2 * CAN bus driver for the alone generic (as possible as) MSCAN controller.
4 * Copyright (C) 2005-2006 Andrey Volkov <avolkov@varma-el.com>,
6 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
7 * Copytight (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the version 2 of the GNU General Public License
11 * as published by the Free Software Foundation
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/netdevice.h>
28 #include <linux/if_arp.h>
29 #include <linux/if_ether.h>
30 #include <linux/list.h>
31 #include <linux/can.h>
32 #include <linux/can/dev.h>
33 #include <linux/can/error.h>
38 static struct can_bittiming_const mscan_bittiming_const = {
56 static enum can_state state_map[] = {
57 CAN_STATE_ERROR_ACTIVE,
58 CAN_STATE_ERROR_WARNING,
59 CAN_STATE_ERROR_PASSIVE,
63 static int mscan_set_mode(struct net_device *dev, u8 mode)
65 struct mscan_priv *priv = netdev_priv(dev);
66 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
71 if (mode != MSCAN_NORMAL_MODE) {
72 if (priv->tx_active) {
73 /* Abort transfers before going to sleep */#
74 out_8(®s->cantarq, priv->tx_active);
75 /* Suppress TX done interrupts */
76 out_8(®s->cantier, 0);
79 canctl1 = in_8(®s->canctl1);
80 if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
82 in_8(®s->canctl0) | MSCAN_SLPRQ);
83 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
84 if (in_8(®s->canctl1) & MSCAN_SLPAK)
89 * The mscan controller will fail to enter sleep mode,
90 * while there are irregular activities on bus, like
91 * somebody keeps retransmitting. This behavior is
92 * undocumented and seems to differ between mscan built
93 * in mpc5200b and mpc5200. We proceed in that case,
94 * since otherwise the slprq will be kept set and the
95 * controller will get stuck. NOTE: INITRQ or CSWAI
96 * will abort all active transmit actions, if still
99 if (i >= MSCAN_SET_MODE_RETRIES)
100 dev_dbg(dev->dev.parent,
101 "device failed to enter sleep mode. "
102 "We proceed anyhow.\n");
104 priv->can.state = CAN_STATE_SLEEPING;
107 if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
108 out_8(®s->canctl0,
109 in_8(®s->canctl0) | MSCAN_INITRQ);
110 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
111 if (in_8(®s->canctl1) & MSCAN_INITAK)
114 if (i >= MSCAN_SET_MODE_RETRIES)
118 priv->can.state = CAN_STATE_STOPPED;
120 if (mode & MSCAN_CSWAI)
121 out_8(®s->canctl0,
122 in_8(®s->canctl0) | MSCAN_CSWAI);
125 canctl1 = in_8(®s->canctl1);
126 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
127 out_8(®s->canctl0, in_8(®s->canctl0) &
128 ~(MSCAN_SLPRQ | MSCAN_INITRQ));
129 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
130 canctl1 = in_8(®s->canctl1);
131 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
134 if (i >= MSCAN_SET_MODE_RETRIES)
137 priv->can.state = CAN_STATE_ERROR_ACTIVE;
143 static int mscan_start(struct net_device *dev)
145 struct mscan_priv *priv = netdev_priv(dev);
146 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
150 out_8(®s->canrier, 0);
152 INIT_LIST_HEAD(&priv->tx_head);
153 priv->prev_buf_id = 0;
156 priv->shadow_canrier = 0;
159 err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
163 canrflg = in_8(®s->canrflg);
164 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
165 priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
166 MSCAN_STATE_TX(canrflg))];
167 out_8(®s->cantier, 0);
169 /* Enable receive interrupts. */
170 out_8(®s->canrier, MSCAN_OVRIE | MSCAN_RXFIE | MSCAN_CSCIE |
171 MSCAN_RSTATE1 | MSCAN_RSTATE0 | MSCAN_TSTATE1 | MSCAN_TSTATE0);
176 static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
178 struct can_frame *frame = (struct can_frame *)skb->data;
179 struct mscan_priv *priv = netdev_priv(dev);
180 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
184 if (frame->can_dlc > 8)
187 out_8(®s->cantier, 0);
189 i = ~priv->tx_active & MSCAN_TXE;
191 switch (hweight8(i)) {
193 netif_stop_queue(dev);
194 dev_err(dev->dev.parent, "Tx Ring full when queue awake!\n");
195 return NETDEV_TX_BUSY;
198 * if buf_id < 3, then current frame will be send out of order,
199 * since buffer with lower id have higher priority (hell..)
201 netif_stop_queue(dev);
203 if (buf_id < priv->prev_buf_id) {
205 if (priv->cur_pri == 0xff) {
206 set_bit(F_TX_WAIT_ALL, &priv->flags);
207 netif_stop_queue(dev);
210 set_bit(F_TX_PROGRESS, &priv->flags);
213 priv->prev_buf_id = buf_id;
214 out_8(®s->cantbsel, i);
216 rtr = frame->can_id & CAN_RTR_FLAG;
218 if (frame->can_id & CAN_EFF_FLAG) {
219 can_id = (frame->can_id & CAN_EFF_MASK) << 1;
222 out_be16(®s->tx.idr3_2, can_id);
225 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0) | (3 << 3);
227 can_id = (frame->can_id & CAN_SFF_MASK) << 5;
231 out_be16(®s->tx.idr1_0, can_id);
234 void __iomem *data = ®s->tx.dsr1_0;
235 u16 *payload = (u16 *)frame->data;
237 /* It is safe to write into dsr[dlc+1] */
238 for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
239 out_be16(data, *payload++);
240 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
244 out_8(®s->tx.dlr, frame->can_dlc);
245 out_8(®s->tx.tbpr, priv->cur_pri);
247 /* Start transmission. */
248 out_8(®s->cantflg, 1 << buf_id);
250 if (!test_bit(F_TX_PROGRESS, &priv->flags))
251 dev->trans_start = jiffies;
253 list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
255 can_put_echo_skb(skb, dev, buf_id);
257 /* Enable interrupt. */
258 priv->tx_active |= 1 << buf_id;
259 out_8(®s->cantier, priv->tx_active);
264 /* This function returns the old state to see where we came from */
265 static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
267 struct mscan_priv *priv = netdev_priv(dev);
268 enum can_state state, old_state = priv->can.state;
270 if (canrflg & MSCAN_CSCIF && old_state <= CAN_STATE_BUS_OFF) {
271 state = state_map[max(MSCAN_STATE_RX(canrflg),
272 MSCAN_STATE_TX(canrflg))];
273 priv->can.state = state;
278 static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
280 struct mscan_priv *priv = netdev_priv(dev);
281 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
285 can_id = in_be16(®s->rx.idr1_0);
286 if (can_id & (1 << 3)) {
287 frame->can_id = CAN_EFF_FLAG;
288 can_id = ((can_id << 16) | in_be16(®s->rx.idr3_2));
289 can_id = ((can_id & 0xffe00000) |
290 ((can_id & 0x7ffff) << 2)) >> 2;
296 frame->can_id |= can_id >> 1;
298 frame->can_id |= CAN_RTR_FLAG;
299 frame->can_dlc = in_8(®s->rx.dlr) & 0xf;
301 if (!(frame->can_id & CAN_RTR_FLAG)) {
302 void __iomem *data = ®s->rx.dsr1_0;
303 u16 *payload = (u16 *)frame->data;
305 for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
306 *payload++ = in_be16(data);
307 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
311 out_8(®s->canrflg, MSCAN_RXF);
314 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
317 struct mscan_priv *priv = netdev_priv(dev);
318 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
319 struct net_device_stats *stats = &dev->stats;
320 enum can_state old_state;
322 dev_dbg(dev->dev.parent, "error interrupt (canrflg=%#x)\n", canrflg);
323 frame->can_id = CAN_ERR_FLAG;
325 if (canrflg & MSCAN_OVRIF) {
326 frame->can_id |= CAN_ERR_CRTL;
327 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
328 stats->rx_over_errors++;
334 old_state = check_set_state(dev, canrflg);
336 if (old_state != priv->can.state) {
337 switch (priv->can.state) {
338 case CAN_STATE_ERROR_WARNING:
339 frame->can_id |= CAN_ERR_CRTL;
340 priv->can.can_stats.error_warning++;
341 if ((priv->shadow_statflg & MSCAN_RSTAT_MSK) <
342 (canrflg & MSCAN_RSTAT_MSK))
343 frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
344 if ((priv->shadow_statflg & MSCAN_TSTAT_MSK) <
345 (canrflg & MSCAN_TSTAT_MSK))
346 frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
348 case CAN_STATE_ERROR_PASSIVE:
349 frame->can_id |= CAN_ERR_CRTL;
350 priv->can.can_stats.error_passive++;
351 frame->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
353 case CAN_STATE_BUS_OFF:
354 frame->can_id |= CAN_ERR_BUSOFF;
356 * The MSCAN on the MPC5200 does recover from bus-off
357 * automatically. To avoid that we stop the chip doing
358 * a light-weight stop (we are in irq-context).
360 out_8(®s->cantier, 0);
361 out_8(®s->canrier, 0);
362 out_8(®s->canctl0, in_8(®s->canctl0) |
363 MSCAN_SLPRQ | MSCAN_INITRQ);
370 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
371 frame->can_dlc = CAN_ERR_DLC;
372 out_8(®s->canrflg, MSCAN_ERR_IF);
375 static int mscan_rx_poll(struct napi_struct *napi, int quota)
377 struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
378 struct net_device *dev = napi->dev;
379 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
380 struct net_device_stats *stats = &dev->stats;
384 struct can_frame *frame;
387 while (npackets < quota && ((canrflg = in_8(®s->canrflg)) &
388 (MSCAN_RXF | MSCAN_ERR_IF))) {
390 skb = alloc_can_skb(dev, &frame);
392 if (printk_ratelimit())
393 dev_notice(dev->dev.parent, "packet dropped\n");
395 out_8(®s->canrflg, canrflg);
399 if (canrflg & MSCAN_RXF)
400 mscan_get_rx_frame(dev, frame);
401 else if (canrflg & MSCAN_ERR_IF)
402 mscan_get_err_frame(dev, frame, canrflg);
405 stats->rx_bytes += frame->can_dlc;
407 netif_receive_skb(skb);
410 if (!(in_8(®s->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
411 napi_complete(&priv->napi);
412 clear_bit(F_RX_PROGRESS, &priv->flags);
413 if (priv->can.state < CAN_STATE_BUS_OFF)
414 out_8(®s->canrier, priv->shadow_canrier);
420 static irqreturn_t mscan_isr(int irq, void *dev_id)
422 struct net_device *dev = (struct net_device *)dev_id;
423 struct mscan_priv *priv = netdev_priv(dev);
424 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
425 struct net_device_stats *stats = &dev->stats;
426 u8 cantier, cantflg, canrflg;
427 irqreturn_t ret = IRQ_NONE;
429 cantier = in_8(®s->cantier) & MSCAN_TXE;
430 cantflg = in_8(®s->cantflg) & cantier;
432 if (cantier && cantflg) {
433 struct list_head *tmp, *pos;
435 list_for_each_safe(pos, tmp, &priv->tx_head) {
436 struct tx_queue_entry *entry =
437 list_entry(pos, struct tx_queue_entry, list);
438 u8 mask = entry->mask;
440 if (!(cantflg & mask))
443 out_8(®s->cantbsel, mask);
444 stats->tx_bytes += in_8(®s->tx.dlr);
446 can_get_echo_skb(dev, entry->id);
447 priv->tx_active &= ~mask;
451 if (list_empty(&priv->tx_head)) {
452 clear_bit(F_TX_WAIT_ALL, &priv->flags);
453 clear_bit(F_TX_PROGRESS, &priv->flags);
456 dev->trans_start = jiffies;
459 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
460 netif_wake_queue(dev);
462 out_8(®s->cantier, priv->tx_active);
466 canrflg = in_8(®s->canrflg);
467 if ((canrflg & ~MSCAN_STAT_MSK) &&
468 !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
469 if (canrflg & ~MSCAN_STAT_MSK) {
470 priv->shadow_canrier = in_8(®s->canrier);
471 out_8(®s->canrier, 0);
472 napi_schedule(&priv->napi);
475 clear_bit(F_RX_PROGRESS, &priv->flags);
481 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
483 struct mscan_priv *priv = netdev_priv(dev);
486 if (!priv->open_time)
492 netif_stop_queue(dev);
495 CAN_MODE_STOP) ? MSCAN_INIT_MODE :
499 if (priv->can.state <= CAN_STATE_BUS_OFF)
500 mscan_set_mode(dev, MSCAN_INIT_MODE);
501 ret = mscan_start(dev);
504 if (netif_queue_stopped(dev))
505 netif_wake_queue(dev);
515 static int mscan_do_set_bittiming(struct net_device *dev)
517 struct mscan_priv *priv = netdev_priv(dev);
518 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
519 struct can_bittiming *bt = &priv->can.bittiming;
522 btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
523 btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
524 BTR1_SET_TSEG2(bt->phase_seg2) |
525 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
527 dev_info(dev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
530 out_8(®s->canbtr0, btr0);
531 out_8(®s->canbtr1, btr1);
536 static int mscan_open(struct net_device *dev)
539 struct mscan_priv *priv = netdev_priv(dev);
540 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
543 ret = open_candev(dev);
547 napi_enable(&priv->napi);
549 ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
551 napi_disable(&priv->napi);
552 printk(KERN_ERR "%s - failed to attach interrupt\n",
557 priv->open_time = jiffies;
559 out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_LISTEN);
561 ret = mscan_start(dev);
565 netif_start_queue(dev);
570 static int mscan_close(struct net_device *dev)
572 struct mscan_priv *priv = netdev_priv(dev);
573 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
575 netif_stop_queue(dev);
576 napi_disable(&priv->napi);
578 out_8(®s->cantier, 0);
579 out_8(®s->canrier, 0);
580 mscan_set_mode(dev, MSCAN_INIT_MODE);
582 free_irq(dev->irq, dev);
588 static const struct net_device_ops mscan_netdev_ops = {
589 .ndo_open = mscan_open,
590 .ndo_stop = mscan_close,
591 .ndo_start_xmit = mscan_start_xmit,
594 int register_mscandev(struct net_device *dev, int clock_src)
596 struct mscan_priv *priv = netdev_priv(dev);
597 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
600 ctl1 = in_8(®s->canctl1);
602 ctl1 |= MSCAN_CLKSRC;
604 ctl1 &= ~MSCAN_CLKSRC;
607 out_8(®s->canctl1, ctl1);
610 /* acceptance mask/acceptance code (accept everything) */
611 out_be16(®s->canidar1_0, 0);
612 out_be16(®s->canidar3_2, 0);
613 out_be16(®s->canidar5_4, 0);
614 out_be16(®s->canidar7_6, 0);
616 out_be16(®s->canidmr1_0, 0xffff);
617 out_be16(®s->canidmr3_2, 0xffff);
618 out_be16(®s->canidmr5_4, 0xffff);
619 out_be16(®s->canidmr7_6, 0xffff);
620 /* Two 32 bit Acceptance Filters */
621 out_8(®s->canidac, MSCAN_AF_32BIT);
623 mscan_set_mode(dev, MSCAN_INIT_MODE);
625 return register_candev(dev);
627 EXPORT_SYMBOL_GPL(register_mscandev);
629 void unregister_mscandev(struct net_device *dev)
631 struct mscan_priv *priv = netdev_priv(dev);
632 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
633 mscan_set_mode(dev, MSCAN_INIT_MODE);
634 out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_CANE);
635 unregister_candev(dev);
637 EXPORT_SYMBOL_GPL(unregister_mscandev);
639 struct net_device *alloc_mscandev(void)
641 struct net_device *dev;
642 struct mscan_priv *priv;
645 dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
648 priv = netdev_priv(dev);
650 dev->netdev_ops = &mscan_netdev_ops;
652 dev->flags |= IFF_ECHO; /* we support local echo */
654 netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
656 priv->can.bittiming_const = &mscan_bittiming_const;
657 priv->can.do_set_bittiming = mscan_do_set_bittiming;
658 priv->can.do_set_mode = mscan_do_set_mode;
660 for (i = 0; i < TX_QUEUE_SIZE; i++) {
661 priv->tx_queue[i].id = i;
662 priv->tx_queue[i].mask = 1 << i;
667 EXPORT_SYMBOL_GPL(alloc_mscandev);
669 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
670 MODULE_LICENSE("GPL v2");
671 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");