From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Ravnborg Subject: Re: [PATCH v1 02/36] dt-bindings: spi: support non-spi bindings as SPI slaves Date: Mon, 16 Mar 2020 19:57:33 +0100 Message-ID: <20200316185733.GA18307@ravnborg.org> References: <20200315134416.16527-1-sam@ravnborg.org> <20200315134416.16527-3-sam@ravnborg.org> <20200316120239.GC5010@sirena.org.uk> <20200316132844.GA22822@ravnborg.org> <20200316163538.GJ5010@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Thierry Reding , Rob Herring , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Alexandre Courbot , Andrzej Hajda , Brian Masney , Chris Zhong , Douglas Anderson , Guido Gunther , Heiko Schocher , Nikolaus Schaller , Hoegeun Kwon , Jagan Teki , Jerry Han , Jonathan Bakker , Laurent Pinchart , Lin Huang , Linus Walleij , linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Marco Fr To: Mark Brown Return-path: Content-Disposition: inline In-Reply-To: <20200316163538.GJ5010-GFdadSzt00ze9xe1eoZjHA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Hi Mark. On Mon, Mar 16, 2020 at 04:35:38PM +0000, Mark Brown wrote: > On Mon, Mar 16, 2020 at 02:28:44PM +0100, Sam Ravnborg wrote: > > On Mon, Mar 16, 2020 at 12:02:41PM +0000, Mark Brown wrote: > > > On Sun, Mar 15, 2020 at 02:43:42PM +0100, Sam Ravnborg wrote: > > > > > Independent bindings can be SPI slaves which for example is > > > > the case for several panel bindings. > > > > What is an "independent binding"? > > > For several panels we have device trees that looks like this: > > So what you're trying to do is define a generic class for SPI slaves > which are just normal children of SPI nodes? I really can't get to > there from your changelog so we need some work there - in particular > "non-spi bindings" is *very* confusing as as far as I can see these are > bindings for SPI devices. > > > The bindings are child of the spi controller node, but not specified > > in the same binding file as the spi controller node. > > Of course not, this how all buses work isn't it? > > > So SPI slaves can now reference spi-slave.yaml to get access to > > the SPI slave properties - and the copies can be avoided. > > Likewise spi-controller.yml now references spi-slave.yaml. > > > This was the best way I saw it could be done. > > Rob didn't do the binding conversion but he did review it - I'm a bit > surprised that there's issues here? For panels we have panel-common.yaml that list all the typical properties used by a panel - so the individual panel bindings shall not repeat them. This is also aligned with the principle of re-using properties rather than inventing new properties all over. And with a number of bindings describing HW that is SPI slaves the idea is to do something like we do for panels. I look forward for Rob's feedback - but as he is on vacation this week we may have to wait a week for that. The simple way forward had been to do like we do in many other places and include a few SPI properties and be done with it. This is an attempt to do something better. If there is push-back or a nack, then we can always do like we do in other places and just duplicate the properties. > Also shouldn't there be some constraint that these devices have to be > the child of a SPI controller or something? Just including a file > doesn't look right for something like class definition. It was the best I could come up with - and this patch was called out for review in the hope there is a better way than this patch. We have similar examples like: - pincfg-node.yaml - regulatro.yaml - dma-common.yaml They are not exactly 1:1 to what we do with spi-slave.yaml, but they served as inspiration. Sam