linux-kernel - Re: [PATCH] regulator: twl: mark vdd1/2 as continuous on twl4030

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Date:   Mon, 17 Jun 2019 18:27:43 +0200
From:   Andreas Kemnade <andreas@...nade.info>
To:     Mark Brown <broonie@...nel.org>
Cc:     tony@...mide.com, lgirdwood@...il.com, linux-omap@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        sboyd@...nel.org, nm@...com, vireshk@...nel.org,
        letux-kernel@...nphoenux.org
Subject: Re: [PATCH] regulator: twl: mark vdd1/2 as continuous on twl4030

On Mon, 17 Jun 2019 12:40:48 +0100
Mark Brown <broonie@...nel.org> wrote:

> On Mon, Jun 17, 2019 at 01:03:57PM +0200, Andreas Kemnade wrote:
> > Mark Brown <broonie@...nel.org> wrote:  
> > > On Sat, Jun 15, 2019 at 06:33:14PM +0200, Andreas Kemnade wrote:  
> 
> > > Why is this a good fix and not defining the supported voltages?  These
> > > look like fairly standard linear range regulators.  
> 
> > I am fixing the definition of the two regulators in the patch.
> > I am defining them as continuous. 
> > Voltage ranges are defined in
> > arch/arm/boot/dts/twl4030.dtsi
> > Only the continuous flag is missing.  
> 
> > Is there anything else do you want to be defined?  
> 
> These regulators are not continuous regulators as far as I can see, they
> are normal linear range regulators and so should have their voltages
> enumerable like any other linear range regulator.

Citing tps65950 trm page 55:

The device contains three switch-mode power supplies (SMPS):
• VDD1: 1.2-A, buck DC/DC converter (VOUT = 0.6 V to 1.45 V, in steps of 12.5 mV)
• VDD2: 600-mA buck DC/DC converter (VOUT = 0.6 V to 1.45 V, in steps of 12.5 mV, and 1.5 V as a
   single programmable value)

you are right, they are not really continuous. So should I add these
68 steps they have as a voltage list?

I think they are nearly continuous, so we should IMHO rather take that
not that strict. I guess there are no really continuous regulators, all
have steps as voltage is specified in a limited resolution. So what is
the exact meaning of that flag here?

I think it is common sense to specify these regulators as continuous.
Max and min values are already in arch/arm/boot/dts/twl4030.dtsi.

Regards,
Andreas