emu20k1 has a native timer interrupt based on the audio clock, which
is more accurate than the system timer (from the synchronization POV).
This patch adds the code to handle this with multiple streams.

The system timer is still used on emu20k2, and can be used also for
emu20k1 easily by changing USE_SYSTEM_TIMER to 1 in cttimer.c.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Use SG-buffers instead of contiguous pages.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The device seems supporting only U8, S16, S24_3LE, S32.  Other linear
formats result in bad outputs.

Also, added the support for 32bit float format, which wasn't listed
in the original code.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

PCM names for surround streams should be also fixed as well as the mixer
element names.  Also, a bit clean up for PCM name setup.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Added ctxfi: prefix to each debug print.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The Sound Blaster X-Fi driver supports Creative solutions based on
20K1 and 20K2 chipsets.

Supported hardware :

Creative Sound Blaster X-Fi Titanium Fatal1ty® Champion Series
Creative Sound Blaster X-Fi Titanium Fatal1ty Professional Series
Creative Sound Blaster X-Fi Titanium Professional Audio
Creative Sound Blaster X-Fi Titanium
Creative Sound Blaster X-Fi Elite Pro
Creative Sound Blaster X-Fi Platinum
Creative Sound Blaster X-Fi Fatal1ty
Creative Sound Blaster X-Fi XtremeGamer
Creative Sound Blaster X-Fi XtremeMusic

Current release features:

* ALSA PCM Playback
* ALSA Record
* ALSA Mixer

Note:

* External I/O modules detection not included.
Signed-off-by: NWai Yew CHAY <wychay@ctl.creative.com>
Singed-off-by: NRyan RICHARDS <ryan_richards@creativelabs.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>