ACPI / PM: Allow attach/detach routines to change device power states

Make it possible to ask the routines used for adding/removing devices
to/from the general ACPI PM domain, acpi_dev_pm_attach() and
acpi_dev_pm_detach(), respectively, to change the power states of
devices so that they are put into the full-power state automatically
by acpi_dev_pm_attach() and into the lowest-power state available
automatically by acpi_dev_pm_detach().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 24 insertions, 4 deletions

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index a8e059f69d50..f09dc987cf17 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -599,10 +599,12 @@ static struct dev_pm_domain acpi_general_pm_domain = {
 /**
  * acpi_dev_pm_attach - Prepare device for ACPI power management.
  * @dev: Device to prepare.
+ * @power_on: Whether or not to power on the device.
  *
  * If @dev has a valid ACPI handle that has a valid struct acpi_device object
  * attached to it, install a wakeup notification handler for the device and
- * add it to the general ACPI PM domain.
+ * add it to the general ACPI PM domain.  If @power_on is set, the device will
+ * be put into the ACPI D0 state before the function returns.
  *
  * This assumes that the @dev's bus type uses generic power management callbacks
  * (or doesn't use any power management callbacks at all).
@@ -610,7 +612,7 @@ static struct dev_pm_domain acpi_general_pm_domain = {
  * Callers must ensure proper synchronization of this function with power
  * management callbacks.
  */
-int acpi_dev_pm_attach(struct device *dev)
+int acpi_dev_pm_attach(struct device *dev, bool power_on)
 {
         struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 
@@ -622,6 +624,10 @@ int acpi_dev_pm_attach(struct device *dev)
 
         acpi_add_pm_notifier(adev, acpi_wakeup_device, dev);
         dev->pm_domain = &acpi_general_pm_domain;
+        if (power_on) {
+                acpi_dev_pm_full_power(adev);
+                __acpi_device_run_wake(adev, false);
+        }
         return 0;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
@@ -629,20 +635,34 @@ EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
 /**
  * acpi_dev_pm_detach - Remove ACPI power management from the device.
  * @dev: Device to take care of.
+ * @power_off: Whether or not to try to remove power from the device.
  *
  * Remove the device from the general ACPI PM domain and remove its wakeup
- * notifier.
+ * notifier.  If @power_off is set, additionally remove power from the device if
+ * possible.
  *
  * Callers must ensure proper synchronization of this function with power
  * management callbacks.
  */
-void acpi_dev_pm_detach(struct device *dev)
+void acpi_dev_pm_detach(struct device *dev, bool power_off)
 {
         struct acpi_device *adev = acpi_dev_pm_get_node(dev);
 
         if (adev && dev->pm_domain == &acpi_general_pm_domain) {
                 dev->pm_domain = NULL;
                 acpi_remove_pm_notifier(adev, acpi_wakeup_device);
+                if (power_off) {
+                        /*
+                         * If the device's PM QoS resume latency limit or flags
+                         * have been exposed to user space, they have to be
+                         * hidden at this point, so that they don't affect the
+                         * choice of the low-power state to put the device into.
+                         */
+                        dev_pm_qos_hide_latency_limit(dev);
+                        dev_pm_qos_hide_flags(dev);
+                        __acpi_device_run_wake(adev, false);
+                        acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
+                }
         }
 }
 EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);