1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c
index f4a9258aa9d0..1bb8498f14be 100644
--- a/drivers/power/ds2760_battery.c
+++ b/drivers/power/ds2760_battery.c
@@ -56,6 +56,7 @@ struct ds2760_device_info {
         struct device *w1_dev;
         struct workqueue_struct *monitor_wqueue;
         struct delayed_work monitor_work;
+        struct delayed_work set_charged_work;
 };
 
 static unsigned int cache_time = 1000;
@@ -327,6 +328,52 @@ static void ds2760_battery_external_power_changed(struct power_supply *psy)
         queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
 }
 
+
+static void ds2760_battery_set_charged_work(struct work_struct *work)
+{
+        char bias;
+        struct ds2760_device_info *di = container_of(work,
+                struct ds2760_device_info, set_charged_work.work);
+
+        dev_dbg(di->dev, "%s\n", __func__);
+
+        ds2760_battery_read_status(di);
+
+        /* When we get notified by external circuitry that the battery is
+         * considered fully charged now, we know that there is no current
+         * flow any more. However, the ds2760's internal current meter is
+         * too inaccurate to rely on - spec say something ~15% failure.
+         * Hence, we use the current offset bias register to compensate
+         * that error.
+         */
+
+        if (!power_supply_am_i_supplied(&di->bat))
+                return;
+
+        bias = (signed char) di->current_raw +
+                (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
+
+        dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
+
+        w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
+        w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
+        w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
+
+        /* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
+         * value won't be read back by ds2760_battery_read_status() */
+        di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
+}
+
+static void ds2760_battery_set_charged(struct power_supply *psy)
+{
+        struct ds2760_device_info *di = to_ds2760_device_info(psy);
+
+        /* postpone the actual work by 20 secs. This is for debouncing GPIO
+         * signals and to let the current value settle. See AN4188. */
+        cancel_delayed_work(&di->set_charged_work);
+        queue_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
+}
+
 static int ds2760_battery_get_property(struct power_supply *psy,
                                        enum power_supply_property psp,
                                        union power_supply_propval *val)
@@ -412,6 +459,7 @@ static int ds2760_battery_probe(struct platform_device *pdev)
         di->bat.properties      = ds2760_battery_props;
         di->bat.num_properties  = ARRAY_SIZE(ds2760_battery_props);
         di->bat.get_property    = ds2760_battery_get_property;
+        di->bat.set_charged     = ds2760_battery_set_charged;
         di->bat.external_power_changed =
                                   ds2760_battery_external_power_changed;
 
@@ -443,6 +491,8 @@ static int ds2760_battery_probe(struct platform_device *pdev)
         }
 
         INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
+        INIT_DELAYED_WORK(&di->set_charged_work,
+                          ds2760_battery_set_charged_work);
         di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
         if (!di->monitor_wqueue) {
                 retval = -ESRCH;
@@ -467,6 +517,8 @@ static int ds2760_battery_remove(struct platform_device *pdev)
 
         cancel_rearming_delayed_workqueue(di->monitor_wqueue,
                                           &di->monitor_work);
+        cancel_rearming_delayed_workqueue(di->monitor_wqueue,
+                                          &di->set_charged_work);
         destroy_workqueue(di->monitor_wqueue);
         power_supply_unregister(&di->bat);