1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /*****************************************************************************/ 3 4 /* 5 * baycom_par.c -- baycom par96 and picpar radio modem driver. 6 * 7 * Copyright (C) 1996-2000 Thomas Sailer (sailer@ife.ee.ethz.ch) 8 * 9 * Please note that the GPL allows you to use the driver, NOT the radio. 10 * In order to use the radio, you need a license from the communications 11 * authority of your country. 12 * 13 * Supported modems 14 * 15 * par96: This is a modem for 9600 baud FSK compatible to the G3RUH standard. 16 * The modem does all the filtering and regenerates the receiver clock. 17 * Data is transferred from and to the PC via a shift register. 18 * The shift register is filled with 16 bits and an interrupt is 19 * signalled. The PC then empties the shift register in a burst. This 20 * modem connects to the parallel port, hence the name. The modem 21 * leaves the implementation of the HDLC protocol and the scrambler 22 * polynomial to the PC. This modem is no longer available (at least 23 * from Baycom) and has been replaced by the PICPAR modem (see below). 24 * You may however still build one from the schematics published in 25 * cq-DL :-). 26 * 27 * picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The 28 * modem is protocol compatible to par96, but uses only three low 29 * power ICs and can therefore be fed from the parallel port and 30 * does not require an additional power supply. It features 31 * built in DCD circuitry. The driver should therefore be configured 32 * for hardware DCD. 33 * 34 * Command line options (insmod command line) 35 * 36 * mode driver mode string. Valid choices are par96 and picpar. 37 * iobase base address of the port; common values are 0x378, 0x278, 0x3bc 38 * 39 * History: 40 * 0.1 26.06.1996 Adapted from baycom.c and made network driver interface 41 * 18.10.1996 Changed to new user space access routines (copy_{to,from}_user) 42 * 0.3 26.04.1997 init code/data tagged 43 * 0.4 08.07.1997 alternative ser12 decoding algorithm (uses delta CTS ints) 44 * 0.5 11.11.1997 split into separate files for ser12/par96 45 * 0.6 03.08.1999 adapt to Linus' new __setup/__initcall 46 * removed some pre-2.2 kernel compatibility cruft 47 * 0.7 10.08.1999 Check if parport can do SPP and is safe to access during interrupt contexts 48 * 0.8 12.02.2000 adapted to softnet driver interface 49 * removed direct parport access, uses parport driver methods 50 * 0.9 03.07.2000 fix interface name handling 51 */ 52 53 /*****************************************************************************/ 54 55 #include <linux/module.h> 56 #include <linux/kernel.h> 57 #include <linux/types.h> 58 #include <linux/fcntl.h> 59 #include <linux/interrupt.h> 60 #include <linux/ioport.h> 61 #include <linux/in.h> 62 #include <linux/string.h> 63 #include <linux/init.h> 64 #include <linux/delay.h> 65 #include <linux/errno.h> 66 #include <linux/netdevice.h> 67 #include <linux/hdlcdrv.h> 68 #include <linux/baycom.h> 69 #include <linux/parport.h> 70 #include <linux/bitops.h> 71 #include <linux/jiffies.h> 72 73 #include <linux/uaccess.h> 74 75 /* --------------------------------------------------------------------- */ 76 77 #define BAYCOM_DEBUG 78 79 /* 80 * modem options; bit mask 81 */ 82 #define BAYCOM_OPTIONS_SOFTDCD 1 83 84 /* --------------------------------------------------------------------- */ 85 86 static const char bc_drvname[] = "baycom_par"; 87 static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n" 88 "baycom_par: version 0.9\n"; 89 90 /* --------------------------------------------------------------------- */ 91 92 #define NR_PORTS 4 93 94 static struct net_device *baycom_device[NR_PORTS]; 95 96 /* --------------------------------------------------------------------- */ 97 98 #define PAR96_BURSTBITS 16 99 #define PAR96_BURST 4 100 #define PAR96_PTT 2 101 #define PAR96_TXBIT 1 102 #define PAR96_ACK 0x40 103 #define PAR96_RXBIT 0x20 104 #define PAR96_DCD 0x10 105 #define PAR97_POWER 0xf8 106 107 /* ---------------------------------------------------------------------- */ 108 /* 109 * Information that need to be kept for each board. 110 */ 111 112 struct baycom_state { 113 struct hdlcdrv_state hdrv; 114 115 struct pardevice *pdev; 116 unsigned int options; 117 118 struct modem_state { 119 short arb_divider; 120 unsigned char flags; 121 unsigned int shreg; 122 struct modem_state_par96 { 123 int dcd_count; 124 unsigned int dcd_shreg; 125 unsigned long descram; 126 unsigned long scram; 127 } par96; 128 } modem; 129 130 #ifdef BAYCOM_DEBUG 131 struct debug_vals { 132 unsigned long last_jiffies; 133 unsigned cur_intcnt; 134 unsigned last_intcnt; 135 int cur_pllcorr; 136 int last_pllcorr; 137 } debug_vals; 138 #endif /* BAYCOM_DEBUG */ 139 }; 140 141 /* --------------------------------------------------------------------- */ 142 143 static inline void baycom_int_freq(struct baycom_state *bc) 144 { 145 #ifdef BAYCOM_DEBUG 146 unsigned long cur_jiffies = jiffies; 147 /* 148 * measure the interrupt frequency 149 */ 150 bc->debug_vals.cur_intcnt++; 151 if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) { 152 bc->debug_vals.last_jiffies = cur_jiffies; 153 bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt; 154 bc->debug_vals.cur_intcnt = 0; 155 bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr; 156 bc->debug_vals.cur_pllcorr = 0; 157 } 158 #endif /* BAYCOM_DEBUG */ 159 } 160 161 /* --------------------------------------------------------------------- */ 162 /* 163 * ===================== PAR96 specific routines ========================= 164 */ 165 166 #define PAR96_DESCRAM_TAP1 0x20000 167 #define PAR96_DESCRAM_TAP2 0x01000 168 #define PAR96_DESCRAM_TAP3 0x00001 169 170 #define PAR96_DESCRAM_TAPSH1 17 171 #define PAR96_DESCRAM_TAPSH2 12 172 #define PAR96_DESCRAM_TAPSH3 0 173 174 #define PAR96_SCRAM_TAP1 0x20000 /* X^17 */ 175 #define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */ 176 177 /* --------------------------------------------------------------------- */ 178 179 static inline void par96_tx(struct net_device *dev, struct baycom_state *bc) 180 { 181 int i; 182 unsigned int data = hdlcdrv_getbits(&bc->hdrv); 183 struct parport *pp = bc->pdev->port; 184 185 for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) { 186 unsigned char val = PAR97_POWER; 187 bc->modem.par96.scram = ((bc->modem.par96.scram << 1) | 188 (bc->modem.par96.scram & 1)); 189 if (!(data & 1)) 190 bc->modem.par96.scram ^= 1; 191 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1)) 192 bc->modem.par96.scram ^= 193 (PAR96_SCRAM_TAPN << 1); 194 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2)) 195 val |= PAR96_TXBIT; 196 pp->ops->write_data(pp, val); 197 pp->ops->write_data(pp, val | PAR96_BURST); 198 } 199 } 200 201 /* --------------------------------------------------------------------- */ 202 203 static inline void par96_rx(struct net_device *dev, struct baycom_state *bc) 204 { 205 int i; 206 unsigned int data, mask, mask2, descx; 207 struct parport *pp = bc->pdev->port; 208 209 /* 210 * do receiver; differential decode and descramble on the fly 211 */ 212 for(data = i = 0; i < PAR96_BURSTBITS; i++) { 213 bc->modem.par96.descram = (bc->modem.par96.descram << 1); 214 if (pp->ops->read_status(pp) & PAR96_RXBIT) 215 bc->modem.par96.descram |= 1; 216 descx = bc->modem.par96.descram ^ 217 (bc->modem.par96.descram >> 1); 218 /* now the diff decoded data is inverted in descram */ 219 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT); 220 descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^ 221 (descx >> PAR96_DESCRAM_TAPSH2)); 222 data >>= 1; 223 if (!(descx & 1)) 224 data |= 0x8000; 225 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST); 226 } 227 hdlcdrv_putbits(&bc->hdrv, data); 228 /* 229 * do DCD algorithm 230 */ 231 if (bc->options & BAYCOM_OPTIONS_SOFTDCD) { 232 bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16) 233 | (data << 16); 234 /* search for flags and set the dcd counter appropriately */ 235 for(mask = 0x1fe00, mask2 = 0xfc00, i = 0; 236 i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1) 237 if ((bc->modem.par96.dcd_shreg & mask) == mask2) 238 bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4; 239 /* check for abort/noise sequences */ 240 for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0; 241 i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1) 242 if (((bc->modem.par96.dcd_shreg & mask) == mask2) && 243 (bc->modem.par96.dcd_count >= 0)) 244 bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10; 245 /* decrement and set the dcd variable */ 246 if (bc->modem.par96.dcd_count >= 0) 247 bc->modem.par96.dcd_count -= 2; 248 hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0); 249 } else { 250 hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD)); 251 } 252 } 253 254 /* --------------------------------------------------------------------- */ 255 256 static void par96_interrupt(void *dev_id) 257 { 258 struct net_device *dev = dev_id; 259 struct baycom_state *bc = netdev_priv(dev); 260 261 baycom_int_freq(bc); 262 /* 263 * check if transmitter active 264 */ 265 if (hdlcdrv_ptt(&bc->hdrv)) 266 par96_tx(dev, bc); 267 else { 268 par96_rx(dev, bc); 269 if (--bc->modem.arb_divider <= 0) { 270 bc->modem.arb_divider = 6; 271 local_irq_enable(); 272 hdlcdrv_arbitrate(dev, &bc->hdrv); 273 } 274 } 275 local_irq_enable(); 276 hdlcdrv_transmitter(dev, &bc->hdrv); 277 hdlcdrv_receiver(dev, &bc->hdrv); 278 local_irq_disable(); 279 } 280 281 /* --------------------------------------------------------------------- */ 282 283 static void par96_wakeup(void *handle) 284 { 285 struct net_device *dev = (struct net_device *)handle; 286 struct baycom_state *bc = netdev_priv(dev); 287 288 printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name); 289 if (!parport_claim(bc->pdev)) 290 printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name); 291 } 292 293 /* --------------------------------------------------------------------- */ 294 295 static int par96_open(struct net_device *dev) 296 { 297 struct baycom_state *bc = netdev_priv(dev); 298 struct pardev_cb par_cb; 299 struct parport *pp; 300 int i; 301 302 if (!dev || !bc) 303 return -ENXIO; 304 pp = parport_find_base(dev->base_addr); 305 if (!pp) { 306 printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr); 307 return -ENXIO; 308 } 309 if (pp->irq < 0) { 310 printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base); 311 parport_put_port(pp); 312 return -ENXIO; 313 } 314 if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) { 315 printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base); 316 parport_put_port(pp); 317 return -ENXIO; 318 } 319 memset(&bc->modem, 0, sizeof(bc->modem)); 320 bc->hdrv.par.bitrate = 9600; 321 memset(&par_cb, 0, sizeof(par_cb)); 322 par_cb.wakeup = par96_wakeup; 323 par_cb.irq_func = par96_interrupt; 324 par_cb.private = (void *)dev; 325 par_cb.flags = PARPORT_DEV_EXCL; 326 for (i = 0; i < NR_PORTS; i++) 327 if (baycom_device[i] == dev) 328 break; 329 330 if (i == NR_PORTS) { 331 pr_err("%s: no device found\n", bc_drvname); 332 parport_put_port(pp); 333 return -ENODEV; 334 } 335 bc->pdev = parport_register_dev_model(pp, dev->name, &par_cb, i); 336 parport_put_port(pp); 337 if (!bc->pdev) { 338 printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr); 339 return -ENXIO; 340 } 341 if (parport_claim(bc->pdev)) { 342 printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base); 343 parport_unregister_device(bc->pdev); 344 return -EBUSY; 345 } 346 pp = bc->pdev->port; 347 dev->irq = pp->irq; 348 pp->ops->data_forward(pp); 349 bc->hdrv.par.bitrate = 9600; 350 pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */ 351 pp->ops->enable_irq(pp); 352 printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n", 353 bc_drvname, dev->base_addr, dev->irq, bc->options); 354 return 0; 355 } 356 357 /* --------------------------------------------------------------------- */ 358 359 static int par96_close(struct net_device *dev) 360 { 361 struct baycom_state *bc = netdev_priv(dev); 362 struct parport *pp; 363 364 if (!dev || !bc) 365 return -EINVAL; 366 pp = bc->pdev->port; 367 /* disable interrupt */ 368 pp->ops->disable_irq(pp); 369 /* switch off PTT */ 370 pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); 371 parport_release(bc->pdev); 372 parport_unregister_device(bc->pdev); 373 printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n", 374 bc_drvname, dev->base_addr, dev->irq); 375 return 0; 376 } 377 378 /* --------------------------------------------------------------------- */ 379 /* 380 * ===================== hdlcdrv driver interface ========================= 381 */ 382 383 static int baycom_ioctl(struct net_device *dev, void __user *data, 384 struct hdlcdrv_ioctl *hi, int cmd); 385 386 /* --------------------------------------------------------------------- */ 387 388 static const struct hdlcdrv_ops par96_ops = { 389 .drvname = bc_drvname, 390 .drvinfo = bc_drvinfo, 391 .open = par96_open, 392 .close = par96_close, 393 .ioctl = baycom_ioctl 394 }; 395 396 /* --------------------------------------------------------------------- */ 397 398 static int baycom_setmode(struct baycom_state *bc, const char *modestr) 399 { 400 if (!strncmp(modestr, "picpar", 6)) 401 bc->options = 0; 402 else if (!strncmp(modestr, "par96", 5)) 403 bc->options = BAYCOM_OPTIONS_SOFTDCD; 404 else 405 bc->options = !!strchr(modestr, '*'); 406 return 0; 407 } 408 409 /* --------------------------------------------------------------------- */ 410 411 static int baycom_ioctl(struct net_device *dev, void __user *data, 412 struct hdlcdrv_ioctl *hi, int cmd) 413 { 414 struct baycom_state *bc; 415 struct baycom_ioctl bi; 416 417 if (!dev) 418 return -EINVAL; 419 420 bc = netdev_priv(dev); 421 BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC); 422 423 if (cmd != SIOCDEVPRIVATE) 424 return -ENOIOCTLCMD; 425 switch (hi->cmd) { 426 default: 427 break; 428 429 case HDLCDRVCTL_GETMODE: 430 strcpy(hi->data.modename, bc->options ? "par96" : "picpar"); 431 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl))) 432 return -EFAULT; 433 return 0; 434 435 case HDLCDRVCTL_SETMODE: 436 if (netif_running(dev) || !capable(CAP_NET_ADMIN)) 437 return -EACCES; 438 hi->data.modename[sizeof(hi->data.modename)-1] = '\0'; 439 return baycom_setmode(bc, hi->data.modename); 440 441 case HDLCDRVCTL_MODELIST: 442 strcpy(hi->data.modename, "par96,picpar"); 443 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl))) 444 return -EFAULT; 445 return 0; 446 447 case HDLCDRVCTL_MODEMPARMASK: 448 return HDLCDRV_PARMASK_IOBASE; 449 450 } 451 452 if (copy_from_user(&bi, data, sizeof(bi))) 453 return -EFAULT; 454 switch (bi.cmd) { 455 default: 456 return -ENOIOCTLCMD; 457 458 #ifdef BAYCOM_DEBUG 459 case BAYCOMCTL_GETDEBUG: 460 bi.data.dbg.debug1 = bc->hdrv.ptt_keyed; 461 bi.data.dbg.debug2 = bc->debug_vals.last_intcnt; 462 bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr; 463 break; 464 #endif /* BAYCOM_DEBUG */ 465 466 } 467 if (copy_to_user(data, &bi, sizeof(bi))) 468 return -EFAULT; 469 return 0; 470 471 } 472 473 /* --------------------------------------------------------------------- */ 474 475 /* 476 * command line settable parameters 477 */ 478 static char *mode[NR_PORTS] = { "picpar", }; 479 static int iobase[NR_PORTS] = { 0x378, }; 480 481 module_param_array(mode, charp, NULL, 0); 482 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar"); 483 module_param_hw_array(iobase, int, ioport, NULL, 0); 484 MODULE_PARM_DESC(iobase, "baycom io base address"); 485 486 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu"); 487 MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver"); 488 MODULE_LICENSE("GPL"); 489 490 /* --------------------------------------------------------------------- */ 491 492 static int baycom_par_probe(struct pardevice *par_dev) 493 { 494 struct device_driver *drv = par_dev->dev.driver; 495 int len = strlen(drv->name); 496 497 if (strncmp(par_dev->name, drv->name, len)) 498 return -ENODEV; 499 500 return 0; 501 } 502 503 static struct parport_driver baycom_par_driver = { 504 .name = "bcp", 505 .probe = baycom_par_probe, 506 .devmodel = true, 507 }; 508 509 static int __init init_baycompar(void) 510 { 511 int i, found = 0, ret; 512 char set_hw = 1; 513 514 printk(bc_drvinfo); 515 516 ret = parport_register_driver(&baycom_par_driver); 517 if (ret) 518 return ret; 519 520 /* 521 * register net devices 522 */ 523 for (i = 0; i < NR_PORTS; i++) { 524 struct net_device *dev; 525 struct baycom_state *bc; 526 char ifname[IFNAMSIZ]; 527 528 sprintf(ifname, "bcp%d", i); 529 530 if (!mode[i]) 531 set_hw = 0; 532 if (!set_hw) 533 iobase[i] = 0; 534 535 dev = hdlcdrv_register(&par96_ops, 536 sizeof(struct baycom_state), 537 ifname, iobase[i], 0, 0); 538 if (IS_ERR(dev)) 539 break; 540 541 bc = netdev_priv(dev); 542 if (set_hw && baycom_setmode(bc, mode[i])) 543 set_hw = 0; 544 found++; 545 baycom_device[i] = dev; 546 } 547 548 if (!found) { 549 parport_unregister_driver(&baycom_par_driver); 550 return -ENXIO; 551 } 552 return 0; 553 } 554 555 static void __exit cleanup_baycompar(void) 556 { 557 int i; 558 559 for(i = 0; i < NR_PORTS; i++) { 560 struct net_device *dev = baycom_device[i]; 561 562 if (dev) 563 hdlcdrv_unregister(dev); 564 } 565 parport_unregister_driver(&baycom_par_driver); 566 } 567 568 module_init(init_baycompar); 569 module_exit(cleanup_baycompar); 570 571 /* --------------------------------------------------------------------- */ 572 573 #ifndef MODULE 574 575 /* 576 * format: baycom_par=io,mode 577 * mode: par96,picpar 578 */ 579 580 static int __init baycom_par_setup(char *str) 581 { 582 static unsigned nr_dev; 583 int ints[2]; 584 585 if (nr_dev >= NR_PORTS) 586 return 0; 587 str = get_options(str, 2, ints); 588 if (ints[0] < 1) 589 return 0; 590 mode[nr_dev] = str; 591 iobase[nr_dev] = ints[1]; 592 nr_dev++; 593 return 1; 594 } 595 596 __setup("baycom_par=", baycom_par_setup); 597 598 #endif /* MODULE */ 599 /* --------------------------------------------------------------------- */ 600