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>

1 files changed, 551 insertions, 0 deletions

diff --git a/drivers/isdn/mISDN/dsp_tones.c b/drivers/isdn/mISDN/dsp_tones.c
new file mode 100644
index 000000000000..23dd0dd21524
--- /dev/null
+++ b/drivers/isdn/mISDN/dsp_tones.c
@@ -0,0 +1,551 @@
+/*
+ * Audio support data for ISDN4Linux.
+ *
+ * Copyright Andreas Eversberg (jolly@eversberg.eu)
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ */
+
+#include <linux/mISDNif.h>
+#include <linux/mISDNdsp.h>
+#include "core.h"
+#include "dsp.h"
+
+
+#define DATA_S sample_silence
+#define SIZE_S (&sizeof_silence)
+#define DATA_GA sample_german_all
+#define SIZE_GA (&sizeof_german_all)
+#define DATA_GO sample_german_old
+#define SIZE_GO (&sizeof_german_old)
+#define DATA_DT sample_american_dialtone
+#define SIZE_DT (&sizeof_american_dialtone)
+#define DATA_RI sample_american_ringing
+#define SIZE_RI (&sizeof_american_ringing)
+#define DATA_BU sample_american_busy
+#define SIZE_BU (&sizeof_american_busy)
+#define DATA_S1 sample_special1
+#define SIZE_S1 (&sizeof_special1)
+#define DATA_S2 sample_special2
+#define SIZE_S2 (&sizeof_special2)
+#define DATA_S3 sample_special3
+#define SIZE_S3 (&sizeof_special3)
+
+/***************/
+/* tones loops */
+/***************/
+
+/* all tones are alaw encoded */
+/* the last sample+1 is in phase with the first sample. the error is low */
+
+static u8 sample_german_all[] = {
+	0x80, 0xab, 0x81, 0x6d, 0xfd, 0xdd, 0x5d, 0x9d,
+	0x4d, 0xd1, 0x89, 0x88, 0xd0, 0x4c, 0x9c, 0x5c,
+	0xdc, 0xfc, 0x6c,
+	0x80, 0xab, 0x81, 0x6d, 0xfd, 0xdd, 0x5d, 0x9d,
+	0x4d, 0xd1, 0x89, 0x88, 0xd0, 0x4c, 0x9c, 0x5c,
+	0xdc, 0xfc, 0x6c,
+	0x80, 0xab, 0x81, 0x6d, 0xfd, 0xdd, 0x5d, 0x9d,
+	0x4d, 0xd1, 0x89, 0x88, 0xd0, 0x4c, 0x9c, 0x5c,
+	0xdc, 0xfc, 0x6c,
+	0x80, 0xab, 0x81, 0x6d, 0xfd, 0xdd, 0x5d, 0x9d,
+	0x4d, 0xd1, 0x89, 0x88, 0xd0, 0x4c, 0x9c, 0x5c,
+	0xdc, 0xfc, 0x6c,
+};
+static u32 sizeof_german_all = sizeof(sample_german_all);
+
+static u8 sample_german_old[] = {
+	0xec, 0x68, 0xe1, 0x6d, 0x6d, 0x91, 0x51, 0xed,
+	0x6d, 0x01, 0x1e, 0x10, 0x0c, 0x90, 0x60, 0x70,
+	0x8c,
+	0xec, 0x68, 0xe1, 0x6d, 0x6d, 0x91, 0x51, 0xed,
+	0x6d, 0x01, 0x1e, 0x10, 0x0c, 0x90, 0x60, 0x70,
+	0x8c,
+	0xec, 0x68, 0xe1, 0x6d, 0x6d, 0x91, 0x51, 0xed,
+	0x6d, 0x01, 0x1e, 0x10, 0x0c, 0x90, 0x60, 0x70,
+	0x8c,
+	0xec, 0x68, 0xe1, 0x6d, 0x6d, 0x91, 0x51, 0xed,
+	0x6d, 0x01, 0x1e, 0x10, 0x0c, 0x90, 0x60, 0x70,
+	0x8c,
+};
+static u32 sizeof_german_old = sizeof(sample_german_old);
+
+static u8 sample_american_dialtone[] = {
+	0x2a, 0x18, 0x90, 0x6c, 0x4c, 0xbc, 0x4c, 0x6c,
+	0x10, 0x58, 0x32, 0xb9, 0x31, 0x2d, 0x8d, 0x0d,
+	0x8d, 0x2d, 0x31, 0x99, 0x0f, 0x28, 0x60, 0xf0,
+	0xd0, 0x50, 0xd0, 0x30, 0x60, 0x08, 0x8e, 0x67,
+	0x09, 0x19, 0x21, 0xe1, 0xd9, 0xb9, 0x29, 0x67,
+	0x83, 0x02, 0xce, 0xbe, 0xee, 0x1a, 0x1b, 0xef,
+	0xbf, 0xcf, 0x03, 0x82, 0x66, 0x28, 0xb8, 0xd8,
+	0xe0, 0x20, 0x18, 0x08, 0x66, 0x8f, 0x09, 0x61,
+	0x31, 0xd1, 0x51, 0xd1, 0xf1, 0x61, 0x29, 0x0e,
+	0x98, 0x30, 0x2c, 0x8c, 0x0c, 0x8c, 0x2c, 0x30,
+	0xb8, 0x33, 0x59, 0x11, 0x6d, 0x4d, 0xbd, 0x4d,
+	0x6d, 0x91, 0x19,
+};
+static u32 sizeof_american_dialtone = sizeof(sample_american_dialtone);
+
+static u8 sample_american_ringing[] = {
+	0x2a, 0xe0, 0xac, 0x0c, 0xbc, 0x4c, 0x8c, 0x90,
+	0x48, 0xc7, 0xc1, 0xed, 0xcd, 0x4d, 0xcd, 0xed,
+	0xc1, 0xb7, 0x08, 0x30, 0xec, 0xcc, 0xcc, 0x8c,
+	0x10, 0x58, 0x1a, 0x99, 0x71, 0xed, 0x8d, 0x8d,
+	0x2d, 0x41, 0x89, 0x9e, 0x20, 0x70, 0x2c, 0xec,
+	0x2c, 0x70, 0x20, 0x86, 0x77, 0xe1, 0x31, 0x11,
+	0xd1, 0xf1, 0x81, 0x09, 0xa3, 0x56, 0x58, 0x00,
+	0x40, 0xc0, 0x60, 0x38, 0x46, 0x43, 0x57, 0x39,
+	0xd9, 0x59, 0x99, 0xc9, 0x77, 0x2f, 0x2e, 0xc6,
+	0xd6, 0x28, 0xd6, 0x36, 0x26, 0x2e, 0x8a, 0xa3,
+	0x43, 0x63, 0x4b, 0x4a, 0x62, 0x42, 0xa2, 0x8b,
+	0x2f, 0x27, 0x37, 0xd7, 0x29, 0xd7, 0xc7, 0x2f,
+	0x2e, 0x76, 0xc8, 0x98, 0x58, 0xd8, 0x38, 0x56,
+	0x42, 0x47, 0x39, 0x61, 0xc1, 0x41, 0x01, 0x59,
+	0x57, 0xa2, 0x08, 0x80, 0xf0, 0xd0, 0x10, 0x30,
+	0xe0, 0x76, 0x87, 0x21, 0x71, 0x2d, 0xed, 0x2d,
+	0x71, 0x21, 0x9f, 0x88, 0x40, 0x2c, 0x8c, 0x8c,
+	0xec, 0x70, 0x98, 0x1b, 0x59, 0x11, 0x8d, 0xcd,
+	0xcd, 0xed, 0x31, 0x09, 0xb6, 0xc0, 0xec, 0xcc,
+	0x4c, 0xcc, 0xec, 0xc0, 0xc6, 0x49, 0x91, 0x8d,
+	0x4d, 0xbd, 0x0d, 0xad, 0xe1,
+};
+static u32 sizeof_american_ringing = sizeof(sample_american_ringing);
+
+static u8 sample_american_busy[] = {
+	0x2a, 0x00, 0x6c, 0x4c, 0x4c, 0x6c, 0xb0, 0x66,
+	0x99, 0x11, 0x6d, 0x8d, 0x2d, 0x41, 0xd7, 0x96,
+	0x60, 0xf0, 0x70, 0x40, 0x58, 0xf6, 0x53, 0x57,
+	0x09, 0x89, 0xd7, 0x5f, 0xe3, 0x2a, 0xe3, 0x5f,
+	0xd7, 0x89, 0x09, 0x57, 0x53, 0xf6, 0x58, 0x40,
+	0x70, 0xf0, 0x60, 0x96, 0xd7, 0x41, 0x2d, 0x8d,
+	0x6d, 0x11, 0x99, 0x66, 0xb0, 0x6c, 0x4c, 0x4c,
+	0x6c, 0x00, 0x2a, 0x01, 0x6d, 0x4d, 0x4d, 0x6d,
+	0xb1, 0x67, 0x98, 0x10, 0x6c, 0x8c, 0x2c, 0x40,
+	0xd6, 0x97, 0x61, 0xf1, 0x71, 0x41, 0x59, 0xf7,
+	0x52, 0x56, 0x08, 0x88, 0xd6, 0x5e, 0xe2, 0x2a,
+	0xe2, 0x5e, 0xd6, 0x88, 0x08, 0x56, 0x52, 0xf7,
+	0x59, 0x41, 0x71, 0xf1, 0x61, 0x97, 0xd6, 0x40,
+	0x2c, 0x8c, 0x6c, 0x10, 0x98, 0x67, 0xb1, 0x6d,
+	0x4d, 0x4d, 0x6d, 0x01,
+};
+static u32 sizeof_american_busy = sizeof(sample_american_busy);
+
+static u8 sample_special1[] = {
+	0x2a, 0x2c, 0xbc, 0x6c, 0xd6, 0x71, 0xbd, 0x0d,
+	0xd9, 0x80, 0xcc, 0x4c, 0x40, 0x39, 0x0d, 0xbd,
+	0x11, 0x86, 0xec, 0xbc, 0xec, 0x0e, 0x51, 0xbd,
+	0x8d, 0x89, 0x30, 0x4c, 0xcc, 0xe0, 0xe1, 0xcd,
+	0x4d, 0x31, 0x88, 0x8c, 0xbc, 0x50, 0x0f, 0xed,
+	0xbd, 0xed, 0x87, 0x10, 0xbc, 0x0c, 0x38, 0x41,
+	0x4d, 0xcd, 0x81, 0xd8, 0x0c, 0xbc, 0x70, 0xd7,
+	0x6d, 0xbd, 0x2d,
+};
+static u32 sizeof_special1 = sizeof(sample_special1);
+
+static u8 sample_special2[] = {
+	0x2a, 0xcc, 0x8c, 0xd7, 0x4d, 0x2d, 0x18, 0xbc,
+	0x10, 0xc1, 0xbd, 0xc1, 0x10, 0xbc, 0x18, 0x2d,
+	0x4d, 0xd7, 0x8c, 0xcc, 0x2a, 0xcd, 0x8d, 0xd6,
+	0x4c, 0x2c, 0x19, 0xbd, 0x11, 0xc0, 0xbc, 0xc0,
+	0x11, 0xbd, 0x19, 0x2c, 0x4c, 0xd6, 0x8d, 0xcd,
+	0x2a, 0xcc, 0x8c, 0xd7, 0x4d, 0x2d, 0x18, 0xbc,
+	0x10, 0xc1, 0xbd, 0xc1, 0x10, 0xbc, 0x18, 0x2d,
+	0x4d, 0xd7, 0x8c, 0xcc, 0x2a, 0xcd, 0x8d, 0xd6,
+	0x4c, 0x2c, 0x19, 0xbd, 0x11, 0xc0, 0xbc, 0xc0,
+	0x11, 0xbd, 0x19, 0x2c, 0x4c, 0xd6, 0x8d, 0xcd,
+};
+static u32 sizeof_special2 = sizeof(sample_special2);
+
+static u8 sample_special3[] = {
+	0x2a, 0xbc, 0x18, 0xcd, 0x11, 0x2c, 0x8c, 0xc1,
+	0x4d, 0xd6, 0xbc, 0xd6, 0x4d, 0xc1, 0x8c, 0x2c,
+	0x11, 0xcd, 0x18, 0xbc, 0x2a, 0xbd, 0x19, 0xcc,
+	0x10, 0x2d, 0x8d, 0xc0, 0x4c, 0xd7, 0xbd, 0xd7,
+	0x4c, 0xc0, 0x8d, 0x2d, 0x10, 0xcc, 0x19, 0xbd,
+	0x2a, 0xbc, 0x18, 0xcd, 0x11, 0x2c, 0x8c, 0xc1,
+	0x4d, 0xd6, 0xbc, 0xd6, 0x4d, 0xc1, 0x8c, 0x2c,
+	0x11, 0xcd, 0x18, 0xbc, 0x2a, 0xbd, 0x19, 0xcc,
+	0x10, 0x2d, 0x8d, 0xc0, 0x4c, 0xd7, 0xbd, 0xd7,
+	0x4c, 0xc0, 0x8d, 0x2d, 0x10, 0xcc, 0x19, 0xbd,
+};
+static u32 sizeof_special3 = sizeof(sample_special3);
+
+static u8 sample_silence[] = {
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+	0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
+};
+static u32 sizeof_silence = sizeof(sample_silence);
+
+struct tones_samples {
+	u32 *len;
+	u8 *data;
+};
+static struct
+tones_samples samples[] = {
+	{&sizeof_german_all, sample_german_all},
+	{&sizeof_german_old, sample_german_old},
+	{&sizeof_american_dialtone, sample_american_dialtone},
+	{&sizeof_american_ringing, sample_american_ringing},
+	{&sizeof_american_busy, sample_american_busy},
+	{&sizeof_special1, sample_special1},
+	{&sizeof_special2, sample_special2},
+	{&sizeof_special3, sample_special3},
+	{NULL, NULL},
+};
+
+/***********************************
+ * generate ulaw from alaw samples *
+ ***********************************/
+
+void
+dsp_audio_generate_ulaw_samples(void)
+{
+	int i, j;
+
+	i = 0;
+	while (samples[i].len) {
+		j = 0;
+		while (j < (*samples[i].len)) {
+			samples[i].data[j] =
+				dsp_audio_alaw_to_ulaw[samples[i].data[j]];
+			j++;
+		}
+		i++;
+	}
+}
+
+
+/****************************
+ * tone sequence definition *
+ ****************************/
+
+struct pattern {
+	int tone;
+	u8 *data[10];
+	u32 *siz[10];
+	u32 seq[10];
+} pattern[] = {
+	{TONE_GERMAN_DIALTONE,
+	{DATA_GA, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GA, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{1900, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_OLDDIALTONE,
+	{DATA_GO, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GO, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{1998, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_AMERICAN_DIALTONE,
+	{DATA_DT, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_DT, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{8000, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_DIALPBX,
+	{DATA_GA, DATA_S, DATA_GA, DATA_S, DATA_GA, DATA_S, 0, 0, 0, 0},
+	{SIZE_GA, SIZE_S, SIZE_GA, SIZE_S, SIZE_GA, SIZE_S, 0, 0, 0, 0},
+	{2000, 2000, 2000, 2000, 2000, 12000, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_OLDDIALPBX,
+	{DATA_GO, DATA_S, DATA_GO, DATA_S, DATA_GO, DATA_S, 0, 0, 0, 0},
+	{SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, 0, 0, 0, 0},
+	{2000, 2000, 2000, 2000, 2000, 12000, 0, 0, 0, 0} },
+
+	{TONE_AMERICAN_DIALPBX,
+	{DATA_DT, DATA_S, DATA_DT, DATA_S, DATA_DT, DATA_S, 0, 0, 0, 0},
+	{SIZE_DT, SIZE_S, SIZE_DT, SIZE_S, SIZE_DT, SIZE_S, 0, 0, 0, 0},
+	{2000, 2000, 2000, 2000, 2000, 12000, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_RINGING,
+	{DATA_GA, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GA, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{8000, 32000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_OLDRINGING,
+	{DATA_GO, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GO, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{8000, 40000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_AMERICAN_RINGING,
+	{DATA_RI, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_RI, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{8000, 32000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_RINGPBX,
+	{DATA_GA, DATA_S, DATA_GA, DATA_S, 0, 0, 0, 0, 0, 0},
+	{SIZE_GA, SIZE_S, SIZE_GA, SIZE_S, 0, 0, 0, 0, 0, 0},
+	{4000, 4000, 4000, 28000, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_OLDRINGPBX,
+	{DATA_GO, DATA_S, DATA_GO, DATA_S, 0, 0, 0, 0, 0, 0},
+	{SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, 0, 0, 0, 0, 0, 0},
+	{4000, 4000, 4000, 28000, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_AMERICAN_RINGPBX,
+	{DATA_RI, DATA_S, DATA_RI, DATA_S, 0, 0, 0, 0, 0, 0},
+	{SIZE_RI, SIZE_S, SIZE_RI, SIZE_S, 0, 0, 0, 0, 0, 0},
+	{4000, 4000, 4000, 28000, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_BUSY,
+	{DATA_GA, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GA, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{4000, 4000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_OLDBUSY,
+	{DATA_GO, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GO, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{1000, 5000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_AMERICAN_BUSY,
+	{DATA_BU, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_BU, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{4000, 4000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_HANGUP,
+	{DATA_GA, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GA, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{4000, 4000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_OLDHANGUP,
+	{DATA_GO, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GO, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{1000, 5000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_AMERICAN_HANGUP,
+	{DATA_DT, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_DT, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{8000, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_SPECIAL_INFO,
+	{DATA_S1, DATA_S2, DATA_S3, DATA_S, 0, 0, 0, 0, 0, 0},
+	{SIZE_S1, SIZE_S2, SIZE_S3, SIZE_S, 0, 0, 0, 0, 0, 0},
+	{2666, 2666, 2666, 8002, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_GASSENBESETZT,
+	{DATA_GA, DATA_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{SIZE_GA, SIZE_S, 0, 0, 0, 0, 0, 0, 0, 0},
+	{2000, 2000, 0, 0, 0, 0, 0, 0, 0, 0} },
+
+	{TONE_GERMAN_AUFSCHALTTON,
+	{DATA_GO, DATA_S, DATA_GO, DATA_S, 0, 0, 0, 0, 0, 0},
+	{SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, 0, 0, 0, 0, 0, 0},
+	{1000, 5000, 1000, 17000, 0, 0, 0, 0, 0, 0} },
+
+	{0,
+	{0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+	{0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
+};
+
+/******************
+ * copy tone data *
+ ******************/
+
+/* an sk_buff is generated from the number of samples needed.
+ * the count will be changed and may begin from 0 each pattern period.
+ * the clue is to precalculate the pointers and legths to use only one
+ * memcpy per function call, or two memcpy if the tone sequence changes.
+ *
+ * pattern - the type of the pattern
+ * count - the sample from the beginning of the pattern (phase)
+ * len - the number of bytes
+ *
+ * return - the sk_buff with the sample
+ *
+ * if tones has finished (e.g. knocking tone), dsp->tones is turned off
+ */
+void dsp_tone_copy(struct dsp *dsp, u8 *data, int len)
+{
+	int index, count, start, num;
+	struct pattern *pat;
+	struct dsp_tone *tone = &dsp->tone;
+
+	/* if we have no tone, we copy silence */
+	if (!tone->tone) {
+		memset(data, dsp_silence, len);
+		return;
+	}
+
+	/* process pattern */
+	pat = (struct pattern *)tone->pattern;
+		/* points to the current pattern */
+	index = tone->index; /* gives current sequence index */
+	count = tone->count; /* gives current sample */
+
+	/* copy sample */
+	while (len) {
+		/* find sample to start with */
+		while (42) {
+			/* warp arround */
+			if (!pat->seq[index]) {
+				count = 0;
+				index = 0;
+			}
+			/* check if we are currently playing this tone */
+			if (count < pat->seq[index])
+				break;
+			if (dsp_debug & DEBUG_DSP_TONE)
+				printk(KERN_DEBUG "%s: reaching next sequence "
+					"(index=%d)\n", __func__, index);
+			count -= pat->seq[index];
+			index++;
+		}
+		/* calculate start and number of samples */
+		start = count % (*(pat->siz[index]));
+		num = len;
+		if (num+count > pat->seq[index])
+			num = pat->seq[index] - count;
+		if (num+start > (*(pat->siz[index])))
+			num = (*(pat->siz[index])) - start;
+		/* copy memory */
+		memcpy(data, pat->data[index]+start, num);
+		/* reduce length */
+		data += num;
+		count += num;
+		len -= num;
+	}
+	tone->index = index;
+	tone->count = count;
+
+	/* return sk_buff */
+	return;
+}
+
+
+/*******************************
+ * send HW message to hfc card *
+ *******************************/
+
+static void
+dsp_tone_hw_message(struct dsp *dsp, u8 *sample, int len)
+{
+	struct sk_buff *nskb;
+
+	/* unlocking is not required, because we don't expect a response */
+	nskb = _alloc_mISDN_skb(PH_CONTROL_REQ,
+		(len)?HFC_SPL_LOOP_ON:HFC_SPL_LOOP_OFF, len, sample,
+		GFP_ATOMIC);
+	if (nskb) {
+		if (dsp->ch.peer) {
+			if (dsp->ch.recv(dsp->ch.peer, nskb))
+				dev_kfree_skb(nskb);
+		} else
+			dev_kfree_skb(nskb);
+	}
+}
+
+
+/*****************
+ * timer expires *
+ *****************/
+void
+dsp_tone_timeout(void *arg)
+{
+	struct dsp *dsp = arg;
+	struct dsp_tone *tone = &dsp->tone;
+	struct pattern *pat = (struct pattern *)tone->pattern;
+	int index = tone->index;
+
+	if (!tone->tone)
+		return;
+
+	index++;
+	if (!pat->seq[index])
+		index = 0;
+	tone->index = index;
+
+	/* set next tone */
+	if (pat->data[index] == DATA_S)
+		dsp_tone_hw_message(dsp, 0, 0);
+	else
+		dsp_tone_hw_message(dsp, pat->data[index], *(pat->siz[index]));
+	/* set timer */
+	init_timer(&tone->tl);
+	tone->tl.expires = jiffies + (pat->seq[index] * HZ) / 8000;
+	add_timer(&tone->tl);
+}
+
+
+/********************
+ * set/release tone *
+ ********************/
+
+/*
+ * tones are relaized by streaming or by special loop commands if supported
+ * by hardware. when hardware is used, the patterns will be controlled by
+ * timers.
+ */
+int
+dsp_tone(struct dsp *dsp, int tone)
+{
+	struct pattern *pat;
+	int i;
+	struct dsp_tone *tonet = &dsp->tone;
+
+	tonet->software = 0;
+	tonet->hardware = 0;
+
+	/* we turn off the tone */
+	if (!tone) {
+		if (dsp->features.hfc_loops)
+		if (timer_pending(&tonet->tl))
+			del_timer(&tonet->tl);
+		if (dsp->features.hfc_loops)
+			dsp_tone_hw_message(dsp, NULL, 0);
+		tonet->tone = 0;
+		return 0;
+	}
+
+	pat = NULL;
+	i = 0;
+	while (pattern[i].tone) {
+		if (pattern[i].tone == tone) {
+			pat = &pattern[i];
+			break;
+		}
+		i++;
+	}
+	if (!pat) {
+		printk(KERN_WARNING "dsp: given tone 0x%x is invalid\n", tone);
+		return -EINVAL;
+	}
+	if (dsp_debug & DEBUG_DSP_TONE)
+		printk(KERN_DEBUG "%s: now starting tone %d (index=%d)\n",
+			__func__, tone, 0);
+	tonet->tone = tone;
+	tonet->pattern = pat;
+	tonet->index = 0;
+	tonet->count = 0;
+
+	if (dsp->features.hfc_loops) {
+		tonet->hardware = 1;
+		/* set first tone */
+		dsp_tone_hw_message(dsp, pat->data[0], *(pat->siz[0]));
+		/* set timer */
+		if (timer_pending(&tonet->tl))
+			del_timer(&tonet->tl);
+		init_timer(&tonet->tl);
+		tonet->tl.expires = jiffies + (pat->seq[0] * HZ) / 8000;
+		add_timer(&tonet->tl);
+	} else {
+		tonet->software = 1;
+	}
+
+	return 0;
+}
+
+
+
+
+