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>

6 files changed, 35 insertions, 6 deletions

diff --git a/misc-utils/Makemodule.am b/misc-utils/Makemodule.am
index bc69b1c..1ce1a68 100644
--- a/misc-utils/Makemodule.am
+++ b/misc-utils/Makemodule.am
@@ -7,8 +7,10 @@ ftl_check_SOURCES = misc-utils/ftl_check.c include/mtd_swab.h
 ftl_check_SOURCES += include/mtd/ftl-user.h
 
 mtd_debug_SOURCES = misc-utils/mtd_debug.c
+mtd_debug_LDADD = libmtd.a
 
 mtdpart_SOURCES = misc-utils/mtdpart.c
+mtdpart_LDADD = libmtd.a
 
 docfdisk_SOURCES = misc-utils/docfdisk.c include/mtd_swab.h
 docfdisk_SOURCES += include/mtd/inftl-user.h include/mtd/ftl-user.h
@@ -23,8 +25,10 @@ fectest_SOURCES = misc-utils/fectest.c misc-utils/mcast_image.h
 fectest_LDADD = libmtd.a
 
 flash_lock_SOURCES = misc-utils/flash_lock.c
+flash_lock_LDADD = libmtd.a
 
 flash_unlock_SOURCES = misc-utils/flash_unlock.c
+flash_unlock_LDADD = libmtd.a
 
 flash_otp_info_SOURCES = misc-utils/flash_otp_info.c
 
@@ -37,6 +41,7 @@ flash_otp_erase_SOURCES = misc-utils/flash_otp_erase.c
 flash_otp_write_SOURCES = misc-utils/flash_otp_write.c
 
 flashcp_SOURCES = misc-utils/flashcp.c
+flashcp_LDADD = libmtd.a
 
 flash_erase_SOURCES = misc-utils/flash_erase.c
 flash_erase_LDADD = libmtd.a
diff --git a/misc-utils/flash_erase.c b/misc-utils/flash_erase.c
index 49a880f..000f94a 100644
--- a/misc-utils/flash_erase.c
+++ b/misc-utils/flash_erase.c
@@ -71,6 +71,8 @@ static void display_help (void)
 			"      --silent      same as --quiet\n"
 			"      --help        display this help and exit\n"
 			"      --version     output version information and exit\n",
+			"\n"
+			"  MTD_DEVICE  MTD device node or 'mtd:<name>'\n"
 			PROGRAM_NAME);
 }
 
@@ -169,7 +171,9 @@ int main(int argc, char *argv[])
 	}
 	switch (argc - optind) {
 	case 3:
-		mtd_device = argv[optind];
+		mtd_device = mtd_find_dev_node(argv[optind]);
+		if (!mtd_device)
+			return errmsg("Can't find MTD device %s", argv[optind]);
 		start = simple_strtoull(argv[optind + 1], &error);
 		eb_cnt = simple_strtoul(argv[optind + 2], &error);
 		break;
diff --git a/misc-utils/flash_unlock.c b/misc-utils/flash_unlock.c
index fbbfa51..fa5decb 100644
--- a/misc-utils/flash_unlock.c
+++ b/misc-utils/flash_unlock.c
@@ -51,6 +51,8 @@ static NORETURN void usage(int status)
 		" -l         --lock              Lock a region of flash\n"
 		" -u         --unlock            Unlock a region of flash\n"
 		"\n"
+		" <mtd device>  MTD device node or 'mtd:<name>'\n"
+		"\n"
 		"If offset is not specified, it defaults to 0.\n"
 		"If block count is not specified, it defaults to all blocks.\n"
 		"A block count of -1 means all blocks.\n",
@@ -125,7 +127,12 @@ static void process_args(int argc, char *argv[])
 	}
 
 	/* First non-option argument */
-	dev = argv[arg_idx++];
+	dev = mtd_find_dev_node(argv[arg_idx]);
+	if (!dev) {
+		errmsg("MTD device not found %s", argv[arg_idx]);
+		usage(EXIT_FAILURE);
+	}
+	arg_idx++;
 
 	/* Second non-option argument */
 	if (arg_idx < argc)
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);
 	}
 
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) {
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++];