drivers/acpi/device_sysfs.c

   1 /*
   2  * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
   3  *
   4  * Copyright (C) 2015, Intel Corp.
   5  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   6  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2 as published
  12  *  by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  20  */
  21
  22 #include <linux/acpi.h>
  23 #include <linux/device.h>
  24 #include <linux/export.h>
  25 #include <linux/nls.h>
  26
  27 #include "internal.h"
  28
  29 static ssize_t acpi_object_path(acpi_handle handle, char *buf)
  30 {
  31         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
  32         int result;
  33
  34         result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
  35         if (result)
  36                 return result;
  37
  38         result = sprintf(buf, "%s\n", (char *)path.pointer);
  39         kfree(path.pointer);
  40         return result;
  41 }
  42
  43 struct acpi_data_node_attr {
  44         struct attribute attr;
  45         ssize_t (*show)(struct acpi_data_node *, char *);
  46         ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
  47 };
  48
  49 #define DATA_NODE_ATTR(_name)                   \
  50         static struct acpi_data_node_attr data_node_##_name =   \
  51                 __ATTR(_name, 0444, data_node_show_##_name, NULL)
  52
  53 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
  54 {
  55         return acpi_object_path(dn->handle, buf);
  56 }
  57
  58 DATA_NODE_ATTR(path);
  59
  60 static struct attribute *acpi_data_node_default_attrs[] = {
  61         &data_node_path.attr,
  62         NULL
  63 };
  64
  65 #define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
  66 #define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
  67
  68 static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
  69                                         struct attribute *attr, char *buf)
  70 {
  71         struct acpi_data_node *dn = to_data_node(kobj);
  72         struct acpi_data_node_attr *dn_attr = to_attr(attr);
  73
  74         return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
  75 }
  76
  77 static const struct sysfs_ops acpi_data_node_sysfs_ops = {
  78         .show   = acpi_data_node_attr_show,
  79 };
  80
  81 static void acpi_data_node_release(struct kobject *kobj)
  82 {
  83         struct acpi_data_node *dn = to_data_node(kobj);
  84         complete(&dn->kobj_done);
  85 }
  86
  87 static struct kobj_type acpi_data_node_ktype = {
  88         .sysfs_ops = &acpi_data_node_sysfs_ops,
  89         .default_attrs = acpi_data_node_default_attrs,
  90         .release = acpi_data_node_release,
  91 };
  92
  93 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
  94                                         struct acpi_device_data *data)
  95 {
  96         struct list_head *list = &data->subnodes;
  97         struct acpi_data_node *dn;
  98
  99         if (list_empty(list))
 100                 return;
 101
 102         list_for_each_entry(dn, list, sibling) {
 103                 int ret;
 104
 105                 init_completion(&dn->kobj_done);
 106                 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
 107                                            kobj, "%s", dn->name);
 108                 if (ret)
 109                         acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
 110                 else
 111                         acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
 112         }
 113 }
 114
 115 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
 116 {
 117         struct list_head *list = &data->subnodes;
 118         struct acpi_data_node *dn;
 119
 120         if (list_empty(list))
 121                 return;
 122
 123         list_for_each_entry_reverse(dn, list, sibling) {
 124                 acpi_hide_nondev_subnodes(&dn->data);
 125                 kobject_put(&dn->kobj);
 126         }
 127 }
 128
 129 /**
 130  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
 131  * @acpi_dev: ACPI device object.
 132  * @modalias: Buffer to print into.
 133  * @size: Size of the buffer.
 134  *
 135  * Creates hid/cid(s) string needed for modalias and uevent
 136  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 137  * char *modalias: "acpi:IBM0001:ACPI0001"
 138  * Return: 0: no _HID and no _CID
 139  *         -EINVAL: output error
 140  *         -ENOMEM: output is truncated
 141 */
 142 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
 143                                int size)
 144 {
 145         int len;
 146         int count;
 147         struct acpi_hardware_id *id;
 148
 149         /*
 150          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 151          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 152          * device's list.
 153          */
 154         count = 0;
 155         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 156                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 157                         count++;
 158
 159         if (!count)
 160                 return 0;
 161
 162         len = snprintf(modalias, size, "acpi:");
 163         if (len <= 0)
 164                 return len;
 165
 166         size -= len;
 167
 168         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 169                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 170                         continue;
 171
 172                 count = snprintf(&modalias[len], size, "%s:", id->id);
 173                 if (count < 0)
 174                         return -EINVAL;
 175
 176                 if (count >= size)
 177                         return -ENOMEM;
 178
 179                 len += count;
 180                 size -= count;
 181         }
 182         modalias[len] = '\0';
 183         return len;
 184 }
 185
 186 /**
 187  * create_of_modalias - Creates DT compatible string for modalias and uevent
 188  * @acpi_dev: ACPI device object.
 189  * @modalias: Buffer to print into.
 190  * @size: Size of the buffer.
 191  *
 192  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 193  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 194  * ACPI/PNP IDs.
 195  */
 196 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 197                               int size)
 198 {
 199         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 200         const union acpi_object *of_compatible, *obj;
 201         int len, count;
 202         int i, nval;
 203         char *c;
 204
 205         acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 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 <= 0)
 214                 return len;
 215
 216         of_compatible = acpi_dev->data.of_compatible;
 217         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 218                 nval = of_compatible->package.count;
 219                 obj = of_compatible->package.elements;
 220         } else { /* Must be ACPI_TYPE_STRING. */
 221                 nval = 1;
 222                 obj = of_compatible;
 223         }
 224         for (i = 0; i < nval; i++, obj++) {
 225                 count = snprintf(&modalias[len], size, "C%s",
 226                                  obj->string.pointer);
 227                 if (count < 0)
 228                         return -EINVAL;
 229
 230                 if (count >= size)
 231                         return -ENOMEM;
 232
 233                 len += count;
 234                 size -= count;
 235         }
 236         modalias[len] = '\0';
 237         return len;
 238 }
 239
 240 int __acpi_device_uevent_modalias(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         len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 255                                   sizeof(env->buf) - env->buflen);
 256         if (len < 0)
 257                 return len;
 258
 259         env->buflen += len;
 260         if (!adev->data.of_compatible)
 261                 return 0;
 262
 263         if (len > 0 && add_uevent_var(env, "MODALIAS="))
 264                 return -ENOMEM;
 265
 266         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 267                                  sizeof(env->buf) - env->buflen);
 268         if (len < 0)
 269                 return len;
 270
 271         env->buflen += len;
 272
 273         return 0;
 274 }
 275
 276 /**
 277  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 278  *
 279  * Create the uevent modalias field for ACPI-enumerated devices.
 280  *
 281  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 282  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 283  */
 284 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 285 {
 286         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 287 }
 288 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 289
 290 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 291 {
 292         int len, count;
 293
 294         if (!adev)
 295                 return -ENODEV;
 296
 297         if (list_empty(&adev->pnp.ids))
 298                 return 0;
 299
 300         len = create_pnp_modalias(adev, buf, size - 1);
 301         if (len < 0) {
 302                 return len;
 303         } else if (len > 0) {
 304                 buf[len++] = '\n';
 305                 size -= len;
 306         }
 307         if (!adev->data.of_compatible)
 308                 return len;
 309
 310         count = create_of_modalias(adev, buf + len, size - 1);
 311         if (count < 0) {
 312                 return count;
 313         } else if (count > 0) {
 314                 len += count;
 315                 buf[len++] = '\n';
 316         }
 317
 318         return len;
 319 }
 320
 321 /**
 322  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 323  *
 324  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 325  *
 326  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 327  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 328  */
 329 int acpi_device_modalias(struct device *dev, char *buf, int size)
 330 {
 331         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 332 }
 333 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 334
 335 static ssize_t
 336 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 337 {
 338         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 339 }
 340 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 341
 342 static ssize_t real_power_state_show(struct device *dev,
 343                                      struct device_attribute *attr, char *buf)
 344 {
 345         struct acpi_device *adev = to_acpi_device(dev);
 346         int state;
 347         int ret;
 348
 349         ret = acpi_device_get_power(adev, &state);
 350         if (ret)
 351                 return ret;
 352
 353         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 354 }
 355
 356 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 357
 358 static ssize_t power_state_show(struct device *dev,
 359                                 struct device_attribute *attr, char *buf)
 360 {
 361         struct acpi_device *adev = to_acpi_device(dev);
 362
 363         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 364 }
 365
 366 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 367
 368 static ssize_t
 369 acpi_eject_store(struct device *d, struct device_attribute *attr,
 370                 const char *buf, size_t count)
 371 {
 372         struct acpi_device *acpi_device = to_acpi_device(d);
 373         acpi_object_type not_used;
 374         acpi_status status;
 375
 376         if (!count || buf[0] != '1')
 377                 return -EINVAL;
 378
 379         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 380             && !acpi_device->driver)
 381                 return -ENODEV;
 382
 383         status = acpi_get_type(acpi_device->handle, &not_used);
 384         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 385                 return -ENODEV;
 386
 387         get_device(&acpi_device->dev);
 388         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 389         if (ACPI_SUCCESS(status))
 390                 return count;
 391
 392         put_device(&acpi_device->dev);
 393         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 394                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 395         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 396 }
 397
 398 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 399
 400 static ssize_t
 401 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 402 {
 403         struct acpi_device *acpi_dev = to_acpi_device(dev);
 404
 405         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 406 }
 407 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 408
 409 static ssize_t acpi_device_uid_show(struct device *dev,
 410                                     struct device_attribute *attr, char *buf)
 411 {
 412         struct acpi_device *acpi_dev = to_acpi_device(dev);
 413
 414         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 415 }
 416 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 417
 418 static ssize_t acpi_device_adr_show(struct device *dev,
 419                                     struct device_attribute *attr, char *buf)
 420 {
 421         struct acpi_device *acpi_dev = to_acpi_device(dev);
 422
 423         return sprintf(buf, "0x%08x\n",
 424                        (unsigned int)(acpi_dev->pnp.bus_address));
 425 }
 426 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 427
 428 static ssize_t acpi_device_path_show(struct device *dev,
 429                                      struct device_attribute *attr, char *buf)
 430 {
 431         struct acpi_device *acpi_dev = to_acpi_device(dev);
 432
 433         return acpi_object_path(acpi_dev->handle, buf);
 434 }
 435 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 436
 437 /* sysfs file that shows description text from the ACPI _STR method */
 438 static ssize_t description_show(struct device *dev,
 439                                 struct device_attribute *attr,
 440                                 char *buf) {
 441         struct acpi_device *acpi_dev = to_acpi_device(dev);
 442         int result;
 443
 444         if (acpi_dev->pnp.str_obj == NULL)
 445                 return 0;
 446
 447         /*
 448          * The _STR object contains a Unicode identifier for a device.
 449          * We need to convert to utf-8 so it can be displayed.
 450          */
 451         result = utf16s_to_utf8s(
 452                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 453                 acpi_dev->pnp.str_obj->buffer.length,
 454                 UTF16_LITTLE_ENDIAN, buf,
 455                 PAGE_SIZE);
 456
 457         buf[result++] = '\n';
 458
 459         return result;
 460 }
 461 static DEVICE_ATTR(description, 0444, description_show, NULL);
 462
 463 static ssize_t
 464 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 465                      char *buf) {
 466         struct acpi_device *acpi_dev = to_acpi_device(dev);
 467         acpi_status status;
 468         unsigned long long sun;
 469
 470         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 471         if (ACPI_FAILURE(status))
 472                 return -EIO;
 473
 474         return sprintf(buf, "%llu\n", sun);
 475 }
 476 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 477
 478 static ssize_t
 479 acpi_device_hrv_show(struct device *dev, struct device_attribute *attr,
 480                      char *buf) {
 481         struct acpi_device *acpi_dev = to_acpi_device(dev);
 482         acpi_status status;
 483         unsigned long long hrv;
 484
 485         status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 486         if (ACPI_FAILURE(status))
 487                 return -EIO;
 488
 489         return sprintf(buf, "%llu\n", hrv);
 490 }
 491 static DEVICE_ATTR(hrv, 0444, acpi_device_hrv_show, NULL);
 492
 493 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 494                                 char *buf) {
 495         struct acpi_device *acpi_dev = to_acpi_device(dev);
 496         acpi_status status;
 497         unsigned long long sta;
 498
 499         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 500         if (ACPI_FAILURE(status))
 501                 return -EIO;
 502
 503         return sprintf(buf, "%llu\n", sta);
 504 }
 505 static DEVICE_ATTR_RO(status);
 506
 507 /**
 508  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 509  * @dev: ACPI device object.
 510  */
 511 int acpi_device_setup_files(struct acpi_device *dev)
 512 {
 513         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 514         acpi_status status;
 515         int result = 0;
 516
 517         /*
 518          * Devices gotten from FADT don't have a "path" attribute
 519          */
 520         if (dev->handle) {
 521                 result = device_create_file(&dev->dev, &dev_attr_path);
 522                 if (result)
 523                         goto end;
 524         }
 525
 526         if (!list_empty(&dev->pnp.ids)) {
 527                 result = device_create_file(&dev->dev, &dev_attr_hid);
 528                 if (result)
 529                         goto end;
 530
 531                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 532                 if (result)
 533                         goto end;
 534         }
 535
 536         /*
 537          * If device has _STR, 'description' file is created
 538          */
 539         if (acpi_has_method(dev->handle, "_STR")) {
 540                 status = acpi_evaluate_object(dev->handle, "_STR",
 541                                         NULL, &buffer);
 542                 if (ACPI_FAILURE(status))
 543                         buffer.pointer = NULL;
 544                 dev->pnp.str_obj = buffer.pointer;
 545                 result = device_create_file(&dev->dev, &dev_attr_description);
 546                 if (result)
 547                         goto end;
 548         }
 549
 550         if (dev->pnp.type.bus_address)
 551                 result = device_create_file(&dev->dev, &dev_attr_adr);
 552         if (dev->pnp.unique_id)
 553                 result = device_create_file(&dev->dev, &dev_attr_uid);
 554
 555         if (acpi_has_method(dev->handle, "_SUN")) {
 556                 result = device_create_file(&dev->dev, &dev_attr_sun);
 557                 if (result)
 558                         goto end;
 559         }
 560
 561         if (acpi_has_method(dev->handle, "_HRV")) {
 562                 result = device_create_file(&dev->dev, &dev_attr_hrv);
 563                 if (result)
 564                         goto end;
 565         }
 566
 567         if (acpi_has_method(dev->handle, "_STA")) {
 568                 result = device_create_file(&dev->dev, &dev_attr_status);
 569                 if (result)
 570                         goto end;
 571         }
 572
 573         /*
 574          * If device has _EJ0, 'eject' file is created that is used to trigger
 575          * hot-removal function from userland.
 576          */
 577         if (acpi_has_method(dev->handle, "_EJ0")) {
 578                 result = device_create_file(&dev->dev, &dev_attr_eject);
 579                 if (result)
 580                         return result;
 581         }
 582
 583         if (dev->flags.power_manageable) {
 584                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 585                 if (result)
 586                         return result;
 587
 588                 if (dev->power.flags.power_resources)
 589                         result = device_create_file(&dev->dev,
 590                                                     &dev_attr_real_power_state);
 591         }
 592
 593         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 594
 595 end:
 596         return result;
 597 }
 598
 599 /**
 600  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 601  * @dev: ACPI device object.
 602  */
 603 void acpi_device_remove_files(struct acpi_device *dev)
 604 {
 605         acpi_hide_nondev_subnodes(&dev->data);
 606
 607         if (dev->flags.power_manageable) {
 608                 device_remove_file(&dev->dev, &dev_attr_power_state);
 609                 if (dev->power.flags.power_resources)
 610                         device_remove_file(&dev->dev,
 611                                            &dev_attr_real_power_state);
 612         }
 613
 614         /*
 615          * If device has _STR, remove 'description' file
 616          */
 617         if (acpi_has_method(dev->handle, "_STR")) {
 618                 kfree(dev->pnp.str_obj);
 619                 device_remove_file(&dev->dev, &dev_attr_description);
 620         }
 621         /*
 622          * If device has _EJ0, remove 'eject' file.
 623          */
 624         if (acpi_has_method(dev->handle, "_EJ0"))
 625                 device_remove_file(&dev->dev, &dev_attr_eject);
 626
 627         if (acpi_has_method(dev->handle, "_SUN"))
 628                 device_remove_file(&dev->dev, &dev_attr_sun);
 629
 630         if (acpi_has_method(dev->handle, "_HRV"))
 631                 device_remove_file(&dev->dev, &dev_attr_hrv);
 632
 633         if (dev->pnp.unique_id)
 634                 device_remove_file(&dev->dev, &dev_attr_uid);
 635         if (dev->pnp.type.bus_address)
 636                 device_remove_file(&dev->dev, &dev_attr_adr);
 637         device_remove_file(&dev->dev, &dev_attr_modalias);
 638         device_remove_file(&dev->dev, &dev_attr_hid);
 639         if (acpi_has_method(dev->handle, "_STA"))
 640                 device_remove_file(&dev->dev, &dev_attr_status);
 641         if (dev->handle)
 642                 device_remove_file(&dev->dev, &dev_attr_path);
 643 }