5 #include <linux/types.h>
6 #include <linux/errno.h>
8 #include <linux/tty_driver.h>
9 #include <linux/tty_flip.h>
10 #include <linux/serial.h>
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>
21 void tty_port_init(struct tty_port *port)
23 memset(port, 0, sizeof(*port));
24 init_waitqueue_head(&port->open_wait);
25 init_waitqueue_head(&port->close_wait);
26 mutex_init(&port->mutex);
27 spin_lock_init(&port->lock);
28 port->close_delay = (50 * HZ) / 100;
29 port->closing_wait = (3000 * HZ) / 100;
31 EXPORT_SYMBOL(tty_port_init);
33 int tty_port_alloc_xmit_buf(struct tty_port *port)
35 /* We may sleep in get_zeroed_page() */
36 mutex_lock(&port->mutex);
37 if (port->xmit_buf == NULL)
38 port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
39 mutex_unlock(&port->mutex);
40 if (port->xmit_buf == NULL)
44 EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
46 void tty_port_free_xmit_buf(struct tty_port *port)
48 mutex_lock(&port->mutex);
49 if (port->xmit_buf != NULL) {
50 free_page((unsigned long)port->xmit_buf);
51 port->xmit_buf = NULL;
53 mutex_unlock(&port->mutex);
55 EXPORT_SYMBOL(tty_port_free_xmit_buf);
59 * tty_port_tty_get - get a tty reference
62 * Return a refcount protected tty instance or NULL if the port is not
63 * associated with a tty (eg due to close or hangup)
66 struct tty_struct *tty_port_tty_get(struct tty_port *port)
69 struct tty_struct *tty;
71 spin_lock_irqsave(&port->lock, flags);
72 tty = tty_kref_get(port->tty);
73 spin_unlock_irqrestore(&port->lock, flags);
76 EXPORT_SYMBOL(tty_port_tty_get);
79 * tty_port_tty_set - set the tty of a port
83 * Associate the port and tty pair. Manages any internal refcounts.
84 * Pass NULL to deassociate a port
87 void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
91 spin_lock_irqsave(&port->lock, flags);
93 tty_kref_put(port->tty);
94 port->tty = tty_kref_get(tty);
95 spin_unlock_irqrestore(&port->lock, flags);
97 EXPORT_SYMBOL(tty_port_tty_set);
100 * tty_port_hangup - hangup helper
103 * Perform port level tty hangup flag and count changes. Drop the tty
107 void tty_port_hangup(struct tty_port *port)
111 spin_lock_irqsave(&port->lock, flags);
113 port->flags &= ~ASYNC_NORMAL_ACTIVE;
115 tty_kref_put(port->tty);
117 spin_unlock_irqrestore(&port->lock, flags);
118 wake_up_interruptible(&port->open_wait);
120 EXPORT_SYMBOL(tty_port_hangup);
123 * tty_port_carrier_raised - carrier raised check
126 * Wrapper for the carrier detect logic. For the moment this is used
127 * to hide some internal details. This will eventually become entirely
128 * internal to the tty port.
131 int tty_port_carrier_raised(struct tty_port *port)
133 if (port->ops->carrier_raised == NULL)
135 return port->ops->carrier_raised(port);
137 EXPORT_SYMBOL(tty_port_carrier_raised);
140 * tty_port_raise_dtr_rts - Riase DTR/RTS
143 * Wrapper for the DTR/RTS raise logic. For the moment this is used
144 * to hide some internal details. This will eventually become entirely
145 * internal to the tty port.
148 void tty_port_raise_dtr_rts(struct tty_port *port)
150 if (port->ops->raise_dtr_rts)
151 port->ops->raise_dtr_rts(port);
153 EXPORT_SYMBOL(tty_port_raise_dtr_rts);