Re: [PATCH 3/7] arm64: dts: qcom: ipq6018: Add the IMEM node

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 7/2/25 12:50 PM, Krzysztof Kozlowski wrote:
> On 02/07/2025 12:17, 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 approximately 32KB but only initial
>> 4KB is accessible by all masters in the SoC.
>>
>> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
>> ---
>>  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..7eca5ba416c2ef5ef1c4e0eb4f58f1ca94fc92f0 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";
> 
> No, this is not a simple MFD. Where are any children if this is a MFD?

IMEM is just a block of SRAM shared across cores on the platform.
It's present on all Qualcomm platforms and usually stores cookies
such as reboot reason.

A user would be welcome, but I'm not opposed to a lone description
either, at it still shrinks the undescribed-reg-space-hole

Konrad