drivers: misc: therm_est: add get_trend using dT/dt

Added get_trend to use dTemp/dTime in trend calculation.

Bug 1158323

Change-Id: I7a3e80a768e3ebd72f657222eb0d3b546a3fabba
Signed-off-by: Hyungwoo Yang <hyungwooy@nvidia.com>
Reviewed-on: http://git-master/r/188582

2 files changed, 29 insertions, 0 deletions

diff --git a/drivers/misc/therm_est.c b/drivers/misc/therm_est.c
index 553764d66..81270480f 100644
--- a/drivers/misc/therm_est.c
+++ b/drivers/misc/therm_est.c
@@ -45,6 +45,8 @@ struct therm_estimator {
         struct thermal_zone_device *thz;
         char *cdev_type;
         long trip_temp;
+        int tc1;
+        int tc2;
 #ifdef CONFIG_PM
         struct notifier_block pm_nb;
 #endif
@@ -148,6 +150,28 @@ static int therm_est_get_temp(struct thermal_zone_device *thz,
         return 0;
 }
 
+static int therm_est_get_trend(struct thermal_zone_device *thz,
+                                int trip,
+                                enum thermal_trend *trend)
+{
+        struct therm_estimator *est = thz->devdata;
+        int new_trend;
+        int cur_temp;
+
+        cur_temp = thz->temperature;
+        new_trend = (est->tc1 * (cur_temp - thz->last_temperature)) +
+                    (est->tc2 * (cur_temp - est->trip_temp));
+
+        if (new_trend > 0)
+                *trend = THERMAL_TREND_RAISING;
+        else if (new_trend < 0)
+                *trend = THERMAL_TREND_DROPPING;
+        else
+                *trend = THERMAL_TREND_STABLE;
+
+        return 0;
+}
+
 static struct thermal_zone_device_ops therm_est_ops = {
         .bind = therm_est_bind,
         .unbind = therm_est_unbind,
@@ -155,6 +179,7 @@ static struct thermal_zone_device_ops therm_est_ops = {
         .get_trip_temp = therm_est_get_trip_temp,
         .set_trip_temp = therm_est_set_trip_temp,
         .get_temp = therm_est_get_temp,
+        .get_trend = therm_est_get_trend,
 };
 
 static ssize_t show_coeff(struct device *dev,
@@ -341,6 +366,8 @@ static int __devinit therm_est_probe(struct platform_device *pdev)
         est->ndevs = data->ndevs;
         est->toffset = data->toffset;
         est->polling_period = data->polling_period;
+        est->tc1 = data->tc1;
+        est->tc2 = data->tc2;
 
         /* initialize history */
         therm_est_init_history(est);
diff --git a/include/linux/therm_est.h b/include/linux/therm_est.h
index 8d48ed1db..514c5aeac 100644
--- a/include/linux/therm_est.h
+++ b/include/linux/therm_est.h
@@ -40,6 +40,8 @@ struct therm_est_data {
         long polling_period;
         int passive_delay;
         int ndevs;
+        int tc1;
+        int tc2;
         struct therm_est_subdevice devs[];
 };