Thank you so much for your suggestion.

I've already copied a codec source for wm8980 from linux-2.6-ASoC main trunk. I have already to modify it back to the old api's and old structures for kernel v2.6.21. What remains I can't get through are those points I listed in my previous email.

Could you give me some hints?

Best Regards, LEUNG, Chi Tat Senior Software Engineer CCT Tech Advanced Products Limited 18/F, CCT Telecom Building, 11 Wo Shing Street Fo Tan, Shatin, N.T., Hong Kong Tel: +852 26005276 Fax: +852 26948660 Email: ctleung@cct.com.hk Website: http://www.cct-tech.com.hk

-----Original Message----- From: Jon Smirl [mailto:jonsmirl@gmail.com] Sent: Monday, May 25, 2009 11:45 AM To: Leung Chi Tat Cc: alsa-devel@alsa-project.org Subject: Re: [alsa-devel] Help on writing an ALSA ASoC Driver for WM8985

On Sun, May 24, 2009 at 11:31 PM, Leung Chi Tat ctleung@cct.com.hk wrote:

Hi all,

I'm new to ALSA ASoC and ALSA.  I'd like get some advice where I can get more information about writing an ASoC driver. I've browsed the internet couples of days and I can only find links on ALSA driver api's and writing an ALSA driver for PCI devices.

It seems there is not much information on how to writing an ALSA ASoC driver.  I'm stuck on the following questions:        1. describing those important structures, e.g. struct soc_enum, struct snd_kcontrol_new, struct snd_soc_dapm_widget;        2. what is/are the relationships among those important structures;        3. what is the differences between those controls for struct snd_kcontrol_new and struct snd_soc_dapm_widget;        4. Should those sinks, sources, paths be defined in the arrays of struct snd_dapm_widget;        5. How can I select those defined paths through ALSA user-mode library as I can't find any examples in those ALSA tutorials;

Indeed, I'm right now trying to write a WM8985 driver for my s3c6400 based platform based on the kernel source v2.6.21 from Samsung.

Look in sound/soc/codecs. There are implementations for many similar Wolfson chips. Just cut and paste them together to make the wm8985.

Thank you so much for your valuable advice and suggestions in advance.

Best Regards, LEUNG, Chi Tat Senior Software Engineer CCT Tech Advanced Products Limited 18/F, CCT Telecom Building, 11 Wo Shing Street Fo Tan, Shatin, N.T., Hong Kong Tel: +852 26005276 Fax: +852 26948660 Email: ctleung@cct.com.hk Website: http://www.cct-tech.com.hk

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