ACPICA: Introduce acpi_gpe_wakeup()

ACPICA uses reference counters to avoid disabling GPEs too early in
case they have been enabled for many times.  This is done separately
for runtime and for wakeup, but the wakeup GPE reference counter is
not really necessary, because GPEs are only enabled to wake up the
system at the hardware level by acpi_enter_sleep_state().  Thus it
only is necessary to set the corresponding bits in the wakeup enable
masks of these GPEs' registers right before the system enters a sleep
state.  Moreover, the GPE wakeup enable bits can only be set when the
target sleep state of the system is known and they need to be cleared
immediately after wakeup regardless of how many wakeup devices are
associated with a given GPE.

On the basis of the above observations, introduce function
acpi_gpe_wakeup() to be used for setting or clearing the enable bit
corresponding to a given GPE in its enable register's enable_for_wake
mask.  Modify the ACPI suspend and wakeup code the use
acpi_gpe_wakeup() instead of acpi_{enable|disable}_gpe() to set
and clear GPE enable bits in their registers' enable_for_wake masks
during system transitions to a sleep state and back to the working
state, respectively.  [This will allow us to drop the third
argument of acpi_{enable|disable}_gpe() and simplify the GPE
handling code.]

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 3 insertions, 1 deletions

diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 8aaa596e1208..17396e83e1a4 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -292,6 +292,8 @@ acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 gpe_type);
 
 acpi_status acpi_clear_gpe(acpi_handle gpe_device, u32 gpe_number);
 
+acpi_status acpi_gpe_wakeup(acpi_handle gpe_device, u32 gpe_number, u8 action);
+
 acpi_status
 acpi_get_gpe_status(acpi_handle gpe_device,
                     u32 gpe_number, acpi_event_status *event_status);
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index d55f4a7b824d..6a65a94897bf 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -663,7 +663,7 @@ typedef u32 acpi_event_status;
 #define ACPI_GPE_MAX                    0xFF
 #define ACPI_NUM_GPE                    256
 
-/* Actions for acpi_set_gpe and acpi_hw_low_set_gpe */
+/* Actions for acpi_set_gpe, acpi_gpe_wakeup, acpi_hw_low_set_gpe */
 
 #define ACPI_GPE_ENABLE                 0
 #define ACPI_GPE_DISABLE                1