3 files changed, 29 insertions, 20 deletions
diff --git a/board/flapjack/battery.c b/board/flapjack/battery.c
index 6ba167b3fe..f7d5afc1ef 100644
--- a/board/flapjack/battery.c
+++ b/board/flapjack/battery.c
@@ -150,35 +150,19 @@ static const struct {
 	},
 };
 
-static struct {
-	enum battery_type type;
-	int expect_mv;
-} const batteries[] = {
+static const struct mv_to_id batteries[] = {
 	{ BATTERY_C18_ATL,       900 },  /* 100K  */
 	{ BATTERY_C19_ATL,       576 },  /* 47K   */
 };
 BUILD_ASSERT(ARRAY_SIZE(batteries) < BATTERY_COUNT);
 
-#define MARGIN_MV 56 /* Simply assume 1800/16/2 */
-
 static enum battery_type batt_type = BATTERY_UNKNOWN;
 
 static void board_get_battery_type(void)
 {
-	int mv;
-	int i;
-
-	mv = adc_read_channel(ADC_BATT_ID);
-	if (mv == ADC_READ_ERROR)
-		mv = adc_read_channel(ADC_BATT_ID);
-
-	for (i = 0; i < ARRAY_SIZE(batteries); i++) {
-		if (ABS(mv - batteries[i].expect_mv) < MARGIN_MV) {
-			batt_type = batteries[i].type;
-			break;
-		}
-	}
-
+	int id = board_read_id(ADC_BATT_ID, batteries, ARRAY_SIZE(batteries));
+	if (id != ADC_READ_ERROR)
+		batt_type = id;
 	CPRINTS("Battery Type: %d", batt_type);
 }
 DECLARE_HOOK(HOOK_INIT, board_get_battery_type, HOOK_PRIO_FIRST);
diff --git a/board/flapjack/board.c b/board/flapjack/board.c
index 23f42c1cd4..862a6c12a4 100644
--- a/board/flapjack/board.c
+++ b/board/flapjack/board.c
@@ -54,6 +54,22 @@ uint16_t board_version;
 uint8_t oem;
 uint32_t sku;
 
+int board_read_id(enum adc_channel ch, const struct mv_to_id *table, int size)
+{
+	int mv = adc_read_channel(ch);
+	int i;
+
+	if (mv == ADC_READ_ERROR)
+		mv = adc_read_channel(ch);
+
+	for (i = 0; i < size; i++) {
+		if (ABS(mv - table[i].median_mv) < ADC_MARGIN_MV)
+			return table[i].id;
+	}
+
+	return ADC_READ_ERROR;
+}
+
 static void board_setup_panel(void)
 {
 	uint8_t channel;
diff --git a/board/flapjack/board.h b/board/flapjack/board.h
index 1c41659577..ebe887d3cb 100644
--- a/board/flapjack/board.h
+++ b/board/flapjack/board.h
@@ -279,6 +279,15 @@ void emmc_cmd_interrupt(enum gpio_signal signal);
 
 void board_reset_pd_mcu(void);
 
+#define ADC_MARGIN_MV 56 /* Simply assume 1800/16/2 */
+
+struct mv_to_id {
+	int id;
+	int median_mv;
+};
+
+int board_read_id(enum adc_channel, const struct mv_to_id *table, int size);
+
 #endif /* !__ASSEMBLER__ */
 
 #endif /* __CROS_EC_BOARD_H */