summaryrefslogtreecommitdiffstats
path: root/drivers/net/can/cc770/cc770.c
blob: 0f12abf6591ce79bdc30b1f69844f7d811ac5d1e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
/*
 * Core driver for the CC770 and AN82527 CAN controllers
 *
 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/delay.h>

#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/platform/cc770.h>

#include "cc770.h"

MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");

/*
 * The CC770 is a CAN controller from Bosch, which is 100% compatible
 * with the AN82527 from Intel, but with "bugs" being fixed and some
 * additional functionality, mainly:
 *
 * 1. RX and TX error counters are readable.
 * 2. Support of silent (listen-only) mode.
 * 3. Message object 15 can receive all types of frames, also RTR and EFF.
 *
 * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
 * which explains in detail the compatibility between the CC770 and the
 * 82527. This driver use the additional functionality 3. on real CC770
 * devices. Unfortunately, the CC770 does still not store the message
 * identifier of received remote transmission request frames and
 * therefore it's set to 0.
 *
 * The message objects 1..14 can be used for TX and RX while the message
 * objects 15 is optimized for RX. It has a shadow register for reliable
 * data receiption under heavy bus load. Therefore it makes sense to use
 * this message object for the needed use case. The frame type (EFF/SFF)
 * for the message object 15 can be defined via kernel module parameter
 * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
 * otherwise 11 bit SFF messages.
 */
static int msgobj15_eff;
module_param(msgobj15_eff, int, S_IRUGO);
MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
		 "(default: 11-bit standard frames)");

static int i82527_compat;
module_param(i82527_compat, int, S_IRUGO);
MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 comptibility mode "
		 "without using additional functions");

/*
 * This driver uses the last 5 message objects 11..15. The definitions
 * and structure below allows to configure and assign them to the real
 * message object.
 */
static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
	[CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
	[CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
	[CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
	[CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
			      CC770_OBJ_FLAG_EFF,
	[CC770_OBJ_TX] = 0,
};

static const struct can_bittiming_const cc770_bittiming_const = {
	.name = KBUILD_MODNAME,
	.tseg1_min = 1,
	.tseg1_max = 16,
	.tseg2_min = 1,
	.tseg2_max = 8,
	.sjw_max = 4,
	.brp_min = 1,
	.brp_max = 64,
	.brp_inc = 1,
};

static inline int intid2obj(unsigned int intid)
{
	if (intid == 2)
		return 0;
	else
		return MSGOBJ_LAST + 2 - intid;
}

static void enable_all_objs(const struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);
	u8 msgcfg;
	unsigned char obj_flags;
	unsigned int o, mo;

	for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
		obj_flags = priv->obj_flags[o];
		mo = obj2msgobj(o);

		if (obj_flags & CC770_OBJ_FLAG_RX) {
			/*
			 * We don't need extra objects for RTR and EFF if
			 * the additional CC770 functions are enabled.
			 */
			if (priv->control_normal_mode & CTRL_EAF) {
				if (o > 0)
					continue;
				netdev_dbg(dev, "Message object %d for "
					   "RX data, RTR, SFF and EFF\n", mo);
			} else {
				netdev_dbg(dev,
					   "Message object %d for RX %s %s\n",
					   mo, obj_flags & CC770_OBJ_FLAG_RTR ?
					   "RTR" : "data",
					   obj_flags & CC770_OBJ_FLAG_EFF ?
					   "EFF" : "SFF");
			}

			if (obj_flags & CC770_OBJ_FLAG_EFF)
				msgcfg = MSGCFG_XTD;
			else
				msgcfg = 0;
			if (obj_flags & CC770_OBJ_FLAG_RTR)
				msgcfg |= MSGCFG_DIR;

			cc770_write_reg(priv, msgobj[mo].config, msgcfg);
			cc770_write_reg(priv, msgobj[mo].ctrl0,
					MSGVAL_SET | TXIE_RES |
					RXIE_SET | INTPND_RES);

			if (obj_flags & CC770_OBJ_FLAG_RTR)
				cc770_write_reg(priv, msgobj[mo].ctrl1,
						NEWDAT_RES | CPUUPD_SET |
						TXRQST_RES | RMTPND_RES);
			else
				cc770_write_reg(priv, msgobj[mo].ctrl1,
						NEWDAT_RES | MSGLST_RES |
						TXRQST_RES | RMTPND_RES);
		} else {
			netdev_dbg(dev, "Message object %d for "
				   "TX data, RTR, SFF and EFF\n", mo);

			cc770_write_reg(priv, msgobj[mo].ctrl1,
					RMTPND_RES | TXRQST_RES |
					CPUUPD_RES | NEWDAT_RES);
			cc770_write_reg(priv, msgobj[mo].ctrl0,
					MSGVAL_RES | TXIE_RES |
					RXIE_RES | INTPND_RES);
		}
	}
}

static void disable_all_objs(const struct cc770_priv *priv)
{
	int o, mo;

	for (o = 0; o <  ARRAY_SIZE(priv->obj_flags); o++) {
		mo = obj2msgobj(o);

		if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
			if (o > 0 && priv->control_normal_mode & CTRL_EAF)
				continue;

			cc770_write_reg(priv, msgobj[mo].ctrl1,
					NEWDAT_RES | MSGLST_RES |
					TXRQST_RES | RMTPND_RES);
			cc770_write_reg(priv, msgobj[mo].ctrl0,
					MSGVAL_RES | TXIE_RES |
					RXIE_RES | INTPND_RES);
		} else {
			/* Clear message object for send */
			cc770_write_reg(priv, msgobj[mo].ctrl1,
					RMTPND_RES | TXRQST_RES |
					CPUUPD_RES | NEWDAT_RES);
			cc770_write_reg(priv, msgobj[mo].ctrl0,
					MSGVAL_RES | TXIE_RES |
					RXIE_RES | INTPND_RES);
		}
	}
}

static void set_reset_mode(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);

	/* Enable configuration and puts chip in bus-off, disable interrupts */
	cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);

	priv->can.state = CAN_STATE_STOPPED;

	/* Clear interrupts */
	cc770_read_reg(priv, interrupt);

	/* Clear status register */
	cc770_write_reg(priv, status, 0);

	/* Disable all used message objects */
	disable_all_objs(priv);
}

static void set_normal_mode(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);

	/* Clear interrupts */
	cc770_read_reg(priv, interrupt);

	/* Clear status register and pre-set last error code */
	cc770_write_reg(priv, status, STAT_LEC_MASK);

	/* Enable all used message objects*/
	enable_all_objs(dev);

	/*
	 * Clear bus-off, interrupts only for errors,
	 * not for status change
	 */
	cc770_write_reg(priv, control, priv->control_normal_mode);

	priv->can.state = CAN_STATE_ERROR_ACTIVE;
}

static void chipset_init(struct cc770_priv *priv)
{
	int mo, id, data;

	/* Enable configuration and put chip in bus-off, disable interrupts */
	cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));

	/* Set CLKOUT divider and slew rates */
	cc770_write_reg(priv, clkout, priv->clkout);

	/* Configure CPU interface / CLKOUT enable */
	cc770_write_reg(priv, cpu_interface, priv->cpu_interface);

	/* Set bus configuration  */
	cc770_write_reg(priv, bus_config, priv->bus_config);

	/* Clear interrupts */
	cc770_read_reg(priv, interrupt);

	/* Clear status register */
	cc770_write_reg(priv, status, 0);

	/* Clear and invalidate message objects */
	for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
		cc770_write_reg(priv, msgobj[mo].ctrl0,
				INTPND_UNC | RXIE_RES |
				TXIE_RES | MSGVAL_RES);
		cc770_write_reg(priv, msgobj[mo].ctrl0,
				INTPND_RES | RXIE_RES |
				TXIE_RES | MSGVAL_RES);
		cc770_write_reg(priv, msgobj[mo].ctrl1,
				NEWDAT_RES | MSGLST_RES |
				TXRQST_RES | RMTPND_RES);
		for (data = 0; data < 8; data++)
			cc770_write_reg(priv, msgobj[mo].data[data], 0);
		for (id = 0; id < 4; id++)
			cc770_write_reg(priv, msgobj[mo].id[id], 0);
		cc770_write_reg(priv, msgobj[mo].config, 0);
	}

	/* Set all global ID masks to "don't care" */
	cc770_write_reg(priv, global_mask_std[0], 0);
	cc770_write_reg(priv, global_mask_std[1], 0);
	cc770_write_reg(priv, global_mask_ext[0], 0);
	cc770_write_reg(priv, global_mask_ext[1], 0);
	cc770_write_reg(priv, global_mask_ext[2], 0);
	cc770_write_reg(priv, global_mask_ext[3], 0);

}

static int cc770_probe_chip(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);

	/* Enable configuration, put chip in bus-off, disable ints */
	cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
	/* Configure cpu interface / CLKOUT disable */
	cc770_write_reg(priv, cpu_interface, priv->cpu_interface);

	/*
	 * Check if hardware reset is still inactive or maybe there
	 * is no chip in this address space
	 */
	if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
		netdev_info(dev, "probing @0x%p failed (reset)\n",
			    priv->reg_base);
		return -ENODEV;
	}

	/* Write and read back test pattern (some arbitrary values) */
	cc770_write_reg(priv, msgobj[1].data[1], 0x25);
	cc770_write_reg(priv, msgobj[2].data[3], 0x52);
	cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
	if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
	    (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
	    (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
		netdev_info(dev, "probing @0x%p failed (pattern)\n",
			    priv->reg_base);
		return -ENODEV;
	}

	/* Check if this chip is a CC770 supporting additional functions */
	if (cc770_read_reg(priv, control) & CTRL_EAF)
		priv->control_normal_mode |= CTRL_EAF;

	return 0;
}

static void cc770_start(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);

	/* leave reset mode */
	if (priv->can.state != CAN_STATE_STOPPED)
		set_reset_mode(dev);

	/* leave reset mode */
	set_normal_mode(dev);
}

static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
{
	switch (mode) {
	case CAN_MODE_START:
		cc770_start(dev);
		netif_wake_queue(dev);
		break;

	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int cc770_set_bittiming(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);
	struct can_bittiming *bt = &priv->can.bittiming;
	u8 btr0, btr1;

	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
		(((bt->phase_seg2 - 1) & 0x7) << 4);
	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
		btr1 |= 0x80;

	netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);

	cc770_write_reg(priv, bit_timing_0, btr0);
	cc770_write_reg(priv, bit_timing_1, btr1);

	return 0;
}

static int cc770_get_berr_counter(const struct net_device *dev,
				  struct can_berr_counter *bec)
{
	struct cc770_priv *priv = netdev_priv(dev);

	bec->txerr = cc770_read_reg(priv, tx_error_counter);
	bec->rxerr = cc770_read_reg(priv, rx_error_counter);

	return 0;
}

static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf = (struct can_frame *)skb->data;
	unsigned int mo = obj2msgobj(CC770_OBJ_TX);
	u8 dlc, rtr;
	u32 id;
	int i;

	if (can_dropped_invalid_skb(dev, skb))
		return NETDEV_TX_OK;

	if ((cc770_read_reg(priv,
			    msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
		netdev_err(dev, "TX register is still occupied!\n");
		return NETDEV_TX_BUSY;
	}

	netif_stop_queue(dev);

	dlc = cf->can_dlc;
	id = cf->can_id;
	if (cf->can_id & CAN_RTR_FLAG)
		rtr = 0;
	else
		rtr = MSGCFG_DIR;
	cc770_write_reg(priv, msgobj[mo].ctrl1,
			RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
	cc770_write_reg(priv, msgobj[mo].ctrl0,
			MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
	if (id & CAN_EFF_FLAG) {
		id &= CAN_EFF_MASK;
		cc770_write_reg(priv, msgobj[mo].config,
				(dlc << 4) | rtr | MSGCFG_XTD);
		cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
		cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
		cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
		cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
	} else {
		id &= CAN_SFF_MASK;
		cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
		cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
		cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
	}

	for (i = 0; i < dlc; i++)
		cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);

	/* Store echo skb before starting the transfer */
	can_put_echo_skb(skb, dev, 0);

	cc770_write_reg(priv, msgobj[mo].ctrl1,
			RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);

	stats->tx_bytes += dlc;


	/*
	 * HM: We had some cases of repeated IRQs so make sure the
	 * INT is acknowledged I know it's already further up, but
	 * doing again fixed the issue
	 */
	cc770_write_reg(priv, msgobj[mo].ctrl0,
			MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);

	return NETDEV_TX_OK;
}

static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
{
	struct cc770_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf;
	struct sk_buff *skb;
	u8 config;
	u32 id;
	int i;

	skb = alloc_can_skb(dev, &cf);
	if (!skb)
		return;

	config = cc770_read_reg(priv, msgobj[mo].config);

	if (ctrl1 & RMTPND_SET) {
		/*
		 * Unfortunately, the chip does not store the real message
		 * identifier of the received remote transmission request
		 * frame. Therefore we set it to 0.
		 */
		cf->can_id = CAN_RTR_FLAG;
		if (config & MSGCFG_XTD)
			cf->can_id |= CAN_EFF_FLAG;
		cf->can_dlc = 0;
	} else {
		if (config & MSGCFG_XTD) {
			id = cc770_read_reg(priv, msgobj[mo].id[3]);
			id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
			id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
			id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
			id >>= 3;
			id |= CAN_EFF_FLAG;
		} else {
			id = cc770_read_reg(priv, msgobj[mo].id[1]);
			id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
			id >>= 5;
		}

		cf->can_id = id;
		cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
		for (i = 0; i < cf->can_dlc; i++)
			cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
	}
	netif_rx(skb);

	stats->rx_packets++;
	stats->rx_bytes += cf->can_dlc;
}

static int cc770_err(struct net_device *dev, u8 status)
{
	struct cc770_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf;
	struct sk_buff *skb;
	u8 lec;

	netdev_dbg(dev, "status interrupt (%#x)\n", status);

	skb = alloc_can_err_skb(dev, &cf);
	if (!skb)
		return -ENOMEM;

	/* Use extended functions of the CC770 */
	if (priv->control_normal_mode & CTRL_EAF) {
		cf->data[6] = cc770_read_reg(priv, tx_error_counter);
		cf->data[7] = cc770_read_reg(priv, rx_error_counter);
	}

	if (status & STAT_BOFF) {
		/* Disable interrupts */
		cc770_write_reg(priv, control, CTRL_INI);
		cf->can_id |= CAN_ERR_BUSOFF;
		priv->can.state = CAN_STATE_BUS_OFF;
		can_bus_off(dev);
	} else if (status & STAT_WARN) {
		cf->can_id |= CAN_ERR_CRTL;
		/* Only the CC770 does show error passive */
		if (cf->data[7] > 127) {
			cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
				CAN_ERR_CRTL_TX_PASSIVE;
			priv->can.state = CAN_STATE_ERROR_PASSIVE;
			priv->can.can_stats.error_passive++;
		} else {
			cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
				CAN_ERR_CRTL_TX_WARNING;
			priv->can.state = CAN_STATE_ERROR_WARNING;
			priv->can.can_stats.error_warning++;
		}
	} else {
		/* Back to error avtive */
		cf->can_id |= CAN_ERR_PROT;
		cf->data[2] = CAN_ERR_PROT_ACTIVE;
		priv->can.state = CAN_STATE_ERROR_ACTIVE;
	}

	lec = status & STAT_LEC_MASK;
	if (lec < 7 && lec > 0) {
		if (lec == STAT_LEC_ACK) {
			cf->can_id |= CAN_ERR_ACK;
		} else {
			cf->can_id |= CAN_ERR_PROT;
			switch (lec) {
			case STAT_LEC_STUFF:
				cf->data[2] |= CAN_ERR_PROT_STUFF;
				break;
			case STAT_LEC_FORM:
				cf->data[2] |= CAN_ERR_PROT_FORM;
				break;
			case STAT_LEC_BIT1:
				cf->data[2] |= CAN_ERR_PROT_BIT1;
				break;
			case STAT_LEC_BIT0:
				cf->data[2] |= CAN_ERR_PROT_BIT0;
				break;
			case STAT_LEC_CRC:
				cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
				break;
			}
		}
	}

	netif_rx(skb);

	stats->rx_packets++;
	stats->rx_bytes += cf->can_dlc;

	return 0;
}

static int cc770_status_interrupt(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);
	u8 status;

	status = cc770_read_reg(priv, status);
	/* Reset the status register including RXOK and TXOK */
	cc770_write_reg(priv, status, STAT_LEC_MASK);

	if (status & (STAT_WARN | STAT_BOFF) ||
	    (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
		cc770_err(dev, status);
		return status & STAT_BOFF;
	}

	return 0;
}

static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
{
	struct cc770_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	unsigned int mo = obj2msgobj(o);
	u8 ctrl1;
	int n = CC770_MAX_MSG;

	while (n--) {
		ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);

		if (!(ctrl1 & NEWDAT_SET))  {
			/* Check for RTR if additional functions are enabled */
			if (priv->control_normal_mode & CTRL_EAF) {
				if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
				      INTPND_SET))
					break;
			} else {
				break;
			}
		}

		if (ctrl1 & MSGLST_SET) {
			stats->rx_over_errors++;
			stats->rx_errors++;
		}
		if (mo < MSGOBJ_LAST)
			cc770_write_reg(priv, msgobj[mo].ctrl1,
					NEWDAT_RES | MSGLST_RES |
					TXRQST_UNC | RMTPND_UNC);
		cc770_rx(dev, mo, ctrl1);

		cc770_write_reg(priv, msgobj[mo].ctrl0,
				MSGVAL_SET | TXIE_RES |
				RXIE_SET | INTPND_RES);
		cc770_write_reg(priv, msgobj[mo].ctrl1,
				NEWDAT_RES | MSGLST_RES |
				TXRQST_RES | RMTPND_RES);
	}
}

static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
{
	struct cc770_priv *priv = netdev_priv(dev);
	unsigned int mo = obj2msgobj(o);
	u8 ctrl0, ctrl1;
	int n = CC770_MAX_MSG;

	while (n--) {
		ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
		if (!(ctrl0 & INTPND_SET))
			break;

		ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
		cc770_rx(dev, mo, ctrl1);

		cc770_write_reg(priv, msgobj[mo].ctrl0,
				MSGVAL_SET | TXIE_RES |
				RXIE_SET | INTPND_RES);
		cc770_write_reg(priv, msgobj[mo].ctrl1,
				NEWDAT_RES | CPUUPD_SET |
				TXRQST_RES | RMTPND_RES);
	}
}

static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
{
	struct cc770_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	unsigned int mo = obj2msgobj(o);

	/* Nothing more to send, switch off interrupts */
	cc770_write_reg(priv, msgobj[mo].ctrl0,
			MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
	/*
	 * We had some cases of repeated IRQ so make sure the
	 * INT is acknowledged
	 */
	cc770_write_reg(priv, msgobj[mo].ctrl0,
			MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);

	stats->tx_packets++;
	can_get_echo_skb(dev, 0);
	netif_wake_queue(dev);
}

static irqreturn_t cc770_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct cc770_priv *priv = netdev_priv(dev);
	u8 intid;
	int o, n = 0;

	/* Shared interrupts and IRQ off? */
	if (priv->can.state == CAN_STATE_STOPPED)
		return IRQ_NONE;

	if (priv->pre_irq)
		priv->pre_irq(priv);

	while (n < CC770_MAX_IRQ) {
		/* Read the highest pending interrupt request */
		intid = cc770_read_reg(priv, interrupt);
		if (!intid)
			break;
		n++;

		if (intid == 1) {
			/* Exit in case of bus-off */
			if (cc770_status_interrupt(dev))
				break;
		} else {
			o = intid2obj(intid);

			if (o >= CC770_OBJ_MAX) {
				netdev_err(dev, "Unexpected interrupt id %d\n",
					   intid);
				continue;
			}

			if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
				cc770_rtr_interrupt(dev, o);
			else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
				cc770_rx_interrupt(dev, o);
			else
				cc770_tx_interrupt(dev, o);
		}
	}

	if (priv->post_irq)
		priv->post_irq(priv);

	if (n >= CC770_MAX_IRQ)
		netdev_dbg(dev, "%d messages handled in ISR", n);

	return (n) ? IRQ_HANDLED : IRQ_NONE;
}

static int cc770_open(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);
	int err;

	/* set chip into reset mode */
	set_reset_mode(dev);

	/* common open */
	err = open_candev(dev);
	if (err)
		return err;

	err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
			  dev->name, dev);
	if (err) {
		close_candev(dev);
		return -EAGAIN;
	}

	/* init and start chip */
	cc770_start(dev);

	netif_start_queue(dev);

	return 0;
}

static int cc770_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	set_reset_mode(dev);

	free_irq(dev->irq, dev);
	close_candev(dev);

	return 0;
}

struct net_device *alloc_cc770dev(int sizeof_priv)
{
	struct net_device *dev;
	struct cc770_priv *priv;

	dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
			   CC770_ECHO_SKB_MAX);
	if (!dev)
		return NULL;

	priv = netdev_priv(dev);

	priv->dev = dev;
	priv->can.bittiming_const = &cc770_bittiming_const;
	priv->can.do_set_bittiming = cc770_set_bittiming;
	priv->can.do_set_mode = cc770_set_mode;
	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;

	memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));

	if (sizeof_priv)
		priv->priv = (void *)priv + sizeof(struct cc770_priv);

	return dev;
}
EXPORT_SYMBOL_GPL(alloc_cc770dev);

void free_cc770dev(struct net_device *dev)
{
	free_candev(dev);
}
EXPORT_SYMBOL_GPL(free_cc770dev);

static const struct net_device_ops cc770_netdev_ops = {
	.ndo_open = cc770_open,
	.ndo_stop = cc770_close,
	.ndo_start_xmit = cc770_start_xmit,
};

int register_cc770dev(struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);
	int err;

	err = cc770_probe_chip(dev);
	if (err)
		return err;

	dev->netdev_ops = &cc770_netdev_ops;

	dev->flags |= IFF_ECHO;	/* we support local echo */

	/* Should we use additional functions? */
	if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
		priv->can.do_get_berr_counter = cc770_get_berr_counter;
		priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
		netdev_dbg(dev, "i82527 mode with additional functions\n");
	} else {
		priv->control_normal_mode = CTRL_IE | CTRL_EIE;
		netdev_dbg(dev, "strict i82527 compatibility mode\n");
	}

	chipset_init(priv);
	set_reset_mode(dev);

	return register_candev(dev);
}
EXPORT_SYMBOL_GPL(register_cc770dev);

void unregister_cc770dev(struct net_device *dev)
{
	set_reset_mode(dev);
	unregister_candev(dev);
}
EXPORT_SYMBOL_GPL(unregister_cc770dev);

static __init int cc770_init(void)
{
	if (msgobj15_eff) {
		cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
		cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
	}

	pr_info("CAN netdevice driver\n");

	return 0;
}
module_init(cc770_init);

static __exit void cc770_exit(void)
{
	pr_info("driver removed\n");
}
module_exit(cc770_exit);
OpenPOWER on IntegriCloud