diff --git a/arch/arm/src/gd32f4/gd32f4xx_spi.c b/arch/arm/src/gd32f4/gd32f4xx_spi.c
index 13ee2ac536..fee72e36bc 100644
--- a/arch/arm/src/gd32f4/gd32f4xx_spi.c
+++ b/arch/arm/src/gd32f4/gd32f4xx_spi.c
@@ -193,12 +193,6 @@ static inline void     spi_putreg(struct gd32_spidev_s *priv,
                                   uint8_t offset, uint32_t value);
 static inline uint16_t spi_getreg16(struct gd32_spidev_s *priv,
                                     uint8_t offset);
-static inline void     spi_putreg16(struct gd32_spidev_s *priv,
-                                    uint8_t offset, uint16_t value);
-static inline uint8_t  spi_getreg8(struct gd32_spidev_s *priv,
-                                   uint8_t offset);
-static inline void     spi_putreg8(struct gd32_spidev_s *priv,
-                                   uint8_t offset, uint8_t value);
 
 static inline uint16_t spi_readword(struct gd32_spidev_s *priv);
 static inline void     spi_writeword(struct gd32_spidev_s *priv,
@@ -905,71 +899,6 @@ static inline uint16_t spi_getreg16(struct gd32_spidev_s *priv,
   return getreg16(priv->spibase + offset);
 }
 
-/****************************************************************************
- * Name: spi_putreg16
- *
- * Description:
- *   Write a 16-bit value to the SPI register at offset
- *
- * Input Parameters:
- *   priv   - private SPI device structure
- *   offset - offset to the register of interest
- *   value  - the 16-bit value to be written
- *
- * Returned Value:
- *   Nothing
- *
- ****************************************************************************/
-
-static inline void spi_putreg16(struct gd32_spidev_s *priv,
-                                uint8_t offset, uint16_t value)
-{
-  putreg16(value, priv->spibase + offset);
-}
-
-/****************************************************************************
- * Name: spi_getreg8
- *
- * Description:
- *   Get the 8 bit contents of the SPI register at offset
- *
- * Input Parameters:
- *   priv   - private SPI device structure
- *   offset - offset to the register of interest
- *
- * Returned Value:
- *   The contents of the 8-bit register
- *
- ****************************************************************************/
-
-static inline uint8_t spi_getreg8(struct gd32_spidev_s *priv,
-                                  uint8_t offset)
-{
-  return getreg8(priv->spibase + offset);
-}
-
-/****************************************************************************
- * Name: spi_putreg8
- *
- * Description:
- *   Write a 8-bit value to the SPI register at offset
- *
- * Input Parameters:
- *   priv   - private SPI device structure
- *   offset - offset to the register of interest
- *   value  - the 8-bit value to be written
- *
- * Returned Value:
- *   Nothing
- *
- ****************************************************************************/
-
-static inline void spi_putreg8(struct gd32_spidev_s *priv,
-                               uint8_t offset, uint8_t value)
-{
-  putreg8(value, priv->spibase + offset);
-}
-
 /****************************************************************************
  * Name: spi_modifyreg
  *