Re: [alsa-devel] [PATCH 4/4] sound: codecs: pcm1792a: introduce channel side

From: RaphaÃl Poggi
Date: Tue Nov 24 2015 - 03:22:41 EST


Hi,

2015-11-21 10:37 GMT+01:00 Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx>:
> Hi
>
> On Fri, Nov 20, 2015 at 11:09 AM, Raphael Poggi <poggi.raph@xxxxxxxxx> wrote:
>> From: Raphael Poggi <poggi.raph@xxxxxxxxx>
>>
>> Add possibility to choose the channel side using the device tree,
>> and also modify it using alsa ctrl.
>>
>> Signed-off-by: Raphael Poggi <poggi.raph@xxxxxxxxx>
>> ---
>> sound/soc/codecs/pcm1792a.c | 46 +++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 46 insertions(+)
>>
>> diff --git a/sound/soc/codecs/pcm1792a.c b/sound/soc/codecs/pcm1792a.c
>> index febaa48..005b679 100644
>> --- a/sound/soc/codecs/pcm1792a.c
>> +++ b/sound/soc/codecs/pcm1792a.c
>> @@ -65,6 +65,12 @@ static const struct reg_default pcm1792a_reg_defaults[] = {
>> { PCM1792A_DEVICE_ID, 0x00 },
>> };
>>
>> +enum __pcm1792_side {
>> + STEREO,
>> + MONORAL_LEFT,
>> + MONORAL_RIGHT
>> +};
>> +
>> static bool pcm1792a_accessible_reg(struct device *dev, unsigned int reg)
>> {
>> return reg >= 0x10 && reg <= 0x17;
>> @@ -83,6 +89,7 @@ struct pcm1792a_private {
>> struct regmap *regmap;
>> unsigned int format;
>> unsigned int rate;
>> + unsigned int side;
>> };
>>
>> static int pcm1792a_set_dai_fmt(struct snd_soc_dai *codec_dai,
>> @@ -153,6 +160,13 @@ static int pcm1792a_hw_params(struct snd_pcm_substream *substream,
>> ret = regmap_update_bits(priv->regmap, PCM1792A_FMT_CONTROL,
>> PCM1792A_FMT_MASK | PCM1792A_ATLD_ENABLE, val);
>>
>> + if (priv->side == MONORAL_LEFT)
>> + val = PCM1792A_CHANNEL_MONO_LEFT;
>> + else if (priv->side == MONORAL_RIGHT)
>> + val = PCM1792A_CHANNEL_MONO_RIGHT;
>> +
>> + regmap_update_bits(priv->regmap, PCM1792A_CHANNEL, PCM1792A_CHANNEL_MONO_MASK, val);
>> +
>> return ret;
>> }
>>
>> @@ -222,10 +236,31 @@ static struct snd_soc_codec_driver soc_codec_dev_pcm1792a = {
>> .num_dapm_routes = ARRAY_SIZE(pcm1792a_dapm_routes),
>> };
>>
>> +static int pcm1792a_of_init(struct spi_device *spi)
>> +{
>> + int ret = 0;
>> + struct pcm1792a_private *pcm1792a = dev_get_drvdata(&spi->dev);
>> + const char *name;
>> + struct device_node *np = spi->dev.of_node;
>> +
>> + name = of_get_property(np, "ti,side", NULL);
>> + if (name) {
>> + if (!strcmp(name, "left"))
>> + pcm1792a->side = MONORAL_LEFT;
>> + else
>> + pcm1792a->side = MONORAL_RIGHT;
>> + }
>> + else
>> + pcm1792a->side = STEREO;
>> +
>> + return ret;
>> +}
>> +
>> static int pcm1792a_spi_probe(struct spi_device *spi)
>> {
>> struct pcm1792a_private *pcm1792a;
>> int ret;
>> + struct device_node *np = spi->dev.of_node;
>>
>> pcm1792a = devm_kzalloc(&spi->dev, sizeof(struct pcm1792a_private),
>> GFP_KERNEL);
>> @@ -241,6 +276,17 @@ static int pcm1792a_spi_probe(struct spi_device *spi)
>> return ret;
>> }
>>
>> + if (np) {
>> + ret = pcm1792a_of_init(spi);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + if (pcm1792a->side == MONORAL_LEFT)
>> + regmap_update_bits(pcm1792a->regmap, PCM1792A_CHANNEL, PCM1792A_CHANNEL_MONO_MASK, PCM1792A_CHANNEL_MONO_LEFT);
>> + else if (pcm1792a->side == MONORAL_RIGHT)
>> + regmap_update_bits(pcm1792a->regmap, PCM1792A_CHANNEL, PCM1792A_CHANNEL_MONO_MASK, PCM1792A_CHANNEL_MONO_RIGHT);
>> +
>
> Why this is a part of dts and not a part of mixer control?
>
> Michael
>

The "channel side" bindings should be used when the pcm7192a is used
in monaural mode (which requires two DACs, both DACs operate in a
balanced mode for one channel of audio input data).
This is a hardware level design, it will never change at runtime.
I feel that a device tree binding is more appropriate than a control.

>> return snd_soc_register_codec(&spi->dev,
>> &soc_codec_dev_pcm1792a, &pcm1792a_dai, 1);
>> }
>> --
>> 2.1.0
>>
>> _______________________________________________
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>> Alsa-devel@xxxxxxxxxxxxxxxx
>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>
>
>
> --
> | Michael Nazzareno Trimarchi Amarula Solutions BV |
> | COO - Founder Cruquiuskade 47 |
> | +31(0)851119172 Amsterdam 1018 AM NL |
> | [`as] http://www.amarulasolutions.com |
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