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 
28 static 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 
sirdev_tx_complete_fsm(struct sir_dev * dev)36 static 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 
sirdev_config_fsm(struct work_struct * work)104 static 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->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 			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 
sirdev_schedule_request(struct sir_dev * dev,int initial_state,unsigned param)285 int 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 
sirdev_enable_rx(struct sir_dev * dev)322 void 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 
sirdev_is_receiving(struct sir_dev * dev)335 static 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 
sirdev_set_dongle(struct sir_dev * dev,IRDA_DONGLE type)343 int 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 }
357 EXPORT_SYMBOL(sirdev_set_dongle);
358 
359 /* used by dongle drivers for dongle programming */
360 
sirdev_raw_write(struct sir_dev * dev,const char * buf,int len)361 int 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 }
392 EXPORT_SYMBOL(sirdev_raw_write);
393 
394 /* seems some dongle drivers may need this */
395 
sirdev_raw_read(struct sir_dev * dev,char * buf,int len)396 int 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 }
415 EXPORT_SYMBOL(sirdev_raw_read);
416 
sirdev_set_dtr_rts(struct sir_dev * dev,int dtr,int rts)417 int 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 }
424 EXPORT_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 
sirdev_write_complete(struct sir_dev * dev)433 void 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 
525 done:
526 	spin_unlock_irqrestore(&dev->tx_lock, flags);
527 }
528 EXPORT_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 
sirdev_receive(struct sir_dev * dev,const unsigned char * cp,size_t count)535 int 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 }
581 EXPORT_SYMBOL(sirdev_receive);
582 
583 /**********************************************************************/
584 
585 /* callbacks from network layer */
586 
sirdev_hard_xmit(struct sk_buff * skb,struct net_device * ndev)587 static 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 
sirdev_ioctl(struct net_device * ndev,struct ifreq * rq,int cmd)678 static 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 
sirdev_alloc_buffers(struct sir_dev * dev)752 static 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 
sirdev_free_buffers(struct sir_dev * dev)783 static 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 
sirdev_open(struct net_device * ndev)791 static 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 
825 errout_stop:
826 	atomic_set(&dev->enable_rx, 0);
827 	if (dev->drv->stop_dev)
828 		dev->drv->stop_dev(dev);
829 errout_free:
830 	sirdev_free_buffers(dev);
831 errout_dec:
832 	module_put(drv->owner);
833 	return -EAGAIN;
834 }
835 
sirdev_close(struct net_device * ndev)836 static 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 
864 out:
865 	dev->speed = 0;
866 	up(&dev->fsm.sem);
867 	return 0;
868 }
869 
870 static 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 
sirdev_get_instance(const struct sir_driver * drv,const char * name)878 struct 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 
928 out_freenetdev:
929 	free_netdev(ndev);
930 out:
931 	return NULL;
932 }
933 EXPORT_SYMBOL(sirdev_get_instance);
934 
sirdev_put_instance(struct sir_dev * dev)935 int 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 }
966 EXPORT_SYMBOL(sirdev_put_instance);
967 
sir_wq_init(void)968 static 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 
sir_wq_exit(void)976 static void __exit sir_wq_exit(void)
977 {
978 	destroy_workqueue(irda_sir_wq);
979 }
980 
981 module_init(sir_wq_init);
982 module_exit(sir_wq_exit);
983 
984 MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>");
985 MODULE_DESCRIPTION("IrDA SIR core");
986 MODULE_LICENSE("GPL");
987