Re: [PATCH 0/3] Add power domain driver support for i.mx8m family

Schrempf Frieder
2020-02-13T09:16:47Z

Hi,

On 07.11.19 22:28, Adam Ford wrote:
> On Thu, Apr 18, 2019 at 9:43 AM Sudeep Holla <sudeep.holla@arm.com> wrote:
>>
>> On Wed, Apr 17, 2019 at 04:21:55PM +0000, Leonard Crestez wrote:
>>> On 4/17/2019 4:33 PM, Sudeep Holla wrote:
>>>>>> I don't yet buy the security argument. There are many more shared parts
>>>>>> on the SoC, like the clock controller, that would need to be taken away
>>>>>> from the non-secure world if one would want to run an untrusted OS
>>>>>> kernel on a i.MX8M system.
>>>>>>
>>>>>> To properly implement security on any i.MX8M based system the firmware
>>>>>> would need to grow something like a full ARM SCPI implementation, so
>>>>>> all shared critical peripherals are solely under firmware control.
>>>>>
>>>>> It might be possible to rework this to use some form of SCMI-over-SMC
>>>>> instead of vendor-specific SMCCC SIP calls
>
> I was just curious to know if there is any progress being made on
> this. The i.mx8mm-evk is missing functionality upstream and I think
> the power domain support would help enable some of these features.
>

Has there been any decision or action taken in this topic?
Will the power domain driver as proposed in this patch be upstreamed at
some time, or rather not?

I try to build a mainline BSP for i.MX8MM (ML U-Boot, ML TF-A, ML Linux)
and I integrated display and graphics support from the downstream NXP
kernel.

While most things already work fine, there's the issue of how to handle
the power domains. Currently I need to ungate some clocks in the TF-A
BL31 to get for example the GPU running. If I understand this correctly
the proposed power domain driver could handle this in Linux otherwise.

Thanks,
Frieder