drivers/extcon/extcon.c

   1 /*
   2  *  drivers/extcon/extcon.c - External Connector (extcon) framework.
   3  *
   4  *  External connector (extcon) class driver
   5  *
   6  * Copyright (C) 2015 Samsung Electronics
   7  * Author: Chanwoo Choi <cw00.choi@samsung.com>
   8  *
   9  * Copyright (C) 2012 Samsung Electronics
  10  * Author: Donggeun Kim <dg77.kim@samsung.com>
  11  * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
  12  *
  13  * based on android/drivers/switch/switch_class.c
  14  * Copyright (C) 2008 Google, Inc.
  15  * Author: Mike Lockwood <lockwood@android.com>
  16  *
  17  * This software is licensed under the terms of the GNU General Public
  18  * License version 2, as published by the Free Software Foundation, and
  19  * may be copied, distributed, and modified under those terms.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/types.h>
  29 #include <linux/init.h>
  30 #include <linux/device.h>
  31 #include <linux/fs.h>
  32 #include <linux/err.h>
  33 #include <linux/extcon.h>
  34 #include <linux/of.h>
  35 #include <linux/slab.h>
  36 #include <linux/sysfs.h>
  37
  38 #define SUPPORTED_CABLE_MAX     32
  39 #define CABLE_NAME_MAX          30
  40
  41 static const char *extcon_name[] =  {
  42         [EXTCON_NONE]           = "NONE",
  43
  44         /* USB external connector */
  45         [EXTCON_USB]            = "USB",
  46         [EXTCON_USB_HOST]       = "USB-HOST",
  47
  48         /* Charger external connector */
  49         [EXTCON_TA]             = "TA",
  50         [EXTCON_FAST_CHARGER]   = "FAST-CHARGER",
  51         [EXTCON_SLOW_CHARGER]   = "SLOW-CHARGER",
  52         [EXTCON_CHARGE_DOWNSTREAM] = "CHARGE-DOWNSTREAM",
  53
  54         /* Audio/Video external connector */
  55         [EXTCON_LINE_IN]        = "LINE-IN",
  56         [EXTCON_LINE_OUT]       = "LINE-OUT",
  57         [EXTCON_MICROPHONE]     = "MICROPHONE",
  58         [EXTCON_HEADPHONE]      = "HEADPHONE",
  59
  60         [EXTCON_HDMI]           = "HDMI",
  61         [EXTCON_MHL]            = "MHL",
  62         [EXTCON_DVI]            = "DVI",
  63         [EXTCON_VGA]            = "VGA",
  64         [EXTCON_SPDIF_IN]       = "SPDIF-IN",
  65         [EXTCON_SPDIF_OUT]      = "SPDIF-OUT",
  66         [EXTCON_VIDEO_IN]       = "VIDEO-IN",
  67         [EXTCON_VIDEO_OUT]      = "VIDEO-OUT",
  68
  69         /* Etc external connector */
  70         [EXTCON_DOCK]           = "DOCK",
  71         [EXTCON_JIG]            = "JIG",
  72         [EXTCON_MECHANICAL]     = "MECHANICAL",
  73
  74         NULL,
  75 };
  76
  77 static struct class *extcon_class;
  78 #if defined(CONFIG_ANDROID)
  79 static struct class_compat *switch_class;
  80 #endif /* CONFIG_ANDROID */
  81
  82 static LIST_HEAD(extcon_dev_list);
  83 static DEFINE_MUTEX(extcon_dev_list_lock);
  84
  85 /**
  86  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
  87  *                            condition.
  88  * @edev:       the extcon device
  89  * @new_state:  new cable attach status for @edev
  90  *
  91  * Returns 0 if nothing violates. Returns the index + 1 for the first
  92  * violated condition.
  93  */
  94 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
  95 {
  96         int i = 0;
  97
  98         if (!edev->mutually_exclusive)
  99                 return 0;
 100
 101         for (i = 0; edev->mutually_exclusive[i]; i++) {
 102                 int weight;
 103                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 104
 105                 /* calculate the total number of bits set */
 106                 weight = hweight32(correspondants);
 107                 if (weight > 1)
 108                         return i + 1;
 109         }
 110
 111         return 0;
 112 }
 113
 114 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 115 {
 116         int i;
 117
 118         /* Find the the index of extcon cable in edev->supported_cable */
 119         for (i = 0; i < edev->max_supported; i++) {
 120                 if (edev->supported_cable[i] == id)
 121                         return i;
 122         }
 123
 124         return -EINVAL;
 125 }
 126
 127 static int find_cable_id_by_name(struct extcon_dev *edev, const char *name)
 128 {
 129         unsigned int id = -EINVAL;
 130         int i = 0;
 131
 132         /* Find the id of extcon cable */
 133         while (extcon_name[i]) {
 134                 if (!strncmp(extcon_name[i], name, CABLE_NAME_MAX)) {
 135                         id = i;
 136                         break;
 137                 }
 138                 i++;
 139         }
 140
 141         return id;
 142 }
 143
 144 static int find_cable_index_by_name(struct extcon_dev *edev, const char *name)
 145 {
 146         unsigned int id;
 147
 148         if (edev->max_supported == 0)
 149                 return -EINVAL;
 150
 151         /* Find the the number of extcon cable */
 152         id = find_cable_id_by_name(edev, name);
 153         if (id < 0)
 154                 return id;
 155
 156         return find_cable_index_by_id(edev, id);
 157 }
 158
 159 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 160 {
 161         if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
 162                 *attached = new ? true : false;
 163                 return true;
 164         }
 165
 166         return false;
 167 }
 168
 169 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 170                           char *buf)
 171 {
 172         int i, count = 0;
 173         struct extcon_dev *edev = dev_get_drvdata(dev);
 174
 175         if (edev->print_state) {
 176                 int ret = edev->print_state(edev, buf);
 177
 178                 if (ret >= 0)
 179                         return ret;
 180                 /* Use default if failed */
 181         }
 182
 183         if (edev->max_supported == 0)
 184                 return sprintf(buf, "%u\n", edev->state);
 185
 186         for (i = 0; i < edev->max_supported; i++) {
 187                 count += sprintf(buf + count, "%s=%d\n",
 188                                 extcon_name[edev->supported_cable[i]],
 189                                  !!(edev->state & (1 << i)));
 190         }
 191
 192         return count;
 193 }
 194
 195 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 196                            const char *buf, size_t count)
 197 {
 198         u32 state;
 199         ssize_t ret = 0;
 200         struct extcon_dev *edev = dev_get_drvdata(dev);
 201
 202         ret = sscanf(buf, "0x%x", &state);
 203         if (ret == 0)
 204                 ret = -EINVAL;
 205         else
 206                 ret = extcon_set_state(edev, state);
 207
 208         if (ret < 0)
 209                 return ret;
 210
 211         return count;
 212 }
 213 static DEVICE_ATTR_RW(state);
 214
 215 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 216                 char *buf)
 217 {
 218         struct extcon_dev *edev = dev_get_drvdata(dev);
 219
 220         return sprintf(buf, "%s\n", edev->name);
 221 }
 222 static DEVICE_ATTR_RO(name);
 223
 224 static ssize_t cable_name_show(struct device *dev,
 225                                struct device_attribute *attr, char *buf)
 226 {
 227         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 228                                                   attr_name);
 229         int i = cable->cable_index;
 230
 231         return sprintf(buf, "%s\n",
 232                         extcon_name[cable->edev->supported_cable[i]]);
 233 }
 234
 235 static ssize_t cable_state_show(struct device *dev,
 236                                 struct device_attribute *attr, char *buf)
 237 {
 238         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 239                                                   attr_state);
 240
 241         int i = cable->cable_index;
 242
 243         return sprintf(buf, "%d\n",
 244                        extcon_get_cable_state_(cable->edev,
 245                                                cable->edev->supported_cable[i]));
 246 }
 247
 248 /**
 249  * extcon_update_state() - Update the cable attach states of the extcon device
 250  *                         only for the masked bits.
 251  * @edev:       the extcon device
 252  * @mask:       the bit mask to designate updated bits.
 253  * @state:      new cable attach status for @edev
 254  *
 255  * Changing the state sends uevent with environment variable containing
 256  * the name of extcon device (envp[0]) and the state output (envp[1]).
 257  * Tizen uses this format for extcon device to get events from ports.
 258  * Android uses this format as well.
 259  *
 260  * Note that the notifier provides which bits are changed in the state
 261  * variable with the val parameter (second) to the callback.
 262  */
 263 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 264 {
 265         char name_buf[120];
 266         char state_buf[120];
 267         char *prop_buf;
 268         char *envp[3];
 269         int env_offset = 0;
 270         int length;
 271         int index;
 272         unsigned long flags;
 273         bool attached;
 274
 275         spin_lock_irqsave(&edev->lock, flags);
 276
 277         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 278                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 279                                                    (state & mask))) {
 280                         spin_unlock_irqrestore(&edev->lock, flags);
 281                         return -EPERM;
 282                 }
 283
 284                 for (index = 0; index < edev->max_supported; index++) {
 285                         if (is_extcon_changed(edev->state, state, index, &attached))
 286                                 raw_notifier_call_chain(&edev->nh[index], attached, edev);
 287                 }
 288
 289                 edev->state &= ~mask;
 290                 edev->state |= state & mask;
 291
 292                 /* This could be in interrupt handler */
 293                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 294                 if (prop_buf) {
 295                         length = name_show(&edev->dev, NULL, prop_buf);
 296                         if (length > 0) {
 297                                 if (prop_buf[length - 1] == '\n')
 298                                         prop_buf[length - 1] = 0;
 299                                 snprintf(name_buf, sizeof(name_buf),
 300                                         "NAME=%s", prop_buf);
 301                                 envp[env_offset++] = name_buf;
 302                         }
 303                         length = state_show(&edev->dev, NULL, prop_buf);
 304                         if (length > 0) {
 305                                 if (prop_buf[length - 1] == '\n')
 306                                         prop_buf[length - 1] = 0;
 307                                 snprintf(state_buf, sizeof(state_buf),
 308                                         "STATE=%s", prop_buf);
 309                                 envp[env_offset++] = state_buf;
 310                         }
 311                         envp[env_offset] = NULL;
 312                         /* Unlock early before uevent */
 313                         spin_unlock_irqrestore(&edev->lock, flags);
 314
 315                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 316                         free_page((unsigned long)prop_buf);
 317                 } else {
 318                         /* Unlock early before uevent */
 319                         spin_unlock_irqrestore(&edev->lock, flags);
 320
 321                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 322                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 323                 }
 324         } else {
 325                 /* No changes */
 326                 spin_unlock_irqrestore(&edev->lock, flags);
 327         }
 328
 329         return 0;
 330 }
 331 EXPORT_SYMBOL_GPL(extcon_update_state);
 332
 333 /**
 334  * extcon_set_state() - Set the cable attach states of the extcon device.
 335  * @edev:       the extcon device
 336  * @state:      new cable attach status for @edev
 337  *
 338  * Note that notifier provides which bits are changed in the state
 339  * variable with the val parameter (second) to the callback.
 340  */
 341 int extcon_set_state(struct extcon_dev *edev, u32 state)
 342 {
 343         return extcon_update_state(edev, 0xffffffff, state);
 344 }
 345 EXPORT_SYMBOL_GPL(extcon_set_state);
 346
 347 /**
 348  * extcon_get_cable_state_() - Get the status of a specific cable.
 349  * @edev:       the extcon device that has the cable.
 350  * @id:         the unique id of each external connector in extcon enumeration.
 351  */
 352 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 353 {
 354         int index;
 355
 356         index = find_cable_index_by_id(edev, id);
 357         if (index < 0)
 358                 return index;
 359
 360         if (edev->max_supported && edev->max_supported <= index)
 361                 return -EINVAL;
 362
 363         return !!(edev->state & (1 << index));
 364 }
 365 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 366
 367 /**
 368  * extcon_get_cable_state() - Get the status of a specific cable.
 369  * @edev:       the extcon device that has the cable.
 370  * @cable_name: cable name.
 371  *
 372  * Note that this is slower than extcon_get_cable_state_.
 373  */
 374 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 375 {
 376         unsigned int id;
 377
 378         id = find_cable_id_by_name(edev, cable_name);
 379         if (id < 0)
 380                 return id;
 381
 382         return extcon_get_cable_state_(edev, id);
 383 }
 384 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 385
 386 /**
 387  * extcon_set_cable_state_() - Set the status of a specific cable.
 388  * @edev:               the extcon device that has the cable.
 389  * @id:                 the unique id of each external connector
 390  *                      in extcon enumeration.
 391  * @state:              the new cable status. The default semantics is
 392  *                      true: attached / false: detached.
 393  */
 394 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 395                                 bool cable_state)
 396 {
 397         u32 state;
 398         int index;
 399
 400         index = find_cable_index_by_id(edev, id);
 401         if (index < 0)
 402                 return index;
 403
 404         if (edev->max_supported && edev->max_supported <= index)
 405                 return -EINVAL;
 406
 407         state = cable_state ? (1 << index) : 0;
 408         return extcon_update_state(edev, 1 << index, state);
 409 }
 410 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 411
 412 /**
 413  * extcon_set_cable_state() - Set the status of a specific cable.
 414  * @edev:               the extcon device that has the cable.
 415  * @cable_name:         cable name.
 416  * @cable_state:        the new cable status. The default semantics is
 417  *                      true: attached / false: detached.
 418  *
 419  * Note that this is slower than extcon_set_cable_state_.
 420  */
 421 int extcon_set_cable_state(struct extcon_dev *edev,
 422                         const char *cable_name, bool cable_state)
 423 {
 424         unsigned int id;
 425
 426         id = find_cable_id_by_name(edev, cable_name);
 427         if (id < 0)
 428                 return id;
 429
 430         return extcon_set_cable_state_(edev, id, cable_state);
 431 }
 432 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 433
 434 /**
 435  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 436  * @extcon_name:        The extcon name provided with extcon_dev_register()
 437  */
 438 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 439 {
 440         struct extcon_dev *sd;
 441
 442         mutex_lock(&extcon_dev_list_lock);
 443         list_for_each_entry(sd, &extcon_dev_list, entry) {
 444                 if (!strcmp(sd->name, extcon_name))
 445                         goto out;
 446         }
 447         sd = NULL;
 448 out:
 449         mutex_unlock(&extcon_dev_list_lock);
 450         return sd;
 451 }
 452 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 453
 454 /**
 455  * extcon_register_interest() - Register a notifier for a state change of a
 456  *                              specific cable, not an entier set of cables of a
 457  *                              extcon device.
 458  * @obj:                an empty extcon_specific_cable_nb object to be returned.
 459  * @extcon_name:        the name of extcon device.
 460  *                      if NULL, extcon_register_interest will register
 461  *                      every cable with the target cable_name given.
 462  * @cable_name:         the target cable name.
 463  * @nb:                 the notifier block to get notified.
 464  *
 465  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 466  * the struct for you.
 467  *
 468  * extcon_register_interest is a helper function for those who want to get
 469  * notification for a single specific cable's status change. If a user wants
 470  * to get notification for any changes of all cables of a extcon device,
 471  * he/she should use the general extcon_register_notifier().
 472  *
 473  * Note that the second parameter given to the callback of nb (val) is
 474  * "old_state", not the current state. The current state can be retrieved
 475  * by looking at the third pameter (edev pointer)'s state value.
 476  */
 477 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 478                              const char *extcon_name, const char *cable_name,
 479                              struct notifier_block *nb)
 480 {
 481         unsigned long flags;
 482         int ret;
 483
 484         if (!obj || !cable_name || !nb)
 485                 return -EINVAL;
 486
 487         if (extcon_name) {
 488                 obj->edev = extcon_get_extcon_dev(extcon_name);
 489                 if (!obj->edev)
 490                         return -ENODEV;
 491
 492                 obj->cable_index = find_cable_index_by_name(obj->edev,
 493                                                         cable_name);
 494                 if (obj->cable_index < 0)
 495                         return obj->cable_index;
 496
 497                 obj->user_nb = nb;
 498
 499                 spin_lock_irqsave(&obj->edev->lock, flags);
 500                 ret = raw_notifier_chain_register(
 501                                         &obj->edev->nh[obj->cable_index],
 502                                         obj->user_nb);
 503                 spin_unlock_irqrestore(&obj->edev->lock, flags);
 504         } else {
 505                 struct class_dev_iter iter;
 506                 struct extcon_dev *extd;
 507                 struct device *dev;
 508
 509                 if (!extcon_class)
 510                         return -ENODEV;
 511                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 512                 while ((dev = class_dev_iter_next(&iter))) {
 513                         extd = dev_get_drvdata(dev);
 514
 515                         if (find_cable_index_by_name(extd, cable_name) < 0)
 516                                 continue;
 517
 518                         class_dev_iter_exit(&iter);
 519                         return extcon_register_interest(obj, extd->name,
 520                                                 cable_name, nb);
 521                 }
 522
 523                 ret = -ENODEV;
 524         }
 525
 526         return ret;
 527 }
 528 EXPORT_SYMBOL_GPL(extcon_register_interest);
 529
 530 /**
 531  * extcon_unregister_interest() - Unregister the notifier registered by
 532  *                                extcon_register_interest().
 533  * @obj:        the extcon_specific_cable_nb object returned by
 534  *              extcon_register_interest().
 535  */
 536 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 537 {
 538         unsigned long flags;
 539         int ret;
 540
 541         if (!obj)
 542                 return -EINVAL;
 543
 544         spin_lock_irqsave(&obj->edev->lock, flags);
 545         ret = raw_notifier_chain_unregister(
 546                         &obj->edev->nh[obj->cable_index], obj->user_nb);
 547         spin_unlock_irqrestore(&obj->edev->lock, flags);
 548
 549         return ret;
 550 }
 551 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 552
 553 /**
 554  * extcon_register_notifier() - Register a notifiee to get notified by
 555  *                              any attach status changes from the extcon.
 556  * @edev:       the extcon device that has the external connecotr.
 557  * @id:         the unique id of each external connector in extcon enumeration.
 558  * @nb:         a notifier block to be registered.
 559  *
 560  * Note that the second parameter given to the callback of nb (val) is
 561  * "old_state", not the current state. The current state can be retrieved
 562  * by looking at the third pameter (edev pointer)'s state value.
 563  */
 564 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 565                              struct notifier_block *nb)
 566 {
 567         unsigned long flags;
 568         int ret, idx;
 569
 570         idx = find_cable_index_by_id(edev, id);
 571
 572         spin_lock_irqsave(&edev->lock, flags);
 573         ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 574         spin_unlock_irqrestore(&edev->lock, flags);
 575
 576         return ret;
 577 }
 578 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 579
 580 /**
 581  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 582  * @edev:       the extcon device that has the external connecotr.
 583  * @id:         the unique id of each external connector in extcon enumeration.
 584  * @nb:         a notifier block to be registered.
 585  */
 586 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 587                                 struct notifier_block *nb)
 588 {
 589         unsigned long flags;
 590         int ret, idx;
 591
 592         idx = find_cable_index_by_id(edev, id);
 593
 594         spin_lock_irqsave(&edev->lock, flags);
 595         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 596         spin_unlock_irqrestore(&edev->lock, flags);
 597
 598         return ret;
 599 }
 600 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 601
 602 static struct attribute *extcon_attrs[] = {
 603         &dev_attr_state.attr,
 604         &dev_attr_name.attr,
 605         NULL,
 606 };
 607 ATTRIBUTE_GROUPS(extcon);
 608
 609 static int create_extcon_class(void)
 610 {
 611         if (!extcon_class) {
 612                 extcon_class = class_create(THIS_MODULE, "extcon");
 613                 if (IS_ERR(extcon_class))
 614                         return PTR_ERR(extcon_class);
 615                 extcon_class->dev_groups = extcon_groups;
 616
 617 #if defined(CONFIG_ANDROID)
 618                 switch_class = class_compat_register("switch");
 619                 if (WARN(!switch_class, "cannot allocate"))
 620                         return -ENOMEM;
 621 #endif /* CONFIG_ANDROID */
 622         }
 623
 624         return 0;
 625 }
 626
 627 static void extcon_dev_release(struct device *dev)
 628 {
 629 }
 630
 631 static const char *muex_name = "mutually_exclusive";
 632 static void dummy_sysfs_dev_release(struct device *dev)
 633 {
 634 }
 635
 636 /*
 637  * extcon_dev_allocate() - Allocate the memory of extcon device.
 638  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 639  *                      If supported_cable is NULL, cable name related APIs
 640  *                      are disabled.
 641  *
 642  * This function allocates the memory for extcon device without allocating
 643  * memory in each extcon provider driver and initialize default setting for
 644  * extcon device.
 645  *
 646  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 647  */
 648 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 649 {
 650         struct extcon_dev *edev;
 651
 652         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 653         if (!edev)
 654                 return ERR_PTR(-ENOMEM);
 655
 656         edev->max_supported = 0;
 657         edev->supported_cable = supported_cable;
 658
 659         return edev;
 660 }
 661
 662 /*
 663  * extcon_dev_free() - Free the memory of extcon device.
 664  * @edev:       the extcon device to free
 665  */
 666 void extcon_dev_free(struct extcon_dev *edev)
 667 {
 668         kfree(edev);
 669 }
 670 EXPORT_SYMBOL_GPL(extcon_dev_free);
 671
 672 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 673 {
 674         struct extcon_dev **r = res;
 675
 676         if (WARN_ON(!r || !*r))
 677                 return 0;
 678
 679         return *r == data;
 680 }
 681
 682 static void devm_extcon_dev_release(struct device *dev, void *res)
 683 {
 684         extcon_dev_free(*(struct extcon_dev **)res);
 685 }
 686
 687 /**
 688  * devm_extcon_dev_allocate - Allocate managed extcon device
 689  * @dev:                device owning the extcon device being created
 690  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 691  *                      If supported_cable is NULL, cable name related APIs
 692  *                      are disabled.
 693  *
 694  * This function manages automatically the memory of extcon device using device
 695  * resource management and simplify the control of freeing the memory of extcon
 696  * device.
 697  *
 698  * Returns the pointer memory of allocated extcon_dev if success
 699  * or ERR_PTR(err) if fail
 700  */
 701 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 702                                         const unsigned int *supported_cable)
 703 {
 704         struct extcon_dev **ptr, *edev;
 705
 706         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 707         if (!ptr)
 708                 return ERR_PTR(-ENOMEM);
 709
 710         edev = extcon_dev_allocate(supported_cable);
 711         if (IS_ERR(edev)) {
 712                 devres_free(ptr);
 713                 return edev;
 714         }
 715
 716         edev->dev.parent = dev;
 717
 718         *ptr = edev;
 719         devres_add(dev, ptr);
 720
 721         return edev;
 722 }
 723 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 724
 725 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 726 {
 727         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 728                                devm_extcon_dev_match, edev));
 729 }
 730 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 731
 732 /**
 733  * extcon_dev_register() - Register a new extcon device
 734  * @edev        : the new extcon device (should be allocated before calling)
 735  *
 736  * Among the members of edev struct, please set the "user initializing data"
 737  * in any case and set the "optional callbacks" if required. However, please
 738  * do not set the values of "internal data", which are initialized by
 739  * this function.
 740  */
 741 int extcon_dev_register(struct extcon_dev *edev)
 742 {
 743         int ret, index = 0;
 744         static atomic_t edev_no = ATOMIC_INIT(-1);
 745
 746         if (!extcon_class) {
 747                 ret = create_extcon_class();
 748                 if (ret < 0)
 749                         return ret;
 750         }
 751
 752         if (!edev->supported_cable)
 753                 return -EINVAL;
 754
 755         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 756
 757         edev->max_supported = index;
 758         if (index > SUPPORTED_CABLE_MAX) {
 759                 dev_err(&edev->dev,
 760                         "exceed the maximum number of supported cables\n");
 761                 return -EINVAL;
 762         }
 763
 764         edev->dev.class = extcon_class;
 765         edev->dev.release = extcon_dev_release;
 766
 767         edev->name = dev_name(edev->dev.parent);
 768         if (IS_ERR_OR_NULL(edev->name)) {
 769                 dev_err(&edev->dev,
 770                         "extcon device name is null\n");
 771                 return -EINVAL;
 772         }
 773         dev_set_name(&edev->dev, "extcon%lu",
 774                         (unsigned long)atomic_inc_return(&edev_no));
 775
 776         if (edev->max_supported) {
 777                 char buf[10];
 778                 char *str;
 779                 struct extcon_cable *cable;
 780
 781                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 782                                        edev->max_supported, GFP_KERNEL);
 783                 if (!edev->cables) {
 784                         ret = -ENOMEM;
 785                         goto err_sysfs_alloc;
 786                 }
 787                 for (index = 0; index < edev->max_supported; index++) {
 788                         cable = &edev->cables[index];
 789
 790                         snprintf(buf, 10, "cable.%d", index);
 791                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 792                                       GFP_KERNEL);
 793                         if (!str) {
 794                                 for (index--; index >= 0; index--) {
 795                                         cable = &edev->cables[index];
 796                                         kfree(cable->attr_g.name);
 797                                 }
 798                                 ret = -ENOMEM;
 799
 800                                 goto err_alloc_cables;
 801                         }
 802                         strcpy(str, buf);
 803
 804                         cable->edev = edev;
 805                         cable->cable_index = index;
 806                         cable->attrs[0] = &cable->attr_name.attr;
 807                         cable->attrs[1] = &cable->attr_state.attr;
 808                         cable->attrs[2] = NULL;
 809                         cable->attr_g.name = str;
 810                         cable->attr_g.attrs = cable->attrs;
 811
 812                         sysfs_attr_init(&cable->attr_name.attr);
 813                         cable->attr_name.attr.name = "name";
 814                         cable->attr_name.attr.mode = 0444;
 815                         cable->attr_name.show = cable_name_show;
 816
 817                         sysfs_attr_init(&cable->attr_state.attr);
 818                         cable->attr_state.attr.name = "state";
 819                         cable->attr_state.attr.mode = 0444;
 820                         cable->attr_state.show = cable_state_show;
 821                 }
 822         }
 823
 824         if (edev->max_supported && edev->mutually_exclusive) {
 825                 char buf[80];
 826                 char *name;
 827
 828                 /* Count the size of mutually_exclusive array */
 829                 for (index = 0; edev->mutually_exclusive[index]; index++)
 830                         ;
 831
 832                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 833                                            (index + 1), GFP_KERNEL);
 834                 if (!edev->attrs_muex) {
 835                         ret = -ENOMEM;
 836                         goto err_muex;
 837                 }
 838
 839                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 840                                              index, GFP_KERNEL);
 841                 if (!edev->d_attrs_muex) {
 842                         ret = -ENOMEM;
 843                         kfree(edev->attrs_muex);
 844                         goto err_muex;
 845                 }
 846
 847                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 848                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 849                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 850                                        GFP_KERNEL);
 851                         if (!name) {
 852                                 for (index--; index >= 0; index--) {
 853                                         kfree(edev->d_attrs_muex[index].attr.
 854                                               name);
 855                                 }
 856                                 kfree(edev->d_attrs_muex);
 857                                 kfree(edev->attrs_muex);
 858                                 ret = -ENOMEM;
 859                                 goto err_muex;
 860                         }
 861                         strcpy(name, buf);
 862                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 863                         edev->d_attrs_muex[index].attr.name = name;
 864                         edev->d_attrs_muex[index].attr.mode = 0000;
 865                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 866                                                         .attr;
 867                 }
 868                 edev->attr_g_muex.name = muex_name;
 869                 edev->attr_g_muex.attrs = edev->attrs_muex;
 870
 871         }
 872
 873         if (edev->max_supported) {
 874                 edev->extcon_dev_type.groups =
 875                         kzalloc(sizeof(struct attribute_group *) *
 876                                 (edev->max_supported + 2), GFP_KERNEL);
 877                 if (!edev->extcon_dev_type.groups) {
 878                         ret = -ENOMEM;
 879                         goto err_alloc_groups;
 880                 }
 881
 882                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 883                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 884
 885                 for (index = 0; index < edev->max_supported; index++)
 886                         edev->extcon_dev_type.groups[index] =
 887                                 &edev->cables[index].attr_g;
 888                 if (edev->mutually_exclusive)
 889                         edev->extcon_dev_type.groups[index] =
 890                                 &edev->attr_g_muex;
 891
 892                 edev->dev.type = &edev->extcon_dev_type;
 893         }
 894
 895         ret = device_register(&edev->dev);
 896         if (ret) {
 897                 put_device(&edev->dev);
 898                 goto err_dev;
 899         }
 900 #if defined(CONFIG_ANDROID)
 901         if (switch_class)
 902                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 903 #endif /* CONFIG_ANDROID */
 904
 905         spin_lock_init(&edev->lock);
 906
 907         edev->nh = devm_kzalloc(&edev->dev,
 908                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 909         if (!edev->nh) {
 910                 ret = -ENOMEM;
 911                 goto err_dev;
 912         }
 913
 914         for (index = 0; index < edev->max_supported; index++)
 915                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 916
 917         dev_set_drvdata(&edev->dev, edev);
 918         edev->state = 0;
 919
 920         mutex_lock(&extcon_dev_list_lock);
 921         list_add(&edev->entry, &extcon_dev_list);
 922         mutex_unlock(&extcon_dev_list_lock);
 923
 924         return 0;
 925
 926 err_dev:
 927         if (edev->max_supported)
 928                 kfree(edev->extcon_dev_type.groups);
 929 err_alloc_groups:
 930         if (edev->max_supported && edev->mutually_exclusive) {
 931                 for (index = 0; edev->mutually_exclusive[index]; index++)
 932                         kfree(edev->d_attrs_muex[index].attr.name);
 933                 kfree(edev->d_attrs_muex);
 934                 kfree(edev->attrs_muex);
 935         }
 936 err_muex:
 937         for (index = 0; index < edev->max_supported; index++)
 938                 kfree(edev->cables[index].attr_g.name);
 939 err_alloc_cables:
 940         if (edev->max_supported)
 941                 kfree(edev->cables);
 942 err_sysfs_alloc:
 943         return ret;
 944 }
 945 EXPORT_SYMBOL_GPL(extcon_dev_register);
 946
 947 /**
 948  * extcon_dev_unregister() - Unregister the extcon device.
 949  * @edev:       the extcon device instance to be unregistered.
 950  *
 951  * Note that this does not call kfree(edev) because edev was not allocated
 952  * by this class.
 953  */
 954 void extcon_dev_unregister(struct extcon_dev *edev)
 955 {
 956         int index;
 957
 958         mutex_lock(&extcon_dev_list_lock);
 959         list_del(&edev->entry);
 960         mutex_unlock(&extcon_dev_list_lock);
 961
 962         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 963                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 964                                 dev_name(&edev->dev));
 965                 return;
 966         }
 967
 968         device_unregister(&edev->dev);
 969
 970         if (edev->mutually_exclusive && edev->max_supported) {
 971                 for (index = 0; edev->mutually_exclusive[index];
 972                                 index++)
 973                         kfree(edev->d_attrs_muex[index].attr.name);
 974                 kfree(edev->d_attrs_muex);
 975                 kfree(edev->attrs_muex);
 976         }
 977
 978         for (index = 0; index < edev->max_supported; index++)
 979                 kfree(edev->cables[index].attr_g.name);
 980
 981         if (edev->max_supported) {
 982                 kfree(edev->extcon_dev_type.groups);
 983                 kfree(edev->cables);
 984         }
 985
 986 #if defined(CONFIG_ANDROID)
 987         if (switch_class)
 988                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 989 #endif
 990         put_device(&edev->dev);
 991 }
 992 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 993
 994 static void devm_extcon_dev_unreg(struct device *dev, void *res)
 995 {
 996         extcon_dev_unregister(*(struct extcon_dev **)res);
 997 }
 998
 999 /**
1000  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
1001  * @dev:        device to allocate extcon device
1002  * @edev:       the new extcon device to register
1003  *
1004  * Managed extcon_dev_register() function. If extcon device is attached with
1005  * this function, that extcon device is automatically unregistered on driver
1006  * detach. Internally this function calls extcon_dev_register() function.
1007  * To get more information, refer that function.
1008  *
1009  * If extcon device is registered with this function and the device needs to be
1010  * unregistered separately, devm_extcon_dev_unregister() should be used.
1011  *
1012  * Returns 0 if success or negaive error number if failure.
1013  */
1014 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
1015 {
1016         struct extcon_dev **ptr;
1017         int ret;
1018
1019         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
1020         if (!ptr)
1021                 return -ENOMEM;
1022
1023         ret = extcon_dev_register(edev);
1024         if (ret) {
1025                 devres_free(ptr);
1026                 return ret;
1027         }
1028
1029         *ptr = edev;
1030         devres_add(dev, ptr);
1031
1032         return 0;
1033 }
1034 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
1035
1036 /**
1037  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
1038  * @dev:        device the extcon belongs to
1039  * @edev:       the extcon device to unregister
1040  *
1041  * Unregister extcon device that is registered with devm_extcon_dev_register()
1042  * function.
1043  */
1044 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
1045 {
1046         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
1047                                devm_extcon_dev_match, edev));
1048 }
1049 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1050
1051 #ifdef CONFIG_OF
1052 /*
1053  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1054  * @dev - instance to the given device
1055  * @index - index into list of extcon_dev
1056  *
1057  * return the instance of extcon device
1058  */
1059 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1060 {
1061         struct device_node *node;
1062         struct extcon_dev *edev;
1063
1064         if (!dev->of_node) {
1065                 dev_err(dev, "device does not have a device node entry\n");
1066                 return ERR_PTR(-EINVAL);
1067         }
1068
1069         node = of_parse_phandle(dev->of_node, "extcon", index);
1070         if (!node) {
1071                 dev_err(dev, "failed to get phandle in %s node\n",
1072                         dev->of_node->full_name);
1073                 return ERR_PTR(-ENODEV);
1074         }
1075
1076         mutex_lock(&extcon_dev_list_lock);
1077         list_for_each_entry(edev, &extcon_dev_list, entry) {
1078                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1079                         mutex_unlock(&extcon_dev_list_lock);
1080                         return edev;
1081                 }
1082         }
1083         mutex_unlock(&extcon_dev_list_lock);
1084
1085         return ERR_PTR(-EPROBE_DEFER);
1086 }
1087 #else
1088 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1089 {
1090         return ERR_PTR(-ENOSYS);
1091 }
1092 #endif /* CONFIG_OF */
1093 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1094
1095 /**
1096  * extcon_get_edev_name() - Get the name of the extcon device.
1097  * @edev:       the extcon device
1098  */
1099 const char *extcon_get_edev_name(struct extcon_dev *edev)
1100 {
1101         return !edev ? NULL : edev->name;
1102 }
1103
1104 static int __init extcon_class_init(void)
1105 {
1106         return create_extcon_class();
1107 }
1108 module_init(extcon_class_init);
1109
1110 static void __exit extcon_class_exit(void)
1111 {
1112 #if defined(CONFIG_ANDROID)
1113         class_compat_unregister(switch_class);
1114 #endif
1115         class_destroy(extcon_class);
1116 }
1117 module_exit(extcon_class_exit);
1118
1119 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1120 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1121 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1122 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1123 MODULE_DESCRIPTION("External connector (extcon) class driver");
1124 MODULE_LICENSE("GPL");