drivers/base/power/sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* sysfs entries for device PM */
   3 #include <linux/device.h>
   4 #include <linux/string.h>
   5 #include <linux/export.h>
   6 #include <linux/pm_qos.h>
   7 #include <linux/pm_runtime.h>
   8 #include <linux/atomic.h>
   9 #include <linux/jiffies.h>
  10 #include "power.h"
  11
  12 /*
  13  *      control - Report/change current runtime PM setting of the device
  14  *
  15  *      Runtime power management of a device can be blocked with the help of
  16  *      this attribute.  All devices have one of the following two values for
  17  *      the power/control file:
  18  *
  19  *       + "auto\n" to allow the device to be power managed at run time;
  20  *       + "on\n" to prevent the device from being power managed at run time;
  21  *
  22  *      The default for all devices is "auto", which means that devices may be
  23  *      subject to automatic power management, depending on their drivers.
  24  *      Changing this attribute to "on" prevents the driver from power managing
  25  *      the device at run time.  Doing that while the device is suspended causes
  26  *      it to be woken up.
  27  *
  28  *      wakeup - Report/change current wakeup option for device
  29  *
  30  *      Some devices support "wakeup" events, which are hardware signals
  31  *      used to activate devices from suspended or low power states.  Such
  32  *      devices have one of three values for the sysfs power/wakeup file:
  33  *
  34  *       + "enabled\n" to issue the events;
  35  *       + "disabled\n" not to do so; or
  36  *       + "\n" for temporary or permanent inability to issue wakeup.
  37  *
  38  *      (For example, unconfigured USB devices can't issue wakeups.)
  39  *
  40  *      Familiar examples of devices that can issue wakeup events include
  41  *      keyboards and mice (both PS2 and USB styles), power buttons, modems,
  42  *      "Wake-On-LAN" Ethernet links, GPIO lines, and more.  Some events
  43  *      will wake the entire system from a suspend state; others may just
  44  *      wake up the device (if the system as a whole is already active).
  45  *      Some wakeup events use normal IRQ lines; other use special out
  46  *      of band signaling.
  47  *
  48  *      It is the responsibility of device drivers to enable (or disable)
  49  *      wakeup signaling as part of changing device power states, respecting
  50  *      the policy choices provided through the driver model.
  51  *
  52  *      Devices may not be able to generate wakeup events from all power
  53  *      states.  Also, the events may be ignored in some configurations;
  54  *      for example, they might need help from other devices that aren't
  55  *      active, or which may have wakeup disabled.  Some drivers rely on
  56  *      wakeup events internally (unless they are disabled), keeping
  57  *      their hardware in low power modes whenever they're unused.  This
  58  *      saves runtime power, without requiring system-wide sleep states.
  59  *
  60  *      async - Report/change current async suspend setting for the device
  61  *
  62  *      Asynchronous suspend and resume of the device during system-wide power
  63  *      state transitions can be enabled by writing "enabled" to this file.
  64  *      Analogously, if "disabled" is written to this file, the device will be
  65  *      suspended and resumed synchronously.
  66  *
  67  *      All devices have one of the following two values for power/async:
  68  *
  69  *       + "enabled\n" to permit the asynchronous suspend/resume of the device;
  70  *       + "disabled\n" to forbid it;
  71  *
  72  *      NOTE: It generally is unsafe to permit the asynchronous suspend/resume
  73  *      of a device unless it is certain that all of the PM dependencies of the
  74  *      device are known to the PM core.  However, for some devices this
  75  *      attribute is set to "enabled" by bus type code or device drivers and in
  76  *      that cases it should be safe to leave the default value.
  77  *
  78  *      autosuspend_delay_ms - Report/change a device's autosuspend_delay value
  79  *
  80  *      Some drivers don't want to carry out a runtime suspend as soon as a
  81  *      device becomes idle; they want it always to remain idle for some period
  82  *      of time before suspending it.  This period is the autosuspend_delay
  83  *      value (expressed in milliseconds) and it can be controlled by the user.
  84  *      If the value is negative then the device will never be runtime
  85  *      suspended.
  86  *
  87  *      NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
  88  *      value are used only if the driver calls pm_runtime_use_autosuspend().
  89  *
  90  *      wakeup_count - Report the number of wakeup events related to the device
  91  */
  92
  93 const char power_group_name[] = "power";
  94 EXPORT_SYMBOL_GPL(power_group_name);
  95
  96 static const char ctrl_auto[] = "auto";
  97 static const char ctrl_on[] = "on";
  98
  99 static ssize_t control_show(struct device *dev, struct device_attribute *attr,
 100                             char *buf)
 101 {
 102         return sprintf(buf, "%s\n",
 103                                 dev->power.runtime_auto ? ctrl_auto : ctrl_on);
 104 }
 105
 106 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
 107                              const char * buf, size_t n)
 108 {
 109         device_lock(dev);
 110         if (sysfs_streq(buf, ctrl_auto))
 111                 pm_runtime_allow(dev);
 112         else if (sysfs_streq(buf, ctrl_on))
 113                 pm_runtime_forbid(dev);
 114         else
 115                 n = -EINVAL;
 116         device_unlock(dev);
 117         return n;
 118 }
 119
 120 static DEVICE_ATTR_RW(control);
 121
 122 static ssize_t runtime_active_time_show(struct device *dev,
 123                                 struct device_attribute *attr, char *buf)
 124 {
 125         int ret;
 126         u64 tmp = pm_runtime_active_time(dev);
 127         do_div(tmp, NSEC_PER_MSEC);
 128         ret = sprintf(buf, "%llu\n", tmp);
 129         return ret;
 130 }
 131
 132 static DEVICE_ATTR_RO(runtime_active_time);
 133
 134 static ssize_t runtime_suspended_time_show(struct device *dev,
 135                                 struct device_attribute *attr, char *buf)
 136 {
 137         int ret;
 138         u64 tmp = pm_runtime_suspended_time(dev);
 139         do_div(tmp, NSEC_PER_MSEC);
 140         ret = sprintf(buf, "%llu\n", tmp);
 141         return ret;
 142 }
 143
 144 static DEVICE_ATTR_RO(runtime_suspended_time);
 145
 146 static ssize_t runtime_status_show(struct device *dev,
 147                                 struct device_attribute *attr, char *buf)
 148 {
 149         const char *p;
 150
 151         if (dev->power.runtime_error) {
 152                 p = "error\n";
 153         } else if (dev->power.disable_depth) {
 154                 p = "unsupported\n";
 155         } else {
 156                 switch (dev->power.runtime_status) {
 157                 case RPM_SUSPENDED:
 158                         p = "suspended\n";
 159                         break;
 160                 case RPM_SUSPENDING:
 161                         p = "suspending\n";
 162                         break;
 163                 case RPM_RESUMING:
 164                         p = "resuming\n";
 165                         break;
 166                 case RPM_ACTIVE:
 167                         p = "active\n";
 168                         break;
 169                 default:
 170                         return -EIO;
 171                 }
 172         }
 173         return sprintf(buf, p);
 174 }
 175
 176 static DEVICE_ATTR_RO(runtime_status);
 177
 178 static ssize_t autosuspend_delay_ms_show(struct device *dev,
 179                 struct device_attribute *attr, char *buf)
 180 {
 181         if (!dev->power.use_autosuspend)
 182                 return -EIO;
 183         return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
 184 }
 185
 186 static ssize_t autosuspend_delay_ms_store(struct device *dev,
 187                 struct device_attribute *attr, const char *buf, size_t n)
 188 {
 189         long delay;
 190
 191         if (!dev->power.use_autosuspend)
 192                 return -EIO;
 193
 194         if (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay)
 195                 return -EINVAL;
 196
 197         device_lock(dev);
 198         pm_runtime_set_autosuspend_delay(dev, delay);
 199         device_unlock(dev);
 200         return n;
 201 }
 202
 203 static DEVICE_ATTR_RW(autosuspend_delay_ms);
 204
 205 static ssize_t pm_qos_resume_latency_us_show(struct device *dev,
 206                                              struct device_attribute *attr,
 207                                              char *buf)
 208 {
 209         s32 value = dev_pm_qos_requested_resume_latency(dev);
 210
 211         if (value == 0)
 212                 return sprintf(buf, "n/a\n");
 213         if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
 214                 value = 0;
 215
 216         return sprintf(buf, "%d\n", value);
 217 }
 218
 219 static ssize_t pm_qos_resume_latency_us_store(struct device *dev,
 220                                               struct device_attribute *attr,
 221                                               const char *buf, size_t n)
 222 {
 223         s32 value;
 224         int ret;
 225
 226         if (!kstrtos32(buf, 0, &value)) {
 227                 /*
 228                  * Prevent users from writing negative or "no constraint" values
 229                  * directly.
 230                  */
 231                 if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
 232                         return -EINVAL;
 233
 234                 if (value == 0)
 235                         value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
 236         } else if (sysfs_streq(buf, "n/a")) {
 237                 value = 0;
 238         } else {
 239                 return -EINVAL;
 240         }
 241
 242         ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
 243                                         value);
 244         return ret < 0 ? ret : n;
 245 }
 246
 247 static DEVICE_ATTR_RW(pm_qos_resume_latency_us);
 248
 249 static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
 250                                                 struct device_attribute *attr,
 251                                                 char *buf)
 252 {
 253         s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
 254
 255         if (value < 0)
 256                 return sprintf(buf, "auto\n");
 257         if (value == PM_QOS_LATENCY_ANY)
 258                 return sprintf(buf, "any\n");
 259
 260         return sprintf(buf, "%d\n", value);
 261 }
 262
 263 static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev,
 264                                                  struct device_attribute *attr,
 265                                                  const char *buf, size_t n)
 266 {
 267         s32 value;
 268         int ret;
 269
 270         if (kstrtos32(buf, 0, &value) == 0) {
 271                 /* Users can't write negative values directly */
 272                 if (value < 0)
 273                         return -EINVAL;
 274         } else {
 275                 if (sysfs_streq(buf, "auto"))
 276                         value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
 277                 else if (sysfs_streq(buf, "any"))
 278                         value = PM_QOS_LATENCY_ANY;
 279                 else
 280                         return -EINVAL;
 281         }
 282         ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
 283         return ret < 0 ? ret : n;
 284 }
 285
 286 static DEVICE_ATTR_RW(pm_qos_latency_tolerance_us);
 287
 288 static ssize_t pm_qos_no_power_off_show(struct device *dev,
 289                                         struct device_attribute *attr,
 290                                         char *buf)
 291 {
 292         return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
 293                                         & PM_QOS_FLAG_NO_POWER_OFF));
 294 }
 295
 296 static ssize_t pm_qos_no_power_off_store(struct device *dev,
 297                                          struct device_attribute *attr,
 298                                          const char *buf, size_t n)
 299 {
 300         int ret;
 301
 302         if (kstrtoint(buf, 0, &ret))
 303                 return -EINVAL;
 304
 305         if (ret != 0 && ret != 1)
 306                 return -EINVAL;
 307
 308         ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
 309         return ret < 0 ? ret : n;
 310 }
 311
 312 static DEVICE_ATTR_RW(pm_qos_no_power_off);
 313
 314 #ifdef CONFIG_PM_SLEEP
 315 static const char _enabled[] = "enabled";
 316 static const char _disabled[] = "disabled";
 317
 318 static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr,
 319                            char *buf)
 320 {
 321         return sprintf(buf, "%s\n", device_can_wakeup(dev)
 322                 ? (device_may_wakeup(dev) ? _enabled : _disabled)
 323                 : "");
 324 }
 325
 326 static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr,
 327                             const char *buf, size_t n)
 328 {
 329         if (!device_can_wakeup(dev))
 330                 return -EINVAL;
 331
 332         if (sysfs_streq(buf, _enabled))
 333                 device_set_wakeup_enable(dev, 1);
 334         else if (sysfs_streq(buf, _disabled))
 335                 device_set_wakeup_enable(dev, 0);
 336         else
 337                 return -EINVAL;
 338         return n;
 339 }
 340
 341 static DEVICE_ATTR_RW(wakeup);
 342
 343 static ssize_t wakeup_count_show(struct device *dev,
 344                                  struct device_attribute *attr, char *buf)
 345 {
 346         unsigned long count = 0;
 347         bool enabled = false;
 348
 349         spin_lock_irq(&dev->power.lock);
 350         if (dev->power.wakeup) {
 351                 count = dev->power.wakeup->wakeup_count;
 352                 enabled = true;
 353         }
 354         spin_unlock_irq(&dev->power.lock);
 355         return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 356 }
 357
 358 static DEVICE_ATTR_RO(wakeup_count);
 359
 360 static ssize_t wakeup_active_count_show(struct device *dev,
 361                                         struct device_attribute *attr,
 362                                         char *buf)
 363 {
 364         unsigned long count = 0;
 365         bool enabled = false;
 366
 367         spin_lock_irq(&dev->power.lock);
 368         if (dev->power.wakeup) {
 369                 count = dev->power.wakeup->active_count;
 370                 enabled = true;
 371         }
 372         spin_unlock_irq(&dev->power.lock);
 373         return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 374 }
 375
 376 static DEVICE_ATTR_RO(wakeup_active_count);
 377
 378 static ssize_t wakeup_abort_count_show(struct device *dev,
 379                                        struct device_attribute *attr,
 380                                        char *buf)
 381 {
 382         unsigned long count = 0;
 383         bool enabled = false;
 384
 385         spin_lock_irq(&dev->power.lock);
 386         if (dev->power.wakeup) {
 387                 count = dev->power.wakeup->wakeup_count;
 388                 enabled = true;
 389         }
 390         spin_unlock_irq(&dev->power.lock);
 391         return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 392 }
 393
 394 static DEVICE_ATTR_RO(wakeup_abort_count);
 395
 396 static ssize_t wakeup_expire_count_show(struct device *dev,
 397                                         struct device_attribute *attr,
 398                                         char *buf)
 399 {
 400         unsigned long count = 0;
 401         bool enabled = false;
 402
 403         spin_lock_irq(&dev->power.lock);
 404         if (dev->power.wakeup) {
 405                 count = dev->power.wakeup->expire_count;
 406                 enabled = true;
 407         }
 408         spin_unlock_irq(&dev->power.lock);
 409         return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 410 }
 411
 412 static DEVICE_ATTR_RO(wakeup_expire_count);
 413
 414 static ssize_t wakeup_active_show(struct device *dev,
 415                                   struct device_attribute *attr, char *buf)
 416 {
 417         unsigned int active = 0;
 418         bool enabled = false;
 419
 420         spin_lock_irq(&dev->power.lock);
 421         if (dev->power.wakeup) {
 422                 active = dev->power.wakeup->active;
 423                 enabled = true;
 424         }
 425         spin_unlock_irq(&dev->power.lock);
 426         return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
 427 }
 428
 429 static DEVICE_ATTR_RO(wakeup_active);
 430
 431 static ssize_t wakeup_total_time_ms_show(struct device *dev,
 432                                          struct device_attribute *attr,
 433                                          char *buf)
 434 {
 435         s64 msec = 0;
 436         bool enabled = false;
 437
 438         spin_lock_irq(&dev->power.lock);
 439         if (dev->power.wakeup) {
 440                 msec = ktime_to_ms(dev->power.wakeup->total_time);
 441                 enabled = true;
 442         }
 443         spin_unlock_irq(&dev->power.lock);
 444         return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 445 }
 446
 447 static DEVICE_ATTR_RO(wakeup_total_time_ms);
 448
 449 static ssize_t wakeup_max_time_ms_show(struct device *dev,
 450                                        struct device_attribute *attr, char *buf)
 451 {
 452         s64 msec = 0;
 453         bool enabled = false;
 454
 455         spin_lock_irq(&dev->power.lock);
 456         if (dev->power.wakeup) {
 457                 msec = ktime_to_ms(dev->power.wakeup->max_time);
 458                 enabled = true;
 459         }
 460         spin_unlock_irq(&dev->power.lock);
 461         return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 462 }
 463
 464 static DEVICE_ATTR_RO(wakeup_max_time_ms);
 465
 466 static ssize_t wakeup_last_time_ms_show(struct device *dev,
 467                                         struct device_attribute *attr,
 468                                         char *buf)
 469 {
 470         s64 msec = 0;
 471         bool enabled = false;
 472
 473         spin_lock_irq(&dev->power.lock);
 474         if (dev->power.wakeup) {
 475                 msec = ktime_to_ms(dev->power.wakeup->last_time);
 476                 enabled = true;
 477         }
 478         spin_unlock_irq(&dev->power.lock);
 479         return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 480 }
 481
 482 static DEVICE_ATTR_RO(wakeup_last_time_ms);
 483
 484 #ifdef CONFIG_PM_AUTOSLEEP
 485 static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
 486                                                  struct device_attribute *attr,
 487                                                  char *buf)
 488 {
 489         s64 msec = 0;
 490         bool enabled = false;
 491
 492         spin_lock_irq(&dev->power.lock);
 493         if (dev->power.wakeup) {
 494                 msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
 495                 enabled = true;
 496         }
 497         spin_unlock_irq(&dev->power.lock);
 498         return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 499 }
 500
 501 static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms);
 502 #endif /* CONFIG_PM_AUTOSLEEP */
 503 #endif /* CONFIG_PM_SLEEP */
 504
 505 #ifdef CONFIG_PM_ADVANCED_DEBUG
 506 static ssize_t runtime_usage_show(struct device *dev,
 507                                   struct device_attribute *attr, char *buf)
 508 {
 509         return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
 510 }
 511 static DEVICE_ATTR_RO(runtime_usage);
 512
 513 static ssize_t runtime_active_kids_show(struct device *dev,
 514                                         struct device_attribute *attr,
 515                                         char *buf)
 516 {
 517         return sprintf(buf, "%d\n", dev->power.ignore_children ?
 518                 0 : atomic_read(&dev->power.child_count));
 519 }
 520 static DEVICE_ATTR_RO(runtime_active_kids);
 521
 522 static ssize_t runtime_enabled_show(struct device *dev,
 523                                     struct device_attribute *attr, char *buf)
 524 {
 525         if (dev->power.disable_depth && (dev->power.runtime_auto == false))
 526                 return sprintf(buf, "disabled & forbidden\n");
 527         if (dev->power.disable_depth)
 528                 return sprintf(buf, "disabled\n");
 529         if (dev->power.runtime_auto == false)
 530                 return sprintf(buf, "forbidden\n");
 531         return sprintf(buf, "enabled\n");
 532 }
 533 static DEVICE_ATTR_RO(runtime_enabled);
 534
 535 #ifdef CONFIG_PM_SLEEP
 536 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
 537                           char *buf)
 538 {
 539         return sprintf(buf, "%s\n",
 540                         device_async_suspend_enabled(dev) ?
 541                                 _enabled : _disabled);
 542 }
 543
 544 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
 545                            const char *buf, size_t n)
 546 {
 547         if (sysfs_streq(buf, _enabled))
 548                 device_enable_async_suspend(dev);
 549         else if (sysfs_streq(buf, _disabled))
 550                 device_disable_async_suspend(dev);
 551         else
 552                 return -EINVAL;
 553         return n;
 554 }
 555
 556 static DEVICE_ATTR_RW(async);
 557
 558 #endif /* CONFIG_PM_SLEEP */
 559 #endif /* CONFIG_PM_ADVANCED_DEBUG */
 560
 561 static struct attribute *power_attrs[] = {
 562 #ifdef CONFIG_PM_ADVANCED_DEBUG
 563 #ifdef CONFIG_PM_SLEEP
 564         &dev_attr_async.attr,
 565 #endif
 566         &dev_attr_runtime_status.attr,
 567         &dev_attr_runtime_usage.attr,
 568         &dev_attr_runtime_active_kids.attr,
 569         &dev_attr_runtime_enabled.attr,
 570 #endif /* CONFIG_PM_ADVANCED_DEBUG */
 571         NULL,
 572 };
 573 static const struct attribute_group pm_attr_group = {
 574         .name   = power_group_name,
 575         .attrs  = power_attrs,
 576 };
 577
 578 static struct attribute *wakeup_attrs[] = {
 579 #ifdef CONFIG_PM_SLEEP
 580         &dev_attr_wakeup.attr,
 581         &dev_attr_wakeup_count.attr,
 582         &dev_attr_wakeup_active_count.attr,
 583         &dev_attr_wakeup_abort_count.attr,
 584         &dev_attr_wakeup_expire_count.attr,
 585         &dev_attr_wakeup_active.attr,
 586         &dev_attr_wakeup_total_time_ms.attr,
 587         &dev_attr_wakeup_max_time_ms.attr,
 588         &dev_attr_wakeup_last_time_ms.attr,
 589 #ifdef CONFIG_PM_AUTOSLEEP
 590         &dev_attr_wakeup_prevent_sleep_time_ms.attr,
 591 #endif
 592 #endif
 593         NULL,
 594 };
 595 static const struct attribute_group pm_wakeup_attr_group = {
 596         .name   = power_group_name,
 597         .attrs  = wakeup_attrs,
 598 };
 599
 600 static struct attribute *runtime_attrs[] = {
 601 #ifndef CONFIG_PM_ADVANCED_DEBUG
 602         &dev_attr_runtime_status.attr,
 603 #endif
 604         &dev_attr_control.attr,
 605         &dev_attr_runtime_suspended_time.attr,
 606         &dev_attr_runtime_active_time.attr,
 607         &dev_attr_autosuspend_delay_ms.attr,
 608         NULL,
 609 };
 610 static const struct attribute_group pm_runtime_attr_group = {
 611         .name   = power_group_name,
 612         .attrs  = runtime_attrs,
 613 };
 614
 615 static struct attribute *pm_qos_resume_latency_attrs[] = {
 616         &dev_attr_pm_qos_resume_latency_us.attr,
 617         NULL,
 618 };
 619 static const struct attribute_group pm_qos_resume_latency_attr_group = {
 620         .name   = power_group_name,
 621         .attrs  = pm_qos_resume_latency_attrs,
 622 };
 623
 624 static struct attribute *pm_qos_latency_tolerance_attrs[] = {
 625         &dev_attr_pm_qos_latency_tolerance_us.attr,
 626         NULL,
 627 };
 628 static const struct attribute_group pm_qos_latency_tolerance_attr_group = {
 629         .name   = power_group_name,
 630         .attrs  = pm_qos_latency_tolerance_attrs,
 631 };
 632
 633 static struct attribute *pm_qos_flags_attrs[] = {
 634         &dev_attr_pm_qos_no_power_off.attr,
 635         NULL,
 636 };
 637 static const struct attribute_group pm_qos_flags_attr_group = {
 638         .name   = power_group_name,
 639         .attrs  = pm_qos_flags_attrs,
 640 };
 641
 642 int dpm_sysfs_add(struct device *dev)
 643 {
 644         int rc;
 645
 646         /* No need to create PM sysfs if explicitly disabled. */
 647         if (device_pm_not_required(dev))
 648                 return 0;
 649
 650         rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
 651         if (rc)
 652                 return rc;
 653
 654         if (pm_runtime_callbacks_present(dev)) {
 655                 rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
 656                 if (rc)
 657                         goto err_out;
 658         }
 659         if (device_can_wakeup(dev)) {
 660                 rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
 661                 if (rc)
 662                         goto err_runtime;
 663         }
 664         if (dev->power.set_latency_tolerance) {
 665                 rc = sysfs_merge_group(&dev->kobj,
 666                                        &pm_qos_latency_tolerance_attr_group);
 667                 if (rc)
 668                         goto err_wakeup;
 669         }
 670         return 0;
 671
 672  err_wakeup:
 673         sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 674  err_runtime:
 675         sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
 676  err_out:
 677         sysfs_remove_group(&dev->kobj, &pm_attr_group);
 678         return rc;
 679 }
 680
 681 int wakeup_sysfs_add(struct device *dev)
 682 {
 683         return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
 684 }
 685
 686 void wakeup_sysfs_remove(struct device *dev)
 687 {
 688         sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 689 }
 690
 691 int pm_qos_sysfs_add_resume_latency(struct device *dev)
 692 {
 693         return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
 694 }
 695
 696 void pm_qos_sysfs_remove_resume_latency(struct device *dev)
 697 {
 698         sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
 699 }
 700
 701 int pm_qos_sysfs_add_flags(struct device *dev)
 702 {
 703         return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
 704 }
 705
 706 void pm_qos_sysfs_remove_flags(struct device *dev)
 707 {
 708         sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
 709 }
 710
 711 int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
 712 {
 713         return sysfs_merge_group(&dev->kobj,
 714                                  &pm_qos_latency_tolerance_attr_group);
 715 }
 716
 717 void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
 718 {
 719         sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
 720 }
 721
 722 void rpm_sysfs_remove(struct device *dev)
 723 {
 724         sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
 725 }
 726
 727 void dpm_sysfs_remove(struct device *dev)
 728 {
 729         if (device_pm_not_required(dev))
 730                 return;
 731         sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
 732         dev_pm_qos_constraints_destroy(dev);
 733         rpm_sysfs_remove(dev);
 734         sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 735         sysfs_remove_group(&dev->kobj, &pm_attr_group);
 736 }