Automatic merge of /spare/repo/netdev-2.6 branch natsemi
[linux-2.6] / drivers / net / irda / sir_dev.c
1 /*********************************************************************
2  *
3  *      sir_dev.c:      irda sir network device
4  * 
5  *      Copyright (c) 2002 Martin Diehl
6  * 
7  *      This program is free software; you can redistribute it and/or 
8  *      modify it under the terms of the GNU General Public License as 
9  *      published by the Free Software Foundation; either version 2 of 
10  *      the License, or (at your option) any later version.
11  *
12  ********************************************************************/    
13
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/smp_lock.h>
18 #include <linux/delay.h>
19
20 #include <net/irda/irda.h>
21 #include <net/irda/wrapper.h>
22 #include <net/irda/irda_device.h>
23
24 #include "sir-dev.h"
25
26 /***************************************************************************/
27
28 void sirdev_enable_rx(struct sir_dev *dev)
29 {
30         if (unlikely(atomic_read(&dev->enable_rx)))
31                 return;
32
33         /* flush rx-buffer - should also help in case of problems with echo cancelation */
34         dev->rx_buff.data = dev->rx_buff.head;
35         dev->rx_buff.len = 0;
36         dev->rx_buff.in_frame = FALSE;
37         dev->rx_buff.state = OUTSIDE_FRAME;
38         atomic_set(&dev->enable_rx, 1);
39 }
40
41 static int sirdev_is_receiving(struct sir_dev *dev)
42 {
43         if (!atomic_read(&dev->enable_rx))
44                 return 0;
45
46         return (dev->rx_buff.state != OUTSIDE_FRAME);
47 }
48
49 int sirdev_set_dongle(struct sir_dev *dev, IRDA_DONGLE type)
50 {
51         int err;
52
53         IRDA_DEBUG(3, "%s : requesting dongle %d.\n", __FUNCTION__, type);
54
55         err = sirdev_schedule_dongle_open(dev, type);
56         if (unlikely(err))
57                 return err;
58         down(&dev->fsm.sem);            /* block until config change completed */
59         err = dev->fsm.result;
60         up(&dev->fsm.sem);
61         return err;
62 }
63
64 /* used by dongle drivers for dongle programming */
65
66 int sirdev_raw_write(struct sir_dev *dev, const char *buf, int len)
67 {
68         unsigned long flags;
69         int ret;
70
71         if (unlikely(len > dev->tx_buff.truesize))
72                 return -ENOSPC;
73
74         spin_lock_irqsave(&dev->tx_lock, flags);        /* serialize with other tx operations */
75         while (dev->tx_buff.len > 0) {                  /* wait until tx idle */
76                 spin_unlock_irqrestore(&dev->tx_lock, flags);
77                 msleep(10);
78                 spin_lock_irqsave(&dev->tx_lock, flags);
79         }
80
81         dev->tx_buff.data = dev->tx_buff.head;
82         memcpy(dev->tx_buff.data, buf, len);    
83         dev->tx_buff.len = len;
84
85         ret = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
86         if (ret > 0) {
87                 IRDA_DEBUG(3, "%s(), raw-tx started\n", __FUNCTION__);
88
89                 dev->tx_buff.data += ret;
90                 dev->tx_buff.len -= ret;
91                 dev->raw_tx = 1;
92                 ret = len;              /* all data is going to be sent */
93         }
94         spin_unlock_irqrestore(&dev->tx_lock, flags);
95         return ret;
96 }
97
98 /* seems some dongle drivers may need this */
99
100 int sirdev_raw_read(struct sir_dev *dev, char *buf, int len)
101 {
102         int count;
103
104         if (atomic_read(&dev->enable_rx))
105                 return -EIO;            /* fail if we expect irda-frames */
106
107         count = (len < dev->rx_buff.len) ? len : dev->rx_buff.len;
108
109         if (count > 0) {
110                 memcpy(buf, dev->rx_buff.data, count);
111                 dev->rx_buff.data += count;
112                 dev->rx_buff.len -= count;
113         }
114
115         /* remaining stuff gets flushed when re-enabling normal rx */
116
117         return count;
118 }
119
120 int sirdev_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
121 {
122         int ret = -ENXIO;
123         if (dev->drv->set_dtr_rts != 0)
124                 ret =  dev->drv->set_dtr_rts(dev, dtr, rts);
125         return ret;
126 }
127         
128 /**********************************************************************/
129
130 /* called from client driver - likely with bh-context - to indicate
131  * it made some progress with transmission. Hence we send the next
132  * chunk, if any, or complete the skb otherwise
133  */
134
135 void sirdev_write_complete(struct sir_dev *dev)
136 {
137         unsigned long flags;
138         struct sk_buff *skb;
139         int actual = 0;
140         int err;
141         
142         spin_lock_irqsave(&dev->tx_lock, flags);
143
144         IRDA_DEBUG(3, "%s() - dev->tx_buff.len = %d\n",
145                    __FUNCTION__, dev->tx_buff.len);
146
147         if (likely(dev->tx_buff.len > 0))  {
148                 /* Write data left in transmit buffer */
149                 actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
150
151                 if (likely(actual>0)) {
152                         dev->tx_buff.data += actual;
153                         dev->tx_buff.len  -= actual;
154                 }
155                 else if (unlikely(actual<0)) {
156                         /* could be dropped later when we have tx_timeout to recover */
157                         IRDA_ERROR("%s: drv->do_write failed (%d)\n",
158                                    __FUNCTION__, actual);
159                         if ((skb=dev->tx_skb) != NULL) {
160                                 dev->tx_skb = NULL;
161                                 dev_kfree_skb_any(skb);
162                                 dev->stats.tx_errors++;               
163                                 dev->stats.tx_dropped++;                      
164                         }
165                         dev->tx_buff.len = 0;
166                 }
167                 if (dev->tx_buff.len > 0)
168                         goto done;      /* more data to send later */
169         }
170
171         if (unlikely(dev->raw_tx != 0)) {
172                 /* in raw mode we are just done now after the buffer was sent
173                  * completely. Since this was requested by some dongle driver
174                  * running under the control of the irda-thread we must take
175                  * care here not to re-enable the queue. The queue will be
176                  * restarted when the irda-thread has completed the request.
177                  */
178
179                 IRDA_DEBUG(3, "%s(), raw-tx done\n", __FUNCTION__);
180                 dev->raw_tx = 0;
181                 goto done;      /* no post-frame handling in raw mode */
182         }
183
184         /* we have finished now sending this skb.
185          * update statistics and free the skb.
186          * finally we check and trigger a pending speed change, if any.
187          * if not we switch to rx mode and wake the queue for further
188          * packets.
189          * note the scheduled speed request blocks until the lower
190          * client driver and the corresponding hardware has really
191          * finished sending all data (xmit fifo drained f.e.)
192          * before the speed change gets finally done and the queue
193          * re-activated.
194          */
195
196         IRDA_DEBUG(5, "%s(), finished with frame!\n", __FUNCTION__);
197                 
198         if ((skb=dev->tx_skb) != NULL) {
199                 dev->tx_skb = NULL;
200                 dev->stats.tx_packets++;                      
201                 dev->stats.tx_bytes += skb->len;
202                 dev_kfree_skb_any(skb);
203         }
204
205         if (unlikely(dev->new_speed > 0)) {
206                 IRDA_DEBUG(5, "%s(), Changing speed!\n", __FUNCTION__);
207                 err = sirdev_schedule_speed(dev, dev->new_speed);
208                 if (unlikely(err)) {
209                         /* should never happen
210                          * forget the speed change and hope the stack recovers
211                          */
212                         IRDA_ERROR("%s - schedule speed change failed: %d\n",
213                                    __FUNCTION__, err);
214                         netif_wake_queue(dev->netdev);
215                 }
216                 /* else: success
217                  *      speed change in progress now
218                  *      on completion dev->new_speed gets cleared,
219                  *      rx-reenabled and the queue restarted
220                  */
221         }
222         else {
223                 sirdev_enable_rx(dev);
224                 netif_wake_queue(dev->netdev);
225         }
226
227 done:
228         spin_unlock_irqrestore(&dev->tx_lock, flags);
229 }
230
231 /* called from client driver - likely with bh-context - to give us
232  * some more received bytes. We put them into the rx-buffer,
233  * normally unwrapping and building LAP-skb's (unless rx disabled)
234  */
235
236 int sirdev_receive(struct sir_dev *dev, const unsigned char *cp, size_t count) 
237 {
238         if (!dev || !dev->netdev) {
239                 IRDA_WARNING("%s(), not ready yet!\n", __FUNCTION__);
240                 return -1;
241         }
242
243         if (!dev->irlap) {
244                 IRDA_WARNING("%s - too early: %p / %zd!\n",
245                              __FUNCTION__, cp, count);
246                 return -1;
247         }
248
249         if (cp==NULL) {
250                 /* error already at lower level receive
251                  * just update stats and set media busy
252                  */
253                 irda_device_set_media_busy(dev->netdev, TRUE);
254                 dev->stats.rx_dropped++;
255                 IRDA_DEBUG(0, "%s; rx-drop: %zd\n", __FUNCTION__, count);
256                 return 0;
257         }
258
259         /* Read the characters into the buffer */
260         if (likely(atomic_read(&dev->enable_rx))) {
261                 while (count--)
262                         /* Unwrap and destuff one byte */
263                         async_unwrap_char(dev->netdev, &dev->stats, 
264                                           &dev->rx_buff, *cp++);
265         } else {
266                 while (count--) {
267                         /* rx not enabled: save the raw bytes and never
268                          * trigger any netif_rx. The received bytes are flushed
269                          * later when we re-enable rx but might be read meanwhile
270                          * by the dongle driver.
271                          */
272                         dev->rx_buff.data[dev->rx_buff.len++] = *cp++;
273
274                         /* What should we do when the buffer is full? */
275                         if (unlikely(dev->rx_buff.len == dev->rx_buff.truesize))
276                                 dev->rx_buff.len = 0;
277                 }
278         }
279
280         return 0;
281 }
282
283 /**********************************************************************/
284
285 /* callbacks from network layer */
286
287 static struct net_device_stats *sirdev_get_stats(struct net_device *ndev)
288 {
289         struct sir_dev *dev = ndev->priv;
290
291         return (dev) ? &dev->stats : NULL;
292 }
293
294 static int sirdev_hard_xmit(struct sk_buff *skb, struct net_device *ndev)
295 {
296         struct sir_dev *dev = ndev->priv;
297         unsigned long flags;
298         int actual = 0;
299         int err;
300         s32 speed;
301
302         IRDA_ASSERT(dev != NULL, return 0;);
303
304         netif_stop_queue(ndev);
305
306         IRDA_DEBUG(3, "%s(), skb->len = %d\n", __FUNCTION__, skb->len);
307
308         speed = irda_get_next_speed(skb);
309         if ((speed != dev->speed) && (speed != -1)) {
310                 if (!skb->len) {
311                         err = sirdev_schedule_speed(dev, speed);
312                         if (unlikely(err == -EWOULDBLOCK)) {
313                                 /* Failed to initiate the speed change, likely the fsm
314                                  * is still busy (pretty unlikely, but...)
315                                  * We refuse to accept the skb and return with the queue
316                                  * stopped so the network layer will retry after the
317                                  * fsm completes and wakes the queue.
318                                  */
319                                  return 1;
320                         }
321                         else if (unlikely(err)) {
322                                 /* other fatal error - forget the speed change and
323                                  * hope the stack will recover somehow
324                                  */
325                                  netif_start_queue(ndev);
326                         }
327                         /* else: success
328                          *      speed change in progress now
329                          *      on completion the queue gets restarted
330                          */
331
332                         dev_kfree_skb_any(skb);
333                         return 0;
334                 } else
335                         dev->new_speed = speed;
336         }
337
338         /* Init tx buffer*/
339         dev->tx_buff.data = dev->tx_buff.head;
340
341         /* Check problems */
342         if(spin_is_locked(&dev->tx_lock)) {
343                 IRDA_DEBUG(3, "%s(), write not completed\n", __FUNCTION__);
344         }
345
346         /* serialize with write completion */
347         spin_lock_irqsave(&dev->tx_lock, flags);
348
349         /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
350         dev->tx_buff.len = async_wrap_skb(skb, dev->tx_buff.data, dev->tx_buff.truesize); 
351
352         /* transmission will start now - disable receive.
353          * if we are just in the middle of an incoming frame,
354          * treat it as collision. probably it's a good idea to
355          * reset the rx_buf OUTSIDE_FRAME in this case too?
356          */
357         atomic_set(&dev->enable_rx, 0);
358         if (unlikely(sirdev_is_receiving(dev)))
359                 dev->stats.collisions++;
360
361         actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
362
363         if (likely(actual > 0)) {
364                 dev->tx_skb = skb;
365                 ndev->trans_start = jiffies;
366                 dev->tx_buff.data += actual;
367                 dev->tx_buff.len -= actual;
368         }
369         else if (unlikely(actual < 0)) {
370                 /* could be dropped later when we have tx_timeout to recover */
371                 IRDA_ERROR("%s: drv->do_write failed (%d)\n",
372                            __FUNCTION__, actual);
373                 dev_kfree_skb_any(skb);
374                 dev->stats.tx_errors++;               
375                 dev->stats.tx_dropped++;                      
376                 netif_wake_queue(ndev);
377         }
378         spin_unlock_irqrestore(&dev->tx_lock, flags);
379
380         return 0;
381 }
382
383 /* called from network layer with rtnl hold */
384
385 static int sirdev_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
386 {
387         struct if_irda_req *irq = (struct if_irda_req *) rq;
388         struct sir_dev *dev = ndev->priv;
389         int ret = 0;
390
391         IRDA_ASSERT(dev != NULL, return -1;);
392
393         IRDA_DEBUG(3, "%s(), %s, (cmd=0x%X)\n", __FUNCTION__, ndev->name, cmd);
394         
395         switch (cmd) {
396         case SIOCSBANDWIDTH: /* Set bandwidth */
397                 if (!capable(CAP_NET_ADMIN))
398                         ret = -EPERM;
399                 else
400                         ret = sirdev_schedule_speed(dev, irq->ifr_baudrate);
401                 /* cannot sleep here for completion
402                  * we are called from network layer with rtnl hold
403                  */
404                 break;
405
406         case SIOCSDONGLE: /* Set dongle */
407                 if (!capable(CAP_NET_ADMIN))
408                         ret = -EPERM;
409                 else
410                         ret = sirdev_schedule_dongle_open(dev, irq->ifr_dongle);
411                 /* cannot sleep here for completion
412                  * we are called from network layer with rtnl hold
413                  */
414                 break;
415
416         case SIOCSMEDIABUSY: /* Set media busy */
417                 if (!capable(CAP_NET_ADMIN))
418                         ret = -EPERM;
419                 else
420                         irda_device_set_media_busy(dev->netdev, TRUE);
421                 break;
422
423         case SIOCGRECEIVING: /* Check if we are receiving right now */
424                 irq->ifr_receiving = sirdev_is_receiving(dev);
425                 break;
426
427         case SIOCSDTRRTS:
428                 if (!capable(CAP_NET_ADMIN))
429                         ret = -EPERM;
430                 else
431                         ret = sirdev_schedule_dtr_rts(dev, irq->ifr_dtr, irq->ifr_rts);
432                 /* cannot sleep here for completion
433                  * we are called from network layer with rtnl hold
434                  */
435                 break;
436
437         case SIOCSMODE:
438 #if 0
439                 if (!capable(CAP_NET_ADMIN))
440                         ret = -EPERM;
441                 else
442                         ret = sirdev_schedule_mode(dev, irq->ifr_mode);
443                 /* cannot sleep here for completion
444                  * we are called from network layer with rtnl hold
445                  */
446                 break;
447 #endif
448         default:
449                 ret = -EOPNOTSUPP;
450         }
451         
452         return ret;
453 }
454
455 /* ----------------------------------------------------------------------------- */
456
457 #define SIRBUF_ALLOCSIZE 4269   /* worst case size of a wrapped IrLAP frame */
458
459 static int sirdev_alloc_buffers(struct sir_dev *dev)
460 {
461         dev->tx_buff.truesize = SIRBUF_ALLOCSIZE;
462         dev->rx_buff.truesize = IRDA_SKB_MAX_MTU; 
463
464         /* Bootstrap ZeroCopy Rx */
465         dev->rx_buff.skb = __dev_alloc_skb(dev->rx_buff.truesize, GFP_KERNEL);
466         if (dev->rx_buff.skb == NULL)
467                 return -ENOMEM;
468         skb_reserve(dev->rx_buff.skb, 1);
469         dev->rx_buff.head = dev->rx_buff.skb->data;
470
471         dev->tx_buff.head = kmalloc(dev->tx_buff.truesize, GFP_KERNEL);
472         if (dev->tx_buff.head == NULL) {
473                 kfree_skb(dev->rx_buff.skb);
474                 dev->rx_buff.skb = NULL;
475                 dev->rx_buff.head = NULL;
476                 return -ENOMEM;
477         }
478
479         dev->tx_buff.data = dev->tx_buff.head;
480         dev->rx_buff.data = dev->rx_buff.head;
481         dev->tx_buff.len = 0;
482         dev->rx_buff.len = 0;
483
484         dev->rx_buff.in_frame = FALSE;
485         dev->rx_buff.state = OUTSIDE_FRAME;
486         return 0;
487 };
488
489 static void sirdev_free_buffers(struct sir_dev *dev)
490 {
491         if (dev->rx_buff.skb)
492                 kfree_skb(dev->rx_buff.skb);
493         if (dev->tx_buff.head)
494                 kfree(dev->tx_buff.head);
495         dev->rx_buff.head = dev->tx_buff.head = NULL;
496         dev->rx_buff.skb = NULL;
497 }
498
499 static int sirdev_open(struct net_device *ndev)
500 {
501         struct sir_dev *dev = ndev->priv;
502         const struct sir_driver *drv = dev->drv;
503
504         if (!drv)
505                 return -ENODEV;
506
507         /* increase the reference count of the driver module before doing serious stuff */
508         if (!try_module_get(drv->owner))
509                 return -ESTALE;
510
511         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
512
513         if (sirdev_alloc_buffers(dev))
514                 goto errout_dec;
515
516         if (!dev->drv->start_dev  ||  dev->drv->start_dev(dev))
517                 goto errout_free;
518
519         sirdev_enable_rx(dev);
520         dev->raw_tx = 0;
521
522         netif_start_queue(ndev);
523         dev->irlap = irlap_open(ndev, &dev->qos, dev->hwname);
524         if (!dev->irlap)
525                 goto errout_stop;
526
527         netif_wake_queue(ndev);
528
529         IRDA_DEBUG(2, "%s - done, speed = %d\n", __FUNCTION__, dev->speed);
530
531         return 0;
532
533 errout_stop:
534         atomic_set(&dev->enable_rx, 0);
535         if (dev->drv->stop_dev)
536                 dev->drv->stop_dev(dev);
537 errout_free:
538         sirdev_free_buffers(dev);
539 errout_dec:
540         module_put(drv->owner);
541         return -EAGAIN;
542 }
543
544 static int sirdev_close(struct net_device *ndev)
545 {
546         struct sir_dev *dev = ndev->priv;
547         const struct sir_driver *drv;
548
549 //      IRDA_DEBUG(0, "%s\n", __FUNCTION__);
550
551         netif_stop_queue(ndev);
552
553         down(&dev->fsm.sem);            /* block on pending config completion */
554
555         atomic_set(&dev->enable_rx, 0);
556
557         if (unlikely(!dev->irlap))
558                 goto out;
559         irlap_close(dev->irlap);
560         dev->irlap = NULL;
561
562         drv = dev->drv;
563         if (unlikely(!drv  ||  !dev->priv))
564                 goto out;
565
566         if (drv->stop_dev)
567                 drv->stop_dev(dev);
568
569         sirdev_free_buffers(dev);
570         module_put(drv->owner);
571
572 out:
573         dev->speed = 0;
574         up(&dev->fsm.sem);
575         return 0;
576 }
577
578 /* ----------------------------------------------------------------------------- */
579
580 struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *name)
581 {
582         struct net_device *ndev;
583         struct sir_dev *dev;
584
585         IRDA_DEBUG(0, "%s - %s\n", __FUNCTION__, name);
586
587         /* instead of adding tests to protect against drv->do_write==NULL
588          * at several places we refuse to create a sir_dev instance for
589          * drivers which don't implement do_write.
590          */
591         if (!drv ||  !drv->do_write)
592                 return NULL;
593
594         /*
595          *  Allocate new instance of the device
596          */
597         ndev = alloc_irdadev(sizeof(*dev));
598         if (ndev == NULL) {
599                 IRDA_ERROR("%s - Can't allocate memory for IrDA control block!\n", __FUNCTION__);
600                 goto out;
601         }
602         dev = ndev->priv;
603
604         irda_init_max_qos_capabilies(&dev->qos);
605         dev->qos.baud_rate.bits = IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
606         dev->qos.min_turn_time.bits = drv->qos_mtt_bits;
607         irda_qos_bits_to_value(&dev->qos);
608
609         strncpy(dev->hwname, name, sizeof(dev->hwname)-1);
610
611         atomic_set(&dev->enable_rx, 0);
612         dev->tx_skb = NULL;
613
614         spin_lock_init(&dev->tx_lock);
615         init_MUTEX(&dev->fsm.sem);
616
617         INIT_LIST_HEAD(&dev->fsm.rq.lh_request);
618         dev->fsm.rq.pending = 0;
619         init_timer(&dev->fsm.rq.timer);
620
621         dev->drv = drv;
622         dev->netdev = ndev;
623
624         SET_MODULE_OWNER(ndev);
625
626         /* Override the network functions we need to use */
627         ndev->hard_start_xmit = sirdev_hard_xmit;
628         ndev->open = sirdev_open;
629         ndev->stop = sirdev_close;
630         ndev->get_stats = sirdev_get_stats;
631         ndev->do_ioctl = sirdev_ioctl;
632
633         if (register_netdev(ndev)) {
634                 IRDA_ERROR("%s(), register_netdev() failed!\n", __FUNCTION__);
635                 goto out_freenetdev;
636         }
637
638         return dev;
639
640 out_freenetdev:
641         free_netdev(ndev);
642 out:
643         return NULL;
644 }
645
646 int sirdev_put_instance(struct sir_dev *dev)
647 {
648         int err = 0;
649
650         IRDA_DEBUG(0, "%s\n", __FUNCTION__);
651
652         atomic_set(&dev->enable_rx, 0);
653
654         netif_carrier_off(dev->netdev);
655         netif_device_detach(dev->netdev);
656
657         if (dev->dongle_drv)
658                 err = sirdev_schedule_dongle_close(dev);
659         if (err)
660                 IRDA_ERROR("%s - error %d\n", __FUNCTION__, err);
661
662         sirdev_close(dev->netdev);
663
664         down(&dev->fsm.sem);
665         dev->fsm.state = SIRDEV_STATE_DEAD;     /* mark staled */
666         dev->dongle_drv = NULL;
667         dev->priv = NULL;
668         up(&dev->fsm.sem);
669
670         /* Remove netdevice */
671         unregister_netdev(dev->netdev);
672
673         free_netdev(dev->netdev);
674
675         return 0;
676 }
677