xref: /linux/drivers/net/can/cc770/cc770.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1 /*
2  * Core driver for the CC770 and AN82527 CAN controllers
3  *
4  * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the version 2 of the GNU General Public License
8  * as published by the Free Software Foundation
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/types.h>
23 #include <linux/fcntl.h>
24 #include <linux/interrupt.h>
25 #include <linux/ptrace.h>
26 #include <linux/string.h>
27 #include <linux/errno.h>
28 #include <linux/netdevice.h>
29 #include <linux/if_arp.h>
30 #include <linux/if_ether.h>
31 #include <linux/skbuff.h>
32 #include <linux/delay.h>
33 
34 #include <linux/can.h>
35 #include <linux/can/dev.h>
36 #include <linux/can/error.h>
37 #include <linux/can/dev.h>
38 #include <linux/can/platform/cc770.h>
39 
40 #include "cc770.h"
41 
42 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
43 MODULE_LICENSE("GPL v2");
44 MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
45 
46 /*
47  * The CC770 is a CAN controller from Bosch, which is 100% compatible
48  * with the AN82527 from Intel, but with "bugs" being fixed and some
49  * additional functionality, mainly:
50  *
51  * 1. RX and TX error counters are readable.
52  * 2. Support of silent (listen-only) mode.
53  * 3. Message object 15 can receive all types of frames, also RTR and EFF.
54  *
55  * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
56  * which explains in detail the compatibility between the CC770 and the
57  * 82527. This driver use the additional functionality 3. on real CC770
58  * devices. Unfortunately, the CC770 does still not store the message
59  * identifier of received remote transmission request frames and
60  * therefore it's set to 0.
61  *
62  * The message objects 1..14 can be used for TX and RX while the message
63  * objects 15 is optimized for RX. It has a shadow register for reliable
64  * data receiption under heavy bus load. Therefore it makes sense to use
65  * this message object for the needed use case. The frame type (EFF/SFF)
66  * for the message object 15 can be defined via kernel module parameter
67  * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
68  * otherwise 11 bit SFF messages.
69  */
70 static int msgobj15_eff;
71 module_param(msgobj15_eff, int, S_IRUGO);
72 MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
73 		 "(default: 11-bit standard frames)");
74 
75 static int i82527_compat;
76 module_param(i82527_compat, int, S_IRUGO);
77 MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 comptibility mode "
78 		 "without using additional functions");
79 
80 /*
81  * This driver uses the last 5 message objects 11..15. The definitions
82  * and structure below allows to configure and assign them to the real
83  * message object.
84  */
85 static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
86 	[CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
87 	[CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
88 	[CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
89 	[CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
90 			      CC770_OBJ_FLAG_EFF,
91 	[CC770_OBJ_TX] = 0,
92 };
93 
94 static struct can_bittiming_const cc770_bittiming_const = {
95 	.name = KBUILD_MODNAME,
96 	.tseg1_min = 1,
97 	.tseg1_max = 16,
98 	.tseg2_min = 1,
99 	.tseg2_max = 8,
100 	.sjw_max = 4,
101 	.brp_min = 1,
102 	.brp_max = 64,
103 	.brp_inc = 1,
104 };
105 
106 static inline int intid2obj(unsigned int intid)
107 {
108 	if (intid == 2)
109 		return 0;
110 	else
111 		return MSGOBJ_LAST + 2 - intid;
112 }
113 
114 static void enable_all_objs(const struct net_device *dev)
115 {
116 	struct cc770_priv *priv = netdev_priv(dev);
117 	u8 msgcfg;
118 	unsigned char obj_flags;
119 	unsigned int o, mo;
120 
121 	for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
122 		obj_flags = priv->obj_flags[o];
123 		mo = obj2msgobj(o);
124 
125 		if (obj_flags & CC770_OBJ_FLAG_RX) {
126 			/*
127 			 * We don't need extra objects for RTR and EFF if
128 			 * the additional CC770 functions are enabled.
129 			 */
130 			if (priv->control_normal_mode & CTRL_EAF) {
131 				if (o > 0)
132 					continue;
133 				netdev_dbg(dev, "Message object %d for "
134 					   "RX data, RTR, SFF and EFF\n", mo);
135 			} else {
136 				netdev_dbg(dev,
137 					   "Message object %d for RX %s %s\n",
138 					   mo, obj_flags & CC770_OBJ_FLAG_RTR ?
139 					   "RTR" : "data",
140 					   obj_flags & CC770_OBJ_FLAG_EFF ?
141 					   "EFF" : "SFF");
142 			}
143 
144 			if (obj_flags & CC770_OBJ_FLAG_EFF)
145 				msgcfg = MSGCFG_XTD;
146 			else
147 				msgcfg = 0;
148 			if (obj_flags & CC770_OBJ_FLAG_RTR)
149 				msgcfg |= MSGCFG_DIR;
150 
151 			cc770_write_reg(priv, msgobj[mo].config, msgcfg);
152 			cc770_write_reg(priv, msgobj[mo].ctrl0,
153 					MSGVAL_SET | TXIE_RES |
154 					RXIE_SET | INTPND_RES);
155 
156 			if (obj_flags & CC770_OBJ_FLAG_RTR)
157 				cc770_write_reg(priv, msgobj[mo].ctrl1,
158 						NEWDAT_RES | CPUUPD_SET |
159 						TXRQST_RES | RMTPND_RES);
160 			else
161 				cc770_write_reg(priv, msgobj[mo].ctrl1,
162 						NEWDAT_RES | MSGLST_RES |
163 						TXRQST_RES | RMTPND_RES);
164 		} else {
165 			netdev_dbg(dev, "Message object %d for "
166 				   "TX data, RTR, SFF and EFF\n", mo);
167 
168 			cc770_write_reg(priv, msgobj[mo].ctrl1,
169 					RMTPND_RES | TXRQST_RES |
170 					CPUUPD_RES | NEWDAT_RES);
171 			cc770_write_reg(priv, msgobj[mo].ctrl0,
172 					MSGVAL_RES | TXIE_RES |
173 					RXIE_RES | INTPND_RES);
174 		}
175 	}
176 }
177 
178 static void disable_all_objs(const struct cc770_priv *priv)
179 {
180 	int o, mo;
181 
182 	for (o = 0; o <  ARRAY_SIZE(priv->obj_flags); o++) {
183 		mo = obj2msgobj(o);
184 
185 		if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
186 			if (o > 0 && priv->control_normal_mode & CTRL_EAF)
187 				continue;
188 
189 			cc770_write_reg(priv, msgobj[mo].ctrl1,
190 					NEWDAT_RES | MSGLST_RES |
191 					TXRQST_RES | RMTPND_RES);
192 			cc770_write_reg(priv, msgobj[mo].ctrl0,
193 					MSGVAL_RES | TXIE_RES |
194 					RXIE_RES | INTPND_RES);
195 		} else {
196 			/* Clear message object for send */
197 			cc770_write_reg(priv, msgobj[mo].ctrl1,
198 					RMTPND_RES | TXRQST_RES |
199 					CPUUPD_RES | NEWDAT_RES);
200 			cc770_write_reg(priv, msgobj[mo].ctrl0,
201 					MSGVAL_RES | TXIE_RES |
202 					RXIE_RES | INTPND_RES);
203 		}
204 	}
205 }
206 
207 static void set_reset_mode(struct net_device *dev)
208 {
209 	struct cc770_priv *priv = netdev_priv(dev);
210 
211 	/* Enable configuration and puts chip in bus-off, disable interrupts */
212 	cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
213 
214 	priv->can.state = CAN_STATE_STOPPED;
215 
216 	/* Clear interrupts */
217 	cc770_read_reg(priv, interrupt);
218 
219 	/* Clear status register */
220 	cc770_write_reg(priv, status, 0);
221 
222 	/* Disable all used message objects */
223 	disable_all_objs(priv);
224 }
225 
226 static void set_normal_mode(struct net_device *dev)
227 {
228 	struct cc770_priv *priv = netdev_priv(dev);
229 
230 	/* Clear interrupts */
231 	cc770_read_reg(priv, interrupt);
232 
233 	/* Clear status register and pre-set last error code */
234 	cc770_write_reg(priv, status, STAT_LEC_MASK);
235 
236 	/* Enable all used message objects*/
237 	enable_all_objs(dev);
238 
239 	/*
240 	 * Clear bus-off, interrupts only for errors,
241 	 * not for status change
242 	 */
243 	cc770_write_reg(priv, control, priv->control_normal_mode);
244 
245 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
246 }
247 
248 static void chipset_init(struct cc770_priv *priv)
249 {
250 	int mo, id, data;
251 
252 	/* Enable configuration and put chip in bus-off, disable interrupts */
253 	cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
254 
255 	/* Set CLKOUT divider and slew rates */
256 	cc770_write_reg(priv, clkout, priv->clkout);
257 
258 	/* Configure CPU interface / CLKOUT enable */
259 	cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
260 
261 	/* Set bus configuration  */
262 	cc770_write_reg(priv, bus_config, priv->bus_config);
263 
264 	/* Clear interrupts */
265 	cc770_read_reg(priv, interrupt);
266 
267 	/* Clear status register */
268 	cc770_write_reg(priv, status, 0);
269 
270 	/* Clear and invalidate message objects */
271 	for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
272 		cc770_write_reg(priv, msgobj[mo].ctrl0,
273 				INTPND_UNC | RXIE_RES |
274 				TXIE_RES | MSGVAL_RES);
275 		cc770_write_reg(priv, msgobj[mo].ctrl0,
276 				INTPND_RES | RXIE_RES |
277 				TXIE_RES | MSGVAL_RES);
278 		cc770_write_reg(priv, msgobj[mo].ctrl1,
279 				NEWDAT_RES | MSGLST_RES |
280 				TXRQST_RES | RMTPND_RES);
281 		for (data = 0; data < 8; data++)
282 			cc770_write_reg(priv, msgobj[mo].data[data], 0);
283 		for (id = 0; id < 4; id++)
284 			cc770_write_reg(priv, msgobj[mo].id[id], 0);
285 		cc770_write_reg(priv, msgobj[mo].config, 0);
286 	}
287 
288 	/* Set all global ID masks to "don't care" */
289 	cc770_write_reg(priv, global_mask_std[0], 0);
290 	cc770_write_reg(priv, global_mask_std[1], 0);
291 	cc770_write_reg(priv, global_mask_ext[0], 0);
292 	cc770_write_reg(priv, global_mask_ext[1], 0);
293 	cc770_write_reg(priv, global_mask_ext[2], 0);
294 	cc770_write_reg(priv, global_mask_ext[3], 0);
295 
296 }
297 
298 static int cc770_probe_chip(struct net_device *dev)
299 {
300 	struct cc770_priv *priv = netdev_priv(dev);
301 
302 	/* Enable configuration, put chip in bus-off, disable ints */
303 	cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
304 	/* Configure cpu interface / CLKOUT disable */
305 	cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
306 
307 	/*
308 	 * Check if hardware reset is still inactive or maybe there
309 	 * is no chip in this address space
310 	 */
311 	if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
312 		netdev_info(dev, "probing @0x%p failed (reset)\n",
313 			    priv->reg_base);
314 		return -ENODEV;
315 	}
316 
317 	/* Write and read back test pattern (some arbitrary values) */
318 	cc770_write_reg(priv, msgobj[1].data[1], 0x25);
319 	cc770_write_reg(priv, msgobj[2].data[3], 0x52);
320 	cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
321 	if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
322 	    (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
323 	    (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
324 		netdev_info(dev, "probing @0x%p failed (pattern)\n",
325 			    priv->reg_base);
326 		return -ENODEV;
327 	}
328 
329 	/* Check if this chip is a CC770 supporting additional functions */
330 	if (cc770_read_reg(priv, control) & CTRL_EAF)
331 		priv->control_normal_mode |= CTRL_EAF;
332 
333 	return 0;
334 }
335 
336 static void cc770_start(struct net_device *dev)
337 {
338 	struct cc770_priv *priv = netdev_priv(dev);
339 
340 	/* leave reset mode */
341 	if (priv->can.state != CAN_STATE_STOPPED)
342 		set_reset_mode(dev);
343 
344 	/* leave reset mode */
345 	set_normal_mode(dev);
346 }
347 
348 static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
349 {
350 	switch (mode) {
351 	case CAN_MODE_START:
352 		cc770_start(dev);
353 		netif_wake_queue(dev);
354 		break;
355 
356 	default:
357 		return -EOPNOTSUPP;
358 	}
359 
360 	return 0;
361 }
362 
363 static int cc770_set_bittiming(struct net_device *dev)
364 {
365 	struct cc770_priv *priv = netdev_priv(dev);
366 	struct can_bittiming *bt = &priv->can.bittiming;
367 	u8 btr0, btr1;
368 
369 	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
370 	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
371 		(((bt->phase_seg2 - 1) & 0x7) << 4);
372 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
373 		btr1 |= 0x80;
374 
375 	netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
376 
377 	cc770_write_reg(priv, bit_timing_0, btr0);
378 	cc770_write_reg(priv, bit_timing_1, btr1);
379 
380 	return 0;
381 }
382 
383 static int cc770_get_berr_counter(const struct net_device *dev,
384 				  struct can_berr_counter *bec)
385 {
386 	struct cc770_priv *priv = netdev_priv(dev);
387 
388 	bec->txerr = cc770_read_reg(priv, tx_error_counter);
389 	bec->rxerr = cc770_read_reg(priv, rx_error_counter);
390 
391 	return 0;
392 }
393 
394 static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
395 {
396 	struct cc770_priv *priv = netdev_priv(dev);
397 	struct net_device_stats *stats = &dev->stats;
398 	struct can_frame *cf = (struct can_frame *)skb->data;
399 	unsigned int mo = obj2msgobj(CC770_OBJ_TX);
400 	u8 dlc, rtr;
401 	u32 id;
402 	int i;
403 
404 	if (can_dropped_invalid_skb(dev, skb))
405 		return NETDEV_TX_OK;
406 
407 	if ((cc770_read_reg(priv,
408 			    msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
409 		netdev_err(dev, "TX register is still occupied!\n");
410 		return NETDEV_TX_BUSY;
411 	}
412 
413 	netif_stop_queue(dev);
414 
415 	dlc = cf->can_dlc;
416 	id = cf->can_id;
417 	if (cf->can_id & CAN_RTR_FLAG)
418 		rtr = 0;
419 	else
420 		rtr = MSGCFG_DIR;
421 	cc770_write_reg(priv, msgobj[mo].ctrl1,
422 			RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
423 	cc770_write_reg(priv, msgobj[mo].ctrl0,
424 			MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
425 	if (id & CAN_EFF_FLAG) {
426 		id &= CAN_EFF_MASK;
427 		cc770_write_reg(priv, msgobj[mo].config,
428 				(dlc << 4) | rtr | MSGCFG_XTD);
429 		cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
430 		cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
431 		cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
432 		cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
433 	} else {
434 		id &= CAN_SFF_MASK;
435 		cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
436 		cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
437 		cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
438 	}
439 
440 	for (i = 0; i < dlc; i++)
441 		cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
442 
443 	cc770_write_reg(priv, msgobj[mo].ctrl1,
444 			RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
445 
446 	stats->tx_bytes += dlc;
447 
448 	can_put_echo_skb(skb, dev, 0);
449 
450 	/*
451 	 * HM: We had some cases of repeated IRQs so make sure the
452 	 * INT is acknowledged I know it's already further up, but
453 	 * doing again fixed the issue
454 	 */
455 	cc770_write_reg(priv, msgobj[mo].ctrl0,
456 			MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
457 
458 	return NETDEV_TX_OK;
459 }
460 
461 static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
462 {
463 	struct cc770_priv *priv = netdev_priv(dev);
464 	struct net_device_stats *stats = &dev->stats;
465 	struct can_frame *cf;
466 	struct sk_buff *skb;
467 	u8 config;
468 	u32 id;
469 	int i;
470 
471 	skb = alloc_can_skb(dev, &cf);
472 	if (!skb)
473 		return;
474 
475 	config = cc770_read_reg(priv, msgobj[mo].config);
476 
477 	if (ctrl1 & RMTPND_SET) {
478 		/*
479 		 * Unfortunately, the chip does not store the real message
480 		 * identifier of the received remote transmission request
481 		 * frame. Therefore we set it to 0.
482 		 */
483 		cf->can_id = CAN_RTR_FLAG;
484 		if (config & MSGCFG_XTD)
485 			cf->can_id |= CAN_EFF_FLAG;
486 		cf->can_dlc = 0;
487 	} else {
488 		if (config & MSGCFG_XTD) {
489 			id = cc770_read_reg(priv, msgobj[mo].id[3]);
490 			id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
491 			id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
492 			id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
493 			id >>= 3;
494 			id |= CAN_EFF_FLAG;
495 		} else {
496 			id = cc770_read_reg(priv, msgobj[mo].id[1]);
497 			id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
498 			id >>= 5;
499 		}
500 
501 		cf->can_id = id;
502 		cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
503 		for (i = 0; i < cf->can_dlc; i++)
504 			cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
505 	}
506 	netif_rx(skb);
507 
508 	stats->rx_packets++;
509 	stats->rx_bytes += cf->can_dlc;
510 }
511 
512 static int cc770_err(struct net_device *dev, u8 status)
513 {
514 	struct cc770_priv *priv = netdev_priv(dev);
515 	struct net_device_stats *stats = &dev->stats;
516 	struct can_frame *cf;
517 	struct sk_buff *skb;
518 	u8 lec;
519 
520 	netdev_dbg(dev, "status interrupt (%#x)\n", status);
521 
522 	skb = alloc_can_err_skb(dev, &cf);
523 	if (!skb)
524 		return -ENOMEM;
525 
526 	/* Use extended functions of the CC770 */
527 	if (priv->control_normal_mode & CTRL_EAF) {
528 		cf->data[6] = cc770_read_reg(priv, tx_error_counter);
529 		cf->data[7] = cc770_read_reg(priv, rx_error_counter);
530 	}
531 
532 	if (status & STAT_BOFF) {
533 		/* Disable interrupts */
534 		cc770_write_reg(priv, control, CTRL_INI);
535 		cf->can_id |= CAN_ERR_BUSOFF;
536 		priv->can.state = CAN_STATE_BUS_OFF;
537 		can_bus_off(dev);
538 	} else if (status & STAT_WARN) {
539 		cf->can_id |= CAN_ERR_CRTL;
540 		/* Only the CC770 does show error passive */
541 		if (cf->data[7] > 127) {
542 			cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
543 				CAN_ERR_CRTL_TX_PASSIVE;
544 			priv->can.state = CAN_STATE_ERROR_PASSIVE;
545 			priv->can.can_stats.error_passive++;
546 		} else {
547 			cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
548 				CAN_ERR_CRTL_TX_WARNING;
549 			priv->can.state = CAN_STATE_ERROR_WARNING;
550 			priv->can.can_stats.error_warning++;
551 		}
552 	} else {
553 		/* Back to error avtive */
554 		cf->can_id |= CAN_ERR_PROT;
555 		cf->data[2] = CAN_ERR_PROT_ACTIVE;
556 		priv->can.state = CAN_STATE_ERROR_ACTIVE;
557 	}
558 
559 	lec = status & STAT_LEC_MASK;
560 	if (lec < 7 && lec > 0) {
561 		if (lec == STAT_LEC_ACK) {
562 			cf->can_id |= CAN_ERR_ACK;
563 		} else {
564 			cf->can_id |= CAN_ERR_PROT;
565 			switch (lec) {
566 			case STAT_LEC_STUFF:
567 				cf->data[2] |= CAN_ERR_PROT_STUFF;
568 				break;
569 			case STAT_LEC_FORM:
570 				cf->data[2] |= CAN_ERR_PROT_FORM;
571 				break;
572 			case STAT_LEC_BIT1:
573 				cf->data[2] |= CAN_ERR_PROT_BIT1;
574 				break;
575 			case STAT_LEC_BIT0:
576 				cf->data[2] |= CAN_ERR_PROT_BIT0;
577 				break;
578 			case STAT_LEC_CRC:
579 				cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
580 				break;
581 			}
582 		}
583 	}
584 
585 	netif_rx(skb);
586 
587 	stats->rx_packets++;
588 	stats->rx_bytes += cf->can_dlc;
589 
590 	return 0;
591 }
592 
593 static int cc770_status_interrupt(struct net_device *dev)
594 {
595 	struct cc770_priv *priv = netdev_priv(dev);
596 	u8 status;
597 
598 	status = cc770_read_reg(priv, status);
599 	/* Reset the status register including RXOK and TXOK */
600 	cc770_write_reg(priv, status, STAT_LEC_MASK);
601 
602 	if (status & (STAT_WARN | STAT_BOFF) ||
603 	    (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
604 		cc770_err(dev, status);
605 		return status & STAT_BOFF;
606 	}
607 
608 	return 0;
609 }
610 
611 static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
612 {
613 	struct cc770_priv *priv = netdev_priv(dev);
614 	struct net_device_stats *stats = &dev->stats;
615 	unsigned int mo = obj2msgobj(o);
616 	u8 ctrl1;
617 	int n = CC770_MAX_MSG;
618 
619 	while (n--) {
620 		ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
621 
622 		if (!(ctrl1 & NEWDAT_SET))  {
623 			/* Check for RTR if additional functions are enabled */
624 			if (priv->control_normal_mode & CTRL_EAF) {
625 				if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
626 				      INTPND_SET))
627 					break;
628 			} else {
629 				break;
630 			}
631 		}
632 
633 		if (ctrl1 & MSGLST_SET) {
634 			stats->rx_over_errors++;
635 			stats->rx_errors++;
636 		}
637 		if (mo < MSGOBJ_LAST)
638 			cc770_write_reg(priv, msgobj[mo].ctrl1,
639 					NEWDAT_RES | MSGLST_RES |
640 					TXRQST_UNC | RMTPND_UNC);
641 		cc770_rx(dev, mo, ctrl1);
642 
643 		cc770_write_reg(priv, msgobj[mo].ctrl0,
644 				MSGVAL_SET | TXIE_RES |
645 				RXIE_SET | INTPND_RES);
646 		cc770_write_reg(priv, msgobj[mo].ctrl1,
647 				NEWDAT_RES | MSGLST_RES |
648 				TXRQST_RES | RMTPND_RES);
649 	}
650 }
651 
652 static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
653 {
654 	struct cc770_priv *priv = netdev_priv(dev);
655 	unsigned int mo = obj2msgobj(o);
656 	u8 ctrl0, ctrl1;
657 	int n = CC770_MAX_MSG;
658 
659 	while (n--) {
660 		ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
661 		if (!(ctrl0 & INTPND_SET))
662 			break;
663 
664 		ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
665 		cc770_rx(dev, mo, ctrl1);
666 
667 		cc770_write_reg(priv, msgobj[mo].ctrl0,
668 				MSGVAL_SET | TXIE_RES |
669 				RXIE_SET | INTPND_RES);
670 		cc770_write_reg(priv, msgobj[mo].ctrl1,
671 				NEWDAT_RES | CPUUPD_SET |
672 				TXRQST_RES | RMTPND_RES);
673 	}
674 }
675 
676 static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
677 {
678 	struct cc770_priv *priv = netdev_priv(dev);
679 	struct net_device_stats *stats = &dev->stats;
680 	unsigned int mo = obj2msgobj(o);
681 
682 	/* Nothing more to send, switch off interrupts */
683 	cc770_write_reg(priv, msgobj[mo].ctrl0,
684 			MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
685 	/*
686 	 * We had some cases of repeated IRQ so make sure the
687 	 * INT is acknowledged
688 	 */
689 	cc770_write_reg(priv, msgobj[mo].ctrl0,
690 			MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
691 
692 	stats->tx_packets++;
693 	can_get_echo_skb(dev, 0);
694 	netif_wake_queue(dev);
695 }
696 
697 irqreturn_t cc770_interrupt(int irq, void *dev_id)
698 {
699 	struct net_device *dev = (struct net_device *)dev_id;
700 	struct cc770_priv *priv = netdev_priv(dev);
701 	u8 intid;
702 	int o, n = 0;
703 
704 	/* Shared interrupts and IRQ off? */
705 	if (priv->can.state == CAN_STATE_STOPPED)
706 		return IRQ_NONE;
707 
708 	if (priv->pre_irq)
709 		priv->pre_irq(priv);
710 
711 	while (n < CC770_MAX_IRQ) {
712 		/* Read the highest pending interrupt request */
713 		intid = cc770_read_reg(priv, interrupt);
714 		if (!intid)
715 			break;
716 		n++;
717 
718 		if (intid == 1) {
719 			/* Exit in case of bus-off */
720 			if (cc770_status_interrupt(dev))
721 				break;
722 		} else {
723 			o = intid2obj(intid);
724 
725 			if (o >= CC770_OBJ_MAX) {
726 				netdev_err(dev, "Unexpected interrupt id %d\n",
727 					   intid);
728 				continue;
729 			}
730 
731 			if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
732 				cc770_rtr_interrupt(dev, o);
733 			else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
734 				cc770_rx_interrupt(dev, o);
735 			else
736 				cc770_tx_interrupt(dev, o);
737 		}
738 	}
739 
740 	if (priv->post_irq)
741 		priv->post_irq(priv);
742 
743 	if (n >= CC770_MAX_IRQ)
744 		netdev_dbg(dev, "%d messages handled in ISR", n);
745 
746 	return (n) ? IRQ_HANDLED : IRQ_NONE;
747 }
748 
749 static int cc770_open(struct net_device *dev)
750 {
751 	struct cc770_priv *priv = netdev_priv(dev);
752 	int err;
753 
754 	/* set chip into reset mode */
755 	set_reset_mode(dev);
756 
757 	/* common open */
758 	err = open_candev(dev);
759 	if (err)
760 		return err;
761 
762 	err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
763 			  dev->name, dev);
764 	if (err) {
765 		close_candev(dev);
766 		return -EAGAIN;
767 	}
768 
769 	/* init and start chip */
770 	cc770_start(dev);
771 
772 	netif_start_queue(dev);
773 
774 	return 0;
775 }
776 
777 static int cc770_close(struct net_device *dev)
778 {
779 	netif_stop_queue(dev);
780 	set_reset_mode(dev);
781 
782 	free_irq(dev->irq, dev);
783 	close_candev(dev);
784 
785 	return 0;
786 }
787 
788 struct net_device *alloc_cc770dev(int sizeof_priv)
789 {
790 	struct net_device *dev;
791 	struct cc770_priv *priv;
792 
793 	dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
794 			   CC770_ECHO_SKB_MAX);
795 	if (!dev)
796 		return NULL;
797 
798 	priv = netdev_priv(dev);
799 
800 	priv->dev = dev;
801 	priv->can.bittiming_const = &cc770_bittiming_const;
802 	priv->can.do_set_bittiming = cc770_set_bittiming;
803 	priv->can.do_set_mode = cc770_set_mode;
804 	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
805 
806 	memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
807 
808 	if (sizeof_priv)
809 		priv->priv = (void *)priv + sizeof(struct cc770_priv);
810 
811 	return dev;
812 }
813 EXPORT_SYMBOL_GPL(alloc_cc770dev);
814 
815 void free_cc770dev(struct net_device *dev)
816 {
817 	free_candev(dev);
818 }
819 EXPORT_SYMBOL_GPL(free_cc770dev);
820 
821 static const struct net_device_ops cc770_netdev_ops = {
822 	.ndo_open = cc770_open,
823 	.ndo_stop = cc770_close,
824 	.ndo_start_xmit = cc770_start_xmit,
825 };
826 
827 int register_cc770dev(struct net_device *dev)
828 {
829 	struct cc770_priv *priv = netdev_priv(dev);
830 	int err;
831 
832 	err = cc770_probe_chip(dev);
833 	if (err)
834 		return err;
835 
836 	dev->netdev_ops = &cc770_netdev_ops;
837 
838 	dev->flags |= IFF_ECHO;	/* we support local echo */
839 
840 	/* Should we use additional functions? */
841 	if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
842 		priv->can.do_get_berr_counter = cc770_get_berr_counter;
843 		priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
844 		netdev_dbg(dev, "i82527 mode with additional functions\n");
845 	} else {
846 		priv->control_normal_mode = CTRL_IE | CTRL_EIE;
847 		netdev_dbg(dev, "strict i82527 compatibility mode\n");
848 	}
849 
850 	chipset_init(priv);
851 	set_reset_mode(dev);
852 
853 	return register_candev(dev);
854 }
855 EXPORT_SYMBOL_GPL(register_cc770dev);
856 
857 void unregister_cc770dev(struct net_device *dev)
858 {
859 	set_reset_mode(dev);
860 	unregister_candev(dev);
861 }
862 EXPORT_SYMBOL_GPL(unregister_cc770dev);
863 
864 static __init int cc770_init(void)
865 {
866 	if (msgobj15_eff) {
867 		cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
868 		cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
869 	}
870 
871 	pr_info("CAN netdevice driver\n");
872 
873 	return 0;
874 }
875 module_init(cc770_init);
876 
877 static __exit void cc770_exit(void)
878 {
879 	pr_info("driver removed\n");
880 }
881 module_exit(cc770_exit);
882