On Sun, 23 Oct 2016 09:38:04 +0800 Chen-Yu Tsai wens@csie.org wrote:
Recently, an announce about Tina OS for the R series https://www.youtube.com/watch?v=h7KD-6HblAU was followed by the upload of a new linux-3.4 source tree https://github.com/tinalinux/linux-3.4 with files containing GPL headers.
Well, I don't know if these sources are really from Allwinner, but anyway, this is the opportunity to propose a new version of my DRM HDMI driver.
Could you clarify about this bit? Did you just clean up Allwinner's existing drivers? Or just use them as reference? Either way I think this deserves some mention in all your copyright headers.
Otherwise what difference does the new release make?
- Allwinner's video driver is not DRM. - their driver has no hardware cursor nor video overlay. - I wrote the video DRM driver from the document Allwinner_H3_Datasheet_V1.2.pdf and the structures defined in linux-3.4/drivers/video/sunxi/disp2/disp/de/lowlevel_sun8iw7/de_rtmx.h Reading Allwinner's code helped me to understand how the DE2 is working. - my lowlevel HDMI is just a cleanup of theirs with explanations about the registers. Magic constants remain due to the lack of knowledge about the PHYs. - the mention of Allwinner in the copyright headers is needed to indicate the source of the structures (DE2) and code (HDMI).
The main difference is the DRM interface and the use of the EDID, permitting dynamic video resolution change with xrandr.