Subject: Re: [PATCH can-next 1/2] CAN: rcar: add gen[12] fallback compatibility strings

From: Marc Kleine-Budde <[email-masked]>
Date: Mon, 22 Feb 2016 10:40:37 +0100

On 02/22/2016 04:37 AM, Rob Herring wrote:
> On Mon, Feb 22, 2016 at 11:15:49AM +0900, Simon Horman wrote:
>> Add fallback compatibility string for R-Car Gen 1 and Gen2 families.
>> This is in keeping with the fallback scheme being adopted wherever
>> appropriate for drivers for Renesas SoCs.
>>
>> Signed-off-by: Simon Horman <[email-masked]>
>> ---
>>  Documentation/devicetree/bindings/net/can/rcar_can.txt | 4 +++-
>>  drivers/net/can/rcar_can.c                             | 2 ++
>>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> Acked-by: Rob Herring <[email-masked]>

I'm not following the latest DT discussions, is there a (new) decision
to add such "generic" compatibles? AFAIK you add the oldest device
that's compatible with your driver to your SoC dtsi at rightmost
compatible. You can add one that identifies your SoC's IP core in front
of it. So there's no need to modify the driver until an IP core needs
different handling.

In your case you'd identify the oldest SoC that implements the Gen1 IP
core and use this instead of "renesas,can-gen1. Same for Gen2 IP core.

regards,
Marc

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