Merge branch 'for-33' of git://repo.or.cz/linux-kbuild
[linux-2.6-block.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 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 netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
242                                             struct net_device *dev)
243 {
244         struct sja1000_priv *priv = netdev_priv(dev);
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         dev->trans_start = jiffies;
279
280         can_put_echo_skb(skb, dev, 0);
281
282         priv->write_reg(priv, REG_CMR, CMD_TR);
283
284         return NETDEV_TX_OK;
285 }
286
287 static void sja1000_rx(struct net_device *dev)
288 {
289         struct sja1000_priv *priv = netdev_priv(dev);
290         struct net_device_stats *stats = &dev->stats;
291         struct can_frame *cf;
292         struct sk_buff *skb;
293         uint8_t fi;
294         uint8_t dreg;
295         canid_t id;
296         int i;
297
298         /* create zero'ed CAN frame buffer */
299         skb = alloc_can_skb(dev, &cf);
300         if (skb == NULL)
301                 return;
302
303         fi = priv->read_reg(priv, REG_FI);
304
305         if (fi & FI_FF) {
306                 /* extended frame format (EFF) */
307                 dreg = EFF_BUF;
308                 id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
309                     | (priv->read_reg(priv, REG_ID2) << (5 + 8))
310                     | (priv->read_reg(priv, REG_ID3) << 5)
311                     | (priv->read_reg(priv, REG_ID4) >> 3);
312                 id |= CAN_EFF_FLAG;
313         } else {
314                 /* standard frame format (SFF) */
315                 dreg = SFF_BUF;
316                 id = (priv->read_reg(priv, REG_ID1) << 3)
317                     | (priv->read_reg(priv, REG_ID2) >> 5);
318         }
319
320         if (fi & FI_RTR) {
321                 id |= CAN_RTR_FLAG;
322         } else {
323                 cf->can_dlc = get_can_dlc(fi & 0x0F);
324                 for (i = 0; i < cf->can_dlc; i++)
325                         cf->data[i] = priv->read_reg(priv, dreg++);
326         }
327
328         cf->can_id = id;
329
330         /* release receive buffer */
331         priv->write_reg(priv, REG_CMR, CMD_RRB);
332
333         netif_rx(skb);
334
335         stats->rx_packets++;
336         stats->rx_bytes += cf->can_dlc;
337 }
338
339 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
340 {
341         struct sja1000_priv *priv = netdev_priv(dev);
342         struct net_device_stats *stats = &dev->stats;
343         struct can_frame *cf;
344         struct sk_buff *skb;
345         enum can_state state = priv->can.state;
346         uint8_t ecc, alc;
347
348         skb = alloc_can_err_skb(dev, &cf);
349         if (skb == NULL)
350                 return -ENOMEM;
351
352         if (isrc & IRQ_DOI) {
353                 /* data overrun interrupt */
354                 dev_dbg(dev->dev.parent, "data overrun interrupt\n");
355                 cf->can_id |= CAN_ERR_CRTL;
356                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
357                 stats->rx_over_errors++;
358                 stats->rx_errors++;
359                 priv->write_reg(priv, REG_CMR, CMD_CDO);        /* clear bit */
360         }
361
362         if (isrc & IRQ_EI) {
363                 /* error warning interrupt */
364                 dev_dbg(dev->dev.parent, "error warning interrupt\n");
365
366                 if (status & SR_BS) {
367                         state = CAN_STATE_BUS_OFF;
368                         cf->can_id |= CAN_ERR_BUSOFF;
369                         can_bus_off(dev);
370                 } else if (status & SR_ES) {
371                         state = CAN_STATE_ERROR_WARNING;
372                 } else
373                         state = CAN_STATE_ERROR_ACTIVE;
374         }
375         if (isrc & IRQ_BEI) {
376                 /* bus error interrupt */
377                 priv->can.can_stats.bus_error++;
378                 stats->rx_errors++;
379
380                 ecc = priv->read_reg(priv, REG_ECC);
381
382                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
383
384                 switch (ecc & ECC_MASK) {
385                 case ECC_BIT:
386                         cf->data[2] |= CAN_ERR_PROT_BIT;
387                         break;
388                 case ECC_FORM:
389                         cf->data[2] |= CAN_ERR_PROT_FORM;
390                         break;
391                 case ECC_STUFF:
392                         cf->data[2] |= CAN_ERR_PROT_STUFF;
393                         break;
394                 default:
395                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
396                         cf->data[3] = ecc & ECC_SEG;
397                         break;
398                 }
399                 /* Error occured during transmission? */
400                 if ((ecc & ECC_DIR) == 0)
401                         cf->data[2] |= CAN_ERR_PROT_TX;
402         }
403         if (isrc & IRQ_EPI) {
404                 /* error passive interrupt */
405                 dev_dbg(dev->dev.parent, "error passive interrupt\n");
406                 if (status & SR_ES)
407                         state = CAN_STATE_ERROR_PASSIVE;
408                 else
409                         state = CAN_STATE_ERROR_ACTIVE;
410         }
411         if (isrc & IRQ_ALI) {
412                 /* arbitration lost interrupt */
413                 dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
414                 alc = priv->read_reg(priv, REG_ALC);
415                 priv->can.can_stats.arbitration_lost++;
416                 stats->tx_errors++;
417                 cf->can_id |= CAN_ERR_LOSTARB;
418                 cf->data[0] = alc & 0x1f;
419         }
420
421         if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
422                                          state == CAN_STATE_ERROR_PASSIVE)) {
423                 uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
424                 uint8_t txerr = priv->read_reg(priv, REG_TXERR);
425                 cf->can_id |= CAN_ERR_CRTL;
426                 if (state == CAN_STATE_ERROR_WARNING) {
427                         priv->can.can_stats.error_warning++;
428                         cf->data[1] = (txerr > rxerr) ?
429                                 CAN_ERR_CRTL_TX_WARNING :
430                                 CAN_ERR_CRTL_RX_WARNING;
431                 } else {
432                         priv->can.can_stats.error_passive++;
433                         cf->data[1] = (txerr > rxerr) ?
434                                 CAN_ERR_CRTL_TX_PASSIVE :
435                                 CAN_ERR_CRTL_RX_PASSIVE;
436                 }
437         }
438
439         priv->can.state = state;
440
441         netif_rx(skb);
442
443         stats->rx_packets++;
444         stats->rx_bytes += cf->can_dlc;
445
446         return 0;
447 }
448
449 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
450 {
451         struct net_device *dev = (struct net_device *)dev_id;
452         struct sja1000_priv *priv = netdev_priv(dev);
453         struct net_device_stats *stats = &dev->stats;
454         uint8_t isrc, status;
455         int n = 0;
456
457         /* Shared interrupts and IRQ off? */
458         if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
459                 return IRQ_NONE;
460
461         if (priv->pre_irq)
462                 priv->pre_irq(priv);
463
464         while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
465                 n++;
466                 status = priv->read_reg(priv, REG_SR);
467
468                 if (isrc & IRQ_WUI)
469                         dev_warn(dev->dev.parent, "wakeup interrupt\n");
470
471                 if (isrc & IRQ_TI) {
472                         /* transmission complete interrupt */
473                         stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf;
474                         stats->tx_packets++;
475                         can_get_echo_skb(dev, 0);
476                         netif_wake_queue(dev);
477                 }
478                 if (isrc & IRQ_RI) {
479                         /* receive interrupt */
480                         while (status & SR_RBS) {
481                                 sja1000_rx(dev);
482                                 status = priv->read_reg(priv, REG_SR);
483                         }
484                 }
485                 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
486                         /* error interrupt */
487                         if (sja1000_err(dev, isrc, status))
488                                 break;
489                 }
490         }
491
492         if (priv->post_irq)
493                 priv->post_irq(priv);
494
495         if (n >= SJA1000_MAX_IRQ)
496                 dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);
497
498         return (n) ? IRQ_HANDLED : IRQ_NONE;
499 }
500 EXPORT_SYMBOL_GPL(sja1000_interrupt);
501
502 static int sja1000_open(struct net_device *dev)
503 {
504         struct sja1000_priv *priv = netdev_priv(dev);
505         int err;
506
507         /* set chip into reset mode */
508         set_reset_mode(dev);
509
510         /* common open */
511         err = open_candev(dev);
512         if (err)
513                 return err;
514
515         /* register interrupt handler, if not done by the device driver */
516         if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
517                 err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
518                                   dev->name, (void *)dev);
519                 if (err) {
520                         close_candev(dev);
521                         return -EAGAIN;
522                 }
523         }
524
525         /* init and start chi */
526         sja1000_start(dev);
527         priv->open_time = jiffies;
528
529         netif_start_queue(dev);
530
531         return 0;
532 }
533
534 static int sja1000_close(struct net_device *dev)
535 {
536         struct sja1000_priv *priv = netdev_priv(dev);
537
538         netif_stop_queue(dev);
539         set_reset_mode(dev);
540
541         if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
542                 free_irq(dev->irq, (void *)dev);
543
544         close_candev(dev);
545
546         priv->open_time = 0;
547
548         return 0;
549 }
550
551 struct net_device *alloc_sja1000dev(int sizeof_priv)
552 {
553         struct net_device *dev;
554         struct sja1000_priv *priv;
555
556         dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
557                 SJA1000_ECHO_SKB_MAX);
558         if (!dev)
559                 return NULL;
560
561         priv = netdev_priv(dev);
562
563         priv->dev = dev;
564         priv->can.bittiming_const = &sja1000_bittiming_const;
565         priv->can.do_set_bittiming = sja1000_set_bittiming;
566         priv->can.do_set_mode = sja1000_set_mode;
567
568         if (sizeof_priv)
569                 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
570
571         return dev;
572 }
573 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
574
575 void free_sja1000dev(struct net_device *dev)
576 {
577         free_candev(dev);
578 }
579 EXPORT_SYMBOL_GPL(free_sja1000dev);
580
581 static const struct net_device_ops sja1000_netdev_ops = {
582        .ndo_open               = sja1000_open,
583        .ndo_stop               = sja1000_close,
584        .ndo_start_xmit         = sja1000_start_xmit,
585 };
586
587 int register_sja1000dev(struct net_device *dev)
588 {
589         if (!sja1000_probe_chip(dev))
590                 return -ENODEV;
591
592         dev->flags |= IFF_ECHO; /* we support local echo */
593         dev->netdev_ops = &sja1000_netdev_ops;
594
595         set_reset_mode(dev);
596         chipset_init(dev);
597
598         return register_candev(dev);
599 }
600 EXPORT_SYMBOL_GPL(register_sja1000dev);
601
602 void unregister_sja1000dev(struct net_device *dev)
603 {
604         set_reset_mode(dev);
605         unregister_candev(dev);
606 }
607 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
608
609 static __init int sja1000_init(void)
610 {
611         printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
612
613         return 0;
614 }
615
616 module_init(sja1000_init);
617
618 static __exit void sja1000_exit(void)
619 {
620         printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
621 }
622
623 module_exit(sja1000_exit);