power_supply: Register battery as a thermal zone

Battery and charger contribute to Thermals in most of the embedded
devices. So, it makes sense to identify them as Thermal zones in a
particular platform.

This patch registers a thermal zone if the power supply is reporting
a temperature property. The thermal zone will be used by platform's
thermal management solution.

Signed-off-by: Jenny TC <jenny.tc@intel.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 6ad61272678..ff990d26a0c 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -17,6 +17,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/power_supply.h>
+#include <linux/thermal.h>
 #include "power_supply.h"
 
 /* exported for the APM Power driver, APM emulation */
@@ -169,6 +170,63 @@ static void power_supply_dev_release(struct device *dev)
         kfree(dev);
 }
 
+#ifdef CONFIG_THERMAL
+static int power_supply_read_temp(struct thermal_zone_device *tzd,
+                unsigned long *temp)
+{
+        struct power_supply *psy;
+        union power_supply_propval val;
+        int ret;
+
+        WARN_ON(tzd == NULL);
+        psy = tzd->devdata;
+        ret = psy->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);
+
+        /* Convert tenths of degree Celsius to milli degree Celsius. */
+        if (!ret)
+                *temp = val.intval * 100;
+
+        return ret;
+}
+
+static struct thermal_zone_device_ops psy_tzd_ops = {
+        .get_temp = power_supply_read_temp,
+};
+
+static int psy_register_thermal(struct power_supply *psy)
+{
+        int i;
+
+        /* Register battery zone device psy reports temperature */
+        for (i = 0; i < psy->num_properties; i++) {
+                if (psy->properties[i] == POWER_SUPPLY_PROP_TEMP) {
+                        psy->tzd = thermal_zone_device_register(psy->name, 0,
+                                        psy, &psy_tzd_ops, 0, 0, 0, 0);
+                        if (IS_ERR(psy->tzd))
+                                return PTR_ERR(psy->tzd);
+                        break;
+                }
+        }
+        return 0;
+}
+
+static void psy_unregister_thermal(struct power_supply *psy)
+{
+        if (IS_ERR_OR_NULL(psy->tzd))
+                return;
+        thermal_zone_device_unregister(psy->tzd);
+}
+#else
+static int psy_register_thermal(struct power_supply *psy)
+{
+        return 0;
+}
+
+static void psy_unregister_thermal(struct power_supply *psy)
+{
+}
+#endif
+
 int power_supply_register(struct device *parent, struct power_supply *psy)
 {
         struct device *dev;
@@ -197,6 +255,10 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
         if (rc)
                 goto device_add_failed;
 
+        rc = psy_register_thermal(psy);
+        if (rc)
+                goto register_thermal_failed;
+
         rc = power_supply_create_triggers(psy);
         if (rc)
                 goto create_triggers_failed;
@@ -206,6 +268,8 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
         goto success;
 
 create_triggers_failed:
+        psy_unregister_thermal(psy);
+register_thermal_failed:
         device_del(dev);
 kobject_set_name_failed:
 device_add_failed:
@@ -220,6 +284,7 @@ void power_supply_unregister(struct power_supply *psy)
         cancel_work_sync(&psy->changed_work);
         sysfs_remove_link(&psy->dev->kobj, "powers");
         power_supply_remove_triggers(psy);
+        psy_unregister_thermal(psy);
         device_unregister(psy->dev);
 }
 EXPORT_SYMBOL_GPL(power_supply_unregister);