diff options
author | Ralf Baechle <ralf@linux-mips.org> | 1998-08-25 09:12:35 +0000 |
---|---|---|
committer | Ralf Baechle <ralf@linux-mips.org> | 1998-08-25 09:12:35 +0000 |
commit | c7fc24dc4420057f103afe8fc64524ebc25c5d37 (patch) | |
tree | 3682407a599b8f9f03fc096298134cafba1c9b2f /drivers/net/hamradio/soundmodem/sm_afsk2666.c | |
parent | 1d793fade8b063fde3cf275bf1a5c2d381292cd9 (diff) |
o Merge with Linux 2.1.116.
o New Newport console code.
o New G364 console code.
Diffstat (limited to 'drivers/net/hamradio/soundmodem/sm_afsk2666.c')
-rw-r--r-- | drivers/net/hamradio/soundmodem/sm_afsk2666.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/drivers/net/hamradio/soundmodem/sm_afsk2666.c b/drivers/net/hamradio/soundmodem/sm_afsk2666.c new file mode 100644 index 000000000..2aa2972e4 --- /dev/null +++ b/drivers/net/hamradio/soundmodem/sm_afsk2666.c @@ -0,0 +1,356 @@ +/*****************************************************************************/ + +/* + * sm_afsk2666.c -- soundcard radio modem driver, 2666 baud AFSK modem + * + * Copyright (C) 1997 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. + * + */ + +#include "sm.h" +#include "sm_tbl_afsk2666.h" + +/* --------------------------------------------------------------------- */ + +struct demod_state_afsk26 { + unsigned int shreg; + unsigned long descram; + int dem_sum[8]; + int dem_sum_mean; + int dem_cnt; + unsigned int bit_pll; + unsigned char last_sample; + unsigned int dcd_shreg; + int dcd_sum0, dcd_sum1, dcd_sum2; + unsigned int dcd_time; +}; + +struct mod_state_afsk26 { + unsigned int shreg; + unsigned long scram; + unsigned int bit_pll; + unsigned int phinc; + unsigned int tx_seq; +}; + +/* --------------------------------------------------------------------- */ + +#define DESCRAM_TAP1 0x20000 +#define DESCRAM_TAP2 0x01000 +#define DESCRAM_TAP3 0x00001 + +#define DESCRAM_TAPSH1 17 +#define DESCRAM_TAPSH2 12 +#define DESCRAM_TAPSH3 0 + +#define SCRAM_TAP1 0x20000 /* X^17 */ +#define SCRAM_TAPN 0x00021 /* X^0+X^5 */ + +/* --------------------------------------------------------------------- */ + +static void modulator_2666_u8(struct sm_state *sm, unsigned char *buf, unsigned int buflen) +{ + struct mod_state_afsk26 *st = (struct mod_state_afsk26 *)(&sm->m); + + for (; buflen > 0; buflen--, buf++) { + if (!st->tx_seq++) { + if (st->shreg <= 1) + st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; + st->scram = ((st->scram << 1) | (st->scram & 1)); + st->scram ^= (!(st->shreg & 1)); + st->shreg >>= 1; + if (st->scram & (SCRAM_TAP1 << 1)) + st->scram ^= SCRAM_TAPN << 1; + st->phinc = afsk26_carfreq[!(st->scram & (SCRAM_TAP1 << 2))]; + } + if (st->tx_seq >= 6) + st->tx_seq = 0; + *buf = OFFSCOS(st->bit_pll); + st->bit_pll += st->phinc; + } +} + +/* --------------------------------------------------------------------- */ + +static void modulator_2666_s16(struct sm_state *sm, short *buf, unsigned int buflen) +{ + struct mod_state_afsk26 *st = (struct mod_state_afsk26 *)(&sm->m); + + for (; buflen > 0; buflen--, buf++) { + if (!st->tx_seq++) { + if (st->shreg <= 1) + st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000; + st->scram = ((st->scram << 1) | (st->scram & 1)); + st->scram ^= (!(st->shreg & 1)); + st->shreg >>= 1; + if (st->scram & (SCRAM_TAP1 << 1)) + st->scram ^= SCRAM_TAPN << 1; + st->phinc = afsk26_carfreq[!(st->scram & (SCRAM_TAP1 << 2))]; + } + if (st->tx_seq >= 6) + st->tx_seq = 0; + *buf = COS(st->bit_pll); + st->bit_pll += st->phinc; + } +} + +/* --------------------------------------------------------------------- */ + +extern __inline__ int convolution12_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]); + + return sum; +} + +extern __inline__ int convolution12_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 >>= 8; + return sum; +} + +/* ---------------------------------------------------------------------- */ + +#if 0 +static int binexp(unsigned int i) +{ + int ret = 31; + + if (!i) + return 0; + if (i < 0x10000LU) { + i <<= 16; + ret -= 16; + } + if (i < 0x1000000LU) { + i <<= 8; + ret -= 8; + } + if (i < 0x10000000LU) { + i <<= 4; + ret -= 4; + } + if (i < 0x40000000LU) { + i <<= 2; + ret -= 2; + } + if (i < 0x80000000LU) + ret -= 1; + return ret; +} + +static const sqrt_tab[16] = { + 00000, 16384, 23170, 28378, 32768, 36636, 40132, 43348, + 46341, 49152, 51811, 54340, 56756, 59073, 61303, 63455 +}; + + +static unsigned int int_sqrt_approx(unsigned int i) +{ + unsigned int j; + + if (i < 16) + return sqrt_tab[i] >> 14; + j = binexp(i) >> 1; + i >>= (j * 2 - 2); + return (sqrt_tab[i & 0xf] << j) >> 15; +} +#endif + +/* --------------------------------------------------------------------- */ + +extern unsigned int est_pwr(int i, int q) +{ + unsigned int ui = abs(i); + unsigned int uq = abs(q); + + if (uq > ui) { + unsigned int tmp; + tmp = ui; + ui = uq; + uq = tmp; + } + if (uq > (ui >> 1)) + return 7*(ui>>3) + 9*(uq>>4); + else + return ui + (uq>>2); +} + +/* --------------------------------------------------------------------- */ + +static void demod_one_sample(struct sm_state *sm, struct demod_state_afsk26 *st, int curval, + int loi, int loq, int hii, int hiq) +{ + static const int pll_corr[2] = { -0xa00, 0xa00 }; + unsigned char curbit; + unsigned int descx; + int val; + + /* + * estimate power + */ + val = est_pwr(hii, hiq) - est_pwr(loi, loq); + /* + * estimate center value + */ + st->dem_sum[0] += val >> 8; + if ((++st->dem_cnt) >= 256) { + st->dem_cnt = 0; + st->dem_sum_mean = (st->dem_sum[0]+st->dem_sum[1]+ + st->dem_sum[2]+st->dem_sum[3]+ + st->dem_sum[4]+st->dem_sum[5]+ + st->dem_sum[6]+st->dem_sum[7]) >> 3; + memmove(st->dem_sum+1, st->dem_sum, + sizeof(st->dem_sum)-sizeof(st->dem_sum[0])); + st->dem_sum[0] = 0; + } + /* + * decision and bit clock regen + */ + val -= st->dem_sum_mean; + diag_add(sm, curval, val); + + st->dcd_shreg <<= 1; + st->bit_pll += 0x1555; + curbit = (val > 0); + if (st->last_sample ^ curbit) { + st->dcd_shreg |= 1; + st->bit_pll += pll_corr[st->bit_pll < (0x8000+0x1555)]; + st->dcd_sum0 += 4*hweight8(st->dcd_shreg & 0x1e) - + hweight16(st->dcd_shreg & 0xfe00); + } + st->last_sample = curbit; + hdlcdrv_channelbit(&sm->hdrv, curbit); + 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 = 400; + } + if (st->bit_pll >= 0x10000) { + st->bit_pll &= 0xffffu; + st->descram = (st->descram << 1) | curbit; + descx = st->descram ^ (st->descram >> 1); + descx ^= ((descx >> DESCRAM_TAPSH1) ^ + (descx >> DESCRAM_TAPSH2)); + st->shreg >>= 1; + st->shreg |= (!(descx & 1)) << 16; + if (st->shreg & 1) { + hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1); + st->shreg = 0x10000; + } + diag_trigger(sm); + } +} + +/* --------------------------------------------------------------------- */ + +static void demodulator_2666_u8(struct sm_state *sm, const unsigned char *buf, unsigned int buflen) +{ + struct demod_state_afsk26 *st = (struct demod_state_afsk26 *)(&sm->d); + + for (; buflen > 0; buflen--, buf++) { + demod_one_sample(sm, st, (*buf-0x80)<<8, + convolution12_u8(buf, afsk26_dem_tables[0][0].i, AFSK26_DEM_SUM_I_0_0), + convolution12_u8(buf, afsk26_dem_tables[0][0].q, AFSK26_DEM_SUM_Q_0_0), + convolution12_u8(buf, afsk26_dem_tables[0][1].i, AFSK26_DEM_SUM_I_0_1), + convolution12_u8(buf, afsk26_dem_tables[0][1].q, AFSK26_DEM_SUM_Q_0_1)); + demod_one_sample(sm, st, (*buf-0x80)<<8, + convolution12_u8(buf, afsk26_dem_tables[1][0].i, AFSK26_DEM_SUM_I_1_0), + convolution12_u8(buf, afsk26_dem_tables[1][0].q, AFSK26_DEM_SUM_Q_1_0), + convolution12_u8(buf, afsk26_dem_tables[1][1].i, AFSK26_DEM_SUM_I_1_1), + convolution12_u8(buf, afsk26_dem_tables[1][1].q, AFSK26_DEM_SUM_Q_1_1)); + } +} + +/* --------------------------------------------------------------------- */ + +static void demodulator_2666_s16(struct sm_state *sm, const short *buf, unsigned int buflen) +{ + struct demod_state_afsk26 *st = (struct demod_state_afsk26 *)(&sm->d); + + for (; buflen > 0; buflen--, buf++) { + demod_one_sample(sm, st, *buf, + convolution12_s16(buf, afsk26_dem_tables[0][0].i, AFSK26_DEM_SUM_I_0_0), + convolution12_s16(buf, afsk26_dem_tables[0][0].q, AFSK26_DEM_SUM_Q_0_0), + convolution12_s16(buf, afsk26_dem_tables[0][1].i, AFSK26_DEM_SUM_I_0_1), + convolution12_s16(buf, afsk26_dem_tables[0][1].q, AFSK26_DEM_SUM_Q_0_1)); + demod_one_sample(sm, st, *buf, + convolution12_s16(buf, afsk26_dem_tables[1][0].i, AFSK26_DEM_SUM_I_1_0), + convolution12_s16(buf, afsk26_dem_tables[1][0].q, AFSK26_DEM_SUM_Q_1_0), + convolution12_s16(buf, afsk26_dem_tables[1][1].i, AFSK26_DEM_SUM_I_1_1), + convolution12_s16(buf, afsk26_dem_tables[1][1].q, AFSK26_DEM_SUM_Q_1_1)); + } +} + +/* --------------------------------------------------------------------- */ + +static void demod_init_2666(struct sm_state *sm) +{ + struct demod_state_afsk26 *st = (struct demod_state_afsk26 *)(&sm->d); + + st->dcd_time = 400; + st->dcd_sum0 = 2; +} + +/* --------------------------------------------------------------------- */ + +const struct modem_tx_info sm_afsk2666_tx = { + "afsk2666", sizeof(struct mod_state_afsk26), AFSK26_SAMPLERATE, 2666, + modulator_2666_u8, modulator_2666_s16, NULL +}; + +const struct modem_rx_info sm_afsk2666_rx = { + "afsk2666", sizeof(struct demod_state_afsk26), AFSK26_SAMPLERATE, 2666, 12, 6, + demodulator_2666_u8, demodulator_2666_s16, demod_init_2666 +}; + +/* --------------------------------------------------------------------- */ |