Hi, First of this series is based on work done by Helen in 2017 [1], I have synced with her that it's OK for me to takeover the work. This series aims to reduce the amount of boiler plate code in video device drivers who's inputs and/or outputs are controlled by the Media Controller instead of the V4L2 API. Patch 1/6 adds a default handler for VIDIOC_{G,S}_{INPUT,OUTPUT} as suggested by Hans in v1. This allows video drivers (disregarding of the V4L2_CAP_IO_MC flag) to remove callbacks for these operations if they only provide a single input/output. Patch 3/6 adds the core parts of this change by adding a new video device capability flag V4L2_CAP_IO_MC which if set provides helper implementations for the enum inputs and outputs ioctrls freeing the video device driver from the need to implement them. Patch 2/6, 3/6, 5/6 and 6/6 converts the R-Car VIN and Intel IPU3 drivers to use the new default handlers and flag and delete the now redundant boiler plate code. I'm sure more video device drivers can make use of this new flag but as I can only test on these two platforms I have limited my changes to those. 1. https://patchwork.linuxtv.org/patch/41857/ Niklas Söderlund (6): v4l2-dev/ioctl: Add default handlers for VIDIOC_{G,S}_{INPUT,OUTPUT} rcar-vin: Use default VIDIOC_{G,S}_{INPUT,OUTPUT} handler staging/intel-ipu3: Use default VIDIOC_{G,S}_{INPUT,OUTPUT} handler v4l2-dev/ioctl: Add V4L2_CAP_IO_MC rcar-vin: Make use of V4L2_CAP_IO_MC staging/intel-ipu3: Make use of V4L2_CAP_IO_MC .../media/uapi/v4l/vidioc-querycap.rst | 3 + .../media/videodev2.h.rst.exceptions | 1 + drivers/media/platform/rcar-vin/rcar-v4l2.c | 32 +------- drivers/media/v4l2-core/v4l2-dev.c | 18 +++-- drivers/media/v4l2-core/v4l2-ioctl.c | 80 ++++++++++++++++++- drivers/staging/media/ipu3/ipu3-v4l2.c | 60 +------------- include/uapi/linux/videodev2.h | 2 + 7 files changed, 97 insertions(+), 99 deletions(-) -- 2.24.0