cmd/mtd.c:447:13: warning: ‘mtd_help_text’ defined but not used [-Wunused-variable]
static char mtd_help_text[] =
            ^~~~~~~~~~~~~

When SYS_LONGHELP is not defined. After looking at how other commands
work, we should surround the whole help text (even its declaration) with
an #ifdef CONFIG_SYS_LONGHELP, since it's compiled out when calling
_CMD_HELP[1] on the help text variable argument to U_BOOT_CMD.

[1] https://elixir.bootlin.com/u-boot/latest/source/include/command.h#L181

Signed-off-by: Quentin Schulz <quentin.schulz@bootlin.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

It's way simpler this way, and we also gain auto-completion support for
free (MTD name auto-completion has been added with mtd_name_complete())

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

There should not be a 'nand' command, a 'sf' command and certainly not
a new 'spi-nand' command. Write a 'mtd' command instead to manage all
MTD devices/partitions at once. This should be the preferred way to
access any MTD device.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jagan Teki <jagan@openedev.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>