2 * sja1000.c - Philips SJA1000 network device driver
4 * Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
5 * 38106 Braunschweig, GERMANY
7 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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.
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.
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
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>
61 #include <linux/can/dev.h>
62 #include <linux/can/error.h>
66 #define DRV_NAME "sja1000"
68 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
69 MODULE_LICENSE("Dual BSD/GPL");
70 MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
72 static const struct can_bittiming_const sja1000_bittiming_const = {
84 static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
89 * The command register needs some locking and time to settle
90 * the write_reg() operation - especially on SMP systems.
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);
98 static int sja1000_is_absent(struct sja1000_priv *priv)
100 return (priv->read_reg(priv, REG_MOD) == 0xFF);
103 static int sja1000_probe_chip(struct net_device *dev)
105 struct sja1000_priv *priv = netdev_priv(dev);
107 if (priv->reg_base && sja1000_is_absent(priv)) {
108 printk(KERN_INFO "%s: probing @0x%lX failed\n",
109 DRV_NAME, dev->base_addr);
115 static void set_reset_mode(struct net_device *dev)
117 struct sja1000_priv *priv = netdev_priv(dev);
118 unsigned char status = priv->read_reg(priv, REG_MOD);
121 /* disable interrupts */
122 priv->write_reg(priv, REG_IER, IRQ_OFF);
124 for (i = 0; i < 100; i++) {
125 /* check reset bit */
126 if (status & MOD_RM) {
127 priv->can.state = CAN_STATE_STOPPED;
131 priv->write_reg(priv, REG_MOD, MOD_RM); /* reset chip */
133 status = priv->read_reg(priv, REG_MOD);
136 netdev_err(dev, "setting SJA1000 into reset mode failed!\n");
139 static void set_normal_mode(struct net_device *dev)
141 struct sja1000_priv *priv = netdev_priv(dev);
142 unsigned char status = priv->read_reg(priv, REG_MOD);
145 for (i = 0; i < 100; i++) {
146 /* check reset bit */
147 if ((status & MOD_RM) == 0) {
148 priv->can.state = CAN_STATE_ERROR_ACTIVE;
149 /* enable interrupts */
150 if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
151 priv->write_reg(priv, REG_IER, IRQ_ALL);
153 priv->write_reg(priv, REG_IER,
158 /* set chip to normal mode */
159 priv->write_reg(priv, REG_MOD, 0x00);
161 status = priv->read_reg(priv, REG_MOD);
164 netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
167 static void sja1000_start(struct net_device *dev)
169 struct sja1000_priv *priv = netdev_priv(dev);
171 /* leave reset mode */
172 if (priv->can.state != CAN_STATE_STOPPED)
175 /* Clear error counters and error code capture */
176 priv->write_reg(priv, REG_TXERR, 0x0);
177 priv->write_reg(priv, REG_RXERR, 0x0);
178 priv->read_reg(priv, REG_ECC);
180 /* leave reset mode */
181 set_normal_mode(dev);
184 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
186 struct sja1000_priv *priv = netdev_priv(dev);
188 if (!priv->open_time)
194 if (netif_queue_stopped(dev))
195 netif_wake_queue(dev);
205 static int sja1000_set_bittiming(struct net_device *dev)
207 struct sja1000_priv *priv = netdev_priv(dev);
208 struct can_bittiming *bt = &priv->can.bittiming;
211 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
212 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
213 (((bt->phase_seg2 - 1) & 0x7) << 4);
214 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
217 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
219 priv->write_reg(priv, REG_BTR0, btr0);
220 priv->write_reg(priv, REG_BTR1, btr1);
225 static int sja1000_get_berr_counter(const struct net_device *dev,
226 struct can_berr_counter *bec)
228 struct sja1000_priv *priv = netdev_priv(dev);
230 bec->txerr = priv->read_reg(priv, REG_TXERR);
231 bec->rxerr = priv->read_reg(priv, REG_RXERR);
237 * initialize SJA1000 chip:
241 * - enable interrupts
242 * - start operating mode
244 static void chipset_init(struct net_device *dev)
246 struct sja1000_priv *priv = netdev_priv(dev);
248 /* set clock divider and output control register */
249 priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN);
251 /* set acceptance filter (accept all) */
252 priv->write_reg(priv, REG_ACCC0, 0x00);
253 priv->write_reg(priv, REG_ACCC1, 0x00);
254 priv->write_reg(priv, REG_ACCC2, 0x00);
255 priv->write_reg(priv, REG_ACCC3, 0x00);
257 priv->write_reg(priv, REG_ACCM0, 0xFF);
258 priv->write_reg(priv, REG_ACCM1, 0xFF);
259 priv->write_reg(priv, REG_ACCM2, 0xFF);
260 priv->write_reg(priv, REG_ACCM3, 0xFF);
262 priv->write_reg(priv, REG_OCR, priv->ocr | OCR_MODE_NORMAL);
266 * transmit a CAN message
267 * message layout in the sk_buff should be like this:
268 * xx xx xx xx ff ll 00 11 22 33 44 55 66 77
269 * [ can-id ] [flags] [len] [can data (up to 8 bytes]
271 static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
272 struct net_device *dev)
274 struct sja1000_priv *priv = netdev_priv(dev);
275 struct can_frame *cf = (struct can_frame *)skb->data;
282 if (can_dropped_invalid_skb(dev, skb))
285 netif_stop_queue(dev);
287 fi = dlc = cf->can_dlc;
290 if (id & CAN_RTR_FLAG)
293 if (id & CAN_EFF_FLAG) {
296 priv->write_reg(priv, REG_FI, fi);
297 priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
298 priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
299 priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
300 priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
303 priv->write_reg(priv, REG_FI, fi);
304 priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
305 priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
308 for (i = 0; i < dlc; i++)
309 priv->write_reg(priv, dreg++, cf->data[i]);
311 can_put_echo_skb(skb, dev, 0);
313 sja1000_write_cmdreg(priv, CMD_TR);
318 static void sja1000_rx(struct net_device *dev)
320 struct sja1000_priv *priv = netdev_priv(dev);
321 struct net_device_stats *stats = &dev->stats;
322 struct can_frame *cf;
329 /* create zero'ed CAN frame buffer */
330 skb = alloc_can_skb(dev, &cf);
334 fi = priv->read_reg(priv, REG_FI);
337 /* extended frame format (EFF) */
339 id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
340 | (priv->read_reg(priv, REG_ID2) << (5 + 8))
341 | (priv->read_reg(priv, REG_ID3) << 5)
342 | (priv->read_reg(priv, REG_ID4) >> 3);
345 /* standard frame format (SFF) */
347 id = (priv->read_reg(priv, REG_ID1) << 3)
348 | (priv->read_reg(priv, REG_ID2) >> 5);
351 cf->can_dlc = get_can_dlc(fi & 0x0F);
355 for (i = 0; i < cf->can_dlc; i++)
356 cf->data[i] = priv->read_reg(priv, dreg++);
361 /* release receive buffer */
362 sja1000_write_cmdreg(priv, CMD_RRB);
367 stats->rx_bytes += cf->can_dlc;
370 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
372 struct sja1000_priv *priv = netdev_priv(dev);
373 struct net_device_stats *stats = &dev->stats;
374 struct can_frame *cf;
376 enum can_state state = priv->can.state;
379 skb = alloc_can_err_skb(dev, &cf);
383 if (isrc & IRQ_DOI) {
384 /* data overrun interrupt */
385 netdev_dbg(dev, "data overrun interrupt\n");
386 cf->can_id |= CAN_ERR_CRTL;
387 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
388 stats->rx_over_errors++;
390 sja1000_write_cmdreg(priv, CMD_CDO); /* clear bit */
394 /* error warning interrupt */
395 netdev_dbg(dev, "error warning interrupt\n");
397 if (status & SR_BS) {
398 state = CAN_STATE_BUS_OFF;
399 cf->can_id |= CAN_ERR_BUSOFF;
401 } else if (status & SR_ES) {
402 state = CAN_STATE_ERROR_WARNING;
404 state = CAN_STATE_ERROR_ACTIVE;
406 if (isrc & IRQ_BEI) {
407 /* bus error interrupt */
408 priv->can.can_stats.bus_error++;
411 ecc = priv->read_reg(priv, REG_ECC);
413 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
415 switch (ecc & ECC_MASK) {
417 cf->data[2] |= CAN_ERR_PROT_BIT;
420 cf->data[2] |= CAN_ERR_PROT_FORM;
423 cf->data[2] |= CAN_ERR_PROT_STUFF;
426 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
427 cf->data[3] = ecc & ECC_SEG;
430 /* Error occurred during transmission? */
431 if ((ecc & ECC_DIR) == 0)
432 cf->data[2] |= CAN_ERR_PROT_TX;
434 if (isrc & IRQ_EPI) {
435 /* error passive interrupt */
436 netdev_dbg(dev, "error passive interrupt\n");
438 state = CAN_STATE_ERROR_PASSIVE;
440 state = CAN_STATE_ERROR_ACTIVE;
442 if (isrc & IRQ_ALI) {
443 /* arbitration lost interrupt */
444 netdev_dbg(dev, "arbitration lost interrupt\n");
445 alc = priv->read_reg(priv, REG_ALC);
446 priv->can.can_stats.arbitration_lost++;
448 cf->can_id |= CAN_ERR_LOSTARB;
449 cf->data[0] = alc & 0x1f;
452 if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
453 state == CAN_STATE_ERROR_PASSIVE)) {
454 uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
455 uint8_t txerr = priv->read_reg(priv, REG_TXERR);
456 cf->can_id |= CAN_ERR_CRTL;
457 if (state == CAN_STATE_ERROR_WARNING) {
458 priv->can.can_stats.error_warning++;
459 cf->data[1] = (txerr > rxerr) ?
460 CAN_ERR_CRTL_TX_WARNING :
461 CAN_ERR_CRTL_RX_WARNING;
463 priv->can.can_stats.error_passive++;
464 cf->data[1] = (txerr > rxerr) ?
465 CAN_ERR_CRTL_TX_PASSIVE :
466 CAN_ERR_CRTL_RX_PASSIVE;
472 priv->can.state = state;
477 stats->rx_bytes += cf->can_dlc;
482 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
484 struct net_device *dev = (struct net_device *)dev_id;
485 struct sja1000_priv *priv = netdev_priv(dev);
486 struct net_device_stats *stats = &dev->stats;
487 uint8_t isrc, status;
490 /* Shared interrupts and IRQ off? */
491 if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
497 while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
499 status = priv->read_reg(priv, REG_SR);
500 /* check for absent controller due to hw unplug */
501 if (status == 0xFF && sja1000_is_absent(priv))
505 netdev_warn(dev, "wakeup interrupt\n");
508 /* transmission complete interrupt */
509 stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf;
511 can_get_echo_skb(dev, 0);
512 netif_wake_queue(dev);
515 /* receive interrupt */
516 while (status & SR_RBS) {
518 status = priv->read_reg(priv, REG_SR);
519 /* check for absent controller */
520 if (status == 0xFF && sja1000_is_absent(priv))
524 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
525 /* error interrupt */
526 if (sja1000_err(dev, isrc, status))
532 priv->post_irq(priv);
534 if (n >= SJA1000_MAX_IRQ)
535 netdev_dbg(dev, "%d messages handled in ISR", n);
537 return (n) ? IRQ_HANDLED : IRQ_NONE;
539 EXPORT_SYMBOL_GPL(sja1000_interrupt);
541 static int sja1000_open(struct net_device *dev)
543 struct sja1000_priv *priv = netdev_priv(dev);
546 /* set chip into reset mode */
550 err = open_candev(dev);
554 /* register interrupt handler, if not done by the device driver */
555 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
556 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
557 dev->name, (void *)dev);
564 /* init and start chi */
566 priv->open_time = jiffies;
568 netif_start_queue(dev);
573 static int sja1000_close(struct net_device *dev)
575 struct sja1000_priv *priv = netdev_priv(dev);
577 netif_stop_queue(dev);
580 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
581 free_irq(dev->irq, (void *)dev);
590 struct net_device *alloc_sja1000dev(int sizeof_priv)
592 struct net_device *dev;
593 struct sja1000_priv *priv;
595 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
596 SJA1000_ECHO_SKB_MAX);
600 priv = netdev_priv(dev);
603 priv->can.bittiming_const = &sja1000_bittiming_const;
604 priv->can.do_set_bittiming = sja1000_set_bittiming;
605 priv->can.do_set_mode = sja1000_set_mode;
606 priv->can.do_get_berr_counter = sja1000_get_berr_counter;
607 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
608 CAN_CTRLMODE_BERR_REPORTING;
610 spin_lock_init(&priv->cmdreg_lock);
613 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
617 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
619 void free_sja1000dev(struct net_device *dev)
623 EXPORT_SYMBOL_GPL(free_sja1000dev);
625 static const struct net_device_ops sja1000_netdev_ops = {
626 .ndo_open = sja1000_open,
627 .ndo_stop = sja1000_close,
628 .ndo_start_xmit = sja1000_start_xmit,
631 int register_sja1000dev(struct net_device *dev)
633 if (!sja1000_probe_chip(dev))
636 dev->flags |= IFF_ECHO; /* we support local echo */
637 dev->netdev_ops = &sja1000_netdev_ops;
642 return register_candev(dev);
644 EXPORT_SYMBOL_GPL(register_sja1000dev);
646 void unregister_sja1000dev(struct net_device *dev)
649 unregister_candev(dev);
651 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
653 static __init int sja1000_init(void)
655 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
660 module_init(sja1000_init);
662 static __exit void sja1000_exit(void)
664 printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
667 module_exit(sja1000_exit);