Re: [RFC PATCH] dt-bindings: add a jsonschema binding example

From: Rob Herring <robh@kernel.org>
To: jonsmirl@gmail.com
Cc: Frank Rowand <frowand.list@gmail.com>,
	devicetree@vger.kernel.org, devicetree-spec@vger.kernel.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Grant Likely <grant.likely@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Linus Walleij <linus.walleij@linaro.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Mark Brown <broonie@kernel.org>, Shawn Guo <shawnguo@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Arnd Bergmann <arnd@arndb.de>, Stephen Boyd <sboyd@kernel.org>,
	Jonathan Cameron <jic23@kernel.org>
Subject: Re: [RFC PATCH] dt-bindings: add a jsonschema binding example
Date: Thu, 15 Nov 2018 17:42:14 -0600	[thread overview]
Message-ID: <CAL_JsqJd7F7=yyW5X0P4W0N+0UDA8MLPDGvbBBK+VqMKqajC7Q@mail.gmail.com> (raw)
In-Reply-To: <CAKON4OxwAmmPv2+CEtT+eO3Uu8duCKD8OqyWj8+w2Y5SZ4bfOQ@mail.gmail.com>

On Wed, Nov 14, 2018 at 1:39 PM jonsmirl@gmail.com <jonsmirl@gmail.com> wrote:
>
> On Fri, Apr 20, 2018 at 9:36 PM Rob Herring <robh@kernel.org> wrote:
> > I share the concern as I doubt most kernel developers don't know
> > jsonschema. But then the alternative is us defining and writing our
> > own thing which is C like 'cause that's what kernel developers
> > understand. My hope is to simplify and restrict things enough that it
> > writing a binding doc is straightforward without being jsonschema
> > experts. That was the intent of this patch without going into all the
> > details behind it.
>
> When schemas were first discussed long, long ago the idea was to have
> a n arbitrator who controls the schema (like Grant/Rob) so there is no
> need for general schema design knowledge in random kernel developers.
>
> First a developer should try and build their device tree using the
> existing schema. Then only if they find that impossible to do so
> should they propose schema changes. The schema arbitrator would then
> look at those changes and work them into the existing schemas as
> needed. Doing this via an arbitrator will ensure consistency in the
> overall schema design while eliminating redundancy with slight
> variations (like we have now).
>
> Another side effect of schemas is that as they evolve and enforce
> commonality among driver implementation it will become possible to
> turn those in-common pieces into driver libraries.

If we replace 'schemas' everywhere above with 'bindings', then this
pretty much describes the status quo today. Most device specific
bindings are a collection of standard bindings. Occasionally, we have
new common bindings. All the bindings get reviewed by me. The only
real change here is submitters have to have some level of
understanding of json-schema instead of just English (for writing free
form text). I think it will continue to largely be following existing
examples of other bindings.

Rob