power: android: battery monitor polling with wakeup alarms

Based on Tuna code from 3.0 ported to 3.4 alarm API.

Change-Id: I9b13209963d5a5043237e9e29f3cb07c40583af2
Signed-off-by: Todd Poynor <toddpoynor@google.com>

diff --git a/drivers/power/android_battery.c b/drivers/power/android_battery.c
index f638e18b579cec008f6164ba31c1723c39508a37..867e6b59b26b54f289f1c051073d03c19a636070 100644 (file)
--- a/drivers/power/android_battery.c
+++ b/drivers/power/android_battery.c
@@ -31,10 +31,14 @@
 #include <linux/slab.h>
 #include <linux/wakelock.h>
 #include <linux/workqueue.h>
+#include <linux/alarmtimer.h>
 #include <linux/timer.h>
 #include <linux/debugfs.h>
 #include <linux/platform_data/android_battery.h>
 
+#define FAST_POLL               (1 * 60)
+#define SLOW_POLL               (10 * 60)
+
 struct android_bat_data {
        struct android_bat_platform_data *pdata;
        struct android_bat_callbacks callbacks;
@@ -56,11 +60,11 @@ struct android_bat_data {
        unsigned int            charging_status;
 
        struct workqueue_struct *monitor_wqueue;
-       struct delayed_work     monitor_work;
+       struct work_struct      monitor_work;
        struct work_struct      charger_work;
 
-       bool            slow_poll;
-       ktime_t         last_poll;
+       struct alarm            monitor_alarm;
+       ktime_t                 last_poll;
 
        struct dentry           *debugfs_entry;
 };
@@ -270,11 +274,18 @@ static void android_bat_charger_work(struct work_struct *work)
        wake_lock_timeout(&battery->charger_wake_lock, HZ * 2);
 }
 
+
+static void android_bat_monitor_set_alarm(struct android_bat_data *battery,
+                                         int seconds)
+{
+       alarm_start(&battery->monitor_alarm,
+                   ktime_add(battery->last_poll, ktime_set(seconds, 0)));
+}
+
 static void android_bat_monitor_work(struct work_struct *work)
 {
        struct android_bat_data *battery;
-       battery = container_of(work, struct android_bat_data,
-                              monitor_work.work);
+       battery = container_of(work, struct android_bat_data, monitor_work);
 
        wake_lock(&battery->monitor_wake_lock);
        android_bat_update_data(battery);
@@ -314,10 +325,9 @@ static void android_bat_monitor_work(struct work_struct *work)
                }
                break;
        default:
-               wake_unlock(&battery->monitor_wake_lock);
                pr_err("%s: Undefined battery status: %d\n", __func__,
                       battery->charging_status);
-               return;
+               break;
        }
 
        pr_info("battery: l=%d v=%d c=%d temp=%d h=%d st=%d type=%s\n",
@@ -326,13 +336,23 @@ static void android_bat_monitor_work(struct work_struct *work)
                battery->charging_status,
                charge_source_str(battery->charge_source));
        power_supply_changed(&battery->psy_bat);
-       queue_delayed_work(battery->monitor_wqueue,
-               &battery->monitor_work, msecs_to_jiffies(50000));
+       battery->last_poll = ktime_get_boottime();
+       android_bat_monitor_set_alarm(battery, FAST_POLL);
        wake_unlock(&battery->monitor_wake_lock);
-
        return;
 }
 
+static enum alarmtimer_restart android_bat_monitor_alarm(
+       struct alarm *alarm, ktime_t now)
+{
+       struct android_bat_data *battery =
+               container_of(alarm, struct android_bat_data, monitor_alarm);
+
+       wake_lock(&battery->monitor_wake_lock);
+       queue_work(battery->monitor_wqueue, &battery->monitor_work);
+       return ALARMTIMER_NORESTART;
+}
+
 static int android_power_debug_dump(struct seq_file *s, void *unused)
 {
        struct android_bat_data *battery = s->private;
@@ -410,8 +430,7 @@ static int android_bat_probe(struct platform_device *pdev)
                goto err_wq;
        }
 
-       INIT_DELAYED_WORK_DEFERRABLE(&battery->monitor_work,
-               android_bat_monitor_work);
+       INIT_WORK(&battery->monitor_work, android_bat_monitor_work);
        INIT_WORK(&battery->charger_work, android_bat_charger_work);
 
        battery->callbacks.charge_source_changed =
@@ -426,8 +445,11 @@ static int android_bat_probe(struct platform_device *pdev)
        wake_lock(&battery->charger_wake_lock);
        queue_work(battery->monitor_wqueue, &battery->charger_work);
 
-       queue_delayed_work(battery->monitor_wqueue,
-               &battery->monitor_work, msecs_to_jiffies(0));
+       wake_lock(&battery->monitor_wake_lock);
+       battery->last_poll = ktime_get_boottime();
+       alarm_init(&battery->monitor_alarm, ALARM_BOOTTIME,
+                  android_bat_monitor_alarm);
+       queue_work(battery->monitor_wqueue, &battery->monitor_work);
 
        battery->debugfs_entry =
                debugfs_create_file("android-power", S_IRUGO, NULL,
@@ -452,6 +474,7 @@ static int android_bat_remove(struct platform_device *pdev)
 {
        struct android_bat_data *battery = platform_get_drvdata(pdev);
 
+       alarm_cancel(&battery->monitor_alarm);
        flush_workqueue(battery->monitor_wqueue);
        destroy_workqueue(battery->monitor_wqueue);
        power_supply_unregister(&battery->psy_bat);
@@ -466,7 +489,8 @@ static int android_bat_suspend(struct device *dev)
 {
        struct android_bat_data *battery = dev_get_drvdata(dev);
 
-       cancel_delayed_work_sync(&battery->monitor_work);
+       cancel_work_sync(&battery->monitor_work);
+       android_bat_monitor_set_alarm(battery, SLOW_POLL);
        return 0;
 }
 
@@ -474,8 +498,7 @@ static int android_bat_resume(struct device *dev)
 {
        struct android_bat_data *battery = dev_get_drvdata(dev);
 
-       queue_delayed_work(battery->monitor_wqueue,
-               &battery->monitor_work, msecs_to_jiffies(0));
+       android_bat_monitor_set_alarm(battery, FAST_POLL);
        return 0;
 }