RE: [PATCH 2/2] arm64: dts: lx2160a: add device tree for lx2162aqds board

[Meenakshi Aggarwal]

> -----Original Message-----
> From: Shawn Guo <shawnguo@xxxxxxxxxx>
> Sent: Saturday, September 12, 2020 3:19 PM
> To: Meenakshi Aggarwal <meenakshi.aggarwal@xxxxxxx>
> Cc: robh+dt@xxxxxxxxxx; Varun Sethi <V.Sethi@xxxxxxx>; Leo Li
> <leoyang.li@xxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ioana Ciornei
> <ioana.ciornei@xxxxxxx>; Kuldeep Singh <kuldeep.singh@xxxxxxx>
> Subject: Re: [PATCH 2/2] arm64: dts: lx2160a: add device tree for lx2162aqds
> board
> 
> On Wed, Sep 09, 2020 at 07:10:12AM +0000, Meenakshi Aggarwal wrote:
> > > > +	sb_3v3: regulator-sb3v3 {
> > > > +		compatible = "regulator-fixed";
> > > > +		regulator-name = "MC34717-3.3VSB";
> > > > +		regulator-min-microvolt = <3300000>;
> > > > +		regulator-max-microvolt = <3300000>;
> > > > +		regulator-boot-on;
> > > > +		regulator-always-on;
> > >
> > > I do not see any point to have regulator-boot-on or
> > > regulator-always-on for a regulator that doesn't have on/off control.
> > [Meenakshi Aggarwal] Properties are added to specify that platform
> > firmware's out of reset configuration enabled the regulator and regulator
> should never be disabled or change its operative status.
> 
> What I was wondering if how this regulator is enabled by firmware, by some
> GPIO control?  In that case, 'gpio' property should be there to describe the GPIO
> control.
> 
[Meenakshi Aggarwal] Its not controlled by GPIO. Its gets power on with board.
> >
> > Can you help in understanding why these optional properties cannot be
> > used together
> 
> It's totally fine to use these properties together.  But if the regulator doesn't
> have on/off control, neither of them makes sense.
[Meenakshi Aggarwal] As per documentation, we should keep " regulator-always-on " as per description, we
Can remove " regulator-boot-on" property from dts.

regulator-always-on:
    description: boolean, regulator should never be disabled                                  
  
 
.
> 
> Shawn