2022-09-01 11:33:21

by Max Krummenacher

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Subject: [PATCH] arm64: dts: imx8mp-verdin: board regulators: add always-on

From: Max Krummenacher <[email protected]>

These regulators are switched on by HW during power up and can not
be influenced by SW.
Set the always-on property.

Signed-off-by: Max Krummenacher <[email protected]>

---

arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi b/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi
index 557cfef8f049..76cc89296150 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi
@@ -62,6 +62,7 @@ button-wakeup {
/* Carrier Board Supplies */
reg_1p8v: regulator-1p8v {
compatible = "regulator-fixed";
+ regulator-always-on;
regulator-max-microvolt = <1800000>;
regulator-min-microvolt = <1800000>;
regulator-name = "+V1.8_SW";
@@ -69,6 +70,7 @@ reg_1p8v: regulator-1p8v {

reg_3p3v: regulator-3p3v {
compatible = "regulator-fixed";
+ regulator-always-on;
regulator-max-microvolt = <3300000>;
regulator-min-microvolt = <3300000>;
regulator-name = "+V3.3_SW";
@@ -76,6 +78,7 @@ reg_3p3v: regulator-3p3v {

reg_5p0v: regulator-5p0v {
compatible = "regulator-fixed";
+ regulator-always-on;
regulator-max-microvolt = <5000000>;
regulator-min-microvolt = <5000000>;
regulator-name = "+V5_SW";
--
2.35.3


2022-09-01 18:35:04

by Laurent Pinchart

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Subject: Re: [PATCH] arm64: dts: imx8mp-verdin: board regulators: add always-on

Hi Max,

(CC'ing Mark and Liam)

Thank you for the patch.

On Thu, Sep 01, 2022 at 01:04:22PM +0200, Max Krummenacher wrote:
> From: Max Krummenacher <[email protected]>
>
> These regulators are switched on by HW during power up and can not
> be influenced by SW.
> Set the always-on property.

Is this needed ? When a fixed regulator has no control GPIO or clock, as
is the case here, I would expect the driver and/or regulator core to
understand that it's always on, as the alternative is always-off, which
is pointless :-) Mark, Liam, what do you think ?

> Signed-off-by: Max Krummenacher <[email protected]>
>
> ---
>
> arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi b/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi
> index 557cfef8f049..76cc89296150 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mp-verdin.dtsi
> @@ -62,6 +62,7 @@ button-wakeup {
> /* Carrier Board Supplies */
> reg_1p8v: regulator-1p8v {
> compatible = "regulator-fixed";
> + regulator-always-on;
> regulator-max-microvolt = <1800000>;
> regulator-min-microvolt = <1800000>;
> regulator-name = "+V1.8_SW";
> @@ -69,6 +70,7 @@ reg_1p8v: regulator-1p8v {
>
> reg_3p3v: regulator-3p3v {
> compatible = "regulator-fixed";
> + regulator-always-on;
> regulator-max-microvolt = <3300000>;
> regulator-min-microvolt = <3300000>;
> regulator-name = "+V3.3_SW";
> @@ -76,6 +78,7 @@ reg_3p3v: regulator-3p3v {
>
> reg_5p0v: regulator-5p0v {
> compatible = "regulator-fixed";
> + regulator-always-on;
> regulator-max-microvolt = <5000000>;
> regulator-min-microvolt = <5000000>;
> regulator-name = "+V5_SW";

--
Regards,

Laurent Pinchart

2022-09-01 18:51:27

by Mark Brown

[permalink] [raw]
Subject: Re: [PATCH] arm64: dts: imx8mp-verdin: board regulators: add always-on

On Thu, Sep 01, 2022 at 09:29:13PM +0300, Laurent Pinchart wrote:
> On Thu, Sep 01, 2022 at 01:04:22PM +0200, Max Krummenacher wrote:
> > From: Max Krummenacher <[email protected]>

> > These regulators are switched on by HW during power up and can not
> > be influenced by SW.
> > Set the always-on property.
>
> Is this needed ? When a fixed regulator has no control GPIO or clock, as
> is the case here, I would expect the driver and/or regulator core to
> understand that it's always on, as the alternative is always-off, which
> is pointless :-) Mark, Liam, what do you think ?

If there's no physical control setting always-on does nothing.


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