How to support various hardware blocks in drm driver

[Daniel Vetter]

On Tue, Mar 18, 2014 at 1:42 PM, Inki Dae <inki.dae at samsung.com> wrote:
> I think now drm_bridge couldn't do what we want for embedded systems
> as long as drm_encoder has drm_bridge.
> See the blow hardware pipeline,
> Display Controller-----Image Enhancement chip-----MIP DSI-----MIPI TO
> LVDS Bridge-----LCD Panel
>
> In above hardware pipeline, Display controller is controlled by crtc,
> and Image Enhancement chip receives output from display controller.
> So the use of existing drm_bridge would be suitable to only bridge
> devices between MIPI DSI and LCD Panel, but not to Image Enhancement
> chip.
>
> For such hardware, drm_panel infrastructure is more reasonable to me,
> and that is why I try to integrate drm_panel and drm_bridge to one
> integrated framework which has infrastructure same as existing
> drm_panel.
> The important thing is to free this integrated framework from
> drm_encoder so that crtc device can also use this framework.

Hm, what is this image enhancement chip? Is that some IP block on the
SoC? Is it optional? Can it be attached to different crtcs?

I think we have similar things on intel hardware, but without details
on what it does and how it works I can't really say how to best expose
it to userspace and how to best handle it internally in the driver.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch