Re: [PATCH 2/5] Documentation: devicetree: Add property for controlling power saving mode for the us5182 als sensor

Rob Herring
2015-11-25T00:01:30Z

On Tue, Nov 24, 2015 at 12:59:49PM +0200, Adriana Reus wrote:
> Add a property to allow changing the default power-saving mode.
> By default, at read raw the chip will activate and provide
> one measurent, then it will shut itself down. However, the
> chip can also work in "continuous" mode which may be more reliable
> but is also more power consuming.
>
> Signed-off-by: Adriana Reus <adriana.reus-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
> Documentation/devicetree/bindings/iio/light/us5182d.txt | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iio/light/us5182d.txt b/Documentation/devicetree/bindings/iio/light/us5182d.txt
> index 6f0a530..a619799 100644
> --- a/Documentation/devicetree/bindings/iio/light/us5182d.txt
> +++ b/Documentation/devicetree/bindings/iio/light/us5182d.txt
> @@ -7,13 +7,24 @@ Required properties:
> Optional properties:
> - upisemi,glass-coef: glass attenuation factor - compensation factor of
> resolution 1000 for material transmittance.
> +
> - upisemi,dark-ths: array of 8 elements containing 16-bit thresholds (adc
> counts) corresponding to every scale.
> +
> - upisemi,upper-dark-gain: 8-bit dark gain compensation factor(4 int and 4
> fractional bits - Q4.4) applied when light > threshold
> +
> - upisemi,lower-dark-gain: 8-bit dark gain compensation factor(4 int and 4
> fractional bits - Q4.4) applied when light < threshold
>
> +- upisemi,continuous: This chip has two power modes: one-shot (chip takes one
> + measurement and then shuts itself down) and continuous (
> + chip takes continuous measurements). The one-shot mode is
> + more power-friendly but the continuous mode may be more
> + reliable. If this property is specified the continuous
> + mode will be used instead of the default one-shot one for
> + raw reads.

I could imagine an OS may want to decide this on its own or use a
mixture of the modes.

Rob