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  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			net_err_ratelimited("%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	pr_debug("%s(), <%ld>\n", __func__, jiffies);
113
114	do {
115		pr_debug("%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->set_speed) {
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			net_err_ratelimited("%s - undefined state\n", __func__);
255			fsm->result = -EINVAL;
256			/* fall thru */
257
258		case SIRDEV_STATE_ERROR:
259			net_err_ratelimited("%s - error: %d\n",
260					    __func__, fsm->result);
261
262#if 0	/* don't enable this before we have netdev->tx_timeout to recover */
263			netif_stop_queue(dev->netdev);
264#else
265			netif_wake_queue(dev->netdev);
266#endif
267			/* fall thru */
268
269		case SIRDEV_STATE_COMPLETE:
270			/* config change finished, so we are not busy any longer */
271			sirdev_enable_rx(dev);
272			up(&fsm->sem);
273			return;
274		}
275		fsm->state = next_state;
276	} while(!delay);
277
278	queue_delayed_work(irda_sir_wq, &fsm->work, msecs_to_jiffies(delay));
279}
280
281/* schedule some device configuration task for execution by kIrDAd
282 * on behalf of the above state machine.
283 * can be called from process or interrupt/tasklet context.
284 */
285
286int sirdev_schedule_request(struct sir_dev *dev, int initial_state, unsigned param)
287{
288	struct sir_fsm *fsm = &dev->fsm;
289
290	pr_debug("%s - state=0x%04x / param=%u\n", __func__,
291		 initial_state, param);
292
293	if (down_trylock(&fsm->sem)) {
294		if (in_interrupt()  ||  in_atomic()  ||  irqs_disabled()) {
295			pr_debug("%s(), state machine busy!\n", __func__);
296			return -EWOULDBLOCK;
297		} else
298			down(&fsm->sem);
299	}
300
301	if (fsm->state == SIRDEV_STATE_DEAD) {
302		/* race with sirdev_close should never happen */
303		net_err_ratelimited("%s(), instance staled!\n", __func__);
304		up(&fsm->sem);
305		return -ESTALE;		/* or better EPIPE? */
306	}
307
308	netif_stop_queue(dev->netdev);
309	atomic_set(&dev->enable_rx, 0);
310
311	fsm->state = initial_state;
312	fsm->param = param;
313	fsm->result = 0;
314
315	INIT_DELAYED_WORK(&fsm->work, sirdev_config_fsm);
316	queue_delayed_work(irda_sir_wq, &fsm->work, 0);
317	return 0;
318}
319
320
321/***************************************************************************/
322
323void sirdev_enable_rx(struct sir_dev *dev)
324{
325	if (unlikely(atomic_read(&dev->enable_rx)))
326		return;
327
328	/* flush rx-buffer - should also help in case of problems with echo cancelation */
329	dev->rx_buff.data = dev->rx_buff.head;
330	dev->rx_buff.len = 0;
331	dev->rx_buff.in_frame = FALSE;
332	dev->rx_buff.state = OUTSIDE_FRAME;
333	atomic_set(&dev->enable_rx, 1);
334}
335
336static int sirdev_is_receiving(struct sir_dev *dev)
337{
338	if (!atomic_read(&dev->enable_rx))
339		return 0;
340
341	return dev->rx_buff.state != OUTSIDE_FRAME;
342}
343
344int sirdev_set_dongle(struct sir_dev *dev, IRDA_DONGLE type)
345{
346	int err;
347
348	pr_debug("%s : requesting dongle %d.\n", __func__, type);
349
350	err = sirdev_schedule_dongle_open(dev, type);
351	if (unlikely(err))
352		return err;
353	down(&dev->fsm.sem);		/* block until config change completed */
354	err = dev->fsm.result;
355	up(&dev->fsm.sem);
356	return err;
357}
358EXPORT_SYMBOL(sirdev_set_dongle);
359
360/* used by dongle drivers for dongle programming */
361
362int sirdev_raw_write(struct sir_dev *dev, const char *buf, int len)
363{
364	unsigned long flags;
365	int ret;
366
367	if (unlikely(len > dev->tx_buff.truesize))
368		return -ENOSPC;
369
370	spin_lock_irqsave(&dev->tx_lock, flags);	/* serialize with other tx operations */
371	while (dev->tx_buff.len > 0) {			/* wait until tx idle */
372		spin_unlock_irqrestore(&dev->tx_lock, flags);
373		msleep(10);
374		spin_lock_irqsave(&dev->tx_lock, flags);
375	}
376
377	dev->tx_buff.data = dev->tx_buff.head;
378	memcpy(dev->tx_buff.data, buf, len);	
379	dev->tx_buff.len = len;
380
381	ret = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
382	if (ret > 0) {
383		pr_debug("%s(), raw-tx started\n", __func__);
384
385		dev->tx_buff.data += ret;
386		dev->tx_buff.len -= ret;
387		dev->raw_tx = 1;
388		ret = len;		/* all data is going to be sent */
389	}
390	spin_unlock_irqrestore(&dev->tx_lock, flags);
391	return ret;
392}
393EXPORT_SYMBOL(sirdev_raw_write);
394
395/* seems some dongle drivers may need this */
396
397int sirdev_raw_read(struct sir_dev *dev, char *buf, int len)
398{
399	int count;
400
401	if (atomic_read(&dev->enable_rx))
402		return -EIO;		/* fail if we expect irda-frames */
403
404	count = (len < dev->rx_buff.len) ? len : dev->rx_buff.len;
405
406	if (count > 0) {
407		memcpy(buf, dev->rx_buff.data, count);
408		dev->rx_buff.data += count;
409		dev->rx_buff.len -= count;
410	}
411
412	/* remaining stuff gets flushed when re-enabling normal rx */
413
414	return count;
415}
416EXPORT_SYMBOL(sirdev_raw_read);
417
418int sirdev_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
419{
420	int ret = -ENXIO;
421	if (dev->drv->set_dtr_rts)
422		ret =  dev->drv->set_dtr_rts(dev, dtr, rts);
423	return ret;
424}
425EXPORT_SYMBOL(sirdev_set_dtr_rts);
426
427/**********************************************************************/
428
429/* called from client driver - likely with bh-context - to indicate
430 * it made some progress with transmission. Hence we send the next
431 * chunk, if any, or complete the skb otherwise
432 */
433
434void sirdev_write_complete(struct sir_dev *dev)
435{
436	unsigned long flags;
437	struct sk_buff *skb;
438	int actual = 0;
439	int err;
440	
441	spin_lock_irqsave(&dev->tx_lock, flags);
442
443	pr_debug("%s() - dev->tx_buff.len = %d\n",
444		 __func__, dev->tx_buff.len);
445
446	if (likely(dev->tx_buff.len > 0))  {
447		/* Write data left in transmit buffer */
448		actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
449
450		if (likely(actual>0)) {
451			dev->tx_buff.data += actual;
452			dev->tx_buff.len  -= actual;
453		}
454		else if (unlikely(actual<0)) {
455			/* could be dropped later when we have tx_timeout to recover */
456			net_err_ratelimited("%s: drv->do_write failed (%d)\n",
457					    __func__, actual);
458			if ((skb=dev->tx_skb) != NULL) {
459				dev->tx_skb = NULL;
460				dev_kfree_skb_any(skb);
461				dev->netdev->stats.tx_errors++;
462				dev->netdev->stats.tx_dropped++;
463			}
464			dev->tx_buff.len = 0;
465		}
466		if (dev->tx_buff.len > 0)
467			goto done;	/* more data to send later */
468	}
469
470	if (unlikely(dev->raw_tx != 0)) {
471		/* in raw mode we are just done now after the buffer was sent
472		 * completely. Since this was requested by some dongle driver
473		 * running under the control of the irda-thread we must take
474		 * care here not to re-enable the queue. The queue will be
475		 * restarted when the irda-thread has completed the request.
476		 */
477
478		pr_debug("%s(), raw-tx done\n", __func__);
479		dev->raw_tx = 0;
480		goto done;	/* no post-frame handling in raw mode */
481	}
482
483	/* we have finished now sending this skb.
484	 * update statistics and free the skb.
485	 * finally we check and trigger a pending speed change, if any.
486	 * if not we switch to rx mode and wake the queue for further
487	 * packets.
488	 * note the scheduled speed request blocks until the lower
489	 * client driver and the corresponding hardware has really
490	 * finished sending all data (xmit fifo drained f.e.)
491	 * before the speed change gets finally done and the queue
492	 * re-activated.
493	 */
494
495	pr_debug("%s(), finished with frame!\n", __func__);
496		
497	if ((skb=dev->tx_skb) != NULL) {
498		dev->tx_skb = NULL;
499		dev->netdev->stats.tx_packets++;
500		dev->netdev->stats.tx_bytes += skb->len;
501		dev_kfree_skb_any(skb);
502	}
503
504	if (unlikely(dev->new_speed > 0)) {
505		pr_debug("%s(), Changing speed!\n", __func__);
506		err = sirdev_schedule_speed(dev, dev->new_speed);
507		if (unlikely(err)) {
508			/* should never happen
509			 * forget the speed change and hope the stack recovers
510			 */
511			net_err_ratelimited("%s - schedule speed change failed: %d\n",
512					    __func__, err);
513			netif_wake_queue(dev->netdev);
514		}
515		/* else: success
516		 *	speed change in progress now
517		 *	on completion dev->new_speed gets cleared,
518		 *	rx-reenabled and the queue restarted
519		 */
520	}
521	else {
522		sirdev_enable_rx(dev);
523		netif_wake_queue(dev->netdev);
524	}
525
526done:
527	spin_unlock_irqrestore(&dev->tx_lock, flags);
528}
529EXPORT_SYMBOL(sirdev_write_complete);
530
531/* called from client driver - likely with bh-context - to give us
532 * some more received bytes. We put them into the rx-buffer,
533 * normally unwrapping and building LAP-skb's (unless rx disabled)
534 */
535
536int sirdev_receive(struct sir_dev *dev, const unsigned char *cp, size_t count) 
537{
538	if (!dev || !dev->netdev) {
539		net_warn_ratelimited("%s(), not ready yet!\n", __func__);
540		return -1;
541	}
542
543	if (!dev->irlap) {
544		net_warn_ratelimited("%s - too early: %p / %zd!\n",
545				     __func__, cp, count);
546		return -1;
547	}
548
549	if (cp==NULL) {
550		/* error already at lower level receive
551		 * just update stats and set media busy
552		 */
553		irda_device_set_media_busy(dev->netdev, TRUE);
554		dev->netdev->stats.rx_dropped++;
555		pr_debug("%s; rx-drop: %zd\n", __func__, count);
556		return 0;
557	}
558
559	/* Read the characters into the buffer */
560	if (likely(atomic_read(&dev->enable_rx))) {
561		while (count--)
562			/* Unwrap and destuff one byte */
563			async_unwrap_char(dev->netdev, &dev->netdev->stats,
564					  &dev->rx_buff, *cp++);
565	} else {
566		while (count--) {
567			/* rx not enabled: save the raw bytes and never
568			 * trigger any netif_rx. The received bytes are flushed
569			 * later when we re-enable rx but might be read meanwhile
570			 * by the dongle driver.
571			 */
572			dev->rx_buff.data[dev->rx_buff.len++] = *cp++;
573
574			/* What should we do when the buffer is full? */
575			if (unlikely(dev->rx_buff.len == dev->rx_buff.truesize))
576				dev->rx_buff.len = 0;
577		}
578	}
579
580	return 0;
581}
582EXPORT_SYMBOL(sirdev_receive);
583
584/**********************************************************************/
585
586/* callbacks from network layer */
587
588static netdev_tx_t sirdev_hard_xmit(struct sk_buff *skb,
589					  struct net_device *ndev)
590{
591	struct sir_dev *dev = netdev_priv(ndev);
592	unsigned long flags;
593	int actual = 0;
594	int err;
595	s32 speed;
596
597	IRDA_ASSERT(dev != NULL, return NETDEV_TX_OK;);
598
599	netif_stop_queue(ndev);
600
601	pr_debug("%s(), skb->len = %d\n", __func__, skb->len);
602
603	speed = irda_get_next_speed(skb);
604	if ((speed != dev->speed) && (speed != -1)) {
605		if (!skb->len) {
606			err = sirdev_schedule_speed(dev, speed);
607			if (unlikely(err == -EWOULDBLOCK)) {
608				/* Failed to initiate the speed change, likely the fsm
609				 * is still busy (pretty unlikely, but...)
610				 * We refuse to accept the skb and return with the queue
611				 * stopped so the network layer will retry after the
612				 * fsm completes and wakes the queue.
613				 */
614				 return NETDEV_TX_BUSY;
615			}
616			else if (unlikely(err)) {
617				/* other fatal error - forget the speed change and
618				 * hope the stack will recover somehow
619				 */
620				 netif_start_queue(ndev);
621			}
622			/* else: success
623			 *	speed change in progress now
624			 *	on completion the queue gets restarted
625			 */
626
627			dev_kfree_skb_any(skb);
628			return NETDEV_TX_OK;
629		} else
630			dev->new_speed = speed;
631	}
632
633	/* Init tx buffer*/
634	dev->tx_buff.data = dev->tx_buff.head;
635
636	/* Check problems */
637	if(spin_is_locked(&dev->tx_lock)) {
638		pr_debug("%s(), write not completed\n", __func__);
639	}
640
641	/* serialize with write completion */
642	spin_lock_irqsave(&dev->tx_lock, flags);
643
644        /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
645	dev->tx_buff.len = async_wrap_skb(skb, dev->tx_buff.data, dev->tx_buff.truesize); 
646
647	/* transmission will start now - disable receive.
648	 * if we are just in the middle of an incoming frame,
649	 * treat it as collision. probably it's a good idea to
650	 * reset the rx_buf OUTSIDE_FRAME in this case too?
651	 */
652	atomic_set(&dev->enable_rx, 0);
653	if (unlikely(sirdev_is_receiving(dev)))
654		dev->netdev->stats.collisions++;
655
656	actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
657
658	if (likely(actual > 0)) {
659		dev->tx_skb = skb;
660		dev->tx_buff.data += actual;
661		dev->tx_buff.len -= actual;
662	}
663	else if (unlikely(actual < 0)) {
664		/* could be dropped later when we have tx_timeout to recover */
665		net_err_ratelimited("%s: drv->do_write failed (%d)\n",
666				    __func__, actual);
667		dev_kfree_skb_any(skb);
668		dev->netdev->stats.tx_errors++;
669		dev->netdev->stats.tx_dropped++;
670		netif_wake_queue(ndev);
671	}
672	spin_unlock_irqrestore(&dev->tx_lock, flags);
673
674	return NETDEV_TX_OK;
675}
676
677/* called from network layer with rtnl hold */
678
679static int sirdev_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
680{
681	struct if_irda_req *irq = (struct if_irda_req *) rq;
682	struct sir_dev *dev = netdev_priv(ndev);
683	int ret = 0;
684
685	IRDA_ASSERT(dev != NULL, return -1;);
686
687	pr_debug("%s(), %s, (cmd=0x%X)\n", __func__, ndev->name, cmd);
688	
689	switch (cmd) {
690	case SIOCSBANDWIDTH: /* Set bandwidth */
691		if (!capable(CAP_NET_ADMIN))
692			ret = -EPERM;
693		else
694			ret = sirdev_schedule_speed(dev, irq->ifr_baudrate);
695		/* cannot sleep here for completion
696		 * we are called from network layer with rtnl hold
697		 */
698		break;
699
700	case SIOCSDONGLE: /* Set dongle */
701		if (!capable(CAP_NET_ADMIN))
702			ret = -EPERM;
703		else
704			ret = sirdev_schedule_dongle_open(dev, irq->ifr_dongle);
705		/* cannot sleep here for completion
706		 * we are called from network layer with rtnl hold
707		 */
708		break;
709
710	case SIOCSMEDIABUSY: /* Set media busy */
711		if (!capable(CAP_NET_ADMIN))
712			ret = -EPERM;
713		else
714			irda_device_set_media_busy(dev->netdev, TRUE);
715		break;
716
717	case SIOCGRECEIVING: /* Check if we are receiving right now */
718		irq->ifr_receiving = sirdev_is_receiving(dev);
719		break;
720
721	case SIOCSDTRRTS:
722		if (!capable(CAP_NET_ADMIN))
723			ret = -EPERM;
724		else
725			ret = sirdev_schedule_dtr_rts(dev, irq->ifr_dtr, irq->ifr_rts);
726		/* cannot sleep here for completion
727		 * we are called from network layer with rtnl hold
728		 */
729		break;
730
731	case SIOCSMODE:
732#if 0
733		if (!capable(CAP_NET_ADMIN))
734			ret = -EPERM;
735		else
736			ret = sirdev_schedule_mode(dev, irq->ifr_mode);
737		/* cannot sleep here for completion
738		 * we are called from network layer with rtnl hold
739		 */
740		break;
741#endif
742	default:
743		ret = -EOPNOTSUPP;
744	}
745	
746	return ret;
747}
748
749/* ----------------------------------------------------------------------------- */
750
751#define SIRBUF_ALLOCSIZE 4269	/* worst case size of a wrapped IrLAP frame */
752
753static int sirdev_alloc_buffers(struct sir_dev *dev)
754{
755	dev->tx_buff.truesize = SIRBUF_ALLOCSIZE;
756	dev->rx_buff.truesize = IRDA_SKB_MAX_MTU; 
757
758	/* Bootstrap ZeroCopy Rx */
759	dev->rx_buff.skb = __netdev_alloc_skb(dev->netdev, dev->rx_buff.truesize,
760					      GFP_KERNEL);
761	if (dev->rx_buff.skb == NULL)
762		return -ENOMEM;
763	skb_reserve(dev->rx_buff.skb, 1);
764	dev->rx_buff.head = dev->rx_buff.skb->data;
765
766	dev->tx_buff.head = kmalloc(dev->tx_buff.truesize, GFP_KERNEL);
767	if (dev->tx_buff.head == NULL) {
768		kfree_skb(dev->rx_buff.skb);
769		dev->rx_buff.skb = NULL;
770		dev->rx_buff.head = NULL;
771		return -ENOMEM;
772	}
773
774	dev->tx_buff.data = dev->tx_buff.head;
775	dev->rx_buff.data = dev->rx_buff.head;
776	dev->tx_buff.len = 0;
777	dev->rx_buff.len = 0;
778
779	dev->rx_buff.in_frame = FALSE;
780	dev->rx_buff.state = OUTSIDE_FRAME;
781	return 0;
782};
783
784static void sirdev_free_buffers(struct sir_dev *dev)
785{
786	kfree_skb(dev->rx_buff.skb);
787	kfree(dev->tx_buff.head);
788	dev->rx_buff.head = dev->tx_buff.head = NULL;
789	dev->rx_buff.skb = NULL;
790}
791
792static int sirdev_open(struct net_device *ndev)
793{
794	struct sir_dev *dev = netdev_priv(ndev);
795	const struct sir_driver *drv = dev->drv;
796
797	if (!drv)
798		return -ENODEV;
799
800	/* increase the reference count of the driver module before doing serious stuff */
801	if (!try_module_get(drv->owner))
802		return -ESTALE;
803
804	if (sirdev_alloc_buffers(dev))
805		goto errout_dec;
806
807	if (!dev->drv->start_dev  ||  dev->drv->start_dev(dev))
808		goto errout_free;
809
810	sirdev_enable_rx(dev);
811	dev->raw_tx = 0;
812
813	netif_start_queue(ndev);
814	dev->irlap = irlap_open(ndev, &dev->qos, dev->hwname);
815	if (!dev->irlap)
816		goto errout_stop;
817
818	netif_wake_queue(ndev);
819
820	pr_debug("%s - done, speed = %d\n", __func__, dev->speed);
821
822	return 0;
823
824errout_stop:
825	atomic_set(&dev->enable_rx, 0);
826	if (dev->drv->stop_dev)
827		dev->drv->stop_dev(dev);
828errout_free:
829	sirdev_free_buffers(dev);
830errout_dec:
831	module_put(drv->owner);
832	return -EAGAIN;
833}
834
835static int sirdev_close(struct net_device *ndev)
836{
837	struct sir_dev *dev = netdev_priv(ndev);
838	const struct sir_driver *drv;
839
840/* pr_debug("%s\n", __func__); */
841
842	netif_stop_queue(ndev);
843
844	down(&dev->fsm.sem);		/* block on pending config completion */
845
846	atomic_set(&dev->enable_rx, 0);
847
848	if (unlikely(!dev->irlap))
849		goto out;
850	irlap_close(dev->irlap);
851	dev->irlap = NULL;
852
853	drv = dev->drv;
854	if (unlikely(!drv  ||  !dev->priv))
855		goto out;
856
857	if (drv->stop_dev)
858		drv->stop_dev(dev);
859
860	sirdev_free_buffers(dev);
861	module_put(drv->owner);
862
863out:
864	dev->speed = 0;
865	up(&dev->fsm.sem);
866	return 0;
867}
868
869static const struct net_device_ops sirdev_ops = {
870	.ndo_start_xmit	= sirdev_hard_xmit,
871	.ndo_open	= sirdev_open,
872	.ndo_stop	= sirdev_close,
873	.ndo_do_ioctl	= sirdev_ioctl,
874};
875/* ----------------------------------------------------------------------------- */
876
877struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *name)
878{
879	struct net_device *ndev;
880	struct sir_dev *dev;
881
882	pr_debug("%s - %s\n", __func__, name);
883
884	/* instead of adding tests to protect against drv->do_write==NULL
885	 * at several places we refuse to create a sir_dev instance for
886	 * drivers which don't implement do_write.
887	 */
888	if (!drv ||  !drv->do_write)
889		return NULL;
890
891	/*
892	 *  Allocate new instance of the device
893	 */
894	ndev = alloc_irdadev(sizeof(*dev));
895	if (ndev == NULL) {
896		net_err_ratelimited("%s - Can't allocate memory for IrDA control block!\n",
897				    __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		net_err_ratelimited("%s(), register_netdev() failed!\n",
923				    __func__);
924		goto out_freenetdev;
925	}
926
927	return dev;
928
929out_freenetdev:
930	free_netdev(ndev);
931out:
932	return NULL;
933}
934EXPORT_SYMBOL(sirdev_get_instance);
935
936int sirdev_put_instance(struct sir_dev *dev)
937{
938	int err = 0;
939
940	pr_debug("%s\n", __func__);
941
942	atomic_set(&dev->enable_rx, 0);
943
944	netif_carrier_off(dev->netdev);
945	netif_device_detach(dev->netdev);
946
947	if (dev->dongle_drv)
948		err = sirdev_schedule_dongle_close(dev);
949	if (err)
950		net_err_ratelimited("%s - error %d\n", __func__, err);
951
952	sirdev_close(dev->netdev);
953
954	down(&dev->fsm.sem);
955	dev->fsm.state = SIRDEV_STATE_DEAD;	/* mark staled */
956	dev->dongle_drv = NULL;
957	dev->priv = NULL;
958	up(&dev->fsm.sem);
959
960	/* Remove netdevice */
961	unregister_netdev(dev->netdev);
962
963	free_netdev(dev->netdev);
964
965	return 0;
966}
967EXPORT_SYMBOL(sirdev_put_instance);
968
969static int __init sir_wq_init(void)
970{
971	irda_sir_wq = create_singlethread_workqueue("irda_sir_wq");
972	if (!irda_sir_wq)
973		return -ENOMEM;
974	return 0;
975}
976
977static void __exit sir_wq_exit(void)
978{
979	destroy_workqueue(irda_sir_wq);
980}
981
982module_init(sir_wq_init);
983module_exit(sir_wq_exit);
984
985MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>");
986MODULE_DESCRIPTION("IrDA SIR core");
987MODULE_LICENSE("GPL");