Subject: [PATCH] ARM: tegra: Remove 3.3V supply and modem regulators

From: [email-masked] (Thierry Reding)
Date: Wed, 8 Jan 2014 14:41:07 +0100

On Mon, Jan 06, 2014 at 01:59:27PM -0700, Stephen Warren wrote:
> On 01/06/2014 08:25 AM, Thierry Reding wrote:
> > GPIO 1 and 2 of the PMIC are not used for the described purpose, so
> > remove them.
> 
> As far as I can tell, this patch is correct, since those GPIOs are in
> fact used to discharge the rails after disabling them, rather than to
> enable/disable the rails.
> 
> Equally, these GPIOs affect multiple rails at once, so listing the GPIO
> as a property of a single regulator seems wrong either way.
> 
> However, PMU_REGEN1 does seem to feed the "EN" pin of U13C1, a DC/DC
> switcher for power rail 3.3v_modem, so perhaps there's more going on
> here than I see?
> 
> In summary, I need Laxman to comment on this and ack the change, and
> explain why these GPIOs were listed as regulator enables when it doesn't
> seem that they are.
> 
> > Note: Removing these makes the work-in-progress eDP support work again.
> 
> > diff --git a/arch/arm/boot/dts/tegra124-venice2.dts b/arch/arm/boot/dts/tegra124-venice2.dts
> 
> > -		vdd_3v3_reg: regulator at 1 {
> > -			compatible = "regulator-fixed";
> > -			reg = <1>;
> > -			regulator-name = "vdd_3v3";
> > -			regulator-min-microvolt = <3300000>;
> > -			regulator-max-microvolt = <3300000>;
> > -			regulator-always-on;
> > -			regulator-boot-on;
> > -			enable-active-high;
> > -			gpio = <&as3722 1 GPIO_ACTIVE_HIGH>;
> > -		};
> > -
> > -		vdd_3v3_modem_reg: regulator at 2 {
> > -			compatible = "regulator-fixed";
> > -			reg = <2>;
> > -			regulator-name = "vdd-modem-3v3";
> > -			regulator-min-microvolt = <3300000>;
> > -			regulator-max-microvolt = <3300000>;
> > -			enable-active-high;
> > -			gpio = <&as3722 2 GPIO_ACTIVE_HIGH>;
> > -		};
> 
> Don't you want to simply remove the "enable-active-high" and "gpio"
> properties, but leave the regulator definitions present, in case
> something wants to reference these fixed(?) rails as their supply?

Yes, I guess that could probably work.

Thierry
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