7 * CAN bus driver for the alone generic (as possible as) MSCAN controller.
10 * Andrey Volkov <avolkov@varma-el.com>
13 * 2005-2006, Varma Electronics Oy
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
32 #include <linux/config.h>
33 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/interrupt.h>
36 #include <linux/delay.h>
37 #include <linux/netdevice.h>
38 #include <linux/can/can.h>
39 #include <linux/list.h>
42 #include <can/can_device.h>
43 #include <can/mscan/mscan.h>
45 #define MSCAN_NORMAL_MODE 0
46 #define MSCAN_SLEEP_MODE MSCAN_SLPRQ
47 #define MSCAN_INIT_MODE (MSCAN_INITRQ | MSCAN_SLPRQ)
48 #define MSCAN_POWEROFF_MODE (MSCAN_CSWAI | MSCAN_SLPRQ)
50 #define BTR0_BRP_MASK 0x3f
51 #define BTR0_SJW_SHIFT 6
52 #define BTR0_SJW_MASK (0x3 << BTR0_SJW_SHIFT)
54 #define BTR1_TSEG1_MASK 0xf
55 #define BTR1_TSEG2_SHIFT 4
56 #define BTR1_TSEG2_MASK (0x7 << BTR1_TSEG2_SHIFT)
57 #define BTR1_SAM_SHIFT 7
59 #define BTR0_SET_BRP(brp) (((brp)-1)&BTR0_BRP_MASK)
60 #define BTR0_SET_SJW(sjw) ((((sjw)-1)<<BTR0_SJW_SHIFT)&BTR0_SJW_MASK)
62 #define BTR1_SET_TSEG1(tseg1) (((tseg1)-1)&BTR1_TSEG1_MASK)
63 #define BTR1_SET_TSEG2(tseg2) ((((tseg2)-1)<<BTR1_TSEG2_SHIFT)&BTR1_TSEG2_MASK)
64 #define BTR1_SET_SAM(sam) (((sam)&1)<<BTR1_SAM_SHIFT)
72 #define TX_QUEUE_SIZE 3
75 struct list_head list;
80 volatile unsigned long flags;
86 struct list_head tx_head;
87 tx_queue_entry_t tx_queue[TX_QUEUE_SIZE];
90 #define F_RX_PROGRESS 0
91 #define F_TX_PROGRESS 1
92 #define F_TX_WAIT_ALL 2
94 static int mscan_set_mode(struct can_device *can, u8 mode)
96 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
101 if( mode != MSCAN_NORMAL_MODE ) {
102 canctl1 = in_8(®s->canctl1);
103 if ((mode & MSCAN_SLPRQ) && (canctl1 & MSCAN_SLPAK) == 0) {
104 out_8( ®s->canctl0, in_8(®s->canctl0) | MSCAN_SLPRQ );
105 for (i = 0; i < 255; i++ ) {
106 if ( in_8(®s->canctl1) & MSCAN_SLPAK )
114 if ( !ret && (mode & MSCAN_INITRQ) && (canctl1 & MSCAN_INITAK) == 0) {
115 out_8( ®s->canctl0, in_8( ®s->canctl0 ) | MSCAN_INITRQ);
116 for (i = 0; i < 255; i++ ) {
117 if ( in_8(®s->canctl1) & MSCAN_INITAK )
124 if ( !ret && (mode & MSCAN_CSWAI) )
125 out_8( ®s->canctl0, in_8(®s->canctl0) | MSCAN_CSWAI);
128 canctl1 = in_8(®s->canctl1);
129 if ( canctl1 & (MSCAN_SLPAK | MSCAN_INITAK) ) {
130 out_8(®s->canctl0, in_8(®s->canctl0) &
131 ~(MSCAN_SLPRQ | MSCAN_INITRQ));
132 for (i = 0; i < 255; i++ ) {
133 canctl1 = in_8(®s->canctl1);
134 if ( (canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)) ==0 )
144 static void mscan_push_state(struct can_device *can, struct mscan_state *state)
146 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
148 state->mode = in_8(®s->canctl0) &
149 (MSCAN_SLPRQ | MSCAN_INITRQ | MSCAN_CSWAI);
150 state->canrier = in_8(®s->canrier);
151 state->cantier = in_8(®s->cantier);
154 static int mscan_pop_state(struct can_device *can, struct mscan_state *state)
156 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
158 ret = mscan_set_mode(can, state->mode);
160 out_8( ®s->canrier, state->canrier);
161 out_8( ®s->cantier, state->cantier);
166 static int mscan_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
168 struct can_frame *frame = (struct can_frame *)skb->data;
169 struct can_device *can = ND2CAN(ndev);
170 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
171 struct mscan_priv *priv = can->priv;
175 if ( frame->can_dlc > 8 )
178 dev_dbg( ND2D(ndev), "%s\n", __FUNCTION__);
179 out_8(®s->cantier, 0);
181 i = ~priv->tx_active & MSCAN_TXE;
183 switch ( hweight8(i) ) {
185 netif_stop_queue(ndev);
186 dev_err( ND2D(ndev), "BUG! Tx Ring full when queue awake!\n" );
187 return NETDEV_TX_BUSY;
189 /* if buf_id < 3, then current frame will be send out of order,
190 since buffer with lower id have higher priority (hell..) */
193 if(priv->cur_pri==0xff)
194 set_bit(F_TX_WAIT_ALL, &priv->flags);
195 netif_stop_queue(ndev);
197 set_bit(F_TX_PROGRESS, &priv->flags);
199 out_8(®s->cantbsel, i);
201 rtr = frame->can_id & CAN_RTR_FLAG;
203 if (frame->can_id & CAN_EFF_FLAG) {
204 dev_dbg(ND2D(ndev), "sending extended frame\n");
206 can_id = (frame->can_id & CAN_EFF_MASK) << 1;
209 out_be16(®s->tx.idr3_2, can_id);
212 can_id = (can_id & 0x7) | ((can_id<<2) & 0xffe0) | (3<<3);
214 dev_dbg(ND2D(ndev), "sending standard frame\n");
215 can_id = (frame->can_id & CAN_SFF_MASK) << 5;
219 out_be16(®s->tx.idr1_0, can_id);
222 volatile void __iomem *data = ®s->tx.dsr1_0;
223 u16 *payload = (u16 *)frame->data;
224 /*Its safe to write into dsr[dlc+1]*/
225 for (i=0; i<(frame->can_dlc+1)/2; i++) {
226 out_be16(data, *payload++);
227 data += 2+_MSCAN_RESERVED_DSR_SIZE;
231 out_8(®s->tx.dlr, frame->can_dlc);
232 out_8(®s->tx.tbpr, priv->cur_pri);
234 /* Start transmission. */
235 out_8(®s->cantflg, 1<<buf_id);
237 if ( ! test_bit(F_TX_PROGRESS, &priv->flags) )
238 ndev->trans_start = jiffies;
240 list_add_tail( &priv->tx_queue[buf_id].list, &priv->tx_head);
244 /* Enable interrupt. */
245 priv->tx_active |= 1<<buf_id;
246 out_8( ®s->cantier, priv->tx_active);
252 static void mscan_tx_timeout(struct net_device *ndev)
255 struct can_device *can = ND2CAN(ndev);
256 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
257 struct mscan_priv *priv = can->priv;
258 struct can_frame *frame;
261 printk ("%s\n", __FUNCTION__);
263 out_8(®s->cantier, 0);
265 mask = list_entry( priv->tx_head.next, tx_queue_entry_t, list)->mask;
266 ndev->trans_start = jiffies;
267 out_8(®s->cantarq, mask);
268 out_8(®s->cantier, priv->tx_active);
270 skb = dev_alloc_skb(sizeof(struct can_frame));
272 if(printk_ratelimit())
273 dev_notice(ND2D(ndev), "TIMEOUT packet dropped\n");
276 frame = (struct can_frame *)skb_put(skb,sizeof(struct can_frame));
278 frame->can_id = CAN_ERR_FLAG | CAN_ERR_TX_TIMEOUT;
279 frame->can_dlc = CAN_ERR_DLC;
282 skb->protocol = __constant_htons(ETH_P_CAN);
283 skb->ip_summed = CHECKSUM_UNNECESSARY;
288 static can_state_t state_map[] = {
290 CAN_STATE_BUS_WARNING,
291 CAN_STATE_BUS_PASSIVE,
295 static inline int check_set_state(struct can_device *can, u8 canrflg)
300 if ( !(canrflg & MSCAN_CSCIF) || can->state > CAN_STATE_BUS_OFF)
303 state = state_map[max( MSCAN_STATE_RX(canrflg), MSCAN_STATE_TX(canrflg))];
304 if(can->state < state)
306 if(state == CAN_STATE_BUS_OFF)
307 netif_carrier_off(CAN2ND(can));
308 else if(can->state == CAN_STATE_BUS_OFF && state != CAN_STATE_BUS_OFF)
309 netif_carrier_on(CAN2ND(can));
314 static int mscan_rx_poll(struct net_device *ndev, int *budget)
316 struct can_device *can = ND2CAN(ndev);
317 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
318 struct mscan_priv *priv = can->priv;
319 int npackets = 0, quota = min(ndev->quota, *budget);
322 struct can_frame *frame;
327 while ( npackets < quota &&
328 ( (canrflg = in_8(®s->canrflg)) & (MSCAN_RXF | MSCAN_ERR_IF) )) {
330 skb = dev_alloc_skb(sizeof(struct can_frame));
332 if(printk_ratelimit())
333 dev_notice(ND2D(ndev), "packet dropped\n");
334 can->net_stats.rx_dropped++;
335 out_8(®s->canrflg, canrflg);
339 frame = (struct can_frame *)skb_put(skb,sizeof(struct can_frame));
341 if (canrflg & MSCAN_RXF) {
342 can_id = in_be16( ®s->rx.idr1_0 );
343 if (can_id & (1<<3) ) {
344 frame->can_id = CAN_EFF_FLAG;
345 can_id = (can_id << 16) | in_be16(®s->rx.idr3_2);
346 can_id = ((can_id & 0xffe00000) | ((can_id & 0x7ffff) << 2 ))>>2;
353 frame->can_id |= can_id>>1;
355 frame->can_id |= CAN_RTR_FLAG;
356 frame->can_dlc = in_8(®s->rx.dlr) & 0xf;
358 if( !(frame->can_id & CAN_RTR_FLAG ) ) {
359 volatile void __iomem * data = ®s->rx.dsr1_0;
360 u16 *payload = (u16 *)frame->data;
361 for (i=0; i<(frame->can_dlc+1)/2; i++) {
362 *payload++ = in_be16(data);
363 data += 2+_MSCAN_RESERVED_DSR_SIZE;
367 dev_dbg(ND2D(ndev), "received pkt: id: %u dlc: %u data: ",
368 frame->can_id,frame->can_dlc);
370 for(i=0; i<frame->can_dlc && !(frame->can_id & CAN_FLAG_RTR ); i++)
371 printk( "%2x ",frame->payload.data[i]);
375 out_8(®s->canrflg, MSCAN_RXF);
376 ndev->last_rx = jiffies;
377 can->net_stats.rx_packets++;
378 can->net_stats.rx_bytes += frame->can_dlc;
380 else if (canrflg & MSCAN_ERR_IF ) {
381 frame->can_id = CAN_ERR_FLAG;
383 if (canrflg & MSCAN_OVRIF) {
384 frame->can_id |= CAN_ERR_CRTL;
385 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
386 can->net_stats.rx_over_errors++;
391 if ( check_set_state(can, canrflg)) {
392 frame->can_id |= CAN_ERR_CRTL;
393 switch( can->state ) {
394 case CAN_STATE_BUS_WARNING:
395 if( (priv->shadow_statflg & MSCAN_RSTAT_MSK) <
396 (canrflg & MSCAN_RSTAT_MSK))
397 frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
399 if( (priv->shadow_statflg & MSCAN_TSTAT_MSK) <
400 (canrflg & MSCAN_TSTAT_MSK))
401 frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
403 case CAN_STATE_BUS_PASSIVE:
404 frame->data[1] |= CAN_ERR_CRTL_PASSIVE;
406 case CAN_STATE_BUS_OFF:
407 frame->can_id |= CAN_ERR_BUSOFF;
408 frame->can_id &= ~CAN_ERR_CRTL;
412 priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
413 frame->can_dlc = CAN_ERR_DLC;
414 out_8(®s->canrflg, MSCAN_ERR_IF);
419 skb->protocol = __constant_htons(ETH_P_CAN);
420 skb->ip_summed = CHECKSUM_UNNECESSARY;
421 netif_receive_skb(skb);
425 ndev->quota -= npackets;
427 if ( !(in_8(®s->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
428 netif_rx_complete(ndev);
429 clear_bit(F_RX_PROGRESS, &priv->flags);
430 out_8(®s->canrier, in_8(®s->canrier) | MSCAN_ERR_IF | MSCAN_RXFIE);
437 mscan_isr(int irq, void *dev_id, struct pt_regs *r)
439 struct net_device *ndev = (struct net_device *) dev_id;
440 struct can_device *can = ND2CAN(ndev);
441 struct mscan_regs *regs = (struct mscan_regs *)(ndev->base_addr);
442 struct mscan_priv *priv = can->priv;
444 irqreturn_t ret = IRQ_NONE;
446 if ( in_8(®s->cantier) & MSCAN_TXE )
448 struct list_head *tmp, *pos;
450 cantflg = in_8(®s->cantflg) & MSCAN_TXE;
452 list_for_each_safe(pos, tmp, &priv->tx_head) {
453 tx_queue_entry_t *entry = list_entry(pos, tx_queue_entry_t, list);
454 u8 mask = entry->mask;
456 if( !(cantflg & mask) )
459 if ( in_8(®s->cantaak) & mask ) {
460 can->net_stats.tx_dropped++;
461 can->net_stats.tx_aborted_errors++;
464 out_8(®s->cantbsel, mask);
465 can->net_stats.tx_bytes += in_8(®s->tx.dlr);
466 can->net_stats.tx_packets++;
468 priv->tx_active &= ~mask;
472 if ( list_empty(&priv->tx_head) ) {
473 clear_bit(F_TX_WAIT_ALL, &priv->flags);
474 clear_bit(F_TX_PROGRESS, &priv->flags);
478 ndev->trans_start = jiffies;
480 if( !test_bit(F_TX_WAIT_ALL, &priv->flags) )
481 netif_wake_queue(ndev);
483 out_8( ®s->cantier, priv->tx_active );
487 if ( !test_and_set_bit(F_RX_PROGRESS, &priv->flags) &&
488 (((canrflg = in_8(®s->canrflg)) & ~MSCAN_STAT_MSK))) {
489 if ( check_set_state(can, canrflg) ) {
490 out_8(®s->canrflg, MSCAN_CSCIF);
493 if (canrflg & ~MSCAN_STAT_MSK) {
494 priv->shadow_canrier = in_8(®s->canrier);
495 out_8(®s->canrier, 0);
496 netif_rx_schedule(ndev);
500 clear_bit(F_RX_PROGRESS, &priv->flags);
505 static int mscan_do_set_mode(struct can_device *can, can_mode_t mode)
510 netif_stop_queue(CAN2ND(can));
512 (mode==CAN_MODE_STOP)? MSCAN_INIT_MODE: MSCAN_SLEEP_MODE);
515 printk("%s: CAN_MODE_START requested\n",__FUNCTION__);
516 mscan_set_mode(can, MSCAN_NORMAL_MODE);
517 netif_wake_queue(CAN2ND(can));
527 int mscan_do_set_bit_time(struct can_device *can, struct can_bittime *bt)
531 struct mscan_state state;
532 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
534 if(bt->type != CAN_BITTIME_STD)
537 spin_lock_irq(&can->irq_lock);
539 mscan_push_state(can, &state);
540 ret = mscan_set_mode(can, MSCAN_INIT_MODE);
542 reg = BTR0_SET_BRP(bt->std.brp) | BTR0_SET_SJW(bt->std.sjw);
543 out_8(®s->canbtr0, reg);
545 reg = BTR1_SET_TSEG1(bt->std.prop_seg + bt->std.phase_seg1) |
546 BTR1_SET_TSEG2(bt->std.phase_seg2) | BTR1_SET_SAM(bt->std.sam);
547 out_8(®s->canbtr1, reg);
549 ret = mscan_pop_state(can, &state);
552 spin_unlock_irq(&can->irq_lock);
556 static int mscan_open(struct net_device *ndev)
559 struct can_device *can = ND2CAN(ndev);
560 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
561 struct mscan_priv *priv = can->priv;
563 if((ret = request_irq(ndev->irq, mscan_isr, SA_SHIRQ, ndev->name, ndev)) < 0) {
564 printk(KERN_ERR "%s - failed to attach interrupt\n", ndev->name);
568 INIT_LIST_HEAD(&priv->tx_head);
569 /* acceptance mask/acceptance code (accept everything) */
570 out_be16(®s->canidar1_0, 0);
571 out_be16(®s->canidar3_2, 0);
572 out_be16(®s->canidar5_4, 0);
573 out_be16(®s->canidar7_6, 0);
575 out_be16(®s->canidmr1_0, 0xffff);
576 out_be16(®s->canidmr3_2, 0xffff);
577 out_be16(®s->canidmr5_4, 0xffff);
578 out_be16(®s->canidmr7_6, 0xffff);
579 /* Two 32 bit Acceptance Filters */
580 out_8(®s->canidac, MSCAN_AF_32BIT);
582 out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_LISTEN);
583 mscan_set_mode( can, MSCAN_NORMAL_MODE);
585 priv->shadow_statflg = in_8(®s->canrflg) & MSCAN_STAT_MSK;
589 out_8(®s->cantier, 0);
590 /* Enable receive interrupts. */
591 out_8(®s->canrier, MSCAN_OVRIE | MSCAN_RXFIE | MSCAN_CSCIE |
592 MSCAN_RSTATE1 | MSCAN_RSTATE0 |
593 MSCAN_TSTATE1 | MSCAN_TSTATE0);
595 netif_start_queue(ndev);
600 static int mscan_close(struct net_device *ndev)
602 struct can_device *can = ND2CAN(ndev);
603 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
605 netif_stop_queue(ndev);
607 /* disable interrupts */
608 out_8(®s->cantier, 0);
609 out_8(®s->canrier, 0);
610 free_irq(ndev->irq, ndev);
612 mscan_set_mode( can, MSCAN_INIT_MODE);
616 int mscan_register(struct can_device *can, int clock_src)
618 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
621 ctl1 = in_8(®s->canctl1);
623 ctl1 |= MSCAN_CLKSRC;
625 ctl1 &= ~MSCAN_CLKSRC;
628 out_8(®s->canctl1, ctl1);
631 mscan_set_mode( can, MSCAN_INIT_MODE );
633 return register_netdev(CAN2ND(can));
635 EXPORT_SYMBOL(mscan_register);
637 void mscan_unregister(struct can_device *can)
639 struct mscan_regs *regs = (struct mscan_regs *)(CAN2ND(can)->base_addr);
640 mscan_set_mode( can, MSCAN_INIT_MODE );
641 out_8(®s->canctl1, in_8(®s->canctl1) & ~MSCAN_CANE);
642 unregister_netdev(CAN2ND(can));
645 EXPORT_SYMBOL(mscan_unregister);
647 struct can_device *alloc_mscandev()
649 struct can_device *can;
650 struct net_device *ndev;
651 struct mscan_priv *priv;
654 can = alloc_candev(sizeof(struct mscan_priv));
660 ndev->watchdog_timeo = MSCAN_WATCHDOG_TIMEOUT;
661 ndev->open = mscan_open;
662 ndev->stop = mscan_close;
663 ndev->hard_start_xmit = mscan_hard_start_xmit;
664 ndev->tx_timeout = mscan_tx_timeout;
666 ndev->poll = mscan_rx_poll;
669 can->do_set_bit_time = mscan_do_set_bit_time;
670 can->do_set_mode = mscan_do_set_mode;
672 for(i=0; i< TX_QUEUE_SIZE; i++)
673 priv->tx_queue[i].mask = 1<<i;
678 EXPORT_SYMBOL(alloc_mscandev);
680 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
681 MODULE_LICENSE("GPL v2");
682 MODULE_DESCRIPTION("CAN port driver for a mscan based chips");