spi: fsl-dspi: Fix CTAR selection

commit 5cc7b047 upstream.

There are only 4 CTAR registers (CTAR0 - CTAR3) so we can only use the
lower 2 bits of the chip select to select a CTAR register.
SPI_PUSHR_CTAS used the lower 3 bits which would result in wrong bit values
if the chip selects 4/5 are used. For those chip selects SPI_CTAR even
calculated offsets of non-existing registers.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/spi/spi-fsl-dspi.c

@@ -46,7 +46,7 @@
 
 #define SPI_TCR			0x08
 
-#define SPI_CTAR(x)		(0x0c + (x * 4))
+#define SPI_CTAR(x)		(0x0c + (((x) & 0x3) * 4))
 #define SPI_CTAR_FMSZ(x)	(((x) & 0x0000000f) << 27)
 #define SPI_CTAR_CPOL(x)	((x) << 26)
 #define SPI_CTAR_CPHA(x)	((x) << 25)
@@ -70,7 +70,7 @@
 
 #define SPI_PUSHR		0x34
 #define SPI_PUSHR_CONT		(1 << 31)
-#define SPI_PUSHR_CTAS(x)	(((x) & 0x00000007) << 28)
+#define SPI_PUSHR_CTAS(x)	(((x) & 0x00000003) << 28)
 #define SPI_PUSHR_EOQ		(1 << 27)
 #define SPI_PUSHR_CTCNT	(1 << 26)
 #define SPI_PUSHR_PCS(x)	(((1 << x) & 0x0000003f) << 16)