sound/core/ctljack.c

   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                 /* reset numid; otherwise snd_ctl_find_id() hits this again */
  47                 sid.numid = 0;
  48         }
  49
  50         return sid.index;
  51 }
  52
  53 static void jack_kctl_name_gen(char *name, const char *src_name, int size)
  54 {
  55         size_t count = strlen(src_name);
  56         bool need_cat = true;
  57
  58         /* remove redundant " Jack" from src_name */
  59         if (count >= 5)
  60                 need_cat = strncmp(&src_name[count - 5], " Jack", 5) ? true : false;
  61
  62         snprintf(name, size, need_cat ? "%s Jack" : "%s", src_name);
  63
  64 }
  65
  66 struct snd_kcontrol *
  67 snd_kctl_jack_new(const char *name, struct snd_card *card)
  68 {
  69         struct snd_kcontrol *kctl;
  70
  71         kctl = snd_ctl_new1(&jack_detect_kctl, NULL);
  72         if (!kctl)
  73                 return NULL;
  74
  75         jack_kctl_name_gen(kctl->id.name, name, sizeof(kctl->id.name));
  76         kctl->id.index = get_available_index(card, kctl->id.name);
  77         kctl->private_value = 0;
  78         return kctl;
  79 }
  80
  81 void snd_kctl_jack_report(struct snd_card *card,
  82                           struct snd_kcontrol *kctl, bool status)
  83 {
  84         if (kctl->private_value == status)
  85                 return;
  86         kctl->private_value = status;
  87         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
  88 }