Re: [PATCH v5 1/4] dt-bindings: firmware: Add bindings for ZynqMP firmware

[Sudeep Holla]

On 12/03/18 23:07, Jolly Shah wrote:
> Hi Sudeep,

>>>> Do you foresee using SMC/HVC for this firmware even on future platforms?
>>>> If not, I suggest to keep the protocol part separate from the transport i.e.
>>>> smc/hvc via ATF. It could be replaced with mailbox or some h/w
>>>> mechanism in future ?
>>>>
>>>
>>> We have PSCI and EEMI interfaces exposed to linux from ATF. PSCI is an
>>> EEMI client. We do not have current plans to switch to mailbox as it
>>> will require 2 communication channels to PMU as PSCI is through ATF.
>>>
>>
>> OK, but I just saw some bindings that has mailbox interface, honestly it's getting
>> too confusing with multiple series on the same thing floating and hence I
>> requested to put it together as one series.
> 
> Mailbox binding is used for power management driver. Mailbox is only
> used for PMU->APU communication. APU->PMU communication is always
> through EEMI firmware interface which is using SMC/HVC.
> 

Ah OK, is it because there's no non-secure mailbox or to avoid races,
all non-secure EEMI is channeled through SMC ?

-- 
Regards,
Sudeep