drivers/acpi/device_sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
   4  *
   5  * Copyright (C) 2015, Intel Corp.
   6  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   7  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   8  *
   9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  10  *
  11  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  12  */
  13
  14 #include <linux/acpi.h>
  15 #include <linux/device.h>
  16 #include <linux/export.h>
  17 #include <linux/nls.h>
  18
  19 #include "internal.h"
  20
  21 static ssize_t acpi_object_path(acpi_handle handle, char *buf)
  22 {
  23         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
  24         int result;
  25
  26         result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
  27         if (result)
  28                 return result;
  29
  30         result = sprintf(buf, "%s\n", (char *)path.pointer);
  31         kfree(path.pointer);
  32         return result;
  33 }
  34
  35 struct acpi_data_node_attr {
  36         struct attribute attr;
  37         ssize_t (*show)(struct acpi_data_node *, char *);
  38         ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
  39 };
  40
  41 #define DATA_NODE_ATTR(_name)                   \
  42         static struct acpi_data_node_attr data_node_##_name =   \
  43                 __ATTR(_name, 0444, data_node_show_##_name, NULL)
  44
  45 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
  46 {
  47         return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
  48 }
  49
  50 DATA_NODE_ATTR(path);
  51
  52 static struct attribute *acpi_data_node_default_attrs[] = {
  53         &data_node_path.attr,
  54         NULL
  55 };
  56
  57 #define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
  58 #define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
  59
  60 static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
  61                                         struct attribute *attr, char *buf)
  62 {
  63         struct acpi_data_node *dn = to_data_node(kobj);
  64         struct acpi_data_node_attr *dn_attr = to_attr(attr);
  65
  66         return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
  67 }
  68
  69 static const struct sysfs_ops acpi_data_node_sysfs_ops = {
  70         .show   = acpi_data_node_attr_show,
  71 };
  72
  73 static void acpi_data_node_release(struct kobject *kobj)
  74 {
  75         struct acpi_data_node *dn = to_data_node(kobj);
  76         complete(&dn->kobj_done);
  77 }
  78
  79 static struct kobj_type acpi_data_node_ktype = {
  80         .sysfs_ops = &acpi_data_node_sysfs_ops,
  81         .default_attrs = acpi_data_node_default_attrs,
  82         .release = acpi_data_node_release,
  83 };
  84
  85 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
  86                                         struct acpi_device_data *data)
  87 {
  88         struct list_head *list = &data->subnodes;
  89         struct acpi_data_node *dn;
  90
  91         if (list_empty(list))
  92                 return;
  93
  94         list_for_each_entry(dn, list, sibling) {
  95                 int ret;
  96
  97                 init_completion(&dn->kobj_done);
  98                 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
  99                                            kobj, "%s", dn->name);
 100                 if (!ret)
 101                         acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
 102                 else if (dn->handle)
 103                         acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
 104         }
 105 }
 106
 107 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
 108 {
 109         struct list_head *list = &data->subnodes;
 110         struct acpi_data_node *dn;
 111
 112         if (list_empty(list))
 113                 return;
 114
 115         list_for_each_entry_reverse(dn, list, sibling) {
 116                 acpi_hide_nondev_subnodes(&dn->data);
 117                 kobject_put(&dn->kobj);
 118         }
 119 }
 120
 121 /**
 122  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
 123  * @acpi_dev: ACPI device object.
 124  * @modalias: Buffer to print into.
 125  * @size: Size of the buffer.
 126  *
 127  * Creates hid/cid(s) string needed for modalias and uevent
 128  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 129  * char *modalias: "acpi:IBM0001:ACPI0001"
 130  * Return: 0: no _HID and no _CID
 131  *         -EINVAL: output error
 132  *         -ENOMEM: output is truncated
 133 */
 134 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
 135                                int size)
 136 {
 137         int len;
 138         int count;
 139         struct acpi_hardware_id *id;
 140
 141         /* Avoid unnecessarily loading modules for non present devices. */
 142         if (!acpi_device_is_present(acpi_dev))
 143                 return 0;
 144
 145         /*
 146          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 147          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 148          * device's list.
 149          */
 150         count = 0;
 151         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 152                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 153                         count++;
 154
 155         if (!count)
 156                 return 0;
 157
 158         len = snprintf(modalias, size, "acpi:");
 159         if (len <= 0)
 160                 return len;
 161
 162         size -= len;
 163
 164         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 165                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 166                         continue;
 167
 168                 count = snprintf(&modalias[len], size, "%s:", id->id);
 169                 if (count < 0)
 170                         return -EINVAL;
 171
 172                 if (count >= size)
 173                         return -ENOMEM;
 174
 175                 len += count;
 176                 size -= count;
 177         }
 178         modalias[len] = '\0';
 179         return len;
 180 }
 181
 182 /**
 183  * create_of_modalias - Creates DT compatible string for modalias and uevent
 184  * @acpi_dev: ACPI device object.
 185  * @modalias: Buffer to print into.
 186  * @size: Size of the buffer.
 187  *
 188  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 189  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 190  * ACPI/PNP IDs.
 191  */
 192 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 193                               int size)
 194 {
 195         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 196         const union acpi_object *of_compatible, *obj;
 197         acpi_status status;
 198         int len, count;
 199         int i, nval;
 200         char *c;
 201
 202         status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 203         if (ACPI_FAILURE(status))
 204                 return -ENODEV;
 205
 206         /* DT strings are all in lower case */
 207         for (c = buf.pointer; *c != '\0'; c++)
 208                 *c = tolower(*c);
 209
 210         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 211         ACPI_FREE(buf.pointer);
 212
 213         if (len <= 0)
 214                 return len;
 215
 216         of_compatible = acpi_dev->data.of_compatible;
 217         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 218                 nval = of_compatible->package.count;
 219                 obj = of_compatible->package.elements;
 220         } else { /* Must be ACPI_TYPE_STRING. */
 221                 nval = 1;
 222                 obj = of_compatible;
 223         }
 224         for (i = 0; i < nval; i++, obj++) {
 225                 count = snprintf(&modalias[len], size, "C%s",
 226                                  obj->string.pointer);
 227                 if (count < 0)
 228                         return -EINVAL;
 229
 230                 if (count >= size)
 231                         return -ENOMEM;
 232
 233                 len += count;
 234                 size -= count;
 235         }
 236         modalias[len] = '\0';
 237         return len;
 238 }
 239
 240 int __acpi_device_uevent_modalias(struct acpi_device *adev,
 241                                   struct kobj_uevent_env *env)
 242 {
 243         int len;
 244
 245         if (!adev)
 246                 return -ENODEV;
 247
 248         if (list_empty(&adev->pnp.ids))
 249                 return 0;
 250
 251         if (add_uevent_var(env, "MODALIAS="))
 252                 return -ENOMEM;
 253
 254         if (adev->data.of_compatible)
 255                 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 256                                          sizeof(env->buf) - env->buflen);
 257         else
 258                 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 259                                           sizeof(env->buf) - env->buflen);
 260         if (len < 0)
 261                 return len;
 262
 263         env->buflen += len;
 264
 265         return 0;
 266 }
 267
 268 /**
 269  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 270  *
 271  * Create the uevent modalias field for ACPI-enumerated devices.
 272  *
 273  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 274  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 275  */
 276 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 277 {
 278         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 279 }
 280 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 281
 282 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 283 {
 284         int len, count;
 285
 286         if (!adev)
 287                 return -ENODEV;
 288
 289         if (list_empty(&adev->pnp.ids))
 290                 return 0;
 291
 292         len = create_pnp_modalias(adev, buf, size - 1);
 293         if (len < 0) {
 294                 return len;
 295         } else if (len > 0) {
 296                 buf[len++] = '\n';
 297                 size -= len;
 298         }
 299         if (!adev->data.of_compatible)
 300                 return len;
 301
 302         count = create_of_modalias(adev, buf + len, size - 1);
 303         if (count < 0) {
 304                 return count;
 305         } else if (count > 0) {
 306                 len += count;
 307                 buf[len++] = '\n';
 308         }
 309
 310         return len;
 311 }
 312
 313 /**
 314  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 315  *
 316  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 317  *
 318  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 319  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 320  */
 321 int acpi_device_modalias(struct device *dev, char *buf, int size)
 322 {
 323         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 324 }
 325 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 326
 327 static ssize_t
 328 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 329 {
 330         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 331 }
 332 static DEVICE_ATTR_RO(modalias);
 333
 334 static ssize_t real_power_state_show(struct device *dev,
 335                                      struct device_attribute *attr, char *buf)
 336 {
 337         struct acpi_device *adev = to_acpi_device(dev);
 338         int state;
 339         int ret;
 340
 341         ret = acpi_device_get_power(adev, &state);
 342         if (ret)
 343                 return ret;
 344
 345         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 346 }
 347
 348 static DEVICE_ATTR_RO(real_power_state);
 349
 350 static ssize_t power_state_show(struct device *dev,
 351                                 struct device_attribute *attr, char *buf)
 352 {
 353         struct acpi_device *adev = to_acpi_device(dev);
 354
 355         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 356 }
 357
 358 static DEVICE_ATTR_RO(power_state);
 359
 360 static ssize_t
 361 eject_store(struct device *d, struct device_attribute *attr,
 362             const char *buf, size_t count)
 363 {
 364         struct acpi_device *acpi_device = to_acpi_device(d);
 365         acpi_object_type not_used;
 366         acpi_status status;
 367
 368         if (!count || buf[0] != '1')
 369                 return -EINVAL;
 370
 371         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 372             && !acpi_device->driver)
 373                 return -ENODEV;
 374
 375         status = acpi_get_type(acpi_device->handle, &not_used);
 376         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 377                 return -ENODEV;
 378
 379         get_device(&acpi_device->dev);
 380         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 381         if (ACPI_SUCCESS(status))
 382                 return count;
 383
 384         put_device(&acpi_device->dev);
 385         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 386                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 387         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 388 }
 389
 390 static DEVICE_ATTR_WO(eject);
 391
 392 static ssize_t
 393 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 394 {
 395         struct acpi_device *acpi_dev = to_acpi_device(dev);
 396
 397         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 398 }
 399 static DEVICE_ATTR_RO(hid);
 400
 401 static ssize_t uid_show(struct device *dev,
 402                         struct device_attribute *attr, char *buf)
 403 {
 404         struct acpi_device *acpi_dev = to_acpi_device(dev);
 405
 406         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 407 }
 408 static DEVICE_ATTR_RO(uid);
 409
 410 static ssize_t adr_show(struct device *dev,
 411                         struct device_attribute *attr, char *buf)
 412 {
 413         struct acpi_device *acpi_dev = to_acpi_device(dev);
 414
 415         if (acpi_dev->pnp.bus_address > U32_MAX)
 416                 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
 417         else
 418                 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
 419 }
 420 static DEVICE_ATTR_RO(adr);
 421
 422 static ssize_t path_show(struct device *dev,
 423                          struct device_attribute *attr, char *buf)
 424 {
 425         struct acpi_device *acpi_dev = to_acpi_device(dev);
 426
 427         return acpi_object_path(acpi_dev->handle, buf);
 428 }
 429 static DEVICE_ATTR_RO(path);
 430
 431 /* sysfs file that shows description text from the ACPI _STR method */
 432 static ssize_t description_show(struct device *dev,
 433                                 struct device_attribute *attr,
 434                                 char *buf) {
 435         struct acpi_device *acpi_dev = to_acpi_device(dev);
 436         int result;
 437
 438         if (acpi_dev->pnp.str_obj == NULL)
 439                 return 0;
 440
 441         /*
 442          * The _STR object contains a Unicode identifier for a device.
 443          * We need to convert to utf-8 so it can be displayed.
 444          */
 445         result = utf16s_to_utf8s(
 446                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 447                 acpi_dev->pnp.str_obj->buffer.length,
 448                 UTF16_LITTLE_ENDIAN, buf,
 449                 PAGE_SIZE);
 450
 451         buf[result++] = '\n';
 452
 453         return result;
 454 }
 455 static DEVICE_ATTR_RO(description);
 456
 457 static ssize_t
 458 sun_show(struct device *dev, struct device_attribute *attr,
 459          char *buf) {
 460         struct acpi_device *acpi_dev = to_acpi_device(dev);
 461         acpi_status status;
 462         unsigned long long sun;
 463
 464         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 465         if (ACPI_FAILURE(status))
 466                 return -EIO;
 467
 468         return sprintf(buf, "%llu\n", sun);
 469 }
 470 static DEVICE_ATTR_RO(sun);
 471
 472 static ssize_t
 473 hrv_show(struct device *dev, struct device_attribute *attr,
 474          char *buf) {
 475         struct acpi_device *acpi_dev = to_acpi_device(dev);
 476         acpi_status status;
 477         unsigned long long hrv;
 478
 479         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 480         if (ACPI_FAILURE(status))
 481                 return -EIO;
 482
 483         return sprintf(buf, "%llu\n", hrv);
 484 }
 485 static DEVICE_ATTR_RO(hrv);
 486
 487 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 488                                 char *buf) {
 489         struct acpi_device *acpi_dev = to_acpi_device(dev);
 490         acpi_status status;
 491         unsigned long long sta;
 492
 493         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 494         if (ACPI_FAILURE(status))
 495                 return -EIO;
 496
 497         return sprintf(buf, "%llu\n", sta);
 498 }
 499 static DEVICE_ATTR_RO(status);
 500
 501 /**
 502  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 503  * @dev: ACPI device object.
 504  */
 505 int acpi_device_setup_files(struct acpi_device *dev)
 506 {
 507         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 508         acpi_status status;
 509         int result = 0;
 510
 511         /*
 512          * Devices gotten from FADT don't have a "path" attribute
 513          */
 514         if (dev->handle) {
 515                 result = device_create_file(&dev->dev, &dev_attr_path);
 516                 if (result)
 517                         goto end;
 518         }
 519
 520         if (!list_empty(&dev->pnp.ids)) {
 521                 result = device_create_file(&dev->dev, &dev_attr_hid);
 522                 if (result)
 523                         goto end;
 524
 525                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 526                 if (result)
 527                         goto end;
 528         }
 529
 530         /*
 531          * If device has _STR, 'description' file is created
 532          */
 533         if (acpi_has_method(dev->handle, "_STR")) {
 534                 status = acpi_evaluate_object(dev->handle, "_STR",
 535                                         NULL, &buffer);
 536                 if (ACPI_FAILURE(status))
 537                         buffer.pointer = NULL;
 538                 dev->pnp.str_obj = buffer.pointer;
 539                 result = device_create_file(&dev->dev, &dev_attr_description);
 540                 if (result)
 541                         goto end;
 542         }
 543
 544         if (dev->pnp.type.bus_address)
 545                 result = device_create_file(&dev->dev, &dev_attr_adr);
 546         if (dev->pnp.unique_id)
 547                 result = device_create_file(&dev->dev, &dev_attr_uid);
 548
 549         if (acpi_has_method(dev->handle, "_SUN")) {
 550                 result = device_create_file(&dev->dev, &dev_attr_sun);
 551                 if (result)
 552                         goto end;
 553         }
 554
 555         if (acpi_has_method(dev->handle, "_HRV")) {
 556                 result = device_create_file(&dev->dev, &dev_attr_hrv);
 557                 if (result)
 558                         goto end;
 559         }
 560
 561         if (acpi_has_method(dev->handle, "_STA")) {
 562                 result = device_create_file(&dev->dev, &dev_attr_status);
 563                 if (result)
 564                         goto end;
 565         }
 566
 567         /*
 568          * If device has _EJ0, 'eject' file is created that is used to trigger
 569          * hot-removal function from userland.
 570          */
 571         if (acpi_has_method(dev->handle, "_EJ0")) {
 572                 result = device_create_file(&dev->dev, &dev_attr_eject);
 573                 if (result)
 574                         return result;
 575         }
 576
 577         if (dev->flags.power_manageable) {
 578                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 579                 if (result)
 580                         return result;
 581
 582                 if (dev->power.flags.power_resources)
 583                         result = device_create_file(&dev->dev,
 584                                                     &dev_attr_real_power_state);
 585         }
 586
 587         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 588
 589 end:
 590         return result;
 591 }
 592
 593 /**
 594  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 595  * @dev: ACPI device object.
 596  */
 597 void acpi_device_remove_files(struct acpi_device *dev)
 598 {
 599         acpi_hide_nondev_subnodes(&dev->data);
 600
 601         if (dev->flags.power_manageable) {
 602                 device_remove_file(&dev->dev, &dev_attr_power_state);
 603                 if (dev->power.flags.power_resources)
 604                         device_remove_file(&dev->dev,
 605                                            &dev_attr_real_power_state);
 606         }
 607
 608         /*
 609          * If device has _STR, remove 'description' file
 610          */
 611         if (acpi_has_method(dev->handle, "_STR")) {
 612                 kfree(dev->pnp.str_obj);
 613                 device_remove_file(&dev->dev, &dev_attr_description);
 614         }
 615         /*
 616          * If device has _EJ0, remove 'eject' file.
 617          */
 618         if (acpi_has_method(dev->handle, "_EJ0"))
 619                 device_remove_file(&dev->dev, &dev_attr_eject);
 620
 621         if (acpi_has_method(dev->handle, "_SUN"))
 622                 device_remove_file(&dev->dev, &dev_attr_sun);
 623
 624         if (acpi_has_method(dev->handle, "_HRV"))
 625                 device_remove_file(&dev->dev, &dev_attr_hrv);
 626
 627         if (dev->pnp.unique_id)
 628                 device_remove_file(&dev->dev, &dev_attr_uid);
 629         if (dev->pnp.type.bus_address)
 630                 device_remove_file(&dev->dev, &dev_attr_adr);
 631         device_remove_file(&dev->dev, &dev_attr_modalias);
 632         device_remove_file(&dev->dev, &dev_attr_hid);
 633         if (acpi_has_method(dev->handle, "_STA"))
 634                 device_remove_file(&dev->dev, &dev_attr_status);
 635         if (dev->handle)
 636                 device_remove_file(&dev->dev, &dev_attr_path);
 637 }