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Commit 3b1a696b authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
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tty: fix up and plug in tty_ioctl kernel-doc 

The ioctl helpers are well documented, except they are not plugged in
the Documentation. So fix up the minor issues in the kernel-doc and plug
it in.

The minor issues include:
* bad \t on every line (sphinx misinterprets the description otherwise)
* missing colon after Return
* superfluous \n after the comment
* make some struct members and constants a hyperlink
* and so on

Perhaps better to use --word-diff if one wants to see the "real"
changes.
Signed-off-by: default avatar"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-9-jirislaby@kernel.orgSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5b4f9cf3
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Showing with 115 additions and 111 deletions
Documentation/driver-api/tty/index.rst
View file @ 3b1a696b
......@@ -36,6 +36,7 @@ In-detail description of the named TTY structures is in separate documents:
tty_struct
tty_ldisc
tty_buffer
tty_ioctl
tty_internals
Writing TTY Driver
......
Documentation/driver-api/tty/tty_ioctl.rst 0 → 100644
View file @ 3b1a696b
.. SPDX-License-Identifier: GPL-2.0
=================
TTY IOCTL Helpers
=================
.. kernel-doc:: drivers/tty/tty_ioctl.c
drivers/tty/tty_ioctl.c
View file @ 3b1a696b
......@@ -38,16 +38,13 @@
#define TERMIOS_TERMIO BIT(2)
#define TERMIOS_OLD BIT(3)
/**
* tty_chars_in_buffer - characters pending
* @tty: terminal
* 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.
* Returns: 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.
*/
unsigned int tty_chars_in_buffer(struct tty_struct *tty)
{
if (tty->ops->chars_in_buffer)
......@@ -57,16 +54,15 @@ unsigned int tty_chars_in_buffer(struct tty_struct *tty)
EXPORT_SYMBOL(tty_chars_in_buffer);
/**
* tty_write_room - write queue space
* @tty: terminal
* 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.
* Returns: 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.
*/
unsigned int tty_write_room(struct tty_struct *tty)
{
if (tty->ops->write_room)
......@@ -76,12 +72,12 @@ unsigned int tty_write_room(struct tty_struct *tty)
EXPORT_SYMBOL(tty_write_room);
/**
* tty_driver_flush_buffer - discard internal buffer
* @tty: terminal
* 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.
* 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)
{
......@@ -91,18 +87,17 @@ void tty_driver_flush_buffer(struct tty_struct *tty)
EXPORT_SYMBOL(tty_driver_flush_buffer);
/**
* tty_unthrottle - flow control
* @tty: terminal
* tty_unthrottle - flow control
* @tty: terminal
*
* Indicate that a tty may continue transmitting data down the stack.
* Takes the termios rwsem to protect against parallel throttle/unthrottle
* and also to ensure the driver can consistently reference its own
* termios data at this point when implementing software flow control.
* Indicate that a @tty may continue transmitting data down the stack. Takes
* the &tty_struct->termios_rwsem to protect against parallel
* throttle/unthrottle and also to ensure the driver can consistently reference
* its own termios data at this point when implementing software flow control.
*
* Drivers should however remember that the stack can issue a throttle,
* then change flow control method, then unthrottle.
* Drivers should however remember that the stack can issue a throttle, then
* change flow control method, then unthrottle.
*/
void tty_unthrottle(struct tty_struct *tty)
{
down_write(&tty->termios_rwsem);
......@@ -115,16 +110,15 @@ void tty_unthrottle(struct tty_struct *tty)
EXPORT_SYMBOL(tty_unthrottle);
/**
* tty_throttle_safe - flow control
* @tty: terminal
* tty_throttle_safe - flow control
* @tty: terminal
*
* Indicate that a tty should stop transmitting data down the stack.
* tty_throttle_safe will only attempt throttle if tty->flow_change is
* TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race
* conditions when throttling is conditional on factors evaluated prior to
* throttling.
* Indicate that a @tty should stop transmitting data down the stack.
* tty_throttle_safe() will only attempt throttle if @tty->flow_change is
* %TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race conditions
* when throttling is conditional on factors evaluated prior to throttling.
*
* Returns true if tty is throttled (or was already throttled)
* Returns: %true if @tty is throttled (or was already throttled)
*/
bool tty_throttle_safe(struct tty_struct *tty)
{
......@@ -146,15 +140,15 @@ bool tty_throttle_safe(struct tty_struct *tty)
}
/**
* tty_unthrottle_safe - flow control
* @tty: terminal
* tty_unthrottle_safe - flow control
* @tty: terminal
*
* Similar to tty_unthrottle() but will only attempt unthrottle
* if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
* unthrottle due to race conditions when unthrottling is conditional
* on factors evaluated prior to unthrottling.
* Similar to tty_unthrottle() but will only attempt unthrottle if
* @tty->flow_change is %TTY_UNTHROTTLE_SAFE. Prevents an accidental unthrottle
* due to race conditions when unthrottling is conditional on factors evaluated
* prior to unthrottling.
*
* Returns true if tty is unthrottled (or was already unthrottled)
* Returns: %true if @tty is unthrottled (or was already unthrottled)
*/
bool tty_unthrottle_safe(struct tty_struct *tty)
{
......@@ -176,14 +170,14 @@ bool tty_unthrottle_safe(struct tty_struct *tty)
}
/**
* tty_wait_until_sent - wait for I/O to finish
* @tty: tty we are waiting for
* @timeout: how long we will wait
* 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)
* 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
* Locking: none
*/
void tty_wait_until_sent(struct tty_struct *tty, long timeout)
......@@ -229,16 +223,15 @@ static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *
}
/**
* tty_termios_copy_hw - copy hardware settings
* @new: New termios
* @old: Old termios
* tty_termios_copy_hw - copy hardware settings
* @new: new termios
* @old: old termios
*
* Propagate the hardware specific terminal setting bits from
* the old termios structure to the new one. This is used in cases
* where the hardware does not support reconfiguration or as a helper
* in some cases where only minimal reconfiguration is supported
* Propagate the hardware specific terminal setting bits from the @old termios
* structure to the @new one. This is used in cases where the hardware does not
* support reconfiguration or as a helper in some cases where only minimal
* reconfiguration is supported.
*/
void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old)
{
/* The bits a dumb device handles in software. Smart devices need
......@@ -251,14 +244,15 @@ void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old)
EXPORT_SYMBOL(tty_termios_copy_hw);
/**
* tty_termios_hw_change - check for setting change
* @a: termios
* @b: termios to compare
* tty_termios_hw_change - check for setting change
* @a: termios
* @b: termios to compare
*
* Check if any of the bits that affect a dumb device have changed
* between the two termios structures, or a speed change is needed.
* Check if any of the bits that affect a dumb device have changed between the
* two termios structures, or a speed change is needed.
*
* Returns: %true if change is needed
*/
bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
{
if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
......@@ -270,11 +264,10 @@ bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
EXPORT_SYMBOL(tty_termios_hw_change);
/**
* tty_get_char_size - get size of a character
* @cflag: termios cflag value
* tty_get_char_size - get size of a character
* @cflag: termios cflag value
*
* Get the size (in bits) of a character depending on @cflag's %CSIZE
* setting.
* Returns: size (in bits) of a character depending on @cflag's %CSIZE setting
*/
unsigned char tty_get_char_size(unsigned int cflag)
{
......@@ -293,13 +286,14 @@ unsigned char tty_get_char_size(unsigned int cflag)
EXPORT_SYMBOL_GPL(tty_get_char_size);
/**
* tty_get_frame_size - get size of a frame
* @cflag: termios cflag value
* tty_get_frame_size - get size of a frame
* @cflag: termios cflag value
*
* Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB,
* and %PARENB setting. The result is a sum of character size, start and
* stop bits -- one bit each -- second stop bit (if set), and parity bit
* (if set).
* Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB, and
* %PARENB setting. The result is a sum of character size, start and stop bits
* -- one bit each -- second stop bit (if set), and parity bit (if set).
*
* Returns: size (in bits) of a frame depending on @cflag's setting.
*/
unsigned char tty_get_frame_size(unsigned int cflag)
{
......@@ -317,16 +311,15 @@ unsigned char tty_get_frame_size(unsigned int cflag)
EXPORT_SYMBOL_GPL(tty_get_frame_size);
/**
* tty_set_termios - update termios values
* @tty: tty to update
* @new_termios: desired new value
* tty_set_termios - update termios values
* @tty: tty to update
* @new_termios: desired new value
*
* Perform updates to the termios values set on this terminal.
* A master pty's termios should never be set.
* Perform updates to the termios values set on this @tty. A master pty's
* termios should never be set.
*
* Locking: termios_rwsem
* Locking: &tty_struct->termios_rwsem
*/
int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
struct ktermios old_termios;
......@@ -439,18 +432,19 @@ __weak int kernel_termios_to_user_termios(struct termios __user *u,
#endif /* TCGETS2 */
/**
* set_termios - set termios values for a tty
* @tty: terminal device
* @arg: user data
* @opt: option information
* set_termios - set termios values for a tty
* @tty: terminal device
* @arg: user data
* @opt: option information
*
* Helper function to prepare termios data and run necessary other
* functions before using tty_set_termios to do the actual changes.
* Helper function to prepare termios data and run necessary other functions
* before using tty_set_termios() to do the actual changes.
*
* Locking:
* Called functions take ldisc and termios_rwsem locks
* Locking: called functions take &tty_struct->ldisc_sem and
* &tty_struct->termios_rwsem locks
*
* Returns: 0 on success, an error otherwise
*/
static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
{
struct ktermios tmp_termios;
......@@ -622,16 +616,16 @@ static void set_sgflags(struct ktermios *termios, int flags)
}
/**
* set_sgttyb - set legacy terminal values
* @tty: tty structure
* @sgttyb: pointer to old style terminal structure
* set_sgttyb - set legacy terminal values
* @tty: tty structure
* @sgttyb: pointer to old style terminal structure
*
* Updates a terminal from the legacy BSD style terminal information
* structure.
* Updates a terminal from the legacy BSD style terminal information structure.
*
* Locking: termios_rwsem
* Locking: &tty_struct->termios_rwsem
*
* Returns: 0 on success, an error otherwise
*/
static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
{
int retval;
......@@ -733,14 +727,17 @@ static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
#endif
/**
* tty_change_softcar - carrier change ioctl helper
* @tty: tty to update
* @enable: enable/disable CLOCAL
* tty_change_softcar - carrier change ioctl helper
* @tty: tty to update
* @enable: enable/disable %CLOCAL
*
* Perform a change to the CLOCAL state and call into the driver
* layer to make it visible. All done with the termios rwsem
* Perform a change to the %CLOCAL state and call into the driver layer to make
* it visible.
*
* Locking: &tty_struct->termios_rwsem.
*
* Returns: 0 on success, an error otherwise
*/
static int tty_change_softcar(struct tty_struct *tty, bool enable)
{
int ret = 0;
......@@ -760,16 +757,15 @@ static int tty_change_softcar(struct tty_struct *tty, bool enable)
}
/**
* tty_mode_ioctl - mode related ioctls
* @tty: tty for the ioctl
* @cmd: command
* @arg: ioctl argument
* tty_mode_ioctl - mode related ioctls
* @tty: tty for the ioctl
* @cmd: command
* @arg: ioctl argument
*
* Perform non line discipline specific mode control ioctls. This
* is designed to be called by line disciplines to ensure they provide
* consistent mode setting.
* Perform non-line discipline specific mode control ioctls. This is designed
* to be called by line disciplines to ensure they provide consistent mode
* setting.
*/
int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
{
struct tty_struct *real_tty;
......
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