Re: [RFC] K-Line protocol via SocketCAN

[Marek Vasut <marex@denx.de>]

On 06/15/2016 08:57 AM, Oliver Hartkopp wrote:
> On 06/15/2016 05:42 AM, Marek Vasut wrote:
>> On 06/14/2016 08:10 AM, Oliver Hartkopp wrote:
>>>
>>>>> On 06/11/2016 09:42 PM, Marek Vasut wrote:
>>>>>> Well, I was talking about arinc 429 .
>>>>>>
>>>>>
>>>>> Ah - I remember that discussion:
>>>>> https://lwn.net/Articles/663130/
>>>>> http://thread.gmane.org/gmane.linux.network/385449
>>>>>
>>>>> What happed to it?
>>>>
>>>> Priorities shifted. I still hope to return to it and get it into
>>>> mainline proper. Since I did some digging in the socketcan recently,
>>>> I have a better understanding of it now too. I believe the agreement
>>>> there was to put it into the socketcan stack as an extension, does it
>>>> still make sense ?
>>>>
>>>
>>> There were intensive discussions about the original patchset and I think
>>> the copy&paste hell from the PF_CAN won't make it.
>>
>> Yeah, that's pretty clear to me. But does it make sense to extend
>> socketcan with that arinc429 stuff instead then ?
> 
> You might think into the direction of the SLLIN implementation:
> 
> Create a ldisc which smells like a CAN interface.
> SLLIN doesn't change SocketCAN either.

The sllin looks like a hack which abuses the can interface by recycling
various bits instead of extending it properly last time I looked into
the code. I don't think that's an approach I want to follow. Anyway, I
don't think sllin should be mixed into the arinc stuff.

The arinc429 requires it's own dedicated controller(s), usually SPI ones
or such, it would have to be plugged into the can device interface or
somewhere there. Certainly not via ldisc.

-- 
Best regards,
Marek Vasut