LXR linux/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
  19static 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
  26static const 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
  34static 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
  53static 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
  66struct snd_kcontrol *
  67snd_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
  81void 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}
  89