On Wed, Apr 04, 2012 at 08:26:48PM +0800, Axel Lin wrote:

> I forgot to mention that s5m8767 needs this patch to work.
> s5m8767 implements set_voltage, get_voltage_sel and
> set_voltage_time_sel callbacks.

We should be fine without it usually, generally the ramp times are
relatively fast in comparison with the time taken for the physical I/O
to complete.