Re: [PATCH v4 8/8] arm64: dts: qcom: sc7180: Update QUSB2 V2 Phy params for SC7180 IDP device

[Doug Anderson]

Hi,

On Mon, Feb 3, 2020 at 4:53 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
>
> Quoting Sandeep Maheswaram (2020-01-29 05:51:59)
> > Overriding the QUSB2 V2 Phy tuning parameters for SC7180 IDP device.
> >
> > Signed-off-by: Sandeep Maheswaram <sanm@xxxxxxxxxxxxxx>
> > ---
> >  arch/arm64/boot/dts/qcom/sc7180-idp.dts | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sc7180-idp.dts b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
> > index 388f50a..826cf02 100644
> > --- a/arch/arm64/boot/dts/qcom/sc7180-idp.dts
> > +++ b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
> > @@ -276,9 +276,11 @@
> >         vdda-pll-supply = <&vreg_l11a_1p8>;
> >         vdda-phy-dpdm-supply = <&vreg_l17a_3p0>;
> >         qcom,imp-res-offset-value = <8>;
> > -       qcom,hstx-trim-value = <QUSB2_V2_HSTX_TRIM_21_6_MA>;
> > -       qcom,preemphasis-level = <QUSB2_V2_PREEMPHASIS_5_PERCENT>;
> > +       qcom,preemphasis-level = <QUSB2_V2_PREEMPHASIS_15_PERCENT>;
> >         qcom,preemphasis-width = <QUSB2_V2_PREEMPHASIS_WIDTH_HALF_BIT>;
> > +       qcom,bias-ctrl-value = <0x22>;
> > +       qcom,charge-ctrl-value = <3>;
> > +       qcom,hsdisc-trim-value = <0>;
>
> Actually, I'd prefer it uses /bits/ 8 here if it's just 8 bits.

I have been giving the opposite advice and I thought in general Rob H
suggests against adding "/bits/ 8" unless it's absolutely needed (like
for an array).

One example from
<http://lore.kernel.org/r/97cd8c1d98d7406347e4e48f4c7383a394a2ae93.1451997697.git.oreste.salerno@xxxxxxxxxx>

> > + lp_intrvl = /bits/ 8 <0x0A>;
>
> If the size is not 32-bits, you need to state that in the description.
> There is not really much point in making these 8-bit though.

-Doug