[PATCH v2] mtd: spi: nor: force mtd name to "nor%d"

[Patrick Delaunay]

Force the mtd name of spi-nor to "nor" + the driver sequence number:
"nor0", "nor1"...

This patch is coherent with existing "nand" and "spi-nand"
mtd device names.

I keep the existing "nor" name to don't disturb the existing users of mtd
functions.
The mtd name 'nor' was configured previously by the function
drivers/mtd/spi/sf_mtd.c:spi_flash_mtd_register() =
  "nor%d" + spi_flash_mtd_number()

The 'nor' name is also coherent with get_mtd_info() and the macro
MTD_DEV_TYPE(): MTD_DEV_TYPE_NOR is associated with "nor" name.

This generic name can be use to identify the mtd spi-nor device
without knowing the real device name or the DT path of the device,
used with API get_mtd_device_nm().

And also avoid issue when the same NOR device is present 2 times,
for example on STM32MP15F-EV1:

STM32MP> mtd list
SF: Detected mx66l51235l with page size 256 Bytes, erase size 64 KiB, \
total 64 MiB

List of MTD devices:
* nand0
  - type: NAND flash
  - block size: 0x40000 bytes
  - min I/O: 0x1000 bytes
  - OOB size: 224 bytes
  - OOB available: 118 bytes
  - ECC strength: 8 bits
  - ECC step size: 512 bytes
  - bitflip threshold: 6 bits
  - 0x000000000000-0x000040000000 : "nand0"
* mx66l51235l
  - device: mx66l51235l at 0
  - parent: spi at 58003000
  - driver: jedec_spi_nor
  - path: /soc/spi at 58003000/mx66l51235l at 0
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "mx66l51235l"
* mx66l51235l
  - device: mx66l51235l at 1
  - parent: spi at 58003000
  - driver: jedec_spi_nor
  - path: /soc/spi at 58003000/mx66l51235l at 1
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "mx66l51235l"

The same mtd name "mx66l51235l" identify the 2 instance
mx66l51235l at 0 and mx66l51235l at 1.

This patch solves a ST32CubeProgrammer / stm32prog command issue
with nor0 target on STM32MP157C-EV1 board.

Fixes: b7f060565e31 ("mtd: spi-nor: allow registering multiple MTDs when DM is enabled")
Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
---
For other device, the mtd name are hardcoded in each MTD driver:

drivers/mtd/nand/spi/core.c:1169:
        sprintf(mtd->name, "spi-nand%d", spi_nand_idx++);
drivers/mtd/nand/raw/nand.c:59:
        sprintf(dev_name[devnum], "nand%d", devnum);

The existing user with "nor..."

arch/arm/mach-stm32mp/cmd_stm32prog/stm32prog.c:625:
  mtd = get_mtd_device_nm(mtd_id);
board/emulation/common/qemu_mtdparts.c:63:
  mtd = get_mtd_device_nm("nor0");
board/emulation/common/qemu_mtdparts.c:70:
  mtd = get_mtd_device_nm("nor1");
board/emulation/common/qemu_dfu.c:61:
  mtd = get_mtd_device_nm("nor0");
board/st/common/stm32mp_dfu.c:132:
  mtd = get_mtd_device_nm("nor0");
drivers/dfu/dfu_mtd.c:259:
  mtd = get_mtd_device_nm(devstr);
 => see "dfu mtd" support in doc/usage/dfu.rst


Changes in v2:
- update commit message, change invalid patman tag "Series-Cc"

 drivers/mtd/spi/spi-nor-core.c | 8 +++++---
 include/linux/mtd/spi-nor.h    | 1 +
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index d5d905fa5a..3eb7dcfddb 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -3715,8 +3715,10 @@ int spi_nor_scan(struct spi_nor *nor)
 	if (ret)
 		return ret;
 
-	if (!mtd->name)
-		mtd->name = info->name;
+	if (!mtd->name) {
+		sprintf(nor->mtd_name, "nor%d",  dev_seq(nor->dev));
+		mtd->name = nor->mtd_name;
+	}
 	mtd->dev = nor->dev;
 	mtd->priv = nor;
 	mtd->type = MTD_NORFLASH;
@@ -3821,7 +3823,7 @@ int spi_nor_scan(struct spi_nor *nor)
 
 	nor->rdsr_dummy = params.rdsr_dummy;
 	nor->rdsr_addr_nbytes = params.rdsr_addr_nbytes;
-	nor->name = mtd->name;
+	nor->name = info->name;
 	nor->size = mtd->size;
 	nor->erase_size = mtd->erasesize;
 	nor->sector_size = mtd->erasesize;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 7ddc4ba2bf..8c3d5032e3 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -561,6 +561,7 @@ struct spi_nor {
 	int (*ready)(struct spi_nor *nor);
 
 	void *priv;
+	char mtd_name[10];
 /* Compatibility for spi_flash, remove once sf layer is merged with mtd */
 	const char *name;
 	u32 size;
-- 
2.25.1