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1da177e4 LT |
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/tty_flip.h> | |
30 | #include <linux/delay.h> | |
1da177e4 LT |
31 | #include <asm/uaccess.h> |
32 | ||
33 | #define DEBUG | |
34 | ||
1da177e4 LT |
35 | static int gs_debug; |
36 | ||
37 | #ifdef DEBUG | |
38 | #define gs_dprintk(f, str...) if (gs_debug & f) printk (str) | |
39 | #else | |
40 | #define gs_dprintk(f, str...) /* nothing */ | |
41 | #endif | |
42 | ||
43 | #define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter %s\n", __FUNCTION__) | |
44 | #define func_exit() gs_dprintk (GS_DEBUG_FLOW, "gs: exit %s\n", __FUNCTION__) | |
1da177e4 LT |
45 | |
46 | #define RS_EVENT_WRITE_WAKEUP 1 | |
47 | ||
48 | module_param(gs_debug, int, 0644); | |
49 | ||
50 | ||
51 | void gs_put_char(struct tty_struct * tty, unsigned char ch) | |
52 | { | |
53 | struct gs_port *port; | |
1da177e4 LT |
54 | |
55 | func_enter (); | |
56 | ||
57 | if (!tty) return; | |
58 | ||
59 | port = tty->driver_data; | |
60 | ||
61 | if (!port) return; | |
62 | ||
63 | if (! (port->flags & ASYNC_INITIALIZED)) return; | |
64 | ||
65 | /* Take a lock on the serial tranmit buffer! */ | |
35426128 | 66 | mutex_lock(& port->port_write_mutex); |
1da177e4 LT |
67 | |
68 | if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) { | |
69 | /* Sorry, buffer is full, drop character. Update statistics???? -- REW */ | |
35426128 | 70 | mutex_unlock(&port->port_write_mutex); |
1da177e4 LT |
71 | return; |
72 | } | |
73 | ||
74 | port->xmit_buf[port->xmit_head++] = ch; | |
75 | port->xmit_head &= SERIAL_XMIT_SIZE - 1; | |
76 | port->xmit_cnt++; /* Characters in buffer */ | |
77 | ||
35426128 | 78 | mutex_unlock(&port->port_write_mutex); |
1da177e4 LT |
79 | func_exit (); |
80 | } | |
81 | ||
82 | ||
1da177e4 LT |
83 | /* |
84 | > Problems to take into account are: | |
85 | > -1- Interrupts that empty part of the buffer. | |
86 | > -2- page faults on the access to userspace. | |
87 | > -3- Other processes that are also trying to do a "write". | |
88 | */ | |
89 | ||
90 | int gs_write(struct tty_struct * tty, | |
91 | const unsigned char *buf, int count) | |
92 | { | |
93 | struct gs_port *port; | |
94 | int c, total = 0; | |
95 | int t; | |
96 | ||
97 | func_enter (); | |
98 | ||
99 | if (!tty) return 0; | |
100 | ||
101 | port = tty->driver_data; | |
102 | ||
103 | if (!port) return 0; | |
104 | ||
105 | if (! (port->flags & ASYNC_INITIALIZED)) | |
106 | return 0; | |
107 | ||
108 | /* get exclusive "write" access to this port (problem 3) */ | |
109 | /* This is not a spinlock because we can have a disk access (page | |
110 | fault) in copy_from_user */ | |
81861d78 | 111 | mutex_lock(& port->port_write_mutex); |
1da177e4 LT |
112 | |
113 | while (1) { | |
114 | ||
115 | c = count; | |
116 | ||
117 | /* This is safe because we "OWN" the "head". Noone else can | |
81861d78 | 118 | change the "head": we own the port_write_mutex. */ |
1da177e4 LT |
119 | /* Don't overrun the end of the buffer */ |
120 | t = SERIAL_XMIT_SIZE - port->xmit_head; | |
121 | if (t < c) c = t; | |
122 | ||
123 | /* This is safe because the xmit_cnt can only decrease. This | |
124 | would increase "t", so we might copy too little chars. */ | |
125 | /* Don't copy past the "head" of the buffer */ | |
126 | t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt; | |
127 | if (t < c) c = t; | |
128 | ||
129 | /* Can't copy more? break out! */ | |
130 | if (c <= 0) break; | |
131 | ||
132 | memcpy (port->xmit_buf + port->xmit_head, buf, c); | |
133 | ||
134 | port -> xmit_cnt += c; | |
135 | port -> xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE -1); | |
136 | buf += c; | |
137 | count -= c; | |
138 | total += c; | |
139 | } | |
81861d78 | 140 | mutex_unlock(& port->port_write_mutex); |
1da177e4 LT |
141 | |
142 | gs_dprintk (GS_DEBUG_WRITE, "write: interrupts are %s\n", | |
143 | (port->flags & GS_TX_INTEN)?"enabled": "disabled"); | |
144 | ||
145 | if (port->xmit_cnt && | |
146 | !tty->stopped && | |
147 | !tty->hw_stopped && | |
148 | !(port->flags & GS_TX_INTEN)) { | |
149 | port->flags |= GS_TX_INTEN; | |
150 | port->rd->enable_tx_interrupts (port); | |
151 | } | |
152 | func_exit (); | |
153 | return total; | |
154 | } | |
1da177e4 LT |
155 | |
156 | ||
157 | ||
158 | int gs_write_room(struct tty_struct * tty) | |
159 | { | |
160 | struct gs_port *port = tty->driver_data; | |
161 | int ret; | |
162 | ||
163 | func_enter (); | |
164 | ret = SERIAL_XMIT_SIZE - port->xmit_cnt - 1; | |
165 | if (ret < 0) | |
166 | ret = 0; | |
167 | func_exit (); | |
168 | return ret; | |
169 | } | |
170 | ||
171 | ||
172 | int gs_chars_in_buffer(struct tty_struct *tty) | |
173 | { | |
174 | struct gs_port *port = tty->driver_data; | |
175 | func_enter (); | |
176 | ||
177 | func_exit (); | |
178 | return port->xmit_cnt; | |
179 | } | |
180 | ||
181 | ||
182 | static int gs_real_chars_in_buffer(struct tty_struct *tty) | |
183 | { | |
184 | struct gs_port *port; | |
185 | func_enter (); | |
186 | ||
187 | if (!tty) return 0; | |
188 | port = tty->driver_data; | |
189 | ||
190 | if (!port->rd) return 0; | |
191 | if (!port->rd->chars_in_buffer) return 0; | |
192 | ||
193 | func_exit (); | |
194 | return port->xmit_cnt + port->rd->chars_in_buffer (port); | |
195 | } | |
196 | ||
197 | ||
198 | static int gs_wait_tx_flushed (void * ptr, unsigned long timeout) | |
199 | { | |
200 | struct gs_port *port = ptr; | |
201 | unsigned long end_jiffies; | |
202 | int jiffies_to_transmit, charsleft = 0, rv = 0; | |
203 | int rcib; | |
204 | ||
205 | func_enter(); | |
206 | ||
207 | gs_dprintk (GS_DEBUG_FLUSH, "port=%p.\n", port); | |
208 | if (port) { | |
209 | gs_dprintk (GS_DEBUG_FLUSH, "xmit_cnt=%x, xmit_buf=%p, tty=%p.\n", | |
210 | port->xmit_cnt, port->xmit_buf, port->tty); | |
211 | } | |
212 | ||
213 | if (!port || port->xmit_cnt < 0 || !port->xmit_buf) { | |
214 | gs_dprintk (GS_DEBUG_FLUSH, "ERROR: !port, !port->xmit_buf or prot->xmit_cnt < 0.\n"); | |
215 | func_exit(); | |
216 | return -EINVAL; /* This is an error which we don't know how to handle. */ | |
217 | } | |
218 | ||
219 | rcib = gs_real_chars_in_buffer(port->tty); | |
220 | ||
221 | if(rcib <= 0) { | |
222 | gs_dprintk (GS_DEBUG_FLUSH, "nothing to wait for.\n"); | |
223 | func_exit(); | |
224 | return rv; | |
225 | } | |
226 | /* stop trying: now + twice the time it would normally take + seconds */ | |
227 | if (timeout == 0) timeout = MAX_SCHEDULE_TIMEOUT; | |
228 | end_jiffies = jiffies; | |
229 | if (timeout != MAX_SCHEDULE_TIMEOUT) | |
230 | end_jiffies += port->baud?(2 * rcib * 10 * HZ / port->baud):0; | |
231 | end_jiffies += timeout; | |
232 | ||
233 | gs_dprintk (GS_DEBUG_FLUSH, "now=%lx, end=%lx (%ld).\n", | |
234 | jiffies, end_jiffies, end_jiffies-jiffies); | |
235 | ||
236 | /* the expression is actually jiffies < end_jiffies, but that won't | |
237 | work around the wraparound. Tricky eh? */ | |
238 | while ((charsleft = gs_real_chars_in_buffer (port->tty)) && | |
239 | time_after (end_jiffies, jiffies)) { | |
240 | /* Units check: | |
241 | chars * (bits/char) * (jiffies /sec) / (bits/sec) = jiffies! | |
242 | check! */ | |
243 | ||
244 | charsleft += 16; /* Allow 16 chars more to be transmitted ... */ | |
245 | jiffies_to_transmit = port->baud?(1 + charsleft * 10 * HZ / port->baud):0; | |
246 | /* ^^^ Round up.... */ | |
247 | if (jiffies_to_transmit <= 0) jiffies_to_transmit = 1; | |
248 | ||
249 | gs_dprintk (GS_DEBUG_FLUSH, "Expect to finish in %d jiffies " | |
250 | "(%d chars).\n", jiffies_to_transmit, charsleft); | |
251 | ||
252 | msleep_interruptible(jiffies_to_msecs(jiffies_to_transmit)); | |
253 | if (signal_pending (current)) { | |
254 | gs_dprintk (GS_DEBUG_FLUSH, "Signal pending. Bombing out: "); | |
255 | rv = -EINTR; | |
256 | break; | |
257 | } | |
258 | } | |
259 | ||
260 | gs_dprintk (GS_DEBUG_FLUSH, "charsleft = %d.\n", charsleft); | |
261 | set_current_state (TASK_RUNNING); | |
262 | ||
263 | func_exit(); | |
264 | return rv; | |
265 | } | |
266 | ||
267 | ||
268 | ||
269 | void gs_flush_buffer(struct tty_struct *tty) | |
270 | { | |
271 | struct gs_port *port; | |
272 | unsigned long flags; | |
273 | ||
274 | func_enter (); | |
275 | ||
276 | if (!tty) return; | |
277 | ||
278 | port = tty->driver_data; | |
279 | ||
280 | if (!port) return; | |
281 | ||
282 | /* XXX Would the write semaphore do? */ | |
283 | spin_lock_irqsave (&port->driver_lock, flags); | |
284 | port->xmit_cnt = port->xmit_head = port->xmit_tail = 0; | |
285 | spin_unlock_irqrestore (&port->driver_lock, flags); | |
286 | ||
1da177e4 LT |
287 | tty_wakeup(tty); |
288 | func_exit (); | |
289 | } | |
290 | ||
291 | ||
292 | void gs_flush_chars(struct tty_struct * tty) | |
293 | { | |
294 | struct gs_port *port; | |
295 | ||
296 | func_enter (); | |
297 | ||
298 | if (!tty) return; | |
299 | ||
300 | port = tty->driver_data; | |
301 | ||
302 | if (!port) return; | |
303 | ||
304 | if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped || | |
305 | !port->xmit_buf) { | |
306 | func_exit (); | |
307 | return; | |
308 | } | |
309 | ||
310 | /* Beats me -- REW */ | |
311 | port->flags |= GS_TX_INTEN; | |
312 | port->rd->enable_tx_interrupts (port); | |
313 | func_exit (); | |
314 | } | |
315 | ||
316 | ||
317 | void gs_stop(struct tty_struct * tty) | |
318 | { | |
319 | struct gs_port *port; | |
320 | ||
321 | func_enter (); | |
322 | ||
323 | if (!tty) return; | |
324 | ||
325 | port = tty->driver_data; | |
326 | ||
327 | if (!port) return; | |
328 | ||
329 | if (port->xmit_cnt && | |
330 | port->xmit_buf && | |
331 | (port->flags & GS_TX_INTEN) ) { | |
332 | port->flags &= ~GS_TX_INTEN; | |
333 | port->rd->disable_tx_interrupts (port); | |
334 | } | |
335 | func_exit (); | |
336 | } | |
337 | ||
338 | ||
339 | void gs_start(struct tty_struct * tty) | |
340 | { | |
341 | struct gs_port *port; | |
342 | ||
343 | if (!tty) return; | |
344 | ||
345 | port = tty->driver_data; | |
346 | ||
347 | if (!port) return; | |
348 | ||
349 | if (port->xmit_cnt && | |
350 | port->xmit_buf && | |
351 | !(port->flags & GS_TX_INTEN) ) { | |
352 | port->flags |= GS_TX_INTEN; | |
353 | port->rd->enable_tx_interrupts (port); | |
354 | } | |
355 | func_exit (); | |
356 | } | |
357 | ||
358 | ||
359 | static void gs_shutdown_port (struct gs_port *port) | |
360 | { | |
361 | unsigned long flags; | |
362 | ||
363 | func_enter(); | |
364 | ||
365 | if (!port) return; | |
366 | ||
367 | if (!(port->flags & ASYNC_INITIALIZED)) | |
368 | return; | |
369 | ||
370 | spin_lock_irqsave(&port->driver_lock, flags); | |
371 | ||
372 | if (port->xmit_buf) { | |
373 | free_page((unsigned long) port->xmit_buf); | |
374 | port->xmit_buf = NULL; | |
375 | } | |
376 | ||
377 | if (port->tty) | |
378 | set_bit(TTY_IO_ERROR, &port->tty->flags); | |
379 | ||
380 | port->rd->shutdown_port (port); | |
381 | ||
382 | port->flags &= ~ASYNC_INITIALIZED; | |
383 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
384 | ||
385 | func_exit(); | |
386 | } | |
387 | ||
388 | ||
389 | void gs_hangup(struct tty_struct *tty) | |
390 | { | |
391 | struct gs_port *port; | |
392 | ||
393 | func_enter (); | |
394 | ||
395 | if (!tty) return; | |
396 | ||
397 | port = tty->driver_data; | |
398 | tty = port->tty; | |
399 | if (!tty) | |
400 | return; | |
401 | ||
402 | gs_shutdown_port (port); | |
403 | port->flags &= ~(ASYNC_NORMAL_ACTIVE|GS_ACTIVE); | |
404 | port->tty = NULL; | |
405 | port->count = 0; | |
406 | ||
407 | wake_up_interruptible(&port->open_wait); | |
408 | func_exit (); | |
409 | } | |
410 | ||
411 | ||
412 | int gs_block_til_ready(void *port_, struct file * filp) | |
413 | { | |
414 | struct gs_port *port = port_; | |
415 | DECLARE_WAITQUEUE(wait, current); | |
416 | int retval; | |
417 | int do_clocal = 0; | |
418 | int CD; | |
419 | struct tty_struct *tty; | |
420 | unsigned long flags; | |
421 | ||
422 | func_enter (); | |
423 | ||
424 | if (!port) return 0; | |
425 | ||
426 | tty = port->tty; | |
427 | ||
428 | if (!tty) return 0; | |
429 | ||
430 | gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n"); | |
431 | /* | |
432 | * If the device is in the middle of being closed, then block | |
433 | * until it's done, and then try again. | |
434 | */ | |
435 | if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { | |
436 | interruptible_sleep_on(&port->close_wait); | |
437 | if (port->flags & ASYNC_HUP_NOTIFY) | |
438 | return -EAGAIN; | |
439 | else | |
440 | return -ERESTARTSYS; | |
441 | } | |
442 | ||
443 | gs_dprintk (GS_DEBUG_BTR, "after hung up\n"); | |
444 | ||
445 | /* | |
446 | * If non-blocking mode is set, or the port is not enabled, | |
447 | * then make the check up front and then exit. | |
448 | */ | |
449 | if ((filp->f_flags & O_NONBLOCK) || | |
450 | (tty->flags & (1 << TTY_IO_ERROR))) { | |
451 | port->flags |= ASYNC_NORMAL_ACTIVE; | |
452 | return 0; | |
453 | } | |
454 | ||
455 | gs_dprintk (GS_DEBUG_BTR, "after nonblock\n"); | |
456 | ||
457 | if (C_CLOCAL(tty)) | |
458 | do_clocal = 1; | |
459 | ||
460 | /* | |
461 | * Block waiting for the carrier detect and the line to become | |
462 | * free (i.e., not in use by the callout). While we are in | |
463 | * this loop, port->count is dropped by one, so that | |
464 | * rs_close() knows when to free things. We restore it upon | |
465 | * exit, either normal or abnormal. | |
466 | */ | |
467 | retval = 0; | |
468 | ||
469 | add_wait_queue(&port->open_wait, &wait); | |
470 | ||
471 | gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n"); | |
472 | spin_lock_irqsave(&port->driver_lock, flags); | |
473 | if (!tty_hung_up_p(filp)) { | |
474 | port->count--; | |
475 | } | |
476 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
477 | port->blocked_open++; | |
478 | while (1) { | |
479 | CD = port->rd->get_CD (port); | |
480 | gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD); | |
481 | set_current_state (TASK_INTERRUPTIBLE); | |
482 | if (tty_hung_up_p(filp) || | |
483 | !(port->flags & ASYNC_INITIALIZED)) { | |
484 | if (port->flags & ASYNC_HUP_NOTIFY) | |
485 | retval = -EAGAIN; | |
486 | else | |
487 | retval = -ERESTARTSYS; | |
488 | break; | |
489 | } | |
490 | if (!(port->flags & ASYNC_CLOSING) && | |
491 | (do_clocal || CD)) | |
492 | break; | |
493 | gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n", | |
494 | (int)signal_pending (current), *(long*)(¤t->blocked)); | |
495 | if (signal_pending(current)) { | |
496 | retval = -ERESTARTSYS; | |
497 | break; | |
498 | } | |
499 | schedule(); | |
500 | } | |
501 | gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n", | |
502 | port->blocked_open); | |
503 | set_current_state (TASK_RUNNING); | |
504 | remove_wait_queue(&port->open_wait, &wait); | |
505 | if (!tty_hung_up_p(filp)) { | |
506 | port->count++; | |
507 | } | |
508 | port->blocked_open--; | |
509 | if (retval) | |
510 | return retval; | |
511 | ||
512 | port->flags |= ASYNC_NORMAL_ACTIVE; | |
513 | func_exit (); | |
514 | return 0; | |
515 | } | |
516 | ||
517 | ||
518 | void gs_close(struct tty_struct * tty, struct file * filp) | |
519 | { | |
520 | unsigned long flags; | |
521 | struct gs_port *port; | |
522 | ||
523 | func_enter (); | |
524 | ||
525 | if (!tty) return; | |
526 | ||
527 | port = (struct gs_port *) tty->driver_data; | |
528 | ||
529 | if (!port) return; | |
530 | ||
531 | if (!port->tty) { | |
532 | /* This seems to happen when this is called from vhangup. */ | |
533 | gs_dprintk (GS_DEBUG_CLOSE, "gs: Odd: port->tty is NULL\n"); | |
534 | port->tty = tty; | |
535 | } | |
536 | ||
537 | spin_lock_irqsave(&port->driver_lock, flags); | |
538 | ||
539 | if (tty_hung_up_p(filp)) { | |
540 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
541 | if (port->rd->hungup) | |
542 | port->rd->hungup (port); | |
543 | func_exit (); | |
544 | return; | |
545 | } | |
546 | ||
547 | if ((tty->count == 1) && (port->count != 1)) { | |
548 | printk(KERN_ERR "gs: gs_close port %p: bad port count;" | |
549 | " tty->count is 1, port count is %d\n", port, port->count); | |
550 | port->count = 1; | |
551 | } | |
552 | if (--port->count < 0) { | |
553 | printk(KERN_ERR "gs: gs_close port %p: bad port count: %d\n", port, port->count); | |
554 | port->count = 0; | |
555 | } | |
556 | ||
557 | if (port->count) { | |
558 | gs_dprintk(GS_DEBUG_CLOSE, "gs_close port %p: count: %d\n", port, port->count); | |
559 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
560 | func_exit (); | |
561 | return; | |
562 | } | |
563 | port->flags |= ASYNC_CLOSING; | |
564 | ||
565 | /* | |
566 | * Now we wait for the transmit buffer to clear; and we notify | |
567 | * the line discipline to only process XON/XOFF characters. | |
568 | */ | |
569 | tty->closing = 1; | |
570 | /* if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) | |
571 | tty_wait_until_sent(tty, port->closing_wait); */ | |
572 | ||
573 | /* | |
574 | * At this point we stop accepting input. To do this, we | |
575 | * disable the receive line status interrupts, and tell the | |
576 | * interrupt driver to stop checking the data ready bit in the | |
577 | * line status register. | |
578 | */ | |
579 | ||
580 | port->rd->disable_rx_interrupts (port); | |
581 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
582 | ||
583 | /* close has no way of returning "EINTR", so discard return value */ | |
584 | if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) | |
585 | gs_wait_tx_flushed (port, port->closing_wait); | |
586 | ||
587 | port->flags &= ~GS_ACTIVE; | |
588 | ||
589 | if (tty->driver->flush_buffer) | |
590 | tty->driver->flush_buffer(tty); | |
591 | ||
592 | tty_ldisc_flush(tty); | |
593 | tty->closing = 0; | |
594 | ||
595 | port->event = 0; | |
596 | port->rd->close (port); | |
597 | port->rd->shutdown_port (port); | |
598 | port->tty = NULL; | |
599 | ||
600 | if (port->blocked_open) { | |
601 | if (port->close_delay) { | |
602 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
603 | msleep_interruptible(jiffies_to_msecs(port->close_delay)); | |
604 | spin_lock_irqsave(&port->driver_lock, flags); | |
605 | } | |
606 | wake_up_interruptible(&port->open_wait); | |
607 | } | |
608 | port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING | ASYNC_INITIALIZED); | |
609 | wake_up_interruptible(&port->close_wait); | |
610 | ||
611 | func_exit (); | |
612 | } | |
613 | ||
614 | ||
1da177e4 | 615 | void gs_set_termios (struct tty_struct * tty, |
606d099c | 616 | struct ktermios * old_termios) |
1da177e4 LT |
617 | { |
618 | struct gs_port *port; | |
619 | int baudrate, tmp, rv; | |
606d099c | 620 | struct ktermios *tiosp; |
1da177e4 LT |
621 | |
622 | func_enter(); | |
623 | ||
624 | if (!tty) return; | |
625 | ||
626 | port = tty->driver_data; | |
627 | ||
628 | if (!port) return; | |
629 | if (!port->tty) { | |
630 | /* This seems to happen when this is called after gs_close. */ | |
631 | gs_dprintk (GS_DEBUG_TERMIOS, "gs: Odd: port->tty is NULL\n"); | |
632 | port->tty = tty; | |
633 | } | |
634 | ||
635 | ||
636 | tiosp = tty->termios; | |
637 | ||
638 | if (gs_debug & GS_DEBUG_TERMIOS) { | |
639 | gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp); | |
640 | } | |
641 | ||
1da177e4 LT |
642 | if(old_termios && (gs_debug & GS_DEBUG_TERMIOS)) { |
643 | if(tiosp->c_iflag != old_termios->c_iflag) printk("c_iflag changed\n"); | |
644 | if(tiosp->c_oflag != old_termios->c_oflag) printk("c_oflag changed\n"); | |
645 | if(tiosp->c_cflag != old_termios->c_cflag) printk("c_cflag changed\n"); | |
646 | if(tiosp->c_lflag != old_termios->c_lflag) printk("c_lflag changed\n"); | |
647 | if(tiosp->c_line != old_termios->c_line) printk("c_line changed\n"); | |
648 | if(!memcmp(tiosp->c_cc, old_termios->c_cc, NCC)) printk("c_cc changed\n"); | |
649 | } | |
650 | ||
d720bc4b | 651 | baudrate = tty_get_baud_rate(tty); |
1da177e4 | 652 | |
1da177e4 LT |
653 | if ((tiosp->c_cflag & CBAUD) == B38400) { |
654 | if ( (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI) | |
655 | baudrate = 57600; | |
656 | else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI) | |
657 | baudrate = 115200; | |
658 | else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI) | |
659 | baudrate = 230400; | |
660 | else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP) | |
661 | baudrate = 460800; | |
662 | else if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) | |
663 | baudrate = (port->baud_base / port->custom_divisor); | |
664 | } | |
665 | ||
666 | /* I recommend using THIS instead of the mess in termios (and | |
667 | duplicating the above code). Next we should create a clean | |
668 | interface towards this variable. If your card supports arbitrary | |
669 | baud rates, (e.g. CD1400 or 16550 based cards) then everything | |
670 | will be very easy..... */ | |
671 | port->baud = baudrate; | |
672 | ||
673 | /* Two timer ticks seems enough to wakeup something like SLIP driver */ | |
674 | /* Baudrate/10 is cps. Divide by HZ to get chars per tick. */ | |
675 | tmp = (baudrate / 10 / HZ) * 2; | |
676 | ||
677 | if (tmp < 0) tmp = 0; | |
678 | if (tmp >= SERIAL_XMIT_SIZE) tmp = SERIAL_XMIT_SIZE-1; | |
679 | ||
680 | port->wakeup_chars = tmp; | |
681 | ||
682 | /* We should really wait for the characters to be all sent before | |
683 | changing the settings. -- CAL */ | |
684 | rv = gs_wait_tx_flushed (port, MAX_SCHEDULE_TIMEOUT); | |
685 | if (rv < 0) return /* rv */; | |
686 | ||
687 | rv = port->rd->set_real_termios(port); | |
688 | if (rv < 0) return /* rv */; | |
689 | ||
690 | if ((!old_termios || | |
691 | (old_termios->c_cflag & CRTSCTS)) && | |
692 | !( tiosp->c_cflag & CRTSCTS)) { | |
693 | tty->stopped = 0; | |
694 | gs_start(tty); | |
695 | } | |
696 | ||
697 | #ifdef tytso_patch_94Nov25_1726 | |
698 | /* This "makes sense", Why is it commented out? */ | |
699 | ||
700 | if (!(old_termios->c_cflag & CLOCAL) && | |
701 | (tty->termios->c_cflag & CLOCAL)) | |
702 | wake_up_interruptible(&port->gs.open_wait); | |
703 | #endif | |
704 | ||
705 | func_exit(); | |
706 | return /* 0 */; | |
707 | } | |
708 | ||
709 | ||
710 | ||
711 | /* Must be called with interrupts enabled */ | |
712 | int gs_init_port(struct gs_port *port) | |
713 | { | |
714 | unsigned long flags; | |
1da177e4 LT |
715 | |
716 | func_enter (); | |
717 | ||
1da177e4 LT |
718 | if (port->flags & ASYNC_INITIALIZED) { |
719 | func_exit (); | |
720 | return 0; | |
721 | } | |
722 | if (!port->xmit_buf) { | |
723 | /* We may sleep in get_zeroed_page() */ | |
724 | unsigned long tmp; | |
725 | ||
726 | tmp = get_zeroed_page(GFP_KERNEL); | |
727 | spin_lock_irqsave (&port->driver_lock, flags); | |
728 | if (port->xmit_buf) | |
729 | free_page (tmp); | |
730 | else | |
731 | port->xmit_buf = (unsigned char *) tmp; | |
732 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
733 | if (!port->xmit_buf) { | |
734 | func_exit (); | |
735 | return -ENOMEM; | |
736 | } | |
737 | } | |
738 | ||
739 | spin_lock_irqsave (&port->driver_lock, flags); | |
740 | if (port->tty) | |
741 | clear_bit(TTY_IO_ERROR, &port->tty->flags); | |
81861d78 | 742 | mutex_init(&port->port_write_mutex); |
1da177e4 LT |
743 | port->xmit_cnt = port->xmit_head = port->xmit_tail = 0; |
744 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
745 | gs_set_termios(port->tty, NULL); | |
746 | spin_lock_irqsave (&port->driver_lock, flags); | |
747 | port->flags |= ASYNC_INITIALIZED; | |
748 | port->flags &= ~GS_TX_INTEN; | |
749 | ||
750 | spin_unlock_irqrestore(&port->driver_lock, flags); | |
751 | func_exit (); | |
752 | return 0; | |
753 | } | |
754 | ||
755 | ||
756 | int gs_setserial(struct gs_port *port, struct serial_struct __user *sp) | |
757 | { | |
758 | struct serial_struct sio; | |
759 | ||
760 | if (copy_from_user(&sio, sp, sizeof(struct serial_struct))) | |
761 | return(-EFAULT); | |
762 | ||
763 | if (!capable(CAP_SYS_ADMIN)) { | |
764 | if ((sio.baud_base != port->baud_base) || | |
765 | (sio.close_delay != port->close_delay) || | |
766 | ((sio.flags & ~ASYNC_USR_MASK) != | |
767 | (port->flags & ~ASYNC_USR_MASK))) | |
768 | return(-EPERM); | |
769 | } | |
770 | ||
771 | port->flags = (port->flags & ~ASYNC_USR_MASK) | | |
772 | (sio.flags & ASYNC_USR_MASK); | |
773 | ||
774 | port->baud_base = sio.baud_base; | |
775 | port->close_delay = sio.close_delay; | |
776 | port->closing_wait = sio.closing_wait; | |
777 | port->custom_divisor = sio.custom_divisor; | |
778 | ||
779 | gs_set_termios (port->tty, NULL); | |
780 | ||
781 | return 0; | |
782 | } | |
783 | ||
784 | ||
785 | /*****************************************************************************/ | |
786 | ||
787 | /* | |
788 | * Generate the serial struct info. | |
789 | */ | |
790 | ||
791 | int gs_getserial(struct gs_port *port, struct serial_struct __user *sp) | |
792 | { | |
793 | struct serial_struct sio; | |
794 | ||
795 | memset(&sio, 0, sizeof(struct serial_struct)); | |
796 | sio.flags = port->flags; | |
797 | sio.baud_base = port->baud_base; | |
798 | sio.close_delay = port->close_delay; | |
799 | sio.closing_wait = port->closing_wait; | |
800 | sio.custom_divisor = port->custom_divisor; | |
801 | sio.hub6 = 0; | |
802 | ||
803 | /* If you want you can override these. */ | |
804 | sio.type = PORT_UNKNOWN; | |
805 | sio.xmit_fifo_size = -1; | |
806 | sio.line = -1; | |
807 | sio.port = -1; | |
808 | sio.irq = -1; | |
809 | ||
810 | if (port->rd->getserial) | |
811 | port->rd->getserial (port, &sio); | |
812 | ||
813 | if (copy_to_user(sp, &sio, sizeof(struct serial_struct))) | |
814 | return -EFAULT; | |
815 | return 0; | |
816 | ||
817 | } | |
818 | ||
819 | ||
820 | void gs_got_break(struct gs_port *port) | |
821 | { | |
822 | func_enter (); | |
823 | ||
824 | tty_insert_flip_char(port->tty, 0, TTY_BREAK); | |
825 | tty_schedule_flip(port->tty); | |
826 | if (port->flags & ASYNC_SAK) { | |
827 | do_SAK (port->tty); | |
828 | } | |
829 | ||
830 | func_exit (); | |
831 | } | |
832 | ||
833 | ||
834 | EXPORT_SYMBOL(gs_put_char); | |
835 | EXPORT_SYMBOL(gs_write); | |
836 | EXPORT_SYMBOL(gs_write_room); | |
837 | EXPORT_SYMBOL(gs_chars_in_buffer); | |
838 | EXPORT_SYMBOL(gs_flush_buffer); | |
839 | EXPORT_SYMBOL(gs_flush_chars); | |
840 | EXPORT_SYMBOL(gs_stop); | |
841 | EXPORT_SYMBOL(gs_start); | |
842 | EXPORT_SYMBOL(gs_hangup); | |
843 | EXPORT_SYMBOL(gs_block_til_ready); | |
844 | EXPORT_SYMBOL(gs_close); | |
845 | EXPORT_SYMBOL(gs_set_termios); | |
846 | EXPORT_SYMBOL(gs_init_port); | |
847 | EXPORT_SYMBOL(gs_setserial); | |
848 | EXPORT_SYMBOL(gs_getserial); | |
849 | EXPORT_SYMBOL(gs_got_break); | |
850 | ||
851 | MODULE_LICENSE("GPL"); |