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) {
73 if (priv->tx_active) {
74 /* Abort transfers before going to sleep */#
75 out_8(®s->cantarq, priv->tx_active);
76 /* Suppress TX done interrupts */
77 out_8(®s->cantier, 0);
80 canctl1 = in_8(®s->canctl1);
81 if ((mode & MSCAN_SLPRQ) && (canctl1 & MSCAN_SLPAK) == 0) {
83 in_8(®s->canctl0) | MSCAN_SLPRQ);
84 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
85 if (in_8(®s->canctl1) & MSCAN_SLPAK)
90 * The mscan controller will fail to enter sleep mode,
91 * while there are irregular activities on bus, like
92 * somebody keeps retransmitting. This behavior is
93 * undocumented and seems to differ between mscan built
94 * in mpc5200b and mpc5200. We proceed in that case,
95 * since otherwise the slprq will be kept set and the
96 * controller will get stuck. NOTE: INITRQ or CSWAI
97 * will abort all active transmit actions, if still
100 if (i >= MSCAN_SET_MODE_RETRIES)
101 dev_dbg(dev->dev.parent,
102 "device failed to enter sleep mode. "
103 "We proceed anyhow.\n");
105 priv->can.state = CAN_STATE_SLEEPING;
108 if ((mode & MSCAN_INITRQ) && (canctl1 & MSCAN_INITAK) == 0) {
109 out_8(®s->canctl0,
110 in_8(®s->canctl0) | MSCAN_INITRQ);
111 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
112 if (in_8(®s->canctl1) & MSCAN_INITAK)
115 if (i >= MSCAN_SET_MODE_RETRIES)
119 priv->can.state = CAN_STATE_STOPPED;
121 if (mode & MSCAN_CSWAI)
122 out_8(®s->canctl0,
123 in_8(®s->canctl0) | MSCAN_CSWAI);
126 canctl1 = in_8(®s->canctl1);
127 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
128 out_8(®s->canctl0, in_8(®s->canctl0) &
129 ~(MSCAN_SLPRQ | MSCAN_INITRQ));
130 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
131 canctl1 = in_8(®s->canctl1);
132 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
135 if (i >= MSCAN_SET_MODE_RETRIES)
138 priv->can.state = CAN_STATE_ERROR_ACTIVE;
144 static int mscan_start(struct net_device *dev)
146 struct mscan_priv *priv = netdev_priv(dev);
147 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
151 out_8(®s->canrier, 0);
153 INIT_LIST_HEAD(&priv->tx_head);
154 priv->prev_buf_id = 0;
157 priv->shadow_canrier = 0;
160 err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
164 canrflg = in_8(®s->canrflg);
165 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
166 priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
167 MSCAN_STATE_TX(canrflg))];
168 out_8(®s->cantier, 0);
170 /* Enable receive interrupts. */
171 out_8(®s->canrier, MSCAN_OVRIE | MSCAN_RXFIE | MSCAN_CSCIE |
172 MSCAN_RSTATE1 | MSCAN_RSTATE0 | MSCAN_TSTATE1 | MSCAN_TSTATE0);
177 static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
179 struct can_frame *frame = (struct can_frame *)skb->data;
180 struct mscan_priv *priv = netdev_priv(dev);
181 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
185 if (frame->can_dlc > 8)
188 out_8(®s->cantier, 0);
190 i = ~priv->tx_active & MSCAN_TXE;
192 switch (hweight8(i)) {
194 netif_stop_queue(dev);
195 dev_err(dev->dev.parent, "Tx Ring full when queue awake!\n");
196 return NETDEV_TX_BUSY;
199 * if buf_id < 3, then current frame will be send out of order,
200 * since buffer with lower id have higher priority (hell..)
202 netif_stop_queue(dev);
204 if (buf_id < priv->prev_buf_id) {
206 if (priv->cur_pri == 0xff) {
207 set_bit(F_TX_WAIT_ALL, &priv->flags);
208 netif_stop_queue(dev);
211 set_bit(F_TX_PROGRESS, &priv->flags);
214 priv->prev_buf_id = buf_id;
215 out_8(®s->cantbsel, i);
217 rtr = frame->can_id & CAN_RTR_FLAG;
219 if (frame->can_id & CAN_EFF_FLAG) {
220 can_id = (frame->can_id & CAN_EFF_MASK) << 1;
223 out_be16(®s->tx.idr3_2, can_id);
226 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0) | (3 << 3);
228 can_id = (frame->can_id & CAN_SFF_MASK) << 5;
232 out_be16(®s->tx.idr1_0, can_id);
235 void __iomem *data = ®s->tx.dsr1_0;
236 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;
304 for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
305 *payload++ = in_be16(data);
306 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
310 out_8(®s->canrflg, MSCAN_RXF);
313 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
316 struct mscan_priv *priv = netdev_priv(dev);
317 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
318 struct net_device_stats *stats = &dev->stats;
319 enum can_state old_state;
321 dev_dbg(dev->dev.parent, "error interrupt (canrflg=%#x)\n", canrflg);
322 frame->can_id = CAN_ERR_FLAG;
324 if (canrflg & MSCAN_OVRIF) {
325 frame->can_id |= CAN_ERR_CRTL;
326 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
327 stats->rx_over_errors++;
332 old_state = check_set_state(dev, canrflg);
334 if (old_state != priv->can.state) {
335 switch (priv->can.state) {
336 case CAN_STATE_ERROR_WARNING:
337 frame->can_id |= CAN_ERR_CRTL;
338 priv->can.can_stats.error_warning++;
339 if ((priv->shadow_statflg & MSCAN_RSTAT_MSK) <
340 (canrflg & MSCAN_RSTAT_MSK))
341 frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
343 if ((priv->shadow_statflg & MSCAN_TSTAT_MSK) <
344 (canrflg & MSCAN_TSTAT_MSK))
345 frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
347 case CAN_STATE_ERROR_PASSIVE:
348 frame->can_id |= CAN_ERR_CRTL;
349 priv->can.can_stats.error_passive++;
350 frame->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
352 case CAN_STATE_BUS_OFF:
353 frame->can_id |= CAN_ERR_BUSOFF;
355 * The MSCAN on the MPC5200 does recover from bus-off
356 * automatically. To avoid that we stop the chip doing
357 * a light-weight stop (we are in irq-context).
359 out_8(®s->cantier, 0);
360 out_8(®s->canrier, 0);
361 out_8(®s->canctl0, in_8(®s->canctl0) |
362 MSCAN_SLPRQ | MSCAN_INITRQ);
369 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
370 frame->can_dlc = CAN_ERR_DLC;
371 out_8(®s->canrflg, MSCAN_ERR_IF);
374 static int mscan_rx_poll(struct napi_struct *napi, int quota)
376 struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
377 struct net_device *dev = napi->dev;
378 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
379 struct net_device_stats *stats = &dev->stats;
383 struct can_frame *frame;
386 while (npackets < quota && ((canrflg = in_8(®s->canrflg)) &
387 (MSCAN_RXF | MSCAN_ERR_IF))) {
389 skb = alloc_can_skb(dev, &frame);
391 if (printk_ratelimit())
392 dev_notice(dev->dev.parent, "packet dropped\n");
394 out_8(®s->canrflg, canrflg);
398 if (canrflg & MSCAN_RXF)
399 mscan_get_rx_frame(dev, frame);
400 else if (canrflg & MSCAN_ERR_IF)
401 mscan_get_err_frame(dev, frame, canrflg);
404 stats->rx_bytes += frame->can_dlc;
406 netif_receive_skb(skb);
409 if (!(in_8(®s->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
410 napi_complete(&priv->napi);
411 clear_bit(F_RX_PROGRESS, &priv->flags);
412 if (priv->can.state < CAN_STATE_BUS_OFF)
413 out_8(®s->canrier, priv->shadow_canrier);
419 static irqreturn_t mscan_isr(int irq, void *dev_id)
421 struct net_device *dev = (struct net_device *)dev_id;
422 struct mscan_priv *priv = netdev_priv(dev);
423 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
424 struct net_device_stats *stats = &dev->stats;
425 u8 cantier, cantflg, canrflg;
426 irqreturn_t ret = IRQ_NONE;
428 cantier = in_8(®s->cantier) & MSCAN_TXE;
429 cantflg = in_8(®s->cantflg) & cantier;
431 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;
458 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
459 netif_wake_queue(dev);
461 out_8(®s->cantier, priv->tx_active);
465 canrflg = in_8(®s->canrflg);
466 if ((canrflg & ~MSCAN_STAT_MSK) &&
467 !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
468 if (canrflg & ~MSCAN_STAT_MSK) {
469 priv->shadow_canrier = in_8(®s->canrier);
470 out_8(®s->canrier, 0);
471 napi_schedule(&priv->napi);
474 clear_bit(F_RX_PROGRESS, &priv->flags);
479 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
482 struct mscan_priv *priv = netdev_priv(dev);
485 if (!priv->open_time)
491 netif_stop_queue(dev);
494 CAN_MODE_STOP) ? MSCAN_INIT_MODE :
498 if (priv->can.state <= CAN_STATE_BUS_OFF)
499 mscan_set_mode(dev, MSCAN_INIT_MODE);
500 ret = mscan_start(dev);
503 if (netif_queue_stopped(dev))
504 netif_wake_queue(dev);
514 static int mscan_do_set_bittiming(struct net_device *dev)
516 struct mscan_priv *priv = netdev_priv(dev);
517 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
518 struct can_bittiming *bt = &priv->can.bittiming;
521 btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
522 btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
523 BTR1_SET_TSEG2(bt->phase_seg2) |
524 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
526 dev_info(dev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
529 out_8(®s->canbtr0, btr0);
530 out_8(®s->canbtr1, btr1);
535 static int mscan_open(struct net_device *dev)
538 struct mscan_priv *priv = netdev_priv(dev);
539 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
542 ret = open_candev(dev);
546 napi_enable(&priv->napi);
548 ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
550 napi_disable(&priv->napi);
551 printk(KERN_ERR "%s - failed to attach interrupt\n",
556 priv->open_time = jiffies;
558 out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_LISTEN);
560 ret = mscan_start(dev);
564 netif_start_queue(dev);
569 static int mscan_close(struct net_device *dev)
571 struct mscan_priv *priv = netdev_priv(dev);
572 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
574 netif_stop_queue(dev);
575 napi_disable(&priv->napi);
577 out_8(®s->cantier, 0);
578 out_8(®s->canrier, 0);
579 mscan_set_mode(dev, MSCAN_INIT_MODE);
581 free_irq(dev->irq, dev);
587 static const struct net_device_ops mscan_netdev_ops = {
588 .ndo_open = mscan_open,
589 .ndo_stop = mscan_close,
590 .ndo_start_xmit = mscan_start_xmit,
593 int register_mscandev(struct net_device *dev, int clock_src)
595 struct mscan_priv *priv = netdev_priv(dev);
596 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
599 ctl1 = in_8(®s->canctl1);
601 ctl1 |= MSCAN_CLKSRC;
603 ctl1 &= ~MSCAN_CLKSRC;
606 out_8(®s->canctl1, ctl1);
609 /* acceptance mask/acceptance code (accept everything) */
610 out_be16(®s->canidar1_0, 0);
611 out_be16(®s->canidar3_2, 0);
612 out_be16(®s->canidar5_4, 0);
613 out_be16(®s->canidar7_6, 0);
615 out_be16(®s->canidmr1_0, 0xffff);
616 out_be16(®s->canidmr3_2, 0xffff);
617 out_be16(®s->canidmr5_4, 0xffff);
618 out_be16(®s->canidmr7_6, 0xffff);
619 /* Two 32 bit Acceptance Filters */
620 out_8(®s->canidac, MSCAN_AF_32BIT);
622 mscan_set_mode(dev, MSCAN_INIT_MODE);
624 return register_candev(dev);
626 EXPORT_SYMBOL_GPL(register_mscandev);
628 void unregister_mscandev(struct net_device *dev)
630 struct mscan_priv *priv = netdev_priv(dev);
631 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
632 mscan_set_mode(dev, MSCAN_INIT_MODE);
633 out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_CANE);
634 unregister_candev(dev);
636 EXPORT_SYMBOL_GPL(unregister_mscandev);
638 struct net_device *alloc_mscandev(void)
640 struct net_device *dev;
641 struct mscan_priv *priv;
644 dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
647 priv = netdev_priv(dev);
649 dev->netdev_ops = &mscan_netdev_ops;
651 dev->flags |= IFF_ECHO; /* we support local echo */
653 netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
655 priv->can.bittiming_const = &mscan_bittiming_const;
656 priv->can.do_set_bittiming = mscan_do_set_bittiming;
657 priv->can.do_set_mode = mscan_do_set_mode;
659 for (i = 0; i < TX_QUEUE_SIZE; i++) {
660 priv->tx_queue[i].id = i;
661 priv->tx_queue[i].mask = 1 << i;
666 EXPORT_SYMBOL_GPL(alloc_mscandev);
668 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
669 MODULE_LICENSE("GPL v2");
670 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");