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 >= size)
 160                 return -ENOMEM;
 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 >= size)
 214                 return -ENOMEM;
 215
 216         size -= len;
 217
 218         of_compatible = acpi_dev->data.of_compatible;
 219         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 220                 nval = of_compatible->package.count;
 221                 obj = of_compatible->package.elements;
 222         } else { /* Must be ACPI_TYPE_STRING. */
 223                 nval = 1;
 224                 obj = of_compatible;
 225         }
 226         for (i = 0; i < nval; i++, obj++) {
 227                 count = snprintf(&modalias[len], size, "C%s",
 228                                  obj->string.pointer);
 229                 if (count < 0)
 230                         return -EINVAL;
 231
 232                 if (count >= size)
 233                         return -ENOMEM;
 234
 235                 len += count;
 236                 size -= count;
 237         }
 238         modalias[len] = '\0';
 239         return len;
 240 }
 241
 242 int __acpi_device_uevent_modalias(struct acpi_device *adev,
 243                                   struct kobj_uevent_env *env)
 244 {
 245         int len;
 246
 247         if (!adev)
 248                 return -ENODEV;
 249
 250         if (list_empty(&adev->pnp.ids))
 251                 return 0;
 252
 253         if (add_uevent_var(env, "MODALIAS="))
 254                 return -ENOMEM;
 255
 256         if (adev->data.of_compatible)
 257                 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 258                                          sizeof(env->buf) - env->buflen);
 259         else
 260                 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 261                                           sizeof(env->buf) - env->buflen);
 262         if (len < 0)
 263                 return len;
 264
 265         env->buflen += len;
 266
 267         return 0;
 268 }
 269
 270 /**
 271  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 272  *
 273  * Create the uevent modalias field for ACPI-enumerated devices.
 274  *
 275  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 276  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 277  */
 278 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 279 {
 280         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 281 }
 282 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 283
 284 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 285 {
 286         int len, count;
 287
 288         if (!adev)
 289                 return -ENODEV;
 290
 291         if (list_empty(&adev->pnp.ids))
 292                 return 0;
 293
 294         len = create_pnp_modalias(adev, buf, size - 1);
 295         if (len < 0) {
 296                 return len;
 297         } else if (len > 0) {
 298                 buf[len++] = '\n';
 299                 size -= len;
 300         }
 301         if (!adev->data.of_compatible)
 302                 return len;
 303
 304         count = create_of_modalias(adev, buf + len, size - 1);
 305         if (count < 0) {
 306                 return count;
 307         } else if (count > 0) {
 308                 len += count;
 309                 buf[len++] = '\n';
 310         }
 311
 312         return len;
 313 }
 314
 315 /**
 316  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 317  *
 318  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 319  *
 320  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 321  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 322  */
 323 int acpi_device_modalias(struct device *dev, char *buf, int size)
 324 {
 325         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 326 }
 327 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 328
 329 static ssize_t
 330 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 331 {
 332         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 333 }
 334 static DEVICE_ATTR_RO(modalias);
 335
 336 static ssize_t real_power_state_show(struct device *dev,
 337                                      struct device_attribute *attr, char *buf)
 338 {
 339         struct acpi_device *adev = to_acpi_device(dev);
 340         int state;
 341         int ret;
 342
 343         ret = acpi_device_get_power(adev, &state);
 344         if (ret)
 345                 return ret;
 346
 347         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 348 }
 349
 350 static DEVICE_ATTR_RO(real_power_state);
 351
 352 static ssize_t power_state_show(struct device *dev,
 353                                 struct device_attribute *attr, char *buf)
 354 {
 355         struct acpi_device *adev = to_acpi_device(dev);
 356
 357         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 358 }
 359
 360 static DEVICE_ATTR_RO(power_state);
 361
 362 static ssize_t
 363 eject_store(struct device *d, struct device_attribute *attr,
 364             const char *buf, size_t count)
 365 {
 366         struct acpi_device *acpi_device = to_acpi_device(d);
 367         acpi_object_type not_used;
 368         acpi_status status;
 369
 370         if (!count || buf[0] != '1')
 371                 return -EINVAL;
 372
 373         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 374             && !acpi_device->driver)
 375                 return -ENODEV;
 376
 377         status = acpi_get_type(acpi_device->handle, &not_used);
 378         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 379                 return -ENODEV;
 380
 381         get_device(&acpi_device->dev);
 382         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 383         if (ACPI_SUCCESS(status))
 384                 return count;
 385
 386         put_device(&acpi_device->dev);
 387         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 388                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 389         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 390 }
 391
 392 static DEVICE_ATTR_WO(eject);
 393
 394 static ssize_t
 395 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 396 {
 397         struct acpi_device *acpi_dev = to_acpi_device(dev);
 398
 399         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 400 }
 401 static DEVICE_ATTR_RO(hid);
 402
 403 static ssize_t uid_show(struct device *dev,
 404                         struct device_attribute *attr, char *buf)
 405 {
 406         struct acpi_device *acpi_dev = to_acpi_device(dev);
 407
 408         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 409 }
 410 static DEVICE_ATTR_RO(uid);
 411
 412 static ssize_t adr_show(struct device *dev,
 413                         struct device_attribute *attr, char *buf)
 414 {
 415         struct acpi_device *acpi_dev = to_acpi_device(dev);
 416
 417         if (acpi_dev->pnp.bus_address > U32_MAX)
 418                 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
 419         else
 420                 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
 421 }
 422 static DEVICE_ATTR_RO(adr);
 423
 424 static ssize_t path_show(struct device *dev,
 425                          struct device_attribute *attr, char *buf)
 426 {
 427         struct acpi_device *acpi_dev = to_acpi_device(dev);
 428
 429         return acpi_object_path(acpi_dev->handle, buf);
 430 }
 431 static DEVICE_ATTR_RO(path);
 432
 433 /* sysfs file that shows description text from the ACPI _STR method */
 434 static ssize_t description_show(struct device *dev,
 435                                 struct device_attribute *attr,
 436                                 char *buf) {
 437         struct acpi_device *acpi_dev = to_acpi_device(dev);
 438         int result;
 439
 440         if (acpi_dev->pnp.str_obj == NULL)
 441                 return 0;
 442
 443         /*
 444          * The _STR object contains a Unicode identifier for a device.
 445          * We need to convert to utf-8 so it can be displayed.
 446          */
 447         result = utf16s_to_utf8s(
 448                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 449                 acpi_dev->pnp.str_obj->buffer.length,
 450                 UTF16_LITTLE_ENDIAN, buf,
 451                 PAGE_SIZE - 1);
 452
 453         buf[result++] = '\n';
 454
 455         return result;
 456 }
 457 static DEVICE_ATTR_RO(description);
 458
 459 static ssize_t
 460 sun_show(struct device *dev, struct device_attribute *attr,
 461          char *buf) {
 462         struct acpi_device *acpi_dev = to_acpi_device(dev);
 463         acpi_status status;
 464         unsigned long long sun;
 465
 466         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 467         if (ACPI_FAILURE(status))
 468                 return -EIO;
 469
 470         return sprintf(buf, "%llu\n", sun);
 471 }
 472 static DEVICE_ATTR_RO(sun);
 473
 474 static ssize_t
 475 hrv_show(struct device *dev, struct device_attribute *attr,
 476          char *buf) {
 477         struct acpi_device *acpi_dev = to_acpi_device(dev);
 478         acpi_status status;
 479         unsigned long long hrv;
 480
 481         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 482         if (ACPI_FAILURE(status))
 483                 return -EIO;
 484
 485         return sprintf(buf, "%llu\n", hrv);
 486 }
 487 static DEVICE_ATTR_RO(hrv);
 488
 489 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 490                                 char *buf) {
 491         struct acpi_device *acpi_dev = to_acpi_device(dev);
 492         acpi_status status;
 493         unsigned long long sta;
 494
 495         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 496         if (ACPI_FAILURE(status))
 497                 return -EIO;
 498
 499         return sprintf(buf, "%llu\n", sta);
 500 }
 501 static DEVICE_ATTR_RO(status);
 502
 503 /**
 504  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 505  * @dev: ACPI device object.
 506  */
 507 int acpi_device_setup_files(struct acpi_device *dev)
 508 {
 509         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 510         acpi_status status;
 511         int result = 0;
 512
 513         /*
 514          * Devices gotten from FADT don't have a "path" attribute
 515          */
 516         if (dev->handle) {
 517                 result = device_create_file(&dev->dev, &dev_attr_path);
 518                 if (result)
 519                         goto end;
 520         }
 521
 522         if (!list_empty(&dev->pnp.ids)) {
 523                 result = device_create_file(&dev->dev, &dev_attr_hid);
 524                 if (result)
 525                         goto end;
 526
 527                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 528                 if (result)
 529                         goto end;
 530         }
 531
 532         /*
 533          * If device has _STR, 'description' file is created
 534          */
 535         if (acpi_has_method(dev->handle, "_STR")) {
 536                 status = acpi_evaluate_object(dev->handle, "_STR",
 537                                         NULL, &buffer);
 538                 if (ACPI_FAILURE(status))
 539                         buffer.pointer = NULL;
 540                 dev->pnp.str_obj = buffer.pointer;
 541                 result = device_create_file(&dev->dev, &dev_attr_description);
 542                 if (result)
 543                         goto end;
 544         }
 545
 546         if (dev->pnp.type.bus_address)
 547                 result = device_create_file(&dev->dev, &dev_attr_adr);
 548         if (dev->pnp.unique_id)
 549                 result = device_create_file(&dev->dev, &dev_attr_uid);
 550
 551         if (acpi_has_method(dev->handle, "_SUN")) {
 552                 result = device_create_file(&dev->dev, &dev_attr_sun);
 553                 if (result)
 554                         goto end;
 555         }
 556
 557         if (acpi_has_method(dev->handle, "_HRV")) {
 558                 result = device_create_file(&dev->dev, &dev_attr_hrv);
 559                 if (result)
 560                         goto end;
 561         }
 562
 563         if (acpi_has_method(dev->handle, "_STA")) {
 564                 result = device_create_file(&dev->dev, &dev_attr_status);
 565                 if (result)
 566                         goto end;
 567         }
 568
 569         /*
 570          * If device has _EJ0, 'eject' file is created that is used to trigger
 571          * hot-removal function from userland.
 572          */
 573         if (acpi_has_method(dev->handle, "_EJ0")) {
 574                 result = device_create_file(&dev->dev, &dev_attr_eject);
 575                 if (result)
 576                         return result;
 577         }
 578
 579         if (dev->flags.power_manageable) {
 580                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 581                 if (result)
 582                         return result;
 583
 584                 if (dev->power.flags.power_resources)
 585                         result = device_create_file(&dev->dev,
 586                                                     &dev_attr_real_power_state);
 587         }
 588
 589         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 590
 591 end:
 592         return result;
 593 }
 594
 595 /**
 596  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 597  * @dev: ACPI device object.
 598  */
 599 void acpi_device_remove_files(struct acpi_device *dev)
 600 {
 601         acpi_hide_nondev_subnodes(&dev->data);
 602
 603         if (dev->flags.power_manageable) {
 604                 device_remove_file(&dev->dev, &dev_attr_power_state);
 605                 if (dev->power.flags.power_resources)
 606                         device_remove_file(&dev->dev,
 607                                            &dev_attr_real_power_state);
 608         }
 609
 610         /*
 611          * If device has _STR, remove 'description' file
 612          */
 613         if (acpi_has_method(dev->handle, "_STR")) {
 614                 kfree(dev->pnp.str_obj);
 615                 device_remove_file(&dev->dev, &dev_attr_description);
 616         }
 617         /*
 618          * If device has _EJ0, remove 'eject' file.
 619          */
 620         if (acpi_has_method(dev->handle, "_EJ0"))
 621                 device_remove_file(&dev->dev, &dev_attr_eject);
 622
 623         if (acpi_has_method(dev->handle, "_SUN"))
 624                 device_remove_file(&dev->dev, &dev_attr_sun);
 625
 626         if (acpi_has_method(dev->handle, "_HRV"))
 627                 device_remove_file(&dev->dev, &dev_attr_hrv);
 628
 629         if (dev->pnp.unique_id)
 630                 device_remove_file(&dev->dev, &dev_attr_uid);
 631         if (dev->pnp.type.bus_address)
 632                 device_remove_file(&dev->dev, &dev_attr_adr);
 633         device_remove_file(&dev->dev, &dev_attr_modalias);
 634         device_remove_file(&dev->dev, &dev_attr_hid);
 635         if (acpi_has_method(dev->handle, "_STA"))
 636                 device_remove_file(&dev->dev, &dev_attr_status);
 637         if (dev->handle)
 638                 device_remove_file(&dev->dev, &dev_attr_path);
 639 }