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/platform/cc770.h>
38
39#include "cc770.h"
40
41MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
42MODULE_LICENSE("GPL v2");
43MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
44
45/*
46 * The CC770 is a CAN controller from Bosch, which is 100% compatible
47 * with the AN82527 from Intel, but with "bugs" being fixed and some
48 * additional functionality, mainly:
49 *
50 * 1. RX and TX error counters are readable.
51 * 2. Support of silent (listen-only) mode.
52 * 3. Message object 15 can receive all types of frames, also RTR and EFF.
53 *
54 * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
55 * which explains in detail the compatibility between the CC770 and the
56 * 82527. This driver use the additional functionality 3. on real CC770
57 * devices. Unfortunately, the CC770 does still not store the message
58 * identifier of received remote transmission request frames and
59 * therefore it's set to 0.
60 *
61 * The message objects 1..14 can be used for TX and RX while the message
62 * objects 15 is optimized for RX. It has a shadow register for reliable
63 * data reception under heavy bus load. Therefore it makes sense to use
64 * this message object for the needed use case. The frame type (EFF/SFF)
65 * for the message object 15 can be defined via kernel module parameter
66 * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
67 * otherwise 11 bit SFF messages.
68 */
69static int msgobj15_eff;
70module_param(msgobj15_eff, int, S_IRUGO);
71MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
72		 "(default: 11-bit standard frames)");
73
74static int i82527_compat;
75module_param(i82527_compat, int, S_IRUGO);
76MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 comptibility mode "
77		 "without using additional functions");
78
79/*
80 * This driver uses the last 5 message objects 11..15. The definitions
81 * and structure below allows to configure and assign them to the real
82 * message object.
83 */
84static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
85	[CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
86	[CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
87	[CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
88	[CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
89			      CC770_OBJ_FLAG_EFF,
90	[CC770_OBJ_TX] = 0,
91};
92
93static const struct can_bittiming_const cc770_bittiming_const = {
94	.name = KBUILD_MODNAME,
95	.tseg1_min = 1,
96	.tseg1_max = 16,
97	.tseg2_min = 1,
98	.tseg2_max = 8,
99	.sjw_max = 4,
100	.brp_min = 1,
101	.brp_max = 64,
102	.brp_inc = 1,
103};
104
105static inline int intid2obj(unsigned int intid)
106{
107	if (intid == 2)
108		return 0;
109	else
110		return MSGOBJ_LAST + 2 - intid;
111}
112
113static void enable_all_objs(const struct net_device *dev)
114{
115	struct cc770_priv *priv = netdev_priv(dev);
116	u8 msgcfg;
117	unsigned char obj_flags;
118	unsigned int o, mo;
119
120	for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
121		obj_flags = priv->obj_flags[o];
122		mo = obj2msgobj(o);
123
124		if (obj_flags & CC770_OBJ_FLAG_RX) {
125			/*
126			 * We don't need extra objects for RTR and EFF if
127			 * the additional CC770 functions are enabled.
128			 */
129			if (priv->control_normal_mode & CTRL_EAF) {
130				if (o > 0)
131					continue;
132				netdev_dbg(dev, "Message object %d for "
133					   "RX data, RTR, SFF and EFF\n", mo);
134			} else {
135				netdev_dbg(dev,
136					   "Message object %d for RX %s %s\n",
137					   mo, obj_flags & CC770_OBJ_FLAG_RTR ?
138					   "RTR" : "data",
139					   obj_flags & CC770_OBJ_FLAG_EFF ?
140					   "EFF" : "SFF");
141			}
142
143			if (obj_flags & CC770_OBJ_FLAG_EFF)
144				msgcfg = MSGCFG_XTD;
145			else
146				msgcfg = 0;
147			if (obj_flags & CC770_OBJ_FLAG_RTR)
148				msgcfg |= MSGCFG_DIR;
149
150			cc770_write_reg(priv, msgobj[mo].config, msgcfg);
151			cc770_write_reg(priv, msgobj[mo].ctrl0,
152					MSGVAL_SET | TXIE_RES |
153					RXIE_SET | INTPND_RES);
154
155			if (obj_flags & CC770_OBJ_FLAG_RTR)
156				cc770_write_reg(priv, msgobj[mo].ctrl1,
157						NEWDAT_RES | CPUUPD_SET |
158						TXRQST_RES | RMTPND_RES);
159			else
160				cc770_write_reg(priv, msgobj[mo].ctrl1,
161						NEWDAT_RES | MSGLST_RES |
162						TXRQST_RES | RMTPND_RES);
163		} else {
164			netdev_dbg(dev, "Message object %d for "
165				   "TX data, RTR, SFF and EFF\n", mo);
166
167			cc770_write_reg(priv, msgobj[mo].ctrl1,
168					RMTPND_RES | TXRQST_RES |
169					CPUUPD_RES | NEWDAT_RES);
170			cc770_write_reg(priv, msgobj[mo].ctrl0,
171					MSGVAL_RES | TXIE_RES |
172					RXIE_RES | INTPND_RES);
173		}
174	}
175}
176
177static void disable_all_objs(const struct cc770_priv *priv)
178{
179	int o, mo;
180
181	for (o = 0; o <  ARRAY_SIZE(priv->obj_flags); o++) {
182		mo = obj2msgobj(o);
183
184		if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
185			if (o > 0 && priv->control_normal_mode & CTRL_EAF)
186				continue;
187
188			cc770_write_reg(priv, msgobj[mo].ctrl1,
189					NEWDAT_RES | MSGLST_RES |
190					TXRQST_RES | RMTPND_RES);
191			cc770_write_reg(priv, msgobj[mo].ctrl0,
192					MSGVAL_RES | TXIE_RES |
193					RXIE_RES | INTPND_RES);
194		} else {
195			/* Clear message object for send */
196			cc770_write_reg(priv, msgobj[mo].ctrl1,
197					RMTPND_RES | TXRQST_RES |
198					CPUUPD_RES | NEWDAT_RES);
199			cc770_write_reg(priv, msgobj[mo].ctrl0,
200					MSGVAL_RES | TXIE_RES |
201					RXIE_RES | INTPND_RES);
202		}
203	}
204}
205
206static void set_reset_mode(struct net_device *dev)
207{
208	struct cc770_priv *priv = netdev_priv(dev);
209
210	/* Enable configuration and puts chip in bus-off, disable interrupts */
211	cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
212
213	priv->can.state = CAN_STATE_STOPPED;
214
215	/* Clear interrupts */
216	cc770_read_reg(priv, interrupt);
217
218	/* Clear status register */
219	cc770_write_reg(priv, status, 0);
220
221	/* Disable all used message objects */
222	disable_all_objs(priv);
223}
224
225static void set_normal_mode(struct net_device *dev)
226{
227	struct cc770_priv *priv = netdev_priv(dev);
228
229	/* Clear interrupts */
230	cc770_read_reg(priv, interrupt);
231
232	/* Clear status register and pre-set last error code */
233	cc770_write_reg(priv, status, STAT_LEC_MASK);
234
235	/* Enable all used message objects*/
236	enable_all_objs(dev);
237
238	/*
239	 * Clear bus-off, interrupts only for errors,
240	 * not for status change
241	 */
242	cc770_write_reg(priv, control, priv->control_normal_mode);
243
244	priv->can.state = CAN_STATE_ERROR_ACTIVE;
245}
246
247static void chipset_init(struct cc770_priv *priv)
248{
249	int mo, id, data;
250
251	/* Enable configuration and put chip in bus-off, disable interrupts */
252	cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
253
254	/* Set CLKOUT divider and slew rates */
255	cc770_write_reg(priv, clkout, priv->clkout);
256
257	/* Configure CPU interface / CLKOUT enable */
258	cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
259
260	/* Set bus configuration  */
261	cc770_write_reg(priv, bus_config, priv->bus_config);
262
263	/* Clear interrupts */
264	cc770_read_reg(priv, interrupt);
265
266	/* Clear status register */
267	cc770_write_reg(priv, status, 0);
268
269	/* Clear and invalidate message objects */
270	for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
271		cc770_write_reg(priv, msgobj[mo].ctrl0,
272				INTPND_UNC | RXIE_RES |
273				TXIE_RES | MSGVAL_RES);
274		cc770_write_reg(priv, msgobj[mo].ctrl0,
275				INTPND_RES | RXIE_RES |
276				TXIE_RES | MSGVAL_RES);
277		cc770_write_reg(priv, msgobj[mo].ctrl1,
278				NEWDAT_RES | MSGLST_RES |
279				TXRQST_RES | RMTPND_RES);
280		for (data = 0; data < 8; data++)
281			cc770_write_reg(priv, msgobj[mo].data[data], 0);
282		for (id = 0; id < 4; id++)
283			cc770_write_reg(priv, msgobj[mo].id[id], 0);
284		cc770_write_reg(priv, msgobj[mo].config, 0);
285	}
286
287	/* Set all global ID masks to "don't care" */
288	cc770_write_reg(priv, global_mask_std[0], 0);
289	cc770_write_reg(priv, global_mask_std[1], 0);
290	cc770_write_reg(priv, global_mask_ext[0], 0);
291	cc770_write_reg(priv, global_mask_ext[1], 0);
292	cc770_write_reg(priv, global_mask_ext[2], 0);
293	cc770_write_reg(priv, global_mask_ext[3], 0);
294
295}
296
297static int cc770_probe_chip(struct net_device *dev)
298{
299	struct cc770_priv *priv = netdev_priv(dev);
300
301	/* Enable configuration, put chip in bus-off, disable ints */
302	cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
303	/* Configure cpu interface / CLKOUT disable */
304	cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
305
306	/*
307	 * Check if hardware reset is still inactive or maybe there
308	 * is no chip in this address space
309	 */
310	if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
311		netdev_info(dev, "probing @0x%p failed (reset)\n",
312			    priv->reg_base);
313		return -ENODEV;
314	}
315
316	/* Write and read back test pattern (some arbitrary values) */
317	cc770_write_reg(priv, msgobj[1].data[1], 0x25);
318	cc770_write_reg(priv, msgobj[2].data[3], 0x52);
319	cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
320	if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
321	    (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
322	    (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
323		netdev_info(dev, "probing @0x%p failed (pattern)\n",
324			    priv->reg_base);
325		return -ENODEV;
326	}
327
328	/* Check if this chip is a CC770 supporting additional functions */
329	if (cc770_read_reg(priv, control) & CTRL_EAF)
330		priv->control_normal_mode |= CTRL_EAF;
331
332	return 0;
333}
334
335static void cc770_start(struct net_device *dev)
336{
337	struct cc770_priv *priv = netdev_priv(dev);
338
339	/* leave reset mode */
340	if (priv->can.state != CAN_STATE_STOPPED)
341		set_reset_mode(dev);
342
343	/* leave reset mode */
344	set_normal_mode(dev);
345}
346
347static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
348{
349	switch (mode) {
350	case CAN_MODE_START:
351		cc770_start(dev);
352		netif_wake_queue(dev);
353		break;
354
355	default:
356		return -EOPNOTSUPP;
357	}
358
359	return 0;
360}
361
362static int cc770_set_bittiming(struct net_device *dev)
363{
364	struct cc770_priv *priv = netdev_priv(dev);
365	struct can_bittiming *bt = &priv->can.bittiming;
366	u8 btr0, btr1;
367
368	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
369	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
370		(((bt->phase_seg2 - 1) & 0x7) << 4);
371	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
372		btr1 |= 0x80;
373
374	netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
375
376	cc770_write_reg(priv, bit_timing_0, btr0);
377	cc770_write_reg(priv, bit_timing_1, btr1);
378
379	return 0;
380}
381
382static int cc770_get_berr_counter(const struct net_device *dev,
383				  struct can_berr_counter *bec)
384{
385	struct cc770_priv *priv = netdev_priv(dev);
386
387	bec->txerr = cc770_read_reg(priv, tx_error_counter);
388	bec->rxerr = cc770_read_reg(priv, rx_error_counter);
389
390	return 0;
391}
392
393static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
394{
395	struct cc770_priv *priv = netdev_priv(dev);
396	struct net_device_stats *stats = &dev->stats;
397	struct can_frame *cf = (struct can_frame *)skb->data;
398	unsigned int mo = obj2msgobj(CC770_OBJ_TX);
399	u8 dlc, rtr;
400	u32 id;
401	int i;
402
403	if (can_dropped_invalid_skb(dev, skb))
404		return NETDEV_TX_OK;
405
406	if ((cc770_read_reg(priv,
407			    msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
408		netdev_err(dev, "TX register is still occupied!\n");
409		return NETDEV_TX_BUSY;
410	}
411
412	netif_stop_queue(dev);
413
414	dlc = cf->can_dlc;
415	id = cf->can_id;
416	if (cf->can_id & CAN_RTR_FLAG)
417		rtr = 0;
418	else
419		rtr = MSGCFG_DIR;
420	cc770_write_reg(priv, msgobj[mo].ctrl1,
421			RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
422	cc770_write_reg(priv, msgobj[mo].ctrl0,
423			MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
424	if (id & CAN_EFF_FLAG) {
425		id &= CAN_EFF_MASK;
426		cc770_write_reg(priv, msgobj[mo].config,
427				(dlc << 4) | rtr | MSGCFG_XTD);
428		cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
429		cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
430		cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
431		cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
432	} else {
433		id &= CAN_SFF_MASK;
434		cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
435		cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
436		cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
437	}
438
439	for (i = 0; i < dlc; i++)
440		cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
441
442	/* Store echo skb before starting the transfer */
443	can_put_echo_skb(skb, dev, 0);
444
445	cc770_write_reg(priv, msgobj[mo].ctrl1,
446			RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
447
448	stats->tx_bytes += dlc;
449
450
451	/*
452	 * HM: We had some cases of repeated IRQs so make sure the
453	 * INT is acknowledged I know it's already further up, but
454	 * doing again fixed the issue
455	 */
456	cc770_write_reg(priv, msgobj[mo].ctrl0,
457			MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
458
459	return NETDEV_TX_OK;
460}
461
462static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
463{
464	struct cc770_priv *priv = netdev_priv(dev);
465	struct net_device_stats *stats = &dev->stats;
466	struct can_frame *cf;
467	struct sk_buff *skb;
468	u8 config;
469	u32 id;
470	int i;
471
472	skb = alloc_can_skb(dev, &cf);
473	if (!skb)
474		return;
475
476	config = cc770_read_reg(priv, msgobj[mo].config);
477
478	if (ctrl1 & RMTPND_SET) {
479		/*
480		 * Unfortunately, the chip does not store the real message
481		 * identifier of the received remote transmission request
482		 * frame. Therefore we set it to 0.
483		 */
484		cf->can_id = CAN_RTR_FLAG;
485		if (config & MSGCFG_XTD)
486			cf->can_id |= CAN_EFF_FLAG;
487		cf->can_dlc = 0;
488	} else {
489		if (config & MSGCFG_XTD) {
490			id = cc770_read_reg(priv, msgobj[mo].id[3]);
491			id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
492			id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
493			id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
494			id >>= 3;
495			id |= CAN_EFF_FLAG;
496		} else {
497			id = cc770_read_reg(priv, msgobj[mo].id[1]);
498			id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
499			id >>= 5;
500		}
501
502		cf->can_id = id;
503		cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
504		for (i = 0; i < cf->can_dlc; i++)
505			cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
506	}
507
508	stats->rx_packets++;
509	stats->rx_bytes += cf->can_dlc;
510	netif_rx(skb);
511}
512
513static int cc770_err(struct net_device *dev, u8 status)
514{
515	struct cc770_priv *priv = netdev_priv(dev);
516	struct net_device_stats *stats = &dev->stats;
517	struct can_frame *cf;
518	struct sk_buff *skb;
519	u8 lec;
520
521	netdev_dbg(dev, "status interrupt (%#x)\n", status);
522
523	skb = alloc_can_err_skb(dev, &cf);
524	if (!skb)
525		return -ENOMEM;
526
527	/* Use extended functions of the CC770 */
528	if (priv->control_normal_mode & CTRL_EAF) {
529		cf->data[6] = cc770_read_reg(priv, tx_error_counter);
530		cf->data[7] = cc770_read_reg(priv, rx_error_counter);
531	}
532
533	if (status & STAT_BOFF) {
534		/* Disable interrupts */
535		cc770_write_reg(priv, control, CTRL_INI);
536		cf->can_id |= CAN_ERR_BUSOFF;
537		priv->can.state = CAN_STATE_BUS_OFF;
538		priv->can.can_stats.bus_off++;
539		can_bus_off(dev);
540	} else if (status & STAT_WARN) {
541		cf->can_id |= CAN_ERR_CRTL;
542		/* Only the CC770 does show error passive */
543		if (cf->data[7] > 127) {
544			cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
545				CAN_ERR_CRTL_TX_PASSIVE;
546			priv->can.state = CAN_STATE_ERROR_PASSIVE;
547			priv->can.can_stats.error_passive++;
548		} else {
549			cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
550				CAN_ERR_CRTL_TX_WARNING;
551			priv->can.state = CAN_STATE_ERROR_WARNING;
552			priv->can.can_stats.error_warning++;
553		}
554	} else {
555		/* Back to error avtive */
556		cf->can_id |= CAN_ERR_PROT;
557		cf->data[2] = CAN_ERR_PROT_ACTIVE;
558		priv->can.state = CAN_STATE_ERROR_ACTIVE;
559	}
560
561	lec = status & STAT_LEC_MASK;
562	if (lec < 7 && lec > 0) {
563		if (lec == STAT_LEC_ACK) {
564			cf->can_id |= CAN_ERR_ACK;
565		} else {
566			cf->can_id |= CAN_ERR_PROT;
567			switch (lec) {
568			case STAT_LEC_STUFF:
569				cf->data[2] |= CAN_ERR_PROT_STUFF;
570				break;
571			case STAT_LEC_FORM:
572				cf->data[2] |= CAN_ERR_PROT_FORM;
573				break;
574			case STAT_LEC_BIT1:
575				cf->data[2] |= CAN_ERR_PROT_BIT1;
576				break;
577			case STAT_LEC_BIT0:
578				cf->data[2] |= CAN_ERR_PROT_BIT0;
579				break;
580			case STAT_LEC_CRC:
581				cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
582				break;
583			}
584		}
585	}
586
587
588	stats->rx_packets++;
589	stats->rx_bytes += cf->can_dlc;
590	netif_rx(skb);
591
592	return 0;
593}
594
595static int cc770_status_interrupt(struct net_device *dev)
596{
597	struct cc770_priv *priv = netdev_priv(dev);
598	u8 status;
599
600	status = cc770_read_reg(priv, status);
601	/* Reset the status register including RXOK and TXOK */
602	cc770_write_reg(priv, status, STAT_LEC_MASK);
603
604	if (status & (STAT_WARN | STAT_BOFF) ||
605	    (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
606		cc770_err(dev, status);
607		return status & STAT_BOFF;
608	}
609
610	return 0;
611}
612
613static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
614{
615	struct cc770_priv *priv = netdev_priv(dev);
616	struct net_device_stats *stats = &dev->stats;
617	unsigned int mo = obj2msgobj(o);
618	u8 ctrl1;
619	int n = CC770_MAX_MSG;
620
621	while (n--) {
622		ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
623
624		if (!(ctrl1 & NEWDAT_SET))  {
625			/* Check for RTR if additional functions are enabled */
626			if (priv->control_normal_mode & CTRL_EAF) {
627				if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
628				      INTPND_SET))
629					break;
630			} else {
631				break;
632			}
633		}
634
635		if (ctrl1 & MSGLST_SET) {
636			stats->rx_over_errors++;
637			stats->rx_errors++;
638		}
639		if (mo < MSGOBJ_LAST)
640			cc770_write_reg(priv, msgobj[mo].ctrl1,
641					NEWDAT_RES | MSGLST_RES |
642					TXRQST_UNC | RMTPND_UNC);
643		cc770_rx(dev, mo, ctrl1);
644
645		cc770_write_reg(priv, msgobj[mo].ctrl0,
646				MSGVAL_SET | TXIE_RES |
647				RXIE_SET | INTPND_RES);
648		cc770_write_reg(priv, msgobj[mo].ctrl1,
649				NEWDAT_RES | MSGLST_RES |
650				TXRQST_RES | RMTPND_RES);
651	}
652}
653
654static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
655{
656	struct cc770_priv *priv = netdev_priv(dev);
657	unsigned int mo = obj2msgobj(o);
658	u8 ctrl0, ctrl1;
659	int n = CC770_MAX_MSG;
660
661	while (n--) {
662		ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
663		if (!(ctrl0 & INTPND_SET))
664			break;
665
666		ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
667		cc770_rx(dev, mo, ctrl1);
668
669		cc770_write_reg(priv, msgobj[mo].ctrl0,
670				MSGVAL_SET | TXIE_RES |
671				RXIE_SET | INTPND_RES);
672		cc770_write_reg(priv, msgobj[mo].ctrl1,
673				NEWDAT_RES | CPUUPD_SET |
674				TXRQST_RES | RMTPND_RES);
675	}
676}
677
678static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
679{
680	struct cc770_priv *priv = netdev_priv(dev);
681	struct net_device_stats *stats = &dev->stats;
682	unsigned int mo = obj2msgobj(o);
683
684	/* Nothing more to send, switch off interrupts */
685	cc770_write_reg(priv, msgobj[mo].ctrl0,
686			MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
687	/*
688	 * We had some cases of repeated IRQ so make sure the
689	 * INT is acknowledged
690	 */
691	cc770_write_reg(priv, msgobj[mo].ctrl0,
692			MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
693
694	stats->tx_packets++;
695	can_get_echo_skb(dev, 0);
696	netif_wake_queue(dev);
697}
698
699static irqreturn_t cc770_interrupt(int irq, void *dev_id)
700{
701	struct net_device *dev = (struct net_device *)dev_id;
702	struct cc770_priv *priv = netdev_priv(dev);
703	u8 intid;
704	int o, n = 0;
705
706	/* Shared interrupts and IRQ off? */
707	if (priv->can.state == CAN_STATE_STOPPED)
708		return IRQ_NONE;
709
710	if (priv->pre_irq)
711		priv->pre_irq(priv);
712
713	while (n < CC770_MAX_IRQ) {
714		/* Read the highest pending interrupt request */
715		intid = cc770_read_reg(priv, interrupt);
716		if (!intid)
717			break;
718		n++;
719
720		if (intid == 1) {
721			/* Exit in case of bus-off */
722			if (cc770_status_interrupt(dev))
723				break;
724		} else {
725			o = intid2obj(intid);
726
727			if (o >= CC770_OBJ_MAX) {
728				netdev_err(dev, "Unexpected interrupt id %d\n",
729					   intid);
730				continue;
731			}
732
733			if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
734				cc770_rtr_interrupt(dev, o);
735			else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
736				cc770_rx_interrupt(dev, o);
737			else
738				cc770_tx_interrupt(dev, o);
739		}
740	}
741
742	if (priv->post_irq)
743		priv->post_irq(priv);
744
745	if (n >= CC770_MAX_IRQ)
746		netdev_dbg(dev, "%d messages handled in ISR", n);
747
748	return (n) ? IRQ_HANDLED : IRQ_NONE;
749}
750
751static int cc770_open(struct net_device *dev)
752{
753	struct cc770_priv *priv = netdev_priv(dev);
754	int err;
755
756	/* set chip into reset mode */
757	set_reset_mode(dev);
758
759	/* common open */
760	err = open_candev(dev);
761	if (err)
762		return err;
763
764	err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
765			  dev->name, dev);
766	if (err) {
767		close_candev(dev);
768		return -EAGAIN;
769	}
770
771	/* init and start chip */
772	cc770_start(dev);
773
774	netif_start_queue(dev);
775
776	return 0;
777}
778
779static int cc770_close(struct net_device *dev)
780{
781	netif_stop_queue(dev);
782	set_reset_mode(dev);
783
784	free_irq(dev->irq, dev);
785	close_candev(dev);
786
787	return 0;
788}
789
790struct net_device *alloc_cc770dev(int sizeof_priv)
791{
792	struct net_device *dev;
793	struct cc770_priv *priv;
794
795	dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
796			   CC770_ECHO_SKB_MAX);
797	if (!dev)
798		return NULL;
799
800	priv = netdev_priv(dev);
801
802	priv->dev = dev;
803	priv->can.bittiming_const = &cc770_bittiming_const;
804	priv->can.do_set_bittiming = cc770_set_bittiming;
805	priv->can.do_set_mode = cc770_set_mode;
806	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
807
808	memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
809
810	if (sizeof_priv)
811		priv->priv = (void *)priv + sizeof(struct cc770_priv);
812
813	return dev;
814}
815EXPORT_SYMBOL_GPL(alloc_cc770dev);
816
817void free_cc770dev(struct net_device *dev)
818{
819	free_candev(dev);
820}
821EXPORT_SYMBOL_GPL(free_cc770dev);
822
823static const struct net_device_ops cc770_netdev_ops = {
824	.ndo_open = cc770_open,
825	.ndo_stop = cc770_close,
826	.ndo_start_xmit = cc770_start_xmit,
827	.ndo_change_mtu = can_change_mtu,
828};
829
830int register_cc770dev(struct net_device *dev)
831{
832	struct cc770_priv *priv = netdev_priv(dev);
833	int err;
834
835	err = cc770_probe_chip(dev);
836	if (err)
837		return err;
838
839	dev->netdev_ops = &cc770_netdev_ops;
840
841	dev->flags |= IFF_ECHO;	/* we support local echo */
842
843	/* Should we use additional functions? */
844	if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
845		priv->can.do_get_berr_counter = cc770_get_berr_counter;
846		priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
847		netdev_dbg(dev, "i82527 mode with additional functions\n");
848	} else {
849		priv->control_normal_mode = CTRL_IE | CTRL_EIE;
850		netdev_dbg(dev, "strict i82527 compatibility mode\n");
851	}
852
853	chipset_init(priv);
854	set_reset_mode(dev);
855
856	return register_candev(dev);
857}
858EXPORT_SYMBOL_GPL(register_cc770dev);
859
860void unregister_cc770dev(struct net_device *dev)
861{
862	set_reset_mode(dev);
863	unregister_candev(dev);
864}
865EXPORT_SYMBOL_GPL(unregister_cc770dev);
866
867static __init int cc770_init(void)
868{
869	if (msgobj15_eff) {
870		cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
871		cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
872	}
873
874	pr_info("CAN netdevice driver\n");
875
876	return 0;
877}
878module_init(cc770_init);
879
880static __exit void cc770_exit(void)
881{
882	pr_info("driver removed\n");
883}
884module_exit(cc770_exit);
885