[v5] arm64: dts: qcom: sdm845-lg-{common, judyln}: Improve HW support in dts

[PATCH v5 10/12] arm64: dts: qcom: sdm845-lg-judyln: Add lab/ibb

Posted by Paul Sajna 1 week, 6 days ago

These regulators are required for the LCD

Signed-off-by: Paul Sajna <sajattack@postmarketos.org>
---
 arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
index 8b88f75b36af..cdaf84de5e6c 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
+++ b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
@@ -56,10 +56,27 @@ zap-shader {
 	};
 };
 
+&ibb {
+	regulator-min-microvolt = <5500000>;
+	regulator-max-microvolt = <5700000>;
+	regulator-over-current-protection;
+	regulator-pull-down;
+	regulator-soft-start;
+	qcom,discharge-resistor-kohms = <300>;
+};
+
 &ipa {
 	firmware-name = "qcom/sdm845/lg/judyln/ipa_fws.mbn";
 };
 
+&lab {
+	regulator-min-microvolt = <5500000>;
+	regulator-max-microvolt = <5700000>;
+	regulator-over-current-protection;
+	regulator-pull-down;
+	regulator-soft-start;
+};
+
 &mdss {
 	status = "okay";
 };

-- 
2.52.0

Re: [PATCH v5 10/12] arm64: dts: qcom: sdm845-lg-judyln: Add lab/ibb

Posted by Konrad Dybcio 1 week, 5 days ago

On 12/3/25 10:40 AM, Paul Sajna wrote:
> These regulators are required for the LCD
> 
> Signed-off-by: Paul Sajna <sajattack@postmarketos.org>
> ---
>  arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> index 8b88f75b36af..cdaf84de5e6c 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> @@ -56,10 +56,27 @@ zap-shader {
>  	};
>  };
>  
> +&ibb {
> +	regulator-min-microvolt = <5500000>;
> +	regulator-max-microvolt = <5700000>;

These ranges seem much more reasonable, although I would still
expect there's a single operational voltage - unless the panel driver
is supposed to call regulator_set_voltage() in some different power
modes?

Konrad

Re: [PATCH v5 10/12] arm64: dts: qcom: sdm845-lg-judyln: Add lab/ibb

Posted by Paul Sajna 1 week, 5 days ago

December 4, 2025 at 12:50 PM, "Konrad Dybcio" <konrad.dybcio@oss.qualcomm.com mailto:konrad.dybcio@oss.qualcomm.com?to=%22Konrad%20Dybcio%22%20%3Ckonrad.dybcio%40oss.qualcomm.com%3E > wrote:


> 
> On 12/3/25 10:40 AM, Paul Sajna wrote:
> 
> > 
> > These regulators are required for the LCD
> >  
> >  Signed-off-by: Paul Sajna <sajattack@postmarketos.org>
> >  ---
> >  arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts | 17 +++++++++++++++++
> >  1 file changed, 17 insertions(+)
> >  
> >  diff --git a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> >  index 8b88f75b36af..cdaf84de5e6c 100644
> >  --- a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> >  +++ b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> >  @@ -56,10 +56,27 @@ zap-shader {
> >  };
> >  };
> >  
> >  +&ibb {
> >  + regulator-min-microvolt = <5500000>;
> >  + regulator-max-microvolt = <5700000>;
> > 
> These ranges seem much more reasonable, although I would still
> expect there's a single operational voltage - unless the panel driver
> is supposed to call regulator_set_voltage() in some different power
> modes?
> 
> Konrad
>

So min/max both 55? Or is there another property I should use?
I wasn't sure if that would be physically hard for the regulator to maintain such precision, so I cross-referenced some other DTs in the qcom folder and found this 200mv allowance in one of the sony devices.

Re: [PATCH v5 10/12] arm64: dts: qcom: sdm845-lg-judyln: Add lab/ibb

Posted by Konrad Dybcio 1 week, 4 days ago

On 12/4/25 7:47 PM, Paul Sajna wrote:
> December 4, 2025 at 12:50 PM, "Konrad Dybcio" <konrad.dybcio@oss.qualcomm.com mailto:konrad.dybcio@oss.qualcomm.com?to=%22Konrad%20Dybcio%22%20%3Ckonrad.dybcio%40oss.qualcomm.com%3E > wrote:
> 
> 
>>
>> On 12/3/25 10:40 AM, Paul Sajna wrote:
>>
>>>
>>> These regulators are required for the LCD
>>>  
>>>  Signed-off-by: Paul Sajna <sajattack@postmarketos.org>
>>>  ---
>>>  arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts | 17 +++++++++++++++++
>>>  1 file changed, 17 insertions(+)
>>>  
>>>  diff --git a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
>>>  index 8b88f75b36af..cdaf84de5e6c 100644
>>>  --- a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
>>>  +++ b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
>>>  @@ -56,10 +56,27 @@ zap-shader {
>>>  };
>>>  };
>>>  
>>>  +&ibb {
>>>  + regulator-min-microvolt = <5500000>;
>>>  + regulator-max-microvolt = <5700000>;
>>>
>> These ranges seem much more reasonable, although I would still
>> expect there's a single operational voltage - unless the panel driver
>> is supposed to call regulator_set_voltage() in some different power
>> modes?
>>
>> Konrad
>>
> 
> So min/max both 55? Or is there another property I should use?
> I wasn't sure if that would be physically hard for the regulator to maintain such precision, so I cross-referenced some other DTs in the qcom folder and found this 200mv allowance in one of the sony devices.

These regulators are very accurate - set it to 5.5

Konrad