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