sja1000.c revision aabdfd6adb804d0aaba0188ade0f1afe42a52e31
1/* 2 * sja1000.c - Philips SJA1000 network device driver 3 * 4 * Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33, 5 * 38106 Braunschweig, GERMANY 6 * 7 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of Volkswagen nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * Alternatively, provided that this notice is retained in full, this 23 * software may be distributed under the terms of the GNU General 24 * Public License ("GPL") version 2, in which case the provisions of the 25 * GPL apply INSTEAD OF those given above. 26 * 27 * The provided data structures and external interfaces from this code 28 * are not restricted to be used by modules with a GPL compatible license. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 31 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 32 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 33 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 34 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 36 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 40 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 41 * DAMAGE. 42 * 43 */ 44 45#include <linux/module.h> 46#include <linux/init.h> 47#include <linux/kernel.h> 48#include <linux/sched.h> 49#include <linux/types.h> 50#include <linux/fcntl.h> 51#include <linux/interrupt.h> 52#include <linux/ptrace.h> 53#include <linux/string.h> 54#include <linux/errno.h> 55#include <linux/netdevice.h> 56#include <linux/if_arp.h> 57#include <linux/if_ether.h> 58#include <linux/skbuff.h> 59#include <linux/delay.h> 60 61#include <linux/can/dev.h> 62#include <linux/can/error.h> 63 64#include "sja1000.h" 65 66#define DRV_NAME "sja1000" 67 68MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 69MODULE_LICENSE("Dual BSD/GPL"); 70MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver"); 71 72static struct can_bittiming_const sja1000_bittiming_const = { 73 .name = DRV_NAME, 74 .tseg1_min = 1, 75 .tseg1_max = 16, 76 .tseg2_min = 1, 77 .tseg2_max = 8, 78 .sjw_max = 4, 79 .brp_min = 1, 80 .brp_max = 64, 81 .brp_inc = 1, 82}; 83 84static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val) 85{ 86 unsigned long flags; 87 88 /* 89 * The command register needs some locking and time to settle 90 * the write_reg() operation - especially on SMP systems. 91 */ 92 spin_lock_irqsave(&priv->cmdreg_lock, flags); 93 priv->write_reg(priv, REG_CMR, val); 94 priv->read_reg(priv, REG_SR); 95 spin_unlock_irqrestore(&priv->cmdreg_lock, flags); 96} 97 98static int sja1000_probe_chip(struct net_device *dev) 99{ 100 struct sja1000_priv *priv = netdev_priv(dev); 101 102 if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) { 103 printk(KERN_INFO "%s: probing @0x%lX failed\n", 104 DRV_NAME, dev->base_addr); 105 return 0; 106 } 107 return -1; 108} 109 110static void set_reset_mode(struct net_device *dev) 111{ 112 struct sja1000_priv *priv = netdev_priv(dev); 113 unsigned char status = priv->read_reg(priv, REG_MOD); 114 int i; 115 116 /* disable interrupts */ 117 priv->write_reg(priv, REG_IER, IRQ_OFF); 118 119 for (i = 0; i < 100; i++) { 120 /* check reset bit */ 121 if (status & MOD_RM) { 122 priv->can.state = CAN_STATE_STOPPED; 123 return; 124 } 125 126 priv->write_reg(priv, REG_MOD, MOD_RM); /* reset chip */ 127 udelay(10); 128 status = priv->read_reg(priv, REG_MOD); 129 } 130 131 netdev_err(dev, "setting SJA1000 into reset mode failed!\n"); 132} 133 134static void set_normal_mode(struct net_device *dev) 135{ 136 struct sja1000_priv *priv = netdev_priv(dev); 137 unsigned char status = priv->read_reg(priv, REG_MOD); 138 int i; 139 140 for (i = 0; i < 100; i++) { 141 /* check reset bit */ 142 if ((status & MOD_RM) == 0) { 143 priv->can.state = CAN_STATE_ERROR_ACTIVE; 144 /* enable interrupts */ 145 if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) 146 priv->write_reg(priv, REG_IER, IRQ_ALL); 147 else 148 priv->write_reg(priv, REG_IER, 149 IRQ_ALL & ~IRQ_BEI); 150 return; 151 } 152 153 /* set chip to normal mode */ 154 priv->write_reg(priv, REG_MOD, 0x00); 155 udelay(10); 156 status = priv->read_reg(priv, REG_MOD); 157 } 158 159 netdev_err(dev, "setting SJA1000 into normal mode failed!\n"); 160} 161 162static void sja1000_start(struct net_device *dev) 163{ 164 struct sja1000_priv *priv = netdev_priv(dev); 165 166 /* leave reset mode */ 167 if (priv->can.state != CAN_STATE_STOPPED) 168 set_reset_mode(dev); 169 170 /* Clear error counters and error code capture */ 171 priv->write_reg(priv, REG_TXERR, 0x0); 172 priv->write_reg(priv, REG_RXERR, 0x0); 173 priv->read_reg(priv, REG_ECC); 174 175 /* leave reset mode */ 176 set_normal_mode(dev); 177} 178 179static int sja1000_set_mode(struct net_device *dev, enum can_mode mode) 180{ 181 struct sja1000_priv *priv = netdev_priv(dev); 182 183 if (!priv->open_time) 184 return -EINVAL; 185 186 switch (mode) { 187 case CAN_MODE_START: 188 sja1000_start(dev); 189 if (netif_queue_stopped(dev)) 190 netif_wake_queue(dev); 191 break; 192 193 default: 194 return -EOPNOTSUPP; 195 } 196 197 return 0; 198} 199 200static int sja1000_set_bittiming(struct net_device *dev) 201{ 202 struct sja1000_priv *priv = netdev_priv(dev); 203 struct can_bittiming *bt = &priv->can.bittiming; 204 u8 btr0, btr1; 205 206 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 207 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 208 (((bt->phase_seg2 - 1) & 0x7) << 4); 209 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 210 btr1 |= 0x80; 211 212 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 213 214 priv->write_reg(priv, REG_BTR0, btr0); 215 priv->write_reg(priv, REG_BTR1, btr1); 216 217 return 0; 218} 219 220static int sja1000_get_berr_counter(const struct net_device *dev, 221 struct can_berr_counter *bec) 222{ 223 struct sja1000_priv *priv = netdev_priv(dev); 224 225 bec->txerr = priv->read_reg(priv, REG_TXERR); 226 bec->rxerr = priv->read_reg(priv, REG_RXERR); 227 228 return 0; 229} 230 231/* 232 * initialize SJA1000 chip: 233 * - reset chip 234 * - set output mode 235 * - set baudrate 236 * - enable interrupts 237 * - start operating mode 238 */ 239static void chipset_init(struct net_device *dev) 240{ 241 struct sja1000_priv *priv = netdev_priv(dev); 242 243 /* set clock divider and output control register */ 244 priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN); 245 246 /* set acceptance filter (accept all) */ 247 priv->write_reg(priv, REG_ACCC0, 0x00); 248 priv->write_reg(priv, REG_ACCC1, 0x00); 249 priv->write_reg(priv, REG_ACCC2, 0x00); 250 priv->write_reg(priv, REG_ACCC3, 0x00); 251 252 priv->write_reg(priv, REG_ACCM0, 0xFF); 253 priv->write_reg(priv, REG_ACCM1, 0xFF); 254 priv->write_reg(priv, REG_ACCM2, 0xFF); 255 priv->write_reg(priv, REG_ACCM3, 0xFF); 256 257 priv->write_reg(priv, REG_OCR, priv->ocr | OCR_MODE_NORMAL); 258} 259 260/* 261 * transmit a CAN message 262 * message layout in the sk_buff should be like this: 263 * xx xx xx xx ff ll 00 11 22 33 44 55 66 77 264 * [ can-id ] [flags] [len] [can data (up to 8 bytes] 265 */ 266static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb, 267 struct net_device *dev) 268{ 269 struct sja1000_priv *priv = netdev_priv(dev); 270 struct can_frame *cf = (struct can_frame *)skb->data; 271 uint8_t fi; 272 uint8_t dlc; 273 canid_t id; 274 uint8_t dreg; 275 int i; 276 277 if (can_dropped_invalid_skb(dev, skb)) 278 return NETDEV_TX_OK; 279 280 netif_stop_queue(dev); 281 282 fi = dlc = cf->can_dlc; 283 id = cf->can_id; 284 285 if (id & CAN_RTR_FLAG) 286 fi |= FI_RTR; 287 288 if (id & CAN_EFF_FLAG) { 289 fi |= FI_FF; 290 dreg = EFF_BUF; 291 priv->write_reg(priv, REG_FI, fi); 292 priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16)); 293 priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8)); 294 priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5); 295 priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3); 296 } else { 297 dreg = SFF_BUF; 298 priv->write_reg(priv, REG_FI, fi); 299 priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3); 300 priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5); 301 } 302 303 for (i = 0; i < dlc; i++) 304 priv->write_reg(priv, dreg++, cf->data[i]); 305 306 can_put_echo_skb(skb, dev, 0); 307 308 sja1000_write_cmdreg(priv, CMD_TR); 309 310 return NETDEV_TX_OK; 311} 312 313static void sja1000_rx(struct net_device *dev) 314{ 315 struct sja1000_priv *priv = netdev_priv(dev); 316 struct net_device_stats *stats = &dev->stats; 317 struct can_frame *cf; 318 struct sk_buff *skb; 319 uint8_t fi; 320 uint8_t dreg; 321 canid_t id; 322 int i; 323 324 /* create zero'ed CAN frame buffer */ 325 skb = alloc_can_skb(dev, &cf); 326 if (skb == NULL) 327 return; 328 329 fi = priv->read_reg(priv, REG_FI); 330 331 if (fi & FI_FF) { 332 /* extended frame format (EFF) */ 333 dreg = EFF_BUF; 334 id = (priv->read_reg(priv, REG_ID1) << (5 + 16)) 335 | (priv->read_reg(priv, REG_ID2) << (5 + 8)) 336 | (priv->read_reg(priv, REG_ID3) << 5) 337 | (priv->read_reg(priv, REG_ID4) >> 3); 338 id |= CAN_EFF_FLAG; 339 } else { 340 /* standard frame format (SFF) */ 341 dreg = SFF_BUF; 342 id = (priv->read_reg(priv, REG_ID1) << 3) 343 | (priv->read_reg(priv, REG_ID2) >> 5); 344 } 345 346 cf->can_dlc = get_can_dlc(fi & 0x0F); 347 if (fi & FI_RTR) { 348 id |= CAN_RTR_FLAG; 349 } else { 350 for (i = 0; i < cf->can_dlc; i++) 351 cf->data[i] = priv->read_reg(priv, dreg++); 352 } 353 354 cf->can_id = id; 355 356 /* release receive buffer */ 357 sja1000_write_cmdreg(priv, CMD_RRB); 358 359 netif_rx(skb); 360 361 stats->rx_packets++; 362 stats->rx_bytes += cf->can_dlc; 363} 364 365static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status) 366{ 367 struct sja1000_priv *priv = netdev_priv(dev); 368 struct net_device_stats *stats = &dev->stats; 369 struct can_frame *cf; 370 struct sk_buff *skb; 371 enum can_state state = priv->can.state; 372 uint8_t ecc, alc; 373 374 skb = alloc_can_err_skb(dev, &cf); 375 if (skb == NULL) 376 return -ENOMEM; 377 378 if (isrc & IRQ_DOI) { 379 /* data overrun interrupt */ 380 netdev_dbg(dev, "data overrun interrupt\n"); 381 cf->can_id |= CAN_ERR_CRTL; 382 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 383 stats->rx_over_errors++; 384 stats->rx_errors++; 385 sja1000_write_cmdreg(priv, CMD_CDO); /* clear bit */ 386 } 387 388 if (isrc & IRQ_EI) { 389 /* error warning interrupt */ 390 netdev_dbg(dev, "error warning interrupt\n"); 391 392 if (status & SR_BS) { 393 state = CAN_STATE_BUS_OFF; 394 cf->can_id |= CAN_ERR_BUSOFF; 395 can_bus_off(dev); 396 } else if (status & SR_ES) { 397 state = CAN_STATE_ERROR_WARNING; 398 } else 399 state = CAN_STATE_ERROR_ACTIVE; 400 } 401 if (isrc & IRQ_BEI) { 402 /* bus error interrupt */ 403 priv->can.can_stats.bus_error++; 404 stats->rx_errors++; 405 406 ecc = priv->read_reg(priv, REG_ECC); 407 408 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 409 410 switch (ecc & ECC_MASK) { 411 case ECC_BIT: 412 cf->data[2] |= CAN_ERR_PROT_BIT; 413 break; 414 case ECC_FORM: 415 cf->data[2] |= CAN_ERR_PROT_FORM; 416 break; 417 case ECC_STUFF: 418 cf->data[2] |= CAN_ERR_PROT_STUFF; 419 break; 420 default: 421 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 422 cf->data[3] = ecc & ECC_SEG; 423 break; 424 } 425 /* Error occurred during transmission? */ 426 if ((ecc & ECC_DIR) == 0) 427 cf->data[2] |= CAN_ERR_PROT_TX; 428 } 429 if (isrc & IRQ_EPI) { 430 /* error passive interrupt */ 431 netdev_dbg(dev, "error passive interrupt\n"); 432 if (status & SR_ES) 433 state = CAN_STATE_ERROR_PASSIVE; 434 else 435 state = CAN_STATE_ERROR_ACTIVE; 436 } 437 if (isrc & IRQ_ALI) { 438 /* arbitration lost interrupt */ 439 netdev_dbg(dev, "arbitration lost interrupt\n"); 440 alc = priv->read_reg(priv, REG_ALC); 441 priv->can.can_stats.arbitration_lost++; 442 stats->tx_errors++; 443 cf->can_id |= CAN_ERR_LOSTARB; 444 cf->data[0] = alc & 0x1f; 445 } 446 447 if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING || 448 state == CAN_STATE_ERROR_PASSIVE)) { 449 uint8_t rxerr = priv->read_reg(priv, REG_RXERR); 450 uint8_t txerr = priv->read_reg(priv, REG_TXERR); 451 cf->can_id |= CAN_ERR_CRTL; 452 if (state == CAN_STATE_ERROR_WARNING) { 453 priv->can.can_stats.error_warning++; 454 cf->data[1] = (txerr > rxerr) ? 455 CAN_ERR_CRTL_TX_WARNING : 456 CAN_ERR_CRTL_RX_WARNING; 457 } else { 458 priv->can.can_stats.error_passive++; 459 cf->data[1] = (txerr > rxerr) ? 460 CAN_ERR_CRTL_TX_PASSIVE : 461 CAN_ERR_CRTL_RX_PASSIVE; 462 } 463 cf->data[6] = txerr; 464 cf->data[7] = rxerr; 465 } 466 467 priv->can.state = state; 468 469 netif_rx(skb); 470 471 stats->rx_packets++; 472 stats->rx_bytes += cf->can_dlc; 473 474 return 0; 475} 476 477irqreturn_t sja1000_interrupt(int irq, void *dev_id) 478{ 479 struct net_device *dev = (struct net_device *)dev_id; 480 struct sja1000_priv *priv = netdev_priv(dev); 481 struct net_device_stats *stats = &dev->stats; 482 uint8_t isrc, status; 483 int n = 0; 484 485 /* Shared interrupts and IRQ off? */ 486 if (priv->read_reg(priv, REG_IER) == IRQ_OFF) 487 return IRQ_NONE; 488 489 if (priv->pre_irq) 490 priv->pre_irq(priv); 491 492 while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) { 493 n++; 494 status = priv->read_reg(priv, REG_SR); 495 496 if (isrc & IRQ_WUI) 497 netdev_warn(dev, "wakeup interrupt\n"); 498 499 if (isrc & IRQ_TI) { 500 /* transmission complete interrupt */ 501 stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf; 502 stats->tx_packets++; 503 can_get_echo_skb(dev, 0); 504 netif_wake_queue(dev); 505 } 506 if (isrc & IRQ_RI) { 507 /* receive interrupt */ 508 while (status & SR_RBS) { 509 sja1000_rx(dev); 510 status = priv->read_reg(priv, REG_SR); 511 } 512 } 513 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) { 514 /* error interrupt */ 515 if (sja1000_err(dev, isrc, status)) 516 break; 517 } 518 } 519 520 if (priv->post_irq) 521 priv->post_irq(priv); 522 523 if (n >= SJA1000_MAX_IRQ) 524 netdev_dbg(dev, "%d messages handled in ISR", n); 525 526 return (n) ? IRQ_HANDLED : IRQ_NONE; 527} 528EXPORT_SYMBOL_GPL(sja1000_interrupt); 529 530static int sja1000_open(struct net_device *dev) 531{ 532 struct sja1000_priv *priv = netdev_priv(dev); 533 int err; 534 535 /* set chip into reset mode */ 536 set_reset_mode(dev); 537 538 /* common open */ 539 err = open_candev(dev); 540 if (err) 541 return err; 542 543 /* register interrupt handler, if not done by the device driver */ 544 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) { 545 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags, 546 dev->name, (void *)dev); 547 if (err) { 548 close_candev(dev); 549 return -EAGAIN; 550 } 551 } 552 553 /* init and start chi */ 554 sja1000_start(dev); 555 priv->open_time = jiffies; 556 557 netif_start_queue(dev); 558 559 return 0; 560} 561 562static int sja1000_close(struct net_device *dev) 563{ 564 struct sja1000_priv *priv = netdev_priv(dev); 565 566 netif_stop_queue(dev); 567 set_reset_mode(dev); 568 569 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) 570 free_irq(dev->irq, (void *)dev); 571 572 close_candev(dev); 573 574 priv->open_time = 0; 575 576 return 0; 577} 578 579struct net_device *alloc_sja1000dev(int sizeof_priv) 580{ 581 struct net_device *dev; 582 struct sja1000_priv *priv; 583 584 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv, 585 SJA1000_ECHO_SKB_MAX); 586 if (!dev) 587 return NULL; 588 589 priv = netdev_priv(dev); 590 591 priv->dev = dev; 592 priv->can.bittiming_const = &sja1000_bittiming_const; 593 priv->can.do_set_bittiming = sja1000_set_bittiming; 594 priv->can.do_set_mode = sja1000_set_mode; 595 priv->can.do_get_berr_counter = sja1000_get_berr_counter; 596 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | 597 CAN_CTRLMODE_BERR_REPORTING; 598 599 spin_lock_init(&priv->cmdreg_lock); 600 601 if (sizeof_priv) 602 priv->priv = (void *)priv + sizeof(struct sja1000_priv); 603 604 return dev; 605} 606EXPORT_SYMBOL_GPL(alloc_sja1000dev); 607 608void free_sja1000dev(struct net_device *dev) 609{ 610 free_candev(dev); 611} 612EXPORT_SYMBOL_GPL(free_sja1000dev); 613 614static const struct net_device_ops sja1000_netdev_ops = { 615 .ndo_open = sja1000_open, 616 .ndo_stop = sja1000_close, 617 .ndo_start_xmit = sja1000_start_xmit, 618}; 619 620int register_sja1000dev(struct net_device *dev) 621{ 622 if (!sja1000_probe_chip(dev)) 623 return -ENODEV; 624 625 dev->flags |= IFF_ECHO; /* we support local echo */ 626 dev->netdev_ops = &sja1000_netdev_ops; 627 628 set_reset_mode(dev); 629 chipset_init(dev); 630 631 return register_candev(dev); 632} 633EXPORT_SYMBOL_GPL(register_sja1000dev); 634 635void unregister_sja1000dev(struct net_device *dev) 636{ 637 set_reset_mode(dev); 638 unregister_candev(dev); 639} 640EXPORT_SYMBOL_GPL(unregister_sja1000dev); 641 642static __init int sja1000_init(void) 643{ 644 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME); 645 646 return 0; 647} 648 649module_init(sja1000_init); 650 651static __exit void sja1000_exit(void) 652{ 653 printk(KERN_INFO "%s: driver removed\n", DRV_NAME); 654} 655 656module_exit(sja1000_exit); 657