[PATCH v2] mtd: fsl-quadspi: Distinguish the mtd device names

Fabio Estevam
2018-01-11T13:15:30Z

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

# cat /proc/mtd
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:

# cat /proc/mtd
dev: size erasesize name
mtd0: 01000000 00010000 "21e4000.qspi-0"
mtd1: 01000000 00010000 "21e4000.qspi-1"

Reported-by: David Wolfe <david.wolfe@nxp.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
---
Changes since v1:
- Use 'spiflash_idx' for the variable name
- Use the mtd->name in the format 21e4000.qspi-0
- Do not assing the mtd name relying on the dts ordering and use the reg
property instead
- Call devm_kasprintf() after spi_nor_set_flash_node().

drivers/mtd/spi-nor/fsl-quadspi.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 2901c7b..b28ad8b 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -967,7 +967,7 @@ static int fsl_qspi_probe(struct platform_device *pdev)
struct resource *res;
struct spi_nor *nor;
struct mtd_info *mtd;
- int ret, i = 0;
+ int ret, i = 0, spiflash_idx;

q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
if (!q)
@@ -1051,6 +1051,22 @@ static int fsl_qspi_probe(struct platform_device *pdev)
spi_nor_set_flash_node(nor, np);
nor->priv = q;

+ ret = of_property_read_u32(np, "reg", &spiflash_idx);
+ if (ret) {
+ dev_err(dev, "could not get reg property: %d\n", ret);
+ ret = -EINVAL;
+ goto mutex_failed;
+ }
+
+ if (!mtd->name) {
+ mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s-%d",
+ dev_name(dev), spiflash_idx);
+ if (!mtd->name) {
+ ret = -ENOMEM;
+ goto mutex_failed;
+ }
+ }
+
/* fill the hooks */
nor->read_reg = fsl_qspi_read_reg;
nor->write_reg = fsl_qspi_write_reg;
--
2.7.4