power_supply: cleanup of the OLPC battery driver

Move portions of the massive switch statement into functions.  The layout of
this thing has already caused one bug (a break in the wrong place), it needed
to shrink.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/power/olpc_battery.c

@@ -86,33 +86,8 @@ static struct power_supply olpc_ac = {
 
 static char bat_serial[17]; /* Ick */
 
-/*********************************************************************
- *		Battery properties
- *********************************************************************/
-static int olpc_bat_get_property(struct power_supply *psy,
-				 enum power_supply_property psp,
-				 union power_supply_propval *val)
+static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
 {
-	int ret = 0;
-	int16_t ec_word;
-	uint8_t ec_byte;
-	uint64_t ser_buf;
-
-	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
-	if (ret)
-		return ret;
-
-	/* Theoretically there's a race here -- the battery could be
-	   removed immediately after we check whether it's present, and
-	   then we query for some other property of the now-absent battery.
-	   It doesn't matter though -- the EC will return the last-known
-	   information, and it's as if we just ran that _little_ bit faster
-	   and managed to read it out before the battery went away. */
-	if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
-		return -ENODEV;
-
-	switch (psp) {
-	case POWER_SUPPLY_PROP_STATUS:
 	if (olpc_platform_info.ecver > 0x44) {
 		if (ec_byte & BAT_STAT_CHARGING)
 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
@@ -130,16 +105,16 @@ static int olpc_bat_get_property(struct power_supply *psy,
 			val->intval = POWER_SUPPLY_STATUS_FULL;
 		else /* Not _necessarily_ true but EC doesn't tell all yet */
 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
-			break;
 	}
-	case POWER_SUPPLY_PROP_PRESENT:
-		val->intval = !!(ec_byte & BAT_STAT_PRESENT);
-		break;
 
-	case POWER_SUPPLY_PROP_HEALTH:
-		if (ec_byte & BAT_STAT_DESTROY)
-			val->intval = POWER_SUPPLY_HEALTH_DEAD;
-		else {
+	return 0;
+}
+
+static int olpc_bat_get_health(union power_supply_propval *val)
+{
+	uint8_t ec_byte;
+	int ret;
+
 	ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 	if (ret)
 		return ret;
@@ -166,12 +141,17 @@ static int olpc_bat_get_property(struct power_supply *psy,
 
 	default:
 		/* Eep. We don't know this failure code */
-				return -EIO;
-			}
+		ret = -EIO;
 	}
-		break;
 
-	case POWER_SUPPLY_PROP_MANUFACTURER:
+	return ret;
+}
+
+static int olpc_bat_get_mfr(union power_supply_propval *val)
+{
+	uint8_t ec_byte;
+	int ret;
+
 	ec_byte = BAT_ADDR_MFR_TYPE;
 	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 	if (ret)
@@ -188,8 +168,15 @@ static int olpc_bat_get_property(struct power_supply *psy,
 		val->strval = "Unknown";
 		break;
 	}
-		break;
-	case POWER_SUPPLY_PROP_TECHNOLOGY:
+
+	return ret;
+}
+
+static int olpc_bat_get_tech(union power_supply_propval *val)
+{
+	uint8_t ec_byte;
+	int ret;
+
 	ec_byte = BAT_ADDR_MFR_TYPE;
 	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 	if (ret)
@@ -206,6 +193,64 @@ static int olpc_bat_get_property(struct power_supply *psy,
 		val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 		break;
 	}
+
+	return ret;
+}
+
+/*********************************************************************
+ *		Battery properties
+ *********************************************************************/
+static int olpc_bat_get_property(struct power_supply *psy,
+				 enum power_supply_property psp,
+				 union power_supply_propval *val)
+{
+	int ret = 0;
+	int16_t ec_word;
+	uint8_t ec_byte;
+	uint64_t ser_buf;
+
+	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
+	if (ret)
+		return ret;
+
+	/* Theoretically there's a race here -- the battery could be
+	   removed immediately after we check whether it's present, and
+	   then we query for some other property of the now-absent battery.
+	   It doesn't matter though -- the EC will return the last-known
+	   information, and it's as if we just ran that _little_ bit faster
+	   and managed to read it out before the battery went away. */
+	if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
+		return -ENODEV;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		ret = olpc_bat_get_status(val, ec_byte);
+		if (ret)
+			return ret;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = !!(ec_byte & BAT_STAT_PRESENT);
+		break;
+
+	case POWER_SUPPLY_PROP_HEALTH:
+		if (ec_byte & BAT_STAT_DESTROY)
+			val->intval = POWER_SUPPLY_HEALTH_DEAD;
+		else {
+			ret = olpc_bat_get_health(val);
+			if (ret)
+				return ret;
+		}
+		break;
+
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		ret = olpc_bat_get_mfr(val);
+		if (ret)
+			return ret;
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		ret = olpc_bat_get_tech(val);
+		if (ret)
+			return ret;
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 		ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);