1 files changed, 84 insertions, 0 deletions
diff --git a/sound/core/ctljack.c b/sound/core/ctljack.c
new file mode 100644
index 000000000..9be4e282f
--- /dev/null
+++ b/sound/core/ctljack.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Helper functions for jack-detection kcontrols
+ *
+ * Copyright (c) 2011 Takashi Iwai <tiwai@suse.de>
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/control.h>
+
+#define jack_detect_kctl_info	snd_ctl_boolean_mono_info
+
+static int jack_detect_kctl_get(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.integer.value[0] = kcontrol->private_value;
+	return 0;
+}
+
+static const struct snd_kcontrol_new jack_detect_kctl = {
+	/* name is filled later */
+	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ,
+	.info = jack_detect_kctl_info,
+	.get = jack_detect_kctl_get,
+};
+
+static int get_available_index(struct snd_card *card, const char *name)
+{
+	struct snd_ctl_elem_id sid;
+
+	memset(&sid, 0, sizeof(sid));
+
+	sid.index = 0;
+	sid.iface = SNDRV_CTL_ELEM_IFACE_CARD;
+	strlcpy(sid.name, name, sizeof(sid.name));
+
+	while (snd_ctl_find_id(card, &sid)) {
+		sid.index++;
+		/* reset numid; otherwise snd_ctl_find_id() hits this again */
+		sid.numid = 0;
+	}
+
+	return sid.index;
+}
+
+static void jack_kctl_name_gen(char *name, const char *src_name, int size)
+{
+	size_t count = strlen(src_name);
+	bool need_cat = true;
+
+	/* remove redundant " Jack" from src_name */
+	if (count >= 5)
+		need_cat = strncmp(&src_name[count - 5], " Jack", 5) ? true : false;
+
+	snprintf(name, size, need_cat ? "%s Jack" : "%s", src_name);
+
+}
+
+struct snd_kcontrol *
+snd_kctl_jack_new(const char *name, struct snd_card *card)
+{
+	struct snd_kcontrol *kctl;
+
+	kctl = snd_ctl_new1(&jack_detect_kctl, NULL);
+	if (!kctl)
+		return NULL;
+
+	jack_kctl_name_gen(kctl->id.name, name, sizeof(kctl->id.name));
+	kctl->id.index = get_available_index(card, kctl->id.name);
+	kctl->private_value = 0;
+	return kctl;
+}
+
+void snd_kctl_jack_report(struct snd_card *card,
+			  struct snd_kcontrol *kctl, bool status)
+{
+	if (kctl->private_value == status)
+		return;
+	kctl->private_value = status;
+	snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
+}