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 24KB but only initial 4KB is
accessible by all masters in the SoC.

Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
---
Changes in v2:
- Rounded off the size to 0x6000 (Konrad)
---
 arch/arm64/boot/dts/qcom/ipq8074.dtsi | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
index fffb47ec244899cf45984adbe8c4f9820bef5c5f..2ba07a02c222958b924c5bc178ac67f955088f7a 100644
--- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
+++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
@@ -625,6 +625,15 @@ qpic_nand: nand-controller@79b0000 {
 			status = "disabled";
 		};
 
+		sram@8600000 {
+			compatible = "qcom,ipq8074-imem", "syscon", "simple-mfd";
+			reg = <0x08600000 0x6000>;
+			ranges = <0 0x08600000 0x6000>;
+
+			#address-cells = <1>;
+			#size-cells = <1>;
+		};
+
 		usb_0: usb@8af8800 {
 			compatible = "qcom,ipq8074-dwc3", "qcom,dwc3";
 			reg = <0x08af8800 0x400>;

-- 
2.34.1

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 24KB but only initial 4KB is
> accessible by all masters in the SoC.
> 
> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
> ---
> Changes in v2:
> - Rounded off the size to 0x6000 (Konrad)
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

On 08/07/2025 07:39, 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 24KB but only initial 4KB is
> accessible by all masters in the SoC.
> 
> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
> ---
> Changes in v2:
> - Rounded off the size to 0x6000 (Konrad)
> ---
>  arch/arm64/boot/dts/qcom/ipq8074.dtsi | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> index fffb47ec244899cf45984adbe8c4f9820bef5c5f..2ba07a02c222958b924c5bc178ac67f955088f7a 100644
> --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> @@ -625,6 +625,15 @@ qpic_nand: nand-controller@79b0000 {
>  			status = "disabled";
>  		};
>  
> +		sram@8600000 {
> +			compatible = "qcom,ipq8074-imem", "syscon", "simple-mfd";


It is still not simple-mfd. You should post complete node with children
or do not make it a simple-mfd.

Best regards,
Krzysztof

On 7/8/2025 12:17 PM, Krzysztof Kozlowski wrote:
> On 08/07/2025 07:39, 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 24KB but only initial 4KB is
>> accessible by all masters in the SoC.
>>
>> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
>> ---
>> Changes in v2:
>> - Rounded off the size to 0x6000 (Konrad)
>> ---
>>   arch/arm64/boot/dts/qcom/ipq8074.dtsi | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>> index fffb47ec244899cf45984adbe8c4f9820bef5c5f..2ba07a02c222958b924c5bc178ac67f955088f7a 100644
>> --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>> @@ -625,6 +625,15 @@ qpic_nand: nand-controller@79b0000 {
>>   			status = "disabled";
>>   		};
>>   
>> +		sram@8600000 {
>> +			compatible = "qcom,ipq8074-imem", "syscon", "simple-mfd";
>
> It is still not simple-mfd. You should post complete node with children
> or do not make it a simple-mfd.


Sure. Based on the outcome of the series[1], will update it.

[1] 
https://lore.kernel.org/linux-arm-msm/073480a2-0b6f-4dc0-b7eb-eec500b3106e@oss.qualcomm.com/


>
> Best regards,
> Krzysztof