spi: zynq-qspi: Anything else than CS0 is not supported yet

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@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-2-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c
index b1c56e9d7c94c5a88d36a6b4c58fa7d26e8abfd1..9f53ea08adf7abf97756870a21817437c86f0e1f 100644 (file)
--- a/drivers/spi/spi-zynq-qspi.c
+++ b/drivers/spi/spi-zynq-qspi.c
@@ -680,10 +680,14 @@ static int zynq_qspi_probe(struct platform_device *pdev)
 
        ret = of_property_read_u32(np, "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;