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
  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  *
 272  * Create the uevent modalias field for ACPI-enumerated devices.
 273  *
 274  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 275  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 276  */
 277 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 278 {
 279         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 280 }
 281 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 282
 283 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 284 {
 285         int len, count;
 286
 287         if (!adev)
 288                 return -ENODEV;
 289
 290         if (list_empty(&adev->pnp.ids))
 291                 return 0;
 292
 293         len = create_pnp_modalias(adev, buf, size - 1);
 294         if (len < 0) {
 295                 return len;
 296         } else if (len > 0) {
 297                 buf[len++] = '\n';
 298                 size -= len;
 299         }
 300         if (!adev->data.of_compatible)
 301                 return len;
 302
 303         count = create_of_modalias(adev, buf + len, size - 1);
 304         if (count < 0) {
 305                 return count;
 306         } else if (count > 0) {
 307                 len += count;
 308                 buf[len++] = '\n';
 309         }
 310
 311         return len;
 312 }
 313
 314 /**
 315  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 316  *
 317  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 318  *
 319  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 320  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 321  */
 322 int acpi_device_modalias(struct device *dev, char *buf, int size)
 323 {
 324         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 325 }
 326 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 327
 328 static ssize_t
 329 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 330 {
 331         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 332 }
 333 static DEVICE_ATTR_RO(modalias);
 334
 335 static ssize_t real_power_state_show(struct device *dev,
 336                                      struct device_attribute *attr, char *buf)
 337 {
 338         struct acpi_device *adev = to_acpi_device(dev);
 339         int state;
 340         int ret;
 341
 342         ret = acpi_device_get_power(adev, &state);
 343         if (ret)
 344                 return ret;
 345
 346         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 347 }
 348
 349 static DEVICE_ATTR_RO(real_power_state);
 350
 351 static ssize_t power_state_show(struct device *dev,
 352                                 struct device_attribute *attr, char *buf)
 353 {
 354         struct acpi_device *adev = to_acpi_device(dev);
 355
 356         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 357 }
 358
 359 static DEVICE_ATTR_RO(power_state);
 360
 361 static ssize_t
 362 eject_store(struct device *d, struct device_attribute *attr,
 363             const char *buf, size_t count)
 364 {
 365         struct acpi_device *acpi_device = to_acpi_device(d);
 366         acpi_object_type not_used;
 367         acpi_status status;
 368
 369         if (!count || buf[0] != '1')
 370                 return -EINVAL;
 371
 372         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 373             && !acpi_device->driver)
 374                 return -ENODEV;
 375
 376         status = acpi_get_type(acpi_device->handle, &not_used);
 377         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 378                 return -ENODEV;
 379
 380         acpi_dev_get(acpi_device);
 381         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 382         if (ACPI_SUCCESS(status))
 383                 return count;
 384
 385         acpi_dev_put(acpi_device);
 386         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 387                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 388         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 389 }
 390
 391 static DEVICE_ATTR_WO(eject);
 392
 393 static ssize_t
 394 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 395 {
 396         struct acpi_device *acpi_dev = to_acpi_device(dev);
 397
 398         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 399 }
 400 static DEVICE_ATTR_RO(hid);
 401
 402 static ssize_t uid_show(struct device *dev,
 403                         struct device_attribute *attr, char *buf)
 404 {
 405         struct acpi_device *acpi_dev = to_acpi_device(dev);
 406
 407         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 408 }
 409 static DEVICE_ATTR_RO(uid);
 410
 411 static ssize_t adr_show(struct device *dev,
 412                         struct device_attribute *attr, char *buf)
 413 {
 414         struct acpi_device *acpi_dev = to_acpi_device(dev);
 415
 416         if (acpi_dev->pnp.bus_address > U32_MAX)
 417                 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
 418         else
 419                 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
 420 }
 421 static DEVICE_ATTR_RO(adr);
 422
 423 static ssize_t path_show(struct device *dev,
 424                          struct device_attribute *attr, char *buf)
 425 {
 426         struct acpi_device *acpi_dev = to_acpi_device(dev);
 427
 428         return acpi_object_path(acpi_dev->handle, buf);
 429 }
 430 static DEVICE_ATTR_RO(path);
 431
 432 /* sysfs file that shows description text from the ACPI _STR method */
 433 static ssize_t description_show(struct device *dev,
 434                                 struct device_attribute *attr,
 435                                 char *buf)
 436 {
 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);
 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 {
 463         struct acpi_device *acpi_dev = to_acpi_device(dev);
 464         acpi_status status;
 465         unsigned long long sun;
 466
 467         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 468         if (ACPI_FAILURE(status))
 469                 return -EIO;
 470
 471         return sprintf(buf, "%llu\n", sun);
 472 }
 473 static DEVICE_ATTR_RO(sun);
 474
 475 static ssize_t
 476 hrv_show(struct device *dev, struct device_attribute *attr,
 477          char *buf)
 478 {
 479         struct acpi_device *acpi_dev = to_acpi_device(dev);
 480         acpi_status status;
 481         unsigned long long hrv;
 482
 483         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 484         if (ACPI_FAILURE(status))
 485                 return -EIO;
 486
 487         return sprintf(buf, "%llu\n", hrv);
 488 }
 489 static DEVICE_ATTR_RO(hrv);
 490
 491 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 492                                 char *buf)
 493 {
 494         struct acpi_device *acpi_dev = to_acpi_device(dev);
 495         acpi_status status;
 496         unsigned long long sta;
 497
 498         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 499         if (ACPI_FAILURE(status))
 500                 return -EIO;
 501
 502         return sprintf(buf, "%llu\n", sta);
 503 }
 504 static DEVICE_ATTR_RO(status);
 505
 506 /**
 507  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 508  * @dev: ACPI device object.
 509  */
 510 int acpi_device_setup_files(struct acpi_device *dev)
 511 {
 512         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 513         acpi_status status;
 514         int result = 0;
 515
 516         /*
 517          * Devices gotten from FADT don't have a "path" attribute
 518          */
 519         if (dev->handle) {
 520                 result = device_create_file(&dev->dev, &dev_attr_path);
 521                 if (result)
 522                         goto end;
 523         }
 524
 525         if (!list_empty(&dev->pnp.ids)) {
 526                 result = device_create_file(&dev->dev, &dev_attr_hid);
 527                 if (result)
 528                         goto end;
 529
 530                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 531                 if (result)
 532                         goto end;
 533         }
 534
 535         /*
 536          * If device has _STR, 'description' file is created
 537          */
 538         if (acpi_has_method(dev->handle, "_STR")) {
 539                 status = acpi_evaluate_object(dev->handle, "_STR",
 540                                         NULL, &buffer);
 541                 if (ACPI_FAILURE(status))
 542                         buffer.pointer = NULL;
 543                 dev->pnp.str_obj = buffer.pointer;
 544                 result = device_create_file(&dev->dev, &dev_attr_description);
 545                 if (result)
 546                         goto end;
 547         }
 548
 549         if (dev->pnp.type.bus_address)
 550                 result = device_create_file(&dev->dev, &dev_attr_adr);
 551         if (dev->pnp.unique_id)
 552                 result = device_create_file(&dev->dev, &dev_attr_uid);
 553
 554         if (acpi_has_method(dev->handle, "_SUN")) {
 555                 result = device_create_file(&dev->dev, &dev_attr_sun);
 556                 if (result)
 557                         goto end;
 558         }
 559
 560         if (acpi_has_method(dev->handle, "_HRV")) {
 561                 result = device_create_file(&dev->dev, &dev_attr_hrv);
 562                 if (result)
 563                         goto end;
 564         }
 565
 566         if (acpi_has_method(dev->handle, "_STA")) {
 567                 result = device_create_file(&dev->dev, &dev_attr_status);
 568                 if (result)
 569                         goto end;
 570         }
 571
 572         /*
 573          * If device has _EJ0, 'eject' file is created that is used to trigger
 574          * hot-removal function from userland.
 575          */
 576         if (acpi_has_method(dev->handle, "_EJ0")) {
 577                 result = device_create_file(&dev->dev, &dev_attr_eject);
 578                 if (result)
 579                         return result;
 580         }
 581
 582         if (dev->flags.power_manageable) {
 583                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 584                 if (result)
 585                         return result;
 586
 587                 if (dev->power.flags.power_resources)
 588                         result = device_create_file(&dev->dev,
 589                                                     &dev_attr_real_power_state);
 590         }
 591
 592         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 593
 594 end:
 595         return result;
 596 }
 597
 598 /**
 599  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 600  * @dev: ACPI device object.
 601  */
 602 void acpi_device_remove_files(struct acpi_device *dev)
 603 {
 604         acpi_hide_nondev_subnodes(&dev->data);
 605
 606         if (dev->flags.power_manageable) {
 607                 device_remove_file(&dev->dev, &dev_attr_power_state);
 608                 if (dev->power.flags.power_resources)
 609                         device_remove_file(&dev->dev,
 610                                            &dev_attr_real_power_state);
 611         }
 612
 613         /*
 614          * If device has _STR, remove 'description' file
 615          */
 616         if (acpi_has_method(dev->handle, "_STR")) {
 617                 kfree(dev->pnp.str_obj);
 618                 device_remove_file(&dev->dev, &dev_attr_description);
 619         }
 620         /*
 621          * If device has _EJ0, remove 'eject' file.
 622          */
 623         if (acpi_has_method(dev->handle, "_EJ0"))
 624                 device_remove_file(&dev->dev, &dev_attr_eject);
 625
 626         if (acpi_has_method(dev->handle, "_SUN"))
 627                 device_remove_file(&dev->dev, &dev_attr_sun);
 628
 629         if (acpi_has_method(dev->handle, "_HRV"))
 630                 device_remove_file(&dev->dev, &dev_attr_hrv);
 631
 632         if (dev->pnp.unique_id)
 633                 device_remove_file(&dev->dev, &dev_attr_uid);
 634         if (dev->pnp.type.bus_address)
 635                 device_remove_file(&dev->dev, &dev_attr_adr);
 636         device_remove_file(&dev->dev, &dev_attr_modalias);
 637         device_remove_file(&dev->dev, &dev_attr_hid);
 638         if (acpi_has_method(dev->handle, "_STA"))
 639                 device_remove_file(&dev->dev, &dev_attr_status);
 640         if (dev->handle)
 641                 device_remove_file(&dev->dev, &dev_attr_path);
 642 }