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 * Send feedback to <socketcan-users@lists.berlios.de> 44 * 45 */ 46 47 #include <linux/module.h> 48 #include <linux/init.h> 49 #include <linux/kernel.h> 50 #include <linux/sched.h> 51 #include <linux/types.h> 52 #include <linux/fcntl.h> 53 #include <linux/interrupt.h> 54 #include <linux/ptrace.h> 55 #include <linux/string.h> 56 #include <linux/errno.h> 57 #include <linux/netdevice.h> 58 #include <linux/if_arp.h> 59 #include <linux/if_ether.h> 60 #include <linux/skbuff.h> 61 #include <linux/delay.h> 62 63 #include <linux/can.h> 64 #include <linux/can/dev.h> 65 #include <linux/can/error.h> 66 67 #include "sja1000.h" 68 69 #define DRV_NAME "sja1000" 70 71 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); 72 MODULE_LICENSE("Dual BSD/GPL"); 73 MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver"); 74 75 static struct can_bittiming_const sja1000_bittiming_const = { 76 .name = DRV_NAME, 77 .tseg1_min = 1, 78 .tseg1_max = 16, 79 .tseg2_min = 1, 80 .tseg2_max = 8, 81 .sjw_max = 4, 82 .brp_min = 1, 83 .brp_max = 64, 84 .brp_inc = 1, 85 }; 86 87 static int sja1000_probe_chip(struct net_device *dev) 88 { 89 struct sja1000_priv *priv = netdev_priv(dev); 90 91 if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) { 92 printk(KERN_INFO "%s: probing @0x%lX failed\n", 93 DRV_NAME, dev->base_addr); 94 return 0; 95 } 96 return -1; 97 } 98 99 static void set_reset_mode(struct net_device *dev) 100 { 101 struct sja1000_priv *priv = netdev_priv(dev); 102 unsigned char status = priv->read_reg(priv, REG_MOD); 103 int i; 104 105 /* disable interrupts */ 106 priv->write_reg(priv, REG_IER, IRQ_OFF); 107 108 for (i = 0; i < 100; i++) { 109 /* check reset bit */ 110 if (status & MOD_RM) { 111 priv->can.state = CAN_STATE_STOPPED; 112 return; 113 } 114 115 priv->write_reg(priv, REG_MOD, MOD_RM); /* reset chip */ 116 udelay(10); 117 status = priv->read_reg(priv, REG_MOD); 118 } 119 120 dev_err(dev->dev.parent, "setting SJA1000 into reset mode failed!\n"); 121 } 122 123 static void set_normal_mode(struct net_device *dev) 124 { 125 struct sja1000_priv *priv = netdev_priv(dev); 126 unsigned char status = priv->read_reg(priv, REG_MOD); 127 int i; 128 129 for (i = 0; i < 100; i++) { 130 /* check reset bit */ 131 if ((status & MOD_RM) == 0) { 132 priv->can.state = CAN_STATE_ERROR_ACTIVE; 133 /* enable all interrupts */ 134 priv->write_reg(priv, REG_IER, IRQ_ALL); 135 return; 136 } 137 138 /* set chip to normal mode */ 139 priv->write_reg(priv, REG_MOD, 0x00); 140 udelay(10); 141 status = priv->read_reg(priv, REG_MOD); 142 } 143 144 dev_err(dev->dev.parent, "setting SJA1000 into normal mode failed!\n"); 145 } 146 147 static void sja1000_start(struct net_device *dev) 148 { 149 struct sja1000_priv *priv = netdev_priv(dev); 150 151 /* leave reset mode */ 152 if (priv->can.state != CAN_STATE_STOPPED) 153 set_reset_mode(dev); 154 155 /* Clear error counters and error code capture */ 156 priv->write_reg(priv, REG_TXERR, 0x0); 157 priv->write_reg(priv, REG_RXERR, 0x0); 158 priv->read_reg(priv, REG_ECC); 159 160 /* leave reset mode */ 161 set_normal_mode(dev); 162 } 163 164 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode) 165 { 166 struct sja1000_priv *priv = netdev_priv(dev); 167 168 if (!priv->open_time) 169 return -EINVAL; 170 171 switch (mode) { 172 case CAN_MODE_START: 173 sja1000_start(dev); 174 if (netif_queue_stopped(dev)) 175 netif_wake_queue(dev); 176 break; 177 178 default: 179 return -EOPNOTSUPP; 180 } 181 182 return 0; 183 } 184 185 static int sja1000_set_bittiming(struct net_device *dev) 186 { 187 struct sja1000_priv *priv = netdev_priv(dev); 188 struct can_bittiming *bt = &priv->can.bittiming; 189 u8 btr0, btr1; 190 191 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 192 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 193 (((bt->phase_seg2 - 1) & 0x7) << 4); 194 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 195 btr1 |= 0x80; 196 197 dev_info(dev->dev.parent, 198 "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 199 200 priv->write_reg(priv, REG_BTR0, btr0); 201 priv->write_reg(priv, REG_BTR1, btr1); 202 203 return 0; 204 } 205 206 /* 207 * initialize SJA1000 chip: 208 * - reset chip 209 * - set output mode 210 * - set baudrate 211 * - enable interrupts 212 * - start operating mode 213 */ 214 static void chipset_init(struct net_device *dev) 215 { 216 struct sja1000_priv *priv = netdev_priv(dev); 217 218 /* set clock divider and output control register */ 219 priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN); 220 221 /* set acceptance filter (accept all) */ 222 priv->write_reg(priv, REG_ACCC0, 0x00); 223 priv->write_reg(priv, REG_ACCC1, 0x00); 224 priv->write_reg(priv, REG_ACCC2, 0x00); 225 priv->write_reg(priv, REG_ACCC3, 0x00); 226 227 priv->write_reg(priv, REG_ACCM0, 0xFF); 228 priv->write_reg(priv, REG_ACCM1, 0xFF); 229 priv->write_reg(priv, REG_ACCM2, 0xFF); 230 priv->write_reg(priv, REG_ACCM3, 0xFF); 231 232 priv->write_reg(priv, REG_OCR, priv->ocr | OCR_MODE_NORMAL); 233 } 234 235 /* 236 * transmit a CAN message 237 * message layout in the sk_buff should be like this: 238 * xx xx xx xx ff ll 00 11 22 33 44 55 66 77 239 * [ can-id ] [flags] [len] [can data (up to 8 bytes] 240 */ 241 static int sja1000_start_xmit(struct sk_buff *skb, struct net_device *dev) 242 { 243 struct sja1000_priv *priv = netdev_priv(dev); 244 struct net_device_stats *stats = &dev->stats; 245 struct can_frame *cf = (struct can_frame *)skb->data; 246 uint8_t fi; 247 uint8_t dlc; 248 canid_t id; 249 uint8_t dreg; 250 int i; 251 252 netif_stop_queue(dev); 253 254 fi = dlc = cf->can_dlc; 255 id = cf->can_id; 256 257 if (id & CAN_RTR_FLAG) 258 fi |= FI_RTR; 259 260 if (id & CAN_EFF_FLAG) { 261 fi |= FI_FF; 262 dreg = EFF_BUF; 263 priv->write_reg(priv, REG_FI, fi); 264 priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16)); 265 priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8)); 266 priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5); 267 priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3); 268 } else { 269 dreg = SFF_BUF; 270 priv->write_reg(priv, REG_FI, fi); 271 priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3); 272 priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5); 273 } 274 275 for (i = 0; i < dlc; i++) 276 priv->write_reg(priv, dreg++, cf->data[i]); 277 278 stats->tx_bytes += dlc; 279 dev->trans_start = jiffies; 280 281 can_put_echo_skb(skb, dev, 0); 282 283 priv->write_reg(priv, REG_CMR, CMD_TR); 284 285 return 0; 286 } 287 288 static void sja1000_rx(struct net_device *dev) 289 { 290 struct sja1000_priv *priv = netdev_priv(dev); 291 struct net_device_stats *stats = &dev->stats; 292 struct can_frame *cf; 293 struct sk_buff *skb; 294 uint8_t fi; 295 uint8_t dreg; 296 canid_t id; 297 uint8_t dlc; 298 int i; 299 300 skb = dev_alloc_skb(sizeof(struct can_frame)); 301 if (skb == NULL) 302 return; 303 skb->dev = dev; 304 skb->protocol = htons(ETH_P_CAN); 305 306 fi = priv->read_reg(priv, REG_FI); 307 dlc = fi & 0x0F; 308 309 if (fi & FI_FF) { 310 /* extended frame format (EFF) */ 311 dreg = EFF_BUF; 312 id = (priv->read_reg(priv, REG_ID1) << (5 + 16)) 313 | (priv->read_reg(priv, REG_ID2) << (5 + 8)) 314 | (priv->read_reg(priv, REG_ID3) << 5) 315 | (priv->read_reg(priv, REG_ID4) >> 3); 316 id |= CAN_EFF_FLAG; 317 } else { 318 /* standard frame format (SFF) */ 319 dreg = SFF_BUF; 320 id = (priv->read_reg(priv, REG_ID1) << 3) 321 | (priv->read_reg(priv, REG_ID2) >> 5); 322 } 323 324 if (fi & FI_RTR) 325 id |= CAN_RTR_FLAG; 326 327 cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 328 memset(cf, 0, sizeof(struct can_frame)); 329 cf->can_id = id; 330 cf->can_dlc = dlc; 331 for (i = 0; i < dlc; i++) 332 cf->data[i] = priv->read_reg(priv, dreg++); 333 334 while (i < 8) 335 cf->data[i++] = 0; 336 337 /* release receive buffer */ 338 priv->write_reg(priv, REG_CMR, CMD_RRB); 339 340 netif_rx(skb); 341 342 dev->last_rx = jiffies; 343 stats->rx_packets++; 344 stats->rx_bytes += dlc; 345 } 346 347 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status) 348 { 349 struct sja1000_priv *priv = netdev_priv(dev); 350 struct net_device_stats *stats = &dev->stats; 351 struct can_frame *cf; 352 struct sk_buff *skb; 353 enum can_state state = priv->can.state; 354 uint8_t ecc, alc; 355 356 skb = dev_alloc_skb(sizeof(struct can_frame)); 357 if (skb == NULL) 358 return -ENOMEM; 359 skb->dev = dev; 360 skb->protocol = htons(ETH_P_CAN); 361 cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 362 memset(cf, 0, sizeof(struct can_frame)); 363 cf->can_id = CAN_ERR_FLAG; 364 cf->can_dlc = CAN_ERR_DLC; 365 366 if (isrc & IRQ_DOI) { 367 /* data overrun interrupt */ 368 dev_dbg(dev->dev.parent, "data overrun interrupt\n"); 369 cf->can_id |= CAN_ERR_CRTL; 370 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 371 stats->rx_over_errors++; 372 stats->rx_errors++; 373 priv->write_reg(priv, REG_CMR, CMD_CDO); /* clear bit */ 374 } 375 376 if (isrc & IRQ_EI) { 377 /* error warning interrupt */ 378 dev_dbg(dev->dev.parent, "error warning interrupt\n"); 379 380 if (status & SR_BS) { 381 state = CAN_STATE_BUS_OFF; 382 cf->can_id |= CAN_ERR_BUSOFF; 383 can_bus_off(dev); 384 } else if (status & SR_ES) { 385 state = CAN_STATE_ERROR_WARNING; 386 } else 387 state = CAN_STATE_ERROR_ACTIVE; 388 } 389 if (isrc & IRQ_BEI) { 390 /* bus error interrupt */ 391 priv->can.can_stats.bus_error++; 392 stats->rx_errors++; 393 394 ecc = priv->read_reg(priv, REG_ECC); 395 396 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 397 398 switch (ecc & ECC_MASK) { 399 case ECC_BIT: 400 cf->data[2] |= CAN_ERR_PROT_BIT; 401 break; 402 case ECC_FORM: 403 cf->data[2] |= CAN_ERR_PROT_FORM; 404 break; 405 case ECC_STUFF: 406 cf->data[2] |= CAN_ERR_PROT_STUFF; 407 break; 408 default: 409 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 410 cf->data[3] = ecc & ECC_SEG; 411 break; 412 } 413 /* Error occured during transmission? */ 414 if ((ecc & ECC_DIR) == 0) 415 cf->data[2] |= CAN_ERR_PROT_TX; 416 } 417 if (isrc & IRQ_EPI) { 418 /* error passive interrupt */ 419 dev_dbg(dev->dev.parent, "error passive interrupt\n"); 420 if (status & SR_ES) 421 state = CAN_STATE_ERROR_PASSIVE; 422 else 423 state = CAN_STATE_ERROR_ACTIVE; 424 } 425 if (isrc & IRQ_ALI) { 426 /* arbitration lost interrupt */ 427 dev_dbg(dev->dev.parent, "arbitration lost interrupt\n"); 428 alc = priv->read_reg(priv, REG_ALC); 429 priv->can.can_stats.arbitration_lost++; 430 stats->rx_errors++; 431 cf->can_id |= CAN_ERR_LOSTARB; 432 cf->data[0] = alc & 0x1f; 433 } 434 435 if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING || 436 state == CAN_STATE_ERROR_PASSIVE)) { 437 uint8_t rxerr = priv->read_reg(priv, REG_RXERR); 438 uint8_t txerr = priv->read_reg(priv, REG_TXERR); 439 cf->can_id |= CAN_ERR_CRTL; 440 if (state == CAN_STATE_ERROR_WARNING) { 441 priv->can.can_stats.error_warning++; 442 cf->data[1] = (txerr > rxerr) ? 443 CAN_ERR_CRTL_TX_WARNING : 444 CAN_ERR_CRTL_RX_WARNING; 445 } else { 446 priv->can.can_stats.error_passive++; 447 cf->data[1] = (txerr > rxerr) ? 448 CAN_ERR_CRTL_TX_PASSIVE : 449 CAN_ERR_CRTL_RX_PASSIVE; 450 } 451 } 452 453 priv->can.state = state; 454 455 netif_rx(skb); 456 457 dev->last_rx = jiffies; 458 stats->rx_packets++; 459 stats->rx_bytes += cf->can_dlc; 460 461 return 0; 462 } 463 464 irqreturn_t sja1000_interrupt(int irq, void *dev_id) 465 { 466 struct net_device *dev = (struct net_device *)dev_id; 467 struct sja1000_priv *priv = netdev_priv(dev); 468 struct net_device_stats *stats = &dev->stats; 469 uint8_t isrc, status; 470 int n = 0; 471 472 /* Shared interrupts and IRQ off? */ 473 if (priv->read_reg(priv, REG_IER) == IRQ_OFF) 474 return IRQ_NONE; 475 476 if (priv->pre_irq) 477 priv->pre_irq(priv); 478 479 while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) { 480 n++; 481 status = priv->read_reg(priv, REG_SR); 482 483 if (isrc & IRQ_WUI) 484 dev_warn(dev->dev.parent, "wakeup interrupt\n"); 485 486 if (isrc & IRQ_TI) { 487 /* transmission complete interrupt */ 488 stats->tx_packets++; 489 can_get_echo_skb(dev, 0); 490 netif_wake_queue(dev); 491 } 492 if (isrc & IRQ_RI) { 493 /* receive interrupt */ 494 while (status & SR_RBS) { 495 sja1000_rx(dev); 496 status = priv->read_reg(priv, REG_SR); 497 } 498 } 499 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) { 500 /* error interrupt */ 501 if (sja1000_err(dev, isrc, status)) 502 break; 503 } 504 } 505 506 if (priv->post_irq) 507 priv->post_irq(priv); 508 509 if (n >= SJA1000_MAX_IRQ) 510 dev_dbg(dev->dev.parent, "%d messages handled in ISR", n); 511 512 return (n) ? IRQ_HANDLED : IRQ_NONE; 513 } 514 EXPORT_SYMBOL_GPL(sja1000_interrupt); 515 516 static int sja1000_open(struct net_device *dev) 517 { 518 struct sja1000_priv *priv = netdev_priv(dev); 519 int err; 520 521 /* set chip into reset mode */ 522 set_reset_mode(dev); 523 524 /* common open */ 525 err = open_candev(dev); 526 if (err) 527 return err; 528 529 /* register interrupt handler, if not done by the device driver */ 530 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) { 531 err = request_irq(dev->irq, &sja1000_interrupt, priv->irq_flags, 532 dev->name, (void *)dev); 533 if (err) { 534 close_candev(dev); 535 return -EAGAIN; 536 } 537 } 538 539 /* init and start chi */ 540 sja1000_start(dev); 541 priv->open_time = jiffies; 542 543 netif_start_queue(dev); 544 545 return 0; 546 } 547 548 static int sja1000_close(struct net_device *dev) 549 { 550 struct sja1000_priv *priv = netdev_priv(dev); 551 552 netif_stop_queue(dev); 553 set_reset_mode(dev); 554 555 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) 556 free_irq(dev->irq, (void *)dev); 557 558 close_candev(dev); 559 560 priv->open_time = 0; 561 562 return 0; 563 } 564 565 struct net_device *alloc_sja1000dev(int sizeof_priv) 566 { 567 struct net_device *dev; 568 struct sja1000_priv *priv; 569 570 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv); 571 if (!dev) 572 return NULL; 573 574 priv = netdev_priv(dev); 575 576 priv->dev = dev; 577 priv->can.bittiming_const = &sja1000_bittiming_const; 578 priv->can.do_set_bittiming = sja1000_set_bittiming; 579 priv->can.do_set_mode = sja1000_set_mode; 580 581 if (sizeof_priv) 582 priv->priv = (void *)priv + sizeof(struct sja1000_priv); 583 584 return dev; 585 } 586 EXPORT_SYMBOL_GPL(alloc_sja1000dev); 587 588 void free_sja1000dev(struct net_device *dev) 589 { 590 free_candev(dev); 591 } 592 EXPORT_SYMBOL_GPL(free_sja1000dev); 593 594 static const struct net_device_ops sja1000_netdev_ops = { 595 .ndo_open = sja1000_open, 596 .ndo_stop = sja1000_close, 597 .ndo_start_xmit = sja1000_start_xmit, 598 }; 599 600 int register_sja1000dev(struct net_device *dev) 601 { 602 if (!sja1000_probe_chip(dev)) 603 return -ENODEV; 604 605 dev->flags |= IFF_ECHO; /* we support local echo */ 606 dev->netdev_ops = &sja1000_netdev_ops; 607 608 set_reset_mode(dev); 609 chipset_init(dev); 610 611 return register_candev(dev); 612 } 613 EXPORT_SYMBOL_GPL(register_sja1000dev); 614 615 void unregister_sja1000dev(struct net_device *dev) 616 { 617 set_reset_mode(dev); 618 unregister_candev(dev); 619 } 620 EXPORT_SYMBOL_GPL(unregister_sja1000dev); 621 622 static __init int sja1000_init(void) 623 { 624 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME); 625 626 return 0; 627 } 628 629 module_init(sja1000_init); 630 631 static __exit void sja1000_exit(void) 632 { 633 printk(KERN_INFO "%s: driver removed\n", DRV_NAME); 634 } 635 636 module_exit(sja1000_exit); 637