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         /* Charging external connector */
  49         [EXTCON_CHG_USB_SDP]            = "SDP",
  50         [EXTCON_CHG_USB_DCP]            = "DCP",
  51         [EXTCON_CHG_USB_CDP]            = "CDP",
  52         [EXTCON_CHG_USB_ACA]            = "ACA",
  53         [EXTCON_CHG_USB_FAST]           = "FAST-CHARGER",
  54         [EXTCON_CHG_USB_SLOW]           = "SLOW-CHARGER",
  55
  56         /* Jack external connector */
  57         [EXTCON_JACK_MICROPHONE]        = "MICROPHONE",
  58         [EXTCON_JACK_HEADPHONE]         = "HEADPHONE",
  59         [EXTCON_JACK_LINE_IN]           = "LINE-IN",
  60         [EXTCON_JACK_LINE_OUT]          = "LINE-OUT",
  61         [EXTCON_JACK_VIDEO_IN]          = "VIDEO-IN",
  62         [EXTCON_JACK_VIDEO_OUT]         = "VIDEO-OUT",
  63         [EXTCON_JACK_SPDIF_IN]          = "SPDIF-IN",
  64         [EXTCON_JACK_SPDIF_OUT]         = "SPDIF-OUT",
  65
  66         /* Display external connector */
  67         [EXTCON_DISP_HDMI]              = "HDMI",
  68         [EXTCON_DISP_MHL]               = "MHL",
  69         [EXTCON_DISP_DVI]               = "DVI",
  70         [EXTCON_DISP_VGA]               = "VGA",
  71
  72         /* Miscellaneous external connector */
  73         [EXTCON_DOCK]                   = "DOCK",
  74         [EXTCON_JIG]                    = "JIG",
  75         [EXTCON_MECHANICAL]             = "MECHANICAL",
  76
  77         NULL,
  78 };
  79
  80 /**
  81  * struct extcon_cable - An internal data for each cable of extcon device.
  82  * @edev:               The extcon device
  83  * @cable_index:        Index of this cable in the edev
  84  * @attr_g:             Attribute group for the cable
  85  * @attr_name:          "name" sysfs entry
  86  * @attr_state:         "state" sysfs entry
  87  * @attrs:              Array pointing to attr_name and attr_state for attr_g
  88  */
  89 struct extcon_cable {
  90         struct extcon_dev *edev;
  91         int cable_index;
  92
  93         struct attribute_group attr_g;
  94         struct device_attribute attr_name;
  95         struct device_attribute attr_state;
  96
  97         struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
  98 };
  99
 100 static struct class *extcon_class;
 101 #if defined(CONFIG_ANDROID)
 102 static struct class_compat *switch_class;
 103 #endif /* CONFIG_ANDROID */
 104
 105 static LIST_HEAD(extcon_dev_list);
 106 static DEFINE_MUTEX(extcon_dev_list_lock);
 107
 108 /**
 109  * check_mutually_exclusive - Check if new_state violates mutually_exclusive
 110  *                            condition.
 111  * @edev:       the extcon device
 112  * @new_state:  new cable attach status for @edev
 113  *
 114  * Returns 0 if nothing violates. Returns the index + 1 for the first
 115  * violated condition.
 116  */
 117 static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
 118 {
 119         int i = 0;
 120
 121         if (!edev->mutually_exclusive)
 122                 return 0;
 123
 124         for (i = 0; edev->mutually_exclusive[i]; i++) {
 125                 int weight;
 126                 u32 correspondants = new_state & edev->mutually_exclusive[i];
 127
 128                 /* calculate the total number of bits set */
 129                 weight = hweight32(correspondants);
 130                 if (weight > 1)
 131                         return i + 1;
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id)
 138 {
 139         int i;
 140
 141         /* Find the the index of extcon cable in edev->supported_cable */
 142         for (i = 0; i < edev->max_supported; i++) {
 143                 if (edev->supported_cable[i] == id)
 144                         return i;
 145         }
 146
 147         return -EINVAL;
 148 }
 149
 150 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 151 {
 152         if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
 153                 *attached = ((new >> idx) & 0x1) ? true : false;
 154                 return true;
 155         }
 156
 157         return false;
 158 }
 159
 160 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 161                           char *buf)
 162 {
 163         int i, count = 0;
 164         struct extcon_dev *edev = dev_get_drvdata(dev);
 165
 166         if (edev->max_supported == 0)
 167                 return sprintf(buf, "%u\n", edev->state);
 168
 169         for (i = 0; i < edev->max_supported; i++) {
 170                 count += sprintf(buf + count, "%s=%d\n",
 171                                 extcon_name[edev->supported_cable[i]],
 172                                  !!(edev->state & (1 << i)));
 173         }
 174
 175         return count;
 176 }
 177 static DEVICE_ATTR_RO(state);
 178
 179 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 180                 char *buf)
 181 {
 182         struct extcon_dev *edev = dev_get_drvdata(dev);
 183
 184         return sprintf(buf, "%s\n", edev->name);
 185 }
 186 static DEVICE_ATTR_RO(name);
 187
 188 static ssize_t cable_name_show(struct device *dev,
 189                                struct device_attribute *attr, char *buf)
 190 {
 191         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 192                                                   attr_name);
 193         int i = cable->cable_index;
 194
 195         return sprintf(buf, "%s\n",
 196                         extcon_name[cable->edev->supported_cable[i]]);
 197 }
 198
 199 static ssize_t cable_state_show(struct device *dev,
 200                                 struct device_attribute *attr, char *buf)
 201 {
 202         struct extcon_cable *cable = container_of(attr, struct extcon_cable,
 203                                                   attr_state);
 204
 205         int i = cable->cable_index;
 206
 207         return sprintf(buf, "%d\n",
 208                        extcon_get_cable_state_(cable->edev,
 209                                                cable->edev->supported_cable[i]));
 210 }
 211
 212 /**
 213  * extcon_update_state() - Update the cable attach states of the extcon device
 214  *                         only for the masked bits.
 215  * @edev:       the extcon device
 216  * @mask:       the bit mask to designate updated bits.
 217  * @state:      new cable attach status for @edev
 218  *
 219  * Changing the state sends uevent with environment variable containing
 220  * the name of extcon device (envp[0]) and the state output (envp[1]).
 221  * Tizen uses this format for extcon device to get events from ports.
 222  * Android uses this format as well.
 223  *
 224  * Note that the notifier provides which bits are changed in the state
 225  * variable with the val parameter (second) to the callback.
 226  */
 227 int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
 228 {
 229         char name_buf[120];
 230         char state_buf[120];
 231         char *prop_buf;
 232         char *envp[3];
 233         int env_offset = 0;
 234         int length;
 235         int index;
 236         unsigned long flags;
 237         bool attached;
 238
 239         if (!edev)
 240                 return -EINVAL;
 241
 242         spin_lock_irqsave(&edev->lock, flags);
 243
 244         if (edev->state != ((edev->state & ~mask) | (state & mask))) {
 245                 u32 old_state;
 246
 247                 if (check_mutually_exclusive(edev, (edev->state & ~mask) |
 248                                                    (state & mask))) {
 249                         spin_unlock_irqrestore(&edev->lock, flags);
 250                         return -EPERM;
 251                 }
 252
 253                 old_state = edev->state;
 254                 edev->state &= ~mask;
 255                 edev->state |= state & mask;
 256
 257                 for (index = 0; index < edev->max_supported; index++) {
 258                         if (is_extcon_changed(old_state, edev->state, index,
 259                                               &attached))
 260                                 raw_notifier_call_chain(&edev->nh[index],
 261                                                         attached, edev);
 262                 }
 263
 264                 /* This could be in interrupt handler */
 265                 prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
 266                 if (prop_buf) {
 267                         length = name_show(&edev->dev, NULL, prop_buf);
 268                         if (length > 0) {
 269                                 if (prop_buf[length - 1] == '\n')
 270                                         prop_buf[length - 1] = 0;
 271                                 snprintf(name_buf, sizeof(name_buf),
 272                                         "NAME=%s", prop_buf);
 273                                 envp[env_offset++] = name_buf;
 274                         }
 275                         length = state_show(&edev->dev, NULL, prop_buf);
 276                         if (length > 0) {
 277                                 if (prop_buf[length - 1] == '\n')
 278                                         prop_buf[length - 1] = 0;
 279                                 snprintf(state_buf, sizeof(state_buf),
 280                                         "STATE=%s", prop_buf);
 281                                 envp[env_offset++] = state_buf;
 282                         }
 283                         envp[env_offset] = NULL;
 284                         /* Unlock early before uevent */
 285                         spin_unlock_irqrestore(&edev->lock, flags);
 286
 287                         kobject_uevent_env(&edev->dev.kobj, KOBJ_CHANGE, envp);
 288                         free_page((unsigned long)prop_buf);
 289                 } else {
 290                         /* Unlock early before uevent */
 291                         spin_unlock_irqrestore(&edev->lock, flags);
 292
 293                         dev_err(&edev->dev, "out of memory in extcon_set_state\n");
 294                         kobject_uevent(&edev->dev.kobj, KOBJ_CHANGE);
 295                 }
 296         } else {
 297                 /* No changes */
 298                 spin_unlock_irqrestore(&edev->lock, flags);
 299         }
 300
 301         return 0;
 302 }
 303 EXPORT_SYMBOL_GPL(extcon_update_state);
 304
 305 /**
 306  * extcon_set_state() - Set the cable attach states of the extcon device.
 307  * @edev:       the extcon device
 308  * @state:      new cable attach status for @edev
 309  *
 310  * Note that notifier provides which bits are changed in the state
 311  * variable with the val parameter (second) to the callback.
 312  */
 313 int extcon_set_state(struct extcon_dev *edev, u32 state)
 314 {
 315         if (!edev)
 316                 return -EINVAL;
 317
 318         return extcon_update_state(edev, 0xffffffff, state);
 319 }
 320 EXPORT_SYMBOL_GPL(extcon_set_state);
 321
 322 /**
 323  * extcon_get_cable_state_() - Get the status of a specific cable.
 324  * @edev:       the extcon device that has the cable.
 325  * @id:         the unique id of each external connector in extcon enumeration.
 326  */
 327 int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 328 {
 329         int index;
 330
 331         if (!edev)
 332                 return -EINVAL;
 333
 334         index = find_cable_index_by_id(edev, id);
 335         if (index < 0)
 336                 return index;
 337
 338         if (edev->max_supported && edev->max_supported <= index)
 339                 return -EINVAL;
 340
 341         return !!(edev->state & (1 << index));
 342 }
 343 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 344
 345 /**
 346  * extcon_set_cable_state_() - Set the status of a specific cable.
 347  * @edev:               the extcon device that has the cable.
 348  * @id:                 the unique id of each external connector
 349  *                      in extcon enumeration.
 350  * @state:              the new cable status. The default semantics is
 351  *                      true: attached / false: detached.
 352  */
 353 int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 354                                 bool cable_state)
 355 {
 356         u32 state;
 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         state = cable_state ? (1 << index) : 0;
 370         return extcon_update_state(edev, 1 << index, state);
 371 }
 372 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 373
 374 /**
 375  * extcon_get_extcon_dev() - Get the extcon device instance from the name
 376  * @extcon_name:        The extcon name provided with extcon_dev_register()
 377  */
 378 struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 379 {
 380         struct extcon_dev *sd;
 381
 382         if (!extcon_name)
 383                 return ERR_PTR(-EINVAL);
 384
 385         mutex_lock(&extcon_dev_list_lock);
 386         list_for_each_entry(sd, &extcon_dev_list, entry) {
 387                 if (!strcmp(sd->name, extcon_name))
 388                         goto out;
 389         }
 390         sd = NULL;
 391 out:
 392         mutex_unlock(&extcon_dev_list_lock);
 393         return sd;
 394 }
 395 EXPORT_SYMBOL_GPL(extcon_get_extcon_dev);
 396
 397 /**
 398  * extcon_register_notifier() - Register a notifiee to get notified by
 399  *                              any attach status changes from the extcon.
 400  * @edev:       the extcon device that has the external connecotr.
 401  * @id:         the unique id of each external connector in extcon enumeration.
 402  * @nb:         a notifier block to be registered.
 403  *
 404  * Note that the second parameter given to the callback of nb (val) is
 405  * "old_state", not the current state. The current state can be retrieved
 406  * by looking at the third pameter (edev pointer)'s state value.
 407  */
 408 int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 409                              struct notifier_block *nb)
 410 {
 411         unsigned long flags;
 412         int ret, idx;
 413
 414         if (!nb)
 415                 return -EINVAL;
 416
 417         if (edev) {
 418                 idx = find_cable_index_by_id(edev, id);
 419                 if (idx < 0)
 420                         return idx;
 421
 422                 spin_lock_irqsave(&edev->lock, flags);
 423                 ret = raw_notifier_chain_register(&edev->nh[idx], nb);
 424                 spin_unlock_irqrestore(&edev->lock, flags);
 425         } else {
 426                 struct extcon_dev *extd;
 427
 428                 mutex_lock(&extcon_dev_list_lock);
 429                 list_for_each_entry(extd, &extcon_dev_list, entry) {
 430                         idx = find_cable_index_by_id(extd, id);
 431                         if (idx >= 0)
 432                                 break;
 433                 }
 434                 mutex_unlock(&extcon_dev_list_lock);
 435
 436                 if (idx >= 0) {
 437                         edev = extd;
 438                         return extcon_register_notifier(extd, id, nb);
 439                 } else {
 440                         ret = -ENODEV;
 441                 }
 442         }
 443
 444         return ret;
 445 }
 446 EXPORT_SYMBOL_GPL(extcon_register_notifier);
 447
 448 /**
 449  * extcon_unregister_notifier() - Unregister a notifiee from the extcon device.
 450  * @edev:       the extcon device that has the external connecotr.
 451  * @id:         the unique id of each external connector in extcon enumeration.
 452  * @nb:         a notifier block to be registered.
 453  */
 454 int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 455                                 struct notifier_block *nb)
 456 {
 457         unsigned long flags;
 458         int ret, idx;
 459
 460         if (!edev || !nb)
 461                 return -EINVAL;
 462
 463         idx = find_cable_index_by_id(edev, id);
 464         if (idx < 0)
 465                 return idx;
 466
 467         spin_lock_irqsave(&edev->lock, flags);
 468         ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);
 469         spin_unlock_irqrestore(&edev->lock, flags);
 470
 471         return ret;
 472 }
 473 EXPORT_SYMBOL_GPL(extcon_unregister_notifier);
 474
 475 static struct attribute *extcon_attrs[] = {
 476         &dev_attr_state.attr,
 477         &dev_attr_name.attr,
 478         NULL,
 479 };
 480 ATTRIBUTE_GROUPS(extcon);
 481
 482 static int create_extcon_class(void)
 483 {
 484         if (!extcon_class) {
 485                 extcon_class = class_create(THIS_MODULE, "extcon");
 486                 if (IS_ERR(extcon_class))
 487                         return PTR_ERR(extcon_class);
 488                 extcon_class->dev_groups = extcon_groups;
 489
 490 #if defined(CONFIG_ANDROID) && !defined(CONFIG_SWITCH)
 491                 switch_class = class_compat_register("switch");
 492                 if (WARN(!switch_class, "cannot allocate"))
 493                         return -ENOMEM;
 494 #endif /* CONFIG_ANDROID */
 495         }
 496
 497         return 0;
 498 }
 499
 500 static void extcon_dev_release(struct device *dev)
 501 {
 502 }
 503
 504 static const char *muex_name = "mutually_exclusive";
 505 static void dummy_sysfs_dev_release(struct device *dev)
 506 {
 507 }
 508
 509 /*
 510  * extcon_dev_allocate() - Allocate the memory of extcon device.
 511  * @supported_cable:    Array of supported extcon ending with EXTCON_NONE.
 512  *                      If supported_cable is NULL, cable name related APIs
 513  *                      are disabled.
 514  *
 515  * This function allocates the memory for extcon device without allocating
 516  * memory in each extcon provider driver and initialize default setting for
 517  * extcon device.
 518  *
 519  * Return the pointer of extcon device if success or ERR_PTR(err) if fail
 520  */
 521 struct extcon_dev *extcon_dev_allocate(const unsigned int *supported_cable)
 522 {
 523         struct extcon_dev *edev;
 524
 525         if (!supported_cable)
 526                 return ERR_PTR(-EINVAL);
 527
 528         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
 529         if (!edev)
 530                 return ERR_PTR(-ENOMEM);
 531
 532         edev->max_supported = 0;
 533         edev->supported_cable = supported_cable;
 534
 535         return edev;
 536 }
 537
 538 /*
 539  * extcon_dev_free() - Free the memory of extcon device.
 540  * @edev:       the extcon device to free
 541  */
 542 void extcon_dev_free(struct extcon_dev *edev)
 543 {
 544         kfree(edev);
 545 }
 546 EXPORT_SYMBOL_GPL(extcon_dev_free);
 547
 548 /**
 549  * extcon_dev_register() - Register a new extcon device
 550  * @edev        : the new extcon device (should be allocated before calling)
 551  *
 552  * Among the members of edev struct, please set the "user initializing data"
 553  * in any case and set the "optional callbacks" if required. However, please
 554  * do not set the values of "internal data", which are initialized by
 555  * this function.
 556  */
 557 int extcon_dev_register(struct extcon_dev *edev)
 558 {
 559         int ret, index = 0;
 560         static atomic_t edev_no = ATOMIC_INIT(-1);
 561
 562         if (!extcon_class) {
 563                 ret = create_extcon_class();
 564                 if (ret < 0)
 565                         return ret;
 566         }
 567
 568         if (!edev || !edev->supported_cable)
 569                 return -EINVAL;
 570
 571         for (; edev->supported_cable[index] != EXTCON_NONE; index++);
 572
 573         edev->max_supported = index;
 574         if (index > SUPPORTED_CABLE_MAX) {
 575                 dev_err(&edev->dev,
 576                         "exceed the maximum number of supported cables\n");
 577                 return -EINVAL;
 578         }
 579
 580         edev->dev.class = extcon_class;
 581         edev->dev.release = extcon_dev_release;
 582
 583         edev->name = dev_name(edev->dev.parent);
 584         if (IS_ERR_OR_NULL(edev->name)) {
 585                 dev_err(&edev->dev,
 586                         "extcon device name is null\n");
 587                 return -EINVAL;
 588         }
 589         dev_set_name(&edev->dev, "extcon%lu",
 590                         (unsigned long)atomic_inc_return(&edev_no));
 591
 592         if (edev->max_supported) {
 593                 char buf[10];
 594                 char *str;
 595                 struct extcon_cable *cable;
 596
 597                 edev->cables = kzalloc(sizeof(struct extcon_cable) *
 598                                        edev->max_supported, GFP_KERNEL);
 599                 if (!edev->cables) {
 600                         ret = -ENOMEM;
 601                         goto err_sysfs_alloc;
 602                 }
 603                 for (index = 0; index < edev->max_supported; index++) {
 604                         cable = &edev->cables[index];
 605
 606                         snprintf(buf, 10, "cable.%d", index);
 607                         str = kzalloc(sizeof(char) * (strlen(buf) + 1),
 608                                       GFP_KERNEL);
 609                         if (!str) {
 610                                 for (index--; index >= 0; index--) {
 611                                         cable = &edev->cables[index];
 612                                         kfree(cable->attr_g.name);
 613                                 }
 614                                 ret = -ENOMEM;
 615
 616                                 goto err_alloc_cables;
 617                         }
 618                         strcpy(str, buf);
 619
 620                         cable->edev = edev;
 621                         cable->cable_index = index;
 622                         cable->attrs[0] = &cable->attr_name.attr;
 623                         cable->attrs[1] = &cable->attr_state.attr;
 624                         cable->attrs[2] = NULL;
 625                         cable->attr_g.name = str;
 626                         cable->attr_g.attrs = cable->attrs;
 627
 628                         sysfs_attr_init(&cable->attr_name.attr);
 629                         cable->attr_name.attr.name = "name";
 630                         cable->attr_name.attr.mode = 0444;
 631                         cable->attr_name.show = cable_name_show;
 632
 633                         sysfs_attr_init(&cable->attr_state.attr);
 634                         cable->attr_state.attr.name = "state";
 635                         cable->attr_state.attr.mode = 0444;
 636                         cable->attr_state.show = cable_state_show;
 637                 }
 638         }
 639
 640         if (edev->max_supported && edev->mutually_exclusive) {
 641                 char buf[80];
 642                 char *name;
 643
 644                 /* Count the size of mutually_exclusive array */
 645                 for (index = 0; edev->mutually_exclusive[index]; index++)
 646                         ;
 647
 648                 edev->attrs_muex = kzalloc(sizeof(struct attribute *) *
 649                                            (index + 1), GFP_KERNEL);
 650                 if (!edev->attrs_muex) {
 651                         ret = -ENOMEM;
 652                         goto err_muex;
 653                 }
 654
 655                 edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) *
 656                                              index, GFP_KERNEL);
 657                 if (!edev->d_attrs_muex) {
 658                         ret = -ENOMEM;
 659                         kfree(edev->attrs_muex);
 660                         goto err_muex;
 661                 }
 662
 663                 for (index = 0; edev->mutually_exclusive[index]; index++) {
 664                         sprintf(buf, "0x%x", edev->mutually_exclusive[index]);
 665                         name = kzalloc(sizeof(char) * (strlen(buf) + 1),
 666                                        GFP_KERNEL);
 667                         if (!name) {
 668                                 for (index--; index >= 0; index--) {
 669                                         kfree(edev->d_attrs_muex[index].attr.
 670                                               name);
 671                                 }
 672                                 kfree(edev->d_attrs_muex);
 673                                 kfree(edev->attrs_muex);
 674                                 ret = -ENOMEM;
 675                                 goto err_muex;
 676                         }
 677                         strcpy(name, buf);
 678                         sysfs_attr_init(&edev->d_attrs_muex[index].attr);
 679                         edev->d_attrs_muex[index].attr.name = name;
 680                         edev->d_attrs_muex[index].attr.mode = 0000;
 681                         edev->attrs_muex[index] = &edev->d_attrs_muex[index]
 682                                                         .attr;
 683                 }
 684                 edev->attr_g_muex.name = muex_name;
 685                 edev->attr_g_muex.attrs = edev->attrs_muex;
 686
 687         }
 688
 689         if (edev->max_supported) {
 690                 edev->extcon_dev_type.groups =
 691                         kzalloc(sizeof(struct attribute_group *) *
 692                                 (edev->max_supported + 2), GFP_KERNEL);
 693                 if (!edev->extcon_dev_type.groups) {
 694                         ret = -ENOMEM;
 695                         goto err_alloc_groups;
 696                 }
 697
 698                 edev->extcon_dev_type.name = dev_name(&edev->dev);
 699                 edev->extcon_dev_type.release = dummy_sysfs_dev_release;
 700
 701                 for (index = 0; index < edev->max_supported; index++)
 702                         edev->extcon_dev_type.groups[index] =
 703                                 &edev->cables[index].attr_g;
 704                 if (edev->mutually_exclusive)
 705                         edev->extcon_dev_type.groups[index] =
 706                                 &edev->attr_g_muex;
 707
 708                 edev->dev.type = &edev->extcon_dev_type;
 709         }
 710
 711         ret = device_register(&edev->dev);
 712         if (ret) {
 713                 put_device(&edev->dev);
 714                 goto err_dev;
 715         }
 716 #if defined(CONFIG_ANDROID)
 717         if (switch_class)
 718                 ret = class_compat_create_link(switch_class, &edev->dev, NULL);
 719 #endif /* CONFIG_ANDROID */
 720
 721         spin_lock_init(&edev->lock);
 722
 723         edev->nh = devm_kzalloc(&edev->dev,
 724                         sizeof(*edev->nh) * edev->max_supported, GFP_KERNEL);
 725         if (!edev->nh) {
 726                 ret = -ENOMEM;
 727                 goto err_dev;
 728         }
 729
 730         for (index = 0; index < edev->max_supported; index++)
 731                 RAW_INIT_NOTIFIER_HEAD(&edev->nh[index]);
 732
 733         dev_set_drvdata(&edev->dev, edev);
 734         edev->state = 0;
 735
 736         mutex_lock(&extcon_dev_list_lock);
 737         list_add(&edev->entry, &extcon_dev_list);
 738         mutex_unlock(&extcon_dev_list_lock);
 739
 740         return 0;
 741
 742 err_dev:
 743         if (edev->max_supported)
 744                 kfree(edev->extcon_dev_type.groups);
 745 err_alloc_groups:
 746         if (edev->max_supported && edev->mutually_exclusive) {
 747                 for (index = 0; edev->mutually_exclusive[index]; index++)
 748                         kfree(edev->d_attrs_muex[index].attr.name);
 749                 kfree(edev->d_attrs_muex);
 750                 kfree(edev->attrs_muex);
 751         }
 752 err_muex:
 753         for (index = 0; index < edev->max_supported; index++)
 754                 kfree(edev->cables[index].attr_g.name);
 755 err_alloc_cables:
 756         if (edev->max_supported)
 757                 kfree(edev->cables);
 758 err_sysfs_alloc:
 759         return ret;
 760 }
 761 EXPORT_SYMBOL_GPL(extcon_dev_register);
 762
 763 /**
 764  * extcon_dev_unregister() - Unregister the extcon device.
 765  * @edev:       the extcon device instance to be unregistered.
 766  *
 767  * Note that this does not call kfree(edev) because edev was not allocated
 768  * by this class.
 769  */
 770 void extcon_dev_unregister(struct extcon_dev *edev)
 771 {
 772         int index;
 773
 774         if (!edev)
 775                 return;
 776
 777         mutex_lock(&extcon_dev_list_lock);
 778         list_del(&edev->entry);
 779         mutex_unlock(&extcon_dev_list_lock);
 780
 781         if (IS_ERR_OR_NULL(get_device(&edev->dev))) {
 782                 dev_err(&edev->dev, "Failed to unregister extcon_dev (%s)\n",
 783                                 dev_name(&edev->dev));
 784                 return;
 785         }
 786
 787         device_unregister(&edev->dev);
 788
 789         if (edev->mutually_exclusive && edev->max_supported) {
 790                 for (index = 0; edev->mutually_exclusive[index];
 791                                 index++)
 792                         kfree(edev->d_attrs_muex[index].attr.name);
 793                 kfree(edev->d_attrs_muex);
 794                 kfree(edev->attrs_muex);
 795         }
 796
 797         for (index = 0; index < edev->max_supported; index++)
 798                 kfree(edev->cables[index].attr_g.name);
 799
 800         if (edev->max_supported) {
 801                 kfree(edev->extcon_dev_type.groups);
 802                 kfree(edev->cables);
 803         }
 804
 805 #if defined(CONFIG_ANDROID)
 806         if (switch_class)
 807                 class_compat_remove_link(switch_class, &edev->dev, NULL);
 808 #endif
 809         put_device(&edev->dev);
 810 }
 811 EXPORT_SYMBOL_GPL(extcon_dev_unregister);
 812
 813 #ifdef CONFIG_OF
 814 /*
 815  * extcon_get_edev_by_phandle - Get the extcon device from devicetree
 816  * @dev - instance to the given device
 817  * @index - index into list of extcon_dev
 818  *
 819  * return the instance of extcon device
 820  */
 821 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 822 {
 823         struct device_node *node;
 824         struct extcon_dev *edev;
 825
 826         if (!dev)
 827                 return ERR_PTR(-EINVAL);
 828
 829         if (!dev->of_node) {
 830                 dev_dbg(dev, "device does not have a device node entry\n");
 831                 return ERR_PTR(-EINVAL);
 832         }
 833
 834         node = of_parse_phandle(dev->of_node, "extcon", index);
 835         if (!node) {
 836                 dev_dbg(dev, "failed to get phandle in %s node\n",
 837                         dev->of_node->full_name);
 838                 return ERR_PTR(-ENODEV);
 839         }
 840
 841         mutex_lock(&extcon_dev_list_lock);
 842         list_for_each_entry(edev, &extcon_dev_list, entry) {
 843                 if (edev->dev.parent && edev->dev.parent->of_node == node) {
 844                         mutex_unlock(&extcon_dev_list_lock);
 845                         of_node_put(node);
 846                         return edev;
 847                 }
 848         }
 849         mutex_unlock(&extcon_dev_list_lock);
 850         of_node_put(node);
 851
 852         return ERR_PTR(-EPROBE_DEFER);
 853 }
 854 #else
 855 struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev, int index)
 856 {
 857         return ERR_PTR(-ENOSYS);
 858 }
 859 #endif /* CONFIG_OF */
 860 EXPORT_SYMBOL_GPL(extcon_get_edev_by_phandle);
 861
 862 /**
 863  * extcon_get_edev_name() - Get the name of the extcon device.
 864  * @edev:       the extcon device
 865  */
 866 const char *extcon_get_edev_name(struct extcon_dev *edev)
 867 {
 868         return !edev ? NULL : edev->name;
 869 }
 870
 871 static int __init extcon_class_init(void)
 872 {
 873         return create_extcon_class();
 874 }
 875 module_init(extcon_class_init);
 876
 877 static void __exit extcon_class_exit(void)
 878 {
 879 #if defined(CONFIG_ANDROID)
 880         class_compat_unregister(switch_class);
 881 #endif
 882         class_destroy(extcon_class);
 883 }
 884 module_exit(extcon_class_exit);
 885
 886 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
 887 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
 888 MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
 889 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 890 MODULE_DESCRIPTION("External connector (extcon) class driver");
 891 MODULE_LICENSE("GPL");