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Commit | Line | Data |
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9e48565d AC |
1 | /* |
2 | * Tty port functions | |
3 | */ | |
4 | ||
5 | #include <linux/types.h> | |
6 | #include <linux/errno.h> | |
7 | #include <linux/tty.h> | |
8 | #include <linux/tty_driver.h> | |
9 | #include <linux/tty_flip.h> | |
3e61696b | 10 | #include <linux/serial.h> |
9e48565d AC |
11 | #include <linux/timer.h> |
12 | #include <linux/string.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/wait.h> | |
17 | #include <linux/bitops.h> | |
18 | #include <linux/delay.h> | |
19 | #include <linux/module.h> | |
20 | ||
21 | void tty_port_init(struct tty_port *port) | |
22 | { | |
23 | memset(port, 0, sizeof(*port)); | |
ecbbfd44 | 24 | tty_buffer_init(port); |
9e48565d AC |
25 | init_waitqueue_head(&port->open_wait); |
26 | init_waitqueue_head(&port->close_wait); | |
bdc04e31 | 27 | init_waitqueue_head(&port->delta_msr_wait); |
9e48565d | 28 | mutex_init(&port->mutex); |
44e4909e | 29 | mutex_init(&port->buf_mutex); |
4a90f09b | 30 | spin_lock_init(&port->lock); |
9e48565d AC |
31 | port->close_delay = (50 * HZ) / 100; |
32 | port->closing_wait = (3000 * HZ) / 100; | |
568aafc6 | 33 | kref_init(&port->kref); |
9e48565d AC |
34 | } |
35 | EXPORT_SYMBOL(tty_port_init); | |
36 | ||
2cb4ca02 JS |
37 | /** |
38 | * tty_port_link_device - link tty and tty_port | |
39 | * @port: tty_port of the device | |
40 | * @driver: tty_driver for this device | |
41 | * @index: index of the tty | |
42 | * | |
43 | * Provide the tty layer wit ha link from a tty (specified by @index) to a | |
44 | * tty_port (@port). Use this only if neither tty_port_register_device nor | |
45 | * tty_port_install is used in the driver. If used, this has to be called before | |
46 | * tty_register_driver. | |
47 | */ | |
48 | void tty_port_link_device(struct tty_port *port, | |
49 | struct tty_driver *driver, unsigned index) | |
50 | { | |
51 | if (WARN_ON(index >= driver->num)) | |
52 | return; | |
53 | driver->ports[index] = port; | |
54 | } | |
55 | EXPORT_SYMBOL_GPL(tty_port_link_device); | |
56 | ||
72a33bf5 JS |
57 | /** |
58 | * tty_port_register_device - register tty device | |
59 | * @port: tty_port of the device | |
60 | * @driver: tty_driver for this device | |
61 | * @index: index of the tty | |
62 | * @device: parent if exists, otherwise NULL | |
63 | * | |
64 | * It is the same as tty_register_device except the provided @port is linked to | |
65 | * a concrete tty specified by @index. Use this or tty_port_install (or both). | |
66 | * Call tty_port_link_device as a last resort. | |
67 | */ | |
057eb856 JS |
68 | struct device *tty_port_register_device(struct tty_port *port, |
69 | struct tty_driver *driver, unsigned index, | |
70 | struct device *device) | |
71 | { | |
2cb4ca02 | 72 | tty_port_link_device(port, driver, index); |
057eb856 JS |
73 | return tty_register_device(driver, index, device); |
74 | } | |
75 | EXPORT_SYMBOL_GPL(tty_port_register_device); | |
76 | ||
b1b79916 TH |
77 | /** |
78 | * tty_port_register_device_attr - register tty device | |
79 | * @port: tty_port of the device | |
80 | * @driver: tty_driver for this device | |
81 | * @index: index of the tty | |
82 | * @device: parent if exists, otherwise NULL | |
83 | * @drvdata: Driver data to be set to device. | |
84 | * @attr_grp: Attribute group to be set on device. | |
85 | * | |
86 | * It is the same as tty_register_device_attr except the provided @port is | |
87 | * linked to a concrete tty specified by @index. Use this or tty_port_install | |
88 | * (or both). Call tty_port_link_device as a last resort. | |
89 | */ | |
90 | struct device *tty_port_register_device_attr(struct tty_port *port, | |
91 | struct tty_driver *driver, unsigned index, | |
92 | struct device *device, void *drvdata, | |
93 | const struct attribute_group **attr_grp) | |
94 | { | |
95 | tty_port_link_device(port, driver, index); | |
96 | return tty_register_device_attr(driver, index, device, drvdata, | |
97 | attr_grp); | |
98 | } | |
99 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr); | |
100 | ||
9e48565d AC |
101 | int tty_port_alloc_xmit_buf(struct tty_port *port) |
102 | { | |
103 | /* We may sleep in get_zeroed_page() */ | |
44e4909e | 104 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
105 | if (port->xmit_buf == NULL) |
106 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); | |
44e4909e | 107 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
108 | if (port->xmit_buf == NULL) |
109 | return -ENOMEM; | |
110 | return 0; | |
111 | } | |
112 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); | |
113 | ||
114 | void tty_port_free_xmit_buf(struct tty_port *port) | |
115 | { | |
44e4909e | 116 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
117 | if (port->xmit_buf != NULL) { |
118 | free_page((unsigned long)port->xmit_buf); | |
119 | port->xmit_buf = NULL; | |
120 | } | |
44e4909e | 121 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
122 | } |
123 | EXPORT_SYMBOL(tty_port_free_xmit_buf); | |
124 | ||
de274bfe JS |
125 | /** |
126 | * tty_port_destroy -- destroy inited port | |
127 | * @port: tty port to be doestroyed | |
128 | * | |
129 | * When a port was initialized using tty_port_init, one has to destroy the | |
130 | * port by this function. Either indirectly by using tty_port refcounting | |
131 | * (tty_port_put) or directly if refcounting is not used. | |
132 | */ | |
133 | void tty_port_destroy(struct tty_port *port) | |
134 | { | |
135 | tty_buffer_free_all(port); | |
136 | } | |
137 | EXPORT_SYMBOL(tty_port_destroy); | |
138 | ||
568aafc6 AC |
139 | static void tty_port_destructor(struct kref *kref) |
140 | { | |
141 | struct tty_port *port = container_of(kref, struct tty_port, kref); | |
142 | if (port->xmit_buf) | |
143 | free_page((unsigned long)port->xmit_buf); | |
de274bfe | 144 | tty_port_destroy(port); |
81c79838 | 145 | if (port->ops && port->ops->destruct) |
568aafc6 AC |
146 | port->ops->destruct(port); |
147 | else | |
148 | kfree(port); | |
149 | } | |
150 | ||
151 | void tty_port_put(struct tty_port *port) | |
152 | { | |
153 | if (port) | |
154 | kref_put(&port->kref, tty_port_destructor); | |
155 | } | |
156 | EXPORT_SYMBOL(tty_port_put); | |
9e48565d | 157 | |
4a90f09b AC |
158 | /** |
159 | * tty_port_tty_get - get a tty reference | |
160 | * @port: tty port | |
161 | * | |
162 | * Return a refcount protected tty instance or NULL if the port is not | |
163 | * associated with a tty (eg due to close or hangup) | |
164 | */ | |
165 | ||
166 | struct tty_struct *tty_port_tty_get(struct tty_port *port) | |
167 | { | |
168 | unsigned long flags; | |
169 | struct tty_struct *tty; | |
170 | ||
171 | spin_lock_irqsave(&port->lock, flags); | |
172 | tty = tty_kref_get(port->tty); | |
173 | spin_unlock_irqrestore(&port->lock, flags); | |
174 | return tty; | |
175 | } | |
176 | EXPORT_SYMBOL(tty_port_tty_get); | |
177 | ||
178 | /** | |
179 | * tty_port_tty_set - set the tty of a port | |
180 | * @port: tty port | |
181 | * @tty: the tty | |
182 | * | |
183 | * Associate the port and tty pair. Manages any internal refcounts. | |
184 | * Pass NULL to deassociate a port | |
185 | */ | |
186 | ||
187 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) | |
188 | { | |
189 | unsigned long flags; | |
190 | ||
191 | spin_lock_irqsave(&port->lock, flags); | |
192 | if (port->tty) | |
193 | tty_kref_put(port->tty); | |
cb4bca35 | 194 | port->tty = tty_kref_get(tty); |
4a90f09b AC |
195 | spin_unlock_irqrestore(&port->lock, flags); |
196 | } | |
197 | EXPORT_SYMBOL(tty_port_tty_set); | |
31f35939 | 198 | |
7ca0ff9a AC |
199 | static void tty_port_shutdown(struct tty_port *port) |
200 | { | |
64bc3979 | 201 | mutex_lock(&port->mutex); |
336cee42 | 202 | if (port->ops->shutdown && !port->console && |
1f5c13fa | 203 | test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) |
7ca0ff9a | 204 | port->ops->shutdown(port); |
64bc3979 | 205 | mutex_unlock(&port->mutex); |
7ca0ff9a AC |
206 | } |
207 | ||
3e61696b AC |
208 | /** |
209 | * tty_port_hangup - hangup helper | |
210 | * @port: tty port | |
211 | * | |
212 | * Perform port level tty hangup flag and count changes. Drop the tty | |
213 | * reference. | |
214 | */ | |
215 | ||
216 | void tty_port_hangup(struct tty_port *port) | |
217 | { | |
218 | unsigned long flags; | |
219 | ||
220 | spin_lock_irqsave(&port->lock, flags); | |
221 | port->count = 0; | |
222 | port->flags &= ~ASYNC_NORMAL_ACTIVE; | |
d74e8286 AC |
223 | if (port->tty) { |
224 | set_bit(TTY_IO_ERROR, &port->tty->flags); | |
3e61696b | 225 | tty_kref_put(port->tty); |
d74e8286 | 226 | } |
3e61696b AC |
227 | port->tty = NULL; |
228 | spin_unlock_irqrestore(&port->lock, flags); | |
229 | wake_up_interruptible(&port->open_wait); | |
bdc04e31 | 230 | wake_up_interruptible(&port->delta_msr_wait); |
7ca0ff9a | 231 | tty_port_shutdown(port); |
3e61696b AC |
232 | } |
233 | EXPORT_SYMBOL(tty_port_hangup); | |
234 | ||
6aad04f2 JS |
235 | /** |
236 | * tty_port_tty_wakeup - helper to wake up a tty | |
237 | * | |
238 | * @port: tty port | |
239 | */ | |
240 | void tty_port_tty_wakeup(struct tty_port *port) | |
241 | { | |
242 | struct tty_struct *tty = tty_port_tty_get(port); | |
243 | ||
244 | if (tty) { | |
245 | tty_wakeup(tty); | |
246 | tty_kref_put(tty); | |
247 | } | |
248 | } | |
249 | EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); | |
250 | ||
31f35939 AC |
251 | /** |
252 | * tty_port_carrier_raised - carrier raised check | |
253 | * @port: tty port | |
254 | * | |
255 | * Wrapper for the carrier detect logic. For the moment this is used | |
256 | * to hide some internal details. This will eventually become entirely | |
257 | * internal to the tty port. | |
258 | */ | |
259 | ||
260 | int tty_port_carrier_raised(struct tty_port *port) | |
261 | { | |
262 | if (port->ops->carrier_raised == NULL) | |
263 | return 1; | |
264 | return port->ops->carrier_raised(port); | |
265 | } | |
266 | EXPORT_SYMBOL(tty_port_carrier_raised); | |
5d951fb4 AC |
267 | |
268 | /** | |
fcc8ac18 | 269 | * tty_port_raise_dtr_rts - Raise DTR/RTS |
5d951fb4 AC |
270 | * @port: tty port |
271 | * | |
272 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
273 | * to hide some internal details. This will eventually become entirely | |
274 | * internal to the tty port. | |
275 | */ | |
276 | ||
277 | void tty_port_raise_dtr_rts(struct tty_port *port) | |
278 | { | |
fcc8ac18 AC |
279 | if (port->ops->dtr_rts) |
280 | port->ops->dtr_rts(port, 1); | |
5d951fb4 AC |
281 | } |
282 | EXPORT_SYMBOL(tty_port_raise_dtr_rts); | |
36c621d8 | 283 | |
fcc8ac18 AC |
284 | /** |
285 | * tty_port_lower_dtr_rts - Lower DTR/RTS | |
286 | * @port: tty port | |
287 | * | |
288 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
289 | * to hide some internal details. This will eventually become entirely | |
290 | * internal to the tty port. | |
291 | */ | |
292 | ||
293 | void tty_port_lower_dtr_rts(struct tty_port *port) | |
294 | { | |
295 | if (port->ops->dtr_rts) | |
296 | port->ops->dtr_rts(port, 0); | |
297 | } | |
298 | EXPORT_SYMBOL(tty_port_lower_dtr_rts); | |
299 | ||
36c621d8 AC |
300 | /** |
301 | * tty_port_block_til_ready - Waiting logic for tty open | |
302 | * @port: the tty port being opened | |
303 | * @tty: the tty device being bound | |
304 | * @filp: the file pointer of the opener | |
305 | * | |
306 | * Implement the core POSIX/SuS tty behaviour when opening a tty device. | |
307 | * Handles: | |
308 | * - hangup (both before and during) | |
309 | * - non blocking open | |
310 | * - rts/dtr/dcd | |
311 | * - signals | |
312 | * - port flags and counts | |
313 | * | |
314 | * The passed tty_port must implement the carrier_raised method if it can | |
fcc8ac18 | 315 | * do carrier detect and the dtr_rts method if it supports software |
36c621d8 AC |
316 | * management of these lines. Note that the dtr/rts raise is done each |
317 | * iteration as a hangup may have previously dropped them while we wait. | |
318 | */ | |
d774a56d | 319 | |
36c621d8 AC |
320 | int tty_port_block_til_ready(struct tty_port *port, |
321 | struct tty_struct *tty, struct file *filp) | |
322 | { | |
323 | int do_clocal = 0, retval; | |
324 | unsigned long flags; | |
6af9a43d | 325 | DEFINE_WAIT(wait); |
36c621d8 AC |
326 | |
327 | /* block if port is in the process of being closed */ | |
328 | if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { | |
89c8d91e | 329 | wait_event_interruptible_tty(tty, port->close_wait, |
5fc5b42a | 330 | !(port->flags & ASYNC_CLOSING)); |
36c621d8 AC |
331 | if (port->flags & ASYNC_HUP_NOTIFY) |
332 | return -EAGAIN; | |
333 | else | |
334 | return -ERESTARTSYS; | |
335 | } | |
336 | ||
337 | /* if non-blocking mode is set we can pass directly to open unless | |
338 | the port has just hung up or is in another error state */ | |
8627b96d AC |
339 | if (tty->flags & (1 << TTY_IO_ERROR)) { |
340 | port->flags |= ASYNC_NORMAL_ACTIVE; | |
341 | return 0; | |
342 | } | |
343 | if (filp->f_flags & O_NONBLOCK) { | |
4175f3e3 | 344 | /* Indicate we are open */ |
adc8d746 | 345 | if (tty->termios.c_cflag & CBAUD) |
4175f3e3 | 346 | tty_port_raise_dtr_rts(port); |
36c621d8 AC |
347 | port->flags |= ASYNC_NORMAL_ACTIVE; |
348 | return 0; | |
349 | } | |
350 | ||
351 | if (C_CLOCAL(tty)) | |
352 | do_clocal = 1; | |
353 | ||
354 | /* Block waiting until we can proceed. We may need to wait for the | |
355 | carrier, but we must also wait for any close that is in progress | |
356 | before the next open may complete */ | |
357 | ||
358 | retval = 0; | |
36c621d8 AC |
359 | |
360 | /* The port lock protects the port counts */ | |
361 | spin_lock_irqsave(&port->lock, flags); | |
362 | if (!tty_hung_up_p(filp)) | |
363 | port->count--; | |
364 | port->blocked_open++; | |
365 | spin_unlock_irqrestore(&port->lock, flags); | |
366 | ||
367 | while (1) { | |
368 | /* Indicate we are open */ | |
adc8d746 | 369 | if (tty->termios.c_cflag & CBAUD) |
7834909f | 370 | tty_port_raise_dtr_rts(port); |
36c621d8 | 371 | |
3e3b5c08 | 372 | prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); |
d774a56d AC |
373 | /* Check for a hangup or uninitialised port. |
374 | Return accordingly */ | |
36c621d8 AC |
375 | if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) { |
376 | if (port->flags & ASYNC_HUP_NOTIFY) | |
377 | retval = -EAGAIN; | |
378 | else | |
379 | retval = -ERESTARTSYS; | |
380 | break; | |
381 | } | |
0eee50af JS |
382 | /* |
383 | * Probe the carrier. For devices with no carrier detect | |
384 | * tty_port_carrier_raised will always return true. | |
385 | * Never ask drivers if CLOCAL is set, this causes troubles | |
386 | * on some hardware. | |
387 | */ | |
36c621d8 | 388 | if (!(port->flags & ASYNC_CLOSING) && |
0eee50af | 389 | (do_clocal || tty_port_carrier_raised(port))) |
36c621d8 AC |
390 | break; |
391 | if (signal_pending(current)) { | |
392 | retval = -ERESTARTSYS; | |
393 | break; | |
394 | } | |
89c8d91e | 395 | tty_unlock(tty); |
36c621d8 | 396 | schedule(); |
89c8d91e | 397 | tty_lock(tty); |
36c621d8 | 398 | } |
3e3b5c08 | 399 | finish_wait(&port->open_wait, &wait); |
36c621d8 AC |
400 | |
401 | /* Update counts. A parallel hangup will have set count to zero and | |
402 | we must not mess that up further */ | |
403 | spin_lock_irqsave(&port->lock, flags); | |
404 | if (!tty_hung_up_p(filp)) | |
405 | port->count++; | |
406 | port->blocked_open--; | |
407 | if (retval == 0) | |
408 | port->flags |= ASYNC_NORMAL_ACTIVE; | |
409 | spin_unlock_irqrestore(&port->lock, flags); | |
ecc2e05e | 410 | return retval; |
36c621d8 AC |
411 | } |
412 | EXPORT_SYMBOL(tty_port_block_til_ready); | |
413 | ||
d774a56d AC |
414 | int tty_port_close_start(struct tty_port *port, |
415 | struct tty_struct *tty, struct file *filp) | |
a6614999 AC |
416 | { |
417 | unsigned long flags; | |
418 | ||
419 | spin_lock_irqsave(&port->lock, flags); | |
420 | if (tty_hung_up_p(filp)) { | |
421 | spin_unlock_irqrestore(&port->lock, flags); | |
422 | return 0; | |
423 | } | |
424 | ||
d774a56d | 425 | if (tty->count == 1 && port->count != 1) { |
a6614999 AC |
426 | printk(KERN_WARNING |
427 | "tty_port_close_start: tty->count = 1 port count = %d.\n", | |
428 | port->count); | |
429 | port->count = 1; | |
430 | } | |
431 | if (--port->count < 0) { | |
432 | printk(KERN_WARNING "tty_port_close_start: count = %d\n", | |
433 | port->count); | |
434 | port->count = 0; | |
435 | } | |
436 | ||
437 | if (port->count) { | |
438 | spin_unlock_irqrestore(&port->lock, flags); | |
7ca0ff9a AC |
439 | if (port->ops->drop) |
440 | port->ops->drop(port); | |
a6614999 AC |
441 | return 0; |
442 | } | |
1f5c13fa | 443 | set_bit(ASYNCB_CLOSING, &port->flags); |
a6614999 AC |
444 | tty->closing = 1; |
445 | spin_unlock_irqrestore(&port->lock, flags); | |
fba85e01 AC |
446 | /* Don't block on a stalled port, just pull the chain */ |
447 | if (tty->flow_stopped) | |
448 | tty_driver_flush_buffer(tty); | |
7ca0ff9a | 449 | if (test_bit(ASYNCB_INITIALIZED, &port->flags) && |
6ed1dbae | 450 | port->closing_wait != ASYNC_CLOSING_WAIT_NONE) |
424cc039 | 451 | tty_wait_until_sent_from_close(tty, port->closing_wait); |
1ec739be AC |
452 | if (port->drain_delay) { |
453 | unsigned int bps = tty_get_baud_rate(tty); | |
454 | long timeout; | |
455 | ||
456 | if (bps > 1200) | |
d774a56d AC |
457 | timeout = max_t(long, |
458 | (HZ * 10 * port->drain_delay) / bps, HZ / 10); | |
1ec739be AC |
459 | else |
460 | timeout = 2 * HZ; | |
461 | schedule_timeout_interruptible(timeout); | |
462 | } | |
e707c35c AC |
463 | /* Flush the ldisc buffering */ |
464 | tty_ldisc_flush(tty); | |
465 | ||
466 | /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to | |
467 | hang up the line */ | |
adc8d746 | 468 | if (tty->termios.c_cflag & HUPCL) |
e707c35c AC |
469 | tty_port_lower_dtr_rts(port); |
470 | ||
7ca0ff9a AC |
471 | /* Don't call port->drop for the last reference. Callers will want |
472 | to drop the last active reference in ->shutdown() or the tty | |
473 | shutdown path */ | |
a6614999 AC |
474 | return 1; |
475 | } | |
476 | EXPORT_SYMBOL(tty_port_close_start); | |
477 | ||
478 | void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) | |
479 | { | |
480 | unsigned long flags; | |
481 | ||
a6614999 AC |
482 | spin_lock_irqsave(&port->lock, flags); |
483 | tty->closing = 0; | |
484 | ||
485 | if (port->blocked_open) { | |
486 | spin_unlock_irqrestore(&port->lock, flags); | |
487 | if (port->close_delay) { | |
488 | msleep_interruptible( | |
489 | jiffies_to_msecs(port->close_delay)); | |
490 | } | |
491 | spin_lock_irqsave(&port->lock, flags); | |
492 | wake_up_interruptible(&port->open_wait); | |
493 | } | |
494 | port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING); | |
495 | wake_up_interruptible(&port->close_wait); | |
496 | spin_unlock_irqrestore(&port->lock, flags); | |
497 | } | |
498 | EXPORT_SYMBOL(tty_port_close_end); | |
7ca0ff9a AC |
499 | |
500 | void tty_port_close(struct tty_port *port, struct tty_struct *tty, | |
501 | struct file *filp) | |
502 | { | |
503 | if (tty_port_close_start(port, tty, filp) == 0) | |
504 | return; | |
505 | tty_port_shutdown(port); | |
d74e8286 | 506 | set_bit(TTY_IO_ERROR, &tty->flags); |
7ca0ff9a AC |
507 | tty_port_close_end(port, tty); |
508 | tty_port_tty_set(port, NULL); | |
509 | } | |
510 | EXPORT_SYMBOL(tty_port_close); | |
64bc3979 | 511 | |
72a33bf5 JS |
512 | /** |
513 | * tty_port_install - generic tty->ops->install handler | |
514 | * @port: tty_port of the device | |
515 | * @driver: tty_driver for this device | |
516 | * @tty: tty to be installed | |
517 | * | |
518 | * It is the same as tty_standard_install except the provided @port is linked | |
519 | * to a concrete tty specified by @tty. Use this or tty_port_register_device | |
520 | * (or both). Call tty_port_link_device as a last resort. | |
521 | */ | |
695586ca JS |
522 | int tty_port_install(struct tty_port *port, struct tty_driver *driver, |
523 | struct tty_struct *tty) | |
524 | { | |
525 | tty->port = port; | |
526 | return tty_standard_install(driver, tty); | |
527 | } | |
528 | EXPORT_SYMBOL_GPL(tty_port_install); | |
529 | ||
64bc3979 | 530 | int tty_port_open(struct tty_port *port, struct tty_struct *tty, |
d774a56d | 531 | struct file *filp) |
64bc3979 AC |
532 | { |
533 | spin_lock_irq(&port->lock); | |
534 | if (!tty_hung_up_p(filp)) | |
535 | ++port->count; | |
536 | spin_unlock_irq(&port->lock); | |
537 | tty_port_tty_set(port, tty); | |
538 | ||
539 | /* | |
540 | * Do the device-specific open only if the hardware isn't | |
541 | * already initialized. Serialize open and shutdown using the | |
542 | * port mutex. | |
543 | */ | |
544 | ||
545 | mutex_lock(&port->mutex); | |
546 | ||
547 | if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) { | |
a9a37ec3 | 548 | clear_bit(TTY_IO_ERROR, &tty->flags); |
64bc3979 AC |
549 | if (port->ops->activate) { |
550 | int retval = port->ops->activate(port, tty); | |
551 | if (retval) { | |
d774a56d AC |
552 | mutex_unlock(&port->mutex); |
553 | return retval; | |
554 | } | |
555 | } | |
64bc3979 AC |
556 | set_bit(ASYNCB_INITIALIZED, &port->flags); |
557 | } | |
558 | mutex_unlock(&port->mutex); | |
559 | return tty_port_block_til_ready(port, tty, filp); | |
560 | } | |
561 | ||
562 | EXPORT_SYMBOL(tty_port_open); |