From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f174.google.com (mail-lb0-f174.google.com [209.85.217.174]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id C4A59E0151C for ; Mon, 10 Jun 2013 23:20:17 -0700 (PDT) Received: by mail-lb0-f174.google.com with SMTP id x10so4984050lbi.5 for ; Mon, 10 Jun 2013 23:20:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject :content-type:content-transfer-encoding; bh=85Lg53oWEoO8ljGmk1sqPDFq0pKKFZnnBqQk7hcG0TI=; b=m4LiDeAa8dBkh/H4GkVQ9eBIiMx9qu0MZDNuiD0sG3cHFphik/OM+FfajxdglT1Rbb NgZIEfbOFjhuJrK5KKi0ZOt+lOlEqFnQxZ2A/m/viC/ilOB6VZKK6ps1KSppoDfHw6OZ VV65M+dPEZNVHTHRvTfPlp6SK0od+rOfhlOJbgyiRBY96BU52OTukaie4krpyMWPTKu9 v4e6xDs0q7UZkN9gkoogQICM8xh6pZrEJtyAJ39dIFxu4pgqTziJBawMdOjKmgSk3GMP 5Ad1+Pg0E8lgB0GC7jQc4DOe1ZzRJYIWo49T0uhSNtZYBsEoYNdM3zpdURYmUtheQ9+F 8KpQ== X-Received: by 10.112.138.230 with SMTP id qt6mr8072655lbb.34.1370931207240; Mon, 10 Jun 2013 23:13:27 -0700 (PDT) Received: from [10.0.2.15] ([78.25.120.24]) by mx.google.com with ESMTPSA id n3sm167510lag.9.2013.06.10.23.13.25 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Mon, 10 Jun 2013 23:13:26 -0700 (PDT) Message-ID: <51B6C005.5050009@gmail.com> Date: Tue, 11 Jun 2013 10:13:25 +0400 From: Alexander Smirnov User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: "meta-freescale@yoctoproject.org" Subject: i.MX6 ASRC problem X-BeenThere: meta-freescale@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Usage and development list for the meta-fsl-* layers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Jun 2013 06:20:18 -0000 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Dear all, last 3 weeks I spent in attempts to get ASRC working for my codec but all of them seem to be failed. So, at the moment I'm still stuck with ASRC due to several black spots in RM and source code. My environment: =============== 1. I use kernel from the following package L3.0.35_4.0.0_130424_source 2. I have a custom board with a custom DAC codec 3. Codec is connected to CPU over SSI2 My base support package works good, so I can play audio over codec by using 'aplay' at fixed sample rates: $ aplay -D "hw:0,0" foo.wav What I've done: =============== 1. I've implemented ASRC support for CS4344 according to the CS42888 reference code. But in some configurations I got I/O error (ASRC doesn't start and aborts by timeout), in other - empty stream 2. I've posted a question to Freescale's community, but after 2 weeks there is still no reply. The link is: https://community.freescale.com/message/332039#332039 Questions: ========== 1. ASRC requires 2 physical clocks: input and output. According to the Reference Manual (RM), ASRC fetches data from each enabled FIFO and processes the data sample-by-sample after each rising edge of input clock (chapter 15.1.2.1.1, page 639 of RM). But, there is no information about output clock usage, only mentioned that it should be physically available. The ratio Fs_in/Fs_out is provided as integers. So what's the meaning of input/output physical clocks, sample clocks? Which physical clocks are required to get ASRC working? 2. Why SSI3_RX clock is called INCLK_NONE in Linux? What does it mean? 3. I use SSI2 bus for my DAC. Which clocks should I use to get mxc_asrc driver work properly? 4. Does the current ASRC driver work? I found some old linux-2.6-imx kernel, which has support for i.MX5 family only. I noticed, that all codecs (3-stack) in 'sound/soc/imx/' have ASRC support. But in current kernel only cs42888 has ASRC support... 5. Is there some more detailed ASRC specification? 6. Does ALSA utils require some extra ASRC support? I've tried ASRC by the following command: $ aplay -D "hw:0,1" foo.wav I will highly appreciate any hints on this topic, thanks in advance! BTW: I have several several fixes for ASRC driver, but they are mostly cosmetic. I'm going to send them after I'll be sure that the driver works. With best regards, Alex