1. Add drive strength property for mi2s1 on sc7280 based platforms.
2. Disbale the pull-up mi2s1_data0, mi2s1_sclk.
Signed-off-by: Judy Hsiao <[email protected]>
---
arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
index 9cb1bc8ed6b5..6d8744e130b0 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
@@ -612,6 +612,20 @@ &dp_hot_plug_det {
bias-disable;
};
+&mi2s1_data0 {
+ drive-strength = <6>;
+ bias-disable;
+};
+
+&mi2s1_sclk {
+ drive-strength = <6>;
+ bias-disable;
+};
+
+&mi2s1_ws {
+ drive-strength = <6>;
+};
+
&pcie1_clkreq_n {
bias-pull-up;
drive-strength = <2>;
--
2.36.1.124.g0e6072fb45-goog
Hi,
On Fri, May 20, 2022 at 2:01 PM Stephen Boyd <[email protected]> wrote:
>
> Quoting Doug Anderson (2022-05-20 13:39:21)
> > On Fri, May 20, 2022 at 1:38 PM Stephen Boyd <[email protected]> wrote:
> > >
> > > Quoting Judy Hsiao (2022-05-20 09:10:02)
> > > > +};
> > > > +
> > > > +&mi2s1_sclk {
> > > > + drive-strength = <6>;
> > > > + bias-disable;
> > >
> > > Is there an external pull on this line? If so please add that details as
> > > a comment like we do for other external pulls.
> >
> > Actually, I think they are output lines, which is why they have a
> > drive-strength. I think for output lines we don't usually comment
> > about why we're disabling the pulls, only for input lines?
>
> Ok makes sense. Even for an open drain signal it would be an "input" so
> that rule still applies?
I think open drain is mostly used for bidirectional signals, like i2c
lines. In that case then you're right, you can have a drive-strength
and a pull. ...I thought i2s was not bidirectoinal and not open-drain,
but I certainly could be wrong.
-Doug
On Fri, May 20, 2022 at 04:10:02PM +0000, Judy Hsiao wrote:
> 1. Add drive strength property for mi2s1 on sc7280 based platforms.
> 2. Disbale the pull-up mi2s1_data0, mi2s1_sclk.
>
> Signed-off-by: Judy Hsiao <[email protected]>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Quoting Judy Hsiao (2022-05-20 09:10:02)
> 1. Add drive strength property for mi2s1 on sc7280 based platforms.
> 2. Disbale the pull-up mi2s1_data0, mi2s1_sclk.
s/Disbale/Disable/
The commit text is a list of things done but no reason why they're done.
I'd appreciate more freeform text with a blurb why a drive strength is
chosen and why pulls are disabled.
> Signed-off-by: Judy Hsiao <[email protected]>
> ---
> arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> index 9cb1bc8ed6b5..6d8744e130b0 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> @@ -612,6 +612,20 @@ &dp_hot_plug_det {
> bias-disable;
> };
>
> +&mi2s1_data0 {
> + drive-strength = <6>;
> + bias-disable;
Is there an external pull on this line?
> +};
> +
> +&mi2s1_sclk {
> + drive-strength = <6>;
> + bias-disable;
Is there an external pull on this line? If so please add that details as
a comment like we do for other external pulls.
> +};
Hi,
On Fri, May 20, 2022 at 9:10 AM Judy Hsiao <[email protected]> wrote:
>
> 1. Add drive strength property for mi2s1 on sc7280 based platforms.
> 2. Disbale the pull-up mi2s1_data0, mi2s1_sclk.
>
> Signed-off-by: Judy Hsiao <[email protected]>
> ---
> arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> index 9cb1bc8ed6b5..6d8744e130b0 100644
> --- a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> @@ -612,6 +612,20 @@ &dp_hot_plug_det {
> bias-disable;
> };
>
> +&mi2s1_data0 {
> + drive-strength = <6>;
> + bias-disable;
> +};
> +
> +&mi2s1_sclk {
> + drive-strength = <6>;
> + bias-disable;
> +};
> +
> +&mi2s1_ws {
> + drive-strength = <6>;
> +};
I'm actually curious why this line has a drive-strength but _no_ bias
setting. I guess I should figure out what the heck "ws" is. Ah, I
guess it is word select.
Since this is an output I'd expect to see "bias-disable" here too.
-Doug
Hi,
On Fri, May 20, 2022 at 1:38 PM Stephen Boyd <[email protected]> wrote:
>
> Quoting Judy Hsiao (2022-05-20 09:10:02)
> > 1. Add drive strength property for mi2s1 on sc7280 based platforms.
> > 2. Disbale the pull-up mi2s1_data0, mi2s1_sclk.
>
> s/Disbale/Disable/
>
> The commit text is a list of things done but no reason why they're done.
> I'd appreciate more freeform text with a blurb why a drive strength is
> chosen and why pulls are disabled.
>
> > Signed-off-by: Judy Hsiao <[email protected]>
> > ---
> > arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> > index 9cb1bc8ed6b5..6d8744e130b0 100644
> > --- a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
> > @@ -612,6 +612,20 @@ &dp_hot_plug_det {
> > bias-disable;
> > };
> >
> > +&mi2s1_data0 {
> > + drive-strength = <6>;
> > + bias-disable;
>
> Is there an external pull on this line?
>
> > +};
> > +
> > +&mi2s1_sclk {
> > + drive-strength = <6>;
> > + bias-disable;
>
> Is there an external pull on this line? If so please add that details as
> a comment like we do for other external pulls.
Actually, I think they are output lines, which is why they have a
drive-strength. I think for output lines we don't usually comment
about why we're disabling the pulls, only for input lines?
-Doug