1 files changed, 20 insertions, 10 deletions

diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
index e3c5e677eaa5..8e67ebf98404 100644
--- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
+++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
@@ -38,6 +38,7 @@
 /* common data structures */
 struct ti_thermal_data {
         struct thermal_zone_device *ti_thermal;
+        struct thermal_zone_device *pcb_tz;
         struct thermal_cooling_device *cool_dev;
         struct ti_bandgap *bgp;
         enum thermal_device_mode mode;
@@ -77,10 +78,12 @@ static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
 static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
                                       unsigned long *temp)
 {
+        struct thermal_zone_device *pcb_tz = NULL;
         struct ti_thermal_data *data = thermal->devdata;
         struct ti_bandgap *bgp;
         const struct ti_temp_sensor *s;
-        int ret, tmp, pcb_temp, slope, constant;
+        int ret, tmp, slope, constant;
+        unsigned long pcb_temp;
 
         if (!data)
                 return 0;
@@ -92,16 +95,22 @@ static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
         if (ret)
                 return ret;
 
-        pcb_temp = 0;
-        /* TODO: Introduce pcb temperature lookup */
+        /* Default constants */
+        slope = s->slope;
+        constant = s->constant;
+
+        pcb_tz = data->pcb_tz;
         /* In case pcb zone is available, use the extrapolation rule with it */
-        if (pcb_temp) {
-                tmp -= pcb_temp;
-                slope = s->slope_pcb;
-                constant = s->constant_pcb;
-        } else {
-                slope = s->slope;
-                constant = s->constant;
+        if (!IS_ERR_OR_NULL(pcb_tz)) {
+                ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
+                if (!ret) {
+                        tmp -= pcb_temp; /* got a valid PCB temp */
+                        slope = s->slope_pcb;
+                        constant = s->constant_pcb;
+                } else {
+                        dev_err(bgp->dev,
+                                "Failed to read PCB state. Using defaults\n");
+                }
         }
         *temp = ti_thermal_hotspot_temperature(tmp, slope, constant);
 
@@ -273,6 +282,7 @@ static struct ti_thermal_data
         data->sensor_id = id;
         data->bgp = bgp;
         data->mode = THERMAL_DEVICE_ENABLED;
+        data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
         INIT_WORK(&data->thermal_wq, ti_thermal_work);
 
         return data;