Re: [PATCH 4/5] arm64: dts: qcom: r0q: enable hardware clocks

[Eric Gonçalves]

On October 6, 2025 9:31:42 AM GMT-03:00, Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
>On 10/5/25 5:50 AM, Eric Gonçalves wrote:
>> 
>> 
>> On September 25, 2025 10:09:48 AM GMT-03:00, Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
>>> On 9/20/25 3:46 AM, Eric Gonçalves wrote:
>>>> Enable the real-time clocks found in R0Q board.
>>>>
>>>> Signed-off-by: Eric Gonçalves <ghatto404@xxxxxxxxx>
>>>> ---
>>>>  arch/arm64/boot/dts/qcom/sm8450-samsung-r0q.dts | 15 +++++++++++++++
>>>>  1 file changed, 15 insertions(+)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/qcom/sm8450-samsung-r0q.dts b/arch/arm64/boot/dts/qcom/sm8450-samsung-r0q.dts
>>>> index c1b0b21c0ec5..c088f1acf6ea 100644
>>>> --- a/arch/arm64/boot/dts/qcom/sm8450-samsung-r0q.dts
>>>> +++ b/arch/arm64/boot/dts/qcom/sm8450-samsung-r0q.dts
>>>> @@ -225,6 +225,21 @@ vol_up_n: vol-up-n-state {
>>>>  	};
>>>>  };
>>>>  
>>>> +&pmk8350_rtc {
>>>> +	nvmem-cells = <&rtc_offset>;
>>>> +	nvmem-cell-names = "offset";
>>>> +
>>>> +	status = "okay";
>>>> +};
>>>> +
>>>> +&pmk8350_sdam_2 {
>>>> +	status = "okay";
>>>> +
>>>> +	rtc_offset: rtc-offset@bc {
>>>
>>> Is this an offset you took from somewhere downstream?
>>>
>>> Generally you *really don't want to* poke at random SDAM cells,
>>> as they contain a lot of important settings (incl. battery/charging)
>> From another sm8450 device, I'm sure it's okay.
>
>That as an argument alone doesn't sound convincing to me, since vendors
>also sometimes repurpose unused-by-Qualcomm SDAM cells
>
>I actually found a data source internally and this cell you're trying
>to use is reserved for PBS (see drivers/soc/qcom/qcom-pbs.c), meaning
>you already fell into this trap..
Interesting, in this case then why does rtc still work? And
how can I find the real cell? It's not in downstream DT.
>
>Konrad