From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: Re: [PATCH 2/2] ASoc: wm8731: add normal mode with 12MHz XTAL Date: Mon, 13 Jun 2016 09:37:14 +0100 Message-ID: <20160613083714.GU20422@localhost.localdomain> References: <1465517516-1917-1-git-send-email-flatmax@flatmax.org> <1465517516-1917-2-git-send-email-flatmax@flatmax.org> <575BD6F2.70600@flatmax.org> <575CD572.2040700@flatmax.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx0a-001ae601.pphosted.com (mx0a-001ae601.pphosted.com [67.231.149.25]) by alsa0.perex.cz (Postfix) with ESMTP id 2D710265328 for ; Mon, 13 Jun 2016 10:37:06 +0200 (CEST) Content-Disposition: inline In-Reply-To: <575CD572.2040700@flatmax.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Matt Flax Cc: alsa-devel@alsa-project.org, broonie@kernel.org, patches@opensource.wolfsonmicro.com List-Id: alsa-devel@alsa-project.org On Sun, Jun 12, 2016 at 01:22:26PM +1000, Matt Flax wrote: > It appears that my logic here is flawed. > From what I can tell, it isn't possible to get a suitable bit clock out of > the codec when using a 12 MHz crystal. For that reason, in my hardware I > will change crystals from 12 MHz. This looks correct the chip only has simple dividers so you won't be able to get a good audio rate clock from a 12MHz crystal. > > I just want to check ... are there any versions of this codec which output > the bit clock when in USB mode on the BCLK pin ? > Apologies I am not quite sure I follow what USB mode is in this context, and the bit clock surely always comes out of the BCLK pin. Do you simply mean a system with a clock speed that relates to the 48MHz USB clock, such as your 12MHz? Basically any part that has a PLL/FLL should work for that, for example the wm8998: http://www.cirrus.com/en/products/pro/detail/P1265.html Thanks, Charles