RE: [PATCH V2 1/5] dt-bindings: fsl: scu: add scu power key binding

[Anson Huang]

Hi, Oleksij

> On 03.09.19 16:03, Anson Huang wrote:
> > NXP i.MX8QXP is an ARMv8 SoC with a Cortex-M4 core inside as system
> > controller, the system controller is in charge of system power, clock
> > and power key event etc. management, Linux kernel has to communicate
> > with system controller via MU (message unit) IPC to get power key
> > event, add binding doc for i.MX system controller power key driver.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> > ---
> > Changes since V1:
> > 	- remove "wakeup-source" property, as it is NOT needed for SCU
> interrupt;
> > 	- remove "status" in example.
> > ---
> >   .../devicetree/bindings/arm/freescale/fsl,scu.txt          | 14
> ++++++++++++++
> >   1 file changed, 14 insertions(+)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
> > b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
> > index c149fad..f93e2e4 100644
> > --- a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
> > +++ b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
> > @@ -157,6 +157,15 @@ Required properties:
> >   Optional properties:
> >   - timeout-sec: contains the watchdog timeout in seconds.
> >
> > +Power key bindings based on SCU Message Protocol
> > +------------------------------------------------------------
> > +
> > +Required properties:
> > +- compatible: should be:
> > +              "fsl,imx8qxp-sc-pwrkey"
> > +              followed by "fsl,imx-sc-pwrkey";
> > +- linux,keycodes: See
> > +Documentation/devicetree/bindings/input/keys.txt
> 
> linux,keycodes is required parameter. So, this kay cab be anything. Why the
> compatible is called pwrkey? Probably it is better to call it "*-sc-key"

This key is kind of special, it is ON/OFF button which is designed for power key
purpose, it has HW function such as long pressing it would shutdown the system power,
so we always use it as power key, NOT general key, does it make sense?

Thanks,
Anson.