power: supply: sysfs: Use enum to specify property

Power supply property is in fact enum, so reflect it in code.
Also use switch statement in show property function as is done
for storing property.
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

drivers/power/supply/power_supply_sysfs.c

@@ -76,15 +76,15 @@ static const char * const power_supply_scope_text[] = {
 static ssize_t power_supply_show_property(struct device *dev,
 					  struct device_attribute *attr,
 					  char *buf) {
-	ssize_t ret = 0;
+	ssize_t ret;
 	struct power_supply *psy = dev_get_drvdata(dev);
-	const ptrdiff_t off = attr - power_supply_attrs;
+	enum power_supply_property psp = attr - power_supply_attrs;
 	union power_supply_propval value;
 
-	if (off == POWER_SUPPLY_PROP_TYPE) {
+	if (psp == POWER_SUPPLY_PROP_TYPE) {
 		value.intval = psy->desc->type;
 	} else {
-		ret = power_supply_get_property(psy, off, &value);
+		ret = power_supply_get_property(psy, psp, &value);
 
 		if (ret < 0) {
 			if (ret == -ENODATA)
@@ -97,31 +97,43 @@ static ssize_t power_supply_show_property(struct device *dev,
 		}
 	}
 
-	if (off == POWER_SUPPLY_PROP_STATUS)
-		return sprintf(buf, "%s\n",
-			       power_supply_status_text[value.intval]);
-	else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
-		return sprintf(buf, "%s\n",
-			       power_supply_charge_type_text[value.intval]);
-	else if (off == POWER_SUPPLY_PROP_HEALTH)
-		return sprintf(buf, "%s\n",
-			       power_supply_health_text[value.intval]);
-	else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
-		return sprintf(buf, "%s\n",
-			       power_supply_technology_text[value.intval]);
-	else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
-		return sprintf(buf, "%s\n",
-			       power_supply_capacity_level_text[value.intval]);
-	else if (off == POWER_SUPPLY_PROP_TYPE)
-		return sprintf(buf, "%s\n",
-			       power_supply_type_text[value.intval]);
-	else if (off == POWER_SUPPLY_PROP_SCOPE)
-		return sprintf(buf, "%s\n",
-			       power_supply_scope_text[value.intval]);
-	else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
-		return sprintf(buf, "%s\n", value.strval);
-
-	return sprintf(buf, "%d\n", value.intval);
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		ret = sprintf(buf, "%s\n",
+			      power_supply_status_text[value.intval]);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		ret = sprintf(buf, "%s\n",
+			      power_supply_charge_type_text[value.intval]);
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		ret = sprintf(buf, "%s\n",
+			      power_supply_health_text[value.intval]);
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		ret = sprintf(buf, "%s\n",
+			      power_supply_technology_text[value.intval]);
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+		ret = sprintf(buf, "%s\n",
+			      power_supply_capacity_level_text[value.intval]);
+		break;
+	case POWER_SUPPLY_PROP_TYPE:
+		ret = sprintf(buf, "%s\n",
+			      power_supply_type_text[value.intval]);
+		break;
+	case POWER_SUPPLY_PROP_SCOPE:
+		ret = sprintf(buf, "%s\n",
+			      power_supply_scope_text[value.intval]);
+		break;
+	case POWER_SUPPLY_PROP_MODEL_NAME ... POWER_SUPPLY_PROP_SERIAL_NUMBER:
+		ret = sprintf(buf, "%s\n", value.strval);
+		break;
+	default:
+		ret = sprintf(buf, "%d\n", value.intval);
+	}
+
+	return ret;
 }
 
 static ssize_t power_supply_store_property(struct device *dev,
@@ -129,11 +141,10 @@ static ssize_t power_supply_store_property(struct device *dev,
 					   const char *buf, size_t count) {
 	ssize_t ret;
 	struct power_supply *psy = dev_get_drvdata(dev);
-	const ptrdiff_t off = attr - power_supply_attrs;
+	enum power_supply_property psp = attr - power_supply_attrs;
 	union power_supply_propval value;
 
-	/* maybe it is a enum property? */
-	switch (off) {
+	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		ret = sysfs_match_string(power_supply_status_text, buf);
 		break;
@@ -172,7 +183,7 @@ static ssize_t power_supply_store_property(struct device *dev,
 
 	value.intval = ret;
 
-	ret = power_supply_set_property(psy, off, &value);
+	ret = power_supply_set_property(psy, psp, &value);
 	if (ret < 0)
 		return ret;