[Patch 1/2] ACPI: thermal: Add Thermal fast Sampling Period (_TFP) support

[Sumit Gupta <sumitg@nvidia.com>]

From: Jeff Brasen <jbrasen@nvidia.com>

Add support for Thermal fast Sampling Period (_TFP) for Passive cooling.
As per UEFI spec, _TFP overrides the "Thermal Sampling Period (_TSP)"
if both are present in a Thermal zone.

Signed-off-by: Jeff Brasen <jbrasen@nvidia.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---
 drivers/acpi/thermal.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index f9f6ebb08fdb..5dee3722509c 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -111,7 +111,7 @@ struct acpi_thermal_passive {
 	unsigned long temperature;
 	unsigned long tc1;
 	unsigned long tc2;
-	unsigned long tsp;
+	unsigned long sampling_period;
 	bool valid;
 };
 
@@ -289,11 +289,18 @@ static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 					tz->trips.passive.tc2 = tmp;
 
 				status = acpi_evaluate_integer(tz->device->handle,
-							       "_TSP", NULL, &tmp);
-				if (ACPI_FAILURE(status))
-					tz->trips.passive.valid = false;
-				else
-					tz->trips.passive.tsp = tmp;
+							       "_TFP", NULL, &tmp);
+				if (ACPI_FAILURE(status)) {
+					status = acpi_evaluate_integer(tz->device->handle,
+								       "_TSP", NULL, &tmp);
+					if (ACPI_FAILURE(status))
+						tz->trips.passive.valid = false;
+					else
+						tz->trips.passive.sampling_period = tmp * 100;
+
+				} else {
+					tz->trips.passive.sampling_period = tmp;
+				}
 			}
 		}
 	}
@@ -765,7 +772,7 @@ static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 	if (tz->trips.passive.valid)
 		tz->thermal_zone = thermal_zone_device_register("acpitz", trips, 0, tz,
 								&acpi_thermal_zone_ops, NULL,
-								tz->trips.passive.tsp * 100,
+								tz->trips.passive.sampling_period,
 								tz->polling_frequency * 100);
 	else
 		tz->thermal_zone =
-- 
2.17.1