blob: e769811e74172d36bff0d845a9fab7327299b158 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/tty_flip.h>
30#include <linux/delay.h>
31#include <asm/semaphore.h>
32#include <asm/uaccess.h>
33
34#define DEBUG
35
Linus Torvalds1da177e2005-04-16 15:20:36 -070036static int gs_debug;
37
38#ifdef DEBUG
39#define gs_dprintk(f, str...) if (gs_debug & f) printk (str)
40#else
41#define gs_dprintk(f, str...) /* nothing */
42#endif
43
44#define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter %s\n", __FUNCTION__)
45#define func_exit() gs_dprintk (GS_DEBUG_FLOW, "gs: exit %s\n", __FUNCTION__)
46#define NEW_WRITE_LOCKING 1
47#if NEW_WRITE_LOCKING
48#define DECL /* Nothing */
Ingo Molnar81861d72006-03-23 03:00:44 -080049#define LOCKIT mutex_lock(& port->port_write_mutex);
50#define RELEASEIT mutex_unlock(&port->port_write_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#else
52#define DECL unsigned long flags;
53#define LOCKIT save_flags (flags);cli ()
54#define RELEASEIT restore_flags (flags)
55#endif
56
57#define RS_EVENT_WRITE_WAKEUP 1
58
59module_param(gs_debug, int, 0644);
60
61
62void gs_put_char(struct tty_struct * tty, unsigned char ch)
63{
64 struct gs_port *port;
65 DECL
66
67 func_enter ();
68
69 if (!tty) return;
70
71 port = tty->driver_data;
72
73 if (!port) return;
74
75 if (! (port->flags & ASYNC_INITIALIZED)) return;
76
77 /* Take a lock on the serial tranmit buffer! */
78 LOCKIT;
79
80 if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
81 /* Sorry, buffer is full, drop character. Update statistics???? -- REW */
82 RELEASEIT;
83 return;
84 }
85
86 port->xmit_buf[port->xmit_head++] = ch;
87 port->xmit_head &= SERIAL_XMIT_SIZE - 1;
88 port->xmit_cnt++; /* Characters in buffer */
89
90 RELEASEIT;
91 func_exit ();
92}
93
94
95#ifdef NEW_WRITE_LOCKING
96
97/*
98> Problems to take into account are:
99> -1- Interrupts that empty part of the buffer.
100> -2- page faults on the access to userspace.
101> -3- Other processes that are also trying to do a "write".
102*/
103
104int gs_write(struct tty_struct * tty,
105 const unsigned char *buf, int count)
106{
107 struct gs_port *port;
108 int c, total = 0;
109 int t;
110
111 func_enter ();
112
113 if (!tty) return 0;
114
115 port = tty->driver_data;
116
117 if (!port) return 0;
118
119 if (! (port->flags & ASYNC_INITIALIZED))
120 return 0;
121
122 /* get exclusive "write" access to this port (problem 3) */
123 /* This is not a spinlock because we can have a disk access (page
124 fault) in copy_from_user */
Ingo Molnar81861d72006-03-23 03:00:44 -0800125 mutex_lock(& port->port_write_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127 while (1) {
128
129 c = count;
130
131 /* This is safe because we "OWN" the "head". Noone else can
Ingo Molnar81861d72006-03-23 03:00:44 -0800132 change the "head": we own the port_write_mutex. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 /* Don't overrun the end of the buffer */
134 t = SERIAL_XMIT_SIZE - port->xmit_head;
135 if (t < c) c = t;
136
137 /* This is safe because the xmit_cnt can only decrease. This
138 would increase "t", so we might copy too little chars. */
139 /* Don't copy past the "head" of the buffer */
140 t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt;
141 if (t < c) c = t;
142
143 /* Can't copy more? break out! */
144 if (c <= 0) break;
145
146 memcpy (port->xmit_buf + port->xmit_head, buf, c);
147
148 port -> xmit_cnt += c;
149 port -> xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE -1);
150 buf += c;
151 count -= c;
152 total += c;
153 }
Ingo Molnar81861d72006-03-23 03:00:44 -0800154 mutex_unlock(& port->port_write_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 gs_dprintk (GS_DEBUG_WRITE, "write: interrupts are %s\n",
157 (port->flags & GS_TX_INTEN)?"enabled": "disabled");
158
159 if (port->xmit_cnt &&
160 !tty->stopped &&
161 !tty->hw_stopped &&
162 !(port->flags & GS_TX_INTEN)) {
163 port->flags |= GS_TX_INTEN;
164 port->rd->enable_tx_interrupts (port);
165 }
166 func_exit ();
167 return total;
168}
169#else
170/*
171> Problems to take into account are:
172> -1- Interrupts that empty part of the buffer.
173> -2- page faults on the access to userspace.
174> -3- Other processes that are also trying to do a "write".
175*/
176
177int gs_write(struct tty_struct * tty,
178 const unsigned char *buf, int count)
179{
180 struct gs_port *port;
181 int c, total = 0;
182 int t;
183 unsigned long flags;
184
185 func_enter ();
186
187 /* The standard serial driver returns 0 in this case.
188 That sounds to me as "No error, I just didn't get to writing any
189 bytes. Feel free to try again."
190 The "official" way to write n bytes from buf is:
191
192 for (nwritten = 0;nwritten < n;nwritten += rv) {
193 rv = write (fd, buf+nwritten, n-nwritten);
194 if (rv < 0) break; // Error: bail out. //
195 }
196
197 which will loop endlessly in this case. The manual page for write
198 agrees with me. In practise almost everybody writes
199 "write (fd, buf,n);" but some people might have had to deal with
200 incomplete writes in the past and correctly implemented it by now...
201 */
202
203 if (!tty) return -EIO;
204
205 port = tty->driver_data;
Jiri Slabyb3218a72006-10-04 02:15:27 -0700206 if (!port || !port->xmit_buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 return -EIO;
208
209 local_save_flags(flags);
210 while (1) {
211 cli();
212 c = count;
213
214 /* This is safe because we "OWN" the "head". Noone else can
Ingo Molnar81861d72006-03-23 03:00:44 -0800215 change the "head": we own the port_write_mutex. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 /* Don't overrun the end of the buffer */
217 t = SERIAL_XMIT_SIZE - port->xmit_head;
218 if (t < c) c = t;
219
220 /* This is safe because the xmit_cnt can only decrease. This
221 would increase "t", so we might copy too little chars. */
222 /* Don't copy past the "head" of the buffer */
223 t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt;
224 if (t < c) c = t;
225
226 /* Can't copy more? break out! */
227 if (c <= 0) {
228 local_restore_flags(flags);
229 break;
230 }
231 memcpy(port->xmit_buf + port->xmit_head, buf, c);
232 port->xmit_head = ((port->xmit_head + c) &
233 (SERIAL_XMIT_SIZE-1));
234 port->xmit_cnt += c;
235 local_restore_flags(flags);
236 buf += c;
237 count -= c;
238 total += c;
239 }
240
241 if (port->xmit_cnt &&
242 !tty->stopped &&
243 !tty->hw_stopped &&
244 !(port->flags & GS_TX_INTEN)) {
245 port->flags |= GS_TX_INTEN;
246 port->rd->enable_tx_interrupts (port);
247 }
248 func_exit ();
249 return total;
250}
251
252#endif
253
254
255
256int gs_write_room(struct tty_struct * tty)
257{
258 struct gs_port *port = tty->driver_data;
259 int ret;
260
261 func_enter ();
262 ret = SERIAL_XMIT_SIZE - port->xmit_cnt - 1;
263 if (ret < 0)
264 ret = 0;
265 func_exit ();
266 return ret;
267}
268
269
270int gs_chars_in_buffer(struct tty_struct *tty)
271{
272 struct gs_port *port = tty->driver_data;
273 func_enter ();
274
275 func_exit ();
276 return port->xmit_cnt;
277}
278
279
280static int gs_real_chars_in_buffer(struct tty_struct *tty)
281{
282 struct gs_port *port;
283 func_enter ();
284
285 if (!tty) return 0;
286 port = tty->driver_data;
287
288 if (!port->rd) return 0;
289 if (!port->rd->chars_in_buffer) return 0;
290
291 func_exit ();
292 return port->xmit_cnt + port->rd->chars_in_buffer (port);
293}
294
295
296static int gs_wait_tx_flushed (void * ptr, unsigned long timeout)
297{
298 struct gs_port *port = ptr;
299 unsigned long end_jiffies;
300 int jiffies_to_transmit, charsleft = 0, rv = 0;
301 int rcib;
302
303 func_enter();
304
305 gs_dprintk (GS_DEBUG_FLUSH, "port=%p.\n", port);
306 if (port) {
307 gs_dprintk (GS_DEBUG_FLUSH, "xmit_cnt=%x, xmit_buf=%p, tty=%p.\n",
308 port->xmit_cnt, port->xmit_buf, port->tty);
309 }
310
311 if (!port || port->xmit_cnt < 0 || !port->xmit_buf) {
312 gs_dprintk (GS_DEBUG_FLUSH, "ERROR: !port, !port->xmit_buf or prot->xmit_cnt < 0.\n");
313 func_exit();
314 return -EINVAL; /* This is an error which we don't know how to handle. */
315 }
316
317 rcib = gs_real_chars_in_buffer(port->tty);
318
319 if(rcib <= 0) {
320 gs_dprintk (GS_DEBUG_FLUSH, "nothing to wait for.\n");
321 func_exit();
322 return rv;
323 }
324 /* stop trying: now + twice the time it would normally take + seconds */
325 if (timeout == 0) timeout = MAX_SCHEDULE_TIMEOUT;
326 end_jiffies = jiffies;
327 if (timeout != MAX_SCHEDULE_TIMEOUT)
328 end_jiffies += port->baud?(2 * rcib * 10 * HZ / port->baud):0;
329 end_jiffies += timeout;
330
331 gs_dprintk (GS_DEBUG_FLUSH, "now=%lx, end=%lx (%ld).\n",
332 jiffies, end_jiffies, end_jiffies-jiffies);
333
334 /* the expression is actually jiffies < end_jiffies, but that won't
335 work around the wraparound. Tricky eh? */
336 while ((charsleft = gs_real_chars_in_buffer (port->tty)) &&
337 time_after (end_jiffies, jiffies)) {
338 /* Units check:
339 chars * (bits/char) * (jiffies /sec) / (bits/sec) = jiffies!
340 check! */
341
342 charsleft += 16; /* Allow 16 chars more to be transmitted ... */
343 jiffies_to_transmit = port->baud?(1 + charsleft * 10 * HZ / port->baud):0;
344 /* ^^^ Round up.... */
345 if (jiffies_to_transmit <= 0) jiffies_to_transmit = 1;
346
347 gs_dprintk (GS_DEBUG_FLUSH, "Expect to finish in %d jiffies "
348 "(%d chars).\n", jiffies_to_transmit, charsleft);
349
350 msleep_interruptible(jiffies_to_msecs(jiffies_to_transmit));
351 if (signal_pending (current)) {
352 gs_dprintk (GS_DEBUG_FLUSH, "Signal pending. Bombing out: ");
353 rv = -EINTR;
354 break;
355 }
356 }
357
358 gs_dprintk (GS_DEBUG_FLUSH, "charsleft = %d.\n", charsleft);
359 set_current_state (TASK_RUNNING);
360
361 func_exit();
362 return rv;
363}
364
365
366
367void gs_flush_buffer(struct tty_struct *tty)
368{
369 struct gs_port *port;
370 unsigned long flags;
371
372 func_enter ();
373
374 if (!tty) return;
375
376 port = tty->driver_data;
377
378 if (!port) return;
379
380 /* XXX Would the write semaphore do? */
381 spin_lock_irqsave (&port->driver_lock, flags);
382 port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
383 spin_unlock_irqrestore (&port->driver_lock, flags);
384
385 wake_up_interruptible(&tty->write_wait);
386 tty_wakeup(tty);
387 func_exit ();
388}
389
390
391void gs_flush_chars(struct tty_struct * tty)
392{
393 struct gs_port *port;
394
395 func_enter ();
396
397 if (!tty) return;
398
399 port = tty->driver_data;
400
401 if (!port) return;
402
403 if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
404 !port->xmit_buf) {
405 func_exit ();
406 return;
407 }
408
409 /* Beats me -- REW */
410 port->flags |= GS_TX_INTEN;
411 port->rd->enable_tx_interrupts (port);
412 func_exit ();
413}
414
415
416void gs_stop(struct tty_struct * tty)
417{
418 struct gs_port *port;
419
420 func_enter ();
421
422 if (!tty) return;
423
424 port = tty->driver_data;
425
426 if (!port) return;
427
428 if (port->xmit_cnt &&
429 port->xmit_buf &&
430 (port->flags & GS_TX_INTEN) ) {
431 port->flags &= ~GS_TX_INTEN;
432 port->rd->disable_tx_interrupts (port);
433 }
434 func_exit ();
435}
436
437
438void gs_start(struct tty_struct * tty)
439{
440 struct gs_port *port;
441
442 if (!tty) return;
443
444 port = tty->driver_data;
445
446 if (!port) return;
447
448 if (port->xmit_cnt &&
449 port->xmit_buf &&
450 !(port->flags & GS_TX_INTEN) ) {
451 port->flags |= GS_TX_INTEN;
452 port->rd->enable_tx_interrupts (port);
453 }
454 func_exit ();
455}
456
457
458static void gs_shutdown_port (struct gs_port *port)
459{
460 unsigned long flags;
461
462 func_enter();
463
464 if (!port) return;
465
466 if (!(port->flags & ASYNC_INITIALIZED))
467 return;
468
469 spin_lock_irqsave(&port->driver_lock, flags);
470
471 if (port->xmit_buf) {
472 free_page((unsigned long) port->xmit_buf);
473 port->xmit_buf = NULL;
474 }
475
476 if (port->tty)
477 set_bit(TTY_IO_ERROR, &port->tty->flags);
478
479 port->rd->shutdown_port (port);
480
481 port->flags &= ~ASYNC_INITIALIZED;
482 spin_unlock_irqrestore(&port->driver_lock, flags);
483
484 func_exit();
485}
486
487
488void gs_hangup(struct tty_struct *tty)
489{
490 struct gs_port *port;
491
492 func_enter ();
493
494 if (!tty) return;
495
496 port = tty->driver_data;
497 tty = port->tty;
498 if (!tty)
499 return;
500
501 gs_shutdown_port (port);
502 port->flags &= ~(ASYNC_NORMAL_ACTIVE|GS_ACTIVE);
503 port->tty = NULL;
504 port->count = 0;
505
506 wake_up_interruptible(&port->open_wait);
507 func_exit ();
508}
509
510
511int gs_block_til_ready(void *port_, struct file * filp)
512{
513 struct gs_port *port = port_;
514 DECLARE_WAITQUEUE(wait, current);
515 int retval;
516 int do_clocal = 0;
517 int CD;
518 struct tty_struct *tty;
519 unsigned long flags;
520
521 func_enter ();
522
523 if (!port) return 0;
524
525 tty = port->tty;
526
527 if (!tty) return 0;
528
529 gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n");
530 /*
531 * If the device is in the middle of being closed, then block
532 * until it's done, and then try again.
533 */
534 if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
535 interruptible_sleep_on(&port->close_wait);
536 if (port->flags & ASYNC_HUP_NOTIFY)
537 return -EAGAIN;
538 else
539 return -ERESTARTSYS;
540 }
541
542 gs_dprintk (GS_DEBUG_BTR, "after hung up\n");
543
544 /*
545 * If non-blocking mode is set, or the port is not enabled,
546 * then make the check up front and then exit.
547 */
548 if ((filp->f_flags & O_NONBLOCK) ||
549 (tty->flags & (1 << TTY_IO_ERROR))) {
550 port->flags |= ASYNC_NORMAL_ACTIVE;
551 return 0;
552 }
553
554 gs_dprintk (GS_DEBUG_BTR, "after nonblock\n");
555
556 if (C_CLOCAL(tty))
557 do_clocal = 1;
558
559 /*
560 * Block waiting for the carrier detect and the line to become
561 * free (i.e., not in use by the callout). While we are in
562 * this loop, port->count is dropped by one, so that
563 * rs_close() knows when to free things. We restore it upon
564 * exit, either normal or abnormal.
565 */
566 retval = 0;
567
568 add_wait_queue(&port->open_wait, &wait);
569
570 gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n");
571 spin_lock_irqsave(&port->driver_lock, flags);
572 if (!tty_hung_up_p(filp)) {
573 port->count--;
574 }
575 spin_unlock_irqrestore(&port->driver_lock, flags);
576 port->blocked_open++;
577 while (1) {
578 CD = port->rd->get_CD (port);
579 gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD);
580 set_current_state (TASK_INTERRUPTIBLE);
581 if (tty_hung_up_p(filp) ||
582 !(port->flags & ASYNC_INITIALIZED)) {
583 if (port->flags & ASYNC_HUP_NOTIFY)
584 retval = -EAGAIN;
585 else
586 retval = -ERESTARTSYS;
587 break;
588 }
589 if (!(port->flags & ASYNC_CLOSING) &&
590 (do_clocal || CD))
591 break;
592 gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n",
593 (int)signal_pending (current), *(long*)(&current->blocked));
594 if (signal_pending(current)) {
595 retval = -ERESTARTSYS;
596 break;
597 }
598 schedule();
599 }
600 gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n",
601 port->blocked_open);
602 set_current_state (TASK_RUNNING);
603 remove_wait_queue(&port->open_wait, &wait);
604 if (!tty_hung_up_p(filp)) {
605 port->count++;
606 }
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
617void 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 spin_lock_irqsave(&port->driver_lock, flags);
637
638 if (tty_hung_up_p(filp)) {
639 spin_unlock_irqrestore(&port->driver_lock, flags);
640 if (port->rd->hungup)
641 port->rd->hungup (port);
642 func_exit ();
643 return;
644 }
645
646 if ((tty->count == 1) && (port->count != 1)) {
647 printk(KERN_ERR "gs: gs_close port %p: bad port count;"
648 " tty->count is 1, port count is %d\n", port, port->count);
649 port->count = 1;
650 }
651 if (--port->count < 0) {
652 printk(KERN_ERR "gs: gs_close port %p: bad port count: %d\n", port, port->count);
653 port->count = 0;
654 }
655
656 if (port->count) {
657 gs_dprintk(GS_DEBUG_CLOSE, "gs_close port %p: count: %d\n", port, port->count);
658 spin_unlock_irqrestore(&port->driver_lock, flags);
659 func_exit ();
660 return;
661 }
662 port->flags |= ASYNC_CLOSING;
663
664 /*
665 * Now we wait for the transmit buffer to clear; and we notify
666 * the line discipline to only process XON/XOFF characters.
667 */
668 tty->closing = 1;
669 /* if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
670 tty_wait_until_sent(tty, port->closing_wait); */
671
672 /*
673 * At this point we stop accepting input. To do this, we
674 * disable the receive line status interrupts, and tell the
675 * interrupt driver to stop checking the data ready bit in the
676 * line status register.
677 */
678
679 port->rd->disable_rx_interrupts (port);
680 spin_unlock_irqrestore(&port->driver_lock, flags);
681
682 /* close has no way of returning "EINTR", so discard return value */
683 if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
684 gs_wait_tx_flushed (port, port->closing_wait);
685
686 port->flags &= ~GS_ACTIVE;
687
688 if (tty->driver->flush_buffer)
689 tty->driver->flush_buffer(tty);
690
691 tty_ldisc_flush(tty);
692 tty->closing = 0;
693
694 port->event = 0;
695 port->rd->close (port);
696 port->rd->shutdown_port (port);
697 port->tty = NULL;
698
699 if (port->blocked_open) {
700 if (port->close_delay) {
701 spin_unlock_irqrestore(&port->driver_lock, flags);
702 msleep_interruptible(jiffies_to_msecs(port->close_delay));
703 spin_lock_irqsave(&port->driver_lock, flags);
704 }
705 wake_up_interruptible(&port->open_wait);
706 }
707 port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING | ASYNC_INITIALIZED);
708 wake_up_interruptible(&port->close_wait);
709
710 func_exit ();
711}
712
713
714static unsigned int gs_baudrates[] = {
715 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
716 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
717};
718
719
720void gs_set_termios (struct tty_struct * tty,
Alan Cox606d0992006-12-08 02:38:45 -0800721 struct ktermios * old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722{
723 struct gs_port *port;
724 int baudrate, tmp, rv;
Alan Cox606d0992006-12-08 02:38:45 -0800725 struct ktermios *tiosp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726
727 func_enter();
728
729 if (!tty) return;
730
731 port = tty->driver_data;
732
733 if (!port) return;
734 if (!port->tty) {
735 /* This seems to happen when this is called after gs_close. */
736 gs_dprintk (GS_DEBUG_TERMIOS, "gs: Odd: port->tty is NULL\n");
737 port->tty = tty;
738 }
739
740
741 tiosp = tty->termios;
742
743 if (gs_debug & GS_DEBUG_TERMIOS) {
744 gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp);
745 }
746
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 /* This is an optimization that is only allowed for dumb cards */
748 /* Smart cards require knowledge of iflags and oflags too: that
749 might change hardware cooking mode.... */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 if (old_termios) {
751 if( (tiosp->c_iflag == old_termios->c_iflag)
752 && (tiosp->c_oflag == old_termios->c_oflag)
753 && (tiosp->c_cflag == old_termios->c_cflag)
754 && (tiosp->c_lflag == old_termios->c_lflag)
755 && (tiosp->c_line == old_termios->c_line)
756 && (memcmp(tiosp->c_cc, old_termios->c_cc, NCC) == 0)) {
757 gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: optimized away\n");
758 return /* 0 */;
759 }
760 } else
761 gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: no old_termios: "
762 "no optimization\n");
763
764 if(old_termios && (gs_debug & GS_DEBUG_TERMIOS)) {
765 if(tiosp->c_iflag != old_termios->c_iflag) printk("c_iflag changed\n");
766 if(tiosp->c_oflag != old_termios->c_oflag) printk("c_oflag changed\n");
767 if(tiosp->c_cflag != old_termios->c_cflag) printk("c_cflag changed\n");
768 if(tiosp->c_lflag != old_termios->c_lflag) printk("c_lflag changed\n");
769 if(tiosp->c_line != old_termios->c_line) printk("c_line changed\n");
770 if(!memcmp(tiosp->c_cc, old_termios->c_cc, NCC)) printk("c_cc changed\n");
771 }
772
Alan Coxd720bc42006-09-29 02:01:38 -0700773 baudrate = tty_get_baud_rate(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774
775 baudrate = gs_baudrates[baudrate];
776 if ((tiosp->c_cflag & CBAUD) == B38400) {
777 if ( (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
778 baudrate = 57600;
779 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
780 baudrate = 115200;
781 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
782 baudrate = 230400;
783 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
784 baudrate = 460800;
785 else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
786 baudrate = (port->baud_base / port->custom_divisor);
787 }
788
789 /* I recommend using THIS instead of the mess in termios (and
790 duplicating the above code). Next we should create a clean
791 interface towards this variable. If your card supports arbitrary
792 baud rates, (e.g. CD1400 or 16550 based cards) then everything
793 will be very easy..... */
794 port->baud = baudrate;
795
796 /* Two timer ticks seems enough to wakeup something like SLIP driver */
797 /* Baudrate/10 is cps. Divide by HZ to get chars per tick. */
798 tmp = (baudrate / 10 / HZ) * 2;
799
800 if (tmp < 0) tmp = 0;
801 if (tmp >= SERIAL_XMIT_SIZE) tmp = SERIAL_XMIT_SIZE-1;
802
803 port->wakeup_chars = tmp;
804
805 /* We should really wait for the characters to be all sent before
806 changing the settings. -- CAL */
807 rv = gs_wait_tx_flushed (port, MAX_SCHEDULE_TIMEOUT);
808 if (rv < 0) return /* rv */;
809
810 rv = port->rd->set_real_termios(port);
811 if (rv < 0) return /* rv */;
812
813 if ((!old_termios ||
814 (old_termios->c_cflag & CRTSCTS)) &&
815 !( tiosp->c_cflag & CRTSCTS)) {
816 tty->stopped = 0;
817 gs_start(tty);
818 }
819
820#ifdef tytso_patch_94Nov25_1726
821 /* This "makes sense", Why is it commented out? */
822
823 if (!(old_termios->c_cflag & CLOCAL) &&
824 (tty->termios->c_cflag & CLOCAL))
825 wake_up_interruptible(&port->gs.open_wait);
826#endif
827
828 func_exit();
829 return /* 0 */;
830}
831
832
833
834/* Must be called with interrupts enabled */
835int gs_init_port(struct gs_port *port)
836{
837 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838
839 func_enter ();
840
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 if (port->flags & ASYNC_INITIALIZED) {
842 func_exit ();
843 return 0;
844 }
845 if (!port->xmit_buf) {
846 /* We may sleep in get_zeroed_page() */
847 unsigned long tmp;
848
849 tmp = get_zeroed_page(GFP_KERNEL);
850 spin_lock_irqsave (&port->driver_lock, flags);
851 if (port->xmit_buf)
852 free_page (tmp);
853 else
854 port->xmit_buf = (unsigned char *) tmp;
855 spin_unlock_irqrestore(&port->driver_lock, flags);
856 if (!port->xmit_buf) {
857 func_exit ();
858 return -ENOMEM;
859 }
860 }
861
862 spin_lock_irqsave (&port->driver_lock, flags);
863 if (port->tty)
864 clear_bit(TTY_IO_ERROR, &port->tty->flags);
Ingo Molnar81861d72006-03-23 03:00:44 -0800865 mutex_init(&port->port_write_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
867 spin_unlock_irqrestore(&port->driver_lock, flags);
868 gs_set_termios(port->tty, NULL);
869 spin_lock_irqsave (&port->driver_lock, flags);
870 port->flags |= ASYNC_INITIALIZED;
871 port->flags &= ~GS_TX_INTEN;
872
873 spin_unlock_irqrestore(&port->driver_lock, flags);
874 func_exit ();
875 return 0;
876}
877
878
879int gs_setserial(struct gs_port *port, struct serial_struct __user *sp)
880{
881 struct serial_struct sio;
882
883 if (copy_from_user(&sio, sp, sizeof(struct serial_struct)))
884 return(-EFAULT);
885
886 if (!capable(CAP_SYS_ADMIN)) {
887 if ((sio.baud_base != port->baud_base) ||
888 (sio.close_delay != port->close_delay) ||
889 ((sio.flags & ~ASYNC_USR_MASK) !=
890 (port->flags & ~ASYNC_USR_MASK)))
891 return(-EPERM);
892 }
893
894 port->flags = (port->flags & ~ASYNC_USR_MASK) |
895 (sio.flags & ASYNC_USR_MASK);
896
897 port->baud_base = sio.baud_base;
898 port->close_delay = sio.close_delay;
899 port->closing_wait = sio.closing_wait;
900 port->custom_divisor = sio.custom_divisor;
901
902 gs_set_termios (port->tty, NULL);
903
904 return 0;
905}
906
907
908/*****************************************************************************/
909
910/*
911 * Generate the serial struct info.
912 */
913
914int gs_getserial(struct gs_port *port, struct serial_struct __user *sp)
915{
916 struct serial_struct sio;
917
918 memset(&sio, 0, sizeof(struct serial_struct));
919 sio.flags = port->flags;
920 sio.baud_base = port->baud_base;
921 sio.close_delay = port->close_delay;
922 sio.closing_wait = port->closing_wait;
923 sio.custom_divisor = port->custom_divisor;
924 sio.hub6 = 0;
925
926 /* If you want you can override these. */
927 sio.type = PORT_UNKNOWN;
928 sio.xmit_fifo_size = -1;
929 sio.line = -1;
930 sio.port = -1;
931 sio.irq = -1;
932
933 if (port->rd->getserial)
934 port->rd->getserial (port, &sio);
935
936 if (copy_to_user(sp, &sio, sizeof(struct serial_struct)))
937 return -EFAULT;
938 return 0;
939
940}
941
942
943void gs_got_break(struct gs_port *port)
944{
945 func_enter ();
946
947 tty_insert_flip_char(port->tty, 0, TTY_BREAK);
948 tty_schedule_flip(port->tty);
949 if (port->flags & ASYNC_SAK) {
950 do_SAK (port->tty);
951 }
952
953 func_exit ();
954}
955
956
957EXPORT_SYMBOL(gs_put_char);
958EXPORT_SYMBOL(gs_write);
959EXPORT_SYMBOL(gs_write_room);
960EXPORT_SYMBOL(gs_chars_in_buffer);
961EXPORT_SYMBOL(gs_flush_buffer);
962EXPORT_SYMBOL(gs_flush_chars);
963EXPORT_SYMBOL(gs_stop);
964EXPORT_SYMBOL(gs_start);
965EXPORT_SYMBOL(gs_hangup);
966EXPORT_SYMBOL(gs_block_til_ready);
967EXPORT_SYMBOL(gs_close);
968EXPORT_SYMBOL(gs_set_termios);
969EXPORT_SYMBOL(gs_init_port);
970EXPORT_SYMBOL(gs_setserial);
971EXPORT_SYMBOL(gs_getserial);
972EXPORT_SYMBOL(gs_got_break);
973
974MODULE_LICENSE("GPL");