performance issues.
* Access to the GPIO bus is already locked by requesting
and releasing the bus - thus the lock isn't really needed
for each GPIO pin change.
* Don't lock and unlock the GPIO bus for -each- i2c access -
the i2c bus code is already doing this by calling the upper
layer callback to request/release the bus. This thus locks
the bus for the entirety of the transaction.
TODO:
* Further verify that everything is correctly requesting/
releasing the GPIO bus.
* Look at how to lock the GPIO pin configuration stuff,
potentially by locking/unlocking the bus at the gpiobus
layer.
ddd7699151