Re: [PATCH v2 11/13] mmc: sdhci-esdhc-imx: Add sdhc support for i.MXRT series

[Rob Herring <robh@xxxxxxxxxx>]

On Wed, Nov 03, 2021 at 12:30:17AM +0100, Giulio Benetti wrote:
> Hi Fabio, Jesse, All,
> 
> On 11/3/21 12:25 AM, Jesse Taube wrote:
> > 
> > 
> > On 11/2/21 19:17, Fabio Estevam wrote:
> > > On Tue, Nov 2, 2021 at 7:57 PM Jesse Taube <mr.bossman075@xxxxxxxxx> wrote:
> > > 
> > > >    static struct esdhc_soc_data usdhc_imx8qxp_data = {
> > > >           .flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
> > > > @@ -357,6 +363,7 @@ static const struct of_device_id imx_esdhc_dt_ids[] = {
> > > >           { .compatible = "fsl,imx7ulp-usdhc", .data = &usdhc_imx7ulp_data, },
> > > >           { .compatible = "fsl,imx8qxp-usdhc", .data = &usdhc_imx8qxp_data, },
> > > >           { .compatible = "fsl,imx8mm-usdhc", .data = &usdhc_imx8mm_data, },
> > > > +       { .compatible = "fsl,imxrt-usdhc", .data = &usdhc_imxrt_data, },
> > > 
> > > I thought Rob suggested to use the SoC name, so this would be:
> > > 
> > Uh i think that may have been for the UART.
> > > { .compatible = "fsl,imxrt1050-usdhc", .data = &usdhc_imxrt1050_data, },
> > > 
> > > The same applies to the other bindings in the series.
> > > 
> > > This way it would be possible to differentiate between future
> > > supported i.MX RT devices.
> > > 
> > This makes sense will do in V3.
> > 
> 
> If we add every SoC we will end up having a long list for every device
> driver. At the moment it would be 7 parts:
> 1) imxrt1020
> 2) imxrt1024
> .
> .
> .
> 7) imxrt1170

You don't need a driver update if you use a fallback. When you add 
the 2nd chip, if you think it is 'the same', then you do:

compatible = "fsl,imxrt1024-usdhc", "fsl,imxrt1050-usdhc";

That requires no driver update until the driver needs to handle some 
difference. And when there is a difference, you don't need a DT update.

You could make "fsl,imxrt-usdhc" the fallback from the start if you are 
adverse to the first way.

Rob