[alsa-devel] Please help in adding ams-delta support to ASoC
jkrzyszt at tis.icnet.pl
Wed May 27 16:52:46 CEST 2009
On Wed, May 27, 2009 at 12:47, Mark Brown wrote:
> On Tue, May 26, 2009 at 03:17:23PM +0200, Janusz Krzysztofik wrote:
>> ... aplay
>> and arecord wait forever, cat to/from /dev/dsp breaks with hardware
> Do they really wait for ever or do they eventually time out? The
> default for both programs is to give up after 10 seconds if there's no
> DMA happening.
That was more than 10 seconds for sure.
> ... A few comments below.
>> +#include <sound/ac97_codec.h>
>> +#include <sound/initval.h>
>> +#include <sound/soc.h>
>> +#include "cx20442.h"
> Shouldn't need ac97_codec.h if it's not an AC97 CODEC.
Yes, I am going to clean up the code if it ever starts working.
>> +static int cx20442_soc_probe(struct platform_device *pdev)
>> + struct snd_soc_device *socdev = platform_get_drvdata(pdev);
>> + struct snd_soc_codec *codec;
>> + int ret = 0;
>> + codec = kzalloc(sizeof(struct snd_soc_codec), GFP_KERNEL);
>> + if (codec == NULL)
>> + return -ENOMEM;
>> + mutex_init(&codec->mutex);
>> + codec->name = "CX20442";
>> + codec->owner = THIS_MODULE;
>> + codec->dai = &cx20442_dai;
>> + codec->num_dai = 1;
> It'd be nice to switch this over to registering the CODEC as a platform
> device rather than using the old style ASoC probing - see something line
> WM8731 for a relatively simple example.
OK, I'll follow it.
>> +MODULE_DESCRIPTION("ASoC cx20442 driver");
>> +MODULE_AUTHOR("Cliff Cai ");
> You possibly want to update this one :)
> Basically, the CODEC driver looks fine from an ASoC point of view.
>> + * File: sound/soc/codec/cx20442.h
>> + * Based on: sound/soc/codec/ad73311.h
>> + * Author: Cliff Cai <cliff.cai at analog.com>
>> + *
>> + * Created: Thur Sep 25, 2008
>> + * Description: definitions for cx20442 registers
>> + *
>> + *
>> + * Modified:
>> + * Copyright 2006 Analog Devices Inc.
>> + *
>> + * Bugs: Enter bugs at http://blackfin.uclinux.org/
> These comments have cut'n'paste issues too, and the register definitions
> should all be removed.
Yes, only extern struct declarations required here, I think.
>> +static int ams_delta_startup(struct snd_pcm_substream *substream)
>> + ams_delta_latch2_write(AMS_DELTA_LATCH2_MODEM_CODEC, 0);
>> + return clk_enable(cx20442_mclk);
>> +static void ams_delta_shutdown(struct snd_pcm_substream *substream)
>> + clk_disable(cx20442_mclk);
> Possibly not an issue with this device but you might want to move the
> MCLK handling to your machine set_bias_level() function. That will
> mean that your MCLK will be left running for a while after audio stops,
> ensuring that the DAC has had time to clock out the final sample.
> Without that sometimes you can end up causing an audible artefact when
> starting the next playback.
OK, I'll look at this, but first I have to learn what MCLK really is ;)
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