LXR linux/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
  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        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
  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(name, size, 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(&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
  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, &kctl->id);
  84}
  85