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 ATTRIBUTE_GROUPS(acpi_data_node_default);
  57
  58 #define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
  59 #define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
  60
  61 static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
  62                                         struct attribute *attr, char *buf)
  63 {
  64         struct acpi_data_node *dn = to_data_node(kobj);
  65         struct acpi_data_node_attr *dn_attr = to_attr(attr);
  66
  67         return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
  68 }
  69
  70 static const struct sysfs_ops acpi_data_node_sysfs_ops = {
  71         .show   = acpi_data_node_attr_show,
  72 };
  73
  74 static void acpi_data_node_release(struct kobject *kobj)
  75 {
  76         struct acpi_data_node *dn = to_data_node(kobj);
  77
  78         complete(&dn->kobj_done);
  79 }
  80
  81 static const struct kobj_type acpi_data_node_ktype = {
  82         .sysfs_ops = &acpi_data_node_sysfs_ops,
  83         .default_groups = acpi_data_node_default_groups,
  84         .release = acpi_data_node_release,
  85 };
  86
  87 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
  88                                         struct acpi_device_data *data)
  89 {
  90         struct list_head *list = &data->subnodes;
  91         struct acpi_data_node *dn;
  92
  93         if (list_empty(list))
  94                 return;
  95
  96         list_for_each_entry(dn, list, sibling) {
  97                 int ret;
  98
  99                 init_completion(&dn->kobj_done);
 100                 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
 101                                            kobj, "%s", dn->name);
 102                 if (!ret)
 103                         acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
 104                 else if (dn->handle)
 105                         acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
 106         }
 107 }
 108
 109 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
 110 {
 111         struct list_head *list = &data->subnodes;
 112         struct acpi_data_node *dn;
 113
 114         if (list_empty(list))
 115                 return;
 116
 117         list_for_each_entry_reverse(dn, list, sibling) {
 118                 acpi_hide_nondev_subnodes(&dn->data);
 119                 kobject_put(&dn->kobj);
 120         }
 121 }
 122
 123 /**
 124  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
 125  * @acpi_dev: ACPI device object.
 126  * @modalias: Buffer to print into.
 127  * @size: Size of the buffer.
 128  *
 129  * Creates hid/cid(s) string needed for modalias and uevent
 130  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 131  * char *modalias: "acpi:IBM0001:ACPI0001"
 132  * Return: 0: no _HID and no _CID
 133  *         -EINVAL: output error
 134  *         -ENOMEM: output is truncated
 135  */
 136 static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalias,
 137                                int size)
 138 {
 139         int len;
 140         int count;
 141         struct acpi_hardware_id *id;
 142
 143         /* Avoid unnecessarily loading modules for non present devices. */
 144         if (!acpi_device_is_present(acpi_dev))
 145                 return 0;
 146
 147         /*
 148          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 149          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 150          * device's list.
 151          */
 152         count = 0;
 153         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 154                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 155                         count++;
 156
 157         if (!count)
 158                 return 0;
 159
 160         len = snprintf(modalias, size, "acpi:");
 161         if (len >= size)
 162                 return -ENOMEM;
 163
 164         size -= len;
 165
 166         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 167                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 168                         continue;
 169
 170                 count = snprintf(&modalias[len], size, "%s:", id->id);
 171                 if (count < 0)
 172                         return -EINVAL;
 173
 174                 if (count >= size)
 175                         return -ENOMEM;
 176
 177                 len += count;
 178                 size -= count;
 179         }
 180         modalias[len] = '\0';
 181         return len;
 182 }
 183
 184 /**
 185  * create_of_modalias - Creates DT compatible string for modalias and uevent
 186  * @acpi_dev: ACPI device object.
 187  * @modalias: Buffer to print into.
 188  * @size: Size of the buffer.
 189  *
 190  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 191  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 192  * ACPI/PNP IDs.
 193  */
 194 static int create_of_modalias(const struct acpi_device *acpi_dev, char *modalias,
 195                               int size)
 196 {
 197         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 198         const union acpi_object *of_compatible, *obj;
 199         acpi_status status;
 200         int len, count;
 201         int i, nval;
 202         char *c;
 203
 204         status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 205         if (ACPI_FAILURE(status))
 206                 return -ENODEV;
 207
 208         /* DT strings are all in lower case */
 209         for (c = buf.pointer; *c != '\0'; c++)
 210                 *c = tolower(*c);
 211
 212         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 213         ACPI_FREE(buf.pointer);
 214
 215         if (len >= size)
 216                 return -ENOMEM;
 217
 218         size -= len;
 219
 220         of_compatible = acpi_dev->data.of_compatible;
 221         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 222                 nval = of_compatible->package.count;
 223                 obj = of_compatible->package.elements;
 224         } else { /* Must be ACPI_TYPE_STRING. */
 225                 nval = 1;
 226                 obj = of_compatible;
 227         }
 228         for (i = 0; i < nval; i++, obj++) {
 229                 count = snprintf(&modalias[len], size, "C%s",
 230                                  obj->string.pointer);
 231                 if (count < 0)
 232                         return -EINVAL;
 233
 234                 if (count >= size)
 235                         return -ENOMEM;
 236
 237                 len += count;
 238                 size -= count;
 239         }
 240         modalias[len] = '\0';
 241         return len;
 242 }
 243
 244 int __acpi_device_uevent_modalias(const struct acpi_device *adev,
 245                                   struct kobj_uevent_env *env)
 246 {
 247         int len;
 248
 249         if (!adev)
 250                 return -ENODEV;
 251
 252         if (list_empty(&adev->pnp.ids))
 253                 return 0;
 254
 255         if (add_uevent_var(env, "MODALIAS="))
 256                 return -ENOMEM;
 257
 258         if (adev->data.of_compatible)
 259                 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 260                                          sizeof(env->buf) - env->buflen);
 261         else
 262                 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 263                                           sizeof(env->buf) - env->buflen);
 264         if (len < 0)
 265                 return len;
 266
 267         env->buflen += len;
 268
 269         return 0;
 270 }
 271
 272 /**
 273  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 274  * @dev: Struct device to get ACPI device node.
 275  * @env: Environment variables of the kobject uevent.
 276  *
 277  * Create the uevent modalias field for ACPI-enumerated devices.
 278  *
 279  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 280  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 281  */
 282 int acpi_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
 283 {
 284         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 285 }
 286 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 287
 288 static int __acpi_device_modalias(const struct acpi_device *adev, char *buf, int size)
 289 {
 290         int len, count;
 291
 292         if (!adev)
 293                 return -ENODEV;
 294
 295         if (list_empty(&adev->pnp.ids))
 296                 return 0;
 297
 298         len = create_pnp_modalias(adev, buf, size - 1);
 299         if (len < 0) {
 300                 return len;
 301         } else if (len > 0) {
 302                 buf[len++] = '\n';
 303                 size -= len;
 304         }
 305         if (!adev->data.of_compatible)
 306                 return len;
 307
 308         count = create_of_modalias(adev, buf + len, size - 1);
 309         if (count < 0) {
 310                 return count;
 311         } else if (count > 0) {
 312                 len += count;
 313                 buf[len++] = '\n';
 314         }
 315
 316         return len;
 317 }
 318
 319 /**
 320  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 321  * @dev: Struct device to get ACPI device node.
 322  * @buf: The buffer to save pnp_modalias and of_modalias.
 323  * @size: Size of buffer.
 324  *
 325  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 326  *
 327  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 328  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 329  */
 330 int acpi_device_modalias(struct device *dev, char *buf, int size)
 331 {
 332         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 333 }
 334 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 335
 336 static ssize_t
 337 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 338 {
 339         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 340 }
 341 static DEVICE_ATTR_RO(modalias);
 342
 343 static ssize_t real_power_state_show(struct device *dev,
 344                                      struct device_attribute *attr, char *buf)
 345 {
 346         struct acpi_device *adev = to_acpi_device(dev);
 347         int state;
 348         int ret;
 349
 350         ret = acpi_device_get_power(adev, &state);
 351         if (ret)
 352                 return ret;
 353
 354         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 355 }
 356
 357 static DEVICE_ATTR_RO(real_power_state);
 358
 359 static ssize_t power_state_show(struct device *dev,
 360                                 struct device_attribute *attr, char *buf)
 361 {
 362         struct acpi_device *adev = to_acpi_device(dev);
 363
 364         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 365 }
 366
 367 static DEVICE_ATTR_RO(power_state);
 368
 369 static ssize_t
 370 eject_store(struct device *d, struct device_attribute *attr,
 371             const char *buf, size_t count)
 372 {
 373         struct acpi_device *acpi_device = to_acpi_device(d);
 374         acpi_object_type not_used;
 375         acpi_status status;
 376
 377         if (!count || buf[0] != '1')
 378                 return -EINVAL;
 379
 380         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 381             && !d->driver)
 382                 return -ENODEV;
 383
 384         status = acpi_get_type(acpi_device->handle, &not_used);
 385         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 386                 return -ENODEV;
 387
 388         acpi_dev_get(acpi_device);
 389         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 390         if (ACPI_SUCCESS(status))
 391                 return count;
 392
 393         acpi_dev_put(acpi_device);
 394         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 395                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 396         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 397 }
 398
 399 static DEVICE_ATTR_WO(eject);
 400
 401 static ssize_t
 402 hid_show(struct device *dev, 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_device_hid(acpi_dev));
 407 }
 408 static DEVICE_ATTR_RO(hid);
 409
 410 static ssize_t uid_show(struct device *dev,
 411                         struct device_attribute *attr, char *buf)
 412 {
 413         struct acpi_device *acpi_dev = to_acpi_device(dev);
 414
 415         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 416 }
 417 static DEVICE_ATTR_RO(uid);
 418
 419 static ssize_t adr_show(struct device *dev,
 420                         struct device_attribute *attr, char *buf)
 421 {
 422         struct acpi_device *acpi_dev = to_acpi_device(dev);
 423
 424         if (acpi_dev->pnp.bus_address > U32_MAX)
 425                 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
 426         else
 427                 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
 428 }
 429 static DEVICE_ATTR_RO(adr);
 430
 431 static ssize_t path_show(struct device *dev,
 432                          struct device_attribute *attr, char *buf)
 433 {
 434         struct acpi_device *acpi_dev = to_acpi_device(dev);
 435
 436         return acpi_object_path(acpi_dev->handle, buf);
 437 }
 438 static DEVICE_ATTR_RO(path);
 439
 440 /* sysfs file that shows description text from the ACPI _STR method */
 441 static ssize_t description_show(struct device *dev,
 442                                 struct device_attribute *attr,
 443                                 char *buf)
 444 {
 445         struct acpi_device *acpi_dev = to_acpi_device(dev);
 446         int result;
 447
 448         if (acpi_dev->pnp.str_obj == NULL)
 449                 return 0;
 450
 451         /*
 452          * The _STR object contains a Unicode identifier for a device.
 453          * We need to convert to utf-8 so it can be displayed.
 454          */
 455         result = utf16s_to_utf8s(
 456                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 457                 acpi_dev->pnp.str_obj->buffer.length,
 458                 UTF16_LITTLE_ENDIAN, buf,
 459                 PAGE_SIZE - 1);
 460
 461         buf[result++] = '\n';
 462
 463         return result;
 464 }
 465 static DEVICE_ATTR_RO(description);
 466
 467 static ssize_t
 468 sun_show(struct device *dev, struct device_attribute *attr,
 469          char *buf)
 470 {
 471         struct acpi_device *acpi_dev = to_acpi_device(dev);
 472         acpi_status status;
 473         unsigned long long sun;
 474
 475         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 476         if (ACPI_FAILURE(status))
 477                 return -EIO;
 478
 479         return sprintf(buf, "%llu\n", sun);
 480 }
 481 static DEVICE_ATTR_RO(sun);
 482
 483 static ssize_t
 484 hrv_show(struct device *dev, struct device_attribute *attr,
 485          char *buf)
 486 {
 487         struct acpi_device *acpi_dev = to_acpi_device(dev);
 488         acpi_status status;
 489         unsigned long long hrv;
 490
 491         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 492         if (ACPI_FAILURE(status))
 493                 return -EIO;
 494
 495         return sprintf(buf, "%llu\n", hrv);
 496 }
 497 static DEVICE_ATTR_RO(hrv);
 498
 499 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 500                                 char *buf)
 501 {
 502         struct acpi_device *acpi_dev = to_acpi_device(dev);
 503         acpi_status status;
 504         unsigned long long sta;
 505
 506         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 507         if (ACPI_FAILURE(status))
 508                 return -EIO;
 509
 510         return sprintf(buf, "%llu\n", sta);
 511 }
 512 static DEVICE_ATTR_RO(status);
 513
 514 /**
 515  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 516  * @dev: ACPI device object.
 517  */
 518 int acpi_device_setup_files(struct acpi_device *dev)
 519 {
 520         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 521         acpi_status status;
 522         int result = 0;
 523
 524         /*
 525          * Devices gotten from FADT don't have a "path" attribute
 526          */
 527         if (dev->handle) {
 528                 result = device_create_file(&dev->dev, &dev_attr_path);
 529                 if (result)
 530                         goto end;
 531         }
 532
 533         if (!list_empty(&dev->pnp.ids)) {
 534                 result = device_create_file(&dev->dev, &dev_attr_hid);
 535                 if (result)
 536                         goto end;
 537
 538                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 539                 if (result)
 540                         goto end;
 541         }
 542
 543         /*
 544          * If device has _STR, 'description' file is created
 545          */
 546         if (acpi_has_method(dev->handle, "_STR")) {
 547                 status = acpi_evaluate_object(dev->handle, "_STR",
 548                                         NULL, &buffer);
 549                 if (ACPI_FAILURE(status))
 550                         buffer.pointer = NULL;
 551                 dev->pnp.str_obj = buffer.pointer;
 552                 result = device_create_file(&dev->dev, &dev_attr_description);
 553                 if (result)
 554                         goto end;
 555         }
 556
 557         if (dev->pnp.type.bus_address)
 558                 result = device_create_file(&dev->dev, &dev_attr_adr);
 559         if (dev->pnp.unique_id)
 560                 result = device_create_file(&dev->dev, &dev_attr_uid);
 561
 562         if (acpi_has_method(dev->handle, "_SUN")) {
 563                 result = device_create_file(&dev->dev, &dev_attr_sun);
 564                 if (result)
 565                         goto end;
 566         }
 567
 568         if (acpi_has_method(dev->handle, "_HRV")) {
 569                 result = device_create_file(&dev->dev, &dev_attr_hrv);
 570                 if (result)
 571                         goto end;
 572         }
 573
 574         if (acpi_has_method(dev->handle, "_STA")) {
 575                 result = device_create_file(&dev->dev, &dev_attr_status);
 576                 if (result)
 577                         goto end;
 578         }
 579
 580         /*
 581          * If device has _EJ0, 'eject' file is created that is used to trigger
 582          * hot-removal function from userland.
 583          */
 584         if (acpi_has_method(dev->handle, "_EJ0")) {
 585                 result = device_create_file(&dev->dev, &dev_attr_eject);
 586                 if (result)
 587                         return result;
 588         }
 589
 590         if (dev->flags.power_manageable) {
 591                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 592                 if (result)
 593                         return result;
 594
 595                 if (dev->power.flags.power_resources)
 596                         result = device_create_file(&dev->dev,
 597                                                     &dev_attr_real_power_state);
 598         }
 599
 600         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 601
 602 end:
 603         return result;
 604 }
 605
 606 /**
 607  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 608  * @dev: ACPI device object.
 609  */
 610 void acpi_device_remove_files(struct acpi_device *dev)
 611 {
 612         acpi_hide_nondev_subnodes(&dev->data);
 613
 614         if (dev->flags.power_manageable) {
 615                 device_remove_file(&dev->dev, &dev_attr_power_state);
 616                 if (dev->power.flags.power_resources)
 617                         device_remove_file(&dev->dev,
 618                                            &dev_attr_real_power_state);
 619         }
 620
 621         /*
 622          * If device has _STR, remove 'description' file
 623          */
 624         if (acpi_has_method(dev->handle, "_STR")) {
 625                 kfree(dev->pnp.str_obj);
 626                 device_remove_file(&dev->dev, &dev_attr_description);
 627         }
 628         /*
 629          * If device has _EJ0, remove 'eject' file.
 630          */
 631         if (acpi_has_method(dev->handle, "_EJ0"))
 632                 device_remove_file(&dev->dev, &dev_attr_eject);
 633
 634         if (acpi_has_method(dev->handle, "_SUN"))
 635                 device_remove_file(&dev->dev, &dev_attr_sun);
 636
 637         if (acpi_has_method(dev->handle, "_HRV"))
 638                 device_remove_file(&dev->dev, &dev_attr_hrv);
 639
 640         if (dev->pnp.unique_id)
 641                 device_remove_file(&dev->dev, &dev_attr_uid);
 642         if (dev->pnp.type.bus_address)
 643                 device_remove_file(&dev->dev, &dev_attr_adr);
 644         device_remove_file(&dev->dev, &dev_attr_modalias);
 645         device_remove_file(&dev->dev, &dev_attr_hid);
 646         if (acpi_has_method(dev->handle, "_STA"))
 647                 device_remove_file(&dev->dev, &dev_attr_status);
 648         if (dev->handle)
 649                 device_remove_file(&dev->dev, &dev_attr_path);
 650 }