Re: [PATCH V2 01/13] dt-bindings: remoteproc: qcom: Add support for multipd model

From: Manikanta Mylavarapu
Date: Fri Jun 30 2023 - 03:13:08 EST




On 6/24/2023 12:49 PM, Krzysztof Kozlowski wrote:
On 21/06/2023 13:39, Manikanta Mylavarapu wrote:
on number of wcss radios connected on that board and only one instance
of 'qcom,ipq5018-q6-mpd'.


I don't understand why the user protection domains need a specific
compatible. Why do they need compatible at all?

Not mentioning that amount of your domains on Q6 is actually fixed per
SoC and probably should not be in DT at all.

root domain is fixed per soc (One Q6 DSP, one per soc)
user domain(s) are variable (based on number of wcss radios attached)

The sequence to initialize, bring up, tear down the Q6 and wcss radios
are completely different. So in order to differentiate them, we will
need different compatibles. So this is a new rproc driver/architecture
which has a parent/child topology (Q6 DSP -> Master/parent controls
the WCSS (child)).

I understand you need different properties, but I don't see yet the
benefit of creating here artificial compatibles. Look at your ipq9574
DTSI change - it does not use even ipq9574 compatibles for 66% of its
children.

Maybe you should have there just property describing type of device or
bringup?


Yeah i got your point. Indeed the requirement here is to
have device specific compatibles, so will have just two
compatible one for Q6-MPD and another for WCSS-MPD device's


"qcom,q6-mpd" --> For Q6-MPD device
"qcom,wcss-mpd" --> For WCSS-MPD device

Is this approach fine ?

Given SoC cannot come with different amount of children (PD) and
different amount of radios. You even fix the firmware name, so
boards/customers cannot use anything else. It's fixed and the only
variable element here is disabling some of the blocks per board, if they
do not have physical interface (e.g. radio).

You even hard-code the number of PD by using "pd-[123]", without unit
address, so you do not expect it will grow.

Unless you want to say that these are devices? But your binding does not
really suggest it...


Yes, as i mentioned above the requirement is to have device
specific bindings. We will remove "PD-X" from soc dtsi and
add it in board dts file.

So soc dts would have "Q6-MPD" master node & board dts have
"WCSS-MPD" child nodes based on number of radio's connected
on board.

Is this fine ?

Thanks & Regards,
Manikanta.