path: root/drivers/char/tty_ioctl.c

/*
 *  linux/drivers/char/tty_ioctl.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
 * which can be dynamically activated and de-activated by the line
 * discipline handling modules (like SLIP).
 */

#include <linux/types.h>
#include <linux/termios.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/tty.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/mutex.h>

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>

#undef TTY_DEBUG_WAIT_UNTIL_SENT

#undef	DEBUG

/*
 * Internal flag options for termios setting behavior
 */
#define TERMIOS_FLUSH	1
#define TERMIOS_WAIT	2
#define TERMIOS_TERMIO	4
#define TERMIOS_OLD	8


/**
 *	tty_wait_until_sent	-	wait for I/O to finish
 *	@tty: tty we are waiting for
 *	@timeout: how long we will wait
 *
 *	Wait for characters pending in a tty driver to hit the wire, or
 *	for a timeout to occur (eg due to flow control)
 *
 *	Locking: none
 */

void tty_wait_until_sent(struct tty_struct * tty, long timeout)
{
#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
	char buf[64];
	
	printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
#endif
	if (!tty->driver->chars_in_buffer)
		return;
	if (!timeout)
		timeout = MAX_SCHEDULE_TIMEOUT;
	if (wait_event_interruptible_timeout(tty->write_wait,
			!tty->driver->chars_in_buffer(tty), timeout))
		return;
	if (tty->driver->wait_until_sent)
		tty->driver->wait_until_sent(tty, timeout);
}

EXPORT_SYMBOL(tty_wait_until_sent);

static void unset_locked_termios(struct ktermios *termios,
				 struct ktermios *old,
				 struct ktermios *locked)
{
	int	i;
	
#define NOSET_MASK(x,y,z) (x = ((x) & ~(z)) | ((y) & (z)))

	if (!locked) {
		printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
		return;
	}

	NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
	NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
	NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
	NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
	termios->c_line = locked->c_line ? old->c_line : termios->c_line;
	for (i=0; i < NCCS; i++)
		termios->c_cc[i] = locked->c_cc[i] ?
			old->c_cc[i] : termios->c_cc[i];
	/* FIXME: What should we do for i/ospeed */
}

/*
 * Routine which returns the baud rate of the tty
 *
 * Note that the baud_table needs to be kept in sync with the
 * include/asm/termbits.h file.
 */
static const speed_t baud_table[] = {
	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
	9600, 19200, 38400, 57600, 115200, 230400, 460800,
#ifdef __sparc__
	76800, 153600, 307200, 614400, 921600
#else
	500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
	2500000, 3000000, 3500000, 4000000
#endif
};

#ifndef __sparc__
static const tcflag_t baud_bits[] = {
	B0, B50, B75, B110, B134, B150, B200, B300, B600,
	B1200, B1800, B2400, B4800, B9600, B19200, B38400,
	B57600, B115200, B230400, B460800, B500000, B576000,
	B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
	B3000000, B3500000, B4000000
};
#else
static const tcflag_t baud_bits[] = {
	B0, B50, B75, B110, B134, B150, B200, B300, B600,
	B1200, B1800, B2400, B4800, B9600, B19200, B38400,
	B57600, B115200, B230400, B460800, B76800, B153600,
	B307200, B614400, B921600
};
#endif

static int n_baud_table = ARRAY_SIZE(baud_table);

/**
 *	tty_termios_baud_rate
 *	@termios: termios structure
 *
 *	Convert termios baud rate data into a speed. This should be called
 *	with the termios lock held if this termios is a terminal termios
 *	structure. May change the termios data. Device drivers can call this
 *	function but should use ->c_[io]speed directly as they are updated.
 *
 *	Locking: none
 */

speed_t tty_termios_baud_rate(struct ktermios *termios)
{
	unsigned int cbaud;

	cbaud = termios->c_cflag & CBAUD;

#ifdef BOTHER
	/* Magic token for arbitary speed via c_ispeed/c_ospeed */
	if (cbaud == BOTHER)
		return termios->c_ospeed;
#endif
	if (cbaud & CBAUDEX) {
		cbaud &= ~CBAUDEX;

		if (cbaud < 1 || cbaud + 15 > n_baud_table)
			termios->c_cflag &= ~CBAUDEX;
		else