linux/drivers/net/hamradio/baycom_par.c
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   1/*****************************************************************************/
   2
   3/*
   4 *      baycom_par.c  -- baycom par96 and picpar radio modem driver.
   5 *
   6 *      Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
   7 *
   8 *      This program is free software; you can redistribute it and/or modify
   9 *      it under the terms of the GNU General Public License as published by
  10 *      the Free Software Foundation; either version 2 of the License, or
  11 *      (at your option) any later version.
  12 *
  13 *      This program is distributed in the hope that it will be useful,
  14 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 *      GNU General Public License for more details.
  17 *
  18 *      You should have received a copy of the GNU General Public License
  19 *      along with this program; if not, write to the Free Software
  20 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 *
  22 *  Please note that the GPL allows you to use the driver, NOT the radio.
  23 *  In order to use the radio, you need a license from the communications
  24 *  authority of your country.
  25 *
  26 *
  27 *  Supported modems
  28 *
  29 *  par96:  This is a modem for 9600 baud FSK compatible to the G3RUH standard.
  30 *          The modem does all the filtering and regenerates the receiver clock.
  31 *          Data is transferred from and to the PC via a shift register.
  32 *          The shift register is filled with 16 bits and an interrupt is
  33 *          signalled. The PC then empties the shift register in a burst. This
  34 *          modem connects to the parallel port, hence the name. The modem
  35 *          leaves the implementation of the HDLC protocol and the scrambler
  36 *          polynomial to the PC. This modem is no longer available (at least
  37 *          from Baycom) and has been replaced by the PICPAR modem (see below).
  38 *          You may however still build one from the schematics published in
  39 *          cq-DL :-).
  40 *
  41 *  picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
  42 *          modem is protocol compatible to par96, but uses only three low
  43 *          power ICs and can therefore be fed from the parallel port and
  44 *          does not require an additional power supply. It features
  45 *          built in DCD circuitry. The driver should therefore be configured
  46 *          for hardware DCD.
  47 *
  48 *
  49 *  Command line options (insmod command line)
  50 *
  51 *  mode     driver mode string. Valid choices are par96 and picpar.
  52 *  iobase   base address of the port; common values are 0x378, 0x278, 0x3bc
  53 *
  54 *
  55 *  History:
  56 *   0.1  26.06.1996  Adapted from baycom.c and made network driver interface
  57 *        18.10.1996  Changed to new user space access routines (copy_{to,from}_user)
  58 *   0.3  26.04.1997  init code/data tagged
  59 *   0.4  08.07.1997  alternative ser12 decoding algorithm (uses delta CTS ints)
  60 *   0.5  11.11.1997  split into separate files for ser12/par96
  61 *   0.6  03.08.1999  adapt to Linus' new __setup/__initcall
  62 *                    removed some pre-2.2 kernel compatibility cruft
  63 *   0.7  10.08.1999  Check if parport can do SPP and is safe to access during interrupt contexts
  64 *   0.8  12.02.2000  adapted to softnet driver interface
  65 *                    removed direct parport access, uses parport driver methods
  66 *   0.9  03.07.2000  fix interface name handling
  67 */
  68
  69/*****************************************************************************/
  70
  71#include <linux/module.h>
  72#include <linux/kernel.h>
  73#include <linux/types.h>
  74#include <linux/fcntl.h>
  75#include <linux/interrupt.h>
  76#include <linux/ioport.h>
  77#include <linux/in.h>
  78#include <linux/string.h>
  79#include <linux/init.h>
  80#include <linux/delay.h>
  81#include <linux/errno.h>
  82#include <linux/netdevice.h>
  83#include <linux/hdlcdrv.h>
  84#include <linux/baycom.h>
  85#include <linux/parport.h>
  86#include <linux/bitops.h>
  87#include <linux/jiffies.h>
  88
  89#include <asm/system.h>
  90#include <asm/uaccess.h>
  91
  92/* --------------------------------------------------------------------- */
  93
  94#define BAYCOM_DEBUG
  95
  96/*
  97 * modem options; bit mask
  98 */
  99#define BAYCOM_OPTIONS_SOFTDCD  1
 100
 101/* --------------------------------------------------------------------- */
 102
 103static const char bc_drvname[] = "baycom_par";
 104static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
 105"baycom_par: version 0.9 compiled " __TIME__ " " __DATE__ "\n";
 106
 107/* --------------------------------------------------------------------- */
 108
 109#define NR_PORTS 4
 110
 111static struct net_device *baycom_device[NR_PORTS];
 112
 113/* --------------------------------------------------------------------- */
 114
 115#define PAR96_BURSTBITS 16
 116#define PAR96_BURST     4
 117#define PAR96_PTT       2
 118#define PAR96_TXBIT     1
 119#define PAR96_ACK       0x40
 120#define PAR96_RXBIT     0x20
 121#define PAR96_DCD       0x10
 122#define PAR97_POWER     0xf8
 123
 124/* ---------------------------------------------------------------------- */
 125/*
 126 * Information that need to be kept for each board.
 127 */
 128
 129struct baycom_state {
 130        struct hdlcdrv_state hdrv;
 131
 132        struct pardevice *pdev;
 133        unsigned int options;
 134
 135        struct modem_state {
 136                short arb_divider;
 137                unsigned char flags;
 138                unsigned int shreg;
 139                struct modem_state_par96 {
 140                        int dcd_count;
 141                        unsigned int dcd_shreg;
 142                        unsigned long descram;
 143                        unsigned long scram;
 144                } par96;
 145        } modem;
 146
 147#ifdef BAYCOM_DEBUG
 148        struct debug_vals {
 149                unsigned long last_jiffies;
 150                unsigned cur_intcnt;
 151                unsigned last_intcnt;
 152                int cur_pllcorr;
 153                int last_pllcorr;
 154        } debug_vals;
 155#endif /* BAYCOM_DEBUG */
 156};
 157
 158/* --------------------------------------------------------------------- */
 159
 160static void __inline__ baycom_int_freq(struct baycom_state *bc)
 161{
 162#ifdef BAYCOM_DEBUG
 163        unsigned long cur_jiffies = jiffies;
 164        /*
 165         * measure the interrupt frequency
 166         */
 167        bc->debug_vals.cur_intcnt++;
 168        if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
 169                bc->debug_vals.last_jiffies = cur_jiffies;
 170                bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
 171                bc->debug_vals.cur_intcnt = 0;
 172                bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
 173                bc->debug_vals.cur_pllcorr = 0;
 174        }
 175#endif /* BAYCOM_DEBUG */
 176}
 177
 178/* --------------------------------------------------------------------- */
 179/*
 180 * ===================== PAR96 specific routines =========================
 181 */
 182
 183#define PAR96_DESCRAM_TAP1 0x20000
 184#define PAR96_DESCRAM_TAP2 0x01000
 185#define PAR96_DESCRAM_TAP3 0x00001
 186
 187#define PAR96_DESCRAM_TAPSH1 17
 188#define PAR96_DESCRAM_TAPSH2 12
 189#define PAR96_DESCRAM_TAPSH3 0
 190
 191#define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
 192#define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
 193
 194/* --------------------------------------------------------------------- */
 195
 196static __inline__ void par96_tx(struct net_device *dev, struct baycom_state *bc)
 197{
 198        int i;
 199        unsigned int data = hdlcdrv_getbits(&bc->hdrv);
 200        struct parport *pp = bc->pdev->port;
 201
 202        for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
 203                unsigned char val = PAR97_POWER;
 204                bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
 205                                         (bc->modem.par96.scram & 1));
 206                if (!(data & 1))
 207                        bc->modem.par96.scram ^= 1;
 208                if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
 209                        bc->modem.par96.scram ^=
 210                                (PAR96_SCRAM_TAPN << 1);
 211                if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
 212                        val |= PAR96_TXBIT;
 213                pp->ops->write_data(pp, val);
 214                pp->ops->write_data(pp, val | PAR96_BURST);
 215        }
 216}
 217
 218/* --------------------------------------------------------------------- */
 219
 220static __inline__ void par96_rx(struct net_device *dev, struct baycom_state *bc)
 221{
 222        int i;
 223        unsigned int data, mask, mask2, descx;
 224        struct parport *pp = bc->pdev->port;
 225
 226        /*
 227         * do receiver; differential decode and descramble on the fly
 228         */
 229        for(data = i = 0; i < PAR96_BURSTBITS; i++) {
 230                bc->modem.par96.descram = (bc->modem.par96.descram << 1);
 231                if (pp->ops->read_status(pp) & PAR96_RXBIT)
 232                        bc->modem.par96.descram |= 1;
 233                descx = bc->modem.par96.descram ^
 234                        (bc->modem.par96.descram >> 1);
 235                /* now the diff decoded data is inverted in descram */
 236                pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
 237                descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
 238                          (descx >> PAR96_DESCRAM_TAPSH2));
 239                data >>= 1;
 240                if (!(descx & 1))
 241                        data |= 0x8000;
 242                pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
 243        }
 244        hdlcdrv_putbits(&bc->hdrv, data);
 245        /*
 246         * do DCD algorithm
 247         */
 248        if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
 249                bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
 250                        | (data << 16);
 251                /* search for flags and set the dcd counter appropriately */
 252                for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
 253                    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 254                        if ((bc->modem.par96.dcd_shreg & mask) == mask2)
 255                                bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
 256                /* check for abort/noise sequences */
 257                for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
 258                    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 259                        if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
 260                            (bc->modem.par96.dcd_count >= 0))
 261                                bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
 262                /* decrement and set the dcd variable */
 263                if (bc->modem.par96.dcd_count >= 0)
 264                        bc->modem.par96.dcd_count -= 2;
 265                hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
 266        } else {
 267                hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
 268        }
 269}
 270
 271/* --------------------------------------------------------------------- */
 272
 273static void par96_interrupt(void *dev_id)
 274{
 275        struct net_device *dev = dev_id;
 276        struct baycom_state *bc = netdev_priv(dev);
 277
 278        baycom_int_freq(bc);
 279        /*
 280         * check if transmitter active
 281         */
 282        if (hdlcdrv_ptt(&bc->hdrv))
 283                par96_tx(dev, bc);
 284        else {
 285                par96_rx(dev, bc);
 286                if (--bc->modem.arb_divider <= 0) {
 287                        bc->modem.arb_divider = 6;
 288                        local_irq_enable();
 289                        hdlcdrv_arbitrate(dev, &bc->hdrv);
 290                }
 291        }
 292        local_irq_enable();
 293        hdlcdrv_transmitter(dev, &bc->hdrv);
 294        hdlcdrv_receiver(dev, &bc->hdrv);
 295        local_irq_disable();
 296}
 297
 298/* --------------------------------------------------------------------- */
 299
 300static void par96_wakeup(void *handle)
 301{
 302        struct net_device *dev = (struct net_device *)handle;
 303        struct baycom_state *bc = netdev_priv(dev);
 304
 305        printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
 306        if (!parport_claim(bc->pdev))
 307                printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
 308}
 309
 310/* --------------------------------------------------------------------- */
 311
 312static int par96_open(struct net_device *dev)
 313{
 314        struct baycom_state *bc = netdev_priv(dev);
 315        struct parport *pp;
 316
 317        if (!dev || !bc)
 318                return -ENXIO;
 319        pp = parport_find_base(dev->base_addr);
 320        if (!pp) {
 321                printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
 322                return -ENXIO;
 323        }
 324        if (pp->irq < 0) {
 325                printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
 326                parport_put_port(pp);
 327                return -ENXIO;
 328        }
 329        if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
 330                printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
 331                parport_put_port(pp);
 332                return -ENXIO;
 333        }
 334        memset(&bc->modem, 0, sizeof(bc->modem));
 335        bc->hdrv.par.bitrate = 9600;
 336        bc->pdev = parport_register_device(pp, dev->name, NULL, par96_wakeup, 
 337                                 par96_interrupt, PARPORT_DEV_EXCL, dev);
 338        parport_put_port(pp);
 339        if (!bc->pdev) {
 340                printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
 341                return -ENXIO;
 342        }
 343        if (parport_claim(bc->pdev)) {
 344                printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
 345                parport_unregister_device(bc->pdev);
 346                return -EBUSY;
 347        }
 348        pp = bc->pdev->port;
 349        dev->irq = pp->irq;
 350        pp->ops->data_forward(pp);
 351        bc->hdrv.par.bitrate = 9600;
 352        pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
 353        pp->ops->enable_irq(pp);
 354        printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
 355               bc_drvname, dev->base_addr, dev->irq, bc->options);
 356        return 0;
 357}
 358
 359/* --------------------------------------------------------------------- */
 360
 361static int par96_close(struct net_device *dev)
 362{
 363        struct baycom_state *bc = netdev_priv(dev);
 364        struct parport *pp;
 365
 366        if (!dev || !bc)
 367                return -EINVAL;
 368        pp = bc->pdev->port;
 369        /* disable interrupt */
 370        pp->ops->disable_irq(pp);
 371        /* switch off PTT */
 372        pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
 373        parport_release(bc->pdev);
 374        parport_unregister_device(bc->pdev);
 375        printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
 376               bc_drvname, dev->base_addr, dev->irq);
 377        return 0;
 378}
 379
 380/* --------------------------------------------------------------------- */
 381/*
 382 * ===================== hdlcdrv driver interface =========================
 383 */
 384
 385static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 386                        struct hdlcdrv_ioctl *hi, int cmd);
 387
 388/* --------------------------------------------------------------------- */
 389
 390static struct hdlcdrv_ops par96_ops = {
 391        .drvname = bc_drvname,
 392        .drvinfo = bc_drvinfo,
 393        .open    = par96_open,
 394        .close   = par96_close,
 395        .ioctl   = baycom_ioctl
 396};
 397
 398/* --------------------------------------------------------------------- */
 399
 400static int baycom_setmode(struct baycom_state *bc, const char *modestr)
 401{
 402        if (!strncmp(modestr, "picpar", 6))
 403                bc->options = 0;
 404        else if (!strncmp(modestr, "par96", 5))
 405                bc->options = BAYCOM_OPTIONS_SOFTDCD;
 406        else
 407                bc->options = !!strchr(modestr, '*');
 408        return 0;
 409}
 410
 411/* --------------------------------------------------------------------- */
 412
 413static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 414                        struct hdlcdrv_ioctl *hi, int cmd)
 415{
 416        struct baycom_state *bc;
 417        struct baycom_ioctl bi;
 418
 419        if (!dev)
 420                return -EINVAL;
 421
 422        bc = netdev_priv(dev);
 423        BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
 424
 425        if (cmd != SIOCDEVPRIVATE)
 426                return -ENOIOCTLCMD;
 427        switch (hi->cmd) {
 428        default:
 429                break;
 430
 431        case HDLCDRVCTL_GETMODE:
 432                strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
 433                if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 434                        return -EFAULT;
 435                return 0;
 436
 437        case HDLCDRVCTL_SETMODE:
 438                if (netif_running(dev) || !capable(CAP_NET_ADMIN))
 439                        return -EACCES;
 440                hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
 441                return baycom_setmode(bc, hi->data.modename);
 442
 443        case HDLCDRVCTL_MODELIST:
 444                strcpy(hi->data.modename, "par96,picpar");
 445                if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 446                        return -EFAULT;
 447                return 0;
 448
 449        case HDLCDRVCTL_MODEMPARMASK:
 450                return HDLCDRV_PARMASK_IOBASE;
 451
 452        }
 453
 454        if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 455                return -EFAULT;
 456        switch (bi.cmd) {
 457        default:
 458                return -ENOIOCTLCMD;
 459
 460#ifdef BAYCOM_DEBUG
 461        case BAYCOMCTL_GETDEBUG:
 462                bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
 463                bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
 464                bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
 465                break;
 466#endif /* BAYCOM_DEBUG */
 467
 468        }
 469        if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 470                return -EFAULT;
 471        return 0;
 472
 473}
 474
 475/* --------------------------------------------------------------------- */
 476
 477/*
 478 * command line settable parameters
 479 */
 480static const char *mode[NR_PORTS] = { "picpar", };
 481static int iobase[NR_PORTS] = { 0x378, };
 482
 483module_param_array(mode, charp, NULL, 0);
 484MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
 485module_param_array(iobase, int, NULL, 0);
 486MODULE_PARM_DESC(iobase, "baycom io base address");
 487
 488MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 489MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
 490MODULE_LICENSE("GPL");
 491
 492/* --------------------------------------------------------------------- */
 493
 494static int __init init_baycompar(void)
 495{
 496        int i, found = 0;
 497        char set_hw = 1;
 498
 499        printk(bc_drvinfo);
 500        /*
 501         * register net devices
 502         */
 503        for (i = 0; i < NR_PORTS; i++) {
 504                struct net_device *dev;
 505                struct baycom_state *bc;
 506                char ifname[IFNAMSIZ];
 507
 508                sprintf(ifname, "bcp%d", i);
 509
 510                if (!mode[i])
 511                        set_hw = 0;
 512                if (!set_hw)
 513                        iobase[i] = 0;
 514
 515                dev = hdlcdrv_register(&par96_ops,
 516                                       sizeof(struct baycom_state),
 517                                       ifname, iobase[i], 0, 0);
 518                if (IS_ERR(dev)) 
 519                        break;
 520
 521                bc = netdev_priv(dev);
 522                if (set_hw && baycom_setmode(bc, mode[i]))
 523                        set_hw = 0;
 524                found++;
 525                baycom_device[i] = dev;
 526        }
 527
 528        if (!found)
 529                return -ENXIO;
 530        return 0;
 531}
 532
 533static void __exit cleanup_baycompar(void)
 534{
 535        int i;
 536
 537        for(i = 0; i < NR_PORTS; i++) {
 538                struct net_device *dev = baycom_device[i];
 539
 540                if (dev)
 541                        hdlcdrv_unregister(dev);
 542        }
 543}
 544
 545module_init(init_baycompar);
 546module_exit(cleanup_baycompar);
 547
 548/* --------------------------------------------------------------------- */
 549
 550#ifndef MODULE
 551
 552/*
 553 * format: baycom_par=io,mode
 554 * mode: par96,picpar
 555 */
 556
 557static int __init baycom_par_setup(char *str)
 558{
 559        static unsigned nr_dev;
 560        int ints[2];
 561
 562        if (nr_dev >= NR_PORTS)
 563                return 0;
 564        str = get_options(str, 2, ints);
 565        if (ints[0] < 1)
 566                return 0;
 567        mode[nr_dev] = str;
 568        iobase[nr_dev] = ints[1];
 569        nr_dev++;
 570        return 1;
 571}
 572
 573__setup("baycom_par=", baycom_par_setup);
 574
 575#endif /* MODULE */
 576/* --------------------------------------------------------------------- */
 577
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