+Sakari On 1/24/19 3:53 AM, Ken Sloat wrote: > There are a number of v4l2 subdevices in the kernel that support a > Bt.656 bus also known as "embedded sync." Previously in older versions > of the kernel (and in the current 4.14 LTS kernel), the standard way > to enable this in device tree on a parallel bus was to simply omit all > hysync and vsync flags. > > During some other kernel development I was doing, it was brought to my > attention that there is now a standard defined binding in > "video-interfaces.txt" called "bus-type" that should be used in order > to enable Bt.656 mode. While omitting the flags still appears to work > because of other assumptions made in v4l2-fwnode driver, this method > is now outdated and improper. > > However, I have noticed that several dt binding docs have not been > updated to reflect this change and still reference the old method: > > Documentation/devicetree/bindings/media/sun6i-csi.txt > /* If hsync-active/vsync-active are missing, > embedded BT.656 sync is used */ > > Documentation/devicetree/bindings/media/i2c/tvp5150.txt > "If none of hsync-active, vsync-active and field-even-active is specified, > the endpoint is assumed to use embedded BT.656 synchronization." > > Documentation/devicetree/bindings/media/i2c/adv7604.txt > "If none of hsync-active, vsync-active and pclk-sample is specified the > endpoint will use embedded BT.656 synchronization." > > and amazingly even > Documentation/devicetree/bindings/media/video-interfaces.txt in one of > the code snippets > /* If hsync-active/vsync-active are missing, > embedded BT.656 sync is used */ > > In order to avoid future confusion in the matter and ensure that the > proper bindings are used, I am proposing submitting patches to update > these docs to at minimum remove these statements and maybe even adding > additional comments specifying the optional property and value for > Bt.656 where missing. I wanted to open a discussion here first before > doing this though. Thoughts? > > Thanks, > Ken Sloat > I certainly agree that this should be updated to make it all consistent. Regards, Hans
