drivers: Kill now superfluous ->last_rx stores
[GitHub/mt8127/android_kernel_alcatel_ttab.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 net_device_stats *stats = &dev->stats;
246 struct can_frame *cf = (struct can_frame *)skb->data;
247 uint8_t fi;
248 uint8_t dlc;
249 canid_t id;
250 uint8_t dreg;
251 int i;
252
253 netif_stop_queue(dev);
254
255 fi = dlc = cf->can_dlc;
256 id = cf->can_id;
257
258 if (id & CAN_RTR_FLAG)
259 fi |= FI_RTR;
260
261 if (id & CAN_EFF_FLAG) {
262 fi |= FI_FF;
263 dreg = EFF_BUF;
264 priv->write_reg(priv, REG_FI, fi);
265 priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
266 priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
267 priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
268 priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
269 } else {
270 dreg = SFF_BUF;
271 priv->write_reg(priv, REG_FI, fi);
272 priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
273 priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
274 }
275
276 for (i = 0; i < dlc; i++)
277 priv->write_reg(priv, dreg++, cf->data[i]);
278
279 stats->tx_bytes += dlc;
280 dev->trans_start = jiffies;
281
282 can_put_echo_skb(skb, dev, 0);
283
284 priv->write_reg(priv, REG_CMR, CMD_TR);
285
286 return NETDEV_TX_OK;
287 }
288
289 static void sja1000_rx(struct net_device *dev)
290 {
291 struct sja1000_priv *priv = netdev_priv(dev);
292 struct net_device_stats *stats = &dev->stats;
293 struct can_frame *cf;
294 struct sk_buff *skb;
295 uint8_t fi;
296 uint8_t dreg;
297 canid_t id;
298 uint8_t dlc;
299 int i;
300
301 skb = dev_alloc_skb(sizeof(struct can_frame));
302 if (skb == NULL)
303 return;
304 skb->dev = dev;
305 skb->protocol = htons(ETH_P_CAN);
306
307 fi = priv->read_reg(priv, REG_FI);
308 dlc = fi & 0x0F;
309
310 if (fi & FI_FF) {
311 /* extended frame format (EFF) */
312 dreg = EFF_BUF;
313 id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
314 | (priv->read_reg(priv, REG_ID2) << (5 + 8))
315 | (priv->read_reg(priv, REG_ID3) << 5)
316 | (priv->read_reg(priv, REG_ID4) >> 3);
317 id |= CAN_EFF_FLAG;
318 } else {
319 /* standard frame format (SFF) */
320 dreg = SFF_BUF;
321 id = (priv->read_reg(priv, REG_ID1) << 3)
322 | (priv->read_reg(priv, REG_ID2) >> 5);
323 }
324
325 if (fi & FI_RTR)
326 id |= CAN_RTR_FLAG;
327
328 cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
329 memset(cf, 0, sizeof(struct can_frame));
330 cf->can_id = id;
331 cf->can_dlc = dlc;
332 for (i = 0; i < dlc; i++)
333 cf->data[i] = priv->read_reg(priv, dreg++);
334
335 while (i < 8)
336 cf->data[i++] = 0;
337
338 /* release receive buffer */
339 priv->write_reg(priv, REG_CMR, CMD_RRB);
340
341 netif_rx(skb);
342
343 stats->rx_packets++;
344 stats->rx_bytes += dlc;
345 }
346
347 static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
348 {
349 struct sja1000_priv *priv = netdev_priv(dev);
350 struct net_device_stats *stats = &dev->stats;
351 struct can_frame *cf;
352 struct sk_buff *skb;
353 enum can_state state = priv->can.state;
354 uint8_t ecc, alc;
355
356 skb = dev_alloc_skb(sizeof(struct can_frame));
357 if (skb == NULL)
358 return -ENOMEM;
359 skb->dev = dev;
360 skb->protocol = htons(ETH_P_CAN);
361 cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
362 memset(cf, 0, sizeof(struct can_frame));
363 cf->can_id = CAN_ERR_FLAG;
364 cf->can_dlc = CAN_ERR_DLC;
365
366 if (isrc & IRQ_DOI) {
367 /* data overrun interrupt */
368 dev_dbg(dev->dev.parent, "data overrun interrupt\n");
369 cf->can_id |= CAN_ERR_CRTL;
370 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
371 stats->rx_over_errors++;
372 stats->rx_errors++;
373 priv->write_reg(priv, REG_CMR, CMD_CDO); /* clear bit */
374 }
375
376 if (isrc & IRQ_EI) {
377 /* error warning interrupt */
378 dev_dbg(dev->dev.parent, "error warning interrupt\n");
379
380 if (status & SR_BS) {
381 state = CAN_STATE_BUS_OFF;
382 cf->can_id |= CAN_ERR_BUSOFF;
383 can_bus_off(dev);
384 } else if (status & SR_ES) {
385 state = CAN_STATE_ERROR_WARNING;
386 } else
387 state = CAN_STATE_ERROR_ACTIVE;
388 }
389 if (isrc & IRQ_BEI) {
390 /* bus error interrupt */
391 priv->can.can_stats.bus_error++;
392 stats->rx_errors++;
393
394 ecc = priv->read_reg(priv, REG_ECC);
395
396 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
397
398 switch (ecc & ECC_MASK) {
399 case ECC_BIT:
400 cf->data[2] |= CAN_ERR_PROT_BIT;
401 break;
402 case ECC_FORM:
403 cf->data[2] |= CAN_ERR_PROT_FORM;
404 break;
405 case ECC_STUFF:
406 cf->data[2] |= CAN_ERR_PROT_STUFF;
407 break;
408 default:
409 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
410 cf->data[3] = ecc & ECC_SEG;
411 break;
412 }
413 /* Error occured during transmission? */
414 if ((ecc & ECC_DIR) == 0)
415 cf->data[2] |= CAN_ERR_PROT_TX;
416 }
417 if (isrc & IRQ_EPI) {
418 /* error passive interrupt */
419 dev_dbg(dev->dev.parent, "error passive interrupt\n");
420 if (status & SR_ES)
421 state = CAN_STATE_ERROR_PASSIVE;
422 else
423 state = CAN_STATE_ERROR_ACTIVE;
424 }
425 if (isrc & IRQ_ALI) {
426 /* arbitration lost interrupt */
427 dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
428 alc = priv->read_reg(priv, REG_ALC);
429 priv->can.can_stats.arbitration_lost++;
430 stats->rx_errors++;
431 cf->can_id |= CAN_ERR_LOSTARB;
432 cf->data[0] = alc & 0x1f;
433 }
434
435 if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
436 state == CAN_STATE_ERROR_PASSIVE)) {
437 uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
438 uint8_t txerr = priv->read_reg(priv, REG_TXERR);
439 cf->can_id |= CAN_ERR_CRTL;
440 if (state == CAN_STATE_ERROR_WARNING) {
441 priv->can.can_stats.error_warning++;
442 cf->data[1] = (txerr > rxerr) ?
443 CAN_ERR_CRTL_TX_WARNING :
444 CAN_ERR_CRTL_RX_WARNING;
445 } else {
446 priv->can.can_stats.error_passive++;
447 cf->data[1] = (txerr > rxerr) ?
448 CAN_ERR_CRTL_TX_PASSIVE :
449 CAN_ERR_CRTL_RX_PASSIVE;
450 }
451 }
452
453 priv->can.state = state;
454
455 netif_rx(skb);
456
457 stats->rx_packets++;
458 stats->rx_bytes += cf->can_dlc;
459
460 return 0;
461 }
462
463 irqreturn_t sja1000_interrupt(int irq, void *dev_id)
464 {
465 struct net_device *dev = (struct net_device *)dev_id;
466 struct sja1000_priv *priv = netdev_priv(dev);
467 struct net_device_stats *stats = &dev->stats;
468 uint8_t isrc, status;
469 int n = 0;
470
471 /* Shared interrupts and IRQ off? */
472 if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
473 return IRQ_NONE;
474
475 if (priv->pre_irq)
476 priv->pre_irq(priv);
477
478 while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
479 n++;
480 status = priv->read_reg(priv, REG_SR);
481
482 if (isrc & IRQ_WUI)
483 dev_warn(dev->dev.parent, "wakeup interrupt\n");
484
485 if (isrc & IRQ_TI) {
486 /* transmission complete interrupt */
487 stats->tx_packets++;
488 can_get_echo_skb(dev, 0);
489 netif_wake_queue(dev);
490 }
491 if (isrc & IRQ_RI) {
492 /* receive interrupt */
493 while (status & SR_RBS) {
494 sja1000_rx(dev);
495 status = priv->read_reg(priv, REG_SR);
496 }
497 }
498 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
499 /* error interrupt */
500 if (sja1000_err(dev, isrc, status))
501 break;
502 }
503 }
504
505 if (priv->post_irq)
506 priv->post_irq(priv);
507
508 if (n >= SJA1000_MAX_IRQ)
509 dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);
510
511 return (n) ? IRQ_HANDLED : IRQ_NONE;
512 }
513 EXPORT_SYMBOL_GPL(sja1000_interrupt);
514
515 static int sja1000_open(struct net_device *dev)
516 {
517 struct sja1000_priv *priv = netdev_priv(dev);
518 int err;
519
520 /* set chip into reset mode */
521 set_reset_mode(dev);
522
523 /* common open */
524 err = open_candev(dev);
525 if (err)
526 return err;
527
528 /* register interrupt handler, if not done by the device driver */
529 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
530 err = request_irq(dev->irq, &sja1000_interrupt, priv->irq_flags,
531 dev->name, (void *)dev);
532 if (err) {
533 close_candev(dev);
534 return -EAGAIN;
535 }
536 }
537
538 /* init and start chi */
539 sja1000_start(dev);
540 priv->open_time = jiffies;
541
542 netif_start_queue(dev);
543
544 return 0;
545 }
546
547 static int sja1000_close(struct net_device *dev)
548 {
549 struct sja1000_priv *priv = netdev_priv(dev);
550
551 netif_stop_queue(dev);
552 set_reset_mode(dev);
553
554 if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
555 free_irq(dev->irq, (void *)dev);
556
557 close_candev(dev);
558
559 priv->open_time = 0;
560
561 return 0;
562 }
563
564 struct net_device *alloc_sja1000dev(int sizeof_priv)
565 {
566 struct net_device *dev;
567 struct sja1000_priv *priv;
568
569 dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv);
570 if (!dev)
571 return NULL;
572
573 priv = netdev_priv(dev);
574
575 priv->dev = dev;
576 priv->can.bittiming_const = &sja1000_bittiming_const;
577 priv->can.do_set_bittiming = sja1000_set_bittiming;
578 priv->can.do_set_mode = sja1000_set_mode;
579
580 if (sizeof_priv)
581 priv->priv = (void *)priv + sizeof(struct sja1000_priv);
582
583 return dev;
584 }
585 EXPORT_SYMBOL_GPL(alloc_sja1000dev);
586
587 void free_sja1000dev(struct net_device *dev)
588 {
589 free_candev(dev);
590 }
591 EXPORT_SYMBOL_GPL(free_sja1000dev);
592
593 static const struct net_device_ops sja1000_netdev_ops = {
594 .ndo_open = sja1000_open,
595 .ndo_stop = sja1000_close,
596 .ndo_start_xmit = sja1000_start_xmit,
597 };
598
599 int register_sja1000dev(struct net_device *dev)
600 {
601 if (!sja1000_probe_chip(dev))
602 return -ENODEV;
603
604 dev->flags |= IFF_ECHO; /* we support local echo */
605 dev->netdev_ops = &sja1000_netdev_ops;
606
607 set_reset_mode(dev);
608 chipset_init(dev);
609
610 return register_candev(dev);
611 }
612 EXPORT_SYMBOL_GPL(register_sja1000dev);
613
614 void unregister_sja1000dev(struct net_device *dev)
615 {
616 set_reset_mode(dev);
617 unregister_candev(dev);
618 }
619 EXPORT_SYMBOL_GPL(unregister_sja1000dev);
620
621 static __init int sja1000_init(void)
622 {
623 printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
624
625 return 0;
626 }
627
628 module_init(sja1000_init);
629
630 static __exit void sja1000_exit(void)
631 {
632 printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
633 }
634
635 module_exit(sja1000_exit);