spi: s3c64xx: define a magic value

Define a magic value, it will be used in the next patch as well.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://msgid.link/r/20240216070555.2483977-3-tudor.ambarus@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: ambarus

drivers/spi/spi-s3c64xx.c

@@ -78,6 +78,7 @@
 #define S3C64XX_SPI_INT_RX_FIFORDY_EN		(1<<1)
 #define S3C64XX_SPI_INT_TX_FIFORDY_EN		(1<<0)
 
+#define S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT	6
 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR		(1<<4)
 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
@@ -108,7 +109,8 @@
 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
-#define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
+#define TX_FIFO_LVL(v, i) (((v) >> S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT) &	\
+			   FIFO_LVL_MASK(i))
 #define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
 					FIFO_LVL_MASK(i))
 #define FIFO_DEPTH(i) ((FIFO_LVL_MASK(i) >> 1) + 1)