[PATCH] power_supply: Add voltage_ocv property and use it for max17042 driver

From: Ramakrishna Pallala
Date: Tue Apr 10 2012 - 14:57:13 EST


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@xxxxxxxxx>
---
Documentation/power/power_supply_class.txt | 2 ++
drivers/power/max17042_battery.c | 8 ++++++++
drivers/power/power_supply_sysfs.c | 1 +
include/linux/power_supply.h | 2 ++
4 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/Documentation/power/power_supply_class.txt b/Documentation/power/power_supply_class.txt
index 9f16c51..211831d 100644
--- a/Documentation/power/power_supply_class.txt
+++ b/Documentation/power/power_supply_class.txt
@@ -84,6 +84,8 @@ are already charged or discharging, 'n/a' can be displayed (or
HEALTH - represents health of the battery, values corresponds to
POWER_SUPPLY_HEALTH_*, defined in battery.h.

+VOLTAGE_OCV - open circuit voltage of the battery.
+
VOLTAGE_MAX_DESIGN, VOLTAGE_MIN_DESIGN - design values for maximal and
minimal power supply voltages. Maximal/minimal means values of voltages
when battery considered "full"/"empty" at normal conditions. Yes, there is
diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index 04620c2..915767d 100644
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -105,6 +105,7 @@ 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,
@@ -171,6 +172,13 @@ 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 4368e7d..4150747 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),
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index c38c13d..fd17ae0 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -96,6 +96,7 @@ enum power_supply_property {
POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_VOLTAGE_AVG,
+ POWER_SUPPLY_PROP_VOLTAGE_OCV,
POWER_SUPPLY_PROP_CURRENT_MAX,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CURRENT_AVG,
@@ -261,6 +262,7 @@ static inline bool power_supply_is_watt_property(enum power_supply_property psp)
case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
case POWER_SUPPLY_PROP_VOLTAGE_AVG:
+ case POWER_SUPPLY_PROP_VOLTAGE_OCV:
case POWER_SUPPLY_PROP_POWER_NOW:
return 1;
default:
--
1.7.0.4

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