Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-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 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         uint8_t dlc;
297         int i;
298
299         skb = alloc_can_skb(dev, &cf);
300         if (skb == NULL)
301                 return;
302
303         fi = priv->read_reg(priv, REG_FI);
304         dlc = fi & 0x0F;
305
306         if (fi & FI_FF) {
307                 /* extended frame format (EFF) */
308                 dreg = EFF_BUF;
309                 id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
310                     | (priv->read_reg(priv, REG_ID2) << (5 + 8))
311                     | (priv->read_reg(priv, REG_ID3) << 5)
312                     | (priv->read_reg(priv, REG_ID4) >> 3);
313                 id |= CAN_EFF_FLAG;
314         } else {
315                 /* standard frame format (SFF) */
316                 dreg = SFF_BUF;
317                 id = (priv->read_reg(priv, REG_ID1) << 3)
318                     | (priv->read_reg(priv, REG_ID2) >> 5);
319         }
320
321         if (fi & FI_RTR)
322                 id |= CAN_RTR_FLAG;
323
324         cf->can_id = id;
325         cf->can_dlc = dlc;
326         for (i = 0; i < dlc; i++)
327                 cf->data[i] = priv->read_reg(priv, dreg++);
328
329         while (i < 8)
330                 cf->data[i++] = 0;
331
332         /* release receive buffer */
333         priv->write_reg(priv, REG_CMR, CMD_RRB);
334
335         netif_rx(skb);
336
337         stats->rx_packets++;
338         stats->rx_bytes += dlc;
339 }
340
341 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
342 {
343         struct sja1000_priv *priv = netdev_priv(dev);
344         struct net_device_stats *stats = &dev->stats;
345         struct can_frame *cf;
346         struct sk_buff *skb;
347         enum can_state state = priv->can.state;
348         uint8_t ecc, alc;
349
350         skb = alloc_can_err_skb(dev, &cf);
351         if (skb == NULL)
352                 return -ENOMEM;
353
354         if (isrc & IRQ_DOI) {
355                 /* data overrun interrupt */
356                 dev_dbg(dev->dev.parent, "data overrun interrupt\n");
357                 cf->can_id |= CAN_ERR_CRTL;
358                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
359                 stats->rx_over_errors++;
360                 stats->rx_errors++;
361                 priv->write_reg(priv, REG_CMR, CMD_CDO);        /* clear bit */
362         }
363
364         if (isrc & IRQ_EI) {
365                 /* error warning interrupt */
366                 dev_dbg(dev->dev.parent, "error warning interrupt\n");
367
368                 if (status & SR_BS) {
369                         state = CAN_STATE_BUS_OFF;
370                         cf->can_id |= CAN_ERR_BUSOFF;
371                         can_bus_off(dev);
372                 } else if (status & SR_ES) {
373                         state = CAN_STATE_ERROR_WARNING;
374                 } else
375                         state = CAN_STATE_ERROR_ACTIVE;
376         }
377         if (isrc & IRQ_BEI) {
378                 /* bus error interrupt */
379                 priv->can.can_stats.bus_error++;
380                 stats->rx_errors++;
381
382                 ecc = priv->read_reg(priv, REG_ECC);
383
384                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
385
386                 switch (ecc & ECC_MASK) {
387                 case ECC_BIT:
388                         cf->data[2] |= CAN_ERR_PROT_BIT;
389                         break;
390                 case ECC_FORM:
391                         cf->data[2] |= CAN_ERR_PROT_FORM;
392                         break;
393                 case ECC_STUFF:
394                         cf->data[2] |= CAN_ERR_PROT_STUFF;
395                         break;
396                 default:
397                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
398                         cf->data[3] = ecc & ECC_SEG;
399                         break;
400                 }
401                 /* Error occured during transmission? */
402                 if ((ecc & ECC_DIR) == 0)
403                         cf->data[2] |= CAN_ERR_PROT_TX;
404         }
405         if (isrc & IRQ_EPI) {
406                 /* error passive interrupt */
407                 dev_dbg(dev->dev.parent, "error passive interrupt\n");
408                 if (status & SR_ES)
409                         state = CAN_STATE_ERROR_PASSIVE;
410                 else
411                         state = CAN_STATE_ERROR_ACTIVE;
412         }
413         if (isrc & IRQ_ALI) {
414                 /* arbitration lost interrupt */
415                 dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
416                 alc = priv->read_reg(priv, REG_ALC);
417                 priv->can.can_stats.arbitration_lost++;
418                 stats->tx_errors++;
419                 cf->can_id |= CAN_ERR_LOSTARB;
420                 cf->data[0] = alc & 0x1f;
421         }
422
423         if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
424                                          state == CAN_STATE_ERROR_PASSIVE)) {
425                 uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
426                 uint8_t txerr = priv->read_reg(priv, REG_TXERR);
427                 cf->can_id |= CAN_ERR_CRTL;
428                 if (state == CAN_STATE_ERROR_WARNING) {
429                         priv->can.can_stats.error_warning++;
430                         cf->data[1] = (txerr > rxerr) ?
431                                 CAN_ERR_CRTL_TX_WARNING :
432                                 CAN_ERR_CRTL_RX_WARNING;
433                 } else {
434                         priv->can.can_stats.error_passive++;
435                         cf->data[1] = (txerr > rxerr) ?
436                                 CAN_ERR_CRTL_TX_PASSIVE :
437                                 CAN_ERR_CRTL_RX_PASSIVE;
438                 }
439         }
440
441         priv->can.state = state;
442
443         netif_rx(skb);
444
445         stats->rx_packets++;
446         stats->rx_bytes += cf->can_dlc;
447
448         return 0;
449 }
450
451 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
452 {
453         struct net_device *dev = (struct net_device *)dev_id;
454         struct sja1000_priv *priv = netdev_priv(dev);
455         struct net_device_stats *stats = &dev->stats;
456         uint8_t isrc, status;
457         int n = 0;
458
459         /* Shared interrupts and IRQ off? */
460         if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
461                 return IRQ_NONE;
462
463         if (priv->pre_irq)
464                 priv->pre_irq(priv);
465
466         while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
467                 n++;
468                 status = priv->read_reg(priv, REG_SR);
469
470                 if (isrc & IRQ_WUI)
471                         dev_warn(dev->dev.parent, "wakeup interrupt\n");
472
473                 if (isrc & IRQ_TI) {
474                         /* transmission complete interrupt */
475                         stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf;
476                         stats->tx_packets++;
477                         can_get_echo_skb(dev, 0);
478                         netif_wake_queue(dev);
479                 }
480                 if (isrc & IRQ_RI) {
481                         /* receive interrupt */
482                         while (status & SR_RBS) {
483                                 sja1000_rx(dev);
484                                 status = priv->read_reg(priv, REG_SR);
485                         }
486                 }
487                 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
488                         /* error interrupt */
489                         if (sja1000_err(dev, isrc, status))
490                                 break;
491                 }
492         }
493
494         if (priv->post_irq)
495                 priv->post_irq(priv);
496
497         if (n >= SJA1000_MAX_IRQ)
498                 dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);
499
500         return (n) ? IRQ_HANDLED : IRQ_NONE;
501 }
502 EXPORT_SYMBOL_GPL(sja1000_interrupt);
503
504 static int sja1000_open(struct net_device *dev)
505 {
506         struct sja1000_priv *priv = netdev_priv(dev);
507         int err;
508
509         /* set chip into reset mode */
510         set_reset_mode(dev);
511
512         /* common open */
513         err = open_candev(dev);
514         if (err)
515                 return err;
516
517         /* register interrupt handler, if not done by the device driver */
518         if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
519                 err = request_irq(dev->irq, &sja1000_interrupt, priv->irq_flags,
520                                   dev->name, (void *)dev);
521                 if (err) {
522                         close_candev(dev);
523                         return -EAGAIN;
524                 }
525         }
526
527         /* init and start chi */
528         sja1000_start(dev);
529         priv->open_time = jiffies;
530
531         netif_start_queue(dev);
532
533         return 0;
534 }
535
536 static int sja1000_close(struct net_device *dev)
537 {
538         struct sja1000_priv *priv = netdev_priv(dev);
539
540         netif_stop_queue(dev);
541         set_reset_mode(dev);
542
543         if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
544                 free_irq(dev->irq, (void *)dev);
545
546         close_candev(dev);
547
548         priv->open_time = 0;
549
550         return 0;
551 }
552
553 struct net_device *alloc_sja1000dev(int sizeof_priv)
554 {
555         struct net_device *dev;
556         struct sja1000_priv *priv;
557
558         dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
559                 SJA1000_ECHO_SKB_MAX);
560         if (!dev)
561                 return NULL;
562
563         priv = netdev_priv(dev);
564
565         priv->dev = dev;
566         priv->can.bittiming_const = &sja1000_bittiming_const;
567         priv->can.do_set_bittiming = sja1000_set_bittiming;
568         priv->can.do_set_mode = sja1000_set_mode;
569
570         if (sizeof_priv)
571                 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
572
573         return dev;
574 }
575 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
576
577 void free_sja1000dev(struct net_device *dev)
578 {
579         free_candev(dev);
580 }
581 EXPORT_SYMBOL_GPL(free_sja1000dev);
582
583 static const struct net_device_ops sja1000_netdev_ops = {
584        .ndo_open               = sja1000_open,
585        .ndo_stop               = sja1000_close,
586        .ndo_start_xmit         = sja1000_start_xmit,
587 };
588
589 int register_sja1000dev(struct net_device *dev)
590 {
591         if (!sja1000_probe_chip(dev))
592                 return -ENODEV;
593
594         dev->flags |= IFF_ECHO; /* we support local echo */
595         dev->netdev_ops = &sja1000_netdev_ops;
596
597         set_reset_mode(dev);
598         chipset_init(dev);
599
600         return register_candev(dev);
601 }
602 EXPORT_SYMBOL_GPL(register_sja1000dev);
603
604 void unregister_sja1000dev(struct net_device *dev)
605 {
606         set_reset_mode(dev);
607         unregister_candev(dev);
608 }
609 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
610
611 static __init int sja1000_init(void)
612 {
613         printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
614
615         return 0;
616 }
617
618 module_init(sja1000_init);
619
620 static __exit void sja1000_exit(void)
621 {
622         printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
623 }
624
625 module_exit(sja1000_exit);