Re: [PATCH v2 1/4] dt-bindings: soc: qcom: Add qcom,kaanapali-imem compatible

[Jingyi Wang <jingyi.wang@oss.qualcomm.com>]

On 10/23/2025 8:06 AM, Dmitry Baryshkov wrote:
> On Wed, Oct 22, 2025 at 05:42:58PM -0500, Bjorn Andersson wrote:
>> On Wed, Oct 22, 2025 at 12:34:58PM +0300, Dmitry Baryshkov wrote:
>>> On Wed, Oct 22, 2025 at 05:05:30PM +0800, Jingyi Wang wrote:
>>>>
>>>>
>>>> On 10/22/2025 4:49 PM, Dmitry Baryshkov wrote:
>>>>> On Wed, Oct 22, 2025 at 12:28:41AM -0700, Jingyi Wang wrote:
>>>>>> Document qcom,kaanapali-imem compatible.
>>>>>>
>>>>>> Reviewed-by: Eugen Hristev <eugen.hristev@linaro.org>
>>>>>> Signed-off-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
>>>>>> ---
>>>>>>  Documentation/devicetree/bindings/sram/qcom,imem.yaml | 1 +
>>>>>>  1 file changed, 1 insertion(+)
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/sram/qcom,imem.yaml b/Documentation/devicetree/bindings/sram/qcom,imem.yaml
>>>>>> index 6a627c57ae2f..1e29a8ff287f 100644
>>>>>> --- a/Documentation/devicetree/bindings/sram/qcom,imem.yaml
>>>>>> +++ b/Documentation/devicetree/bindings/sram/qcom,imem.yaml
>>>>>> @@ -19,6 +19,7 @@ properties:
>>>>>>        - enum:
>>>>>>            - qcom,apq8064-imem
>>>>>>            - qcom,ipq5424-imem
>>>>>> +          - qcom,kaanapali-imem
>>>>>
>>>>> Can you use mmio-sram instead?
>>>>>
>>>>
>>>> Here is the node: 
>>>>
>>>> 		sram@14680000 {
>>>> 			compatible = "qcom,kaanapali-imem", "syscon", "simple-mfd";
>>>> 			reg = <0x0 0x14680000 0x0 0x1000>;
>>>> 			ranges = <0 0 0x14680000 0x1000>;
>>>>
>>>> 			#address-cells = <1>;
>>>> 			#size-cells = <1>;
>>>>
>>>> 			pil-reloc@94c {
>>>> 				compatible = "qcom,pil-reloc-info";
>>>> 				reg = <0x94c 0xc8>;
>>>> 			};
>>>> 		};
>>>>
>>>> other qualcomm are also using imem, could you please give more details on why
>>>> we should use mmio-sram here?
>>>
>>> https://lore.kernel.org/linux-arm-msm/e4c5ecc3-fd97-4b13-a057-bb1a3b7f9207@kernel.org/
>>>
>>
>> I considered exactly this when I wrote the binding back then...
>>
>> But the binding defines mmio-sram as "Simple IO memory regions to be
>> managed by the genalloc API." and the Linux sram driver follows that and
>> registers a gen_pool across the sram memory region.
>>
>> I believe IMEM is SRAM (it's at least not registers), but its memory
>> layout is fixed, so it's not a pool in any form.
>>
>>
>> What Krzysztof says makes sense, but rather than just throwing a yak at
>> Jingyi, it would be nice if you provided some guidance on how you would
>> like to see this turn out.
> 
> I tested, pretty same approach seems to work:
> 
> 	sram@14680000 {
> 		compatible = "mmio-sram";
> 		reg = <0x0 0x14680000 0x0 0x1000>;
> 		ranges = <0 0 0x14680000 0x1000>;
> 
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 
> 		pil-reloc-sram@94c {
> 			compatible = "qcom,pil-reloc-info";
> 			reg = <0x94c 0xc8>;
> 		};
> 	};
> 
> 

Thanks for clarify, I will drop this patch and make the change in dt.
Meanwhile change in sram.yaml should also be required.

Thanks,
Jingyi