xref: /linux/drivers/net/can/softing/softing_main.c (revision bd4af432cc71b5fbfe4833510359a6ad3ada250d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2008-2010
4  *
5  * - Kurt Van Dijck, EIA Electronics
6  */
7 
8 #include <linux/module.h>
9 #include <linux/interrupt.h>
10 #include <asm/io.h>
11 
12 #include "softing.h"
13 
14 #define TX_ECHO_SKB_MAX (((TXMAX+1)/2)-1)
15 
16 /*
17  * test is a specific CAN netdev
18  * is online (ie. up 'n running, not sleeping, not busoff
19  */
20 static inline int canif_is_active(struct net_device *netdev)
21 {
22 	struct can_priv *can = netdev_priv(netdev);
23 
24 	if (!netif_running(netdev))
25 		return 0;
26 	return (can->state <= CAN_STATE_ERROR_PASSIVE);
27 }
28 
29 /* reset DPRAM */
30 static inline void softing_set_reset_dpram(struct softing *card)
31 {
32 	if (card->pdat->generation >= 2) {
33 		spin_lock_bh(&card->spin);
34 		iowrite8(ioread8(&card->dpram[DPRAM_V2_RESET]) & ~1,
35 				&card->dpram[DPRAM_V2_RESET]);
36 		spin_unlock_bh(&card->spin);
37 	}
38 }
39 
40 static inline void softing_clr_reset_dpram(struct softing *card)
41 {
42 	if (card->pdat->generation >= 2) {
43 		spin_lock_bh(&card->spin);
44 		iowrite8(ioread8(&card->dpram[DPRAM_V2_RESET]) | 1,
45 				&card->dpram[DPRAM_V2_RESET]);
46 		spin_unlock_bh(&card->spin);
47 	}
48 }
49 
50 /* trigger the tx queue-ing */
51 static netdev_tx_t softing_netdev_start_xmit(struct sk_buff *skb,
52 		struct net_device *dev)
53 {
54 	struct softing_priv *priv = netdev_priv(dev);
55 	struct softing *card = priv->card;
56 	int ret;
57 	uint8_t *ptr;
58 	uint8_t fifo_wr, fifo_rd;
59 	struct can_frame *cf = (struct can_frame *)skb->data;
60 	uint8_t buf[DPRAM_TX_SIZE];
61 
62 	if (can_dropped_invalid_skb(dev, skb))
63 		return NETDEV_TX_OK;
64 
65 	spin_lock(&card->spin);
66 
67 	ret = NETDEV_TX_BUSY;
68 	if (!card->fw.up ||
69 			(card->tx.pending >= TXMAX) ||
70 			(priv->tx.pending >= TX_ECHO_SKB_MAX))
71 		goto xmit_done;
72 	fifo_wr = ioread8(&card->dpram[DPRAM_TX_WR]);
73 	fifo_rd = ioread8(&card->dpram[DPRAM_TX_RD]);
74 	if (fifo_wr == fifo_rd)
75 		/* fifo full */
76 		goto xmit_done;
77 	memset(buf, 0, sizeof(buf));
78 	ptr = buf;
79 	*ptr = CMD_TX;
80 	if (cf->can_id & CAN_RTR_FLAG)
81 		*ptr |= CMD_RTR;
82 	if (cf->can_id & CAN_EFF_FLAG)
83 		*ptr |= CMD_XTD;
84 	if (priv->index)
85 		*ptr |= CMD_BUS2;
86 	++ptr;
87 	*ptr++ = cf->can_dlc;
88 	*ptr++ = (cf->can_id >> 0);
89 	*ptr++ = (cf->can_id >> 8);
90 	if (cf->can_id & CAN_EFF_FLAG) {
91 		*ptr++ = (cf->can_id >> 16);
92 		*ptr++ = (cf->can_id >> 24);
93 	} else {
94 		/* increment 1, not 2 as you might think */
95 		ptr += 1;
96 	}
97 	if (!(cf->can_id & CAN_RTR_FLAG))
98 		memcpy(ptr, &cf->data[0], cf->can_dlc);
99 	memcpy_toio(&card->dpram[DPRAM_TX + DPRAM_TX_SIZE * fifo_wr],
100 			buf, DPRAM_TX_SIZE);
101 	if (++fifo_wr >= DPRAM_TX_CNT)
102 		fifo_wr = 0;
103 	iowrite8(fifo_wr, &card->dpram[DPRAM_TX_WR]);
104 	card->tx.last_bus = priv->index;
105 	++card->tx.pending;
106 	++priv->tx.pending;
107 	can_put_echo_skb(skb, dev, priv->tx.echo_put);
108 	++priv->tx.echo_put;
109 	if (priv->tx.echo_put >= TX_ECHO_SKB_MAX)
110 		priv->tx.echo_put = 0;
111 	/* can_put_echo_skb() saves the skb, safe to return TX_OK */
112 	ret = NETDEV_TX_OK;
113 xmit_done:
114 	spin_unlock(&card->spin);
115 	if (card->tx.pending >= TXMAX) {
116 		int j;
117 		for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
118 			if (card->net[j])
119 				netif_stop_queue(card->net[j]);
120 		}
121 	}
122 	if (ret != NETDEV_TX_OK)
123 		netif_stop_queue(dev);
124 
125 	return ret;
126 }
127 
128 /*
129  * shortcut for skb delivery
130  */
131 int softing_netdev_rx(struct net_device *netdev, const struct can_frame *msg,
132 		ktime_t ktime)
133 {
134 	struct sk_buff *skb;
135 	struct can_frame *cf;
136 
137 	skb = alloc_can_skb(netdev, &cf);
138 	if (!skb)
139 		return -ENOMEM;
140 	memcpy(cf, msg, sizeof(*msg));
141 	skb->tstamp = ktime;
142 	return netif_rx(skb);
143 }
144 
145 /*
146  * softing_handle_1
147  * pop 1 entry from the DPRAM queue, and process
148  */
149 static int softing_handle_1(struct softing *card)
150 {
151 	struct net_device *netdev;
152 	struct softing_priv *priv;
153 	ktime_t ktime;
154 	struct can_frame msg;
155 	int cnt = 0, lost_msg;
156 	uint8_t fifo_rd, fifo_wr, cmd;
157 	uint8_t *ptr;
158 	uint32_t tmp_u32;
159 	uint8_t buf[DPRAM_RX_SIZE];
160 
161 	memset(&msg, 0, sizeof(msg));
162 	/* test for lost msgs */
163 	lost_msg = ioread8(&card->dpram[DPRAM_RX_LOST]);
164 	if (lost_msg) {
165 		int j;
166 		/* reset condition */
167 		iowrite8(0, &card->dpram[DPRAM_RX_LOST]);
168 		/* prepare msg */
169 		msg.can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
170 		msg.can_dlc = CAN_ERR_DLC;
171 		msg.data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
172 		/*
173 		 * service to all busses, we don't know which it was applicable
174 		 * but only service busses that are online
175 		 */
176 		for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
177 			netdev = card->net[j];
178 			if (!netdev)
179 				continue;
180 			if (!canif_is_active(netdev))
181 				/* a dead bus has no overflows */
182 				continue;
183 			++netdev->stats.rx_over_errors;
184 			softing_netdev_rx(netdev, &msg, 0);
185 		}
186 		/* prepare for other use */
187 		memset(&msg, 0, sizeof(msg));
188 		++cnt;
189 	}
190 
191 	fifo_rd = ioread8(&card->dpram[DPRAM_RX_RD]);
192 	fifo_wr = ioread8(&card->dpram[DPRAM_RX_WR]);
193 
194 	if (++fifo_rd >= DPRAM_RX_CNT)
195 		fifo_rd = 0;
196 	if (fifo_wr == fifo_rd)
197 		return cnt;
198 
199 	memcpy_fromio(buf, &card->dpram[DPRAM_RX + DPRAM_RX_SIZE*fifo_rd],
200 			DPRAM_RX_SIZE);
201 	mb();
202 	/* trigger dual port RAM */
203 	iowrite8(fifo_rd, &card->dpram[DPRAM_RX_RD]);
204 
205 	ptr = buf;
206 	cmd = *ptr++;
207 	if (cmd == 0xff)
208 		/* not quite useful, probably the card has got out */
209 		return 0;
210 	netdev = card->net[0];
211 	if (cmd & CMD_BUS2)
212 		netdev = card->net[1];
213 	priv = netdev_priv(netdev);
214 
215 	if (cmd & CMD_ERR) {
216 		uint8_t can_state, state;
217 
218 		state = *ptr++;
219 
220 		msg.can_id = CAN_ERR_FLAG;
221 		msg.can_dlc = CAN_ERR_DLC;
222 
223 		if (state & SF_MASK_BUSOFF) {
224 			can_state = CAN_STATE_BUS_OFF;
225 			msg.can_id |= CAN_ERR_BUSOFF;
226 			state = STATE_BUSOFF;
227 		} else if (state & SF_MASK_EPASSIVE) {
228 			can_state = CAN_STATE_ERROR_PASSIVE;
229 			msg.can_id |= CAN_ERR_CRTL;
230 			msg.data[1] = CAN_ERR_CRTL_TX_PASSIVE;
231 			state = STATE_EPASSIVE;
232 		} else {
233 			can_state = CAN_STATE_ERROR_ACTIVE;
234 			msg.can_id |= CAN_ERR_CRTL;
235 			state = STATE_EACTIVE;
236 		}
237 		/* update DPRAM */
238 		iowrite8(state, &card->dpram[priv->index ?
239 				DPRAM_INFO_BUSSTATE2 : DPRAM_INFO_BUSSTATE]);
240 		/* timestamp */
241 		tmp_u32 = le32_to_cpup((void *)ptr);
242 		ptr += 4;
243 		ktime = softing_raw2ktime(card, tmp_u32);
244 
245 		++netdev->stats.rx_errors;
246 		/* update internal status */
247 		if (can_state != priv->can.state) {
248 			priv->can.state = can_state;
249 			if (can_state == CAN_STATE_ERROR_PASSIVE)
250 				++priv->can.can_stats.error_passive;
251 			else if (can_state == CAN_STATE_BUS_OFF) {
252 				/* this calls can_close_cleanup() */
253 				++priv->can.can_stats.bus_off;
254 				can_bus_off(netdev);
255 				netif_stop_queue(netdev);
256 			}
257 			/* trigger socketcan */
258 			softing_netdev_rx(netdev, &msg, ktime);
259 		}
260 
261 	} else {
262 		if (cmd & CMD_RTR)
263 			msg.can_id |= CAN_RTR_FLAG;
264 		msg.can_dlc = get_can_dlc(*ptr++);
265 		if (cmd & CMD_XTD) {
266 			msg.can_id |= CAN_EFF_FLAG;
267 			msg.can_id |= le32_to_cpup((void *)ptr);
268 			ptr += 4;
269 		} else {
270 			msg.can_id |= le16_to_cpup((void *)ptr);
271 			ptr += 2;
272 		}
273 		/* timestamp */
274 		tmp_u32 = le32_to_cpup((void *)ptr);
275 		ptr += 4;
276 		ktime = softing_raw2ktime(card, tmp_u32);
277 		if (!(msg.can_id & CAN_RTR_FLAG))
278 			memcpy(&msg.data[0], ptr, 8);
279 		ptr += 8;
280 		/* update socket */
281 		if (cmd & CMD_ACK) {
282 			/* acknowledge, was tx msg */
283 			struct sk_buff *skb;
284 			skb = priv->can.echo_skb[priv->tx.echo_get];
285 			if (skb)
286 				skb->tstamp = ktime;
287 			can_get_echo_skb(netdev, priv->tx.echo_get);
288 			++priv->tx.echo_get;
289 			if (priv->tx.echo_get >= TX_ECHO_SKB_MAX)
290 				priv->tx.echo_get = 0;
291 			if (priv->tx.pending)
292 				--priv->tx.pending;
293 			if (card->tx.pending)
294 				--card->tx.pending;
295 			++netdev->stats.tx_packets;
296 			if (!(msg.can_id & CAN_RTR_FLAG))
297 				netdev->stats.tx_bytes += msg.can_dlc;
298 		} else {
299 			int ret;
300 
301 			ret = softing_netdev_rx(netdev, &msg, ktime);
302 			if (ret == NET_RX_SUCCESS) {
303 				++netdev->stats.rx_packets;
304 				if (!(msg.can_id & CAN_RTR_FLAG))
305 					netdev->stats.rx_bytes += msg.can_dlc;
306 			} else {
307 				++netdev->stats.rx_dropped;
308 			}
309 		}
310 	}
311 	++cnt;
312 	return cnt;
313 }
314 
315 /*
316  * real interrupt handler
317  */
318 static irqreturn_t softing_irq_thread(int irq, void *dev_id)
319 {
320 	struct softing *card = (struct softing *)dev_id;
321 	struct net_device *netdev;
322 	struct softing_priv *priv;
323 	int j, offset, work_done;
324 
325 	work_done = 0;
326 	spin_lock_bh(&card->spin);
327 	while (softing_handle_1(card) > 0) {
328 		++card->irq.svc_count;
329 		++work_done;
330 	}
331 	spin_unlock_bh(&card->spin);
332 	/* resume tx queue's */
333 	offset = card->tx.last_bus;
334 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
335 		if (card->tx.pending >= TXMAX)
336 			break;
337 		netdev = card->net[(j + offset + 1) % card->pdat->nbus];
338 		if (!netdev)
339 			continue;
340 		priv = netdev_priv(netdev);
341 		if (!canif_is_active(netdev))
342 			/* it makes no sense to wake dead busses */
343 			continue;
344 		if (priv->tx.pending >= TX_ECHO_SKB_MAX)
345 			continue;
346 		++work_done;
347 		netif_wake_queue(netdev);
348 	}
349 	return work_done ? IRQ_HANDLED : IRQ_NONE;
350 }
351 
352 /*
353  * interrupt routines:
354  * schedule the 'real interrupt handler'
355  */
356 static irqreturn_t softing_irq_v2(int irq, void *dev_id)
357 {
358 	struct softing *card = (struct softing *)dev_id;
359 	uint8_t ir;
360 
361 	ir = ioread8(&card->dpram[DPRAM_V2_IRQ_TOHOST]);
362 	iowrite8(0, &card->dpram[DPRAM_V2_IRQ_TOHOST]);
363 	return (1 == ir) ? IRQ_WAKE_THREAD : IRQ_NONE;
364 }
365 
366 static irqreturn_t softing_irq_v1(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_IRQ_TOHOST]);
372 	iowrite8(0, &card->dpram[DPRAM_IRQ_TOHOST]);
373 	return ir ? IRQ_WAKE_THREAD : IRQ_NONE;
374 }
375 
376 /*
377  * netdev/candev inter-operability
378  */
379 static int softing_netdev_open(struct net_device *ndev)
380 {
381 	int ret;
382 
383 	/* check or determine and set bittime */
384 	ret = open_candev(ndev);
385 	if (!ret)
386 		ret = softing_startstop(ndev, 1);
387 	return ret;
388 }
389 
390 static int softing_netdev_stop(struct net_device *ndev)
391 {
392 	int ret;
393 
394 	netif_stop_queue(ndev);
395 
396 	/* softing cycle does close_candev() */
397 	ret = softing_startstop(ndev, 0);
398 	return ret;
399 }
400 
401 static int softing_candev_set_mode(struct net_device *ndev, enum can_mode mode)
402 {
403 	int ret;
404 
405 	switch (mode) {
406 	case CAN_MODE_START:
407 		/* softing_startstop does close_candev() */
408 		ret = softing_startstop(ndev, 1);
409 		return ret;
410 	case CAN_MODE_STOP:
411 	case CAN_MODE_SLEEP:
412 		return -EOPNOTSUPP;
413 	}
414 	return 0;
415 }
416 
417 /*
418  * Softing device management helpers
419  */
420 int softing_enable_irq(struct softing *card, int enable)
421 {
422 	int ret;
423 
424 	if (!card->irq.nr) {
425 		return 0;
426 	} else if (card->irq.requested && !enable) {
427 		free_irq(card->irq.nr, card);
428 		card->irq.requested = 0;
429 	} else if (!card->irq.requested && enable) {
430 		ret = request_threaded_irq(card->irq.nr,
431 				(card->pdat->generation >= 2) ?
432 					softing_irq_v2 : softing_irq_v1,
433 				softing_irq_thread, IRQF_SHARED,
434 				dev_name(&card->pdev->dev), card);
435 		if (ret) {
436 			dev_alert(&card->pdev->dev,
437 					"request_threaded_irq(%u) failed\n",
438 					card->irq.nr);
439 			return ret;
440 		}
441 		card->irq.requested = 1;
442 	}
443 	return 0;
444 }
445 
446 static void softing_card_shutdown(struct softing *card)
447 {
448 	int fw_up = 0;
449 
450 	if (mutex_lock_interruptible(&card->fw.lock))
451 		/* return -ERESTARTSYS */;
452 	fw_up = card->fw.up;
453 	card->fw.up = 0;
454 
455 	if (card->irq.requested && card->irq.nr) {
456 		free_irq(card->irq.nr, card);
457 		card->irq.requested = 0;
458 	}
459 	if (fw_up) {
460 		if (card->pdat->enable_irq)
461 			card->pdat->enable_irq(card->pdev, 0);
462 		softing_set_reset_dpram(card);
463 		if (card->pdat->reset)
464 			card->pdat->reset(card->pdev, 1);
465 	}
466 	mutex_unlock(&card->fw.lock);
467 }
468 
469 static int softing_card_boot(struct softing *card)
470 {
471 	int ret, j;
472 	static const uint8_t stream[] = {
473 		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, };
474 	unsigned char back[sizeof(stream)];
475 
476 	if (mutex_lock_interruptible(&card->fw.lock))
477 		return -ERESTARTSYS;
478 	if (card->fw.up) {
479 		mutex_unlock(&card->fw.lock);
480 		return 0;
481 	}
482 	/* reset board */
483 	if (card->pdat->enable_irq)
484 		card->pdat->enable_irq(card->pdev, 1);
485 	/* boot card */
486 	softing_set_reset_dpram(card);
487 	if (card->pdat->reset)
488 		card->pdat->reset(card->pdev, 1);
489 	for (j = 0; (j + sizeof(stream)) < card->dpram_size;
490 			j += sizeof(stream)) {
491 
492 		memcpy_toio(&card->dpram[j], stream, sizeof(stream));
493 		/* flush IO cache */
494 		mb();
495 		memcpy_fromio(back, &card->dpram[j], sizeof(stream));
496 
497 		if (!memcmp(back, stream, sizeof(stream)))
498 			continue;
499 		/* memory is not equal */
500 		dev_alert(&card->pdev->dev, "dpram failed at 0x%04x\n", j);
501 		ret = -EIO;
502 		goto failed;
503 	}
504 	wmb();
505 	/* load boot firmware */
506 	ret = softing_load_fw(card->pdat->boot.fw, card, card->dpram,
507 				card->dpram_size,
508 				card->pdat->boot.offs - card->pdat->boot.addr);
509 	if (ret < 0)
510 		goto failed;
511 	/* load loader firmware */
512 	ret = softing_load_fw(card->pdat->load.fw, card, card->dpram,
513 				card->dpram_size,
514 				card->pdat->load.offs - card->pdat->load.addr);
515 	if (ret < 0)
516 		goto failed;
517 
518 	if (card->pdat->reset)
519 		card->pdat->reset(card->pdev, 0);
520 	softing_clr_reset_dpram(card);
521 	ret = softing_bootloader_command(card, 0, "card boot");
522 	if (ret < 0)
523 		goto failed;
524 	ret = softing_load_app_fw(card->pdat->app.fw, card);
525 	if (ret < 0)
526 		goto failed;
527 
528 	ret = softing_chip_poweron(card);
529 	if (ret < 0)
530 		goto failed;
531 
532 	card->fw.up = 1;
533 	mutex_unlock(&card->fw.lock);
534 	return 0;
535 failed:
536 	card->fw.up = 0;
537 	if (card->pdat->enable_irq)
538 		card->pdat->enable_irq(card->pdev, 0);
539 	softing_set_reset_dpram(card);
540 	if (card->pdat->reset)
541 		card->pdat->reset(card->pdev, 1);
542 	mutex_unlock(&card->fw.lock);
543 	return ret;
544 }
545 
546 /*
547  * netdev sysfs
548  */
549 static ssize_t show_chip(struct device *dev, struct device_attribute *attr,
550 		char *buf)
551 {
552 	struct net_device *ndev = to_net_dev(dev);
553 	struct softing_priv *priv = netdev2softing(ndev);
554 
555 	return sprintf(buf, "%i\n", priv->chip);
556 }
557 
558 static ssize_t show_output(struct device *dev, struct device_attribute *attr,
559 		char *buf)
560 {
561 	struct net_device *ndev = to_net_dev(dev);
562 	struct softing_priv *priv = netdev2softing(ndev);
563 
564 	return sprintf(buf, "0x%02x\n", priv->output);
565 }
566 
567 static ssize_t store_output(struct device *dev, struct device_attribute *attr,
568 		const char *buf, size_t count)
569 {
570 	struct net_device *ndev = to_net_dev(dev);
571 	struct softing_priv *priv = netdev2softing(ndev);
572 	struct softing *card = priv->card;
573 	unsigned long val;
574 	int ret;
575 
576 	ret = kstrtoul(buf, 0, &val);
577 	if (ret < 0)
578 		return ret;
579 	val &= 0xFF;
580 
581 	ret = mutex_lock_interruptible(&card->fw.lock);
582 	if (ret)
583 		return -ERESTARTSYS;
584 	if (netif_running(ndev)) {
585 		mutex_unlock(&card->fw.lock);
586 		return -EBUSY;
587 	}
588 	priv->output = val;
589 	mutex_unlock(&card->fw.lock);
590 	return count;
591 }
592 
593 static const DEVICE_ATTR(chip, 0444, show_chip, NULL);
594 static const DEVICE_ATTR(output, 0644, show_output, store_output);
595 
596 static const struct attribute *const netdev_sysfs_attrs[] = {
597 	&dev_attr_chip.attr,
598 	&dev_attr_output.attr,
599 	NULL,
600 };
601 static const struct attribute_group netdev_sysfs_group = {
602 	.name = NULL,
603 	.attrs = (struct attribute **)netdev_sysfs_attrs,
604 };
605 
606 static const struct net_device_ops softing_netdev_ops = {
607 	.ndo_open = softing_netdev_open,
608 	.ndo_stop = softing_netdev_stop,
609 	.ndo_start_xmit	= softing_netdev_start_xmit,
610 	.ndo_change_mtu = can_change_mtu,
611 };
612 
613 static const struct can_bittiming_const softing_btr_const = {
614 	.name = "softing",
615 	.tseg1_min = 1,
616 	.tseg1_max = 16,
617 	.tseg2_min = 1,
618 	.tseg2_max = 8,
619 	.sjw_max = 4, /* overruled */
620 	.brp_min = 1,
621 	.brp_max = 32, /* overruled */
622 	.brp_inc = 1,
623 };
624 
625 
626 static struct net_device *softing_netdev_create(struct softing *card,
627 						uint16_t chip_id)
628 {
629 	struct net_device *netdev;
630 	struct softing_priv *priv;
631 
632 	netdev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX);
633 	if (!netdev) {
634 		dev_alert(&card->pdev->dev, "alloc_candev failed\n");
635 		return NULL;
636 	}
637 	priv = netdev_priv(netdev);
638 	priv->netdev = netdev;
639 	priv->card = card;
640 	memcpy(&priv->btr_const, &softing_btr_const, sizeof(priv->btr_const));
641 	priv->btr_const.brp_max = card->pdat->max_brp;
642 	priv->btr_const.sjw_max = card->pdat->max_sjw;
643 	priv->can.bittiming_const = &priv->btr_const;
644 	priv->can.clock.freq = 8000000;
645 	priv->chip = chip_id;
646 	priv->output = softing_default_output(netdev);
647 	SET_NETDEV_DEV(netdev, &card->pdev->dev);
648 
649 	netdev->flags |= IFF_ECHO;
650 	netdev->netdev_ops = &softing_netdev_ops;
651 	priv->can.do_set_mode = softing_candev_set_mode;
652 	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
653 
654 	return netdev;
655 }
656 
657 static int softing_netdev_register(struct net_device *netdev)
658 {
659 	int ret;
660 
661 	ret = register_candev(netdev);
662 	if (ret) {
663 		dev_alert(&netdev->dev, "register failed\n");
664 		return ret;
665 	}
666 	if (sysfs_create_group(&netdev->dev.kobj, &netdev_sysfs_group) < 0)
667 		netdev_alert(netdev, "sysfs group failed\n");
668 
669 	return 0;
670 }
671 
672 static void softing_netdev_cleanup(struct net_device *netdev)
673 {
674 	sysfs_remove_group(&netdev->dev.kobj, &netdev_sysfs_group);
675 	unregister_candev(netdev);
676 	free_candev(netdev);
677 }
678 
679 /*
680  * sysfs for Platform device
681  */
682 #define DEV_ATTR_RO(name, member) \
683 static ssize_t show_##name(struct device *dev, \
684 		struct device_attribute *attr, char *buf) \
685 { \
686 	struct softing *card = dev_get_drvdata(dev); \
687 	return sprintf(buf, "%u\n", card->member); \
688 } \
689 static DEVICE_ATTR(name, 0444, show_##name, NULL)
690 
691 #define DEV_ATTR_RO_STR(name, member) \
692 static ssize_t show_##name(struct device *dev, \
693 		struct device_attribute *attr, char *buf) \
694 { \
695 	struct softing *card = dev_get_drvdata(dev); \
696 	return sprintf(buf, "%s\n", card->member); \
697 } \
698 static DEVICE_ATTR(name, 0444, show_##name, NULL)
699 
700 DEV_ATTR_RO(serial, id.serial);
701 DEV_ATTR_RO_STR(firmware, pdat->app.fw);
702 DEV_ATTR_RO(firmware_version, id.fw_version);
703 DEV_ATTR_RO_STR(hardware, pdat->name);
704 DEV_ATTR_RO(hardware_version, id.hw_version);
705 DEV_ATTR_RO(license, id.license);
706 
707 static struct attribute *softing_pdev_attrs[] = {
708 	&dev_attr_serial.attr,
709 	&dev_attr_firmware.attr,
710 	&dev_attr_firmware_version.attr,
711 	&dev_attr_hardware.attr,
712 	&dev_attr_hardware_version.attr,
713 	&dev_attr_license.attr,
714 	NULL,
715 };
716 
717 static const struct attribute_group softing_pdev_group = {
718 	.name = NULL,
719 	.attrs = softing_pdev_attrs,
720 };
721 
722 /*
723  * platform driver
724  */
725 static int softing_pdev_remove(struct platform_device *pdev)
726 {
727 	struct softing *card = platform_get_drvdata(pdev);
728 	int j;
729 
730 	/* first, disable card*/
731 	softing_card_shutdown(card);
732 
733 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
734 		if (!card->net[j])
735 			continue;
736 		softing_netdev_cleanup(card->net[j]);
737 		card->net[j] = NULL;
738 	}
739 	sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);
740 
741 	iounmap(card->dpram);
742 	kfree(card);
743 	return 0;
744 }
745 
746 static int softing_pdev_probe(struct platform_device *pdev)
747 {
748 	const struct softing_platform_data *pdat = dev_get_platdata(&pdev->dev);
749 	struct softing *card;
750 	struct net_device *netdev;
751 	struct softing_priv *priv;
752 	struct resource *pres;
753 	int ret;
754 	int j;
755 
756 	if (!pdat) {
757 		dev_warn(&pdev->dev, "no platform data\n");
758 		return -EINVAL;
759 	}
760 	if (pdat->nbus > ARRAY_SIZE(card->net)) {
761 		dev_warn(&pdev->dev, "%u nets??\n", pdat->nbus);
762 		return -EINVAL;
763 	}
764 
765 	card = kzalloc(sizeof(*card), GFP_KERNEL);
766 	if (!card)
767 		return -ENOMEM;
768 	card->pdat = pdat;
769 	card->pdev = pdev;
770 	platform_set_drvdata(pdev, card);
771 	mutex_init(&card->fw.lock);
772 	spin_lock_init(&card->spin);
773 
774 	ret = -EINVAL;
775 	pres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
776 	if (!pres)
777 		goto platform_resource_failed;
778 	card->dpram_phys = pres->start;
779 	card->dpram_size = resource_size(pres);
780 	card->dpram = ioremap(card->dpram_phys, card->dpram_size);
781 	if (!card->dpram) {
782 		dev_alert(&card->pdev->dev, "dpram ioremap failed\n");
783 		goto ioremap_failed;
784 	}
785 
786 	pres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
787 	if (pres)
788 		card->irq.nr = pres->start;
789 
790 	/* reset card */
791 	ret = softing_card_boot(card);
792 	if (ret < 0) {
793 		dev_alert(&pdev->dev, "failed to boot\n");
794 		goto boot_failed;
795 	}
796 
797 	/* only now, the chip's are known */
798 	card->id.freq = card->pdat->freq;
799 
800 	ret = sysfs_create_group(&pdev->dev.kobj, &softing_pdev_group);
801 	if (ret < 0) {
802 		dev_alert(&card->pdev->dev, "sysfs failed\n");
803 		goto sysfs_failed;
804 	}
805 
806 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
807 		card->net[j] = netdev =
808 			softing_netdev_create(card, card->id.chip[j]);
809 		if (!netdev) {
810 			dev_alert(&pdev->dev, "failed to make can[%i]", j);
811 			ret = -ENOMEM;
812 			goto netdev_failed;
813 		}
814 		netdev->dev_id = j;
815 		priv = netdev_priv(card->net[j]);
816 		priv->index = j;
817 		ret = softing_netdev_register(netdev);
818 		if (ret) {
819 			free_candev(netdev);
820 			card->net[j] = NULL;
821 			dev_alert(&card->pdev->dev,
822 					"failed to register can[%i]\n", j);
823 			goto netdev_failed;
824 		}
825 	}
826 	dev_info(&card->pdev->dev, "%s ready.\n", card->pdat->name);
827 	return 0;
828 
829 netdev_failed:
830 	for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
831 		if (!card->net[j])
832 			continue;
833 		softing_netdev_cleanup(card->net[j]);
834 	}
835 	sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);
836 sysfs_failed:
837 	softing_card_shutdown(card);
838 boot_failed:
839 	iounmap(card->dpram);
840 ioremap_failed:
841 platform_resource_failed:
842 	kfree(card);
843 	return ret;
844 }
845 
846 static struct platform_driver softing_driver = {
847 	.driver = {
848 		.name = "softing",
849 	},
850 	.probe = softing_pdev_probe,
851 	.remove = softing_pdev_remove,
852 };
853 
854 module_platform_driver(softing_driver);
855 
856 MODULE_ALIAS("platform:softing");
857 MODULE_DESCRIPTION("Softing DPRAM CAN driver");
858 MODULE_AUTHOR("Kurt Van Dijck <kurt.van.dijck@eia.be>");
859 MODULE_LICENSE("GPL v2");
860