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

Marco Felsch
2019-04-16T10:46:03Z

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
>
>
>
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>

--
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 |