Re: [PATCH v1 01/11] arm64: dts: freescale: imx8mm-verdin: Add SPI alias

[Frank Li <Frank.li@oss.nxp.com>]

On Fri, Nov 13, 2026 at 08:31:35AM +0100, Francesco Dolcini wrote:
> Hello Frank,
>
> On Thu, Nov 12, 2026 at 09:41:31AM -0600, Frank Li wrote:
> > On Thu, Nov 12, 2026 at 04:02:23PM +0100, Francesco Dolcini wrote:
> > > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > >
> > > The Verdin family pinout defines the SoM interfaces and their
> > > numbering, SPI_1 being the SPI bus available to the carrier board,
> > > implemented by ecspi2 on Verdin iMX8MM.
> > >
> > > imx8mm.dtsi numbers ecspi2 as spi1, so the Linux bus number in sysfs
> > > and the spidev name do not match the Verdin interface. Add a spi0
> > > alias in the SoM dtsi and delete the inherited spi1, so ecspi2 is
> > > bus 0, zero-based with SPI_1 being spi0, and carries a single alias.
> > > ecspi3, internal to the SoM with the CAN controller and the TPM, keeps
> > > the spi2 alias inherited from the SoC.
> > >
> > > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > > ---
> > >  arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi | 2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> > > index 1ac9d000d415..0369803a4d46 100644
> > > --- a/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> > > +++ b/arch/arm64/boot/dts/freescale/imx8mm-verdin.dtsi
> > > @@ -16,6 +16,8 @@ chosen {
> > >  	aliases {
> > >  		rtc0 = &rtc_i2c;
> > >  		rtc1 = &snvs_rtc;
> > > +		spi0 = &ecspi2;
> > > +		/delete-property/ spi1;
> >
> > Can you avoid delete property for new platform?
>
> Unfortunately this is needed.
>
> The included imx8mm.dtsi has
>
>   spi1 = &ecspi2;

Create patch move aliase to each boards' dts from imx8mm.dtsi, which is
board feature, not soc features.

Frank

>
> so, without the /delete-property/ we will have both
>
>   spi0 = &ecspi2;
>   spi1 = &ecspi2;
>
> and what is happening with that is implementation dependent, and this
> would not be ok.
>
> The original issue is that imx8mm.dtsi should not define the aliases in
> the first place, unfortunately removing it now is no longer possible,
> it will introduce regressions everywhere [0][1].
>
> This issue, and the reason I have the delete-property, is already
> explained in the commit message.
>
> Francesco
>
> [0] https://lore.kernel.org/all/20250425-dts-imx-aliases-ethernet-v1-0-15b9d5cca611@linaro.org/
> [1] https://lore.kernel.org/all/aca3addbe510c58524af8d3fd069fe2ae4b1cd24.camel@pengutronix.de/