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 				can_bus_off(netdev);
265 				netif_stop_queue(netdev);
266 			}
267 			/* trigger socketcan */
268 			softing_netdev_rx(netdev, &msg, ktime);
269 		}
270 
271 	} else {
272 		if (cmd & CMD_RTR)
273 			msg.can_id |= CAN_RTR_FLAG;
274 		msg.can_dlc = get_can_dlc(*ptr++);
275 		if (cmd & CMD_XTD) {
276 			msg.can_id |= CAN_EFF_FLAG;
277 			msg.can_id |= le32_to_cpup((void *)ptr);
278 			ptr += 4;
279 		} else {
280 			msg.can_id |= le16_to_cpup((void *)ptr);
281 			ptr += 2;
282 		}
283 		/* timestamp */
284 		tmp_u32 = le32_to_cpup((void *)ptr);
285 		ptr += 4;
286 		ktime = softing_raw2ktime(card, tmp_u32);
287 		if (!(msg.can_id & CAN_RTR_FLAG))
288 			memcpy(&msg.data[0], ptr, 8);
289 		ptr += 8;
290 		/* update socket */
291 		if (cmd & CMD_ACK) {
292 			/* acknowledge, was tx msg */
293 			struct sk_buff *skb;
294 			skb = priv->can.echo_skb[priv->tx.echo_get];
295 			if (skb)
296 				skb->tstamp = ktime;
297 			can_get_echo_skb(netdev, priv->tx.echo_get);
298 			++priv->tx.echo_get;
299 			if (priv->tx.echo_get >= TX_ECHO_SKB_MAX)
300 				priv->tx.echo_get = 0;
301 			if (priv->tx.pending)
302 				--priv->tx.pending;
303 			if (card->tx.pending)
304 				--card->tx.pending;
305 			++netdev->stats.tx_packets;
306 			if (!(msg.can_id & CAN_RTR_FLAG))
307 				netdev->stats.tx_bytes += msg.can_dlc;
308 		} else {
309 			int ret;
310 
311 			ret = softing_netdev_rx(netdev, &msg, ktime);
312 			if (ret == NET_RX_SUCCESS) {
313 				++netdev->stats.rx_packets;
314 				if (!(msg.can_id & CAN_RTR_FLAG))
315 					netdev->stats.rx_bytes += msg.can_dlc;
316 			} else {
317 				++netdev->stats.rx_dropped;
318 			}
319 		}
320 	}
321 	++cnt;
322 	return cnt;
323 }
324 
325 /*
326  * real interrupt handler
327  */
328 static irqreturn_t softing_irq_thread(int irq, void *dev_id)
329 {
330 	struct softing *card = (struct softing *)dev_id;
331 	struct net_device *netdev;
332 	struct softing_priv *priv;
333 	int j, offset, work_done;
334 
335 	work_done = 0;
336 	spin_lock_bh(&card->spin);
337 	while (softing_handle_1(card) > 0) {
338 		++card->irq.svc_count;
339 		++work_done;
340 	}
341 	spin_unlock_bh(&card->spin);
342 	/* resume tx queue's */
343 	offset = card->tx.last_bus;
344 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
345 		if (card->tx.pending >= TXMAX)
346 			break;
347 		netdev = card->net[(j + offset + 1) % card->pdat->nbus];
348 		if (!netdev)
349 			continue;
350 		priv = netdev_priv(netdev);
351 		if (!canif_is_active(netdev))
352 			/* it makes no sense to wake dead busses */
353 			continue;
354 		if (priv->tx.pending >= TX_ECHO_SKB_MAX)
355 			continue;
356 		++work_done;
357 		netif_wake_queue(netdev);
358 	}
359 	return work_done ? IRQ_HANDLED : IRQ_NONE;
360 }
361 
362 /*
363  * interrupt routines:
364  * schedule the 'real interrupt handler'
365  */
366 static irqreturn_t softing_irq_v2(int irq, void *dev_id)
367 {
368 	struct softing *card = (struct softing *)dev_id;
369 	uint8_t ir;
370 
371 	ir = ioread8(&card->dpram[DPRAM_V2_IRQ_TOHOST]);
372 	iowrite8(0, &card->dpram[DPRAM_V2_IRQ_TOHOST]);
373 	return (1 == ir) ? IRQ_WAKE_THREAD : IRQ_NONE;
374 }
375 
376 static irqreturn_t softing_irq_v1(int irq, void *dev_id)
377 {
378 	struct softing *card = (struct softing *)dev_id;
379 	uint8_t ir;
380 
381 	ir = ioread8(&card->dpram[DPRAM_IRQ_TOHOST]);
382 	iowrite8(0, &card->dpram[DPRAM_IRQ_TOHOST]);
383 	return ir ? IRQ_WAKE_THREAD : IRQ_NONE;
384 }
385 
386 /*
387  * netdev/candev inter-operability
388  */
389 static int softing_netdev_open(struct net_device *ndev)
390 {
391 	int ret;
392 
393 	/* check or determine and set bittime */
394 	ret = open_candev(ndev);
395 	if (!ret)
396 		ret = softing_startstop(ndev, 1);
397 	return ret;
398 }
399 
400 static int softing_netdev_stop(struct net_device *ndev)
401 {
402 	int ret;
403 
404 	netif_stop_queue(ndev);
405 
406 	/* softing cycle does close_candev() */
407 	ret = softing_startstop(ndev, 0);
408 	return ret;
409 }
410 
411 static int softing_candev_set_mode(struct net_device *ndev, enum can_mode mode)
412 {
413 	int ret;
414 
415 	switch (mode) {
416 	case CAN_MODE_START:
417 		/* softing_startstop does close_candev() */
418 		ret = softing_startstop(ndev, 1);
419 		return ret;
420 	case CAN_MODE_STOP:
421 	case CAN_MODE_SLEEP:
422 		return -EOPNOTSUPP;
423 	}
424 	return 0;
425 }
426 
427 /*
428  * Softing device management helpers
429  */
430 int softing_enable_irq(struct softing *card, int enable)
431 {
432 	int ret;
433 
434 	if (!card->irq.nr) {
435 		return 0;
436 	} else if (card->irq.requested && !enable) {
437 		free_irq(card->irq.nr, card);
438 		card->irq.requested = 0;
439 	} else if (!card->irq.requested && enable) {
440 		ret = request_threaded_irq(card->irq.nr,
441 				(card->pdat->generation >= 2) ?
442 					softing_irq_v2 : softing_irq_v1,
443 				softing_irq_thread, IRQF_SHARED,
444 				dev_name(&card->pdev->dev), card);
445 		if (ret) {
446 			dev_alert(&card->pdev->dev,
447 					"request_threaded_irq(%u) failed\n",
448 					card->irq.nr);
449 			return ret;
450 		}
451 		card->irq.requested = 1;
452 	}
453 	return 0;
454 }
455 
456 static void softing_card_shutdown(struct softing *card)
457 {
458 	int fw_up = 0;
459 
460 	if (mutex_lock_interruptible(&card->fw.lock))
461 		/* return -ERESTARTSYS */;
462 	fw_up = card->fw.up;
463 	card->fw.up = 0;
464 
465 	if (card->irq.requested && card->irq.nr) {
466 		free_irq(card->irq.nr, card);
467 		card->irq.requested = 0;
468 	}
469 	if (fw_up) {
470 		if (card->pdat->enable_irq)
471 			card->pdat->enable_irq(card->pdev, 0);
472 		softing_set_reset_dpram(card);
473 		if (card->pdat->reset)
474 			card->pdat->reset(card->pdev, 1);
475 	}
476 	mutex_unlock(&card->fw.lock);
477 }
478 
479 static int softing_card_boot(struct softing *card)
480 {
481 	int ret, j;
482 	static const uint8_t stream[] = {
483 		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, };
484 	unsigned char back[sizeof(stream)];
485 
486 	if (mutex_lock_interruptible(&card->fw.lock))
487 		return -ERESTARTSYS;
488 	if (card->fw.up) {
489 		mutex_unlock(&card->fw.lock);
490 		return 0;
491 	}
492 	/* reset board */
493 	if (card->pdat->enable_irq)
494 		card->pdat->enable_irq(card->pdev, 1);
495 	/* boot card */
496 	softing_set_reset_dpram(card);
497 	if (card->pdat->reset)
498 		card->pdat->reset(card->pdev, 1);
499 	for (j = 0; (j + sizeof(stream)) < card->dpram_size;
500 			j += sizeof(stream)) {
501 
502 		memcpy_toio(&card->dpram[j], stream, sizeof(stream));
503 		/* flush IO cache */
504 		mb();
505 		memcpy_fromio(back, &card->dpram[j], sizeof(stream));
506 
507 		if (!memcmp(back, stream, sizeof(stream)))
508 			continue;
509 		/* memory is not equal */
510 		dev_alert(&card->pdev->dev, "dpram failed at 0x%04x\n", j);
511 		ret = -EIO;
512 		goto failed;
513 	}
514 	wmb();
515 	/* load boot firmware */
516 	ret = softing_load_fw(card->pdat->boot.fw, card, card->dpram,
517 				card->dpram_size,
518 				card->pdat->boot.offs - card->pdat->boot.addr);
519 	if (ret < 0)
520 		goto failed;
521 	/* load loader firmware */
522 	ret = softing_load_fw(card->pdat->load.fw, card, card->dpram,
523 				card->dpram_size,
524 				card->pdat->load.offs - card->pdat->load.addr);
525 	if (ret < 0)
526 		goto failed;
527 
528 	if (card->pdat->reset)
529 		card->pdat->reset(card->pdev, 0);
530 	softing_clr_reset_dpram(card);
531 	ret = softing_bootloader_command(card, 0, "card boot");
532 	if (ret < 0)
533 		goto failed;
534 	ret = softing_load_app_fw(card->pdat->app.fw, card);
535 	if (ret < 0)
536 		goto failed;
537 
538 	ret = softing_chip_poweron(card);
539 	if (ret < 0)
540 		goto failed;
541 
542 	card->fw.up = 1;
543 	mutex_unlock(&card->fw.lock);
544 	return 0;
545 failed:
546 	card->fw.up = 0;
547 	if (card->pdat->enable_irq)
548 		card->pdat->enable_irq(card->pdev, 0);
549 	softing_set_reset_dpram(card);
550 	if (card->pdat->reset)
551 		card->pdat->reset(card->pdev, 1);
552 	mutex_unlock(&card->fw.lock);
553 	return ret;
554 }
555 
556 /*
557  * netdev sysfs
558  */
559 static ssize_t show_chip(struct device *dev, struct device_attribute *attr,
560 		char *buf)
561 {
562 	struct net_device *ndev = to_net_dev(dev);
563 	struct softing_priv *priv = netdev2softing(ndev);
564 
565 	return sprintf(buf, "%i\n", priv->chip);
566 }
567 
568 static ssize_t show_output(struct device *dev, struct device_attribute *attr,
569 		char *buf)
570 {
571 	struct net_device *ndev = to_net_dev(dev);
572 	struct softing_priv *priv = netdev2softing(ndev);
573 
574 	return sprintf(buf, "0x%02x\n", priv->output);
575 }
576 
577 static ssize_t store_output(struct device *dev, struct device_attribute *attr,
578 		const char *buf, size_t count)
579 {
580 	struct net_device *ndev = to_net_dev(dev);
581 	struct softing_priv *priv = netdev2softing(ndev);
582 	struct softing *card = priv->card;
583 	unsigned long val;
584 	int ret;
585 
586 	ret = kstrtoul(buf, 0, &val);
587 	if (ret < 0)
588 		return ret;
589 	val &= 0xFF;
590 
591 	ret = mutex_lock_interruptible(&card->fw.lock);
592 	if (ret)
593 		return -ERESTARTSYS;
594 	if (netif_running(ndev)) {
595 		mutex_unlock(&card->fw.lock);
596 		return -EBUSY;
597 	}
598 	priv->output = val;
599 	mutex_unlock(&card->fw.lock);
600 	return count;
601 }
602 
603 static const DEVICE_ATTR(chip, S_IRUGO, show_chip, NULL);
604 static const DEVICE_ATTR(output, S_IRUGO | S_IWUSR, show_output, store_output);
605 
606 static const struct attribute *const netdev_sysfs_attrs[] = {
607 	&dev_attr_chip.attr,
608 	&dev_attr_output.attr,
609 	NULL,
610 };
611 static const struct attribute_group netdev_sysfs_group = {
612 	.name = NULL,
613 	.attrs = (struct attribute **)netdev_sysfs_attrs,
614 };
615 
616 static const struct net_device_ops softing_netdev_ops = {
617 	.ndo_open = softing_netdev_open,
618 	.ndo_stop = softing_netdev_stop,
619 	.ndo_start_xmit	= softing_netdev_start_xmit,
620 	.ndo_change_mtu = can_change_mtu,
621 };
622 
623 static const struct can_bittiming_const softing_btr_const = {
624 	.name = "softing",
625 	.tseg1_min = 1,
626 	.tseg1_max = 16,
627 	.tseg2_min = 1,
628 	.tseg2_max = 8,
629 	.sjw_max = 4, /* overruled */
630 	.brp_min = 1,
631 	.brp_max = 32, /* overruled */
632 	.brp_inc = 1,
633 };
634 
635 
636 static struct net_device *softing_netdev_create(struct softing *card,
637 						uint16_t chip_id)
638 {
639 	struct net_device *netdev;
640 	struct softing_priv *priv;
641 
642 	netdev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX);
643 	if (!netdev) {
644 		dev_alert(&card->pdev->dev, "alloc_candev failed\n");
645 		return NULL;
646 	}
647 	priv = netdev_priv(netdev);
648 	priv->netdev = netdev;
649 	priv->card = card;
650 	memcpy(&priv->btr_const, &softing_btr_const, sizeof(priv->btr_const));
651 	priv->btr_const.brp_max = card->pdat->max_brp;
652 	priv->btr_const.sjw_max = card->pdat->max_sjw;
653 	priv->can.bittiming_const = &priv->btr_const;
654 	priv->can.clock.freq = 8000000;
655 	priv->chip = chip_id;
656 	priv->output = softing_default_output(netdev);
657 	SET_NETDEV_DEV(netdev, &card->pdev->dev);
658 
659 	netdev->flags |= IFF_ECHO;
660 	netdev->netdev_ops = &softing_netdev_ops;
661 	priv->can.do_set_mode = softing_candev_set_mode;
662 	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
663 
664 	return netdev;
665 }
666 
667 static int softing_netdev_register(struct net_device *netdev)
668 {
669 	int ret;
670 
671 	ret = register_candev(netdev);
672 	if (ret) {
673 		dev_alert(&netdev->dev, "register failed\n");
674 		return ret;
675 	}
676 	if (sysfs_create_group(&netdev->dev.kobj, &netdev_sysfs_group) < 0)
677 		netdev_alert(netdev, "sysfs group failed\n");
678 
679 	return 0;
680 }
681 
682 static void softing_netdev_cleanup(struct net_device *netdev)
683 {
684 	sysfs_remove_group(&netdev->dev.kobj, &netdev_sysfs_group);
685 	unregister_candev(netdev);
686 	free_candev(netdev);
687 }
688 
689 /*
690  * sysfs for Platform device
691  */
692 #define DEV_ATTR_RO(name, member) \
693 static ssize_t show_##name(struct device *dev, \
694 		struct device_attribute *attr, char *buf) \
695 { \
696 	struct softing *card = platform_get_drvdata(to_platform_device(dev)); \
697 	return sprintf(buf, "%u\n", card->member); \
698 } \
699 static DEVICE_ATTR(name, 0444, show_##name, NULL)
700 
701 #define DEV_ATTR_RO_STR(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, "%s\n", card->member); \
707 } \
708 static DEVICE_ATTR(name, 0444, show_##name, NULL)
709 
710 DEV_ATTR_RO(serial, id.serial);
711 DEV_ATTR_RO_STR(firmware, pdat->app.fw);
712 DEV_ATTR_RO(firmware_version, id.fw_version);
713 DEV_ATTR_RO_STR(hardware, pdat->name);
714 DEV_ATTR_RO(hardware_version, id.hw_version);
715 DEV_ATTR_RO(license, id.license);
716 
717 static struct attribute *softing_pdev_attrs[] = {
718 	&dev_attr_serial.attr,
719 	&dev_attr_firmware.attr,
720 	&dev_attr_firmware_version.attr,
721 	&dev_attr_hardware.attr,
722 	&dev_attr_hardware_version.attr,
723 	&dev_attr_license.attr,
724 	NULL,
725 };
726 
727 static const struct attribute_group softing_pdev_group = {
728 	.name = NULL,
729 	.attrs = softing_pdev_attrs,
730 };
731 
732 /*
733  * platform driver
734  */
735 static int softing_pdev_remove(struct platform_device *pdev)
736 {
737 	struct softing *card = platform_get_drvdata(pdev);
738 	int j;
739 
740 	/* first, disable card*/
741 	softing_card_shutdown(card);
742 
743 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
744 		if (!card->net[j])
745 			continue;
746 		softing_netdev_cleanup(card->net[j]);
747 		card->net[j] = NULL;
748 	}
749 	sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);
750 
751 	iounmap(card->dpram);
752 	kfree(card);
753 	return 0;
754 }
755 
756 static int softing_pdev_probe(struct platform_device *pdev)
757 {
758 	const struct softing_platform_data *pdat = dev_get_platdata(&pdev->dev);
759 	struct softing *card;
760 	struct net_device *netdev;
761 	struct softing_priv *priv;
762 	struct resource *pres;
763 	int ret;
764 	int j;
765 
766 	if (!pdat) {
767 		dev_warn(&pdev->dev, "no platform data\n");
768 		return -EINVAL;
769 	}
770 	if (pdat->nbus > ARRAY_SIZE(card->net)) {
771 		dev_warn(&pdev->dev, "%u nets??\n", pdat->nbus);
772 		return -EINVAL;
773 	}
774 
775 	card = kzalloc(sizeof(*card), GFP_KERNEL);
776 	if (!card)
777 		return -ENOMEM;
778 	card->pdat = pdat;
779 	card->pdev = pdev;
780 	platform_set_drvdata(pdev, card);
781 	mutex_init(&card->fw.lock);
782 	spin_lock_init(&card->spin);
783 
784 	ret = -EINVAL;
785 	pres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
786 	if (!pres)
787 		goto platform_resource_failed;
788 	card->dpram_phys = pres->start;
789 	card->dpram_size = resource_size(pres);
790 	card->dpram = ioremap_nocache(card->dpram_phys, card->dpram_size);
791 	if (!card->dpram) {
792 		dev_alert(&card->pdev->dev, "dpram ioremap failed\n");
793 		goto ioremap_failed;
794 	}
795 
796 	pres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
797 	if (pres)
798 		card->irq.nr = pres->start;
799 
800 	/* reset card */
801 	ret = softing_card_boot(card);
802 	if (ret < 0) {
803 		dev_alert(&pdev->dev, "failed to boot\n");
804 		goto boot_failed;
805 	}
806 
807 	/* only now, the chip's are known */
808 	card->id.freq = card->pdat->freq;
809 
810 	ret = sysfs_create_group(&pdev->dev.kobj, &softing_pdev_group);
811 	if (ret < 0) {
812 		dev_alert(&card->pdev->dev, "sysfs failed\n");
813 		goto sysfs_failed;
814 	}
815 
816 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
817 		card->net[j] = netdev =
818 			softing_netdev_create(card, card->id.chip[j]);
819 		if (!netdev) {
820 			dev_alert(&pdev->dev, "failed to make can[%i]", j);
821 			ret = -ENOMEM;
822 			goto netdev_failed;
823 		}
824 		netdev->dev_id = j;
825 		priv = netdev_priv(card->net[j]);
826 		priv->index = j;
827 		ret = softing_netdev_register(netdev);
828 		if (ret) {
829 			free_candev(netdev);
830 			card->net[j] = NULL;
831 			dev_alert(&card->pdev->dev,
832 					"failed to register can[%i]\n", j);
833 			goto netdev_failed;
834 		}
835 	}
836 	dev_info(&card->pdev->dev, "%s ready.\n", card->pdat->name);
837 	return 0;
838 
839 netdev_failed:
840 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
841 		if (!card->net[j])
842 			continue;
843 		softing_netdev_cleanup(card->net[j]);
844 	}
845 	sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);
846 sysfs_failed:
847 	softing_card_shutdown(card);
848 boot_failed:
849 	iounmap(card->dpram);
850 ioremap_failed:
851 platform_resource_failed:
852 	kfree(card);
853 	return ret;
854 }
855 
856 static struct platform_driver softing_driver = {
857 	.driver = {
858 		.name = "softing",
859 	},
860 	.probe = softing_pdev_probe,
861 	.remove = softing_pdev_remove,
862 };
863 
864 module_platform_driver(softing_driver);
865 
866 MODULE_ALIAS("platform:softing");
867 MODULE_DESCRIPTION("Softing DPRAM CAN driver");
868 MODULE_AUTHOR("Kurt Van Dijck <kurt.van.dijck@eia.be>");
869 MODULE_LICENSE("GPL v2");
870