Subject: [alsa-devel] [PATCH V2 1/2] ASoC: samsung: Add machine driver for Odroid X2/U3

From: [email-masked] (Sylwester Nawrocki)
Date: Thu, 26 Jun 2014 10:47:59 +0200

On 25/06/14 05:31, Tushar Behera wrote:
> On 06/18/2014 09:52 PM, Sylwester Nawrocki wrote:
>> This patch adds the sound subsystem driver for Odroid-X2 and
>> Odroid-U3 boards. The codec works in I2S master mode; there are
>> 2 separate audio routing paths defined as there are differences
>> in the signal routing between the X2 and U3 boards, i.e. U3 uses
>> single jack for headphones and microphone.
>>
>> Signed-off-by: Chen Zhen <[email-masked]>
>> Signed-off-by: Sylwester Nawrocki <[email-masked]>
>> ---
>>  sound/soc/samsung/Kconfig             |    8 ++
>>  sound/soc/samsung/Makefile            |    2 +
>>  sound/soc/samsung/odroidx2_max98090.c |  191 +++++++++++++++++++++++++++++++++
>>  3 files changed, 201 insertions(+)
>>  create mode 100644 sound/soc/samsung/odroidx2_max98090.c
>>
> 
> [ ... ]
> 
>> +static int odroidx2_hw_params(struct snd_pcm_substream *substream,
>> +	struct snd_pcm_hw_params *params)
>> +{
>> +	struct snd_soc_pcm_runtime *rtd = substream->private_data;
>> +	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
>> +	struct snd_soc_dai *codec_dai = rtd->codec_dai;
>> +	int ret;
>> +
>> +	ret = snd_soc_dai_set_sysclk(codec_dai, 0, MAX98090_MCLK,
>> +						SND_SOC_CLOCK_IN);
>> +	if (ret < 0) {
>> +		dev_err(codec_dai->dev,
>> +			"Unable to switch to FLL1: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	/* Set the cpu DAI configuration in order to use CDCLK */
>> +	ret = snd_soc_dai_set_sysclk(cpu_dai, SAMSUNG_I2S_CDCLK,
>> +					0, SND_SOC_CLOCK_OUT);
>> +	if (ret < 0)
>> +		return ret;
>> +
> 
> While upstreaming sound-card driver for Snow board, I had a comment from
> Mark to move this to probe, if possible. That way, the clock operations
> would be done only once and this function and odroidx2_ops can be
> removed altogether.

Thanks for the suggestion, I'll change it for the next iteration.

>> +	dev_dbg(codec_dai->dev, "HiFi DAI %s params: channels: %d, rate: %d\n",
>> +		snd_pcm_stream_str(substream), params_channels(params),
>> +		params_rate(params));
>> +
>> +	return 0;
>> +}
>> +
>> +static struct snd_soc_ops odroidx2_ops = {
>> +	.hw_params	= odroidx2_hw_params,
>> +};
>> +
> 
> [ ... ]
> 
>> +
>> +	ret = snd_soc_register_card(card);
> 
> devm_snd_soc_register_card ?

Could be, although snd_soc_unregister_card() wouldn't release references
to the OF nodes, i.e. there would be no related of_node_put() calls.
And for correctness, the of_node_put() calls should be made _after_
a snd_soc_unregister_card() call, and I can't see how it could be possible
if I left only of_node_put() calls in the odroidx2_audio_remove() callback.

>> +	if (ret) {
>> +		dev_err(&pdev->dev, "snd_soc_register_card failed: %d\n", ret);
>> +		goto err_put_cpu_n;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_put_cpu_n:
>> +	of_node_put(odroidx2_dai[0].cpu_of_node);
>> +err_put_cod_n:
>> +	of_node_put(odroidx2_dai[0].codec_of_node);
>> +	return ret;
>> +}
>> +
>> +static int odroidx2_audio_remove(struct platform_device *pdev)
>> +{
>> +	struct snd_soc_card *card = platform_get_drvdata(pdev);
>> +
>> +	snd_soc_unregister_card(card);
> 
> This can be removed when devm_snd_soc_register_card is used.

--
Regards,
Sylwester