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
