Re: [PATCH] arm64: dts: qcs404: evb: Fix voltages for s5 and l3

From: Niklas Cassel
Date: Tue Jan 29 2019 - 17:47:01 EST


Adding Mark Brown on CC.

On Tue, Jan 29, 2019 at 10:58:47PM +0100, Jorge Ramirez wrote:
> On 1/26/19 00:29, Bjorn Andersson wrote:
> > PMS405 S5 was upstreamed without a voltage and PMS405 L3 is outside the
> > acceptable range, causing PCIe to fail. Fix these.
> >
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/qcom/qcs404-evb.dtsi | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi b/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi
> > index 579ddaf4f5fa..072061aa1b79 100644
> > --- a/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/qcs404-evb.dtsi
> > @@ -72,8 +72,8 @@
> > };
> >
> > vreg_s5_1p35: s5 {
> > - regulator-min-microvolt = <>;
> > - regulator-max-microvolt = <>;
> > + regulator-min-microvolt = <1352000>;
> > + regulator-max-microvolt = <1352000>;
> > };
> >
> > vreg_l1_1p3: l1 {
> > @@ -87,7 +87,7 @@
> > };
> >
> > vreg_l3_1p05: l3 {
> > - regulator-min-microvolt = <976000>;
> > + regulator-min-microvolt = <1050000>;
>
>
> the linear range for this regulator is
> - REGULATOR_LINEAR_RANGE(312000, 0, 127, 8000),
>
> meaning that 1050000 is actually not a valid selectable value (ie, after
> applying the above constrains 1056000 would be selected instead)
>
> In order for a driver to be able to successfully request min = 1050000,
> regulator-min-microvolt should be set to 1048000 (and 1056000 would be
> applied)
>
> the question is, should this property contain only hardware achievable
> values? or should drivers only request hardware achievable values? the
> way the constrains are implemented it has to be one of the two (I think
> the former would be more intuitive - ie if the dts
> regulator-min-microvolt is a valid value)
>
> > regulator-max-microvolt = <1160000>;
> > };
> >
> >
>