2 * PCBIT-D low-layer interface
4 * Copyright (C) 1996 Universidade de Lisboa
6 * Written by Pedro Roque Marques (roque@di.fc.ul.pt)
8 * This software may be used and distributed according to the terms of
9 * the GNU General Public License, incorporated herein by reference.
13 * 19991203 - Fernando Carvalho - takion@superbofh.org
14 * Hacked to compile with egcs and run with current version of isdn modules
18 * Based on documentation provided by Inesc:
19 * - "Interface com bus do PC para o PCBIT e PCBIT-D", Inesc, Jan 93
23 * TODO: better handling of errors
24 * re-write/remove debug printks
27 #include <linux/sched.h>
28 #include <linux/string.h>
29 #include <linux/kernel.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/interrupt.h>
33 #include <linux/workqueue.h>
35 #include <linux/skbuff.h>
37 #include <linux/isdnif.h>
39 #include <asm/system.h>
54 static void pcbit_transmit(struct pcbit_dev *dev);
56 static void pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack);
58 static void pcbit_l2_error(struct pcbit_dev *dev);
59 static void pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info);
60 static void pcbit_l2_err_recover(unsigned long data);
62 static void pcbit_firmware_bug(struct pcbit_dev *dev);
64 static __inline__ void
65 pcbit_sched_delivery(struct pcbit_dev *dev)
67 schedule_work(&dev->qdelivery);
76 pcbit_l2_write(struct pcbit_dev *dev, ulong msg, ushort refnum,
77 struct sk_buff *skb, unsigned short hdr_len)
79 struct frame_buf *frame,
83 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) {
87 if ((frame = kmalloc(sizeof(struct frame_buf),
88 GFP_ATOMIC)) == NULL) {
89 printk(KERN_WARNING "pcbit_2_write: kmalloc failed\n");
94 frame->refnum = refnum;
96 frame->hdr_len = hdr_len;
99 frame->dt_len = skb->len - hdr_len;
107 spin_lock_irqsave(&dev->lock, flags);
109 if (dev->write_queue == NULL) {
110 dev->write_queue = frame;
111 spin_unlock_irqrestore(&dev->lock, flags);
114 for (ptr = dev->write_queue; ptr->next; ptr = ptr->next);
117 spin_unlock_irqrestore(&dev->lock, flags);
122 static __inline__ void
123 pcbit_tx_update(struct pcbit_dev *dev, ushort len)
127 dev->send_seq = (dev->send_seq + 1) % 8;
129 dev->fsize[dev->send_seq] = len;
131 info |= dev->rcv_seq << 3;
132 info |= dev->send_seq;
134 writeb(info, dev->sh_mem + BANK4);
139 * called by interrupt service routine or by write_2
143 pcbit_transmit(struct pcbit_dev *dev)
145 struct frame_buf *frame = NULL;
146 unsigned char unacked;
147 int flen; /* fragment frame length including all headers */
154 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING)
157 unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07;
159 spin_lock_irqsave(&dev->lock, flags);
161 if (dev->free > 16 && dev->write_queue && unacked < 7) {
166 spin_unlock_irqrestore(&dev->lock, flags);
171 frame = dev->write_queue;
174 spin_unlock_irqrestore(&dev->lock, flags);
176 if (frame->copied == 0) {
183 flen = FRAME_HDR_LEN + PREHDR_LEN + frame->skb->len;
185 flen = FRAME_HDR_LEN + PREHDR_LEN;
193 * Board level 2 header
196 pcbit_writew(dev, flen - FRAME_HDR_LEN);
198 pcbit_writeb(dev, GET_MSG_CPU(msg));
200 pcbit_writeb(dev, GET_MSG_PROC(msg));
203 pcbit_writew(dev, frame->hdr_len + PREHDR_LEN);
206 pcbit_writew(dev, frame->dt_len);
210 * Board level 3 fixed-header
214 pcbit_writew(dev, frame->hdr_len + PREHDR_LEN);
217 pcbit_writew(dev, 0);
220 pcbit_writeb(dev, GET_MSG_CMD(msg));
221 pcbit_writeb(dev, GET_MSG_SCMD(msg));
224 pcbit_writew(dev, frame->refnum);
226 count = FRAME_HDR_LEN + PREHDR_LEN;
230 flen = 2 + (frame->skb->len - frame->copied);
236 tt = ((ushort) (flen - 2)) | 0x8000U; /* Type 1 */
237 pcbit_writew(dev, tt);
243 cp_len = frame->skb->len - frame->copied;
244 if (cp_len > flen - count)
245 cp_len = flen - count;
247 memcpy_topcbit(dev, frame->skb->data + frame->copied,
249 frame->copied += cp_len;
253 pcbit_tx_update(dev, flen);
255 spin_lock_irqsave(&dev->lock, flags);
257 if (frame->skb == NULL || frame->copied == frame->skb->len) {
259 dev->write_queue = frame->next;
261 if (frame->skb != NULL) {
263 dev_kfree_skb(frame->skb);
268 spin_unlock_irqrestore(&dev->lock, flags);
270 spin_unlock_irqrestore(&dev->lock, flags);
272 printk(KERN_DEBUG "unacked %d free %d write_queue %s\n",
273 unacked, dev->free, dev->write_queue ? "not empty" :
281 * deliver a queued frame to the upper layer
285 pcbit_deliver(struct work_struct *work)
287 struct frame_buf *frame;
288 unsigned long flags, msg;
289 struct pcbit_dev *dev =
290 container_of(work, struct pcbit_dev, qdelivery);
292 spin_lock_irqsave(&dev->lock, flags);
294 while ((frame = dev->read_queue)) {
295 dev->read_queue = frame->next;
296 spin_unlock_irqrestore(&dev->lock, flags);
300 SET_MSG_PROC(msg, 0);
301 SET_MSG_CMD(msg, frame->skb->data[2]);
302 SET_MSG_SCMD(msg, frame->skb->data[3]);
304 frame->refnum = *((ushort *) frame->skb->data + 4);
305 frame->msg = *((ulong *) & msg);
307 skb_pull(frame->skb, 6);
309 pcbit_l3_receive(dev, frame->msg, frame->skb, frame->hdr_len,
314 spin_lock_irqsave(&dev->lock, flags);
317 spin_unlock_irqrestore(&dev->lock, flags);
321 * Reads BANK 2 & Reassembles
325 pcbit_receive(struct pcbit_dev *dev)
330 struct frame_buf *frame = NULL;
334 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING)
337 tt = pcbit_readw(dev);
339 if ((tt & 0x7fffU) > 511) {
340 printk(KERN_INFO "pcbit: invalid frame length -> TT=%04x\n",
345 if (!(tt & 0x8000U)) { /* Type 0 */
348 if (dev->read_frame) {
349 printk(KERN_DEBUG "pcbit_receive: Type 0 frame and read_frame != NULL\n");
350 /* discard previous queued frame */
351 if (dev->read_frame->skb)
352 kfree_skb(dev->read_frame->skb);
353 kfree(dev->read_frame);
354 dev->read_frame = NULL;
356 frame = kzalloc(sizeof(struct frame_buf), GFP_ATOMIC);
359 printk(KERN_WARNING "kmalloc failed\n");
363 cpu = pcbit_readb(dev);
364 proc = pcbit_readb(dev);
367 if (cpu != 0x06 && cpu != 0x02) {
368 printk(KERN_DEBUG "pcbit: invalid cpu value\n");
374 * we discard cpu & proc on receiving
375 * but we read it to update the pointer
378 frame->hdr_len = pcbit_readw(dev);
379 frame->dt_len = pcbit_readw(dev);
383 * I don't know if they are an error or not...
384 * But they are very frequent
388 if (frame->hdr_len == 0) {
391 printk(KERN_DEBUG "0 sized frame\n");
393 pcbit_firmware_bug(dev);
396 /* sanity check the length values */
397 if (frame->hdr_len > 1024 || frame->dt_len > 2048) {
399 printk(KERN_DEBUG "length problem: ");
400 printk(KERN_DEBUG "TH=%04x TD=%04x\n",
408 /* minimum frame read */
410 frame->skb = dev_alloc_skb(frame->hdr_len + frame->dt_len +
411 ((frame->hdr_len + 15) & ~15));
414 printk(KERN_DEBUG "pcbit_receive: out of memory\n");
418 /* 16 byte alignment for IP */
420 skb_reserve(frame->skb, (frame->hdr_len + 15) & ~15);
427 if (!(frame = dev->read_frame)) {
428 printk("Type 1 frame and no frame queued\n");
429 /* usually after an error: toss frame */
431 if (dev->readptr > dev->sh_mem + BANK2 + BANKLEN)
432 dev->readptr -= BANKLEN;
438 memcpy_frompcbit(dev, skb_put(frame->skb, tt), tt);
441 spin_lock_irqsave(&dev->lock, flags);
442 if (frame->copied == frame->hdr_len + frame->dt_len) {
445 dev->read_frame = NULL;
447 if (dev->read_queue) {
448 struct frame_buf *ptr;
449 for (ptr = dev->read_queue; ptr->next; ptr = ptr->next);
452 dev->read_queue = frame;
455 dev->read_frame = frame;
457 spin_unlock_irqrestore(&dev->lock, flags);
461 * The board sends 0 sized frames
462 * They are TDATA_CONFs that get messed up somehow
463 * gotta send a fake acknowledgment to the upper layer somehow
466 static __inline__ void
467 pcbit_fake_conf(struct pcbit_dev *dev, struct pcbit_chan *chan)
474 ictl.driver = dev->id;
475 ictl.command = ISDN_STAT_BSENT;
477 dev->dev_if->statcallb(&ictl);
482 pcbit_firmware_bug(struct pcbit_dev *dev)
484 struct pcbit_chan *chan;
488 if (chan->fsm_state == ST_ACTIVE) {
489 pcbit_fake_conf(dev, chan);
493 if (chan->fsm_state == ST_ACTIVE) {
494 pcbit_fake_conf(dev, chan);
499 pcbit_irq_handler(int interrupt, void *devptr)
501 struct pcbit_dev *dev;
506 dev = (struct pcbit_dev *) devptr;
509 printk(KERN_WARNING "pcbit_irq_handler: wrong device\n");
512 if (dev->interrupt) {
513 printk(KERN_DEBUG "pcbit: reentering interrupt hander\n");
518 info = readb(dev->sh_mem + BANK3);
520 if (dev->l2_state == L2_STARTING || dev->l2_state == L2_ERROR) {
521 pcbit_l2_active_conf(dev, info);
525 if (info & 0x40U) { /* E bit set */
527 printk(KERN_DEBUG "pcbit_irq_handler: E bit on\n");
533 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) {
537 ack_seq = (info >> 3) & 0x07U;
538 read_seq = (info & 0x07U);
542 if (read_seq != dev->rcv_seq) {
543 while (read_seq != dev->rcv_seq) {
545 dev->rcv_seq = (dev->rcv_seq + 1) % 8;
547 pcbit_sched_delivery(dev);
549 if (ack_seq != dev->unack_seq) {
550 pcbit_recv_ack(dev, ack_seq);
552 info = dev->rcv_seq << 3;
553 info |= dev->send_seq;
555 writeb(info, dev->sh_mem + BANK4);
561 pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info)
565 state = dev->l2_state;
568 printk(KERN_DEBUG "layer2_active_confirm\n");
573 dev->rcv_seq = info & 0x07U;
574 dev->l2_state = L2_RUNNING;
576 dev->l2_state = L2_DOWN;
578 if (state == L2_STARTING)
579 wake_up_interruptible(&dev->set_running_wq);
581 if (state == L2_ERROR && dev->l2_state == L2_RUNNING) {
587 pcbit_l2_err_recover(unsigned long data)
590 struct pcbit_dev *dev;
591 struct frame_buf *frame;
593 dev = (struct pcbit_dev *) data;
595 del_timer(&dev->error_recover_timer);
596 if (dev->w_busy || dev->r_busy) {
597 init_timer(&dev->error_recover_timer);
598 dev->error_recover_timer.expires = jiffies + ERRTIME;
599 add_timer(&dev->error_recover_timer);
602 dev->w_busy = dev->r_busy = 1;
604 if (dev->read_frame) {
605 if (dev->read_frame->skb)
606 kfree_skb(dev->read_frame->skb);
607 kfree(dev->read_frame);
608 dev->read_frame = NULL;
610 if (dev->write_queue) {
611 frame = dev->write_queue;
613 dev->write_queue = dev->write_queue->next;
616 dev_kfree_skb(frame->skb);
623 dev->rcv_seq = dev->send_seq = dev->unack_seq = 0;
625 dev->l2_state = L2_ERROR;
627 /* this is an hack... */
628 pcbit_firmware_bug(dev);
630 dev->writeptr = dev->sh_mem;
631 dev->readptr = dev->sh_mem + BANK2;
633 writeb((0x80U | ((dev->rcv_seq & 0x07) << 3) | (dev->send_seq & 0x07)),
634 dev->sh_mem + BANK4);
635 dev->w_busy = dev->r_busy = 0;
640 pcbit_l2_error(struct pcbit_dev *dev)
642 if (dev->l2_state == L2_RUNNING) {
644 printk(KERN_INFO "pcbit: layer 2 error\n");
650 dev->l2_state = L2_DOWN;
652 init_timer(&dev->error_recover_timer);
653 dev->error_recover_timer.function = &pcbit_l2_err_recover;
654 dev->error_recover_timer.data = (ulong) dev;
655 dev->error_recover_timer.expires = jiffies + ERRTIME;
656 add_timer(&dev->error_recover_timer);
662 * if board acks frames
664 * call pcbit_transmit to write possible queued frames
668 pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack)
674 unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07;
676 /* dev->unack_seq < ack <= dev->send_seq; */
680 if (dev->send_seq > dev->unack_seq) {
681 if (ack <= dev->unack_seq || ack > dev->send_seq) {
683 "layer 2 ack unacceptable - dev %d",
687 } else if (ack > dev->send_seq && ack <= dev->unack_seq) {
689 "layer 2 ack unacceptable - dev %d",
694 /* ack is acceptable */
700 dev->unack_seq = i = (i + 1) % 8;
701 dev->free += dev->fsize[i];
705 while (count < 7 && dev->write_queue) {
706 u8 lsend_seq = dev->send_seq;
710 if (dev->send_seq == lsend_seq)
715 printk(KERN_DEBUG "recv_ack: unacked = 0\n");