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)) {
81 setbits8(®s->canctl0, MSCAN_SLPRQ);
82 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
83 if (in_8(®s->canctl1) & MSCAN_SLPAK)
88 * The mscan controller will fail to enter sleep mode,
89 * while there are irregular activities on bus, like
90 * somebody keeps retransmitting. This behavior is
91 * undocumented and seems to differ between mscan built
92 * in mpc5200b and mpc5200. We proceed in that case,
93 * since otherwise the slprq will be kept set and the
94 * controller will get stuck. NOTE: INITRQ or CSWAI
95 * will abort all active transmit actions, if still
98 if (i >= MSCAN_SET_MODE_RETRIES)
99 dev_dbg(dev->dev.parent,
100 "device failed to enter sleep mode. "
101 "We proceed anyhow.\n");
103 priv->can.state = CAN_STATE_SLEEPING;
106 if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
107 setbits8(®s->canctl0, MSCAN_INITRQ);
108 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
109 if (in_8(®s->canctl1) & MSCAN_INITAK)
112 if (i >= MSCAN_SET_MODE_RETRIES)
116 priv->can.state = CAN_STATE_STOPPED;
118 if (mode & MSCAN_CSWAI)
119 setbits8(®s->canctl0, MSCAN_CSWAI);
122 canctl1 = in_8(®s->canctl1);
123 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
124 clrbits8(®s->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
125 for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
126 canctl1 = in_8(®s->canctl1);
127 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
130 if (i >= MSCAN_SET_MODE_RETRIES)
133 priv->can.state = CAN_STATE_ERROR_ACTIVE;
139 static int mscan_start(struct net_device *dev)
141 struct mscan_priv *priv = netdev_priv(dev);
142 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
146 out_8(®s->canrier, 0);
148 INIT_LIST_HEAD(&priv->tx_head);
149 priv->prev_buf_id = 0;
152 priv->shadow_canrier = 0;
155 err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
159 canrflg = in_8(®s->canrflg);
160 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
161 priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
162 MSCAN_STATE_TX(canrflg))];
163 out_8(®s->cantier, 0);
165 /* Enable receive interrupts. */
166 out_8(®s->canrier, MSCAN_OVRIE | MSCAN_RXFIE | MSCAN_CSCIE |
167 MSCAN_RSTATE1 | MSCAN_RSTATE0 | MSCAN_TSTATE1 | MSCAN_TSTATE0);
172 static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
174 struct can_frame *frame = (struct can_frame *)skb->data;
175 struct mscan_priv *priv = netdev_priv(dev);
176 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
180 if (frame->can_dlc > 8)
183 out_8(®s->cantier, 0);
185 i = ~priv->tx_active & MSCAN_TXE;
187 switch (hweight8(i)) {
189 netif_stop_queue(dev);
190 dev_err(dev->dev.parent, "Tx Ring full when queue awake!\n");
191 return NETDEV_TX_BUSY;
194 * if buf_id < 3, then current frame will be send out of order,
195 * since buffer with lower id have higher priority (hell..)
197 netif_stop_queue(dev);
199 if (buf_id < priv->prev_buf_id) {
201 if (priv->cur_pri == 0xff) {
202 set_bit(F_TX_WAIT_ALL, &priv->flags);
203 netif_stop_queue(dev);
206 set_bit(F_TX_PROGRESS, &priv->flags);
209 priv->prev_buf_id = buf_id;
210 out_8(®s->cantbsel, i);
212 rtr = frame->can_id & CAN_RTR_FLAG;
214 if (frame->can_id & CAN_EFF_FLAG) {
215 can_id = (frame->can_id & CAN_EFF_MASK) << 1;
218 out_be16(®s->tx.idr3_2, can_id);
221 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0) | (3 << 3);
223 can_id = (frame->can_id & CAN_SFF_MASK) << 5;
227 out_be16(®s->tx.idr1_0, can_id);
230 void __iomem *data = ®s->tx.dsr1_0;
231 u16 *payload = (u16 *)frame->data;
233 /* It is safe to write into dsr[dlc+1] */
234 for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
235 out_be16(data, *payload++);
236 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
240 out_8(®s->tx.dlr, frame->can_dlc);
241 out_8(®s->tx.tbpr, priv->cur_pri);
243 /* Start transmission. */
244 out_8(®s->cantflg, 1 << buf_id);
246 if (!test_bit(F_TX_PROGRESS, &priv->flags))
247 dev->trans_start = jiffies;
249 list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
251 can_put_echo_skb(skb, dev, buf_id);
253 /* Enable interrupt. */
254 priv->tx_active |= 1 << buf_id;
255 out_8(®s->cantier, priv->tx_active);
260 /* This function returns the old state to see where we came from */
261 static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
263 struct mscan_priv *priv = netdev_priv(dev);
264 enum can_state state, old_state = priv->can.state;
266 if (canrflg & MSCAN_CSCIF && old_state <= CAN_STATE_BUS_OFF) {
267 state = state_map[max(MSCAN_STATE_RX(canrflg),
268 MSCAN_STATE_TX(canrflg))];
269 priv->can.state = state;
274 static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
276 struct mscan_priv *priv = netdev_priv(dev);
277 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
281 can_id = in_be16(®s->rx.idr1_0);
282 if (can_id & (1 << 3)) {
283 frame->can_id = CAN_EFF_FLAG;
284 can_id = ((can_id << 16) | in_be16(®s->rx.idr3_2));
285 can_id = ((can_id & 0xffe00000) |
286 ((can_id & 0x7ffff) << 2)) >> 2;
292 frame->can_id |= can_id >> 1;
294 frame->can_id |= CAN_RTR_FLAG;
295 frame->can_dlc = in_8(®s->rx.dlr) & 0xf;
297 if (!(frame->can_id & CAN_RTR_FLAG)) {
298 void __iomem *data = ®s->rx.dsr1_0;
299 u16 *payload = (u16 *)frame->data;
301 for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
302 *payload++ = in_be16(data);
303 data += 2 + _MSCAN_RESERVED_DSR_SIZE;
307 out_8(®s->canrflg, MSCAN_RXF);
310 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
313 struct mscan_priv *priv = netdev_priv(dev);
314 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
315 struct net_device_stats *stats = &dev->stats;
316 enum can_state old_state;
318 dev_dbg(dev->dev.parent, "error interrupt (canrflg=%#x)\n", canrflg);
319 frame->can_id = CAN_ERR_FLAG;
321 if (canrflg & MSCAN_OVRIF) {
322 frame->can_id |= CAN_ERR_CRTL;
323 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
324 stats->rx_over_errors++;
330 old_state = check_set_state(dev, canrflg);
332 if (old_state != priv->can.state) {
333 switch (priv->can.state) {
334 case CAN_STATE_ERROR_WARNING:
335 frame->can_id |= CAN_ERR_CRTL;
336 priv->can.can_stats.error_warning++;
337 if ((priv->shadow_statflg & MSCAN_RSTAT_MSK) <
338 (canrflg & MSCAN_RSTAT_MSK))
339 frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
340 if ((priv->shadow_statflg & MSCAN_TSTAT_MSK) <
341 (canrflg & MSCAN_TSTAT_MSK))
342 frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
344 case CAN_STATE_ERROR_PASSIVE:
345 frame->can_id |= CAN_ERR_CRTL;
346 priv->can.can_stats.error_passive++;
347 frame->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
349 case CAN_STATE_BUS_OFF:
350 frame->can_id |= CAN_ERR_BUSOFF;
352 * The MSCAN on the MPC5200 does recover from bus-off
353 * automatically. To avoid that we stop the chip doing
354 * a light-weight stop (we are in irq-context).
356 out_8(®s->cantier, 0);
357 out_8(®s->canrier, 0);
358 setbits8(®s->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
365 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
366 frame->can_dlc = CAN_ERR_DLC;
367 out_8(®s->canrflg, MSCAN_ERR_IF);
370 static int mscan_rx_poll(struct napi_struct *napi, int quota)
372 struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
373 struct net_device *dev = napi->dev;
374 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
375 struct net_device_stats *stats = &dev->stats;
379 struct can_frame *frame;
382 while (npackets < quota && ((canrflg = in_8(®s->canrflg)) &
383 (MSCAN_RXF | MSCAN_ERR_IF))) {
385 skb = alloc_can_skb(dev, &frame);
387 if (printk_ratelimit())
388 dev_notice(dev->dev.parent, "packet dropped\n");
390 out_8(®s->canrflg, canrflg);
394 if (canrflg & MSCAN_RXF)
395 mscan_get_rx_frame(dev, frame);
396 else if (canrflg & MSCAN_ERR_IF)
397 mscan_get_err_frame(dev, frame, canrflg);
400 stats->rx_bytes += frame->can_dlc;
402 netif_receive_skb(skb);
405 if (!(in_8(®s->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
406 napi_complete(&priv->napi);
407 clear_bit(F_RX_PROGRESS, &priv->flags);
408 if (priv->can.state < CAN_STATE_BUS_OFF)
409 out_8(®s->canrier, priv->shadow_canrier);
415 static irqreturn_t mscan_isr(int irq, void *dev_id)
417 struct net_device *dev = (struct net_device *)dev_id;
418 struct mscan_priv *priv = netdev_priv(dev);
419 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
420 struct net_device_stats *stats = &dev->stats;
421 u8 cantier, cantflg, canrflg;
422 irqreturn_t ret = IRQ_NONE;
424 cantier = in_8(®s->cantier) & MSCAN_TXE;
425 cantflg = in_8(®s->cantflg) & cantier;
427 if (cantier && cantflg) {
428 struct list_head *tmp, *pos;
430 list_for_each_safe(pos, tmp, &priv->tx_head) {
431 struct tx_queue_entry *entry =
432 list_entry(pos, struct tx_queue_entry, list);
433 u8 mask = entry->mask;
435 if (!(cantflg & mask))
438 out_8(®s->cantbsel, mask);
439 stats->tx_bytes += in_8(®s->tx.dlr);
441 can_get_echo_skb(dev, entry->id);
442 priv->tx_active &= ~mask;
446 if (list_empty(&priv->tx_head)) {
447 clear_bit(F_TX_WAIT_ALL, &priv->flags);
448 clear_bit(F_TX_PROGRESS, &priv->flags);
451 dev->trans_start = jiffies;
454 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
455 netif_wake_queue(dev);
457 out_8(®s->cantier, priv->tx_active);
461 canrflg = in_8(®s->canrflg);
462 if ((canrflg & ~MSCAN_STAT_MSK) &&
463 !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
464 if (canrflg & ~MSCAN_STAT_MSK) {
465 priv->shadow_canrier = in_8(®s->canrier);
466 out_8(®s->canrier, 0);
467 napi_schedule(&priv->napi);
470 clear_bit(F_RX_PROGRESS, &priv->flags);
476 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
478 struct mscan_priv *priv = netdev_priv(dev);
481 if (!priv->open_time)
486 if (priv->can.state <= CAN_STATE_BUS_OFF)
487 mscan_set_mode(dev, MSCAN_INIT_MODE);
488 ret = mscan_start(dev);
491 if (netif_queue_stopped(dev))
492 netif_wake_queue(dev);
502 static int mscan_do_set_bittiming(struct net_device *dev)
504 struct mscan_priv *priv = netdev_priv(dev);
505 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
506 struct can_bittiming *bt = &priv->can.bittiming;
509 btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
510 btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
511 BTR1_SET_TSEG2(bt->phase_seg2) |
512 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
514 dev_info(dev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
517 out_8(®s->canbtr0, btr0);
518 out_8(®s->canbtr1, btr1);
523 static int mscan_open(struct net_device *dev)
526 struct mscan_priv *priv = netdev_priv(dev);
527 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
530 ret = open_candev(dev);
534 napi_enable(&priv->napi);
536 ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
538 napi_disable(&priv->napi);
539 printk(KERN_ERR "%s - failed to attach interrupt\n",
544 priv->open_time = jiffies;
546 clrbits8(®s->canctl1, MSCAN_LISTEN);
548 ret = mscan_start(dev);
552 netif_start_queue(dev);
557 static int mscan_close(struct net_device *dev)
559 struct mscan_priv *priv = netdev_priv(dev);
560 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
562 netif_stop_queue(dev);
563 napi_disable(&priv->napi);
565 out_8(®s->cantier, 0);
566 out_8(®s->canrier, 0);
567 mscan_set_mode(dev, MSCAN_INIT_MODE);
569 free_irq(dev->irq, dev);
575 static const struct net_device_ops mscan_netdev_ops = {
576 .ndo_open = mscan_open,
577 .ndo_stop = mscan_close,
578 .ndo_start_xmit = mscan_start_xmit,
581 int register_mscandev(struct net_device *dev, int clock_src)
583 struct mscan_priv *priv = netdev_priv(dev);
584 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
587 ctl1 = in_8(®s->canctl1);
589 ctl1 |= MSCAN_CLKSRC;
591 ctl1 &= ~MSCAN_CLKSRC;
594 out_8(®s->canctl1, ctl1);
597 /* acceptance mask/acceptance code (accept everything) */
598 out_be16(®s->canidar1_0, 0);
599 out_be16(®s->canidar3_2, 0);
600 out_be16(®s->canidar5_4, 0);
601 out_be16(®s->canidar7_6, 0);
603 out_be16(®s->canidmr1_0, 0xffff);
604 out_be16(®s->canidmr3_2, 0xffff);
605 out_be16(®s->canidmr5_4, 0xffff);
606 out_be16(®s->canidmr7_6, 0xffff);
607 /* Two 32 bit Acceptance Filters */
608 out_8(®s->canidac, MSCAN_AF_32BIT);
610 mscan_set_mode(dev, MSCAN_INIT_MODE);
612 return register_candev(dev);
615 void unregister_mscandev(struct net_device *dev)
617 struct mscan_priv *priv = netdev_priv(dev);
618 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
619 mscan_set_mode(dev, MSCAN_INIT_MODE);
620 clrbits8(®s->canctl1, MSCAN_CANE);
621 unregister_candev(dev);
624 struct net_device *alloc_mscandev(void)
626 struct net_device *dev;
627 struct mscan_priv *priv;
630 dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
633 priv = netdev_priv(dev);
635 dev->netdev_ops = &mscan_netdev_ops;
637 dev->flags |= IFF_ECHO; /* we support local echo */
639 netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
641 priv->can.bittiming_const = &mscan_bittiming_const;
642 priv->can.do_set_bittiming = mscan_do_set_bittiming;
643 priv->can.do_set_mode = mscan_do_set_mode;
645 for (i = 0; i < TX_QUEUE_SIZE; i++) {
646 priv->tx_queue[i].id = i;
647 priv->tx_queue[i].mask = 1 << i;
653 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
654 MODULE_LICENSE("GPL v2");
655 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");