[PATCH 1/4] ASoC: simple-card-utils: Add simple_util_remove_jack()

[Chancel Liu <chancel.liu@oss.nxp.com>]

From: Chancel Liu <chancel.liu@nxp.com>

simple_util_init_jack() acquires a GPIO descriptor with
gpiod_get_optional() and hands it to snd_soc_jack_add_gpios(), which
additionally installs an IRQ handler, a PM notifier, a delayed work and
a sysfs export for it. simple-card-utils has no counterpart that
releases any of this again.

Add simple_util_remove_jack(), the counterpart of
simple_util_init_jack(). It releases the jack GPIO and everything
snd_soc_jack_add_gpios() installed for it via snd_soc_jack_free_gpios(),
and clears sjack->gpio.desc so the descriptor is not left dangling after
it has been put.

This gives the generic card drivers a card->remove() path to release the
jack when the card goes away. The devres cleanup alone is not enough:
it is tied to the platform device, so it does not run when the card is
unregistered and re-registered while the platform device stays bound -
for example when a codec component is unbound and bound again.

Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
---
 include/sound/simple_card_utils.h     |  1 +
 sound/soc/generic/simple-card-utils.c | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/sound/simple_card_utils.h b/include/sound/simple_card_utils.h
index bd8c3a033577..b0e00555092e 100644
--- a/include/sound/simple_card_utils.h
+++ b/include/sound/simple_card_utils.h
@@ -219,6 +219,7 @@ static inline int simple_util_parse_aux_devs(struct simple_util_priv *priv, char
 int simple_util_init_jack(struct snd_soc_card *card,
 			       struct simple_util_jack *sjack,
 			       int is_hp, char *prefix, char *pin);
+void simple_util_remove_jack(struct simple_util_jack *sjack);
 int simple_util_init_aux_jacks(struct snd_soc_card *card, char *prefix);
 int simple_util_init_priv(struct simple_util_priv *priv,
 			       struct link_info *li);
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 7df5253499cd..b91924d31c1a 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -825,6 +825,16 @@ int simple_util_init_jack(struct snd_soc_card *card,
 }
 EXPORT_SYMBOL_GPL(simple_util_init_jack);
 
+void simple_util_remove_jack(struct simple_util_jack *sjack)
+{
+	if (!sjack->gpio.desc)
+		return;
+
+	snd_soc_jack_free_gpios(&sjack->jack, 1, &sjack->gpio);
+	sjack->gpio.desc = NULL;
+}
+EXPORT_SYMBOL_GPL(simple_util_remove_jack);
+
 int simple_util_init_aux_jacks(struct snd_soc_card *card, char *prefix)
 {
 	struct simple_util_priv *priv = snd_soc_card_get_drvdata(card);
-- 
2.50.1