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linux-zen-server/drivers/net/hamradio/baycom_par.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*****************************************************************************/
/*
* baycom_par.c -- baycom par96 and picpar radio modem driver.
*
* Copyright (C) 1996-2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
*
* 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* from Baycom) and has been replaced by the PICPAR modem (see below).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 <linux/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) == mask2) &&
(bc->modem.par96.dcd_count >= 0))
bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
/* decrement and set the dcd variable */
if (bc->modem.par96.dcd_count >= 0)
bc->modem.par96.dcd_count -= 2;
hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
} else {
hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
}
}
/* --------------------------------------------------------------------- */
static void par96_interrupt(void *dev_id)
{
struct net_device *dev = dev_id;
struct baycom_state *bc = netdev_priv(dev);
baycom_int_freq(bc);
/*
* check if transmitter active
*/
if (hdlcdrv_ptt(&bc->hdrv))
par96_tx(dev, bc);
else {
par96_rx(dev, bc);
if (--bc->modem.arb_divider <= 0) {
bc->modem.arb_divider = 6;
local_irq_enable();
hdlcdrv_arbitrate(dev, &bc->hdrv);
}
}
local_irq_enable();
hdlcdrv_transmitter(dev, &bc->hdrv);
hdlcdrv_receiver(dev, &bc->hdrv);
local_irq_disable();
}
/* --------------------------------------------------------------------- */
static void par96_wakeup(void *handle)
{
struct net_device *dev = (struct net_device *)handle;
struct baycom_state *bc = netdev_priv(dev);
printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
if (!parport_claim(bc->pdev))
printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
}
/* --------------------------------------------------------------------- */
static int par96_open(struct net_device *dev)
{
struct baycom_state *bc = netdev_priv(dev);
struct pardev_cb par_cb;
struct parport *pp;
int i;
if (!dev || !bc)
return -ENXIO;
pp = parport_find_base(dev->base_addr);
if (!pp) {
printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
return -ENXIO;
}
if (pp->irq < 0) {
printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
parport_put_port(pp);
return -ENXIO;
}
if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
parport_put_port(pp);
return -ENXIO;
}
memset(&bc->modem, 0, sizeof(bc->modem));
bc->hdrv.par.bitrate = 9600;
memset(&par_cb, 0, sizeof(par_cb));
par_cb.wakeup = par96_wakeup;
par_cb.irq_func = par96_interrupt;
par_cb.private = (void *)dev;
par_cb.flags = PARPORT_DEV_EXCL;
for (i = 0; i < NR_PORTS; i++)
if (baycom_device[i] == dev)
break;
if (i == NR_PORTS) {
pr_err("%s: no device found\n", bc_drvname);
parport_put_port(pp);
return -ENODEV;
}
bc->pdev = parport_register_dev_model(pp, dev->name, &par_cb, i);
parport_put_port(pp);
if (!bc->pdev) {
printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
return -ENXIO;
}
if (parport_claim(bc->pdev)) {
printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
parport_unregister_device(bc->pdev);
return -EBUSY;
}
pp = bc->pdev->port;
dev->irq = pp->irq;
pp->ops->data_forward(pp);
bc->hdrv.par.bitrate = 9600;
pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
pp->ops->enable_irq(pp);
printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
bc_drvname, dev->base_addr, dev->irq, bc->options);
return 0;
}
/* --------------------------------------------------------------------- */
static int par96_close(struct net_device *dev)
{
struct baycom_state *bc = netdev_priv(dev);
struct parport *pp;
if (!dev || !bc)
return -EINVAL;
pp = bc->pdev->port;
/* disable interrupt */
pp->ops->disable_irq(pp);
/* switch off PTT */
pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
parport_release(bc->pdev);
parport_unregister_device(bc->pdev);
printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
bc_drvname, dev->base_addr, dev->irq);
return 0;
}
/* --------------------------------------------------------------------- */
/*
* ===================== hdlcdrv driver interface =========================
*/
static int baycom_ioctl(struct net_device *dev, void __user *data,
struct hdlcdrv_ioctl *hi, int cmd);
/* --------------------------------------------------------------------- */
static const struct hdlcdrv_ops par96_ops = {
.drvname = bc_drvname,
.drvinfo = bc_drvinfo,
.open = par96_open,
.close = par96_close,
.ioctl = baycom_ioctl
};
/* --------------------------------------------------------------------- */
static int baycom_setmode(struct baycom_state *bc, const char *modestr)
{
if (!strncmp(modestr, "picpar", 6))
bc->options = 0;
else if (!strncmp(modestr, "par96", 5))
bc->options = BAYCOM_OPTIONS_SOFTDCD;
else
bc->options = !!strchr(modestr, '*');
return 0;
}
/* --------------------------------------------------------------------- */
static int baycom_ioctl(struct net_device *dev, void __user *data,
struct hdlcdrv_ioctl *hi, int cmd)
{
struct baycom_state *bc;
struct baycom_ioctl bi;
if (!dev)
return -EINVAL;
bc = netdev_priv(dev);
BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
if (cmd != SIOCDEVPRIVATE)
return -ENOIOCTLCMD;
switch (hi->cmd) {
default:
break;
case HDLCDRVCTL_GETMODE:
strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))
return -EFAULT;
return 0;
case HDLCDRVCTL_SETMODE:
if (netif_running(dev) || !capable(CAP_NET_ADMIN))
return -EACCES;
hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
return baycom_setmode(bc, hi->data.modename);
case HDLCDRVCTL_MODELIST:
strcpy(hi->data.modename, "par96,picpar");
if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))
return -EFAULT;
return 0;
case HDLCDRVCTL_MODEMPARMASK:
return HDLCDRV_PARMASK_IOBASE;
}
if (copy_from_user(&bi, data, sizeof(bi)))
return -EFAULT;
switch (bi.cmd) {
default:
return -ENOIOCTLCMD;
#ifdef BAYCOM_DEBUG
case BAYCOMCTL_GETDEBUG:
bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
break;
#endif /* BAYCOM_DEBUG */
}
if (copy_to_user(data, &bi, sizeof(bi)))
return -EFAULT;
return 0;
}
/* --------------------------------------------------------------------- */
/*
* command line settable parameters
*/
static char *mode[NR_PORTS] = { "picpar", };
static int iobase[NR_PORTS] = { 0x378, };
module_param_array(mode, charp, NULL, 0);
MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
module_param_hw_array(iobase, int, ioport, NULL, 0);
MODULE_PARM_DESC(iobase, "baycom io base address");
MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
MODULE_LICENSE("GPL");
/* --------------------------------------------------------------------- */
static int baycom_par_probe(struct pardevice *par_dev)
{
struct device_driver *drv = par_dev->dev.driver;
int len = strlen(drv->name);
if (strncmp(par_dev->name, drv->name, len))
return -ENODEV;
return 0;
}
static struct parport_driver baycom_par_driver = {
.name = "bcp",
.probe = baycom_par_probe,
.devmodel = true,
};
static int __init init_baycompar(void)
{
int i, found = 0, ret;
char set_hw = 1;
printk(bc_drvinfo);
ret = parport_register_driver(&baycom_par_driver);
if (ret)
return ret;
/*
* register net devices
*/
for (i = 0; i < NR_PORTS; i++) {
struct net_device *dev;
struct baycom_state *bc;
char ifname[IFNAMSIZ];
sprintf(ifname, "bcp%d", i);
if (!mode[i])
set_hw = 0;
if (!set_hw)
iobase[i] = 0;
dev = hdlcdrv_register(&par96_ops,
sizeof(struct baycom_state),
ifname, iobase[i], 0, 0);
if (IS_ERR(dev))
break;
bc = netdev_priv(dev);
if (set_hw && baycom_setmode(bc, mode[i]))
set_hw = 0;
found++;
baycom_device[i] = dev;
}
if (!found) {
parport_unregister_driver(&baycom_par_driver);
return -ENXIO;
}
return 0;
}
static void __exit cleanup_baycompar(void)
{
int i;
for(i = 0; i < NR_PORTS; i++) {
struct net_device *dev = baycom_device[i];
if (dev)
hdlcdrv_unregister(dev);
}
parport_unregister_driver(&baycom_par_driver);
}
module_init(init_baycompar);
module_exit(cleanup_baycompar);
/* --------------------------------------------------------------------- */
#ifndef MODULE
/*
* format: baycom_par=io,mode
* mode: par96,picpar
*/
static int __init baycom_par_setup(char *str)
{
static unsigned nr_dev;
int ints[2];
if (nr_dev >= NR_PORTS)
return 0;
str = get_options(str, 2, ints);
if (ints[0] < 1)
return 0;
mode[nr_dev] = str;
iobase[nr_dev] = ints[1];
nr_dev++;
return 1;
}
__setup("baycom_par=", baycom_par_setup);
#endif /* MODULE */
/* --------------------------------------------------------------------- */