ASoC: jack: Manage gpios via devres

Let's be lazy -- this patch adds the devres code to
snd_soc_jack_add_gpios() for releasing the gpio resources at device
removal automagically.  After this patch, you don't have to call
snd_soc_jack_free_gpios() manually as long as it's managed from the
machine driver.

What about the gpios assigned in other levels?  Well, you might still
need to free the resources manually, depending on how the component
unbind works.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-jack.c

@@ -22,6 +22,12 @@
 #include <linux/suspend.h>
 #include <trace/events/asoc.h>
 
+struct jack_gpio_tbl {
+	int count;
+	struct snd_soc_jack *jack;
+	struct snd_soc_jack_gpio *gpios;
+};
+
 /**
  * snd_soc_codec_set_jack - configure codec jack.
  * @codec: CODEC
@@ -333,6 +339,28 @@ static int snd_soc_jack_pm_notifier(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+static void jack_free_gpios(struct snd_soc_jack *jack, int count,
+			    struct snd_soc_jack_gpio *gpios)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		gpiod_unexport(gpios[i].desc);
+		unregister_pm_notifier(&gpios[i].pm_notifier);
+		free_irq(gpiod_to_irq(gpios[i].desc), &gpios[i]);
+		cancel_delayed_work_sync(&gpios[i].work);
+		gpiod_put(gpios[i].desc);
+		gpios[i].jack = NULL;
+	}
+}
+
+static void jack_devres_free_gpios(struct device *dev, void *res)
+{
+	struct jack_gpio_tbl *tbl = res;
+
+	jack_free_gpios(tbl->jack, tbl->count, tbl->gpios);
+}
+
 /**
  * snd_soc_jack_add_gpios - Associate GPIO pins with an ASoC jack
  *
@@ -347,6 +375,14 @@ int snd_soc_jack_add_gpios(struct snd_soc_jack *jack, int count,
 			struct snd_soc_jack_gpio *gpios)
 {
 	int i, ret;
+	struct jack_gpio_tbl *tbl;
+
+	tbl = devres_alloc(jack_devres_free_gpios, sizeof(*tbl), GFP_KERNEL);
+	if (!tbl)
+		return -ENOMEM;
+	tbl->jack = jack;
+	tbl->count = count;
+	tbl->gpios = gpios;
 
 	for (i = 0; i < count; i++) {
 		if (!gpios[i].name) {
@@ -424,12 +460,14 @@ int snd_soc_jack_add_gpios(struct snd_soc_jack *jack, int count,
 				      msecs_to_jiffies(gpios[i].debounce_time));
 	}
 
+	devres_add(jack->card->dev, tbl);
 	return 0;
 
 err:
 	gpio_free(gpios[i].gpio);
 undo:
-	snd_soc_jack_free_gpios(jack, i, gpios);
+	jack_free_gpios(jack, i, gpios);
+	devres_free(tbl);
 
 	return ret;
 }
@@ -471,16 +509,8 @@ EXPORT_SYMBOL_GPL(snd_soc_jack_add_gpiods);
 void snd_soc_jack_free_gpios(struct snd_soc_jack *jack, int count,
 			struct snd_soc_jack_gpio *gpios)
 {
-	int i;
-
-	for (i = 0; i < count; i++) {
-		gpiod_unexport(gpios[i].desc);
-		unregister_pm_notifier(&gpios[i].pm_notifier);
-		free_irq(gpiod_to_irq(gpios[i].desc), &gpios[i]);
-		cancel_delayed_work_sync(&gpios[i].work);
-		gpiod_put(gpios[i].desc);
-		gpios[i].jack = NULL;
-	}
+	jack_free_gpios(jack, count, gpios);
+	devres_destroy(jack->card->dev, jack_devres_free_gpios, NULL, NULL);
 }
 EXPORT_SYMBOL_GPL(snd_soc_jack_free_gpios);
 #endif	/* CONFIG_GPIOLIB */