regulator: Add REGULATOR_STATUS_UNDEFINED.

REGULATOR_STATUS_UNDEFINED is to be returned by regulator, if any other state
doesn't really apply.
Signed-off-by: Krystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/core.c

@@ -393,6 +393,9 @@ static ssize_t regulator_status_show(struct device *dev,
 	case REGULATOR_STATUS_STANDBY:
 		label = "standby";
 		break;
+	case REGULATOR_STATUS_UNDEFINED:
+		label = "undefined";
+		break;
 	default:
 		return -ERANGE;
 	}
@@ -2897,7 +2900,7 @@ int regulator_mode_to_status(unsigned int mode)
 	case REGULATOR_MODE_STANDBY:
 		return REGULATOR_STATUS_STANDBY;
 	default:
-		return 0;
+		return REGULATOR_STATUS_UNDEFINED;
 	}
 }
 EXPORT_SYMBOL_GPL(regulator_mode_to_status);

include/linux/regulator/driver.h

@@ -32,6 +32,8 @@ enum regulator_status {
 	REGULATOR_STATUS_NORMAL,
 	REGULATOR_STATUS_IDLE,
 	REGULATOR_STATUS_STANDBY,
+	/* in case that any other status doesn't apply */
+	REGULATOR_STATUS_UNDEFINED,
 };
 
 /**