Re: [PATCH 0/4] media: platform: Add Aspeed Video Engine driver

[Eddie James]

On 08/31/2018 12:56 PM, Stephen Boyd wrote:
> Quoting Eddie James (2018-08-29 14:09:29)
> > The Video Engine (VE) embedded in the Aspeed AST2400 and AST2500 SOCs
> > can capture and compress video data from digital or analog sources. With
> > the Aspeed chip acting as a service processor, the Video Engine can
> > capture the host processor graphics output.
> >
> > This series adds a V4L2 driver for the VE, providing a read() interface
> > only. The driver triggers the hardware to capture the host graphics output
> > and compress it to JPEG format.
> >
> > Testing on an AST2500 determined that the videobuf/streaming/mmap interface
> > was significantly slower than the simple read() interface, so I have not
> > included the streaming part.
> >
> > It's also possible to use an automatic mode for the VE such that
> > re-triggering the HW every frame isn't necessary. However this wasn't
> > reliable on the AST2400, and probably used more CPU anyway due to excessive
> > interrupts. It was approximately 15% faster.
> >
> > The series also adds the necessary parent clock definitions to the Aspeed
> > clock driver, with both a mux and clock divider.
> Please let me know your merge strategy here. I can ack the clk patches
> because they look fine from high-level clk driver perspective (maybe
> Joel can take a closer look) or I can merge the patches into clk-next
> and get them into next release while the video driver gets reviewed.

Thanks for taking a look! Probably preferable to get the clk patches 
into clk-next first (though Joel reviewing would be great). I just put 
everything in the same set for the sake of explaining the necessity of 
the clk changes.

Thanks,
Eddie

>