On 16.07.2021 02:04:56, Joakim Zhang wrote:
> > On 15.07.2021 19:36:06, Dong Aisheng wrote:
> > > Then should it be "fsl,imx8mp-flexcan", "fsl,imx8qxp-flexcan" rather
> > > than only drop "fsl,imx6q-flexcan"?
> > 
> > The driver has compatibles for the 8qm, not for the 8qxp:
> > 
> > |	{ .compatible = "fsl,imx8qm-flexcan", .data =
> > &fsl_imx8qm_devtype_data, },
> > |	{ .compatible = "fsl,imx8mp-flexcan", .data =
> > |&fsl_imx8mp_devtype_data, },
> 
> AFAIK, we first design the i.MX8QM FlexCAN and later i.MX8QXP reuses
> IP from i.MX8QM, so there is no difference for them.
> 
> IMHO, IP design is always backwards compatible,

Hopefully the IP blocks of the i.MX8Q* are compatible, but the other
flexcan IP core are not.

> then we need list each as fallback compatible string? I think it's
> unnecessary.

In the DTs we usually use the name of the SoC we're just describing as
the first compatible, and add a second compatible with the oldest SoC
having this IP core or an IP core that is compatible (so that the driver
works).

As the imx8mp needs the DISABLE_MECR quirk it's not compatible with the
imx6.

regards,
Marc

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