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 <[email protected]>
   7  * Author: Rafael J. Wysocki <[email protected]>
   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
  77         complete(&dn->kobj_done);
  78 }
  79
  80 static struct kobj_type acpi_data_node_ktype = {
  81         .sysfs_ops = &acpi_data_node_sysfs_ops,
  82         .default_attrs = acpi_data_node_default_attrs,
  83         .release = acpi_data_node_release,
  84 };
  85
  86 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
  87                                         struct acpi_device_data *data)
  88 {
  89         struct list_head *list = &data->subnodes;
  90         struct acpi_data_node *dn;
  91
  92         if (list_empty(list))
  93                 return;
  94
  95         list_for_each_entry(dn, list, sibling) {
  96                 int ret;
  97
  98                 init_completion(&dn->kobj_done);
  99                 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
 100                                            kobj, "%s", dn->name);
 101                 if (!ret)
 102                         acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
 103                 else if (dn->handle)
 104                         acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
 105         }
 106 }
 107
 108 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
 109 {
 110         struct list_head *list = &data->subnodes;
 111         struct acpi_data_node *dn;
 112
 113         if (list_empty(list))
 114                 return;
 115
 116         list_for_each_entry_reverse(dn, list, sibling) {
 117                 acpi_hide_nondev_subnodes(&dn->data);
 118                 kobject_put(&dn->kobj);
 119         }
 120 }
 121
 122 /**
 123  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
 124  * @acpi_dev: ACPI device object.
 125  * @modalias: Buffer to print into.
 126  * @size: Size of the buffer.
 127  *
 128  * Creates hid/cid(s) string needed for modalias and uevent
 129  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 130  * char *modalias: "acpi:IBM0001:ACPI0001"
 131  * Return: 0: no _HID and no _CID
 132  *         -EINVAL: output error
 133  *         -ENOMEM: output is truncated
 134  */
 135 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
 136                                int size)
 137 {
 138         int len;
 139         int count;
 140         struct acpi_hardware_id *id;
 141
 142         /* Avoid unnecessarily loading modules for non present devices. */
 143         if (!acpi_device_is_present(acpi_dev))
 144                 return 0;
 145
 146         /*
 147          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 148          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 149          * device's list.
 150          */
 151         count = 0;
 152         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 153                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 154                         count++;
 155
 156         if (!count)
 157                 return 0;
 158
 159         len = snprintf(modalias, size, "acpi:");
 160         if (len <= 0)
 161                 return len;
 162
 163         size -= len;
 164
 165         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 166                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 167                         continue;
 168
 169                 count = snprintf(&modalias[len], size, "%s:", id->id);
 170                 if (count < 0)
 171                         return -EINVAL;
 172
 173                 if (count >= size)
 174                         return -ENOMEM;
 175
 176                 len += count;
 177                 size -= count;
 178         }
 179         modalias[len] = '\0';
 180         return len;
 181 }
 182
 183 /**
 184  * create_of_modalias - Creates DT compatible string for modalias and uevent
 185  * @acpi_dev: ACPI device object.
 186  * @modalias: Buffer to print into.
 187  * @size: Size of the buffer.
 188  *
 189  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 190  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 191  * ACPI/PNP IDs.
 192  */
 193 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 194                               int size)
 195 {
 196         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 197         const union acpi_object *of_compatible, *obj;
 198         acpi_status status;
 199         int len, count;
 200         int i, nval;
 201         char *c;
 202
 203         status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 204         if (ACPI_FAILURE(status))
 205                 return -ENODEV;
 206
 207         /* DT strings are all in lower case */
 208         for (c = buf.pointer; *c != '\0'; c++)
 209                 *c = tolower(*c);
 210
 211         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 212         ACPI_FREE(buf.pointer);
 213
 214         if (len <= 0)
 215                 return len;
 216
 217         of_compatible = acpi_dev->data.of_compatible;
 218         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 219                 nval = of_compatible->package.count;
 220                 obj = of_compatible->package.elements;
 221         } else { /* Must be ACPI_TYPE_STRING. */
 222                 nval = 1;
 223                 obj = of_compatible;
 224         }
 225         for (i = 0; i < nval; i++, obj++) {
 226                 count = snprintf(&modalias[len], size, "C%s",
 227                                  obj->string.pointer);
 228                 if (count < 0)
 229                         return -EINVAL;
 230
 231                 if (count >= size)
 232                         return -ENOMEM;
 233
 234                 len += count;
 235                 size -= count;
 236         }
 237         modalias[len] = '\0';
 238         return len;
 239 }
 240
 241 int __acpi_device_uevent_modalias(struct acpi_device *adev,
 242                                   struct kobj_uevent_env *env)
 243 {
 244         int len;
 245
 246         if (!adev)
 247                 return -ENODEV;
 248
 249         if (list_empty(&adev->pnp.ids))
 250                 return 0;
 251
 252         if (add_uevent_var(env, "MODALIAS="))
 253                 return -ENOMEM;
 254
 255         if (adev->data.of_compatible)
 256                 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 257                                          sizeof(env->buf) - env->buflen);
 258         else
 259                 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 260                                           sizeof(env->buf) - env->buflen);
 261         if (len < 0)
 262                 return len;
 263
 264         env->buflen += len;
 265
 266         return 0;
 267 }
 268
 269 /**
 270  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 271  * @dev: Struct device to get ACPI device node.
 272  * @env: Environment variables of the kobject uevent.
 273  *
 274  * Create the uevent modalias field for ACPI-enumerated devices.
 275  *
 276  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 277  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 278  */
 279 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 280 {
 281         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 282 }
 283 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 284
 285 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 286 {
 287         int len, count;
 288
 289         if (!adev)
 290                 return -ENODEV;
 291
 292         if (list_empty(&adev->pnp.ids))
 293                 return 0;
 294
 295         len = create_pnp_modalias(adev, buf, size - 1);
 296         if (len < 0) {
 297                 return len;
 298         } else if (len > 0) {
 299                 buf[len++] = '\n';
 300                 size -= len;
 301         }
 302         if (!adev->data.of_compatible)
 303                 return len;
 304
 305         count = create_of_modalias(adev, buf + len, size - 1);
 306         if (count < 0) {
 307                 return count;
 308         } else if (count > 0) {
 309                 len += count;
 310                 buf[len++] = '\n';
 311         }
 312
 313         return len;
 314 }
 315
 316 /**
 317  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 318  * @dev: Struct device to get ACPI device node.
 319  * @buf: The buffer to save pnp_modalias and of_modalias.
 320  * @size: Size of buffer.
 321  *
 322  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 323  *
 324  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 325  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 326  */
 327 int acpi_device_modalias(struct device *dev, char *buf, int size)
 328 {
 329         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 330 }
 331 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 332
 333 static ssize_t
 334 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 335 {
 336         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 337 }
 338 static DEVICE_ATTR_RO(modalias);
 339
 340 static ssize_t real_power_state_show(struct device *dev,
 341                                      struct device_attribute *attr, char *buf)
 342 {
 343         struct acpi_device *adev = to_acpi_device(dev);
 344         int state;
 345         int ret;
 346
 347         ret = acpi_device_get_power(adev, &state);
 348         if (ret)
 349                 return ret;
 350
 351         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 352 }
 353
 354 static DEVICE_ATTR_RO(real_power_state);
 355
 356 static ssize_t power_state_show(struct device *dev,
 357                                 struct device_attribute *attr, char *buf)
 358 {
 359         struct acpi_device *adev = to_acpi_device(dev);
 360
 361         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 362 }
 363
 364 static DEVICE_ATTR_RO(power_state);
 365
 366 static ssize_t
 367 eject_store(struct device *d, struct device_attribute *attr,
 368             const char *buf, size_t count)
 369 {
 370         struct acpi_device *acpi_device = to_acpi_device(d);
 371         acpi_object_type not_used;
 372         acpi_status status;
 373
 374         if (!count || buf[0] != '1')
 375                 return -EINVAL;
 376
 377         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 378             && !acpi_device->driver)
 379                 return -ENODEV;
 380
 381         status = acpi_get_type(acpi_device->handle, &not_used);
 382         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 383                 return -ENODEV;
 384
 385         acpi_dev_get(acpi_device);
 386         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 387         if (ACPI_SUCCESS(status))
 388                 return count;
 389
 390         acpi_dev_put(acpi_device);
 391         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 392                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 393         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 394 }
 395
 396 static DEVICE_ATTR_WO(eject);
 397
 398 static ssize_t
 399 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 400 {
 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_RO(hid);
 406
 407 static ssize_t 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_RO(uid);
 415
 416 static ssize_t 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         if (acpi_dev->pnp.bus_address > U32_MAX)
 422                 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
 423         else
 424                 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
 425 }
 426 static DEVICE_ATTR_RO(adr);
 427
 428 static ssize_t path_show(struct device *dev,
 429                          struct device_attribute *attr, char *buf)
 430 {
 431         struct acpi_device *acpi_dev = to_acpi_device(dev);
 432
 433         return acpi_object_path(acpi_dev->handle, buf);
 434 }
 435 static DEVICE_ATTR_RO(path);
 436
 437 /* sysfs file that shows description text from the ACPI _STR method */
 438 static ssize_t description_show(struct device *dev,
 439                                 struct device_attribute *attr,
 440                                 char *buf)
 441 {
 442         struct acpi_device *acpi_dev = to_acpi_device(dev);
 443         int result;
 444
 445         if (acpi_dev->pnp.str_obj == NULL)
 446                 return 0;
 447
 448         /*
 449          * The _STR object contains a Unicode identifier for a device.
 450          * We need to convert to utf-8 so it can be displayed.
 451          */
 452         result = utf16s_to_utf8s(
 453                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 454                 acpi_dev->pnp.str_obj->buffer.length,
 455                 UTF16_LITTLE_ENDIAN, buf,
 456                 PAGE_SIZE - 1);
 457
 458         buf[result++] = '\n';
 459
 460         return result;
 461 }
 462 static DEVICE_ATTR_RO(description);
 463
 464 static ssize_t
 465 sun_show(struct device *dev, struct device_attribute *attr,
 466          char *buf)
 467 {
 468         struct acpi_device *acpi_dev = to_acpi_device(dev);
 469         acpi_status status;
 470         unsigned long long sun;
 471
 472         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 473         if (ACPI_FAILURE(status))
 474                 return -EIO;
 475
 476         return sprintf(buf, "%llu\n", sun);
 477 }
 478 static DEVICE_ATTR_RO(sun);
 479
 480 static ssize_t
 481 hrv_show(struct device *dev, struct device_attribute *attr,
 482          char *buf)
 483 {
 484         struct acpi_device *acpi_dev = to_acpi_device(dev);
 485         acpi_status status;
 486         unsigned long long hrv;
 487
 488         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 489         if (ACPI_FAILURE(status))
 490                 return -EIO;
 491
 492         return sprintf(buf, "%llu\n", hrv);
 493 }
 494 static DEVICE_ATTR_RO(hrv);
 495
 496 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 497                                 char *buf)
 498 {
 499         struct acpi_device *acpi_dev = to_acpi_device(dev);
 500         acpi_status status;
 501         unsigned long long sta;
 502
 503         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 504         if (ACPI_FAILURE(status))
 505                 return -EIO;
 506
 507         return sprintf(buf, "%llu\n", sta);
 508 }
 509 static DEVICE_ATTR_RO(status);
 510
 511 /**
 512  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 513  * @dev: ACPI device object.
 514  */
 515 int acpi_device_setup_files(struct acpi_device *dev)
 516 {
 517         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 518         acpi_status status;
 519         int result = 0;
 520
 521         /*
 522          * Devices gotten from FADT don't have a "path" attribute
 523          */
 524         if (dev->handle) {
 525                 result = device_create_file(&dev->dev, &dev_attr_path);
 526                 if (result)
 527                         goto end;
 528         }
 529
 530         if (!list_empty(&dev->pnp.ids)) {
 531                 result = device_create_file(&dev->dev, &dev_attr_hid);
 532                 if (result)
 533                         goto end;
 534
 535                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 536                 if (result)
 537                         goto end;
 538         }
 539
 540         /*
 541          * If device has _STR, 'description' file is created
 542          */
 543         if (acpi_has_method(dev->handle, "_STR")) {
 544                 status = acpi_evaluate_object(dev->handle, "_STR",
 545                                         NULL, &buffer);
 546                 if (ACPI_FAILURE(status))
 547                         buffer.pointer = NULL;
 548                 dev->pnp.str_obj = buffer.pointer;
 549                 result = device_create_file(&dev->dev, &dev_attr_description);
 550                 if (result)
 551                         goto end;
 552         }
 553
 554         if (dev->pnp.type.bus_address)
 555                 result = device_create_file(&dev->dev, &dev_attr_adr);
 556         if (dev->pnp.unique_id)
 557                 result = device_create_file(&dev->dev, &dev_attr_uid);
 558
 559         if (acpi_has_method(dev->handle, "_SUN")) {
 560                 result = device_create_file(&dev->dev, &dev_attr_sun);
 561                 if (result)
 562                         goto end;
 563         }
 564
 565         if (acpi_has_method(dev->handle, "_HRV")) {
 566                 result = device_create_file(&dev->dev, &dev_attr_hrv);
 567                 if (result)
 568                         goto end;
 569         }
 570
 571         if (acpi_has_method(dev->handle, "_STA")) {
 572                 result = device_create_file(&dev->dev, &dev_attr_status);
 573                 if (result)
 574                         goto end;
 575         }
 576
 577         /*
 578          * If device has _EJ0, 'eject' file is created that is used to trigger
 579          * hot-removal function from userland.
 580          */
 581         if (acpi_has_method(dev->handle, "_EJ0")) {
 582                 result = device_create_file(&dev->dev, &dev_attr_eject);
 583                 if (result)
 584                         return result;
 585         }
 586
 587         if (dev->flags.power_manageable) {
 588                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 589                 if (result)
 590                         return result;
 591
 592                 if (dev->power.flags.power_resources)
 593                         result = device_create_file(&dev->dev,
 594                                                     &dev_attr_real_power_state);
 595         }
 596
 597         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 598
 599 end:
 600         return result;
 601 }
 602
 603 /**
 604  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 605  * @dev: ACPI device object.
 606  */
 607 void acpi_device_remove_files(struct acpi_device *dev)
 608 {
 609         acpi_hide_nondev_subnodes(&dev->data);
 610
 611         if (dev->flags.power_manageable) {
 612                 device_remove_file(&dev->dev, &dev_attr_power_state);
 613                 if (dev->power.flags.power_resources)
 614                         device_remove_file(&dev->dev,
 615                                            &dev_attr_real_power_state);
 616         }
 617
 618         /*
 619          * If device has _STR, remove 'description' file
 620          */
 621         if (acpi_has_method(dev->handle, "_STR")) {
 622                 kfree(dev->pnp.str_obj);
 623                 device_remove_file(&dev->dev, &dev_attr_description);
 624         }
 625         /*
 626          * If device has _EJ0, remove 'eject' file.
 627          */
 628         if (acpi_has_method(dev->handle, "_EJ0"))
 629                 device_remove_file(&dev->dev, &dev_attr_eject);
 630
 631         if (acpi_has_method(dev->handle, "_SUN"))
 632                 device_remove_file(&dev->dev, &dev_attr_sun);
 633
 634         if (acpi_has_method(dev->handle, "_HRV"))
 635                 device_remove_file(&dev->dev, &dev_attr_hrv);
 636
 637         if (dev->pnp.unique_id)
 638                 device_remove_file(&dev->dev, &dev_attr_uid);
 639         if (dev->pnp.type.bus_address)
 640                 device_remove_file(&dev->dev, &dev_attr_adr);
 641         device_remove_file(&dev->dev, &dev_attr_modalias);
 642         device_remove_file(&dev->dev, &dev_attr_hid);
 643         if (acpi_has_method(dev->handle, "_STA"))
 644                 device_remove_file(&dev->dev, &dev_attr_status);
 645         if (dev->handle)
 646                 device_remove_file(&dev->dev, &dev_attr_path);
 647 }