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         /* Avoid unnecessarily loading modules for non present devices. */
 150         if (!acpi_device_is_present(acpi_dev))
 151                 return 0;
 152
 153         /*
 154          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 155          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 156          * device's list.
 157          */
 158         count = 0;
 159         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 160                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 161                         count++;
 162
 163         if (!count)
 164                 return 0;
 165
 166         len = snprintf(modalias, size, "acpi:");
 167         if (len <= 0)
 168                 return len;
 169
 170         size -= len;
 171
 172         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 173                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 174                         continue;
 175
 176                 count = snprintf(&modalias[len], size, "%s:", id->id);
 177                 if (count < 0)
 178                         return -EINVAL;
 179
 180                 if (count >= size)
 181                         return -ENOMEM;
 182
 183                 len += count;
 184                 size -= count;
 185         }
 186         modalias[len] = '\0';
 187         return len;
 188 }
 189
 190 /**
 191  * create_of_modalias - Creates DT compatible string for modalias and uevent
 192  * @acpi_dev: ACPI device object.
 193  * @modalias: Buffer to print into.
 194  * @size: Size of the buffer.
 195  *
 196  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 197  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 198  * ACPI/PNP IDs.
 199  */
 200 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 201                               int size)
 202 {
 203         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 204         const union acpi_object *of_compatible, *obj;
 205         acpi_status status;
 206         int len, count;
 207         int i, nval;
 208         char *c;
 209
 210         status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 211         if (ACPI_FAILURE(status))
 212                 return -ENODEV;
 213
 214         /* DT strings are all in lower case */
 215         for (c = buf.pointer; *c != '\0'; c++)
 216                 *c = tolower(*c);
 217
 218         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 219         ACPI_FREE(buf.pointer);
 220
 221         if (len <= 0)
 222                 return len;
 223
 224         of_compatible = acpi_dev->data.of_compatible;
 225         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 226                 nval = of_compatible->package.count;
 227                 obj = of_compatible->package.elements;
 228         } else { /* Must be ACPI_TYPE_STRING. */
 229                 nval = 1;
 230                 obj = of_compatible;
 231         }
 232         for (i = 0; i < nval; i++, obj++) {
 233                 count = snprintf(&modalias[len], size, "C%s",
 234                                  obj->string.pointer);
 235                 if (count < 0)
 236                         return -EINVAL;
 237
 238                 if (count >= size)
 239                         return -ENOMEM;
 240
 241                 len += count;
 242                 size -= count;
 243         }
 244         modalias[len] = '\0';
 245         return len;
 246 }
 247
 248 int __acpi_device_uevent_modalias(struct acpi_device *adev,
 249                                   struct kobj_uevent_env *env)
 250 {
 251         int len;
 252
 253         if (!adev)
 254                 return -ENODEV;
 255
 256         if (list_empty(&adev->pnp.ids))
 257                 return 0;
 258
 259         if (add_uevent_var(env, "MODALIAS="))
 260                 return -ENOMEM;
 261
 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         if (!adev->data.of_compatible)
 269                 return 0;
 270
 271         if (len > 0 && add_uevent_var(env, "MODALIAS="))
 272                 return -ENOMEM;
 273
 274         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 275                                  sizeof(env->buf) - env->buflen);
 276         if (len < 0)
 277                 return len;
 278
 279         env->buflen += len;
 280
 281         return 0;
 282 }
 283
 284 /**
 285  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 286  *
 287  * Create the uevent modalias field for ACPI-enumerated devices.
 288  *
 289  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 290  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 291  */
 292 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 293 {
 294         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 295 }
 296 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 297
 298 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 299 {
 300         int len, count;
 301
 302         if (!adev)
 303                 return -ENODEV;
 304
 305         if (list_empty(&adev->pnp.ids))
 306                 return 0;
 307
 308         len = create_pnp_modalias(adev, buf, size - 1);
 309         if (len < 0) {
 310                 return len;
 311         } else if (len > 0) {
 312                 buf[len++] = '\n';
 313                 size -= len;
 314         }
 315         if (!adev->data.of_compatible)
 316                 return len;
 317
 318         count = create_of_modalias(adev, buf + len, size - 1);
 319         if (count < 0) {
 320                 return count;
 321         } else if (count > 0) {
 322                 len += count;
 323                 buf[len++] = '\n';
 324         }
 325
 326         return len;
 327 }
 328
 329 /**
 330  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 331  *
 332  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 333  *
 334  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 335  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 336  */
 337 int acpi_device_modalias(struct device *dev, char *buf, int size)
 338 {
 339         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 340 }
 341 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 342
 343 static ssize_t
 344 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 345         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 346 }
 347 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 348
 349 static ssize_t real_power_state_show(struct device *dev,
 350                                      struct device_attribute *attr, char *buf)
 351 {
 352         struct acpi_device *adev = to_acpi_device(dev);
 353         int state;
 354         int ret;
 355
 356         ret = acpi_device_get_power(adev, &state);
 357         if (ret)
 358                 return ret;
 359
 360         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 361 }
 362
 363 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 364
 365 static ssize_t power_state_show(struct device *dev,
 366                                 struct device_attribute *attr, char *buf)
 367 {
 368         struct acpi_device *adev = to_acpi_device(dev);
 369
 370         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 371 }
 372
 373 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 374
 375 static ssize_t
 376 acpi_eject_store(struct device *d, struct device_attribute *attr,
 377                 const char *buf, size_t count)
 378 {
 379         struct acpi_device *acpi_device = to_acpi_device(d);
 380         acpi_object_type not_used;
 381         acpi_status status;
 382
 383         if (!count || buf[0] != '1')
 384                 return -EINVAL;
 385
 386         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 387             && !acpi_device->driver)
 388                 return -ENODEV;
 389
 390         status = acpi_get_type(acpi_device->handle, &not_used);
 391         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 392                 return -ENODEV;
 393
 394         get_device(&acpi_device->dev);
 395         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 396         if (ACPI_SUCCESS(status))
 397                 return count;
 398
 399         put_device(&acpi_device->dev);
 400         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 401                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 402         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 403 }
 404
 405 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 406
 407 static ssize_t
 408 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 409         struct acpi_device *acpi_dev = to_acpi_device(dev);
 410
 411         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 412 }
 413 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 414
 415 static ssize_t acpi_device_uid_show(struct device *dev,
 416                                     struct device_attribute *attr, char *buf)
 417 {
 418         struct acpi_device *acpi_dev = to_acpi_device(dev);
 419
 420         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 421 }
 422 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 423
 424 static ssize_t acpi_device_adr_show(struct device *dev,
 425                                     struct device_attribute *attr, char *buf)
 426 {
 427         struct acpi_device *acpi_dev = to_acpi_device(dev);
 428
 429         return sprintf(buf, "0x%08x\n",
 430                        (unsigned int)(acpi_dev->pnp.bus_address));
 431 }
 432 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 433
 434 static ssize_t acpi_device_path_show(struct device *dev,
 435                                      struct device_attribute *attr, char *buf)
 436 {
 437         struct acpi_device *acpi_dev = to_acpi_device(dev);
 438
 439         return acpi_object_path(acpi_dev->handle, buf);
 440 }
 441 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 442
 443 /* sysfs file that shows description text from the ACPI _STR method */
 444 static ssize_t description_show(struct device *dev,
 445                                 struct device_attribute *attr,
 446                                 char *buf) {
 447         struct acpi_device *acpi_dev = to_acpi_device(dev);
 448         int result;
 449
 450         if (acpi_dev->pnp.str_obj == NULL)
 451                 return 0;
 452
 453         /*
 454          * The _STR object contains a Unicode identifier for a device.
 455          * We need to convert to utf-8 so it can be displayed.
 456          */
 457         result = utf16s_to_utf8s(
 458                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 459                 acpi_dev->pnp.str_obj->buffer.length,
 460                 UTF16_LITTLE_ENDIAN, buf,
 461                 PAGE_SIZE);
 462
 463         buf[result++] = '\n';
 464
 465         return result;
 466 }
 467 static DEVICE_ATTR(description, 0444, description_show, NULL);
 468
 469 static ssize_t
 470 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 471                      char *buf) {
 472         struct acpi_device *acpi_dev = to_acpi_device(dev);
 473         acpi_status status;
 474         unsigned long long sun;
 475
 476         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 477         if (ACPI_FAILURE(status))
 478                 return -ENODEV;
 479
 480         return sprintf(buf, "%llu\n", sun);
 481 }
 482 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 483
 484 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 485                                 char *buf) {
 486         struct acpi_device *acpi_dev = to_acpi_device(dev);
 487         acpi_status status;
 488         unsigned long long sta;
 489
 490         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 491         if (ACPI_FAILURE(status))
 492                 return -ENODEV;
 493
 494         return sprintf(buf, "%llu\n", sta);
 495 }
 496 static DEVICE_ATTR_RO(status);
 497
 498 /**
 499  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 500  * @dev: ACPI device object.
 501  */
 502 int acpi_device_setup_files(struct acpi_device *dev)
 503 {
 504         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 505         acpi_status status;
 506         int result = 0;
 507
 508         /*
 509          * Devices gotten from FADT don't have a "path" attribute
 510          */
 511         if (dev->handle) {
 512                 result = device_create_file(&dev->dev, &dev_attr_path);
 513                 if (result)
 514                         goto end;
 515         }
 516
 517         if (!list_empty(&dev->pnp.ids)) {
 518                 result = device_create_file(&dev->dev, &dev_attr_hid);
 519                 if (result)
 520                         goto end;
 521
 522                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 523                 if (result)
 524                         goto end;
 525         }
 526
 527         /*
 528          * If device has _STR, 'description' file is created
 529          */
 530         if (acpi_has_method(dev->handle, "_STR")) {
 531                 status = acpi_evaluate_object(dev->handle, "_STR",
 532                                         NULL, &buffer);
 533                 if (ACPI_FAILURE(status))
 534                         buffer.pointer = NULL;
 535                 dev->pnp.str_obj = buffer.pointer;
 536                 result = device_create_file(&dev->dev, &dev_attr_description);
 537                 if (result)
 538                         goto end;
 539         }
 540
 541         if (dev->pnp.type.bus_address)
 542                 result = device_create_file(&dev->dev, &dev_attr_adr);
 543         if (dev->pnp.unique_id)
 544                 result = device_create_file(&dev->dev, &dev_attr_uid);
 545
 546         if (acpi_has_method(dev->handle, "_SUN")) {
 547                 result = device_create_file(&dev->dev, &dev_attr_sun);
 548                 if (result)
 549                         goto end;
 550         }
 551
 552         if (acpi_has_method(dev->handle, "_STA")) {
 553                 result = device_create_file(&dev->dev, &dev_attr_status);
 554                 if (result)
 555                         goto end;
 556         }
 557
 558         /*
 559          * If device has _EJ0, 'eject' file is created that is used to trigger
 560          * hot-removal function from userland.
 561          */
 562         if (acpi_has_method(dev->handle, "_EJ0")) {
 563                 result = device_create_file(&dev->dev, &dev_attr_eject);
 564                 if (result)
 565                         return result;
 566         }
 567
 568         if (dev->flags.power_manageable) {
 569                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 570                 if (result)
 571                         return result;
 572
 573                 if (dev->power.flags.power_resources)
 574                         result = device_create_file(&dev->dev,
 575                                                     &dev_attr_real_power_state);
 576         }
 577
 578         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 579
 580 end:
 581         return result;
 582 }
 583
 584 /**
 585  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 586  * @dev: ACPI device object.
 587  */
 588 void acpi_device_remove_files(struct acpi_device *dev)
 589 {
 590         acpi_hide_nondev_subnodes(&dev->data);
 591
 592         if (dev->flags.power_manageable) {
 593                 device_remove_file(&dev->dev, &dev_attr_power_state);
 594                 if (dev->power.flags.power_resources)
 595                         device_remove_file(&dev->dev,
 596                                            &dev_attr_real_power_state);
 597         }
 598
 599         /*
 600          * If device has _STR, remove 'description' file
 601          */
 602         if (acpi_has_method(dev->handle, "_STR")) {
 603                 kfree(dev->pnp.str_obj);
 604                 device_remove_file(&dev->dev, &dev_attr_description);
 605         }
 606         /*
 607          * If device has _EJ0, remove 'eject' file.
 608          */
 609         if (acpi_has_method(dev->handle, "_EJ0"))
 610                 device_remove_file(&dev->dev, &dev_attr_eject);
 611
 612         if (acpi_has_method(dev->handle, "_SUN"))
 613                 device_remove_file(&dev->dev, &dev_attr_sun);
 614
 615         if (dev->pnp.unique_id)
 616                 device_remove_file(&dev->dev, &dev_attr_uid);
 617         if (dev->pnp.type.bus_address)
 618                 device_remove_file(&dev->dev, &dev_attr_adr);
 619         device_remove_file(&dev->dev, &dev_attr_modalias);
 620         device_remove_file(&dev->dev, &dev_attr_hid);
 621         if (acpi_has_method(dev->handle, "_STA"))
 622                 device_remove_file(&dev->dev, &dev_attr_status);
 623         if (dev->handle)
 624                 device_remove_file(&dev->dev, &dev_attr_path);
 625 }