Add mISDN DSP

Enable support for digital audio processing capability.
This module may be used for special applications that require
cross connecting of bchannels, conferencing, dtmf decoding
echo cancelation, tone generation, and Blowfish encryption and
decryption.
It may use hardware features if available.

Signed-off-by: Karsten Keil <kkeil@suse.de>
diff --git a/drivers/isdn/mISDN/Kconfig b/drivers/isdn/mISDN/Kconfig
index 231bd0d..6a97e86 100644
--- a/drivers/isdn/mISDN/Kconfig
+++ b/drivers/isdn/mISDN/Kconfig
@@ -7,3 +7,21 @@
 	help
 	  Enable support for the modular ISDN driver.
 
+if MISDN != n
+
+config MISDN_DSP
+	tristate "Digital Audio Processing of transparent data"
+	depends on MISDN
+	help
+	  Enable support for digital audio processing capability.
+	  This module may be used for special applications that require
+	  cross connecting of bchannels, conferencing, dtmf decoding
+	  echo cancelation, tone generation, and Blowfish encryption and
+	  decryption.
+	  It may use hardware features if available.
+	  E.g. it is required for PBX4Linux. Go to http://isdn.eversberg.eu
+	  and get more informations about this module and it's usage.
+	  If unsure, say 'N'.
+
+	source "drivers/isdn/hardware/mISDN/Kconfig"
+endif #MISDN