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Import 2.1.42pre1
[davej-history.git] / drivers / net / soundmodem / sm_fsk9600.c
blob8fbf9d2187f3e3eeeac6a712fe326c3c7bb30454
1 /*****************************************************************************/
2
3 /*
4 * sm_fsk9600.c -- soundcard radio modem driver,
5 * 9600 baud G3RUH compatible FSK modem
6 *
7 * Copyright (C) 1996 Thomas Sailer (sailer@ife.ee.ethz.ch)
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 *
23 * Please note that the GPL allows you to use the driver, NOT the radio.
24 * In order to use the radio, you need a license from the communications
25 * authority of your country.
26 *
27 */
28
29 #include "sm.h"
30 #include "sm_tbl_fsk9600.h"
31
32 /* --------------------------------------------------------------------- */
33
34 struct demod_state_fsk96 {
35 unsigned int shreg;
36 unsigned long descram;
37 unsigned int bit_pll;
38 unsigned char last_sample;
39 unsigned int dcd_shreg;
40 int dcd_sum0, dcd_sum1, dcd_sum2;
41 unsigned int dcd_time;
42 };
43
44 struct mod_state_fsk96 {
45 unsigned int shreg;
46 unsigned long scram;
47 unsigned char tx_bit;
48 };
49
50 /* --------------------------------------------------------------------- */
51
52 #define DESCRAM_TAP1 0x20000
53 #define DESCRAM_TAP2 0x01000
54 #define DESCRAM_TAP3 0x00001
55
56 #define DESCRAM_TAPSH1 17
57 #define DESCRAM_TAPSH2 12
58 #define DESCRAM_TAPSH3 0
59
60 #define SCRAM_TAP1 0x20000 /* X^17 */
61 #define SCRAM_TAPN 0x00021 /* X^0+X^5 */
62
63 /* --------------------------------------------------------------------- */
64
65 static void modulator_9600_4(struct sm_state *sm, unsigned char *buf, int buflen)
66 {
67 struct mod_state_fsk96 *st = (struct mod_state_fsk96 *)(&sm->m);
68 int j;
69 const unsigned char *cp;
70
71 for (; buflen >= 4; buflen -= 4) {
72 if (st->shreg <= 1)
73 st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000;
74 st->scram = (st->scram << 1) | (st->scram & 1);
75 st->scram ^= !(st->shreg & 1);
76 st->shreg >>= 1;
77 if (st->scram & (SCRAM_TAP1 << 1))
78 st->scram ^= SCRAM_TAPN << 1;
79 st->tx_bit = (st->tx_bit << 1) | (!!(st->scram & (SCRAM_TAP1 << 2)));
80 cp = fsk96_txfilt_4 + (st->tx_bit & 0xff);
81 for (j = 0; j < 4; j++, cp += 0x100)
82 *buf++ = *cp;
83 }
84 }
85
86 /* --------------------------------------------------------------------- */
87
88 static void demodulator_9600_4(struct sm_state *sm, unsigned char *buf, int buflen)
89 {
90 struct demod_state_fsk96 *st = (struct demod_state_fsk96 *)(&sm->d);
91 static const int pll_corr[2] = { -0x1000, 0x1000 };
92 unsigned char curbit;
93 unsigned int descx;
94
95 for (; buflen > 0; buflen--, buf++) {
96 st->dcd_shreg <<= 1;
97 st->bit_pll += 0x4000;
98 curbit = (*buf >= 0x80);
99 if (st->last_sample ^ curbit) {
100 st->dcd_shreg |= 1;
101 st->bit_pll += pll_corr[st->bit_pll < 0xa000];
102 st->dcd_sum0 += 8 * hweight8(st->dcd_shreg & 0x0c) -
103 !!(st->dcd_shreg & 0x10);
104 }
105 st->last_sample = curbit;
106 hdlcdrv_channelbit(&sm->hdrv, st->last_sample);
107 if ((--st->dcd_time) <= 0) {
108 hdlcdrv_setdcd(&sm->hdrv, (st->dcd_sum0 +
109 st->dcd_sum1 +
110 st->dcd_sum2) < 0);
111 st->dcd_sum2 = st->dcd_sum1;
112 st->dcd_sum1 = st->dcd_sum0;
113 st->dcd_sum0 = 2; /* slight bias */
114 st->dcd_time = 240;
115 }
116 if (st->bit_pll >= 0x10000) {
117 st->bit_pll &= 0xffff;
118 st->descram = (st->descram << 1) | curbit;
119 descx = st->descram ^ (st->descram >> 1);
120 descx ^= ((descx >> DESCRAM_TAPSH1) ^
121 (descx >> DESCRAM_TAPSH2));
122 st->shreg >>= 1;
123 st->shreg |= (!(descx & 1)) << 16;
124 if (st->shreg & 1) {
125 hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1);
126 st->shreg = 0x10000;
127 }
128 diag_trigger(sm);
129 }
130 diag_add_one(sm, ((short)(*buf - 0x80)) << 8);
131 }
132 }
133
134 /* --------------------------------------------------------------------- */
135
136 static void modulator_9600_5(struct sm_state *sm, unsigned char *buf, int buflen)
137 {
138 struct mod_state_fsk96 *st = (struct mod_state_fsk96 *)(&sm->m);
139 int j;
140 const unsigned char *cp;
141
142 for (; buflen >= 5; buflen -= 5) {
143 if (st->shreg <= 1)
144 st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000;
145 st->scram = (st->scram << 1) | (st->scram & 1);
146 st->scram ^= !(st->shreg & 1);
147 st->shreg >>= 1;
148 if (st->scram & (SCRAM_TAP1 << 1))
149 st->scram ^= SCRAM_TAPN << 1;
150 st->tx_bit = (st->tx_bit << 1) | (!!(st->scram & (SCRAM_TAP1 << 2)));
151 cp = fsk96_txfilt_5 + (st->tx_bit & 0xff);
152 for (j = 0; j < 5; j++, cp += 0x100)
153 *buf++ = *cp;
154 }
155 }
156
157 /* --------------------------------------------------------------------- */
158
159 static void demodulator_9600_5(struct sm_state *sm, unsigned char *buf, int buflen)
160 {
161 struct demod_state_fsk96 *st = (struct demod_state_fsk96 *)(&sm->d);
162 static const int pll_corr[2] = { -0x1000, 0x1000 };
163 unsigned char curbit;
164 unsigned int descx;
165
166 for (; buflen > 0; buflen--, buf++) {
167 st->dcd_shreg <<= 1;
168 st->bit_pll += 0x3333;
169 curbit = (*buf >= 0x80);
170 if (st->last_sample ^ curbit) {
171 st->dcd_shreg |= 1;
172 st->bit_pll += pll_corr[st->bit_pll < 0x9999];
173 st->dcd_sum0 += 16 * hweight8(st->dcd_shreg & 0x0c) -
174 hweight8(st->dcd_shreg & 0x70);
175 }
176 st->last_sample = curbit;
177 hdlcdrv_channelbit(&sm->hdrv, st->last_sample);
178 if ((--st->dcd_time) <= 0) {
179 hdlcdrv_setdcd(&sm->hdrv, (st->dcd_sum0 +
180 st->dcd_sum1 +
181 st->dcd_sum2) < 0);
182 st->dcd_sum2 = st->dcd_sum1;
183 st->dcd_sum1 = st->dcd_sum0;
184 st->dcd_sum0 = 2; /* slight bias */
185 st->dcd_time = 240;
186 }
187 if (st->bit_pll >= 0x10000) {
188 st->bit_pll &= 0xffff;
189 st->descram = (st->descram << 1) | curbit;
190 descx = st->descram ^ (st->descram >> 1);
191 descx ^= ((descx >> DESCRAM_TAPSH1) ^
192 (descx >> DESCRAM_TAPSH2));
193 st->shreg >>= 1;
194 st->shreg |= (!(descx & 1)) << 16;
195 if (st->shreg & 1) {
196 hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1);
197 st->shreg = 0x10000;
198 }
199 diag_trigger(sm);
200 }
201 diag_add_one(sm, ((short)(*buf - 0x80)) << 8);
202 }
203 }
204
205 /* --------------------------------------------------------------------- */
206
207 static void demod_init_9600(struct sm_state *sm)
208 {
209 struct demod_state_fsk96 *st = (struct demod_state_fsk96 *)(&sm->d);
210
211 st->dcd_time = 240;
212 st->dcd_sum0 = 2;
213 }
214
215 /* --------------------------------------------------------------------- */
216
217 const struct modem_tx_info sm_fsk9600_4_tx = {
218 "fsk9600", sizeof(struct mod_state_fsk96), 38400, 9600, 4,
219 modulator_9600_4, NULL
220 };
221
222 const struct modem_rx_info sm_fsk9600_4_rx = {
223 "fsk9600", sizeof(struct demod_state_fsk96), 38400, 9600, 4, 4,
224 demodulator_9600_4, demod_init_9600
225 };
226
227 /* --------------------------------------------------------------------- */
228
229 const struct modem_tx_info sm_fsk9600_5_tx = {
230 "fsk9600", sizeof(struct mod_state_fsk96), 48000, 9600, 5,
231 modulator_9600_5, NULL
232 };
233
234 const struct modem_rx_info sm_fsk9600_5_rx = {
235 "fsk9600", sizeof(struct demod_state_fsk96), 48000, 9600, 5, 5,
236 demodulator_9600_5, demod_init_9600
237 };
238
239 /* --------------------------------------------------------------------- */
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