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Add a new API for soundcards that have hardware volume control:

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- The mixer_hwmute() function can be called when a soundcard receives a
  mute request.
- The mixer_hwstep() function can be used to adjust the volume of one or
  both channels.
- The 'hw.snd.hwvol_step' sysctl determines the amount that mixer_hwstep()
  adjusts the volume by on each call.
- The 'hw.snd.hwvol_mixer' sysctl specifies the mixer device to adjust the
  volume on for both functions.  The values used correspond to the
  SOUNDCARD_MIXER_* constants.
This commit is contained in:
John Baldwin 2001-01-03 01:29:47 +00:00
parent b3b7ccfe38
commit d0d4e34743
2 changed files with 39 additions and 0 deletions
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36
sys/dev/sound/pcm/mixer.c
View File

@ -254,6 +254,42 @@ mixer_ioctl(snddev_info *d, u_long cmd, caddr_t arg)
return ENXIO;
}
static int hwvol_step = 5;
SYSCTL_INT(_hw_snd, OID_AUTO, hwvol_step, CTLFLAG_RW, &hwvol_step, 0, "");
static int hwvol_mixer = SOUND_MIXER_VOLUME;
SYSCTL_INT(_hw_snd, OID_AUTO, hwvol_mixer, CTLFLAG_RW, &hwvol_mixer, 0, "");
void
mixer_hwmute(device_t dev)
{
snddev_info *d;
d = device_get_softc(dev);
mixer_set(d->mixer, hwvol_mixer, 0);
}
void
mixer_hwstep(device_t dev, int left_step, int right_step)
{
snddev_info *d;
int level, left, right;
d = device_get_softc(dev);
level = mixer_get(d->mixer, hwvol_mixer);
if (level != -1) {
left = level & 0xff;
right = level >> 8;
left += left_step * hwvol_step;
if (left < 0)
left = 0;
right += right_step * hwvol_step;
if (right < 0)
right = 0;
mixer_set(d->mixer, hwvol_mixer, left | right << 8);
}
}
/*
* The various mixers use a variety of bitmasks etc. The Voxware
* driver had a very nice technique to describe a mixer and interface

3
sys/dev/sound/pcm/mixer.h
View File

@ -33,6 +33,9 @@ extern int mixer_ioctl(snddev_info *d, u_long cmd, caddr_t arg);
extern int mixer_busy(snd_mixer *m, int busy);
extern int mixer_isbusy(snd_mixer *m);
void mixer_hwmute(device_t dev);
void mixer_hwstep(device_t dev, int left_step, int right_step);
extern void change_bits(mixer_tab *t, u_char *regval, int dev, int chn, int newval);
void mix_setdevs(snd_mixer *m, u_int32_t v);