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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> | |
31 | #include <asm/semaphore.h> | |
32 | #include <asm/uaccess.h> | |
33 | ||
34 | #define DEBUG | |
35 | ||
1da177e4 LT |
36 | static 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 */ | |
81861d78 IM |
49 | #define LOCKIT mutex_lock(& port->port_write_mutex); |
50 | #define RELEASEIT mutex_unlock(&port->port_write_mutex); | |
1da177e4 LT |
51 | #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 | ||
59 | module_param(gs_debug, int, 0644); | |
60 | ||
61 | ||
62 | void 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 | ||
104 | int 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 */ | |
81861d78 | 125 | mutex_lock(& port->port_write_mutex); |
1da177e4 LT |
126 | |
127 | while (1) { | |
128 | ||
129 | c = count; | |
130 | ||
131 | /* This is safe because we "OWN" the "head". Noone else can | |
81861d78 | 132 | change the "head": we own the port_write_mutex. */ |
1da177e4 LT |
133 | /* 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 | } | |
81861d78 | 154 | mutex_unlock(& port->port_write_mutex); |
1da177e4 LT |
155 | |
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 | ||
177 | int 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; | |
b3218a79 | 206 | if (!port || !port->xmit_buf) |
1da177e4 LT |
207 | 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 | |
81861d78 | 215 | change the "head": we own the port_write_mutex. */ |
1da177e4 LT |
216 | /* 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 | ||
256 | int 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 | ||
270 | int 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 | ||
280 | static 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 | ||
296 | static 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 | ||
367 | void 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 | ||
391 | void 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 | ||
416 | void 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 | ||
438 | void 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 | ||
458 | static 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 | ||
488 | void 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 | ||
511 | int 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*)(¤t->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 | ||
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 | 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 | ||
714 | static 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 | ||
720 | void gs_set_termios (struct tty_struct * tty, | |
721 | struct termios * old_termios) | |
722 | { | |
723 | struct gs_port *port; | |
724 | int baudrate, tmp, rv; | |
725 | struct termios *tiosp; | |
726 | ||
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 | ||
1da177e4 LT |
747 | /* 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.... */ | |
1da177e4 LT |
750 | 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 | ||
d720bc4b | 773 | baudrate = tty_get_baud_rate(tty); |
1da177e4 LT |
774 | |
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 */ | |
835 | int gs_init_port(struct gs_port *port) | |
836 | { | |
837 | unsigned long flags; | |
1da177e4 LT |
838 | |
839 | func_enter (); | |
840 | ||
1da177e4 LT |
841 | 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); | |
81861d78 | 865 | mutex_init(&port->port_write_mutex); |
1da177e4 LT |
866 | 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 | ||
879 | int 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 | ||
914 | int 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 | ||
943 | void 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 | ||
957 | EXPORT_SYMBOL(gs_put_char); | |
958 | EXPORT_SYMBOL(gs_write); | |
959 | EXPORT_SYMBOL(gs_write_room); | |
960 | EXPORT_SYMBOL(gs_chars_in_buffer); | |
961 | EXPORT_SYMBOL(gs_flush_buffer); | |
962 | EXPORT_SYMBOL(gs_flush_chars); | |
963 | EXPORT_SYMBOL(gs_stop); | |
964 | EXPORT_SYMBOL(gs_start); | |
965 | EXPORT_SYMBOL(gs_hangup); | |
966 | EXPORT_SYMBOL(gs_block_til_ready); | |
967 | EXPORT_SYMBOL(gs_close); | |
968 | EXPORT_SYMBOL(gs_set_termios); | |
969 | EXPORT_SYMBOL(gs_init_port); | |
970 | EXPORT_SYMBOL(gs_setserial); | |
971 | EXPORT_SYMBOL(gs_getserial); | |
972 | EXPORT_SYMBOL(gs_got_break); | |
973 | ||
974 | MODULE_LICENSE("GPL"); |