thermal: core: Rework .get_trend() thermal zone callback

Passing a struct thermal_trip pointer instead of a trip index to the
.get_trend() thermal zone callback allows one of its 2 implementations,
the thermal_get_trend() function in the ACPI thermal driver, to be
simplified quite a bit, and the other implementation of it in the
ti-soc-thermal driver does not even use the relevant callback argument.

For this reason, change the .get_trend() thermal zone callback
definition and adjust the related code accordingly.

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

drivers/acpi/thermal.c

@@ -492,26 +492,22 @@ static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
 }
 
 static int thermal_get_trend(struct thermal_zone_device *thermal,
-			     int trip_index, enum thermal_trend *trend)
+			     struct thermal_trip *trip,
+			     enum thermal_trend *trend)
 {
 	struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 	struct acpi_thermal_trip *acpi_trip;
-	int t, i;
+	int t;
 
-	if (!tz || trip_index < 0)
+	if (!tz || !trip)
 		return -EINVAL;
 
-	if (tz->trips.critical.valid)
-		trip_index--;
-
-	if (tz->trips.hot.valid)
-		trip_index--;
-
-	if (trip_index < 0)
+	acpi_trip = trip->priv;
+	if (!acpi_trip || !acpi_trip->valid)
 		return -EINVAL;
 
-	acpi_trip = &tz->trips.passive.trip;
-	if (acpi_trip->valid && !trip_index--) {
+	switch (trip->type) {
+	case THERMAL_TRIP_PASSIVE:
 		t = tz->trips.passive.tc1 * (tz->temperature -
 						tz->last_temperature) +
 			tz->trips.passive.tc2 * (tz->temperature -
@@ -524,19 +520,18 @@ static int thermal_get_trend(struct thermal_zone_device *thermal,
 			*trend = THERMAL_TREND_STABLE;
 
 		return 0;
-	}
-
-	t = acpi_thermal_temp(tz, tz->temperature);
 
-	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
-		acpi_trip = &tz->trips.active[i].trip;
-		if (acpi_trip->valid && !trip_index--) {
-			if (t > acpi_thermal_temp(tz, acpi_trip->temperature)) {
-				*trend = THERMAL_TREND_RAISING;
-				return 0;
-			}
+	case THERMAL_TRIP_ACTIVE:
+		t = acpi_thermal_temp(tz, tz->temperature);
+		if (t <= trip->temperature)
 			break;
-		}
+
+		*trend = THERMAL_TREND_RAISING;
+
+		return 0;
+
+	default:
+		break;
 	}
 
 	return -EINVAL;

drivers/thermal/thermal_core.h

@@ -70,7 +70,7 @@ static inline bool cdev_is_power_actor(struct thermal_cooling_device *cdev)
 void thermal_cdev_update(struct thermal_cooling_device *);
 void __thermal_cdev_update(struct thermal_cooling_device *cdev);
 
-int get_tz_trend(struct thermal_zone_device *tz, int trip);
+int get_tz_trend(struct thermal_zone_device *tz, int trip_index);
 
 struct thermal_instance *
 get_thermal_instance(struct thermal_zone_device *tz,

drivers/thermal/thermal_helpers.c

@@ -22,8 +22,9 @@
 #include "thermal_core.h"
 #include "thermal_trace.h"
 
-int get_tz_trend(struct thermal_zone_device *tz, int trip)
+int get_tz_trend(struct thermal_zone_device *tz, int trip_index)
 {
+	struct thermal_trip *trip = tz->trips ? &tz->trips[trip_index] : NULL;
 	enum thermal_trend trend;
 
 	if (tz->emul_temperature || !tz->ops->get_trend ||

drivers/thermal/ti-soc-thermal/ti-thermal-common.c

@@ -109,7 +109,8 @@ static inline int __ti_thermal_get_temp(struct thermal_zone_device *tz, int *tem
 	return ret;
 }
 
-static int __ti_thermal_get_trend(struct thermal_zone_device *tz, int trip, enum thermal_trend *trend)
+static int __ti_thermal_get_trend(struct thermal_zone_device *tz,
+				  struct thermal_trip *trip, enum thermal_trend *trend)
 {
 	struct ti_thermal_data *data = thermal_zone_device_priv(tz);
 	struct ti_bandgap *bgp;

include/linux/thermal.h

@@ -53,6 +53,20 @@ enum thermal_notify_event {
 	THERMAL_EVENT_KEEP_ALIVE, /* Request for user space handler to respond */
 };
 
+/**
+ * struct thermal_trip - representation of a point in temperature domain
+ * @temperature: temperature value in miliCelsius
+ * @hysteresis: relative hysteresis in miliCelsius
+ * @type: trip point type
+ * @priv: pointer to driver data associated with this trip
+ */
+struct thermal_trip {
+	int temperature;
+	int hysteresis;
+	enum thermal_trip_type type;
+	void *priv;
+};
+
 struct thermal_zone_device_ops {
 	int (*bind) (struct thermal_zone_device *,
 		     struct thermal_cooling_device *);
@@ -66,26 +80,12 @@ struct thermal_zone_device_ops {
 	int (*set_trip_hyst) (struct thermal_zone_device *, int, int);
 	int (*get_crit_temp) (struct thermal_zone_device *, int *);
 	int (*set_emul_temp) (struct thermal_zone_device *, int);
-	int (*get_trend) (struct thermal_zone_device *, int,
+	int (*get_trend) (struct thermal_zone_device *, struct thermal_trip *,
 			  enum thermal_trend *);
 	void (*hot)(struct thermal_zone_device *);
 	void (*critical)(struct thermal_zone_device *);
 };
 
-/**
- * struct thermal_trip - representation of a point in temperature domain
- * @temperature: temperature value in miliCelsius
- * @hysteresis: relative hysteresis in miliCelsius
- * @type: trip point type
- * @priv: pointer to driver data associated with this trip
- */
-struct thermal_trip {
-	int temperature;
-	int hysteresis;
-	enum thermal_trip_type type;
-	void *priv;
-};
-
 struct thermal_cooling_device_ops {
 	int (*get_max_state) (struct thermal_cooling_device *, unsigned long *);
 	int (*get_cur_state) (struct thermal_cooling_device *, unsigned long *);