Re: [PATCH v2 3/6] riscv: dts: spacemit: k1-musepi-pro: enable QSPI and add SPI NOR

On Tue, May 12, 2026 at 1:51 AM Andre Heider <[email protected]> wrote:
>
> On 12.05.26 4:28 AM, [email protected] wrote:
> > Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
> > - [High] Potential overvoltage risk for the W25Q64FW SPI NOR flash via the 'buck4_3v3' supply.
> > - [Low] The unit-address in the 'uboot' partition node name does not match the base address in its 'reg' property.
> > --
> >
> > commit 470f9c74bd3cfec41ed69dd8c4e22535a7e8164f
> > Author: Andre Heider <[email protected]>
> >
> > riscv: dts: spacemit: k1-musepi-pro: enable QSPI and add SPI NOR
> >
> > This commit adds the QSPI controller node and describes the attached
> > SPI NOR flash. It also provides a corresponding vendor flash partition
> > layout.
> >
> >> diff --git a/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts b/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
> >> --- a/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
> >> +++ b/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
> >
> > [ ... ]
> >
> >> @@ -166,7 +166,7 @@ buck3_1v8: buck3 {
> >>                              regulator-always-on;
> >>                      };
> >>
> >> -                    buck4 {
> >> +                    buck4_3v3: buck4 {
> >>                              regulator-min-microvolt = <500000>;
> >>                              regulator-max-microvolt = <3300000>;
> >>                              regulator-ramp-delay = <5000>;
> >
> > [ ... ]
> >
> >> @@ -249,6 +249,47 @@ dldo7 {
> >>      };
> >>   };
> >>
> >> +&qspi {
> >> +    pinctrl-names = "default";
> >> +    pinctrl-0 = <&qspi_cfg>;
> >> +    status = "okay";
> >> +
> >> +    flash@0 {
> >> +            compatible = "jedec,spi-nor";
> >> +            reg = <0>;
> >> +            spi-max-frequency = <26500000>;
> >> +            spi-rx-bus-width = <4>;
> >> +            spi-tx-bus-width = <4>;
> >> +            vcc-supply = <&buck4_3v3>; /* QSPI_VCC1833 */
> >
> > The commit message notes this flash is a Winbond W25Q64FWSSAQ, which is a
> > strict 1.8V part. Could this vcc-supply assignment cause hardware damage?
> >
> > The buck4 regulator has a maximum voltage of 3.3V. If the regulator defaults
> > to 3.3V or is configured to 3.3V dynamically, it exceeds the absolute maximum
> > ratings for the 1.8V W25Q series flash.
>
> As per the comment, there's a the non controllable regulator QSPI_VCC1833 in between.
> k1-milkv-jupiter.dts matches in this regard.
> I'll keep it unchanged unless someone has an idea how to express that in a better way.

That's what we have fixed-regulator binding for. It can take an input supply.

Rob