[PATCH 1/7] spi: zynq-qspi: Anything else than CS0 is not supported yet

[Miquel Raynal <miquel.raynal@xxxxxxxxxxx>]

Unlike what the driver is currently advertizing, CS0 only can be used,
CS1 is not supported at all. Prevent people to use CS1.

Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
 drivers/spi/spi-zynq-qspi.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c
index 87c9ec21f093..8098b5087708 100644
--- a/drivers/spi/spi-zynq-qspi.c
+++ b/drivers/spi/spi-zynq-qspi.c
@@ -704,10 +704,15 @@ static int zynq_qspi_probe(struct platform_device *pdev)
 
 	ret = of_property_read_u32(pdev->dev.of_node, "num-cs",
 				   &num_cs);
-	if (ret < 0)
+	if (ret < 0) {
 		ctlr->num_chipselect = ZYNQ_QSPI_DEFAULT_NUM_CS;
-	else
+	} else if (num_cs > ZYNQ_QSPI_DEFAULT_NUM_CS) {
+		dev_err(&pdev->dev, "anything but CS0 is not yet supported\n");
+		goto remove_master;
+	} else {
 		ctlr->num_chipselect = num_cs;
+	}
+
 	ctlr->mode_bits =  SPI_RX_DUAL | SPI_RX_QUAD |
 			    SPI_TX_DUAL | SPI_TX_QUAD;
 	ctlr->mem_ops = &zynq_qspi_mem_ops;
-- 
2.20.1