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