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         int len, count;
 206         int i, nval;
 207         char *c;
 208
 209         acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 210         /* DT strings are all in lower case */
 211         for (c = buf.pointer; *c != '\0'; c++)
 212                 *c = tolower(*c);
 213
 214         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 215         ACPI_FREE(buf.pointer);
 216
 217         if (len <= 0)
 218                 return len;
 219
 220         of_compatible = acpi_dev->data.of_compatible;
 221         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 222                 nval = of_compatible->package.count;
 223                 obj = of_compatible->package.elements;
 224         } else { /* Must be ACPI_TYPE_STRING. */
 225                 nval = 1;
 226                 obj = of_compatible;
 227         }
 228         for (i = 0; i < nval; i++, obj++) {
 229                 count = snprintf(&modalias[len], size, "C%s",
 230                                  obj->string.pointer);
 231                 if (count < 0)
 232                         return -EINVAL;
 233
 234                 if (count >= size)
 235                         return -ENOMEM;
 236
 237                 len += count;
 238                 size -= count;
 239         }
 240         modalias[len] = '\0';
 241         return len;
 242 }
 243
 244 int __acpi_device_uevent_modalias(struct acpi_device *adev,
 245                                   struct kobj_uevent_env *env)
 246 {
 247         int len;
 248
 249         if (!adev)
 250                 return -ENODEV;
 251
 252         if (list_empty(&adev->pnp.ids))
 253                 return 0;
 254
 255         if (add_uevent_var(env, "MODALIAS="))
 256                 return -ENOMEM;
 257
 258         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         if (!adev->data.of_compatible)
 265                 return 0;
 266
 267         if (len > 0 && add_uevent_var(env, "MODALIAS="))
 268                 return -ENOMEM;
 269
 270         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 271                                  sizeof(env->buf) - env->buflen);
 272         if (len < 0)
 273                 return len;
 274
 275         env->buflen += len;
 276
 277         return 0;
 278 }
 279
 280 /**
 281  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
 282  *
 283  * Create the uevent modalias field for ACPI-enumerated devices.
 284  *
 285  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 286  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 287  */
 288 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 289 {
 290         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 291 }
 292 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 293
 294 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 295 {
 296         int len, count;
 297
 298         if (!adev)
 299                 return -ENODEV;
 300
 301         if (list_empty(&adev->pnp.ids))
 302                 return 0;
 303
 304         len = create_pnp_modalias(adev, buf, size - 1);
 305         if (len < 0) {
 306                 return len;
 307         } else if (len > 0) {
 308                 buf[len++] = '\n';
 309                 size -= len;
 310         }
 311         if (!adev->data.of_compatible)
 312                 return len;
 313
 314         count = create_of_modalias(adev, buf + len, size - 1);
 315         if (count < 0) {
 316                 return count;
 317         } else if (count > 0) {
 318                 len += count;
 319                 buf[len++] = '\n';
 320         }
 321
 322         return len;
 323 }
 324
 325 /**
 326  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
 327  *
 328  * Create the modalias sysfs attribute for ACPI-enumerated devices.
 329  *
 330  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
 331  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
 332  */
 333 int acpi_device_modalias(struct device *dev, char *buf, int size)
 334 {
 335         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 336 }
 337 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 338
 339 static ssize_t
 340 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 341         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 342 }
 343 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 344
 345 static ssize_t real_power_state_show(struct device *dev,
 346                                      struct device_attribute *attr, char *buf)
 347 {
 348         struct acpi_device *adev = to_acpi_device(dev);
 349         int state;
 350         int ret;
 351
 352         ret = acpi_device_get_power(adev, &state);
 353         if (ret)
 354                 return ret;
 355
 356         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 357 }
 358
 359 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 360
 361 static ssize_t power_state_show(struct device *dev,
 362                                 struct device_attribute *attr, char *buf)
 363 {
 364         struct acpi_device *adev = to_acpi_device(dev);
 365
 366         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 367 }
 368
 369 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 370
 371 static ssize_t
 372 acpi_eject_store(struct device *d, struct device_attribute *attr,
 373                 const char *buf, size_t count)
 374 {
 375         struct acpi_device *acpi_device = to_acpi_device(d);
 376         acpi_object_type not_used;
 377         acpi_status status;
 378
 379         if (!count || buf[0] != '1')
 380                 return -EINVAL;
 381
 382         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 383             && !acpi_device->driver)
 384                 return -ENODEV;
 385
 386         status = acpi_get_type(acpi_device->handle, &not_used);
 387         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 388                 return -ENODEV;
 389
 390         get_device(&acpi_device->dev);
 391         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 392         if (ACPI_SUCCESS(status))
 393                 return count;
 394
 395         put_device(&acpi_device->dev);
 396         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 397                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 398         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 399 }
 400
 401 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 402
 403 static ssize_t
 404 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 405         struct acpi_device *acpi_dev = to_acpi_device(dev);
 406
 407         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 408 }
 409 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 410
 411 static ssize_t acpi_device_uid_show(struct device *dev,
 412                                     struct device_attribute *attr, char *buf)
 413 {
 414         struct acpi_device *acpi_dev = to_acpi_device(dev);
 415
 416         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 417 }
 418 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 419
 420 static ssize_t acpi_device_adr_show(struct device *dev,
 421                                     struct device_attribute *attr, char *buf)
 422 {
 423         struct acpi_device *acpi_dev = to_acpi_device(dev);
 424
 425         return sprintf(buf, "0x%08x\n",
 426                        (unsigned int)(acpi_dev->pnp.bus_address));
 427 }
 428 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 429
 430 static ssize_t acpi_device_path_show(struct device *dev,
 431                                      struct device_attribute *attr, char *buf)
 432 {
 433         struct acpi_device *acpi_dev = to_acpi_device(dev);
 434
 435         return acpi_object_path(acpi_dev->handle, buf);
 436 }
 437 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 438
 439 /* sysfs file that shows description text from the ACPI _STR method */
 440 static ssize_t description_show(struct device *dev,
 441                                 struct device_attribute *attr,
 442                                 char *buf) {
 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);
 458
 459         buf[result++] = '\n';
 460
 461         return result;
 462 }
 463 static DEVICE_ATTR(description, 0444, description_show, NULL);
 464
 465 static ssize_t
 466 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 467                      char *buf) {
 468         struct acpi_device *acpi_dev = to_acpi_device(dev);
 469         acpi_status status;
 470         unsigned long long sun;
 471
 472         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 473         if (ACPI_FAILURE(status))
 474                 return -ENODEV;
 475
 476         return sprintf(buf, "%llu\n", sun);
 477 }
 478 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 479
 480 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 481                                 char *buf) {
 482         struct acpi_device *acpi_dev = to_acpi_device(dev);
 483         acpi_status status;
 484         unsigned long long sta;
 485
 486         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 487         if (ACPI_FAILURE(status))
 488                 return -ENODEV;
 489
 490         return sprintf(buf, "%llu\n", sta);
 491 }
 492 static DEVICE_ATTR_RO(status);
 493
 494 /**
 495  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 496  * @dev: ACPI device object.
 497  */
 498 int acpi_device_setup_files(struct acpi_device *dev)
 499 {
 500         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 501         acpi_status status;
 502         int result = 0;
 503
 504         /*
 505          * Devices gotten from FADT don't have a "path" attribute
 506          */
 507         if (dev->handle) {
 508                 result = device_create_file(&dev->dev, &dev_attr_path);
 509                 if (result)
 510                         goto end;
 511         }
 512
 513         if (!list_empty(&dev->pnp.ids)) {
 514                 result = device_create_file(&dev->dev, &dev_attr_hid);
 515                 if (result)
 516                         goto end;
 517
 518                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 519                 if (result)
 520                         goto end;
 521         }
 522
 523         /*
 524          * If device has _STR, 'description' file is created
 525          */
 526         if (acpi_has_method(dev->handle, "_STR")) {
 527                 status = acpi_evaluate_object(dev->handle, "_STR",
 528                                         NULL, &buffer);
 529                 if (ACPI_FAILURE(status))
 530                         buffer.pointer = NULL;
 531                 dev->pnp.str_obj = buffer.pointer;
 532                 result = device_create_file(&dev->dev, &dev_attr_description);
 533                 if (result)
 534                         goto end;
 535         }
 536
 537         if (dev->pnp.type.bus_address)
 538                 result = device_create_file(&dev->dev, &dev_attr_adr);
 539         if (dev->pnp.unique_id)
 540                 result = device_create_file(&dev->dev, &dev_attr_uid);
 541
 542         if (acpi_has_method(dev->handle, "_SUN")) {
 543                 result = device_create_file(&dev->dev, &dev_attr_sun);
 544                 if (result)
 545                         goto end;
 546         }
 547
 548         if (acpi_has_method(dev->handle, "_STA")) {
 549                 result = device_create_file(&dev->dev, &dev_attr_status);
 550                 if (result)
 551                         goto end;
 552         }
 553
 554         /*
 555          * If device has _EJ0, 'eject' file is created that is used to trigger
 556          * hot-removal function from userland.
 557          */
 558         if (acpi_has_method(dev->handle, "_EJ0")) {
 559                 result = device_create_file(&dev->dev, &dev_attr_eject);
 560                 if (result)
 561                         return result;
 562         }
 563
 564         if (dev->flags.power_manageable) {
 565                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 566                 if (result)
 567                         return result;
 568
 569                 if (dev->power.flags.power_resources)
 570                         result = device_create_file(&dev->dev,
 571                                                     &dev_attr_real_power_state);
 572         }
 573
 574         acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 575
 576 end:
 577         return result;
 578 }
 579
 580 /**
 581  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 582  * @dev: ACPI device object.
 583  */
 584 void acpi_device_remove_files(struct acpi_device *dev)
 585 {
 586         acpi_hide_nondev_subnodes(&dev->data);
 587
 588         if (dev->flags.power_manageable) {
 589                 device_remove_file(&dev->dev, &dev_attr_power_state);
 590                 if (dev->power.flags.power_resources)
 591                         device_remove_file(&dev->dev,
 592                                            &dev_attr_real_power_state);
 593         }
 594
 595         /*
 596          * If device has _STR, remove 'description' file
 597          */
 598         if (acpi_has_method(dev->handle, "_STR")) {
 599                 kfree(dev->pnp.str_obj);
 600                 device_remove_file(&dev->dev, &dev_attr_description);
 601         }
 602         /*
 603          * If device has _EJ0, remove 'eject' file.
 604          */
 605         if (acpi_has_method(dev->handle, "_EJ0"))
 606                 device_remove_file(&dev->dev, &dev_attr_eject);
 607
 608         if (acpi_has_method(dev->handle, "_SUN"))
 609                 device_remove_file(&dev->dev, &dev_attr_sun);
 610
 611         if (dev->pnp.unique_id)
 612                 device_remove_file(&dev->dev, &dev_attr_uid);
 613         if (dev->pnp.type.bus_address)
 614                 device_remove_file(&dev->dev, &dev_attr_adr);
 615         device_remove_file(&dev->dev, &dev_attr_modalias);
 616         device_remove_file(&dev->dev, &dev_attr_hid);
 617         if (acpi_has_method(dev->handle, "_STA"))
 618                 device_remove_file(&dev->dev, &dev_attr_status);
 619         if (dev->handle)
 620                 device_remove_file(&dev->dev, &dev_attr_path);
 621 }