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/hardirq.h>
 15#include <linux/module.h>
 16#include <linux/kernel.h>
 17#include <linux/slab.h>
 18#include <linux/init.h>
 19#include <linux/delay.h>
 20
 21#include <net/irda/irda.h>
 22#include <net/irda/wrapper.h>
 23#include <net/irda/irda_device.h>
 24
 25#include "sir-dev.h"
 26
 27
 28static struct workqueue_struct *irda_sir_wq;
 29
 30/* STATE MACHINE */
 31
 32/* substate handler of the config-fsm to handle the cases where we want
 33 * to wait for transmit completion before changing the port configuration
 34 */
 35
 36static int sirdev_tx_complete_fsm(struct sir_dev *dev)
 37{
 38	struct sir_fsm *fsm = &dev->fsm;
 39	unsigned next_state, delay;
 40	unsigned bytes_left;
 41
 42	do {
 43		next_state = fsm->substate;	/* default: stay in current substate */
 44		delay = 0;
 45
 46		switch(fsm->substate) {
 47
 48		case SIRDEV_STATE_WAIT_XMIT:
 49			if (dev->drv->chars_in_buffer)
 50				bytes_left = dev->drv->chars_in_buffer(dev);
 51			else
 52				bytes_left = 0;
 53			if (!bytes_left) {
 54				next_state = SIRDEV_STATE_WAIT_UNTIL_SENT;
 55				break;
 56			}
 57
 58			if (dev->speed > 115200)
 59				delay = (bytes_left*8*10000) / (dev->speed/100);
 60			else if (dev->speed > 0)
 61				delay = (bytes_left*10*10000) / (dev->speed/100);
 62			else
 63				delay = 0;
 64			/* expected delay (usec) until remaining bytes are sent */
 65			if (delay < 100) {
 66				udelay(delay);
 67				delay = 0;
 68				break;
 69			}
 70			/* sleep some longer delay (msec) */
 71			delay = (delay+999) / 1000;
 72			break;
 73
 74		case SIRDEV_STATE_WAIT_UNTIL_SENT:
 75			/* block until underlaying hardware buffer are empty */
 76			if (dev->drv->wait_until_sent)
 77				dev->drv->wait_until_sent(dev);
 78			next_state = SIRDEV_STATE_TX_DONE;
 79			break;
 80
 81		case SIRDEV_STATE_TX_DONE:
 82			return 0;
 83
 84		default:
 85			IRDA_ERROR("%s - undefined state\n", __func__);
 86			return -EINVAL;
 87		}
 88		fsm->substate = next_state;
 89	} while (delay == 0);
 90	return delay;
 91}
 92
 93/*
 94 * Function sirdev_config_fsm
 95 *
 96 * State machine to handle the configuration of the device (and attached dongle, if any).
 97 * This handler is scheduled for execution in kIrDAd context, so we can sleep.
 98 * however, kIrDAd is shared by all sir_dev devices so we better don't sleep there too
 99 * long. Instead, for longer delays we start a timer to reschedule us later.
100 * On entry, fsm->sem is always locked and the netdev xmit queue stopped.
101 * Both must be unlocked/restarted on completion - but only on final exit.
102 */
103
104static void sirdev_config_fsm(struct work_struct *work)
105{
106	struct sir_dev *dev = container_of(work, struct sir_dev, fsm.work.work);
107	struct sir_fsm *fsm = &dev->fsm;
108	int next_state;
109	int ret = -1;
110	unsigned delay;
111
112	IRDA_DEBUG(2, "%s(), <%ld>\n", __func__, jiffies);
113
114	do {
115		IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n",
116			__func__, fsm->state, fsm->substate);
117
118		next_state = fsm->state;
119		delay = 0;
120
121		switch(fsm->state) {
122
123		case SIRDEV_STATE_DONGLE_OPEN:
124			if (dev->dongle_drv != NULL) {
125				ret = sirdev_put_dongle(dev);
126				if (ret) {
127					fsm->result = -EINVAL;
128					next_state = SIRDEV_STATE_ERROR;
129					break;
130				}
131			}
132
133			/* Initialize dongle */
134			ret = sirdev_get_dongle(dev, fsm->param);
135			if (ret) {
136				fsm->result = ret;
137				next_state = SIRDEV_STATE_ERROR;
138				break;
139			}
140
141			/* Dongles are powered through the modem control lines which
142			 * were just set during open. Before resetting, let's wait for
143			 * the power to stabilize. This is what some dongle drivers did
144			 * in open before, while others didn't - should be safe anyway.
145			 */
146
147			delay = 50;
148			fsm->substate = SIRDEV_STATE_DONGLE_RESET;
149			next_state = SIRDEV_STATE_DONGLE_RESET;
150
151			fsm->param = 9600;
152
153			break;
154
155		case SIRDEV_STATE_DONGLE_CLOSE:
156			/* shouldn't we just treat this as success=? */
157			if (dev->dongle_drv == NULL) {
158				fsm->result = -EINVAL;
159				next_state = SIRDEV_STATE_ERROR;
160				break;
161			}
162
163			ret = sirdev_put_dongle(dev);
164			if (ret) {
165				fsm->result = ret;
166				next_state = SIRDEV_STATE_ERROR;
167				break;
168			}
169			next_state = SIRDEV_STATE_DONE;
170			break;
171
172		case SIRDEV_STATE_SET_DTR_RTS:
173			ret = sirdev_set_dtr_rts(dev,
174				(fsm->param&0x02) ? TRUE : FALSE,
175				(fsm->param&0x01) ? TRUE : FALSE);
176			next_state = SIRDEV_STATE_DONE;
177			break;
178
179		case SIRDEV_STATE_SET_SPEED:
180			fsm->substate = SIRDEV_STATE_WAIT_XMIT;
181			next_state = SIRDEV_STATE_DONGLE_CHECK;
182			break;
183
184		case SIRDEV_STATE_DONGLE_CHECK:
185			ret = sirdev_tx_complete_fsm(dev);
186			if (ret < 0) {
187				fsm->result = ret;
188				next_state = SIRDEV_STATE_ERROR;
189				break;
190			}
191			if ((delay=ret) != 0)
192				break;
193
194			if (dev->dongle_drv) {
195				fsm->substate = SIRDEV_STATE_DONGLE_RESET;
196				next_state = SIRDEV_STATE_DONGLE_RESET;
197			}
198			else {
199				dev->speed = fsm->param;
200				next_state = SIRDEV_STATE_PORT_SPEED;
201			}
202			break;
203
204		case SIRDEV_STATE_DONGLE_RESET:
205			if (dev->dongle_drv->reset) {
206				ret = dev->dongle_drv->reset(dev);
207				if (ret < 0) {
208					fsm->result = ret;
209					next_state = SIRDEV_STATE_ERROR;
210					break;
211				}
212			}
213			else
214				ret = 0;
215			if ((delay=ret) == 0) {
216				/* set serial port according to dongle default speed */
217				if (dev->drv->set_speed)
218					dev->drv->set_speed(dev, dev->speed);
219				fsm->substate = SIRDEV_STATE_DONGLE_SPEED;
220				next_state = SIRDEV_STATE_DONGLE_SPEED;
221			}
222			break;
223
224		case SIRDEV_STATE_DONGLE_SPEED:
225			if (dev->dongle_drv->reset) {
226				ret = dev->dongle_drv->set_speed(dev, fsm->param);
227				if (ret < 0) {
228					fsm->result = ret;
229					next_state = SIRDEV_STATE_ERROR;
230					break;
231				}
232			}
233			else
234				ret = 0;
235			if ((delay=ret) == 0)
236				next_state = SIRDEV_STATE_PORT_SPEED;
237			break;
238
239		case SIRDEV_STATE_PORT_SPEED:
240			/* Finally we are ready to change the serial port speed */
241			if (dev->drv->set_speed)
242				dev->drv->set_speed(dev, dev->speed);
243			dev->new_speed = 0;
244			next_state = SIRDEV_STATE_DONE;
245			break;
246
247		case SIRDEV_STATE_DONE:
248			/* Signal network layer so it can send more frames */
249			netif_wake_queue(dev->netdev);
250			next_state = SIRDEV_STATE_COMPLETE;
251			break;
252
253		default:
254			IRDA_ERROR("%s - undefined state\n", __func__);
255			fsm->result = -EINVAL;
256			/* fall thru */
257
258		case SIRDEV_STATE_ERROR:
259			IRDA_ERROR("%s - error: %d\n", __func__, fsm->result);
 
260
261#if 0	/* don't enable this before we have netdev->tx_timeout to recover */
262			netif_stop_queue(dev->netdev);
263#else
264			netif_wake_queue(dev->netdev);
265#endif
266			/* fall thru */
267
268		case SIRDEV_STATE_COMPLETE:
269			/* config change finished, so we are not busy any longer */
270			sirdev_enable_rx(dev);
271			up(&fsm->sem);
272			return;
273		}
274		fsm->state = next_state;
275	} while(!delay);
276
277	queue_delayed_work(irda_sir_wq, &fsm->work, msecs_to_jiffies(delay));
278}
279
280/* schedule some device configuration task for execution by kIrDAd
281 * on behalf of the above state machine.
282 * can be called from process or interrupt/tasklet context.
283 */
284
285int sirdev_schedule_request(struct sir_dev *dev, int initial_state, unsigned param)
286{
287	struct sir_fsm *fsm = &dev->fsm;
288
289	IRDA_DEBUG(2, "%s - state=0x%04x / param=%u\n", __func__,
290			initial_state, param);
291
292	if (down_trylock(&fsm->sem)) {
293		if (in_interrupt()  ||  in_atomic()  ||  irqs_disabled()) {
294			IRDA_DEBUG(1, "%s(), state machine busy!\n", __func__);
295			return -EWOULDBLOCK;
296		} else
297			down(&fsm->sem);
298	}
299
300	if (fsm->state == SIRDEV_STATE_DEAD) {
301		/* race with sirdev_close should never happen */
302		IRDA_ERROR("%s(), instance staled!\n", __func__);
303		up(&fsm->sem);
304		return -ESTALE;		/* or better EPIPE? */
305	}
306
307	netif_stop_queue(dev->netdev);
308	atomic_set(&dev->enable_rx, 0);
309
310	fsm->state = initial_state;
311	fsm->param = param;
312	fsm->result = 0;
313
314	INIT_DELAYED_WORK(&fsm->work, sirdev_config_fsm);
315	queue_delayed_work(irda_sir_wq, &fsm->work, 0);
316	return 0;
317}
318
319
320/***************************************************************************/
321
322void sirdev_enable_rx(struct sir_dev *dev)
323{
324	if (unlikely(atomic_read(&dev->enable_rx)))
325		return;
326
327	/* flush rx-buffer - should also help in case of problems with echo cancelation */
328	dev->rx_buff.data = dev->rx_buff.head;
329	dev->rx_buff.len = 0;
330	dev->rx_buff.in_frame = FALSE;
331	dev->rx_buff.state = OUTSIDE_FRAME;
332	atomic_set(&dev->enable_rx, 1);
333}
334
335static int sirdev_is_receiving(struct sir_dev *dev)
336{
337	if (!atomic_read(&dev->enable_rx))
338		return 0;
339
340	return dev->rx_buff.state != OUTSIDE_FRAME;
341}
342
343int sirdev_set_dongle(struct sir_dev *dev, IRDA_DONGLE type)
344{
345	int err;
346
347	IRDA_DEBUG(3, "%s : requesting dongle %d.\n", __func__, type);
348
349	err = sirdev_schedule_dongle_open(dev, type);
350	if (unlikely(err))
351		return err;
352	down(&dev->fsm.sem);		/* block until config change completed */
353	err = dev->fsm.result;
354	up(&dev->fsm.sem);
355	return err;
356}
357EXPORT_SYMBOL(sirdev_set_dongle);
358
359/* used by dongle drivers for dongle programming */
360
361int sirdev_raw_write(struct sir_dev *dev, const char *buf, int len)
362{
363	unsigned long flags;
364	int ret;
365
366	if (unlikely(len > dev->tx_buff.truesize))
367		return -ENOSPC;
368
369	spin_lock_irqsave(&dev->tx_lock, flags);	/* serialize with other tx operations */
370	while (dev->tx_buff.len > 0) {			/* wait until tx idle */
371		spin_unlock_irqrestore(&dev->tx_lock, flags);
372		msleep(10);
373		spin_lock_irqsave(&dev->tx_lock, flags);
374	}
375
376	dev->tx_buff.data = dev->tx_buff.head;
377	memcpy(dev->tx_buff.data, buf, len);	
378	dev->tx_buff.len = len;
379
380	ret = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
381	if (ret > 0) {
382		IRDA_DEBUG(3, "%s(), raw-tx started\n", __func__);
383
384		dev->tx_buff.data += ret;
385		dev->tx_buff.len -= ret;
386		dev->raw_tx = 1;
387		ret = len;		/* all data is going to be sent */
388	}
389	spin_unlock_irqrestore(&dev->tx_lock, flags);
390	return ret;
391}
392EXPORT_SYMBOL(sirdev_raw_write);
393
394/* seems some dongle drivers may need this */
395
396int sirdev_raw_read(struct sir_dev *dev, char *buf, int len)
397{
398	int count;
399
400	if (atomic_read(&dev->enable_rx))
401		return -EIO;		/* fail if we expect irda-frames */
402
403	count = (len < dev->rx_buff.len) ? len : dev->rx_buff.len;
404
405	if (count > 0) {
406		memcpy(buf, dev->rx_buff.data, count);
407		dev->rx_buff.data += count;
408		dev->rx_buff.len -= count;
409	}
410
411	/* remaining stuff gets flushed when re-enabling normal rx */
412
413	return count;
414}
415EXPORT_SYMBOL(sirdev_raw_read);
416
417int sirdev_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
418{
419	int ret = -ENXIO;
420	if (dev->drv->set_dtr_rts)
421		ret =  dev->drv->set_dtr_rts(dev, dtr, rts);
422	return ret;
423}
424EXPORT_SYMBOL(sirdev_set_dtr_rts);
425
426/**********************************************************************/
427
428/* called from client driver - likely with bh-context - to indicate
429 * it made some progress with transmission. Hence we send the next
430 * chunk, if any, or complete the skb otherwise
431 */
432
433void sirdev_write_complete(struct sir_dev *dev)
434{
435	unsigned long flags;
436	struct sk_buff *skb;
437	int actual = 0;
438	int err;
439	
440	spin_lock_irqsave(&dev->tx_lock, flags);
441
442	IRDA_DEBUG(3, "%s() - dev->tx_buff.len = %d\n",
443		   __func__, dev->tx_buff.len);
444
445	if (likely(dev->tx_buff.len > 0))  {
446		/* Write data left in transmit buffer */
447		actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
448
449		if (likely(actual>0)) {
450			dev->tx_buff.data += actual;
451			dev->tx_buff.len  -= actual;
452		}
453		else if (unlikely(actual<0)) {
454			/* could be dropped later when we have tx_timeout to recover */
455			IRDA_ERROR("%s: drv->do_write failed (%d)\n",
456				   __func__, actual);
457			if ((skb=dev->tx_skb) != NULL) {
458				dev->tx_skb = NULL;
459				dev_kfree_skb_any(skb);
460				dev->netdev->stats.tx_errors++;
461				dev->netdev->stats.tx_dropped++;
462			}
463			dev->tx_buff.len = 0;
464		}
465		if (dev->tx_buff.len > 0)
466			goto done;	/* more data to send later */
467	}
468
469	if (unlikely(dev->raw_tx != 0)) {
470		/* in raw mode we are just done now after the buffer was sent
471		 * completely. Since this was requested by some dongle driver
472		 * running under the control of the irda-thread we must take
473		 * care here not to re-enable the queue. The queue will be
474		 * restarted when the irda-thread has completed the request.
475		 */
476
477		IRDA_DEBUG(3, "%s(), raw-tx done\n", __func__);
478		dev->raw_tx = 0;
479		goto done;	/* no post-frame handling in raw mode */
480	}
481
482	/* we have finished now sending this skb.
483	 * update statistics and free the skb.
484	 * finally we check and trigger a pending speed change, if any.
485	 * if not we switch to rx mode and wake the queue for further
486	 * packets.
487	 * note the scheduled speed request blocks until the lower
488	 * client driver and the corresponding hardware has really
489	 * finished sending all data (xmit fifo drained f.e.)
490	 * before the speed change gets finally done and the queue
491	 * re-activated.
492	 */
493
494	IRDA_DEBUG(5, "%s(), finished with frame!\n", __func__);
495		
496	if ((skb=dev->tx_skb) != NULL) {
497		dev->tx_skb = NULL;
498		dev->netdev->stats.tx_packets++;
499		dev->netdev->stats.tx_bytes += skb->len;
500		dev_kfree_skb_any(skb);
501	}
502
503	if (unlikely(dev->new_speed > 0)) {
504		IRDA_DEBUG(5, "%s(), Changing speed!\n", __func__);
505		err = sirdev_schedule_speed(dev, dev->new_speed);
506		if (unlikely(err)) {
507			/* should never happen
508			 * forget the speed change and hope the stack recovers
509			 */
510			IRDA_ERROR("%s - schedule speed change failed: %d\n",
511				   __func__, err);
512			netif_wake_queue(dev->netdev);
513		}
514		/* else: success
515		 *	speed change in progress now
516		 *	on completion dev->new_speed gets cleared,
517		 *	rx-reenabled and the queue restarted
518		 */
519	}
520	else {
521		sirdev_enable_rx(dev);
522		netif_wake_queue(dev->netdev);
523	}
524
525done:
526	spin_unlock_irqrestore(&dev->tx_lock, flags);
527}
528EXPORT_SYMBOL(sirdev_write_complete);
529
530/* called from client driver - likely with bh-context - to give us
531 * some more received bytes. We put them into the rx-buffer,
532 * normally unwrapping and building LAP-skb's (unless rx disabled)
533 */
534
535int sirdev_receive(struct sir_dev *dev, const unsigned char *cp, size_t count) 
536{
537	if (!dev || !dev->netdev) {
538		IRDA_WARNING("%s(), not ready yet!\n", __func__);
539		return -1;
540	}
541
542	if (!dev->irlap) {
543		IRDA_WARNING("%s - too early: %p / %zd!\n",
544			     __func__, cp, count);
545		return -1;
546	}
547
548	if (cp==NULL) {
549		/* error already at lower level receive
550		 * just update stats and set media busy
551		 */
552		irda_device_set_media_busy(dev->netdev, TRUE);
553		dev->netdev->stats.rx_dropped++;
554		IRDA_DEBUG(0, "%s; rx-drop: %zd\n", __func__, count);
555		return 0;
556	}
557
558	/* Read the characters into the buffer */
559	if (likely(atomic_read(&dev->enable_rx))) {
560		while (count--)
561			/* Unwrap and destuff one byte */
562			async_unwrap_char(dev->netdev, &dev->netdev->stats,
563					  &dev->rx_buff, *cp++);
564	} else {
565		while (count--) {
566			/* rx not enabled: save the raw bytes and never
567			 * trigger any netif_rx. The received bytes are flushed
568			 * later when we re-enable rx but might be read meanwhile
569			 * by the dongle driver.
570			 */
571			dev->rx_buff.data[dev->rx_buff.len++] = *cp++;
572
573			/* What should we do when the buffer is full? */
574			if (unlikely(dev->rx_buff.len == dev->rx_buff.truesize))
575				dev->rx_buff.len = 0;
576		}
577	}
578
579	return 0;
580}
581EXPORT_SYMBOL(sirdev_receive);
582
583/**********************************************************************/
584
585/* callbacks from network layer */
586
587static netdev_tx_t sirdev_hard_xmit(struct sk_buff *skb,
588					  struct net_device *ndev)
589{
590	struct sir_dev *dev = netdev_priv(ndev);
591	unsigned long flags;
592	int actual = 0;
593	int err;
594	s32 speed;
595
596	IRDA_ASSERT(dev != NULL, return NETDEV_TX_OK;);
597
598	netif_stop_queue(ndev);
599
600	IRDA_DEBUG(3, "%s(), skb->len = %d\n", __func__, skb->len);
601
602	speed = irda_get_next_speed(skb);
603	if ((speed != dev->speed) && (speed != -1)) {
604		if (!skb->len) {
605			err = sirdev_schedule_speed(dev, speed);
606			if (unlikely(err == -EWOULDBLOCK)) {
607				/* Failed to initiate the speed change, likely the fsm
608				 * is still busy (pretty unlikely, but...)
609				 * We refuse to accept the skb and return with the queue
610				 * stopped so the network layer will retry after the
611				 * fsm completes and wakes the queue.
612				 */
613				 return NETDEV_TX_BUSY;
614			}
615			else if (unlikely(err)) {
616				/* other fatal error - forget the speed change and
617				 * hope the stack will recover somehow
618				 */
619				 netif_start_queue(ndev);
620			}
621			/* else: success
622			 *	speed change in progress now
623			 *	on completion the queue gets restarted
624			 */
625
626			dev_kfree_skb_any(skb);
627			return NETDEV_TX_OK;
628		} else
629			dev->new_speed = speed;
630	}
631
632	/* Init tx buffer*/
633	dev->tx_buff.data = dev->tx_buff.head;
634
635	/* Check problems */
636	if(spin_is_locked(&dev->tx_lock)) {
637		IRDA_DEBUG(3, "%s(), write not completed\n", __func__);
638	}
639
640	/* serialize with write completion */
641	spin_lock_irqsave(&dev->tx_lock, flags);
642
643        /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
644	dev->tx_buff.len = async_wrap_skb(skb, dev->tx_buff.data, dev->tx_buff.truesize); 
645
646	/* transmission will start now - disable receive.
647	 * if we are just in the middle of an incoming frame,
648	 * treat it as collision. probably it's a good idea to
649	 * reset the rx_buf OUTSIDE_FRAME in this case too?
650	 */
651	atomic_set(&dev->enable_rx, 0);
652	if (unlikely(sirdev_is_receiving(dev)))
653		dev->netdev->stats.collisions++;
654
655	actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
656
657	if (likely(actual > 0)) {
658		dev->tx_skb = skb;
659		dev->tx_buff.data += actual;
660		dev->tx_buff.len -= actual;
661	}
662	else if (unlikely(actual < 0)) {
663		/* could be dropped later when we have tx_timeout to recover */
664		IRDA_ERROR("%s: drv->do_write failed (%d)\n",
665			   __func__, actual);
666		dev_kfree_skb_any(skb);
667		dev->netdev->stats.tx_errors++;
668		dev->netdev->stats.tx_dropped++;
669		netif_wake_queue(ndev);
670	}
671	spin_unlock_irqrestore(&dev->tx_lock, flags);
672
673	return NETDEV_TX_OK;
674}
675
676/* called from network layer with rtnl hold */
677
678static int sirdev_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
679{
680	struct if_irda_req *irq = (struct if_irda_req *) rq;
681	struct sir_dev *dev = netdev_priv(ndev);
682	int ret = 0;
683
684	IRDA_ASSERT(dev != NULL, return -1;);
685
686	IRDA_DEBUG(3, "%s(), %s, (cmd=0x%X)\n", __func__, ndev->name, cmd);
687	
688	switch (cmd) {
689	case SIOCSBANDWIDTH: /* Set bandwidth */
690		if (!capable(CAP_NET_ADMIN))
691			ret = -EPERM;
692		else
693			ret = sirdev_schedule_speed(dev, irq->ifr_baudrate);
694		/* cannot sleep here for completion
695		 * we are called from network layer with rtnl hold
696		 */
697		break;
698
699	case SIOCSDONGLE: /* Set dongle */
700		if (!capable(CAP_NET_ADMIN))
701			ret = -EPERM;
702		else
703			ret = sirdev_schedule_dongle_open(dev, irq->ifr_dongle);
704		/* cannot sleep here for completion
705		 * we are called from network layer with rtnl hold
706		 */
707		break;
708
709	case SIOCSMEDIABUSY: /* Set media busy */
710		if (!capable(CAP_NET_ADMIN))
711			ret = -EPERM;
712		else
713			irda_device_set_media_busy(dev->netdev, TRUE);
714		break;
715
716	case SIOCGRECEIVING: /* Check if we are receiving right now */
717		irq->ifr_receiving = sirdev_is_receiving(dev);
718		break;
719
720	case SIOCSDTRRTS:
721		if (!capable(CAP_NET_ADMIN))
722			ret = -EPERM;
723		else
724			ret = sirdev_schedule_dtr_rts(dev, irq->ifr_dtr, irq->ifr_rts);
725		/* cannot sleep here for completion
726		 * we are called from network layer with rtnl hold
727		 */
728		break;
729
730	case SIOCSMODE:
731#if 0
732		if (!capable(CAP_NET_ADMIN))
733			ret = -EPERM;
734		else
735			ret = sirdev_schedule_mode(dev, irq->ifr_mode);
736		/* cannot sleep here for completion
737		 * we are called from network layer with rtnl hold
738		 */
739		break;
740#endif
741	default:
742		ret = -EOPNOTSUPP;
743	}
744	
745	return ret;
746}
747
748/* ----------------------------------------------------------------------------- */
749
750#define SIRBUF_ALLOCSIZE 4269	/* worst case size of a wrapped IrLAP frame */
751
752static int sirdev_alloc_buffers(struct sir_dev *dev)
753{
754	dev->tx_buff.truesize = SIRBUF_ALLOCSIZE;
755	dev->rx_buff.truesize = IRDA_SKB_MAX_MTU; 
756
757	/* Bootstrap ZeroCopy Rx */
758	dev->rx_buff.skb = __netdev_alloc_skb(dev->netdev, dev->rx_buff.truesize,
759					      GFP_KERNEL);
760	if (dev->rx_buff.skb == NULL)
761		return -ENOMEM;
762	skb_reserve(dev->rx_buff.skb, 1);
763	dev->rx_buff.head = dev->rx_buff.skb->data;
764
765	dev->tx_buff.head = kmalloc(dev->tx_buff.truesize, GFP_KERNEL);
766	if (dev->tx_buff.head == NULL) {
767		kfree_skb(dev->rx_buff.skb);
768		dev->rx_buff.skb = NULL;
769		dev->rx_buff.head = NULL;
770		return -ENOMEM;
771	}
772
773	dev->tx_buff.data = dev->tx_buff.head;
774	dev->rx_buff.data = dev->rx_buff.head;
775	dev->tx_buff.len = 0;
776	dev->rx_buff.len = 0;
777
778	dev->rx_buff.in_frame = FALSE;
779	dev->rx_buff.state = OUTSIDE_FRAME;
780	return 0;
781};
782
783static void sirdev_free_buffers(struct sir_dev *dev)
784{
785	kfree_skb(dev->rx_buff.skb);
786	kfree(dev->tx_buff.head);
787	dev->rx_buff.head = dev->tx_buff.head = NULL;
788	dev->rx_buff.skb = NULL;
789}
790
791static int sirdev_open(struct net_device *ndev)
792{
793	struct sir_dev *dev = netdev_priv(ndev);
794	const struct sir_driver *drv = dev->drv;
795
796	if (!drv)
797		return -ENODEV;
798
799	/* increase the reference count of the driver module before doing serious stuff */
800	if (!try_module_get(drv->owner))
801		return -ESTALE;
802
803	IRDA_DEBUG(2, "%s()\n", __func__);
804
805	if (sirdev_alloc_buffers(dev))
806		goto errout_dec;
807
808	if (!dev->drv->start_dev  ||  dev->drv->start_dev(dev))
809		goto errout_free;
810
811	sirdev_enable_rx(dev);
812	dev->raw_tx = 0;
813
814	netif_start_queue(ndev);
815	dev->irlap = irlap_open(ndev, &dev->qos, dev->hwname);
816	if (!dev->irlap)
817		goto errout_stop;
818
819	netif_wake_queue(ndev);
820
821	IRDA_DEBUG(2, "%s - done, speed = %d\n", __func__, dev->speed);
822
823	return 0;
824
825errout_stop:
826	atomic_set(&dev->enable_rx, 0);
827	if (dev->drv->stop_dev)
828		dev->drv->stop_dev(dev);
829errout_free:
830	sirdev_free_buffers(dev);
831errout_dec:
832	module_put(drv->owner);
833	return -EAGAIN;
834}
835
836static int sirdev_close(struct net_device *ndev)
837{
838	struct sir_dev *dev = netdev_priv(ndev);
839	const struct sir_driver *drv;
840
841//	IRDA_DEBUG(0, "%s\n", __func__);
842
843	netif_stop_queue(ndev);
844
845	down(&dev->fsm.sem);		/* block on pending config completion */
846
847	atomic_set(&dev->enable_rx, 0);
848
849	if (unlikely(!dev->irlap))
850		goto out;
851	irlap_close(dev->irlap);
852	dev->irlap = NULL;
853
854	drv = dev->drv;
855	if (unlikely(!drv  ||  !dev->priv))
856		goto out;
857
858	if (drv->stop_dev)
859		drv->stop_dev(dev);
860
861	sirdev_free_buffers(dev);
862	module_put(drv->owner);
863
864out:
865	dev->speed = 0;
866	up(&dev->fsm.sem);
867	return 0;
868}
869
870static const struct net_device_ops sirdev_ops = {
871	.ndo_start_xmit	= sirdev_hard_xmit,
872	.ndo_open	= sirdev_open,
873	.ndo_stop	= sirdev_close,
874	.ndo_do_ioctl	= sirdev_ioctl,
875};
876/* ----------------------------------------------------------------------------- */
877
878struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *name)
879{
880	struct net_device *ndev;
881	struct sir_dev *dev;
882
883	IRDA_DEBUG(0, "%s - %s\n", __func__, name);
884
885	/* instead of adding tests to protect against drv->do_write==NULL
886	 * at several places we refuse to create a sir_dev instance for
887	 * drivers which don't implement do_write.
888	 */
889	if (!drv ||  !drv->do_write)
890		return NULL;
891
892	/*
893	 *  Allocate new instance of the device
894	 */
895	ndev = alloc_irdadev(sizeof(*dev));
896	if (ndev == NULL) {
897		IRDA_ERROR("%s - Can't allocate memory for IrDA control block!\n", __func__);
 
898		goto out;
899	}
900	dev = netdev_priv(ndev);
901
902	irda_init_max_qos_capabilies(&dev->qos);
903	dev->qos.baud_rate.bits = IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
904	dev->qos.min_turn_time.bits = drv->qos_mtt_bits;
905	irda_qos_bits_to_value(&dev->qos);
906
907	strncpy(dev->hwname, name, sizeof(dev->hwname)-1);
908
909	atomic_set(&dev->enable_rx, 0);
910	dev->tx_skb = NULL;
911
912	spin_lock_init(&dev->tx_lock);
913	sema_init(&dev->fsm.sem, 1);
914
915	dev->drv = drv;
916	dev->netdev = ndev;
917
918	/* Override the network functions we need to use */
919	ndev->netdev_ops = &sirdev_ops;
920
921	if (register_netdev(ndev)) {
922		IRDA_ERROR("%s(), register_netdev() failed!\n", __func__);
 
923		goto out_freenetdev;
924	}
925
926	return dev;
927
928out_freenetdev:
929	free_netdev(ndev);
930out:
931	return NULL;
932}
933EXPORT_SYMBOL(sirdev_get_instance);
934
935int sirdev_put_instance(struct sir_dev *dev)
936{
937	int err = 0;
938
939	IRDA_DEBUG(0, "%s\n", __func__);
940
941	atomic_set(&dev->enable_rx, 0);
942
943	netif_carrier_off(dev->netdev);
944	netif_device_detach(dev->netdev);
945
946	if (dev->dongle_drv)
947		err = sirdev_schedule_dongle_close(dev);
948	if (err)
949		IRDA_ERROR("%s - error %d\n", __func__, err);
950
951	sirdev_close(dev->netdev);
952
953	down(&dev->fsm.sem);
954	dev->fsm.state = SIRDEV_STATE_DEAD;	/* mark staled */
955	dev->dongle_drv = NULL;
956	dev->priv = NULL;
957	up(&dev->fsm.sem);
958
959	/* Remove netdevice */
960	unregister_netdev(dev->netdev);
961
962	free_netdev(dev->netdev);
963
964	return 0;
965}
966EXPORT_SYMBOL(sirdev_put_instance);
967
968static int __init sir_wq_init(void)
969{
970	irda_sir_wq = create_singlethread_workqueue("irda_sir_wq");
971	if (!irda_sir_wq)
972		return -ENOMEM;
973	return 0;
974}
975
976static void __exit sir_wq_exit(void)
977{
978	destroy_workqueue(irda_sir_wq);
979}
980
981module_init(sir_wq_init);
982module_exit(sir_wq_exit);
983
984MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>");
985MODULE_DESCRIPTION("IrDA SIR core");
986MODULE_LICENSE("GPL");