Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / drivers / net / can / sja1000 / sja1000.c
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 interrupts */
134                         if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
135                                 priv->write_reg(priv, REG_IER, IRQ_ALL);
136                         else
137                                 priv->write_reg(priv, REG_IER,
138                                                 IRQ_ALL & ~IRQ_BEI);
139                         return;
140                 }
141
142                 /* set chip to normal mode */
143                 priv->write_reg(priv, REG_MOD, 0x00);
144                 udelay(10);
145                 status = priv->read_reg(priv, REG_MOD);
146         }
147
148         dev_err(dev->dev.parent, "setting SJA1000 into normal mode failed!\n");
149 }
150
151 static void sja1000_start(struct net_device *dev)
152 {
153         struct sja1000_priv *priv = netdev_priv(dev);
154
155         /* leave reset mode */
156         if (priv->can.state != CAN_STATE_STOPPED)
157                 set_reset_mode(dev);
158
159         /* Clear error counters and error code capture */
160         priv->write_reg(priv, REG_TXERR, 0x0);
161         priv->write_reg(priv, REG_RXERR, 0x0);
162         priv->read_reg(priv, REG_ECC);
163
164         /* leave reset mode */
165         set_normal_mode(dev);
166 }
167
168 static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
169 {
170         struct sja1000_priv *priv = netdev_priv(dev);
171
172         if (!priv->open_time)
173                 return -EINVAL;
174
175         switch (mode) {
176         case CAN_MODE_START:
177                 sja1000_start(dev);
178                 if (netif_queue_stopped(dev))
179                         netif_wake_queue(dev);
180                 break;
181
182         default:
183                 return -EOPNOTSUPP;
184         }
185
186         return 0;
187 }
188
189 static int sja1000_set_bittiming(struct net_device *dev)
190 {
191         struct sja1000_priv *priv = netdev_priv(dev);
192         struct can_bittiming *bt = &priv->can.bittiming;
193         u8 btr0, btr1;
194
195         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
196         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
197                 (((bt->phase_seg2 - 1) & 0x7) << 4);
198         if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
199                 btr1 |= 0x80;
200
201         dev_info(dev->dev.parent,
202                  "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
203
204         priv->write_reg(priv, REG_BTR0, btr0);
205         priv->write_reg(priv, REG_BTR1, btr1);
206
207         return 0;
208 }
209
210 static int sja1000_get_berr_counter(const struct net_device *dev,
211                                     struct can_berr_counter *bec)
212 {
213         struct sja1000_priv *priv = netdev_priv(dev);
214
215         bec->txerr = priv->read_reg(priv, REG_TXERR);
216         bec->rxerr = priv->read_reg(priv, REG_RXERR);
217
218         return 0;
219 }
220
221 /*
222  * initialize SJA1000 chip:
223  *   - reset chip
224  *   - set output mode
225  *   - set baudrate
226  *   - enable interrupts
227  *   - start operating mode
228  */
229 static void chipset_init(struct net_device *dev)
230 {
231         struct sja1000_priv *priv = netdev_priv(dev);
232
233         /* set clock divider and output control register */
234         priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN);
235
236         /* set acceptance filter (accept all) */
237         priv->write_reg(priv, REG_ACCC0, 0x00);
238         priv->write_reg(priv, REG_ACCC1, 0x00);
239         priv->write_reg(priv, REG_ACCC2, 0x00);
240         priv->write_reg(priv, REG_ACCC3, 0x00);
241
242         priv->write_reg(priv, REG_ACCM0, 0xFF);
243         priv->write_reg(priv, REG_ACCM1, 0xFF);
244         priv->write_reg(priv, REG_ACCM2, 0xFF);
245         priv->write_reg(priv, REG_ACCM3, 0xFF);
246
247         priv->write_reg(priv, REG_OCR, priv->ocr | OCR_MODE_NORMAL);
248 }
249
250 /*
251  * transmit a CAN message
252  * message layout in the sk_buff should be like this:
253  * xx xx xx xx   ff      ll   00 11 22 33 44 55 66 77
254  * [  can-id ] [flags] [len] [can data (up to 8 bytes]
255  */
256 static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
257                                             struct net_device *dev)
258 {
259         struct sja1000_priv *priv = netdev_priv(dev);
260         struct can_frame *cf = (struct can_frame *)skb->data;
261         uint8_t fi;
262         uint8_t dlc;
263         canid_t id;
264         uint8_t dreg;
265         int i;
266
267         if (can_dropped_invalid_skb(dev, skb))
268                 return NETDEV_TX_OK;
269
270         netif_stop_queue(dev);
271
272         fi = dlc = cf->can_dlc;
273         id = cf->can_id;
274
275         if (id & CAN_RTR_FLAG)
276                 fi |= FI_RTR;
277
278         if (id & CAN_EFF_FLAG) {
279                 fi |= FI_FF;
280                 dreg = EFF_BUF;
281                 priv->write_reg(priv, REG_FI, fi);
282                 priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
283                 priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
284                 priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
285                 priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
286         } else {
287                 dreg = SFF_BUF;
288                 priv->write_reg(priv, REG_FI, fi);
289                 priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
290                 priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
291         }
292
293         for (i = 0; i < dlc; i++)
294                 priv->write_reg(priv, dreg++, cf->data[i]);
295
296         dev->trans_start = jiffies;
297
298         can_put_echo_skb(skb, dev, 0);
299
300         priv->write_reg(priv, REG_CMR, CMD_TR);
301
302         return NETDEV_TX_OK;
303 }
304
305 static void sja1000_rx(struct net_device *dev)
306 {
307         struct sja1000_priv *priv = netdev_priv(dev);
308         struct net_device_stats *stats = &dev->stats;
309         struct can_frame *cf;
310         struct sk_buff *skb;
311         uint8_t fi;
312         uint8_t dreg;
313         canid_t id;
314         int i;
315
316         /* create zero'ed CAN frame buffer */
317         skb = alloc_can_skb(dev, &cf);
318         if (skb == NULL)
319                 return;
320
321         fi = priv->read_reg(priv, REG_FI);
322
323         if (fi & FI_FF) {
324                 /* extended frame format (EFF) */
325                 dreg = EFF_BUF;
326                 id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
327                     | (priv->read_reg(priv, REG_ID2) << (5 + 8))
328                     | (priv->read_reg(priv, REG_ID3) << 5)
329                     | (priv->read_reg(priv, REG_ID4) >> 3);
330                 id |= CAN_EFF_FLAG;
331         } else {
332                 /* standard frame format (SFF) */
333                 dreg = SFF_BUF;
334                 id = (priv->read_reg(priv, REG_ID1) << 3)
335                     | (priv->read_reg(priv, REG_ID2) >> 5);
336         }
337
338         if (fi & FI_RTR) {
339                 id |= CAN_RTR_FLAG;
340         } else {
341                 cf->can_dlc = get_can_dlc(fi & 0x0F);
342                 for (i = 0; i < cf->can_dlc; i++)
343                         cf->data[i] = priv->read_reg(priv, dreg++);
344         }
345
346         cf->can_id = id;
347
348         /* release receive buffer */
349         priv->write_reg(priv, REG_CMR, CMD_RRB);
350
351         netif_rx(skb);
352
353         stats->rx_packets++;
354         stats->rx_bytes += cf->can_dlc;
355 }
356
357 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
358 {
359         struct sja1000_priv *priv = netdev_priv(dev);
360         struct net_device_stats *stats = &dev->stats;
361         struct can_frame *cf;
362         struct sk_buff *skb;
363         enum can_state state = priv->can.state;
364         uint8_t ecc, alc;
365
366         skb = alloc_can_err_skb(dev, &cf);
367         if (skb == NULL)
368                 return -ENOMEM;
369
370         if (isrc & IRQ_DOI) {
371                 /* data overrun interrupt */
372                 dev_dbg(dev->dev.parent, "data overrun interrupt\n");
373                 cf->can_id |= CAN_ERR_CRTL;
374                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
375                 stats->rx_over_errors++;
376                 stats->rx_errors++;
377                 priv->write_reg(priv, REG_CMR, CMD_CDO);        /* clear bit */
378         }
379
380         if (isrc & IRQ_EI) {
381                 /* error warning interrupt */
382                 dev_dbg(dev->dev.parent, "error warning interrupt\n");
383
384                 if (status & SR_BS) {
385                         state = CAN_STATE_BUS_OFF;
386                         cf->can_id |= CAN_ERR_BUSOFF;
387                         can_bus_off(dev);
388                 } else if (status & SR_ES) {
389                         state = CAN_STATE_ERROR_WARNING;
390                 } else
391                         state = CAN_STATE_ERROR_ACTIVE;
392         }
393         if (isrc & IRQ_BEI) {
394                 /* bus error interrupt */
395                 priv->can.can_stats.bus_error++;
396                 stats->rx_errors++;
397
398                 ecc = priv->read_reg(priv, REG_ECC);
399
400                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
401
402                 switch (ecc & ECC_MASK) {
403                 case ECC_BIT:
404                         cf->data[2] |= CAN_ERR_PROT_BIT;
405                         break;
406                 case ECC_FORM:
407                         cf->data[2] |= CAN_ERR_PROT_FORM;
408                         break;
409                 case ECC_STUFF:
410                         cf->data[2] |= CAN_ERR_PROT_STUFF;
411                         break;
412                 default:
413                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
414                         cf->data[3] = ecc & ECC_SEG;
415                         break;
416                 }
417                 /* Error occured during transmission? */
418                 if ((ecc & ECC_DIR) == 0)
419                         cf->data[2] |= CAN_ERR_PROT_TX;
420         }
421         if (isrc & IRQ_EPI) {
422                 /* error passive interrupt */
423                 dev_dbg(dev->dev.parent, "error passive interrupt\n");
424                 if (status & SR_ES)
425                         state = CAN_STATE_ERROR_PASSIVE;
426                 else
427                         state = CAN_STATE_ERROR_ACTIVE;
428         }
429         if (isrc & IRQ_ALI) {
430                 /* arbitration lost interrupt */
431                 dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
432                 alc = priv->read_reg(priv, REG_ALC);
433                 priv->can.can_stats.arbitration_lost++;
434                 stats->tx_errors++;
435                 cf->can_id |= CAN_ERR_LOSTARB;
436                 cf->data[0] = alc & 0x1f;
437         }
438
439         if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
440                                          state == CAN_STATE_ERROR_PASSIVE)) {
441                 uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
442                 uint8_t txerr = priv->read_reg(priv, REG_TXERR);
443                 cf->can_id |= CAN_ERR_CRTL;
444                 if (state == CAN_STATE_ERROR_WARNING) {
445                         priv->can.can_stats.error_warning++;
446                         cf->data[1] = (txerr > rxerr) ?
447                                 CAN_ERR_CRTL_TX_WARNING :
448                                 CAN_ERR_CRTL_RX_WARNING;
449                 } else {
450                         priv->can.can_stats.error_passive++;
451                         cf->data[1] = (txerr > rxerr) ?
452                                 CAN_ERR_CRTL_TX_PASSIVE :
453                                 CAN_ERR_CRTL_RX_PASSIVE;
454                 }
455                 cf->data[6] = txerr;
456                 cf->data[7] = rxerr;
457         }
458
459         priv->can.state = state;
460
461         netif_rx(skb);
462
463         stats->rx_packets++;
464         stats->rx_bytes += cf->can_dlc;
465
466         return 0;
467 }
468
469 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
470 {
471         struct net_device *dev = (struct net_device *)dev_id;
472         struct sja1000_priv *priv = netdev_priv(dev);
473         struct net_device_stats *stats = &dev->stats;
474         uint8_t isrc, status;
475         int n = 0;
476
477         /* Shared interrupts and IRQ off? */
478         if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
479                 return IRQ_NONE;
480
481         if (priv->pre_irq)
482                 priv->pre_irq(priv);
483
484         while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
485                 n++;
486                 status = priv->read_reg(priv, REG_SR);
487
488                 if (isrc & IRQ_WUI)
489                         dev_warn(dev->dev.parent, "wakeup interrupt\n");
490
491                 if (isrc & IRQ_TI) {
492                         /* transmission complete interrupt */
493                         stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf;
494                         stats->tx_packets++;
495                         can_get_echo_skb(dev, 0);
496                         netif_wake_queue(dev);
497                 }
498                 if (isrc & IRQ_RI) {
499                         /* receive interrupt */
500                         while (status & SR_RBS) {
501                                 sja1000_rx(dev);
502                                 status = priv->read_reg(priv, REG_SR);
503                         }
504                 }
505                 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
506                         /* error interrupt */
507                         if (sja1000_err(dev, isrc, status))
508                                 break;
509                 }
510         }
511
512         if (priv->post_irq)
513                 priv->post_irq(priv);
514
515         if (n >= SJA1000_MAX_IRQ)
516                 dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);
517
518         return (n) ? IRQ_HANDLED : IRQ_NONE;
519 }
520 EXPORT_SYMBOL_GPL(sja1000_interrupt);
521
522 static int sja1000_open(struct net_device *dev)
523 {
524         struct sja1000_priv *priv = netdev_priv(dev);
525         int err;
526
527         /* set chip into reset mode */
528         set_reset_mode(dev);
529
530         /* common open */
531         err = open_candev(dev);
532         if (err)
533                 return err;
534
535         /* register interrupt handler, if not done by the device driver */
536         if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
537                 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
538                                   dev->name, (void *)dev);
539                 if (err) {
540                         close_candev(dev);
541                         return -EAGAIN;
542                 }
543         }
544
545         /* init and start chi */
546         sja1000_start(dev);
547         priv->open_time = jiffies;
548
549         netif_start_queue(dev);
550
551         return 0;
552 }
553
554 static int sja1000_close(struct net_device *dev)
555 {
556         struct sja1000_priv *priv = netdev_priv(dev);
557
558         netif_stop_queue(dev);
559         set_reset_mode(dev);
560
561         if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
562                 free_irq(dev->irq, (void *)dev);
563
564         close_candev(dev);
565
566         priv->open_time = 0;
567
568         return 0;
569 }
570
571 struct net_device *alloc_sja1000dev(int sizeof_priv)
572 {
573         struct net_device *dev;
574         struct sja1000_priv *priv;
575
576         dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
577                 SJA1000_ECHO_SKB_MAX);
578         if (!dev)
579                 return NULL;
580
581         priv = netdev_priv(dev);
582
583         priv->dev = dev;
584         priv->can.bittiming_const = &sja1000_bittiming_const;
585         priv->can.do_set_bittiming = sja1000_set_bittiming;
586         priv->can.do_set_mode = sja1000_set_mode;
587         priv->can.do_get_berr_counter = sja1000_get_berr_counter;
588         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
589                 CAN_CTRLMODE_BERR_REPORTING;
590
591         if (sizeof_priv)
592                 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
593
594         return dev;
595 }
596 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
597
598 void free_sja1000dev(struct net_device *dev)
599 {
600         free_candev(dev);
601 }
602 EXPORT_SYMBOL_GPL(free_sja1000dev);
603
604 static const struct net_device_ops sja1000_netdev_ops = {
605        .ndo_open               = sja1000_open,
606        .ndo_stop               = sja1000_close,
607        .ndo_start_xmit         = sja1000_start_xmit,
608 };
609
610 int register_sja1000dev(struct net_device *dev)
611 {
612         if (!sja1000_probe_chip(dev))
613                 return -ENODEV;
614
615         dev->flags |= IFF_ECHO; /* we support local echo */
616         dev->netdev_ops = &sja1000_netdev_ops;
617
618         set_reset_mode(dev);
619         chipset_init(dev);
620
621         return register_candev(dev);
622 }
623 EXPORT_SYMBOL_GPL(register_sja1000dev);
624
625 void unregister_sja1000dev(struct net_device *dev)
626 {
627         set_reset_mode(dev);
628         unregister_candev(dev);
629 }
630 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
631
632 static __init int sja1000_init(void)
633 {
634         printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
635
636         return 0;
637 }
638
639 module_init(sja1000_init);
640
641 static __exit void sja1000_exit(void)
642 {
643         printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
644 }
645
646 module_exit(sja1000_exit);