1 /*
2 * generic_serial.c
3 *
4 * Copyright (C) 1998/1999 R.E.Wolff@BitWizard.nl
5 *
6 * written for the SX serial driver.
7 * Contains the code that should be shared over all the serial drivers.
8 *
9 * Credit for the idea to do it this way might go to Alan Cox.
10 *
11 *
12 * Version 0.1 -- December, 1998. Initial version.
13 * Version 0.2 -- March, 1999. Some more routines. Bugfixes. Etc.
14 * Version 0.5 -- August, 1999. Some more fixes. Reformat for Linus.
15 *
16 * BitWizard is actively maintaining this file. We sometimes find
17 * that someone submitted changes to this file. We really appreciate
18 * your help, but please submit changes through us. We're doing our
19 * best to be responsive. -- REW
20 * */
21
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/tty.h>
25 #include <linux/serial.h>
26 #include <linux/mm.h>
27 #include <linux/generic_serial.h>
28 #include <linux/interrupt.h>
29 #include <linux/delay.h>
30 #include <asm/semaphore.h>
31 #include <asm/uaccess.h>
32
33 #define DEBUG
34
35 static char * tmp_buf;
36 static DECLARE_MUTEX(tmp_buf_sem);
37
38 static int gs_debug;
39
40 #ifdef DEBUG
41 #define gs_dprintk(f, str...) if (gs_debug & f) printk (str)
42 #else
43 #define gs_dprintk(f, str...) /* nothing */
44 #endif
45
46 #define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter %s\n", __FUNCTION__)
47 #define func_exit() gs_dprintk (GS_DEBUG_FLOW, "gs: exit %s\n", __FUNCTION__)
48
49 #ifdef NEW_WRITE_LOCKING
50 #define DECL /* Nothing */
51 #define LOCKIT down (& port->port_write_sem);
52 #define RELEASEIT up (&port->port_write_sem);
53 #else
54 #define DECL unsigned long flags;
55 #define LOCKIT save_flags (flags);cli ()
56 #define RELEASEIT restore_flags (flags)
57 #endif
58
59 #define RS_EVENT_WRITE_WAKEUP 1
60
61 module_param(gs_debug, int, 0644);
62
63
64 void gs_put_char(struct tty_struct * tty, unsigned char ch)
65 {
66 struct gs_port *port;
67 DECL
68
69 func_enter ();
70
71 if (!tty) return;
72
73 port = tty->driver_data;
74
75 if (!port) return;
76
77 if (! (port->flags & ASYNC_INITIALIZED)) return;
78
79 /* Take a lock on the serial tranmit buffer! */
80 LOCKIT;
81
82 if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
83 /* Sorry, buffer is full, drop character. Update statistics???? -- REW */
84 RELEASEIT;
85 return;
86 }
87
88 port->xmit_buf[port->xmit_head++] = ch;
89 port->xmit_head &= SERIAL_XMIT_SIZE - 1;
90 port->xmit_cnt++; /* Characters in buffer */
91
92 RELEASEIT;
93 func_exit ();
94 }
95
96
97 #ifdef NEW_WRITE_LOCKING
98
99 /*
100 > Problems to take into account are:
101 > -1- Interrupts that empty part of the buffer.
102 > -2- page faults on the access to userspace.
103 > -3- Other processes that are also trying to do a "write".
104 */
105
106 int gs_write(struct tty_struct * tty,
107 const unsigned char *buf, int count)
108 {
109 struct gs_port *port;
110 int c, total = 0;
111 int t;
112
113 func_enter ();
114
115 if (!tty) return 0;
116
117 port = tty->driver_data;
118
119 if (!port) return 0;
120
121 if (! (port->flags & ASYNC_INITIALIZED))
122 return 0;
123
124 /* get exclusive "write" access to this port (problem 3) */
125 /* This is not a spinlock because we can have a disk access (page
126 fault) in copy_from_user */
127 down (& port->port_write_sem);
128
129 while (1) {
130
131 c = count;
132
133 /* This is safe because we "OWN" the "head". Noone else can
134 change the "head": we own the port_write_sem. */
135 /* Don't overrun the end of the buffer */
136 t = SERIAL_XMIT_SIZE - port->xmit_head;
137 if (t < c) c = t;
138
139 /* This is safe because the xmit_cnt can only decrease. This
140 would increase "t", so we might copy too little chars. */
141 /* Don't copy past the "head" of the buffer */
142 t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt;
143 if (t < c) c = t;
144
145 /* Can't copy more? break out! */
146 if (c <= 0) break;
147
148 memcpy (port->xmit_buf + port->xmit_head, buf, c);
149
150 port -> xmit_cnt += c;
151 port -> xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE -1);
152 buf += c;
153 count -= c;
154 total += c;
155 }
156 up (& port->port_write_sem);
157
158 gs_dprintk (GS_DEBUG_WRITE, "write: interrupts are %s\n",
159 (port->flags & GS_TX_INTEN)?"enabled": "disabled");
160
161 if (port->xmit_cnt &&
162 !tty->stopped &&
163 !tty->hw_stopped &&
164 !(port->flags & GS_TX_INTEN)) {
165 port->flags |= GS_TX_INTEN;
166 port->rd->enable_tx_interrupts (port);
167 }
168 func_exit ();
169 return total;
170 }
171 #else
172 /*
173 > Problems to take into account are:
174 > -1- Interrupts that empty part of the buffer.
175 > -2- page faults on the access to userspace.
176 > -3- Other processes that are also trying to do a "write".
177 */
178
179 int gs_write(struct tty_struct * tty,
180 const unsigned char *buf, int count)
181 {
182 struct gs_port *port;
183 int c, total = 0;
184 int t;
185 unsigned long flags;
186
187 func_enter ();
188
189 /* The standard serial driver returns 0 in this case.
190 That sounds to me as "No error, I just didn't get to writing any
191 bytes. Feel free to try again."
192 The "official" way to write n bytes from buf is:
193
194 for (nwritten = 0;nwritten < n;nwritten += rv) {
195 rv = write (fd, buf+nwritten, n-nwritten);
196 if (rv < 0) break; // Error: bail out. //
197 }
198
199 which will loop endlessly in this case. The manual page for write
200 agrees with me. In practise almost everybody writes
201 "write (fd, buf,n);" but some people might have had to deal with
202 incomplete writes in the past and correctly implemented it by now...
203 */
204
205 if (!tty) return -EIO;
206
207 port = tty->driver_data;
208 if (!port || !port->xmit_buf || !tmp_buf)
209 return -EIO;
210
211 save_flags(flags);
212 while (1) {
213 cli();
214 c = count;
215
216 /* This is safe because we "OWN" the "head". Noone else can
217 change the "head": we own the port_write_sem. */
218 /* Don't overrun the end of the buffer */
219 t = SERIAL_XMIT_SIZE - port->xmit_head;
220 if (t < c) c = t;
221
222 /* This is safe because the xmit_cnt can only decrease. This
223 would increase "t", so we might copy too little chars. */
224 /* Don't copy past the "head" of the buffer */
225 t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt;
226 if (t < c) c = t;
227
228 /* Can't copy more? break out! */
229 if (c <= 0) {
230 restore_flags(flags);
231 break;
232 }
233 memcpy(port->xmit_buf + port->xmit_head, buf, c);
234 port->xmit_head = ((port->xmit_head + c) &
235 (SERIAL_XMIT_SIZE-1));
236 port->xmit_cnt += c;
237 restore_flags(flags);
238 buf += c;
239 count -= c;
240 total += c;
241 }
242
243 if (port->xmit_cnt &&
244 !tty->stopped &&
245 !tty->hw_stopped &&
246 !(port->flags & GS_TX_INTEN)) {
247 port->flags |= GS_TX_INTEN;
248 port->rd->enable_tx_interrupts (port);
249 }
250 func_exit ();
251 return total;
252 }
253
254 #endif
255
256
257
258 int gs_write_room(struct tty_struct * tty)
259 {
260 struct gs_port *port = tty->driver_data;
261 int ret;
262
263 func_enter ();
264 ret = SERIAL_XMIT_SIZE - port->xmit_cnt - 1;
265 if (ret < 0)
266 ret = 0;
267 func_exit ();
268 return ret;
269 }
270
271
272 int gs_chars_in_buffer(struct tty_struct *tty)
273 {
274 struct gs_port *port = tty->driver_data;
275 func_enter ();
276
277 func_exit ();
278 return port->xmit_cnt;
279 }
280
281
282 static int gs_real_chars_in_buffer(struct tty_struct *tty)
283 {
284 struct gs_port *port;
285 func_enter ();
286
287 if (!tty) return 0;
288 port = tty->driver_data;
289
290 if (!port->rd) return 0;
291 if (!port->rd->chars_in_buffer) return 0;
292
293 func_exit ();
294 return port->xmit_cnt + port->rd->chars_in_buffer (port);
295 }
296
297
298 static int gs_wait_tx_flushed (void * ptr, int timeout)
299 {
300 struct gs_port *port = ptr;
301 unsigned long end_jiffies;
302 int jiffies_to_transmit, charsleft = 0, rv = 0;
303 int rcib;
304
305 func_enter();
306
307 gs_dprintk (GS_DEBUG_FLUSH, "port=%p.\n", port);
308 if (port) {
309 gs_dprintk (GS_DEBUG_FLUSH, "xmit_cnt=%x, xmit_buf=%p, tty=%p.\n",
310 port->xmit_cnt, port->xmit_buf, port->tty);
311 }
312
313 if (!port || port->xmit_cnt < 0 || !port->xmit_buf) {
314 gs_dprintk (GS_DEBUG_FLUSH, "ERROR: !port, !port->xmit_buf or prot->xmit_cnt < 0.\n");
315 func_exit();
316 return -EINVAL; /* This is an error which we don't know how to handle. */
317 }
318
319 rcib = gs_real_chars_in_buffer(port->tty);
320
321 if(rcib <= 0) {
322 gs_dprintk (GS_DEBUG_FLUSH, "nothing to wait for.\n");
323 func_exit();
324 return rv;
325 }
326 /* stop trying: now + twice the time it would normally take + seconds */
327 if (timeout == 0) timeout = MAX_SCHEDULE_TIMEOUT;
328 end_jiffies = jiffies;
329 if (timeout != MAX_SCHEDULE_TIMEOUT)
330 end_jiffies += port->baud?(2 * rcib * 10 * HZ / port->baud):0;
331 end_jiffies += timeout;
332
333 gs_dprintk (GS_DEBUG_FLUSH, "now=%lx, end=%lx (%ld).\n",
334 jiffies, end_jiffies, end_jiffies-jiffies);
335
336 /* the expression is actually jiffies < end_jiffies, but that won't
337 work around the wraparound. Tricky eh? */
338 while ((charsleft = gs_real_chars_in_buffer (port->tty)) &&
339 time_after (end_jiffies, jiffies)) {
340 /* Units check:
341 chars * (bits/char) * (jiffies /sec) / (bits/sec) = jiffies!
342 check! */
343
344 charsleft += 16; /* Allow 16 chars more to be transmitted ... */
345 jiffies_to_transmit = port->baud?(1 + charsleft * 10 * HZ / port->baud):0;
346 /* ^^^ Round up.... */
347 if (jiffies_to_transmit <= 0) jiffies_to_transmit = 1;
348
349 gs_dprintk (GS_DEBUG_FLUSH, "Expect to finish in %d jiffies "
350 "(%d chars).\n", jiffies_to_transmit, charsleft);
351
352 msleep_interruptible(jiffies_to_msecs(jiffies_to_transmit));
353 if (signal_pending (current)) {
354 gs_dprintk (GS_DEBUG_FLUSH, "Signal pending. Bombing out: ");
355 rv = -EINTR;
356 break;
357 }
358 }
359
360 gs_dprintk (GS_DEBUG_FLUSH, "charsleft = %d.\n", charsleft);
361 set_current_state (TASK_RUNNING);
362
363 func_exit();
364 return rv;
365 }
366
367
368
369 void gs_flush_buffer(struct tty_struct *tty)
370 {
371 struct gs_port *port;
372 unsigned long flags;
373
374 func_enter ();
375
376 if (!tty) return;
377
378 port = tty->driver_data;
379
380 if (!port) return;
381
382 /* XXX Would the write semaphore do? */
383 save_flags(flags); cli();
384 port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
385 restore_flags(flags);
386
387 wake_up_interruptible(&tty->write_wait);
388 tty_wakeup(tty);
389 func_exit ();
390 }
391
392
393 void gs_flush_chars(struct tty_struct * tty)
394 {
395 struct gs_port *port;
396
397 func_enter ();
398
399 if (!tty) return;
400
401 port = tty->driver_data;
402
403 if (!port) return;
404
405 if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
406 !port->xmit_buf) {
407 func_exit ();
408 return;
409 }
410
411 /* Beats me -- REW */
412 port->flags |= GS_TX_INTEN;
413 port->rd->enable_tx_interrupts (port);
414 func_exit ();
415 }
416
417
418 void gs_stop(struct tty_struct * tty)
419 {
420 struct gs_port *port;
421
422 func_enter ();
423
424 if (!tty) return;
425
426 port = tty->driver_data;
427
428 if (!port) return;
429
430 if (port->xmit_cnt &&
431 port->xmit_buf &&
432 (port->flags & GS_TX_INTEN) ) {
433 port->flags &= ~GS_TX_INTEN;
434 port->rd->disable_tx_interrupts (port);
435 }
436 func_exit ();
437 }
438
439
440 void gs_start(struct tty_struct * tty)
441 {
442 struct gs_port *port;
443
444 if (!tty) return;
445
446 port = tty->driver_data;
447
448 if (!port) return;
449
450 if (port->xmit_cnt &&
451 port->xmit_buf &&
452 !(port->flags & GS_TX_INTEN) ) {
453 port->flags |= GS_TX_INTEN;
454 port->rd->enable_tx_interrupts (port);
455 }
456 func_exit ();
457 }
458
459
460 static void gs_shutdown_port (struct gs_port *port)
461 {
462 unsigned long flags;
463
464 func_enter();
465
466 if (!port) return;
467
468 if (!(port->flags & ASYNC_INITIALIZED))
469 return;
470
471 save_flags (flags);
472 cli ();
473
474 if (port->xmit_buf) {
475 free_page((unsigned long) port->xmit_buf);
476 port->xmit_buf = NULL;
477 }
478
479 if (port->tty)
480 set_bit(TTY_IO_ERROR, &port->tty->flags);
481
482 port->rd->shutdown_port (port);
483
484 port->flags &= ~ASYNC_INITIALIZED;
485 restore_flags (flags);
486
487 func_exit();
488 }
489
490
491 void gs_hangup(struct tty_struct *tty)
492 {
493 struct gs_port *port;
494
495 func_enter ();
496
497 if (!tty) return;
498
499 port = tty->driver_data;
500 tty = port->tty;
501 if (!tty)
502 return;
503
504 gs_shutdown_port (port);
505 port->flags &= ~(ASYNC_NORMAL_ACTIVE|GS_ACTIVE);
506 port->tty = NULL;
507 port->count = 0;
508
509 wake_up_interruptible(&port->open_wait);
510 func_exit ();
511 }
512
513
514 int gs_block_til_ready(void *port_, struct file * filp)
515 {
516 struct gs_port *port = port_;
517 DECLARE_WAITQUEUE(wait, current);
518 int retval;
519 int do_clocal = 0;
520 int CD;
521 struct tty_struct *tty;
522
523 func_enter ();
524
525 if (!port) return 0;
526
527 tty = port->tty;
528
529 if (!tty) return 0;
530
531 gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n");
532 /*
533 * If the device is in the middle of being closed, then block
534 * until it's done, and then try again.
535 */
536 if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
537 interruptible_sleep_on(&port->close_wait);
538 if (port->flags & ASYNC_HUP_NOTIFY)
539 return -EAGAIN;
540 else
541 return -ERESTARTSYS;
542 }
543
544 gs_dprintk (GS_DEBUG_BTR, "after hung up\n");
545
546 /*
547 * If non-blocking mode is set, or the port is not enabled,
548 * then make the check up front and then exit.
549 */
550 if ((filp->f_flags & O_NONBLOCK) ||
551 (tty->flags & (1 << TTY_IO_ERROR))) {
552 port->flags |= ASYNC_NORMAL_ACTIVE;
553 return 0;
554 }
555
556 gs_dprintk (GS_DEBUG_BTR, "after nonblock\n");
557
558 if (C_CLOCAL(tty))
559 do_clocal = 1;
560
561 /*
562 * Block waiting for the carrier detect and the line to become
563 * free (i.e., not in use by the callout). While we are in
564 * this loop, port->count is dropped by one, so that
565 * rs_close() knows when to free things. We restore it upon
566 * exit, either normal or abnormal.
567 */
568 retval = 0;
569
570 add_wait_queue(&port->open_wait, &wait);
571
572 gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n");
573 cli();
574 if (!tty_hung_up_p(filp))
575 port->count--;
576 sti();
577 port->blocked_open++;
578 while (1) {
579 CD = port->rd->get_CD (port);
580 gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD);
581 set_current_state (TASK_INTERRUPTIBLE);
582 if (tty_hung_up_p(filp) ||
583 !(port->flags & ASYNC_INITIALIZED)) {
584 if (port->flags & ASYNC_HUP_NOTIFY)
585 retval = -EAGAIN;
586 else
587 retval = -ERESTARTSYS;
588 break;
589 }
590 if (!(port->flags & ASYNC_CLOSING) &&
591 (do_clocal || CD))
592 break;
593 gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n",
594 (int)signal_pending (current), *(long*)(¤t->blocked));
595 if (signal_pending(current)) {
596 retval = -ERESTARTSYS;
597 break;
598 }
599 schedule();
600 }
601 gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n",
602 port->blocked_open);
603 set_current_state (TASK_RUNNING);
604 remove_wait_queue(&port->open_wait, &wait);
605 if (!tty_hung_up_p(filp))
606 port->count++;
607 port->blocked_open--;
608 if (retval)
609 return retval;
610
611 port->flags |= ASYNC_NORMAL_ACTIVE;
612 func_exit ();
613 return 0;
614 }
615
616
617 void gs_close(struct tty_struct * tty, struct file * filp)
618 {
619 unsigned long flags;
620 struct gs_port *port;
621
622 func_enter ();
623
624 if (!tty) return;
625
626 port = (struct gs_port *) tty->driver_data;
627
628 if (!port) return;
629
630 if (!port->tty) {
631 /* This seems to happen when this is called from vhangup. */
632 gs_dprintk (GS_DEBUG_CLOSE, "gs: Odd: port->tty is NULL\n");
633 port->tty = tty;
634 }
635
636 save_flags(flags); cli();
637
638 if (tty_hung_up_p(filp)) {
639 restore_flags(flags);
640 port->rd->hungup (port);
641 func_exit ();
642 return;
643 }
644
645 if ((tty->count == 1) && (port->count != 1)) {
646 printk(KERN_ERR "gs: gs_close: bad port count;"
647 " tty->count is 1, port count is %d\n", port->count);
648 port->count = 1;
649 }
650 if (--port->count < 0) {
651 printk(KERN_ERR "gs: gs_close: bad port count: %d\n", port->count);
652 port->count = 0;
653 }
654 if (port->count) {
655 gs_dprintk(GS_DEBUG_CLOSE, "gs_close: count: %d\n", port->count);
656 restore_flags(flags);
657 func_exit ();
658 return;
659 }
660 port->flags |= ASYNC_CLOSING;
661
662 /*
663 * Now we wait for the transmit buffer to clear; and we notify
664 * the line discipline to only process XON/XOFF characters.
665 */
666 tty->closing = 1;
667 /* if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
668 tty_wait_until_sent(tty, port->closing_wait); */
669
670 /*
671 * At this point we stop accepting input. To do this, we
672 * disable the receive line status interrupts, and tell the
673 * interrupt driver to stop checking the data ready bit in the
674 * line status register.
675 */
676
677 port->rd->disable_rx_interrupts (port);
678
679 /* close has no way of returning "EINTR", so discard return value */
680 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
681 gs_wait_tx_flushed (port, port->closing_wait);
682
683 port->flags &= ~GS_ACTIVE;
684
685 if (tty->driver->flush_buffer)
686 tty->driver->flush_buffer(tty);
687
688 tty_ldisc_flush(tty);
689 tty->closing = 0;
690
691 port->event = 0;
692 port->rd->close (port);
693 port->rd->shutdown_port (port);
694 port->tty = NULL;
695
696 if (port->blocked_open) {
697 if (port->close_delay) {
698 msleep_interruptible(jiffies_to_msecs(port->close_delay));
699 }
700 wake_up_interruptible(&port->open_wait);
701 }
702 port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING | ASYNC_INITIALIZED);
703 wake_up_interruptible(&port->close_wait);
704
705 restore_flags(flags);
706 func_exit ();
707 }
708
709
710 static unsigned int gs_baudrates[] = {
711 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
712 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
713 };
714
715
716 void gs_set_termios (struct tty_struct * tty,
717 struct termios * old_termios)
718 {
719 struct gs_port *port;
720 int baudrate, tmp, rv;
721 struct termios *tiosp;
722
723 func_enter();
724
725 if (!tty) return;
726
727 port = tty->driver_data;
728
729 if (!port) return;
730
731 tiosp = tty->termios;
732
733 if (gs_debug & GS_DEBUG_TERMIOS) {
734 gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp);
735 }
736
737 #if 0
738 /* This is an optimization that is only allowed for dumb cards */
739 /* Smart cards require knowledge of iflags and oflags too: that
740 might change hardware cooking mode.... */
741 #endif
742 if (old_termios) {
743 if( (tiosp->c_iflag == old_termios->c_iflag)
744 && (tiosp->c_oflag == old_termios->c_oflag)
745 && (tiosp->c_cflag == old_termios->c_cflag)
746 && (tiosp->c_lflag == old_termios->c_lflag)
747 && (tiosp->c_line == old_termios->c_line)
748 && (memcmp(tiosp->c_cc, old_termios->c_cc, NCC) == 0)) {
749 gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: optimized away\n");
750 return /* 0 */;
751 }
752 } else
753 gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: no old_termios: "
754 "no optimization\n");
755
756 if(old_termios && (gs_debug & GS_DEBUG_TERMIOS)) {
757 if(tiosp->c_iflag != old_termios->c_iflag) printk("c_iflag changed\n");
758 if(tiosp->c_oflag != old_termios->c_oflag) printk("c_oflag changed\n");
759 if(tiosp->c_cflag != old_termios->c_cflag) printk("c_cflag changed\n");
760 if(tiosp->c_lflag != old_termios->c_lflag) printk("c_lflag changed\n");
761 if(tiosp->c_line != old_termios->c_line) printk("c_line changed\n");
762 if(!memcmp(tiosp->c_cc, old_termios->c_cc, NCC)) printk("c_cc changed\n");
763 }
764
765 baudrate = tiosp->c_cflag & CBAUD;
766 if (baudrate & CBAUDEX) {
767 baudrate &= ~CBAUDEX;
768 if ((baudrate < 1) || (baudrate > 4))
769 tiosp->c_cflag &= ~CBAUDEX;
770 else
771 baudrate += 15;
772 }
773
774 baudrate = gs_baudrates[baudrate];
775 if ((tiosp->c_cflag & CBAUD) == B38400) {
776 if ( (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
777 baudrate = 57600;
778 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
779 baudrate = 115200;
780 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
781 baudrate = 230400;
782 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
783 baudrate = 460800;
784 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
785 baudrate = (port->baud_base / port->custom_divisor);
786 }
787
788 /* I recommend using THIS instead of the mess in termios (and
789 duplicating the above code). Next we should create a clean
790 interface towards this variable. If your card supports arbitrary
791 baud rates, (e.g. CD1400 or 16550 based cards) then everything
792 will be very easy..... */
793 port->baud = baudrate;
794
795 /* Two timer ticks seems enough to wakeup something like SLIP driver */
796 /* Baudrate/10 is cps. Divide by HZ to get chars per tick. */
797 tmp = (baudrate / 10 / HZ) * 2;
798
799 if (tmp < 0) tmp = 0;
800 if (tmp >= SERIAL_XMIT_SIZE) tmp = SERIAL_XMIT_SIZE-1;
801
802 port->wakeup_chars = tmp;
803
804 /* We should really wait for the characters to be all sent before
805 changing the settings. -- CAL */
806 rv = gs_wait_tx_flushed (port, MAX_SCHEDULE_TIMEOUT);
807 if (rv < 0) return /* rv */;
808
809 rv = port->rd->set_real_termios(port);
810 if (rv < 0) return /* rv */;
811
812 if ((!old_termios ||
813 (old_termios->c_cflag & CRTSCTS)) &&
814 !( tiosp->c_cflag & CRTSCTS)) {
815 tty->stopped = 0;
816 gs_start(tty);
817 }
818
819 #ifdef tytso_patch_94Nov25_1726
820 /* This "makes sense", Why is it commented out? */
821
822 if (!(old_termios->c_cflag & CLOCAL) &&
823 (tty->termios->c_cflag & CLOCAL))
824 wake_up_interruptible(&info->open_wait);
825 #endif
826
827 func_exit();
828 return /* 0 */;
829 }
830
831
832
833 /* Must be called with interrupts enabled */
834 int gs_init_port(struct gs_port *port)
835 {
836 unsigned long flags;
837 unsigned long page;
838
839 save_flags (flags);
840 if (!tmp_buf) {
841 page = get_zeroed_page(GFP_KERNEL);
842
843 cli (); /* Don't expect this to make a difference. */
844 if (tmp_buf)
845 free_page(page);
846 else
847 tmp_buf = (unsigned char *) page;
848 restore_flags (flags);
849
850 if (!tmp_buf) {
851 return -ENOMEM;
852 }
853 }
854
855 if (port->flags & ASYNC_INITIALIZED)
856 return 0;
857
858 if (!port->xmit_buf) {
859 /* We may sleep in get_zeroed_page() */
860 unsigned long tmp;
861
862 tmp = get_zeroed_page(GFP_KERNEL);
863
864 /* Spinlock? */
865 cli ();
866 if (port->xmit_buf)
867 free_page (tmp);
868 else
869 port->xmit_buf = (unsigned char *) tmp;
870 restore_flags (flags);
871
872 if (!port->xmit_buf)
873 return -ENOMEM;
874 }
875
876 cli();
877
878 if (port->tty)
879 clear_bit(TTY_IO_ERROR, &port->tty->flags);
880
881 port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
882
883 gs_set_termios(port->tty, NULL);
884
885 port->flags |= ASYNC_INITIALIZED;
886 port->flags &= ~GS_TX_INTEN;
887
888 restore_flags(flags);
889 return 0;
890 }
891
892
893 int gs_setserial(struct gs_port *port, struct serial_struct __user *sp)
894 {
895 struct serial_struct sio;
896
897 if (copy_from_user(&sio, sp, sizeof(struct serial_struct)))
898 return(-EFAULT);
899
900 if (!capable(CAP_SYS_ADMIN)) {
901 if ((sio.baud_base != port->baud_base) ||
902 (sio.close_delay != port->close_delay) ||
903 ((sio.flags & ~ASYNC_USR_MASK) !=
904 (port->flags & ~ASYNC_USR_MASK)))
905 return(-EPERM);
906 }
907
908 port->flags = (port->flags & ~ASYNC_USR_MASK) |
909 (sio.flags & ASYNC_USR_MASK);
910
911 port->baud_base = sio.baud_base;
912 port->close_delay = sio.close_delay;
913 port->closing_wait = sio.closing_wait;
914 port->custom_divisor = sio.custom_divisor;
915
916 gs_set_termios (port->tty, NULL);
917
918 return 0;
919 }
920
921
922 /*****************************************************************************/
923
924 /*
925 * Generate the serial struct info.
926 */
927
928 int gs_getserial(struct gs_port *port, struct serial_struct __user *sp)
929 {
930 struct serial_struct sio;
931
932 memset(&sio, 0, sizeof(struct serial_struct));
933 sio.flags = port->flags;
934 sio.baud_base = port->baud_base;
935 sio.close_delay = port->close_delay;
936 sio.closing_wait = port->closing_wait;
937 sio.custom_divisor = port->custom_divisor;
938 sio.hub6 = 0;
939
940 /* If you want you can override these. */
941 sio.type = PORT_UNKNOWN;
942 sio.xmit_fifo_size = -1;
943 sio.line = -1;
944 sio.port = -1;
945 sio.irq = -1;
946
947 if (port->rd->getserial)
948 port->rd->getserial (port, &sio);
949
950 if (copy_to_user(sp, &sio, sizeof(struct serial_struct)))
951 return -EFAULT;
952 return 0;
953
954 }
955
956
957 void gs_got_break(struct gs_port *port)
958 {
959 if (port->flags & ASYNC_SAK) {
960 do_SAK (port->tty);
961 }
962 *(port->tty->flip.flag_buf_ptr) = TTY_BREAK;
963 port->tty->flip.flag_buf_ptr++;
964 port->tty->flip.char_buf_ptr++;
965 port->tty->flip.count++;
966 }
967
968
969 EXPORT_SYMBOL(gs_put_char);
970 EXPORT_SYMBOL(gs_write);
971 EXPORT_SYMBOL(gs_write_room);
972 EXPORT_SYMBOL(gs_chars_in_buffer);
973 EXPORT_SYMBOL(gs_flush_buffer);
974 EXPORT_SYMBOL(gs_flush_chars);
975 EXPORT_SYMBOL(gs_stop);
976 EXPORT_SYMBOL(gs_start);
977 EXPORT_SYMBOL(gs_hangup);
978 EXPORT_SYMBOL(gs_block_til_ready);
979 EXPORT_SYMBOL(gs_close);
980 EXPORT_SYMBOL(gs_set_termios);
981 EXPORT_SYMBOL(gs_init_port);
982 EXPORT_SYMBOL(gs_setserial);
983 EXPORT_SYMBOL(gs_getserial);
984 EXPORT_SYMBOL(gs_got_break);
985
986 MODULE_LICENSE("GPL");
987
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