py: MappedFrameBuffer: Support non-contextmanager use

Implement non-contextmanager use to MappedFrameBuffer so that we can
either:

with MappedFrameBuffer(fb) as mfb:
	...

or

mfb = MappedFrameBuffer(fb)
mfb.mmap()
...
mfb.munmap()

While at it, improve the error handling a bit.

Note that the mmap() returns self. In other words, one can do this:

mfb = MappedFrameBuffer(fb).mmap()
...
mfb.munmap()

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

0 files changed, 0 insertions, 0 deletions