On 2020/11/2 下午 10:42, Pierre-Louis Bossart wrote:
+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]?
Yes. Currently, I set event on DAPM just with SND_SOC_DAPM_POST_PMU or SND_SOC_DAPM_POST_PMD, so these two specified events will be caught.
If I set SND_SOC_DAPM_PRE_PMU event, it can be caught, too.
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?
Yes, I agree with your opinion.
From the above description, I suppose you might want to point whether the dapm widget of EN_PIN is redundant, right? That's a reason the physical hardware pin is set to high/low in trigger function point of snd_soc_dai_ops, it always occurred after dapm event. If yes, from my current platform of verification, even if the dapm widget of EN_PIN is removed, the result of sound output is same yet. Maybe the first version, I should submit a simpler version.
- 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.
Yes, I follow most of drivers to use this flag.
- .endianness = 1,
- .non_legacy_dai_naming = 1,
+};
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