power: test_power: Use enum as index for array of supplies

Replace hard-coded numbers for indices of power supply array with enum.
This improves a little the readability as one does not have to guess
which power supply is associated with number.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/test_power.c

···
 #include <linux/delay.h>
 #include <linux/vermagic.h>
 
+enum test_power_id {
+	TEST_AC,
+	TEST_BATTERY,
+	TEST_USB,
+	TEST_POWER_NUM,
+};
+
 static int ac_online			= 1;
 static int usb_online			= 1;
 static int battery_status		= POWER_SUPPLY_STATUS_DISCHARGING;
···
 };
 
 static struct power_supply test_power_supplies[] = {
-	{
+	[TEST_AC] = {
 		.name = "test_ac",
 		.type = POWER_SUPPLY_TYPE_MAINS,
 		.supplied_to = test_power_ac_supplied_to,
···
 		.properties = test_power_ac_props,
 		.num_properties = ARRAY_SIZE(test_power_ac_props),
 		.get_property = test_power_get_ac_property,
-	}, {
+	},
+	[TEST_BATTERY] = {
 		.name = "test_battery",
 		.type = POWER_SUPPLY_TYPE_BATTERY,
 		.properties = test_power_battery_props,
 		.num_properties = ARRAY_SIZE(test_power_battery_props),
 		.get_property = test_power_get_battery_property,
-	}, {
+	},
+	[TEST_USB] = {
 		.name = "test_usb",
 		.type = POWER_SUPPLY_TYPE_USB,
 		.supplied_to = test_power_ac_supplied_to,
···
 {
 	int i;
 	int ret;
+
+	BUILD_BUG_ON(TEST_POWER_NUM != ARRAY_SIZE(test_power_supplies));
 
 	for (i = 0; i < ARRAY_SIZE(test_power_supplies); i++) {
 		ret = power_supply_register(NULL, &test_power_supplies[i]);
···
 static int param_set_ac_online(const char *key, const struct kernel_param *kp)
 {
 	ac_online = map_get_value(map_ac_online, key, ac_online);
-	signal_power_supply_changed(&test_power_supplies[0]);
+	signal_power_supply_changed(&test_power_supplies[TEST_AC]);
 	return 0;
 }
 
···
 static int param_set_usb_online(const char *key, const struct kernel_param *kp)
 {
 	usb_online = map_get_value(map_ac_online, key, usb_online);
-	signal_power_supply_changed(&test_power_supplies[2]);
+	signal_power_supply_changed(&test_power_supplies[TEST_USB]);
 	return 0;
 }
 
···
 					const struct kernel_param *kp)
 {
 	battery_status = map_get_value(map_status, key, battery_status);
-	signal_power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[TEST_BATTERY]);
 	return 0;
 }
 
···
 					const struct kernel_param *kp)
 {
 	battery_health = map_get_value(map_health, key, battery_health);
-	signal_power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[TEST_BATTERY]);
 	return 0;
 }
 
···
 					const struct kernel_param *kp)
 {
 	battery_present = map_get_value(map_present, key, battery_present);
-	signal_power_supply_changed(&test_power_supplies[0]);
+	signal_power_supply_changed(&test_power_supplies[TEST_AC]);
 	return 0;
 }
 
···
 {
 	battery_technology = map_get_value(map_technology, key,
 						battery_technology);
-	signal_power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[TEST_BATTERY]);
 	return 0;
 }
 
···
 		return -EINVAL;
 
 	battery_capacity = tmp;
-	signal_power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[TEST_BATTERY]);
 	return 0;
 }
 
···
 		return -EINVAL;
 
 	battery_voltage = tmp;
-	signal_power_supply_changed(&test_power_supplies[1]);
+	signal_power_supply_changed(&test_power_supplies[TEST_BATTERY]);
 	return 0;
 }