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/*****************************************************************************/
/*
* baycom_par.c -- baycom par96 and picpar radio modem driver.
*
* Copyright (C) 1996-2000 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.
*
*
* Supported modems
*
* par96: This is a modem for 9600 baud FSK compatible to the G3RUH standard.
* The modem does all the filtering and regenerates the receiver clock.
* Data is transferred from and to the PC via a shift register.
* The shift register is filled with 16 bits and an interrupt is
* signalled. The PC then empties the shift register in a burst. This
* modem connects to the parallel port, hence the name. The modem
* leaves the implementation of the HDLC protocol and the scrambler
* polynomial to the PC. This modem is no longer available (at least
* from Baycom) and has been replaced by the PICPAR modem (see below).
* You may however still build one from the schematics published in
* cq-DL :-).
*
* picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
* modem is protocol compatible to par96, but uses only three low
* power ICs and can therefore be fed from the parallel port and
* does not require an additional power supply. It features
* built in DCD circuitry. The driver should therefore be configured
* for hardware DCD.
*
*
* Command line options (insmod command line)
*
* mode driver mode string. Valid choices are par96 and picpar.
* iobase base address of the port; common values are 0x378, 0x278, 0x3bc
*
*
* History:
* 0.1 26.06.1996 Adapted from baycom.c and made network driver interface
* 18.10.1996 Changed to new user space access routines (copy_{to,from}_user)
* 0.3 26.04.1997 init code/data tagged
* 0.4 08.07.1997 alternative ser12 decoding algorithm (uses delta CTS ints)
* 0.5 11.11.1997 split into separate files for ser12/par96
* 0.6 03.08.1999 adapt to Linus' new __setup/__initcall
* removed some pre-2.2 kernel compatibility cruft
* 0.7 10.08.1999 Check if parport can do SPP and is safe to access during interrupt contexts
* 0.8 12.02.2000 adapted to softnet driver interface
* removed direct parport access, uses parport driver methods
* 0.9 03.07.2000 fix interface name handling
*/
/*****************************************************************************/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/hdlcdrv.h>
#include <linux/baycom.h>
#include <linux/parport.h>
#include <linux/bitops.h>
#include <linux/jiffies.h>
#include <asm/uaccess.h>
/* --------------------------------------------------------------------- */
#define BAYCOM_DEBUG
/*
* modem options; bit mask
*/
#define BAYCOM_OPTIONS_SOFTDCD 1
/* --------------------------------------------------------------------- */
static const char bc_drvname[] = "baycom_par";
static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
"baycom_par: version 0.9\n";
/* --------------------------------------------------------------------- */
#define NR_PORTS 4
static struct net_device *baycom_device[NR_PORTS];
/* --------------------------------------------------------------------- */
#define PAR96_BURSTBITS 16
#define PAR96_BURST 4
#define PAR96_PTT 2
#define PAR96_TXBIT 1
#define PAR96_ACK 0x40
#define PAR96_RXBIT 0x20
#define PAR96_DCD 0x10
#define PAR97_POWER 0xf8
/* ---------------------------------------------------------------------- */
/*
* Information that need to be kept for each board.
*/
struct baycom_state {
struct hdlcdrv_state hdrv;
struct pardevice *pdev;
unsigned int options;
struct modem_state {
short arb_divider;
unsigned char flags;
unsigned int shreg;
struct modem_state_par96 {
int dcd_count;
unsigned int dcd_shreg;
unsigned long descram;
unsigned long scram;
} par96;
} modem;
#ifdef BAYCOM_DEBUG
struct debug_vals {
unsigned long last_jiffies;
unsigned cur_intcnt;
unsigned last_intcnt;
int cur_pllcorr;
int last_pllcorr;
} debug_vals;
#endif /* BAYCOM_DEBUG */
};
/* --------------------------------------------------------------------- */
static inline void baycom_int_freq(struct baycom_state *bc)
{
#ifdef BAYCOM_DEBUG
unsigned long cur_jiffies = jiffies;
/*
* measure the interrupt frequency
*/
bc->debug_vals.cur_intcnt++;
if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
bc->debug_vals.last_jiffies = cur_jiffies;
bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
bc->debug_vals.cur_intcnt = 0;
bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
bc->debug_vals.cur_pllcorr = 0;
}
#endif /* BAYCOM_DEBUG */
}
/* --------------------------------------------------------------------- */
/*
* ===================== PAR96 specific routines =========================
*/
#define PAR96_DESCRAM_TAP1 0x20000
#define PAR96_DESCRAM_TAP2 0x01000
#define PAR96_DESCRAM_TAP3 0x00001
#define PAR96_DESCRAM_TAPSH1 17
#define PAR96_DESCRAM_TAPSH2 12
#define PAR96_DESCRAM_TAPSH3 0
#define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
#define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
/* --------------------------------------------------------------------- */
static inline void par96_tx(struct net_device *dev, struct baycom_state *bc)
{
int i;
unsigned int data = hdlcdrv_getbits(&bc->hdrv);
struct parport *pp = bc->pdev->port;
for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
unsigned char val = PAR97_POWER;
bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
(bc->modem.par96.scram & 1));
if (!(data & 1))
bc->modem.par96.scram ^= 1;
if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
bc->modem.par96.scram ^=
(PAR96_SCRAM_TAPN << 1);
if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
val |= PAR96_TXBIT;
pp->ops->write_data(pp, val);
pp->ops->write_data(pp, val | PAR96_BURST);
}
}
/* --------------------------------------------------------------------- */
static inline void par96_rx(struct net_device *dev, struct baycom_state *bc)
{
int i;
unsigned int data, mask, mask2, descx;
struct parport *pp = bc->pdev->port;
/*
* do receiver; differential decode and descramble on the fly
*/
for(data = i = 0; i < PAR96_BURSTBITS; i++) {
bc->modem.par96.descram = (bc->modem.par96.descram << 1);
if (pp->ops->read_status(pp) & PAR96_RXBIT)
bc->modem.par96.descram |= 1;
descx = bc->modem.par96.descram ^
(bc->modem.par96.descram >> 1);
/* now the diff decoded data is inverted in descram */
pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
(descx >> PAR96_DESCRAM_TAPSH2));
data >>= 1;
if (!(descx & 1))
data |= 0x8000;
pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
}
hdlcdrv_putbits(&bc->hdrv, data);
/*
* do DCD algorithm
*/
if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
| (data << 16);
/* search for flags and set the dcd counter appropriately */
for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
if ((bc->modem.par96.dcd_shreg & mask) == mask2)
bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
/* check for abort/noise sequences */
for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
if (((bc->modem.par96.dcd_shreg & mask) ==
|