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> | |
174cd4b1 | 14 | #include <linux/sched/signal.h> |
9e48565d AC |
15 | #include <linux/wait.h> |
16 | #include <linux/bitops.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/module.h> | |
8cde11b2 | 19 | #include <linux/serdev.h> |
9e48565d | 20 | |
c3485ee0 RH |
21 | static int tty_port_default_receive_buf(struct tty_port *port, |
22 | const unsigned char *p, | |
23 | const unsigned char *f, size_t count) | |
24 | { | |
25 | int ret; | |
26 | struct tty_struct *tty; | |
27 | struct tty_ldisc *disc; | |
28 | ||
29 | tty = READ_ONCE(port->itty); | |
30 | if (!tty) | |
31 | return 0; | |
32 | ||
33 | disc = tty_ldisc_ref(tty); | |
34 | if (!disc) | |
35 | return 0; | |
36 | ||
37 | ret = tty_ldisc_receive_buf(disc, p, (char *)f, count); | |
38 | ||
39 | tty_ldisc_deref(disc); | |
40 | ||
41 | return ret; | |
42 | } | |
43 | ||
44 | static void tty_port_default_wakeup(struct tty_port *port) | |
45 | { | |
46 | struct tty_struct *tty = tty_port_tty_get(port); | |
47 | ||
48 | if (tty) { | |
49 | tty_wakeup(tty); | |
50 | tty_kref_put(tty); | |
51 | } | |
52 | } | |
53 | ||
54 | static const struct tty_port_client_operations default_client_ops = { | |
55 | .receive_buf = tty_port_default_receive_buf, | |
56 | .write_wakeup = tty_port_default_wakeup, | |
57 | }; | |
58 | ||
9e48565d AC |
59 | void tty_port_init(struct tty_port *port) |
60 | { | |
61 | memset(port, 0, sizeof(*port)); | |
ecbbfd44 | 62 | tty_buffer_init(port); |
9e48565d | 63 | init_waitqueue_head(&port->open_wait); |
bdc04e31 | 64 | init_waitqueue_head(&port->delta_msr_wait); |
9e48565d | 65 | mutex_init(&port->mutex); |
44e4909e | 66 | mutex_init(&port->buf_mutex); |
4a90f09b | 67 | spin_lock_init(&port->lock); |
9e48565d AC |
68 | port->close_delay = (50 * HZ) / 100; |
69 | port->closing_wait = (3000 * HZ) / 100; | |
c3485ee0 | 70 | port->client_ops = &default_client_ops; |
568aafc6 | 71 | kref_init(&port->kref); |
9e48565d AC |
72 | } |
73 | EXPORT_SYMBOL(tty_port_init); | |
74 | ||
2cb4ca02 JS |
75 | /** |
76 | * tty_port_link_device - link tty and tty_port | |
77 | * @port: tty_port of the device | |
78 | * @driver: tty_driver for this device | |
79 | * @index: index of the tty | |
80 | * | |
81 | * Provide the tty layer wit ha link from a tty (specified by @index) to a | |
82 | * tty_port (@port). Use this only if neither tty_port_register_device nor | |
83 | * tty_port_install is used in the driver. If used, this has to be called before | |
84 | * tty_register_driver. | |
85 | */ | |
86 | void tty_port_link_device(struct tty_port *port, | |
87 | struct tty_driver *driver, unsigned index) | |
88 | { | |
89 | if (WARN_ON(index >= driver->num)) | |
90 | return; | |
91 | driver->ports[index] = port; | |
92 | } | |
93 | EXPORT_SYMBOL_GPL(tty_port_link_device); | |
94 | ||
72a33bf5 JS |
95 | /** |
96 | * tty_port_register_device - register tty device | |
97 | * @port: tty_port of the device | |
98 | * @driver: tty_driver for this device | |
99 | * @index: index of the tty | |
100 | * @device: parent if exists, otherwise NULL | |
101 | * | |
102 | * It is the same as tty_register_device except the provided @port is linked to | |
103 | * a concrete tty specified by @index. Use this or tty_port_install (or both). | |
104 | * Call tty_port_link_device as a last resort. | |
105 | */ | |
057eb856 JS |
106 | struct device *tty_port_register_device(struct tty_port *port, |
107 | struct tty_driver *driver, unsigned index, | |
108 | struct device *device) | |
109 | { | |
3086365d | 110 | return tty_port_register_device_attr(port, driver, index, device, NULL, NULL); |
057eb856 JS |
111 | } |
112 | EXPORT_SYMBOL_GPL(tty_port_register_device); | |
113 | ||
b1b79916 TH |
114 | /** |
115 | * tty_port_register_device_attr - register tty device | |
116 | * @port: tty_port of the device | |
117 | * @driver: tty_driver for this device | |
118 | * @index: index of the tty | |
119 | * @device: parent if exists, otherwise NULL | |
120 | * @drvdata: Driver data to be set to device. | |
121 | * @attr_grp: Attribute group to be set on device. | |
122 | * | |
123 | * It is the same as tty_register_device_attr except the provided @port is | |
124 | * linked to a concrete tty specified by @index. Use this or tty_port_install | |
125 | * (or both). Call tty_port_link_device as a last resort. | |
126 | */ | |
127 | struct device *tty_port_register_device_attr(struct tty_port *port, | |
128 | struct tty_driver *driver, unsigned index, | |
129 | struct device *device, void *drvdata, | |
130 | const struct attribute_group **attr_grp) | |
131 | { | |
132 | tty_port_link_device(port, driver, index); | |
133 | return tty_register_device_attr(driver, index, device, drvdata, | |
134 | attr_grp); | |
135 | } | |
136 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr); | |
137 | ||
8cde11b2 JH |
138 | /** |
139 | * tty_port_register_device_attr_serdev - register tty or serdev device | |
140 | * @port: tty_port of the device | |
141 | * @driver: tty_driver for this device | |
142 | * @index: index of the tty | |
143 | * @device: parent if exists, otherwise NULL | |
144 | * @drvdata: driver data for the device | |
145 | * @attr_grp: attribute group for the device | |
146 | * | |
147 | * Register a serdev or tty device depending on if the parent device has any | |
148 | * defined serdev clients or not. | |
149 | */ | |
150 | struct device *tty_port_register_device_attr_serdev(struct tty_port *port, | |
151 | struct tty_driver *driver, unsigned index, | |
152 | struct device *device, void *drvdata, | |
153 | const struct attribute_group **attr_grp) | |
154 | { | |
155 | struct device *dev; | |
156 | ||
157 | tty_port_link_device(port, driver, index); | |
158 | ||
159 | dev = serdev_tty_port_register(port, device, driver, index); | |
160 | if (PTR_ERR(dev) != -ENODEV) { | |
161 | /* Skip creating cdev if we registered a serdev device */ | |
162 | return dev; | |
163 | } | |
164 | ||
165 | return tty_register_device_attr(driver, index, device, drvdata, | |
166 | attr_grp); | |
167 | } | |
168 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr_serdev); | |
169 | ||
170 | /** | |
171 | * tty_port_register_device_serdev - register tty or serdev device | |
172 | * @port: tty_port of the device | |
173 | * @driver: tty_driver for this device | |
174 | * @index: index of the tty | |
175 | * @device: parent if exists, otherwise NULL | |
176 | * | |
177 | * Register a serdev or tty device depending on if the parent device has any | |
178 | * defined serdev clients or not. | |
179 | */ | |
180 | struct device *tty_port_register_device_serdev(struct tty_port *port, | |
181 | struct tty_driver *driver, unsigned index, | |
182 | struct device *device) | |
183 | { | |
184 | return tty_port_register_device_attr_serdev(port, driver, index, | |
185 | device, NULL, NULL); | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(tty_port_register_device_serdev); | |
188 | ||
189 | /** | |
190 | * tty_port_unregister_device - deregister a tty or serdev device | |
191 | * @port: tty_port of the device | |
192 | * @driver: tty_driver for this device | |
193 | * @index: index of the tty | |
194 | * | |
195 | * If a tty or serdev device is registered with a call to | |
196 | * tty_port_register_device_serdev() then this function must be called when | |
197 | * the device is gone. | |
198 | */ | |
199 | void tty_port_unregister_device(struct tty_port *port, | |
200 | struct tty_driver *driver, unsigned index) | |
201 | { | |
202 | int ret; | |
203 | ||
204 | ret = serdev_tty_port_unregister(port); | |
205 | if (ret == 0) | |
206 | return; | |
207 | ||
208 | tty_unregister_device(driver, index); | |
209 | } | |
210 | EXPORT_SYMBOL_GPL(tty_port_unregister_device); | |
211 | ||
9e48565d AC |
212 | int tty_port_alloc_xmit_buf(struct tty_port *port) |
213 | { | |
214 | /* We may sleep in get_zeroed_page() */ | |
44e4909e | 215 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
216 | if (port->xmit_buf == NULL) |
217 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); | |
44e4909e | 218 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
219 | if (port->xmit_buf == NULL) |
220 | return -ENOMEM; | |
221 | return 0; | |
222 | } | |
223 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); | |
224 | ||
225 | void tty_port_free_xmit_buf(struct tty_port *port) | |
226 | { | |
44e4909e | 227 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
228 | if (port->xmit_buf != NULL) { |
229 | free_page((unsigned long)port->xmit_buf); | |
230 | port->xmit_buf = NULL; | |
231 | } | |
44e4909e | 232 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
233 | } |
234 | EXPORT_SYMBOL(tty_port_free_xmit_buf); | |
235 | ||
de274bfe JS |
236 | /** |
237 | * tty_port_destroy -- destroy inited port | |
238 | * @port: tty port to be doestroyed | |
239 | * | |
240 | * When a port was initialized using tty_port_init, one has to destroy the | |
241 | * port by this function. Either indirectly by using tty_port refcounting | |
242 | * (tty_port_put) or directly if refcounting is not used. | |
243 | */ | |
244 | void tty_port_destroy(struct tty_port *port) | |
245 | { | |
e176058f | 246 | tty_buffer_cancel_work(port); |
de274bfe JS |
247 | tty_buffer_free_all(port); |
248 | } | |
249 | EXPORT_SYMBOL(tty_port_destroy); | |
250 | ||
568aafc6 AC |
251 | static void tty_port_destructor(struct kref *kref) |
252 | { | |
253 | struct tty_port *port = container_of(kref, struct tty_port, kref); | |
e3bfea23 PH |
254 | |
255 | /* check if last port ref was dropped before tty release */ | |
256 | if (WARN_ON(port->itty)) | |
257 | return; | |
568aafc6 AC |
258 | if (port->xmit_buf) |
259 | free_page((unsigned long)port->xmit_buf); | |
de274bfe | 260 | tty_port_destroy(port); |
81c79838 | 261 | if (port->ops && port->ops->destruct) |
568aafc6 AC |
262 | port->ops->destruct(port); |
263 | else | |
264 | kfree(port); | |
265 | } | |
266 | ||
267 | void tty_port_put(struct tty_port *port) | |
268 | { | |
269 | if (port) | |
270 | kref_put(&port->kref, tty_port_destructor); | |
271 | } | |
272 | EXPORT_SYMBOL(tty_port_put); | |
9e48565d | 273 | |
4a90f09b AC |
274 | /** |
275 | * tty_port_tty_get - get a tty reference | |
276 | * @port: tty port | |
277 | * | |
278 | * Return a refcount protected tty instance or NULL if the port is not | |
279 | * associated with a tty (eg due to close or hangup) | |
280 | */ | |
281 | ||
282 | struct tty_struct *tty_port_tty_get(struct tty_port *port) | |
283 | { | |
284 | unsigned long flags; | |
285 | struct tty_struct *tty; | |
286 | ||
287 | spin_lock_irqsave(&port->lock, flags); | |
288 | tty = tty_kref_get(port->tty); | |
289 | spin_unlock_irqrestore(&port->lock, flags); | |
290 | return tty; | |
291 | } | |
292 | EXPORT_SYMBOL(tty_port_tty_get); | |
293 | ||
294 | /** | |
295 | * tty_port_tty_set - set the tty of a port | |
296 | * @port: tty port | |
297 | * @tty: the tty | |
298 | * | |
299 | * Associate the port and tty pair. Manages any internal refcounts. | |
300 | * Pass NULL to deassociate a port | |
301 | */ | |
302 | ||
303 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) | |
304 | { | |
305 | unsigned long flags; | |
306 | ||
307 | spin_lock_irqsave(&port->lock, flags); | |
a211b1af | 308 | tty_kref_put(port->tty); |
cb4bca35 | 309 | port->tty = tty_kref_get(tty); |
4a90f09b AC |
310 | spin_unlock_irqrestore(&port->lock, flags); |
311 | } | |
312 | EXPORT_SYMBOL(tty_port_tty_set); | |
31f35939 | 313 | |
957dacae | 314 | static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty) |
7ca0ff9a | 315 | { |
64bc3979 | 316 | mutex_lock(&port->mutex); |
8bde9658 JH |
317 | if (port->console) |
318 | goto out; | |
319 | ||
d41861ca PH |
320 | if (tty_port_initialized(port)) { |
321 | tty_port_set_initialized(port, 0); | |
957dacae JH |
322 | /* |
323 | * Drop DTR/RTS if HUPCL is set. This causes any attached | |
324 | * modem to hang up the line. | |
325 | */ | |
326 | if (tty && C_HUPCL(tty)) | |
327 | tty_port_lower_dtr_rts(port); | |
328 | ||
8bde9658 | 329 | if (port->ops->shutdown) |
7ca0ff9a | 330 | port->ops->shutdown(port); |
8bde9658 JH |
331 | } |
332 | out: | |
64bc3979 | 333 | mutex_unlock(&port->mutex); |
7ca0ff9a AC |
334 | } |
335 | ||
3e61696b AC |
336 | /** |
337 | * tty_port_hangup - hangup helper | |
338 | * @port: tty port | |
339 | * | |
340 | * Perform port level tty hangup flag and count changes. Drop the tty | |
341 | * reference. | |
9c9928bd PH |
342 | * |
343 | * Caller holds tty lock. | |
3e61696b AC |
344 | */ |
345 | ||
346 | void tty_port_hangup(struct tty_port *port) | |
347 | { | |
957dacae | 348 | struct tty_struct *tty; |
3e61696b AC |
349 | unsigned long flags; |
350 | ||
351 | spin_lock_irqsave(&port->lock, flags); | |
352 | port->count = 0; | |
957dacae JH |
353 | tty = port->tty; |
354 | if (tty) | |
355 | set_bit(TTY_IO_ERROR, &tty->flags); | |
3e61696b AC |
356 | port->tty = NULL; |
357 | spin_unlock_irqrestore(&port->lock, flags); | |
807c8d81 | 358 | tty_port_set_active(port, 0); |
957dacae JH |
359 | tty_port_shutdown(port, tty); |
360 | tty_kref_put(tty); | |
3e61696b | 361 | wake_up_interruptible(&port->open_wait); |
bdc04e31 | 362 | wake_up_interruptible(&port->delta_msr_wait); |
3e61696b AC |
363 | } |
364 | EXPORT_SYMBOL(tty_port_hangup); | |
365 | ||
aa27a094 JS |
366 | /** |
367 | * tty_port_tty_hangup - helper to hang up a tty | |
368 | * | |
369 | * @port: tty port | |
370 | * @check_clocal: hang only ttys with CLOCAL unset? | |
371 | */ | |
372 | void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) | |
373 | { | |
374 | struct tty_struct *tty = tty_port_tty_get(port); | |
375 | ||
1d9e689c | 376 | if (tty && (!check_clocal || !C_CLOCAL(tty))) |
aa27a094 | 377 | tty_hangup(tty); |
1d9e689c | 378 | tty_kref_put(tty); |
aa27a094 JS |
379 | } |
380 | EXPORT_SYMBOL_GPL(tty_port_tty_hangup); | |
381 | ||
6aad04f2 JS |
382 | /** |
383 | * tty_port_tty_wakeup - helper to wake up a tty | |
384 | * | |
385 | * @port: tty port | |
386 | */ | |
387 | void tty_port_tty_wakeup(struct tty_port *port) | |
388 | { | |
c3485ee0 | 389 | port->client_ops->write_wakeup(port); |
6aad04f2 JS |
390 | } |
391 | EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); | |
392 | ||
31f35939 AC |
393 | /** |
394 | * tty_port_carrier_raised - carrier raised check | |
395 | * @port: tty port | |
396 | * | |
397 | * Wrapper for the carrier detect logic. For the moment this is used | |
398 | * to hide some internal details. This will eventually become entirely | |
399 | * internal to the tty port. | |
400 | */ | |
401 | ||
402 | int tty_port_carrier_raised(struct tty_port *port) | |
403 | { | |
404 | if (port->ops->carrier_raised == NULL) | |
405 | return 1; | |
406 | return port->ops->carrier_raised(port); | |
407 | } | |
408 | EXPORT_SYMBOL(tty_port_carrier_raised); | |
5d951fb4 AC |
409 | |
410 | /** | |
fcc8ac18 | 411 | * tty_port_raise_dtr_rts - Raise DTR/RTS |
5d951fb4 AC |
412 | * @port: tty port |
413 | * | |
414 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
415 | * to hide some internal details. This will eventually become entirely | |
416 | * internal to the tty port. | |
417 | */ | |
418 | ||
419 | void tty_port_raise_dtr_rts(struct tty_port *port) | |
420 | { | |
fcc8ac18 AC |
421 | if (port->ops->dtr_rts) |
422 | port->ops->dtr_rts(port, 1); | |
5d951fb4 AC |
423 | } |
424 | EXPORT_SYMBOL(tty_port_raise_dtr_rts); | |
36c621d8 | 425 | |
fcc8ac18 AC |
426 | /** |
427 | * tty_port_lower_dtr_rts - Lower DTR/RTS | |
428 | * @port: tty port | |
429 | * | |
430 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
431 | * to hide some internal details. This will eventually become entirely | |
432 | * internal to the tty port. | |
433 | */ | |
434 | ||
435 | void tty_port_lower_dtr_rts(struct tty_port *port) | |
436 | { | |
437 | if (port->ops->dtr_rts) | |
438 | port->ops->dtr_rts(port, 0); | |
439 | } | |
440 | EXPORT_SYMBOL(tty_port_lower_dtr_rts); | |
441 | ||
36c621d8 AC |
442 | /** |
443 | * tty_port_block_til_ready - Waiting logic for tty open | |
444 | * @port: the tty port being opened | |
445 | * @tty: the tty device being bound | |
ed3f0af8 | 446 | * @filp: the file pointer of the opener or NULL |
36c621d8 AC |
447 | * |
448 | * Implement the core POSIX/SuS tty behaviour when opening a tty device. | |
449 | * Handles: | |
450 | * - hangup (both before and during) | |
451 | * - non blocking open | |
452 | * - rts/dtr/dcd | |
453 | * - signals | |
454 | * - port flags and counts | |
455 | * | |
456 | * The passed tty_port must implement the carrier_raised method if it can | |
fcc8ac18 | 457 | * do carrier detect and the dtr_rts method if it supports software |
36c621d8 AC |
458 | * management of these lines. Note that the dtr/rts raise is done each |
459 | * iteration as a hangup may have previously dropped them while we wait. | |
c590f6b6 PH |
460 | * |
461 | * Caller holds tty lock. | |
462 | * | |
463 | * NB: May drop and reacquire tty lock when blocking, so tty and tty_port | |
464 | * may have changed state (eg., may have been hung up). | |
36c621d8 | 465 | */ |
d774a56d | 466 | |
36c621d8 AC |
467 | int tty_port_block_til_ready(struct tty_port *port, |
468 | struct tty_struct *tty, struct file *filp) | |
469 | { | |
470 | int do_clocal = 0, retval; | |
471 | unsigned long flags; | |
6af9a43d | 472 | DEFINE_WAIT(wait); |
36c621d8 | 473 | |
36c621d8 AC |
474 | /* if non-blocking mode is set we can pass directly to open unless |
475 | the port has just hung up or is in another error state */ | |
18900ca6 | 476 | if (tty_io_error(tty)) { |
807c8d81 | 477 | tty_port_set_active(port, 1); |
8627b96d AC |
478 | return 0; |
479 | } | |
ed3f0af8 | 480 | if (filp == NULL || (filp->f_flags & O_NONBLOCK)) { |
4175f3e3 | 481 | /* Indicate we are open */ |
9db276f8 | 482 | if (C_BAUD(tty)) |
4175f3e3 | 483 | tty_port_raise_dtr_rts(port); |
807c8d81 | 484 | tty_port_set_active(port, 1); |
36c621d8 AC |
485 | return 0; |
486 | } | |
487 | ||
488 | if (C_CLOCAL(tty)) | |
489 | do_clocal = 1; | |
490 | ||
491 | /* Block waiting until we can proceed. We may need to wait for the | |
492 | carrier, but we must also wait for any close that is in progress | |
493 | before the next open may complete */ | |
494 | ||
495 | retval = 0; | |
36c621d8 AC |
496 | |
497 | /* The port lock protects the port counts */ | |
498 | spin_lock_irqsave(&port->lock, flags); | |
e359a4e3 | 499 | port->count--; |
36c621d8 AC |
500 | port->blocked_open++; |
501 | spin_unlock_irqrestore(&port->lock, flags); | |
502 | ||
503 | while (1) { | |
504 | /* Indicate we are open */ | |
d41861ca | 505 | if (C_BAUD(tty) && tty_port_initialized(port)) |
7834909f | 506 | tty_port_raise_dtr_rts(port); |
36c621d8 | 507 | |
3e3b5c08 | 508 | prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); |
d774a56d AC |
509 | /* Check for a hangup or uninitialised port. |
510 | Return accordingly */ | |
d41861ca | 511 | if (tty_hung_up_p(filp) || !tty_port_initialized(port)) { |
36c621d8 AC |
512 | if (port->flags & ASYNC_HUP_NOTIFY) |
513 | retval = -EAGAIN; | |
514 | else | |
515 | retval = -ERESTARTSYS; | |
516 | break; | |
517 | } | |
0eee50af JS |
518 | /* |
519 | * Probe the carrier. For devices with no carrier detect | |
520 | * tty_port_carrier_raised will always return true. | |
521 | * Never ask drivers if CLOCAL is set, this causes troubles | |
522 | * on some hardware. | |
523 | */ | |
fef062cb | 524 | if (do_clocal || tty_port_carrier_raised(port)) |
36c621d8 AC |
525 | break; |
526 | if (signal_pending(current)) { | |
527 | retval = -ERESTARTSYS; | |
528 | break; | |
529 | } | |
89c8d91e | 530 | tty_unlock(tty); |
36c621d8 | 531 | schedule(); |
89c8d91e | 532 | tty_lock(tty); |
36c621d8 | 533 | } |
3e3b5c08 | 534 | finish_wait(&port->open_wait, &wait); |
36c621d8 AC |
535 | |
536 | /* Update counts. A parallel hangup will have set count to zero and | |
537 | we must not mess that up further */ | |
538 | spin_lock_irqsave(&port->lock, flags); | |
539 | if (!tty_hung_up_p(filp)) | |
540 | port->count++; | |
541 | port->blocked_open--; | |
36c621d8 | 542 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 PH |
543 | if (retval == 0) |
544 | tty_port_set_active(port, 1); | |
ecc2e05e | 545 | return retval; |
36c621d8 AC |
546 | } |
547 | EXPORT_SYMBOL(tty_port_block_til_ready); | |
548 | ||
b74414f5 JH |
549 | static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty) |
550 | { | |
551 | unsigned int bps = tty_get_baud_rate(tty); | |
552 | long timeout; | |
553 | ||
554 | if (bps > 1200) { | |
555 | timeout = (HZ * 10 * port->drain_delay) / bps; | |
556 | timeout = max_t(long, timeout, HZ / 10); | |
557 | } else { | |
558 | timeout = 2 * HZ; | |
559 | } | |
560 | schedule_timeout_interruptible(timeout); | |
561 | } | |
562 | ||
79c1faa4 | 563 | /* Caller holds tty lock. */ |
d774a56d AC |
564 | int tty_port_close_start(struct tty_port *port, |
565 | struct tty_struct *tty, struct file *filp) | |
a6614999 AC |
566 | { |
567 | unsigned long flags; | |
568 | ||
633caba8 | 569 | if (tty_hung_up_p(filp)) |
a6614999 | 570 | return 0; |
a6614999 | 571 | |
633caba8 | 572 | spin_lock_irqsave(&port->lock, flags); |
d774a56d | 573 | if (tty->count == 1 && port->count != 1) { |
339f36ba PH |
574 | tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, |
575 | port->count); | |
a6614999 AC |
576 | port->count = 1; |
577 | } | |
578 | if (--port->count < 0) { | |
339f36ba PH |
579 | tty_warn(tty, "%s: bad port count (%d)\n", __func__, |
580 | port->count); | |
a6614999 AC |
581 | port->count = 0; |
582 | } | |
583 | ||
584 | if (port->count) { | |
585 | spin_unlock_irqrestore(&port->lock, flags); | |
586 | return 0; | |
587 | } | |
a6614999 | 588 | spin_unlock_irqrestore(&port->lock, flags); |
0b2588ca | 589 | |
ddc7b758 PH |
590 | tty->closing = 1; |
591 | ||
d41861ca | 592 | if (tty_port_initialized(port)) { |
0b2588ca JH |
593 | /* Don't block on a stalled port, just pull the chain */ |
594 | if (tty->flow_stopped) | |
595 | tty_driver_flush_buffer(tty); | |
596 | if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) | |
79c1faa4 | 597 | tty_wait_until_sent(tty, port->closing_wait); |
0b2588ca JH |
598 | if (port->drain_delay) |
599 | tty_port_drain_delay(port, tty); | |
600 | } | |
e707c35c AC |
601 | /* Flush the ldisc buffering */ |
602 | tty_ldisc_flush(tty); | |
603 | ||
469d6d06 | 604 | /* Report to caller this is the last port reference */ |
a6614999 AC |
605 | return 1; |
606 | } | |
607 | EXPORT_SYMBOL(tty_port_close_start); | |
608 | ||
0733db91 | 609 | /* Caller holds tty lock */ |
a6614999 AC |
610 | void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) |
611 | { | |
612 | unsigned long flags; | |
613 | ||
3f40f5b2 | 614 | tty_ldisc_flush(tty); |
a6614999 AC |
615 | tty->closing = 0; |
616 | ||
ddc7b758 PH |
617 | spin_lock_irqsave(&port->lock, flags); |
618 | ||
a6614999 AC |
619 | if (port->blocked_open) { |
620 | spin_unlock_irqrestore(&port->lock, flags); | |
5823323e PH |
621 | if (port->close_delay) |
622 | msleep_interruptible(jiffies_to_msecs(port->close_delay)); | |
a6614999 AC |
623 | spin_lock_irqsave(&port->lock, flags); |
624 | wake_up_interruptible(&port->open_wait); | |
625 | } | |
a6614999 | 626 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 | 627 | tty_port_set_active(port, 0); |
a6614999 AC |
628 | } |
629 | EXPORT_SYMBOL(tty_port_close_end); | |
7ca0ff9a | 630 | |
0733db91 PH |
631 | /** |
632 | * tty_port_close | |
633 | * | |
634 | * Caller holds tty lock | |
0733db91 | 635 | */ |
7ca0ff9a AC |
636 | void tty_port_close(struct tty_port *port, struct tty_struct *tty, |
637 | struct file *filp) | |
638 | { | |
639 | if (tty_port_close_start(port, tty, filp) == 0) | |
640 | return; | |
957dacae | 641 | tty_port_shutdown(port, tty); |
d74e8286 | 642 | set_bit(TTY_IO_ERROR, &tty->flags); |
7ca0ff9a AC |
643 | tty_port_close_end(port, tty); |
644 | tty_port_tty_set(port, NULL); | |
645 | } | |
646 | EXPORT_SYMBOL(tty_port_close); | |
64bc3979 | 647 | |
72a33bf5 JS |
648 | /** |
649 | * tty_port_install - generic tty->ops->install handler | |
650 | * @port: tty_port of the device | |
651 | * @driver: tty_driver for this device | |
652 | * @tty: tty to be installed | |
653 | * | |
654 | * It is the same as tty_standard_install except the provided @port is linked | |
655 | * to a concrete tty specified by @tty. Use this or tty_port_register_device | |
656 | * (or both). Call tty_port_link_device as a last resort. | |
657 | */ | |
695586ca JS |
658 | int tty_port_install(struct tty_port *port, struct tty_driver *driver, |
659 | struct tty_struct *tty) | |
660 | { | |
661 | tty->port = port; | |
662 | return tty_standard_install(driver, tty); | |
663 | } | |
664 | EXPORT_SYMBOL_GPL(tty_port_install); | |
665 | ||
addd4672 PH |
666 | /** |
667 | * tty_port_open | |
668 | * | |
669 | * Caller holds tty lock. | |
670 | * | |
671 | * NB: may drop and reacquire tty lock (in tty_port_block_til_ready()) so | |
672 | * tty and tty_port may have changed state (eg., may be hung up now) | |
673 | */ | |
64bc3979 | 674 | int tty_port_open(struct tty_port *port, struct tty_struct *tty, |
d774a56d | 675 | struct file *filp) |
64bc3979 AC |
676 | { |
677 | spin_lock_irq(&port->lock); | |
e359a4e3 | 678 | ++port->count; |
64bc3979 AC |
679 | spin_unlock_irq(&port->lock); |
680 | tty_port_tty_set(port, tty); | |
681 | ||
682 | /* | |
683 | * Do the device-specific open only if the hardware isn't | |
684 | * already initialized. Serialize open and shutdown using the | |
685 | * port mutex. | |
686 | */ | |
687 | ||
688 | mutex_lock(&port->mutex); | |
689 | ||
d41861ca | 690 | if (!tty_port_initialized(port)) { |
a9a37ec3 | 691 | clear_bit(TTY_IO_ERROR, &tty->flags); |
64bc3979 AC |
692 | if (port->ops->activate) { |
693 | int retval = port->ops->activate(port, tty); | |
694 | if (retval) { | |
d774a56d AC |
695 | mutex_unlock(&port->mutex); |
696 | return retval; | |
697 | } | |
698 | } | |
d41861ca | 699 | tty_port_set_initialized(port, 1); |
64bc3979 AC |
700 | } |
701 | mutex_unlock(&port->mutex); | |
702 | return tty_port_block_til_ready(port, tty, filp); | |
703 | } | |
704 | ||
705 | EXPORT_SYMBOL(tty_port_open); |