Re: [PATCH v2 1/2] ASoC: codec: use enable pin to control dmic start and stop

[hl <hl@rock-chips.com>]

On Monday, September 04, 2017 06:03 PM, Arnaud Pouliquen wrote:
> Hello Lin,
>
> Sorry for this late answer.
> I'm not maintainer, just a contributor... but as some update seems
> strange for me, so i prefer to highlight it to clarify them.
>
> On 08/17/2017 04:24 AM, Lin Huang wrote:
>> From: huang lin <hl@rock-chips.com>
>>
>> on some board use enable pin to control dmic start and stop,
>> so add this feature in dmic driver.
> Please, Could you give data-sheet reference of your DMIC, to help me
> to understand your use-case?
>> Signed-off-by: Lin Huang <hl@rock-chips.com>
>> ---
>>   sound/soc/codecs/Kconfig |  2 +-
>>   sound/soc/codecs/dmic.c  | 46 ++++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 47 insertions(+), 1 deletion(-)
>>
>> diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
>> index 010811e..d98233b 100644
>> --- a/sound/soc/codecs/Kconfig
>> +++ b/sound/soc/codecs/Kconfig
>> @@ -71,7 +71,7 @@ config SND_SOC_ALL_CODECS
>>   	select SND_SOC_DA732X if I2C
>>   	select SND_SOC_DA9055 if I2C
>>   	select SND_SOC_DIO2125
>> -	select SND_SOC_DMIC
>> +	select SND_SOC_DMIC if GPIOLIB
> Dependency also for DMIC without GPIO to handle gating?
>>   	select SND_SOC_ES8316 if I2C
>>   	select SND_SOC_ES8328_SPI if SPI_MASTER
>>   	select SND_SOC_ES8328_I2C if I2C
>> diff --git a/sound/soc/codecs/dmic.c b/sound/soc/codecs/dmic.c
>> index 12e07f9..b88a1ee 100644
>> --- a/sound/soc/codecs/dmic.c
>> +++ b/sound/soc/codecs/dmic.c
>> @@ -19,6 +19,8 @@
>>    *
>>    */
>>   
>> +#include <linux/gpio.h>
>> +#include <linux/gpio/consumer.h>
>>   #include <linux/platform_device.h>
>>   #include <linux/slab.h>
>>   #include <linux/module.h>
>> @@ -27,6 +29,34 @@
>>   #include <sound/soc.h>
>>   #include <sound/soc-dapm.h>
>>   
>> +static int dmic_daiops_trigger(struct snd_pcm_substream *substream,
>> +		int cmd, struct snd_soc_dai *dai)
>> +{
>> +	struct gpio_desc *dmic_en = snd_soc_dai_get_drvdata(dai);
>> +
>> +	if (!dmic_en)
>> +		return 0;
>> +
>> +	switch (cmd) {
>> +	case SNDRV_PCM_TRIGGER_START:
>> +	case SNDRV_PCM_TRIGGER_RESUME:
>> +	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
>> +		gpiod_set_value(dmic_en, 1);
>> +		break;
>> +	case SNDRV_PCM_TRIGGER_STOP:
>> +	case SNDRV_PCM_TRIGGER_SUSPEND:
>> +	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
>> +		gpiod_set_value(dmic_en, 0);
>> +		break;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct snd_soc_dai_ops dmic_dai_ops = {
>> +	.trigger	= dmic_daiops_trigger,
>> +};
>> +
> should it be handle by trigger or DAPM?
>
>
>
>>   static struct snd_soc_dai_driver dmic_dai = {
>>   	.name = "dmic-hifi",
>>   	.capture = {
>> @@ -38,8 +68,23 @@ static struct snd_soc_dai_driver dmic_dai = {
>>   			| SNDRV_PCM_FMTBIT_S24_LE
>>   			| SNDRV_PCM_FMTBIT_S16_LE,
>>   	},
>> +	.ops    = &dmic_dai_ops,
>>   };
>>   
>> +static int dmic_codec_probe(struct snd_soc_codec *codec)
>> +{
>> +	struct gpio_desc *dmic_en;
>> +
>> +	dmic_en = devm_gpiod_get_optional(codec->dev,
>> +					"dmicen", GPIOD_OUT_LOW);
> Hypothesis here is that GPIO is always set to low? seems too limiting.
Yes, you are right, maybe i can set it to 
devm_gpiod_get_optional(codec->dev, "dmicen", GPIOD_ASIS);
>
> Regards
> Arnaud
>> +	if (IS_ERR(dmic_en))
>> +		return PTR_ERR(dmic_en);
>> +
>> +	snd_soc_codec_set_drvdata(codec, dmic_en);
>> +
>> +	return 0;
>> +}
>> +
>>   static const struct snd_soc_dapm_widget dmic_dapm_widgets[] = {
>>   	SND_SOC_DAPM_AIF_OUT("DMIC AIF", "Capture", 0,
>>   			     SND_SOC_NOPM, 0, 0),
>> @@ -51,6 +96,7 @@ static const struct snd_soc_dapm_route intercon[] = {
>>   };
>>   
>>   static const struct snd_soc_codec_driver soc_dmic = {
>> +	.probe = dmic_codec_probe,
>>   	.component_driver = {
>>   		.dapm_widgets		= dmic_dapm_widgets,
>>   		.num_dapm_widgets	= ARRAY_SIZE(dmic_dapm_widgets),
>>
>
>