On Sun, Oct 27, 2019 at 11:09:38PM +0900, Akinobu Mita wrote: > Add DT binding for generic LED level meter which consists of multiple LED > devices by different drivers. Do you have some pointers to actual h/w? > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Bjorn Andersson <bjorn@xxxxxxx> > Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx> > Cc: Jean-Jacques Hiblot <jjhiblot@xxxxxx> > Cc: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> > Cc: Pavel Machek <pavel@xxxxxx> > Cc: Dan Murphy <dmurphy@xxxxxx> > Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx> > --- > .../devicetree/bindings/leds/leds-meter.yaml | 67 ++++++++++++++++++++++ > 1 file changed, 67 insertions(+) > create mode 100644 Documentation/devicetree/bindings/leds/leds-meter.yaml > > diff --git a/Documentation/devicetree/bindings/leds/leds-meter.yaml b/Documentation/devicetree/bindings/leds/leds-meter.yaml > new file mode 100644 > index 0000000..b5fcd98 > --- /dev/null > +++ b/Documentation/devicetree/bindings/leds/leds-meter.yaml > @@ -0,0 +1,67 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/leds/leds-meter.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Generic LED level meter > + > +maintainers: > + - Akinobu Mita <akinobu.mita@xxxxxxxxx> > + > +description: > + Generic LED level meter consists of multiple LED devices by different drivers. Googling this, the only thing I see is audio level meters though those are all just a voltage level input, so it could be any source I guess. > + > +properties: > + $nodename: > + pattern: "^meter-leds(@.*)?" > + > + compatible: > + const: meter-leds > + > + leds: > + allOf: > + - $ref: /schemas/types.yaml#/definitions/phandle-array > + description: List of phandles to LED node that are members of a level meter. > + > + brightness-weights: > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32-array > + description: | > + By default, the brightness of the LED level meter is proportional to the > + number of actual LEDs that are turned on. We can optionally specify > + the contribution ratio for each LED within a level meter by this > + property. The example below shows how to setup an exponential > + relationship between the number of LEDs turned on and the brightness of > + meter-leds. This seems oddly named if this is a bar graph. Yes, more LEDs on is brighter, but it's really a piecewise linear graph you want. Each LED could have variable brightness, so you could also ramp the brightness for an individual LED. Rob
