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
15static 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
22static 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
30static 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 strscpy(p: sid.name, q: name, size: sizeof(sid.name));
39
40 while (snd_ctl_find_id(card, id: &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
49static 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(buf: name, size, fmt: need_cat ? "%s Jack" : "%s", src_name);
59
60}
61
62struct snd_kcontrol *
63snd_kctl_jack_new(const char *name, struct snd_card *card)
64{
65 struct snd_kcontrol *kctl;
66
67 kctl = snd_ctl_new1(kcontrolnew: &jack_detect_kctl, NULL);
68 if (!kctl)
69 return NULL;
70
71 jack_kctl_name_gen(name: kctl->id.name, src_name: name, size: sizeof(kctl->id.name));
72 kctl->id.index = get_available_index(card, name: kctl->id.name);
73 kctl->private_value = 0;
74 return kctl;
75}
76
77void 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, id: &kctl->id);
84}
85

source code of linux/sound/core/ctljack.c