Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751788AbaKYOaS (ORCPT ); Tue, 25 Nov 2014 09:30:18 -0500 Received: from mga09.intel.com ([134.134.136.24]:17512 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbaKYOaQ (ORCPT ); Tue, 25 Nov 2014 09:30:16 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,455,1413270000"; d="scan'208";a="643238681" Message-ID: <1416925686.7260.28.camel@loki> Subject: Re: [alsa-devel] [PATCH 1/2] ASoC: rt5677: Add ACPI device probing From: Liam Girdwood To: Grant Likely Cc: Ben Zhang , Oder Chiou , alsa-devel , Darren Hart , "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 14:28:06 +0000 In-Reply-To: References: <1416034608-24238-1-git-send-email-benzh@chromium.org> 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 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 ! Liam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/