diff options
author | Alan Cox <alan@redhat.com> | 2008-10-13 09:41:42 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-13 16:51:42 (GMT) |
commit | d81ed10307027e1643a65ab5fe17cc01233d376d (patch) | |
tree | e46ac5735124308357f42214a8a26f75dcd3f412 /drivers/char/tty_ioctl.c | |
parent | feebed6515a113eeb33919e9557a8b9710ea627c (diff) | |
download | linux-fsl-qoriq-d81ed10307027e1643a65ab5fe17cc01233d376d.tar.xz |
tty: Remove more special casing and out of place code
Carry on pushing code out of tty_io when it belongs to other drivers. I'm
not 100% happy with some of this and it will be worth revisiting some of the
exports later when the restructuring work is done.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/tty_ioctl.c')
-rw-r--r-- | drivers/char/tty_ioctl.c | 66 |
1 files changed, 60 insertions, 6 deletions
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index 30670851..14cc19c 100644 --- a/drivers/char/tty_ioctl.c +++ b/drivers/char/tty_ioctl.c @@ -40,6 +40,15 @@ #define TERMIOS_OLD 8 +/** + * tty_chars_in_buffer - characters pending + * @tty: terminal + * + * Return the number of bytes of data in the device private + * output queue. If no private method is supplied there is assumed + * to be no queue on the device. + */ + int tty_chars_in_buffer(struct tty_struct *tty) { if (tty->ops->chars_in_buffer) @@ -47,26 +56,49 @@ int tty_chars_in_buffer(struct tty_struct *tty) else return 0; } - EXPORT_SYMBOL(tty_chars_in_buffer); +/** + * tty_write_room - write queue space + * @tty: terminal + * + * Return the number of bytes that can be queued to this device + * at the present time. The result should be treated as a guarantee + * and the driver cannot offer a value it later shrinks by more than + * the number of bytes written. If no method is provided 2K is always + * returned and data may be lost as there will be no flow control. + */ + int tty_write_room(struct tty_struct *tty) { if (tty->ops->write_room) return tty->ops->write_room(tty); return 2048; } - EXPORT_SYMBOL(tty_write_room); +/** + * tty_driver_flush_buffer - discard internal buffer + * @tty: terminal + * + * Discard the internal output buffer for this device. If no method + * is provided then either the buffer cannot be hardware flushed or + * there is no buffer driver side. + */ void tty_driver_flush_buffer(struct tty_struct *tty) { if (tty->ops->flush_buffer) tty->ops->flush_buffer(tty); } - EXPORT_SYMBOL(tty_driver_flush_buffer); +/** + * tty_throttle - flow control + * @tty: terminal + * + * Indicate that a tty should stop transmitting data down the stack. + */ + void tty_throttle(struct tty_struct *tty) { /* check TTY_THROTTLED first so it indicates our state */ @@ -76,6 +108,13 @@ void tty_throttle(struct tty_struct *tty) } EXPORT_SYMBOL(tty_throttle); +/** + * tty_unthrottle - flow control + * @tty: terminal + * + * Indicate that a tty may continue transmitting data down the stack. + */ + void tty_unthrottle(struct tty_struct *tty) { if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) && @@ -112,6 +151,11 @@ void tty_wait_until_sent(struct tty_struct *tty, long timeout) } EXPORT_SYMBOL(tty_wait_until_sent); + +/* + * Termios Helper Methods + */ + static void unset_locked_termios(struct ktermios *termios, struct ktermios *old, struct ktermios *locked) @@ -346,6 +390,16 @@ void tty_termios_encode_baud_rate(struct ktermios *termios, } EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate); +/** + * tty_encode_baud_rate - set baud rate of the tty + * @ibaud: input baud rate + * @obad: output baud rate + * + * Update the current termios data for the tty with the new speed + * settings. The caller must hold the termios_mutex for the tty in + * question. + */ + void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud) { tty_termios_encode_baud_rate(tty->termios, ibaud, obaud); @@ -430,7 +484,7 @@ EXPORT_SYMBOL(tty_termios_hw_change); * is a bit of layering violation here with n_tty in terms of the * internal knowledge of this function. * - * Locking: termios_sem + * Locking: termios_mutex */ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios) @@ -508,7 +562,7 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios) * functions before using change_termios to do the actual changes. * * Locking: - * Called functions take ldisc and termios_sem locks + * Called functions take ldisc and termios_mutex locks */ static int set_termios(struct tty_struct *tty, void __user *arg, int opt) @@ -715,7 +769,7 @@ static void set_sgflags(struct ktermios *termios, int flags) * Updates a terminal from the legacy BSD style terminal information * structure. * - * Locking: termios_sem + * Locking: termios_mutex */ static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb) |