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);