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         /* USB external connector */
  43         [EXTCON_USB]            = "USB",
  44         [EXTCON_USB_HOST]       = "USB-HOST",
  45
  46         /* Charger external connector */
  47         [EXTCON_TA]             = "TA",
  48         [EXTCON_FAST_CHARGER]   = "FAST-CHARGER",
  49         [EXTCON_SLOW_CHARGER]   = "SLOW-CHARGER",
  50         [EXTCON_CHARGE_DOWNSTREAM] = "CHARGE-DOWNSTREAM",
  51
  52         /* Audio/Video external connector */
  53         [EXTCON_LINE_IN]        = "LINE-IN",
  54         [EXTCON_LINE_OUT]       = "LINE-OUT",
  55         [EXTCON_MICROPHONE]     = "MICROPHONE",
  56         [EXTCON_HEADPHONE]      = "HEADPHONE",
  57
  58         [EXTCON_HDMI]           = "HDMI",
  59         [EXTCON_MHL]            = "MHL",
  60         [EXTCON_DVI]            = "DVI",
  61         [EXTCON_VGA]            = "VGA",
  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
  67         /* Etc external connector */
  68         [EXTCON_DOCK]           = "DOCK",
  69         [EXTCON_JIG]            = "JIG",
  70         [EXTCON_MECHANICAL]     = "MECHANICAL",
  71
  72         NULL,
  73 };
  74
  75 static struct class *extcon_class;
  76 #if defined(CONFIG_ANDROID)
  77 static struct class_compat *switch_class;
  78 #endif /* CONFIG_ANDROID */
  79
  80 static LIST_HEAD(extcon_dev_list);
  81 static DEFINE_MUTEX(extcon_dev_list_lock);
  82
  83 /**
  84  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  85  *                            condition.
  86  * @edev:       the extcon device
  87  * @new_state:  new cable attach status for @edev
  88  *
  89  * Returns 0 if nothing violates. Returns the index + 1 for the first
  90  * violated condition.
  91  */
  92 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  93 {
  94         int i = 0;
  95
  96         if (!edev->mutually_exclusive)
  97                 return 0;
  98
  99         for (i = 0; edev->mutually_exclusive[i]; i++) {
 100                 int weight;
 101                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 102
 103                 /* calculate the total number of bits set */
 104                 weight = hweight32(correspondants);
 105                 if (weight > 1)
 106                         return i + 1;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static int find_cable_index_by_id(struct extcon_dev *edev, const enum extcon id)
 113 {
 114         int i;
 115
 116         /* Find the the index of extcon cable in edev->supported_cable */
 117         for (i = 0; i < edev->max_supported; i++) {
 118                 if (edev->supported_cable[i] == id)
 119                         return i;
 120         }
 121
 122         return -EINVAL;
 123 }
 124
 125 static int find_cable_index_by_name(struct extcon_dev *edev, const char *name)
 126 {
 127         enum extcon id = EXTCON_NONE;
 128         int i;
 129
 130         if (edev->max_supported == 0)
 131                 return -EINVAL;
 132
 133         /* Find the the number of extcon cable */
 134         for (i = 0; i < EXTCON_END; i++) {
 135                 if (!extcon_name[i])
 136                         continue;
 137                 if (!strncmp(extcon_name[i], name, CABLE_NAME_MAX)) {
 138                         id = i;
 139                         break;
 140                 }
 141         }
 142
 143         if (id == EXTCON_NONE)
 144                 return -EINVAL;
 145
 146         return find_cable_index_by_id(edev, id);
 147 }
 148
 149 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 150 {
 151         if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
 152                 *attached = new ? true : false;
 153                 return true;
 154         }
 155
 156         return false;
 157 }
 158
 159 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 160                           char *buf)
 161 {
 162         int i, count = 0;
 163         struct extcon_dev *edev = dev_get_drvdata(dev);
 164
 165         if (edev->print_state) {
 166                 int ret = edev->print_state(edev, buf);
 167
 168                 if (ret >= 0)
 169                         return ret;
 170                 /* Use default if failed */
 171         }
 172
 173         if (edev->max_supported == 0)
 174                 return sprintf(buf, "%u\n", edev->state);
 175
 176         for (i = 0; i < edev->max_supported; i++) {
 177                 count += sprintf(buf + count, "%s=%d\n",
 178                                 extcon_name[edev->supported_cable[i]],
 179                                  !!(edev->state & (1 << i)));
 180         }
 181
 182         return count;
 183 }
 184
 185 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 186                            const char *buf, size_t count)
 187 {
 188         u32 state;
 189         ssize_t ret = 0;
 190         struct extcon_dev *edev = dev_get_drvdata(dev);
 191
 192         ret = sscanf(buf, "0x%x", &state);
 193         if (ret == 0)
 194                 ret = -EINVAL;
 195         else
 196                 ret = extcon_set_state(edev, state);
 197
 198         if (ret < 0)
 199                 return ret;
 200
 201         return count;
 202 }
 203 static DEVICE_ATTR_RW(state);
 204
 205 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 206                 char *buf)
 207 {
 208         struct extcon_dev *edev = dev_get_drvdata(dev);
 209
 210         /* Optional callback given by the user */
 211         if (edev->print_name) {
 212                 int ret = edev->print_name(edev, buf);
 213
 214                 if (ret >= 0)
 215                         return ret;
 216         }
 217
 218         return sprintf(buf, "%s\n", edev->name);
 219 }
 220 static DEVICE_ATTR_RO(name);
 221
 222 static ssize_t cable_name_show(struct device *dev,
 223                                struct device_attribute *attr, char *buf)
 224 {
 225         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 226                                                   attr_name);
 227         int i = cable->cable_index;
 228
 229         return sprintf(buf, "%s\n",
 230                         extcon_name[cable->edev->supported_cable[i]]);
 231 }
 232
 233 static ssize_t cable_state_show(struct device *dev,
 234                                 struct device_attribute *attr, char *buf)
 235 {
 236         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 237                                                   attr_state);
 238
 239         return sprintf(buf, "%d\n",
 240                        extcon_get_cable_state_(cable->edev,
 241                                                cable->cable_index));
 242 }
 243
 244 /**
 245  * extcon_update_state() - Update the cable attach states of the extcon device
 246  *                         only for the masked bits.
 247  * @edev:       the extcon device
 248  * @mask:       the bit mask to designate updated bits.
 249  * @state:      new cable attach status for @edev
 250  *
 251  * Changing the state sends uevent with environment variable containing
 252  * the name of extcon device (envp[0]) and the state output (envp[1]).
 253  * Tizen uses this format for extcon device to get events from ports.
 254  * Android uses this format as well.
 255  *
 256  * Note that the notifier provides which bits are changed in the state
 257  * variable with the val parameter (second) to the callback.
 258  */
 259 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 260 {
 261         char name_buf[120];
 262         char state_buf[120];
 263         char *prop_buf;
 264         char *envp[3];
 265         int env_offset = 0;
 266         int length;
 267         int index;
 268         unsigned long flags;
 269         bool attached;
 270
 271         spin_lock_irqsave(&edev->lock, flags);
 272
 273         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 274                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 275                                                    (state & mask))) {
 276                         spin_unlock_irqrestore(&edev->lock, flags);
 277                         return -EPERM;
 278                 }
 279
 280                 for (index = 0; index < edev->max_supported; index++) {
 281                         if (is_extcon_changed(edev->state, state, index, &attached))
 282                                 raw_notifier_call_chain(&edev->nh[index], attached, edev);
 283                 }
 284
 285                 edev->state &= ~mask;
 286                 edev->state |= state & mask;
 287
 288                 /* This could be in interrupt handler */
 289                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 290                 if (prop_buf) {
 291                         length = name_show(&edev->dev, NULL, prop_buf);
 292                         if (length > 0) {
 293                                 if (prop_buf[length - 1] == '\n')
 294                                         prop_buf[length - 1] = 0;
 295                                 snprintf(name_buf, sizeof(name_buf),
 296                                         "NAME=%s", prop_buf);
 297                                 envp[env_offset++] = name_buf;
 298                         }
 299                         length = state_show(&edev->dev, NULL, prop_buf);
 300                         if (length > 0) {
 301                                 if (prop_buf[length - 1] == '\n')
 302                                         prop_buf[length - 1] = 0;
 303                                 snprintf(state_buf, sizeof(state_buf),
 304                                         "STATE=%s", prop_buf);
 305                                 envp[env_offset++] = state_buf;
 306                         }
 307                         envp[env_offset] = NULL;
 308                         /* Unlock early before uevent */
 309                         spin_unlock_irqrestore(&edev->lock, flags);
 310
 311                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 312                         free_page((unsigned long)prop_buf);
 313                 } else {
 314                         /* Unlock early before uevent */
 315                         spin_unlock_irqrestore(&edev->lock, flags);
 316
 317                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 318                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 319                 }
 320         } else {
 321                 /* No changes */
 322                 spin_unlock_irqrestore(&edev->lock, flags);
 323         }
 324
 325         return 0;
 326 }
 327 EXPORT_SYMBOL_GPL(extcon_update_state);
 328
 329 /**
 330  * extcon_set_state() - Set the cable attach states of the extcon device.
 331  * @edev:       the extcon device
 332  * @state:      new cable attach status for @edev
 333  *
 334  * Note that notifier provides which bits are changed in the state
 335  * variable with the val parameter (second) to the callback.
 336  */
 337 int extcon_set_state(struct extcon_dev *edev, u32 state)
 338 {
 339         return extcon_update_state(edev, 0xffffffff, state);
 340 }
 341 EXPORT_SYMBOL_GPL(extcon_set_state);
 342
 343 /**
 344  * extcon_get_cable_state_() - Get the status of a specific cable.
 345  * @edev:       the extcon device that has the cable.
 346  * @id:         the unique id of each external connector in extcon enumeration.
 347  */
 348 int extcon_get_cable_state_(struct extcon_dev *edev, const enum extcon id)
 349 {
 350         int index;
 351
 352         index = find_cable_index_by_id(edev, id);
 353         if (index < 0)
 354                 return index;
 355
 356         if (edev->max_supported && edev->max_supported <= index)
 357                 return -EINVAL;
 358
 359         return !!(edev->state & (1 << index));
 360 }
 361 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 362
 363 /**
 364  * extcon_get_cable_state() - Get the status of a specific cable.
 365  * @edev:       the extcon device that has the cable.
 366  * @cable_name: cable name.
 367  *
 368  * Note that this is slower than extcon_get_cable_state_.
 369  */
 370 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 371 {
 372         return extcon_get_cable_state_(edev, find_cable_index_by_name
 373                                                 (edev, cable_name));
 374 }
 375 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 376
 377 /**
 378  * extcon_set_cable_state_() - Set the status of a specific cable.
 379  * @edev:               the extcon device that has the cable.
 380  * @id:                 the unique id of each external connector
 381  *                      in extcon enumeration.
 382  * @state:              the new cable status. The default semantics is
 383  *                      true: attached / false: detached.
 384  */
 385 int extcon_set_cable_state_(struct extcon_dev *edev, enum extcon id,
 386                                 bool cable_state)
 387 {
 388         u32 state;
 389         int index;
 390
 391         index = find_cable_index_by_id(edev, id);
 392         if (index < 0)
 393                 return index;
 394
 395         if (edev->max_supported && edev->max_supported <= index)
 396                 return -EINVAL;
 397
 398         state = cable_state ? (1 << index) : 0;
 399         return extcon_update_state(edev, 1 << index, state);
 400 }
 401 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 402
 403 /**
 404  * extcon_set_cable_state() - Set the status of a specific cable.
 405  * @edev:               the extcon device that has the cable.
 406  * @cable_name:         cable name.
 407  * @cable_state:        the new cable status. The default semantics is
 408  *                      true: attached / false: detached.
 409  *
 410  * Note that this is slower than extcon_set_cable_state_.
 411  */
 412 int extcon_set_cable_state(struct extcon_dev *edev,
 413                         const char *cable_name, bool cable_state)
 414 {
 415         return extcon_set_cable_state_(edev, find_cable_index_by_name
 416                                         (edev, cable_name), cable_state);
 417 }
 418 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 419
 420 /**
 421  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 422  * @extcon_name:        The extcon name provided with extcon_dev_register()
 423  */
 424 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 425 {
 426         struct extcon_dev *sd;
 427
 428         mutex_lock(&extcon_dev_list_lock);
 429         list_for_each_entry(sd, &extcon_dev_list, entry) {
 430                 if (!strcmp(sd->name, extcon_name))
 431                         goto out;
 432         }
 433         sd = NULL;
 434 out:
 435         mutex_unlock(&extcon_dev_list_lock);
 436         return sd;
 437 }
 438 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 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                 spin_lock_irqsave(&obj->edev->lock, flags);
 486                 ret = raw_notifier_chain_register(
 487                                         &obj->edev->nh[obj->cable_index],
 488                                         obj->user_nb);
 489                 spin_unlock_irqrestore(&obj->edev->lock, flags);
 490         } else {
 491                 struct class_dev_iter iter;
 492                 struct extcon_dev *extd;
 493                 struct device *dev;
 494
 495                 if (!extcon_class)
 496                         return -ENODEV;
 497                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 498                 while ((dev = class_dev_iter_next(&iter))) {
 499                         extd = dev_get_drvdata(dev);
 500
 501                         if (find_cable_index_by_name(extd, cable_name) < 0)
 502                                 continue;
 503
 504                         class_dev_iter_exit(&iter);
 505                         return extcon_register_interest(obj, extd->name,
 506                                                 cable_name, nb);
 507                 }
 508
 509                 ret = -ENODEV;
 510         }
 511
 512         return ret;
 513 }
 514 EXPORT_SYMBOL_GPL(extcon_register_interest);
 515
 516 /**
 517  * extcon_unregister_interest() - Unregister the notifier registered by
 518  *                                extcon_register_interest().
 519  * @obj:        the extcon_specific_cable_nb object returned by
 520  *              extcon_register_interest().
 521  */
 522 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 523 {
 524         unsigned long flags;
 525         int ret;
 526
 527         if (!obj)
 528                 return -EINVAL;
 529
 530         spin_lock_irqsave(&obj->edev->lock, flags);
 531         ret = raw_notifier_chain_unregister(
 532                         &obj->edev->nh[obj->cable_index], obj->user_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 that has the external connecotr.
 543  * @id:         the unique id of each external connector in extcon enumeration.
 544  * @nb:         a notifier block to be registered.
 545  *
 546  * Note that the second parameter given to the callback of nb (val) is
 547  * "old_state", not the current state. The current state can be retrieved
 548  * by looking at the third pameter (edev pointer)'s state value.
 549  */
 550 int extcon_register_notifier(struct extcon_dev *edev, enum extcon id,
 551                              struct notifier_block *nb)
 552 {
 553         unsigned long flags;
 554         int ret, idx;
 555
 556         idx = find_cable_index_by_id(edev, id);
 557
 558         spin_lock_irqsave(&edev->lock, flags);
 559         ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 560         spin_unlock_irqrestore(&edev->lock, flags);
 561
 562         return ret;
 563 }
 564 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 565
 566 /**
 567  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 568  * @edev:       the extcon device that has the external connecotr.
 569  * @id:         the unique id of each external connector in extcon enumeration.
 570  * @nb:         a notifier block to be registered.
 571  */
 572 int extcon_unregister_notifier(struct extcon_dev *edev, enum extcon id,
 573                                 struct notifier_block *nb)
 574 {
 575         unsigned long flags;
 576         int ret, idx;
 577
 578         idx = find_cable_index_by_id(edev, id);
 579
 580         spin_lock_irqsave(&edev->lock, flags);
 581         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 582         spin_unlock_irqrestore(&edev->lock, flags);
 583
 584         return ret;
 585 }
 586 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 587
 588 static struct attribute *extcon_attrs[] = {
 589         &dev_attr_state.attr,
 590         &dev_attr_name.attr,
 591         NULL,
 592 };
 593 ATTRIBUTE_GROUPS(extcon);
 594
 595 static int create_extcon_class(void)
 596 {
 597         if (!extcon_class) {
 598                 extcon_class = class_create(THIS_MODULE, "extcon");
 599                 if (IS_ERR(extcon_class))
 600                         return PTR_ERR(extcon_class);
 601                 extcon_class->dev_groups = extcon_groups;
 602
 603 #if defined(CONFIG_ANDROID)
 604                 switch_class = class_compat_register("switch");
 605                 if (WARN(!switch_class, "cannot allocate"))
 606                         return -ENOMEM;
 607 #endif /* CONFIG_ANDROID */
 608         }
 609
 610         return 0;
 611 }
 612
 613 static void extcon_dev_release(struct device *dev)
 614 {
 615 }
 616
 617 static const char *muex_name = "mutually_exclusive";
 618 static void dummy_sysfs_dev_release(struct device *dev)
 619 {
 620 }
 621
 622 /*
 623  * extcon_dev_allocate() - Allocate the memory of extcon device.
 624  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 625  *                      If supported_cable is NULL, cable name related APIs
 626  *                      are disabled.
 627  *
 628  * This function allocates the memory for extcon device without allocating
 629  * memory in each extcon provider driver and initialize default setting for
 630  * extcon device.
 631  *
 632  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 633  */
 634 struct extcon_dev *extcon_dev_allocate(const enum extcon *supported_cable)
 635 {
 636         struct extcon_dev *edev;
 637
 638         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 639         if (!edev)
 640                 return ERR_PTR(-ENOMEM);
 641
 642         edev->max_supported = 0;
 643         edev->supported_cable = supported_cable;
 644
 645         return edev;
 646 }
 647
 648 /*
 649  * extcon_dev_free() - Free the memory of extcon device.
 650  * @edev:       the extcon device to free
 651  */
 652 void extcon_dev_free(struct extcon_dev *edev)
 653 {
 654         kfree(edev);
 655 }
 656 EXPORT_SYMBOL_GPL(extcon_dev_free);
 657
 658 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 659 {
 660         struct extcon_dev **r = res;
 661
 662         if (WARN_ON(!r || !*r))
 663                 return 0;
 664
 665         return *r == data;
 666 }
 667
 668 static void devm_extcon_dev_release(struct device *dev, void *res)
 669 {
 670         extcon_dev_free(*(struct extcon_dev **)res);
 671 }
 672
 673 /**
 674  * devm_extcon_dev_allocate - Allocate managed extcon device
 675  * @dev:                device owning the extcon device being created
 676  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 677  *                      If supported_cable is NULL, cable name related APIs
 678  *                      are disabled.
 679  *
 680  * This function manages automatically the memory of extcon device using device
 681  * resource management and simplify the control of freeing the memory of extcon
 682  * device.
 683  *
 684  * Returns the pointer memory of allocated extcon_dev if success
 685  * or ERR_PTR(err) if fail
 686  */
 687 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 688                                         const enum extcon *supported_cable)
 689 {
 690         struct extcon_dev **ptr, *edev;
 691
 692         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 693         if (!ptr)
 694                 return ERR_PTR(-ENOMEM);
 695
 696         edev = extcon_dev_allocate(supported_cable);
 697         if (IS_ERR(edev)) {
 698                 devres_free(ptr);
 699                 return edev;
 700         }
 701
 702         edev->dev.parent = dev;
 703
 704         *ptr = edev;
 705         devres_add(dev, ptr);
 706
 707         return edev;
 708 }
 709 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 710
 711 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 712 {
 713         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 714                                devm_extcon_dev_match, edev));
 715 }
 716 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 717
 718 /**
 719  * extcon_dev_register() - Register a new extcon device
 720  * @edev        : the new extcon device (should be allocated before calling)
 721  *
 722  * Among the members of edev struct, please set the "user initializing data"
 723  * in any case and set the "optional callbacks" if required. However, please
 724  * do not set the values of "internal data", which are initialized by
 725  * this function.
 726  */
 727 int extcon_dev_register(struct extcon_dev *edev)
 728 {
 729         int ret, index = 0;
 730         static atomic_t edev_no = ATOMIC_INIT(-1);
 731
 732         if (!extcon_class) {
 733                 ret = create_extcon_class();
 734                 if (ret < 0)
 735                         return ret;
 736         }
 737
 738         if (!edev->supported_cable)
 739                 return -EINVAL;
 740
 741         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 742
 743         edev->max_supported = index;
 744         if (index > SUPPORTED_CABLE_MAX) {
 745                 dev_err(&edev->dev,
 746                         "exceed the maximum number of supported cables\n");
 747                 return -EINVAL;
 748         }
 749
 750         edev->dev.class = extcon_class;
 751         edev->dev.release = extcon_dev_release;
 752
 753         edev->name = dev_name(edev->dev.parent);
 754         if (IS_ERR_OR_NULL(edev->name)) {
 755                 dev_err(&edev->dev,
 756                         "extcon device name is null\n");
 757                 return -EINVAL;
 758         }
 759         dev_set_name(&edev->dev, "extcon%lu",
 760                         (unsigned long)atomic_inc_return(&edev_no));
 761
 762         if (edev->max_supported) {
 763                 char buf[10];
 764                 char *str;
 765                 struct extcon_cable *cable;
 766
 767                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 768                                        edev->max_supported, GFP_KERNEL);
 769                 if (!edev->cables) {
 770                         ret = -ENOMEM;
 771                         goto err_sysfs_alloc;
 772                 }
 773                 for (index = 0; index < edev->max_supported; index++) {
 774                         cable = &edev->cables[index];
 775
 776                         snprintf(buf, 10, "cable.%d", index);
 777                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 778                                       GFP_KERNEL);
 779                         if (!str) {
 780                                 for (index--; index >= 0; index--) {
 781                                         cable = &edev->cables[index];
 782                                         kfree(cable->attr_g.name);
 783                                 }
 784                                 ret = -ENOMEM;
 785
 786                                 goto err_alloc_cables;
 787                         }
 788                         strcpy(str, buf);
 789
 790                         cable->edev = edev;
 791                         cable->cable_index = index;
 792                         cable->attrs[0] = &cable->attr_name.attr;
 793                         cable->attrs[1] = &cable->attr_state.attr;
 794                         cable->attrs[2] = NULL;
 795                         cable->attr_g.name = str;
 796                         cable->attr_g.attrs = cable->attrs;
 797
 798                         sysfs_attr_init(&cable->attr_name.attr);
 799                         cable->attr_name.attr.name = "name";
 800                         cable->attr_name.attr.mode = 0444;
 801                         cable->attr_name.show = cable_name_show;
 802
 803                         sysfs_attr_init(&cable->attr_state.attr);
 804                         cable->attr_state.attr.name = "state";
 805                         cable->attr_state.attr.mode = 0444;
 806                         cable->attr_state.show = cable_state_show;
 807                 }
 808         }
 809
 810         if (edev->max_supported && edev->mutually_exclusive) {
 811                 char buf[80];
 812                 char *name;
 813
 814                 /* Count the size of mutually_exclusive array */
 815                 for (index = 0; edev->mutually_exclusive[index]; index++)
 816                         ;
 817
 818                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 819                                            (index + 1), GFP_KERNEL);
 820                 if (!edev->attrs_muex) {
 821                         ret = -ENOMEM;
 822                         goto err_muex;
 823                 }
 824
 825                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 826                                              index, GFP_KERNEL);
 827                 if (!edev->d_attrs_muex) {
 828                         ret = -ENOMEM;
 829                         kfree(edev->attrs_muex);
 830                         goto err_muex;
 831                 }
 832
 833                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 834                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 835                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 836                                        GFP_KERNEL);
 837                         if (!name) {
 838                                 for (index--; index >= 0; index--) {
 839                                         kfree(edev->d_attrs_muex[index].attr.
 840                                               name);
 841                                 }
 842                                 kfree(edev->d_attrs_muex);
 843                                 kfree(edev->attrs_muex);
 844                                 ret = -ENOMEM;
 845                                 goto err_muex;
 846                         }
 847                         strcpy(name, buf);
 848                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 849                         edev->d_attrs_muex[index].attr.name = name;
 850                         edev->d_attrs_muex[index].attr.mode = 0000;
 851                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 852                                                         .attr;
 853                 }
 854                 edev->attr_g_muex.name = muex_name;
 855                 edev->attr_g_muex.attrs = edev->attrs_muex;
 856
 857         }
 858
 859         if (edev->max_supported) {
 860                 edev->extcon_dev_type.groups =
 861                         kzalloc(sizeof(struct attribute_group *) *
 862                                 (edev->max_supported + 2), GFP_KERNEL);
 863                 if (!edev->extcon_dev_type.groups) {
 864                         ret = -ENOMEM;
 865                         goto err_alloc_groups;
 866                 }
 867
 868                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 869                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 870
 871                 for (index = 0; index < edev->max_supported; index++)
 872                         edev->extcon_dev_type.groups[index] =
 873                                 &edev->cables[index].attr_g;
 874                 if (edev->mutually_exclusive)
 875                         edev->extcon_dev_type.groups[index] =
 876                                 &edev->attr_g_muex;
 877
 878                 edev->dev.type = &edev->extcon_dev_type;
 879         }
 880
 881         ret = device_register(&edev->dev);
 882         if (ret) {
 883                 put_device(&edev->dev);
 884                 goto err_dev;
 885         }
 886 #if defined(CONFIG_ANDROID)
 887         if (switch_class)
 888                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 889 #endif /* CONFIG_ANDROID */
 890
 891         spin_lock_init(&edev->lock);
 892
 893         edev->nh = devm_kzalloc(&edev->dev,
 894                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 895         if (!edev->nh) {
 896                 ret = -ENOMEM;
 897                 goto err_dev;
 898         }
 899
 900         for (index = 0; index < edev->max_supported; index++)
 901                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 902
 903         dev_set_drvdata(&edev->dev, edev);
 904         edev->state = 0;
 905
 906         mutex_lock(&extcon_dev_list_lock);
 907         list_add(&edev->entry, &extcon_dev_list);
 908         mutex_unlock(&extcon_dev_list_lock);
 909
 910         return 0;
 911
 912 err_dev:
 913         if (edev->max_supported)
 914                 kfree(edev->extcon_dev_type.groups);
 915 err_alloc_groups:
 916         if (edev->max_supported && edev->mutually_exclusive) {
 917                 for (index = 0; edev->mutually_exclusive[index]; index++)
 918                         kfree(edev->d_attrs_muex[index].attr.name);
 919                 kfree(edev->d_attrs_muex);
 920                 kfree(edev->attrs_muex);
 921         }
 922 err_muex:
 923         for (index = 0; index < edev->max_supported; index++)
 924                 kfree(edev->cables[index].attr_g.name);
 925 err_alloc_cables:
 926         if (edev->max_supported)
 927                 kfree(edev->cables);
 928 err_sysfs_alloc:
 929         return ret;
 930 }
 931 EXPORT_SYMBOL_GPL(extcon_dev_register);
 932
 933 /**
 934  * extcon_dev_unregister() - Unregister the extcon device.
 935  * @edev:       the extcon device instance to be unregistered.
 936  *
 937  * Note that this does not call kfree(edev) because edev was not allocated
 938  * by this class.
 939  */
 940 void extcon_dev_unregister(struct extcon_dev *edev)
 941 {
 942         int index;
 943
 944         mutex_lock(&extcon_dev_list_lock);
 945         list_del(&edev->entry);
 946         mutex_unlock(&extcon_dev_list_lock);
 947
 948         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 949                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 950                                 dev_name(&edev->dev));
 951                 return;
 952         }
 953
 954         device_unregister(&edev->dev);
 955
 956         if (edev->mutually_exclusive && edev->max_supported) {
 957                 for (index = 0; edev->mutually_exclusive[index];
 958                                 index++)
 959                         kfree(edev->d_attrs_muex[index].attr.name);
 960                 kfree(edev->d_attrs_muex);
 961                 kfree(edev->attrs_muex);
 962         }
 963
 964         for (index = 0; index < edev->max_supported; index++)
 965                 kfree(edev->cables[index].attr_g.name);
 966
 967         if (edev->max_supported) {
 968                 kfree(edev->extcon_dev_type.groups);
 969                 kfree(edev->cables);
 970         }
 971
 972 #if defined(CONFIG_ANDROID)
 973         if (switch_class)
 974                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 975 #endif
 976         put_device(&edev->dev);
 977 }
 978 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 979
 980 static void devm_extcon_dev_unreg(struct device *dev, void *res)
 981 {
 982         extcon_dev_unregister(*(struct extcon_dev **)res);
 983 }
 984
 985 /**
 986  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
 987  * @dev:        device to allocate extcon device
 988  * @edev:       the new extcon device to register
 989  *
 990  * Managed extcon_dev_register() function. If extcon device is attached with
 991  * this function, that extcon device is automatically unregistered on driver
 992  * detach. Internally this function calls extcon_dev_register() function.
 993  * To get more information, refer that function.
 994  *
 995  * If extcon device is registered with this function and the device needs to be
 996  * unregistered separately, devm_extcon_dev_unregister() should be used.
 997  *
 998  * Returns 0 if success or negaive error number if failure.
 999  */
1000 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
1001 {
1002         struct extcon_dev **ptr;
1003         int ret;
1004
1005         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
1006         if (!ptr)
1007                 return -ENOMEM;
1008
1009         ret = extcon_dev_register(edev);
1010         if (ret) {
1011                 devres_free(ptr);
1012                 return ret;
1013         }
1014
1015         *ptr = edev;
1016         devres_add(dev, ptr);
1017
1018         return 0;
1019 }
1020 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
1021
1022 /**
1023  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
1024  * @dev:        device the extcon belongs to
1025  * @edev:       the extcon device to unregister
1026  *
1027  * Unregister extcon device that is registered with devm_extcon_dev_register()
1028  * function.
1029  */
1030 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
1031 {
1032         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
1033                                devm_extcon_dev_match, edev));
1034 }
1035 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1036
1037 #ifdef CONFIG_OF
1038 /*
1039  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1040  * @dev - instance to the given device
1041  * @index - index into list of extcon_dev
1042  *
1043  * return the instance of extcon device
1044  */
1045 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1046 {
1047         struct device_node *node;
1048         struct extcon_dev *edev;
1049
1050         if (!dev->of_node) {
1051                 dev_err(dev, "device does not have a device node entry\n");
1052                 return ERR_PTR(-EINVAL);
1053         }
1054
1055         node = of_parse_phandle(dev->of_node, "extcon", index);
1056         if (!node) {
1057                 dev_err(dev, "failed to get phandle in %s node\n",
1058                         dev->of_node->full_name);
1059                 return ERR_PTR(-ENODEV);
1060         }
1061
1062         mutex_lock(&extcon_dev_list_lock);
1063         list_for_each_entry(edev, &extcon_dev_list, entry) {
1064                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1065                         mutex_unlock(&extcon_dev_list_lock);
1066                         return edev;
1067                 }
1068         }
1069         mutex_unlock(&extcon_dev_list_lock);
1070
1071         return ERR_PTR(-EPROBE_DEFER);
1072 }
1073 #else
1074 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1075 {
1076         return ERR_PTR(-ENOSYS);
1077 }
1078 #endif /* CONFIG_OF */
1079 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1080
1081 /**
1082  * extcon_get_edev_name() - Get the name of the extcon device.
1083  * @edev:       the extcon device
1084  */
1085 const char *extcon_get_edev_name(struct extcon_dev *edev)
1086 {
1087         return !edev ? NULL : edev->name;
1088 }
1089
1090 static int __init extcon_class_init(void)
1091 {
1092         return create_extcon_class();
1093 }
1094 module_init(extcon_class_init);
1095
1096 static void __exit extcon_class_exit(void)
1097 {
1098 #if defined(CONFIG_ANDROID)
1099         class_compat_unregister(switch_class);
1100 #endif
1101         class_destroy(extcon_class);
1102 }
1103 module_exit(extcon_class_exit);
1104
1105 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1106 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1107 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1108 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1109 MODULE_DESCRIPTION("External connector (extcon) class driver");
1110 MODULE_LICENSE("GPL");