arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

[PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

Posted by Ayushi Makhija 1 week, 4 days ago

The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.

Signed-off-by: Ayushi Makhija <quic_amakhija@quicinc.com>
---
 arch/arm64/boot/dts/qcom/sm8750-mtp.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
index 3837f6785320..6ba4e69bf377 100644
--- a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
+++ b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
@@ -462,7 +462,7 @@ vreg_l11b_1p0: ldo11 {
 
 		vreg_l12b_1p8: ldo12 {
 			regulator-name = "vreg_l12b_1p8";
-			regulator-min-microvolt = <1200000>;
+			regulator-min-microvolt = <1650000>;
 			regulator-max-microvolt = <1800000>;
 			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
 			regulator-allow-set-load;
-- 
2.34.1

Re: [PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

Posted by Bjorn Andersson 1 week, 3 days ago

On Mon, Mar 23, 2026 at 03:52:29PM +0530, Ayushi Makhija wrote:
> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.
> 

Please add Fixes: tag.

> Signed-off-by: Ayushi Makhija <quic_amakhija@quicinc.com>

Please start using your oss.qualcomm.com address.

> ---
>  arch/arm64/boot/dts/qcom/sm8750-mtp.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> index 3837f6785320..6ba4e69bf377 100644
> --- a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> +++ b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> @@ -462,7 +462,7 @@ vreg_l11b_1p0: ldo11 {
>  
>  		vreg_l12b_1p8: ldo12 {
>  			regulator-name = "vreg_l12b_1p8";
> -			regulator-min-microvolt = <1200000>;
> +			regulator-min-microvolt = <1650000>;

Are you sure it's not supposed to be 1.8V, given the name of the rail?

Regards,
Bjorn

>  			regulator-max-microvolt = <1800000>;
>  			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
>  			regulator-allow-set-load;
> -- 
> 2.34.1
>

Re: [PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

Posted by Ayushi Makhija 1 week, 1 day ago

On 3/24/2026 7:34 AM, Bjorn Andersson wrote:
> On Mon, Mar 23, 2026 at 03:52:29PM +0530, Ayushi Makhija wrote:
>> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
>> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.
>>
> 
> Please add Fixes: tag.
> 

Hi Bjorn,

Sure, will add in new patchset.

>> Signed-off-by: Ayushi Makhija <quic_amakhija@quicinc.com>
> 
> Please start using your oss.qualcomm.com address.
> 
>> ---
>>  arch/arm64/boot/dts/qcom/sm8750-mtp.dts | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
>> index 3837f6785320..6ba4e69bf377 100644
>> --- a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
>> +++ b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
>> @@ -462,7 +462,7 @@ vreg_l11b_1p0: ldo11 {
>>  
>>  		vreg_l12b_1p8: ldo12 {
>>  			regulator-name = "vreg_l12b_1p8";
>> -			regulator-min-microvolt = <1200000>;
>> +			regulator-min-microvolt = <1650000>;
> 
> Are you sure it's not supposed to be 1.8V, given the name of the rail?
> 
> Regards,
> Bjorn

There was already discussion regarding the minimum voltage for this regulator on sm8550 target
on other upstream patch. 

Link: https://lore.kernel.org/all/aQQdQoCLeKhYtY7W@yuanjiey.ap.qualcomm.com/

This values is according to the NT37801 panel sec
"The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states 
VDDI=1.65V~1.95V."

Thanks,
Ayushi

>>  			regulator-max-microvolt = <1800000>;
>>  			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
>>  			regulator-allow-set-load;
>> -- 
>> 2.34.1
>>

Re: [PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

Posted by Bjorn Andersson 1 week, 1 day ago

On Thu, Mar 26, 2026 at 03:06:52PM +0530, Ayushi Makhija wrote:
> On 3/24/2026 7:34 AM, Bjorn Andersson wrote:
> > On Mon, Mar 23, 2026 at 03:52:29PM +0530, Ayushi Makhija wrote:
> >> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
> >> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.
> >>
> > 
> > Please add Fixes: tag.
> > 
> 
> Hi Bjorn,
> 
> Sure, will add in new patchset.
> 
> >> Signed-off-by: Ayushi Makhija <quic_amakhija@quicinc.com>
> > 
> > Please start using your oss.qualcomm.com address.
> > 
> >> ---
> >>  arch/arm64/boot/dts/qcom/sm8750-mtp.dts | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> >> index 3837f6785320..6ba4e69bf377 100644
> >> --- a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> >> +++ b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
> >> @@ -462,7 +462,7 @@ vreg_l11b_1p0: ldo11 {
> >>  
> >>  		vreg_l12b_1p8: ldo12 {
> >>  			regulator-name = "vreg_l12b_1p8";
> >> -			regulator-min-microvolt = <1200000>;
> >> +			regulator-min-microvolt = <1650000>;
> > 
> > Are you sure it's not supposed to be 1.8V, given the name of the rail?
> > 
> > Regards,
> > Bjorn
> 
> There was already discussion regarding the minimum voltage for this regulator on sm8550 target
> on other upstream patch. 
> 
> Link: https://lore.kernel.org/all/aQQdQoCLeKhYtY7W@yuanjiey.ap.qualcomm.com/
> 
> This values is according to the NT37801 panel sec
> "The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states 
> VDDI=1.65V~1.95V."
> 

Yes, so the panel requires 1.65V, so regulator-min-microvolt needs to be
at least that. But regulator-min-microvolt should account for all the
consumers of the rail, are there any others?

Which leads me to my question, the people designing the board named the
rail VREG_L12B_1P8 in the schematics, why didn't they name it
VREG_L12B_1P65?

Please check all the consumers and make the regulator-min-microvolt work
for all of them - if that's 1.65V, then your change is good.

Regards,
Bjorn

> Thanks,
> Ayushi
> 
> >>  			regulator-max-microvolt = <1800000>;
> >>  			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
> >>  			regulator-allow-set-load;
> >> -- 
> >> 2.34.1
> >>
>

Re: [PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

Posted by Ayushi Makhija 1 week, 1 day ago

On 3/24/2026 7:34 AM, Bjorn Andersson wrote:
> On Mon, Mar 23, 2026 at 03:52:29PM +0530, Ayushi Makhija wrote:
>> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
>> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.
>>
> 
> Please add Fixes: tag.

Hi Bjorn,

Sure, will add in new patchset.

> 
>> Signed-off-by: Ayushi Makhija <quic_amakhija@quicinc.com>
> 
> Please start using your oss.qualcomm.com address.
> 
>> ---
>>  arch/arm64/boot/dts/qcom/sm8750-mtp.dts | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
>> index 3837f6785320..6ba4e69bf377 100644
>> --- a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
>> +++ b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts
>> @@ -462,7 +462,7 @@ vreg_l11b_1p0: ldo11 {
>>  
>>  		vreg_l12b_1p8: ldo12 {
>>  			regulator-name = "vreg_l12b_1p8";
>> -			regulator-min-microvolt = <1200000>;
>> +			regulator-min-microvolt = <1650000>;
> 
> Are you sure it's not supposed to be 1.8V, given the name of the rail?
> 
> Regards,
> Bjorn
> 

There was already discussion regarding the minimum voltage for this regulator for sm8550 target
on other upstream patch. Attaching the link of the patch.


This values is according to the NT37801 panel sec
"The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states 
VDDI=1.65V~1.95V."

Thanks,
Ayushi

>>  			regulator-max-microvolt = <1800000>;
>>  			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
>>  			regulator-allow-set-load;
>> -- 
>> 2.34.1
>>

Re: [PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

Posted by Dmitry Baryshkov 1 week, 3 days ago

On Mon, Mar 23, 2026 at 03:52:29PM +0530, Ayushi Makhija wrote:
> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.
> 
> Signed-off-by: Ayushi Makhija <quic_amakhija@quicinc.com>

Please switch to oss.qualcomm.com

Other than that:

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>



-- 
With best wishes
Dmitry

Re: [PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801

Posted by Konrad Dybcio 1 week, 4 days ago

On 3/23/26 11:22 AM, Ayushi Makhija wrote:
> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states
> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801.
> 
> Signed-off-by: Ayushi Makhija <quic_amakhija@quicinc.com>
> ---

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

Konrad