xref: /openbmc/linux/sound/core/ctljack.c (revision 4bce6fce)
1 /*
2  * Helper functions for jack-detection kcontrols
3  *
4  * Copyright (c) 2011 Takashi Iwai <tiwai@suse.de>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/export.h>
14 #include <sound/core.h>
15 #include <sound/control.h>
16 
17 #define jack_detect_kctl_info	snd_ctl_boolean_mono_info
18 
19 static int jack_detect_kctl_get(struct snd_kcontrol *kcontrol,
20 				struct snd_ctl_elem_value *ucontrol)
21 {
22 	ucontrol->value.integer.value[0] = kcontrol->private_value;
23 	return 0;
24 }
25 
26 static struct snd_kcontrol_new jack_detect_kctl = {
27 	/* name is filled later */
28 	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
29 	.access = SNDRV_CTL_ELEM_ACCESS_READ,
30 	.info = jack_detect_kctl_info,
31 	.get = jack_detect_kctl_get,
32 };
33 
34 static int get_available_index(struct snd_card *card, const char *name)
35 {
36 	struct snd_ctl_elem_id sid;
37 
38 	memset(&sid, 0, sizeof(sid));
39 
40 	sid.index = 0;
41 	sid.iface = SNDRV_CTL_ELEM_IFACE_CARD;
42 	strlcpy(sid.name, name, sizeof(sid.name));
43 
44 	while (snd_ctl_find_id(card, &sid))
45 		sid.index++;
46 
47 	return sid.index;
48 }
49 
50 static void jack_kctl_name_gen(char *name, const char *src_name, int size)
51 {
52 	size_t count = strlen(src_name);
53 	bool need_cat = true;
54 
55 	/* remove redundant " Jack" from src_name */
56 	if (count >= 5)
57 		need_cat = strncmp(&src_name[count - 5], " Jack", 5) ? true : false;
58 
59 	snprintf(name, size, need_cat ? "%s Jack" : "%s", src_name);
60 
61 }
62 
63 struct snd_kcontrol *
64 snd_kctl_jack_new(const char *name, struct snd_card *card)
65 {
66 	struct snd_kcontrol *kctl;
67 
68 	kctl = snd_ctl_new1(&jack_detect_kctl, NULL);
69 	if (!kctl)
70 		return NULL;
71 
72 	jack_kctl_name_gen(kctl->id.name, name, sizeof(kctl->id.name));
73 	kctl->id.index = get_available_index(card, name);
74 	kctl->private_value = 0;
75 	return kctl;
76 }
77 
78 void snd_kctl_jack_report(struct snd_card *card,
79 			  struct snd_kcontrol *kctl, bool status)
80 {
81 	if (kctl->private_value == status)
82 		return;
83 	kctl->private_value = status;
84 	snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
85 }
86