patch-2.1.27 linux/drivers/net/soundmodem/sm_hapn4800.c

• Lines: 348
• Date: Fri Feb 21 14:58:35 1997
• Orig file: v2.1.26/linux/drivers/net/soundmodem/sm_hapn4800.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.26/linux/drivers/net/soundmodem/sm_hapn4800.c linux/drivers/net/soundmodem/sm_hapn4800.c
@@ -0,0 +1,347 @@
+/*****************************************************************************/
+
+/*
+ *	sm_hapn4800.h  -- soundcard radio modem driver, 4800 baud HAPN 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 module implements a (hopefully) HAPN (Hamilton Area Packet
+ *  Network) compatible 4800 baud modem.
+ *  The HAPN modem uses kind of "duobinary signalling" (not really,
+ *  duobinary signalling gives ... 0 0 -1 0 1 0 0 ... at the sampling
+ *  instants, whereas HAPN signalling gives ... 0 0 -1 1 0 0 ..., see
+ *  Proakis, Digital Communications).
+ *  The code is untested. It is compatible with itself (i.e. it can decode
+ *  the packets it sent), but I could not test if it is compatible with
+ *  any "real" HAPN modem, since noone uses it in my region of the world.
+ *  Feedback therefore welcome.
+ */
+
+#include "sm.h"
+#include "sm_tbl_hapn4800.h"
+
+/* --------------------------------------------------------------------- */
+
+struct demod_state_hapn48 {
+	unsigned int shreg;
+	unsigned int bit_pll;
+	unsigned char last_bit;
+	unsigned char last_bit2;
+	unsigned int dcd_shreg;
+	int dcd_sum0, dcd_sum1, dcd_sum2;
+	unsigned int dcd_time;
+	int inphist[5];
+	int lvlhi, lvllo;
+};
+
+struct mod_state_hapn48 {
+	unsigned int shreg;
+	unsigned char tx_bit;
+};
+
+/* --------------------------------------------------------------------- */
+
+static void modulator_hapn4800_10(struct sm_state *sm, unsigned char *buf, int buflen)
+{
+	struct mod_state_hapn48 *st = (struct mod_state_hapn48 *)(&sm->m);
+	int j;
+	const unsigned char *cp;
+
+	for (; buflen >= 10; buflen -= 10) {
+		if (st->shreg <= 1)
+			st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000;
+		st->tx_bit = ((st->tx_bit << 1) |
+				     (st->tx_bit & 1));
+		st->tx_bit ^= (!(st->shreg & 1));
+		st->shreg >>= 1;
+		cp = hapn48_txfilt_10 + (st->tx_bit & 0xf);
+		for (j = 0; j < 10; j++, cp += 0x10)
+			*buf++ = *cp;
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static void modulator_hapn4800_8(struct sm_state *sm, unsigned char *buf, int buflen)
+{
+	struct mod_state_hapn48 *st = (struct mod_state_hapn48 *)(&sm->m);
+	int j;
+	const unsigned char *cp;
+
+	for (; buflen >= 8; buflen -= 8) {
+		if (st->shreg <= 1)
+			st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000;
+		st->tx_bit = (st->tx_bit << 1) | (st->tx_bit & 1);
+		st->tx_bit ^= !(st->shreg & 1);
+		st->shreg >>= 1;
+		cp = hapn48_txfilt_8 + (st->tx_bit & 0xf);
+		for (j = 0; j < 8; j++, cp += 0x10)
+			*buf++ = *cp;
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static void modulator_hapn4800_pm10(struct sm_state *sm, unsigned char *buf, int buflen)
+{
+	struct mod_state_hapn48 *st = (struct mod_state_hapn48 *)(&sm->m);
+	int j;
+	const unsigned char *cp;
+
+	for (; buflen >= 10; buflen -= 10) {
+		if (st->shreg <= 1)
+			st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000;
+		st->tx_bit = ((st->tx_bit << 1) |
+				     (st->tx_bit & 1));
+		st->tx_bit ^= (!(st->shreg & 1));
+		st->shreg >>= 1;
+		cp = hapn48_txfilt_pm10 + (st->tx_bit & 0xf);
+		for (j = 0; j < 10; j++, cp += 0x10)
+			*buf++ = *cp;
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static void modulator_hapn4800_pm8(struct sm_state *sm, unsigned char *buf, int buflen)
+{
+	struct mod_state_hapn48 *st = (struct mod_state_hapn48 *)(&sm->m);
+	int j;
+	const unsigned char *cp;
+
+	for (; buflen >= 8; buflen -= 8) {
+		if (st->shreg <= 1)
+			st->shreg = hdlcdrv_getbits(&sm->hdrv) | 0x10000;
+		st->tx_bit = (st->tx_bit << 1) | (st->tx_bit & 1);
+		st->tx_bit ^= !(st->shreg & 1);
+		st->shreg >>= 1;
+		cp = hapn48_txfilt_pm8 + (st->tx_bit & 0xf);
+		for (j = 0; j < 8; j++, cp += 0x10)
+			*buf++ = *cp;
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static void demodulator_hapn4800_10(struct sm_state *sm, unsigned char *buf, int buflen)
+{
+	struct demod_state_hapn48 *st = (struct demod_state_hapn48 *)(&sm->d);
+	static const int pll_corr[2] = { -0x800, 0x800 };
+	int curst, cursync;
+
+	for (; buflen > 0; buflen--, buf++) {
+		st->inphist[4] = st->inphist[3];
+		st->inphist[3] = st->inphist[2];
+		st->inphist[2] = st->inphist[1];
+		st->inphist[1] = st->inphist[0];
+		st->inphist[0] = ((int)(*buf)-0x80) << 8;
+		st->lvlhi = (st->lvlhi * 65309) >> 16; /* decay */
+		st->lvllo = (st->lvllo * 65309) >> 16; /* decay */
+		if (st->inphist[2] > st->lvlhi)
+			st->lvlhi = st->inphist[2];
+		if (st->inphist[2] < st->lvllo)
+			st->lvllo = st->inphist[2];
+		if (buflen & 1)
+			st->dcd_shreg <<= 1;
+		st->bit_pll += 0x199a;
+		curst = cursync = 0;
+		if (st->inphist[2] > st->lvlhi >> 1) {
+			curst = 1;
+			cursync = (st->inphist[2] > st->inphist[1] &&
+				   st->inphist[2] > st->inphist[3] &&
+				   st->inphist[2] > st->inphist[0] &&
+				   st->inphist[2] > st->inphist[4]);
+		} else if (st->inphist[2] < st->lvllo >> 1) {
+			curst = -1;
+			cursync = (st->inphist[2] < st->inphist[1] &&
+				   st->inphist[2] < st->inphist[3] &&
+				   st->inphist[2] < st->inphist[0] &&
+				   st->inphist[2] < st->inphist[4]);
+		}
+		if (cursync) {
+			st->dcd_shreg |= cursync;
+			st->bit_pll += pll_corr[((st->bit_pll - 0x8000u) & 0xffffu) < 0x8ccdu];
+			st->dcd_sum0 += 16 * hweight32(st->dcd_shreg & 0x18c6318c) - 
+				hweight32(st->dcd_shreg & 0xe739ce70);
+		}
+		hdlcdrv_channelbit(&sm->hdrv, cursync);
+		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 = 240;
+		}
+		if (st->bit_pll >= 0x10000) {
+			st->bit_pll &= 0xffff;
+			st->last_bit2 = st->last_bit;
+			if (curst < 0)
+				st->last_bit = 0;
+			else if (curst > 0)
+				st->last_bit = 1;
+			st->shreg >>= 1;
+			st->shreg |= ((st->last_bit ^ st->last_bit2 ^ 1) & 1) << 16;
+			if (st->shreg & 1) {
+				hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1);
+				st->shreg = 0x10000;
+			}
+			diag_trigger(sm);
+		}
+		diag_add_one(sm, st->inphist[2]);
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static void demodulator_hapn4800_8(struct sm_state *sm, unsigned char *buf, int buflen)
+{
+	struct demod_state_hapn48 *st = (struct demod_state_hapn48 *)(&sm->d);
+	static const int pll_corr[2] = { -0x800, 0x800 };
+	int curst, cursync;
+
+	for (; buflen > 0; buflen--, buf++) {
+		st->inphist[4] = st->inphist[3];
+		st->inphist[3] = st->inphist[2];
+		st->inphist[2] = st->inphist[1];
+		st->inphist[1] = st->inphist[0];
+		st->inphist[0] = ((int)(*buf)-0x80) << 8;
+		st->lvlhi = (st->lvlhi * 65309) >> 16; /* decay */
+		st->lvllo = (st->lvllo * 65309) >> 16; /* decay */
+		if (st->inphist[2] > st->lvlhi)
+			st->lvlhi = st->inphist[2];
+		if (st->inphist[2] < st->lvllo)
+			st->lvllo = st->inphist[2];
+		if (buflen & 1)
+			st->dcd_shreg <<= 1;
+		st->bit_pll += 0x2000;
+		curst = cursync = 0;
+		if (st->inphist[2] > st->lvlhi >> 1) {
+			curst = 1;
+			cursync = (st->inphist[2] > st->inphist[1] &&
+				   st->inphist[2] > st->inphist[3] &&
+				   st->inphist[2] > st->inphist[0] &&
+				   st->inphist[2] > st->inphist[4]);
+		} else if (st->inphist[2] < st->lvllo >> 1) {
+			curst = -1;
+			cursync = (st->inphist[2] < st->inphist[1] &&
+				   st->inphist[2] < st->inphist[3] &&
+				   st->inphist[2] < st->inphist[0] &&
+				   st->inphist[2] < st->inphist[4]);
+		}
+		if (cursync) {
+			st->dcd_shreg |= cursync;
+			st->bit_pll += pll_corr[((st->bit_pll - 0x8000u) & 0xffffu) < 0x9000u];
+			st->dcd_sum0 += 16 * hweight32(st->dcd_shreg & 0x44444444) - 
+				hweight32(st->dcd_shreg & 0xbbbbbbbb);
+		}
+		hdlcdrv_channelbit(&sm->hdrv, cursync);
+		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 = 240;
+		}
+		if (st->bit_pll >= 0x10000) {
+			st->bit_pll &= 0xffff;
+			st->last_bit2 = st->last_bit;
+			if (curst < 0)
+				st->last_bit = 0;
+			else if (curst > 0)
+				st->last_bit = 1;
+			st->shreg >>= 1;
+			st->shreg |= ((st->last_bit ^ st->last_bit2 ^ 1) & 1) << 16;
+			if (st->shreg & 1) {
+				hdlcdrv_putbits(&sm->hdrv, st->shreg >> 1);
+				st->shreg = 0x10000;
+			}
+			diag_trigger(sm);
+		}
+		diag_add_one(sm, st->inphist[2]);
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static void demod_init_hapn4800(struct sm_state *sm)
+{
+	struct demod_state_hapn48 *st = (struct demod_state_hapn48 *)(&sm->d);
+
+	st->dcd_time = 120;
+	st->dcd_sum0 = 2;	
+}
+
+/* --------------------------------------------------------------------- */
+
+const struct modem_tx_info sm_hapn4800_8_tx = {
+	"hapn4800", sizeof(struct mod_state_hapn48), 
+	38400, 4800, 8, modulator_hapn4800_8, NULL
+};
+
+const struct modem_rx_info sm_hapn4800_8_rx = {
+	"hapn4800", sizeof(struct demod_state_hapn48), 
+	38400, 4800, 8, 8, demodulator_hapn4800_8, demod_init_hapn4800
+};
+
+/* --------------------------------------------------------------------- */
+
+const struct modem_tx_info sm_hapn4800_10_tx = {
+	"hapn4800", sizeof(struct mod_state_hapn48), 
+	48000, 4800, 10, 
+	modulator_hapn4800_10, NULL
+};
+
+const struct modem_rx_info sm_hapn4800_10_rx = {
+	"hapn4800", sizeof(struct demod_state_hapn48), 
+	48000, 4800, 10, 10, demodulator_hapn4800_10, demod_init_hapn4800
+};
+
+/* --------------------------------------------------------------------- */
+
+const struct modem_tx_info sm_hapn4800_pm8_tx = {
+	"hapn4800pm", sizeof(struct mod_state_hapn48), 
+	38400, 4800, 8, modulator_hapn4800_pm8, NULL
+};
+
+const struct modem_rx_info sm_hapn4800_pm8_rx = {
+	"hapn4800pm", sizeof(struct demod_state_hapn48), 
+	38400, 4800, 8, 8, demodulator_hapn4800_8, demod_init_hapn4800
+};
+
+/* --------------------------------------------------------------------- */
+
+const struct modem_tx_info sm_hapn4800_pm10_tx = {
+	"hapn4800pm", sizeof(struct mod_state_hapn48), 
+	48000, 4800, 10, 
+	modulator_hapn4800_pm10, NULL
+};
+
+const struct modem_rx_info sm_hapn4800_pm10_rx = {
+	"hapn4800pm", sizeof(struct demod_state_hapn48), 
+	48000, 4800, 10, 10, demodulator_hapn4800_10, demod_init_hapn4800
+};
+
+/* --------------------------------------------------------------------- */