[PATCH] drivers/char/pc8736x_gpio.c: unexport a static struct
[linux-2.6.git] / drivers / char / tty_ioctl.c
1 /*
2  *  linux/drivers/char/tty_ioctl.c
3  *
4  *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
5  *
6  * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
7  * which can be dynamically activated and de-activated by the line
8  * discipline handling modules (like SLIP).
9  */
10
11 #include <linux/types.h>
12 #include <linux/termios.h>
13 #include <linux/errno.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/major.h>
17 #include <linux/tty.h>
18 #include <linux/fcntl.h>
19 #include <linux/string.h>
20 #include <linux/mm.h>
21 #include <linux/module.h>
22 #include <linux/bitops.h>
23
24 #include <asm/io.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27
28 #undef TTY_DEBUG_WAIT_UNTIL_SENT
29
30 #undef  DEBUG
31
32 /*
33  * Internal flag options for termios setting behavior
34  */
35 #define TERMIOS_FLUSH   1
36 #define TERMIOS_WAIT    2
37 #define TERMIOS_TERMIO  4
38
39 void tty_wait_until_sent(struct tty_struct * tty, long timeout)
40 {
41         DECLARE_WAITQUEUE(wait, current);
42
43 #ifdef TTY_DEBUG_WAIT_UNTIL_SENT
44         char buf[64];
45         
46         printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
47 #endif
48         if (!tty->driver->chars_in_buffer)
49                 return;
50         add_wait_queue(&tty->write_wait, &wait);
51         if (!timeout)
52                 timeout = MAX_SCHEDULE_TIMEOUT;
53         do {
54 #ifdef TTY_DEBUG_WAIT_UNTIL_SENT
55                 printk(KERN_DEBUG "waiting %s...(%d)\n", tty_name(tty, buf),
56                        tty->driver->chars_in_buffer(tty));
57 #endif
58                 set_current_state(TASK_INTERRUPTIBLE);
59                 if (signal_pending(current))
60                         goto stop_waiting;
61                 if (!tty->driver->chars_in_buffer(tty))
62                         break;
63                 timeout = schedule_timeout(timeout);
64         } while (timeout);
65         if (tty->driver->wait_until_sent)
66                 tty->driver->wait_until_sent(tty, timeout);
67 stop_waiting:
68         set_current_state(TASK_RUNNING);
69         remove_wait_queue(&tty->write_wait, &wait);
70 }
71
72 EXPORT_SYMBOL(tty_wait_until_sent);
73
74 static void unset_locked_termios(struct termios *termios,
75                                  struct termios *old,
76                                  struct termios *locked)
77 {
78         int     i;
79         
80 #define NOSET_MASK(x,y,z) (x = ((x) & ~(z)) | ((y) & (z)))
81
82         if (!locked) {
83                 printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
84                 return;
85         }
86
87         NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
88         NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
89         NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
90         NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
91         termios->c_line = locked->c_line ? old->c_line : termios->c_line;
92         for (i=0; i < NCCS; i++)
93                 termios->c_cc[i] = locked->c_cc[i] ?
94                         old->c_cc[i] : termios->c_cc[i];
95 }
96
97 static void change_termios(struct tty_struct * tty, struct termios * new_termios)
98 {
99         int canon_change;
100         struct termios old_termios = *tty->termios;
101         struct tty_ldisc *ld;
102         
103         /*
104          *      Perform the actual termios internal changes under lock.
105          */
106          
107
108         /* FIXME: we need to decide on some locking/ordering semantics
109            for the set_termios notification eventually */
110         down(&tty->termios_sem);
111
112         *tty->termios = *new_termios;
113         unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
114         canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
115         if (canon_change) {
116                 memset(&tty->read_flags, 0, sizeof tty->read_flags);
117                 tty->canon_head = tty->read_tail;
118                 tty->canon_data = 0;
119                 tty->erasing = 0;
120         }
121         
122         
123         if (canon_change && !L_ICANON(tty) && tty->read_cnt)
124                 /* Get characters left over from canonical mode. */
125                 wake_up_interruptible(&tty->read_wait);
126
127         /* See if packet mode change of state. */
128
129         if (tty->link && tty->link->packet) {
130                 int old_flow = ((old_termios.c_iflag & IXON) &&
131                                 (old_termios.c_cc[VSTOP] == '\023') &&
132                                 (old_termios.c_cc[VSTART] == '\021'));
133                 int new_flow = (I_IXON(tty) &&
134                                 STOP_CHAR(tty) == '\023' &&
135                                 START_CHAR(tty) == '\021');
136                 if (old_flow != new_flow) {
137                         tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
138                         if (new_flow)
139                                 tty->ctrl_status |= TIOCPKT_DOSTOP;
140                         else
141                                 tty->ctrl_status |= TIOCPKT_NOSTOP;
142                         wake_up_interruptible(&tty->link->read_wait);
143                 }
144         }
145            
146         if (tty->driver->set_termios)
147                 (*tty->driver->set_termios)(tty, &old_termios);
148
149         ld = tty_ldisc_ref(tty);
150         if (ld != NULL) {
151                 if (ld->set_termios)
152                         (ld->set_termios)(tty, &old_termios);
153                 tty_ldisc_deref(ld);
154         }
155         up(&tty->termios_sem);
156 }
157
158 static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
159 {
160         struct termios tmp_termios;
161         struct tty_ldisc *ld;
162         int retval = tty_check_change(tty);
163
164         if (retval)
165                 return retval;
166
167         if (opt & TERMIOS_TERMIO) {
168                 memcpy(&tmp_termios, tty->termios, sizeof(struct termios));
169                 if (user_termio_to_kernel_termios(&tmp_termios,
170                                                 (struct termio __user *)arg))
171                         return -EFAULT;
172         } else {
173                 if (user_termios_to_kernel_termios(&tmp_termios,
174                                                 (struct termios __user *)arg))
175                         return -EFAULT;
176         }
177
178         ld = tty_ldisc_ref(tty);
179         
180         if (ld != NULL) {
181                 if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
182                         ld->flush_buffer(tty);
183                 tty_ldisc_deref(ld);
184         }
185         
186         if (opt & TERMIOS_WAIT) {
187                 tty_wait_until_sent(tty, 0);
188                 if (signal_pending(current))
189                         return -EINTR;
190         }
191
192         change_termios(tty, &tmp_termios);
193         return 0;
194 }
195
196 static int get_termio(struct tty_struct * tty, struct termio __user * termio)
197 {
198         if (kernel_termios_to_user_termio(termio, tty->termios))
199                 return -EFAULT;
200         return 0;
201 }
202
203 static unsigned long inq_canon(struct tty_struct * tty)
204 {
205         int nr, head, tail;
206
207         if (!tty->canon_data || !tty->read_buf)
208                 return 0;
209         head = tty->canon_head;
210         tail = tty->read_tail;
211         nr = (head - tail) & (N_TTY_BUF_SIZE-1);
212         /* Skip EOF-chars.. */
213         while (head != tail) {
214                 if (test_bit(tail, tty->read_flags) &&
215                     tty->read_buf[tail] == __DISABLED_CHAR)
216                         nr--;
217                 tail = (tail+1) & (N_TTY_BUF_SIZE-1);
218         }
219         return nr;
220 }
221
222 #ifdef TIOCGETP
223 /*
224  * These are deprecated, but there is limited support..
225  *
226  * The "sg_flags" translation is a joke..
227  */
228 static int get_sgflags(struct tty_struct * tty)
229 {
230         int flags = 0;
231
232         if (!(tty->termios->c_lflag & ICANON)) {
233                 if (tty->termios->c_lflag & ISIG)
234                         flags |= 0x02;          /* cbreak */
235                 else
236                         flags |= 0x20;          /* raw */
237         }
238         if (tty->termios->c_lflag & ECHO)
239                 flags |= 0x08;                  /* echo */
240         if (tty->termios->c_oflag & OPOST)
241                 if (tty->termios->c_oflag & ONLCR)
242                         flags |= 0x10;          /* crmod */
243         return flags;
244 }
245
246 static int get_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
247 {
248         struct sgttyb tmp;
249
250         down(&tty->termios_sem);
251         tmp.sg_ispeed = 0;
252         tmp.sg_ospeed = 0;
253         tmp.sg_erase = tty->termios->c_cc[VERASE];
254         tmp.sg_kill = tty->termios->c_cc[VKILL];
255         tmp.sg_flags = get_sgflags(tty);
256         up(&tty->termios_sem);
257         
258         return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
259 }
260
261 static void set_sgflags(struct termios * termios, int flags)
262 {
263         termios->c_iflag = ICRNL | IXON;
264         termios->c_oflag = 0;
265         termios->c_lflag = ISIG | ICANON;
266         if (flags & 0x02) {     /* cbreak */
267                 termios->c_iflag = 0;
268                 termios->c_lflag &= ~ICANON;
269         }
270         if (flags & 0x08) {             /* echo */
271                 termios->c_lflag |= ECHO | ECHOE | ECHOK |
272                                     ECHOCTL | ECHOKE | IEXTEN;
273         }
274         if (flags & 0x10) {             /* crmod */
275                 termios->c_oflag |= OPOST | ONLCR;
276         }
277         if (flags & 0x20) {     /* raw */
278                 termios->c_iflag = 0;
279                 termios->c_lflag &= ~(ISIG | ICANON);
280         }
281         if (!(termios->c_lflag & ICANON)) {
282                 termios->c_cc[VMIN] = 1;
283                 termios->c_cc[VTIME] = 0;
284         }
285 }
286
287 static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
288 {
289         int retval;
290         struct sgttyb tmp;
291         struct termios termios;
292
293         retval = tty_check_change(tty);
294         if (retval)
295                 return retval;
296         
297         if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
298                 return -EFAULT;
299
300         down(&tty->termios_sem);                
301         termios =  *tty->termios;
302         termios.c_cc[VERASE] = tmp.sg_erase;
303         termios.c_cc[VKILL] = tmp.sg_kill;
304         set_sgflags(&termios, tmp.sg_flags);
305         up(&tty->termios_sem);
306         change_termios(tty, &termios);
307         return 0;
308 }
309 #endif
310
311 #ifdef TIOCGETC
312 static int get_tchars(struct tty_struct * tty, struct tchars __user * tchars)
313 {
314         struct tchars tmp;
315
316         tmp.t_intrc = tty->termios->c_cc[VINTR];
317         tmp.t_quitc = tty->termios->c_cc[VQUIT];
318         tmp.t_startc = tty->termios->c_cc[VSTART];
319         tmp.t_stopc = tty->termios->c_cc[VSTOP];
320         tmp.t_eofc = tty->termios->c_cc[VEOF];
321         tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
322         return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
323 }
324
325 static int set_tchars(struct tty_struct * tty, struct tchars __user * tchars)
326 {
327         struct tchars tmp;
328
329         if (copy_from_user(&tmp, tchars, sizeof(tmp)))
330                 return -EFAULT;
331         tty->termios->c_cc[VINTR] = tmp.t_intrc;
332         tty->termios->c_cc[VQUIT] = tmp.t_quitc;
333         tty->termios->c_cc[VSTART] = tmp.t_startc;
334         tty->termios->c_cc[VSTOP] = tmp.t_stopc;
335         tty->termios->c_cc[VEOF] = tmp.t_eofc;
336         tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
337         return 0;
338 }
339 #endif
340
341 #ifdef TIOCGLTC
342 static int get_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
343 {
344         struct ltchars tmp;
345
346         tmp.t_suspc = tty->termios->c_cc[VSUSP];
347         tmp.t_dsuspc = tty->termios->c_cc[VSUSP];       /* what is dsuspc anyway? */
348         tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
349         tmp.t_flushc = tty->termios->c_cc[VEOL2];       /* what is flushc anyway? */
350         tmp.t_werasc = tty->termios->c_cc[VWERASE];
351         tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
352         return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
353 }
354
355 static int set_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
356 {
357         struct ltchars tmp;
358
359         if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
360                 return -EFAULT;
361
362         tty->termios->c_cc[VSUSP] = tmp.t_suspc;
363         tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;       /* what is dsuspc anyway? */
364         tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
365         tty->termios->c_cc[VEOL2] = tmp.t_flushc;       /* what is flushc anyway? */
366         tty->termios->c_cc[VWERASE] = tmp.t_werasc;
367         tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
368         return 0;
369 }
370 #endif
371
372 /*
373  * Send a high priority character to the tty.
374  */
375 static void send_prio_char(struct tty_struct *tty, char ch)
376 {
377         int     was_stopped = tty->stopped;
378
379         if (tty->driver->send_xchar) {
380                 tty->driver->send_xchar(tty, ch);
381                 return;
382         }
383         if (was_stopped)
384                 start_tty(tty);
385         tty->driver->write(tty, &ch, 1);
386         if (was_stopped)
387                 stop_tty(tty);
388 }
389
390 int n_tty_ioctl(struct tty_struct * tty, struct file * file,
391                        unsigned int cmd, unsigned long arg)
392 {
393         struct tty_struct * real_tty;
394         void __user *p = (void __user *)arg;
395         int retval;
396         struct tty_ldisc *ld;
397
398         if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
399             tty->driver->subtype == PTY_TYPE_MASTER)
400                 real_tty = tty->link;
401         else
402                 real_tty = tty;
403
404         switch (cmd) {
405 #ifdef TIOCGETP
406                 case TIOCGETP:
407                         return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
408                 case TIOCSETP:
409                 case TIOCSETN:
410                         return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
411 #endif
412 #ifdef TIOCGETC
413                 case TIOCGETC:
414                         return get_tchars(real_tty, p);
415                 case TIOCSETC:
416                         return set_tchars(real_tty, p);
417 #endif
418 #ifdef TIOCGLTC
419                 case TIOCGLTC:
420                         return get_ltchars(real_tty, p);
421                 case TIOCSLTC:
422                         return set_ltchars(real_tty, p);
423 #endif
424                 case TCGETS:
425                         if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
426                                 return -EFAULT;
427                         return 0;
428                 case TCSETSF:
429                         return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
430                 case TCSETSW:
431                         return set_termios(real_tty, p, TERMIOS_WAIT);
432                 case TCSETS:
433                         return set_termios(real_tty, p, 0);
434                 case TCGETA:
435                         return get_termio(real_tty, p);
436                 case TCSETAF:
437                         return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
438                 case TCSETAW:
439                         return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
440                 case TCSETA:
441                         return set_termios(real_tty, p, TERMIOS_TERMIO);
442                 case TCXONC:
443                         retval = tty_check_change(tty);
444                         if (retval)
445                                 return retval;
446                         switch (arg) {
447                         case TCOOFF:
448                                 if (!tty->flow_stopped) {
449                                         tty->flow_stopped = 1;
450                                         stop_tty(tty);
451                                 }
452                                 break;
453                         case TCOON:
454                                 if (tty->flow_stopped) {
455                                         tty->flow_stopped = 0;
456                                         start_tty(tty);
457                                 }
458                                 break;
459                         case TCIOFF:
460                                 if (STOP_CHAR(tty) != __DISABLED_CHAR)
461                                         send_prio_char(tty, STOP_CHAR(tty));
462                                 break;
463                         case TCION:
464                                 if (START_CHAR(tty) != __DISABLED_CHAR)
465                                         send_prio_char(tty, START_CHAR(tty));
466                                 break;
467                         default:
468                                 return -EINVAL;
469                         }
470                         return 0;
471                 case TCFLSH:
472                         retval = tty_check_change(tty);
473                         if (retval)
474                                 return retval;
475                                 
476                         ld = tty_ldisc_ref(tty);
477                         switch (arg) {
478                         case TCIFLUSH:
479                                 if (ld && ld->flush_buffer)
480                                         ld->flush_buffer(tty);
481                                 break;
482                         case TCIOFLUSH:
483                                 if (ld && ld->flush_buffer)
484                                         ld->flush_buffer(tty);
485                                 /* fall through */
486                         case TCOFLUSH:
487                                 if (tty->driver->flush_buffer)
488                                         tty->driver->flush_buffer(tty);
489                                 break;
490                         default:
491                                 tty_ldisc_deref(ld);
492                                 return -EINVAL;
493                         }
494                         tty_ldisc_deref(ld);
495                         return 0;
496                 case TIOCOUTQ:
497                         return put_user(tty->driver->chars_in_buffer ?
498                                         tty->driver->chars_in_buffer(tty) : 0,
499                                         (int __user *) arg);
500                 case TIOCINQ:
501                         retval = tty->read_cnt;
502                         if (L_ICANON(tty))
503                                 retval = inq_canon(tty);
504                         return put_user(retval, (unsigned int __user *) arg);
505                 case TIOCGLCKTRMIOS:
506                         if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
507                                 return -EFAULT;
508                         return 0;
509
510                 case TIOCSLCKTRMIOS:
511                         if (!capable(CAP_SYS_ADMIN))
512                                 return -EPERM;
513                         if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios __user *) arg))
514                                 return -EFAULT;
515                         return 0;
516
517                 case TIOCPKT:
518                 {
519                         int pktmode;
520
521                         if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
522                             tty->driver->subtype != PTY_TYPE_MASTER)
523                                 return -ENOTTY;
524                         if (get_user(pktmode, (int __user *) arg))
525                                 return -EFAULT;
526                         if (pktmode) {
527                                 if (!tty->packet) {
528                                         tty->packet = 1;
529                                         tty->link->ctrl_status = 0;
530                                 }
531                         } else
532                                 tty->packet = 0;
533                         return 0;
534                 }
535                 case TIOCGSOFTCAR:
536                         return put_user(C_CLOCAL(tty) ? 1 : 0, (int __user *)arg);
537                 case TIOCSSOFTCAR:
538                         if (get_user(arg, (unsigned int __user *) arg))
539                                 return -EFAULT;
540                         down(&tty->termios_sem);
541                         tty->termios->c_cflag =
542                                 ((tty->termios->c_cflag & ~CLOCAL) |
543                                  (arg ? CLOCAL : 0));
544                         up(&tty->termios_sem);
545                         return 0;
546                 default:
547                         return -ENOIOCTLCMD;
548                 }
549 }
550
551 EXPORT_SYMBOL(n_tty_ioctl);