| Message ID | 20201116135305.81319-3-jacopo+renesas@jmondi.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | media: i2c: Add RDACM21 camera module | expand |
Hello, On Mon, Nov 30, 2020 at 03:00:48PM -0700, Rob Herring wrote: > On Mon, Nov 16, 2020 at 02:52:59PM +0100, Jacopo Mondi wrote: > > Document the 'initial-reverse-channel-mV' 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@ideasonboard.com> > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > --- > > .../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..f61234d204fa 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,initial-reverse-channel-mV: > > Use standard unit suffix. > Which one ? :) I see in v5.10 one 'mV', three 'mv', one 'millivolts', several 'microvolts'. I'll go with the majority and make this 'maxim,initial-reverse-channel-mv' Thanks j > > + $ref: '/schemas/types.yaml#/definitions/uint32' > > + minimum: 30 > > + maximum: 200 > > + default: 170 > > + description: | > > + Initial amplitude of the reverse control channel, in millivolts. > > + > > + 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 170mV. > > + > > + A typical value for the reverse channel amplitude to communicate with > > + a remote serializer whose high-threshold noise immunity is not enabled > > + is 100mV. > > + > > ports: > > type: object > > description: | > > @@ -221,6 +241,7 @@ required: > > - ports > > - i2c-mux > > - gpio-controller > > + - maxim,initial-reverse-channel-mV > > > > additionalProperties: false > > > > @@ -243,6 +264,8 @@ examples: > > gpio-controller; > > #gpio-cells = <2>; > > > > + maxim,initial-reverse-channel-mV = <170>; > > + > > ports { > > #address-cells = <1>; > > #size-cells = <0>; > > -- > > 2.29.1 > >
Hi Jacopo, On Tue, Dec 15, 2020 at 12:14 PM Jacopo Mondi <jacopo@jmondi.org> wrote: > On Mon, Nov 30, 2020 at 03:00:48PM -0700, Rob Herring wrote: > > On Mon, Nov 16, 2020 at 02:52:59PM +0100, Jacopo Mondi wrote: > > > Document the 'initial-reverse-channel-mV' 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@ideasonboard.com> > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > > --- > > > .../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..f61234d204fa 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,initial-reverse-channel-mV: > > > > Use standard unit suffix. > > > > Which one ? :) Documentation/devicetree/bindings/property-units.txt > I see in v5.10 one 'mV', three 'mv', one 'millivolts', several > 'microvolts'. > > I'll go with the majority and make this > 'maxim,initial-reverse-channel-mv' Wrong guess ;-) Gr{oetje,eeting}s, Geert
Hi Geert, On Tue, Dec 15, 2020 at 12:44:17PM +0100, Geert Uytterhoeven wrote: > Hi Jacopo, > > On Tue, Dec 15, 2020 at 12:14 PM Jacopo Mondi <jacopo@jmondi.org> wrote: > > On Mon, Nov 30, 2020 at 03:00:48PM -0700, Rob Herring wrote: > > > On Mon, Nov 16, 2020 at 02:52:59PM +0100, Jacopo Mondi wrote: > > > > Document the 'initial-reverse-channel-mV' 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@ideasonboard.com> > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > > > --- > > > > .../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..f61234d204fa 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,initial-reverse-channel-mV: > > > > > > Use standard unit suffix. > > > > > > > Which one ? :) > > Documentation/devicetree/bindings/property-units.txt > Oh, I had no idea we have this. It's been here since a long time it seems, my bad Date: Mon Feb 8 10:55:55 2016 > > I see in v5.10 one 'mV', three 'mv', one 'millivolts', several > > 'microvolts'. > > > > I'll go with the majority and make this > > 'maxim,initial-reverse-channel-mv' > > Wrong guess ;-) > Maybe a stupid question, but the fact only 'microvolts' is listed, is an implied suggestion to use 'millivolts' for simmetry or to express the value in micro volts ? > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds
On Tue, Dec 15, 2020 at 6:08 AM Jacopo Mondi <jacopo@jmondi.org> wrote: > > Hi Geert, > > On Tue, Dec 15, 2020 at 12:44:17PM +0100, Geert Uytterhoeven wrote: > > Hi Jacopo, > > > > On Tue, Dec 15, 2020 at 12:14 PM Jacopo Mondi <jacopo@jmondi.org> wrote: > > > On Mon, Nov 30, 2020 at 03:00:48PM -0700, Rob Herring wrote: > > > > On Mon, Nov 16, 2020 at 02:52:59PM +0100, Jacopo Mondi wrote: > > > > > Document the 'initial-reverse-channel-mV' 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@ideasonboard.com> > > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > > > > --- > > > > > .../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..f61234d204fa 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,initial-reverse-channel-mV: > > > > > > > > Use standard unit suffix. > > > > > > > > > > Which one ? :) > > > > Documentation/devicetree/bindings/property-units.txt > > > > Oh, I had no idea we have this. > It's been here since a long time it seems, my bad > Date: Mon Feb 8 10:55:55 2016 > > > > I see in v5.10 one 'mV', three 'mv', one 'millivolts', several > > > 'microvolts'. > > > > > > I'll go with the majority and make this > > > 'maxim,initial-reverse-channel-mv' > > > > Wrong guess ;-) > > > > Maybe a stupid question, but the fact only 'microvolts' is listed, is > an implied suggestion to use 'millivolts' for simmetry or to express > the value in micro volts ? Use microvolts. Not having every possible unit is on purpose. Rob
diff --git a/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml b/Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml index 9ea827092fdd..f61234d204fa 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,initial-reverse-channel-mV: + $ref: '/schemas/types.yaml#/definitions/uint32' + minimum: 30 + maximum: 200 + default: 170 + description: | + Initial amplitude of the reverse control channel, in millivolts. + + 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 170mV. + + A typical value for the reverse channel amplitude to communicate with + a remote serializer whose high-threshold noise immunity is not enabled + is 100mV. + ports: type: object description: | @@ -221,6 +241,7 @@ required: - ports - i2c-mux - gpio-controller + - maxim,initial-reverse-channel-mV additionalProperties: false @@ -243,6 +264,8 @@ examples: gpio-controller; #gpio-cells = <2>; + maxim,initial-reverse-channel-mV = <170>; + ports { #address-cells = <1>; #size-cells = <0>;