f88c5ee774
Initial implementation of DE2 planes only supported fixed zpos. Expand implementation with configurable zpos property. Implementation background: Channel in DE2 driver represents one DRM plane, whereas pipe is just mapped channel to known Z position. Pipe 0 will always be at the bottom, pipe 1 just above pipe 0 and so on. If, for example, channel 1 is mapped at pipe 0 and channel 0 at pipe 1, whatever is on channel 0 will appear on top. Before this commit, channel id was used for addressing channel related registers (prefixed with SUN8I_MIXER_CHAN_UI_ or SUN8I_MIXER_CHAN_VI_) and pipe registers (prefixed with SUN8I_MIXER_BLEND_). Additionally, register SUN8I_MIXER_BLEND_ROUTE, which takes care for mapping channels to pipes had fixed value. It mapped channel 0 to pipe 0, 1 to 1 and so on. Consequence of all that was fixed Z order of planes. With this commit, pipe registers are using zpos property as index and channel related registers still use channel id as index. Pipe mapping register is now set dynamically too and pipe enable register is rebuild every time to make sure only active pipes are enabled. Testing was done to confirm that there is no issues if bottom plane contains pixels with alpha value < 0xff and if it doesn't whole screen. Tested-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180706164732.24166-1-jernej.skrabec@siol.net
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.