Re: [PATCH 3/4] dt-binding: remoteproc: venus rproc dt binding document

From: Stanimir Varbanov
Date: Wed Aug 24 2016 - 11:42:09 EST


Hi Rob,

On 08/23/2016 08:32 PM, Rob Herring wrote:
> On Fri, Aug 19, 2016 at 06:53:19PM +0300, Stanimir Varbanov wrote:
>> Add devicetree binding document for Venus remote processor.
>>
>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
>> ---
>> .../devicetree/bindings/remoteproc/qcom,venus.txt | 33 ++++++++++++++++++++++
>> 1 file changed, 33 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/remoteproc/qcom,venus.txt
>>
>> diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,venus.txt b/Documentation/devicetree/bindings/remoteproc/qcom,venus.txt
>> new file mode 100644
>> index 000000000000..06a2db60fa38
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/remoteproc/qcom,venus.txt
>> @@ -0,0 +1,33 @@
>> +Qualcomm Venus Peripheral Image Loader
>> +
>> +This document defines the binding for a component that loads and boots firmware
>> +on the Qualcomm Venus remote processor core.
>
> This does not make sense to me. Venus is the video encoder/decoder h/w,
> right? Why is the firmware loader separate from the codec block? Why
> rproc is used? Are there multiple clients? Naming it rproc_venus implies
> there aren't. And why does the firmware loading need 8MB of memory at a
> fixed address?
>

The firmware for Venus case is 5MB. And here is 8MB because of
dma_alloc_from_coherent size restriction.

The address is not really fixed, cause the firmware could support
relocation. In this example I just picked up the next free memory region
in memory-reserved from msm8916.dtsi.

regards,
Stan