Re: [PATCH 2/2] backlight: arcxcnn: devicetree bindings for ArticSand devices

From: Rob Herring
Date: Mon Oct 31 2016 - 00:38:25 EST


On Wed, Oct 26, 2016 at 04:30:01PM -0400, Olimpiu Dejeu wrote:
> Resubmition of arcxcnn backliught driver bindings with added register
> documentation
>
> Signed-off-by: Olimpiu Dejeu <olimpiu@xxxxxxxxxxxxxx>
>
> ---
> .../bindings/leds/backlight/arcxcnn_bl.txt | 31 ++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/arcxcnn_bl.txt
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/arcxcnn_bl.txt b/Documentation/devicetree/bindings/leds/backlight/arcxcnn_bl.txt
> new file mode 100644
> index 0000000..a7b6ff2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/arcxcnn_bl.txt
> @@ -0,0 +1,31 @@
> +Binding for ArcticSand arc2c0608 LED driver
> +
> +Required properties:
> +- compatible: should be "arc,arc2c0608"

What's the correct vendor prefix? arc or arcticsand used below?

> +- reg: slave address
> +
> +Optional properties:
> +- default-brightness: brightness value on boot, value from: 0-4095
> +- label: The name of the backlight device
> + See Documentation/devicetree/bindings/leds/common.txt
> +- led-sources: List of enabled channels from 0 to 5.
> + See Documentation/devicetree/bindings/leds/common.txt
> +
> +- arcticsand,led-config-0: setting for register ILED_CONFIG_0
> +- arcticsand,led-config-1: setting for register ILED_CONFIG_1
> +- arcticsand,dim-freq: PWM mode frequence setting (bits [3:0] used)
> +- arcticsand,comp-config: setting for register CONFIG_COMP
> +- arcticsand,filter-config: setting for register FILTER_CONFIG
> +- arcticsand,trim-config: setting for register IMAXTUNE

What are the default values if not present?

What determines these settings? If the board design, then okay. If a
an enduser wants to adjust, then they shouldn't be in DT.

> +
> +Example:
> +
> +arc2c0608@30 {
> + compatible = "arc,arc2c0608";
> + reg = <0x30>;
> + default-brightness = <500>;
> + label = "lcd-backlight";
> + linux,default-trigger = "backlight";
> + led-sources = <0 1 2 5>;
> +};
> +
> --
> 2.7.4
>