On Fri, Apr 17, 2020 at 07:08:23PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@xxxxxxxxxx>
>
> The RTC present on MAX77620 can be used to generate an alarm at a given
> time, which in turn can be used as a wakeup source for the system if it
> is properly wired up.
>
> Document how to enable the RTC to act as a wakeup source.
>
> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> ---
> .../devicetree/bindings/mfd/max77620.txt | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mfd/max77620.txt b/Documentation/devicetree/bindings/mfd/max77620.txt
> index 5a642a51d58e..f05005b0993e 100644
> --- a/Documentation/devicetree/bindings/mfd/max77620.txt
> +++ b/Documentation/devicetree/bindings/mfd/max77620.txt
> @@ -125,6 +125,17 @@ MAX77663 supports 20, 40, 80, 160, 320, 640, 1280 and 2540 microseconds.
> control) then, GPIO1/nRST_IO goes LOW.
> this property is valid for max20024 only.
>
> +Realtime Clock
> +--------------
> +The MAX77620 family of power management ICs contain a realtime clock block
> +that can be used to keep track of time even when the system is powered off.
> +
> +The realtime clock can also be programmed to trigger alerts, which can be
> +used to wake the system up from sleep. In order to configure the RTC to act
> +as a wakeup source, add an "rtc" child node and add the "wakeup-source"
> +property.
> +
> +
> For DT binding details of different sub modules like GPIO, pincontrol,
> regulator, power, please refer respective device-tree binding document
> under their respective sub-system directories.
> @@ -159,4 +170,8 @@ max77620@3c {
> maxim,fps-event-source = <MAX77620_FPS_EVENT_SRC_SW>;
> };
> };
> +
> + rtc {
> + wakeup-source;
Is the RTC really the only thing that could wake the system in this
PMIC?
I don't think it's really valid to have 'wakeup-source' without
'interrupts' unless the wakeup mechanism is somehow not an interrupt. So
I think this belongs in the parent node.
Rob
