power_supply: Add voltage_ocv property and use it for max17042 driver

This adds a new sysfs file called 'voltage_ocv' which gives the
Open Circuit Voltage of the battery.

This property can be used for platform shutdown policies and
can be useful for initial capacity estimations.

Note: This patch is generated against linux-next branch.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

2 files changed, 9 insertions, 0 deletions

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index 738648d1d9fc..42c4be9a664b 100644
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -106,6 +106,7 @@ static enum power_supply_property max17042_battery_props[] = {
         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
         POWER_SUPPLY_PROP_VOLTAGE_NOW,
         POWER_SUPPLY_PROP_VOLTAGE_AVG,
+        POWER_SUPPLY_PROP_VOLTAGE_OCV,
         POWER_SUPPLY_PROP_CAPACITY,
         POWER_SUPPLY_PROP_CHARGE_FULL,
         POWER_SUPPLY_PROP_TEMP,
@@ -172,6 +173,13 @@ static int max17042_get_property(struct power_supply *psy,
 
                 val->intval = ret * 625 / 8;
                 break;
+        case POWER_SUPPLY_PROP_VOLTAGE_OCV:
+                ret = max17042_read_reg(chip->client, MAX17042_OCVInternal);
+                if (ret < 0)
+                        return ret;
+
+                val->intval = ret * 625 / 8;
+                break;
         case POWER_SUPPLY_PROP_CAPACITY:
                 ret = max17042_read_reg(chip->client, MAX17042_RepSOC);
                 if (ret < 0)
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
index 4368e7d61316..4150747f9186 100644
--- a/drivers/power/power_supply_sysfs.c
+++ b/drivers/power/power_supply_sysfs.c
@@ -146,6 +146,7 @@ static struct device_attribute power_supply_attrs[] = {
         POWER_SUPPLY_ATTR(voltage_min_design),
         POWER_SUPPLY_ATTR(voltage_now),
         POWER_SUPPLY_ATTR(voltage_avg),
+        POWER_SUPPLY_ATTR(voltage_ocv),
         POWER_SUPPLY_ATTR(current_max),
         POWER_SUPPLY_ATTR(current_now),
         POWER_SUPPLY_ATTR(current_avg),