+/**
+ * pm_runtime_no_callbacks - Ignore run-time PM callbacks for a device.
+ * @dev: Device to handle.
+ *
+ * Set the power.no_callbacks flag, which tells the PM core that this
+ * device is power-managed through its parent and has no run-time PM
+ * callbacks of its own. The run-time sysfs attributes will be removed.
+ */
+void pm_runtime_no_callbacks(struct device *dev)
+{
+ spin_lock_irq(&dev->power.lock);
+ dev->power.no_callbacks = 1;
+ spin_unlock_irq(&dev->power.lock);
+ if (device_is_registered(dev))
+ rpm_sysfs_remove(dev);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
+
+/**
+ * pm_runtime_irq_safe - Leave interrupts disabled during callbacks.
+ * @dev: Device to handle
+ *
+ * Set the power.irq_safe flag, which tells the PM core that the
+ * ->runtime_suspend() and ->runtime_resume() callbacks for this device should
+ * always be invoked with the spinlock held and interrupts disabled. It also
+ * causes the parent's usage counter to be permanently incremented, preventing
+ * the parent from runtime suspending -- otherwise an irq-safe child might have
+ * to wait for a non-irq-safe parent.
+ */
+void pm_runtime_irq_safe(struct device *dev)
+{
+ if (dev->parent)
+ pm_runtime_get_sync(dev->parent);
+ spin_lock_irq(&dev->power.lock);
+ dev->power.irq_safe = 1;
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_irq_safe);
+
+/**
+ * update_autosuspend - Handle a change to a device's autosuspend settings.
+ * @dev: Device to handle.
+ * @old_delay: The former autosuspend_delay value.
+ * @old_use: The former use_autosuspend value.
+ *
+ * Prevent runtime suspend if the new delay is negative and use_autosuspend is
+ * set; otherwise allow it. Send an idle notification if suspends are allowed.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static void update_autosuspend(struct device *dev, int old_delay, int old_use)
+{
+ int delay = dev->power.autosuspend_delay;
+
+ /* Should runtime suspend be prevented now? */
+ if (dev->power.use_autosuspend && delay < 0) {
+
+ /* If it used to be allowed then prevent it. */
+ if (!old_use || old_delay >= 0) {
+ atomic_inc(&dev->power.usage_count);
+ rpm_resume(dev, 0);
+ }
+ }
+
+ /* Runtime suspend should be allowed now. */
+ else {
+
+ /* If it used to be prevented then allow it. */
+ if (old_use && old_delay < 0)
+ atomic_dec(&dev->power.usage_count);
+
+ /* Maybe we can autosuspend now. */
+ rpm_idle(dev, RPM_AUTO);
+ }
+}
+
+/**
+ * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
+ * @dev: Device to handle.
+ * @delay: Value of the new delay in milliseconds.
+ *
+ * Set the device's power.autosuspend_delay value. If it changes to negative
+ * and the power.use_autosuspend flag is set, prevent run-time suspends. If it
+ * changes the other way, allow run-time suspends.
+ */
+void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
+{
+ int old_delay, old_use;
+
+ spin_lock_irq(&dev->power.lock);
+ old_delay = dev->power.autosuspend_delay;
+ old_use = dev->power.use_autosuspend;
+ dev->power.autosuspend_delay = delay;
+ update_autosuspend(dev, old_delay, old_use);
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
+
+/**
+ * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
+ * @dev: Device to handle.
+ * @use: New value for use_autosuspend.
+ *
+ * Set the device's power.use_autosuspend flag, and allow or prevent run-time
+ * suspends as needed.
+ */
+void __pm_runtime_use_autosuspend(struct device *dev, bool use)
+{
+ int old_delay, old_use;
+
+ spin_lock_irq(&dev->power.lock);
+ old_delay = dev->power.autosuspend_delay;
+ old_use = dev->power.use_autosuspend;
+ dev->power.use_autosuspend = use;
+ update_autosuspend(dev, old_delay, old_use);
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
+