HDA-VERB -- Send a HD-audio command

hda-verb is a small program to send HD-audio commands to the given

ALSA hwdep device on the hd-audio interface.

First off, build HD-audio driver with hwdep support.  For the kernel

config, set CONFIG_SND_HDA_HWDEP=y.  When you build ALSA drivers from

alsa-driver tarball, usually this is set automatically.

Once snd-hda-intel driver is built with the hwdep support, you should

have a hwdep device such as /dev/snd/hwC0D0.

The program takes four arguments, the hwdep device name, the widget NID,

the verb and the parameter.  For example,

	% hda-verb /dev/snd/hwC0D0 0x12 0x701 2

The verb argument can be a string like "PARAMETERS".  Also the

parameter argument can be a string like "VENDOR_ID" as well.

	% hda-verb /dev/snd/hwC0D0 0x0 PARAMETERS VENDOR_ID

The string is case insensitive.  Also, it doesn't have to be the full

string but only has to be unique.  E.g. "par" is enough to mean

"PARAMETER", and "set_a" is enough as "SET_AMP_GAIN_MUTE".

	% hda-verb /dev/snd/hwC0D0 2 set_a 0xb080

The program executs the given verb, shows the result and quits.

Usually you need to be root to run this command.

*WARNING*

Use this program carefully.  Sending an invalid verb may screw up the

codec communication, which requires either a reboot or reloading of

the sound driver eventually.