From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liam Girdwood Subject: Re: FW: [PATCH v3] ASoC: Add support for TI LM49453 Audio codec Date: Wed, 08 Feb 2012 10:57:30 +0000 Message-ID: <1328698650.3955.13.camel@odin> References: <290463D19D2E064191F1F96ECA480A89434AC4A96E@EXMAIL02.scwf.nsc.com> <4F323BF5.4010309@ti.com> <1328692723.3955.4.camel@odin> <1328693854.21099.5.camel@vkoul-udesk3> <1328694877.3955.9.camel@odin> <1328697415.21099.8.camel@vkoul-udesk3> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from na3sys009aog105.obsmtp.com (na3sys009aog105.obsmtp.com [74.125.149.75]) by alsa0.perex.cz (Postfix) with ESMTP id 46AF62414C for ; Wed, 8 Feb 2012 11:57:35 +0100 (CET) Received: by mail-ww0-f47.google.com with SMTP id ds11so282652wgb.16 for ; Wed, 08 Feb 2012 02:57:32 -0800 (PST) In-Reply-To: <1328697415.21099.8.camel@vkoul-udesk3> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Vinod Koul Cc: "alsa-devel@alsa-project.org" , Mark Brown , M R Swami Reddy List-Id: alsa-devel@alsa-project.org On Wed, 2012-02-08 at 16:06 +0530, Vinod Koul wrote: > On Wed, 2012-02-08 at 09:54 +0000, Liam Girdwood wrote: > > Atm, the machine driver would have to enable any system clocks before > > the codec driver could use them. > But how would machine driver know _when_? > The machine driver gets all the PCM ops that the codec driver does and is responsible for configuring CODEC PLLs and clocks (usually in it's hw_params()). > We want to dynamical turn off this clock when not is use and turn on > only when codec is using. So I was thinking of turning this ON in > codecs .set_bias_level callback, but how to propagate this into machine > driver? > It's usually done in the machine driver hw_params() since at this point we know the rate, format etc that can have a bearing on the clock configuration. You could switch it OFF in machine hw_free(). Liam