1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* $Id: plip.c,v 1.3.6.2 1997/04/16 15:07:56 phil Exp $ */ 3 /* PLIP: A parallel port "network" driver for Linux. */ 4 /* This driver is for parallel port with 5-bit cable (LapLink (R) cable). */ 5 /* 6 * Authors: Donald Becker <becker@scyld.com> 7 * Tommy Thorn <thorn@daimi.aau.dk> 8 * Tanabe Hiroyasu <hiro@sanpo.t.u-tokyo.ac.jp> 9 * Alan Cox <gw4pts@gw4pts.ampr.org> 10 * Peter Bauer <100136.3530@compuserve.com> 11 * Niibe Yutaka <gniibe@mri.co.jp> 12 * Nimrod Zimerman <zimerman@mailandnews.com> 13 * 14 * Enhancements: 15 * Modularization and ifreq/ifmap support by Alan Cox. 16 * Rewritten by Niibe Yutaka. 17 * parport-sharing awareness code by Philip Blundell. 18 * SMP locking by Niibe Yutaka. 19 * Support for parallel ports with no IRQ (poll mode), 20 * Modifications to use the parallel port API 21 * by Nimrod Zimerman. 22 * 23 * Fixes: 24 * Niibe Yutaka 25 * - Module initialization. 26 * - MTU fix. 27 * - Make sure other end is OK, before sending a packet. 28 * - Fix immediate timer problem. 29 * 30 * Al Viro 31 * - Changed {enable,disable}_irq handling to make it work 32 * with new ("stack") semantics. 33 */ 34 35 /* 36 * Original version and the name 'PLIP' from Donald Becker <becker@scyld.com> 37 * inspired by Russ Nelson's parallel port packet driver. 38 * 39 * NOTE: 40 * Tanabe Hiroyasu had changed the protocol, and it was in Linux v1.0. 41 * Because of the necessity to communicate to DOS machines with the 42 * Crynwr packet driver, Peter Bauer changed the protocol again 43 * back to original protocol. 44 * 45 * This version follows original PLIP protocol. 46 * So, this PLIP can't communicate the PLIP of Linux v1.0. 47 */ 48 49 /* 50 * To use with DOS box, please do (Turn on ARP switch): 51 * # ifconfig plip[0-2] arp 52 */ 53 static const char version[] = "NET3 PLIP version 2.4-parport gniibe@mri.co.jp\n"; 54 55 /* 56 Sources: 57 Ideas and protocols came from Russ Nelson's <nelson@crynwr.com> 58 "parallel.asm" parallel port packet driver. 59 60 The "Crynwr" parallel port standard specifies the following protocol: 61 Trigger by sending nibble '0x8' (this causes interrupt on other end) 62 count-low octet 63 count-high octet 64 ... data octets 65 checksum octet 66 Each octet is sent as <wait for rx. '0x1?'> <send 0x10+(octet&0x0F)> 67 <wait for rx. '0x0?'> <send 0x00+((octet>>4)&0x0F)> 68 69 The packet is encapsulated as if it were ethernet. 70 71 The cable used is a de facto standard parallel null cable -- sold as 72 a "LapLink" cable by various places. You'll need a 12-conductor cable to 73 make one yourself. The wiring is: 74 SLCTIN 17 - 17 75 GROUND 25 - 25 76 D0->ERROR 2 - 15 15 - 2 77 D1->SLCT 3 - 13 13 - 3 78 D2->PAPOUT 4 - 12 12 - 4 79 D3->ACK 5 - 10 10 - 5 80 D4->BUSY 6 - 11 11 - 6 81 Do not connect the other pins. They are 82 D5,D6,D7 are 7,8,9 83 STROBE is 1, FEED is 14, INIT is 16 84 extra grounds are 18,19,20,21,22,23,24 85 */ 86 87 #include <linux/compat.h> 88 #include <linux/module.h> 89 #include <linux/kernel.h> 90 #include <linux/types.h> 91 #include <linux/fcntl.h> 92 #include <linux/interrupt.h> 93 #include <linux/string.h> 94 #include <linux/slab.h> 95 #include <linux/if_ether.h> 96 #include <linux/in.h> 97 #include <linux/errno.h> 98 #include <linux/delay.h> 99 #include <linux/init.h> 100 #include <linux/netdevice.h> 101 #include <linux/etherdevice.h> 102 #include <linux/inetdevice.h> 103 #include <linux/skbuff.h> 104 #include <linux/if_plip.h> 105 #include <linux/workqueue.h> 106 #include <linux/spinlock.h> 107 #include <linux/completion.h> 108 #include <linux/parport.h> 109 #include <linux/bitops.h> 110 111 #include <net/neighbour.h> 112 113 #include <asm/irq.h> 114 #include <asm/byteorder.h> 115 116 /* Maximum number of devices to support. */ 117 #define PLIP_MAX 8 118 119 /* Use 0 for production, 1 for verification, >2 for debug */ 120 #ifndef NET_DEBUG 121 #define NET_DEBUG 1 122 #endif 123 static const unsigned int net_debug = NET_DEBUG; 124 125 #define ENABLE(irq) if (irq != -1) enable_irq(irq) 126 #define DISABLE(irq) if (irq != -1) disable_irq(irq) 127 128 /* In micro second */ 129 #define PLIP_DELAY_UNIT 1 130 131 /* Connection time out = PLIP_TRIGGER_WAIT * PLIP_DELAY_UNIT usec */ 132 #define PLIP_TRIGGER_WAIT 500 133 134 /* Nibble time out = PLIP_NIBBLE_WAIT * PLIP_DELAY_UNIT usec */ 135 #define PLIP_NIBBLE_WAIT 3000 136 137 /* Bottom halves */ 138 static void plip_kick_bh(struct work_struct *work); 139 static void plip_bh(struct work_struct *work); 140 static void plip_timer_bh(struct work_struct *work); 141 142 /* Interrupt handler */ 143 static void plip_interrupt(void *dev_id); 144 145 /* Functions for DEV methods */ 146 static netdev_tx_t plip_tx_packet(struct sk_buff *skb, struct net_device *dev); 147 static int plip_hard_header(struct sk_buff *skb, struct net_device *dev, 148 unsigned short type, const void *daddr, 149 const void *saddr, unsigned len); 150 static int plip_hard_header_cache(const struct neighbour *neigh, 151 struct hh_cache *hh, __be16 type); 152 static int plip_open(struct net_device *dev); 153 static int plip_close(struct net_device *dev); 154 static int plip_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 155 void __user *data, int cmd); 156 static int plip_preempt(void *handle); 157 static void plip_wakeup(void *handle); 158 159 enum plip_connection_state { 160 PLIP_CN_NONE=0, 161 PLIP_CN_RECEIVE, 162 PLIP_CN_SEND, 163 PLIP_CN_CLOSING, 164 PLIP_CN_ERROR 165 }; 166 167 enum plip_packet_state { 168 PLIP_PK_DONE=0, 169 PLIP_PK_TRIGGER, 170 PLIP_PK_LENGTH_LSB, 171 PLIP_PK_LENGTH_MSB, 172 PLIP_PK_DATA, 173 PLIP_PK_CHECKSUM 174 }; 175 176 enum plip_nibble_state { 177 PLIP_NB_BEGIN, 178 PLIP_NB_1, 179 PLIP_NB_2, 180 }; 181 182 struct plip_local { 183 enum plip_packet_state state; 184 enum plip_nibble_state nibble; 185 union { 186 struct { 187 #if defined(__LITTLE_ENDIAN) 188 unsigned char lsb; 189 unsigned char msb; 190 #elif defined(__BIG_ENDIAN) 191 unsigned char msb; 192 unsigned char lsb; 193 #else 194 #error "Please fix the endianness defines in <asm/byteorder.h>" 195 #endif 196 } b; 197 unsigned short h; 198 } length; 199 unsigned short byte; 200 unsigned char checksum; 201 unsigned char data; 202 struct sk_buff *skb; 203 }; 204 205 struct net_local { 206 struct net_device *dev; 207 struct work_struct immediate; 208 struct delayed_work deferred; 209 struct delayed_work timer; 210 struct plip_local snd_data; 211 struct plip_local rcv_data; 212 struct pardevice *pardev; 213 unsigned long trigger; 214 unsigned long nibble; 215 enum plip_connection_state connection; 216 unsigned short timeout_count; 217 int is_deferred; 218 int port_owner; 219 int should_relinquish; 220 spinlock_t lock; 221 atomic_t kill_timer; 222 struct completion killed_timer_cmp; 223 }; 224 225 static inline void enable_parport_interrupts (struct net_device *dev) 226 { 227 if (dev->irq != -1) 228 { 229 struct parport *port = 230 ((struct net_local *)netdev_priv(dev))->pardev->port; 231 port->ops->enable_irq (port); 232 } 233 } 234 235 static inline void disable_parport_interrupts (struct net_device *dev) 236 { 237 if (dev->irq != -1) 238 { 239 struct parport *port = 240 ((struct net_local *)netdev_priv(dev))->pardev->port; 241 port->ops->disable_irq (port); 242 } 243 } 244 245 static inline void write_data (struct net_device *dev, unsigned char data) 246 { 247 struct parport *port = 248 ((struct net_local *)netdev_priv(dev))->pardev->port; 249 250 port->ops->write_data (port, data); 251 } 252 253 static inline unsigned char read_status (struct net_device *dev) 254 { 255 struct parport *port = 256 ((struct net_local *)netdev_priv(dev))->pardev->port; 257 258 return port->ops->read_status (port); 259 } 260 261 static const struct header_ops plip_header_ops = { 262 .create = plip_hard_header, 263 .cache = plip_hard_header_cache, 264 }; 265 266 static const struct net_device_ops plip_netdev_ops = { 267 .ndo_open = plip_open, 268 .ndo_stop = plip_close, 269 .ndo_start_xmit = plip_tx_packet, 270 .ndo_siocdevprivate = plip_siocdevprivate, 271 .ndo_set_mac_address = eth_mac_addr, 272 .ndo_validate_addr = eth_validate_addr, 273 }; 274 275 /* Entry point of PLIP driver. 276 Probe the hardware, and register/initialize the driver. 277 278 PLIP is rather weird, because of the way it interacts with the parport 279 system. It is _not_ initialised from Space.c. Instead, plip_init() 280 is called, and that function makes up a "struct net_device" for each port, and 281 then calls us here. 282 283 */ 284 static void 285 plip_init_netdev(struct net_device *dev) 286 { 287 struct net_local *nl = netdev_priv(dev); 288 289 /* Then, override parts of it */ 290 dev->tx_queue_len = 10; 291 dev->flags = IFF_POINTOPOINT|IFF_NOARP; 292 memset(dev->dev_addr, 0xfc, ETH_ALEN); 293 294 dev->netdev_ops = &plip_netdev_ops; 295 dev->header_ops = &plip_header_ops; 296 297 298 nl->port_owner = 0; 299 300 /* Initialize constants */ 301 nl->trigger = PLIP_TRIGGER_WAIT; 302 nl->nibble = PLIP_NIBBLE_WAIT; 303 304 /* Initialize task queue structures */ 305 INIT_WORK(&nl->immediate, plip_bh); 306 INIT_DELAYED_WORK(&nl->deferred, plip_kick_bh); 307 308 if (dev->irq == -1) 309 INIT_DELAYED_WORK(&nl->timer, plip_timer_bh); 310 311 spin_lock_init(&nl->lock); 312 } 313 314 /* Bottom half handler for the delayed request. 315 This routine is kicked by do_timer(). 316 Request `plip_bh' to be invoked. */ 317 static void 318 plip_kick_bh(struct work_struct *work) 319 { 320 struct net_local *nl = 321 container_of(work, struct net_local, deferred.work); 322 323 if (nl->is_deferred) 324 schedule_work(&nl->immediate); 325 } 326 327 /* Forward declarations of internal routines */ 328 static int plip_none(struct net_device *, struct net_local *, 329 struct plip_local *, struct plip_local *); 330 static int plip_receive_packet(struct net_device *, struct net_local *, 331 struct plip_local *, struct plip_local *); 332 static int plip_send_packet(struct net_device *, struct net_local *, 333 struct plip_local *, struct plip_local *); 334 static int plip_connection_close(struct net_device *, struct net_local *, 335 struct plip_local *, struct plip_local *); 336 static int plip_error(struct net_device *, struct net_local *, 337 struct plip_local *, struct plip_local *); 338 static int plip_bh_timeout_error(struct net_device *dev, struct net_local *nl, 339 struct plip_local *snd, 340 struct plip_local *rcv, 341 int error); 342 343 #define OK 0 344 #define TIMEOUT 1 345 #define ERROR 2 346 #define HS_TIMEOUT 3 347 348 typedef int (*plip_func)(struct net_device *dev, struct net_local *nl, 349 struct plip_local *snd, struct plip_local *rcv); 350 351 static const plip_func connection_state_table[] = 352 { 353 plip_none, 354 plip_receive_packet, 355 plip_send_packet, 356 plip_connection_close, 357 plip_error 358 }; 359 360 /* Bottom half handler of PLIP. */ 361 static void 362 plip_bh(struct work_struct *work) 363 { 364 struct net_local *nl = container_of(work, struct net_local, immediate); 365 struct plip_local *snd = &nl->snd_data; 366 struct plip_local *rcv = &nl->rcv_data; 367 plip_func f; 368 int r; 369 370 nl->is_deferred = 0; 371 f = connection_state_table[nl->connection]; 372 if ((r = (*f)(nl->dev, nl, snd, rcv)) != OK && 373 (r = plip_bh_timeout_error(nl->dev, nl, snd, rcv, r)) != OK) { 374 nl->is_deferred = 1; 375 schedule_delayed_work(&nl->deferred, 1); 376 } 377 } 378 379 static void 380 plip_timer_bh(struct work_struct *work) 381 { 382 struct net_local *nl = 383 container_of(work, struct net_local, timer.work); 384 385 if (!(atomic_read (&nl->kill_timer))) { 386 plip_interrupt (nl->dev); 387 388 schedule_delayed_work(&nl->timer, 1); 389 } 390 else { 391 complete(&nl->killed_timer_cmp); 392 } 393 } 394 395 static int 396 plip_bh_timeout_error(struct net_device *dev, struct net_local *nl, 397 struct plip_local *snd, struct plip_local *rcv, 398 int error) 399 { 400 unsigned char c0; 401 /* 402 * This is tricky. If we got here from the beginning of send (either 403 * with ERROR or HS_TIMEOUT) we have IRQ enabled. Otherwise it's 404 * already disabled. With the old variant of {enable,disable}_irq() 405 * extra disable_irq() was a no-op. Now it became mortal - it's 406 * unbalanced and thus we'll never re-enable IRQ (until rmmod plip, 407 * that is). So we have to treat HS_TIMEOUT and ERROR from send 408 * in a special way. 409 */ 410 411 spin_lock_irq(&nl->lock); 412 if (nl->connection == PLIP_CN_SEND) { 413 414 if (error != ERROR) { /* Timeout */ 415 nl->timeout_count++; 416 if ((error == HS_TIMEOUT && nl->timeout_count <= 10) || 417 nl->timeout_count <= 3) { 418 spin_unlock_irq(&nl->lock); 419 /* Try again later */ 420 return TIMEOUT; 421 } 422 c0 = read_status(dev); 423 printk(KERN_WARNING "%s: transmit timeout(%d,%02x)\n", 424 dev->name, snd->state, c0); 425 } else 426 error = HS_TIMEOUT; 427 dev->stats.tx_errors++; 428 dev->stats.tx_aborted_errors++; 429 } else if (nl->connection == PLIP_CN_RECEIVE) { 430 if (rcv->state == PLIP_PK_TRIGGER) { 431 /* Transmission was interrupted. */ 432 spin_unlock_irq(&nl->lock); 433 return OK; 434 } 435 if (error != ERROR) { /* Timeout */ 436 if (++nl->timeout_count <= 3) { 437 spin_unlock_irq(&nl->lock); 438 /* Try again later */ 439 return TIMEOUT; 440 } 441 c0 = read_status(dev); 442 printk(KERN_WARNING "%s: receive timeout(%d,%02x)\n", 443 dev->name, rcv->state, c0); 444 } 445 dev->stats.rx_dropped++; 446 } 447 rcv->state = PLIP_PK_DONE; 448 if (rcv->skb) { 449 kfree_skb(rcv->skb); 450 rcv->skb = NULL; 451 } 452 snd->state = PLIP_PK_DONE; 453 if (snd->skb) { 454 dev_kfree_skb(snd->skb); 455 snd->skb = NULL; 456 } 457 spin_unlock_irq(&nl->lock); 458 if (error == HS_TIMEOUT) { 459 DISABLE(dev->irq); 460 synchronize_irq(dev->irq); 461 } 462 disable_parport_interrupts (dev); 463 netif_stop_queue (dev); 464 nl->connection = PLIP_CN_ERROR; 465 write_data (dev, 0x00); 466 467 return TIMEOUT; 468 } 469 470 static int 471 plip_none(struct net_device *dev, struct net_local *nl, 472 struct plip_local *snd, struct plip_local *rcv) 473 { 474 return OK; 475 } 476 477 /* PLIP_RECEIVE --- receive a byte(two nibbles) 478 Returns OK on success, TIMEOUT on timeout */ 479 static inline int 480 plip_receive(unsigned short nibble_timeout, struct net_device *dev, 481 enum plip_nibble_state *ns_p, unsigned char *data_p) 482 { 483 unsigned char c0, c1; 484 unsigned int cx; 485 486 switch (*ns_p) { 487 case PLIP_NB_BEGIN: 488 cx = nibble_timeout; 489 while (1) { 490 c0 = read_status(dev); 491 udelay(PLIP_DELAY_UNIT); 492 if ((c0 & 0x80) == 0) { 493 c1 = read_status(dev); 494 if (c0 == c1) 495 break; 496 } 497 if (--cx == 0) 498 return TIMEOUT; 499 } 500 *data_p = (c0 >> 3) & 0x0f; 501 write_data (dev, 0x10); /* send ACK */ 502 *ns_p = PLIP_NB_1; 503 fallthrough; 504 505 case PLIP_NB_1: 506 cx = nibble_timeout; 507 while (1) { 508 c0 = read_status(dev); 509 udelay(PLIP_DELAY_UNIT); 510 if (c0 & 0x80) { 511 c1 = read_status(dev); 512 if (c0 == c1) 513 break; 514 } 515 if (--cx == 0) 516 return TIMEOUT; 517 } 518 *data_p |= (c0 << 1) & 0xf0; 519 write_data (dev, 0x00); /* send ACK */ 520 *ns_p = PLIP_NB_BEGIN; 521 break; 522 case PLIP_NB_2: 523 break; 524 } 525 return OK; 526 } 527 528 /* 529 * Determine the packet's protocol ID. The rule here is that we 530 * assume 802.3 if the type field is short enough to be a length. 531 * This is normal practice and works for any 'now in use' protocol. 532 * 533 * PLIP is ethernet ish but the daddr might not be valid if unicast. 534 * PLIP fortunately has no bus architecture (its Point-to-point). 535 * 536 * We can't fix the daddr thing as that quirk (more bug) is embedded 537 * in far too many old systems not all even running Linux. 538 */ 539 540 static __be16 plip_type_trans(struct sk_buff *skb, struct net_device *dev) 541 { 542 struct ethhdr *eth; 543 unsigned char *rawp; 544 545 skb_reset_mac_header(skb); 546 skb_pull(skb,dev->hard_header_len); 547 eth = eth_hdr(skb); 548 549 if(is_multicast_ether_addr(eth->h_dest)) 550 { 551 if(ether_addr_equal_64bits(eth->h_dest, dev->broadcast)) 552 skb->pkt_type=PACKET_BROADCAST; 553 else 554 skb->pkt_type=PACKET_MULTICAST; 555 } 556 557 /* 558 * This ALLMULTI check should be redundant by 1.4 559 * so don't forget to remove it. 560 */ 561 562 if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) 563 return eth->h_proto; 564 565 rawp = skb->data; 566 567 /* 568 * This is a magic hack to spot IPX packets. Older Novell breaks 569 * the protocol design and runs IPX over 802.3 without an 802.2 LLC 570 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This 571 * won't work for fault tolerant netware but does for the rest. 572 */ 573 if (*(unsigned short *)rawp == 0xFFFF) 574 return htons(ETH_P_802_3); 575 576 /* 577 * Real 802.2 LLC 578 */ 579 return htons(ETH_P_802_2); 580 } 581 582 /* PLIP_RECEIVE_PACKET --- receive a packet */ 583 static int 584 plip_receive_packet(struct net_device *dev, struct net_local *nl, 585 struct plip_local *snd, struct plip_local *rcv) 586 { 587 unsigned short nibble_timeout = nl->nibble; 588 unsigned char *lbuf; 589 590 switch (rcv->state) { 591 case PLIP_PK_TRIGGER: 592 DISABLE(dev->irq); 593 /* Don't need to synchronize irq, as we can safely ignore it */ 594 disable_parport_interrupts (dev); 595 write_data (dev, 0x01); /* send ACK */ 596 if (net_debug > 2) 597 printk(KERN_DEBUG "%s: receive start\n", dev->name); 598 rcv->state = PLIP_PK_LENGTH_LSB; 599 rcv->nibble = PLIP_NB_BEGIN; 600 fallthrough; 601 602 case PLIP_PK_LENGTH_LSB: 603 if (snd->state != PLIP_PK_DONE) { 604 if (plip_receive(nl->trigger, dev, 605 &rcv->nibble, &rcv->length.b.lsb)) { 606 /* collision, here dev->tbusy == 1 */ 607 rcv->state = PLIP_PK_DONE; 608 nl->is_deferred = 1; 609 nl->connection = PLIP_CN_SEND; 610 schedule_delayed_work(&nl->deferred, 1); 611 enable_parport_interrupts (dev); 612 ENABLE(dev->irq); 613 return OK; 614 } 615 } else { 616 if (plip_receive(nibble_timeout, dev, 617 &rcv->nibble, &rcv->length.b.lsb)) 618 return TIMEOUT; 619 } 620 rcv->state = PLIP_PK_LENGTH_MSB; 621 fallthrough; 622 623 case PLIP_PK_LENGTH_MSB: 624 if (plip_receive(nibble_timeout, dev, 625 &rcv->nibble, &rcv->length.b.msb)) 626 return TIMEOUT; 627 if (rcv->length.h > dev->mtu + dev->hard_header_len || 628 rcv->length.h < 8) { 629 printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h); 630 return ERROR; 631 } 632 /* Malloc up new buffer. */ 633 rcv->skb = dev_alloc_skb(rcv->length.h + 2); 634 if (rcv->skb == NULL) { 635 printk(KERN_ERR "%s: Memory squeeze.\n", dev->name); 636 return ERROR; 637 } 638 skb_reserve(rcv->skb, 2); /* Align IP on 16 byte boundaries */ 639 skb_put(rcv->skb,rcv->length.h); 640 rcv->skb->dev = dev; 641 rcv->state = PLIP_PK_DATA; 642 rcv->byte = 0; 643 rcv->checksum = 0; 644 fallthrough; 645 646 case PLIP_PK_DATA: 647 lbuf = rcv->skb->data; 648 do { 649 if (plip_receive(nibble_timeout, dev, 650 &rcv->nibble, &lbuf[rcv->byte])) 651 return TIMEOUT; 652 } while (++rcv->byte < rcv->length.h); 653 do { 654 rcv->checksum += lbuf[--rcv->byte]; 655 } while (rcv->byte); 656 rcv->state = PLIP_PK_CHECKSUM; 657 fallthrough; 658 659 case PLIP_PK_CHECKSUM: 660 if (plip_receive(nibble_timeout, dev, 661 &rcv->nibble, &rcv->data)) 662 return TIMEOUT; 663 if (rcv->data != rcv->checksum) { 664 dev->stats.rx_crc_errors++; 665 if (net_debug) 666 printk(KERN_DEBUG "%s: checksum error\n", dev->name); 667 return ERROR; 668 } 669 rcv->state = PLIP_PK_DONE; 670 fallthrough; 671 672 case PLIP_PK_DONE: 673 /* Inform the upper layer for the arrival of a packet. */ 674 rcv->skb->protocol=plip_type_trans(rcv->skb, dev); 675 netif_rx_ni(rcv->skb); 676 dev->stats.rx_bytes += rcv->length.h; 677 dev->stats.rx_packets++; 678 rcv->skb = NULL; 679 if (net_debug > 2) 680 printk(KERN_DEBUG "%s: receive end\n", dev->name); 681 682 /* Close the connection. */ 683 write_data (dev, 0x00); 684 spin_lock_irq(&nl->lock); 685 if (snd->state != PLIP_PK_DONE) { 686 nl->connection = PLIP_CN_SEND; 687 spin_unlock_irq(&nl->lock); 688 schedule_work(&nl->immediate); 689 enable_parport_interrupts (dev); 690 ENABLE(dev->irq); 691 return OK; 692 } else { 693 nl->connection = PLIP_CN_NONE; 694 spin_unlock_irq(&nl->lock); 695 enable_parport_interrupts (dev); 696 ENABLE(dev->irq); 697 return OK; 698 } 699 } 700 return OK; 701 } 702 703 /* PLIP_SEND --- send a byte (two nibbles) 704 Returns OK on success, TIMEOUT when timeout */ 705 static inline int 706 plip_send(unsigned short nibble_timeout, struct net_device *dev, 707 enum plip_nibble_state *ns_p, unsigned char data) 708 { 709 unsigned char c0; 710 unsigned int cx; 711 712 switch (*ns_p) { 713 case PLIP_NB_BEGIN: 714 write_data (dev, data & 0x0f); 715 *ns_p = PLIP_NB_1; 716 fallthrough; 717 718 case PLIP_NB_1: 719 write_data (dev, 0x10 | (data & 0x0f)); 720 cx = nibble_timeout; 721 while (1) { 722 c0 = read_status(dev); 723 if ((c0 & 0x80) == 0) 724 break; 725 if (--cx == 0) 726 return TIMEOUT; 727 udelay(PLIP_DELAY_UNIT); 728 } 729 write_data (dev, 0x10 | (data >> 4)); 730 *ns_p = PLIP_NB_2; 731 fallthrough; 732 733 case PLIP_NB_2: 734 write_data (dev, (data >> 4)); 735 cx = nibble_timeout; 736 while (1) { 737 c0 = read_status(dev); 738 if (c0 & 0x80) 739 break; 740 if (--cx == 0) 741 return TIMEOUT; 742 udelay(PLIP_DELAY_UNIT); 743 } 744 *ns_p = PLIP_NB_BEGIN; 745 return OK; 746 } 747 return OK; 748 } 749 750 /* PLIP_SEND_PACKET --- send a packet */ 751 static int 752 plip_send_packet(struct net_device *dev, struct net_local *nl, 753 struct plip_local *snd, struct plip_local *rcv) 754 { 755 unsigned short nibble_timeout = nl->nibble; 756 unsigned char *lbuf; 757 unsigned char c0; 758 unsigned int cx; 759 760 if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) { 761 printk(KERN_DEBUG "%s: send skb lost\n", dev->name); 762 snd->state = PLIP_PK_DONE; 763 snd->skb = NULL; 764 return ERROR; 765 } 766 767 switch (snd->state) { 768 case PLIP_PK_TRIGGER: 769 if ((read_status(dev) & 0xf8) != 0x80) 770 return HS_TIMEOUT; 771 772 /* Trigger remote rx interrupt. */ 773 write_data (dev, 0x08); 774 cx = nl->trigger; 775 while (1) { 776 udelay(PLIP_DELAY_UNIT); 777 spin_lock_irq(&nl->lock); 778 if (nl->connection == PLIP_CN_RECEIVE) { 779 spin_unlock_irq(&nl->lock); 780 /* Interrupted. */ 781 dev->stats.collisions++; 782 return OK; 783 } 784 c0 = read_status(dev); 785 if (c0 & 0x08) { 786 spin_unlock_irq(&nl->lock); 787 DISABLE(dev->irq); 788 synchronize_irq(dev->irq); 789 if (nl->connection == PLIP_CN_RECEIVE) { 790 /* Interrupted. 791 We don't need to enable irq, 792 as it is soon disabled. */ 793 /* Yes, we do. New variant of 794 {enable,disable}_irq *counts* 795 them. -- AV */ 796 ENABLE(dev->irq); 797 dev->stats.collisions++; 798 return OK; 799 } 800 disable_parport_interrupts (dev); 801 if (net_debug > 2) 802 printk(KERN_DEBUG "%s: send start\n", dev->name); 803 snd->state = PLIP_PK_LENGTH_LSB; 804 snd->nibble = PLIP_NB_BEGIN; 805 nl->timeout_count = 0; 806 break; 807 } 808 spin_unlock_irq(&nl->lock); 809 if (--cx == 0) { 810 write_data (dev, 0x00); 811 return HS_TIMEOUT; 812 } 813 } 814 break; 815 816 case PLIP_PK_LENGTH_LSB: 817 if (plip_send(nibble_timeout, dev, 818 &snd->nibble, snd->length.b.lsb)) 819 return TIMEOUT; 820 snd->state = PLIP_PK_LENGTH_MSB; 821 fallthrough; 822 823 case PLIP_PK_LENGTH_MSB: 824 if (plip_send(nibble_timeout, dev, 825 &snd->nibble, snd->length.b.msb)) 826 return TIMEOUT; 827 snd->state = PLIP_PK_DATA; 828 snd->byte = 0; 829 snd->checksum = 0; 830 fallthrough; 831 832 case PLIP_PK_DATA: 833 do { 834 if (plip_send(nibble_timeout, dev, 835 &snd->nibble, lbuf[snd->byte])) 836 return TIMEOUT; 837 } while (++snd->byte < snd->length.h); 838 do { 839 snd->checksum += lbuf[--snd->byte]; 840 } while (snd->byte); 841 snd->state = PLIP_PK_CHECKSUM; 842 fallthrough; 843 844 case PLIP_PK_CHECKSUM: 845 if (plip_send(nibble_timeout, dev, 846 &snd->nibble, snd->checksum)) 847 return TIMEOUT; 848 849 dev->stats.tx_bytes += snd->skb->len; 850 dev_kfree_skb(snd->skb); 851 dev->stats.tx_packets++; 852 snd->state = PLIP_PK_DONE; 853 fallthrough; 854 855 case PLIP_PK_DONE: 856 /* Close the connection */ 857 write_data (dev, 0x00); 858 snd->skb = NULL; 859 if (net_debug > 2) 860 printk(KERN_DEBUG "%s: send end\n", dev->name); 861 nl->connection = PLIP_CN_CLOSING; 862 nl->is_deferred = 1; 863 schedule_delayed_work(&nl->deferred, 1); 864 enable_parport_interrupts (dev); 865 ENABLE(dev->irq); 866 return OK; 867 } 868 return OK; 869 } 870 871 static int 872 plip_connection_close(struct net_device *dev, struct net_local *nl, 873 struct plip_local *snd, struct plip_local *rcv) 874 { 875 spin_lock_irq(&nl->lock); 876 if (nl->connection == PLIP_CN_CLOSING) { 877 nl->connection = PLIP_CN_NONE; 878 netif_wake_queue (dev); 879 } 880 spin_unlock_irq(&nl->lock); 881 if (nl->should_relinquish) { 882 nl->should_relinquish = nl->port_owner = 0; 883 parport_release(nl->pardev); 884 } 885 return OK; 886 } 887 888 /* PLIP_ERROR --- wait till other end settled */ 889 static int 890 plip_error(struct net_device *dev, struct net_local *nl, 891 struct plip_local *snd, struct plip_local *rcv) 892 { 893 unsigned char status; 894 895 status = read_status(dev); 896 if ((status & 0xf8) == 0x80) { 897 if (net_debug > 2) 898 printk(KERN_DEBUG "%s: reset interface.\n", dev->name); 899 nl->connection = PLIP_CN_NONE; 900 nl->should_relinquish = 0; 901 netif_start_queue (dev); 902 enable_parport_interrupts (dev); 903 ENABLE(dev->irq); 904 netif_wake_queue (dev); 905 } else { 906 nl->is_deferred = 1; 907 schedule_delayed_work(&nl->deferred, 1); 908 } 909 910 return OK; 911 } 912 913 /* Handle the parallel port interrupts. */ 914 static void 915 plip_interrupt(void *dev_id) 916 { 917 struct net_device *dev = dev_id; 918 struct net_local *nl; 919 struct plip_local *rcv; 920 unsigned char c0; 921 unsigned long flags; 922 923 nl = netdev_priv(dev); 924 rcv = &nl->rcv_data; 925 926 spin_lock_irqsave (&nl->lock, flags); 927 928 c0 = read_status(dev); 929 if ((c0 & 0xf8) != 0xc0) { 930 if ((dev->irq != -1) && (net_debug > 1)) 931 printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name); 932 spin_unlock_irqrestore (&nl->lock, flags); 933 return; 934 } 935 936 if (net_debug > 3) 937 printk(KERN_DEBUG "%s: interrupt.\n", dev->name); 938 939 switch (nl->connection) { 940 case PLIP_CN_CLOSING: 941 netif_wake_queue (dev); 942 fallthrough; 943 case PLIP_CN_NONE: 944 case PLIP_CN_SEND: 945 rcv->state = PLIP_PK_TRIGGER; 946 nl->connection = PLIP_CN_RECEIVE; 947 nl->timeout_count = 0; 948 schedule_work(&nl->immediate); 949 break; 950 951 case PLIP_CN_RECEIVE: 952 /* May occur because there is race condition 953 around test and set of dev->interrupt. 954 Ignore this interrupt. */ 955 break; 956 957 case PLIP_CN_ERROR: 958 printk(KERN_ERR "%s: receive interrupt in error state\n", dev->name); 959 break; 960 } 961 962 spin_unlock_irqrestore(&nl->lock, flags); 963 } 964 965 static netdev_tx_t 966 plip_tx_packet(struct sk_buff *skb, struct net_device *dev) 967 { 968 struct net_local *nl = netdev_priv(dev); 969 struct plip_local *snd = &nl->snd_data; 970 971 if (netif_queue_stopped(dev)) 972 return NETDEV_TX_BUSY; 973 974 /* We may need to grab the bus */ 975 if (!nl->port_owner) { 976 if (parport_claim(nl->pardev)) 977 return NETDEV_TX_BUSY; 978 nl->port_owner = 1; 979 } 980 981 netif_stop_queue (dev); 982 983 if (skb->len > dev->mtu + dev->hard_header_len) { 984 printk(KERN_WARNING "%s: packet too big, %d.\n", dev->name, (int)skb->len); 985 netif_start_queue (dev); 986 return NETDEV_TX_BUSY; 987 } 988 989 if (net_debug > 2) 990 printk(KERN_DEBUG "%s: send request\n", dev->name); 991 992 spin_lock_irq(&nl->lock); 993 snd->skb = skb; 994 snd->length.h = skb->len; 995 snd->state = PLIP_PK_TRIGGER; 996 if (nl->connection == PLIP_CN_NONE) { 997 nl->connection = PLIP_CN_SEND; 998 nl->timeout_count = 0; 999 } 1000 schedule_work(&nl->immediate); 1001 spin_unlock_irq(&nl->lock); 1002 1003 return NETDEV_TX_OK; 1004 } 1005 1006 static void 1007 plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth) 1008 { 1009 const struct in_device *in_dev; 1010 1011 rcu_read_lock(); 1012 in_dev = __in_dev_get_rcu(dev); 1013 if (in_dev) { 1014 /* Any address will do - we take the first */ 1015 const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list); 1016 if (ifa) { 1017 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN); 1018 memset(eth->h_dest, 0xfc, 2); 1019 memcpy(eth->h_dest+2, &ifa->ifa_address, 4); 1020 } 1021 } 1022 rcu_read_unlock(); 1023 } 1024 1025 static int 1026 plip_hard_header(struct sk_buff *skb, struct net_device *dev, 1027 unsigned short type, const void *daddr, 1028 const void *saddr, unsigned len) 1029 { 1030 int ret; 1031 1032 ret = eth_header(skb, dev, type, daddr, saddr, len); 1033 if (ret >= 0) 1034 plip_rewrite_address (dev, (struct ethhdr *)skb->data); 1035 1036 return ret; 1037 } 1038 1039 static int plip_hard_header_cache(const struct neighbour *neigh, 1040 struct hh_cache *hh, __be16 type) 1041 { 1042 int ret; 1043 1044 ret = eth_header_cache(neigh, hh, type); 1045 if (ret == 0) { 1046 struct ethhdr *eth; 1047 1048 eth = (struct ethhdr*)(((u8*)hh->hh_data) + 1049 HH_DATA_OFF(sizeof(*eth))); 1050 plip_rewrite_address (neigh->dev, eth); 1051 } 1052 1053 return ret; 1054 } 1055 1056 /* Open/initialize the board. This is called (in the current kernel) 1057 sometime after booting when the 'ifconfig' program is run. 1058 1059 This routine gets exclusive access to the parallel port by allocating 1060 its IRQ line. 1061 */ 1062 static int 1063 plip_open(struct net_device *dev) 1064 { 1065 struct net_local *nl = netdev_priv(dev); 1066 struct in_device *in_dev; 1067 1068 /* Grab the port */ 1069 if (!nl->port_owner) { 1070 if (parport_claim(nl->pardev)) return -EAGAIN; 1071 nl->port_owner = 1; 1072 } 1073 1074 nl->should_relinquish = 0; 1075 1076 /* Clear the data port. */ 1077 write_data (dev, 0x00); 1078 1079 /* Enable rx interrupt. */ 1080 enable_parport_interrupts (dev); 1081 if (dev->irq == -1) 1082 { 1083 atomic_set (&nl->kill_timer, 0); 1084 schedule_delayed_work(&nl->timer, 1); 1085 } 1086 1087 /* Initialize the state machine. */ 1088 nl->rcv_data.state = nl->snd_data.state = PLIP_PK_DONE; 1089 nl->rcv_data.skb = nl->snd_data.skb = NULL; 1090 nl->connection = PLIP_CN_NONE; 1091 nl->is_deferred = 0; 1092 1093 /* Fill in the MAC-level header. 1094 We used to abuse dev->broadcast to store the point-to-point 1095 MAC address, but we no longer do it. Instead, we fetch the 1096 interface address whenever it is needed, which is cheap enough 1097 because we use the hh_cache. Actually, abusing dev->broadcast 1098 didn't work, because when using plip_open the point-to-point 1099 address isn't yet known. 1100 PLIP doesn't have a real MAC address, but we need it to be 1101 DOS compatible, and to properly support taps (otherwise, 1102 when the device address isn't identical to the address of a 1103 received frame, the kernel incorrectly drops it). */ 1104 1105 in_dev=__in_dev_get_rtnl(dev); 1106 if (in_dev) { 1107 /* Any address will do - we take the first. We already 1108 have the first two bytes filled with 0xfc, from 1109 plip_init_dev(). */ 1110 const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list); 1111 if (ifa != NULL) { 1112 memcpy(dev->dev_addr+2, &ifa->ifa_local, 4); 1113 } 1114 } 1115 1116 netif_start_queue (dev); 1117 1118 return 0; 1119 } 1120 1121 /* The inverse routine to plip_open (). */ 1122 static int 1123 plip_close(struct net_device *dev) 1124 { 1125 struct net_local *nl = netdev_priv(dev); 1126 struct plip_local *snd = &nl->snd_data; 1127 struct plip_local *rcv = &nl->rcv_data; 1128 1129 netif_stop_queue (dev); 1130 DISABLE(dev->irq); 1131 synchronize_irq(dev->irq); 1132 1133 if (dev->irq == -1) 1134 { 1135 init_completion(&nl->killed_timer_cmp); 1136 atomic_set (&nl->kill_timer, 1); 1137 wait_for_completion(&nl->killed_timer_cmp); 1138 } 1139 1140 #ifdef NOTDEF 1141 outb(0x00, PAR_DATA(dev)); 1142 #endif 1143 nl->is_deferred = 0; 1144 nl->connection = PLIP_CN_NONE; 1145 if (nl->port_owner) { 1146 parport_release(nl->pardev); 1147 nl->port_owner = 0; 1148 } 1149 1150 snd->state = PLIP_PK_DONE; 1151 if (snd->skb) { 1152 dev_kfree_skb(snd->skb); 1153 snd->skb = NULL; 1154 } 1155 rcv->state = PLIP_PK_DONE; 1156 if (rcv->skb) { 1157 kfree_skb(rcv->skb); 1158 rcv->skb = NULL; 1159 } 1160 1161 #ifdef NOTDEF 1162 /* Reset. */ 1163 outb(0x00, PAR_CONTROL(dev)); 1164 #endif 1165 return 0; 1166 } 1167 1168 static int 1169 plip_preempt(void *handle) 1170 { 1171 struct net_device *dev = (struct net_device *)handle; 1172 struct net_local *nl = netdev_priv(dev); 1173 1174 /* Stand our ground if a datagram is on the wire */ 1175 if (nl->connection != PLIP_CN_NONE) { 1176 nl->should_relinquish = 1; 1177 return 1; 1178 } 1179 1180 nl->port_owner = 0; /* Remember that we released the bus */ 1181 return 0; 1182 } 1183 1184 static void 1185 plip_wakeup(void *handle) 1186 { 1187 struct net_device *dev = (struct net_device *)handle; 1188 struct net_local *nl = netdev_priv(dev); 1189 1190 if (nl->port_owner) { 1191 /* Why are we being woken up? */ 1192 printk(KERN_DEBUG "%s: why am I being woken up?\n", dev->name); 1193 if (!parport_claim(nl->pardev)) 1194 /* bus_owner is already set (but why?) */ 1195 printk(KERN_DEBUG "%s: I'm broken.\n", dev->name); 1196 else 1197 return; 1198 } 1199 1200 if (!(dev->flags & IFF_UP)) 1201 /* Don't need the port when the interface is down */ 1202 return; 1203 1204 if (!parport_claim(nl->pardev)) { 1205 nl->port_owner = 1; 1206 /* Clear the data port. */ 1207 write_data (dev, 0x00); 1208 } 1209 } 1210 1211 static int 1212 plip_siocdevprivate(struct net_device *dev, struct ifreq *rq, 1213 void __user *data, int cmd) 1214 { 1215 struct net_local *nl = netdev_priv(dev); 1216 struct plipconf *pc = (struct plipconf *) &rq->ifr_ifru; 1217 1218 if (cmd != SIOCDEVPLIP) 1219 return -EOPNOTSUPP; 1220 1221 if (in_compat_syscall()) 1222 return -EOPNOTSUPP; 1223 1224 switch(pc->pcmd) { 1225 case PLIP_GET_TIMEOUT: 1226 pc->trigger = nl->trigger; 1227 pc->nibble = nl->nibble; 1228 break; 1229 case PLIP_SET_TIMEOUT: 1230 if(!capable(CAP_NET_ADMIN)) 1231 return -EPERM; 1232 nl->trigger = pc->trigger; 1233 nl->nibble = pc->nibble; 1234 break; 1235 default: 1236 return -EOPNOTSUPP; 1237 } 1238 return 0; 1239 } 1240 1241 static int parport[PLIP_MAX] = { [0 ... PLIP_MAX-1] = -1 }; 1242 static int timid; 1243 1244 module_param_array(parport, int, NULL, 0); 1245 module_param(timid, int, 0); 1246 MODULE_PARM_DESC(parport, "List of parport device numbers to use by plip"); 1247 1248 static struct net_device *dev_plip[PLIP_MAX] = { NULL, }; 1249 1250 static inline int 1251 plip_searchfor(int list[], int a) 1252 { 1253 int i; 1254 for (i = 0; i < PLIP_MAX && list[i] != -1; i++) { 1255 if (list[i] == a) return 1; 1256 } 1257 return 0; 1258 } 1259 1260 /* plip_attach() is called (by the parport code) when a port is 1261 * available to use. */ 1262 static void plip_attach (struct parport *port) 1263 { 1264 static int unit; 1265 struct net_device *dev; 1266 struct net_local *nl; 1267 char name[IFNAMSIZ]; 1268 struct pardev_cb plip_cb; 1269 1270 if ((parport[0] == -1 && (!timid || !port->devices)) || 1271 plip_searchfor(parport, port->number)) { 1272 if (unit == PLIP_MAX) { 1273 printk(KERN_ERR "plip: too many devices\n"); 1274 return; 1275 } 1276 1277 sprintf(name, "plip%d", unit); 1278 dev = alloc_etherdev(sizeof(struct net_local)); 1279 if (!dev) 1280 return; 1281 1282 strcpy(dev->name, name); 1283 1284 dev->irq = port->irq; 1285 dev->base_addr = port->base; 1286 if (port->irq == -1) { 1287 printk(KERN_INFO "plip: %s has no IRQ. Using IRQ-less mode," 1288 "which is fairly inefficient!\n", port->name); 1289 } 1290 1291 nl = netdev_priv(dev); 1292 nl->dev = dev; 1293 1294 memset(&plip_cb, 0, sizeof(plip_cb)); 1295 plip_cb.private = dev; 1296 plip_cb.preempt = plip_preempt; 1297 plip_cb.wakeup = plip_wakeup; 1298 plip_cb.irq_func = plip_interrupt; 1299 1300 nl->pardev = parport_register_dev_model(port, dev->name, 1301 &plip_cb, unit); 1302 1303 if (!nl->pardev) { 1304 printk(KERN_ERR "%s: parport_register failed\n", name); 1305 goto err_free_dev; 1306 } 1307 1308 plip_init_netdev(dev); 1309 1310 if (register_netdev(dev)) { 1311 printk(KERN_ERR "%s: network register failed\n", name); 1312 goto err_parport_unregister; 1313 } 1314 1315 printk(KERN_INFO "%s", version); 1316 if (dev->irq != -1) 1317 printk(KERN_INFO "%s: Parallel port at %#3lx, " 1318 "using IRQ %d.\n", 1319 dev->name, dev->base_addr, dev->irq); 1320 else 1321 printk(KERN_INFO "%s: Parallel port at %#3lx, " 1322 "not using IRQ.\n", 1323 dev->name, dev->base_addr); 1324 dev_plip[unit++] = dev; 1325 } 1326 return; 1327 1328 err_parport_unregister: 1329 parport_unregister_device(nl->pardev); 1330 err_free_dev: 1331 free_netdev(dev); 1332 } 1333 1334 /* plip_detach() is called (by the parport code) when a port is 1335 * no longer available to use. */ 1336 static void plip_detach (struct parport *port) 1337 { 1338 /* Nothing to do */ 1339 } 1340 1341 static int plip_probe(struct pardevice *par_dev) 1342 { 1343 struct device_driver *drv = par_dev->dev.driver; 1344 int len = strlen(drv->name); 1345 1346 if (strncmp(par_dev->name, drv->name, len)) 1347 return -ENODEV; 1348 1349 return 0; 1350 } 1351 1352 static struct parport_driver plip_driver = { 1353 .name = "plip", 1354 .probe = plip_probe, 1355 .match_port = plip_attach, 1356 .detach = plip_detach, 1357 .devmodel = true, 1358 }; 1359 1360 static void __exit plip_cleanup_module (void) 1361 { 1362 struct net_device *dev; 1363 int i; 1364 1365 for (i=0; i < PLIP_MAX; i++) { 1366 if ((dev = dev_plip[i])) { 1367 struct net_local *nl = netdev_priv(dev); 1368 unregister_netdev(dev); 1369 if (nl->port_owner) 1370 parport_release(nl->pardev); 1371 parport_unregister_device(nl->pardev); 1372 free_netdev(dev); 1373 dev_plip[i] = NULL; 1374 } 1375 } 1376 1377 parport_unregister_driver(&plip_driver); 1378 } 1379 1380 #ifndef MODULE 1381 1382 static int parport_ptr; 1383 1384 static int __init plip_setup(char *str) 1385 { 1386 int ints[4]; 1387 1388 str = get_options(str, ARRAY_SIZE(ints), ints); 1389 1390 /* Ugh. */ 1391 if (!strncmp(str, "parport", 7)) { 1392 int n = simple_strtoul(str+7, NULL, 10); 1393 if (parport_ptr < PLIP_MAX) 1394 parport[parport_ptr++] = n; 1395 else 1396 printk(KERN_INFO "plip: too many ports, %s ignored.\n", 1397 str); 1398 } else if (!strcmp(str, "timid")) { 1399 timid = 1; 1400 } else { 1401 if (ints[0] == 0 || ints[1] == 0) { 1402 /* disable driver on "plip=" or "plip=0" */ 1403 parport[0] = -2; 1404 } else { 1405 printk(KERN_WARNING "warning: 'plip=0x%x' ignored\n", 1406 ints[1]); 1407 } 1408 } 1409 return 1; 1410 } 1411 1412 __setup("plip=", plip_setup); 1413 1414 #endif /* !MODULE */ 1415 1416 static int __init plip_init (void) 1417 { 1418 if (parport[0] == -2) 1419 return 0; 1420 1421 if (parport[0] != -1 && timid) { 1422 printk(KERN_WARNING "plip: warning, ignoring `timid' since specific ports given.\n"); 1423 timid = 0; 1424 } 1425 1426 if (parport_register_driver (&plip_driver)) { 1427 printk (KERN_WARNING "plip: couldn't register driver\n"); 1428 return 1; 1429 } 1430 1431 return 0; 1432 } 1433 1434 module_init(plip_init); 1435 module_exit(plip_cleanup_module); 1436 MODULE_LICENSE("GPL"); 1437