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/slab.h>
  33 #include <linux/sysfs.h>
  34 #include <linux/of.h>
  35
  36 /*
  37  * extcon_cable_name suggests the standard cable names for commonly used
  38  * cable types.
  39  *
  40  * However, please do not use extcon_cable_name directly for extcon_dev
  41  * struct's supported_cable pointer unless your device really supports
  42  * every single port-type of the following cable names. Please choose cable
  43  * names that are actually used in your extcon device.
  44  */
  45 const char extcon_cable_name[][CABLE_NAME_MAX + 1] = {
  46         [EXTCON_USB]            = "USB",
  47         [EXTCON_USB_HOST]       = "USB-Host",
  48         [EXTCON_TA]             = "TA",
  49         [EXTCON_FAST_CHARGER]   = "Fast-charger",
  50         [EXTCON_SLOW_CHARGER]   = "Slow-charger",
  51         [EXTCON_CHARGE_DOWNSTREAM]      = "Charge-downstream",
  52         [EXTCON_HDMI]           = "HDMI",
  53         [EXTCON_MHL]            = "MHL",
  54         [EXTCON_DVI]            = "DVI",
  55         [EXTCON_VGA]            = "VGA",
  56         [EXTCON_DOCK]           = "Dock",
  57         [EXTCON_LINE_IN]        = "Line-in",
  58         [EXTCON_LINE_OUT]       = "Line-out",
  59         [EXTCON_MIC_IN]         = "Microphone",
  60         [EXTCON_HEADPHONE_OUT]  = "Headphone",
  61         [EXTCON_SPDIF_IN]       = "SPDIF-in",
  62         [EXTCON_SPDIF_OUT]      = "SPDIF-out",
  63         [EXTCON_VIDEO_IN]       = "Video-in",
  64         [EXTCON_VIDEO_OUT]      = "Video-out",
  65         [EXTCON_MECHANICAL]     = "Mechanical",
  66 };
  67
  68 static struct class *extcon_class;
  69 #if defined(CONFIG_ANDROID)
  70 static struct class_compat *switch_class;
  71 #endif /* CONFIG_ANDROID */
  72
  73 static LIST_HEAD(extcon_dev_list);
  74 static DEFINE_MUTEX(extcon_dev_list_lock);
  75
  76 /**
  77  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  78  *                            condition.
  79  * @edev:       the extcon device
  80  * @new_state:  new cable attach status for @edev
  81  *
  82  * Returns 0 if nothing violates. Returns the index + 1 for the first
  83  * violated condition.
  84  */
  85 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  86 {
  87         int i = 0;
  88
  89         if (!edev->mutually_exclusive)
  90                 return 0;
  91
  92         for (i = 0; edev->mutually_exclusive[i]; i++) {
  93                 int weight;
  94                 u32 correspondants = new_state & edev->mutually_exclusive[i];
  95
  96                 /* calculate the total number of bits set */
  97                 weight = hweight32(correspondants);
  98                 if (weight > 1)
  99                         return i + 1;
 100         }
 101
 102         return 0;
 103 }
 104
 105 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 106                           char *buf)
 107 {
 108         int i, count = 0;
 109         struct extcon_dev *edev = dev_get_drvdata(dev);
 110
 111         if (edev->print_state) {
 112                 int ret = edev->print_state(edev, buf);
 113
 114                 if (ret >= 0)
 115                         return ret;
 116                 /* Use default if failed */
 117         }
 118
 119         if (edev->max_supported == 0)
 120                 return sprintf(buf, "%u\n", edev->state);
 121
 122         for (i = 0; i < SUPPORTED_CABLE_MAX; i++) {
 123                 if (!edev->supported_cable[i])
 124                         break;
 125                 count += sprintf(buf + count, "%s=%d\n",
 126                                  edev->supported_cable[i],
 127                                  !!(edev->state & (1 << i)));
 128         }
 129
 130         return count;
 131 }
 132
 133 static 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 = 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 static DEVICE_ATTR_RW(state);
 152
 153 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 154                 char *buf)
 155 {
 156         struct extcon_dev *edev = dev_get_drvdata(dev);
 157
 158         /* Optional callback given by the user */
 159         if (edev->print_name) {
 160                 int ret = edev->print_name(edev, buf);
 161                 if (ret >= 0)
 162                         return ret;
 163         }
 164
 165         return sprintf(buf, "%s\n", dev_name(&edev->dev));
 166 }
 167 static DEVICE_ATTR_RO(name);
 168
 169 static ssize_t cable_name_show(struct device *dev,
 170                                struct device_attribute *attr, char *buf)
 171 {
 172         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 173                                                   attr_name);
 174
 175         return sprintf(buf, "%s\n",
 176                        cable->edev->supported_cable[cable->cable_index]);
 177 }
 178
 179 static ssize_t cable_state_show(struct device *dev,
 180                                 struct device_attribute *attr, char *buf)
 181 {
 182         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 183                                                   attr_state);
 184
 185         return sprintf(buf, "%d\n",
 186                        extcon_get_cable_state_(cable->edev,
 187                                                cable->cable_index));
 188 }
 189
 190 /**
 191  * extcon_update_state() - Update the cable attach states of the extcon device
 192  *                         only for the masked bits.
 193  * @edev:       the extcon device
 194  * @mask:       the bit mask to designate updated bits.
 195  * @state:      new cable attach status for @edev
 196  *
 197  * Changing the state sends uevent with environment variable containing
 198  * the name of extcon device (envp[0]) and the state output (envp[1]).
 199  * Tizen uses this format for extcon device to get events from ports.
 200  * Android uses this format as well.
 201  *
 202  * Note that the notifier provides which bits are changed in the state
 203  * variable with the val parameter (second) to the callback.
 204  */
 205 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 206 {
 207         char name_buf[120];
 208         char state_buf[120];
 209         char *prop_buf;
 210         char *envp[3];
 211         int env_offset = 0;
 212         int length;
 213         unsigned long flags;
 214
 215         spin_lock_irqsave(&edev->lock, flags);
 216
 217         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 218                 u32 old_state = edev->state;
 219
 220                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 221                                                    (state & mask))) {
 222                         spin_unlock_irqrestore(&edev->lock, flags);
 223                         return -EPERM;
 224                 }
 225
 226                 edev->state &= ~mask;
 227                 edev->state |= state & mask;
 228
 229                 raw_notifier_call_chain(&edev->nh, old_state, edev);
 230                 /* This could be in interrupt handler */
 231                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 232                 if (prop_buf) {
 233                         length = name_show(&edev->dev, NULL, prop_buf);
 234                         if (length > 0) {
 235                                 if (prop_buf[length - 1] == '\n')
 236                                         prop_buf[length - 1] = 0;
 237                                 snprintf(name_buf, sizeof(name_buf),
 238                                         "NAME=%s", prop_buf);
 239                                 envp[env_offset++] = name_buf;
 240                         }
 241                         length = state_show(&edev->dev, NULL, prop_buf);
 242                         if (length > 0) {
 243                                 if (prop_buf[length - 1] == '\n')
 244                                         prop_buf[length - 1] = 0;
 245                                 snprintf(state_buf, sizeof(state_buf),
 246                                         "STATE=%s", prop_buf);
 247                                 envp[env_offset++] = state_buf;
 248                         }
 249                         envp[env_offset] = NULL;
 250                         /* Unlock early before uevent */
 251                         spin_unlock_irqrestore(&edev->lock, flags);
 252
 253                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 254                         free_page((unsigned long)prop_buf);
 255                 } else {
 256                         /* Unlock early before uevent */
 257                         spin_unlock_irqrestore(&edev->lock, flags);
 258
 259                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 260                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 261                 }
 262         } else {
 263                 /* No changes */
 264                 spin_unlock_irqrestore(&edev->lock, flags);
 265         }
 266
 267         return 0;
 268 }
 269 EXPORT_SYMBOL_GPL(extcon_update_state);
 270
 271 /**
 272  * extcon_set_state() - Set the cable attach states of the extcon device.
 273  * @edev:       the extcon device
 274  * @state:      new cable attach status for @edev
 275  *
 276  * Note that notifier provides which bits are changed in the state
 277  * variable with the val parameter (second) to the callback.
 278  */
 279 int extcon_set_state(struct extcon_dev *edev, u32 state)
 280 {
 281         return extcon_update_state(edev, 0xffffffff, state);
 282 }
 283 EXPORT_SYMBOL_GPL(extcon_set_state);
 284
 285 /**
 286  * extcon_find_cable_index() - Get the cable index based on the cable name.
 287  * @edev:       the extcon device that has the cable.
 288  * @cable_name: cable name to be searched.
 289  *
 290  * Note that accessing a cable state based on cable_index is faster than
 291  * cable_name because using cable_name induces a loop with strncmp().
 292  * Thus, when get/set_cable_state is repeatedly used, using cable_index
 293  * is recommended.
 294  */
 295 int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name)
 296 {
 297         int i;
 298
 299         if (edev->supported_cable) {
 300                 for (i = 0; edev->supported_cable[i]; i++) {
 301                         if (!strncmp(edev->supported_cable[i],
 302                                 cable_name, CABLE_NAME_MAX))
 303                                 return i;
 304                 }
 305         }
 306
 307         return -EINVAL;
 308 }
 309 EXPORT_SYMBOL_GPL(extcon_find_cable_index);
 310
 311 /**
 312  * extcon_get_cable_state_() - Get the status of a specific cable.
 313  * @edev:       the extcon device that has the cable.
 314  * @index:      cable index that can be retrieved by extcon_find_cable_index().
 315  */
 316 int extcon_get_cable_state_(struct extcon_dev *edev, int index)
 317 {
 318         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 319                 return -EINVAL;
 320
 321         return !!(edev->state & (1 << index));
 322 }
 323 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 324
 325 /**
 326  * extcon_get_cable_state() - Get the status of a specific cable.
 327  * @edev:       the extcon device that has the cable.
 328  * @cable_name: cable name.
 329  *
 330  * Note that this is slower than extcon_get_cable_state_.
 331  */
 332 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 333 {
 334         return extcon_get_cable_state_(edev, extcon_find_cable_index
 335                                                 (edev, cable_name));
 336 }
 337 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 338
 339 /**
 340  * extcon_set_cable_state_() - Set the status of a specific cable.
 341  * @edev:               the extcon device that has the cable.
 342  * @index:              cable index that can be retrieved by
 343  *                      extcon_find_cable_index().
 344  * @cable_state:        the new cable status. The default semantics is
 345  *                      true: attached / false: detached.
 346  */
 347 int extcon_set_cable_state_(struct extcon_dev *edev,
 348                         int index, bool cable_state)
 349 {
 350         u32 state;
 351
 352         if (index < 0 || (edev->max_supported && edev->max_supported <= index))
 353                 return -EINVAL;
 354
 355         state = cable_state ? (1 << index) : 0;
 356         return extcon_update_state(edev, 1 << index, state);
 357 }
 358 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 359
 360 /**
 361  * extcon_set_cable_state() - Set the status of a specific cable.
 362  * @edev:               the extcon device that has the cable.
 363  * @cable_name:         cable name.
 364  * @cable_state:        the new cable status. The default semantics is
 365  *                      true: attached / false: detached.
 366  *
 367  * Note that this is slower than extcon_set_cable_state_.
 368  */
 369 int extcon_set_cable_state(struct extcon_dev *edev,
 370                         const char *cable_name, bool cable_state)
 371 {
 372         return extcon_set_cable_state_(edev, extcon_find_cable_index
 373                                         (edev, cable_name), cable_state);
 374 }
 375 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 376
 377 /**
 378  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 379  * @extcon_name:        The extcon name provided with extcon_dev_register()
 380  */
 381 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 382 {
 383         struct extcon_dev *sd;
 384
 385         mutex_lock(&extcon_dev_list_lock);
 386         list_for_each_entry(sd, &extcon_dev_list, entry) {
 387                 if (!strcmp(sd->name, extcon_name))
 388                         goto out;
 389         }
 390         sd = NULL;
 391 out:
 392         mutex_unlock(&extcon_dev_list_lock);
 393         return sd;
 394 }
 395 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 396
 397 static int _call_per_cable(struct notifier_block *nb, unsigned long val,
 398                            void *ptr)
 399 {
 400         struct extcon_specific_cable_nb *obj = container_of(nb,
 401                         struct extcon_specific_cable_nb, internal_nb);
 402         struct extcon_dev *edev = ptr;
 403
 404         if ((val & (1 << obj->cable_index)) !=
 405             (edev->state & (1 << obj->cable_index))) {
 406                 bool cable_state = true;
 407
 408                 obj->previous_value = val;
 409
 410                 if (val & (1 << obj->cable_index))
 411                         cable_state = false;
 412
 413                 return obj->user_nb->notifier_call(obj->user_nb,
 414                                 cable_state, ptr);
 415         }
 416
 417         return NOTIFY_OK;
 418 }
 419
 420 /**
 421  * extcon_register_interest() - Register a notifier for a state change of a
 422  *                              specific cable, not an entier set of cables of a
 423  *                              extcon device.
 424  * @obj:                an empty extcon_specific_cable_nb object to be returned.
 425  * @extcon_name:        the name of extcon device.
 426  *                      if NULL, extcon_register_interest will register
 427  *                      every cable with the target cable_name given.
 428  * @cable_name:         the target cable name.
 429  * @nb:                 the notifier block to get notified.
 430  *
 431  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 432  * the struct for you.
 433  *
 434  * extcon_register_interest is a helper function for those who want to get
 435  * notification for a single specific cable's status change. If a user wants
 436  * to get notification for any changes of all cables of a extcon device,
 437  * he/she should use the general extcon_register_notifier().
 438  *
 439  * Note that the second parameter given to the callback of nb (val) is
 440  * "old_state", not the current state. The current state can be retrieved
 441  * by looking at the third pameter (edev pointer)'s state value.
 442  */
 443 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 444                              const char *extcon_name, const char *cable_name,
 445                              struct notifier_block *nb)
 446 {
 447         if (!obj || !cable_name || !nb)
 448                 return -EINVAL;
 449
 450         if (extcon_name) {
 451                 obj->edev = extcon_get_extcon_dev(extcon_name);
 452                 if (!obj->edev)
 453                         return -ENODEV;
 454
 455                 obj->cable_index = extcon_find_cable_index(obj->edev,
 456                                                           cable_name);
 457                 if (obj->cable_index < 0)
 458                         return obj->cable_index;
 459
 460                 obj->user_nb = nb;
 461
 462                 obj->internal_nb.notifier_call = _call_per_cable;
 463
 464                 return raw_notifier_chain_register(&obj->edev->nh,
 465                                                   &obj->internal_nb);
 466         } else {
 467                 struct class_dev_iter iter;
 468                 struct extcon_dev *extd;
 469                 struct device *dev;
 470
 471                 if (!extcon_class)
 472                         return -ENODEV;
 473                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 474                 while ((dev = class_dev_iter_next(&iter))) {
 475                         extd = dev_get_drvdata(dev);
 476
 477                         if (extcon_find_cable_index(extd, cable_name) < 0)
 478                                 continue;
 479
 480                         class_dev_iter_exit(&iter);
 481                         return extcon_register_interest(obj, extd->name,
 482                                                 cable_name, nb);
 483                 }
 484
 485                 return -ENODEV;
 486         }
 487 }
 488 EXPORT_SYMBOL_GPL(extcon_register_interest);
 489
 490 /**
 491  * extcon_unregister_interest() - Unregister the notifier registered by
 492  *                                extcon_register_interest().
 493  * @obj:        the extcon_specific_cable_nb object returned by
 494  *              extcon_register_interest().
 495  */
 496 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 497 {
 498         if (!obj)
 499                 return -EINVAL;
 500
 501         return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb);
 502 }
 503 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 504
 505 /**
 506  * extcon_register_notifier() - Register a notifiee to get notified by
 507  *                              any attach status changes from the extcon.
 508  * @edev:       the extcon device.
 509  * @nb:         a notifier block to be registered.
 510  *
 511  * Note that the second parameter given to the callback of nb (val) is
 512  * "old_state", not the current state. The current state can be retrieved
 513  * by looking at the third pameter (edev pointer)'s state value.
 514  */
 515 int extcon_register_notifier(struct extcon_dev *edev,
 516                         struct notifier_block *nb)
 517 {
 518         return raw_notifier_chain_register(&edev->nh, nb);
 519 }
 520 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 521
 522 /**
 523  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 524  * @edev:       the extcon device.
 525  * @nb:         a registered notifier block to be unregistered.
 526  */
 527 int extcon_unregister_notifier(struct extcon_dev *edev,
 528                         struct notifier_block *nb)
 529 {
 530         return raw_notifier_chain_unregister(&edev->nh, nb);
 531 }
 532 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 533
 534 static struct attribute *extcon_attrs[] = {
 535         &dev_attr_state.attr,
 536         &dev_attr_name.attr,
 537         NULL,
 538 };
 539 ATTRIBUTE_GROUPS(extcon);
 540
 541 static int create_extcon_class(void)
 542 {
 543         if (!extcon_class) {
 544                 extcon_class = class_create(THIS_MODULE, "extcon");
 545                 if (IS_ERR(extcon_class))
 546                         return PTR_ERR(extcon_class);
 547                 extcon_class->dev_groups = extcon_groups;
 548
 549 #if defined(CONFIG_ANDROID)
 550                 switch_class = class_compat_register("switch");
 551                 if (WARN(!switch_class, "cannot allocate"))
 552                         return -ENOMEM;
 553 #endif /* CONFIG_ANDROID */
 554         }
 555
 556         return 0;
 557 }
 558
 559 static void extcon_dev_release(struct device *dev)
 560 {
 561 }
 562
 563 static const char *muex_name = "mutually_exclusive";
 564 static void dummy_sysfs_dev_release(struct device *dev)
 565 {
 566 }
 567
 568 /*
 569  * extcon_dev_allocate() - Allocate the memory of extcon device.
 570  * @supported_cable:    Array of supported cable names ending with NULL.
 571  *                      If supported_cable is NULL, cable name related APIs
 572  *                      are disabled.
 573  *
 574  * This function allocates the memory for extcon device without allocating
 575  * memory in each extcon provider driver and initialize default setting for
 576  * extcon device.
 577  *
 578  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 579  */
 580 struct extcon_dev *extcon_dev_allocate(const char **supported_cable)
 581 {
 582         struct extcon_dev *edev;
 583
 584         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 585         if (!edev)
 586                 return ERR_PTR(-ENOMEM);
 587
 588         edev->max_supported = 0;
 589         edev->supported_cable = supported_cable;
 590
 591         return edev;
 592 }
 593
 594 /*
 595  * extcon_dev_free() - Free the memory of extcon device.
 596  * @edev:       the extcon device to free
 597  */
 598 void extcon_dev_free(struct extcon_dev *edev)
 599 {
 600         kfree(edev);
 601 }
 602 EXPORT_SYMBOL_GPL(extcon_dev_free);
 603
 604 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 605 {
 606         struct extcon_dev **r = res;
 607
 608         if (WARN_ON(!r || !*r))
 609                 return 0;
 610
 611         return *r == data;
 612 }
 613
 614 static void devm_extcon_dev_release(struct device *dev, void *res)
 615 {
 616         extcon_dev_free(*(struct extcon_dev **)res);
 617 }
 618
 619 /**
 620  * devm_extcon_dev_allocate - Allocate managed extcon device
 621  * @dev:                device owning the extcon device being created
 622  * @supported_cable:    Array of supported cable names ending with NULL.
 623  *                      If supported_cable is NULL, cable name related APIs
 624  *                      are disabled.
 625  *
 626  * This function manages automatically the memory of extcon device using device
 627  * resource management and simplify the control of freeing the memory of extcon
 628  * device.
 629  *
 630  * Returns the pointer memory of allocated extcon_dev if success
 631  * or ERR_PTR(err) if fail
 632  */
 633 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 634                                             const char **supported_cable)
 635 {
 636         struct extcon_dev **ptr, *edev;
 637
 638         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 639         if (!ptr)
 640                 return ERR_PTR(-ENOMEM);
 641
 642         edev = extcon_dev_allocate(supported_cable);
 643         if (IS_ERR(edev)) {
 644                 devres_free(ptr);
 645                 return edev;
 646         }
 647
 648         edev->dev.parent = dev;
 649
 650         *ptr = edev;
 651         devres_add(dev, ptr);
 652
 653         return edev;
 654 }
 655 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 656
 657 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 658 {
 659         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 660                                devm_extcon_dev_match, edev));
 661 }
 662 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 663
 664 /**
 665  * extcon_dev_register() - Register a new extcon device
 666  * @edev        : the new extcon device (should be allocated before calling)
 667  *
 668  * Among the members of edev struct, please set the "user initializing data"
 669  * in any case and set the "optional callbacks" if required. However, please
 670  * do not set the values of "internal data", which are initialized by
 671  * this function.
 672  */
 673 int extcon_dev_register(struct extcon_dev *edev)
 674 {
 675         int ret, index = 0;
 676
 677         if (!extcon_class) {
 678                 ret = create_extcon_class();
 679                 if (ret < 0)
 680                         return ret;
 681         }
 682
 683         if (edev->supported_cable) {
 684                 /* Get size of array */
 685                 for (index = 0; edev->supported_cable[index]; index++)
 686                         ;
 687                 edev->max_supported = index;
 688         } else {
 689                 edev->max_supported = 0;
 690         }
 691
 692         if (index > SUPPORTED_CABLE_MAX) {
 693                 dev_err(&edev->dev, "extcon: maximum number of supported cables exceeded.\n");
 694                 return -EINVAL;
 695         }
 696
 697         edev->dev.class = extcon_class;
 698         edev->dev.release = extcon_dev_release;
 699
 700         edev->name = edev->name ? edev->name : dev_name(edev->dev.parent);
 701         if (IS_ERR_OR_NULL(edev->name)) {
 702                 dev_err(&edev->dev,
 703                         "extcon device name is null\n");
 704                 return -EINVAL;
 705         }
 706         dev_set_name(&edev->dev, "%s", edev->name);
 707
 708         if (edev->max_supported) {
 709                 char buf[10];
 710                 char *str;
 711                 struct extcon_cable *cable;
 712
 713                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 714                                        edev->max_supported, GFP_KERNEL);
 715                 if (!edev->cables) {
 716                         ret = -ENOMEM;
 717                         goto err_sysfs_alloc;
 718                 }
 719                 for (index = 0; index < edev->max_supported; index++) {
 720                         cable = &edev->cables[index];
 721
 722                         snprintf(buf, 10, "cable.%d", index);
 723                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 724                                       GFP_KERNEL);
 725                         if (!str) {
 726                                 for (index--; index >= 0; index--) {
 727                                         cable = &edev->cables[index];
 728                                         kfree(cable->attr_g.name);
 729                                 }
 730                                 ret = -ENOMEM;
 731
 732                                 goto err_alloc_cables;
 733                         }
 734                         strcpy(str, buf);
 735
 736                         cable->edev = edev;
 737                         cable->cable_index = index;
 738                         cable->attrs[0] = &cable->attr_name.attr;
 739                         cable->attrs[1] = &cable->attr_state.attr;
 740                         cable->attrs[2] = NULL;
 741                         cable->attr_g.name = str;
 742                         cable->attr_g.attrs = cable->attrs;
 743
 744                         sysfs_attr_init(&cable->attr_name.attr);
 745                         cable->attr_name.attr.name = "name";
 746                         cable->attr_name.attr.mode = 0444;
 747                         cable->attr_name.show = cable_name_show;
 748
 749                         sysfs_attr_init(&cable->attr_state.attr);
 750                         cable->attr_state.attr.name = "state";
 751                         cable->attr_state.attr.mode = 0444;
 752                         cable->attr_state.show = cable_state_show;
 753                 }
 754         }
 755
 756         if (edev->max_supported && edev->mutually_exclusive) {
 757                 char buf[80];
 758                 char *name;
 759
 760                 /* Count the size of mutually_exclusive array */
 761                 for (index = 0; edev->mutually_exclusive[index]; index++)
 762                         ;
 763
 764                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 765                                            (index + 1), GFP_KERNEL);
 766                 if (!edev->attrs_muex) {
 767                         ret = -ENOMEM;
 768                         goto err_muex;
 769                 }
 770
 771                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 772                                              index, GFP_KERNEL);
 773                 if (!edev->d_attrs_muex) {
 774                         ret = -ENOMEM;
 775                         kfree(edev->attrs_muex);
 776                         goto err_muex;
 777                 }
 778
 779                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 780                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 781                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 782                                        GFP_KERNEL);
 783                         if (!name) {
 784                                 for (index--; index >= 0; index--) {
 785                                         kfree(edev->d_attrs_muex[index].attr.
 786                                               name);
 787                                 }
 788                                 kfree(edev->d_attrs_muex);
 789                                 kfree(edev->attrs_muex);
 790                                 ret = -ENOMEM;
 791                                 goto err_muex;
 792                         }
 793                         strcpy(name, buf);
 794                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 795                         edev->d_attrs_muex[index].attr.name = name;
 796                         edev->d_attrs_muex[index].attr.mode = 0000;
 797                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 798                                                         .attr;
 799                 }
 800                 edev->attr_g_muex.name = muex_name;
 801                 edev->attr_g_muex.attrs = edev->attrs_muex;
 802
 803         }
 804
 805         if (edev->max_supported) {
 806                 edev->extcon_dev_type.groups =
 807                         kzalloc(sizeof(struct attribute_group *) *
 808                                 (edev->max_supported + 2), GFP_KERNEL);
 809                 if (!edev->extcon_dev_type.groups) {
 810                         ret = -ENOMEM;
 811                         goto err_alloc_groups;
 812                 }
 813
 814                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 815                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 816
 817                 for (index = 0; index < edev->max_supported; index++)
 818                         edev->extcon_dev_type.groups[index] =
 819                                 &edev->cables[index].attr_g;
 820                 if (edev->mutually_exclusive)
 821                         edev->extcon_dev_type.groups[index] =
 822                                 &edev->attr_g_muex;
 823
 824                 edev->dev.type = &edev->extcon_dev_type;
 825         }
 826
 827         ret = device_register(&edev->dev);
 828         if (ret) {
 829                 put_device(&edev->dev);
 830                 goto err_dev;
 831         }
 832 #if defined(CONFIG_ANDROID)
 833         if (switch_class)
 834                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 835 #endif /* CONFIG_ANDROID */
 836
 837         spin_lock_init(&edev->lock);
 838
 839         RAW_INIT_NOTIFIER_HEAD(&edev->nh);
 840
 841         dev_set_drvdata(&edev->dev, edev);
 842         edev->state = 0;
 843
 844         mutex_lock(&extcon_dev_list_lock);
 845         list_add(&edev->entry, &extcon_dev_list);
 846         mutex_unlock(&extcon_dev_list_lock);
 847
 848         return 0;
 849
 850 err_dev:
 851         if (edev->max_supported)
 852                 kfree(edev->extcon_dev_type.groups);
 853 err_alloc_groups:
 854         if (edev->max_supported && edev->mutually_exclusive) {
 855                 for (index = 0; edev->mutually_exclusive[index]; index++)
 856                         kfree(edev->d_attrs_muex[index].attr.name);
 857                 kfree(edev->d_attrs_muex);
 858                 kfree(edev->attrs_muex);
 859         }
 860 err_muex:
 861         for (index = 0; index < edev->max_supported; index++)
 862                 kfree(edev->cables[index].attr_g.name);
 863 err_alloc_cables:
 864         if (edev->max_supported)
 865                 kfree(edev->cables);
 866 err_sysfs_alloc:
 867         return ret;
 868 }
 869 EXPORT_SYMBOL_GPL(extcon_dev_register);
 870
 871 /**
 872  * extcon_dev_unregister() - Unregister the extcon device.
 873  * @edev:       the extcon device instance to be unregistered.
 874  *
 875  * Note that this does not call kfree(edev) because edev was not allocated
 876  * by this class.
 877  */
 878 void extcon_dev_unregister(struct extcon_dev *edev)
 879 {
 880         int index;
 881
 882         mutex_lock(&extcon_dev_list_lock);
 883         list_del(&edev->entry);
 884         mutex_unlock(&extcon_dev_list_lock);
 885
 886         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 887                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 888                                 dev_name(&edev->dev));
 889                 return;
 890         }
 891
 892         device_unregister(&edev->dev);
 893
 894         if (edev->mutually_exclusive && edev->max_supported) {
 895                 for (index = 0; edev->mutually_exclusive[index];
 896                                 index++)
 897                         kfree(edev->d_attrs_muex[index].attr.name);
 898                 kfree(edev->d_attrs_muex);
 899                 kfree(edev->attrs_muex);
 900         }
 901
 902         for (index = 0; index < edev->max_supported; index++)
 903                 kfree(edev->cables[index].attr_g.name);
 904
 905         if (edev->max_supported) {
 906                 kfree(edev->extcon_dev_type.groups);
 907                 kfree(edev->cables);
 908         }
 909
 910 #if defined(CONFIG_ANDROID)
 911         if (switch_class)
 912                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 913 #endif
 914         put_device(&edev->dev);
 915 }
 916 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 917
 918 static void devm_extcon_dev_unreg(struct device *dev, void *res)
 919 {
 920         extcon_dev_unregister(*(struct extcon_dev **)res);
 921 }
 922
 923 /**
 924  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
 925  * @dev:        device to allocate extcon device
 926  * @edev:       the new extcon device to register
 927  *
 928  * Managed extcon_dev_register() function. If extcon device is attached with
 929  * this function, that extcon device is automatically unregistered on driver
 930  * detach. Internally this function calls extcon_dev_register() function.
 931  * To get more information, refer that function.
 932  *
 933  * If extcon device is registered with this function and the device needs to be
 934  * unregistered separately, devm_extcon_dev_unregister() should be used.
 935  *
 936  * Returns 0 if success or negaive error number if failure.
 937  */
 938 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
 939 {
 940         struct extcon_dev **ptr;
 941         int ret;
 942
 943         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
 944         if (!ptr)
 945                 return -ENOMEM;
 946
 947         ret = extcon_dev_register(edev);
 948         if (ret) {
 949                 devres_free(ptr);
 950                 return ret;
 951         }
 952
 953         *ptr = edev;
 954         devres_add(dev, ptr);
 955
 956         return 0;
 957 }
 958 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
 959
 960 /**
 961  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
 962  * @dev:        device the extcon belongs to
 963  * @edev:       the extcon device to unregister
 964  *
 965  * Unregister extcon device that is registered with devm_extcon_dev_register()
 966  * function.
 967  */
 968 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
 969 {
 970         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
 971                                devm_extcon_dev_match, edev));
 972 }
 973 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
 974
 975 #ifdef CONFIG_OF
 976 /*
 977  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
 978  * @dev - instance to the given device
 979  * @index - index into list of extcon_dev
 980  *
 981  * return the instance of extcon device
 982  */
 983 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 984 {
 985         struct device_node *node;
 986         struct extcon_dev *edev;
 987
 988         if (!dev->of_node) {
 989                 dev_err(dev, "device does not have a device node entry\n");
 990                 return ERR_PTR(-EINVAL);
 991         }
 992
 993         node = of_parse_phandle(dev->of_node, "extcon", index);
 994         if (!node) {
 995                 dev_err(dev, "failed to get phandle in %s node\n",
 996                         dev->of_node->full_name);
 997                 return ERR_PTR(-ENODEV);
 998         }
 999
1000         edev = extcon_get_extcon_dev(node->name);
1001         if (!edev) {
1002                 dev_err(dev, "unable to get extcon device : %s\n", node->name);
1003                 return ERR_PTR(-ENODEV);
1004         }
1005
1006         return edev;
1007 }
1008 #else
1009 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1010 {
1011         return ERR_PTR(-ENOSYS);
1012 }
1013 #endif /* CONFIG_OF */
1014 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1015
1016 static int __init extcon_class_init(void)
1017 {
1018         return create_extcon_class();
1019 }
1020 module_init(extcon_class_init);
1021
1022 static void __exit extcon_class_exit(void)
1023 {
1024 #if defined(CONFIG_ANDROID)
1025         class_compat_unregister(switch_class);
1026 #endif
1027         class_destroy(extcon_class);
1028 }
1029 module_exit(extcon_class_exit);
1030
1031 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1032 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1033 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1034 MODULE_DESCRIPTION("External connector (extcon) class driver");
1035 MODULE_LICENSE("GPL");