain_unregister(&edev->nh, nb);
 532 }
 533 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 534
 535 static struct attribute *extcon_attrs[] = {
 536         &dev_attr_state.attr,
 537         &dev_attr_name.attr,
 538         NULL,
 539 };
 540 ATTRIBUTE_GROUPS(extcon);
 541
 542 static int create_extcon_class(void)
 543 {
 544         if (!extcon_class) {
 545                 extcon_class = class_create(THIS_MODULE, "extcon");
 546                 if (IS_ERR(extcon_class))
 547                         return PTR_ERR(extcon_class);
 548                 extcon_class->dev_groups = extcon_groups;
 549
 550 #if defined(CONFIG_ANDROID)
 551                 switch_class = class_compat_register("switch");
 552                 if (WARN(!switch_class, "cannot allocate"))
 553                         return -ENOMEM;
 554 #endif /* CONFIG_ANDROID */
 555         }
 556
 557         return 0;
 558 }
 559
 560 static void extcon_dev_release(struct device *dev)
 561 {
 562 }
 563
 564 static const char *muex_name = "mutually_exclusive";
 565 static void dummy_sysfs_dev_release(struct device *dev)
 566 {
 567 }
 568
 569 /*
 570  * extcon_dev_allocate() - Allocate the memory of extcon device.
 571  * @supported_cable:    Array of supported cable names ending with NULL.
 572  *                      If supported_cable is NULL, cable name related APIs
 573  *                      are disabled.
 574  *
 575  * This function allocates the memory for extcon device without allocating
 576  * memory in each extcon provider driver and initialize default setting for
 577  * extcon device.
 578  *
 579  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 580  */
 581 struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
 582 {
 583         struct extcon_dev *edev;
 584
 585         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 586         if (!edev)
 587                 return ERR_PTR(-ENOMEM);
 588
 589         edev->max_supported = 0;
 590         edev->supported_cable = supported_cable;
 591
 592         return edev;
 593 }
 594
 595 /*
 596  * extcon_dev_free() - Free the memory of extcon device.
 597  * @edev:       the extcon device to free
 598  */
 599 void extcon_dev_free(struct extcon_dev *edev)
 600 {
 601         kfree(edev);
 602 }
 603 EXPORT_SYMBOL_GPL(extcon_dev_free);
 604
 605 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 606 {
 607         struct extcon_dev **r = res;
 608
 609         if (WARN_ON(!r || !*r))
 610                 return 0;
 611
 612         return *r == data;
 613 }
 614
 615 static void devm_extcon_dev_release(struct device *dev, void *res)
 616 {
 617         extcon_dev_free(*(struct extcon_dev **)res);
 618 }
 619
 620 /**
 621  * devm_extcon_dev_allocate - Allocate managed extcon device
 622  * @dev:                device owning the extcon device being created
 623  * @supported_cable:    Array of supported cable names ending with NULL.
 624  *                      If supported_cable is NULL, cable name related APIs
 625  *                      are disabled.
 626  *
 627  * This function manages automatically the memory of extcon device using device
 628  * resource management and simplify the control of freeing the memory of extcon
 629  * device.
 630  *
 631  * Returns the pointer memory of allocated extcon_dev if success
 632  * or ERR_PTR(err) if fail
 633  */
 634 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 635                                             const char **supported_cable)
 636 {
 637         struct extcon_dev **ptr, *edev;
 638
 639         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 640         if (!ptr)
 641                 return ERR_PTR(-ENOMEM);
 642
 643         edev = extcon_dev_allocate(supported_cable);
 644         if (IS_ERR(edev)) {
 645                 devres_free(ptr);
 646                 return edev;
 647         }
 648
 649         edev->dev.parent = dev;
 650
 651         *ptr = edev;
 652         devres_add(dev, ptr);
 653
 654         return edev;
 655 }
 656 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 657
 658 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 659 {
 660         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 661                                devm_extcon_dev_match, edev));
 662 }
 663 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 664
 665 /**
 666  * extcon_dev_register() - Register a new extcon device
 667  * @edev        : the new extcon device (should be allocated before calling)
 668  *
 669  * Among the members of edev struct, please set the "user initializing data"
 670  * in any case and set the "optional callbacks" if required. However, please
 671  * do not set the values of "internal data", which are initialized by
 672  * this function.
 673  */
 674 int extcon_dev_register(struct extcon_dev *edev)
 675 {
 676         int ret, index = 0;
 677
 678         if (!extcon_class) {
 679                 ret = create_extcon_class();
 680                 if (ret < 0)
 681                         return ret;
 682         }
 683
 684         if (edev->supported_cable) {
 685                 /* Get size of array */
 686                 for (index = 0; edev->supported_cable[index]; index++)
 687                         ;
 688                 edev->max_supported = index;
 689         } else {
 690                 edev->max_supported = 0;
 691         }
 692
 693         if (index > SUPPORTED_CABLE_MAX) {
 694                 dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 695                 return -EINVAL;
 696         }
 697
 698         edev->dev.class = extcon_class;
 699         edev->dev.release = extcon_dev_release;
 700
 701         edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
 702         if (IS_ERR_OR_NULL(edev->name)) {
 703                 dev_err(&edev->dev,
 704                         "extcon device name is null\n");
 705                 return -EINVAL;
 706         }
 707         dev_set_name(&edev->dev, "%s", edev->name);
 708
 709         if (edev->max_supported) {
 710                 char buf[10];
 711                 char *str;
 712                 struct extcon_cable *cable;
 713
 714                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 715                                        edev->max_supported, GFP_KERNEL);
 716                 if (!edev->cables) {
 717                         ret = -ENOMEM;
 718                         goto err_sysfs_alloc;
 719                 }
 720                 for (index = 0; index < edev->max_supported; index++) {
 721                         cable = &edev->cables[index];
 722
 723                         snprintf(buf, 10, "cable.%d", index);
 724                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 725                                       GFP_KERNEL);
 726                         if (!str) {
 727                                 for (index--; index >= 0; index--) {
 728                                         cable = &edev->cables[index];
 729                                         kfree(cable->attr_g.name);
 730                                 }
 731                                 ret = -ENOMEM;
 732
 733                                 goto err_alloc_cables;
 734                         }
 735                         strcpy(str, buf);
 736
 737                         cable->edev = edev;
 738                         cable->cable_index = index;
 739                         cable->attrs[0] = &cable->attr_name.attr;
 740                         cable->attrs[1] = &cable->attr_state.attr;
 741                         cable->attrs[2] = NULL;
 742                         cable->attr_g.name = str;
 743                         cable->attr_g.attrs = cable->attrs;
 744
 745                         sysfs_attr_init(&cable->attr_name.attr);
 746                         cable->attr_name.attr.name = "name";
 747                         cable->attr_name.attr.mode = 0444;
 748                         cable->attr_name.show = cable_name_show;
 749
 750                         sysfs_attr_init(&cable->attr_state.attr);
 751                         cable->attr_state.attr.name = "state";
 752                         cable->attr_state.attr.mode = 0444;
 753                         cable->attr_state.show = cable_state_show;
 754                 }
 755         }
 756
 757         if (edev->max_supported && edev->mutually_exclusive) {
 758                 char buf[80];
 759                 char *name;
 760
 761                 /* Count the size of mutually_exclusive array */
 762                 for (index = 0; edev->mutually_exclusive[index]; index++)
 763                         ;
 764
 765                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 766                                            (index + 1), GFP_KERNEL);
 767                 if (!edev->attrs_muex) {
 768                         ret = -ENOMEM;
 769                         goto err_muex;
 770                 }
 771
 772                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 773                                              index, GFP_KERNEL);
 774                 if (!edev->d_attrs_muex) {
 775                         ret = -ENOMEM;
 776                         kfree(edev->attrs_muex);
 777                         goto err_muex;
 778                 }
 779
 780                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 781                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 782                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 783                                        GFP_KERNEL);
 784                         if (!name) {
 785                                 for (index--; index >= 0; index--) {
 786                                         kfree(edev->d_attrs_muex[index].attr.
 787                                               name);
 788                                 }
 789                                 kfree(edev->d_attrs_muex);
 790                                 kfree(edev->attrs_muex);
 791                                 ret = -ENOMEM;
 792                                 goto err_muex;
 793                         }
 794                         strcpy(name, buf);
 795                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 796                         edev->d_attrs_muex[index].attr.name = name;
 797                         edev->d_attrs_muex[index].attr.mode = 0000;
 798                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 799                                                         .attr;
 800                 }
 801                 edev->attr_g_muex.name = muex_name;
 802                 edev->attr_g_muex.attrs = edev->attrs_muex;
 803
 804         }
 805
 806         if (edev->max_supported) {
 807                 edev->extcon_dev_type.groups =
 808                         kzalloc(sizeof(struct attribute_group *) *
 809                                 (edev->max_supported + 2), GFP_KERNEL);
 810                 if (!edev->extcon_dev_type.groups) {
 811                         ret = -ENOMEM;
 812                         goto err_alloc_groups;
 813                 }
 814
 815                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 816                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 817
 818                 for (index = 0; index < edev->max_supported; index++)
 819                         edev->extcon_dev_type.groups[index] =
 820                                 &edev->cables[index].attr_g;
 821                 if (edev->mutually_exclusive)
 822                         edev->extcon_dev_type.groups[index] =
 823                                 &edev->attr_g_muex;
 824
 825                 edev->dev.type = &edev->extcon_dev_type;
 826         }
 827
 828         ret = device_register(&edev->dev);
 829         if (ret) {
 830                 put_device(&edev->dev);
 831                 goto err_dev;
 832         }
 833 #if defined(CONFIG_ANDROID)
 834         if (switch_class)
 835                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 836 #endif /* CONFIG_ANDROID */
 837
 838         spin_lock_init(&edev->lock);
 839
 840         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 841
 842         dev_set_drvdata(&edev->dev, edev);
 843         edev->state = 0;
 844
 845         mutex_lock(&extcon_dev_list_lock);
 846         list_add(&edev->entry, &extcon_dev_list);
 847         mutex_unlock(&extcon_dev_list_lock);
 848
 849         return 0;
 850
 851 err_dev:
 852         if (edev->max_supported)
 853                 kfree(edev->extcon_dev_type.groups);
 854 err_alloc_groups:
 855         if (edev->max_supported && edev->mutually_exclusive) {
 856                 for (index = 0; edev->mutually_exclusive[index]; index++)
 857                         kfree(edev->d_attrs_muex[index].attr.name);
 858                 kfree(edev->d_attrs_muex);
 859                 kfree(edev->attrs_muex);
 860         }
 861 err_muex:
 862         for (index = 0; index < edev->max_supported; index++)
 863                 kfree(edev->cables[index].attr_g.name);
 864 err_alloc_cables:
 865         if (edev->max_supported)
 866                 kfree(edev->cables);
 867 err_sysfs_alloc:
 868         return ret;
 869 }
 870 EXPORT_SYMBOL_GPL(extcon_dev_register);
 871
 872 /**
 873  * extcon_dev_unregister() - Unregister the extcon device.
 874  * @edev:       the extcon device instance to be unregistered.
 875  *
 876  * Note that this does not call kfree(edev) because edev was not allocated
 877  * by this class.
 878  */
 879 void extcon_dev_unregister(struct extcon_dev *edev)
 880 {
 881         int index;
 882
 883         mutex_lock(&extcon_dev_list_lock);
 884         list_del(&edev->entry);
 885         mutex_unlock(&extcon_dev_list_lock);
 886
 887         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 888                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 889                                 dev_name(&edev->dev));
 890                 return;
 891         }
 892
 893         device_unregister(&edev->dev);
 894
 895         if (edev->mutually_exclusive && edev->max_supported) {
 896                 for (index = 0; edev->mutually_exclusive[index];
 897                                 index++)
 898                         kfree(edev->d_attrs_muex[index].attr.name);
 899                 kfree(edev->d_attrs_muex);
 900                 kfree(edev->attrs_muex);
 901         }
 902
 903         for (index = 0; index < edev->max_supported; index++)
 904                 kfree(edev->cables[index].attr_g.name);
 905
 906         if (edev->max_supported) {
 907                 kfree(edev->extcon_dev_type.groups);
 908                 kfree(edev->cables);
 909         }
 910
 911 #if defined(CONFIG_ANDROID)
 912         if (switch_class)
 913                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 914 #endif
 915         put_device(&edev->dev);
 916 }
 917 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 918
 919 static void devm_extcon_dev_unreg(struct device *dev, void *res)
 920 {
 921         extcon_dev_unregister(*(struct extcon_dev **)res);
 922 }
 923
 924 /**
 925  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
 926  * @dev:        device to allocate extcon device
 927  * @edev:       the new extcon device to register
 928  *
 929  * Managed extcon_dev_register() function. If extcon device is attached with
 930  * this function, that extcon device is automatically unregistered on driver
 931  * detach. Internally this function calls extcon_dev_register() function.
 932  * To get more information, refer that function.
 933  *
 934  * If extcon device is registered with this function and the device needs to be
 935  * unregistered separately, devm_extcon_dev_unregister() should be used.
 936  *
 937  * Returns 0 if success or negaive error number if failure.
 938  */
 939 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
 940 {
 941         struct extcon_dev **ptr;
 942         int ret;
 943
 944         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
 945         if (!ptr)
 946                 return -ENOMEM;
 947
 948         ret = extcon_dev_register(edev);
 949         if (ret) {
 950                 devres_free(ptr);
 951                 return ret;
 952         }
 953
 954         *ptr = edev;
 955         devres_add(dev, ptr);
 956
 957         return 0;
 958 }
 959 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
 960
 961 /**
 962  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
 963  * @dev:        device the extcon belongs to
 964  * @edev:       the extcon device to unregister
 965  *
 966  * Unregister extcon device that is registered with devm_extcon_dev_register()
 967  * function.
 968  */
 969 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
 970 {
 971         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
 972                                devm_extcon_dev_match, edev));
 973 }
 974 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
 975
 976 #ifdef CONFIG_OF
 977 /*
 978  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
 979  * @dev - instance to the given device
 980  * @index - index into list of extcon_dev
 981  *
 982  * return the instance of extcon device
 983  */
 984 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 985 {
 986         struct device_node *node;
 987         struct extcon_dev *edev;
 988
 989         if (!dev->of_node) {
 990                 dev_err(dev, "device does not have a device node entry\n");
 991                 return ERR_PTR(-EINVAL);
 992         }
 993
 994         node = of_parse_phandle(dev->of_node, "extcon", index);
 995         if (!node) {
 996                 dev_err(dev, "failed to get phandle in %s node\n",
 997                         dev->of_node->full_name);
 998                 return ERR_PTR(-ENODEV);
 999         }
1000
1001         mutex_lock(&extcon_dev_list_lock);
1002         list_for_each_entry(edev, &extcon_dev_list, entry) {
1003                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1004                         mutex_unlock(&extcon_dev_list_lock);
1005                         return edev;
1006                 }
1007         }
1008         mutex_unlock(&extcon_dev_list_lock);
1009
1010         return ERR_PTR(-EPROBE_DEFER);
1011 }
1012 #else
1013 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1014 {
1015         return ERR_PTR(-ENOSYS);
1016 }
1017 #endif /* CONFIG_OF */
1018 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1019
1020 static int __init extcon_class_init(void)
1021 {
1022         return create_extcon_class();
1023 }
1024 module_init(extcon_class_init);
1025
1026 static void __exit extcon_class_exit(void)
1027 {
1028 #if defined(CONFIG_ANDROID)
1029         class_compat_unregister(switch_class);
1030 #endif
1031         class_destroy(extcon_class);
1032 }
1033 module_exit(extcon_class_exit);
1034
1035 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1036 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1037 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1038 MODULE_DESCRIPTION("External connector (extcon) class driver");
1039 MODULE_LICENSE("GPL");