Re: [PATCH v3 1/6] dt-bindings: sram: Describe the IMEM present in Qualcomm IPQ SoCs

[Krzysztof Kozlowski <krzk@kernel.org>]

On 04/03/2026 12:38, Konrad Dybcio wrote:
> On 3/4/26 12:29 PM, Krzysztof Kozlowski wrote:
>> On 04/03/2026 12:16, Kathiravan Thirumoorthy wrote:
>>>
>>> On 3/3/2026 4:18 PM, Konrad Dybcio wrote:
>>>> On 3/2/26 5:33 PM, Krzysztof Kozlowski wrote:
>>>>> On 02/03/2026 15:56, Konrad Dybcio wrote:
>>>>>> On 3/2/26 3:54 PM, Krzysztof Kozlowski wrote:
>>>>>>> On 02/03/2026 15:10, Konrad Dybcio wrote:
>>>>>>>>> Also not accurate - "sram" is not the reboot reason, which has node name
>>>>>>>>> called "reboot-mode".
>>>>>>>> What I was referring to is:
>>>>>>>>
>>>>>>>> patternProperties:
>>>>>>>>    "^([a-z0-9]*-)?sram(-section)?@[a-f0-9]+$":
>>>>>>>>
>>>>>>>> where the 'sram' (not 'smem' as I typo'd above) is obligatory
>>>>>>> I know and sram is not part of "reboot-mode" name. It is "reboot-mode"
>>>>>>> in existing binding and DTS, not "reboot-mode-sram".
>>>>>> In any case, I believe it'd be good to drop that requirement
>>>>> Ah, and one more thing, the syscon-reboot-mode is Linux driver with its
>>>>> own Linux requirements - syscon - so probably not working with sram
>>>>> bindings. That's another reason full binding should be posted and tested
>>>>> - I speculate it simply does not work.
>>>> It won't even probe, we talked about that a long time ago on a similar
>>>> occasion
>>>>
>>>> https://lore.kernel.org/linux-arm-msm/f6b16d1d-3730-46d1-81aa-bfaf09c20754@oss.qualcomm.com/
>>>
>>>
>>> Sorry, TBH, I'm confused here...
>>>
>>> I agree that, DT node should be as simple as below for now until the 
>>> child node is added.
>>>
>>> sram@8600000 {
>>>     compatible = "qcom,ipq5332-imem", "mmio-sram";
>>>     reg = <0x08600000 0x14000>;
>>>     no-memory-wc;
>>> };
>>>
>>> When I add the child node, it will eventually become like
>>>
>>> sram@8600000 {
>>>          compatible = "qcom,ipq5332-imem", "mmio-sram";
>>>          reg = <0 0x08600000 0 0x1c000>;
>>>          ranges = <0 0 0x08600000 0x1c000>;
>>>
>>>          no-memory-wc;
>>>
>>>          #address-cells = <1>;
>>>          #size-cells = <1>;
>>>
>>>          restart_reason: restartreason-sram@7b0 {
>>>                  reg = <0x7b0 0x4>;
>>>          };
>>> };
>>>
>>> which seems to be matching with the binding requirements.
>>>
>>> and the consumer can reference to this node like
>>>
>>> sram = <&restart_reason>;
>>>
>>> I'm not following what's being suggested here. Can you please help me to 
>>> understand further on this.
>>
>> I already asked you what to do.
>>
>> "Nope, sorry. Bindings must be posted complete, see writing-bindings."
>>
>> So post it after testing. We suggest that it simply does not work, but
>> you can always prove us wrong.
> 
> Are you by chance confusing 'syscon-reboot-mode' (write TO imem to set the
> restart reason) with this node (read FROM imem to present a restart reason
> via wdog)?

Previously IMEM was in with reboot-mode, so that is why I am asking.
Commit msg mentions only "restart reason" but also states it is not
adding complete picture, so I am done guessing here.


Best regards,
Krzysztof