[U-Boot] [PATCH v2 1/2] spi: mxs: Introduce spi_cs_is_valid()

[Fabio Estevam]

Introduce spi_cs_is_valid() for validating spi bus and chip select numbers.

Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
---
Changes since v1:
- Newly introduced in v2

 drivers/spi/mxs_spi.c |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
index 4e6f14e..e7237e7 100644
--- a/drivers/spi/mxs_spi.c
+++ b/drivers/spi/mxs_spi.c
@@ -51,14 +51,23 @@ void spi_init(void)
 {
 }
 
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	/* MXS SPI: 4 ports and 3 chip selects maximum */
+	if (bus > 3 || cs > 2)
+		return 0;
+	else
+		return 1;
+}
+
 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 				  unsigned int max_hz, unsigned int mode)
 {
 	struct mxs_spi_slave *mxs_slave;
 	uint32_t addr;
 
-	if (bus > 3) {
-		printf("MXS SPI: Max bus number is 3\n");
+	if (!spi_cs_is_valid(bus, cs)) {
+		printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
 		return NULL;
 	}
 
-- 
1.7.1