ACPI / PM: Introduce concept of a _PR0 dependent device

If there are shared power resources between otherwise unrelated devices
turning them on causes the other devices sharing them to be powered up
as well. In case of PCI devices go into D0uninitialized state meaning
that if they were configured to trigger wake that configuration is lost
at this point.

For this reason introduce a concept of "_PR0 dependent device" that can
be added to any ACPI device that has power resources. The dependent
device will be included in a list of dependent devices for all power
resources returned by the ACPI device's _PR0 (assuming it has one).
Whenever a power resource having dependent devices is turned physically
on (its _ON method is called) we runtime resume all of them to allow
their driver or in case of PCI the PCI core to re-initialize the device
and its wake configuration.

This adds two functions that can be used to add and remove these
dependent devices. Note the dependent device does not necessary need
share power resources so this functionality can be used to add "software
dependencies" as well if needed.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 31b6c87d6240..4752ff0a9d9b 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -513,6 +513,10 @@ int acpi_device_fix_up_power(struct acpi_device *device);
 int acpi_bus_update_power(acpi_handle handle, int *state_p);
 int acpi_device_update_power(struct acpi_device *device, int *state_p);
 bool acpi_bus_power_manageable(acpi_handle handle);
+int acpi_device_power_add_dependent(struct acpi_device *adev,
+				    struct device *dev);
+void acpi_device_power_remove_dependent(struct acpi_device *adev,
+					struct device *dev);
 
 #ifdef CONFIG_PM
 bool acpi_bus_can_wakeup(acpi_handle handle);