Commit | Line | Data |
---|---|---|
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> | |
9e48565d AC |
15 | #include <linux/wait.h> |
16 | #include <linux/bitops.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/module.h> | |
19 | ||
20 | void tty_port_init(struct tty_port *port) | |
21 | { | |
22 | memset(port, 0, sizeof(*port)); | |
ecbbfd44 | 23 | tty_buffer_init(port); |
9e48565d | 24 | init_waitqueue_head(&port->open_wait); |
bdc04e31 | 25 | init_waitqueue_head(&port->delta_msr_wait); |
9e48565d | 26 | mutex_init(&port->mutex); |
44e4909e | 27 | mutex_init(&port->buf_mutex); |
4a90f09b | 28 | spin_lock_init(&port->lock); |
9e48565d AC |
29 | port->close_delay = (50 * HZ) / 100; |
30 | port->closing_wait = (3000 * HZ) / 100; | |
568aafc6 | 31 | kref_init(&port->kref); |
9e48565d AC |
32 | } |
33 | EXPORT_SYMBOL(tty_port_init); | |
34 | ||
2cb4ca02 JS |
35 | /** |
36 | * tty_port_link_device - link tty and tty_port | |
37 | * @port: tty_port of the device | |
38 | * @driver: tty_driver for this device | |
39 | * @index: index of the tty | |
40 | * | |
41 | * Provide the tty layer wit ha link from a tty (specified by @index) to a | |
42 | * tty_port (@port). Use this only if neither tty_port_register_device nor | |
43 | * tty_port_install is used in the driver. If used, this has to be called before | |
44 | * tty_register_driver. | |
45 | */ | |
46 | void tty_port_link_device(struct tty_port *port, | |
47 | struct tty_driver *driver, unsigned index) | |
48 | { | |
49 | if (WARN_ON(index >= driver->num)) | |
50 | return; | |
51 | driver->ports[index] = port; | |
52 | } | |
53 | EXPORT_SYMBOL_GPL(tty_port_link_device); | |
54 | ||
72a33bf5 JS |
55 | /** |
56 | * tty_port_register_device - register tty device | |
57 | * @port: tty_port of the device | |
58 | * @driver: tty_driver for this device | |
59 | * @index: index of the tty | |
60 | * @device: parent if exists, otherwise NULL | |
61 | * | |
62 | * It is the same as tty_register_device except the provided @port is linked to | |
63 | * a concrete tty specified by @index. Use this or tty_port_install (or both). | |
64 | * Call tty_port_link_device as a last resort. | |
65 | */ | |
057eb856 JS |
66 | struct device *tty_port_register_device(struct tty_port *port, |
67 | struct tty_driver *driver, unsigned index, | |
68 | struct device *device) | |
69 | { | |
2cb4ca02 | 70 | tty_port_link_device(port, driver, index); |
057eb856 JS |
71 | return tty_register_device(driver, index, device); |
72 | } | |
73 | EXPORT_SYMBOL_GPL(tty_port_register_device); | |
74 | ||
b1b79916 TH |
75 | /** |
76 | * tty_port_register_device_attr - register tty device | |
77 | * @port: tty_port of the device | |
78 | * @driver: tty_driver for this device | |
79 | * @index: index of the tty | |
80 | * @device: parent if exists, otherwise NULL | |
81 | * @drvdata: Driver data to be set to device. | |
82 | * @attr_grp: Attribute group to be set on device. | |
83 | * | |
84 | * It is the same as tty_register_device_attr except the provided @port is | |
85 | * linked to a concrete tty specified by @index. Use this or tty_port_install | |
86 | * (or both). Call tty_port_link_device as a last resort. | |
87 | */ | |
88 | struct device *tty_port_register_device_attr(struct tty_port *port, | |
89 | struct tty_driver *driver, unsigned index, | |
90 | struct device *device, void *drvdata, | |
91 | const struct attribute_group **attr_grp) | |
92 | { | |
93 | tty_port_link_device(port, driver, index); | |
94 | return tty_register_device_attr(driver, index, device, drvdata, | |
95 | attr_grp); | |
96 | } | |
97 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr); | |
98 | ||
9e48565d AC |
99 | int tty_port_alloc_xmit_buf(struct tty_port *port) |
100 | { | |
101 | /* We may sleep in get_zeroed_page() */ | |
44e4909e | 102 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
103 | if (port->xmit_buf == NULL) |
104 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); | |
44e4909e | 105 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
106 | if (port->xmit_buf == NULL) |
107 | return -ENOMEM; | |
108 | return 0; | |
109 | } | |
110 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); | |
111 | ||
112 | void tty_port_free_xmit_buf(struct tty_port *port) | |
113 | { | |
44e4909e | 114 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
115 | if (port->xmit_buf != NULL) { |
116 | free_page((unsigned long)port->xmit_buf); | |
117 | port->xmit_buf = NULL; | |
118 | } | |
44e4909e | 119 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
120 | } |
121 | EXPORT_SYMBOL(tty_port_free_xmit_buf); | |
122 | ||
de274bfe JS |
123 | /** |
124 | * tty_port_destroy -- destroy inited port | |
125 | * @port: tty port to be doestroyed | |
126 | * | |
127 | * When a port was initialized using tty_port_init, one has to destroy the | |
128 | * port by this function. Either indirectly by using tty_port refcounting | |
129 | * (tty_port_put) or directly if refcounting is not used. | |
130 | */ | |
131 | void tty_port_destroy(struct tty_port *port) | |
132 | { | |
e176058f | 133 | tty_buffer_cancel_work(port); |
de274bfe JS |
134 | tty_buffer_free_all(port); |
135 | } | |
136 | EXPORT_SYMBOL(tty_port_destroy); | |
137 | ||
568aafc6 AC |
138 | static void tty_port_destructor(struct kref *kref) |
139 | { | |
140 | struct tty_port *port = container_of(kref, struct tty_port, kref); | |
e3bfea23 PH |
141 | |
142 | /* check if last port ref was dropped before tty release */ | |
143 | if (WARN_ON(port->itty)) | |
144 | return; | |
568aafc6 AC |
145 | if (port->xmit_buf) |
146 | free_page((unsigned long)port->xmit_buf); | |
de274bfe | 147 | tty_port_destroy(port); |
81c79838 | 148 | if (port->ops && port->ops->destruct) |
568aafc6 AC |
149 | port->ops->destruct(port); |
150 | else | |
151 | kfree(port); | |
152 | } | |
153 | ||
154 | void tty_port_put(struct tty_port *port) | |
155 | { | |
156 | if (port) | |
157 | kref_put(&port->kref, tty_port_destructor); | |
158 | } | |
159 | EXPORT_SYMBOL(tty_port_put); | |
9e48565d | 160 | |
4a90f09b AC |
161 | /** |
162 | * tty_port_tty_get - get a tty reference | |
163 | * @port: tty port | |
164 | * | |
165 | * Return a refcount protected tty instance or NULL if the port is not | |
166 | * associated with a tty (eg due to close or hangup) | |
167 | */ | |
168 | ||
169 | struct tty_struct *tty_port_tty_get(struct tty_port *port) | |
170 | { | |
171 | unsigned long flags; | |
172 | struct tty_struct *tty; | |
173 | ||
174 | spin_lock_irqsave(&port->lock, flags); | |
175 | tty = tty_kref_get(port->tty); | |
176 | spin_unlock_irqrestore(&port->lock, flags); | |
177 | return tty; | |
178 | } | |
179 | EXPORT_SYMBOL(tty_port_tty_get); | |
180 | ||
181 | /** | |
182 | * tty_port_tty_set - set the tty of a port | |
183 | * @port: tty port | |
184 | * @tty: the tty | |
185 | * | |
186 | * Associate the port and tty pair. Manages any internal refcounts. | |
187 | * Pass NULL to deassociate a port | |
188 | */ | |
189 | ||
190 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) | |
191 | { | |
192 | unsigned long flags; | |
193 | ||
194 | spin_lock_irqsave(&port->lock, flags); | |
a211b1af | 195 | tty_kref_put(port->tty); |
cb4bca35 | 196 | port->tty = tty_kref_get(tty); |
4a90f09b AC |
197 | spin_unlock_irqrestore(&port->lock, flags); |
198 | } | |
199 | EXPORT_SYMBOL(tty_port_tty_set); | |
31f35939 | 200 | |
957dacae | 201 | static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty) |
7ca0ff9a | 202 | { |
64bc3979 | 203 | mutex_lock(&port->mutex); |
8bde9658 JH |
204 | if (port->console) |
205 | goto out; | |
206 | ||
d41861ca PH |
207 | if (tty_port_initialized(port)) { |
208 | tty_port_set_initialized(port, 0); | |
957dacae JH |
209 | /* |
210 | * Drop DTR/RTS if HUPCL is set. This causes any attached | |
211 | * modem to hang up the line. | |
212 | */ | |
213 | if (tty && C_HUPCL(tty)) | |
214 | tty_port_lower_dtr_rts(port); | |
215 | ||
8bde9658 | 216 | if (port->ops->shutdown) |
7ca0ff9a | 217 | port->ops->shutdown(port); |
8bde9658 JH |
218 | } |
219 | out: | |
64bc3979 | 220 | mutex_unlock(&port->mutex); |
7ca0ff9a AC |
221 | } |
222 | ||
3e61696b AC |
223 | /** |
224 | * tty_port_hangup - hangup helper | |
225 | * @port: tty port | |
226 | * | |
227 | * Perform port level tty hangup flag and count changes. Drop the tty | |
228 | * reference. | |
9c9928bd PH |
229 | * |
230 | * Caller holds tty lock. | |
3e61696b AC |
231 | */ |
232 | ||
233 | void tty_port_hangup(struct tty_port *port) | |
234 | { | |
957dacae | 235 | struct tty_struct *tty; |
3e61696b AC |
236 | unsigned long flags; |
237 | ||
238 | spin_lock_irqsave(&port->lock, flags); | |
239 | port->count = 0; | |
957dacae JH |
240 | tty = port->tty; |
241 | if (tty) | |
242 | set_bit(TTY_IO_ERROR, &tty->flags); | |
3e61696b AC |
243 | port->tty = NULL; |
244 | spin_unlock_irqrestore(&port->lock, flags); | |
807c8d81 | 245 | tty_port_set_active(port, 0); |
957dacae JH |
246 | tty_port_shutdown(port, tty); |
247 | tty_kref_put(tty); | |
3e61696b | 248 | wake_up_interruptible(&port->open_wait); |
bdc04e31 | 249 | wake_up_interruptible(&port->delta_msr_wait); |
3e61696b AC |
250 | } |
251 | EXPORT_SYMBOL(tty_port_hangup); | |
252 | ||
aa27a094 JS |
253 | /** |
254 | * tty_port_tty_hangup - helper to hang up a tty | |
255 | * | |
256 | * @port: tty port | |
257 | * @check_clocal: hang only ttys with CLOCAL unset? | |
258 | */ | |
259 | void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) | |
260 | { | |
261 | struct tty_struct *tty = tty_port_tty_get(port); | |
262 | ||
1d9e689c | 263 | if (tty && (!check_clocal || !C_CLOCAL(tty))) |
aa27a094 | 264 | tty_hangup(tty); |
1d9e689c | 265 | tty_kref_put(tty); |
aa27a094 JS |
266 | } |
267 | EXPORT_SYMBOL_GPL(tty_port_tty_hangup); | |
268 | ||
6aad04f2 JS |
269 | /** |
270 | * tty_port_tty_wakeup - helper to wake up a tty | |
271 | * | |
272 | * @port: tty port | |
273 | */ | |
274 | void tty_port_tty_wakeup(struct tty_port *port) | |
275 | { | |
276 | struct tty_struct *tty = tty_port_tty_get(port); | |
277 | ||
278 | if (tty) { | |
279 | tty_wakeup(tty); | |
280 | tty_kref_put(tty); | |
281 | } | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); | |
284 | ||
31f35939 AC |
285 | /** |
286 | * tty_port_carrier_raised - carrier raised check | |
287 | * @port: tty port | |
288 | * | |
289 | * Wrapper for the carrier detect logic. For the moment this is used | |
290 | * to hide some internal details. This will eventually become entirely | |
291 | * internal to the tty port. | |
292 | */ | |
293 | ||
294 | int tty_port_carrier_raised(struct tty_port *port) | |
295 | { | |
296 | if (port->ops->carrier_raised == NULL) | |
297 | return 1; | |
298 | return port->ops->carrier_raised(port); | |
299 | } | |
300 | EXPORT_SYMBOL(tty_port_carrier_raised); | |
5d951fb4 AC |
301 | |
302 | /** | |
fcc8ac18 | 303 | * tty_port_raise_dtr_rts - Raise DTR/RTS |
5d951fb4 AC |
304 | * @port: tty port |
305 | * | |
306 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
307 | * to hide some internal details. This will eventually become entirely | |
308 | * internal to the tty port. | |
309 | */ | |
310 | ||
311 | void tty_port_raise_dtr_rts(struct tty_port *port) | |
312 | { | |
fcc8ac18 AC |
313 | if (port->ops->dtr_rts) |
314 | port->ops->dtr_rts(port, 1); | |
5d951fb4 AC |
315 | } |
316 | EXPORT_SYMBOL(tty_port_raise_dtr_rts); | |
36c621d8 | 317 | |
fcc8ac18 AC |
318 | /** |
319 | * tty_port_lower_dtr_rts - Lower DTR/RTS | |
320 | * @port: tty port | |
321 | * | |
322 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
323 | * to hide some internal details. This will eventually become entirely | |
324 | * internal to the tty port. | |
325 | */ | |
326 | ||
327 | void tty_port_lower_dtr_rts(struct tty_port *port) | |
328 | { | |
329 | if (port->ops->dtr_rts) | |
330 | port->ops->dtr_rts(port, 0); | |
331 | } | |
332 | EXPORT_SYMBOL(tty_port_lower_dtr_rts); | |
333 | ||
36c621d8 AC |
334 | /** |
335 | * tty_port_block_til_ready - Waiting logic for tty open | |
336 | * @port: the tty port being opened | |
337 | * @tty: the tty device being bound | |
338 | * @filp: the file pointer of the opener | |
339 | * | |
340 | * Implement the core POSIX/SuS tty behaviour when opening a tty device. | |
341 | * Handles: | |
342 | * - hangup (both before and during) | |
343 | * - non blocking open | |
344 | * - rts/dtr/dcd | |
345 | * - signals | |
346 | * - port flags and counts | |
347 | * | |
348 | * The passed tty_port must implement the carrier_raised method if it can | |
fcc8ac18 | 349 | * do carrier detect and the dtr_rts method if it supports software |
36c621d8 AC |
350 | * management of these lines. Note that the dtr/rts raise is done each |
351 | * iteration as a hangup may have previously dropped them while we wait. | |
c590f6b6 PH |
352 | * |
353 | * Caller holds tty lock. | |
354 | * | |
355 | * NB: May drop and reacquire tty lock when blocking, so tty and tty_port | |
356 | * may have changed state (eg., may have been hung up). | |
36c621d8 | 357 | */ |
d774a56d | 358 | |
36c621d8 AC |
359 | int tty_port_block_til_ready(struct tty_port *port, |
360 | struct tty_struct *tty, struct file *filp) | |
361 | { | |
362 | int do_clocal = 0, retval; | |
363 | unsigned long flags; | |
6af9a43d | 364 | DEFINE_WAIT(wait); |
36c621d8 | 365 | |
36c621d8 AC |
366 | /* if non-blocking mode is set we can pass directly to open unless |
367 | the port has just hung up or is in another error state */ | |
18900ca6 | 368 | if (tty_io_error(tty)) { |
807c8d81 | 369 | tty_port_set_active(port, 1); |
8627b96d AC |
370 | return 0; |
371 | } | |
372 | if (filp->f_flags & O_NONBLOCK) { | |
4175f3e3 | 373 | /* Indicate we are open */ |
9db276f8 | 374 | if (C_BAUD(tty)) |
4175f3e3 | 375 | tty_port_raise_dtr_rts(port); |
807c8d81 | 376 | tty_port_set_active(port, 1); |
36c621d8 AC |
377 | return 0; |
378 | } | |
379 | ||
380 | if (C_CLOCAL(tty)) | |
381 | do_clocal = 1; | |
382 | ||
383 | /* Block waiting until we can proceed. We may need to wait for the | |
384 | carrier, but we must also wait for any close that is in progress | |
385 | before the next open may complete */ | |
386 | ||
387 | retval = 0; | |
36c621d8 AC |
388 | |
389 | /* The port lock protects the port counts */ | |
390 | spin_lock_irqsave(&port->lock, flags); | |
e359a4e3 | 391 | port->count--; |
36c621d8 AC |
392 | port->blocked_open++; |
393 | spin_unlock_irqrestore(&port->lock, flags); | |
394 | ||
395 | while (1) { | |
396 | /* Indicate we are open */ | |
d41861ca | 397 | if (C_BAUD(tty) && tty_port_initialized(port)) |
7834909f | 398 | tty_port_raise_dtr_rts(port); |
36c621d8 | 399 | |
3e3b5c08 | 400 | prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); |
d774a56d AC |
401 | /* Check for a hangup or uninitialised port. |
402 | Return accordingly */ | |
d41861ca | 403 | if (tty_hung_up_p(filp) || !tty_port_initialized(port)) { |
36c621d8 AC |
404 | if (port->flags & ASYNC_HUP_NOTIFY) |
405 | retval = -EAGAIN; | |
406 | else | |
407 | retval = -ERESTARTSYS; | |
408 | break; | |
409 | } | |
0eee50af JS |
410 | /* |
411 | * Probe the carrier. For devices with no carrier detect | |
412 | * tty_port_carrier_raised will always return true. | |
413 | * Never ask drivers if CLOCAL is set, this causes troubles | |
414 | * on some hardware. | |
415 | */ | |
fef062cb | 416 | if (do_clocal || tty_port_carrier_raised(port)) |
36c621d8 AC |
417 | break; |
418 | if (signal_pending(current)) { | |
419 | retval = -ERESTARTSYS; | |
420 | break; | |
421 | } | |
89c8d91e | 422 | tty_unlock(tty); |
36c621d8 | 423 | schedule(); |
89c8d91e | 424 | tty_lock(tty); |
36c621d8 | 425 | } |
3e3b5c08 | 426 | finish_wait(&port->open_wait, &wait); |
36c621d8 AC |
427 | |
428 | /* Update counts. A parallel hangup will have set count to zero and | |
429 | we must not mess that up further */ | |
430 | spin_lock_irqsave(&port->lock, flags); | |
431 | if (!tty_hung_up_p(filp)) | |
432 | port->count++; | |
433 | port->blocked_open--; | |
36c621d8 | 434 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 PH |
435 | if (retval == 0) |
436 | tty_port_set_active(port, 1); | |
ecc2e05e | 437 | return retval; |
36c621d8 AC |
438 | } |
439 | EXPORT_SYMBOL(tty_port_block_til_ready); | |
440 | ||
b74414f5 JH |
441 | static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty) |
442 | { | |
443 | unsigned int bps = tty_get_baud_rate(tty); | |
444 | long timeout; | |
445 | ||
446 | if (bps > 1200) { | |
447 | timeout = (HZ * 10 * port->drain_delay) / bps; | |
448 | timeout = max_t(long, timeout, HZ / 10); | |
449 | } else { | |
450 | timeout = 2 * HZ; | |
451 | } | |
452 | schedule_timeout_interruptible(timeout); | |
453 | } | |
454 | ||
79c1faa4 | 455 | /* Caller holds tty lock. */ |
d774a56d AC |
456 | int tty_port_close_start(struct tty_port *port, |
457 | struct tty_struct *tty, struct file *filp) | |
a6614999 AC |
458 | { |
459 | unsigned long flags; | |
460 | ||
633caba8 | 461 | if (tty_hung_up_p(filp)) |
a6614999 | 462 | return 0; |
a6614999 | 463 | |
633caba8 | 464 | spin_lock_irqsave(&port->lock, flags); |
d774a56d | 465 | if (tty->count == 1 && port->count != 1) { |
339f36ba PH |
466 | tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, |
467 | port->count); | |
a6614999 AC |
468 | port->count = 1; |
469 | } | |
470 | if (--port->count < 0) { | |
339f36ba PH |
471 | tty_warn(tty, "%s: bad port count (%d)\n", __func__, |
472 | port->count); | |
a6614999 AC |
473 | port->count = 0; |
474 | } | |
475 | ||
476 | if (port->count) { | |
477 | spin_unlock_irqrestore(&port->lock, flags); | |
478 | return 0; | |
479 | } | |
a6614999 | 480 | spin_unlock_irqrestore(&port->lock, flags); |
0b2588ca | 481 | |
ddc7b758 PH |
482 | tty->closing = 1; |
483 | ||
d41861ca | 484 | if (tty_port_initialized(port)) { |
0b2588ca JH |
485 | /* Don't block on a stalled port, just pull the chain */ |
486 | if (tty->flow_stopped) | |
487 | tty_driver_flush_buffer(tty); | |
488 | if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) | |
79c1faa4 | 489 | tty_wait_until_sent(tty, port->closing_wait); |
0b2588ca JH |
490 | if (port->drain_delay) |
491 | tty_port_drain_delay(port, tty); | |
492 | } | |
e707c35c AC |
493 | /* Flush the ldisc buffering */ |
494 | tty_ldisc_flush(tty); | |
495 | ||
469d6d06 | 496 | /* Report to caller this is the last port reference */ |
a6614999 AC |
497 | return 1; |
498 | } | |
499 | EXPORT_SYMBOL(tty_port_close_start); | |
500 | ||
0733db91 | 501 | /* Caller holds tty lock */ |
a6614999 AC |
502 | void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) |
503 | { | |
504 | unsigned long flags; | |
505 | ||
3f40f5b2 | 506 | tty_ldisc_flush(tty); |
a6614999 AC |
507 | tty->closing = 0; |
508 | ||
ddc7b758 PH |
509 | spin_lock_irqsave(&port->lock, flags); |
510 | ||
a6614999 AC |
511 | if (port->blocked_open) { |
512 | spin_unlock_irqrestore(&port->lock, flags); | |
5823323e PH |
513 | if (port->close_delay) |
514 | msleep_interruptible(jiffies_to_msecs(port->close_delay)); | |
a6614999 AC |
515 | spin_lock_irqsave(&port->lock, flags); |
516 | wake_up_interruptible(&port->open_wait); | |
517 | } | |
a6614999 | 518 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 | 519 | tty_port_set_active(port, 0); |
a6614999 AC |
520 | } |
521 | EXPORT_SYMBOL(tty_port_close_end); | |
7ca0ff9a | 522 | |
0733db91 PH |
523 | /** |
524 | * tty_port_close | |
525 | * | |
526 | * Caller holds tty lock | |
0733db91 | 527 | */ |
7ca0ff9a AC |
528 | void tty_port_close(struct tty_port *port, struct tty_struct *tty, |
529 | struct file *filp) | |
530 | { | |
531 | if (tty_port_close_start(port, tty, filp) == 0) | |
532 | return; | |
957dacae | 533 | tty_port_shutdown(port, tty); |
d74e8286 | 534 | set_bit(TTY_IO_ERROR, &tty->flags); |
7ca0ff9a AC |
535 | tty_port_close_end(port, tty); |
536 | tty_port_tty_set(port, NULL); | |
537 | } | |
538 | EXPORT_SYMBOL(tty_port_close); | |
64bc3979 | 539 | |
72a33bf5 JS |
540 | /** |
541 | * tty_port_install - generic tty->ops->install handler | |
542 | * @port: tty_port of the device | |
543 | * @driver: tty_driver for this device | |
544 | * @tty: tty to be installed | |
545 | * | |
546 | * It is the same as tty_standard_install except the provided @port is linked | |
547 | * to a concrete tty specified by @tty. Use this or tty_port_register_device | |
548 | * (or both). Call tty_port_link_device as a last resort. | |
549 | */ | |
695586ca JS |
550 | int tty_port_install(struct tty_port *port, struct tty_driver *driver, |
551 | struct tty_struct *tty) | |
552 | { | |
553 | tty->port = port; | |
554 | return tty_standard_install(driver, tty); | |
555 | } | |
556 | EXPORT_SYMBOL_GPL(tty_port_install); | |
557 | ||
addd4672 PH |
558 | /** |
559 | * tty_port_open | |
560 | * | |
561 | * Caller holds tty lock. | |
562 | * | |
563 | * NB: may drop and reacquire tty lock (in tty_port_block_til_ready()) so | |
564 | * tty and tty_port may have changed state (eg., may be hung up now) | |
565 | */ | |
64bc3979 | 566 | int tty_port_open(struct tty_port *port, struct tty_struct *tty, |
d774a56d | 567 | struct file *filp) |
64bc3979 AC |
568 | { |
569 | spin_lock_irq(&port->lock); | |
e359a4e3 | 570 | ++port->count; |
64bc3979 AC |
571 | spin_unlock_irq(&port->lock); |
572 | tty_port_tty_set(port, tty); | |
573 | ||
574 | /* | |
575 | * Do the device-specific open only if the hardware isn't | |
576 | * already initialized. Serialize open and shutdown using the | |
577 | * port mutex. | |
578 | */ | |
579 | ||
580 | mutex_lock(&port->mutex); | |
581 | ||
d41861ca | 582 | if (!tty_port_initialized(port)) { |
a9a37ec3 | 583 | clear_bit(TTY_IO_ERROR, &tty->flags); |
64bc3979 AC |
584 | if (port->ops->activate) { |
585 | int retval = port->ops->activate(port, tty); | |
586 | if (retval) { | |
d774a56d AC |
587 | mutex_unlock(&port->mutex); |
588 | return retval; | |
589 | } | |
590 | } | |
d41861ca | 591 | tty_port_set_initialized(port, 1); |
64bc3979 AC |
592 | } |
593 | mutex_unlock(&port->mutex); | |
594 | return tty_port_block_til_ready(port, tty, filp); | |
595 | } | |
596 | ||
597 | EXPORT_SYMBOL(tty_port_open); |