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/mtd_debug.c b/misc-utils/mtd_debug.c
index c0b7109..abee5e3 100644
--- a/misc-utils/mtd_debug.c
+++ b/misc-utils/mtd_debug.c
@@ -348,6 +348,7 @@ int main(int argc, char *argv[])
 {
 	int err = 0, fd;
 	int open_flag;
+	char *dev;
 
 	enum {
 		OPT_INFO,
@@ -369,8 +370,12 @@ int main(int argc, char *argv[])
 		showusage();
 
 	/* open device */
+	dev = mtd_find_dev_node(argv[2]);
+	if (!dev)
+		errmsg_die("Failed to find MTD device %s", argv[2]);
+
 	open_flag = (option == OPT_INFO || option == OPT_READ) ? O_RDONLY : O_RDWR;
-	if ((fd = open(argv[2], O_SYNC | open_flag)) < 0)
+	if ((fd = open(dev, O_SYNC | open_flag)) < 0)
 		errmsg_die("open()");
 
 	switch (option) {