diff --git a/arch/arm/src/calypso/calypso_power.c b/arch/arm/src/calypso/calypso_power.c
index 03db7def7f9..721d8969d46 100644
--- a/arch/arm/src/calypso/calypso_power.c
+++ b/arch/arm/src/calypso/calypso_power.c
@@ -1,18 +1,39 @@
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
 #include <stdio.h>
+
+#include <nuttx/board.h>
 #include <nuttx/spi/spi.h>
 
-int board_power_off(void)
+/****************************************************************************
+ * Name: board_power_off
+ *
+ * Description:
+ *   Power off the board.
+ *
+ *   If this function returns, then it was not possible to power-off the
+ *   board due to some other constraints.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void board_power_off(void)
 {
-	uint16_t tx;
-	struct spi_dev_s *spi = up_spiinitialize(0);
+  uint16_t tx;
+  struct spi_dev_s *spi = up_spiinitialize(0);
 
-	SPI_SETBITS(spi, 16);
+  SPI_SETBITS(spi, 16);
 
-	tx = (1 << 6) | (1 << 1);
-	SPI_SNDBLOCK(spi, &tx, 1);
+  tx = (1 << 6) | (1 << 1);
+  SPI_SNDBLOCK(spi, &tx, 1);
 
-	tx = (1 << 6) | (30 << 1);
-	SPI_SNDBLOCK(spi, &tx, 1);
-
-	return 0;
+  tx = (1 << 6) | (30 << 1);
+  SPI_SNDBLOCK(spi, &tx, 1);
 }