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/include/linux/mISDNdsp.h b/include/linux/mISDNdsp.h
new file mode 100644
index 0000000..6b71d2d
--- /dev/null
+++ b/include/linux/mISDNdsp.h
@@ -0,0 +1,37 @@
+#ifndef __mISDNdsp_H__
+#define __mISDNdsp_H__
+
+struct mISDN_dsp_element_arg {
+	char	*name;
+	char	*def;
+	char	*desc;
+};
+
+struct mISDN_dsp_element {
+	char	*name;
+	void	*(*new)(const char *arg);
+	void	(*free)(void *p);
+	void	(*process_tx)(void *p, unsigned char *data, int len);
+	void	(*process_rx)(void *p, unsigned char *data, int len);
+	int	num_args;
+	struct mISDN_dsp_element_arg
+		*args;
+};
+
+extern int  mISDN_dsp_element_register(struct mISDN_dsp_element *elem);
+extern void mISDN_dsp_element_unregister(struct mISDN_dsp_element *elem);
+
+struct dsp_features {
+	int	hfc_id; /* unique id to identify the chip (or -1) */
+	int	hfc_dtmf; /* set if HFCmulti card supports dtmf */
+	int	hfc_loops; /* set if card supports tone loops */
+	int	hfc_echocanhw; /* set if card supports echocancelation*/
+	int	pcm_id; /* unique id to identify the pcm bus (or -1) */
+	int	pcm_slots; /* number of slots on the pcm bus */
+	int	pcm_banks; /* number of IO banks of pcm bus */
+	int	unclocked; /* data is not clocked (has jitter/loss) */
+	int	unordered; /* data is unordered (packets have index) */
+};
+
+#endif
+