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
 172                 if (count >= size)
 173                         return -ENOMEM;
 174
 175                 len += count;
 176                 size -= count;
 177         }
 178
 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(const 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
 230                 if (count >= size)
 231                         return -ENOMEM;
 232
 233                 len += count;
 234                 size -= count;
 235         }
 236
 237         return len;
 238 }
 239
 240 int __acpi_device_uevent_modalias(const struct acpi_device *adev,
 241                                   struct kobj_uevent_env *env)
 242 {
 243         int len;
 244
 245         if (!adev)
 246                 return -ENODEV;
 247
 248         if (list_empty(&adev->pnp.ids))
 249                 return 0;
 250
 251         if (add_uevent_var(env, "MODALIAS="))
 252                 return -ENOMEM;
 253
 254         if (adev->data.of_compatible)
 255                 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 256                                          sizeof(env->buf) - env->buflen);
 257         else
 258                 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 259                                           sizeof(env->buf) - env->buflen);
 260         if (len < 0)
 261                 return len;
 262
 263         env->buflen += len;
 264
 265         return 0;
 266 }
 267
 268 /**
 269  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 270  * @dev: Struct device to get ACPI device node.
 271  * @env: Environment variables of the kobject uevent.
 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(const 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(const 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  * @dev: Struct device to get ACPI device node.
 318  * @buf: The buffer to save pnp_modalias and of_modalias.
 319  * @size: Size of buffer.
 320  *
 321  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 322  *
 323  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 324  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 325  */
 326 int acpi_device_modalias(struct device *dev, char *buf, int size)
 327 {
 328         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 329 }
 330 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 331
 332 static ssize_t
 333 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 334 {
 335         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 336 }
 337 static DEVICE_ATTR_RO(modalias);
 338
 339 static ssize_t real_power_state_show(struct device *dev,
 340                                      struct device_attribute *attr, char *buf)
 341 {
 342         struct acpi_device *adev = to_acpi_device(dev);
 343         int state;
 344         int ret;
 345
 346         ret = acpi_device_get_power(adev, &state);
 347         if (ret)
 348                 return ret;
 349
 350         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 351 }
 352
 353 static DEVICE_ATTR_RO(real_power_state);
 354
 355 static ssize_t power_state_show(struct device *dev,
 356                                 struct device_attribute *attr, char *buf)
 357 {
 358         struct acpi_device *adev = to_acpi_device(dev);
 359
 360         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 361 }
 362
 363 static DEVICE_ATTR_RO(power_state);
 364
 365 static ssize_t
 366 eject_store(struct device *d, struct device_attribute *attr,
 367             const char *buf, size_t count)
 368 {
 369         struct acpi_device *acpi_device = to_acpi_device(d);
 370         acpi_object_type not_used;
 371         acpi_status status;
 372
 373         if (!count || buf[0] != '1')
 374                 return -EINVAL;
 375
 376         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 377             && !d->driver)
 378                 return -ENODEV;
 379
 380         status = acpi_get_type(acpi_device->handle, &not_used);
 381         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 382                 return -ENODEV;
 383
 384         acpi_dev_get(acpi_device);
 385         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 386         if (ACPI_SUCCESS(status))
 387                 return count;
 388
 389         acpi_dev_put(acpi_device);
 390         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 391                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 392         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 393 }
 394
 395 static DEVICE_ATTR_WO(eject);
 396
 397 static ssize_t
 398 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 399 {
 400         struct acpi_device *acpi_dev = to_acpi_device(dev);
 401
 402         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 403 }
 404 static DEVICE_ATTR_RO(hid);
 405
 406 static ssize_t uid_show(struct device *dev,
 407                         struct device_attribute *attr, char *buf)
 408 {
 409         struct acpi_device *acpi_dev = to_acpi_device(dev);
 410
 411         return sprintf(buf, "%s\n", acpi_device_uid(acpi_dev));
 412 }
 413 static DEVICE_ATTR_RO(uid);
 414
 415 static ssize_t adr_show(struct device *dev,
 416                         struct device_attribute *attr, char *buf)
 417 {
 418         struct acpi_device *acpi_dev = to_acpi_device(dev);
 419
 420         if (acpi_dev->pnp.bus_address > U32_MAX)
 421                 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
 422         else
 423                 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
 424 }
 425 static DEVICE_ATTR_RO(adr);
 426
 427 static ssize_t path_show(struct device *dev,
 428                          struct device_attribute *attr, char *buf)
 429 {
 430         struct acpi_device *acpi_dev = to_acpi_device(dev);
 431
 432         return acpi_object_path(acpi_dev->handle, buf);
 433 }
 434 static DEVICE_ATTR_RO(path);
 435
 436 /* sysfs file that shows description text from the ACPI _STR method */
 437 static ssize_t description_show(struct device *dev,
 438                                 struct device_attribute *attr,
 439                                 char *buf)
 440 {
 441         struct acpi_device *acpi_dev = to_acpi_device(dev);
 442         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 443         union acpi_object *str_obj;
 444         acpi_status status;
 445         int result;
 446
 447         status = acpi_evaluate_object_typed(acpi_dev->handle, "_STR",
 448                                             NULL, &buffer,
 449                                             ACPI_TYPE_BUFFER);
 450         if (ACPI_FAILURE(status))
 451                 return -EIO;
 452
 453         str_obj = buffer.pointer;
 454
 455         /*
 456          * The _STR object contains a Unicode identifier for a device.
 457          * We need to convert to utf-8 so it can be displayed.
 458          */
 459         result = utf16s_to_utf8s(
 460                 (wchar_t *)str_obj->buffer.pointer,
 461                 str_obj->buffer.length,
 462                 UTF16_LITTLE_ENDIAN, buf,
 463                 PAGE_SIZE - 1);
 464
 465         buf[result++] = '\n';
 466
 467         kfree(str_obj);
 468
 469         return result;
 470 }
 471 static DEVICE_ATTR_RO(description);
 472
 473 static ssize_t
 474 sun_show(struct device *dev, struct device_attribute *attr,
 475          char *buf)
 476 {
 477         struct acpi_device *acpi_dev = to_acpi_device(dev);
 478         acpi_status status;
 479         unsigned long long sun;
 480
 481         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 482         if (ACPI_FAILURE(status))
 483                 return -EIO;
 484
 485         return sprintf(buf, "%llu\n", sun);
 486 }
 487 static DEVICE_ATTR_RO(sun);
 488
 489 static ssize_t
 490 hrv_show(struct device *dev, struct device_attribute *attr,
 491          char *buf)
 492 {
 493         struct acpi_device *acpi_dev = to_acpi_device(dev);
 494         acpi_status status;
 495         unsigned long long hrv;
 496
 497         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 498         if (ACPI_FAILURE(status))
 499                 return -EIO;
 500
 501         return sprintf(buf, "%llu\n", hrv);
 502 }
 503 static DEVICE_ATTR_RO(hrv);
 504
 505 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 506                                 char *buf)
 507 {
 508         struct acpi_device *acpi_dev = to_acpi_device(dev);
 509         acpi_status status;
 510         unsigned long long sta;
 511
 512         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 513         if (ACPI_FAILURE(status))
 514                 return -EIO;
 515
 516         return sprintf(buf, "%llu\n", sta);
 517 }
 518 static DEVICE_ATTR_RO(status);
 519
 520 static struct attribute *acpi_attrs[] = {
 521         &dev_attr_path.attr,
 522         &dev_attr_hid.attr,
 523         &dev_attr_modalias.attr,
 524         &dev_attr_description.attr,
 525         &dev_attr_adr.attr,
 526         &dev_attr_uid.attr,
 527         &dev_attr_sun.attr,
 528         &dev_attr_hrv.attr,
 529         &dev_attr_status.attr,
 530         &dev_attr_eject.attr,
 531         &dev_attr_power_state.attr,
 532         &dev_attr_real_power_state.attr,
 533         NULL
 534 };
 535
 536 static bool acpi_show_attr(struct acpi_device *dev, const struct device_attribute *attr)
 537 {
 538         /*
 539          * Devices gotten from FADT don't have a "path" attribute
 540          */
 541         if (attr == &dev_attr_path)
 542                 return dev->handle;
 543
 544         if (attr == &dev_attr_hid || attr == &dev_attr_modalias)
 545                 return !list_empty(&dev->pnp.ids);
 546
 547         if (attr == &dev_attr_description)
 548                 return acpi_has_method(dev->handle, "_STR");
 549
 550         if (attr == &dev_attr_adr)
 551                 return dev->pnp.type.bus_address;
 552
 553         if (attr == &dev_attr_uid)
 554                 return acpi_device_uid(dev);
 555
 556         if (attr == &dev_attr_sun)
 557                 return acpi_has_method(dev->handle, "_SUN");
 558
 559         if (attr == &dev_attr_hrv)
 560                 return acpi_has_method(dev->handle, "_HRV");
 561
 562         if (attr == &dev_attr_status)
 563                 return acpi_has_method(dev->handle, "_STA");
 564
 565         /*
 566          * If device has _EJ0, 'eject' file is created that is used to trigger
 567          * hot-removal function from userland.
 568          */
 569         if (attr == &dev_attr_eject)
 570                 return acpi_has_method(dev->handle, "_EJ0");
 571
 572         if (attr == &dev_attr_power_state)
 573                 return dev->flags.power_manageable;
 574
 575         if (attr == &dev_attr_real_power_state)
 576                 return dev->flags.power_manageable && dev->power.flags.power_resources;
 577
 578         dev_warn_once(&dev->dev, "Unexpected attribute: %s\n", attr->attr.name);
 579         return false;
 580 }
 581
 582 static umode_t acpi_attr_is_visible(struct kobject *kobj,
 583                                     struct attribute *attr,
 584                                     int attrno)
 585 {
 586         struct acpi_device *dev = to_acpi_device(kobj_to_dev(kobj));
 587
 588         if (acpi_show_attr(dev, container_of(attr, struct device_attribute, attr)))
 589                 return attr->mode;
 590         else
 591                 return 0;
 592 }
 593
 594 static const struct attribute_group acpi_group = {
 595         .attrs = acpi_attrs,
 596         .is_visible = acpi_attr_is_visible,
 597 };
 598
 599 const struct attribute_group *acpi_groups[] = {
 600         &acpi_group,
 601         NULL
 602 };
 603
 604 /**
 605  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 606  * @dev: ACPI device object.
 607  */
 608 void acpi_device_setup_files(struct acpi_device *dev)
 609 {
 610         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 611 }
 612
 613 /**
 614  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 615  * @dev: ACPI device object.
 616  */
 617 void acpi_device_remove_files(struct acpi_device *dev)
 618 {
 619         acpi_hide_nondev_subnodes(&dev->data);
 620 }