Avoid duplicating the code which deals with getc() and putc(). It is fairly
simple, but may expand later.
Signed-off-by: Simon Glass <sjg@chromium.org>
In some cases we really want to move forward with a deregister, add a force
parameter to allow this, and replace the dev with a nulldev in this case.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Serial devices support simple byte input/output and a few operations to find
out whether data is available. Add a basic uclass for serial devices to be
used by drivers that are converted to driver model.
Signed-off-by: Simon Glass <sjg@chromium.org>
