sound/core/ctljack.c

   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 }