On Mon, Jul 20, 2020 at 12:23:59PM +0100, miguelborgesdefreitas@xxxxxxxxx wrote:
> From: Miguel Borges de Freitas <miguelborgesdefreitas@xxxxxxxxx>
>
> This adds direct-switching mode as a configurable DT flag for
> RTC modules supporting it (e.g. nxp pcf8523).
> DSM switches the power source to the battery supply whenever the
> VDD drops below VBAT. The option is recommended for hw designs
> where VDD is always expected to be higher than VBAT.
>
> Signed-off-by: Miguel Borges de Freitas <miguelborgesdefreitas@xxxxxxxxx>
> ---
> Changes in v2:
> - Added extended commit message for git history
> - Separate dt bindings documentation into a single patch
>
> Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt | 7 ++++++-
> Documentation/devicetree/bindings/rtc/rtc.yaml | 7 +++++++
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt b/Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt
> index 0b1080c..f715a8f 100644
> --- a/Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt
> +++ b/Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt
> @@ -4,10 +4,14 @@ Required properties:
> - compatible: Should contain "nxp,pcf8523".
> - reg: I2C address for chip.
>
> -Optional property:
> +Optional properties:
> - quartz-load-femtofarads: The capacitive load of the quartz(x-tal),
> expressed in femto Farad (fF). Valid values are 7000 and 12500.
> Default value (if no value is specified) is 12500fF.
> +- pm-enable-dsm: battery switch-over function is enabled in direct
> + switching mode. The power failure condition happens when VDD < VBAT,
> + without requiring VDD to drop below Vth(sw)bat.
> + Default value (if not provided) is the standard mode.
>
> Example:
>
> @@ -15,4 +19,5 @@ pcf8523: rtc@68 {
> compatible = "nxp,pcf8523";
> reg = <0x68>;
> quartz-load-femtofarads = <7000>;
> + pm-enable-dsm;
> };
> diff --git a/Documentation/devicetree/bindings/rtc/rtc.yaml b/Documentation/devicetree/bindings/rtc/rtc.yaml
> index ee237b2..a0048f4 100644
> --- a/Documentation/devicetree/bindings/rtc/rtc.yaml
> +++ b/Documentation/devicetree/bindings/rtc/rtc.yaml
> @@ -47,4 +47,11 @@ properties:
> description:
> Enables wake up of host system on alarm.
>
> + pm-enable-dsm:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description:
> + Enables the battery switch-over function in direct switching
> + mode. Should be set in systems where VDD is higher than VBAT
> + at all times.
I'm all for common properties, but is this common across vendors?
> +
> ...
> --
> 1.8.3.1
>
