Sound Mega-commit. Expect further cleanup until code freeze.

For a slightly thorough explaination, please refer to
	[1] http://people.freebsd.org/~ariff/SOUND_4.TXT.html .

Summary of changes includes:

1 Volume Per-Channel (vpc).  Provides private / standalone volume control
  unique per-stream pcm channel without touching master volume / pcm.
  Applications can directly use SNDCTL_DSP_[GET|SET][PLAY|REC]VOL, or for
  backwards compatibility, SOUND_MIXER_PCM through the opened dsp device
  instead of /dev/mixer.  Special "bypass" mode is enabled through
  /dev/mixer which will automatically detect if the adjustment is made
  through /dev/mixer and forward its request to this private volume
  controller.  Changes to this volume object will not interfere with
  other channels.

  Requirements:
    - SNDCTL_DSP_[GET|SET][PLAY|REC]_VOL are newer ioctls (OSSv4) which
      require specific application modifications (preferred).
    - No modifications required for using bypass mode, so applications
      like mplayer or xmms should work out of the box.

  Kernel hints:
    - hint.pcm.%d.vpc (0 = disable vpc).

  Kernel sysctls:
    - hw.snd.vpc_mixer_bypass (default: 1).  Enable or disable /dev/mixer
      bypass mode.
    - hw.snd.vpc_autoreset (default: 1).  By default, closing/opening
      /dev/dsp will reset the volume back to 0 db gain/attenuation.
      Setting this to 0 will preserve its settings across device
      closing/opening.
    - hw.snd.vpc_reset (default: 0).  Panic/reset button to reset all
      volume settings back to 0 db.
    - hw.snd.vpc_0db (default: 45).  0 db relative to linear mixer value.

2 High quality fixed-point Bandlimited SINC sampling rate converter,
  based on Julius O'Smith's Digital Audio Resampling -
  http://ccrma.stanford.edu/~jos/resample/.  It includes a filter design
  script written in awk (the clumsiest joke I've ever written)
    - 100% 32bit fixed-point, 64bit accumulator.
    - Possibly among the fastest (if not fastest) of its kind.
    - Resampling quality is tunable, either runtime or during kernel
      compilation (FEEDER_RATE_PRESETS).
    - Quality can be further customized during kernel compilation by
      defining FEEDER_RATE_PRESETS in /etc/make.conf.

  Kernel sysctls:
    - hw.snd.feeder_rate_quality.
      0 - Zero-order Hold (ZOH).  Fastest, bad quality.
      1 - Linear Interpolation (LINEAR).  Slightly slower than ZOH,
          better quality but still does not eliminate aliasing.
      2 - (and above) - Sinc Interpolation(SINC).  Best quality.  SINC
          quality always start from 2 and above.

  Rough quality comparisons:
    - http://people.freebsd.org/~ariff/z_comparison/

3 Bit-perfect mode.  Bypasses all feeder/dsp effects.  Pure sound will be
  directly fed into the hardware.

4 Parametric (compile time) Software Equalizer (Bass/Treble mixer). Can
  be customized by defining FEEDER_EQ_PRESETS in /etc/make.conf.

5 Transparent/Adaptive Virtual Channel. Now you don't have to disable
  vchans in order to make digital format pass through.  It also makes
  vchans more dynamic by choosing a better format/rate among all the
  concurrent streams, which means that dev.pcm.X.play.vchanformat/rate
  becomes sort of optional.

6 Exclusive Stream, with special open() mode O_EXCL.  This will "mute"
  other concurrent vchan streams and only allow a single channel with
  O_EXCL set to keep producing sound.

Other Changes:
    * most feeder_* stuffs are compilable in userland. Let's not
      speculate whether we should go all out for it (save that for
      FreeBSD 16.0-RELEASE).
    * kobj signature fixups, thanks to Andriy Gapon <avg@freebsd.org>
    * pull out channel mixing logic out of vchan.c and create its own
      feeder_mixer for world justice.
    * various refactoring here and there, for good or bad.
    * activation of few more OSSv4 ioctls() (see [1] above).
    * opt_snd.h for possible compile time configuration:
      (mostly for debugging purposes, don't try these at home)
        SND_DEBUG
        SND_DIAGNOSTIC
        SND_FEEDER_MULTIFORMAT
        SND_FEEDER_FULL_MULTIFORMAT
        SND_FEEDER_RATE_HP
        SND_PCM_64
        SND_OLDSTEREO

Manual page updates are on the way.

Tested by:	joel, Olivier SMEDTS <olivier at gid0 d org>, too many
          	unsung / unnamed heroes.

1 files changed, 20 insertions, 16 deletions

diff --git a/sys/dev/sound/sbus/cs4231.c b/sys/dev/sound/sbus/cs4231.c
index a785f96dbe56..90c947f5aaf3 100644
--- a/sys/dev/sound/sbus/cs4231.c
+++ b/sys/dev/sound/sbus/cs4231.c
@@ -50,6 +50,10 @@ __FBSDID("$FreeBSD$");
 #include <machine/bus.h>
 #include <machine/ofw_machdep.h>
 
+#ifdef HAVE_KERNEL_OPTION_HEADERS
+#include "opt_snd.h"
+#endif
+
 #include <dev/sound/pcm/sound.h>
 #include <dev/sound/sbus/apcdmareg.h>
 #include <dev/sound/sbus/cs4231.h>
@@ -260,18 +264,18 @@ MODULE_VERSION(snd_audiocs, 1);
 
 
 static u_int32_t cs4231_fmt[] = {
-	AFMT_U8,
-	AFMT_STEREO | AFMT_U8,
-	AFMT_MU_LAW,
-	AFMT_STEREO | AFMT_MU_LAW,
-	AFMT_A_LAW,
-	AFMT_STEREO | AFMT_A_LAW,
-	AFMT_IMA_ADPCM,
-	AFMT_STEREO | AFMT_IMA_ADPCM,
-	AFMT_S16_LE,
-	AFMT_STEREO | AFMT_S16_LE,
-	AFMT_S16_BE,
-	AFMT_STEREO | AFMT_S16_BE,
+	SND_FORMAT(AFMT_U8, 1, 0),
+	SND_FORMAT(AFMT_U8, 2, 0),
+	SND_FORMAT(AFMT_MU_LAW, 1, 0),
+	SND_FORMAT(AFMT_MU_LAW, 2, 0),
+	SND_FORMAT(AFMT_A_LAW, 1, 0),
+	SND_FORMAT(AFMT_A_LAW, 2, 0),
+	SND_FORMAT(AFMT_IMA_ADPCM, 1, 0),
+	SND_FORMAT(AFMT_IMA_ADPCM, 2, 0),
+	SND_FORMAT(AFMT_S16_LE, 1, 0),
+	SND_FORMAT(S16_LE, 2, 0),
+	SND_FORMAT(AFMT_S16_BE, 1, 0),
+	SND_FORMAT(AFMT_S16_BE, 2, 0),
 	0
 };
 
@@ -288,7 +292,7 @@ static kobj_method_t cs4231_chan_methods[] = {
 	KOBJMETHOD(channel_trigger,		cs4231_chan_trigger),
 	KOBJMETHOD(channel_getptr,		cs4231_chan_getptr),
 	KOBJMETHOD(channel_getcaps,		cs4231_chan_getcaps),
-	{ 0, 0 }
+	KOBJMETHOD_END
 };
 CHANNEL_DECLARE(cs4231_chan); 
 
@@ -299,7 +303,7 @@ static kobj_method_t cs4231_mixer_methods[] = {
 	KOBJMETHOD(mixer_init,		cs4231_mixer_init),
 	KOBJMETHOD(mixer_set,		cs4231_mixer_set),
 	KOBJMETHOD(mixer_setrecsrc,	cs4231_mixer_setrecsrc),
-	{ 0, 0 }
+	KOBJMETHOD_END
 };
 MIXER_DECLARE(cs4231_mixer);
 
@@ -1057,7 +1061,7 @@ cs4231_chan_setformat(kobj_t obj, void *data, u_int32_t format)
 		return (0);
 	}
 
-	encoding = format & ~AFMT_STEREO;
+	encoding = AFMT_ENCODING(format);
 	fs = 0;
 	switch (encoding) {
 	case AFMT_U8:
@@ -1084,7 +1088,7 @@ cs4231_chan_setformat(kobj_t obj, void *data, u_int32_t format)
 		break;
 	}
 
-	if (format & AFMT_STEREO)
+	if (AFMT_CHANNEL(format) > 1)
 		fs |= CS_AFMT_STEREO;
 	
 	DPRINTF(("FORMAT: %s : 0x%x\n", ch->dir == PCMDIR_PLAY ? "playback" :