mscan.c revision 05780d9808f72dc28a5c3602e11a7c53aef972ad
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, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/interrupt.h>
25#include <linux/delay.h>
26#include <linux/netdevice.h>
27#include <linux/if_arp.h>
28#include <linux/if_ether.h>
29#include <linux/list.h>
30#include <linux/can/dev.h>
31#include <linux/can/error.h>
32#include <linux/io.h>
33
34#include "mscan.h"
35
36static const struct can_bittiming_const mscan_bittiming_const = {
37	.name = "mscan",
38	.tseg1_min = 4,
39	.tseg1_max = 16,
40	.tseg2_min = 2,
41	.tseg2_max = 8,
42	.sjw_max = 4,
43	.brp_min = 1,
44	.brp_max = 64,
45	.brp_inc = 1,
46};
47
48struct mscan_state {
49	u8 mode;
50	u8 canrier;
51	u8 cantier;
52};
53
54static enum can_state state_map[] = {
55	CAN_STATE_ERROR_ACTIVE,
56	CAN_STATE_ERROR_WARNING,
57	CAN_STATE_ERROR_PASSIVE,
58	CAN_STATE_BUS_OFF
59};
60
61static int mscan_set_mode(struct net_device *dev, u8 mode)
62{
63	struct mscan_priv *priv = netdev_priv(dev);
64	struct mscan_regs __iomem *regs = priv->reg_base;
65	int ret = 0;
66	int i;
67	u8 canctl1;
68
69	if (mode != MSCAN_NORMAL_MODE) {
70		if (priv->tx_active) {
71			/* Abort transfers before going to sleep */#
72			out_8(&regs->cantarq, priv->tx_active);
73			/* Suppress TX done interrupts */
74			out_8(&regs->cantier, 0);
75		}
76
77		canctl1 = in_8(&regs->canctl1);
78		if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
79			setbits8(&regs->canctl0, MSCAN_SLPRQ);
80			for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
81				if (in_8(&regs->canctl1) & MSCAN_SLPAK)
82					break;
83				udelay(100);
84			}
85			/*
86			 * The mscan controller will fail to enter sleep mode,
87			 * while there are irregular activities on bus, like
88			 * somebody keeps retransmitting. This behavior is
89			 * undocumented and seems to differ between mscan built
90			 * in mpc5200b and mpc5200. We proceed in that case,
91			 * since otherwise the slprq will be kept set and the
92			 * controller will get stuck. NOTE: INITRQ or CSWAI
93			 * will abort all active transmit actions, if still
94			 * any, at once.
95			 */
96			if (i >= MSCAN_SET_MODE_RETRIES)
97				netdev_dbg(dev,
98					   "device failed to enter sleep mode. "
99					   "We proceed anyhow.\n");
100			else
101				priv->can.state = CAN_STATE_SLEEPING;
102		}
103
104		if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
105			setbits8(&regs->canctl0, MSCAN_INITRQ);
106			for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
107				if (in_8(&regs->canctl1) & MSCAN_INITAK)
108					break;
109			}
110			if (i >= MSCAN_SET_MODE_RETRIES)
111				ret = -ENODEV;
112		}
113		if (!ret)
114			priv->can.state = CAN_STATE_STOPPED;
115
116		if (mode & MSCAN_CSWAI)
117			setbits8(&regs->canctl0, MSCAN_CSWAI);
118
119	} else {
120		canctl1 = in_8(&regs->canctl1);
121		if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
122			clrbits8(&regs->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
123			for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
124				canctl1 = in_8(&regs->canctl1);
125				if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
126					break;
127			}
128			if (i >= MSCAN_SET_MODE_RETRIES)
129				ret = -ENODEV;
130			else
131				priv->can.state = CAN_STATE_ERROR_ACTIVE;
132		}
133	}
134	return ret;
135}
136
137static int mscan_start(struct net_device *dev)
138{
139	struct mscan_priv *priv = netdev_priv(dev);
140	struct mscan_regs __iomem *regs = priv->reg_base;
141	u8 canrflg;
142	int err;
143
144	out_8(&regs->canrier, 0);
145
146	INIT_LIST_HEAD(&priv->tx_head);
147	priv->prev_buf_id = 0;
148	priv->cur_pri = 0;
149	priv->tx_active = 0;
150	priv->shadow_canrier = 0;
151	priv->flags = 0;
152
153	if (priv->type == MSCAN_TYPE_MPC5121) {
154		/* Clear pending bus-off condition */
155		if (in_8(&regs->canmisc) & MSCAN_BOHOLD)
156			out_8(&regs->canmisc, MSCAN_BOHOLD);
157	}
158
159	err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
160	if (err)
161		return err;
162
163	canrflg = in_8(&regs->canrflg);
164	priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
165	priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
166				    MSCAN_STATE_TX(canrflg))];
167	out_8(&regs->cantier, 0);
168
169	/* Enable receive interrupts. */
170	out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
171
172	return 0;
173}
174
175static int mscan_restart(struct net_device *dev)
176{
177	struct mscan_priv *priv = netdev_priv(dev);
178
179	if (priv->type == MSCAN_TYPE_MPC5121) {
180		struct mscan_regs __iomem *regs = priv->reg_base;
181
182		priv->can.state = CAN_STATE_ERROR_ACTIVE;
183		WARN(!(in_8(&regs->canmisc) & MSCAN_BOHOLD),
184		     "bus-off state expected\n");
185		out_8(&regs->canmisc, MSCAN_BOHOLD);
186		/* Re-enable receive interrupts. */
187		out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
188	} else {
189		if (priv->can.state <= CAN_STATE_BUS_OFF)
190			mscan_set_mode(dev, MSCAN_INIT_MODE);
191		return mscan_start(dev);
192	}
193
194	return 0;
195}
196
197static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
198{
199	struct can_frame *frame = (struct can_frame *)skb->data;
200	struct mscan_priv *priv = netdev_priv(dev);
201	struct mscan_regs __iomem *regs = priv->reg_base;
202	int i, rtr, buf_id;
203	u32 can_id;
204
205	if (can_dropped_invalid_skb(dev, skb))
206		return NETDEV_TX_OK;
207
208	out_8(&regs->cantier, 0);
209
210	i = ~priv->tx_active & MSCAN_TXE;
211	buf_id = ffs(i) - 1;
212	switch (hweight8(i)) {
213	case 0:
214		netif_stop_queue(dev);
215		netdev_err(dev, "Tx Ring full when queue awake!\n");
216		return NETDEV_TX_BUSY;
217	case 1:
218		/*
219		 * if buf_id < 3, then current frame will be send out of order,
220		 * since buffer with lower id have higher priority (hell..)
221		 */
222		netif_stop_queue(dev);
223	case 2:
224		if (buf_id < priv->prev_buf_id) {
225			priv->cur_pri++;
226			if (priv->cur_pri == 0xff) {
227				set_bit(F_TX_WAIT_ALL, &priv->flags);
228				netif_stop_queue(dev);
229			}
230		}
231		set_bit(F_TX_PROGRESS, &priv->flags);
232		break;
233	}
234	priv->prev_buf_id = buf_id;
235	out_8(&regs->cantbsel, i);
236
237	rtr = frame->can_id & CAN_RTR_FLAG;
238
239	/* RTR is always the lowest bit of interest, then IDs follow */
240	if (frame->can_id & CAN_EFF_FLAG) {
241		can_id = (frame->can_id & CAN_EFF_MASK)
242			 << (MSCAN_EFF_RTR_SHIFT + 1);
243		if (rtr)
244			can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
245		out_be16(&regs->tx.idr3_2, can_id);
246
247		can_id >>= 16;
248		/* EFF_FLAGS are between the IDs :( */
249		can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
250			 | MSCAN_EFF_FLAGS;
251	} else {
252		can_id = (frame->can_id & CAN_SFF_MASK)
253			 << (MSCAN_SFF_RTR_SHIFT + 1);
254		if (rtr)
255			can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
256	}
257	out_be16(&regs->tx.idr1_0, can_id);
258
259	if (!rtr) {
260		void __iomem *data = &regs->tx.dsr1_0;
261		u16 *payload = (u16 *)frame->data;
262
263		for (i = 0; i < frame->can_dlc / 2; i++) {
264			out_be16(data, *payload++);
265			data += 2 + _MSCAN_RESERVED_DSR_SIZE;
266		}
267		/* write remaining byte if necessary */
268		if (frame->can_dlc & 1)
269			out_8(data, frame->data[frame->can_dlc - 1]);
270	}
271
272	out_8(&regs->tx.dlr, frame->can_dlc);
273	out_8(&regs->tx.tbpr, priv->cur_pri);
274
275	/* Start transmission. */
276	out_8(&regs->cantflg, 1 << buf_id);
277
278	if (!test_bit(F_TX_PROGRESS, &priv->flags))
279		dev->trans_start = jiffies;
280
281	list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
282
283	can_put_echo_skb(skb, dev, buf_id);
284
285	/* Enable interrupt. */
286	priv->tx_active |= 1 << buf_id;
287	out_8(&regs->cantier, priv->tx_active);
288
289	return NETDEV_TX_OK;
290}
291
292/* This function returns the old state to see where we came from */
293static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
294{
295	struct mscan_priv *priv = netdev_priv(dev);
296	enum can_state state, old_state = priv->can.state;
297
298	if (canrflg & MSCAN_CSCIF && old_state <= CAN_STATE_BUS_OFF) {
299		state = state_map[max(MSCAN_STATE_RX(canrflg),
300				      MSCAN_STATE_TX(canrflg))];
301		priv->can.state = state;
302	}
303	return old_state;
304}
305
306static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
307{
308	struct mscan_priv *priv = netdev_priv(dev);
309	struct mscan_regs __iomem *regs = priv->reg_base;
310	u32 can_id;
311	int i;
312
313	can_id = in_be16(&regs->rx.idr1_0);
314	if (can_id & (1 << 3)) {
315		frame->can_id = CAN_EFF_FLAG;
316		can_id = ((can_id << 16) | in_be16(&regs->rx.idr3_2));
317		can_id = ((can_id & 0xffe00000) |
318			  ((can_id & 0x7ffff) << 2)) >> 2;
319	} else {
320		can_id >>= 4;
321		frame->can_id = 0;
322	}
323
324	frame->can_id |= can_id >> 1;
325	if (can_id & 1)
326		frame->can_id |= CAN_RTR_FLAG;
327
328	frame->can_dlc = get_can_dlc(in_8(&regs->rx.dlr) & 0xf);
329
330	if (!(frame->can_id & CAN_RTR_FLAG)) {
331		void __iomem *data = &regs->rx.dsr1_0;
332		u16 *payload = (u16 *)frame->data;
333
334		for (i = 0; i < frame->can_dlc / 2; i++) {
335			*payload++ = in_be16(data);
336			data += 2 + _MSCAN_RESERVED_DSR_SIZE;
337		}
338		/* read remaining byte if necessary */
339		if (frame->can_dlc & 1)
340			frame->data[frame->can_dlc - 1] = in_8(data);
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 __iomem *regs = priv->reg_base;
351	struct net_device_stats *stats = &dev->stats;
352	enum can_state old_state;
353
354	netdev_dbg(dev, "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 __iomem *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				netdev_notice(dev, "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 __iomem *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	int ret = 0;
520
521	switch (mode) {
522	case CAN_MODE_START:
523		ret = mscan_restart(dev);
524		if (ret)
525			break;
526		if (netif_queue_stopped(dev))
527			netif_wake_queue(dev);
528		break;
529
530	default:
531		ret = -EOPNOTSUPP;
532		break;
533	}
534	return ret;
535}
536
537static int mscan_do_set_bittiming(struct net_device *dev)
538{
539	struct mscan_priv *priv = netdev_priv(dev);
540	struct mscan_regs __iomem *regs = priv->reg_base;
541	struct can_bittiming *bt = &priv->can.bittiming;
542	u8 btr0, btr1;
543
544	btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
545	btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
546		BTR1_SET_TSEG2(bt->phase_seg2) |
547		BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
548
549	netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
550
551	out_8(&regs->canbtr0, btr0);
552	out_8(&regs->canbtr1, btr1);
553
554	return 0;
555}
556
557static int mscan_get_berr_counter(const struct net_device *dev,
558				  struct can_berr_counter *bec)
559{
560	struct mscan_priv *priv = netdev_priv(dev);
561	struct mscan_regs __iomem *regs = priv->reg_base;
562
563	bec->txerr = in_8(&regs->cantxerr);
564	bec->rxerr = in_8(&regs->canrxerr);
565
566	return 0;
567}
568
569static int mscan_open(struct net_device *dev)
570{
571	int ret;
572	struct mscan_priv *priv = netdev_priv(dev);
573	struct mscan_regs __iomem *regs = priv->reg_base;
574
575	if (priv->clk_ipg) {
576		ret = clk_prepare_enable(priv->clk_ipg);
577		if (ret)
578			goto exit_retcode;
579	}
580	if (priv->clk_can) {
581		ret = clk_prepare_enable(priv->clk_can);
582		if (ret)
583			goto exit_dis_ipg_clock;
584	}
585
586	/* common open */
587	ret = open_candev(dev);
588	if (ret)
589		goto exit_dis_can_clock;
590
591	napi_enable(&priv->napi);
592
593	ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
594	if (ret < 0) {
595		netdev_err(dev, "failed to attach interrupt\n");
596		goto exit_napi_disable;
597	}
598
599	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
600		setbits8(&regs->canctl1, MSCAN_LISTEN);
601	else
602		clrbits8(&regs->canctl1, MSCAN_LISTEN);
603
604	ret = mscan_start(dev);
605	if (ret)
606		goto exit_free_irq;
607
608	netif_start_queue(dev);
609
610	return 0;
611
612exit_free_irq:
613	free_irq(dev->irq, dev);
614exit_napi_disable:
615	napi_disable(&priv->napi);
616	close_candev(dev);
617exit_dis_can_clock:
618	if (priv->clk_can)
619		clk_disable_unprepare(priv->clk_can);
620exit_dis_ipg_clock:
621	if (priv->clk_ipg)
622		clk_disable_unprepare(priv->clk_ipg);
623exit_retcode:
624	return ret;
625}
626
627static int mscan_close(struct net_device *dev)
628{
629	struct mscan_priv *priv = netdev_priv(dev);
630	struct mscan_regs __iomem *regs = priv->reg_base;
631
632	netif_stop_queue(dev);
633	napi_disable(&priv->napi);
634
635	out_8(&regs->cantier, 0);
636	out_8(&regs->canrier, 0);
637	mscan_set_mode(dev, MSCAN_INIT_MODE);
638	close_candev(dev);
639	free_irq(dev->irq, dev);
640
641	if (priv->clk_can)
642		clk_disable_unprepare(priv->clk_can);
643	if (priv->clk_ipg)
644		clk_disable_unprepare(priv->clk_ipg);
645
646	return 0;
647}
648
649static const struct net_device_ops mscan_netdev_ops = {
650       .ndo_open               = mscan_open,
651       .ndo_stop               = mscan_close,
652       .ndo_start_xmit         = mscan_start_xmit,
653};
654
655int register_mscandev(struct net_device *dev, int mscan_clksrc)
656{
657	struct mscan_priv *priv = netdev_priv(dev);
658	struct mscan_regs __iomem *regs = priv->reg_base;
659	u8 ctl1;
660
661	ctl1 = in_8(&regs->canctl1);
662	if (mscan_clksrc)
663		ctl1 |= MSCAN_CLKSRC;
664	else
665		ctl1 &= ~MSCAN_CLKSRC;
666
667	if (priv->type == MSCAN_TYPE_MPC5121) {
668		priv->can.do_get_berr_counter = mscan_get_berr_counter;
669		ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
670	}
671
672	ctl1 |= MSCAN_CANE;
673	out_8(&regs->canctl1, ctl1);
674	udelay(100);
675
676	/* acceptance mask/acceptance code (accept everything) */
677	out_be16(&regs->canidar1_0, 0);
678	out_be16(&regs->canidar3_2, 0);
679	out_be16(&regs->canidar5_4, 0);
680	out_be16(&regs->canidar7_6, 0);
681
682	out_be16(&regs->canidmr1_0, 0xffff);
683	out_be16(&regs->canidmr3_2, 0xffff);
684	out_be16(&regs->canidmr5_4, 0xffff);
685	out_be16(&regs->canidmr7_6, 0xffff);
686	/* Two 32 bit Acceptance Filters */
687	out_8(&regs->canidac, MSCAN_AF_32BIT);
688
689	mscan_set_mode(dev, MSCAN_INIT_MODE);
690
691	return register_candev(dev);
692}
693
694void unregister_mscandev(struct net_device *dev)
695{
696	struct mscan_priv *priv = netdev_priv(dev);
697	struct mscan_regs __iomem *regs = priv->reg_base;
698	mscan_set_mode(dev, MSCAN_INIT_MODE);
699	clrbits8(&regs->canctl1, MSCAN_CANE);
700	unregister_candev(dev);
701}
702
703struct net_device *alloc_mscandev(void)
704{
705	struct net_device *dev;
706	struct mscan_priv *priv;
707	int i;
708
709	dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
710	if (!dev)
711		return NULL;
712	priv = netdev_priv(dev);
713
714	dev->netdev_ops = &mscan_netdev_ops;
715
716	dev->flags |= IFF_ECHO;	/* we support local echo */
717
718	netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
719
720	priv->can.bittiming_const = &mscan_bittiming_const;
721	priv->can.do_set_bittiming = mscan_do_set_bittiming;
722	priv->can.do_set_mode = mscan_do_set_mode;
723	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
724		CAN_CTRLMODE_LISTENONLY;
725
726	for (i = 0; i < TX_QUEUE_SIZE; i++) {
727		priv->tx_queue[i].id = i;
728		priv->tx_queue[i].mask = 1 << i;
729	}
730
731	return dev;
732}
733
734MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
735MODULE_LICENSE("GPL v2");
736MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");
737