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.
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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