mtd: fsl-quadspi: Distinguish the mtd device names

Currently on a imx6sx-sdb board, which has two SPI NOR chips connected
to QSPI2 the following output from /proc/mtd is seen:

dev:    size   erasesize  name
mtd0: 01000000 00010000 "21e4000.qspi"
mtd1: 01000000 00010000 "21e4000.qspi"

Attempts to partition them on the kernel command line result in both
chips with identical (and identically named) partitions, which is
an inconvenient behavior.

Assign a different mtd->name for each mtd device to avoid this problem.

After this change the output from /proc/mtd becomes:

dev:    size   erasesize  name
mtd0: 01000000 00010000 "21e4000.qspi-0"
mtd1: 01000000 00010000 "21e4000.qspi-1"

In order to keep mtdparts compatibility keep the mtd->name
unchanged when a single SPI NOR is present.

Reported-by: David Wolfe <david.wolfe@nxp.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index dc9914fce296..3e3c0bbc45c0 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -1051,6 +1051,24 @@ static int fsl_qspi_probe(struct platform_device *pdev)
                 spi_nor_set_flash_node(nor, np);
                 nor->priv = q;
 
+                if (q->nor_num > 1 && !mtd->name) {
+                        int spiflash_idx;
+
+                        ret = of_property_read_u32(np, "reg", &spiflash_idx);
+                        if (!ret) {
+                                mtd->name = devm_kasprintf(dev, GFP_KERNEL,
+                                                           "%s-%d",
+                                                           dev_name(dev),
+                                                           spiflash_idx);
+                                if (!mtd->name) {
+                                        ret = -ENOMEM;
+                                        goto mutex_failed;
+                                }
+                        } else {
+                                dev_warn(dev, "reg property is missing\n");
+                        }
+                }
+
                 /* fill the hooks */
                 nor->read_reg = fsl_qspi_read_reg;
                 nor->write_reg = fsl_qspi_write_reg;