From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751349AbaKYSho (ORCPT ); Tue, 25 Nov 2014 13:37:44 -0500 Received: from mga11.intel.com ([192.55.52.93]:42187 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751252AbaKYShm (ORCPT ); Tue, 25 Nov 2014 13:37:42 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,457,1413270000"; d="scan'208";a="637944576" Message-ID: <1416940656.7260.48.camel@loki> Subject: Re: [alsa-devel] [PATCH 1/2] ASoC: rt5677: Add ACPI device probing From: Liam Girdwood To: Darren Hart Cc: Grant Likely , Ben Zhang , Oder Chiou , alsa-devel , "Rafael J. Wysocki" , Liam Girdwood , Linux Kernel Mailing List , Mark Brown , Anatol Pomozov , Bard Liao , Dylan Reid , flove@realtek.com Date: Tue, 25 Nov 2014 18:37:36 +0000 In-Reply-To: <5474A7CA.3020106@linux.intel.com> References: <1416034608-24238-1-git-send-email-benzh@chromium.org> <1416925686.7260.28.camel@loki> <5474A7CA.3020106@linux.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2014-11-25 at 08:01 -0800, Darren Hart wrote: > > On 11/25/14 06:28, Liam Girdwood wrote: > > On Tue, 2014-11-25 at 12:11 +0000, Grant Likely wrote: > >> On Sat, Nov 15, 2014 at 6:56 AM, Ben Zhang wrote: > >>> The rt5677 codec driver looks for ACPI device ID "RT5677CE", > >>> which is specified in coreboot. This patch allows platform > >>> data to be obtained via ACPI > >>> > >>> Signed-off-by: Ben Zhang > >> > >> This looks like an ideal time to talk about shared DT and ACPI driver > >> bindings. This driver /already/ has a firmware binding. It is > >> documented in the kernel under > >> Documentation/bindings/sound/rt5677.txt. We now have a standard method > >> for sharing bindings between DT and ACPI in the _DSD method[1]. > >> Support for DSD is in linux-next and getting merged into v3.19. This > >> is exactly the case that _DSD should be used for passing additional > >> data to the driver, and it should use the existing binding. > >> > >> [1] http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf > >> > >> For a long time we've had the rule on DT that new bindings must be > >> documented before we merge a patch. That rule I think has been a good > >> one, even if it is a little chaoitc. I think when it comes to ACPI > >> drivers that we should be requiring the same: Document the binding, > >> either in the kernel as a DT binding, or point to somewhere else that > >> has the binding documented. > >> > >> Also, since this patch is targeted at v3.19 or later, the > >> device-properties API should be used. Don't create something custom. > >> > > > > My sentiments exactly, there would be little point having bespoke device > > properties for every single device. Btw, we also need to align here with > > Windows too ! > > > > The Windows folks definitely know about _DSD (and helped define it), so > this is a good opportunity to work through that process. Liam, do you > have a good contact to start that discussion? > I do, I've contacted them off-list to align on this with Realtek. Liam