From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [RFC v2 PATCH] mipi-dsi-bus: add MIPI DSI bus support Date: Fri, 13 Dec 2013 13:06:04 +0100 Message-ID: <20131213120603.GA9820@ulmo.nvidia.com> References: <52A08FB3.5040800@ti.com> <20131206125424.GA30625@ulmo.nvidia.com> <52A5AAAE.5090601@ti.com> <20131209131015.GB17693@ulmo.nvidia.com> <52A5DC30.5030801@ti.com> <20131209161048.GA11742@ulmo.nvidia.com> <52A6DCBA.7060801@ti.com> <20131212121941.GF11524@ulmo.nvidia.com> <52AAEDEB.5090102@samsung.com> <52AAEF8D.7040804@ti.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2074621238==" Return-path: Received: from mail-bk0-f48.google.com (mail-bk0-f48.google.com [209.85.214.48]) by gabe.freedesktop.org (Postfix) with ESMTP id 486CBFAF43 for ; Fri, 13 Dec 2013 04:07:22 -0800 (PST) Received: by mail-bk0-f48.google.com with SMTP id r7so1321720bkg.7 for ; Fri, 13 Dec 2013 04:07:21 -0800 (PST) In-Reply-To: <52AAEF8D.7040804@ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org To: Tomi Valkeinen Cc: Andrzej Hajda , Kyungmin Park , Thierry Reding , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============2074621238== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="UlVJffcvxoiEqYs2" Content-Disposition: inline --UlVJffcvxoiEqYs2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Dec 13, 2013 at 01:29:17PM +0200, Tomi Valkeinen wrote: > On 2013-12-13 13:22, Andrzej Hajda wrote: > > On 12/12/2013 01:19 PM, Thierry Reding wrote: > >> On Tue, Dec 10, 2013 at 11:19:54AM +0200, Tomi Valkeinen wrote: > >>> On 2013-12-09 18:10, Thierry Reding wrote: > >>> > >>> Btw, about single linux device handling multiple VC IDs: I noticed th= at > >>> the DSI spec has an example, in which a DSI peripheral receives > >>> interlaced video, and the video packets containing even field have VC= ID > >>> 0 and packets for odd field have VC ID 1. I'm not sure how relevant > >>> interlaced video is, but I think there's an example where having > >>> separate linux devices for each VC ID would be somewhat clumsy. > >> Ugh... that's pretty bad. > > I wonder if this scenario could not be solved just > > by allowing range of VCs per device, for example: > > dsi { > > #address-cells =3D <1>; > > #size-cells =3D <1>; > > panel_with_interleaved_vc@0 { > > reg =3D <0, 2>; > > }; > > }; >=20 > I don't think range is good, as then you can't have, say, VC IDs 0 and > 2. But giving the VC IDs individually as I did in my recent reply, > should do the same thing as above, without ranges. >=20 > It's still open to me if that method is good or not. I think we can actually support both of those variants with the same binding. #address-cells =3D <1> and #size-cells =3D <0> means that every device has a single address, which matches Tomi's example: dsi { peripheral@0 { reg =3D <0, /* first VC ID */ 2>; /* second VC ID */ }; }; The difference to what Andrzej proposed is that we additionally have #size-cells =3D <1>, which implies each entry in reg can have a "size" as well: dsi { peripheral@0 { reg =3D <0 2>; /* VC IDs 0 and 1 */ }; }; While I could be wrong of course, I do think that the former is unlikely since it's much easier to support consecutive addresses than completely separate ones. Or perhaps it isn't. Either way I think the binding would support both of those cases. I'll see if I can come up with some wording to make that a part of the binding and perhaps mention that only one-to-one relationships are taken into account in the binding. Thierry --UlVJffcvxoiEqYs2 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJSqvgrAAoJEN0jrNd/PrOhWG8P/izbvrDSy3jeQCLYHtVnElNM Ms08XeogLokX4se72fvO1iED9nhzpjijaCFY26MfjnqBZnJY3tw28mTpchvsoLDf 3OuzrczyMSahqHVdVg7GFFYeiCkLWKnLekqFraa8pFAu3ldI0kPFZCKPM0Hzr25d QwoijDycr6E6zJHgTrRZ8bzgj4g28p6Bugrssbv+p7CBlHymy+wykn3FB0tsmeWo jB7Izxd7NOWOclfTgE9YTVjxTNzy1nbDeLWaUOdVG7LKBYV3UJf9NaGTdtXLtyuN g+u7TVwoUgxW+SIWL2NlKlIJUTmrPYCiB7Tu5rKp8B3Vu1RhP66GZWF38mfsS1nW J09DLVBaUDGviTASyeRrRZJu8Ds3ICTuyBvk15/Uet2gZDlBD73MR2FhKeJtxtHc O14ZRyqIC8GXqOEO4Owii8dl4+IxgL7bSSRoBVEsdXkz6zs2vY1UzeFE8KF6qkrp o4utcE/uxZLRHBvaEgmD0barupiGUSFwvxO2P7fcTCGaS/RN/wGL1u06vnrkQs3s dCK/FMgxLbNzMT4c9MIoH5RlUdujGvLOYQoFTveul92HJthQl1yh5rLXHI+DDPY8 YPhCAwBUdZ4wWtsaAxuIkzqfOIlnk0bMEmUp13wwOP8GyISI0Gp2bbq9YyrsBAgi KXhyzlBZLdtKYL0/btvz =N0q/ -----END PGP SIGNATURE----- --UlVJffcvxoiEqYs2-- --===============2074621238== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel --===============2074621238==--