Re: [PATCH v2 1/2] dt-bindings: interrupt-controller: mpm: Pass MSG RAM slice through phandle

From: Konrad Dybcio
Date: Wed Apr 12 2023 - 08:09:50 EST




On 12.04.2023 13:55, Krzysztof Kozlowski wrote:
> On 12/04/2023 13:47, Konrad Dybcio wrote:
>>> For unrelated reasons I actually have some patches for this, that switch
>>> the /smd top-level node to a "remoteproc-like" node dedicated to the
>>> RPM, similar to how WCNSS/ADSP/Modem/etc are represented. I need this to
>>> add additional (optional) properties like "resets" and "iommus" for the
>>> RPM, but it would allow adding arbitrary subnodes as well:
>>>
>>> https://github.com/msm8916-mainline/linux/commit/35231ac28703805daa8220f1233847c7df34589e
>>>
>>> I could finish those up and post them if that would help...
>> Krzysztof, what do you think?
>
> I don't know what is there in MSM8916 and how it should be represented.
Similarly to other Qualcomm SoCs, MSM8916 has a RPM (Cortex-M3) core,
which communicates over the SMD protocol (or G-LINK on >=8996).

The Qualcomm firmware loads the RPM fw blob and sets it up early in
the boot process, but msm8916-mainline folks managed to get TF-A
going and due to it being less.. invasive.. than the Qualcomm TZ,
RPM needs a bit more handling to be accessible.

The M3 core is wired up through the CNoC bus and we communicate
with it through the MSG RAM and the "APCS mailbox".

Konrad
>
> Best regards,
> Krzysztof
>