Hello Etienne,
On 16.03.22 12:01, Etienne Carriere wrote:
> Hi Ahmad,
>
>> Helo Gabriel,
>>
>> On 03.03.22 14:09, Gabriel FERNANDEZ wrote:
>>>
>>> On 2/25/22 16:13, Ahmad Fatoum wrote:
>>>> Hello Gabriel,
>>>>
>>>> On 25.02.22 14:31, gabriel.fernandez@xxxxxxxxxxx wrote:
>>>>> From: Gabriel Fernandez <gabriel.fernandez@xxxxxxxxxxx>
>>>>> + firmware {
>>>>> + optee {
>>>>> + method = "smc";
>>>>> + compatible = "linaro,optee-tz";
>>>>> + };
>>>>> +
>>>>> + scmi: scmi {
>>>>> + compatible = "linaro,scmi-optee";
>>>> This compatible doesn't seem to be documented upstream. I am looking at v5.17-rc5.
>>>> Do you have a reference detailing the difference between this conduit and
>>>> plain arm,scmi-smc (as used with TF-A on the STM32MP151).
>>>>
>>>> Cheers,
>>>> Ahmad
>>>
>>> Hi
>>>
>>> Ahmad,
>>>
>>> it's on going.
>>>
>>> https://lore.kernel.org/linux-arm-kernel/20211029102118.GG6526@e120937-lin/T/#mf46c83f0aadce3061ee93fa22159405f38d881a0
>>
>> I've found that thread in the meantime and got some clarification on why a new
>> transport for OP-TEE was added. One question I still have though is why make
>> this transport the default for STM32MP13x instead of using SCMI over SMC like
>> you do for STM32MP15x. OP-TEE could still be made to service SCMI over SMC
>> and it would allow people employing TF-A as SCMI provider an easier migration
>> to the newer SoC.
>>
>
> Just to rephrase a bit what's being said in the referred mail thread:
> On STM32MP13x, there are SCMI messages that must be processed inside a
> thread execution context in the SCMI server. There is no standard SMC
> function ID defined that the SCMI/SMC transport could use for that
> purpose. OP-TEE provides such a threaded context. Therefore STM32MP13x
> explicitly expects SCMI services based on SCMI/OP-TEE transport, not
> SCMI/SMC transport.
I see. Users can still override it as they see fit and I understand that
ST would prefer to have the "fully-featured" boot chain be the default
for the new SoC. So no concerns from my side.
Thanks a lot for the clarification!
Cheers,
Ahmad
>
> Best regards,
> etienne
>
>> Cheers,
>> Ahmad
>
>>
>>>
>>>> + #address-cells = <1>;
>>>> + #size-cells = <0>;
>>>> + linaro,optee-channel-id = <0>;
>>>> + shmem = <&scmi_shm>;
>>>> +
>>>> + scmi_clk: protocol@14 {
>>>> + reg = <0x14>;
>>>> + #clock-cells = <1>;
>>>> + };
>>>> +
>>>> + scmi_reset: protocol@16 {
>>>> + reg = <0x16>;
>>>> + #reset-cells = <1>;
>>>> + };
>>>> + };
>>>> + };
>>>> clocks {
>>>> clk_axi: clk-axi {
>>>> #clock-cells = <0>;
>>>
>>
>
>
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