RE: [PATCH 3/3] ARM: dts: imx6sll: Add Rev A board support

[Anson Huang]

> Subject: Re: [PATCH 3/3] ARM: dts: imx6sll: Add Rev A board support
> 
> On Wed, Nov 06, 2019 at 05:47:30PM +0800, Anson Huang wrote:
> > i.MX6SLL EVK Rev A board is same with latest i.MX6SLL EVK board except
> > eMMC can ONLY run at HS200 mode, add support for this board.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> > ---
> >  arch/arm/boot/dts/Makefile             |  1 +
> >  arch/arm/boot/dts/imx6sll-evk-reva.dts | 12 ++++++++++++
> >  2 files changed, 13 insertions(+)
> >  create mode 100644 arch/arm/boot/dts/imx6sll-evk-reva.dts
> >
> > diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> > index 71f08e7..3845bbf 100644
> > --- a/arch/arm/boot/dts/Makefile
> > +++ b/arch/arm/boot/dts/Makefile
> > @@ -557,6 +557,7 @@ dtb-$(CONFIG_SOC_IMX6SL) += \
> >  	imx6sl-warp.dtb
> >  dtb-$(CONFIG_SOC_IMX6SLL) += \
> >  	imx6sll-evk.dtb \
> > +	imx6sll-evk-reva.dtb \
> >  	imx6sll-kobo-clarahd.dtb
> >  dtb-$(CONFIG_SOC_IMX6SX) += \
> >  	imx6sx-nitrogen6sx.dtb \
> > diff --git a/arch/arm/boot/dts/imx6sll-evk-reva.dts
> > b/arch/arm/boot/dts/imx6sll-evk-reva.dts
> > new file mode 100644
> > index 0000000..7ca2563
> > --- /dev/null
> > +++ b/arch/arm/boot/dts/imx6sll-evk-reva.dts
> > @@ -0,0 +1,12 @@
> > +// SPDX-License-Identifier: (GPL-2.0 OR MIT)
> > +/*
> > + * Copyright 2016 Freescale Semiconductor, Inc.
> > + * Copyright 2017-2019 NXP.
> > + *
> > + */
> > +
> > +#include "imx6sll-evk.dts"
> > +
> > +&usdhc2 {
> > +	compatible = "fsl,imx6sll-usdhc", "fsl,imx6sx-usdhc";
> 
> It looks odd to me that we need to deal with a board level difference with a
> SoC level compatible.  The USDHC compatible should be solely determined by
> the IP programming model, not the board level capability.

So how to handle such scenario? Current usdhc driver uses SoC compatible to distinguish
different functions of uSDHC IP, if some boards can NOT support dedicated function due to
board design regardless of the IP inside, the easy way is just to downgrade the SoC compatible,
or need uSDHC driver to provide some DT properties for such case? 

Thanks,
Anson