[alsa-devel] [RFC v2 5/6] ASoc: hdmi-codec: add IEC control.

[Jyri Sarha]

On 01/22/16 19:48, Arnaud Pouliquen wrote:
> Create 'IEC958 Playback Default' controls to support IEC61937 formats.
> the use of the alsa control is optional, using 'iec_ctl' flag.
>

I applied the patches "ALSA: pcm: add IEC958 channel status control 
helper", "ASoC: core: add code to complete dai init after pcm creation", 
and "ASoc: hdmi-codec: add IEC control" to my BBB HDMI audio branch. I 
needed to do some trivial conflict solving, but after that everything 
compiled fine. However, when I tried to read the iec mixer with:

# amixer -c0 cget name='IEC958 Playback Default',device=0
amixer: Cannot find the given element from control hw:0

The same command worked just fine on my intel based laptop:
# amixer -c0 cget iface=MIXER,name='IEC958 Playback Default',device=0
numid=31,iface=MIXER,name='IEC958 Playback Default'
   ; type=IEC958,access=rw------,values=1
   : values=[AES0=0x04 AES1=0x00 AES2=0x00 AES3=0x00]

How did you test the mixer yourself?

Best regards,
Jyri

> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
> ---
>   include/sound/hdmi-codec.h    |  1 +
>   sound/soc/codecs/hdmi-codec.c | 59 +++++++++++++++++++++++++++++++++----------
>   2 files changed, 46 insertions(+), 14 deletions(-)
>
> diff --git a/include/sound/hdmi-codec.h b/include/sound/hdmi-codec.h
> index ed780b2..58e8eae 100644
> --- a/include/sound/hdmi-codec.h
> +++ b/include/sound/hdmi-codec.h
> @@ -96,6 +96,7 @@ struct hdmi_codec_pdata {
>   	const struct hdmi_codec_ops *ops;
>   	uint i2s:1;
>   	uint spdif:1;
> +	uint iec_ctl:1;
>   	int max_i2s_channels;
>   };
>
> diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
> index 94349b3..1b6cb5a 100644
> --- a/sound/soc/codecs/hdmi-codec.c
> +++ b/sound/soc/codecs/hdmi-codec.c
> @@ -32,6 +32,7 @@ struct hdmi_codec_priv {
>   	struct snd_pcm_substream *current_stream;
>   	struct snd_pcm_hw_constraint_list ratec;
>   	uint8_t eld[MAX_ELD_BYTES];
> +	struct snd_aes_iec958 iec;
>   };
>
>   static const struct snd_soc_dapm_widget hdmi_widgets[] = {
> @@ -140,27 +141,30 @@ static int hdmi_codec_hw_params(struct snd_pcm_substream *substream,
>   				struct snd_soc_dai *dai)
>   {
>   	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
> -	struct hdmi_codec_params hp = {
> -		.iec = {
> -			.status = { 0 },
> -			.subcode = { 0 },
> -			.pad = 0,
> -			.dig_subframe = { 0 },
> -		}
> -	};
> +	struct hdmi_codec_params hp;
>   	int ret;
>
>   	dev_dbg(dai->dev, "%s() width %d rate %d channels %d\n", __func__,
>   		params_width(params), params_rate(params),
>   		params_channels(params));
>
> -	ret = snd_pcm_create_iec958_consumer_hw_params(params, hp.iec.status,
> -						       sizeof(hp.iec.status));
> -	if (ret < 0) {
> -		dev_err(dai->dev, "Creating IEC958 channel status failed %d\n",
> -			ret);
> -		return ret;
> +	mutex_lock(&hcp->current_stream_lock);
> +	hp.iec = hcp->iec;
> +
> +	if (!hcp->hcd.iec_ctl) {
> +		/*
> +		* only PCM format supported
> +		*channel status set according to runtime parameters
> +		*/
> +		ret = snd_pcm_create_iec958_consumer_hw_params(params,
> +					hp.iec.status, sizeof(hp.iec.status));
> +		if (ret < 0) {
> +			dev_err(dai->dev, "Creating IEC958 status failed %d\n",
> +				ret);
> +			return ret;
> +		}
>   	}
> +	mutex_unlock(&hcp->current_stream_lock);
>
>   	ret = hdmi_codec_new_stream(substream, dai);
>   	if (ret)
> @@ -266,12 +270,37 @@ static int hdmi_codec_digital_mute(struct snd_soc_dai *dai, int mute)
>   	return 0;
>   }
>
> +static int hdmi_codec_pcm_new(struct snd_soc_pcm_runtime *rtd,
> +			      struct snd_soc_dai *dai)
> +{
> +	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
> +	struct snd_pcm_iec958_params *iec958_params;
> +
> +	dev_dbg(dai->dev, "%s()\n", __func__);
> +
> +	if (!hcp->hcd.iec_ctl)
> +		return 0;
> +
> +	iec958_params = devm_kzalloc(dai->dev, sizeof(*iec958_params),
> +				     GFP_KERNEL);
> +	if (!iec958_params)
> +		return -ENOMEM;
> +
> +	iec958_params->iec = &hcp->iec;
> +	iec958_params->pdata = hcp;
> +	iec958_params->mutex = &hcp->current_stream_lock;
> +
> +	return snd_pcm_create_iec958_ctl(rtd->pcm, iec958_params,
> +					 SNDRV_PCM_STREAM_PLAYBACK);
> +}
> +
>   static const struct snd_soc_dai_ops hdmi_dai_ops = {
>   	.startup        = hdmi_codec_startup,
>   	.shutdown       = hdmi_codec_shutdown,
>   	.hw_params      = hdmi_codec_hw_params,
>   	.set_fmt        = hdmi_codec_set_fmt,
>   	.digital_mute   = hdmi_codec_digital_mute,
> +	.pcm_new        = hdmi_codec_pcm_new,
>   };
>
>
> @@ -352,6 +381,8 @@ static int hdmi_codec_probe(struct platform_device *pdev)
>   	if (!hcp)
>   		return -ENOMEM;
>
> +	memset(&hcp->iec, 0, sizeof(hcp->iec));
> +
>   	hcp->hcd = *hcd;
>   	mutex_init(&hcp->current_stream_lock);
>
>