Re: [linux-sunxi] [PATCH 2/3] spidev: Add DT binding example.
From: Maxime Ripard
Date: Mon Apr 27 2015 - 06:10:27 EST
On Mon, Apr 27, 2015 at 08:51:12AM +0200, Michal Suchanek wrote:
> On 26 April 2015 at 17:47, Maxime Ripard
> <maxime.ripard@xxxxxxxxxxxxxxxxxx> 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.
Which is exactly what my patch did but didn't seem like good enough
for you at the time...
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
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