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

From: Konrad Dybcio

Date: Wed Mar 04 2026 - 06:41:06 EST


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@xxxxxxxxxxxxxxxx/
>>
>>
>> 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)?

Konrad