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>

diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 7287c0e..6b68d15 100644 (file)
--- 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 0e86840..9aec029 100644 (file)
--- 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;