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

From: Michael Trimarchi
Date: Tue Nov 24 2015 - 03:27:47 EST


Hi

On Tue, Nov 24, 2015 at 9:21 AM, RaphaÃl Poggi <poggi.raph@xxxxxxxxx> wrote:
> 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.
>

Well I know exactly why is used for, but I don't really know if it's
somenthing that should be
in dts. Do I want to do channel inversion?

Michael

>>> return snd_soc_register_codec(&spi->dev,
>>> &soc_codec_dev_pcm1792a, &pcm1792a_dai, 1);
>>> }
>>> --
>>> 2.1.0
>>>
>>> _______________________________________________
>>> Alsa-devel mailing list
>>> 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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--
| 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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