[PATCH 6/8] v4l: videobuf2: add read() and write() emulator

Add a generic file io (read and write) emulator for videobuf2. It uses MMAP memory type buffers and generic vb2 calls: req_bufs, qbuf and dqbuf. Video date is being copied from mmap buffers to userspace with standard copy_to_user() function. To add support for file io the driver needs to provide an

[PATCH 6/8] v4l: videobuf2: add read() and write() emulator

Add a generic file io (read and write) emulator for videobuf2. It uses MMAP memory type buffers and generic vb2 calls: req_bufs, qbuf and dqbuf. Video date is being copied from mmap buffers to userspace with standard copy_to_user() function. To add support for file io the driver needs to provide an