[PATCH 4/5] fb: Add DCU framebuffer driver for Vybrid VF610 platform
From: Bill Pringlemeir <hidden>
Date: 2014-01-06 18:50:09
On Fri, Jul 12, 2013 at 02:07:55PM +0800, Alison Wang wrote:quoted
The Display Controller Unit (DCU) module is a system master that fetches graphics stored in internal or external memory and displays them on a TFT LCD panel. A wide range of panel sizes is supported and the timing of the interface signals is highly configurable. Graphics are read directly from memory and then blended in real-time, which allows for dynamic content creation with minimal CPU intervention.
On 29 Jul 2013, s.hauer at pengutronix.de wrote:
Maybe the real question is whether we want to introduce another framebuffer driver at all instead of making it a DRM driver.
I didn't understand this comment at first. I thought that the DRM infra-structure had changed or something. I see a recent post on IMX-DRM and I think there is a mis-conception on the Vybrid SOC. At first, Freescale was to incorporate a Vivante GC355 GPU for OpenVG. However, this was removed from the design and is only present on some 'Automotive' parts, and not the VF610 nor the Tower boards. These SOCs only have a multi-level framebuffer with alpha blending. Was it meant that this be part of the DRM? It seems that the hardware without the 'Vivante GC355 GPU' is best served by an fb driver. Certainly, there are very few Vybrid chips with this OpenVG on board. I am also not really certain what sort of user space code would use it. Most graphics stacks seems to want OpenGL; of course that is not a reason not to put it in the kernel, but I don't think any Linux Vybrid devices will actually have an OpenVG register set on board? The majority will have none. Fwiw, Bill Pringlemeir.