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[/] [or1k/] [tags/] [before_ORP/] [uclinux/] [uClinux-2.0.x/] [drivers/] [net/] [soundmodem/] [sm_afsk2400_8.c] - Rev 1765
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/*****************************************************************************/ /* * sm_afsk2400_8.c -- soundcard radio modem driver, 2400 baud AFSK modem * * Copyright (C) 1996 Thomas Sailer (sailer@ife.ee.ethz.ch) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * Please note that the GPL allows you to use the driver, NOT the radio. * In order to use the radio, you need a license from the communications * authority of your country. * */ /* * This driver is intended to be compatible with TCM3105 modems * overclocked to 8MHz. The mark and space frequencies therefore * lie at 3970 and 2165 Hz. * Note that I do _not_ recommend the building of such links, I provide * this only for the users who live in the coverage area of such * a "legacy" link. */ #include "sm.h" #include "sm_tbl_afsk2400_8.h" /* --------------------------------------------------------------------- */ struct demod_state_afsk24 { unsigned int shreg; unsigned int bit_pll; unsigned char last_sample; unsigned int dcd_shreg; int dcd_sum0, dcd_sum1, dcd_sum2; unsigned int dcd_time; unsigned char last_rxbit; }; struct mod_state_afsk24 { unsigned int shreg; unsigned char tx_bit; unsigned int bit_pll; unsigned int tx_seq; unsigned int phinc; }; /* --------------------------------------------------------------------- */ static const int dds_inc[2] = { AFSK24_TX_FREQ_LO*0x10000/AFSK24_SAMPLERATE, AFSK24_TX_FREQ_HI*0x10000/AFSK24_SAMPLERATE }; static void modulator_2400_u8(struct sm_state *sm, unsigned char *buf, unsigned int buflen) { struct mod_state_afsk24 *st = (struct mod_state_afsk24 *)(&sm->m); for (; buflen > 0; buflen--, buf++) { if (st->tx_seq < 0x5555) { if (st->shreg <= 1) st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; st->tx_bit = (st->tx_bit ^ (!(st->shreg & 1))) & 1; st->shreg >>= 1; st->phinc = dds_inc[st->tx_bit & 1]; } st->tx_seq += 0x5555; st->tx_seq &= 0xffff; *buf = OFFSCOS(st->bit_pll); st->bit_pll += st->phinc; } } /* --------------------------------------------------------------------- */ static void modulator_2400_s16(struct sm_state *sm, short *buf, unsigned int buflen) { struct mod_state_afsk24 *st = (struct mod_state_afsk24 *)(&sm->m); for (; buflen > 0; buflen--, buf++) { if (st->tx_seq < 0x5555) { if (st->shreg <= 1) st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; st->tx_bit = (st->tx_bit ^ (!(st->shreg & 1))) & 1; st->shreg >>= 1; st->phinc = dds_inc[st->tx_bit & 1]; } st->tx_seq += 0x5555; st->tx_seq &= 0xffff; *buf = COS(st->bit_pll); st->bit_pll += st->phinc; } } /* --------------------------------------------------------------------- */ extern __inline__ int convolution14_u8(const unsigned char *st, const int *coeff, int csum) { int sum = -0x80 * csum; sum += (st[0] * coeff[0]); sum += (st[-1] * coeff[1]); sum += (st[-2] * coeff[2]); sum += (st[-3] * coeff[3]); sum += (st[-4] * coeff[4]); sum += (st[-5] * coeff[5]); sum += (st[-6] * coeff[6]); sum += (st[-7] * coeff[7]); sum += (st[-8] * coeff[8]); sum += (st[-9] * coeff[9]); sum += (st[-10] * coeff[10]); sum += (st[-11] * coeff[11]); sum += (st[-12] * coeff[12]); sum += (st[-13] * coeff[13]); sum >>= 7; return sum * sum; } extern __inline__ int convolution14_s16(const short *st, const int *coeff, int csum) { int sum = 0; sum += (st[0] * coeff[0]); sum += (st[-1] * coeff[1]); sum += (st[-2] * coeff[2]); sum += (st[-3] * coeff[3]); sum += (st[-4] * coeff[4]); sum += (st[-5] * coeff[5]); sum += (st[-6] * coeff[6]); sum += (st[-7] * coeff[7]); sum += (st[-8] * coeff[8]); sum += (st[-9] * coeff[9]); sum += (st[-10] * coeff[10]); sum += (st[-11] * coeff[11]); sum += (st[-12] * coeff[12]); sum += (st[-13] * coeff[13]); sum >>= 15; return sum * sum; } extern __inline__ int do_filter_2400_u8(const unsigned char *buf) { int sum = convolution14_u8(buf, afsk24_tx_lo_i, SUM_AFSK24_TX_LO_I); sum += convolution14_u8(buf, afsk24_tx_lo_q, SUM_AFSK24_TX_LO_Q); sum -= convolution14_u8(buf, afsk24_tx_hi_i, SUM_AFSK24_TX_HI_I); sum -= convolution14_u8(buf, afsk24_tx_hi_q, SUM_AFSK24_TX_HI_Q); return sum; } extern __inline__ int do_filter_2400_s16(const short *buf) { int sum = convolution14_s16(buf, afsk24_tx_lo_i, SUM_AFSK24_TX_LO_I); sum += convolution14_s16(buf, afsk24_tx_lo_q, SUM_AFSK24_TX_LO_Q); sum -= convolution14_s16(buf, afsk24_tx_hi_i, SUM_AFSK24_TX_HI_I); sum -= convolution14_s16(buf, afsk24_tx_hi_q, SUM_AFSK24_TX_HI_Q); return sum; } /* --------------------------------------------------------------------- */ static void demodulator_2400_u8(struct sm_state *sm, const unsigned char *buf, unsigned int buflen) { struct demod_state_afsk24 *st = (struct demod_state_afsk24 *)(&sm->d); int j; int sum; unsigned char newsample; for (; buflen > 0; buflen--, buf++) { sum = do_filter_2400_u8(buf); st->dcd_shreg <<= 1; st->bit_pll += AFSK24_BITPLL_INC; newsample = (sum > 0); if (st->last_sample ^ newsample) { st->last_sample = newsample; st->dcd_shreg |= 1; if (st->bit_pll < (0x8000+AFSK24_BITPLL_INC/2)) st->bit_pll += AFSK24_BITPLL_INC/2; else st->bit_pll -= AFSK24_BITPLL_INC/2; j = /* 2 * */ hweight8(st->dcd_shreg & 0x1c) - hweight16(st->dcd_shreg & 0x1e0); st->dcd_sum0 += j; } hdlcdrv_channelbit(&sm->hdrv, st->last_sample); if ((--st->dcd_time) <= 0) { hdlcdrv_setdcd(&sm->hdrv, (st->dcd_sum0 + st->dcd_sum1 + st->dcd_sum2) < 0); st->dcd_sum2 = st->dcd_sum1; st->dcd_sum1 = st->dcd_sum0; st->dcd_sum0 = 2; /* slight bias */ st->dcd_time = 120; } if (st->bit_pll >= 0x10000) { st->bit_pll &= 0xffff; st->shreg >>= 1; st->shreg |= (!(st->last_rxbit ^ st->last_sample)) << 16; st->last_rxbit = st->last_sample; diag_trigger(sm); if (st->shreg & 1) { hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1); st->shreg = 0x10000; } } diag_add(sm, (((int)*buf)-0x80) << 8, sum); } } /* --------------------------------------------------------------------- */ static void demodulator_2400_s16(struct sm_state *sm, const short *buf, unsigned int buflen) { struct demod_state_afsk24 *st = (struct demod_state_afsk24 *)(&sm->d); int j; int sum; unsigned char newsample; for (; buflen > 0; buflen--, buf++) { sum = do_filter_2400_s16(buf); st->dcd_shreg <<= 1; st->bit_pll += AFSK24_BITPLL_INC; newsample = (sum > 0); if (st->last_sample ^ newsample) { st->last_sample = newsample; st->dcd_shreg |= 1; if (st->bit_pll < (0x8000+AFSK24_BITPLL_INC/2)) st->bit_pll += AFSK24_BITPLL_INC/2; else st->bit_pll -= AFSK24_BITPLL_INC/2; j = /* 2 * */ hweight8(st->dcd_shreg & 0x1c) - hweight16(st->dcd_shreg & 0x1e0); st->dcd_sum0 += j; } hdlcdrv_channelbit(&sm->hdrv, st->last_sample); if ((--st->dcd_time) <= 0) { hdlcdrv_setdcd(&sm->hdrv, (st->dcd_sum0 + st->dcd_sum1 + st->dcd_sum2) < 0); st->dcd_sum2 = st->dcd_sum1; st->dcd_sum1 = st->dcd_sum0; st->dcd_sum0 = 2; /* slight bias */ st->dcd_time = 120; } if (st->bit_pll >= 0x10000) { st->bit_pll &= 0xffff; st->shreg >>= 1; st->shreg |= (!(st->last_rxbit ^ st->last_sample)) << 16; st->last_rxbit = st->last_sample; diag_trigger(sm); if (st->shreg & 1) { hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1); st->shreg = 0x10000; } } diag_add(sm, *buf, sum); } } /* --------------------------------------------------------------------- */ static void demod_init_2400(struct sm_state *sm) { struct demod_state_afsk24 *st = (struct demod_state_afsk24 *)(&sm->d); st->dcd_time = 120; st->dcd_sum0 = 2; } /* --------------------------------------------------------------------- */ const struct modem_tx_info sm_afsk2400_8_tx = { "afsk2400_8", sizeof(struct mod_state_afsk24), AFSK24_SAMPLERATE, 2400, modulator_2400_u8, modulator_2400_s16, NULL }; const struct modem_rx_info sm_afsk2400_8_rx = { "afsk2400_8", sizeof(struct demod_state_afsk24), AFSK24_SAMPLERATE, 2400, 14, AFSK24_SAMPLERATE/2400, demodulator_2400_u8, demodulator_2400_s16, demod_init_2400 }; /* --------------------------------------------------------------------- */