/*
 * 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/gfp.h>
#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 *
 ****************************/

static struct pattern {
        int tone;
        u8 *data[10];
        u32 *siz[10];
        u32 seq[10];
} pattern[] = {
        {TONE_GERMAN_DIALTONE,
         {DATA_GA, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GA, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {1900, 0, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_OLDDIALTONE,
         {DATA_GO, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GO, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {1998, 0, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_AMERICAN_DIALTONE,
         {DATA_DT, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_DT, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {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, NULL, NULL, NULL,
          NULL},
         {SIZE_GA, SIZE_S, SIZE_GA, SIZE_S, SIZE_GA, SIZE_S, NULL, NULL, NULL,
          NULL},
         {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, NULL, NULL, NULL,
          NULL},
         {SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, NULL, NULL, NULL,
          NULL},
         {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, NULL, NULL, NULL,
          NULL},
         {SIZE_DT, SIZE_S, SIZE_DT, SIZE_S, SIZE_DT, SIZE_S, NULL, NULL, NULL,
          NULL},
         {2000, 2000, 2000, 2000, 2000, 12000, 0, 0, 0, 0} },

        {TONE_GERMAN_RINGING,
         {DATA_GA, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GA, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {8000, 32000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_OLDRINGING,
         {DATA_GO, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GO, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {8000, 40000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_AMERICAN_RINGING,
         {DATA_RI, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_RI, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {8000, 32000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_RINGPBX,
         {DATA_GA, DATA_S, DATA_GA, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GA, SIZE_S, SIZE_GA, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {4000, 4000, 4000, 28000, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_OLDRINGPBX,
         {DATA_GO, DATA_S, DATA_GO, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {4000, 4000, 4000, 28000, 0, 0, 0, 0, 0, 0} },

        {TONE_AMERICAN_RINGPBX,
         {DATA_RI, DATA_S, DATA_RI, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_RI, SIZE_S, SIZE_RI, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {4000, 4000, 4000, 28000, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_BUSY,
         {DATA_GA, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GA, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {4000, 4000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_OLDBUSY,
         {DATA_GO, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GO, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {1000, 5000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_AMERICAN_BUSY,
         {DATA_BU, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_BU, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {4000, 4000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_HANGUP,
         {DATA_GA, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GA, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {4000, 4000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_OLDHANGUP,
         {DATA_GO, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GO, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {1000, 5000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_AMERICAN_HANGUP,
         {DATA_DT, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_DT, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {8000, 0, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_SPECIAL_INFO,
         {DATA_S1, DATA_S2, DATA_S3, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_S1, SIZE_S2, SIZE_S3, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {2666, 2666, 2666, 8002, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_GASSENBESETZT,
         {DATA_GA, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GA, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {2000, 2000, 0, 0, 0, 0, 0, 0, 0, 0} },

        {TONE_GERMAN_AUFSCHALTTON,
         {DATA_GO, DATA_S, DATA_GO, DATA_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {SIZE_GO, SIZE_S, SIZE_GO, SIZE_S, NULL, NULL, NULL, NULL, NULL, NULL},
         {1000, 5000, 1000, 17000, 0, 0, 0, 0, 0, 0} },

        {0,
         {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
         {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) {
                        /* wrap around */
                        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(struct timer_list *t)
{
        struct dsp *dsp = timer_container_of(dsp, t, tone.tl);
        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, NULL, 0);
        else
                dsp_tone_hw_message(dsp, pat->data[index], *(pat->siz[index]));
        /* set timer */
        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 && timer_pending(&tonet->tl))
                        timer_delete(&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))
                        timer_delete(&tonet->tl);
                tonet->tl.expires = jiffies + (pat->seq[0] * HZ) / 8000;
                add_timer(&tonet->tl);
        } else {
                tonet->software = 1;
        }

        return 0;
}