/spare/repo/netdev-2.6 branch 'ieee80211'
[linux-2.6] / drivers / net / irda / irtty-sir.c
1 /*********************************************************************
2  *                
3  * Filename:      irtty-sir.c
4  * Version:       2.0
5  * Description:   IrDA line discipline implementation
6  * Status:        Experimental.
7  * Author:        Dag Brattli <dagb@cs.uit.no>
8  * Created at:    Tue Dec  9 21:18:38 1997
9  * Modified at:   Sun Oct 27 22:13:30 2002
10  * Modified by:   Martin Diehl <mad@mdiehl.de>
11  * Sources:       slip.c by Laurence Culhane,   <loz@holmes.demon.co.uk>
12  *                          Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
13  * 
14  *     Copyright (c) 1998-2000 Dag Brattli,
15  *     Copyright (c) 2002 Martin Diehl,
16  *     All Rights Reserved.
17  *      
18  *     This program is free software; you can redistribute it and/or 
19  *     modify it under the terms of the GNU General Public License as 
20  *     published by the Free Software Foundation; either version 2 of 
21  *     the License, or (at your option) any later version.
22  *  
23  *     Neither Dag Brattli nor University of Tromsø admit liability nor
24  *     provide warranty for any of this software. This material is 
25  *     provided "AS-IS" and at no charge.
26  *     
27  ********************************************************************/    
28
29 #include <linux/module.h>
30 #include <linux/kernel.h>
31 #include <linux/tty.h>
32 #include <linux/init.h>
33 #include <asm/uaccess.h>
34 #include <linux/smp_lock.h>
35 #include <linux/delay.h>
36
37 #include <net/irda/irda.h>
38 #include <net/irda/irda_device.h>
39
40 #include "sir-dev.h"
41 #include "irtty-sir.h"
42
43 static int qos_mtt_bits = 0x03;      /* 5 ms or more */
44
45 module_param(qos_mtt_bits, int, 0);
46 MODULE_PARM_DESC(qos_mtt_bits, "Minimum Turn Time");
47
48 /* ------------------------------------------------------- */
49
50 /* device configuration callbacks always invoked with irda-thread context */
51
52 /* find out, how many chars we have in buffers below us
53  * this is allowed to lie, i.e. return less chars than we
54  * actually have. The returned value is used to determine
55  * how long the irdathread should wait before doing the
56  * real blocking wait_until_sent()
57  */
58
59 static int irtty_chars_in_buffer(struct sir_dev *dev)
60 {
61         struct sirtty_cb *priv = dev->priv;
62
63         IRDA_ASSERT(priv != NULL, return -1;);
64         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return -1;);
65
66         return priv->tty->driver->chars_in_buffer(priv->tty);
67 }
68
69 /* Wait (sleep) until underlaying hardware finished transmission
70  * i.e. hardware buffers are drained
71  * this must block and not return before all characters are really sent
72  *
73  * If the tty sits on top of a 16550A-like uart, there are typically
74  * up to 16 bytes in the fifo - f.e. 9600 bps 8N1 needs 16.7 msec
75  *
76  * With usbserial the uart-fifo is basically replaced by the converter's
77  * outgoing endpoint buffer, which can usually hold 64 bytes (at least).
78  * With pl2303 it appears we are safe with 60msec here.
79  *
80  * I really wish all serial drivers would provide
81  * correct implementation of wait_until_sent()
82  */
83
84 #define USBSERIAL_TX_DONE_DELAY 60
85
86 static void irtty_wait_until_sent(struct sir_dev *dev)
87 {
88         struct sirtty_cb *priv = dev->priv;
89         struct tty_struct *tty;
90
91         IRDA_ASSERT(priv != NULL, return;);
92         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return;);
93
94         tty = priv->tty;
95         if (tty->driver->wait_until_sent) {
96                 lock_kernel();
97                 tty->driver->wait_until_sent(tty, msecs_to_jiffies(100));
98                 unlock_kernel();
99         }
100         else {
101                 msleep(USBSERIAL_TX_DONE_DELAY);
102         }
103 }
104
105 /* 
106  *  Function irtty_change_speed (dev, speed)
107  *
108  *    Change the speed of the serial port.
109  *
110  * This may sleep in set_termios (usbserial driver f.e.) and must
111  * not be called from interrupt/timer/tasklet therefore.
112  * All such invocations are deferred to kIrDAd now so we can sleep there.
113  */
114
115 static int irtty_change_speed(struct sir_dev *dev, unsigned speed)
116 {
117         struct sirtty_cb *priv = dev->priv;
118         struct tty_struct *tty;
119         struct termios old_termios;
120         int cflag;
121
122         IRDA_ASSERT(priv != NULL, return -1;);
123         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return -1;);
124
125         tty = priv->tty;
126
127         lock_kernel();
128         old_termios = *(tty->termios);
129         cflag = tty->termios->c_cflag;
130
131         cflag &= ~CBAUD;
132
133         IRDA_DEBUG(2, "%s(), Setting speed to %d\n", __FUNCTION__, speed);
134
135         switch (speed) {
136         case 1200:
137                 cflag |= B1200;
138                 break;
139         case 2400:
140                 cflag |= B2400;
141                 break;
142         case 4800:
143                 cflag |= B4800;
144                 break;
145         case 19200:
146                 cflag |= B19200;
147                 break;
148         case 38400:
149                 cflag |= B38400;
150                 break;
151         case 57600:
152                 cflag |= B57600;
153                 break;
154         case 115200:
155                 cflag |= B115200;
156                 break;
157         case 9600:
158         default:
159                 cflag |= B9600;
160                 break;
161         }       
162
163         tty->termios->c_cflag = cflag;
164         if (tty->driver->set_termios)
165                 tty->driver->set_termios(tty, &old_termios);
166         unlock_kernel();
167
168         priv->io.speed = speed;
169
170         return 0;
171 }
172
173 /*
174  * Function irtty_set_dtr_rts (dev, dtr, rts)
175  *
176  *    This function can be used by dongles etc. to set or reset the status
177  *    of the dtr and rts lines
178  */
179
180 static int irtty_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
181 {
182         struct sirtty_cb *priv = dev->priv;
183         int set = 0;
184         int clear = 0;
185
186         IRDA_ASSERT(priv != NULL, return -1;);
187         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return -1;);
188
189         if (rts)
190                 set |= TIOCM_RTS;
191         else
192                 clear |= TIOCM_RTS;
193         if (dtr)
194                 set |= TIOCM_DTR;
195         else
196                 clear |= TIOCM_DTR;
197
198         /*
199          * We can't use ioctl() because it expects a non-null file structure,
200          * and we don't have that here.
201          * This function is not yet defined for all tty driver, so
202          * let's be careful... Jean II
203          */
204         IRDA_ASSERT(priv->tty->driver->tiocmset != NULL, return -1;);
205         priv->tty->driver->tiocmset(priv->tty, NULL, set, clear);
206
207         return 0;
208 }
209
210 /* ------------------------------------------------------- */
211
212 /* called from sir_dev when there is more data to send
213  * context is either netdev->hard_xmit or some transmit-completion bh
214  * i.e. we are under spinlock here and must not sleep.
215  */
216
217 static int irtty_do_write(struct sir_dev *dev, const unsigned char *ptr, size_t len)
218 {
219         struct sirtty_cb *priv = dev->priv;
220         struct tty_struct *tty;
221         int writelen;
222
223         IRDA_ASSERT(priv != NULL, return -1;);
224         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return -1;);
225
226         tty = priv->tty;
227         if (!tty->driver->write)
228                 return 0;
229         tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
230         if (tty->driver->write_room) {
231                 writelen = tty->driver->write_room(tty);
232                 if (writelen > len)
233                         writelen = len;
234         }
235         else
236                 writelen = len;
237         return tty->driver->write(tty, ptr, writelen);
238 }
239
240 /* ------------------------------------------------------- */
241
242 /* irda line discipline callbacks */
243
244 /* 
245  *  Function irtty_receive_buf( tty, cp, count)
246  *
247  *    Handle the 'receiver data ready' interrupt.  This function is called
248  *    by the 'tty_io' module in the kernel when a block of IrDA data has
249  *    been received, which can now be decapsulated and delivered for
250  *    further processing 
251  *
252  * calling context depends on underlying driver and tty->low_latency!
253  * for example (low_latency: 1 / 0):
254  * serial.c:    uart-interrupt / softint
255  * usbserial:   urb-complete-interrupt / softint
256  */
257
258 static void irtty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
259                               char *fp, int count) 
260 {
261         struct sir_dev *dev;
262         struct sirtty_cb *priv = tty->disc_data;
263         int     i;
264
265         IRDA_ASSERT(priv != NULL, return;);
266         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return;);
267
268         if (unlikely(count==0))         /* yes, this happens */
269                 return;
270
271         dev = priv->dev;
272         if (!dev) {
273                 IRDA_WARNING("%s(), not ready yet!\n", __FUNCTION__);
274                 return;
275         }
276
277         for (i = 0; i < count; i++) {
278                 /* 
279                  *  Characters received with a parity error, etc?
280                  */
281                 if (fp && *fp++) { 
282                         IRDA_DEBUG(0, "Framing or parity error!\n");
283                         sirdev_receive(dev, NULL, 0);   /* notify sir_dev (updating stats) */
284                         return;
285                 }
286         }
287
288         sirdev_receive(dev, cp, count);
289 }
290
291 /*
292  * Function irtty_receive_room (tty)
293  *
294  *    Used by the TTY to find out how much data we can receive at a time
295  * 
296 */
297 static int irtty_receive_room(struct tty_struct *tty) 
298 {
299         struct sirtty_cb *priv = tty->disc_data;
300
301         IRDA_ASSERT(priv != NULL, return 0;);
302         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return 0;);
303
304         return 65536;  /* We can handle an infinite amount of data. :-) */
305 }
306
307 /*
308  * Function irtty_write_wakeup (tty)
309  *
310  *    Called by the driver when there's room for more data.  If we have
311  *    more packets to send, we send them here.
312  *
313  */
314 static void irtty_write_wakeup(struct tty_struct *tty) 
315 {
316         struct sirtty_cb *priv = tty->disc_data;
317
318         IRDA_ASSERT(priv != NULL, return;);
319         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return;);
320
321         tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
322
323         if (priv->dev)
324                 sirdev_write_complete(priv->dev);
325 }
326
327 /* ------------------------------------------------------- */
328
329 /*
330  * Function irtty_stop_receiver (tty, stop)
331  *
332  */
333
334 static inline void irtty_stop_receiver(struct tty_struct *tty, int stop)
335 {
336         struct termios old_termios;
337         int cflag;
338
339         lock_kernel();
340         old_termios = *(tty->termios);
341         cflag = tty->termios->c_cflag;
342         
343         if (stop)
344                 cflag &= ~CREAD;
345         else
346                 cflag |= CREAD;
347
348         tty->termios->c_cflag = cflag;
349         if (tty->driver->set_termios)
350                 tty->driver->set_termios(tty, &old_termios);
351         unlock_kernel();
352 }
353
354 /*****************************************************************/
355
356 /* serialize ldisc open/close with sir_dev */
357 static DECLARE_MUTEX(irtty_sem);
358
359 /* notifier from sir_dev when irda% device gets opened (ifup) */
360
361 static int irtty_start_dev(struct sir_dev *dev)
362 {
363         struct sirtty_cb *priv;
364         struct tty_struct *tty;
365
366         /* serialize with ldisc open/close */
367         down(&irtty_sem);
368
369         priv = dev->priv;
370         if (unlikely(!priv || priv->magic!=IRTTY_MAGIC)) {
371                 up(&irtty_sem);
372                 return -ESTALE;
373         }
374
375         tty = priv->tty;
376
377         if (tty->driver->start)
378                 tty->driver->start(tty);
379         /* Make sure we can receive more data */
380         irtty_stop_receiver(tty, FALSE);
381
382         up(&irtty_sem);
383         return 0;
384 }
385
386 /* notifier from sir_dev when irda% device gets closed (ifdown) */
387
388 static int irtty_stop_dev(struct sir_dev *dev)
389 {
390         struct sirtty_cb *priv;
391         struct tty_struct *tty;
392
393         /* serialize with ldisc open/close */
394         down(&irtty_sem);
395
396         priv = dev->priv;
397         if (unlikely(!priv || priv->magic!=IRTTY_MAGIC)) {
398                 up(&irtty_sem);
399                 return -ESTALE;
400         }
401
402         tty = priv->tty;
403
404         /* Make sure we don't receive more data */
405         irtty_stop_receiver(tty, TRUE);
406         if (tty->driver->stop)
407                 tty->driver->stop(tty);
408
409         up(&irtty_sem);
410
411         return 0;
412 }
413
414 /* ------------------------------------------------------- */
415
416 static struct sir_driver sir_tty_drv = {
417         .owner                  = THIS_MODULE,
418         .driver_name            = "sir_tty",
419         .start_dev              = irtty_start_dev,
420         .stop_dev               = irtty_stop_dev,
421         .do_write               = irtty_do_write,
422         .chars_in_buffer        = irtty_chars_in_buffer,
423         .wait_until_sent        = irtty_wait_until_sent,
424         .set_speed              = irtty_change_speed,
425         .set_dtr_rts            = irtty_set_dtr_rts,
426 };
427
428 /* ------------------------------------------------------- */
429
430 /*
431  * Function irtty_ioctl (tty, file, cmd, arg)
432  *
433  *     The Swiss army knife of system calls :-)
434  *
435  */
436 static int irtty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
437 {
438         struct irtty_info { char name[6]; } info;
439         struct sir_dev *dev;
440         struct sirtty_cb *priv = tty->disc_data;
441         int err = 0;
442
443         IRDA_ASSERT(priv != NULL, return -ENODEV;);
444         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return -EBADR;);
445
446         IRDA_DEBUG(3, "%s(cmd=0x%X)\n", __FUNCTION__, cmd);
447
448         dev = priv->dev;
449         IRDA_ASSERT(dev != NULL, return -1;);
450
451         switch (cmd) {
452         case TCGETS:
453         case TCGETA:
454                 err = n_tty_ioctl(tty, file, cmd, arg);
455                 break;
456
457         case IRTTY_IOCTDONGLE:
458                 /* this call blocks for completion */
459                 err = sirdev_set_dongle(dev, (IRDA_DONGLE) arg);
460                 break;
461
462         case IRTTY_IOCGET:
463                 IRDA_ASSERT(dev->netdev != NULL, return -1;);
464
465                 memset(&info, 0, sizeof(info)); 
466                 strncpy(info.name, dev->netdev->name, sizeof(info.name)-1);
467
468                 if (copy_to_user((void __user *)arg, &info, sizeof(info)))
469                         err = -EFAULT;
470                 break;
471         default:
472                 err = -ENOIOCTLCMD;
473                 break;
474         }
475         return err;
476 }
477
478
479 /* 
480  *  Function irtty_open(tty)
481  *
482  *    This function is called by the TTY module when the IrDA line
483  *    discipline is called for.  Because we are sure the tty line exists,
484  *    we only have to link it to a free IrDA channel.  
485  */
486 static int irtty_open(struct tty_struct *tty) 
487 {
488         struct sir_dev *dev;
489         struct sirtty_cb *priv;
490         int ret = 0;
491
492         /* Module stuff handled via irda_ldisc.owner - Jean II */
493
494         /* First make sure we're not already connected. */
495         if (tty->disc_data != NULL) {
496                 priv = tty->disc_data;
497                 if (priv && priv->magic == IRTTY_MAGIC) {
498                         ret = -EEXIST;
499                         goto out;
500                 }
501                 tty->disc_data = NULL;          /* ### */
502         }
503
504         /* stop the underlying  driver */
505         irtty_stop_receiver(tty, TRUE);
506         if (tty->driver->stop)
507                 tty->driver->stop(tty);
508
509         if (tty->driver->flush_buffer)
510                 tty->driver->flush_buffer(tty);
511         
512         /* apply mtt override */
513         sir_tty_drv.qos_mtt_bits = qos_mtt_bits;
514
515         /* get a sir device instance for this driver */
516         dev = sirdev_get_instance(&sir_tty_drv, tty->name);
517         if (!dev) {
518                 ret = -ENODEV;
519                 goto out;
520         }
521
522         /* allocate private device info block */
523         priv = kmalloc(sizeof(*priv), GFP_KERNEL);
524         if (!priv)
525                 goto out_put;
526         memset(priv, 0, sizeof(*priv));
527
528         priv->magic = IRTTY_MAGIC;
529         priv->tty = tty;
530         priv->dev = dev;
531
532         /* serialize with start_dev - in case we were racing with ifup */
533         down(&irtty_sem);
534
535         dev->priv = priv;
536         tty->disc_data = priv;
537
538         up(&irtty_sem);
539
540         IRDA_DEBUG(0, "%s - %s: irda line discipline opened\n", __FUNCTION__, tty->name);
541
542         return 0;
543
544 out_put:
545         sirdev_put_instance(dev);
546 out:
547         return ret;
548 }
549
550 /* 
551  *  Function irtty_close (tty)
552  *
553  *    Close down a IrDA channel. This means flushing out any pending queues,
554  *    and then restoring the TTY line discipline to what it was before it got
555  *    hooked to IrDA (which usually is TTY again).  
556  */
557 static void irtty_close(struct tty_struct *tty) 
558 {
559         struct sirtty_cb *priv = tty->disc_data;
560
561         IRDA_ASSERT(priv != NULL, return;);
562         IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return;);
563
564         /* Hm, with a dongle attached the dongle driver wants
565          * to close the dongle - which requires the use of
566          * some tty write and/or termios or ioctl operations.
567          * Are we allowed to call those when already requested
568          * to shutdown the ldisc?
569          * If not, we should somehow mark the dev being staled.
570          * Question remains, how to close the dongle in this case...
571          * For now let's assume we are granted to issue tty driver calls
572          * until we return here from the ldisc close. I'm just wondering
573          * how this behaves with hotpluggable serial hardware like
574          * rs232-pcmcia card or usb-serial...
575          *
576          * priv->tty = NULL?;
577          */
578
579         /* we are dead now */
580         tty->disc_data = NULL;
581
582         sirdev_put_instance(priv->dev);
583
584         /* Stop tty */
585         irtty_stop_receiver(tty, TRUE);
586         tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
587         if (tty->driver->stop)
588                 tty->driver->stop(tty);
589
590         kfree(priv);
591
592         IRDA_DEBUG(0, "%s - %s: irda line discipline closed\n", __FUNCTION__, tty->name);
593 }
594
595 /* ------------------------------------------------------- */
596
597 static struct tty_ldisc irda_ldisc = {
598         .magic          = TTY_LDISC_MAGIC,
599         .name           = "irda",
600         .flags          = 0,
601         .open           = irtty_open,
602         .close          = irtty_close,
603         .read           = NULL,
604         .write          = NULL,
605         .ioctl          = irtty_ioctl,
606         .poll           = NULL,
607         .receive_buf    = irtty_receive_buf,
608         .receive_room   = irtty_receive_room,
609         .write_wakeup   = irtty_write_wakeup,
610         .owner          = THIS_MODULE,
611 };
612
613 /* ------------------------------------------------------- */
614
615 static int __init irtty_sir_init(void)
616 {
617         int err;
618
619         if ((err = tty_register_ldisc(N_IRDA, &irda_ldisc)) != 0)
620                 IRDA_ERROR("IrDA: can't register line discipline (err = %d)\n",
621                            err);
622         return err;
623 }
624
625 static void __exit irtty_sir_cleanup(void) 
626 {
627         int err;
628
629         if ((err = tty_unregister_ldisc(N_IRDA))) {
630                 IRDA_ERROR("%s(), can't unregister line discipline (err = %d)\n",
631                            __FUNCTION__, err);
632         }
633 }
634
635 module_init(irtty_sir_init);
636 module_exit(irtty_sir_cleanup);
637
638 MODULE_AUTHOR("Dag Brattli <dagb@cs.uit.no>");
639 MODULE_DESCRIPTION("IrDA TTY device driver");
640 MODULE_ALIAS_LDISC(N_IRDA);
641 MODULE_LICENSE("GPL");
642