charger-manager: Modify the way of checking battery's temperature

Charger-manager driver used to check battery temperature through the
callback function passed by platform data. Unfortunatley, without that
pre-defined callback function, charger-manager can't get battery's
temperature at all. Also passing callback function through platform data
ruins DT support for charger-manager.

This patch mondifies charger-manager driver to get temperature of battery
without pre-defined callback function. Now, charger-manager can use either
of battery thermometer in fuel-gauge and ouside of battery. It uses
thermal framework interface for outer thermometer if thermal fw is
enabled. Otherwise, it tries to use fuel-gauge's through the power supply
interface.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

2 files changed, 136 insertions, 49 deletions

diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 7287c0efd6bf..6b68d158e3c1 100644
--- a/drivers/power/charger-manager.c
+++ b/drivers/power/charger-manager.c
@@ -25,12 +25,22 @@
 #include <linux/power/charger-manager.h>
 #include <linux/regulator/consumer.h>
 #include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+/*
+ * Default termperature threshold for charging.
+ * Every temperature units are in tenth of centigrade.
+ */
+#define CM_DEFAULT_RECHARGE_TEMP_DIFF   50
+#define CM_DEFAULT_CHARGE_TEMP_MAX      500
 
 static const char * const default_event_names[] = {
         [CM_EVENT_UNKNOWN] = "Unknown",
         [CM_EVENT_BATT_FULL] = "Battery Full",
         [CM_EVENT_BATT_IN] = "Battery Inserted",
         [CM_EVENT_BATT_OUT] = "Battery Pulled Out",
+        [CM_EVENT_BATT_OVERHEAT] = "Battery Overheat",
+        [CM_EVENT_BATT_COLD] = "Battery Cold",
         [CM_EVENT_EXT_PWR_IN_OUT] = "External Power Attach/Detach",
         [CM_EVENT_CHG_START_STOP] = "Charging Start/Stop",
         [CM_EVENT_OTHERS] = "Other battery events"
@@ -540,6 +550,60 @@ static int check_charging_duration(struct charger_manager *cm)
         return ret;
 }
 
+static int cm_get_battery_temperature(struct charger_manager *cm,
+                                        int *temp)
+{
+        int ret;
+
+        if (!cm->desc->measure_battery_temp)
+                return -ENODEV;
+
+#ifdef CONFIG_THERMAL
+        ret = thermal_zone_get_temp(cm->tzd_batt, (unsigned long *)temp);
+        if (!ret)
+                /* Calibrate temperature unit */
+                *temp /= 100;
+#else
+        ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+                                POWER_SUPPLY_PROP_TEMP,
+                                (union power_supply_propval *)temp);
+#endif
+        return ret;
+}
+
+static int cm_check_thermal_status(struct charger_manager *cm)
+{
+        struct charger_desc *desc = cm->desc;
+        int temp, upper_limit, lower_limit;
+        int ret = 0;
+
+        ret = cm_get_battery_temperature(cm, &temp);
+        if (ret) {
+                /* FIXME:
+                 * No information of battery temperature might
+                 * occur hazadous result. We have to handle it
+                 * depending on battery type.
+                 */
+                dev_err(cm->dev, "Failed to get battery temperature\n");
+                return 0;
+        }
+
+        upper_limit = desc->temp_max;
+        lower_limit = desc->temp_min;
+
+        if (cm->emergency_stop) {
+                upper_limit -= desc->temp_diff;
+                lower_limit += desc->temp_diff;
+        }
+
+        if (temp > upper_limit)
+                ret = CM_EVENT_BATT_OVERHEAT;
+        else if (temp < lower_limit)
+                ret = CM_EVENT_BATT_COLD;
+
+        return ret;
+}
+
 /**
  * _cm_monitor - Monitor the temperature and return true for exceptions.
  * @cm: the Charger Manager representing the battery.
@@ -549,28 +613,22 @@ static int check_charging_duration(struct charger_manager *cm)
  */
 static bool _cm_monitor(struct charger_manager *cm)
 {
-        struct charger_desc *desc = cm->desc;
-        int temp = desc->temperature_out_of_range(&cm->last_temp_mC);
+        int temp_alrt;
 
-        dev_dbg(cm->dev, "monitoring (%2.2d.%3.3dC)\n",
-                cm->last_temp_mC / 1000, cm->last_temp_mC % 1000);
+        temp_alrt = cm_check_thermal_status(cm);
 
         /* It has been stopped already */
-        if (temp && cm->emergency_stop)
+        if (temp_alrt && cm->emergency_stop)
                 return false;
 
         /*
          * Check temperature whether overheat or cold.
          * If temperature is out of range normal state, stop charging.
          */
-        if (temp) {
-                cm->emergency_stop = temp;
-                if (!try_charger_enable(cm, false)) {
-                        if (temp > 0)
-                                uevent_notify(cm, "OVERHEAT");
-                        else
-                                uevent_notify(cm, "COLD");
-                }
+        if (temp_alrt) {
+                cm->emergency_stop = temp_alrt;
+                if (!try_charger_enable(cm, false))
+                        uevent_notify(cm, default_event_names[temp_alrt]);
 
         /*
          * Check whole charging duration and discharing duration
@@ -802,21 +860,8 @@ static int charger_get_property(struct power_supply *psy,
                                 POWER_SUPPLY_PROP_CURRENT_NOW, val);
                 break;
         case POWER_SUPPLY_PROP_TEMP:
-                /* in thenth of centigrade */
-                if (cm->last_temp_mC == INT_MIN)
-                        desc->temperature_out_of_range(&cm->last_temp_mC);
-                val->intval = cm->last_temp_mC / 100;
-                if (!desc->measure_battery_temp)
-                        ret = -ENODEV;
-                break;
         case POWER_SUPPLY_PROP_TEMP_AMBIENT:
-                /* in thenth of centigrade */
-                if (cm->last_temp_mC == INT_MIN)
-                        desc->temperature_out_of_range(&cm->last_temp_mC);
-                val->intval = cm->last_temp_mC / 100;
-                if (desc->measure_battery_temp)
-                        ret = -ENODEV;
-                break;
+                return cm_get_battery_temperature(cm, &val->intval);
         case POWER_SUPPLY_PROP_CAPACITY:
                 if (!cm->fuel_gauge) {
                         ret = -ENODEV;
@@ -1439,6 +1484,50 @@ err:
         return ret;
 }
 
+static int cm_init_thermal_data(struct charger_manager *cm)
+{
+        struct charger_desc *desc = cm->desc;
+        union power_supply_propval val;
+        int ret;
+
+        /* Verify whether fuel gauge provides battery temperature */
+        ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+                                        POWER_SUPPLY_PROP_TEMP, &val);
+
+        if (!ret) {
+                cm->charger_psy.properties[cm->charger_psy.num_properties] =
+                                POWER_SUPPLY_PROP_TEMP;
+                cm->charger_psy.num_properties++;
+                cm->desc->measure_battery_temp = true;
+        }
+#ifdef CONFIG_THERMAL
+        cm->tzd_batt = cm->fuel_gauge->tzd;
+
+        if (ret && desc->thermal_zone) {
+                cm->tzd_batt =
+                        thermal_zone_get_zone_by_name(desc->thermal_zone);
+                if (IS_ERR(cm->tzd_batt))
+                        return PTR_ERR(cm->tzd_batt);
+
+                /* Use external thermometer */
+                cm->charger_psy.properties[cm->charger_psy.num_properties] =
+                                POWER_SUPPLY_PROP_TEMP_AMBIENT;
+                cm->charger_psy.num_properties++;
+                cm->desc->measure_battery_temp = true;
+                ret = 0;
+        }
+#endif
+        if (cm->desc->measure_battery_temp) {
+                /* NOTICE : Default allowable minimum charge temperature is 0 */
+                if (!desc->temp_max)
+                        desc->temp_max = CM_DEFAULT_CHARGE_TEMP_MAX;
+                if (!desc->temp_diff)
+                        desc->temp_diff = CM_DEFAULT_RECHARGE_TEMP_DIFF;
+        }
+
+        return ret;
+}
+
 static int charger_manager_probe(struct platform_device *pdev)
 {
         struct charger_desc *desc = dev_get_platdata(&pdev->dev);
@@ -1470,7 +1559,6 @@ static int charger_manager_probe(struct platform_device *pdev)
         /* Basic Values. Unspecified are Null or 0 */
         cm->dev = &pdev->dev;
         cm->desc = desc;
-        cm->last_temp_mC = INT_MIN; /* denotes "unmeasured, yet" */
 
         /*
          * The following two do not need to be errors.
@@ -1533,11 +1621,6 @@ static int charger_manager_probe(struct platform_device *pdev)
                 return -EINVAL;
         }
 
-        if (!desc->temperature_out_of_range) {
-                dev_err(&pdev->dev, "there is no temperature_out_of_range\n");
-                return -EINVAL;
-        }
-
         if (!desc->charging_max_duration_ms ||
                         !desc->discharging_max_duration_ms) {
                 dev_info(&pdev->dev, "Cannot limit charging duration checking mechanism to prevent overcharge/overheat and control discharging duration\n");
@@ -1583,14 +1666,10 @@ static int charger_manager_probe(struct platform_device *pdev)
                 cm->charger_psy.num_properties++;
         }
 
-        if (desc->measure_battery_temp) {
-                cm->charger_psy.properties[cm->charger_psy.num_properties] =
-                                POWER_SUPPLY_PROP_TEMP;
-                cm->charger_psy.num_properties++;
-        } else {
-                cm->charger_psy.properties[cm->charger_psy.num_properties] =
-                                POWER_SUPPLY_PROP_TEMP_AMBIENT;
-                cm->charger_psy.num_properties++;
+        ret = cm_init_thermal_data(cm);
+        if (ret) {
+                dev_err(&pdev->dev, "Failed to initialize thermal data\n");
+                cm->desc->measure_battery_temp = false;
         }
 
         INIT_DELAYED_WORK(&cm->fullbatt_vchk_work, fullbatt_vchk);
diff --git a/include/linux/power/charger-manager.h b/include/linux/power/charger-manager.h
index 0e86840eb603..9aec0293f204 100644
--- a/include/linux/power/charger-manager.h
+++ b/include/linux/power/charger-manager.h
@@ -37,6 +37,8 @@ enum cm_event_types {
         CM_EVENT_BATT_FULL,
         CM_EVENT_BATT_IN,
         CM_EVENT_BATT_OUT,
+        CM_EVENT_BATT_OVERHEAT,
+        CM_EVENT_BATT_COLD,
         CM_EVENT_EXT_PWR_IN_OUT,
         CM_EVENT_CHG_START_STOP,
         CM_EVENT_OTHERS,
@@ -173,11 +175,10 @@ struct charger_regulator {
  * @num_charger_regulator: the number of entries in charger_regulators
  * @charger_regulators: array of charger regulators
  * @psy_fuel_gauge: the name of power-supply for fuel gauge
- * @temperature_out_of_range:
- *      Determine whether the status is overheat or cold or normal.
- *      return_value > 0: overheat
- *      return_value == 0: normal
- *      return_value < 0: cold
+ * @thermal_zone : the name of thermal zone for battery
+ * @temp_min : Minimum battery temperature for charging.
+ * @temp_max : Maximum battery temperature for charging.
+ * @temp_diff : Temperature diffential to restart charging.
  * @measure_battery_temp:
  *      true: measure battery temperature
  *      false: measure ambient temperature
@@ -210,7 +211,12 @@ struct charger_desc {
 
         char *psy_fuel_gauge;
 
-        int (*temperature_out_of_range)(int *mC);
+        char *thermal_zone;
+
+        int temp_min;
+        int temp_max;
+        int temp_diff;
+
         bool measure_battery_temp;
 
         u64 charging_max_duration_ms;
@@ -226,13 +232,13 @@ struct charger_desc {
  * @desc: instance of charger_desc
  * @fuel_gauge: power_supply for fuel gauge
  * @charger_stat: array of power_supply for chargers
+ * @tzd_batt : thermal zone device for battery
  * @charger_enabled: the state of charger
  * @fullbatt_vchk_jiffies_at:
  *      jiffies at the time full battery check will occur.
  * @fullbatt_vchk_work: work queue for full battery check
  * @emergency_stop:
  *      When setting true, stop charging
- * @last_temp_mC: the measured temperature in milli-Celsius
  * @psy_name_buf: the name of power-supply-class for charger manager
  * @charger_psy: power_supply for charger manager
  * @status_save_ext_pwr_inserted:
@@ -250,13 +256,15 @@ struct charger_manager {
         struct power_supply *fuel_gauge;
         struct power_supply **charger_stat;
 
+#ifdef CONFIG_THERMAL
+        struct thermal_zone_device *tzd_batt;
+#endif
         bool charger_enabled;
 
         unsigned long fullbatt_vchk_jiffies_at;
         struct delayed_work fullbatt_vchk_work;
 
         int emergency_stop;
-        int last_temp_mC;
 
         char psy_name_buf[PSY_NAME_MAX + 1];
         struct power_supply charger_psy;