Re: [PATCH 4/7] [media] ir-rx51: add DT support to driver

[Ivaylo Dimitrov]

On 10.05.2016 00:07, Rob Herring wrote:
> On Mon, May 9, 2016 at 3:53 PM, Ivaylo Dimitrov
> <ivo.g.dimitrov.75@xxxxxxxxx> wrote:
> > Hi,
> >
> > On  9.05.2016 23:06, Rob Herring wrote:
> > > On Sat, May 07, 2016 at 06:21:45PM +0300, Ivaylo Dimitrov wrote:
> > > > With the upcoming removal of legacy boot, lets add support to one of the
> > > > last N900 drivers remaining without it. As the driver still uses omap
> > > > dmtimer, add auxdata as well.
> > > >
> > > > Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>
> > > > ---
> > > >    .../devicetree/bindings/media/nokia,lirc-rx51         | 19
> > > > +++++++++++++++++++
> > > >    arch/arm/mach-omap2/pdata-quirks.c                    |  6 +-----
> > > >    drivers/media/rc/ir-rx51.c                            | 11 ++++++++++-
> > > >    3 files changed, 30 insertions(+), 6 deletions(-)
> > > >    create mode 100644
> > > > Documentation/devicetree/bindings/media/nokia,lirc-rx51
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/media/nokia,lirc-rx51
> > > > b/Documentation/devicetree/bindings/media/nokia,lirc-rx51
> > > > new file mode 100644
> > > > index 0000000..5b3081e
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/media/nokia,lirc-rx51
> > > > @@ -0,0 +1,19 @@
> > > > +Device-Tree bindings for LIRC TX driver for Nokia N900(RX51)
> > > > +
> > > > +Required properties:
> > > > +       - compatible: should be "nokia,lirc-rx51".
> > >
> > >
> > > lirc is a Linux term. Also, nokia,rx51-... would be conventional
> > > ordering.
> >
> > I used the driver name ("lirc_rx51") to not bring confusion. Also, it
> > registers itself through lirc_register_driver() call, so having lirc in its
> > name somehow makes sense.
> >
> > I am not very good in inventing names, the best compatible I can think of is
> > "nokia,rx51-ir". Is that ok?
>
> Sure, but...
>
> > > Is this anything more than a PWM LED?
> >
> > It is an IR LED connected through a driver to McSPI2_SIMO pin of OMAP3,
> > which pin can be configured as PWM or GPIO(there are other configurations,
> > but they don't make sense). In theory it could be used for various things
> > (like uni-directional serial TX, or stuff like that), but in practice it
> > allows N900 to be act as an IR remote controller. I guess that fits in
> > "nothing more than a PWM LED", more or less.
>
> There's already a pwm-led binding that can be used. Though there may
> be missing consumer IR to LED subsystem support in the kernel. You
> could list both compatibles, use the rx51 IR driver now, and then move
> to pwm-led driver in the future.

I looked at the pwm-leds (and related) code and couldn't see how it will 
do the job of controlling IR TX LED as a remote controller. So yeah, it 
seems CIR support in LEDS subsystem is non existent.

Could you elaborate on "list both compatibles", I don't really 
understand what I should do.

Ivo