3 files changed, 278 insertions, 1 deletions

diff --git a/Documentation/power/charger-manager.txt b/Documentation/power/charger-manager.txt
index fdcca991df30..9b3863386e54 100644
--- a/Documentation/power/charger-manager.txt
+++ b/Documentation/power/charger-manager.txt
@@ -44,6 +44,12 @@ Charger Manager supports the following:
         Normally, the platform will need to resume and suspend some devices
         that are used by Charger Manager.
 
+* Support for premature full-battery event handling
+        If the battery voltage drops by "fullbatt_vchkdrop_uV" after
+        "fullbatt_vchkdrop_ms" from the full-battery event, the framework
+        restarts charging. This check is also performed while suspended by
+        setting wakeup time accordingly and using suspend_again.
+
 2. Global Charger-Manager Data related with suspend_again
 ========================================================
 In order to setup Charger Manager with suspend-again feature
@@ -55,7 +61,7 @@ if there are multiple batteries. If there are multiple batteries, the
 multiple instances of Charger Manager share the same charger_global_desc
 and it will manage in-suspend monitoring for all instances of Charger Manager.
 
-The user needs to provide all the two entries properly in order to activate
+The user needs to provide all the three entries properly in order to activate
 in-suspend monitoring:
 
 struct charger_global_desc {
@@ -74,6 +80,11 @@ bool (*rtc_only_wakeup)(void);
         same struct. If there is any other wakeup source triggered the
         wakeup, it should return false. If the "rtc" is the only wakeup
         reason, it should return true.
+
+bool assume_timer_stops_in_suspend;
+        : if true, Charger Manager assumes that
+        the timer (CM uses jiffies as timer) stops during suspend. Then, CM
+        assumes that the suspend-duration is same as the alarm length.
 };
 
 3. How to setup suspend_again
@@ -111,6 +122,16 @@ enum polling_modes polling_mode;
           CM_POLL_CHARGING_ONLY: poll this battery if and only if the
                                  battery is being charged.
 
+unsigned int fullbatt_vchkdrop_ms;
+unsigned int fullbatt_vchkdrop_uV;
+        : If both have non-zero values, Charger Manager will check the
+        battery voltage drop fullbatt_vchkdrop_ms after the battery is fully
+        charged. If the voltage drop is over fullbatt_vchkdrop_uV, Charger
+        Manager will try to recharge the battery by disabling and enabling
+        chargers. Recharge with voltage drop condition only (without delay
+        condition) is needed to be implemented with hardware interrupts from
+        fuel gauges or charger devices/chips.
+
 unsigned int fullbatt_uV;
         : If specified with a non-zero value, Charger Manager assumes
         that the battery is full (capacity = 100) if the battery is not being
@@ -122,6 +143,8 @@ unsigned int polling_interval_ms;
         this battery every polling_interval_ms or more frequently.
 
 enum data_source battery_present;
+        : CM_BATTERY_PRESENT: assume that the battery exists.
+        CM_NO_BATTERY: assume that the battery does not exists.
         CM_FUEL_GAUGE: get battery presence information from fuel gauge.
         CM_CHARGER_STAT: get battery presence from chargers.
 
diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 9eca9f1ff0ea..959062d16bac 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;
 }