mtd-utils: Add new syntax to get devices by name

This introduces a new feature to the MTD command line utilities that
allows MTD devices to be referenced by name instead of device node. For
example this looks like:

> # Display info for the MTD device with name "data"
> mtdinfo mtd:data
> # Copy file to MTD device with name "data"
> flashcp /my/file mtd:data

This follows the syntax supported by the kernel which allows MTD
device's to be mounted by name[1].

Add the function mtd_find_dev_node() that accepts an MTD "identifier"
and returns the MTD's device node. The function accepts a string
starting with "mtd:" which it treats as the MTD's name. It then attempts
to search for the MTD, and if found maps it back to the /dev/mtdX device
node. If the string does not start with "mtd:", then assume it's the old
style and refers directly to a MTD device node.

The function is then hooked into existing tools like flashcp, mtdinfo,
flash_unlock, etc. To load in the new MTD parsing code in a consistent
way across programs.

[1] http://www.linux-mtd.infradead.org/faq/jffs2.html#L_mtdblock

Signed-off-by: Brandon Maier <brandon.maier@collins.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 6 insertions, 1 deletions

diff --git a/misc-utils/mtdpart.c b/misc-utils/mtdpart.c
index c8cd79b..a341148 100644
--- a/misc-utils/mtdpart.c
+++ b/misc-utils/mtdpart.c
@@ -36,6 +36,8 @@ static void display_help(int status)
 "  -h, --help    Display this help and exit\n"
 "  -V, --version Output version information and exit\n"
 "\n"
+"  <MTD_DEVICE>  MTD device node or 'mtd:<name>'\n"
+"\n"
 "START location and SIZE of the partition are in bytes. They should align on\n"
 "eraseblock size. If SIZE is 0 the partition will go to end of MTD device.\n",
 	PROGRAM_NAME
@@ -106,7 +108,10 @@ static void process_options(int argc, char * const argv[])
 		display_help(EXIT_FAILURE);
 
 	const char *s_command = argv[optind++];
-	mtddev = argv[optind++];
+	mtddev = mtd_find_dev_node(argv[optind]);
+	if (!mtddev)
+		errmsg_die("MTD device not found %s", argv[optind]);
+	optind++;
 
 	if (strcmp(s_command, "del") == 0 && (argc - optind) == 1) {
 		const char *s_part_no = argv[optind++];