[PATCH 2/3] olpc-battery: add support for CHARGE_NOW

[Sascha Silbe]

CHARGE_NOW is needed by UPower to return the current capacity
('Percentage').

This patch violates the power supply class definition (as we already
do for CAPACITY though it isn't as obvious there), but this is the best
we can do without adding rather sophisticated algorithms to either the EC
or UPower.

Signed-off-by: Sascha Silbe <sascha-pgp at silbe.org>
---
 drivers/power/olpc_battery.c |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/drivers/power/olpc_battery.c b/drivers/power/olpc_battery.c
index dbe5b85..a49e548 100644
--- a/drivers/power/olpc_battery.c
+++ b/drivers/power/olpc_battery.c
@@ -248,6 +248,24 @@ static int olpc_bat_get_charge_full_design(union power_supply_propval *val)
 	return ret;
 }
 
+static int olpc_bat_get_charge_now(union power_supply_propval *val)
+{
+	uint8_t soc;
+	union power_supply_propval full;
+	int ret;
+
+	ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &soc, 1);
+	if (ret)
+		return ret;
+
+	ret = olpc_bat_get_charge_full_design(&full);
+	if (ret)
+		return ret;
+
+	val->intval = soc * (full.intval / 100);
+	return 0;
+}
+
 /*********************************************************************
  *		Battery properties
  *********************************************************************/
@@ -346,6 +364,11 @@ static int olpc_bat_get_property(struct power_supply *psy,
 		if (ret)
 			return ret;
 		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		ret = olpc_bat_get_charge_now(val);
+		if (ret)
+			return ret;
+		break;
 	case POWER_SUPPLY_PROP_TEMP:
 		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
@@ -396,6 +419,7 @@ static enum power_supply_property olpc_bat_props[] = {
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_TEMP,
 #ifndef CONFIG_OLPC_XO_1_5
 	POWER_SUPPLY_PROP_TEMP_AMBIENT,
-- 
1.6.5