On 6/14/2023 7:29 PM, Krzysztof Kozlowski wrote:
On 14/06/2023 13:43, Manikanta Mylavarapu wrote:
+ properties:
+ compatible:
+ enum:
+ - qcom,ipq5018-wcss-ahb-mpd
+ - qcom,ipq9574-wcss-ahb-mpd
+ - qcom,ipq5018-wcss-pcie-mpd
Keep rather alphabetical order (so both 5018 together).
I also do not understand these at all. Why adding bus type to
compatible? This rarely is allowed (unless it is PCIe controller within
soc).
IPQ5018 SOC has in-built PCIE controller. Here QDSP6 will bring up
external(PCIE) and internal (AHB) wifi radio's. To separate AHB, PCIE
radio's properties, i have added bus type to compatible.
It's the same device - WCSS - right? We do not create multiple nodes and
compatibles for the same devices. Bus suffixes are almost never parts of
compatibles.
No it's not the same device. WCSS on inside IPQ5018 and WCSS attached
via pcie to IPQ5018. Here QDSP6 managing both WCSS's.
So for better clarity i will use attached SOC ID in compatible.
Below are the new compatible's.
- qcom,ipq5018-wcss-mpd //IPQ5018 internal radio
- qcom,ipq9574-wcss-mpd //IPQ9574 internal radio
- qcom,qcn6122-wcss-mpd //IPQ5018 attached radio
What mandates that there's just one QCN6122 device attached to PCI?
Assuming fixed PCI configurations like that makes me worried.
IPQ5018 always has one internal radio, attached pcie radio's depends on
no of pcie ports. IPQ5018 has 2 pcie ports, so it supports max two
qcn6122 devices. One compatible (qcom,qcn6122-wcss-mpd) itself support's
number of pcie devices controlled by QDSP6.
So this is hot-pluggable (or at least board-pluggable), then should not
be a part of static DTS.
Some concepts of virtual-processes is anyway far away from hardware
description, thus does not fit into DTS. Adding now to the equation PCIe
with variable number of such processes, brings us even further.
This is not a DT property. Remember - DT describes hardware.
Best regards,
Krzysztof
In the multipd architecture based Socs, There is one Q6 DSP which runs
the OS/kernel and there are one or more instances of WCSS radios
(It can be either internal or pcie attached).
These WCSS cores are controlled by the Q6 (Q6 DSP brings wcss radios out
of reset/ shuts it down etc). Q6 forms the 'root Protection domain' and
the wcss radios are termed as the 'user protection domain'.
The compatible's that is being added here are to manage the 'root
domain' and 'user domain'.
Not sure if using the words 'pcie'/'ahb' made it confusing.
So, 'qcom,ipq5018-q6-mpd' and 'qcom,ipq5018-wcss-mpd'.
There will be multiple instances of 'qcom,ipq5018-wcss-mpd' in DT based
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)).
Qualcomm puts so many so weird stuff into DT which is not a hardware
description. I understand that everything is there a firmware, but then
make it discoverable for example...
Hmm, in order to init/bring up these domains, clks, resets
and some more register access are required. Q6 FW does not have
access to all these resources. Also, HLOS rproc driver is needed to
listen on all the events related to these domains just like any
other rproc driver.
Regards,
Manikanta
