Re: [PATCH 1/2] ARM: dts: imx7-tqma7: correctly specify PMIC voltage constraints

From: Frank Li

Date: Fri Sep 04 2026 - 11:38:51 EST

On Thu, Sep 03, 2026 at 12:11:36PM +0200, Nora Schiffer wrote:
> On Wed, 2026-09-02 at 11:11 -0500, Frank Li wrote:
> > On Wed, Sep 02, 2026 at 10:05:37AM +0200, Nora Schiffer wrote:
> > > regulator-(min|max)-microvolt refer to the supported voltages according
> > > to board design, not the possible range of the regulators themselves.
> >
> > I think make sense, but any document or mail list can be refer to?
> >
> > Frank
>
> Hi Frank,
>
> I've occasionally seen this being mentioned in reviews like [1] when the
> regulator-min/max was used incorrectly. The binding docs [2] say:
>
> regulator-min-microvolt:
> description: smallest voltage consumers may set
>
> regulator-max-microvolt:
> description: largest voltage consumers may set

I suggest create patch to make it clearer, and check what said by dt team
and Mark. If they agree your change, we can refer it in future.

Frank

>
> which is not as clear as I would like... Right now I don't have a source that
> feels definitive enough to include it in the commit description.
>
> Best,
> Nora
>
>
> [1] https://lore.kernel.org/all/7b23de30-06e3-4f02-a8a5-90791628ceed@xxxxxxxxx/
> [2]
> https://www.kernel.org/doc/Documentation/devicetree/bindings/regulator/regulator.yaml
>
>
> >
> > > Update the configuration for the TQMa7x's PMIC and also add a comment
> > > regarding the PMIC's VCC_SD switching feature.
> > >
> > > Fixes: a80a1af6ec8a ("ARM: dts: tq imx7 common board support")
> > > Signed-off-by: Nora Schiffer <nora.schiffer@xxxxxxxxxxxxxxx>
> > > ---
> > > arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi | 40 +++++++++++++----------
> > > 1 file changed, 23 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi b/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi
> > > index e1f740edfb763..7f49c80fef4c6 100644
> > > --- a/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi
> > > +++ b/arch/arm/boot/dts/nxp/imx/imx7-tqma7.dtsi
> > > @@ -46,8 +46,8 @@ pfuze3000: pmic@8 {
> > >
> > > regulators {
> > > sw1a_reg: sw1a {
> > > - regulator-min-microvolt = <700000>;
> > > - regulator-max-microvolt = <3300000>;
> > > + regulator-min-microvolt = <1000000>;
> > > + regulator-max-microvolt = <1225000>;
> > > regulator-boot-on;
> > > regulator-always-on;
> > > regulator-ramp-delay = <6250>;
> > > @@ -55,34 +55,33 @@ sw1a_reg: sw1a {
> > >
> > > /* use sw1c_reg to align with pfuze100/pfuze200 */
> > > sw1c_reg: sw1b {
> > > - regulator-min-microvolt = <700000>;
> > > - regulator-max-microvolt = <1475000>;
> > > + regulator-min-microvolt = <1000000>;
> > > + regulator-max-microvolt = <1000000>;
> > > regulator-boot-on;
> > > regulator-always-on;
> > > regulator-ramp-delay = <6250>;
> > > };
> > >
> > > sw2_reg: sw2 {
> > > - regulator-min-microvolt = <1500000>;
> > > - regulator-max-microvolt = <1850000>;
> > > + regulator-min-microvolt = <1800000>;
> > > + regulator-max-microvolt = <1800000>;
> > > regulator-boot-on;
> > > regulator-always-on;
> > > };
> > >
> > > sw3a_reg: sw3 {
> > > - regulator-min-microvolt = <900000>;
> > > - regulator-max-microvolt = <1650000>;
> > > + regulator-min-microvolt = <1350000>;
> > > + regulator-max-microvolt = <1350000>;
> > > regulator-boot-on;
> > > regulator-always-on;
> > > };
> > >
> > > swbst_reg: swbst {
> > > - regulator-min-microvolt = <5000000>;
> > > - regulator-max-microvolt = <5150000>;
> > > + /* Not connected and left unconfigured */
> > > };
> > >
> > > snvs_reg: vsnvs {
> > > - regulator-min-microvolt = <1000000>;
> > > + regulator-min-microvolt = <3000000>;
> > > regulator-max-microvolt = <3000000>;
> > > regulator-boot-on;
> > > regulator-always-on;
> > > @@ -95,18 +94,25 @@ vref_reg: vrefddr {
> > >
> > > vgen1_reg: vldo1 {
> > > regulator-min-microvolt = <1800000>;
> > > - regulator-max-microvolt = <3300000>;
> > > + regulator-max-microvolt = <1800000>;
> > > regulator-always-on;
> > > };
> > >
> > > vgen2_reg: vldo2 {
> > > - regulator-min-microvolt = <800000>;
> > > - regulator-max-microvolt = <1550000>;
> > > + regulator-min-microvolt = <1500000>;
> > > + regulator-max-microvolt = <1500000>;
> > > regulator-always-on;
> > > };
> > >
> > > vgen3_reg: vccsd {
> > > - regulator-min-microvolt = <2850000>;
> > > + /*
> > > + * Specified values refer to 3.3V operation; voltage for 1.8V
> > > + * operation is derived from this.
> > > + *
> > > + * The base board should usually mux GPIO1_IO08 to SD1_VSELECT for
> > > + * automatic switching of SD card IO voltage.
> > > + */
> > > + regulator-min-microvolt = <3300000>;
> > > regulator-max-microvolt = <3300000>;
> > > regulator-always-on;
> > > };
> > > @@ -118,13 +124,13 @@ vgen4_reg: v33 {
> > > };
> > >
> > > vgen5_reg: vldo3 {
> > > - regulator-min-microvolt = <1800000>;
> > > + regulator-min-microvolt = <3300000>;
> > > regulator-max-microvolt = <3300000>;
> > > regulator-always-on;
> > > };
> > >
> > > vgen6_reg: vldo4 {
> > > - regulator-min-microvolt = <1800000>;
> > > + regulator-min-microvolt = <3300000>;
> > > regulator-max-microvolt = <3300000>;
> > > regulator-always-on;
> > > };
> > > --
> > > TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
> > > Amtsgericht München, HRB 105018
> > > Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
> > > https://www.tq-group.com/
> > >
> > >
>
> --
> TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
> Amtsgericht München, HRB 105018
> Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
> https://www.tq-group.com/