Introduce compatible "qcom,scmi-smc" for SCMI smc/hvc transport channel for
Qualcomm virtual platforms.
This compatible mandates populating an additional parameter 'capability-id'
from the last 8 bytes of the shmem channel.
Signed-off-by: Nikunj Kela <[email protected]>
---
Documentation/devicetree/bindings/firmware/arm,scmi.yaml | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
index 563a87dfb31a..4591523b51a0 100644
--- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
+++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
@@ -38,6 +38,9 @@ properties:
with shmem address(4KB-page, offset) as parameters
items:
- const: arm,scmi-smc-param
+ - description: SCMI compliant firmware with Qualcomm SMC/HVC transport
+ items:
+ - const: qcom,scmi-smc
- description: SCMI compliant firmware with SCMI Virtio transport.
The virtio transport only supports a single device.
items:
@@ -313,6 +316,7 @@ else:
enum:
- arm,scmi-smc
- arm,scmi-smc-param
+ - qcom,scmi-smc
then:
required:
- arm,smc-id
--
2.17.1
On Fri, Oct 06, 2023 at 09:42:05AM -0700, Nikunj Kela wrote:
> Introduce compatible "qcom,scmi-smc" for SCMI smc/hvc transport channel for
> Qualcomm virtual platforms.
>
> This compatible mandates populating an additional parameter 'capability-id'
> from the last 8 bytes of the shmem channel.
>
> Signed-off-by: Nikunj Kela <[email protected]>
Reviewed-by: Brian Masney <[email protected]>
On Fri, Oct 06, 2023 at 09:42:05AM -0700, Nikunj Kela wrote:
> Introduce compatible "qcom,scmi-smc" for SCMI smc/hvc transport channel for
> Qualcomm virtual platforms.
>
> This compatible mandates populating an additional parameter 'capability-id'
> from the last 8 bytes of the shmem channel.
>
While I am happy with the simplification here, I am also bit nervous how
long before Qualcomm abandons this. I hope this is adopted as is in all
internal and downstream code without any modifications and this is not
just a push for upstreaming some change to minimise delta with internal/
downstream code.
--
Regards,
Sudeep
On 10/9/2023 7:41 AM, Sudeep Holla wrote:
> On Fri, Oct 06, 2023 at 09:42:05AM -0700, Nikunj Kela wrote:
>> Introduce compatible "qcom,scmi-smc" for SCMI smc/hvc transport channel for
>> Qualcomm virtual platforms.
>>
>> This compatible mandates populating an additional parameter 'capability-id'
>> from the last 8 bytes of the shmem channel.
>>
> While I am happy with the simplification here, I am also bit nervous how
> long before Qualcomm abandons this. I hope this is adopted as is in all
> internal and downstream code without any modifications and this is not
> just a push for upstreaming some change to minimise delta with internal/
> downstream code.
>
> --
> Regards,
> Sudeep
Qualcomm is using patch on all the virtual auto platforms using
shmem/doorbell as scmi channel. This is already being used without any
modifications in our downstream code. No delta for this patch series.
Thanks!
On 10/9/23 16:52, Nikunj Kela wrote:
>
> On 10/9/2023 7:41 AM, Sudeep Holla wrote:
>> On Fri, Oct 06, 2023 at 09:42:05AM -0700, Nikunj Kela wrote:
>>> Introduce compatible "qcom,scmi-smc" for SCMI smc/hvc transport
>>> channel for
>>> Qualcomm virtual platforms.
>>>
>>> This compatible mandates populating an additional parameter
>>> 'capability-id'
>>> from the last 8 bytes of the shmem channel.
>>>
>> While I am happy with the simplification here, I am also bit nervous how
>> long before Qualcomm abandons this. I hope this is adopted as is in all
>> internal and downstream code without any modifications and this is not
>> just a push for upstreaming some change to minimise delta with internal/
>> downstream code.
>>
>> --
>> Regards,
>> Sudeep
>
> Qualcomm is using patch on all the virtual auto platforms using
> shmem/doorbell as scmi channel. This is already being used without any
> modifications in our downstream code. No delta for this patch series.
> Thanks!
AFAICT Sudeep is looking for a solid guarantee that it will continue to
be used as-is, on more than one platform and on more than one BSP version.
There have been cases where such firmware interfaces had silent ABI
breaks (or were replaced altogether) between qc downstream branches and
this would be unacceptable. Understandably, having a unified means of
communication for *all* Qualcomm chips (i.e. not only auto) going
forward would likely be expected..
Konrad