1 /* $Id: plip.c,v 1.3.6.2 1997/04/16 15:07:56 phil Exp $ */ 2 /* PLIP: A parallel port "network" driver for Linux. */ 3 /* This driver is for parallel port with 5-bit cable (LapLink (R) cable). */ 4 /* 5 * Authors: Donald Becker <becker@scyld.com> 6 * Tommy Thorn <thorn@daimi.aau.dk> 7 * Tanabe Hiroyasu <hiro@sanpo.t.u-tokyo.ac.jp> 8 * Alan Cox <gw4pts@gw4pts.ampr.org> 9 * Peter Bauer <100136.3530@compuserve.com> 10 * Niibe Yutaka <gniibe@mri.co.jp> 11 * Nimrod Zimerman <zimerman@mailandnews.com> 12 * 13 * Enhancements: 14 * Modularization and ifreq/ifmap support by Alan Cox. 15 * Rewritten by Niibe Yutaka. 16 * parport-sharing awareness code by Philip Blundell. 17 * SMP locking by Niibe Yutaka. 18 * Support for parallel ports with no IRQ (poll mode), 19 * Modifications to use the parallel port API 20 * by Nimrod Zimerman. 21 * 22 * Fixes: 23 * Niibe Yutaka 24 * - Module initialization. 25 * - MTU fix. 26 * - Make sure other end is OK, before sending a packet. 27 * - Fix immediate timer problem. 28 * 29 * Al Viro 30 * - Changed {enable,disable}_irq handling to make it work 31 * with new ("stack") semantics. 32 * 33 * This program is free software; you can redistribute it and/or 34 * modify it under the terms of the GNU General Public License 35 * as published by the Free Software Foundation; either version 36 * 2 of the License, or (at your option) any later version. 37 */ 38 39 /* 40 * Original version and the name 'PLIP' from Donald Becker <becker@scyld.com> 41 * inspired by Russ Nelson's parallel port packet driver. 42 * 43 * NOTE: 44 * Tanabe Hiroyasu had changed the protocol, and it was in Linux v1.0. 45 * Because of the necessity to communicate to DOS machines with the 46 * Crynwr packet driver, Peter Bauer changed the protocol again 47 * back to original protocol. 48 * 49 * This version follows original PLIP protocol. 50 * So, this PLIP can't communicate the PLIP of Linux v1.0. 51 */ 52 53 /* 54 * To use with DOS box, please do (Turn on ARP switch): 55 * # ifconfig plip[0-2] arp 56 */ 57 static const char version[] = "NET3 PLIP version 2.4-parport gniibe@mri.co.jp\n"; 58 59 /* 60 Sources: 61 Ideas and protocols came from Russ Nelson's <nelson@crynwr.com> 62 "parallel.asm" parallel port packet driver. 63 64 The "Crynwr" parallel port standard specifies the following protocol: 65 Trigger by sending nibble '0x8' (this causes interrupt on other end) 66 count-low octet 67 count-high octet 68 ... data octets 69 checksum octet 70 Each octet is sent as <wait for rx. '0x1?'> <send 0x10+(octet&0x0F)> 71 <wait for rx. '0x0?'> <send 0x00+((octet>>4)&0x0F)> 72 73 The packet is encapsulated as if it were ethernet. 74 75 The cable used is a de facto standard parallel null cable -- sold as 76 a "LapLink" cable by various places. You'll need a 12-conductor cable to 77 make one yourself. The wiring is: 78 SLCTIN 17 - 17 79 GROUND 25 - 25 80 D0->ERROR 2 - 15 15 - 2 81 D1->SLCT 3 - 13 13 - 3 82 D2->PAPOUT 4 - 12 12 - 4 83 D3->ACK 5 - 10 10 - 5 84 D4->BUSY 6 - 11 11 - 6 85 Do not connect the other pins. They are 86 D5,D6,D7 are 7,8,9 87 STROBE is 1, FEED is 14, INIT is 16 88 extra grounds are 18,19,20,21,22,23,24 89 */ 90 91 #include <linux/module.h> 92 #include <linux/kernel.h> 93 #include <linux/types.h> 94 #include <linux/fcntl.h> 95 #include <linux/interrupt.h> 96 #include <linux/string.h> 97 #include <linux/slab.h> 98 #include <linux/if_ether.h> 99 #include <linux/in.h> 100 #include <linux/errno.h> 101 #include <linux/delay.h> 102 #include <linux/init.h> 103 #include <linux/netdevice.h> 104 #include <linux/etherdevice.h> 105 #include <linux/inetdevice.h> 106 #include <linux/skbuff.h> 107 #include <linux/if_plip.h> 108 #include <linux/workqueue.h> 109 #include <linux/spinlock.h> 110 #include <linux/completion.h> 111 #include <linux/parport.h> 112 #include <linux/bitops.h> 113 114 #include <net/neighbour.h> 115 116 #include <asm/irq.h> 117 #include <asm/byteorder.h> 118 119 /* Maximum number of devices to support. */ 120 #define PLIP_MAX 8 121 122 /* Use 0 for production, 1 for verification, >2 for debug */ 123 #ifndef NET_DEBUG 124 #define NET_DEBUG 1 125 #endif 126 static const unsigned int net_debug = NET_DEBUG; 127 128 #define ENABLE(irq) if (irq != -1) enable_irq(irq) 129 #define DISABLE(irq) if (irq != -1) disable_irq(irq) 130 131 /* In micro second */ 132 #define PLIP_DELAY_UNIT 1 133 134 /* Connection time out = PLIP_TRIGGER_WAIT * PLIP_DELAY_UNIT usec */ 135 #define PLIP_TRIGGER_WAIT 500 136 137 /* Nibble time out = PLIP_NIBBLE_WAIT * PLIP_DELAY_UNIT usec */ 138 #define PLIP_NIBBLE_WAIT 3000 139 140 /* Bottom halves */ 141 static void plip_kick_bh(struct work_struct *work); 142 static void plip_bh(struct work_struct *work); 143 static void plip_timer_bh(struct work_struct *work); 144 145 /* Interrupt handler */ 146 static void plip_interrupt(void *dev_id); 147 148 /* Functions for DEV methods */ 149 static int plip_tx_packet(struct sk_buff *skb, struct net_device *dev); 150 static int plip_hard_header(struct sk_buff *skb, struct net_device *dev, 151 unsigned short type, const void *daddr, 152 const void *saddr, unsigned len); 153 static int plip_hard_header_cache(const struct neighbour *neigh, 154 struct hh_cache *hh, __be16 type); 155 static int plip_open(struct net_device *dev); 156 static int plip_close(struct net_device *dev); 157 static int plip_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 158 static int plip_preempt(void *handle); 159 static void plip_wakeup(void *handle); 160 161 enum plip_connection_state { 162 PLIP_CN_NONE=0, 163 PLIP_CN_RECEIVE, 164 PLIP_CN_SEND, 165 PLIP_CN_CLOSING, 166 PLIP_CN_ERROR 167 }; 168 169 enum plip_packet_state { 170 PLIP_PK_DONE=0, 171 PLIP_PK_TRIGGER, 172 PLIP_PK_LENGTH_LSB, 173 PLIP_PK_LENGTH_MSB, 174 PLIP_PK_DATA, 175 PLIP_PK_CHECKSUM 176 }; 177 178 enum plip_nibble_state { 179 PLIP_NB_BEGIN, 180 PLIP_NB_1, 181 PLIP_NB_2, 182 }; 183 184 struct plip_local { 185 enum plip_packet_state state; 186 enum plip_nibble_state nibble; 187 union { 188 struct { 189 #if defined(__LITTLE_ENDIAN) 190 unsigned char lsb; 191 unsigned char msb; 192 #elif defined(__BIG_ENDIAN) 193 unsigned char msb; 194 unsigned char lsb; 195 #else 196 #error "Please fix the endianness defines in <asm/byteorder.h>" 197 #endif 198 } b; 199 unsigned short h; 200 } length; 201 unsigned short byte; 202 unsigned char checksum; 203 unsigned char data; 204 struct sk_buff *skb; 205 }; 206 207 struct net_local { 208 struct net_device *dev; 209 struct work_struct immediate; 210 struct delayed_work deferred; 211 struct delayed_work timer; 212 struct plip_local snd_data; 213 struct plip_local rcv_data; 214 struct pardevice *pardev; 215 unsigned long trigger; 216 unsigned long nibble; 217 enum plip_connection_state connection; 218 unsigned short timeout_count; 219 int is_deferred; 220 int port_owner; 221 int should_relinquish; 222 spinlock_t lock; 223 atomic_t kill_timer; 224 struct completion killed_timer_cmp; 225 }; 226 227 static inline void enable_parport_interrupts (struct net_device *dev) 228 { 229 if (dev->irq != -1) 230 { 231 struct parport *port = 232 ((struct net_local *)netdev_priv(dev))->pardev->port; 233 port->ops->enable_irq (port); 234 } 235 } 236 237 static inline void disable_parport_interrupts (struct net_device *dev) 238 { 239 if (dev->irq != -1) 240 { 241 struct parport *port = 242 ((struct net_local *)netdev_priv(dev))->pardev->port; 243 port->ops->disable_irq (port); 244 } 245 } 246 247 static inline void write_data (struct net_device *dev, unsigned char data) 248 { 249 struct parport *port = 250 ((struct net_local *)netdev_priv(dev))->pardev->port; 251 252 port->ops->write_data (port, data); 253 } 254 255 static inline unsigned char read_status (struct net_device *dev) 256 { 257 struct parport *port = 258 ((struct net_local *)netdev_priv(dev))->pardev->port; 259 260 return port->ops->read_status (port); 261 } 262 263 static const struct header_ops plip_header_ops = { 264 .create = plip_hard_header, 265 .cache = plip_hard_header_cache, 266 }; 267 268 static const struct net_device_ops plip_netdev_ops = { 269 .ndo_open = plip_open, 270 .ndo_stop = plip_close, 271 .ndo_start_xmit = plip_tx_packet, 272 .ndo_do_ioctl = plip_ioctl, 273 .ndo_change_mtu = eth_change_mtu, 274 .ndo_set_mac_address = eth_mac_addr, 275 .ndo_validate_addr = eth_validate_addr, 276 }; 277 278 /* Entry point of PLIP driver. 279 Probe the hardware, and register/initialize the driver. 280 281 PLIP is rather weird, because of the way it interacts with the parport 282 system. It is _not_ initialised from Space.c. Instead, plip_init() 283 is called, and that function makes up a "struct net_device" for each port, and 284 then calls us here. 285 286 */ 287 static void 288 plip_init_netdev(struct net_device *dev) 289 { 290 struct net_local *nl = netdev_priv(dev); 291 292 /* Then, override parts of it */ 293 dev->tx_queue_len = 10; 294 dev->flags = IFF_POINTOPOINT|IFF_NOARP; 295 memset(dev->dev_addr, 0xfc, ETH_ALEN); 296 297 dev->netdev_ops = &plip_netdev_ops; 298 dev->header_ops = &plip_header_ops; 299 300 301 nl->port_owner = 0; 302 303 /* Initialize constants */ 304 nl->trigger = PLIP_TRIGGER_WAIT; 305 nl->nibble = PLIP_NIBBLE_WAIT; 306 307 /* Initialize task queue structures */ 308 INIT_WORK(&nl->immediate, plip_bh); 309 INIT_DELAYED_WORK(&nl->deferred, plip_kick_bh); 310 311 if (dev->irq == -1) 312 INIT_DELAYED_WORK(&nl->timer, plip_timer_bh); 313 314 spin_lock_init(&nl->lock); 315 } 316 317 /* Bottom half handler for the delayed request. 318 This routine is kicked by do_timer(). 319 Request `plip_bh' to be invoked. */ 320 static void 321 plip_kick_bh(struct work_struct *work) 322 { 323 struct net_local *nl = 324 container_of(work, struct net_local, deferred.work); 325 326 if (nl->is_deferred) 327 schedule_work(&nl->immediate); 328 } 329 330 /* Forward declarations of internal routines */ 331 static int plip_none(struct net_device *, struct net_local *, 332 struct plip_local *, struct plip_local *); 333 static int plip_receive_packet(struct net_device *, struct net_local *, 334 struct plip_local *, struct plip_local *); 335 static int plip_send_packet(struct net_device *, struct net_local *, 336 struct plip_local *, struct plip_local *); 337 static int plip_connection_close(struct net_device *, struct net_local *, 338 struct plip_local *, struct plip_local *); 339 static int plip_error(struct net_device *, struct net_local *, 340 struct plip_local *, struct plip_local *); 341 static int plip_bh_timeout_error(struct net_device *dev, struct net_local *nl, 342 struct plip_local *snd, 343 struct plip_local *rcv, 344 int error); 345 346 #define OK 0 347 #define TIMEOUT 1 348 #define ERROR 2 349 #define HS_TIMEOUT 3 350 351 typedef int (*plip_func)(struct net_device *dev, struct net_local *nl, 352 struct plip_local *snd, struct plip_local *rcv); 353 354 static const plip_func connection_state_table[] = 355 { 356 plip_none, 357 plip_receive_packet, 358 plip_send_packet, 359 plip_connection_close, 360 plip_error 361 }; 362 363 /* Bottom half handler of PLIP. */ 364 static void 365 plip_bh(struct work_struct *work) 366 { 367 struct net_local *nl = container_of(work, struct net_local, immediate); 368 struct plip_local *snd = &nl->snd_data; 369 struct plip_local *rcv = &nl->rcv_data; 370 plip_func f; 371 int r; 372 373 nl->is_deferred = 0; 374 f = connection_state_table[nl->connection]; 375 if ((r = (*f)(nl->dev, nl, snd, rcv)) != OK && 376 (r = plip_bh_timeout_error(nl->dev, nl, snd, rcv, r)) != OK) { 377 nl->is_deferred = 1; 378 schedule_delayed_work(&nl->deferred, 1); 379 } 380 } 381 382 static void 383 plip_timer_bh(struct work_struct *work) 384 { 385 struct net_local *nl = 386 container_of(work, struct net_local, timer.work); 387 388 if (!(atomic_read (&nl->kill_timer))) { 389 plip_interrupt (nl->dev); 390 391 schedule_delayed_work(&nl->timer, 1); 392 } 393 else { 394 complete(&nl->killed_timer_cmp); 395 } 396 } 397 398 static int 399 plip_bh_timeout_error(struct net_device *dev, struct net_local *nl, 400 struct plip_local *snd, struct plip_local *rcv, 401 int error) 402 { 403 unsigned char c0; 404 /* 405 * This is tricky. If we got here from the beginning of send (either 406 * with ERROR or HS_TIMEOUT) we have IRQ enabled. Otherwise it's 407 * already disabled. With the old variant of {enable,disable}_irq() 408 * extra disable_irq() was a no-op. Now it became mortal - it's 409 * unbalanced and thus we'll never re-enable IRQ (until rmmod plip, 410 * that is). So we have to treat HS_TIMEOUT and ERROR from send 411 * in a special way. 412 */ 413 414 spin_lock_irq(&nl->lock); 415 if (nl->connection == PLIP_CN_SEND) { 416 417 if (error != ERROR) { /* Timeout */ 418 nl->timeout_count++; 419 if ((error == HS_TIMEOUT && nl->timeout_count <= 10) || 420 nl->timeout_count <= 3) { 421 spin_unlock_irq(&nl->lock); 422 /* Try again later */ 423 return TIMEOUT; 424 } 425 c0 = read_status(dev); 426 printk(KERN_WARNING "%s: transmit timeout(%d,%02x)\n", 427 dev->name, snd->state, c0); 428 } else 429 error = HS_TIMEOUT; 430 dev->stats.tx_errors++; 431 dev->stats.tx_aborted_errors++; 432 } else if (nl->connection == PLIP_CN_RECEIVE) { 433 if (rcv->state == PLIP_PK_TRIGGER) { 434 /* Transmission was interrupted. */ 435 spin_unlock_irq(&nl->lock); 436 return OK; 437 } 438 if (error != ERROR) { /* Timeout */ 439 if (++nl->timeout_count <= 3) { 440 spin_unlock_irq(&nl->lock); 441 /* Try again later */ 442 return TIMEOUT; 443 } 444 c0 = read_status(dev); 445 printk(KERN_WARNING "%s: receive timeout(%d,%02x)\n", 446 dev->name, rcv->state, c0); 447 } 448 dev->stats.rx_dropped++; 449 } 450 rcv->state = PLIP_PK_DONE; 451 if (rcv->skb) { 452 kfree_skb(rcv->skb); 453 rcv->skb = NULL; 454 } 455 snd->state = PLIP_PK_DONE; 456 if (snd->skb) { 457 dev_kfree_skb(snd->skb); 458 snd->skb = NULL; 459 } 460 spin_unlock_irq(&nl->lock); 461 if (error == HS_TIMEOUT) { 462 DISABLE(dev->irq); 463 synchronize_irq(dev->irq); 464 } 465 disable_parport_interrupts (dev); 466 netif_stop_queue (dev); 467 nl->connection = PLIP_CN_ERROR; 468 write_data (dev, 0x00); 469 470 return TIMEOUT; 471 } 472 473 static int 474 plip_none(struct net_device *dev, struct net_local *nl, 475 struct plip_local *snd, struct plip_local *rcv) 476 { 477 return OK; 478 } 479 480 /* PLIP_RECEIVE --- receive a byte(two nibbles) 481 Returns OK on success, TIMEOUT on timeout */ 482 static inline int 483 plip_receive(unsigned short nibble_timeout, struct net_device *dev, 484 enum plip_nibble_state *ns_p, unsigned char *data_p) 485 { 486 unsigned char c0, c1; 487 unsigned int cx; 488 489 switch (*ns_p) { 490 case PLIP_NB_BEGIN: 491 cx = nibble_timeout; 492 while (1) { 493 c0 = read_status(dev); 494 udelay(PLIP_DELAY_UNIT); 495 if ((c0 & 0x80) == 0) { 496 c1 = read_status(dev); 497 if (c0 == c1) 498 break; 499 } 500 if (--cx == 0) 501 return TIMEOUT; 502 } 503 *data_p = (c0 >> 3) & 0x0f; 504 write_data (dev, 0x10); /* send ACK */ 505 *ns_p = PLIP_NB_1; 506 507 case PLIP_NB_1: 508 cx = nibble_timeout; 509 while (1) { 510 c0 = read_status(dev); 511 udelay(PLIP_DELAY_UNIT); 512 if (c0 & 0x80) { 513 c1 = read_status(dev); 514 if (c0 == c1) 515 break; 516 } 517 if (--cx == 0) 518 return TIMEOUT; 519 } 520 *data_p |= (c0 << 1) & 0xf0; 521 write_data (dev, 0x00); /* send ACK */ 522 *ns_p = PLIP_NB_BEGIN; 523 case PLIP_NB_2: 524 break; 525 } 526 return OK; 527 } 528 529 /* 530 * Determine the packet's protocol ID. The rule here is that we 531 * assume 802.3 if the type field is short enough to be a length. 532 * This is normal practice and works for any 'now in use' protocol. 533 * 534 * PLIP is ethernet ish but the daddr might not be valid if unicast. 535 * PLIP fortunately has no bus architecture (its Point-to-point). 536 * 537 * We can't fix the daddr thing as that quirk (more bug) is embedded 538 * in far too many old systems not all even running Linux. 539 */ 540 541 static __be16 plip_type_trans(struct sk_buff *skb, struct net_device *dev) 542 { 543 struct ethhdr *eth; 544 unsigned char *rawp; 545 546 skb_reset_mac_header(skb); 547 skb_pull(skb,dev->hard_header_len); 548 eth = eth_hdr(skb); 549 550 if(*eth->h_dest&1) 551 { 552 if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0) 553 skb->pkt_type=PACKET_BROADCAST; 554 else 555 skb->pkt_type=PACKET_MULTICAST; 556 } 557 558 /* 559 * This ALLMULTI check should be redundant by 1.4 560 * so don't forget to remove it. 561 */ 562 563 if (ntohs(eth->h_proto) >= 1536) 564 return eth->h_proto; 565 566 rawp = skb->data; 567 568 /* 569 * This is a magic hack to spot IPX packets. Older Novell breaks 570 * the protocol design and runs IPX over 802.3 without an 802.2 LLC 571 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This 572 * won't work for fault tolerant netware but does for the rest. 573 */ 574 if (*(unsigned short *)rawp == 0xFFFF) 575 return htons(ETH_P_802_3); 576 577 /* 578 * Real 802.2 LLC 579 */ 580 return htons(ETH_P_802_2); 581 } 582 583 /* PLIP_RECEIVE_PACKET --- receive a packet */ 584 static int 585 plip_receive_packet(struct net_device *dev, struct net_local *nl, 586 struct plip_local *snd, struct plip_local *rcv) 587 { 588 unsigned short nibble_timeout = nl->nibble; 589 unsigned char *lbuf; 590 591 switch (rcv->state) { 592 case PLIP_PK_TRIGGER: 593 DISABLE(dev->irq); 594 /* Don't need to synchronize irq, as we can safely ignore it */ 595 disable_parport_interrupts (dev); 596 write_data (dev, 0x01); /* send ACK */ 597 if (net_debug > 2) 598 printk(KERN_DEBUG "%s: receive start\n", dev->name); 599 rcv->state = PLIP_PK_LENGTH_LSB; 600 rcv->nibble = PLIP_NB_BEGIN; 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; 621 622 case PLIP_PK_LENGTH_MSB: 623 if (plip_receive(nibble_timeout, dev, 624 &rcv->nibble, &rcv->length.b.msb)) 625 return TIMEOUT; 626 if (rcv->length.h > dev->mtu + dev->hard_header_len || 627 rcv->length.h < 8) { 628 printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h); 629 return ERROR; 630 } 631 /* Malloc up new buffer. */ 632 rcv->skb = dev_alloc_skb(rcv->length.h + 2); 633 if (rcv->skb == NULL) { 634 printk(KERN_ERR "%s: Memory squeeze.\n", dev->name); 635 return ERROR; 636 } 637 skb_reserve(rcv->skb, 2); /* Align IP on 16 byte boundaries */ 638 skb_put(rcv->skb,rcv->length.h); 639 rcv->skb->dev = dev; 640 rcv->state = PLIP_PK_DATA; 641 rcv->byte = 0; 642 rcv->checksum = 0; 643 644 case PLIP_PK_DATA: 645 lbuf = rcv->skb->data; 646 do { 647 if (plip_receive(nibble_timeout, dev, 648 &rcv->nibble, &lbuf[rcv->byte])) 649 return TIMEOUT; 650 } while (++rcv->byte < rcv->length.h); 651 do { 652 rcv->checksum += lbuf[--rcv->byte]; 653 } while (rcv->byte); 654 rcv->state = PLIP_PK_CHECKSUM; 655 656 case PLIP_PK_CHECKSUM: 657 if (plip_receive(nibble_timeout, dev, 658 &rcv->nibble, &rcv->data)) 659 return TIMEOUT; 660 if (rcv->data != rcv->checksum) { 661 dev->stats.rx_crc_errors++; 662 if (net_debug) 663 printk(KERN_DEBUG "%s: checksum error\n", dev->name); 664 return ERROR; 665 } 666 rcv->state = PLIP_PK_DONE; 667 668 case PLIP_PK_DONE: 669 /* Inform the upper layer for the arrival of a packet. */ 670 rcv->skb->protocol=plip_type_trans(rcv->skb, dev); 671 netif_rx_ni(rcv->skb); 672 dev->stats.rx_bytes += rcv->length.h; 673 dev->stats.rx_packets++; 674 rcv->skb = NULL; 675 if (net_debug > 2) 676 printk(KERN_DEBUG "%s: receive end\n", dev->name); 677 678 /* Close the connection. */ 679 write_data (dev, 0x00); 680 spin_lock_irq(&nl->lock); 681 if (snd->state != PLIP_PK_DONE) { 682 nl->connection = PLIP_CN_SEND; 683 spin_unlock_irq(&nl->lock); 684 schedule_work(&nl->immediate); 685 enable_parport_interrupts (dev); 686 ENABLE(dev->irq); 687 return OK; 688 } else { 689 nl->connection = PLIP_CN_NONE; 690 spin_unlock_irq(&nl->lock); 691 enable_parport_interrupts (dev); 692 ENABLE(dev->irq); 693 return OK; 694 } 695 } 696 return OK; 697 } 698 699 /* PLIP_SEND --- send a byte (two nibbles) 700 Returns OK on success, TIMEOUT when timeout */ 701 static inline int 702 plip_send(unsigned short nibble_timeout, struct net_device *dev, 703 enum plip_nibble_state *ns_p, unsigned char data) 704 { 705 unsigned char c0; 706 unsigned int cx; 707 708 switch (*ns_p) { 709 case PLIP_NB_BEGIN: 710 write_data (dev, data & 0x0f); 711 *ns_p = PLIP_NB_1; 712 713 case PLIP_NB_1: 714 write_data (dev, 0x10 | (data & 0x0f)); 715 cx = nibble_timeout; 716 while (1) { 717 c0 = read_status(dev); 718 if ((c0 & 0x80) == 0) 719 break; 720 if (--cx == 0) 721 return TIMEOUT; 722 udelay(PLIP_DELAY_UNIT); 723 } 724 write_data (dev, 0x10 | (data >> 4)); 725 *ns_p = PLIP_NB_2; 726 727 case PLIP_NB_2: 728 write_data (dev, (data >> 4)); 729 cx = nibble_timeout; 730 while (1) { 731 c0 = read_status(dev); 732 if (c0 & 0x80) 733 break; 734 if (--cx == 0) 735 return TIMEOUT; 736 udelay(PLIP_DELAY_UNIT); 737 } 738 *ns_p = PLIP_NB_BEGIN; 739 return OK; 740 } 741 return OK; 742 } 743 744 /* PLIP_SEND_PACKET --- send a packet */ 745 static int 746 plip_send_packet(struct net_device *dev, struct net_local *nl, 747 struct plip_local *snd, struct plip_local *rcv) 748 { 749 unsigned short nibble_timeout = nl->nibble; 750 unsigned char *lbuf; 751 unsigned char c0; 752 unsigned int cx; 753 754 if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) { 755 printk(KERN_DEBUG "%s: send skb lost\n", dev->name); 756 snd->state = PLIP_PK_DONE; 757 snd->skb = NULL; 758 return ERROR; 759 } 760 761 switch (snd->state) { 762 case PLIP_PK_TRIGGER: 763 if ((read_status(dev) & 0xf8) != 0x80) 764 return HS_TIMEOUT; 765 766 /* Trigger remote rx interrupt. */ 767 write_data (dev, 0x08); 768 cx = nl->trigger; 769 while (1) { 770 udelay(PLIP_DELAY_UNIT); 771 spin_lock_irq(&nl->lock); 772 if (nl->connection == PLIP_CN_RECEIVE) { 773 spin_unlock_irq(&nl->lock); 774 /* Interrupted. */ 775 dev->stats.collisions++; 776 return OK; 777 } 778 c0 = read_status(dev); 779 if (c0 & 0x08) { 780 spin_unlock_irq(&nl->lock); 781 DISABLE(dev->irq); 782 synchronize_irq(dev->irq); 783 if (nl->connection == PLIP_CN_RECEIVE) { 784 /* Interrupted. 785 We don't need to enable irq, 786 as it is soon disabled. */ 787 /* Yes, we do. New variant of 788 {enable,disable}_irq *counts* 789 them. -- AV */ 790 ENABLE(dev->irq); 791 dev->stats.collisions++; 792 return OK; 793 } 794 disable_parport_interrupts (dev); 795 if (net_debug > 2) 796 printk(KERN_DEBUG "%s: send start\n", dev->name); 797 snd->state = PLIP_PK_LENGTH_LSB; 798 snd->nibble = PLIP_NB_BEGIN; 799 nl->timeout_count = 0; 800 break; 801 } 802 spin_unlock_irq(&nl->lock); 803 if (--cx == 0) { 804 write_data (dev, 0x00); 805 return HS_TIMEOUT; 806 } 807 } 808 809 case PLIP_PK_LENGTH_LSB: 810 if (plip_send(nibble_timeout, dev, 811 &snd->nibble, snd->length.b.lsb)) 812 return TIMEOUT; 813 snd->state = PLIP_PK_LENGTH_MSB; 814 815 case PLIP_PK_LENGTH_MSB: 816 if (plip_send(nibble_timeout, dev, 817 &snd->nibble, snd->length.b.msb)) 818 return TIMEOUT; 819 snd->state = PLIP_PK_DATA; 820 snd->byte = 0; 821 snd->checksum = 0; 822 823 case PLIP_PK_DATA: 824 do { 825 if (plip_send(nibble_timeout, dev, 826 &snd->nibble, lbuf[snd->byte])) 827 return TIMEOUT; 828 } while (++snd->byte < snd->length.h); 829 do { 830 snd->checksum += lbuf[--snd->byte]; 831 } while (snd->byte); 832 snd->state = PLIP_PK_CHECKSUM; 833 834 case PLIP_PK_CHECKSUM: 835 if (plip_send(nibble_timeout, dev, 836 &snd->nibble, snd->checksum)) 837 return TIMEOUT; 838 839 dev->stats.tx_bytes += snd->skb->len; 840 dev_kfree_skb(snd->skb); 841 dev->stats.tx_packets++; 842 snd->state = PLIP_PK_DONE; 843 844 case PLIP_PK_DONE: 845 /* Close the connection */ 846 write_data (dev, 0x00); 847 snd->skb = NULL; 848 if (net_debug > 2) 849 printk(KERN_DEBUG "%s: send end\n", dev->name); 850 nl->connection = PLIP_CN_CLOSING; 851 nl->is_deferred = 1; 852 schedule_delayed_work(&nl->deferred, 1); 853 enable_parport_interrupts (dev); 854 ENABLE(dev->irq); 855 return OK; 856 } 857 return OK; 858 } 859 860 static int 861 plip_connection_close(struct net_device *dev, struct net_local *nl, 862 struct plip_local *snd, struct plip_local *rcv) 863 { 864 spin_lock_irq(&nl->lock); 865 if (nl->connection == PLIP_CN_CLOSING) { 866 nl->connection = PLIP_CN_NONE; 867 netif_wake_queue (dev); 868 } 869 spin_unlock_irq(&nl->lock); 870 if (nl->should_relinquish) { 871 nl->should_relinquish = nl->port_owner = 0; 872 parport_release(nl->pardev); 873 } 874 return OK; 875 } 876 877 /* PLIP_ERROR --- wait till other end settled */ 878 static int 879 plip_error(struct net_device *dev, struct net_local *nl, 880 struct plip_local *snd, struct plip_local *rcv) 881 { 882 unsigned char status; 883 884 status = read_status(dev); 885 if ((status & 0xf8) == 0x80) { 886 if (net_debug > 2) 887 printk(KERN_DEBUG "%s: reset interface.\n", dev->name); 888 nl->connection = PLIP_CN_NONE; 889 nl->should_relinquish = 0; 890 netif_start_queue (dev); 891 enable_parport_interrupts (dev); 892 ENABLE(dev->irq); 893 netif_wake_queue (dev); 894 } else { 895 nl->is_deferred = 1; 896 schedule_delayed_work(&nl->deferred, 1); 897 } 898 899 return OK; 900 } 901 902 /* Handle the parallel port interrupts. */ 903 static void 904 plip_interrupt(void *dev_id) 905 { 906 struct net_device *dev = dev_id; 907 struct net_local *nl; 908 struct plip_local *rcv; 909 unsigned char c0; 910 unsigned long flags; 911 912 nl = netdev_priv(dev); 913 rcv = &nl->rcv_data; 914 915 spin_lock_irqsave (&nl->lock, flags); 916 917 c0 = read_status(dev); 918 if ((c0 & 0xf8) != 0xc0) { 919 if ((dev->irq != -1) && (net_debug > 1)) 920 printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name); 921 spin_unlock_irqrestore (&nl->lock, flags); 922 return; 923 } 924 925 if (net_debug > 3) 926 printk(KERN_DEBUG "%s: interrupt.\n", dev->name); 927 928 switch (nl->connection) { 929 case PLIP_CN_CLOSING: 930 netif_wake_queue (dev); 931 case PLIP_CN_NONE: 932 case PLIP_CN_SEND: 933 rcv->state = PLIP_PK_TRIGGER; 934 nl->connection = PLIP_CN_RECEIVE; 935 nl->timeout_count = 0; 936 schedule_work(&nl->immediate); 937 break; 938 939 case PLIP_CN_RECEIVE: 940 /* May occur because there is race condition 941 around test and set of dev->interrupt. 942 Ignore this interrupt. */ 943 break; 944 945 case PLIP_CN_ERROR: 946 printk(KERN_ERR "%s: receive interrupt in error state\n", dev->name); 947 break; 948 } 949 950 spin_unlock_irqrestore(&nl->lock, flags); 951 } 952 953 static int 954 plip_tx_packet(struct sk_buff *skb, struct net_device *dev) 955 { 956 struct net_local *nl = netdev_priv(dev); 957 struct plip_local *snd = &nl->snd_data; 958 959 if (netif_queue_stopped(dev)) 960 return NETDEV_TX_BUSY; 961 962 /* We may need to grab the bus */ 963 if (!nl->port_owner) { 964 if (parport_claim(nl->pardev)) 965 return NETDEV_TX_BUSY; 966 nl->port_owner = 1; 967 } 968 969 netif_stop_queue (dev); 970 971 if (skb->len > dev->mtu + dev->hard_header_len) { 972 printk(KERN_WARNING "%s: packet too big, %d.\n", dev->name, (int)skb->len); 973 netif_start_queue (dev); 974 return NETDEV_TX_BUSY; 975 } 976 977 if (net_debug > 2) 978 printk(KERN_DEBUG "%s: send request\n", dev->name); 979 980 spin_lock_irq(&nl->lock); 981 snd->skb = skb; 982 snd->length.h = skb->len; 983 snd->state = PLIP_PK_TRIGGER; 984 if (nl->connection == PLIP_CN_NONE) { 985 nl->connection = PLIP_CN_SEND; 986 nl->timeout_count = 0; 987 } 988 schedule_work(&nl->immediate); 989 spin_unlock_irq(&nl->lock); 990 991 return NETDEV_TX_OK; 992 } 993 994 static void 995 plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth) 996 { 997 const struct in_device *in_dev; 998 999 rcu_read_lock(); 1000 in_dev = __in_dev_get_rcu(dev); 1001 if (in_dev) { 1002 /* Any address will do - we take the first */ 1003 const struct in_ifaddr *ifa = in_dev->ifa_list; 1004 if (ifa) { 1005 memcpy(eth->h_source, dev->dev_addr, 6); 1006 memset(eth->h_dest, 0xfc, 2); 1007 memcpy(eth->h_dest+2, &ifa->ifa_address, 4); 1008 } 1009 } 1010 rcu_read_unlock(); 1011 } 1012 1013 static int 1014 plip_hard_header(struct sk_buff *skb, struct net_device *dev, 1015 unsigned short type, const void *daddr, 1016 const void *saddr, unsigned len) 1017 { 1018 int ret; 1019 1020 ret = eth_header(skb, dev, type, daddr, saddr, len); 1021 if (ret >= 0) 1022 plip_rewrite_address (dev, (struct ethhdr *)skb->data); 1023 1024 return ret; 1025 } 1026 1027 static int plip_hard_header_cache(const struct neighbour *neigh, 1028 struct hh_cache *hh, __be16 type) 1029 { 1030 int ret; 1031 1032 ret = eth_header_cache(neigh, hh, type); 1033 if (ret == 0) { 1034 struct ethhdr *eth; 1035 1036 eth = (struct ethhdr*)(((u8*)hh->hh_data) + 1037 HH_DATA_OFF(sizeof(*eth))); 1038 plip_rewrite_address (neigh->dev, eth); 1039 } 1040 1041 return ret; 1042 } 1043 1044 /* Open/initialize the board. This is called (in the current kernel) 1045 sometime after booting when the 'ifconfig' program is run. 1046 1047 This routine gets exclusive access to the parallel port by allocating 1048 its IRQ line. 1049 */ 1050 static int 1051 plip_open(struct net_device *dev) 1052 { 1053 struct net_local *nl = netdev_priv(dev); 1054 struct in_device *in_dev; 1055 1056 /* Grab the port */ 1057 if (!nl->port_owner) { 1058 if (parport_claim(nl->pardev)) return -EAGAIN; 1059 nl->port_owner = 1; 1060 } 1061 1062 nl->should_relinquish = 0; 1063 1064 /* Clear the data port. */ 1065 write_data (dev, 0x00); 1066 1067 /* Enable rx interrupt. */ 1068 enable_parport_interrupts (dev); 1069 if (dev->irq == -1) 1070 { 1071 atomic_set (&nl->kill_timer, 0); 1072 schedule_delayed_work(&nl->timer, 1); 1073 } 1074 1075 /* Initialize the state machine. */ 1076 nl->rcv_data.state = nl->snd_data.state = PLIP_PK_DONE; 1077 nl->rcv_data.skb = nl->snd_data.skb = NULL; 1078 nl->connection = PLIP_CN_NONE; 1079 nl->is_deferred = 0; 1080 1081 /* Fill in the MAC-level header. 1082 We used to abuse dev->broadcast to store the point-to-point 1083 MAC address, but we no longer do it. Instead, we fetch the 1084 interface address whenever it is needed, which is cheap enough 1085 because we use the hh_cache. Actually, abusing dev->broadcast 1086 didn't work, because when using plip_open the point-to-point 1087 address isn't yet known. 1088 PLIP doesn't have a real MAC address, but we need it to be 1089 DOS compatible, and to properly support taps (otherwise, 1090 when the device address isn't identical to the address of a 1091 received frame, the kernel incorrectly drops it). */ 1092 1093 in_dev=__in_dev_get_rtnl(dev); 1094 if (in_dev) { 1095 /* Any address will do - we take the first. We already 1096 have the first two bytes filled with 0xfc, from 1097 plip_init_dev(). */ 1098 struct in_ifaddr *ifa=in_dev->ifa_list; 1099 if (ifa != NULL) { 1100 memcpy(dev->dev_addr+2, &ifa->ifa_local, 4); 1101 } 1102 } 1103 1104 netif_start_queue (dev); 1105 1106 return 0; 1107 } 1108 1109 /* The inverse routine to plip_open (). */ 1110 static int 1111 plip_close(struct net_device *dev) 1112 { 1113 struct net_local *nl = netdev_priv(dev); 1114 struct plip_local *snd = &nl->snd_data; 1115 struct plip_local *rcv = &nl->rcv_data; 1116 1117 netif_stop_queue (dev); 1118 DISABLE(dev->irq); 1119 synchronize_irq(dev->irq); 1120 1121 if (dev->irq == -1) 1122 { 1123 init_completion(&nl->killed_timer_cmp); 1124 atomic_set (&nl->kill_timer, 1); 1125 wait_for_completion(&nl->killed_timer_cmp); 1126 } 1127 1128 #ifdef NOTDEF 1129 outb(0x00, PAR_DATA(dev)); 1130 #endif 1131 nl->is_deferred = 0; 1132 nl->connection = PLIP_CN_NONE; 1133 if (nl->port_owner) { 1134 parport_release(nl->pardev); 1135 nl->port_owner = 0; 1136 } 1137 1138 snd->state = PLIP_PK_DONE; 1139 if (snd->skb) { 1140 dev_kfree_skb(snd->skb); 1141 snd->skb = NULL; 1142 } 1143 rcv->state = PLIP_PK_DONE; 1144 if (rcv->skb) { 1145 kfree_skb(rcv->skb); 1146 rcv->skb = NULL; 1147 } 1148 1149 #ifdef NOTDEF 1150 /* Reset. */ 1151 outb(0x00, PAR_CONTROL(dev)); 1152 #endif 1153 return 0; 1154 } 1155 1156 static int 1157 plip_preempt(void *handle) 1158 { 1159 struct net_device *dev = (struct net_device *)handle; 1160 struct net_local *nl = netdev_priv(dev); 1161 1162 /* Stand our ground if a datagram is on the wire */ 1163 if (nl->connection != PLIP_CN_NONE) { 1164 nl->should_relinquish = 1; 1165 return 1; 1166 } 1167 1168 nl->port_owner = 0; /* Remember that we released the bus */ 1169 return 0; 1170 } 1171 1172 static void 1173 plip_wakeup(void *handle) 1174 { 1175 struct net_device *dev = (struct net_device *)handle; 1176 struct net_local *nl = netdev_priv(dev); 1177 1178 if (nl->port_owner) { 1179 /* Why are we being woken up? */ 1180 printk(KERN_DEBUG "%s: why am I being woken up?\n", dev->name); 1181 if (!parport_claim(nl->pardev)) 1182 /* bus_owner is already set (but why?) */ 1183 printk(KERN_DEBUG "%s: I'm broken.\n", dev->name); 1184 else 1185 return; 1186 } 1187 1188 if (!(dev->flags & IFF_UP)) 1189 /* Don't need the port when the interface is down */ 1190 return; 1191 1192 if (!parport_claim(nl->pardev)) { 1193 nl->port_owner = 1; 1194 /* Clear the data port. */ 1195 write_data (dev, 0x00); 1196 } 1197 } 1198 1199 static int 1200 plip_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) 1201 { 1202 struct net_local *nl = netdev_priv(dev); 1203 struct plipconf *pc = (struct plipconf *) &rq->ifr_ifru; 1204 1205 if (cmd != SIOCDEVPLIP) 1206 return -EOPNOTSUPP; 1207 1208 switch(pc->pcmd) { 1209 case PLIP_GET_TIMEOUT: 1210 pc->trigger = nl->trigger; 1211 pc->nibble = nl->nibble; 1212 break; 1213 case PLIP_SET_TIMEOUT: 1214 if(!capable(CAP_NET_ADMIN)) 1215 return -EPERM; 1216 nl->trigger = pc->trigger; 1217 nl->nibble = pc->nibble; 1218 break; 1219 default: 1220 return -EOPNOTSUPP; 1221 } 1222 return 0; 1223 } 1224 1225 static int parport[PLIP_MAX] = { [0 ... PLIP_MAX-1] = -1 }; 1226 static int timid; 1227 1228 module_param_array(parport, int, NULL, 0); 1229 module_param(timid, int, 0); 1230 MODULE_PARM_DESC(parport, "List of parport device numbers to use by plip"); 1231 1232 static struct net_device *dev_plip[PLIP_MAX] = { NULL, }; 1233 1234 static inline int 1235 plip_searchfor(int list[], int a) 1236 { 1237 int i; 1238 for (i = 0; i < PLIP_MAX && list[i] != -1; i++) { 1239 if (list[i] == a) return 1; 1240 } 1241 return 0; 1242 } 1243 1244 /* plip_attach() is called (by the parport code) when a port is 1245 * available to use. */ 1246 static void plip_attach (struct parport *port) 1247 { 1248 static int unit; 1249 struct net_device *dev; 1250 struct net_local *nl; 1251 char name[IFNAMSIZ]; 1252 1253 if ((parport[0] == -1 && (!timid || !port->devices)) || 1254 plip_searchfor(parport, port->number)) { 1255 if (unit == PLIP_MAX) { 1256 printk(KERN_ERR "plip: too many devices\n"); 1257 return; 1258 } 1259 1260 sprintf(name, "plip%d", unit); 1261 dev = alloc_etherdev(sizeof(struct net_local)); 1262 if (!dev) 1263 return; 1264 1265 strcpy(dev->name, name); 1266 1267 dev->irq = port->irq; 1268 dev->base_addr = port->base; 1269 if (port->irq == -1) { 1270 printk(KERN_INFO "plip: %s has no IRQ. Using IRQ-less mode," 1271 "which is fairly inefficient!\n", port->name); 1272 } 1273 1274 nl = netdev_priv(dev); 1275 nl->dev = dev; 1276 nl->pardev = parport_register_device(port, dev->name, plip_preempt, 1277 plip_wakeup, plip_interrupt, 1278 0, dev); 1279 1280 if (!nl->pardev) { 1281 printk(KERN_ERR "%s: parport_register failed\n", name); 1282 goto err_free_dev; 1283 } 1284 1285 plip_init_netdev(dev); 1286 1287 if (register_netdev(dev)) { 1288 printk(KERN_ERR "%s: network register failed\n", name); 1289 goto err_parport_unregister; 1290 } 1291 1292 printk(KERN_INFO "%s", version); 1293 if (dev->irq != -1) 1294 printk(KERN_INFO "%s: Parallel port at %#3lx, " 1295 "using IRQ %d.\n", 1296 dev->name, dev->base_addr, dev->irq); 1297 else 1298 printk(KERN_INFO "%s: Parallel port at %#3lx, " 1299 "not using IRQ.\n", 1300 dev->name, dev->base_addr); 1301 dev_plip[unit++] = dev; 1302 } 1303 return; 1304 1305 err_parport_unregister: 1306 parport_unregister_device(nl->pardev); 1307 err_free_dev: 1308 free_netdev(dev); 1309 } 1310 1311 /* plip_detach() is called (by the parport code) when a port is 1312 * no longer available to use. */ 1313 static void plip_detach (struct parport *port) 1314 { 1315 /* Nothing to do */ 1316 } 1317 1318 static struct parport_driver plip_driver = { 1319 .name = "plip", 1320 .attach = plip_attach, 1321 .detach = plip_detach 1322 }; 1323 1324 static void __exit plip_cleanup_module (void) 1325 { 1326 struct net_device *dev; 1327 int i; 1328 1329 parport_unregister_driver (&plip_driver); 1330 1331 for (i=0; i < PLIP_MAX; i++) { 1332 if ((dev = dev_plip[i])) { 1333 struct net_local *nl = netdev_priv(dev); 1334 unregister_netdev(dev); 1335 if (nl->port_owner) 1336 parport_release(nl->pardev); 1337 parport_unregister_device(nl->pardev); 1338 free_netdev(dev); 1339 dev_plip[i] = NULL; 1340 } 1341 } 1342 } 1343 1344 #ifndef MODULE 1345 1346 static int parport_ptr; 1347 1348 static int __init plip_setup(char *str) 1349 { 1350 int ints[4]; 1351 1352 str = get_options(str, ARRAY_SIZE(ints), ints); 1353 1354 /* Ugh. */ 1355 if (!strncmp(str, "parport", 7)) { 1356 int n = simple_strtoul(str+7, NULL, 10); 1357 if (parport_ptr < PLIP_MAX) 1358 parport[parport_ptr++] = n; 1359 else 1360 printk(KERN_INFO "plip: too many ports, %s ignored.\n", 1361 str); 1362 } else if (!strcmp(str, "timid")) { 1363 timid = 1; 1364 } else { 1365 if (ints[0] == 0 || ints[1] == 0) { 1366 /* disable driver on "plip=" or "plip=0" */ 1367 parport[0] = -2; 1368 } else { 1369 printk(KERN_WARNING "warning: 'plip=0x%x' ignored\n", 1370 ints[1]); 1371 } 1372 } 1373 return 1; 1374 } 1375 1376 __setup("plip=", plip_setup); 1377 1378 #endif /* !MODULE */ 1379 1380 static int __init plip_init (void) 1381 { 1382 if (parport[0] == -2) 1383 return 0; 1384 1385 if (parport[0] != -1 && timid) { 1386 printk(KERN_WARNING "plip: warning, ignoring `timid' since specific ports given.\n"); 1387 timid = 0; 1388 } 1389 1390 if (parport_register_driver (&plip_driver)) { 1391 printk (KERN_WARNING "plip: couldn't register driver\n"); 1392 return 1; 1393 } 1394 1395 return 0; 1396 } 1397 1398 module_init(plip_init); 1399 module_exit(plip_cleanup_module); 1400 MODULE_LICENSE("GPL"); 1401