2019年10月30日(水) 23:24 Rob Herring <robh@xxxxxxxxxx>: > > 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? This doesn't require a specific hardware. If there are more than two LEDs that can be described by devicetree, it can be an LED level meter by bundling them up with this binding. > > 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. OK. I'll rewrite the description. > Each LED could have variable brightness, so you could also ramp the > brightness for an individual LED. For now, each LED is set to 0 or max brightness. Maybe we should set middle brightness value for an LED on the border line.
