drivers/gpio/pca953x.c: add a mutex to fix race condition

Add a mutex to register communication and handling.  Without the mutex,
GPIOs didn't switch as expected when toggled in a fast sequence of
status changes of multiple outputs.

Signed-off-by: Roland Stigge <[email protected]>
Acked-by: Eric Miao <[email protected]>
Cc: Grant Likely <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Ben Gardner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions