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