Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Use DEVMETHOD_END macro defined in sys/bus.h instead of {0, 0} sentinel on device_method_t arrays

Reviewed by: cognet
Approved by: cognet

Replace GPL'd headers in the emu10kx snd driver code.

This uses the emuxkireg.h already used in the emu10k1
snd driver. Special thanks go to Alexander Motin as
he was able to find some errors and reverse engineer
some wrong values in the emuxkireg header.

The emu10kx driver is now free from the GPL.

PR: 153901
Tested by: mav, joel
Approved by: jhb (mentor)
MFC after: 2 weeks

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.

Slightly adjust copyright text.

Approved by: matk

Update snd_emu10kx driver with recent perforce changes (and few
other changes too).

(without any real order)

1. Use device_get_nameunit for mutex naming
2. Add timer for low-latency playback
3. Move most mixer controls from sysctls to mixer(8) controls.
This is a largest part of this patch.
4. Add analog/digital switch (as a temporary sysctl)
5. Get back support for low-bitrate playback (with help of (2))
6. Change locking for exclusive I/O. Writing to non-PTR register
is almost safe and does not need to be ordered with PTR operations.
7. Disable MIDI until we get it to detach properly and fix memory
managment problems.
8. Enable multichannel playback by default. It is as stable as
single-channel mode. Multichannel recording is still an
experimental feature.
9. Multichannel options can be changed by loader tunables.
10. Add a way to disable card from a loader tunable.
11. Add new PCI IDs.
12. Debugger settings are loader tunables now.
14. Remove some unused variables.
15. Mark pcm sub-devices MPSAFE.
16. Partially revert (bus_setup_intr -> snd_setup_intr) since it need
to be done independently

Submitted by: Yuriy Tsibizov (driver maintainer)
Approved by: re (bmah)

Fix a compile time problem on amd64. I'm not sure if the fix is correct
from a semantic point of view, but I notified the author of the driver
for confirmation. So far it at least fixes the build and should only
lead to not identifying or wrongly identifying a soundcard in the worst
case.

Make the MIDI kobj class static. This brings it inline with the channel or
ac97 classes.

This allows to link emu10k1 and emu10kx into the same kernel (LINT).

Add snd_emu10kx driver for Creative SoundBlaster Live! and Audigy series
sound cards with optional pseudo-multichannel playback.

It's based on snd_emu10k1 sound driver. Single channel version is available
from audio/emu10kx port since some time.

The two new ALSA header files (GPLed), which contain Audigy 2 ("p16v") and
Audigy 2 Value ("p17v") specific interfaces, are latest versions from ALSA
Mercurial repository.

This is not connected to the build yet.

Submitted by: Yuriy Tsibizov <Yuriy.Tsibizov@gfk.ru>