[PATCH v6 1/2] mtd: fsl-quadspi: Distinguish the mtd device names

[Han Xu]

________________________________________
From: Fabio Estevam <fabio.estevam at nxp.com>
Sent: Thursday, January 18, 2018 8:28 AM
To: boris.brezillon at free-electrons.com
Cc: linux-mtd at lists.infradead.org; Han Xu; David Wolfe; Fabio Estevam
Subject: [PATCH v6 1/2] 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:

# 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"

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

Reported-by: David Wolfe <david.wolfe at nxp.com>
Signed-off-by: Fabio Estevam <fabio.estevam at nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
Changes since v5:
- Preserve the label value, if any. (Boris)

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

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 2901c7b..1038842 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;
--
2.7.4

Acked-by: Han Xu <han.xu at nxp.com>