October 1, 2025 at 9:09 AM, "Konrad Dybcio" <[email protected] 
mailto:[email protected]?to=%22Konrad%20Dybcio%22%20%3Ckonrad.dybcio%40oss.qualcomm.com%3E
 > wrote:


> 
> On 9/29/25 7:05 AM, Paul Sajna wrote:
> 
> > 
> > These regulators seemingly help the lcd to work better
> > 
> Electronics generally work better when the required power supplies
> are enabled..
> 
> > 
> > Signed-off-by: Paul Sajna <[email protected]>
> >  ---
> >  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 
> > 3106fdc9b679bc6a43a1a490c61b73a63003f7e1..9c3662a3d93e124667474753e0f11d0e98698aa0
> >  100644
> >  --- a/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> >  +++ b/arch/arm64/boot/dts/qcom/sdm845-lg-judyln.dts
> >  @@ -48,10 +48,27 @@ zap-shader {
> >  };
> >  };
> >  
> >  +&ibb {
> >  + regulator-min-microvolt = <4600000>;
> >  + regulator-max-microvolt = <6000000>;
> >  + 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 = <4600000>;
> >  + regulator-max-microvolt = <6000000>;
> >  + regulator-over-current-protection;
> >  + regulator-pull-down;
> >  + regulator-soft-start;
> >  +};
> > 
> This patch will allow any values between 4.6 V and 6.0 V to
> be set on your phone, with the kernel defaulting to 4.6 V at
> boot and staying there until (if?) any driver requests that to
> change.
> 
> Your panel probably expects a *very* specific pair of voltages
> and any deviation may cause unpredictable consequences, including
> magic smoke if you happen to go over a certain limit.
> 
> You should most likely hardcode that specific expected voltage here
> 
> Konrad
>

Here is the decompiled downstream dts.

qcom,ibb@dc00 {
                                                qcom,qpnp-ibb-init-voltage = 
<0x53ec60>;
                                                
qcom,qpnp-ibb-init-amoled-voltage = "", "=\t";
                                                qcom,qpnp-ibb-soft-start = 
<0x3e8>;
                                                
qcom,qpnp-ibb-use-default-voltage;
                                                qcom,qpnp-ibb-init-lcd-voltage 
= <0x53ec60>;
                                                reg-names = "ibb_reg";
                                                qcom,qpnp-ibb-slew-rate = 
<0x1e8480>;
                                                qcom,qpnp-ibb-en-discharge;
                                                qcom,qpnp-ibb-ps-enable;
                                                
qcom,qpnp-ibb-limit-max-current-enable;
                                                interrupts = <0x03 0xdc 0x02 
0x01>;
                                                qcom,qpnp-ibb-lab-pwrup-delay = 
<0x3e8>;
                                                phandle = <0x4ec>;
                                                qcom,qpnp-ibb-debounce-cycle = 
<0x10>;
                                                regulator-min-microvolt = 
<0x4630c0>;
                                                
qcom,qpnp-ibb-limit-maximum-current = <0x60e>;
                                                reg = <0xdc00 0x100>;
                                                regulator-max-microvolt = 
<0x5b8d80>;
                                                qcom,qpnp-ibb-step-size = 
<0x186a0>;
                                                qcom,qpnp-ibb-full-pull-down;
                                                
qcom,qpnp-ibb-switching-clock-frequency = <0x5c8>;
                                                regulator-name = "ibb_reg";
                                                interrupt-names = "ibb-sc-err";
                                                qcom,qpnp-ibb-min-voltage = 
<0x155cc0>;
                                                qcom,qpnp-ibb-pull-down-enable;
                                                qcom,qpnp-ibb-lab-pwrdn-delay = 
<0x7d0>;
                                        };
                                };

Should I use the init-voltage for min and max microvolt?

Reply via email to