Re: [PATCH 3/4] rtc: ds1307: add calibration of_ for mt41txx chips.

[Rob Herring <robh+dt@kernel.org>]

On Tue, May 8, 2018 at 9:56 AM, Giulio Benetti
<giulio.benetti@micronovasrl.com> wrote:
> m41txx chips can hold a calibration value to get really near to real
> tick value.

Typo in the subject.

> Add calibration property(ranging between (-31) and 31), so on every probe
> calibration value will be written to rtc.
> This is because ic could loose supply due to low battery.
>
> Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
> ---
>  .../devicetree/bindings/rtc/rtc-ds1307.txt    |  2 ++

Put all the binding changes in separate patch (or maybe 2: new
compatible and new properties).

>  drivers/rtc/rtc-ds1307.c                      | 33 +++++++++++++++++++
>  2 files changed, 35 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt
> index ce6469c1a516..d3d70a5495c5 100644
> --- a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt
> +++ b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt
> @@ -34,6 +34,8 @@ Optional properties:
>  - trickle-diode-disable : ds1339, ds1340 and ds 1388 only
>         Do not use internal trickle charger diode
>         Should be given if internal trickle charger diode should be disabled
> +- calibration: m41t0, m41t00, m41t11 only

Needs a vendor prefix.

Calibration of what and what are the units?

> +       Set calibration value to correct external bias, ranging between (-31) and 31.
>
>  Example:
>         rtc1: ds1339@68 {