1 /*
2  * Copyright (C) 2008-2010
3  *
4  * - Kurt Van Dijck, EIA Electronics
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  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #include <linux/version.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/interrupt.h>
24 
25 #include "softing.h"
26 
27 #define TX_ECHO_SKB_MAX (((TXMAX+1)/2)-1)
28 
29 /*
30  * test is a specific CAN netdev
31  * is online (ie. up 'n running, not sleeping, not busoff
32  */
33 static inline int canif_is_active(struct net_device *netdev)
34 {
35 	struct can_priv *can = netdev_priv(netdev);
36 
37 	if (!netif_running(netdev))
38 		return 0;
39 	return (can->state <= CAN_STATE_ERROR_PASSIVE);
40 }
41 
42 /* reset DPRAM */
43 static inline void softing_set_reset_dpram(struct softing *card)
44 {
45 	if (card->pdat->generation >= 2) {
46 		spin_lock_bh(&card->spin);
47 		iowrite8(ioread8(&card->dpram[DPRAM_V2_RESET]) & ~1,
48 				&card->dpram[DPRAM_V2_RESET]);
49 		spin_unlock_bh(&card->spin);
50 	}
51 }
52 
53 static inline void softing_clr_reset_dpram(struct softing *card)
54 {
55 	if (card->pdat->generation >= 2) {
56 		spin_lock_bh(&card->spin);
57 		iowrite8(ioread8(&card->dpram[DPRAM_V2_RESET]) | 1,
58 				&card->dpram[DPRAM_V2_RESET]);
59 		spin_unlock_bh(&card->spin);
60 	}
61 }
62 
63 /* trigger the tx queue-ing */
64 static netdev_tx_t softing_netdev_start_xmit(struct sk_buff *skb,
65 		struct net_device *dev)
66 {
67 	struct softing_priv *priv = netdev_priv(dev);
68 	struct softing *card = priv->card;
69 	int ret;
70 	uint8_t *ptr;
71 	uint8_t fifo_wr, fifo_rd;
72 	struct can_frame *cf = (struct can_frame *)skb->data;
73 	uint8_t buf[DPRAM_TX_SIZE];
74 
75 	if (can_dropped_invalid_skb(dev, skb))
76 		return NETDEV_TX_OK;
77 
78 	spin_lock(&card->spin);
79 
80 	ret = NETDEV_TX_BUSY;
81 	if (!card->fw.up ||
82 			(card->tx.pending >= TXMAX) ||
83 			(priv->tx.pending >= TX_ECHO_SKB_MAX))
84 		goto xmit_done;
85 	fifo_wr = ioread8(&card->dpram[DPRAM_TX_WR]);
86 	fifo_rd = ioread8(&card->dpram[DPRAM_TX_RD]);
87 	if (fifo_wr == fifo_rd)
88 		/* fifo full */
89 		goto xmit_done;
90 	memset(buf, 0, sizeof(buf));
91 	ptr = buf;
92 	*ptr = CMD_TX;
93 	if (cf->can_id & CAN_RTR_FLAG)
94 		*ptr |= CMD_RTR;
95 	if (cf->can_id & CAN_EFF_FLAG)
96 		*ptr |= CMD_XTD;
97 	if (priv->index)
98 		*ptr |= CMD_BUS2;
99 	++ptr;
100 	*ptr++ = cf->can_dlc;
101 	*ptr++ = (cf->can_id >> 0);
102 	*ptr++ = (cf->can_id >> 8);
103 	if (cf->can_id & CAN_EFF_FLAG) {
104 		*ptr++ = (cf->can_id >> 16);
105 		*ptr++ = (cf->can_id >> 24);
106 	} else {
107 		/* increment 1, not 2 as you might think */
108 		ptr += 1;
109 	}
110 	if (!(cf->can_id & CAN_RTR_FLAG))
111 		memcpy(ptr, &cf->data[0], cf->can_dlc);
112 	memcpy_toio(&card->dpram[DPRAM_TX + DPRAM_TX_SIZE * fifo_wr],
113 			buf, DPRAM_TX_SIZE);
114 	if (++fifo_wr >= DPRAM_TX_CNT)
115 		fifo_wr = 0;
116 	iowrite8(fifo_wr, &card->dpram[DPRAM_TX_WR]);
117 	card->tx.last_bus = priv->index;
118 	++card->tx.pending;
119 	++priv->tx.pending;
120 	can_put_echo_skb(skb, dev, priv->tx.echo_put);
121 	++priv->tx.echo_put;
122 	if (priv->tx.echo_put >= TX_ECHO_SKB_MAX)
123 		priv->tx.echo_put = 0;
124 	/* can_put_echo_skb() saves the skb, safe to return TX_OK */
125 	ret = NETDEV_TX_OK;
126 xmit_done:
127 	spin_unlock(&card->spin);
128 	if (card->tx.pending >= TXMAX) {
129 		int j;
130 		for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
131 			if (card->net[j])
132 				netif_stop_queue(card->net[j]);
133 		}
134 	}
135 	if (ret != NETDEV_TX_OK)
136 		netif_stop_queue(dev);
137 
138 	return ret;
139 }
140 
141 /*
142  * shortcut for skb delivery
143  */
144 int softing_netdev_rx(struct net_device *netdev, const struct can_frame *msg,
145 		ktime_t ktime)
146 {
147 	struct sk_buff *skb;
148 	struct can_frame *cf;
149 
150 	skb = alloc_can_skb(netdev, &cf);
151 	if (!skb)
152 		return -ENOMEM;
153 	memcpy(cf, msg, sizeof(*msg));
154 	skb->tstamp = ktime;
155 	return netif_rx(skb);
156 }
157 
158 /*
159  * softing_handle_1
160  * pop 1 entry from the DPRAM queue, and process
161  */
162 static int softing_handle_1(struct softing *card)
163 {
164 	struct net_device *netdev;
165 	struct softing_priv *priv;
166 	ktime_t ktime;
167 	struct can_frame msg;
168 	int cnt = 0, lost_msg;
169 	uint8_t fifo_rd, fifo_wr, cmd;
170 	uint8_t *ptr;
171 	uint32_t tmp_u32;
172 	uint8_t buf[DPRAM_RX_SIZE];
173 
174 	memset(&msg, 0, sizeof(msg));
175 	/* test for lost msgs */
176 	lost_msg = ioread8(&card->dpram[DPRAM_RX_LOST]);
177 	if (lost_msg) {
178 		int j;
179 		/* reset condition */
180 		iowrite8(0, &card->dpram[DPRAM_RX_LOST]);
181 		/* prepare msg */
182 		msg.can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
183 		msg.can_dlc = CAN_ERR_DLC;
184 		msg.data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
185 		/*
186 		 * service to all busses, we don't know which it was applicable
187 		 * but only service busses that are online
188 		 */
189 		for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
190 			netdev = card->net[j];
191 			if (!netdev)
192 				continue;
193 			if (!canif_is_active(netdev))
194 				/* a dead bus has no overflows */
195 				continue;
196 			++netdev->stats.rx_over_errors;
197 			softing_netdev_rx(netdev, &msg, ktime_set(0, 0));
198 		}
199 		/* prepare for other use */
200 		memset(&msg, 0, sizeof(msg));
201 		++cnt;
202 	}
203 
204 	fifo_rd = ioread8(&card->dpram[DPRAM_RX_RD]);
205 	fifo_wr = ioread8(&card->dpram[DPRAM_RX_WR]);
206 
207 	if (++fifo_rd >= DPRAM_RX_CNT)
208 		fifo_rd = 0;
209 	if (fifo_wr == fifo_rd)
210 		return cnt;
211 
212 	memcpy_fromio(buf, &card->dpram[DPRAM_RX + DPRAM_RX_SIZE*fifo_rd],
213 			DPRAM_RX_SIZE);
214 	mb();
215 	/* trigger dual port RAM */
216 	iowrite8(fifo_rd, &card->dpram[DPRAM_RX_RD]);
217 
218 	ptr = buf;
219 	cmd = *ptr++;
220 	if (cmd == 0xff)
221 		/* not quite usefull, probably the card has got out */
222 		return 0;
223 	netdev = card->net[0];
224 	if (cmd & CMD_BUS2)
225 		netdev = card->net[1];
226 	priv = netdev_priv(netdev);
227 
228 	if (cmd & CMD_ERR) {
229 		uint8_t can_state, state;
230 
231 		state = *ptr++;
232 
233 		msg.can_id = CAN_ERR_FLAG;
234 		msg.can_dlc = CAN_ERR_DLC;
235 
236 		if (state & SF_MASK_BUSOFF) {
237 			can_state = CAN_STATE_BUS_OFF;
238 			msg.can_id |= CAN_ERR_BUSOFF;
239 			state = STATE_BUSOFF;
240 		} else if (state & SF_MASK_EPASSIVE) {
241 			can_state = CAN_STATE_ERROR_PASSIVE;
242 			msg.can_id |= CAN_ERR_CRTL;
243 			msg.data[1] = CAN_ERR_CRTL_TX_PASSIVE;
244 			state = STATE_EPASSIVE;
245 		} else {
246 			can_state = CAN_STATE_ERROR_ACTIVE;
247 			msg.can_id |= CAN_ERR_CRTL;
248 			state = STATE_EACTIVE;
249 		}
250 		/* update DPRAM */
251 		iowrite8(state, &card->dpram[priv->index ?
252 				DPRAM_INFO_BUSSTATE2 : DPRAM_INFO_BUSSTATE]);
253 		/* timestamp */
254 		tmp_u32 = le32_to_cpup((void *)ptr);
255 		ptr += 4;
256 		ktime = softing_raw2ktime(card, tmp_u32);
257 
258 		++netdev->stats.rx_errors;
259 		/* update internal status */
260 		if (can_state != priv->can.state) {
261 			priv->can.state = can_state;
262 			if (can_state == CAN_STATE_ERROR_PASSIVE)
263 				++priv->can.can_stats.error_passive;
264 			else if (can_state == CAN_STATE_BUS_OFF) {
265 				/* this calls can_close_cleanup() */
266 				can_bus_off(netdev);
267 				netif_stop_queue(netdev);
268 			}
269 			/* trigger socketcan */
270 			softing_netdev_rx(netdev, &msg, ktime);
271 		}
272 
273 	} else {
274 		if (cmd & CMD_RTR)
275 			msg.can_id |= CAN_RTR_FLAG;
276 		msg.can_dlc = get_can_dlc(*ptr++);
277 		if (cmd & CMD_XTD) {
278 			msg.can_id |= CAN_EFF_FLAG;
279 			msg.can_id |= le32_to_cpup((void *)ptr);
280 			ptr += 4;
281 		} else {
282 			msg.can_id |= le16_to_cpup((void *)ptr);
283 			ptr += 2;
284 		}
285 		/* timestamp */
286 		tmp_u32 = le32_to_cpup((void *)ptr);
287 		ptr += 4;
288 		ktime = softing_raw2ktime(card, tmp_u32);
289 		if (!(msg.can_id & CAN_RTR_FLAG))
290 			memcpy(&msg.data[0], ptr, 8);
291 		ptr += 8;
292 		/* update socket */
293 		if (cmd & CMD_ACK) {
294 			/* acknowledge, was tx msg */
295 			struct sk_buff *skb;
296 			skb = priv->can.echo_skb[priv->tx.echo_get];
297 			if (skb)
298 				skb->tstamp = ktime;
299 			can_get_echo_skb(netdev, priv->tx.echo_get);
300 			++priv->tx.echo_get;
301 			if (priv->tx.echo_get >= TX_ECHO_SKB_MAX)
302 				priv->tx.echo_get = 0;
303 			if (priv->tx.pending)
304 				--priv->tx.pending;
305 			if (card->tx.pending)
306 				--card->tx.pending;
307 			++netdev->stats.tx_packets;
308 			if (!(msg.can_id & CAN_RTR_FLAG))
309 				netdev->stats.tx_bytes += msg.can_dlc;
310 		} else {
311 			int ret;
312 
313 			ret = softing_netdev_rx(netdev, &msg, ktime);
314 			if (ret == NET_RX_SUCCESS) {
315 				++netdev->stats.rx_packets;
316 				if (!(msg.can_id & CAN_RTR_FLAG))
317 					netdev->stats.rx_bytes += msg.can_dlc;
318 			} else {
319 				++netdev->stats.rx_dropped;
320 			}
321 		}
322 	}
323 	++cnt;
324 	return cnt;
325 }
326 
327 /*
328  * real interrupt handler
329  */
330 static irqreturn_t softing_irq_thread(int irq, void *dev_id)
331 {
332 	struct softing *card = (struct softing *)dev_id;
333 	struct net_device *netdev;
334 	struct softing_priv *priv;
335 	int j, offset, work_done;
336 
337 	work_done = 0;
338 	spin_lock_bh(&card->spin);
339 	while (softing_handle_1(card) > 0) {
340 		++card->irq.svc_count;
341 		++work_done;
342 	}
343 	spin_unlock_bh(&card->spin);
344 	/* resume tx queue's */
345 	offset = card->tx.last_bus;
346 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
347 		if (card->tx.pending >= TXMAX)
348 			break;
349 		netdev = card->net[(j + offset + 1) % card->pdat->nbus];
350 		if (!netdev)
351 			continue;
352 		priv = netdev_priv(netdev);
353 		if (!canif_is_active(netdev))
354 			/* it makes no sense to wake dead busses */
355 			continue;
356 		if (priv->tx.pending >= TX_ECHO_SKB_MAX)
357 			continue;
358 		++work_done;
359 		netif_wake_queue(netdev);
360 	}
361 	return work_done ? IRQ_HANDLED : IRQ_NONE;
362 }
363 
364 /*
365  * interrupt routines:
366  * schedule the 'real interrupt handler'
367  */
368 static irqreturn_t softing_irq_v2(int irq, void *dev_id)
369 {
370 	struct softing *card = (struct softing *)dev_id;
371 	uint8_t ir;
372 
373 	ir = ioread8(&card->dpram[DPRAM_V2_IRQ_TOHOST]);
374 	iowrite8(0, &card->dpram[DPRAM_V2_IRQ_TOHOST]);
375 	return (1 == ir) ? IRQ_WAKE_THREAD : IRQ_NONE;
376 }
377 
378 static irqreturn_t softing_irq_v1(int irq, void *dev_id)
379 {
380 	struct softing *card = (struct softing *)dev_id;
381 	uint8_t ir;
382 
383 	ir = ioread8(&card->dpram[DPRAM_IRQ_TOHOST]);
384 	iowrite8(0, &card->dpram[DPRAM_IRQ_TOHOST]);
385 	return ir ? IRQ_WAKE_THREAD : IRQ_NONE;
386 }
387 
388 /*
389  * netdev/candev inter-operability
390  */
391 static int softing_netdev_open(struct net_device *ndev)
392 {
393 	int ret;
394 
395 	/* check or determine and set bittime */
396 	ret = open_candev(ndev);
397 	if (!ret)
398 		ret = softing_startstop(ndev, 1);
399 	return ret;
400 }
401 
402 static int softing_netdev_stop(struct net_device *ndev)
403 {
404 	int ret;
405 
406 	netif_stop_queue(ndev);
407 
408 	/* softing cycle does close_candev() */
409 	ret = softing_startstop(ndev, 0);
410 	return ret;
411 }
412 
413 static int softing_candev_set_mode(struct net_device *ndev, enum can_mode mode)
414 {
415 	int ret;
416 
417 	switch (mode) {
418 	case CAN_MODE_START:
419 		/* softing_startstop does close_candev() */
420 		ret = softing_startstop(ndev, 1);
421 		return ret;
422 	case CAN_MODE_STOP:
423 	case CAN_MODE_SLEEP:
424 		return -EOPNOTSUPP;
425 	}
426 	return 0;
427 }
428 
429 /*
430  * Softing device management helpers
431  */
432 int softing_enable_irq(struct softing *card, int enable)
433 {
434 	int ret;
435 
436 	if (!card->irq.nr) {
437 		return 0;
438 	} else if (card->irq.requested && !enable) {
439 		free_irq(card->irq.nr, card);
440 		card->irq.requested = 0;
441 	} else if (!card->irq.requested && enable) {
442 		ret = request_threaded_irq(card->irq.nr,
443 				(card->pdat->generation >= 2) ?
444 					softing_irq_v2 : softing_irq_v1,
445 				softing_irq_thread, IRQF_SHARED,
446 				dev_name(&card->pdev->dev), card);
447 		if (ret) {
448 			dev_alert(&card->pdev->dev,
449 					"request_threaded_irq(%u) failed\n",
450 					card->irq.nr);
451 			return ret;
452 		}
453 		card->irq.requested = 1;
454 	}
455 	return 0;
456 }
457 
458 static void softing_card_shutdown(struct softing *card)
459 {
460 	int fw_up = 0;
461 
462 	if (mutex_lock_interruptible(&card->fw.lock))
463 		/* return -ERESTARTSYS */;
464 	fw_up = card->fw.up;
465 	card->fw.up = 0;
466 
467 	if (card->irq.requested && card->irq.nr) {
468 		free_irq(card->irq.nr, card);
469 		card->irq.requested = 0;
470 	}
471 	if (fw_up) {
472 		if (card->pdat->enable_irq)
473 			card->pdat->enable_irq(card->pdev, 0);
474 		softing_set_reset_dpram(card);
475 		if (card->pdat->reset)
476 			card->pdat->reset(card->pdev, 1);
477 	}
478 	mutex_unlock(&card->fw.lock);
479 }
480 
481 static __devinit int softing_card_boot(struct softing *card)
482 {
483 	int ret, j;
484 	static const uint8_t stream[] = {
485 		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, };
486 	unsigned char back[sizeof(stream)];
487 
488 	if (mutex_lock_interruptible(&card->fw.lock))
489 		return -ERESTARTSYS;
490 	if (card->fw.up) {
491 		mutex_unlock(&card->fw.lock);
492 		return 0;
493 	}
494 	/* reset board */
495 	if (card->pdat->enable_irq)
496 		card->pdat->enable_irq(card->pdev, 1);
497 	/* boot card */
498 	softing_set_reset_dpram(card);
499 	if (card->pdat->reset)
500 		card->pdat->reset(card->pdev, 1);
501 	for (j = 0; (j + sizeof(stream)) < card->dpram_size;
502 			j += sizeof(stream)) {
503 
504 		memcpy_toio(&card->dpram[j], stream, sizeof(stream));
505 		/* flush IO cache */
506 		mb();
507 		memcpy_fromio(back, &card->dpram[j], sizeof(stream));
508 
509 		if (!memcmp(back, stream, sizeof(stream)))
510 			continue;
511 		/* memory is not equal */
512 		dev_alert(&card->pdev->dev, "dpram failed at 0x%04x\n", j);
513 		ret = -EIO;
514 		goto failed;
515 	}
516 	wmb();
517 	/* load boot firmware */
518 	ret = softing_load_fw(card->pdat->boot.fw, card, card->dpram,
519 				card->dpram_size,
520 				card->pdat->boot.offs - card->pdat->boot.addr);
521 	if (ret < 0)
522 		goto failed;
523 	/* load loader firmware */
524 	ret = softing_load_fw(card->pdat->load.fw, card, card->dpram,
525 				card->dpram_size,
526 				card->pdat->load.offs - card->pdat->load.addr);
527 	if (ret < 0)
528 		goto failed;
529 
530 	if (card->pdat->reset)
531 		card->pdat->reset(card->pdev, 0);
532 	softing_clr_reset_dpram(card);
533 	ret = softing_bootloader_command(card, 0, "card boot");
534 	if (ret < 0)
535 		goto failed;
536 	ret = softing_load_app_fw(card->pdat->app.fw, card);
537 	if (ret < 0)
538 		goto failed;
539 
540 	ret = softing_chip_poweron(card);
541 	if (ret < 0)
542 		goto failed;
543 
544 	card->fw.up = 1;
545 	mutex_unlock(&card->fw.lock);
546 	return 0;
547 failed:
548 	card->fw.up = 0;
549 	if (card->pdat->enable_irq)
550 		card->pdat->enable_irq(card->pdev, 0);
551 	softing_set_reset_dpram(card);
552 	if (card->pdat->reset)
553 		card->pdat->reset(card->pdev, 1);
554 	mutex_unlock(&card->fw.lock);
555 	return ret;
556 }
557 
558 /*
559  * netdev sysfs
560  */
561 static ssize_t show_channel(struct device *dev, struct device_attribute *attr,
562 		char *buf)
563 {
564 	struct net_device *ndev = to_net_dev(dev);
565 	struct softing_priv *priv = netdev2softing(ndev);
566 
567 	return sprintf(buf, "%i\n", priv->index);
568 }
569 
570 static ssize_t show_chip(struct device *dev, struct device_attribute *attr,
571 		char *buf)
572 {
573 	struct net_device *ndev = to_net_dev(dev);
574 	struct softing_priv *priv = netdev2softing(ndev);
575 
576 	return sprintf(buf, "%i\n", priv->chip);
577 }
578 
579 static ssize_t show_output(struct device *dev, struct device_attribute *attr,
580 		char *buf)
581 {
582 	struct net_device *ndev = to_net_dev(dev);
583 	struct softing_priv *priv = netdev2softing(ndev);
584 
585 	return sprintf(buf, "0x%02x\n", priv->output);
586 }
587 
588 static ssize_t store_output(struct device *dev, struct device_attribute *attr,
589 		const char *buf, size_t count)
590 {
591 	struct net_device *ndev = to_net_dev(dev);
592 	struct softing_priv *priv = netdev2softing(ndev);
593 	struct softing *card = priv->card;
594 	unsigned long val;
595 	int ret;
596 
597 	ret = strict_strtoul(buf, 0, &val);
598 	if (ret < 0)
599 		return ret;
600 	val &= 0xFF;
601 
602 	ret = mutex_lock_interruptible(&card->fw.lock);
603 	if (ret)
604 		return -ERESTARTSYS;
605 	if (netif_running(ndev)) {
606 		mutex_unlock(&card->fw.lock);
607 		return -EBUSY;
608 	}
609 	priv->output = val;
610 	mutex_unlock(&card->fw.lock);
611 	return count;
612 }
613 
614 static const DEVICE_ATTR(channel, S_IRUGO, show_channel, NULL);
615 static const DEVICE_ATTR(chip, S_IRUGO, show_chip, NULL);
616 static const DEVICE_ATTR(output, S_IRUGO | S_IWUSR, show_output, store_output);
617 
618 static const struct attribute *const netdev_sysfs_attrs[] = {
619 	&dev_attr_channel.attr,
620 	&dev_attr_chip.attr,
621 	&dev_attr_output.attr,
622 	NULL,
623 };
624 static const struct attribute_group netdev_sysfs_group = {
625 	.name = NULL,
626 	.attrs = (struct attribute **)netdev_sysfs_attrs,
627 };
628 
629 static const struct net_device_ops softing_netdev_ops = {
630 	.ndo_open = softing_netdev_open,
631 	.ndo_stop = softing_netdev_stop,
632 	.ndo_start_xmit	= softing_netdev_start_xmit,
633 };
634 
635 static const struct can_bittiming_const softing_btr_const = {
636 	.name = "softing",
637 	.tseg1_min = 1,
638 	.tseg1_max = 16,
639 	.tseg2_min = 1,
640 	.tseg2_max = 8,
641 	.sjw_max = 4, /* overruled */
642 	.brp_min = 1,
643 	.brp_max = 32, /* overruled */
644 	.brp_inc = 1,
645 };
646 
647 
648 static __devinit struct net_device *softing_netdev_create(struct softing *card,
649 		uint16_t chip_id)
650 {
651 	struct net_device *netdev;
652 	struct softing_priv *priv;
653 
654 	netdev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX);
655 	if (!netdev) {
656 		dev_alert(&card->pdev->dev, "alloc_candev failed\n");
657 		return NULL;
658 	}
659 	priv = netdev_priv(netdev);
660 	priv->netdev = netdev;
661 	priv->card = card;
662 	memcpy(&priv->btr_const, &softing_btr_const, sizeof(priv->btr_const));
663 	priv->btr_const.brp_max = card->pdat->max_brp;
664 	priv->btr_const.sjw_max = card->pdat->max_sjw;
665 	priv->can.bittiming_const = &priv->btr_const;
666 	priv->can.clock.freq = 8000000;
667 	priv->chip = chip_id;
668 	priv->output = softing_default_output(netdev);
669 	SET_NETDEV_DEV(netdev, &card->pdev->dev);
670 
671 	netdev->flags |= IFF_ECHO;
672 	netdev->netdev_ops = &softing_netdev_ops;
673 	priv->can.do_set_mode = softing_candev_set_mode;
674 	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
675 
676 	return netdev;
677 }
678 
679 static __devinit int softing_netdev_register(struct net_device *netdev)
680 {
681 	int ret;
682 
683 	netdev->sysfs_groups[0] = &netdev_sysfs_group;
684 	ret = register_candev(netdev);
685 	if (ret) {
686 		dev_alert(&netdev->dev, "register failed\n");
687 		return ret;
688 	}
689 	return 0;
690 }
691 
692 static void softing_netdev_cleanup(struct net_device *netdev)
693 {
694 	unregister_candev(netdev);
695 	free_candev(netdev);
696 }
697 
698 /*
699  * sysfs for Platform device
700  */
701 #define DEV_ATTR_RO(name, member) \
702 static ssize_t show_##name(struct device *dev, \
703 		struct device_attribute *attr, char *buf) \
704 { \
705 	struct softing *card = platform_get_drvdata(to_platform_device(dev)); \
706 	return sprintf(buf, "%u\n", card->member); \
707 } \
708 static DEVICE_ATTR(name, 0444, show_##name, NULL)
709 
710 #define DEV_ATTR_RO_STR(name, member) \
711 static ssize_t show_##name(struct device *dev, \
712 		struct device_attribute *attr, char *buf) \
713 { \
714 	struct softing *card = platform_get_drvdata(to_platform_device(dev)); \
715 	return sprintf(buf, "%s\n", card->member); \
716 } \
717 static DEVICE_ATTR(name, 0444, show_##name, NULL)
718 
719 DEV_ATTR_RO(serial, id.serial);
720 DEV_ATTR_RO_STR(firmware, pdat->app.fw);
721 DEV_ATTR_RO(firmware_version, id.fw_version);
722 DEV_ATTR_RO_STR(hardware, pdat->name);
723 DEV_ATTR_RO(hardware_version, id.hw_version);
724 DEV_ATTR_RO(license, id.license);
725 DEV_ATTR_RO(frequency, id.freq);
726 DEV_ATTR_RO(txpending, tx.pending);
727 
728 static struct attribute *softing_pdev_attrs[] = {
729 	&dev_attr_serial.attr,
730 	&dev_attr_firmware.attr,
731 	&dev_attr_firmware_version.attr,
732 	&dev_attr_hardware.attr,
733 	&dev_attr_hardware_version.attr,
734 	&dev_attr_license.attr,
735 	&dev_attr_frequency.attr,
736 	&dev_attr_txpending.attr,
737 	NULL,
738 };
739 
740 static const struct attribute_group softing_pdev_group = {
741 	.name = NULL,
742 	.attrs = softing_pdev_attrs,
743 };
744 
745 /*
746  * platform driver
747  */
748 static __devexit int softing_pdev_remove(struct platform_device *pdev)
749 {
750 	struct softing *card = platform_get_drvdata(pdev);
751 	int j;
752 
753 	/* first, disable card*/
754 	softing_card_shutdown(card);
755 
756 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
757 		if (!card->net[j])
758 			continue;
759 		softing_netdev_cleanup(card->net[j]);
760 		card->net[j] = NULL;
761 	}
762 	sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);
763 
764 	iounmap(card->dpram);
765 	kfree(card);
766 	return 0;
767 }
768 
769 static __devinit int softing_pdev_probe(struct platform_device *pdev)
770 {
771 	const struct softing_platform_data *pdat = pdev->dev.platform_data;
772 	struct softing *card;
773 	struct net_device *netdev;
774 	struct softing_priv *priv;
775 	struct resource *pres;
776 	int ret;
777 	int j;
778 
779 	if (!pdat) {
780 		dev_warn(&pdev->dev, "no platform data\n");
781 		return -EINVAL;
782 	}
783 	if (pdat->nbus > ARRAY_SIZE(card->net)) {
784 		dev_warn(&pdev->dev, "%u nets??\n", pdat->nbus);
785 		return -EINVAL;
786 	}
787 
788 	card = kzalloc(sizeof(*card), GFP_KERNEL);
789 	if (!card)
790 		return -ENOMEM;
791 	card->pdat = pdat;
792 	card->pdev = pdev;
793 	platform_set_drvdata(pdev, card);
794 	mutex_init(&card->fw.lock);
795 	spin_lock_init(&card->spin);
796 
797 	ret = -EINVAL;
798 	pres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
799 	if (!pres)
800 		goto platform_resource_failed;;
801 	card->dpram_phys = pres->start;
802 	card->dpram_size = pres->end - pres->start + 1;
803 	card->dpram = ioremap_nocache(card->dpram_phys, card->dpram_size);
804 	if (!card->dpram) {
805 		dev_alert(&card->pdev->dev, "dpram ioremap failed\n");
806 		goto ioremap_failed;
807 	}
808 
809 	pres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
810 	if (pres)
811 		card->irq.nr = pres->start;
812 
813 	/* reset card */
814 	ret = softing_card_boot(card);
815 	if (ret < 0) {
816 		dev_alert(&pdev->dev, "failed to boot\n");
817 		goto boot_failed;
818 	}
819 
820 	/* only now, the chip's are known */
821 	card->id.freq = card->pdat->freq;
822 
823 	ret = sysfs_create_group(&pdev->dev.kobj, &softing_pdev_group);
824 	if (ret < 0) {
825 		dev_alert(&card->pdev->dev, "sysfs failed\n");
826 		goto sysfs_failed;
827 	}
828 
829 	ret = -ENOMEM;
830 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
831 		card->net[j] = netdev =
832 			softing_netdev_create(card, card->id.chip[j]);
833 		if (!netdev) {
834 			dev_alert(&pdev->dev, "failed to make can[%i]", j);
835 			goto netdev_failed;
836 		}
837 		priv = netdev_priv(card->net[j]);
838 		priv->index = j;
839 		ret = softing_netdev_register(netdev);
840 		if (ret) {
841 			free_candev(netdev);
842 			card->net[j] = NULL;
843 			dev_alert(&card->pdev->dev,
844 					"failed to register can[%i]\n", j);
845 			goto netdev_failed;
846 		}
847 	}
848 	dev_info(&card->pdev->dev, "%s ready.\n", card->pdat->name);
849 	return 0;
850 
851 netdev_failed:
852 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
853 		if (!card->net[j])
854 			continue;
855 		softing_netdev_cleanup(card->net[j]);
856 	}
857 	sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);
858 sysfs_failed:
859 	softing_card_shutdown(card);
860 boot_failed:
861 	iounmap(card->dpram);
862 ioremap_failed:
863 platform_resource_failed:
864 	kfree(card);
865 	return ret;
866 }
867 
868 static struct platform_driver softing_driver = {
869 	.driver = {
870 		.name = "softing",
871 		.owner = THIS_MODULE,
872 	},
873 	.probe = softing_pdev_probe,
874 	.remove = __devexit_p(softing_pdev_remove),
875 };
876 
877 MODULE_ALIAS("platform:softing");
878 
879 static int __init softing_start(void)
880 {
881 	return platform_driver_register(&softing_driver);
882 }
883 
884 static void __exit softing_stop(void)
885 {
886 	platform_driver_unregister(&softing_driver);
887 }
888 
889 module_init(softing_start);
890 module_exit(softing_stop);
891 
892 MODULE_DESCRIPTION("Softing DPRAM CAN driver");
893 MODULE_AUTHOR("Kurt Van Dijck <kurt.van.dijck@eia.be>");
894 MODULE_LICENSE("GPL v2");
895