From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 29 Apr 2019 18:44:28 +0200 From: Marco Felsch Subject: Re: [PATCH 1/3] media: dt-bindings: add bindings for Toshiba TC358746 Message-ID: <20190429164427.naz6fqbbnqi5gqum@pengutronix.de> References: <20190218100333.qvptfllrd4pyhsyb@paasikivi.fi.intel.com> <20190301105235.a23jwiwmxejuv2yf@pengutronix.de> <20190301130118.jy57g5wcsn7mqclk@pengutronix.de> <20190304123621.l3ocvdiya5z5wzal@paasikivi.fi.intel.com> <20190304165528.n4sqxjhfsplmt5km@pengutronix.de> <20190304181747.ax7nvbvhdul4vtna@kekkonen.localdomain> <20190305084902.vzaqr53q77oy2o7r@uno.localdomain> <20190305181419.kqdaqnjte3v7663f@pengutronix.de> <20190416104550.htexnpzgypuuubo4@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190416104550.htexnpzgypuuubo4@pengutronix.de> To: robh+dt@kernel.org Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, Ian Arkver , hans.verkuil@cisco.com, Sakari Ailus , mchehab@kernel.org, graphics@pengutronix.de, linux-media@vger.kernel.org, Jacopo Mondi List-ID: 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 = /* Parallel-in -> CSI-out */ > > > > > > > tc358746,default-mode = /* CSI-in -> Parallel-out */ > > > > > > > > > > > > > > or > > > > > > > > > > > > > > (more generic) > > > > > > > tc358746,default-dir = > > > > > > > tc358746,default-dir = > > > > > > > > > > > > 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 |