Re: [PATCH] arm64: dts: exynos850: Add SRAM node

[Krzysztof Kozlowski <krzk@kernel.org>]

On 14/04/2026 11:00, Alexey Klimov wrote:
> On Mon Apr 13, 2026 at 4:23 PM BST, Krzysztof Kozlowski wrote:
>> On 13/04/2026 16:52, Alexey Klimov wrote:
>>> SRAM is used by the ACPM protocol to retrieve the ACPM channels
>>> information and configuration data. Add the SRAM node.
>>>
>>> Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
>>> ---
>>>  arch/arm64/boot/dts/exynos/exynos850.dtsi | 8 ++++++++
>>>  1 file changed, 8 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
>>> index cb55015c8dce..cf4a6168846c 100644
>>> --- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
>>> +++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
>>> @@ -910,6 +910,14 @@ spi_2: spi@11d20000 {
>>>  			};
>>>  		};
>>>  	};
>>> +
>>> +	apm_sram: sram@2039000 {
>>> +		compatible = "mmio-sram";
>>> +		reg = <0x0 0x2039000 0x40000>;
>>> +		#address-cells = <1>;
>>> +		#size-cells = <1>;
>>> +		ranges = <0x0 0x0 0x2039000 0x40000>;
>>
>> You miss here children.
> 
> Thank you! I guess I should convert it to smth like this:
> 
> apm_sram: sram@2039000 {
> 		compatible = "mmio-sram";
> 		reg = <0x0 0x2039000 0x40000>;
> 		ranges = <0x0 0x0 0x2039000 0x40000>;
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 
> 		acpm_sram_region: sram-section@0 {
> 			reg = <0x0 0x40000>;

This covers entire block, so feels pointless. Maybe requirement of
children should be dropped. What's the point of having children? Why
does the driver need them?

> 		};
> 	};
> 
> And then later reference shmem = &acpm_sram_region from acpm node.
> 
>> Also, 'ranges' should be after 'reg'.
> 
> Thanks, will fix this.
> 
> FWIW this commit is a copy of commit 48e7821b26904
> https://lore.kernel.org/r/20250207-gs101-acpm-dt-v4-1-230ba8663a2d@linaro.org


Huh, we should fix that one as well.


Best regards,
Krzysztof