[PATCH] ASoC: nau8315: add codec driver

[Pierre-Louis Bossart]

> +struct nau8315_priv {
> +	struct gpio_desc *enable;
> +	int enpin_switch;
> +};
> +
> +static int nau8315_daiops_trigger(struct snd_pcm_substream *substream,
> +		int cmd, struct snd_soc_dai *dai)
> +{
> +	struct snd_soc_component *component = dai->component;
> +	struct nau8315_priv *nau8315 =
> +		snd_soc_component_get_drvdata(component);
> +
> +	if (!nau8315->enable)
> +		return 0;
> +
> +	switch (cmd) {
> +	case SNDRV_PCM_TRIGGER_START:
> +	case SNDRV_PCM_TRIGGER_RESUME:
> +	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> +		if (nau8315->enpin_switch) {
> +			gpiod_set_value(nau8315->enable, 1);
> +			dev_dbg(component->dev, "set enable to 1");
> +		}

I know the code is modeled after max98357a.c but I keep wondering if 
this enpin_switch state is actually useful for anything.

Is there actually a case where the trigger happens before the 
DAPM_POST_PMU event handled below [1]?

> +		break;
> +	case SNDRV_PCM_TRIGGER_STOP:
> +	case SNDRV_PCM_TRIGGER_SUSPEND:
> +	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> +		gpiod_set_value(nau8315->enable, 0);
> +		dev_dbg(component->dev, "set enable to 0");
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int nau8315_enpin_event(struct snd_soc_dapm_widget *w,
> +		struct snd_kcontrol *kcontrol, int event)
> +{
> +	struct snd_soc_component *component =
> +		snd_soc_dapm_to_component(w->dapm);
> +	struct nau8315_priv *nau8315 =
> +		snd_soc_component_get_drvdata(component);
> +

[1]

> +	if (event & SND_SOC_DAPM_POST_PMU)
> +		nau8315->enpin_switch = 1;
> +	else if (event & SND_SOC_DAPM_POST_PMD)
> +		nau8315->enpin_switch = 0;

And even if this variable was useful, for symmetry should it be 
PRE_PMU/POST_PMD?

> +
> +	return 0;
> +}
> +
> +static const struct snd_soc_dapm_widget nau8315_dapm_widgets[] = {
> +	SND_SOC_DAPM_OUTPUT("Speaker"),
> +	SND_SOC_DAPM_OUT_DRV_E("EN_Pin", SND_SOC_NOPM, 0, 0, NULL, 0,
> +			nau8315_enpin_event,
> +			SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
> +};
> +
> +static const struct snd_soc_dapm_route nau8315_dapm_routes[] = {
> +	{"EN_Pin", NULL, "HiFi Playback"},
> +	{"Speaker", NULL, "EN_Pin"},
> +};
> +
> +static const struct snd_soc_component_driver nau8315_component_driver = {
> +	.dapm_widgets		= nau8315_dapm_widgets,
> +	.num_dapm_widgets	= ARRAY_SIZE(nau8315_dapm_widgets),
> +	.dapm_routes		= nau8315_dapm_routes,
> +	.num_dapm_routes	= ARRAY_SIZE(nau8315_dapm_routes),
> +	.idle_bias_on		= 1,
> +	.use_pmdown_time	= 1,

is this necessary? This has the side effect of powering-down immediately 
instead of after a delay.

> +	.endianness		= 1,
> +	.non_legacy_dai_naming	= 1,
> +};