dahdi: Do not define trace_printk if CONFIG_TRACING is not defined.

This was an accidental commit that slipped in as part of (a682401 "dahdi: Expose
dahdi devices in sysfs.")

Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
dahdi: Save the current maintstat in the span before calling into the drivers.

Some of the card callbacks needed maintstat set when processing loopup codes
from the remote side. This change is a modification of commit: (6c02c3c
"dahdi-base: Minor maint mode error")

Without this change cetain cards would not properly process the loopup /
loopdown codes (I know I should have more specific information here but the
details escape me at the moment).

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
oct612x: Break the oct612x out into a separate library.

Soon there will be more than one driver in the source tree that will want to use
these files. Compiling it as a library speeds the build since it won't have to
be built for each driver that wants to link it in.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
wct4xxp: Companding on VPM needs to be changed when switching linemodes.

If a user switches linemode with sysfs, the VPM would never switch the
companding mode to alaw, and the result would be extreme static on all channels
of the span when the VPM is enabeld.

Now if the deflaw of the span has changed when an echocan is created, the
companding mode of the VPM channel is changed.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>