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>
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 @@
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 @@
}
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 @@
}
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 @@
}
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 @@
* 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 @@
* 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 @@
* 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)