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, 5 insertions, 2 deletions

diff --git a/misc-utils/flashcp.c b/misc-utils/flashcp.c
index 50f8c04..e1be292 100644
--- a/misc-utils/flashcp.c
+++ b/misc-utils/flashcp.c
@@ -110,7 +110,7 @@ static NORETURN void showusage(bool error)
 			"   -A | --erase-all Erases the whole device regardless of the image size\n"
 			"   -V | --version   Show version information and exit\n"
 			"   <filename>       File which you want to copy to flash\n"
-			"   <device>         Flash device to write to (e.g. /dev/mtd0, /dev/mtd1, etc.)\n"
+			"   <device>         Flash device node or 'mtd:<name>' to write to (e.g. /dev/mtd0, /dev/mtd1, mtd:data, etc.)\n"
 			"\n",
 			PROGRAM_NAME);
 
@@ -275,7 +275,10 @@ int main (int argc,char *argv[])
 		DEBUG("Got filename: %s\n",filename);
 
 		flags |= FLAG_DEVICE;
-		device = argv[optind+1];
+		device = mtd_find_dev_node(argv[optind+1]);
+		if (!device)
+			log_failure("Failed to find device %s\n", argv[optind+1]);
+
 		DEBUG("Got device: %s\n",device);
 	}