3  * Tty port functions
23 static int tty_port_default_receive_buf(struct tty_port *port,  in tty_port_default_receive_buf()  argument
31 	tty = READ_ONCE(port->itty);  in tty_port_default_receive_buf()
46 static void tty_port_default_wakeup(struct tty_port *port)  in tty_port_default_wakeup()  argument
48 	struct tty_struct *tty = tty_port_tty_get(port);  in tty_port_default_wakeup()
62 void tty_port_init(struct tty_port *port)  in tty_port_init()  argument
64 	memset(port, 0, sizeof(*port));  in tty_port_init()
65 	tty_buffer_init(port);  in tty_port_init()
66 	init_waitqueue_head(&port->open_wait);  in tty_port_init()
67 	init_waitqueue_head(&port->delta_msr_wait);  in tty_port_init()
68 	mutex_init(&port->mutex);  in tty_port_init()
69 	mutex_init(&port->buf_mutex);  in tty_port_init()
70 	spin_lock_init(&port->lock);  in tty_port_init()
71 	port->close_delay = (50 * HZ) / 100;  in tty_port_init()
72 	port->closing_wait = (3000 * HZ) / 100;  in tty_port_init()
73 	port->client_ops = &tty_port_default_client_ops;  in tty_port_init()
74 	kref_init(&port->kref);  in tty_port_init()
80  * @port: tty_port of the device
85  * tty_port (@port). Use this only if neither tty_port_register_device nor
89 void tty_port_link_device(struct tty_port *port,  in tty_port_link_device()  argument
94 	driver->ports[index] = port;  in tty_port_link_device()
100  * @port: tty_port of the device
105  * It is the same as tty_register_device except the provided @port is linked to
109 struct device *tty_port_register_device(struct tty_port *port,  in tty_port_register_device()  argument
113 	return tty_port_register_device_attr(port, driver, index, device, NULL, NULL);  in tty_port_register_device()
119  * @port: tty_port of the device
126  * It is the same as tty_register_device_attr except the provided @port is
130 struct device *tty_port_register_device_attr(struct tty_port *port,  in tty_port_register_device_attr()  argument
135 	tty_port_link_device(port, driver, index);  in tty_port_register_device_attr()
143  * @port: tty_port of the device
153 struct device *tty_port_register_device_attr_serdev(struct tty_port *port,  in tty_port_register_device_attr_serdev()  argument
160 	tty_port_link_device(port, driver, index);  in tty_port_register_device_attr_serdev()
162 	dev = serdev_tty_port_register(port, device, driver, index);  in tty_port_register_device_attr_serdev()
175  * @port: tty_port of the device
183 struct device *tty_port_register_device_serdev(struct tty_port *port,  in tty_port_register_device_serdev()  argument
187 	return tty_port_register_device_attr_serdev(port, driver, index,  in tty_port_register_device_serdev()
194  * @port: tty_port of the device
202 void tty_port_unregister_device(struct tty_port *port,  in tty_port_unregister_device()  argument
207 	ret = serdev_tty_port_unregister(port);  in tty_port_unregister_device()
215 int tty_port_alloc_xmit_buf(struct tty_port *port)  in tty_port_alloc_xmit_buf()  argument
218 	mutex_lock(&port->buf_mutex);  in tty_port_alloc_xmit_buf()
219 	if (port->xmit_buf == NULL)  in tty_port_alloc_xmit_buf()
220 		port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);  in tty_port_alloc_xmit_buf()
221 	mutex_unlock(&port->buf_mutex);  in tty_port_alloc_xmit_buf()
222 	if (port->xmit_buf == NULL)  in tty_port_alloc_xmit_buf()
228 void tty_port_free_xmit_buf(struct tty_port *port)  in tty_port_free_xmit_buf()  argument
230 	mutex_lock(&port->buf_mutex);  in tty_port_free_xmit_buf()
231 	if (port->xmit_buf != NULL) {  in tty_port_free_xmit_buf()
232 		free_page((unsigned long)port->xmit_buf);  in tty_port_free_xmit_buf()
233 		port->xmit_buf = NULL;  in tty_port_free_xmit_buf()
235 	mutex_unlock(&port->buf_mutex);  in tty_port_free_xmit_buf()
240  * tty_port_destroy -- destroy inited port
241  * @port: tty port to be destroyed
243  * When a port was initialized using tty_port_init, one has to destroy the
244  * port by this function. Either indirectly by using tty_port refcounting
247 void tty_port_destroy(struct tty_port *port)  in tty_port_destroy()  argument
249 	tty_buffer_cancel_work(port);  in tty_port_destroy()
250 	tty_buffer_free_all(port);  in tty_port_destroy()
256 	struct tty_port *port = container_of(kref, struct tty_port, kref);  in tty_port_destructor()  local
258 	/* check if last port ref was dropped before tty release */  in tty_port_destructor()
259 	if (WARN_ON(port->itty))  in tty_port_destructor()
261 	if (port->xmit_buf)  in tty_port_destructor()
262 		free_page((unsigned long)port->xmit_buf);  in tty_port_destructor()
263 	tty_port_destroy(port);  in tty_port_destructor()
264 	if (port->ops && port->ops->destruct)  in tty_port_destructor()
265 		port->ops->destruct(port);  in tty_port_destructor()
267 		kfree(port);  in tty_port_destructor()
270 void tty_port_put(struct tty_port *port)  in tty_port_put()  argument
272 	if (port)  in tty_port_put()
273 		kref_put(&port->kref, tty_port_destructor);  in tty_port_put()
279  *	@port: tty port
281  *	Return a refcount protected tty instance or NULL if the port is not
284 struct tty_struct *tty_port_tty_get(struct tty_port *port)  in tty_port_tty_get()  argument
289 	spin_lock_irqsave(&port->lock, flags);  in tty_port_tty_get()
290 	tty = tty_kref_get(port->tty);  in tty_port_tty_get()
291 	spin_unlock_irqrestore(&port->lock, flags);  in tty_port_tty_get()
297  *	tty_port_tty_set	-	set the tty of a port
298  *	@port: tty port
301  *	Associate the port and tty pair. Manages any internal refcounts.
302  *	Pass NULL to deassociate a port
304 void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)  in tty_port_tty_set()  argument
308 	spin_lock_irqsave(&port->lock, flags);  in tty_port_tty_set()
309 	tty_kref_put(port->tty);  in tty_port_tty_set()
310 	port->tty = tty_kref_get(tty);  in tty_port_tty_set()
311 	spin_unlock_irqrestore(&port->lock, flags);  in tty_port_tty_set()
315 static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty)  in tty_port_shutdown()  argument
317 	mutex_lock(&port->mutex);  in tty_port_shutdown()
318 	if (port->console)  in tty_port_shutdown()
321 	if (tty_port_initialized(port)) {  in tty_port_shutdown()
322 		tty_port_set_initialized(port, 0);  in tty_port_shutdown()
328 			tty_port_lower_dtr_rts(port);  in tty_port_shutdown()
330 		if (port->ops->shutdown)  in tty_port_shutdown()
331 			port->ops->shutdown(port);  in tty_port_shutdown()
334 	mutex_unlock(&port->mutex);  in tty_port_shutdown()
339  *	@port: tty port
341  *	Perform port level tty hangup flag and count changes. Drop the tty
346 void tty_port_hangup(struct tty_port *port)  in tty_port_hangup()  argument
351 	spin_lock_irqsave(&port->lock, flags);  in tty_port_hangup()
352 	port->count = 0;  in tty_port_hangup()
353 	tty = port->tty;  in tty_port_hangup()
356 	port->tty = NULL;  in tty_port_hangup()
357 	spin_unlock_irqrestore(&port->lock, flags);  in tty_port_hangup()
358 	tty_port_set_active(port, 0);  in tty_port_hangup()
359 	tty_port_shutdown(port, tty);  in tty_port_hangup()
361 	wake_up_interruptible(&port->open_wait);  in tty_port_hangup()
362 	wake_up_interruptible(&port->delta_msr_wait);  in tty_port_hangup()
369  * @port: tty port
372 void tty_port_tty_hangup(struct tty_port *port, bool check_clocal)  in tty_port_tty_hangup()  argument
374 	struct tty_struct *tty = tty_port_tty_get(port);  in tty_port_tty_hangup()
385  * @port: tty port
387 void tty_port_tty_wakeup(struct tty_port *port)  in tty_port_tty_wakeup()  argument
389 	port->client_ops->write_wakeup(port);  in tty_port_tty_wakeup()
395  *	@port: tty port
399  *	internal to the tty port.
401 int tty_port_carrier_raised(struct tty_port *port)  in tty_port_carrier_raised()  argument
403 	if (port->ops->carrier_raised == NULL)  in tty_port_carrier_raised()
405 	return port->ops->carrier_raised(port);  in tty_port_carrier_raised()
411  *	@port: tty port
415  *	internal to the tty port.
417 void tty_port_raise_dtr_rts(struct tty_port *port)  in tty_port_raise_dtr_rts()  argument
419 	if (port->ops->dtr_rts)  in tty_port_raise_dtr_rts()
420 		port->ops->dtr_rts(port, 1);  in tty_port_raise_dtr_rts()
426  *	@port: tty port
430  *	internal to the tty port.
432 void tty_port_lower_dtr_rts(struct tty_port *port)  in tty_port_lower_dtr_rts()  argument
434 	if (port->ops->dtr_rts)  in tty_port_lower_dtr_rts()
435 		port->ops->dtr_rts(port, 0);  in tty_port_lower_dtr_rts()
441  *	@port: the tty port being opened
451  *		- port flags and counts
463 int tty_port_block_til_ready(struct tty_port *port,  in tty_port_block_til_ready()  argument
471 	 * the port has just hung up or is in another error state.  in tty_port_block_til_ready()
474 		tty_port_set_active(port, 1);  in tty_port_block_til_ready()
480 			tty_port_raise_dtr_rts(port);  in tty_port_block_til_ready()
481 		tty_port_set_active(port, 1);  in tty_port_block_til_ready()
495 	/* The port lock protects the port counts */  in tty_port_block_til_ready()
496 	spin_lock_irqsave(&port->lock, flags);  in tty_port_block_til_ready()
497 	port->count--;  in tty_port_block_til_ready()
498 	port->blocked_open++;  in tty_port_block_til_ready()
499 	spin_unlock_irqrestore(&port->lock, flags);  in tty_port_block_til_ready()
503 		if (C_BAUD(tty) && tty_port_initialized(port))  in tty_port_block_til_ready()
504 			tty_port_raise_dtr_rts(port);  in tty_port_block_til_ready()
506 		prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);  in tty_port_block_til_ready()
507 		/* Check for a hangup or uninitialised port.  in tty_port_block_til_ready()
510 		if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {  in tty_port_block_til_ready()
511 			if (port->flags & ASYNC_HUP_NOTIFY)  in tty_port_block_til_ready()
523 		if (do_clocal || tty_port_carrier_raised(port))  in tty_port_block_til_ready()
533 	finish_wait(&port->open_wait, &wait);  in tty_port_block_til_ready()
538 	spin_lock_irqsave(&port->lock, flags);  in tty_port_block_til_ready()
540 		port->count++;  in tty_port_block_til_ready()
541 	port->blocked_open--;  in tty_port_block_til_ready()
542 	spin_unlock_irqrestore(&port->lock, flags);  in tty_port_block_til_ready()
544 		tty_port_set_active(port, 1);  in tty_port_block_til_ready()
549 static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty)  in tty_port_drain_delay()  argument
555 		timeout = (HZ * 10 * port->drain_delay) / bps;  in tty_port_drain_delay()
564 int tty_port_close_start(struct tty_port *port,  in tty_port_close_start()  argument
572 	spin_lock_irqsave(&port->lock, flags);  in tty_port_close_start()
573 	if (tty->count == 1 && port->count != 1) {  in tty_port_close_start()
574 		tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__,  in tty_port_close_start()
575 			 port->count);  in tty_port_close_start()
576 		port->count = 1;  in tty_port_close_start()
578 	if (--port->count < 0) {  in tty_port_close_start()
579 		tty_warn(tty, "%s: bad port count (%d)\n", __func__,  in tty_port_close_start()
580 			 port->count);  in tty_port_close_start()
581 		port->count = 0;  in tty_port_close_start()
584 	if (port->count) {  in tty_port_close_start()
585 		spin_unlock_irqrestore(&port->lock, flags);  in tty_port_close_start()
588 	spin_unlock_irqrestore(&port->lock, flags);  in tty_port_close_start()
592 	if (tty_port_initialized(port)) {  in tty_port_close_start()
593 		/* Don't block on a stalled port, just pull the chain */  in tty_port_close_start()
596 		if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)  in tty_port_close_start()
597 			tty_wait_until_sent(tty, port->closing_wait);  in tty_port_close_start()
598 		if (port->drain_delay)  in tty_port_close_start()
599 			tty_port_drain_delay(port, tty);  in tty_port_close_start()
604 	/* Report to caller this is the last port reference */  in tty_port_close_start()
610 void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)  in tty_port_close_end()  argument
617 	spin_lock_irqsave(&port->lock, flags);  in tty_port_close_end()
619 	if (port->blocked_open) {  in tty_port_close_end()
620 		spin_unlock_irqrestore(&port->lock, flags);  in tty_port_close_end()
621 		if (port->close_delay)  in tty_port_close_end()
622 			msleep_interruptible(jiffies_to_msecs(port->close_delay));  in tty_port_close_end()
623 		spin_lock_irqsave(&port->lock, flags);  in tty_port_close_end()
624 		wake_up_interruptible(&port->open_wait);  in tty_port_close_end()
626 	spin_unlock_irqrestore(&port->lock, flags);  in tty_port_close_end()
627 	tty_port_set_active(port, 0);  in tty_port_close_end()
636 void tty_port_close(struct tty_port *port, struct tty_struct *tty,  in tty_port_close()  argument
639 	if (tty_port_close_start(port, tty, filp) == 0)  in tty_port_close()
641 	tty_port_shutdown(port, tty);  in tty_port_close()
642 	if (!port->console)  in tty_port_close()
644 	tty_port_close_end(port, tty);  in tty_port_close()
645 	tty_port_tty_set(port, NULL);  in tty_port_close()
651  * @port: tty_port of the device
655  * It is the same as tty_standard_install except the provided @port is linked
659 int tty_port_install(struct tty_port *port, struct tty_driver *driver,  in tty_port_install()  argument
662 	tty->port = port;  in tty_port_install()
675 int tty_port_open(struct tty_port *port, struct tty_struct *tty,  in tty_port_open()  argument
678 	spin_lock_irq(&port->lock);  in tty_port_open()
679 	++port->count;  in tty_port_open()
680 	spin_unlock_irq(&port->lock);  in tty_port_open()
681 	tty_port_tty_set(port, tty);  in tty_port_open()
686 	 * port mutex.  in tty_port_open()
689 	mutex_lock(&port->mutex);  in tty_port_open()
691 	if (!tty_port_initialized(port)) {  in tty_port_open()
693 		if (port->ops->activate) {  in tty_port_open()
694 			int retval = port->ops->activate(port, tty);  in tty_port_open()
697 				mutex_unlock(&port->mutex);  in tty_port_open()
701 		tty_port_set_initialized(port, 1);  in tty_port_open()
703 	mutex_unlock(&port->mutex);  in tty_port_open()
704 	return tty_port_block_til_ready(port, tty, filp);  in tty_port_open()