charger-manager: Poll battery health in normal state

Charger-Manager needs to check battery health in normal state
as well as suspend-to-RAM state. When the battery is fully charged,
Charger-Manager needs to determine when the chargers restart charging.

This patch allows Charger-Manager to monitor battery health in normal
state and handle operation for chargers after battery is fully charged.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

1 files changed, 229 insertions, 0 deletions

diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 9eca9f1..959062d 100644
--- a/drivers/power/charger-manager.c
+++ b/drivers/power/charger-manager.c
@@ -57,6 +57,12 @@ static bool cm_suspended;
 static bool cm_rtc_set;
 static unsigned long cm_suspend_duration_ms;
 
+/* About normal (not suspended) monitoring */
+static unsigned long polling_jiffy = ULONG_MAX; /* ULONG_MAX: no polling */
+static unsigned long next_polling; /* Next appointed polling time */
+static struct workqueue_struct *cm_wq; /* init at driver add */
+static struct delayed_work cm_monitor_work; /* init at driver add */
+
 /* Global charger-manager description */
 static struct charger_global_desc *g_desc; /* init with setup_charger_manager */
 
@@ -71,6 +77,11 @@ static bool is_batt_present(struct charger_manager *cm)
 	int i, ret;
 
 	switch (cm->desc->battery_present) {
+	case CM_BATTERY_PRESENT:
+		present = true;
+		break;
+	case CM_NO_BATTERY:
+		break;
 	case CM_FUEL_GAUGE:
 		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
 				POWER_SUPPLY_PROP_PRESENT, &val);
@@ -279,6 +290,26 @@ static int try_charger_enable(struct charger_manager *cm, bool enable)
 }
 
 /**
+ * try_charger_restart - Restart charging.
+ * @cm: the Charger Manager representing the battery.
+ *
+ * Restart charging by turning off and on the charger.
+ */
+static int try_charger_restart(struct charger_manager *cm)
+{
+	int err;
+
+	if (cm->emergency_stop)
+		return -EAGAIN;
+
+	err = try_charger_enable(cm, false);
+	if (err)
+		return err;
+
+	return try_charger_enable(cm, true);
+}
+
+/**
  * uevent_notify - Let users know something has changed.
  * @cm: the Charger Manager representing the battery.
  * @event: the event string.
@@ -334,6 +365,46 @@ static void uevent_notify(struct charger_manager *cm, const char *event)
 }
 
 /**
+ * fullbatt_vchk - Check voltage drop some times after "FULL" event.
+ * @work: the work_struct appointing the function
+ *
+ * If a user has designated "fullbatt_vchkdrop_ms/uV" values with
+ * charger_desc, Charger Manager checks voltage drop after the battery
+ * "FULL" event. It checks whether the voltage has dropped more than
+ * fullbatt_vchkdrop_uV by calling this function after fullbatt_vchkrop_ms.
+ */
+static void fullbatt_vchk(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct charger_manager *cm = container_of(dwork,
+			struct charger_manager, fullbatt_vchk_work);
+	struct charger_desc *desc = cm->desc;
+	int batt_uV, err, diff;
+
+	/* remove the appointment for fullbatt_vchk */
+	cm->fullbatt_vchk_jiffies_at = 0;
+
+	if (!desc->fullbatt_vchkdrop_uV || !desc->fullbatt_vchkdrop_ms)
+		return;
+
+	err = get_batt_uV(cm, &batt_uV);
+	if (err) {
+		dev_err(cm->dev, "%s: get_batt_uV error(%d).\n", __func__, err);
+		return;
+	}
+
+	diff = cm->fullbatt_vchk_uV;
+	diff -= batt_uV;
+
+	dev_dbg(cm->dev, "VBATT dropped %duV after full-batt.\n", diff);
+
+	if (diff > desc->fullbatt_vchkdrop_uV) {
+		try_charger_restart(cm);
+		uevent_notify(cm, "Recharge");
+	}
+}
+
+/**
  * _cm_monitor - Monitor the temperature and return true for exceptions.
  * @cm: the Charger Manager representing the battery.
  *
@@ -392,6 +463,68 @@ static bool cm_monitor(void)
 	return stop;
 }
 
+/**
+ * _setup_polling - Setup the next instance of polling.
+ * @work: work_struct of the function _setup_polling.
+ */
+static void _setup_polling(struct work_struct *work)
+{
+	unsigned long min = ULONG_MAX;
+	struct charger_manager *cm;
+	bool keep_polling = false;
+	unsigned long _next_polling;
+
+	mutex_lock(&cm_list_mtx);
+
+	list_for_each_entry(cm, &cm_list, entry) {
+		if (is_polling_required(cm) && cm->desc->polling_interval_ms) {
+			keep_polling = true;
+
+			if (min > cm->desc->polling_interval_ms)
+				min = cm->desc->polling_interval_ms;
+		}
+	}
+
+	polling_jiffy = msecs_to_jiffies(min);
+	if (polling_jiffy <= CM_JIFFIES_SMALL)
+		polling_jiffy = CM_JIFFIES_SMALL + 1;
+
+	if (!keep_polling)
+		polling_jiffy = ULONG_MAX;
+	if (polling_jiffy == ULONG_MAX)
+		goto out;
+
+	WARN(cm_wq == NULL, "charger-manager: workqueue not initialized"
+			    ". try it later. %s\n", __func__);
+
+	_next_polling = jiffies + polling_jiffy;
+
+	if (!delayed_work_pending(&cm_monitor_work) ||
+	    (delayed_work_pending(&cm_monitor_work) &&
+	     time_after(next_polling, _next_polling))) {
+		cancel_delayed_work_sync(&cm_monitor_work);
+		next_polling = jiffies + polling_jiffy;
+		queue_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
+	}
+
+out:
+	mutex_unlock(&cm_list_mtx);
+}
+static DECLARE_WORK(setup_polling, _setup_polling);
+
+/**
+ * cm_monitor_poller - The Monitor / Poller.
+ * @work: work_struct of the function cm_monitor_poller
+ *
+ * During non-suspended state, cm_monitor_poller is used to poll and monitor
+ * the batteries.
+ */
+static void cm_monitor_poller(struct work_struct *work)
+{
+	cm_monitor();
+	schedule_work(&setup_polling);
+}
+
 static int charger_get_property(struct power_supply *psy,
 		enum power_supply_property psp,
 		union power_supply_propval *val)
@@ -613,6 +746,21 @@ static bool cm_setup_timer(void)
 	mutex_lock(&cm_list_mtx);
 
 	list_for_each_entry(cm, &cm_list, entry) {
+		unsigned int fbchk_ms = 0;
+
+		/* fullbatt_vchk is required. setup timer for that */
+		if (cm->fullbatt_vchk_jiffies_at) {
+			fbchk_ms = jiffies_to_msecs(cm->fullbatt_vchk_jiffies_at
+						    - jiffies);
+			if (time_is_before_eq_jiffies(
+				cm->fullbatt_vchk_jiffies_at) ||
+				msecs_to_jiffies(fbchk_ms) < CM_JIFFIES_SMALL) {
+				fullbatt_vchk(&cm->fullbatt_vchk_work.work);
+				fbchk_ms = 0;
+			}
+		}
+		CM_MIN_VALID(wakeup_ms, fbchk_ms);
+
 		/* Skip if polling is not required for this CM */
 		if (!is_polling_required(cm) && !cm->emergency_stop)
 			continue;
@@ -672,6 +820,23 @@ static bool cm_setup_timer(void)
 	return false;
 }
 
+static void _cm_fbchk_in_suspend(struct charger_manager *cm)
+{
+	unsigned long jiffy_now = jiffies;
+
+	if (!cm->fullbatt_vchk_jiffies_at)
+		return;
+
+	if (g_desc && g_desc->assume_timer_stops_in_suspend)
+		jiffy_now += msecs_to_jiffies(cm_suspend_duration_ms);
+
+	/* Execute now if it's going to be executed not too long after */
+	jiffy_now += CM_JIFFIES_SMALL;
+
+	if (time_after_eq(jiffy_now, cm->fullbatt_vchk_jiffies_at))
+		fullbatt_vchk(&cm->fullbatt_vchk_work.work);
+}
+
 /**
  * cm_suspend_again - Determine whether suspend again or not
  *
@@ -693,6 +858,8 @@ bool cm_suspend_again(void)
 	ret = true;
 	mutex_lock(&cm_list_mtx);
 	list_for_each_entry(cm, &cm_list, entry) {
+		_cm_fbchk_in_suspend(cm);
+
 		if (cm->status_save_ext_pwr_inserted != is_ext_pwr_online(cm) ||
 		    cm->status_save_batt != is_batt_present(cm)) {
 			ret = false;
@@ -796,6 +963,21 @@ static int charger_manager_probe(struct platform_device *pdev)
 	memcpy(cm->desc, desc, sizeof(struct charger_desc));
 	cm->last_temp_mC = INT_MIN; /* denotes "unmeasured, yet" */
 
+	/*
+	 * The following two do not need to be errors.
+	 * Users may intentionally ignore those two features.
+	 */
+	if (desc->fullbatt_uV == 0) {
+		dev_info(&pdev->dev, "Ignoring full-battery voltage threshold"
+					" as it is not supplied.");
+	}
+	if (!desc->fullbatt_vchkdrop_ms || !desc->fullbatt_vchkdrop_uV) {
+		dev_info(&pdev->dev, "Disabling full-battery voltage drop "
+				"checking mechanism as it is not supplied.");
+		desc->fullbatt_vchkdrop_ms = 0;
+		desc->fullbatt_vchkdrop_uV = 0;
+	}
+
 	if (!desc->charger_regulators || desc->num_charger_regulators < 1) {
 		ret = -EINVAL;
 		dev_err(&pdev->dev, "charger_regulators undefined.\n");
@@ -903,6 +1085,8 @@ static int charger_manager_probe(struct platform_device *pdev)
 		cm->charger_psy.num_properties++;
 	}
 
+	INIT_DELAYED_WORK(&cm->fullbatt_vchk_work, fullbatt_vchk);
+
 	ret = power_supply_register(NULL, &cm->charger_psy);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot register charger-manager with"
@@ -928,6 +1112,8 @@ static int charger_manager_probe(struct platform_device *pdev)
 	list_add(&cm->entry, &cm_list);
 	mutex_unlock(&cm_list_mtx);
 
+	schedule_work(&setup_polling);
+
 	return 0;
 
 err_chg_enable:
@@ -958,9 +1144,17 @@ static int __devexit charger_manager_remove(struct platform_device *pdev)
 	list_del(&cm->entry);
 	mutex_unlock(&cm_list_mtx);
 
+	if (work_pending(&setup_polling))
+		cancel_work_sync(&setup_polling);
+	if (delayed_work_pending(&cm_monitor_work))
+		cancel_delayed_work_sync(&cm_monitor_work);
+
 	regulator_bulk_free(desc->num_charger_regulators,
 			    desc->charger_regulators);
 	power_supply_unregister(&cm->charger_psy);
+
+	try_charger_enable(cm, false);
+
 	kfree(cm->charger_psy.properties);
 	kfree(cm->charger_stat);
 	kfree(cm->desc);
@@ -1000,6 +1194,8 @@ static int cm_suspend_prepare(struct device *dev)
 		cm_suspended = true;
 	}
 
+	if (delayed_work_pending(&cm->fullbatt_vchk_work))
+		cancel_delayed_work(&cm->fullbatt_vchk_work);
 	cm->status_save_ext_pwr_inserted = is_ext_pwr_online(cm);
 	cm->status_save_batt = is_batt_present(cm);
 
@@ -1027,6 +1223,33 @@ static void cm_suspend_complete(struct device *dev)
 		cm_rtc_set = false;
 	}
 
+	/* Re-enqueue delayed work (fullbatt_vchk_work) */
+	if (cm->fullbatt_vchk_jiffies_at) {
+		unsigned long delay = 0;
+		unsigned long now = jiffies + CM_JIFFIES_SMALL;
+
+		if (time_after_eq(now, cm->fullbatt_vchk_jiffies_at)) {
+			delay = (unsigned long)((long)now
+				- (long)(cm->fullbatt_vchk_jiffies_at));
+			delay = jiffies_to_msecs(delay);
+		} else {
+			delay = 0;
+		}
+
+		/*
+		 * Account for cm_suspend_duration_ms if
+		 * assume_timer_stops_in_suspend is active
+		 */
+		if (g_desc && g_desc->assume_timer_stops_in_suspend) {
+			if (delay > cm_suspend_duration_ms)
+				delay -= cm_suspend_duration_ms;
+			else
+				delay = 0;
+		}
+
+		queue_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
+				   msecs_to_jiffies(delay));
+	}
 	uevent_notify(cm, NULL);
 }
 
@@ -1048,12 +1271,18 @@ static struct platform_driver charger_manager_driver = {
 
 static int __init charger_manager_init(void)
 {
+	cm_wq = create_freezable_workqueue("charger_manager");
+	INIT_DELAYED_WORK(&cm_monitor_work, cm_monitor_poller);
+
 	return platform_driver_register(&charger_manager_driver);
 }
 late_initcall(charger_manager_init);
 
 static void __exit charger_manager_cleanup(void)
 {
+	destroy_workqueue(cm_wq);
+	cm_wq = NULL;
+
 	platform_driver_unregister(&charger_manager_driver);
 }
 module_exit(charger_manager_cleanup);