drivers/acpi/device_sysfs.c

   1 /*
   2  * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
   3  *
   4  * Copyright (C) 2015, Intel Corp.
   5  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   6  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2 as published
  12  *  by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  20  */
  21
  22 #include <linux/acpi.h>
  23 #include <linux/device.h>
  24 #include <linux/export.h>
  25 #include <linux/nls.h>
  26
  27 #include "internal.h"
  28
  29 static ssize_t acpi_object_path(acpi_handle handle, char *buf)
  30 {
  31         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
  32         int result;
  33
  34         result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
  35         if (result)
  36                 return result;
  37
  38         result = sprintf(buf, "%s\n", (char*)path.pointer);
  39         kfree(path.pointer);
  40         return result;
  41 }
  42
  43 struct acpi_data_node_attr {
  44         struct attribute attr;
  45         ssize_t (*show)(struct acpi_data_node *, char *);
  46         ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
  47 };
  48
  49 #define DATA_NODE_ATTR(_name)                   \
  50         static struct acpi_data_node_attr data_node_##_name =   \
  51                 __ATTR(_name, 0444, data_node_show_##_name, NULL)
  52
  53 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
  54 {
  55         return acpi_object_path(dn->handle, buf);
  56 }
  57
  58 DATA_NODE_ATTR(path);
  59
  60 static struct attribute *acpi_data_node_default_attrs[] = {
  61         &data_node_path.attr,
  62         NULL
  63 };
  64
  65 #define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
  66 #define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
  67
  68 static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
  69                                         struct attribute *attr, char *buf)
  70 {
  71         struct acpi_data_node *dn = to_data_node(kobj);
  72         struct acpi_data_node_attr *dn_attr = to_attr(attr);
  73
  74         return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
  75 }
  76
  77 static const struct sysfs_ops acpi_data_node_sysfs_ops = {
  78         .show   = acpi_data_node_attr_show,
  79 };
  80
  81 static void acpi_data_node_release(struct kobject *kobj)
  82 {
  83         struct acpi_data_node *dn = to_data_node(kobj);
  84         complete(&dn->kobj_done);
  85 }
  86
  87 static struct kobj_type acpi_data_node_ktype = {
  88         .sysfs_ops = &acpi_data_node_sysfs_ops,
  89         .default_attrs = acpi_data_node_default_attrs,
  90         .release = acpi_data_node_release,
  91 };
  92
  93 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
  94                                         struct acpi_device_data *data)
  95 {
  96         struct list_head *list = &data->subnodes;
  97         struct acpi_data_node *dn;
  98
  99         if (list_empty(list))
 100                 return;
 101
 102         list_for_each_entry(dn, list, sibling) {
 103                 int ret;
 104
 105                 init_completion(&dn->kobj_done);
 106                 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
 107                                            kobj, "%s", dn->name);
 108                 if (ret)
 109                         acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
 110                 else
 111                         acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
 112         }
 113 }
 114
 115 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
 116 {
 117         struct list_head *list = &data->subnodes;
 118         struct acpi_data_node *dn;
 119
 120         if (list_empty(list))
 121                 return;
 122
 123         list_for_each_entry_reverse(dn, list, sibling) {
 124                 acpi_hide_nondev_subnodes(&dn->data);
 125                 kobject_put(&dn->kobj);
 126         }
 127 }
 128
 129 /**
 130  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
 131  * @acpi_dev: ACPI device object.
 132  * @modalias: Buffer to print into.
 133  * @size: Size of the buffer.
 134  *
 135  * Creates hid/cid(s) string needed for modalias and uevent
 136  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 137  * char *modalias: "acpi:IBM0001:ACPI0001"
 138  * Return: 0: no _HID and no _CID
 139  *         -EINVAL: output error
 140  *         -ENOMEM: output is truncated
 141 */
 142 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
 143                                int size)
 144 {
 145         int len;
 146         int count;
 147         struct acpi_hardware_id *id;
 148
 149         /* Avoid unnecessarily loading modules for non present devices. */
 150         if (!acpi_device_is_present(acpi_dev))
 151                 return 0;
 152
 153         /*
 154          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 155          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 156          * device's list.
 157          */
 158         count = 0;
 159         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 160                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 161                         count++;
 162
 163         if (!count)
 164                 return 0;
 165
 166         len = snprintf(modalias, size, "acpi:");
 167         if (len <= 0)
 168                 return len;
 169
 170         size -= len;
 171
 172         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 173                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 174                         continue;
 175
 176                 count = snprintf(&modalias[len], size, "%s:", id->id);
 177                 if (count < 0)
 178                         return -EINVAL;
 179
 180                 if (count >= size)
 181                         return -ENOMEM;
 182
 183                 len += count;
 184                 size -= count;
 185         }
 186         modalias[len] = '\0';
 187         return len;
 188 }
 189
 190 /**
 191  * create_of_modalias - Creates DT compatible string for modalias and uevent
 192  * @acpi_dev: ACPI device object.
 193  * @modalias: Buffer to print into.
 194  * @size: Size of the buffer.
 195  *
 196  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 197  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 198  * ACPI/PNP IDs.
 199  */
 200 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 201                               int size)
 202 {
 203         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 204         const union acpi_object *of_compatible, *obj;
 205         acpi_status status;
 206         int len, count;
 207         int i, nval;
 208         char *c;
 209
 210         status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 211         if (ACPI_FAILURE(status))
 212                 return -ENODEV;
 213
 214         /* DT strings are all in lower case */
 215         for (c = buf.pointer; *c != '\0'; c++)
 216                 *c = tolower(*c);
 217
 218         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 219         ACPI_FREE(buf.pointer);
 220
 221         if (len <= 0)
 222                 return len;
 223
 224         of_compatible = acpi_dev->data.of_compatible;
 225         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 226                 nval = of_compatible->package.count;
 227                 obj = of_compatible->package.elements;
 228         } else { /* Must be ACPI_TYPE_STRING. */
 229                 nval = 1;
 230                 obj = of_compatible;
 231         }
 232         for (i = 0; i < nval; i++, obj++) {
 233                 count = snprintf(&modalias[len], size, "C%s",
 234                                  obj->string.pointer);
 235                 if (count < 0)
 236                         return -EINVAL;
 237
 238                 if (count >= size)
 239                         return -ENOMEM;
 240
 241                 len += count;
 242                 size -= count;
 243         }
 244         modalias[len] = '\0';
 245         return len;
 246 }
 247
 248 int __acpi_device_uevent_modalias(struct acpi_device *adev,
 249                                   struct kobj_uevent_env *env)
 250 {
 251         int len;
 252
 253         if (!adev)
 254                 return -ENODEV;
 255
 256         if (list_empty(&adev->pnp.ids))
 257                 return 0;
 258
 259         if (add_uevent_var(env, "MODALIAS="))
 260                 return -ENOMEM;
 261
 262         if (adev->data.of_compatible)
 263                 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 264                                          sizeof(env->buf) - env->buflen);
 265         else
 266                 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 267                                           sizeof(env->buf) - env->buflen);
 268         if (len < 0)
 269                 return len;
 270
 271         env->buflen += len;
 272
 273         return 0;
 274 }
 275
 276 /**
 277  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 278  *
 279  * Create the uevent modalias field for ACPI-enumerated devices.
 280  *
 281  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 282  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 283  */
 284 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 285 {
 286         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 287 }
 288 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 289
 290 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 291 {
 292         int len, count;
 293
 294         if (!adev)
 295                 return -ENODEV;
 296
 297         if (list_empty(&adev->pnp.ids))
 298                 return 0;
 299
 300         len = create_pnp_modalias(adev, buf, size - 1);
 301         if (len < 0) {
 302                 return len;
 303         } else if (len > 0) {
 304                 buf[len++] = '\n';
 305                 size -= len;
 306         }
 307         if (!adev->data.of_compatible)
 308                 return len;
 309
 310         count = create_of_modalias(adev, buf + len, size - 1);
 311         if (count < 0) {
 312                 return count;
 313         } else if (count > 0) {
 314                 len += count;
 315                 buf[len++] = '\n';
 316         }
 317
 318         return len;
 319 }
 320
 321 /**
 322  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 323  *
 324  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 325  *
 326  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 327  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 328  */
 329 int acpi_device_modalias(struct device *dev, char *buf, int size)
 330 {
 331         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 332 }
 333 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 334
 335 static ssize_t
 336 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 337         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 338 }
 339 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 340
 341 static ssize_t real_power_state_show(struct device *dev,
 342                                      struct device_attribute *attr, char *buf)
 343 {
 344         struct acpi_device *adev = to_acpi_device(dev);
 345         int state;
 346         int ret;
 347
 348         ret = acpi_device_get_power(adev, &state);
 349         if (ret)
 350                 return ret;
 351
 352         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 353 }
 354
 355 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 356
 357 static ssize_t power_state_show(struct device *dev,
 358                                 struct device_attribute *attr, char *buf)
 359 {
 360         struct acpi_device *adev = to_acpi_device(dev);
 361
 362         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 363 }
 364
 365 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 366
 367 static ssize_t
 368 acpi_eject_store(struct device *d, struct device_attribute *attr,
 369                 const char *buf, size_t count)
 370 {
 371         struct acpi_device *acpi_device = to_acpi_device(d);
 372         acpi_object_type not_used;
 373         acpi_status status;
 374
 375         if (!count || buf[0] != '1')
 376                 return -EINVAL;
 377
 378         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 379             && !acpi_device->driver)
 380                 return -ENODEV;
 381
 382         status = acpi_get_type(acpi_device->handle, &not_used);
 383         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 384                 return -ENODEV;
 385
 386         get_device(&acpi_device->dev);
 387         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 388         if (ACPI_SUCCESS(status))
 389                 return count;
 390
 391         put_device(&acpi_device->dev);
 392         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 393                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 394         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 395 }
 396
 397 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 398
 399 static ssize_t
 400 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 401         struct acpi_device *acpi_dev = to_acpi_device(dev);
 402
 403         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 404 }
 405 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 406
 407 static ssize_t acpi_device_uid_show(struct device *dev,
 408                                     struct device_attribute *attr, char *buf)
 409 {
 410         struct acpi_device *acpi_dev = to_acpi_device(dev);
 411
 412         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 413 }
 414 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 415
 416 static ssize_t acpi_device_adr_show(struct device *dev,
 417                                     struct device_attribute *attr, char *buf)
 418 {
 419         struct acpi_device *acpi_dev = to_acpi_device(dev);
 420
 421         return sprintf(buf, "0x%08x\n",
 422                        (unsigned int)(acpi_dev->pnp.bus_address));
 423 }
 424 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 425
 426 static ssize_t acpi_device_path_show(struct device *dev,
 427                                      struct device_attribute *attr, char *buf)
 428 {
 429         struct acpi_device *acpi_dev = to_acpi_device(dev);
 430
 431         return acpi_object_path(acpi_dev->handle, buf);
 432 }
 433 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 434
 435 /* sysfs file that shows description text from the ACPI _STR method */
 436 static ssize_t description_show(struct device *dev,
 437                                 struct device_attribute *attr,
 438                                 char *buf) {
 439         struct acpi_device *acpi_dev = to_acpi_device(dev);
 440         int result;
 441
 442         if (acpi_dev->pnp.str_obj == NULL)
 443                 return 0;
 444
 445         /*
 446          * The _STR object contains a Unicode identifier for a device.
 447          * We need to convert to utf-8 so it can be displayed.
 448          */
 449         result = utf16s_to_utf8s(
 450                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 451                 acpi_dev->pnp.str_obj->buffer.length,
 452                 UTF16_LITTLE_ENDIAN, buf,
 453                 PAGE_SIZE - 1);
 454
 455         buf[result++] = '\n';
 456
 457         return result;
 458 }
 459 static DEVICE_ATTR(description, 0444, description_show, NULL);
 460
 461 static ssize_t
 462 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 463                      char *buf) {
 464         struct acpi_device *acpi_dev = to_acpi_device(dev);
 465         acpi_status status;
 466         unsigned long long sun;
 467
 468         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 469         if (ACPI_FAILURE(status))
 470                 return -ENODEV;
 471
 472         return sprintf(buf, "%llu\n", sun);
 473 }
 474 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 475
 476 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 477                                 char *buf) {
 478         struct acpi_device *acpi_dev = to_acpi_device(dev);
 479         acpi_status status;
 480         unsigned long long sta;
 481
 482         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 483         if (ACPI_FAILURE(status))
 484                 return -ENODEV;
 485
 486         return sprintf(buf, "%llu\n", sta);
 487 }
 488 static DEVICE_ATTR_RO(status);
 489
 490 /**
 491  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 492  * @dev: ACPI device object.
 493  */
 494 int acpi_device_setup_files(struct acpi_device *dev)
 495 {
 496         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 497         acpi_status status;
 498         int result = 0;
 499
 500         /*
 501          * Devices gotten from FADT don't have a "path" attribute
 502          */
 503         if (dev->handle) {
 504                 result = device_create_file(&dev->dev, &dev_attr_path);
 505                 if (result)
 506                         goto end;
 507         }
 508
 509         if (!list_empty(&dev->pnp.ids)) {
 510                 result = device_create_file(&dev->dev, &dev_attr_hid);
 511                 if (result)
 512                         goto end;
 513
 514                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 515                 if (result)
 516                         goto end;
 517         }
 518
 519         /*
 520          * If device has _STR, 'description' file is created
 521          */
 522         if (acpi_has_method(dev->handle, "_STR")) {
 523                 status = acpi_evaluate_object(dev->handle, "_STR",
 524                                         NULL, &buffer);
 525                 if (ACPI_FAILURE(status))
 526                         buffer.pointer = NULL;
 527                 dev->pnp.str_obj = buffer.pointer;
 528                 result = device_create_file(&dev->dev, &dev_attr_description);
 529                 if (result)
 530                         goto end;
 531         }
 532
 533         if (dev->pnp.type.bus_address)
 534                 result = device_create_file(&dev->dev, &dev_attr_adr);
 535         if (dev->pnp.unique_id)
 536                 result = device_create_file(&dev->dev, &dev_attr_uid);
 537
 538         if (acpi_has_method(dev->handle, "_SUN")) {
 539                 result = device_create_file(&dev->dev, &dev_attr_sun);
 540                 if (result)
 541                         goto end;
 542         }
 543
 544         if (acpi_has_method(dev->handle, "_STA")) {
 545                 result = device_create_file(&dev->dev, &dev_attr_status);
 546                 if (result)
 547                         goto end;
 548         }
 549
 550         /*
 551          * If device has _EJ0, 'eject' file is created that is used to trigger
 552          * hot-removal function from userland.
 553          */
 554         if (acpi_has_method(dev->handle, "_EJ0")) {
 555                 result = device_create_file(&dev->dev, &dev_attr_eject);
 556                 if (result)
 557                         return result;
 558         }
 559
 560         if (dev->flags.power_manageable) {
 561                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 562                 if (result)
 563                         return result;
 564
 565                 if (dev->power.flags.power_resources)
 566                         result = device_create_file(&dev->dev,
 567                                                     &dev_attr_real_power_state);
 568         }
 569
 570         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 571
 572 end:
 573         return result;
 574 }
 575
 576 /**
 577  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 578  * @dev: ACPI device object.
 579  */
 580 void acpi_device_remove_files(struct acpi_device *dev)
 581 {
 582         acpi_hide_nondev_subnodes(&dev->data);
 583
 584         if (dev->flags.power_manageable) {
 585                 device_remove_file(&dev->dev, &dev_attr_power_state);
 586                 if (dev->power.flags.power_resources)
 587                         device_remove_file(&dev->dev,
 588                                            &dev_attr_real_power_state);
 589         }
 590
 591         /*
 592          * If device has _STR, remove 'description' file
 593          */
 594         if (acpi_has_method(dev->handle, "_STR")) {
 595                 kfree(dev->pnp.str_obj);
 596                 device_remove_file(&dev->dev, &dev_attr_description);
 597         }
 598         /*
 599          * If device has _EJ0, remove 'eject' file.
 600          */
 601         if (acpi_has_method(dev->handle, "_EJ0"))
 602                 device_remove_file(&dev->dev, &dev_attr_eject);
 603
 604         if (acpi_has_method(dev->handle, "_SUN"))
 605                 device_remove_file(&dev->dev, &dev_attr_sun);
 606
 607         if (dev->pnp.unique_id)
 608                 device_remove_file(&dev->dev, &dev_attr_uid);
 609         if (dev->pnp.type.bus_address)
 610                 device_remove_file(&dev->dev, &dev_attr_adr);
 611         device_remove_file(&dev->dev, &dev_attr_modalias);
 612         device_remove_file(&dev->dev, &dev_attr_hid);
 613         if (acpi_has_method(dev->handle, "_STA"))
 614                 device_remove_file(&dev->dev, &dev_attr_status);
 615         if (dev->handle)
 616                 device_remove_file(&dev->dev, &dev_attr_path);
 617 }