spi: cadence-quadspi: Fix cqspi_setup_flash()

commit 858d4d9e0a9d6b64160ef3c824f428c9742172c4 upstream.

The 'max_cs' stores the largest chip select number. It should only
be updated when the current 'cs' is greater than existing 'max_cs'. So,
fix the condition accordingly.

Also, return failure if there are no flash device declared.

Fixes: 0f3841a5e115 ("spi: cadence-qspi: report correct number of chip-select")
CC: stable@vger.kernel.org
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Santhosh Kumar K <s-k6@ti.com>
Message-ID: <20250905185958.3575037-4-s-k6@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 797c570c13ff5711539ae95947d62f25e103aa4a..06e43b184d85dec5d005e03011e24c9de47f63f1 100644 (file)
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -1673,12 +1673,10 @@ static const struct spi_controller_mem_caps cqspi_mem_caps = {
 
 static int cqspi_setup_flash(struct cqspi_st *cqspi)
 {
-       unsigned int max_cs = cqspi->num_chipselect - 1;
        struct platform_device *pdev = cqspi->pdev;
        struct device *dev = &pdev->dev;
        struct cqspi_flash_pdata *f_pdata;
-       unsigned int cs;
-       int ret;
+       int ret, cs, max_cs = -1;
 
        /* Get flash device data */
        for_each_available_child_of_node_scoped(dev->of_node, np) {
@@ -1691,10 +1689,10 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi)
                if (cs >= cqspi->num_chipselect) {
                        dev_err(dev, "Chip select %d out of range.\n", cs);
                        return -EINVAL;
-               } else if (cs < max_cs) {
-                       max_cs = cs;
                }
 
+               max_cs = max_t(int, cs, max_cs);
+
                f_pdata = &cqspi->f_pdata[cs];
                f_pdata->cqspi = cqspi;
                f_pdata->cs = cs;
@@ -1704,6 +1702,11 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi)
                        return ret;
        }
 
+       if (max_cs < 0) {
+               dev_err(dev, "No flash device declared\n");
+               return -ENODEV;
+       }
+
        cqspi->num_chipselect = max_cs + 1;
        return 0;
 }