tree 9e018b1d511a96f745fc870bfdf8bf53759c25ae
parent 0c36ec31473593aa937ff04f3b3b630e81512734
author David Brownell <dbrownell@users.sourceforge.net> 1216675294 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1216745981 -0700

gpio: pcf857x: add lock and handle more chips

Two small updates to the pcf857x driver: (a) the max732[89] chips are
also second sources for the pcf8574/a, and (b) add a mutex to prevent
trashing the cached state.  Adding the lock is effectively a bugfix,
although it seems unlikely that anyone would have run into the issue it
protects against.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>