[PATCH v2 1/7] spi: zynq-qspi: Anything else than CS0 is not supported yet

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Mark Brown <broonie@kernel.org>,
	Michal Simek <michal.simek@xilinx.com>,
	Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
	Tudor Ambarus <Tudor.Ambarus@microchip.com>,
	linux-arm-kernel@lists.infradead.org,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	linux-spi@vger.kernel.org
Subject: [PATCH v2 1/7] spi: zynq-qspi: Anything else than CS0 is not supported yet
Date: Fri,  8 Nov 2019 15:07:38 +0100	[thread overview]
Message-ID: <20191108140744.1734-2-miquel.raynal@bootlin.com> (raw)
In-Reply-To: <20191108140744.1734-1-miquel.raynal@bootlin.com>

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>
---
 drivers/spi/spi-zynq-qspi.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c
index 5cf6993ddce5..713f9a03a40a 100644
--- a/drivers/spi/spi-zynq-qspi.c
+++ b/drivers/spi/spi-zynq-qspi.c
@@ -681,10 +681,14 @@ 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;
-- 
2.20.1
