Re: [PATCH v2 3/6] arm64: dts: qcom: ipq6018: Add the IMEM node

[Konrad Dybcio]

On 7/9/25 6:28 AM, Kathiravan Thirumoorthy wrote:
> 
> On 7/8/2025 7:49 PM, Konrad Dybcio wrote:
>> On 7/8/25 7:39 AM, Kathiravan Thirumoorthy wrote:
>>> Add the IMEM node to the device tree to extract debugging information
>>> like system restart reason, which is populated via IMEM. Define the
>>> IMEM region to enable this functionality.
>>>
>>> As described, overall IMEM region is 32KB but only initial 4KB is
>>> accessible by all masters in the SoC.
>>>
>>> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@xxxxxxxxxxxxxxxx>
>>> ---
>>> Changes in v2:
>>> - Rounded off the size to 0x8000 (Konrad)
>>> - Represent the reg's address space in hexadecimal format (Krzysztof)
>>> ---
>>> In 'ranges' property 0 is used instead of 0x0 to align with the existing
>>> format.
>>> ---
>>>   arch/arm64/boot/dts/qcom/ipq6018.dtsi | 9 +++++++++
>>>   1 file changed, 9 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/ipq6018.dtsi b/arch/arm64/boot/dts/qcom/ipq6018.dtsi
>>> index bfe59b0208415902c69fd0c0c7565d97997d4207..3b9e40045906b26b94e2d2510b0570d3eaf084ce 100644
>>> --- a/arch/arm64/boot/dts/qcom/ipq6018.dtsi
>>> +++ b/arch/arm64/boot/dts/qcom/ipq6018.dtsi
>>> @@ -659,6 +659,15 @@ qpic_nand: nand-controller@79b0000 {
>>>               status = "disabled";
>>>           };
>>>   +        sram@8600000 {
>>> +            compatible = "qcom,ipq6018-imem", "syscon", "simple-mfd";
>>> +            reg = <0x0 0x08600000 0x0 0x8000>;
>>> +            ranges = <0 0 0x08600000 0x8000>;
>>> +
>>> +            #address-cells = <1>;
>>> +            #size-cells = <1>;
>>> +        };
>> On this platform, shouldn't it be 0x6860_0000?
> 
> Actually, that's from the RPM perspective. From the ARM side, the address is 0x0860_0000. The hardware docs show the RPM view by default, so please switch to the ARM view.

Right, this is an odd default..

Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>

Konrad