ASoC: qcom: Parse "pin-switches" and "widgets" from DT

Merge series from Stephan Gerhold <stephan@gerhold.net>:

Some sound card setups might require extra pin switches to allow
turning off certain audio components. simple-card supports this
already using the "pin-switches" and "widgets" device tree property.
This series makes it possible to use the same properties for the Qcom
sound cards.

To implement that, the function that parses the "pin-switches" property
in simple-card-utils.c is first moved into the ASoC core. Then two
simple function calls are added to the common Qcom sound card DT parser.
Finally there is a small patch for the msm8916-wcd-analog codec to make
it possible to model sound card setups used in some MSM8916 smartphones.
(See PATCH 2/4 for an explanation of some real example use cases.)

Using pin switches rather than patching codec drivers with switches was
originally suggested by Mark Brown on a patch for the tfa989x codec:
https://lore.kernel.org/alsa-devel/YXaMVHo9drCIuD3u@sirena.org.uk/

1 files changed, 1 insertions, 44 deletions

diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 850e968677f1..a81323d1691d 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -499,57 +499,14 @@ EXPORT_SYMBOL_GPL(asoc_simple_parse_widgets);
 int asoc_simple_parse_pin_switches(struct snd_soc_card *card,
 				   char *prefix)
 {
-	const unsigned int nb_controls_max = 16;
-	const char **strings, *control_name;
-	struct snd_kcontrol_new *controls;
-	struct device *dev = card->dev;
-	unsigned int i, nb_controls;
 	char prop[128];
-	int ret;
 
 	if (!prefix)
 		prefix = "";
 
 	snprintf(prop, sizeof(prop), "%s%s", prefix, "pin-switches");
 
-	if (!of_property_read_bool(dev->of_node, prop))
-		return 0;
-
-	strings = devm_kcalloc(dev, nb_controls_max,
-			       sizeof(*strings), GFP_KERNEL);
-	if (!strings)
-		return -ENOMEM;
-
-	ret = of_property_read_string_array(dev->of_node, prop,
-					    strings, nb_controls_max);
-	if (ret < 0)
-		return ret;
-
-	nb_controls = (unsigned int)ret;
-
-	controls = devm_kcalloc(dev, nb_controls,
-				sizeof(*controls), GFP_KERNEL);
-	if (!controls)
-		return -ENOMEM;
-
-	for (i = 0; i < nb_controls; i++) {
-		control_name = devm_kasprintf(dev, GFP_KERNEL,
-					      "%s Switch", strings[i]);
-		if (!control_name)
-			return -ENOMEM;
-
-		controls[i].iface = SNDRV_CTL_ELEM_IFACE_MIXER;
-		controls[i].name = control_name;
-		controls[i].info = snd_soc_dapm_info_pin_switch;
-		controls[i].get = snd_soc_dapm_get_pin_switch;
-		controls[i].put = snd_soc_dapm_put_pin_switch;
-		controls[i].private_value = (unsigned long)strings[i];
-	}
-
-	card->controls = controls;
-	card->num_controls = nb_controls;
-
-	return 0;
+	return snd_soc_of_parse_pin_switches(card, prop);
 }
 EXPORT_SYMBOL_GPL(asoc_simple_parse_pin_switches);