linux/drivers/acpi/device_sysfs.c
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   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
  29static 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
  43struct 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
  53static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
  54{
  55        return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
  56}
  57
  58DATA_NODE_ATTR(path);
  59
  60static 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
  68static 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
  77static const struct sysfs_ops acpi_data_node_sysfs_ops = {
  78        .show   = acpi_data_node_attr_show,
  79};
  80
  81static 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
  87static 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
  93static 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_expose_nondev_subnodes(&dn->kobj, &dn->data);
 110                else if (dn->handle)
 111                        acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
 112        }
 113}
 114
 115static 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*/
 142static 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 */
 200static 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
 244int __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 */
 288int 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}
 292EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 293
 294static 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 */
 333int acpi_device_modalias(struct device *dev, char *buf, int size)
 334{
 335        return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 336}
 337EXPORT_SYMBOL_GPL(acpi_device_modalias);
 338
 339static ssize_t
 340acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 341{
 342        return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 343}
 344static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 345
 346static ssize_t real_power_state_show(struct device *dev,
 347                                     struct device_attribute *attr, char *buf)
 348{
 349        struct acpi_device *adev = to_acpi_device(dev);
 350        int state;
 351        int ret;
 352
 353        ret = acpi_device_get_power(adev, &state);
 354        if (ret)
 355                return ret;
 356
 357        return sprintf(buf, "%s\n", acpi_power_state_string(state));
 358}
 359
 360static DEVICE_ATTR_RO(real_power_state);
 361
 362static ssize_t power_state_show(struct device *dev,
 363                                struct device_attribute *attr, char *buf)
 364{
 365        struct acpi_device *adev = to_acpi_device(dev);
 366
 367        return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 368}
 369
 370static DEVICE_ATTR_RO(power_state);
 371
 372static ssize_t
 373acpi_eject_store(struct device *d, struct device_attribute *attr,
 374                const char *buf, size_t count)
 375{
 376        struct acpi_device *acpi_device = to_acpi_device(d);
 377        acpi_object_type not_used;
 378        acpi_status status;
 379
 380        if (!count || buf[0] != '1')
 381                return -EINVAL;
 382
 383        if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 384            && !acpi_device->driver)
 385                return -ENODEV;
 386
 387        status = acpi_get_type(acpi_device->handle, &not_used);
 388        if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 389                return -ENODEV;
 390
 391        get_device(&acpi_device->dev);
 392        status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 393        if (ACPI_SUCCESS(status))
 394                return count;
 395
 396        put_device(&acpi_device->dev);
 397        acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 398                          ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 399        return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 400}
 401
 402static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 403
 404static ssize_t
 405acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf)
 406{
 407        struct acpi_device *acpi_dev = to_acpi_device(dev);
 408
 409        return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 410}
 411static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 412
 413static ssize_t acpi_device_uid_show(struct device *dev,
 414                                    struct device_attribute *attr, char *buf)
 415{
 416        struct acpi_device *acpi_dev = to_acpi_device(dev);
 417
 418        return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 419}
 420static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 421
 422static ssize_t acpi_device_adr_show(struct device *dev,
 423                                    struct device_attribute *attr, char *buf)
 424{
 425        struct acpi_device *acpi_dev = to_acpi_device(dev);
 426
 427        return sprintf(buf, "0x%08x\n",
 428                       (unsigned int)(acpi_dev->pnp.bus_address));
 429}
 430static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 431
 432static ssize_t acpi_device_path_show(struct device *dev,
 433                                     struct device_attribute *attr, char *buf)
 434{
 435        struct acpi_device *acpi_dev = to_acpi_device(dev);
 436
 437        return acpi_object_path(acpi_dev->handle, buf);
 438}
 439static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 440
 441/* sysfs file that shows description text from the ACPI _STR method */
 442static ssize_t description_show(struct device *dev,
 443                                struct device_attribute *attr,
 444                                char *buf) {
 445        struct acpi_device *acpi_dev = to_acpi_device(dev);
 446        int result;
 447
 448        if (acpi_dev->pnp.str_obj == NULL)
 449                return 0;
 450
 451        /*
 452         * The _STR object contains a Unicode identifier for a device.
 453         * We need to convert to utf-8 so it can be displayed.
 454         */
 455        result = utf16s_to_utf8s(
 456                (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 457                acpi_dev->pnp.str_obj->buffer.length,
 458                UTF16_LITTLE_ENDIAN, buf,
 459                PAGE_SIZE);
 460
 461        buf[result++] = '\n';
 462
 463        return result;
 464}
 465static DEVICE_ATTR_RO(description);
 466
 467static ssize_t
 468acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 469                     char *buf) {
 470        struct acpi_device *acpi_dev = to_acpi_device(dev);
 471        acpi_status status;
 472        unsigned long long sun;
 473
 474        status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 475        if (ACPI_FAILURE(status))
 476                return -EIO;
 477
 478        return sprintf(buf, "%llu\n", sun);
 479}
 480static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 481
 482static ssize_t
 483acpi_device_hrv_show(struct device *dev, struct device_attribute *attr,
 484                     char *buf) {
 485        struct acpi_device *acpi_dev = to_acpi_device(dev);
 486        acpi_status status;
 487        unsigned long long hrv;
 488
 489        status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
 490        if (ACPI_FAILURE(status))
 491                return -EIO;
 492
 493        return sprintf(buf, "%llu\n", hrv);
 494}
 495static DEVICE_ATTR(hrv, 0444, acpi_device_hrv_show, NULL);
 496
 497static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 498                                char *buf) {
 499        struct acpi_device *acpi_dev = to_acpi_device(dev);
 500        acpi_status status;
 501        unsigned long long sta;
 502
 503        status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 504        if (ACPI_FAILURE(status))
 505                return -EIO;
 506
 507        return sprintf(buf, "%llu\n", sta);
 508}
 509static DEVICE_ATTR_RO(status);
 510
 511/**
 512 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
 513 * @dev: ACPI device object.
 514 */
 515int acpi_device_setup_files(struct acpi_device *dev)
 516{
 517        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 518        acpi_status status;
 519        int result = 0;
 520
 521        /*
 522         * Devices gotten from FADT don't have a "path" attribute
 523         */
 524        if (dev->handle) {
 525                result = device_create_file(&dev->dev, &dev_attr_path);
 526                if (result)
 527                        goto end;
 528        }
 529
 530        if (!list_empty(&dev->pnp.ids)) {
 531                result = device_create_file(&dev->dev, &dev_attr_hid);
 532                if (result)
 533                        goto end;
 534
 535                result = device_create_file(&dev->dev, &dev_attr_modalias);
 536                if (result)
 537                        goto end;
 538        }
 539
 540        /*
 541         * If device has _STR, 'description' file is created
 542         */
 543        if (acpi_has_method(dev->handle, "_STR")) {
 544                status = acpi_evaluate_object(dev->handle, "_STR",
 545                                        NULL, &buffer);
 546                if (ACPI_FAILURE(status))
 547                        buffer.pointer = NULL;
 548                dev->pnp.str_obj = buffer.pointer;
 549                result = device_create_file(&dev->dev, &dev_attr_description);
 550                if (result)
 551                        goto end;
 552        }
 553
 554        if (dev->pnp.type.bus_address)
 555                result = device_create_file(&dev->dev, &dev_attr_adr);
 556        if (dev->pnp.unique_id)
 557                result = device_create_file(&dev->dev, &dev_attr_uid);
 558
 559        if (acpi_has_method(dev->handle, "_SUN")) {
 560                result = device_create_file(&dev->dev, &dev_attr_sun);
 561                if (result)
 562                        goto end;
 563        }
 564
 565        if (acpi_has_method(dev->handle, "_HRV")) {
 566                result = device_create_file(&dev->dev, &dev_attr_hrv);
 567                if (result)
 568                        goto end;
 569        }
 570
 571        if (acpi_has_method(dev->handle, "_STA")) {
 572                result = device_create_file(&dev->dev, &dev_attr_status);
 573                if (result)
 574                        goto end;
 575        }
 576
 577        /*
 578         * If device has _EJ0, 'eject' file is created that is used to trigger
 579         * hot-removal function from userland.
 580         */
 581        if (acpi_has_method(dev->handle, "_EJ0")) {
 582                result = device_create_file(&dev->dev, &dev_attr_eject);
 583                if (result)
 584                        return result;
 585        }
 586
 587        if (dev->flags.power_manageable) {
 588                result = device_create_file(&dev->dev, &dev_attr_power_state);
 589                if (result)
 590                        return result;
 591
 592                if (dev->power.flags.power_resources)
 593                        result = device_create_file(&dev->dev,
 594                                                    &dev_attr_real_power_state);
 595        }
 596
 597        acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
 598
 599end:
 600        return result;
 601}
 602
 603/**
 604 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
 605 * @dev: ACPI device object.
 606 */
 607void acpi_device_remove_files(struct acpi_device *dev)
 608{
 609        acpi_hide_nondev_subnodes(&dev->data);
 610
 611        if (dev->flags.power_manageable) {
 612                device_remove_file(&dev->dev, &dev_attr_power_state);
 613                if (dev->power.flags.power_resources)
 614                        device_remove_file(&dev->dev,
 615                                           &dev_attr_real_power_state);
 616        }
 617
 618        /*
 619         * If device has _STR, remove 'description' file
 620         */
 621        if (acpi_has_method(dev->handle, "_STR")) {
 622                kfree(dev->pnp.str_obj);
 623                device_remove_file(&dev->dev, &dev_attr_description);
 624        }
 625        /*
 626         * If device has _EJ0, remove 'eject' file.
 627         */
 628        if (acpi_has_method(dev->handle, "_EJ0"))
 629                device_remove_file(&dev->dev, &dev_attr_eject);
 630
 631        if (acpi_has_method(dev->handle, "_SUN"))
 632                device_remove_file(&dev->dev, &dev_attr_sun);
 633
 634        if (acpi_has_method(dev->handle, "_HRV"))
 635                device_remove_file(&dev->dev, &dev_attr_hrv);
 636
 637        if (dev->pnp.unique_id)
 638                device_remove_file(&dev->dev, &dev_attr_uid);
 639        if (dev->pnp.type.bus_address)
 640                device_remove_file(&dev->dev, &dev_attr_adr);
 641        device_remove_file(&dev->dev, &dev_attr_modalias);
 642        device_remove_file(&dev->dev, &dev_attr_hid);
 643        if (acpi_has_method(dev->handle, "_STA"))
 644                device_remove_file(&dev->dev, &dev_attr_status);
 645        if (dev->handle)
 646                device_remove_file(&dev->dev, &dev_attr_path);
 647}
 648