xref: /linux/sound/core/ctljack.c (revision 7505576d1c1ac0cfe85fdf90999433dd8b673012)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Helper functions for jack-detection kcontrols
4  *
5  * Copyright (c) 2011 Takashi Iwai <tiwai@suse.de>
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/export.h>
10 #include <sound/core.h>
11 #include <sound/control.h>
12 
13 #define jack_detect_kctl_info	snd_ctl_boolean_mono_info
14 
15 static int jack_detect_kctl_get(struct snd_kcontrol *kcontrol,
16 				struct snd_ctl_elem_value *ucontrol)
17 {
18 	ucontrol->value.integer.value[0] = kcontrol->private_value;
19 	return 0;
20 }
21 
22 static const struct snd_kcontrol_new jack_detect_kctl = {
23 	/* name is filled later */
24 	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
25 	.access = SNDRV_CTL_ELEM_ACCESS_READ,
26 	.info = jack_detect_kctl_info,
27 	.get = jack_detect_kctl_get,
28 };
29 
30 static int get_available_index(struct snd_card *card, const char *name)
31 {
32 	struct snd_ctl_elem_id sid;
33 
34 	memset(&sid, 0, sizeof(sid));
35 
36 	sid.index = 0;
37 	sid.iface = SNDRV_CTL_ELEM_IFACE_CARD;
38 	strlcpy(sid.name, name, sizeof(sid.name));
39 
40 	while (snd_ctl_find_id(card, &sid)) {
41 		sid.index++;
42 		/* reset numid; otherwise snd_ctl_find_id() hits this again */
43 		sid.numid = 0;
44 	}
45 
46 	return sid.index;
47 }
48 
49 static void jack_kctl_name_gen(char *name, const char *src_name, int size)
50 {
51 	size_t count = strlen(src_name);
52 	bool need_cat = true;
53 
54 	/* remove redundant " Jack" from src_name */
55 	if (count >= 5)
56 		need_cat = strncmp(&src_name[count - 5], " Jack", 5) ? true : false;
57 
58 	snprintf(name, size, need_cat ? "%s Jack" : "%s", src_name);
59 
60 }
61 
62 struct snd_kcontrol *
63 snd_kctl_jack_new(const char *name, struct snd_card *card)
64 {
65 	struct snd_kcontrol *kctl;
66 
67 	kctl = snd_ctl_new1(&jack_detect_kctl, NULL);
68 	if (!kctl)
69 		return NULL;
70 
71 	jack_kctl_name_gen(kctl->id.name, name, sizeof(kctl->id.name));
72 	kctl->id.index = get_available_index(card, kctl->id.name);
73 	kctl->private_value = 0;
74 	return kctl;
75 }
76 
77 void snd_kctl_jack_report(struct snd_card *card,
78 			  struct snd_kcontrol *kctl, bool status)
79 {
80 	if (kctl->private_value == status)
81 		return;
82 	kctl->private_value = status;
83 	snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
84 }
85