[PATCH v3 06/23] mtd: spi-nor: Create an indirection on the part name

[Miquel Raynal]

We currently print through sysfs and debugfs the name of the part if the
.name field, which is legacy, has been filled in the ID table (otherwise
"(null)" is printed). These IDs had an interest until manufacturers
started re-using more and more extensively the so called unique JEDEC
IDs. At this stage, a name that was tailored for a chip sold in 2016 may
no longer be relevant for a chip sold in 2026. Still showing this name
through the various filesystems may confuse people, removing these names
cannot be done since they are now part of the user ABI (because of
sysfs).

In order to allow overwriting the .name field (which is part of a
read-only structure), let's create a spi-nor pointer which will by
default point to that .name, but which can be cleared in fixup hooks to
make sure the name is hidden on newer parts.

Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
---
 drivers/mtd/spi-nor/core.c    | 1 +
 drivers/mtd/spi-nor/debugfs.c | 3 +--
 drivers/mtd/spi-nor/sysfs.c   | 4 ++--
 include/linux/mtd/spi-nor.h   | 1 +
 4 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 3a611283a9e6..cf6eccb4c423 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3492,6 +3492,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 		return PTR_ERR(info);
 
 	nor->info = info;
+	nor->partname = info->name;
 
 	mutex_init(&nor->lock);
 
diff --git a/drivers/mtd/spi-nor/debugfs.c b/drivers/mtd/spi-nor/debugfs.c
index 512825c3fc85..275671222588 100644
--- a/drivers/mtd/spi-nor/debugfs.c
+++ b/drivers/mtd/spi-nor/debugfs.c
@@ -82,13 +82,12 @@ static int spi_nor_params_show(struct seq_file *s, void *data)
 	struct spi_nor_flash_parameter *params = nor->params;
 	struct spi_nor_erase_map *erase_map = &params->erase_map;
 	struct spi_nor_erase_region *region = erase_map->regions;
-	const struct flash_info *info = nor->info;
 	char buf[16], *str;
 	loff_t lock_start;
 	u64 lock_length;
 	unsigned int i;
 
-	seq_printf(s, "name\t\t%s\n", info->name);
+	seq_printf(s, "name\t\t%s\n", nor->partname);
 	seq_printf(s, "id\t\t%*ph\n", SPI_NOR_MAX_ID_LEN, nor->id);
 	string_get_size(params->size, 1, STRING_UNITS_2, buf, sizeof(buf));
 	seq_printf(s, "size\t\t%s\n", buf);
diff --git a/drivers/mtd/spi-nor/sysfs.c b/drivers/mtd/spi-nor/sysfs.c
index 643513ee891b..a2dabe4c6422 100644
--- a/drivers/mtd/spi-nor/sysfs.c
+++ b/drivers/mtd/spi-nor/sysfs.c
@@ -25,7 +25,7 @@ static ssize_t partname_show(struct device *dev,
 	struct spi_mem *spimem = spi_get_drvdata(spi);
 	struct spi_nor *nor = spi_mem_get_drvdata(spimem);
 
-	return sysfs_emit(buf, "%s\n", nor->info->name);
+	return sysfs_emit(buf, "%s\n", nor->partname);
 }
 static DEVICE_ATTR_RO(partname);
 
@@ -78,7 +78,7 @@ static umode_t spi_nor_sysfs_is_visible(struct kobject *kobj,
 
 	if (attr == &dev_attr_manufacturer.attr && !nor->manufacturer)
 		return 0;
-	if (attr == &dev_attr_partname.attr && !nor->info->name)
+	if (attr == &dev_attr_partname.attr && !nor->partname)
 		return 0;
 	if (attr == &dev_attr_jedec_id.attr && !nor->info->id && !nor->id)
 		return 0;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 3a55d76ea77d..b1e573367604 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -395,6 +395,7 @@ struct spi_nor {
 	u8			*id;
 	const struct flash_info	*info;
 	const struct spi_nor_manufacturer *manufacturer;
+	const char		*partname;
 	u8			addr_nbytes;
 	u8			erase_opcode;
 	u8			read_opcode;

-- 
2.54.0