Re: [PATCH v8 5/7] can: ctucanfd: CTU CAN FD open-source IP core - platform/SoC support.

From: Marc Kleine-Budde
Date: Wed May 04 2022 - 02:34:35 EST


On 03.05.2022 17:07:21, Pavel Pisa wrote:
> Hello Geert,
>
> On Tuesday 03 of May 2022 13:37:46 Geert Uytterhoeven wrote:
> > Hi Pavel,
> > > --- /dev/null
> > > +++ b/drivers/net/can/ctucanfd/ctucanfd_platform.c
> > >
> > > +/* Match table for OF platform binding */
> > > +static const struct of_device_id ctucan_of_match[] = {
> > > + { .compatible = "ctu,ctucanfd-2", },
> >
> > Do you need to match on the above compatible value?
> > The driver seems to treat the hardware the same, and the DT
> > bindings state the compatible value below should always be present.
>
> I would keep it because there will be newer revisions and releases
> of the core and I consider "ctu,ctucanfd" as the match to generic
> one with maximal attempt to adjust to the version from provided
> info registers but identification with the fixed version
> "ctu,ctucanfd-2" ensures that some old hardware which is
> in the wild is directly recognized even at /sys level
> and if we need to do some workarounds for autodetection
> etc. it can be recognized.

As Geert said:
- There are 2 bindings in the driver which are (currently) treated the
same.
- The binding documentation says devices must always have the
ctu,ctucanfd compatible.

This means (currently) the ctu,ctucanfd-2 is not needed in the driver.
We can add it back once we need it.

Or are there devices that have a compatible of ctu,ctucanfd-2 without
stating to be compatible with ctu,ctucanfd?

regards,
Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |

Attachment: signature.asc
Description: PGP signature