lib: introduce common method to convert hex digits
hex_to_bin() is a little method which converts hex digit to its actual
value. There are plenty of places where such functionality is needed.
[akpm@linux-foundation.org: use tolower(), saving 3 bytes, test the more common case first - it's quicker]
[akpm@linux-foundation.org: relocate tolower to make it even faster! (Joe)]
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: Duncan Sands <duncan.sands@free.fr>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "Richard Russon (FlatCap)" <ldm@flatcap.org>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 05f332a..8317ec4 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -375,6 +375,8 @@
return buf;
}
+extern int hex_to_bin(char ch);
+
#ifndef pr_fmt
#define pr_fmt(fmt) fmt
#endif