charger-manager: Check fully charged state of battery periodically

This patch check periodically fully charged state of battery to protect
overcharge and overheat. If battery is fully charged, stop charging and
check droped voltage with 'fullbatt_vchkdrop_ms' period. When voltage of
battery is more droped than 'fullbatt_vchkdrop_uV' voltage,
charger-manager will restart charging for battery.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

drivers/power/charger-manager.c

@@ -226,6 +226,58 @@ static bool is_charging(struct charger_manager *cm)
 	return charging;
 }
 
+/**
+ * is_full_charged - Returns true if the battery is fully charged.
+ * @cm: the Charger Manager representing the battery.
+ */
+static bool is_full_charged(struct charger_manager *cm)
+{
+	struct charger_desc *desc = cm->desc;
+	union power_supply_propval val;
+	int ret = 0;
+	int uV;
+
+	/* If there is no battery, it cannot be charged */
+	if (!is_batt_present(cm)) {
+		val.intval = 0;
+		goto out;
+	}
+
+	if (cm->fuel_gauge && desc->fullbatt_full_capacity > 0) {
+		/* Not full if capacity of fuel gauge isn't full */
+		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+				POWER_SUPPLY_PROP_CHARGE_FULL, &val);
+		if (!ret && val.intval > desc->fullbatt_full_capacity) {
+			val.intval = 1;
+			goto out;
+		}
+	}
+
+	/* Full, if it's over the fullbatt voltage */
+	if (desc->fullbatt_uV > 0) {
+		ret = get_batt_uV(cm, &uV);
+		if (!ret && uV >= desc->fullbatt_uV) {
+			val.intval = 1;
+			goto out;
+		}
+	}
+
+	/* Full, if the capacity is more than fullbatt_soc */
+	if (cm->fuel_gauge && desc->fullbatt_soc > 0) {
+		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+				POWER_SUPPLY_PROP_CAPACITY, &val);
+		if (!ret && val.intval >= desc->fullbatt_soc) {
+			val.intval = 1;
+			goto out;
+		}
+	}
+
+	val.intval = 0;
+
+out:
+	return val.intval ? true : false;
+}
+
 /**
  * is_polling_required - Return true if need to continue polling for this CM.
  * @cm: the Charger Manager representing the battery.
@@ -418,7 +470,7 @@ static void fullbatt_vchk(struct work_struct *work)
 	diff = desc->fullbatt_uV;
 	diff -= batt_uV;
 
-	dev_dbg(cm->dev, "VBATT dropped %duV after full-batt.\n", diff);
+	dev_info(cm->dev, "VBATT dropped %duV after full-batt.\n", diff);
 
 	if (diff > desc->fullbatt_vchkdrop_uV) {
 		try_charger_restart(cm);
@@ -441,10 +493,14 @@ static bool _cm_monitor(struct charger_manager *cm)
 	dev_dbg(cm->dev, "monitoring (%2.2d.%3.3dC)\n",
 		cm->last_temp_mC / 1000, cm->last_temp_mC % 1000);
 
-	/* It has been stopped or charging already */
+	/* It has been stopped already */
-	if (!!temp == !!cm->emergency_stop)
+	if (temp && 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)) {
@@ -453,11 +509,35 @@ static bool _cm_monitor(struct charger_manager *cm)
 			else
 				uevent_notify(cm, "COLD");
 		}
+
+	/*
+	 * Check dropped voltage of battery. If battery voltage is more
+	 * dropped than fullbatt_vchkdrop_uV after fully charged state,
+	 * charger-manager have to recharge battery.
+	 */
+	} else if (!cm->emergency_stop && is_ext_pwr_online(cm) &&
+			!cm->charger_enabled) {
+		fullbatt_vchk(&cm->fullbatt_vchk_work.work);
+
+	/*
+	 * Check whether fully charged state to protect overcharge
+	 * if charger-manager is charging for battery.
+	 */
+	} else if (!cm->emergency_stop && is_full_charged(cm) &&
+			cm->charger_enabled) {
+		dev_info(cm->dev, "EVENT_HANDLE: Battery Fully Charged.\n");
+		uevent_notify(cm, default_event_names[CM_EVENT_BATT_FULL]);
+
+		try_charger_enable(cm, false);
+
+		fullbatt_vchk(&cm->fullbatt_vchk_work.work);
 	} else {
 		cm->emergency_stop = 0;
+		if (is_ext_pwr_online(cm)) {
 			if (!try_charger_enable(cm, true))
 				uevent_notify(cm, "CHARGING");
 		}
+	}
 
 	return true;
 }
@@ -719,46 +799,9 @@ static int charger_get_property(struct power_supply *psy,
 			val->intval = 0;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_FULL:
-		if (cm->fuel_gauge) {
+		if (is_full_charged(cm))
-			if (cm->fuel_gauge->get_property(cm->fuel_gauge,
-			    POWER_SUPPLY_PROP_CHARGE_FULL, val) == 0)
-				break;
-		}
-
-		if (is_ext_pwr_online(cm)) {
-			/* Not full if it's charging. */
-			if (is_charging(cm)) {
-				val->intval = 0;
-				break;
-			}
-			/*
-			 * Full if it's powered but not charging andi
-			 * not forced stop by emergency
-			 */
-			if (!cm->emergency_stop) {
 			val->intval = 1;
-				break;
+		else
-			}
-		}
-
-		/* Full if it's over the fullbatt voltage */
-		ret = get_batt_uV(cm, &uV);
-		if (!ret && desc->fullbatt_uV > 0 && uV >= desc->fullbatt_uV &&
-		    !is_charging(cm)) {
-			val->intval = 1;
-			break;
-		}
-
-		/* Full if the cap is 100 */
-		if (cm->fuel_gauge) {
-			ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
-					POWER_SUPPLY_PROP_CAPACITY, val);
-			if (!ret && val->intval >= 100 && !is_charging(cm)) {
-				val->intval = 1;
-				break;
-			}
-		}
-
 			val->intval = 0;
 		ret = 0;
 		break;
@@ -1049,7 +1092,26 @@ static int charger_extcon_notifier(struct notifier_block *self,
 	struct charger_cable *cable =
 		container_of(self, struct charger_cable, nb);
 
+	/*
+	 * The newly state of charger cable.
+	 * If cable is attached, cable->attached is true.
+	 */
 	cable->attached = event;
+
+	/*
+	 * Setup monitoring to check battery state
+	 * when charger cable is attached.
+	 */
+	if (cable->attached && is_polling_required(cable->cm)) {
+		if (work_pending(&setup_polling))
+			cancel_work_sync(&setup_polling);
+		schedule_work(&setup_polling);
+	}
+
+	/*
+	 * Setup work for controlling charger(regulator)
+	 * according to charger cable.
+	 */
 	schedule_work(&cable->wq);
 
 	return NOTIFY_DONE;
@@ -1143,6 +1205,15 @@ static int charger_manager_probe(struct platform_device *pdev)
 		desc->fullbatt_vchkdrop_ms = 0;
 		desc->fullbatt_vchkdrop_uV = 0;
 	}
+	if (desc->fullbatt_soc == 0) {
+		dev_info(&pdev->dev, "Ignoring full-battery soc(state of"
+					" charge) threshold as it is not"
+					" supplied.");
+	}
+	if (desc->fullbatt_full_capacity == 0) {
+		dev_info(&pdev->dev, "Ignoring full-battery full capacity"
+					" threshold as it is not supplied.");
+	}
 
 	if (!desc->charger_regulators || desc->num_charger_regulators < 1) {
 		ret = -EINVAL;

include/linux/power/charger-manager.h

@@ -140,7 +140,11 @@ struct charger_regulator {
  *	If it has dropped more than fullbatt_vchkdrop_uV after
  *	fullbatt_vchkdrop_ms, CM will restart charging.
  * @fullbatt_uV: voltage in microvolt
- *	If it is not being charged and VBATT >= fullbatt_uV,
+ *	If VBATT >= fullbatt_uV, it is assumed to be full.
+ * @fullbatt_soc: state of Charge in %
+ *	If state of Charge >= fullbatt_soc, it is assumed to be full.
+ * @fullbatt_full_capacity: full capacity measure
+ *	If full capacity of battery >= fullbatt_full_capacity,
  *	it is assumed to be full.
  * @polling_interval_ms: interval in millisecond at which
  *	charger manager will monitor battery health
@@ -168,6 +172,8 @@ struct charger_desc {
 	unsigned int fullbatt_vchkdrop_ms;
 	unsigned int fullbatt_vchkdrop_uV;
 	unsigned int fullbatt_uV;
+	unsigned int fullbatt_soc;
+	unsigned int fullbatt_full_capacity;
 
 	enum data_source battery_present;