Re: [linux-sunxi] [PATCH 2/3] spidev: Add DT binding example.

Michal Suchanek
2015-04-27T06:51:58Z

On 26 April 2015 at 17:47, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> On Sun, Apr 26, 2015 at 04:40:50PM +0200, Hans de Goede wrote:
>> Hi,
>>
>> I've a feeling everyone in this thread is ignoring the
>> raspberry pi use-case. Where the board is specifically
>> designed for educational purposes and used with lots of
>> peripherals which are usually programmed from userspace
>> using e.g. python bindings for i2c-dev or spidev, for
>> such a setup we really want spidev to be loaded on the
>> spibus by default and we really do not have a proper
>> compatible for a child device.
>
> I'm not sure we're ignoring it, it just is the exact same use case
> than the whole spidev use case: people want to write SPI userspace
> drivers, the rpi really is not special here, except maybe for its user
> space code base, but it really boils down to the same issue.
>
>> And no having to use per device devicetree overlays
>> for this is not the answer, this needs to be really
>> really easy. With pre device-tree kernels this just
>> works, we should be able to match that ease of use
>> with devicetree.
>
> We do agree on that. We repeatedly told that the DT was not a good
> solution, overlays or not, and this is exactly one of the reasons.
>

Ok, so how about skipping the bindings altogether.

Just instantiate a spidev for each SPI bus and each CS the SPI core
knows of once spidev is loaded.

Thanks

Michal