Revert "power: remove POWER_SUPPLY_PROP_CAPACITY_LEVEL"

This reverts commit 8efe444038a205e79b38b7ad03878824901849a8 and
4cbc76eadf56399cd11fb736b33c53aec9caab8c.

Richard@laptop.org was apparently using CAPACITY_LEVEL for debugging
battery/EC problems, and was upset that it was removed.  This readds it.

Conflicts:

	Documentation/power_supply_class.txt

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

Documentation/power/power_supply_class.txt

@@ -108,6 +108,8 @@ relative, time-based measurements.
 ENERGY_FULL, ENERGY_EMPTY - same as above but for energy.
 
 CAPACITY - capacity in percents.
+CAPACITY_LEVEL - capacity level. This corresponds to
+POWER_SUPPLY_CAPACITY_LEVEL_*.
 
 TEMP - temperature of the power supply.
 TEMP_AMBIENT - ambient temperature.

drivers/power/olpc_battery.c

@@ -276,6 +276,14 @@ static int olpc_bat_get_property(struct power_supply *psy,
 			return ret;
 		val->intval = ec_byte;
 		break;
+	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+		if (ec_byte & BAT_STAT_FULL)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
+		else if (ec_byte & BAT_STAT_LOW)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
+		else
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
+		break;
 	case POWER_SUPPLY_PROP_TEMP:
 		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
@@ -321,6 +329,7 @@ static enum power_supply_property olpc_bat_props[] = {
 	POWER_SUPPLY_PROP_VOLTAGE_AVG,
 	POWER_SUPPLY_PROP_CURRENT_AVG,
 	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_TEMP_AMBIENT,
 	POWER_SUPPLY_PROP_MANUFACTURER,

drivers/power/power_supply_sysfs.c

@@ -51,6 +51,9 @@ static ssize_t power_supply_show_property(struct device *dev,
 		"Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
 		"LiMn"
 	};
+	static char *capacity_level_text[] = {
+		"Unknown", "Critical", "Low", "Normal", "High", "Full"
+	};
 	ssize_t ret;
 	struct power_supply *psy = dev_get_drvdata(dev);
 	const ptrdiff_t off = attr - power_supply_attrs;
@@ -71,6 +74,8 @@ static ssize_t power_supply_show_property(struct device *dev,
 		return sprintf(buf, "%s\n", health_text[value.intval]);
 	else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
 		return sprintf(buf, "%s\n", technology_text[value.intval]);
+	else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
+		return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
 	else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
 		return sprintf(buf, "%s\n", value.strval);
 
@@ -109,6 +114,7 @@ static struct device_attribute power_supply_attrs[] = {
 	POWER_SUPPLY_ATTR(energy_now),
 	POWER_SUPPLY_ATTR(energy_avg),
 	POWER_SUPPLY_ATTR(capacity),
+	POWER_SUPPLY_ATTR(capacity_level),
 	POWER_SUPPLY_ATTR(temp),
 	POWER_SUPPLY_ATTR(temp_ambient),
 	POWER_SUPPLY_ATTR(time_to_empty_now),

include/linux/power_supply.h

@@ -58,6 +58,15 @@ enum {
 	POWER_SUPPLY_TECHNOLOGY_LiMn,
 };
 
+enum {
+	POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN = 0,
+	POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL,
+	POWER_SUPPLY_CAPACITY_LEVEL_LOW,
+	POWER_SUPPLY_CAPACITY_LEVEL_NORMAL,
+	POWER_SUPPLY_CAPACITY_LEVEL_HIGH,
+	POWER_SUPPLY_CAPACITY_LEVEL_FULL,
+};
+
 enum power_supply_property {
 	/* Properties of type `int' */
 	POWER_SUPPLY_PROP_STATUS = 0,
@@ -89,6 +98,7 @@ enum power_supply_property {
 	POWER_SUPPLY_PROP_ENERGY_NOW,
 	POWER_SUPPLY_PROP_ENERGY_AVG,
 	POWER_SUPPLY_PROP_CAPACITY, /* in percents! */
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_TEMP_AMBIENT,
 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,