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 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(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 <= 0)
 162                 return len;
 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(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 <= 0)
 216                 return 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  * @dev: Struct device to get ACPI device node.
 273  * @env: Environment variables of the kobject uevent.
 274  *
 275  * Create the uevent modalias field for ACPI-enumerated devices.
 276  *
 277  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 278  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 279  */
 280 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 281 {
 282         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 283 }
 284 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 285
 286 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 287 {
 288         int len, count;
 289
 290         if (!adev)
 291                 return -ENODEV;
 292
 293         if (list_empty(&adev->pnp.ids))
 294                 return 0;
 295
 296         len = create_pnp_modalias(adev, buf, size - 1);
 297         if (len < 0) {
 298                 return len;
 299         } else if (len > 0) {
 300                 buf[len++] = '\n';
 301                 size -= len;
 302         }
 303         if (!adev->data.of_compatible)
 304                 return len;
 305
 306         count = create_of_modalias(adev, buf + len, size - 1);
 307         if (count < 0) {
 308                 return count;
 309         } else if (count > 0) {
 310                 len += count;
 311                 buf[len++] = '\n';
 312         }
 313
 314         return len;
 315 }
 316
 317 /**
 318  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 319  * @dev: Struct device to get ACPI device node.
 320  * @buf: The buffer to save pnp_modalias and of_modalias.
 321  * @size: Size of buffer.
 322  *
 323  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 324  *
 325  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 326  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 327  */
 328 int acpi_device_modalias(struct device *dev, char *buf, int size)
 329 {
 330         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 331 }
 332 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 333
 334 static ssize_t
 335 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 336 {
 337         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 338 }
 339 static DEVICE_ATTR_RO(modalias);
 340
 341 static ssize_t real_power_state_show(struct device *dev,
 342                                      struct device_attribute *attr, char *buf)
 343 {
 344         struct acpi_device *adev = to_acpi_device(dev);
 345         int state;
 346         int ret;
 347
 348         ret = acpi_device_get_power(adev, &state);
 349         if (ret)
 350                 return ret;
 351
 352         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 353 }
 354
 355 static DEVICE_ATTR_RO(real_power_state);
 356
 357 static ssize_t power_state_show(struct device *dev,
 358                                 struct device_attribute *attr, char *buf)
 359 {
 360         struct acpi_device *adev = to_acpi_device(dev);
 361
 362         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 363 }
 364
 365 static DEVICE_ATTR_RO(power_state);
 366
 367 static ssize_t
 368 eject_store(struct device *d, struct device_attribute *attr,
 369             const char *buf, size_t count)
 370 {
 371         struct acpi_device *acpi_device = to_acpi_device(d);
 372         acpi_object_type not_used;
 373         acpi_status status;
 374
 375         if (!count || buf[0] != '1')
 376                 return -EINVAL;
 377
 378         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 379             && !d->driver)
 380                 return -ENODEV;
 381
 382         status = acpi_get_type(acpi_device->handle, &not_used);
 383         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 384                 return -ENODEV;
 385
 386         acpi_dev_get(acpi_device);
 387         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 388         if (ACPI_SUCCESS(status))
 389                 return count;
 390
 391         acpi_dev_put(acpi_device);
 392         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 393                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 394         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 395 }
 396
 397 static DEVICE_ATTR_WO(eject);
 398
 399 static ssize_t
 400 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 401 {
 402         struct acpi_device *acpi_dev = to_acpi_device(dev);
 403
 404         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 405 }
 406 static DEVICE_ATTR_RO(hid);
 407
 408 static ssize_t uid_show(struct device *dev,
 409                         struct device_attribute *attr, char *buf)
 410 {
 411         struct acpi_device *acpi_dev = to_acpi_device(dev);
 412
 413         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 414 }
 415 static DEVICE_ATTR_RO(uid);
 416
 417 static ssize_t adr_show(struct device *dev,
 418                         struct device_attribute *attr, char *buf)
 419 {
 420         struct acpi_device *acpi_dev = to_acpi_device(dev);
 421
 422         if (acpi_dev->pnp.bus_address > U32_MAX)
 423                 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
 424         else
 425                 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
 426 }
 427 static DEVICE_ATTR_RO(adr);
 428
 429 static ssize_t path_show(struct device *dev,
 430                          struct device_attribute *attr, char *buf)
 431 {
 432         struct acpi_device *acpi_dev = to_acpi_device(dev);
 433
 434         return acpi_object_path(acpi_dev->handle, buf);
 435 }
 436 static DEVICE_ATTR_RO(path);
 437
 438 /* sysfs file that shows description text from the ACPI _STR method */
 439 static ssize_t description_show(struct device *dev,
 440                                 struct device_attribute *attr,
 441                                 char *buf)
 442 {
 443         struct acpi_device *acpi_dev = to_acpi_device(dev);
 444         int result;
 445
 446         if (acpi_dev->pnp.str_obj == NULL)
 447                 return 0;
 448
 449         /*
 450          * The _STR object contains a Unicode identifier for a device.
 451          * We need to convert to utf-8 so it can be displayed.
 452          */
 453         result = utf16s_to_utf8s(
 454                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 455                 acpi_dev->pnp.str_obj->buffer.length,
 456                 UTF16_LITTLE_ENDIAN, buf,
 457                 PAGE_SIZE - 1);
 458
 459         buf[result++] = '\n';
 460
 461         return result;
 462 }
 463 static DEVICE_ATTR_RO(description);
 464
 465 static ssize_t
 466 sun_show(struct device *dev, struct device_attribute *attr,
 467          char *buf)
 468 {
 469         struct acpi_device *acpi_dev = to_acpi_device(dev);
 470         acpi_status status;
 471         unsigned long long sun;
 472
 473         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 474         if (ACPI_FAILURE(status))
 475                 return -EIO;
 476
 477         return sprintf(buf, "%llu\n", sun);
 478 }
 479 static DEVICE_ATTR_RO(sun);
 480
 481 static ssize_t
 482 hrv_show(struct device *dev, struct device_attribute *attr,
 483          char *buf)
 484 {
 485         struct acpi_device *acpi_dev = to_acpi_device(dev);
 486         acpi_status status;
 487         unsigned long long hrv;
 488
 489         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 490         if (ACPI_FAILURE(status))
 491                 return -EIO;
 492
 493         return sprintf(buf, "%llu\n", hrv);
 494 }
 495 static DEVICE_ATTR_RO(hrv);
 496
 497 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 498                                 char *buf)
 499 {
 500         struct acpi_device *acpi_dev = to_acpi_device(dev);
 501         acpi_status status;
 502         unsigned long long sta;
 503
 504         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 505         if (ACPI_FAILURE(status))
 506                 return -EIO;
 507
 508         return sprintf(buf, "%llu\n", sta);
 509 }
 510 static DEVICE_ATTR_RO(status);
 511
 512 /**
 513  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 514  * @dev: ACPI device object.
 515  */
 516 int acpi_device_setup_files(struct acpi_device *dev)
 517 {
 518         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 519         acpi_status status;
 520         int result = 0;
 521
 522         /*
 523          * Devices gotten from FADT don't have a "path" attribute
 524          */
 525         if (dev->handle) {
 526                 result = device_create_file(&dev->dev, &dev_attr_path);
 527                 if (result)
 528                         goto end;
 529         }
 530
 531         if (!list_empty(&dev->pnp.ids)) {
 532                 result = device_create_file(&dev->dev, &dev_attr_hid);
 533                 if (result)
 534                         goto end;
 535
 536                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 537                 if (result)
 538                         goto end;
 539         }
 540
 541         /*
 542          * If device has _STR, 'description' file is created
 543          */
 544         if (acpi_has_method(dev->handle, "_STR")) {
 545                 status = acpi_evaluate_object(dev->handle, "_STR",
 546                                         NULL, &buffer);
 547                 if (ACPI_FAILURE(status))
 548                         buffer.pointer = NULL;
 549                 dev->pnp.str_obj = buffer.pointer;
 550                 result = device_create_file(&dev->dev, &dev_attr_description);
 551                 if (result)
 552                         goto end;
 553         }
 554
 555         if (dev->pnp.type.bus_address)
 556                 result = device_create_file(&dev->dev, &dev_attr_adr);
 557         if (dev->pnp.unique_id)
 558                 result = device_create_file(&dev->dev, &dev_attr_uid);
 559
 560         if (acpi_has_method(dev->handle, "_SUN")) {
 561                 result = device_create_file(&dev->dev, &dev_attr_sun);
 562                 if (result)
 563                         goto end;
 564         }
 565
 566         if (acpi_has_method(dev->handle, "_HRV")) {
 567                 result = device_create_file(&dev->dev, &dev_attr_hrv);
 568                 if (result)
 569                         goto end;
 570         }
 571
 572         if (acpi_has_method(dev->handle, "_STA")) {
 573                 result = device_create_file(&dev->dev, &dev_attr_status);
 574                 if (result)
 575                         goto end;
 576         }
 577
 578         /*
 579          * If device has _EJ0, 'eject' file is created that is used to trigger
 580          * hot-removal function from userland.
 581          */
 582         if (acpi_has_method(dev->handle, "_EJ0")) {
 583                 result = device_create_file(&dev->dev, &dev_attr_eject);
 584                 if (result)
 585                         return result;
 586         }
 587
 588         if (dev->flags.power_manageable) {
 589                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 590                 if (result)
 591                         return result;
 592
 593                 if (dev->power.flags.power_resources)
 594                         result = device_create_file(&dev->dev,
 595                                                     &dev_attr_real_power_state);
 596         }
 597
 598         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 599
 600 end:
 601         return result;
 602 }
 603
 604 /**
 605  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 606  * @dev: ACPI device object.
 607  */
 608 void acpi_device_remove_files(struct acpi_device *dev)
 609 {
 610         acpi_hide_nondev_subnodes(&dev->data);
 611
 612         if (dev->flags.power_manageable) {
 613                 device_remove_file(&dev->dev, &dev_attr_power_state);
 614                 if (dev->power.flags.power_resources)
 615                         device_remove_file(&dev->dev,
 616                                            &dev_attr_real_power_state);
 617         }
 618
 619         /*
 620          * If device has _STR, remove 'description' file
 621          */
 622         if (acpi_has_method(dev->handle, "_STR")) {
 623                 kfree(dev->pnp.str_obj);
 624                 device_remove_file(&dev->dev, &dev_attr_description);
 625         }
 626         /*
 627          * If device has _EJ0, remove 'eject' file.
 628          */
 629         if (acpi_has_method(dev->handle, "_EJ0"))
 630                 device_remove_file(&dev->dev, &dev_attr_eject);
 631
 632         if (acpi_has_method(dev->handle, "_SUN"))
 633                 device_remove_file(&dev->dev, &dev_attr_sun);
 634
 635         if (acpi_has_method(dev->handle, "_HRV"))
 636                 device_remove_file(&dev->dev, &dev_attr_hrv);
 637
 638         if (dev->pnp.unique_id)
 639                 device_remove_file(&dev->dev, &dev_attr_uid);
 640         if (dev->pnp.type.bus_address)
 641                 device_remove_file(&dev->dev, &dev_attr_adr);
 642         device_remove_file(&dev->dev, &dev_attr_modalias);
 643         device_remove_file(&dev->dev, &dev_attr_hid);
 644         if (acpi_has_method(dev->handle, "_STA"))
 645                 device_remove_file(&dev->dev, &dev_attr_status);
 646         if (dev->handle)
 647                 device_remove_file(&dev->dev, &dev_attr_path);
 648 }