android_kernel_xiaomi_sm8350/drivers/char/tty_port.c
Alan Cox 9e48565d21 tty: Split tty_port into its own file
Not much in it yet but this will grow a lot

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:40 -07:00

56 lines
1.3 KiB
C

/*
* Tty port functions
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/module.h>
void tty_port_init(struct tty_port *port)
{
memset(port, 0, sizeof(*port));
init_waitqueue_head(&port->open_wait);
init_waitqueue_head(&port->close_wait);
mutex_init(&port->mutex);
port->close_delay = (50 * HZ) / 100;
port->closing_wait = (3000 * HZ) / 100;
}
EXPORT_SYMBOL(tty_port_init);
int tty_port_alloc_xmit_buf(struct tty_port *port)
{
/* We may sleep in get_zeroed_page() */
mutex_lock(&port->mutex);
if (port->xmit_buf == NULL)
port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
mutex_unlock(&port->mutex);
if (port->xmit_buf == NULL)
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
void tty_port_free_xmit_buf(struct tty_port *port)
{
mutex_lock(&port->mutex);
if (port->xmit_buf != NULL) {
free_page((unsigned long)port->xmit_buf);
port->xmit_buf = NULL;
}
mutex_unlock(&port->mutex);
}
EXPORT_SYMBOL(tty_port_free_xmit_buf);