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>
63 #include <linux/can/led.h>
67 #define DRV_NAME "sja1000"
69 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
70 MODULE_LICENSE("Dual BSD/GPL");
71 MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
73 static const struct can_bittiming_const sja1000_bittiming_const = {
85 static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
90 * The command register needs some locking and time to settle
91 * the write_reg() operation - especially on SMP systems.
93 spin_lock_irqsave(&priv->cmdreg_lock, flags);
94 priv->write_reg(priv, SJA1000_CMR, val);
95 priv->read_reg(priv, SJA1000_SR);
96 spin_unlock_irqrestore(&priv->cmdreg_lock, flags);
99 static int sja1000_is_absent(struct sja1000_priv *priv)
101 return (priv->read_reg(priv, SJA1000_MOD) == 0xFF);
104 static int sja1000_probe_chip(struct net_device *dev)
106 struct sja1000_priv *priv = netdev_priv(dev);
108 if (priv->reg_base && sja1000_is_absent(priv)) {
109 netdev_err(dev, "probing failed\n");
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, SJA1000_MOD);
121 /* disable interrupts */
122 priv->write_reg(priv, SJA1000_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;
132 priv->write_reg(priv, SJA1000_MOD, MOD_RM);
134 status = priv->read_reg(priv, SJA1000_MOD);
137 netdev_err(dev, "setting SJA1000 into reset mode failed!\n");
140 static void set_normal_mode(struct net_device *dev)
142 struct sja1000_priv *priv = netdev_priv(dev);
143 unsigned char status = priv->read_reg(priv, SJA1000_MOD);
144 u8 mod_reg_val = 0x00;
147 for (i = 0; i < 100; i++) {
148 /* check reset bit */
149 if ((status & MOD_RM) == 0) {
150 priv->can.state = CAN_STATE_ERROR_ACTIVE;
151 /* enable interrupts */
152 if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
153 priv->write_reg(priv, SJA1000_IER, IRQ_ALL);
155 priv->write_reg(priv, SJA1000_IER,
160 /* set chip to normal mode */
161 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
162 mod_reg_val |= MOD_LOM;
163 if (priv->can.ctrlmode & CAN_CTRLMODE_PRESUME_ACK)
164 mod_reg_val |= MOD_STM;
165 priv->write_reg(priv, SJA1000_MOD, mod_reg_val);
169 status = priv->read_reg(priv, SJA1000_MOD);
172 netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
176 * initialize SJA1000 chip:
180 * - enable interrupts
181 * - start operating mode
183 static void chipset_init(struct net_device *dev)
185 struct sja1000_priv *priv = netdev_priv(dev);
187 /* set clock divider and output control register */
188 priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
190 /* set acceptance filter (accept all) */
191 priv->write_reg(priv, SJA1000_ACCC0, 0x00);
192 priv->write_reg(priv, SJA1000_ACCC1, 0x00);
193 priv->write_reg(priv, SJA1000_ACCC2, 0x00);
194 priv->write_reg(priv, SJA1000_ACCC3, 0x00);
196 priv->write_reg(priv, SJA1000_ACCM0, 0xFF);
197 priv->write_reg(priv, SJA1000_ACCM1, 0xFF);
198 priv->write_reg(priv, SJA1000_ACCM2, 0xFF);
199 priv->write_reg(priv, SJA1000_ACCM3, 0xFF);
201 priv->write_reg(priv, SJA1000_OCR, priv->ocr | OCR_MODE_NORMAL);
204 static void sja1000_start(struct net_device *dev)
206 struct sja1000_priv *priv = netdev_priv(dev);
208 /* leave reset mode */
209 if (priv->can.state != CAN_STATE_STOPPED)
212 /* Initialize chip if uninitialized at this stage */
213 if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
216 /* Clear error counters and error code capture */
217 priv->write_reg(priv, SJA1000_TXERR, 0x0);
218 priv->write_reg(priv, SJA1000_RXERR, 0x0);
219 priv->read_reg(priv, SJA1000_ECC);
221 /* clear interrupt flags */
222 priv->read_reg(priv, SJA1000_IR);
224 /* leave reset mode */
225 set_normal_mode(dev);
228 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
233 if (netif_queue_stopped(dev))
234 netif_wake_queue(dev);
244 static int sja1000_set_bittiming(struct net_device *dev)
246 struct sja1000_priv *priv = netdev_priv(dev);
247 struct can_bittiming *bt = &priv->can.bittiming;
250 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
251 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
252 (((bt->phase_seg2 - 1) & 0x7) << 4);
253 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
256 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
258 priv->write_reg(priv, SJA1000_BTR0, btr0);
259 priv->write_reg(priv, SJA1000_BTR1, btr1);
264 static int sja1000_get_berr_counter(const struct net_device *dev,
265 struct can_berr_counter *bec)
267 struct sja1000_priv *priv = netdev_priv(dev);
269 bec->txerr = priv->read_reg(priv, SJA1000_TXERR);
270 bec->rxerr = priv->read_reg(priv, SJA1000_RXERR);
276 * transmit a CAN message
277 * message layout in the sk_buff should be like this:
278 * xx xx xx xx ff ll 00 11 22 33 44 55 66 77
279 * [ can-id ] [flags] [len] [can data (up to 8 bytes]
281 static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
282 struct net_device *dev)
284 struct sja1000_priv *priv = netdev_priv(dev);
285 struct can_frame *cf = (struct can_frame *)skb->data;
290 u8 cmd_reg_val = 0x00;
293 if (can_dropped_invalid_skb(dev, skb))
296 netif_stop_queue(dev);
298 fi = dlc = cf->can_dlc;
301 if (id & CAN_RTR_FLAG)
302 fi |= SJA1000_FI_RTR;
304 if (id & CAN_EFF_FLAG) {
306 dreg = SJA1000_EFF_BUF;
307 priv->write_reg(priv, SJA1000_FI, fi);
308 priv->write_reg(priv, SJA1000_ID1, (id & 0x1fe00000) >> 21);
309 priv->write_reg(priv, SJA1000_ID2, (id & 0x001fe000) >> 13);
310 priv->write_reg(priv, SJA1000_ID3, (id & 0x00001fe0) >> 5);
311 priv->write_reg(priv, SJA1000_ID4, (id & 0x0000001f) << 3);
313 dreg = SJA1000_SFF_BUF;
314 priv->write_reg(priv, SJA1000_FI, fi);
315 priv->write_reg(priv, SJA1000_ID1, (id & 0x000007f8) >> 3);
316 priv->write_reg(priv, SJA1000_ID2, (id & 0x00000007) << 5);
319 for (i = 0; i < dlc; i++)
320 priv->write_reg(priv, dreg++, cf->data[i]);
322 can_put_echo_skb(skb, dev, 0);
324 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
325 cmd_reg_val |= CMD_AT;
327 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
328 cmd_reg_val |= CMD_SRR;
330 cmd_reg_val |= CMD_TR;
332 sja1000_write_cmdreg(priv, cmd_reg_val);
337 static void sja1000_rx(struct net_device *dev)
339 struct sja1000_priv *priv = netdev_priv(dev);
340 struct net_device_stats *stats = &dev->stats;
341 struct can_frame *cf;
348 /* create zero'ed CAN frame buffer */
349 skb = alloc_can_skb(dev, &cf);
353 fi = priv->read_reg(priv, SJA1000_FI);
355 if (fi & SJA1000_FI_FF) {
356 /* extended frame format (EFF) */
357 dreg = SJA1000_EFF_BUF;
358 id = (priv->read_reg(priv, SJA1000_ID1) << 21)
359 | (priv->read_reg(priv, SJA1000_ID2) << 13)
360 | (priv->read_reg(priv, SJA1000_ID3) << 5)
361 | (priv->read_reg(priv, SJA1000_ID4) >> 3);
364 /* standard frame format (SFF) */
365 dreg = SJA1000_SFF_BUF;
366 id = (priv->read_reg(priv, SJA1000_ID1) << 3)
367 | (priv->read_reg(priv, SJA1000_ID2) >> 5);
370 cf->can_dlc = get_can_dlc(fi & 0x0F);
371 if (fi & SJA1000_FI_RTR) {
374 for (i = 0; i < cf->can_dlc; i++)
375 cf->data[i] = priv->read_reg(priv, dreg++);
380 /* release receive buffer */
381 sja1000_write_cmdreg(priv, CMD_RRB);
384 stats->rx_bytes += cf->can_dlc;
387 can_led_event(dev, CAN_LED_EVENT_RX);
390 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
392 struct sja1000_priv *priv = netdev_priv(dev);
393 struct net_device_stats *stats = &dev->stats;
394 struct can_frame *cf;
396 enum can_state state = priv->can.state;
397 enum can_state rx_state, tx_state;
398 unsigned int rxerr, txerr;
401 skb = alloc_can_err_skb(dev, &cf);
405 txerr = priv->read_reg(priv, SJA1000_TXERR);
406 rxerr = priv->read_reg(priv, SJA1000_RXERR);
411 if (isrc & IRQ_DOI) {
412 /* data overrun interrupt */
413 netdev_dbg(dev, "data overrun interrupt\n");
414 cf->can_id |= CAN_ERR_CRTL;
415 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
416 stats->rx_over_errors++;
418 sja1000_write_cmdreg(priv, CMD_CDO); /* clear bit */
422 /* error warning interrupt */
423 netdev_dbg(dev, "error warning interrupt\n");
426 state = CAN_STATE_BUS_OFF;
427 else if (status & SR_ES)
428 state = CAN_STATE_ERROR_WARNING;
430 state = CAN_STATE_ERROR_ACTIVE;
432 if (isrc & IRQ_BEI) {
433 /* bus error interrupt */
434 priv->can.can_stats.bus_error++;
437 ecc = priv->read_reg(priv, SJA1000_ECC);
439 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
441 switch (ecc & ECC_MASK) {
443 cf->data[2] |= CAN_ERR_PROT_BIT;
446 cf->data[2] |= CAN_ERR_PROT_FORM;
449 cf->data[2] |= CAN_ERR_PROT_STUFF;
452 cf->data[3] = ecc & ECC_SEG;
455 /* Error occurred during transmission? */
456 if ((ecc & ECC_DIR) == 0)
457 cf->data[2] |= CAN_ERR_PROT_TX;
459 if (isrc & IRQ_EPI) {
460 /* error passive interrupt */
461 netdev_dbg(dev, "error passive interrupt\n");
463 if (state == CAN_STATE_ERROR_PASSIVE)
464 state = CAN_STATE_ERROR_WARNING;
466 state = CAN_STATE_ERROR_PASSIVE;
468 if (isrc & IRQ_ALI) {
469 /* arbitration lost interrupt */
470 netdev_dbg(dev, "arbitration lost interrupt\n");
471 alc = priv->read_reg(priv, SJA1000_ALC);
472 priv->can.can_stats.arbitration_lost++;
474 cf->can_id |= CAN_ERR_LOSTARB;
475 cf->data[0] = alc & 0x1f;
478 if (state != priv->can.state) {
479 tx_state = txerr >= rxerr ? state : 0;
480 rx_state = txerr <= rxerr ? state : 0;
482 can_change_state(dev, cf, tx_state, rx_state);
484 if(state == CAN_STATE_BUS_OFF)
489 stats->rx_bytes += cf->can_dlc;
495 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
497 struct net_device *dev = (struct net_device *)dev_id;
498 struct sja1000_priv *priv = netdev_priv(dev);
499 struct net_device_stats *stats = &dev->stats;
500 uint8_t isrc, status;
506 /* Shared interrupts and IRQ off? */
507 if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
510 while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
511 (n < SJA1000_MAX_IRQ)) {
513 status = priv->read_reg(priv, SJA1000_SR);
514 /* check for absent controller due to hw unplug */
515 if (status == 0xFF && sja1000_is_absent(priv))
519 netdev_warn(dev, "wakeup interrupt\n");
522 /* transmission buffer released */
523 if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
524 !(status & SR_TCS)) {
526 can_free_echo_skb(dev, 0);
528 /* transmission complete */
530 priv->read_reg(priv, SJA1000_FI) & 0xf;
532 can_get_echo_skb(dev, 0);
534 netif_wake_queue(dev);
535 can_led_event(dev, CAN_LED_EVENT_TX);
538 /* receive interrupt */
539 while (status & SR_RBS) {
541 status = priv->read_reg(priv, SJA1000_SR);
542 /* check for absent controller */
543 if (status == 0xFF && sja1000_is_absent(priv))
547 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
548 /* error interrupt */
549 if (sja1000_err(dev, isrc, status))
556 priv->post_irq(priv);
558 if (n >= SJA1000_MAX_IRQ)
559 netdev_dbg(dev, "%d messages handled in ISR", n);
561 return (n) ? IRQ_HANDLED : IRQ_NONE;
563 EXPORT_SYMBOL_GPL(sja1000_interrupt);
565 static int sja1000_open(struct net_device *dev)
567 struct sja1000_priv *priv = netdev_priv(dev);
570 /* set chip into reset mode */
574 err = open_candev(dev);
578 /* register interrupt handler, if not done by the device driver */
579 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
580 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
581 dev->name, (void *)dev);
588 /* init and start chi */
591 can_led_event(dev, CAN_LED_EVENT_OPEN);
593 netif_start_queue(dev);
598 static int sja1000_close(struct net_device *dev)
600 struct sja1000_priv *priv = netdev_priv(dev);
602 netif_stop_queue(dev);
605 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
606 free_irq(dev->irq, (void *)dev);
610 can_led_event(dev, CAN_LED_EVENT_STOP);
615 struct net_device *alloc_sja1000dev(int sizeof_priv)
617 struct net_device *dev;
618 struct sja1000_priv *priv;
620 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
621 SJA1000_ECHO_SKB_MAX);
625 priv = netdev_priv(dev);
628 priv->can.bittiming_const = &sja1000_bittiming_const;
629 priv->can.do_set_bittiming = sja1000_set_bittiming;
630 priv->can.do_set_mode = sja1000_set_mode;
631 priv->can.do_get_berr_counter = sja1000_get_berr_counter;
632 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
633 CAN_CTRLMODE_LISTENONLY |
634 CAN_CTRLMODE_3_SAMPLES |
635 CAN_CTRLMODE_ONE_SHOT |
636 CAN_CTRLMODE_BERR_REPORTING |
637 CAN_CTRLMODE_PRESUME_ACK;
639 spin_lock_init(&priv->cmdreg_lock);
642 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
646 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
648 void free_sja1000dev(struct net_device *dev)
652 EXPORT_SYMBOL_GPL(free_sja1000dev);
654 static const struct net_device_ops sja1000_netdev_ops = {
655 .ndo_open = sja1000_open,
656 .ndo_stop = sja1000_close,
657 .ndo_start_xmit = sja1000_start_xmit,
658 .ndo_change_mtu = can_change_mtu,
661 int register_sja1000dev(struct net_device *dev)
665 if (!sja1000_probe_chip(dev))
668 dev->flags |= IFF_ECHO; /* we support local echo */
669 dev->netdev_ops = &sja1000_netdev_ops;
674 ret = register_candev(dev);
677 devm_can_led_init(dev);
681 EXPORT_SYMBOL_GPL(register_sja1000dev);
683 void unregister_sja1000dev(struct net_device *dev)
686 unregister_candev(dev);
688 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
690 static __init int sja1000_init(void)
692 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
697 module_init(sja1000_init);
699 static __exit void sja1000_exit(void)
701 printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
704 module_exit(sja1000_exit);