thermal: core: Add flags to struct thermal_trip

In order to allow thermal zone creators to specify the writability of
trip point temperature and hysteresis on a per-trip basis, add a flags
field to struct thermal_trip and define flags to represent the desired
trip properties.

Also make thermal_zone_device_register_with_trips() set the
THERMAL_TRIP_FLAG_RW_TEMP flag for all trips covered by the writable
trips mask passed to it and modify the thermal sysfs code to look at
the trip flags instead of using the writable trips mask directly or
checking the presence of the .set_trip_hyst() zone callback.

Additionally, make trip_point_temp_store() and trip_point_hyst_store()
fail with an error code if the trip passed to one of them has
THERMAL_TRIP_FLAG_RW_TEMP or THERMAL_TRIP_FLAG_RW_HYST,
respectively, clear in its flags.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index ec0559e98d6f..6eb6f3297ea0 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -64,15 +64,23 @@ enum thermal_notify_event {
  * @threshold: trip crossing notification threshold miliCelsius
  * @type: trip point type
  * @priv: pointer to driver data associated with this trip
+ * @flags: flags representing binary properties of the trip
  */
 struct thermal_trip {
 	int temperature;
 	int hysteresis;
 	int threshold;
 	enum thermal_trip_type type;
+	u8 flags;
 	void *priv;
 };
 
+#define THERMAL_TRIP_FLAG_RW_TEMP	BIT(0)
+#define THERMAL_TRIP_FLAG_RW_HYST	BIT(1)
+
+#define THERMAL_TRIP_FLAG_RW	(THERMAL_TRIP_FLAG_RW_TEMP | \
+				 THERMAL_TRIP_FLAG_RW_HYST)
+
 struct thermal_zone_device_ops {
 	int (*bind) (struct thermal_zone_device *,
 		     struct thermal_cooling_device *);