Hello, This patch series implements display writeback support for the R-Car Gen3 platforms in the VSP1 driver. DRM/KMS provides a writeback API through a special type of writeback connectors. This series takes a different approach by exposing writeback as a V4L2 device. While there is nothing fundamentally wrong with writeback connectors, display for R-Car Gen3 platforms relies on the VSP1 driver behind the scene, which already implements V4L2 support. Enabling writeback through V4L2 is thus significantly easier in this case. The writeback pixel format is restricted to RGB, due to the VSP1 outputting RGB to the display and lacking a separate colour space conversion unit for writeback. The resolution can be freely picked by will result in cropping or composing, not scaling. Writeback requests are queued to the hardware on page flip (atomic flush), and complete at the next vblank. This means that a queued writeback buffer will not be processed until the next page flip, but once it starts being written to by the VSP, it will complete at the next vblank regardless of whether another page flip occurs at that time. The code is based on a merge of the media master branch, the drm-next branch and the R-Car DT next branch. For convenience patches can be found at git://linuxtv.org/pinchartl/media.git v4l2/vsp1/writeback Kieran Bingham (2): Revert "[media] v4l: vsp1: Supply frames to the DU continuously" media: vsp1: Provide a writeback video device Laurent Pinchart (5): media: vsp1: wpf: Fix partition configuration for display pipelines media: vsp1: Replace leftover occurrence of fragment with body media: vsp1: Fix addresses of display-related registers for VSP-DL media: vsp1: Refactor vsp1_video_complete_buffer() for later reuse media: vsp1: Replace the display list internal flag with a flags field drivers/media/platform/vsp1/vsp1_dl.c | 118 ++++++++++++-- drivers/media/platform/vsp1/vsp1_dl.h | 6 +- drivers/media/platform/vsp1/vsp1_drm.c | 24 ++- drivers/media/platform/vsp1/vsp1_drv.c | 17 +- drivers/media/platform/vsp1/vsp1_pipe.c | 5 + drivers/media/platform/vsp1/vsp1_pipe.h | 6 + drivers/media/platform/vsp1/vsp1_regs.h | 6 +- drivers/media/platform/vsp1/vsp1_rwpf.h | 2 + drivers/media/platform/vsp1/vsp1_video.c | 198 +++++++++++++++++++---- drivers/media/platform/vsp1/vsp1_video.h | 6 + drivers/media/platform/vsp1/vsp1_wpf.c | 65 ++++++-- 11 files changed, 378 insertions(+), 75 deletions(-) -- Regards, Laurent Pinchart
