From mboxrd@z Thu Jan 1 00:00:00 1970 From: lokowich Subject: Re: MPC5200 I2S driver for ASoC Date: Wed, 01 Aug 2007 14:16:23 -0500 Message-ID: <46B0DC07.4050000@acdstar.com> References: <46B0C3EE.5020401@acdstar.com> <46B0C89D.50704@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sentry.acdstar.com (mail.acdstar.com [209.98.244.9]) by alsa0.perex.cz (Postfix) with ESMTP id 3F713103826 for ; Wed, 1 Aug 2007 21:28:50 +0200 (CEST) Received: from MailerDaemon by sentry.acdstar.com with local-bsmtp (Exim 4.63) (envelope-from ) id 1IGJsH-0005Te-6n for alsa-devel@alsa-project.org; Wed, 01 Aug 2007 14:28:49 -0500 Received: from [192.168.2.3] (port=48158 helo=mail.acdstar.com) by sentry.acdstar.com with esmtp (Exim 4.63) (envelope-from ) id 1IGJsE-0005TV-7z for alsa-devel@alsa-project.org; Wed, 01 Aug 2007 14:28:46 -0500 In-Reply-To: <46B0C89D.50704@freescale.com> 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: Timur Tabi Cc: ALSA-devel List-Id: alsa-devel@alsa-project.org Timur Tabi wrote: > lokowich wrote: > >> I'm integrating a ALSA driver for an MPC5200 into the ASoC layer, >> similar to my successful effort for a PXA255 board. >> > > Can you provide your code? I'm working on ASoC support for another MPC SOC, so we need to > synchronize our development. > Yes, I presume you mean using git into the ALSA branch. I need to get more familiar with git, and follow the appropriate coding conventions before it's ready. Any guidance will be appreciated. > I'm modeling the > DMA and ALSA interfaces per ac97mgt driver found in the Lite5200B BSP, > rather than the BestComm API example in the 2.4 kernel. The > speaker-test with 400Hz sine wave is working, but has a slight audible > jitter. A wav file output using aplay produces white noise. > > > What kind of audio samples are you trying to play? Since the MPC5200 is typically > big-endian, you probably can only play S16_BE samples instead of S16_LE samples. > > Yes! I had enabled the S16_BE format in my codec/i2s/pcm driver, but naively thought ALSA would handle the rest. Converted my test file to S16_BE and it sounds much closer to the original. Thanks! Found the "jitter" is due to a FIFO overflow. I'm using same alarm (0x120) and granularity (4) common to 2.4 I2S and ac97 drivers. Is there a more appropriate setting for 16-bit, 2-channel, 44.1kHz audio? Also, can we chat about SDRAM problems on 5200B outside of this forum? This email was Anti Virus checked by Astaro Security Gateway. http://www.astaro.com