On Wed, Dec 16, 2020 at 07:05:34PM +0200, Laurent Pinchart wrote:
> Hi Jacopo,
>
> Thank you for the patch.
>
> On Tue, Dec 15, 2020 at 06:09:54PM +0100, Jacopo Mondi wrote:
> > Document the 'reverse-channel-microvolt' vendor property in the
> > bindings document of the max9286 driver.
> >
> > The newly introduced property allows to specifying the initial
> > configuration of the GMSL reverse control channel to accommodate
> > remote serializers pre-programmed with the high threshold power
> > supply noise immunity enabled.
> >
> > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> > ---
> > v5->v6:
> > - Use standard unit suffix 'microvolt' for the custom property
> > - Drop '$ref' as according to 'example-schema.yaml':
> > "Vendor specific properties having a standard unit suffix don't need a type."
> > ---
> > .../bindings/media/i2c/maxim,max9286.yaml | 23 +++++++++++++++++++
> > 1 file changed, 23 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > index 9ea827092fdd..b22ba3e0db4a 100644
> > --- a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > +++ b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
> > @@ -51,6 +51,26 @@ properties:
> > '#gpio-cells':
> > const: 2
> >
> > + maxim,reverse-channel-microvolt:
> > + minimum: 30000
> > + maximum: 200000
> > + default: 170000
> > + description: |
> > + Initial amplitude of the reverse control channel, in micro volts.
> > +
> > + The initial amplitude shall be adjusted to a value compatible with the
> > + configuration of the connected remote serializer.
> > +
> > + Some camera modules (for example RDACM20) include an on-board MCU that
> > + pre-programs the embedded serializer with power supply noise immunity
> > + (high-threshold) enabled. A typical value of the deserializer's reverse
> > + channel amplitude to communicate with pre-programmed serializers is
> > + 170000 micro volts.
> > +
> > + A typical value for the reverse channel amplitude to communicate with
> > + a remote serializer whose high-threshold noise immunity is not enabled
> > + is 100000 micro volts
> > +
> > ports:
> > type: object
> > description: |
> > @@ -221,6 +241,7 @@ required:
> > - ports
> > - i2c-mux
> > - gpio-controller
> > + - maxim,reverse-channel-microvolt
One comment though: You specify a default value above, which isn't very
useful when the property is required. Should we either drop the default
value, or make the property optional ?
> >
> > additionalProperties: false
> >
> > @@ -243,6 +264,8 @@ examples:
> > gpio-controller;
> > #gpio-cells = <2>;
> >
> > + maxim,reverse-channel-microvolt = <170000>;
> > +
> > ports {
> > #address-cells = <1>;
> > #size-cells = <0>;
--
Regards,
Laurent Pinchart
