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                 u32 old_state;
 279
 280                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 281                                                    (state & mask))) {
 282                         spin_unlock_irqrestore(&edev->lock, flags);
 283                         return -EPERM;
 284                 }
 285
 286                 old_state = edev->state;
 287                 edev->state &= ~mask;
 288                 edev->state |= state & mask;
 289
 290                 for (index = 0; index < edev->max_supported; index++) {
 291                         if (is_extcon_changed(old_state, edev->state, index,
 292                                               &attached))
 293                                 raw_notifier_call_chain(&edev->nh[index],
 294                                                         attached, edev);
 295                 }
 296
 297                 /* This could be in interrupt handler */
 298                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 299                 if (prop_buf) {
 300                         length = name_show(&edev->dev, NULL, prop_buf);
 301                         if (length > 0) {
 302                                 if (prop_buf[length - 1] == '\n')
 303                                         prop_buf[length - 1] = 0;
 304                                 snprintf(name_buf, sizeof(name_buf),
 305                                         "NAME=%s", prop_buf);
 306                                 envp[env_offset++] = name_buf;
 307                         }
 308                         length = state_show(&edev->dev, NULL, prop_buf);
 309                         if (length > 0) {
 310                                 if (prop_buf[length - 1] == '\n')
 311                                         prop_buf[length - 1] = 0;
 312                                 snprintf(state_buf, sizeof(state_buf),
 313                                         "STATE=%s", prop_buf);
 314                                 envp[env_offset++] = state_buf;
 315                         }
 316                         envp[env_offset] = NULL;
 317                         /* Unlock early before uevent */
 318                         spin_unlock_irqrestore(&edev->lock, flags);
 319
 320                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 321                         free_page((unsigned long)prop_buf);
 322                 } else {
 323                         /* Unlock early before uevent */
 324                         spin_unlock_irqrestore(&edev->lock, flags);
 325
 326                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 327                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 328                 }
 329         } else {
 330                 /* No changes */
 331                 spin_unlock_irqrestore(&edev->lock, flags);
 332         }
 333
 334         return 0;
 335 }
 336 EXPORT_SYMBOL_GPL(extcon_update_state);
 337
 338 /**
 339  * extcon_set_state() - Set the cable attach states of the extcon device.
 340  * @edev:       the extcon device
 341  * @state:      new cable attach status for @edev
 342  *
 343  * Note that notifier provides which bits are changed in the state
 344  * variable with the val parameter (second) to the callback.
 345  */
 346 int extcon_set_state(struct extcon_dev *edev, u32 state)
 347 {
 348         return extcon_update_state(edev, 0xffffffff, state);
 349 }
 350 EXPORT_SYMBOL_GPL(extcon_set_state);
 351
 352 /**
 353  * extcon_get_cable_state_() - Get the status of a specific cable.
 354  * @edev:       the extcon device that has the cable.
 355  * @id:         the unique id of each external connector in extcon enumeration.
 356  */
 357 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 358 {
 359         int index;
 360
 361         index = find_cable_index_by_id(edev, id);
 362         if (index < 0)
 363                 return index;
 364
 365         if (edev->max_supported && edev->max_supported <= index)
 366                 return -EINVAL;
 367
 368         return !!(edev->state & (1 << index));
 369 }
 370 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 371
 372 /**
 373  * extcon_get_cable_state() - Get the status of a specific cable.
 374  * @edev:       the extcon device that has the cable.
 375  * @cable_name: cable name.
 376  *
 377  * Note that this is slower than extcon_get_cable_state_.
 378  */
 379 int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name)
 380 {
 381         unsigned int id;
 382
 383         id = find_cable_id_by_name(edev, cable_name);
 384         if (id < 0)
 385                 return id;
 386
 387         return extcon_get_cable_state_(edev, id);
 388 }
 389 EXPORT_SYMBOL_GPL(extcon_get_cable_state);
 390
 391 /**
 392  * extcon_set_cable_state_() - Set the status of a specific cable.
 393  * @edev:               the extcon device that has the cable.
 394  * @id:                 the unique id of each external connector
 395  *                      in extcon enumeration.
 396  * @state:              the new cable status. The default semantics is
 397  *                      true: attached / false: detached.
 398  */
 399 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 400                                 bool cable_state)
 401 {
 402         u32 state;
 403         int index;
 404
 405         index = find_cable_index_by_id(edev, id);
 406         if (index < 0)
 407                 return index;
 408
 409         if (edev->max_supported && edev->max_supported <= index)
 410                 return -EINVAL;
 411
 412         state = cable_state ? (1 << index) : 0;
 413         return extcon_update_state(edev, 1 << index, state);
 414 }
 415 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 416
 417 /**
 418  * extcon_set_cable_state() - Set the status of a specific cable.
 419  * @edev:               the extcon device that has the cable.
 420  * @cable_name:         cable name.
 421  * @cable_state:        the new cable status. The default semantics is
 422  *                      true: attached / false: detached.
 423  *
 424  * Note that this is slower than extcon_set_cable_state_.
 425  */
 426 int extcon_set_cable_state(struct extcon_dev *edev,
 427                         const char *cable_name, bool cable_state)
 428 {
 429         unsigned int id;
 430
 431         id = find_cable_id_by_name(edev, cable_name);
 432         if (id < 0)
 433                 return id;
 434
 435         return extcon_set_cable_state_(edev, id, cable_state);
 436 }
 437 EXPORT_SYMBOL_GPL(extcon_set_cable_state);
 438
 439 /**
 440  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 441  * @extcon_name:        The extcon name provided with extcon_dev_register()
 442  */
 443 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 444 {
 445         struct extcon_dev *sd;
 446
 447         mutex_lock(&extcon_dev_list_lock);
 448         list_for_each_entry(sd, &extcon_dev_list, entry) {
 449                 if (!strcmp(sd->name, extcon_name))
 450                         goto out;
 451         }
 452         sd = NULL;
 453 out:
 454         mutex_unlock(&extcon_dev_list_lock);
 455         return sd;
 456 }
 457 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 458
 459 /**
 460  * extcon_register_interest() - Register a notifier for a state change of a
 461  *                              specific cable, not an entier set of cables of a
 462  *                              extcon device.
 463  * @obj:                an empty extcon_specific_cable_nb object to be returned.
 464  * @extcon_name:        the name of extcon device.
 465  *                      if NULL, extcon_register_interest will register
 466  *                      every cable with the target cable_name given.
 467  * @cable_name:         the target cable name.
 468  * @nb:                 the notifier block to get notified.
 469  *
 470  * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets
 471  * the struct for you.
 472  *
 473  * extcon_register_interest is a helper function for those who want to get
 474  * notification for a single specific cable's status change. If a user wants
 475  * to get notification for any changes of all cables of a extcon device,
 476  * he/she should use the general extcon_register_notifier().
 477  *
 478  * Note that the second parameter given to the callback of nb (val) is
 479  * "old_state", not the current state. The current state can be retrieved
 480  * by looking at the third pameter (edev pointer)'s state value.
 481  */
 482 int extcon_register_interest(struct extcon_specific_cable_nb *obj,
 483                              const char *extcon_name, const char *cable_name,
 484                              struct notifier_block *nb)
 485 {
 486         unsigned long flags;
 487         int ret;
 488
 489         if (!obj || !cable_name || !nb)
 490                 return -EINVAL;
 491
 492         if (extcon_name) {
 493                 obj->edev = extcon_get_extcon_dev(extcon_name);
 494                 if (!obj->edev)
 495                         return -ENODEV;
 496
 497                 obj->cable_index = find_cable_index_by_name(obj->edev,
 498                                                         cable_name);
 499                 if (obj->cable_index < 0)
 500                         return obj->cable_index;
 501
 502                 obj->user_nb = nb;
 503
 504                 spin_lock_irqsave(&obj->edev->lock, flags);
 505                 ret = raw_notifier_chain_register(
 506                                         &obj->edev->nh[obj->cable_index],
 507                                         obj->user_nb);
 508                 spin_unlock_irqrestore(&obj->edev->lock, flags);
 509         } else {
 510                 struct class_dev_iter iter;
 511                 struct extcon_dev *extd;
 512                 struct device *dev;
 513
 514                 if (!extcon_class)
 515                         return -ENODEV;
 516                 class_dev_iter_init(&iter, extcon_class, NULL, NULL);
 517                 while ((dev = class_dev_iter_next(&iter))) {
 518                         extd = dev_get_drvdata(dev);
 519
 520                         if (find_cable_index_by_name(extd, cable_name) < 0)
 521                                 continue;
 522
 523                         class_dev_iter_exit(&iter);
 524                         return extcon_register_interest(obj, extd->name,
 525                                                 cable_name, nb);
 526                 }
 527
 528                 ret = -ENODEV;
 529         }
 530
 531         return ret;
 532 }
 533 EXPORT_SYMBOL_GPL(extcon_register_interest);
 534
 535 /**
 536  * extcon_unregister_interest() - Unregister the notifier registered by
 537  *                                extcon_register_interest().
 538  * @obj:        the extcon_specific_cable_nb object returned by
 539  *              extcon_register_interest().
 540  */
 541 int extcon_unregister_interest(struct extcon_specific_cable_nb *obj)
 542 {
 543         unsigned long flags;
 544         int ret;
 545
 546         if (!obj)
 547                 return -EINVAL;
 548
 549         spin_lock_irqsave(&obj->edev->lock, flags);
 550         ret = raw_notifier_chain_unregister(
 551                         &obj->edev->nh[obj->cable_index], obj->user_nb);
 552         spin_unlock_irqrestore(&obj->edev->lock, flags);
 553
 554         return ret;
 555 }
 556 EXPORT_SYMBOL_GPL(extcon_unregister_interest);
 557
 558 /**
 559  * extcon_register_notifier() - Register a notifiee to get notified by
 560  *                              any attach status changes from the extcon.
 561  * @edev:       the extcon device that has the external connecotr.
 562  * @id:         the unique id of each external connector in extcon enumeration.
 563  * @nb:         a notifier block to be registered.
 564  *
 565  * Note that the second parameter given to the callback of nb (val) is
 566  * "old_state", not the current state. The current state can be retrieved
 567  * by looking at the third pameter (edev pointer)'s state value.
 568  */
 569 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 570                              struct notifier_block *nb)
 571 {
 572         unsigned long flags;
 573         int ret, idx;
 574
 575         idx = find_cable_index_by_id(edev, id);
 576
 577         spin_lock_irqsave(&edev->lock, flags);
 578         ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 579         spin_unlock_irqrestore(&edev->lock, flags);
 580
 581         return ret;
 582 }
 583 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 584
 585 /**
 586  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 587  * @edev:       the extcon device that has the external connecotr.
 588  * @id:         the unique id of each external connector in extcon enumeration.
 589  * @nb:         a notifier block to be registered.
 590  */
 591 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 592                                 struct notifier_block *nb)
 593 {
 594         unsigned long flags;
 595         int ret, idx;
 596
 597         idx = find_cable_index_by_id(edev, id);
 598
 599         spin_lock_irqsave(&edev->lock, flags);
 600         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 601         spin_unlock_irqrestore(&edev->lock, flags);
 602
 603         return ret;
 604 }
 605 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 606
 607 static struct attribute *extcon_attrs[] = {
 608         &dev_attr_state.attr,
 609         &dev_attr_name.attr,
 610         NULL,
 611 };
 612 ATTRIBUTE_GROUPS(extcon);
 613
 614 static int create_extcon_class(void)
 615 {
 616         if (!extcon_class) {
 617                 extcon_class = class_create(THIS_MODULE, "extcon");
 618                 if (IS_ERR(extcon_class))
 619                         return PTR_ERR(extcon_class);
 620                 extcon_class->dev_groups = extcon_groups;
 621
 622 #if defined(CONFIG_ANDROID)
 623                 switch_class = class_compat_register("switch");
 624                 if (WARN(!switch_class, "cannot allocate"))
 625                         return -ENOMEM;
 626 #endif /* CONFIG_ANDROID */
 627         }
 628
 629         return 0;
 630 }
 631
 632 static void extcon_dev_release(struct device *dev)
 633 {
 634 }
 635
 636 static const char *muex_name = "mutually_exclusive";
 637 static void dummy_sysfs_dev_release(struct device *dev)
 638 {
 639 }
 640
 641 /*
 642  * extcon_dev_allocate() - Allocate the memory of extcon device.
 643  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 644  *                      If supported_cable is NULL, cable name related APIs
 645  *                      are disabled.
 646  *
 647  * This function allocates the memory for extcon device without allocating
 648  * memory in each extcon provider driver and initialize default setting for
 649  * extcon device.
 650  *
 651  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 652  */
 653 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 654 {
 655         struct extcon_dev *edev;
 656
 657         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 658         if (!edev)
 659                 return ERR_PTR(-ENOMEM);
 660
 661         edev->max_supported = 0;
 662         edev->supported_cable = supported_cable;
 663
 664         return edev;
 665 }
 666
 667 /*
 668  * extcon_dev_free() - Free the memory of extcon device.
 669  * @edev:       the extcon device to free
 670  */
 671 void extcon_dev_free(struct extcon_dev *edev)
 672 {
 673         kfree(edev);
 674 }
 675 EXPORT_SYMBOL_GPL(extcon_dev_free);
 676
 677 static int devm_extcon_dev_match(struct device *dev, void *res, void *data)
 678 {
 679         struct extcon_dev **r = res;
 680
 681         if (WARN_ON(!r || !*r))
 682                 return 0;
 683
 684         return *r == data;
 685 }
 686
 687 static void devm_extcon_dev_release(struct device *dev, void *res)
 688 {
 689         extcon_dev_free(*(struct extcon_dev **)res);
 690 }
 691
 692 /**
 693  * devm_extcon_dev_allocate - Allocate managed extcon device
 694  * @dev:                device owning the extcon device being created
 695  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 696  *                      If supported_cable is NULL, cable name related APIs
 697  *                      are disabled.
 698  *
 699  * This function manages automatically the memory of extcon device using device
 700  * resource management and simplify the control of freeing the memory of extcon
 701  * device.
 702  *
 703  * Returns the pointer memory of allocated extcon_dev if success
 704  * or ERR_PTR(err) if fail
 705  */
 706 struct extcon_dev *devm_extcon_dev_allocate(struct device *dev,
 707                                         const unsigned int *supported_cable)
 708 {
 709         struct extcon_dev **ptr, *edev;
 710
 711         ptr = devres_alloc(devm_extcon_dev_release, sizeof(*ptr), GFP_KERNEL);
 712         if (!ptr)
 713                 return ERR_PTR(-ENOMEM);
 714
 715         edev = extcon_dev_allocate(supported_cable);
 716         if (IS_ERR(edev)) {
 717                 devres_free(ptr);
 718                 return edev;
 719         }
 720
 721         edev->dev.parent = dev;
 722
 723         *ptr = edev;
 724         devres_add(dev, ptr);
 725
 726         return edev;
 727 }
 728 EXPORT_SYMBOL_GPL(devm_extcon_dev_allocate);
 729
 730 void devm_extcon_dev_free(struct device *dev, struct extcon_dev *edev)
 731 {
 732         WARN_ON(devres_release(dev, devm_extcon_dev_release,
 733                                devm_extcon_dev_match, edev));
 734 }
 735 EXPORT_SYMBOL_GPL(devm_extcon_dev_free);
 736
 737 /**
 738  * extcon_dev_register() - Register a new extcon device
 739  * @edev        : the new extcon device (should be allocated before calling)
 740  *
 741  * Among the members of edev struct, please set the "user initializing data"
 742  * in any case and set the "optional callbacks" if required. However, please
 743  * do not set the values of "internal data", which are initialized by
 744  * this function.
 745  */
 746 int extcon_dev_register(struct extcon_dev *edev)
 747 {
 748         int ret, index = 0;
 749         static atomic_t edev_no = ATOMIC_INIT(-1);
 750
 751         if (!extcon_class) {
 752                 ret = create_extcon_class();
 753                 if (ret < 0)
 754                         return ret;
 755         }
 756
 757         if (!edev->supported_cable)
 758                 return -EINVAL;
 759
 760         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 761
 762         edev->max_supported = index;
 763         if (index > SUPPORTED_CABLE_MAX) {
 764                 dev_err(&edev->dev,
 765                         "exceed the maximum number of supported cables\n");
 766                 return -EINVAL;
 767         }
 768
 769         edev->dev.class = extcon_class;
 770         edev->dev.release = extcon_dev_release;
 771
 772         edev->name = dev_name(edev->dev.parent);
 773         if (IS_ERR_OR_NULL(edev->name)) {
 774                 dev_err(&edev->dev,
 775                         "extcon device name is null\n");
 776                 return -EINVAL;
 777         }
 778         dev_set_name(&edev->dev, "extcon%lu",
 779                         (unsigned long)atomic_inc_return(&edev_no));
 780
 781         if (edev->max_supported) {
 782                 char buf[10];
 783                 char *str;
 784                 struct extcon_cable *cable;
 785
 786                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 787                                        edev->max_supported, GFP_KERNEL);
 788                 if (!edev->cables) {
 789                         ret = -ENOMEM;
 790                         goto err_sysfs_alloc;
 791                 }
 792                 for (index = 0; index < edev->max_supported; index++) {
 793                         cable = &edev->cables[index];
 794
 795                         snprintf(buf, 10, "cable.%d", index);
 796                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 797                                       GFP_KERNEL);
 798                         if (!str) {
 799                                 for (index--; index >= 0; index--) {
 800                                         cable = &edev->cables[index];
 801                                         kfree(cable->attr_g.name);
 802                                 }
 803                                 ret = -ENOMEM;
 804
 805                                 goto err_alloc_cables;
 806                         }
 807                         strcpy(str, buf);
 808
 809                         cable->edev = edev;
 810                         cable->cable_index = index;
 811                         cable->attrs[0] = &cable->attr_name.attr;
 812                         cable->attrs[1] = &cable->attr_state.attr;
 813                         cable->attrs[2] = NULL;
 814                         cable->attr_g.name = str;
 815                         cable->attr_g.attrs = cable->attrs;
 816
 817                         sysfs_attr_init(&cable->attr_name.attr);
 818                         cable->attr_name.attr.name = "name";
 819                         cable->attr_name.attr.mode = 0444;
 820                         cable->attr_name.show = cable_name_show;
 821
 822                         sysfs_attr_init(&cable->attr_state.attr);
 823                         cable->attr_state.attr.name = "state";
 824                         cable->attr_state.attr.mode = 0444;
 825                         cable->attr_state.show = cable_state_show;
 826                 }
 827         }
 828
 829         if (edev->max_supported && edev->mutually_exclusive) {
 830                 char buf[80];
 831                 char *name;
 832
 833                 /* Count the size of mutually_exclusive array */
 834                 for (index = 0; edev->mutually_exclusive[index]; index++)
 835                         ;
 836
 837                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 838                                            (index + 1), GFP_KERNEL);
 839                 if (!edev->attrs_muex) {
 840                         ret = -ENOMEM;
 841                         goto err_muex;
 842                 }
 843
 844                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 845                                              index, GFP_KERNEL);
 846                 if (!edev->d_attrs_muex) {
 847                         ret = -ENOMEM;
 848                         kfree(edev->attrs_muex);
 849                         goto err_muex;
 850                 }
 851
 852                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 853                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 854                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 855                                        GFP_KERNEL);
 856                         if (!name) {
 857                                 for (index--; index >= 0; index--) {
 858                                         kfree(edev->d_attrs_muex[index].attr.
 859                                               name);
 860                                 }
 861                                 kfree(edev->d_attrs_muex);
 862                                 kfree(edev->attrs_muex);
 863                                 ret = -ENOMEM;
 864                                 goto err_muex;
 865                         }
 866                         strcpy(name, buf);
 867                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 868                         edev->d_attrs_muex[index].attr.name = name;
 869                         edev->d_attrs_muex[index].attr.mode = 0000;
 870                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 871                                                         .attr;
 872                 }
 873                 edev->attr_g_muex.name = muex_name;
 874                 edev->attr_g_muex.attrs = edev->attrs_muex;
 875
 876         }
 877
 878         if (edev->max_supported) {
 879                 edev->extcon_dev_type.groups =
 880                         kzalloc(sizeof(struct attribute_group *) *
 881                                 (edev->max_supported + 2), GFP_KERNEL);
 882                 if (!edev->extcon_dev_type.groups) {
 883                         ret = -ENOMEM;
 884                         goto err_alloc_groups;
 885                 }
 886
 887                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 888                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 889
 890                 for (index = 0; index < edev->max_supported; index++)
 891                         edev->extcon_dev_type.groups[index] =
 892                                 &edev->cables[index].attr_g;
 893                 if (edev->mutually_exclusive)
 894                         edev->extcon_dev_type.groups[index] =
 895                                 &edev->attr_g_muex;
 896
 897                 edev->dev.type = &edev->extcon_dev_type;
 898         }
 899
 900         ret = device_register(&edev->dev);
 901         if (ret) {
 902                 put_device(&edev->dev);
 903                 goto err_dev;
 904         }
 905 #if defined(CONFIG_ANDROID)
 906         if (switch_class)
 907                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 908 #endif /* CONFIG_ANDROID */
 909
 910         spin_lock_init(&edev->lock);
 911
 912         edev->nh = devm_kzalloc(&edev->dev,
 913                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 914         if (!edev->nh) {
 915                 ret = -ENOMEM;
 916                 goto err_dev;
 917         }
 918
 919         for (index = 0; index < edev->max_supported; index++)
 920                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 921
 922         dev_set_drvdata(&edev->dev, edev);
 923         edev->state = 0;
 924
 925         mutex_lock(&extcon_dev_list_lock);
 926         list_add(&edev->entry, &extcon_dev_list);
 927         mutex_unlock(&extcon_dev_list_lock);
 928
 929         return 0;
 930
 931 err_dev:
 932         if (edev->max_supported)
 933                 kfree(edev->extcon_dev_type.groups);
 934 err_alloc_groups:
 935         if (edev->max_supported && edev->mutually_exclusive) {
 936                 for (index = 0; edev->mutually_exclusive[index]; index++)
 937                         kfree(edev->d_attrs_muex[index].attr.name);
 938                 kfree(edev->d_attrs_muex);
 939                 kfree(edev->attrs_muex);
 940         }
 941 err_muex:
 942         for (index = 0; index < edev->max_supported; index++)
 943                 kfree(edev->cables[index].attr_g.name);
 944 err_alloc_cables:
 945         if (edev->max_supported)
 946                 kfree(edev->cables);
 947 err_sysfs_alloc:
 948         return ret;
 949 }
 950 EXPORT_SYMBOL_GPL(extcon_dev_register);
 951
 952 /**
 953  * extcon_dev_unregister() - Unregister the extcon device.
 954  * @edev:       the extcon device instance to be unregistered.
 955  *
 956  * Note that this does not call kfree(edev) because edev was not allocated
 957  * by this class.
 958  */
 959 void extcon_dev_unregister(struct extcon_dev *edev)
 960 {
 961         int index;
 962
 963         mutex_lock(&extcon_dev_list_lock);
 964         list_del(&edev->entry);
 965         mutex_unlock(&extcon_dev_list_lock);
 966
 967         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 968                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 969                                 dev_name(&edev->dev));
 970                 return;
 971         }
 972
 973         device_unregister(&edev->dev);
 974
 975         if (edev->mutually_exclusive && edev->max_supported) {
 976                 for (index = 0; edev->mutually_exclusive[index];
 977                                 index++)
 978                         kfree(edev->d_attrs_muex[index].attr.name);
 979                 kfree(edev->d_attrs_muex);
 980                 kfree(edev->attrs_muex);
 981         }
 982
 983         for (index = 0; index < edev->max_supported; index++)
 984                 kfree(edev->cables[index].attr_g.name);
 985
 986         if (edev->max_supported) {
 987                 kfree(edev->extcon_dev_type.groups);
 988                 kfree(edev->cables);
 989         }
 990
 991 #if defined(CONFIG_ANDROID)
 992         if (switch_class)
 993                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 994 #endif
 995         put_device(&edev->dev);
 996 }
 997 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 998
 999 static void devm_extcon_dev_unreg(struct device *dev, void *res)
1000 {
1001         extcon_dev_unregister(*(struct extcon_dev **)res);
1002 }
1003
1004 /**
1005  * devm_extcon_dev_register() - Resource-managed extcon_dev_register()
1006  * @dev:        device to allocate extcon device
1007  * @edev:       the new extcon device to register
1008  *
1009  * Managed extcon_dev_register() function. If extcon device is attached with
1010  * this function, that extcon device is automatically unregistered on driver
1011  * detach. Internally this function calls extcon_dev_register() function.
1012  * To get more information, refer that function.
1013  *
1014  * If extcon device is registered with this function and the device needs to be
1015  * unregistered separately, devm_extcon_dev_unregister() should be used.
1016  *
1017  * Returns 0 if success or negaive error number if failure.
1018  */
1019 int devm_extcon_dev_register(struct device *dev, struct extcon_dev *edev)
1020 {
1021         struct extcon_dev **ptr;
1022         int ret;
1023
1024         ptr = devres_alloc(devm_extcon_dev_unreg, sizeof(*ptr), GFP_KERNEL);
1025         if (!ptr)
1026                 return -ENOMEM;
1027
1028         ret = extcon_dev_register(edev);
1029         if (ret) {
1030                 devres_free(ptr);
1031                 return ret;
1032         }
1033
1034         *ptr = edev;
1035         devres_add(dev, ptr);
1036
1037         return 0;
1038 }
1039 EXPORT_SYMBOL_GPL(devm_extcon_dev_register);
1040
1041 /**
1042  * devm_extcon_dev_unregister() - Resource-managed extcon_dev_unregister()
1043  * @dev:        device the extcon belongs to
1044  * @edev:       the extcon device to unregister
1045  *
1046  * Unregister extcon device that is registered with devm_extcon_dev_register()
1047  * function.
1048  */
1049 void devm_extcon_dev_unregister(struct device *dev, struct extcon_dev *edev)
1050 {
1051         WARN_ON(devres_release(dev, devm_extcon_dev_unreg,
1052                                devm_extcon_dev_match, edev));
1053 }
1054 EXPORT_SYMBOL_GPL(devm_extcon_dev_unregister);
1055
1056 #ifdef CONFIG_OF
1057 /*
1058  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
1059  * @dev - instance to the given device
1060  * @index - index into list of extcon_dev
1061  *
1062  * return the instance of extcon device
1063  */
1064 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1065 {
1066         struct device_node *node;
1067         struct extcon_dev *edev;
1068
1069         if (!dev->of_node) {
1070                 dev_err(dev, "device does not have a device node entry\n");
1071                 return ERR_PTR(-EINVAL);
1072         }
1073
1074         node = of_parse_phandle(dev->of_node, "extcon", index);
1075         if (!node) {
1076                 dev_err(dev, "failed to get phandle in %s node\n",
1077                         dev->of_node->full_name);
1078                 return ERR_PTR(-ENODEV);
1079         }
1080
1081         mutex_lock(&extcon_dev_list_lock);
1082         list_for_each_entry(edev, &extcon_dev_list, entry) {
1083                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
1084                         mutex_unlock(&extcon_dev_list_lock);
1085                         return edev;
1086                 }
1087         }
1088         mutex_unlock(&extcon_dev_list_lock);
1089
1090         return ERR_PTR(-EPROBE_DEFER);
1091 }
1092 #else
1093 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
1094 {
1095         return ERR_PTR(-ENOSYS);
1096 }
1097 #endif /* CONFIG_OF */
1098 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
1099
1100 /**
1101  * extcon_get_edev_name() - Get the name of the extcon device.
1102  * @edev:       the extcon device
1103  */
1104 const char *extcon_get_edev_name(struct extcon_dev *edev)
1105 {
1106         return !edev ? NULL : edev->name;
1107 }
1108
1109 static int __init extcon_class_init(void)
1110 {
1111         return create_extcon_class();
1112 }
1113 module_init(extcon_class_init);
1114
1115 static void __exit extcon_class_exit(void)
1116 {
1117 #if defined(CONFIG_ANDROID)
1118         class_compat_unregister(switch_class);
1119 #endif
1120         class_destroy(extcon_class);
1121 }
1122 module_exit(extcon_class_exit);
1123
1124 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
1125 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
1126 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
1127 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1128 MODULE_DESCRIPTION("External connector (extcon) class driver");
1129 MODULE_LICENSE("GPL");