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         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         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 >> idx) & 0x1) ? 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->max_supported == 0)
 176                 return sprintf(buf, "%u\n", edev->state);
 177
 178         for (i = 0; i < edev->max_supported; i++) {
 179                 count += sprintf(buf + count, "%s=%d\n",
 180                                 extcon_name[edev->supported_cable[i]],
 181                                  !!(edev->state & (1 << i)));
 182         }
 183
 184         return count;
 185 }
 186
 187 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
 188                            const char *buf, size_t count)
 189 {
 190         u32 state;
 191         ssize_t ret = 0;
 192         struct extcon_dev *edev = dev_get_drvdata(dev);
 193
 194         ret = sscanf(buf, "0x%x", &state);
 195         if (ret == 0)
 196                 ret = -EINVAL;
 197         else
 198                 ret = extcon_set_state(edev, state);
 199
 200         if (ret < 0)
 201                 return ret;
 202
 203         return count;
 204 }
 205 static DEVICE_ATTR_RW(state);
 206
 207 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 208                 char *buf)
 209 {
 210         struct extcon_dev *edev = dev_get_drvdata(dev);
 211
 212         return sprintf(buf, "%s\n", edev->name);
 213 }
 214 static DEVICE_ATTR_RO(name);
 215
 216 static ssize_t cable_name_show(struct device *dev,
 217                                struct device_attribute *attr, char *buf)
 218 {
 219         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 220                                                   attr_name);
 221         int i = cable->cable_index;
 222
 223         return sprintf(buf, "%s\n",
 224                         extcon_name[cable->edev->supported_cable[i]]);
 225 }
 226
 227 static ssize_t cable_state_show(struct device *dev,
 228                                 struct device_attribute *attr, char *buf)
 229 {
 230         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 231                                                   attr_state);
 232
 233         int i = cable->cable_index;
 234
 235         return sprintf(buf, "%d\n",
 236                        extcon_get_cable_state_(cable->edev,
 237                                                cable->edev->supported_cable[i]));
 238 }
 239
 240 /**
 241  * extcon_update_state() - Update the cable attach states of the extcon device
 242  *                         only for the masked bits.
 243  * @edev:       the extcon device
 244  * @mask:       the bit mask to designate updated bits.
 245  * @state:      new cable attach status for @edev
 246  *
 247  * Changing the state sends uevent with environment variable containing
 248  * the name of extcon device (envp[0]) and the state output (envp[1]).
 249  * Tizen uses this format for extcon device to get events from ports.
 250  * Android uses this format as well.
 251  *
 252  * Note that the notifier provides which bits are changed in the state
 253  * variable with the val parameter (second) to the callback.
 254  */
 255 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 256 {
 257         char name_buf[120];
 258         char state_buf[120];
 259         char *prop_buf;
 260         char *envp[3];
 261         int env_offset = 0;
 262         int length;
 263         int index;
 264         unsigned long flags;
 265         bool attached;
 266
 267         if (!edev)
 268                 return -EINVAL;
 269
 270         spin_lock_irqsave(&edev->lock, flags);
 271
 272         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 273                 u32 old_state;
 274
 275                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 276                                                    (state & mask))) {
 277                         spin_unlock_irqrestore(&edev->lock, flags);
 278                         return -EPERM;
 279                 }
 280
 281                 old_state = edev->state;
 282                 edev->state &= ~mask;
 283                 edev->state |= state & mask;
 284
 285                 for (index = 0; index < edev->max_supported; index++) {
 286                         if (is_extcon_changed(old_state, edev->state, index,
 287                                               &attached))
 288                                 raw_notifier_call_chain(&edev->nh[index],
 289                                                         attached, edev);
 290                 }
 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         if (!edev)
 344                 return -EINVAL;
 345
 346         return extcon_update_state(edev, 0xffffffff, state);
 347 }
 348 EXPORT_SYMBOL_GPL(extcon_set_state);
 349
 350 /**
 351  * extcon_get_cable_state_() - Get the status of a specific cable.
 352  * @edev:       the extcon device that has the cable.
 353  * @id:         the unique id of each external connector in extcon enumeration.
 354  */
 355 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 356 {
 357         int index;
 358
 359         if (!edev)
 360                 return -EINVAL;
 361
 362         index = find_cable_index_by_id(edev, id);
 363         if (index < 0)
 364                 return index;
 365
 366         if (edev->max_supported && edev->max_supported <= index)
 367                 return -EINVAL;
 368
 369         return !!(edev->state & (1 << index));
 370 }
 371 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 372
 373 /**
 374  * extcon_get_cable_state() - Get the status of a specific cable.
 375  * @edev:       the extcon device that has the cable.
 376  * @cable_name: cable name.
 377  *
 378  * Note that this is slower than extcon_get_cable_state_.
 379  */
 380 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 381 {
 382         int id;
 383
 384         id = find_cable_id_by_name(edev, cable_name);
 385         if (id < 0)
 386                 return id;
 387
 388         return extcon_get_cable_state_(edev, id);
 389 }
 390 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 391
 392 /**
 393  * extcon_set_cable_state_() - Set the status of a specific cable.
 394  * @edev:               the extcon device that has the cable.
 395  * @id:                 the unique id of each external connector
 396  *                      in extcon enumeration.
 397  * @state:              the new cable status. The default semantics is
 398  *                      true: attached / false: detached.
 399  */
 400 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 401                                 bool cable_state)
 402 {
 403         u32 state;
 404         int index;
 405
 406         if (!edev)
 407                 return -EINVAL;
 408
 409         index = find_cable_index_by_id(edev, id);
 410         if (index < 0)
 411                 return index;
 412
 413         if (edev->max_supported && edev->max_supported <= index)
 414                 return -EINVAL;
 415
 416         state = cable_state ? (1 << index) : 0;
 417         return extcon_update_state(edev, 1 << index, state);
 418 }
 419 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 420
 421 /**
 422  * extcon_set_cable_state() - Set the status of a specific cable.
 423  * @edev:               the extcon device that has the cable.
 424  * @cable_name:         cable name.
 425  * @cable_state:        the new cable status. The default semantics is
 426  *                      true: attached / false: detached.
 427  *
 428  * Note that this is slower than extcon_set_cable_state_.
 429  */
 430 int extcon_set_cable_state(struct extcon_dev *edev,
 431                         const char *cable_name, bool cable_state)
 432 {
 433         int id;
 434
 435         id = find_cable_id_by_name(edev, cable_name);
 436         if (id < 0)
 437                 return id;
 438
 439         return extcon_set_cable_state_(edev, id, cable_state);
 440 }
 441 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 442
 443 /**
 444  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 445  * @extcon_name:        The extcon name provided with extcon_dev_register()
 446  */
 447 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 448 {
 449         struct extcon_dev *sd;
 450
 451         if (!extcon_name)
 452                 return ERR_PTR(-EINVAL);
 453
 454         mutex_lock(&extcon_dev_list_lock);
 455         list_for_each_entry(sd, &extcon_dev_list, entry) {
 456                 if (!strcmp(sd->name, extcon_name))
 457                         goto out;
 458         }
 459         sd = NULL;
 460 out:
 461         mutex_unlock(&extcon_dev_list_lock);
 462         return sd;
 463 }
 464 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 465
 466 /**
 467  * extcon_register_interest() - Register a notifier for a state change of a
 468  *                              specific cable, not an entier set of cables of a
 469  *                              extcon device.
 470  * @obj:                an empty extcon_specific_cable_nb object to be returned.
 471  * @extcon_name:        the name of extcon device.
 472  *                      if NULL, extcon_register_interest will register
 473  *                      every cable with the target cable_name given.
 474  * @cable_name:         the target cable name.
 475  * @nb:                 the notifier block to get notified.
 476  *
 477  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 478  * the struct for you.
 479  *
 480  * extcon_register_interest is a helper function for those who want to get
 481  * notification for a single specific cable's status change. If a user wants
 482  * to get notification for any changes of all cables of a extcon device,
 483  * he/she should use the general extcon_register_notifier().
 484  *
 485  * Note that the second parameter given to the callback of nb (val) is
 486  * "old_state", not the current state. The current state can be retrieved
 487  * by looking at the third pameter (edev pointer)'s state value.
 488  */
 489 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 490                              const char *extcon_name, const char *cable_name,
 491                              struct notifier_block *nb)
 492 {
 493         unsigned long flags;
 494         int ret;
 495
 496         if (!obj || !cable_name || !nb)
 497                 return -EINVAL;
 498
 499         if (extcon_name) {
 500                 obj->edev = extcon_get_extcon_dev(extcon_name);
 501                 if (!obj->edev)
 502                         return -ENODEV;
 503
 504                 obj->cable_index = find_cable_index_by_name(obj->edev,
 505                                                         cable_name);
 506                 if (obj->cable_index < 0)
 507                         return obj->cable_index;
 508
 509                 obj->user_nb = nb;
 510
 511                 spin_lock_irqsave(&obj->edev->lock, flags);
 512                 ret = raw_notifier_chain_register(
 513                                         &obj->edev->nh[obj->cable_index],
 514                                         obj->user_nb);
 515                 spin_unlock_irqrestore(&obj->edev->lock, flags);
 516         } else {
 517                 struct class_dev_iter iter;
 518                 struct extcon_dev *extd;
 519                 struct device *dev;
 520
 521                 if (!extcon_class)
 522                         return -ENODEV;
 523                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 524                 while ((dev = class_dev_iter_next(&iter))) {
 525                         extd = dev_get_drvdata(dev);
 526
 527                         if (find_cable_index_by_name(extd, cable_name) < 0)
 528                                 continue;
 529
 530                         class_dev_iter_exit(&iter);
 531                         return extcon_register_interest(obj, extd->name,
 532                                                 cable_name, nb);
 533                 }
 534
 535                 ret = -ENODEV;
 536         }
 537
 538         return ret;
 539 }
 540 EXPORT_SYMBOL_GPL(extcon_register_interest);
 541
 542 /**
 543  * extcon_unregister_interest() - Unregister the notifier registered by
 544  *                                extcon_register_interest().
 545  * @obj:        the extcon_specific_cable_nb object returned by
 546  *              extcon_register_interest().
 547  */
 548 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 549 {
 550         unsigned long flags;
 551         int ret;
 552
 553         if (!obj)
 554                 return -EINVAL;
 555
 556         spin_lock_irqsave(&obj->edev->lock, flags);
 557         ret = raw_notifier_chain_unregister(
 558                         &obj->edev->nh[obj->cable_index], obj->user_nb);
 559         spin_unlock_irqrestore(&obj->edev->lock, flags);
 560
 561         return ret;
 562 }
 563 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 564
 565 /**
 566  * extcon_register_notifier() - Register a notifiee to get notified by
 567  *                              any attach status changes from the extcon.
 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  * Note that the second parameter given to the callback of nb (val) is
 573  * "old_state", not the current state. The current state can be retrieved
 574  * by looking at the third pameter (edev pointer)'s state value.
 575  */
 576 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 577                              struct notifier_block *nb)
 578 {
 579         unsigned long flags;
 580         int ret, idx;
 581
 582         if (!edev || !nb)
 583                 return -EINVAL;
 584
 585         idx = find_cable_index_by_id(edev, id);
 586
 587         spin_lock_irqsave(&edev->lock, flags);
 588         ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 589         spin_unlock_irqrestore(&edev->lock, flags);
 590
 591         return ret;
 592 }
 593 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 594
 595 /**
 596  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 597  * @edev:       the extcon device that has the external connecotr.
 598  * @id:         the unique id of each external connector in extcon enumeration.
 599  * @nb:         a notifier block to be registered.
 600  */
 601 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 602                                 struct notifier_block *nb)
 603 {
 604         unsigned long flags;
 605         int ret, idx;
 606
 607         if (!edev || !nb)
 608                 return -EINVAL;
 609
 610         idx = find_cable_index_by_id(edev, id);
 611
 612         spin_lock_irqsave(&edev->lock, flags);
 613         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 614         spin_unlock_irqrestore(&edev->lock, flags);
 615
 616         return ret;
 617 }
 618 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 619
 620 static struct attribute *extcon_attrs[] = {
 621         &dev_attr_state.attr,
 622         &dev_attr_name.attr,
 623         NULL,
 624 };
 625 ATTRIBUTE_GROUPS(extcon);
 626
 627 static int create_extcon_class(void)
 628 {
 629         if (!extcon_class) {
 630                 extcon_class = class_create(THIS_MODULE, "extcon");
 631                 if (IS_ERR(extcon_class))
 632                         return PTR_ERR(extcon_class);
 633                 extcon_class->dev_groups = extcon_groups;
 634
 635 #if defined(CONFIG_ANDROID)
 636                 switch_class = class_compat_register("switch");
 637                 if (WARN(!switch_class, "cannot allocate"))
 638                         return -ENOMEM;
 639 #endif /* CONFIG_ANDROID */
 640         }
 641
 642         return 0;
 643 }
 644
 645 static void extcon_dev_release(struct device *dev)
 646 {
 647 }
 648
 649 static const char *muex_name = "mutually_exclusive";
 650 static void dummy_sysfs_dev_release(struct device *dev)
 651 {
 652 }
 653
 654 /*
 655  * extcon_dev_allocate() - Allocate the memory of extcon device.
 656  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 657  *                      If supported_cable is NULL, cable name related APIs
 658  *                      are disabled.
 659  *
 660  * This function allocates the memory for extcon device without allocating
 661  * memory in each extcon provider driver and initialize default setting for
 662  * extcon device.
 663  *
 664  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 665  */
 666 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 667 {
 668         struct extcon_dev *edev;
 669
 670         if (!supported_cable)
 671                 return ERR_PTR(-EINVAL);
 672
 673         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 674         if (!edev)
 675                 return ERR_PTR(-ENOMEM);
 676
 677         edev->max_supported = 0;
 678         edev->supported_cable = supported_cable;
 679
 680         return edev;
 681 }
 682
 683 /*
 684  * extcon_dev_free() - Free the memory of extcon device.
 685  * @edev:       the extcon device to free
 686  */
 687 void extcon_dev_free(struct extcon_dev *edev)
 688 {
 689         kfree(edev);
 690 }
 691 EXPORT_SYMBOL_GPL(extcon_dev_free);
 692
 693 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 694 {
 695         struct extcon_dev **r = res;
 696
 697         if (WARN_ON(!r || !*r))
 698                 return 0;
 699
 700         return *r == data;
 701 }
 702
 703 static void devm_extcon_dev_release(struct device *dev, void *res)
 704 {
 705         extcon_dev_free(*(struct extcon_dev **)res);
 706 }
 707
 708 /**
 709  * devm_extcon_dev_allocate - Allocate managed extcon device
 710  * @dev:                device owning the extcon device being created
 711  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 712  *                      If supported_cable is NULL, cable name related APIs
 713  *                      are disabled.
 714  *
 715  * This function manages automatically the memory of extcon device using device
 716  * resource management and simplify the control of freeing the memory of extcon
 717  * device.
 718  *
 719  * Returns the pointer memory of allocated extcon_dev if success
 720  * or ERR_PTR(err) if fail
 721  */
 722 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 723                                         const unsigned int *supported_cable)
 724 {
 725         struct extcon_dev **ptr, *edev;
 726
 727         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 728         if (!ptr)
 729                 return ERR_PTR(-ENOMEM);
 730
 731         edev = extcon_dev_allocate(supported_cable);
 732         if (IS_ERR(edev)) {
 733                 devres_free(ptr);
 734                 return edev;
 735         }
 736
 737         edev->dev.parent = dev;
 738
 739         *ptr = edev;
 740         devres_add(dev, ptr);
 741
 742         return edev;
 743 }
 744 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 745
 746 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 747 {
 748         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 749                                devm_extcon_dev_match, edev));
 750 }
 751 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 752
 753 /**
 754  * extcon_dev_register() - Register a new extcon device
 755  * @edev        : the new extcon device (should be allocated before calling)
 756  *
 757  * Among the members of edev struct, please set the "user initializing data"
 758  * in any case and set the "optional callbacks" if required. However, please
 759  * do not set the values of "internal data", which are initialized by
 760  * this function.
 761  */
 762 int extcon_dev_register(struct extcon_dev *edev)
 763 {
 764         int ret, index = 0;
 765         static atomic_t edev_no = ATOMIC_INIT(-1);
 766
 767         if (!extcon_class) {
 768                 ret = create_extcon_class();
 769                 if (ret < 0)
 770                         return ret;
 771         }
 772
 773         if (!edev || !edev->supported_cable)
 774                 return -EINVAL;
 775
 776         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 777
 778         edev->max_supported = index;
 779         if (index > SUPPORTED_CABLE_MAX) {
 780                 dev_err(&edev->dev,
 781                         "exceed the maximum number of supported cables\n");
 782                 return -EINVAL;
 783         }
 784
 785         edev->dev.class = extcon_class;
 786         edev->dev.release = extcon_dev_release;
 787
 788         edev->name = dev_name(edev->dev.parent);
 789         if (IS_ERR_OR_NULL(edev->name)) {
 790                 dev_err(&edev->dev,
 791                         "extcon device name is null\n");
 792                 return -EINVAL;
 793         }
 794         dev_set_name(&edev->dev, "extcon%lu",
 795                         (unsigned long)atomic_inc_return(&edev_no));
 796
 797         if (edev->max_supported) {
 798                 char buf[10];
 799                 char *str;
 800                 struct extcon_cable *cable;
 801
 802                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 803                                        edev->max_supported, GFP_KERNEL);
 804                 if (!edev->cables) {
 805                         ret = -ENOMEM;
 806                         goto err_sysfs_alloc;
 807                 }
 808                 for (index = 0; index < edev->max_supported; index++) {
 809                         cable = &edev->cables[index];
 810
 811                         snprintf(buf, 10, "cable.%d", index);
 812                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 813                                       GFP_KERNEL);
 814                         if (!str) {
 815                                 for (index--; index >= 0; index--) {
 816                                         cable = &edev->cables[index];
 817                                         kfree(cable->attr_g.name);
 818                                 }
 819                                 ret = -ENOMEM;
 820
 821                                 goto err_alloc_cables;
 822                         }
 823                         strcpy(str, buf);
 824
 825                         cable->edev = edev;
 826                         cable->cable_index = index;
 827                         cable->attrs[0] = &cable->attr_name.attr;
 828                         cable->attrs[1] = &cable->attr_state.attr;
 829                         cable->attrs[2] = NULL;
 830                         cable->attr_g.name = str;
 831                         cable->attr_g.attrs = cable->attrs;
 832
 833                         sysfs_attr_init(&cable->attr_name.attr);
 834                         cable->attr_name.attr.name = "name";
 835                         cable->attr_name.attr.mode = 0444;
 836                         cable->attr_name.show = cable_name_show;
 837
 838                         sysfs_attr_init(&cable->attr_state.attr);
 839                         cable->attr_state.attr.name = "state";
 840                         cable->attr_state.attr.mode = 0444;
 841                         cable->attr_state.show = cable_state_show;
 842                 }
 843         }
 844
 845         if (edev->max_supported && edev->mutually_exclusive) {
 846                 char buf[80];
 847                 char *name;
 848
 849                 /* Count the size of mutually_exclusive array */
 850                 for (index = 0; edev->mutually_exclusive[index]; index++)
 851                         ;
 852
 853                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 854                                            (index + 1), GFP_KERNEL);
 855                 if (!edev->attrs_muex) {
 856                         ret = -ENOMEM;
 857                         goto err_muex;
 858                 }
 859
 860                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 861                                              index, GFP_KERNEL);
 862                 if (!edev->d_attrs_muex) {
 863                         ret = -ENOMEM;
 864                         kfree(edev->attrs_muex);
 865                         goto err_muex;
 866                 }
 867
 868                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 869                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 870                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 871                                        GFP_KERNEL);
 872                         if (!name) {
 873                                 for (index--; index >= 0; index--) {
 874                                         kfree(edev->d_attrs_muex[index].attr.
 875                                               name);
 876                                 }
 877                                 kfree(edev->d_attrs_muex);
 878                                 kfree(edev->attrs_muex);
 879                                 ret = -ENOMEM;
 880                                 goto err_muex;
 881                         }
 882                         strcpy(name, buf);
 883                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 884                         edev->d_attrs_muex[index].attr.name = name;
 885                         edev->d_attrs_muex[index].attr.mode = 0000;
 886                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 887                                                         .attr;
 888                 }
 889                 edev->attr_g_muex.name = muex_name;
 890                 edev->attr_g_muex.attrs = edev->attrs_muex;
 891
 892         }
 893
 894         if (edev->max_supported) {
 895                 edev->extcon_dev_type.groups =
 896                         kzalloc(sizeof(struct attribute_group *) *
 897                                 (edev->max_supported + 2), GFP_KERNEL);
 898                 if (!edev->extcon_dev_type.groups) {
 899                         ret = -ENOMEM;
 900                         goto err_alloc_groups;
 901                 }
 902
 903                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 904                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 905
 906                 for (index = 0; index < edev->max_supported; index++)
 907                         edev->extcon_dev_type.groups[index] =
 908                                 &edev->cables[index].attr_g;
 909                 if (edev->mutually_exclusive)
 910                         edev->extcon_dev_type.groups[index] =
 911                                 &edev->attr_g_muex;
 912
 913                 edev->dev.type = &edev->extcon_dev_type;
 914         }
 915
 916         ret = device_register(&edev->dev);
 917         if (ret) {
 918                 put_device(&edev->dev);
 919                 goto err_dev;
 920         }
 921 #if defined(CONFIG_ANDROID)
 922         if (switch_class)
 923                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 924 #endif /* CONFIG_ANDROID */
 925
 926         spin_lock_init(&edev->lock);
 927
 928         edev->nh = devm_kzalloc(&edev->dev,
 929                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 930         if (!edev->nh) {
 931                 ret = -ENOMEM;
 932                 goto err_dev;
 933         }
 934
 935         for (index = 0; index < edev->max_supported; index++)
 936                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 937
 938         dev_set_drvdata(&edev->dev, edev);
 939         edev->state = 0;
 940
 941         mutex_lock(&extcon_dev_list_lock);
 942         list_add(&edev->entry, &extcon_dev_list);
 943         mutex_unlock(&extcon_dev_list_lock);
 944
 945         return 0;
 946
 947 err_dev:
 948         if (edev->max_supported)
 949                 kfree(edev->extcon_dev_type.groups);
 950 err_alloc_groups:
 951         if (edev->max_supported && edev->mutually_exclusive) {
 952                 for (index = 0; edev->mutually_exclusive[index]; index++)
 953                         kfree(edev->d_attrs_muex[index].attr.name);
 954                 kfree(edev->d_attrs_muex);
 955                 kfree(edev->attrs_muex);
 956         }
 957 err_muex:
 958         for (index = 0; index < edev->max_supported; index++)
 959                 kfree(edev->cables[index].attr_g.name);
 960 err_alloc_cables:
 961         if (edev->max_supported)
 962                 kfree(edev->cables);
 963 err_sysfs_alloc:
 964         return ret;
 965 }
 966 EXPORT_SYMBOL_GPL(extcon_dev_register);
 967
 968 /**
 969  * extcon_dev_unregister() - Unregister the extcon device.
 970  * @edev:       the extcon device instance to be unregistered.
 971  *
 972  * Note that this does not call kfree(edev) because edev was not allocated
 973  * by this class.
 974  */
 975 void extcon_dev_unregister(struct extcon_dev *edev)
 976 {
 977         int index;
 978
 979         if (!edev)
 980                 return;
 981
 982         mutex_lock(&extcon_dev_list_lock);
 983         list_del(&edev->entry);
 984         mutex_unlock(&extcon_dev_list_lock);
 985
 986         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 987                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 988                                 dev_name(&edev->dev));
 989                 return;
 990         }
 991
 992         device_unregister(&edev->dev);
 993
 994         if (edev->mutually_exclusive && edev->max_supported) {
 995                 for (index = 0; edev->mutually_exclusive[index];
 996                                 index++)
 997                         kfree(edev->d_attrs_muex[index].attr.name);
 998                 kfree(edev->d_attrs_muex);
 999                 kfree(edev->attrs_muex);
1000         }
1001
1002         for (index = 0; index < edev->max_supported; index++)
1003                 kfree(edev->cables[index].attr_g.name);
1004
1005         if (edev->max_supported) {
1006                 kfree(edev->extcon_dev_type.groups);
1007                 kfree(edev->cables);
1008         }
1009
1010 #if defined(CONFIG_ANDROID)
1011         if (switch_class)
1012                 class_compat_remove_link(switch_class, &edev->dev, NULL);
1013 #endif
1014         put_device(&edev->dev);
1015 }
1016 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
1017
1018 static void devm_extcon_dev_unreg(struct device *dev, void *res)
1019 {
1020         extcon_dev_unregister(*(struct extcon_dev **)res);
1021 }
1022
1023 /**
1024  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
1025  * @dev:        device to allocate extcon device
1026  * @edev:       the new extcon device to register
1027  *
1028  * Managed extcon_dev_register() function. If extcon device is attached with
1029  * this function, that extcon device is automatically unregistered on driver
1030  * detach. Internally this function calls extcon_dev_register() function.
1031  * To get more information, refer that function.
1032  *
1033  * If extcon device is registered with this function and the device needs to be
1034  * unregistered separately, devm_extcon_dev_unregister() should be used.
1035  *
1036  * Returns 0 if success or negaive error number if failure.
1037  */
1038 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
1039 {
1040         struct extcon_dev **ptr;
1041         int ret;
1042
1043         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
1044         if (!ptr)
1045                 return -ENOMEM;
1046
1047         ret = extcon_dev_register(edev);
1048         if (ret) {
1049                 devres_free(ptr);
1050                 return ret;
1051         }
1052
1053         *ptr = edev;
1054         devres_add(dev, ptr);
1055
1056         return 0;
1057 }
1058 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
1059
1060 /**
1061  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
1062  * @dev:        device the extcon belongs to
1063  * @edev:       the extcon device to unregister
1064  *
1065  * Unregister extcon device that is registered with devm_extcon_dev_register()
1066  * function.
1067  */
1068 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
1069 {
1070         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
1071                                devm_extcon_dev_match, edev));
1072 }
1073 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1074
1075 #ifdef CONFIG_OF
1076 /*
1077  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1078  * @dev - instance to the given device
1079  * @index - index into list of extcon_dev
1080  *
1081  * return the instance of extcon device
1082  */
1083 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1084 {
1085         struct device_node *node;
1086         struct extcon_dev *edev;
1087
1088         if (!dev)
1089                 return ERR_PTR(-EINVAL);
1090
1091         if (!dev->of_node) {
1092                 dev_err(dev, "device does not have a device node entry\n");
1093                 return ERR_PTR(-EINVAL);
1094         }
1095
1096         node = of_parse_phandle(dev->of_node, "extcon", index);
1097         if (!node) {
1098                 dev_err(dev, "failed to get phandle in %s node\n",
1099                         dev->of_node->full_name);
1100                 return ERR_PTR(-ENODEV);
1101         }
1102
1103         mutex_lock(&extcon_dev_list_lock);
1104         list_for_each_entry(edev, &extcon_dev_list, entry) {
1105                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1106                         mutex_unlock(&extcon_dev_list_lock);
1107                         return edev;
1108                 }
1109         }
1110         mutex_unlock(&extcon_dev_list_lock);
1111
1112         return ERR_PTR(-EPROBE_DEFER);
1113 }
1114 #else
1115 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1116 {
1117         return ERR_PTR(-ENOSYS);
1118 }
1119 #endif /* CONFIG_OF */
1120 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1121
1122 /**
1123  * extcon_get_edev_name() - Get the name of the extcon device.
1124  * @edev:       the extcon device
1125  */
1126 const char *extcon_get_edev_name(struct extcon_dev *edev)
1127 {
1128         return !edev ? NULL : edev->name;
1129 }
1130
1131 static int __init extcon_class_init(void)
1132 {
1133         return create_extcon_class();
1134 }
1135 module_init(extcon_class_init);
1136
1137 static void __exit extcon_class_exit(void)
1138 {
1139 #if defined(CONFIG_ANDROID)
1140         class_compat_unregister(switch_class);
1141 #endif
1142         class_destroy(extcon_class);
1143 }
1144 module_exit(extcon_class_exit);
1145
1146 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1147 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1148 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1149 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1150 MODULE_DESCRIPTION("External connector (extcon) class driver");
1151 MODULE_LICENSE("GPL");