mscan.c revision bf3af54732bea5894ccc2cbde3ab566f0af7da56
1/*
2 * CAN bus driver for the alone generic (as possible as) MSCAN controller.
3 *
4 * Copyright (C) 2005-2006 Andrey Volkov <avolkov@varma-el.com>,
5 *                         Varma Electronics Oy
6 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
7 * Copyright (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the version 2 of the GNU General Public License
11 * as published by the Free Software Foundation
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21 */
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/interrupt.h>
26#include <linux/delay.h>
27#include <linux/netdevice.h>
28#include <linux/if_arp.h>
29#include <linux/if_ether.h>
30#include <linux/list.h>
31#include <linux/can.h>
32#include <linux/can/dev.h>
33#include <linux/can/error.h>
34#include <linux/io.h>
35
36#include "mscan.h"
37
38static struct can_bittiming_const mscan_bittiming_const = {
39	.name = "mscan",
40	.tseg1_min = 4,
41	.tseg1_max = 16,
42	.tseg2_min = 2,
43	.tseg2_max = 8,
44	.sjw_max = 4,
45	.brp_min = 1,
46	.brp_max = 64,
47	.brp_inc = 1,
48};
49
50struct mscan_state {
51	u8 mode;
52	u8 canrier;
53	u8 cantier;
54};
55
56static enum can_state state_map[] = {
57	CAN_STATE_ERROR_ACTIVE,
58	CAN_STATE_ERROR_WARNING,
59	CAN_STATE_ERROR_PASSIVE,
60	CAN_STATE_BUS_OFF
61};
62
63static int mscan_set_mode(struct net_device *dev, u8 mode)
64{
65	struct mscan_priv *priv = netdev_priv(dev);
66	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
67	int ret = 0;
68	int i;
69	u8 canctl1;
70
71	if (mode != MSCAN_NORMAL_MODE) {
72		if (priv->tx_active) {
73			/* Abort transfers before going to sleep */#
74			out_8(&regs->cantarq, priv->tx_active);
75			/* Suppress TX done interrupts */
76			out_8(&regs->cantier, 0);
77		}
78
79		canctl1 = in_8(&regs->canctl1);
80		if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
81			setbits8(&regs->canctl0, MSCAN_SLPRQ);
82			for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
83				if (in_8(&regs->canctl1) & MSCAN_SLPAK)
84					break;
85				udelay(100);
86			}
87			/*
88			 * The mscan controller will fail to enter sleep mode,
89			 * while there are irregular activities on bus, like
90			 * somebody keeps retransmitting. This behavior is
91			 * undocumented and seems to differ between mscan built
92			 * in mpc5200b and mpc5200. We proceed in that case,
93			 * since otherwise the slprq will be kept set and the
94			 * controller will get stuck. NOTE: INITRQ or CSWAI
95			 * will abort all active transmit actions, if still
96			 * any, at once.
97			 */
98			if (i >= MSCAN_SET_MODE_RETRIES)
99				dev_dbg(dev->dev.parent,
100					"device failed to enter sleep mode. "
101					"We proceed anyhow.\n");
102			else
103				priv->can.state = CAN_STATE_SLEEPING;
104		}
105
106		if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
107			setbits8(&regs->canctl0, MSCAN_INITRQ);
108			for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
109				if (in_8(&regs->canctl1) & MSCAN_INITAK)
110					break;
111			}
112			if (i >= MSCAN_SET_MODE_RETRIES)
113				ret = -ENODEV;
114		}
115		if (!ret)
116			priv->can.state = CAN_STATE_STOPPED;
117
118		if (mode & MSCAN_CSWAI)
119			setbits8(&regs->canctl0, MSCAN_CSWAI);
120
121	} else {
122		canctl1 = in_8(&regs->canctl1);
123		if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
124			clrbits8(&regs->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
125			for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
126				canctl1 = in_8(&regs->canctl1);
127				if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
128					break;
129			}
130			if (i >= MSCAN_SET_MODE_RETRIES)
131				ret = -ENODEV;
132			else
133				priv->can.state = CAN_STATE_ERROR_ACTIVE;
134		}
135	}
136	return ret;
137}
138
139static int mscan_start(struct net_device *dev)
140{
141	struct mscan_priv *priv = netdev_priv(dev);
142	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
143	u8 canrflg;
144	int err;
145
146	out_8(&regs->canrier, 0);
147
148	INIT_LIST_HEAD(&priv->tx_head);
149	priv->prev_buf_id = 0;
150	priv->cur_pri = 0;
151	priv->tx_active = 0;
152	priv->shadow_canrier = 0;
153	priv->flags = 0;
154
155	if (priv->type == MSCAN_TYPE_MPC5121) {
156		/* Clear pending bus-off condition */
157		if (in_8(&regs->canmisc) & MSCAN_BOHOLD)
158			out_8(&regs->canmisc, MSCAN_BOHOLD);
159	}
160
161	err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
162	if (err)
163		return err;
164
165	canrflg = in_8(&regs->canrflg);
166	priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
167	priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
168				    MSCAN_STATE_TX(canrflg))];
169	out_8(&regs->cantier, 0);
170
171	/* Enable receive interrupts. */
172	out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
173
174	return 0;
175}
176
177static int mscan_restart(struct net_device *dev)
178{
179	struct mscan_priv *priv = netdev_priv(dev);
180
181	if (priv->type == MSCAN_TYPE_MPC5121) {
182		struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
183
184		priv->can.state = CAN_STATE_ERROR_ACTIVE;
185		WARN(!(in_8(&regs->canmisc) & MSCAN_BOHOLD),
186		     "bus-off state expected");
187		out_8(&regs->canmisc, MSCAN_BOHOLD);
188		/* Re-enable receive interrupts. */
189		out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
190	} else {
191		if (priv->can.state <= CAN_STATE_BUS_OFF)
192			mscan_set_mode(dev, MSCAN_INIT_MODE);
193		return mscan_start(dev);
194	}
195
196	return 0;
197}
198
199static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
200{
201	struct can_frame *frame = (struct can_frame *)skb->data;
202	struct mscan_priv *priv = netdev_priv(dev);
203	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
204	int i, rtr, buf_id;
205	u32 can_id;
206
207	if (skb->len != sizeof(*frame) || frame->can_dlc > 8) {
208		kfree_skb(skb);
209		dev->stats.tx_dropped++;
210		return NETDEV_TX_OK;
211	}
212
213	out_8(&regs->cantier, 0);
214
215	i = ~priv->tx_active & MSCAN_TXE;
216	buf_id = ffs(i) - 1;
217	switch (hweight8(i)) {
218	case 0:
219		netif_stop_queue(dev);
220		dev_err(dev->dev.parent, "Tx Ring full when queue awake!\n");
221		return NETDEV_TX_BUSY;
222	case 1:
223		/*
224		 * if buf_id < 3, then current frame will be send out of order,
225		 * since buffer with lower id have higher priority (hell..)
226		 */
227		netif_stop_queue(dev);
228	case 2:
229		if (buf_id < priv->prev_buf_id) {
230			priv->cur_pri++;
231			if (priv->cur_pri == 0xff) {
232				set_bit(F_TX_WAIT_ALL, &priv->flags);
233				netif_stop_queue(dev);
234			}
235		}
236		set_bit(F_TX_PROGRESS, &priv->flags);
237		break;
238	}
239	priv->prev_buf_id = buf_id;
240	out_8(&regs->cantbsel, i);
241
242	rtr = frame->can_id & CAN_RTR_FLAG;
243
244	/* RTR is always the lowest bit of interest, then IDs follow */
245	if (frame->can_id & CAN_EFF_FLAG) {
246		can_id = (frame->can_id & CAN_EFF_MASK)
247			 << (MSCAN_EFF_RTR_SHIFT + 1);
248		if (rtr)
249			can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
250		out_be16(&regs->tx.idr3_2, can_id);
251
252		can_id >>= 16;
253		/* EFF_FLAGS are inbetween the IDs :( */
254		can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
255			 | MSCAN_EFF_FLAGS;
256	} else {
257		can_id = (frame->can_id & CAN_SFF_MASK)
258			 << (MSCAN_SFF_RTR_SHIFT + 1);
259		if (rtr)
260			can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
261	}
262	out_be16(&regs->tx.idr1_0, can_id);
263
264	if (!rtr) {
265		void __iomem *data = &regs->tx.dsr1_0;
266		u16 *payload = (u16 *)frame->data;
267
268		/* It is safe to write into dsr[dlc+1] */
269		for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
270			out_be16(data, *payload++);
271			data += 2 + _MSCAN_RESERVED_DSR_SIZE;
272		}
273	}
274
275	out_8(&regs->tx.dlr, frame->can_dlc);
276	out_8(&regs->tx.tbpr, priv->cur_pri);
277
278	/* Start transmission. */
279	out_8(&regs->cantflg, 1 << buf_id);
280
281	if (!test_bit(F_TX_PROGRESS, &priv->flags))
282		dev->trans_start = jiffies;
283
284	list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
285
286	can_put_echo_skb(skb, dev, buf_id);
287
288	/* Enable interrupt. */
289	priv->tx_active |= 1 << buf_id;
290	out_8(&regs->cantier, priv->tx_active);
291
292	return NETDEV_TX_OK;
293}
294
295/* This function returns the old state to see where we came from */
296static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
297{
298	struct mscan_priv *priv = netdev_priv(dev);
299	enum can_state state, old_state = priv->can.state;
300
301	if (canrflg & MSCAN_CSCIF && old_state <= CAN_STATE_BUS_OFF) {
302		state = state_map[max(MSCAN_STATE_RX(canrflg),
303				      MSCAN_STATE_TX(canrflg))];
304		priv->can.state = state;
305	}
306	return old_state;
307}
308
309static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
310{
311	struct mscan_priv *priv = netdev_priv(dev);
312	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
313	u32 can_id;
314	int i;
315
316	can_id = in_be16(&regs->rx.idr1_0);
317	if (can_id & (1 << 3)) {
318		frame->can_id = CAN_EFF_FLAG;
319		can_id = ((can_id << 16) | in_be16(&regs->rx.idr3_2));
320		can_id = ((can_id & 0xffe00000) |
321			  ((can_id & 0x7ffff) << 2)) >> 2;
322	} else {
323		can_id >>= 4;
324		frame->can_id = 0;
325	}
326
327	frame->can_id |= can_id >> 1;
328	if (can_id & 1)
329		frame->can_id |= CAN_RTR_FLAG;
330
331	frame->can_dlc = get_can_dlc(in_8(&regs->rx.dlr) & 0xf);
332
333	if (!(frame->can_id & CAN_RTR_FLAG)) {
334		void __iomem *data = &regs->rx.dsr1_0;
335		u16 *payload = (u16 *)frame->data;
336
337		for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
338			*payload++ = in_be16(data);
339			data += 2 + _MSCAN_RESERVED_DSR_SIZE;
340		}
341	}
342
343	out_8(&regs->canrflg, MSCAN_RXF);
344}
345
346static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
347				u8 canrflg)
348{
349	struct mscan_priv *priv = netdev_priv(dev);
350	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
351	struct net_device_stats *stats = &dev->stats;
352	enum can_state old_state;
353
354	dev_dbg(dev->dev.parent, "error interrupt (canrflg=%#x)\n", canrflg);
355	frame->can_id = CAN_ERR_FLAG;
356
357	if (canrflg & MSCAN_OVRIF) {
358		frame->can_id |= CAN_ERR_CRTL;
359		frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
360		stats->rx_over_errors++;
361		stats->rx_errors++;
362	} else {
363		frame->data[1] = 0;
364	}
365
366	old_state = check_set_state(dev, canrflg);
367	/* State changed */
368	if (old_state != priv->can.state) {
369		switch (priv->can.state) {
370		case CAN_STATE_ERROR_WARNING:
371			frame->can_id |= CAN_ERR_CRTL;
372			priv->can.can_stats.error_warning++;
373			if ((priv->shadow_statflg & MSCAN_RSTAT_MSK) <
374			    (canrflg & MSCAN_RSTAT_MSK))
375				frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
376			if ((priv->shadow_statflg & MSCAN_TSTAT_MSK) <
377			    (canrflg & MSCAN_TSTAT_MSK))
378				frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
379			break;
380		case CAN_STATE_ERROR_PASSIVE:
381			frame->can_id |= CAN_ERR_CRTL;
382			priv->can.can_stats.error_passive++;
383			frame->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
384			break;
385		case CAN_STATE_BUS_OFF:
386			frame->can_id |= CAN_ERR_BUSOFF;
387			/*
388			 * The MSCAN on the MPC5200 does recover from bus-off
389			 * automatically. To avoid that we stop the chip doing
390			 * a light-weight stop (we are in irq-context).
391			 */
392			if (priv->type != MSCAN_TYPE_MPC5121) {
393				out_8(&regs->cantier, 0);
394				out_8(&regs->canrier, 0);
395				setbits8(&regs->canctl0,
396					 MSCAN_SLPRQ | MSCAN_INITRQ);
397			}
398			can_bus_off(dev);
399			break;
400		default:
401			break;
402		}
403	}
404	priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
405	frame->can_dlc = CAN_ERR_DLC;
406	out_8(&regs->canrflg, MSCAN_ERR_IF);
407}
408
409static int mscan_rx_poll(struct napi_struct *napi, int quota)
410{
411	struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
412	struct net_device *dev = napi->dev;
413	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
414	struct net_device_stats *stats = &dev->stats;
415	int npackets = 0;
416	int ret = 1;
417	struct sk_buff *skb;
418	struct can_frame *frame;
419	u8 canrflg;
420
421	while (npackets < quota) {
422		canrflg = in_8(&regs->canrflg);
423		if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
424			break;
425
426		skb = alloc_can_skb(dev, &frame);
427		if (!skb) {
428			if (printk_ratelimit())
429				dev_notice(dev->dev.parent, "packet dropped\n");
430			stats->rx_dropped++;
431			out_8(&regs->canrflg, canrflg);
432			continue;
433		}
434
435		if (canrflg & MSCAN_RXF)
436			mscan_get_rx_frame(dev, frame);
437		else if (canrflg & MSCAN_ERR_IF)
438			mscan_get_err_frame(dev, frame, canrflg);
439
440		stats->rx_packets++;
441		stats->rx_bytes += frame->can_dlc;
442		npackets++;
443		netif_receive_skb(skb);
444	}
445
446	if (!(in_8(&regs->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
447		napi_complete(&priv->napi);
448		clear_bit(F_RX_PROGRESS, &priv->flags);
449		if (priv->can.state < CAN_STATE_BUS_OFF)
450			out_8(&regs->canrier, priv->shadow_canrier);
451		ret = 0;
452	}
453	return ret;
454}
455
456static irqreturn_t mscan_isr(int irq, void *dev_id)
457{
458	struct net_device *dev = (struct net_device *)dev_id;
459	struct mscan_priv *priv = netdev_priv(dev);
460	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
461	struct net_device_stats *stats = &dev->stats;
462	u8 cantier, cantflg, canrflg;
463	irqreturn_t ret = IRQ_NONE;
464
465	cantier = in_8(&regs->cantier) & MSCAN_TXE;
466	cantflg = in_8(&regs->cantflg) & cantier;
467
468	if (cantier && cantflg) {
469		struct list_head *tmp, *pos;
470
471		list_for_each_safe(pos, tmp, &priv->tx_head) {
472			struct tx_queue_entry *entry =
473			    list_entry(pos, struct tx_queue_entry, list);
474			u8 mask = entry->mask;
475
476			if (!(cantflg & mask))
477				continue;
478
479			out_8(&regs->cantbsel, mask);
480			stats->tx_bytes += in_8(&regs->tx.dlr);
481			stats->tx_packets++;
482			can_get_echo_skb(dev, entry->id);
483			priv->tx_active &= ~mask;
484			list_del(pos);
485		}
486
487		if (list_empty(&priv->tx_head)) {
488			clear_bit(F_TX_WAIT_ALL, &priv->flags);
489			clear_bit(F_TX_PROGRESS, &priv->flags);
490			priv->cur_pri = 0;
491		} else {
492			dev->trans_start = jiffies;
493		}
494
495		if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
496			netif_wake_queue(dev);
497
498		out_8(&regs->cantier, priv->tx_active);
499		ret = IRQ_HANDLED;
500	}
501
502	canrflg = in_8(&regs->canrflg);
503	if ((canrflg & ~MSCAN_STAT_MSK) &&
504	    !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
505		if (canrflg & ~MSCAN_STAT_MSK) {
506			priv->shadow_canrier = in_8(&regs->canrier);
507			out_8(&regs->canrier, 0);
508			napi_schedule(&priv->napi);
509			ret = IRQ_HANDLED;
510		} else {
511			clear_bit(F_RX_PROGRESS, &priv->flags);
512		}
513	}
514	return ret;
515}
516
517static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
518{
519	struct mscan_priv *priv = netdev_priv(dev);
520	int ret = 0;
521
522	if (!priv->open_time)
523		return -EINVAL;
524
525	switch (mode) {
526	case CAN_MODE_START:
527		ret = mscan_restart(dev);
528		if (ret)
529			break;
530		if (netif_queue_stopped(dev))
531			netif_wake_queue(dev);
532		break;
533
534	default:
535		ret = -EOPNOTSUPP;
536		break;
537	}
538	return ret;
539}
540
541static int mscan_do_set_bittiming(struct net_device *dev)
542{
543	struct mscan_priv *priv = netdev_priv(dev);
544	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
545	struct can_bittiming *bt = &priv->can.bittiming;
546	u8 btr0, btr1;
547
548	btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
549	btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
550		BTR1_SET_TSEG2(bt->phase_seg2) |
551		BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
552
553	dev_info(dev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
554		btr0, btr1);
555
556	out_8(&regs->canbtr0, btr0);
557	out_8(&regs->canbtr1, btr1);
558
559	return 0;
560}
561
562static int mscan_open(struct net_device *dev)
563{
564	int ret;
565	struct mscan_priv *priv = netdev_priv(dev);
566	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
567
568	/* common open */
569	ret = open_candev(dev);
570	if (ret)
571		return ret;
572
573	napi_enable(&priv->napi);
574
575	ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
576	if (ret < 0) {
577		dev_err(dev->dev.parent, "failed to attach interrupt\n");
578		goto exit_napi_disable;
579	}
580
581	priv->open_time = jiffies;
582
583	clrbits8(&regs->canctl1, MSCAN_LISTEN);
584
585	ret = mscan_start(dev);
586	if (ret)
587		goto exit_free_irq;
588
589	netif_start_queue(dev);
590
591	return 0;
592
593exit_free_irq:
594	priv->open_time = 0;
595	free_irq(dev->irq, dev);
596exit_napi_disable:
597	napi_disable(&priv->napi);
598	close_candev(dev);
599	return ret;
600}
601
602static int mscan_close(struct net_device *dev)
603{
604	struct mscan_priv *priv = netdev_priv(dev);
605	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
606
607	netif_stop_queue(dev);
608	napi_disable(&priv->napi);
609
610	out_8(&regs->cantier, 0);
611	out_8(&regs->canrier, 0);
612	mscan_set_mode(dev, MSCAN_INIT_MODE);
613	close_candev(dev);
614	free_irq(dev->irq, dev);
615	priv->open_time = 0;
616
617	return 0;
618}
619
620static const struct net_device_ops mscan_netdev_ops = {
621       .ndo_open               = mscan_open,
622       .ndo_stop               = mscan_close,
623       .ndo_start_xmit         = mscan_start_xmit,
624};
625
626int register_mscandev(struct net_device *dev, int mscan_clksrc)
627{
628	struct mscan_priv *priv = netdev_priv(dev);
629	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
630	u8 ctl1;
631
632	ctl1 = in_8(&regs->canctl1);
633	if (mscan_clksrc)
634		ctl1 |= MSCAN_CLKSRC;
635	else
636		ctl1 &= ~MSCAN_CLKSRC;
637
638	if (priv->type == MSCAN_TYPE_MPC5121)
639		ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
640
641	ctl1 |= MSCAN_CANE;
642	out_8(&regs->canctl1, ctl1);
643	udelay(100);
644
645	/* acceptance mask/acceptance code (accept everything) */
646	out_be16(&regs->canidar1_0, 0);
647	out_be16(&regs->canidar3_2, 0);
648	out_be16(&regs->canidar5_4, 0);
649	out_be16(&regs->canidar7_6, 0);
650
651	out_be16(&regs->canidmr1_0, 0xffff);
652	out_be16(&regs->canidmr3_2, 0xffff);
653	out_be16(&regs->canidmr5_4, 0xffff);
654	out_be16(&regs->canidmr7_6, 0xffff);
655	/* Two 32 bit Acceptance Filters */
656	out_8(&regs->canidac, MSCAN_AF_32BIT);
657
658	mscan_set_mode(dev, MSCAN_INIT_MODE);
659
660	return register_candev(dev);
661}
662
663void unregister_mscandev(struct net_device *dev)
664{
665	struct mscan_priv *priv = netdev_priv(dev);
666	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
667	mscan_set_mode(dev, MSCAN_INIT_MODE);
668	clrbits8(&regs->canctl1, MSCAN_CANE);
669	unregister_candev(dev);
670}
671
672struct net_device *alloc_mscandev(void)
673{
674	struct net_device *dev;
675	struct mscan_priv *priv;
676	int i;
677
678	dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
679	if (!dev)
680		return NULL;
681	priv = netdev_priv(dev);
682
683	dev->netdev_ops = &mscan_netdev_ops;
684
685	dev->flags |= IFF_ECHO;	/* we support local echo */
686
687	netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
688
689	priv->can.bittiming_const = &mscan_bittiming_const;
690	priv->can.do_set_bittiming = mscan_do_set_bittiming;
691	priv->can.do_set_mode = mscan_do_set_mode;
692
693	for (i = 0; i < TX_QUEUE_SIZE; i++) {
694		priv->tx_queue[i].id = i;
695		priv->tx_queue[i].mask = 1 << i;
696	}
697
698	return dev;
699}
700
701MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
702MODULE_LICENSE("GPL v2");
703MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");
704