Re: [PATCH 1/3] media: dt-bindings: add bindings for Toshiba TC358746

[Marco Felsch <m.felsch@pengutronix.de>]

Hi Rob,

sorry instead of adding you to To you was on Cc.
Do you have any preferences about the below discussion?

Regards,
  Marco

On 19-04-16 12:45, Marco Felsch wrote:
> Hi Rob,
> 
> gentle ping.
> 
> Regards,
>   Marco
> 
> On 19-03-05 19:14, Marco Felsch wrote:
> > Hi Rob,
> > 
> > I think you didn't followed the discussion in detail so I will ask you
> > personal. In short the tc358746 can act as parallel-in -> csi-out or as
> > csi->in -> parallel-out device. The phyiscal pins are always the same
> > only the internal timings are different. So we have two ports with two
> > endpoints.
> > 
> > Now the question is how we determine the mode. We have two approaches:
> > 1)
> >   port@0 -> input port
> >   port@1 -> output port
> > 
> >   pro:
> >   + no extra vendor specific binding is needed to determine the mode
> > 
> >   con:
> >   - input/output endpoint can be parallel or mipi-csi2.
> > 
> > 2)
> >   port@0 -> parallel port
> >   port@1 -> mipi-csi2 port
> > 
> >   pro:
> >   + input/output endpoint are fixed to parallel or mipi
> > 
> >   con:
> >   - vendor specific binding is needed to determine the mode
> > 
> > Thanks for your comments :)
> > 
> > Regards,
> > Marco
> > 
> > On 19-03-05 09:49, Jacopo Mondi wrote:
> > > Hi Sakari, Marco,
> > > 
> > > On Mon, Mar 04, 2019 at 08:17:48PM +0200, Sakari Ailus wrote:
> > > > Hi Marco,
> > > >
> > > > On Mon, Mar 04, 2019 at 05:55:28PM +0100, Marco Felsch wrote:
> > > > > > > (more device specific)
> > > > > > > tc358746,default-mode = <CSI-Tx> /* Parallel-in -> CSI-out */
> > > > > > > tc358746,default-mode = <CSI-Rx> /* CSI-in -> Parallel-out */
> > > > > > >
> > > > > > > or
> > > > > > >
> > > > > > > (more generic)
> > > > > > > tc358746,default-dir = <PARALLEL_TO_CSI2>
> > > > > > > tc358746,default-dir = <CSI2_TO_PARALLEL>
> > > > > >
> > > > > > The prefix for Toshiba is "toshiba". What would you think of
> > > > > > "toshiba,csi2-direction" with values of either "rx" or "tx"? Or
> > > > > > "toshiba,csi2-mode" with either "master" or "slave", which would be a
> > > > > > little bit more generic, but could be slightly more probable to get wrong
> > > > > > as well.
> > > > >
> > > > > You're right mixed the prefix with the device.. If we need to introduce
> > > > > a property I would prefer the "toshiba,csi2-direction" one. I said if
> > > > > because as Jacopo mentioned we can avoid the property by define port@0
> > > > > as input and port@1 as output. I tink that's the best solution, since we
> > > > > can avoid device specific bindings and it's common to use the last port
> > > > > as output (e.g. video-mux).
> > > >
> > > > The ports represent hardware and I think I would avoid reordering them. I
> > > > wonder what would the DT folks prefer.
> > > >
> > > 
> > > I might have missed why you mention re-ordering? :)
> > > 
> > > > The device specific property is to the point at least: it describes an
> > > > orthogonal part of the device configuration. That's why I'd pick that if I
> > > > were to choose. But I'll let Rob to comment on this.
> > > 
> > > That's true indeed. Let's wait for inputs from DT people, I'm fine
> > > with both approaches.
> > > 
> > > Thanks
> > >    j
> > > 
> > > >
> > > > --
> > > > Regards,
> > > >
> > > > Sakari Ailus
> > > > sakari.ailus@linux.intel.com
> > 
> > 
> > 
> > -- 
> > Pengutronix e.K.                           |                             |
> > Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> > Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> > 
> > 
> 
> -- 
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> 
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |