From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Subject: Re: [PATCH v4 3/3] Documentation: of: Document graph bindings Date: Wed, 26 Feb 2014 16:50:52 +0200 Message-ID: <530DFF4C.8080807@ti.com> References: <1393340304-19005-1-git-send-email-p.zabel@pengutronix.de> <1393340304-19005-4-git-send-email-p.zabel@pengutronix.de> <530DE8A9.9050809@ti.com> <1393426623.3248.70.camel@paszta.hi.pengutronix.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tEHsptXr4FFpWcoGvwDA40KVVAmjgkgcU" Return-path: In-Reply-To: <1393426623.3248.70.camel-+qGW7pzALmz7o/J7KWpOmN53zsg1cpMQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Philipp Zabel Cc: Russell King - ARM Linux , Mauro Carvalho Chehab , Grant Likely , Rob Herring , Sylwester Nawrocki , Laurent Pinchart , Kyungmin Park , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Guennadi Liakhovetski List-Id: devicetree@vger.kernel.org --tEHsptXr4FFpWcoGvwDA40KVVAmjgkgcU Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 26/02/14 16:57, Philipp Zabel wrote: > Hi Tomi, >=20 > Am Mittwoch, den 26.02.2014, 15:14 +0200 schrieb Tomi Valkeinen: >> On 25/02/14 16:58, Philipp Zabel wrote: >> >>> +Optional endpoint properties >>> +---------------------------- >>> + >>> +- remote-endpoint: phandle to an 'endpoint' subnode of a remote devi= ce node. >> >> Why is that optional? What use is an endpoint, if it's not connected t= o >> something? >=20 > This allows to include the an empty endpoint template in a SoC dtsi for= > the convenience of board dts writers. Also, the same property is > currently listed as optional in video-interfaces.txt. >=20 > soc.dtsi: > display-controller { > port { > disp0: endpoint { }; > }; > }; >=20 > board.dts: > #include "soc.dtsi" > &disp0 { > remote-endpoint =3D <&panel_input>; > }; > panel { > port { > panel_in: endpoint { > remote-endpoint =3D <&disp0>; > }; > }; > }; >=20 > Any board not using that port can just leave the endpoint disconnected.= Hmm I see. I'm against that. I think the SoC dtsi should not contain endpoint node, or even port node (at least usually). It doesn't know how many endpoints, if any, a particular board has. That part should be up to the board dts. I've done this with OMAP as (much simplified): SoC.dtsi: dss: dss@58000000 { status =3D "disabled"; }; Nothing else (relevant here). The binding documentation states that dss has one port, and information what data is needed for the port and endpoi= nt. board.dts: &dss { status =3D "ok"; pinctrl-names =3D "default"; pinctrl-0 =3D <&dss_dpi_pins>; dpi_out: endpoint { remote-endpoint =3D <&tfp410_in>; data-lines =3D <24>; }; }; That's using the shortened version without port node. Of course, it's up to the developer how his dts looks like. But to me it makes sense to require the remote-endpoint property, as the endpoint, or even the port, doesn't make much sense if there's nothing to connect to. Tomi --tEHsptXr4FFpWcoGvwDA40KVVAmjgkgcU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJTDf9MAAoJEPo9qoy8lh71JaAQAJbPz+9VpNn17W+xOl/uxT2m 7yfxwYtwoVzI3GP5CHS110ALyJh9cFQ0R/p2QEGESO1l/03gIVteCdypHUdzQDhT gVa7ALqhf5XrN7FneCWD4liAS1kh9vjT77p66RTKHDjH6NjSKDgPlKotUEkwasRC Bx1DwbEQ+6W92TyCp40rNK60buMvJr1yerA9WuPFz/nlynBvB742rYd+xBKS89oR kFq0ZzAeXeKrUxQ4kCk4o/Jlj+GW0QVwQiI4973m5/wfHAHVkxJ7yWD/CLRKHB0e 82OHiHkyOBD6srbsbVGdZBSk/cdYFvpMPCBxyL1hFTWaaZ076sCDozU1RGBPyi8k 41ERnfKWfz70aDwWo6EpG0kXDBSygwZHi20aMNi4gNQQwAHarO6zgZGGsZfyc3Z6 pGomVCRZ4tpcEHyFmCUVm6NrocNFL9p3utQVOECC1VeLhT/Nbxaj96LKsFpBcd/d 4yQjBPhtN22wgmT7maLOPqveUFvVItDLVWGoUeH2w5rOBzEnnTxDzzwV3R27fKvf T7NVF9xFTJnzt+NJChwrlTBgNTSMRThWf8YjmfWAJmk9V83esYHNo65m2DBCOcJE p7FiQOrG3pcrUUJD8HI98H0mEfLp52UB8kdLedJxI0NHCdO5HBHVge2M5sn3MPXT X+MSBcHoIVzFTpb6tGBZ =KzUA -----END PGP SIGNATURE----- --tEHsptXr4FFpWcoGvwDA40KVVAmjgkgcU-- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html