summaryrefslogtreecommitdiffstats
path: root/drivers/net/irda/sir_dev.c
blob: efc5a8870565220e52e9797cb51259aba1a63217 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
/*********************************************************************
 *
 *	sir_dev.c:	irda sir network device
 * 
 *	Copyright (c) 2002 Martin Diehl
 * 
 *	This program is free software; you can redistribute it and/or 
 *	modify it under the terms of the GNU General Public License as 
 *	published by the Free Software Foundation; either version 2 of 
 *	the License, or (at your option) any later version.
 *
 ********************************************************************/    

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/delay.h>

#include <net/irda/irda.h>
#include <net/irda/wrapper.h>
#include <net/irda/irda_device.h>

#include "sir-dev.h"

/***************************************************************************/

void sirdev_enable_rx(struct sir_dev *dev)
{
	if (unlikely(atomic_read(&dev->enable_rx)))
		return;

	/* flush rx-buffer - should also help in case of problems with echo cancelation */
	dev->rx_buff.data = dev->rx_buff.head;
	dev->rx_buff.len = 0;
	dev->rx_buff.in_frame = FALSE;
	dev->rx_buff.state = OUTSIDE_FRAME;
	atomic_set(&dev->enable_rx, 1);
}

static int sirdev_is_receiving(struct sir_dev *dev)
{
	if (!atomic_read(&dev->enable_rx))
		return 0;

	return (dev->rx_buff.state != OUTSIDE_FRAME);
}

int sirdev_set_dongle(struct sir_dev *dev, IRDA_DONGLE type)
{
	int err;

	IRDA_DEBUG(3, "%s : requesting dongle %d.\n", __FUNCTION__, type);

	err = sirdev_schedule_dongle_open(dev, type);
	if (unlikely(err))
		return err;
	down(&dev->fsm.sem);		/* block until config change completed */
	err = dev->fsm.result;
	up(&dev->fsm.sem);
	return err;
}

/* used by dongle drivers for dongle programming */

int sirdev_raw_write(struct sir_dev *dev, const char *buf, int len)
{
	unsigned long flags;
	int ret;

	if (unlikely(len > dev->tx_buff.truesize))
		return -ENOSPC;

	spin_lock_irqsave(&dev->tx_lock, flags);	/* serialize with other tx operations */
	while (dev->tx_buff.len > 0) {			/* wait until tx idle */
		spin_unlock_irqrestore(&dev->tx_lock, flags);
		msleep(10);
		spin_lock_irqsave(&dev->tx_lock, flags);
	}

	dev->tx_buff.data = dev->tx_buff.head;
	memcpy(dev->tx_buff.data, buf, len);	
	dev->tx_buff.len = len;

	ret = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
	if (ret > 0) {
		IRDA_DEBUG(3, "%s(), raw-tx started\n", __FUNCTION__);

		dev->tx_buff.data += ret;
		dev->tx_buff.len -= ret;
		dev->raw_tx = 1;
		ret = len;		/* all data is going to be sent */
	}
	spin_unlock_irqrestore(&dev->tx_lock, flags);
	return ret;
}

/* seems some dongle drivers may need this */

int sirdev_raw_read(struct sir_dev *dev, char *buf, int len)
{
	int count;

	if (atomic_read(&dev->enable_rx))
		return -EIO;		/* fail if we expect irda-frames */

	count = (len < dev->rx_buff.len) ? len : dev->rx_buff.len;

	if (count > 0) {
		memcpy(buf, dev->rx_buff.data, count);
		dev->rx_buff.data += count;
		dev->rx_buff.len -= count;
	}

	/* remaining stuff gets flushed when re-enabling normal rx */

	return count;
}

int sirdev_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
{
	int ret = -ENXIO;
	if (dev->drv->set_dtr_rts != 0)
		ret =  dev->drv->set_dtr_rts(dev, dtr, rts);
	return ret;
}
	
/**********************************************************************/

/* called from client driver - likely with bh-context - to indicate
 * it made some progress with transmission. Hence we send the next
 * chunk, if any, or complete the skb otherwise
 */

void sirdev_write_complete(struct sir_dev *dev)
{
	unsigned long flags;
	struct sk_buff *skb;
	int actual = 0;
	int err;
	
	spin_lock_irqsave(&dev->tx_lock, flags);

	IRDA_DEBUG(3, "%s() - dev->tx_buff.len = %d\n",
		   __FUNCTION__, dev->tx_buff.len);

	if (likely(dev->tx_buff.len > 0))  {
		/* Write data left in transmit buffer */
		actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);

		if (likely(actual>0)) {
			dev->tx_buff.data += actual;
			dev->tx_buff.len  -= actual;
		}
		else if (unlikely(actual<0)) {
			/* could be dropped later when we have tx_timeout to recover */
			IRDA_ERROR("%s: drv->do_write failed (%d)\n",
				   __FUNCTION__, actual);
			if ((skb=dev->tx_skb) != NULL) {
				dev->tx_skb = NULL;
				dev_kfree_skb_any(skb);
				dev->stats.tx_errors++;		      
				dev->stats.tx_dropped++;		      
			}
			dev->tx_buff.len = 0;
		}
		if (dev->tx_buff.len > 0)
			goto done;	/* more data to send later */
	}

	if (unlikely(dev->raw_tx != 0)) {
		/* in raw mode we are just done now after the buffer was sent
		 * completely. Since this was requested by some dongle driver
		 * running under the control of the irda-thread we must take
		 * care here not to re-enable the queue. The queue will be
		 * restarted when the irda-thread has completed the request.
		 */

		IRDA_DEBUG(3, "%s(), raw-tx done\n", __FUNCTION__);
		dev->raw_tx = 0;
		goto done;	/* no post-frame handling in raw mode */
	}

	/* we have finished now sending this skb.
	 * update statistics and free the skb.
	 * finally we check and trigger a pending speed change, if any.
	 * if not we switch to rx mode and wake the queue for further
	 * packets.
	 * note the scheduled speed request blocks until the lower
	 * client driver and the corresponding hardware has really
	 * finished sending all data (xmit fifo drained f.e.)
	 * before the speed change gets finally done and the queue
	 * re-activated.
	 */

	IRDA_DEBUG(5, "%s(), finished with frame!\n", __FUNCTION__);
		
	if ((skb=dev->tx_skb) != NULL) {
		dev->tx_skb = NULL;
		dev->stats.tx_packets++;		      
		dev->stats.tx_bytes += skb->len;
		dev_kfree_skb_any(skb);
	}

	if (unlikely(dev->new_speed > 0)) {
		IRDA_DEBUG(5, "%s(), Changing speed!\n", __FUNCTION__);
		err = sirdev_schedule_speed(dev, dev->new_speed);
		if (unlikely(err)) {
			/* should never happen
			 * forget the speed change and hope the stack recovers
			 */
			IRDA_ERROR("%s - schedule speed change failed: %d\n",
				   __FUNCTION__, err);
			netif_wake_queue(dev->netdev);
		}
		/* else: success
		 *	speed change in progress now
		 *	on completion dev->new_speed gets cleared,
		 *	rx-reenabled and the queue restarted
		 */
	}
	else {
		sirdev_enable_rx(dev);
		netif_wake_queue(dev->netdev);
	}

done:
	spin_unlock_irqrestore(&dev->tx_lock, flags);
}

/* called from client driver - likely with bh-context - to give us
 * some more received bytes. We put them into the rx-buffer,
 * normally unwrapping and building LAP-skb's (unless rx disabled)
 */

int sirdev_receive(struct sir_dev *dev, const unsigned char *cp, size_t count) 
{
	if (!dev || !dev->netdev) {
		IRDA_WARNING("%s(), not ready yet!\n", __FUNCTION__);
		return -1;
	}

	if (!dev->irlap) {
		IRDA_WARNING("%s - too early: %p / %zd!\n",
			     __FUNCTION__, cp, count);
		return -1;
	}

	if (cp==NULL) {
		/* error already at lower level receive
		 * just update stats and set media busy
		 */
		irda_device_set_media_busy(dev->netdev, TRUE);
		dev->stats.rx_dropped++;
		IRDA_DEBUG(0, "%s; rx-drop: %zd\n", __FUNCTION__, count);
		return 0;
	}

	/* Read the characters into the buffer */
	if (likely(atomic_read(&dev->enable_rx))) {
		while (count--)
			/* Unwrap and destuff one byte */
			async_unwrap_char(dev->netdev, &dev->stats, 
					  &dev->rx_buff, *cp++);
	} else {
		while (count--) {
			/* rx not enabled: save the raw bytes and never
			 * trigger any netif_rx. The received bytes are flushed
			 * later when we re-enable rx but might be read meanwhile
			 * by the dongle driver.
			 */
			dev->rx_buff.data[dev->rx_buff.len++] = *cp++;

			/* What should we do when the buffer is full? */
			if (unlikely(dev->rx_buff.len == dev->rx_buff.truesize))
				dev->rx_buff.len = 0;
		}
	}

	return 0;
}

/**********************************************************************/

/* callbacks from network layer */

static struct net_device_stats *sirdev_get_stats(struct net_device *ndev)
{
	struct sir_dev *dev = ndev->priv;

	return (dev) ? &dev->stats : NULL;
}

static int sirdev_hard_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	struct sir_dev *dev = ndev->priv;
	unsigned long flags;
	int actual = 0;
	int err;
	s32 speed;

	IRDA_ASSERT(dev != NULL, return 0;);

	netif_stop_queue(ndev);

	IRDA_DEBUG(3, "%s(), skb->len = %d\n", __FUNCTION__, skb->len);

	speed = irda_get_next_speed(skb);
	if ((speed != dev->speed) && (speed != -1)) {
		if (!skb->len) {
			err = sirdev_schedule_speed(dev, speed);
			if (unlikely(err == -EWOULDBLOCK)) {
				/* Failed to initiate the speed change, likely the fsm
				 * is still busy (pretty unlikely, but...)
				 * We refuse to accept the skb and return with the queue
				 * stopped so the network layer will retry after the
				 * fsm completes and wakes the queue.
				 */
				 return 1;
			}
			else if (unlikely(err)) {
				/* other fatal error - forget the speed change and
				 * hope the stack will recover somehow
				 */
				 netif_start_queue(ndev);
			}
			/* else: success
			 *	speed change in progress now
			 *	on completion the queue gets restarted
			 */

			dev_kfree_skb_any(skb);
			return 0;
		} else
			dev->new_speed = speed;
	}

	/* Init tx buffer*/
	dev->tx_buff.data = dev->tx_buff.head;

	/* Check problems */
	if(spin_is_locked(&dev->tx_lock)) {
		IRDA_DEBUG(3, "%s(), write not completed\n", __FUNCTION__);
	}

	/* serialize with write completion */
	spin_lock_irqsave(&dev->tx_lock, flags);

        /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
	dev->tx_buff.len = async_wrap_skb(skb, dev->tx_buff.data, dev->tx_buff.truesize); 

	/* transmission will start now - disable receive.
	 * if we are just in the middle of an incoming frame,
	 * treat it as collision. probably it's a good idea to
	 * reset the rx_buf OUTSIDE_FRAME in this case too?
	 */
	atomic_set(&dev->enable_rx, 0);
	if (unlikely(sirdev_is_receiving(dev)))
		dev->stats.collisions++;

	actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);

	if (likely(actual > 0)) {
		dev->tx_skb = skb;
		ndev->trans_start = jiffies;
		dev->tx_buff.data += actual;
		dev->tx_buff.len -= actual;
	}
	else if (unlikely(actual < 0)) {
		/* could be dropped later when we have tx_timeout to recover */
		IRDA_ERROR("%s: drv->do_write failed (%d)\n",
			   __FUNCTION__, actual);
		dev_kfree_skb_any(skb);
		dev->stats.tx_errors++;		      
		dev->stats.tx_dropped++;		      
		netif_wake_queue(ndev);
	}
	spin_unlock_irqrestore(&dev->tx_lock, flags);

	return 0;
}

/* called from network layer with rtnl hold */

static int sirdev_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
{
	struct if_irda_req *irq = (struct if_irda_req *) rq;
	struct sir_dev *dev = ndev->priv;
	int ret = 0;

	IRDA_ASSERT(dev != NULL, return -1;);

	IRDA_DEBUG(3, "%s(), %s, (cmd=0x%X)\n", __FUNCTION__, ndev->name, cmd);
	
	switch (cmd) {
	case SIOCSBANDWIDTH: /* Set bandwidth */
		if (!capable(CAP_NET_ADMIN))
			ret = -EPERM;
		else
			ret = sirdev_schedule_speed(dev, irq->ifr_baudrate);
		/* cannot sleep here for completion
		 * we are called from network layer with rtnl hold
		 */
		break;

	case SIOCSDONGLE: /* Set dongle */
		if (!capable(CAP_NET_ADMIN))
			ret = -EPERM;
		else
			ret = sirdev_schedule_dongle_open(dev, irq->ifr_dongle);
		/* cannot sleep here for completion
		 * we are called from network layer with rtnl hold
		 */
		break;

	case SIOCSMEDIABUSY: /* Set media busy */
		if (!capable(CAP_NET_ADMIN))
			ret = -EPERM;
		else
			irda_device_set_media_busy(dev->netdev, TRUE);
		break;

	case SIOCGRECEIVING: /* Check if we are receiving right now */
		irq->ifr_receiving = sirdev_is_receiving(dev);
		break;

	case SIOCSDTRRTS:
		if (!capable(CAP_NET_ADMIN))
			ret = -EPERM;
		else
			ret = sirdev_schedule_dtr_rts(dev, irq->ifr_dtr, irq->ifr_rts);
		/* cannot sleep here for completion
		 * we are called from network layer with rtnl hold
		 */
		break;

	case SIOCSMODE:
#if 0
		if (!capable(CAP_NET_ADMIN))
			ret = -EPERM;
		else
			ret = sirdev_schedule_mode(dev, irq->ifr_mode);
		/* cannot sleep here for completion
		 * we are called from network layer with rtnl hold
		 */
		break;
#endif
	default:
		ret = -EOPNOTSUPP;
	}
	
	return ret;
}

/* ----------------------------------------------------------------------------- */

#define SIRBUF_ALLOCSIZE 4269	/* worst case size of a wrapped IrLAP frame */

static int sirdev_alloc_buffers(struct sir_dev *dev)
{
	dev->tx_buff.truesize = SIRBUF_ALLOCSIZE;
	dev->rx_buff.truesize = IRDA_SKB_MAX_MTU; 

	/* Bootstrap ZeroCopy Rx */
	dev->rx_buff.skb = __dev_alloc_skb(dev->rx_buff.truesize, GFP_KERNEL);
	if (dev->rx_buff.skb == NULL)
		return -ENOMEM;
	skb_reserve(dev->rx_buff.skb, 1);
	dev->rx_buff.head = dev->rx_buff.skb->data;

	dev->tx_buff.head = kmalloc(dev->tx_buff.truesize, GFP_KERNEL);
	if (dev->tx_buff.head == NULL) {
		kfree_skb(dev->rx_buff.skb);
		dev->rx_buff.skb = NULL;
		dev->rx_buff.head = NULL;
		return -ENOMEM;
	}

	dev->tx_buff.data = dev->tx_buff.head;
	dev->rx_buff.data = dev->rx_buff.head;
	dev->tx_buff.len = 0;
	dev->rx_buff.len = 0;

	dev->rx_buff.in_frame = FALSE;
	dev->rx_buff.state = OUTSIDE_FRAME;
	return 0;
};

static void sirdev_free_buffers(struct sir_dev *dev)
{
	if (dev->rx_buff.skb)
		kfree_skb(dev->rx_buff.skb);
	if (dev->tx_buff.head)
		kfree(dev->tx_buff.head);
	dev->rx_buff.head = dev->tx_buff.head = NULL;
	dev->rx_buff.skb = NULL;
}

static int sirdev_open(struct net_device *ndev)
{
	struct sir_dev *dev = ndev->priv;
	const struct sir_driver *drv = dev->drv;

	if (!drv)
		return -ENODEV;

	/* increase the reference count of the driver module before doing serious stuff */
	if (!try_module_get(drv->owner))
		return -ESTALE;

	IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

	if (sirdev_alloc_buffers(dev))
		goto errout_dec;

	if (!dev->drv->start_dev  ||  dev->drv->start_dev(dev))
		goto errout_free;

	sirdev_enable_rx(dev);
	dev->raw_tx = 0;

	netif_start_queue(ndev);
	dev->irlap = irlap_open(ndev, &dev->qos, dev->hwname);
	if (!dev->irlap)
		goto errout_stop;

	netif_wake_queue(ndev);

	IRDA_DEBUG(2, "%s - done, speed = %d\n", __FUNCTION__, dev->speed);

	return 0;

errout_stop:
	atomic_set(&dev->enable_rx, 0);
	if (dev->drv->stop_dev)
		dev->drv->stop_dev(dev);
errout_free:
	sirdev_free_buffers(dev);
errout_dec:
	module_put(drv->owner);
	return -EAGAIN;
}

static int sirdev_close(struct net_device *ndev)
{
	struct sir_dev *dev = ndev->priv;
	const struct sir_driver *drv;

//	IRDA_DEBUG(0, "%s\n", __FUNCTION__);

	netif_stop_queue(ndev);

	down(&dev->fsm.sem);		/* block on pending config completion */

	atomic_set(&dev->enable_rx, 0);

	if (unlikely(!dev->irlap))
		goto out;
	irlap_close(dev->irlap);
	dev->irlap = NULL;

	drv = dev->drv;
	if (unlikely(!drv  ||  !dev->priv))
		goto out;

	if (drv->stop_dev)
		drv->stop_dev(dev);

	sirdev_free_buffers(dev);
	module_put(drv->owner);

out:
	dev->speed = 0;
	up(&dev->fsm.sem);
	return 0;
}

/* ----------------------------------------------------------------------------- */

struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *name)
{
	struct net_device *ndev;
	struct sir_dev *dev;

	IRDA_DEBUG(0, "%s - %s\n", __FUNCTION__, name);

	/* instead of adding tests to protect against drv->do_write==NULL
	 * at several places we refuse to create a sir_dev instance for
	 * drivers which don't implement do_write.
	 */
	if (!drv ||  !drv->do_write)
		return NULL;

	/*
	 *  Allocate new instance of the device
	 */
	ndev = alloc_irdadev(sizeof(*dev));
	if (ndev == NULL) {
		IRDA_ERROR("%s - Can't allocate memory for IrDA control block!\n", __FUNCTION__);
		goto out;
	}
	dev = ndev->priv;

	irda_init_max_qos_capabilies(&dev->qos);
	dev->qos.baud_rate.bits = IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
	dev->qos.min_turn_time.bits = drv->qos_mtt_bits;
	irda_qos_bits_to_value(&dev->qos);

	strncpy(dev->hwname, name, sizeof(dev->hwname)-1);

	atomic_set(&dev->enable_rx, 0);
	dev->tx_skb = NULL;

	spin_lock_init(&dev->tx_lock);
	init_MUTEX(&dev->fsm.sem);

	INIT_LIST_HEAD(&dev->fsm.rq.lh_request);
	dev->fsm.rq.pending = 0;
	init_timer(&dev->fsm.rq.timer);

	dev->drv = drv;
	dev->netdev = ndev;

	SET_MODULE_OWNER(ndev);

	/* Override the network functions we need to use */
	ndev->hard_start_xmit = sirdev_hard_xmit;
	ndev->open = sirdev_open;
	ndev->stop = sirdev_close;
	ndev->get_stats = sirdev_get_stats;
	ndev->do_ioctl = sirdev_ioctl;

	if (register_netdev(ndev)) {
		IRDA_ERROR("%s(), register_netdev() failed!\n", __FUNCTION__);
		goto out_freenetdev;
	}

	return dev;

out_freenetdev:
	free_netdev(ndev);
out:
	return NULL;
}

int sirdev_put_instance(struct sir_dev *dev)
{
	int err = 0;

	IRDA_DEBUG(0, "%s\n", __FUNCTION__);

	atomic_set(&dev->enable_rx, 0);

	netif_carrier_off(dev->netdev);
	netif_device_detach(dev->netdev);

	if (dev->dongle_drv)
		err = sirdev_schedule_dongle_close(dev);
	if (err)
		IRDA_ERROR("%s - error %d\n", __FUNCTION__, err);

	sirdev_close(dev->netdev);

	down(&dev->fsm.sem);
	dev->fsm.state = SIRDEV_STATE_DEAD;	/* mark staled */
	dev->dongle_drv = NULL;
	dev->priv = NULL;
	up(&dev->fsm.sem);

	/* Remove netdevice */
	unregister_netdev(dev->netdev);

	free_netdev(dev->netdev);

	return 0;
}

OpenPOWER on IntegriCloud