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.

[[email protected]: use tolower(), saving 3 bytes, test the more common case first - it's quicker]
[[email protected]: relocate tolower to make it even faster! (Joe)]
Signed-off-by: Andy Shevchenko <[email protected]>
Cc: Tilman Schmidt <[email protected]>
Cc: Duncan Sands <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "Richard Russon (FlatCap)" <[email protected]>
Cc: John W. Linville <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Joe Perches <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions