#ifndef _LINUX_TTY_DRIVER_H
#define _LINUX_TTY_DRIVER_H
-/*
- * This structure defines the interface between the low-level tty
- * driver and the tty routines. The following routines can be
- * defined; unless noted otherwise, they are optional, and can be
- * filled in with a null pointer.
+#include <linux/export.h>
+#include <linux/fs.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/cdev.h>
+#include <linux/termios.h>
+#include <linux/seq_file.h>
+
+struct tty_struct;
+struct tty_driver;
+struct serial_icounter_struct;
+struct serial_struct;
+
+/**
+ * struct tty_operations -- interface between driver and tty
*
- * struct tty_struct * (*lookup)(struct tty_driver *self, struct file *, int idx)
+ * @lookup: ``struct tty_struct *()(struct tty_driver *self, struct file *,
+ * int idx)``
*
- * Return the tty device corresponding to idx, NULL if there is not
- * one currently in use and an ERR_PTR value on error. Called under
- * tty_mutex (for now!)
+ * Return the tty device corresponding to @idx, %NULL if there is not
+ * one currently in use and an %ERR_PTR value on error. Called under
+ * %tty_mutex (for now!)
*
- * Optional method. Default behaviour is to use the ttys array
+ * Optional method. Default behaviour is to use the @self->ttys array.
*
- * int (*install)(struct tty_driver *self, struct tty_struct *tty)
+ * @install: ``int ()(struct tty_driver *self, struct tty_struct *tty)``
*
- * Install a new tty into the tty driver internal tables. Used in
- * conjunction with lookup and remove methods.
+ * Install a new @tty into the @self's internal tables. Used in
+ * conjunction with @lookup and @remove methods.
*
- * Optional method. Default behaviour is to use the ttys array
+ * Optional method. Default behaviour is to use the @self->ttys array.
*
- * void (*remove)(struct tty_driver *self, struct tty_struct *tty)
+ * @remove: ``void ()(struct tty_driver *self, struct tty_struct *tty)``
*
- * Remove a closed tty from the tty driver internal tables. Used in
- * conjunction with lookup and remove methods.
+ * Remove a closed @tty from the @self's internal tables. Used in
+ * conjunction with @lookup and @remove methods.
*
- * Optional method. Default behaviour is to use the ttys array
+ * Optional method. Default behaviour is to use the @self->ttys array.
*
- * int (*open)(struct tty_struct * tty, struct file * filp);
+ * @open: ``int ()(struct tty_struct *tty, struct file *)``
*
- * This routine is called when a particular tty device is opened.
- * This routine is mandatory; if this routine is not filled in,
- * the attempted open will fail with ENODEV.
+ * This routine is called when a particular @tty device is opened. This
+ * routine is mandatory; if this routine is not filled in, the attempted
+ * open will fail with %ENODEV.
*
* Required method. Called with tty lock held.
*
- * void (*close)(struct tty_struct * tty, struct file * filp);
+ * @close: ``void ()(struct tty_struct *tty, struct file *)``
*
- * This routine is called when a particular tty device is closed.
- * Note: called even if the corresponding open() failed.
+ * This routine is called when a particular @tty device is closed.
+ *
+ * Remark: called even if the corresponding @open() failed.
*
* Required method. Called with tty lock held.
*
- * void (*shutdown)(struct tty_struct * tty);
+ * @shutdown: ``void ()(struct tty_struct *tty)``
*
- * This routine is called under the tty lock when a particular tty device
- * is closed for the last time. It executes before the tty resources
- * are freed so may execute while another function holds a tty kref.
+ * This routine is called under the tty lock when a particular @tty device
+ * is closed for the last time. It executes before the @tty resources
+ * are freed so may execute while another function holds a @tty kref.
*
- * void (*cleanup)(struct tty_struct * tty);
+ * @cleanup: ``void ()(struct tty_struct *tty)``
*
- * This routine is called asynchronously when a particular tty device
+ * This routine is called asynchronously when a particular @tty device
* is closed for the last time freeing up the resources. This is
* actually the second part of shutdown for routines that might sleep.
*
+ * @write: ``int ()(struct tty_struct *tty, const unsigned char *buf,
+ * int count)``
*
- * int (*write)(struct tty_struct * tty,
- * const unsigned char *buf, int count);
- *
- * This routine is called by the kernel to write a series of
- * characters to the tty device. The characters may come from
- * user space or kernel space. This routine will return the
+ * This routine is called by the kernel to write a series (@count) of
+ * characters (@buf) to the @tty device. The characters may come from
+ * user space or kernel space. This routine will return the
* number of characters actually accepted for writing.
*
* Optional: Required for writable devices.
*
- * int (*put_char)(struct tty_struct *tty, unsigned char ch);
+ * @put_char: ``int ()(struct tty_struct *tty, unsigned char ch)``
*
- * This routine is called by the kernel to write a single
- * character to the tty device. If the kernel uses this routine,
- * it must call the flush_chars() routine (if defined) when it is
- * done stuffing characters into the driver. If there is no room
- * in the queue, the character is ignored.
+ * This routine is called by the kernel to write a single character @ch to
+ * the @tty device. If the kernel uses this routine, it must call the
+ * @flush_chars() routine (if defined) when it is done stuffing characters
+ * into the driver. If there is no room in the queue, the character is
+ * ignored.
*
- * Optional: Kernel will use the write method if not provided.
+ * Optional: Kernel will use the @write method if not provided. Do not
+ * call this function directly, call tty_put_char().
*
- * Note: Do not call this function directly, call tty_put_char
+ * @flush_chars: ``void ()(struct tty_struct *tty)``
*
- * void (*flush_chars)(struct tty_struct *tty);
+ * This routine is called by the kernel after it has written a
+ * series of characters to the tty device using @put_char().
*
- * This routine is called by the kernel after it has written a
- * series of characters to the tty device using put_char().
+ * Optional. Do not call this function directly, call
+ * tty_driver_flush_chars().
*
- * Optional:
+ * @write_room: ``unsigned int ()(struct tty_struct *tty)``
*
- * Note: Do not call this function directly, call tty_driver_flush_chars
- *
- * unsigned int (*write_room)(struct tty_struct *tty);
- *
- * This routine returns the numbers of characters the tty driver
- * will accept for queuing to be written. This number is subject
- * to change as output buffers get emptied, or if the output flow
+ * This routine returns the numbers of characters the @tty driver
+ * will accept for queuing to be written. This number is subject
+ * to change as output buffers get emptied, or if the output flow
* control is acted.
*
- * Required if write method is provided else not needed.
+ * Required if @write method is provided else not needed. Do not call this
+ * function directly, call tty_write_room()
*
- * Note: Do not call this function directly, call tty_write_room
- *
- * int (*ioctl)(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
+ * @chars_in_buffer: ``unsigned int ()(struct tty_struct *tty)``
*
- * This routine allows the tty driver to implement
- * device-specific ioctls. If the ioctl number passed in cmd
- * is not recognized by the driver, it should return ENOIOCTLCMD.
+ * This routine returns the number of characters in the device private
+ * output queue. Used in tty_wait_until_sent() and for poll()
+ * implementation.
*
- * Optional
+ * Optional: if not provided, it is assumed there is no queue on the
+ * device. Do not call this function directly, call tty_chars_in_buffer().
*
- * long (*compat_ioctl)(struct tty_struct *tty,,
- * unsigned int cmd, unsigned long arg);
+ * @ioctl: ``int ()(struct tty_struct *tty, unsigned int cmd,
+ * unsigned long arg)``
*
- * implement ioctl processing for 32 bit process on 64 bit system
+ * This routine allows the @tty driver to implement device-specific
+ * ioctls. If the ioctl number passed in @cmd is not recognized by the
+ * driver, it should return %ENOIOCTLCMD.
*
- * Optional
- *
- * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
+ * Optional.
*
- * This routine allows the tty driver to be notified when
- * device's termios settings have changed.
+ * @compat_ioctl: ``long ()(struct tty_struct *tty, unsigned int cmd,
+ * unsigned long arg)``
*
- * Optional: Called under the termios lock
+ * Implement ioctl processing for 32 bit process on 64 bit system.
*
+ * Optional.
*
- * void (*set_ldisc)(struct tty_struct *tty);
+ * @set_termios: ``void ()(struct tty_struct *tty, struct ktermios *old)``
*
- * This routine allows the tty driver to be notified when the
- * device's termios settings have changed.
+ * This routine allows the @tty driver to be notified when device's
+ * termios settings have changed.
*
- * Optional: Called under BKL (currently)
- *
- * void (*throttle)(struct tty_struct * tty);
+ * Optional: Called under the @tty->termios_rwsem.
*
- * This routine notifies the tty driver that input buffers for
- * the line discipline are close to full, and it should somehow
- * signal that no more characters should be sent to the tty.
+ * @set_ldisc: ``void ()(struct tty_struct *tty)``
*
- * Optional: Always invoke via tty_throttle_safe(), called under the
- * termios lock.
- *
- * void (*unthrottle)(struct tty_struct * tty);
+ * This routine allows the @tty driver to be notified when the device's
+ * line discipline is being changed.
*
- * This routine notifies the tty drivers that it should signals
- * that characters can now be sent to the tty without fear of
- * overrunning the input buffers of the line disciplines.
- *
- * Optional: Always invoke via tty_unthrottle(), called under the
- * termios lock.
+ * Optional. Called under the @tty->ldisc_sem and @tty->termios_rwsem.
*
- * void (*stop)(struct tty_struct *tty);
+ * @throttle: ``void ()(struct tty_struct *tty)``
*
- * This routine notifies the tty driver that it should stop
- * outputting characters to the tty device.
+ * This routine notifies the @tty driver that input buffers for the line
+ * discipline are close to full, and it should somehow signal that no more
+ * characters should be sent to the @tty.
*
- * Called with ->flow.lock held. Serialized with start() method.
+ * Optional: Always invoke via tty_throttle_safe(). Called under the
+ * @tty->termios_rwsem.
*
- * Optional:
+ * @unthrottle: ``void ()(struct tty_struct *tty)``
*
- * Note: Call stop_tty not this method.
- *
- * void (*start)(struct tty_struct *tty);
+ * This routine notifies the @tty driver that it should signal that
+ * characters can now be sent to the @tty without fear of overrunning the
+ * input buffers of the line disciplines.
*
- * This routine notifies the tty driver that it resume sending
+ * Optional. Always invoke via tty_unthrottle(). Called under the
+ * @tty->termios_rwsem.
+ *
+ * @stop: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine notifies the @tty driver that it should stop outputting
* characters to the tty device.
*
- * Called with ->flow.lock held. Serialized with stop() method.
+ * Called with @tty->flow.lock held. Serialized with @start() method.
*
- * Optional:
+ * Optional. Always invoke via stop_tty().
*
- * Note: Call start_tty not this method.
- *
- * void (*hangup)(struct tty_struct *tty);
+ * @start: ``void ()(struct tty_struct *tty)``
*
- * This routine notifies the tty driver that it should hang up the
- * tty device.
+ * This routine notifies the @tty driver that it resumed sending
+ * characters to the @tty device.
*
- * Optional:
+ * Called with @tty->flow.lock held. Serialized with stop() method.
*
- * Called with tty lock held.
+ * Optional. Always invoke via start_tty().
*
- * int (*break_ctl)(struct tty_struct *tty, int state);
+ * @hangup: ``void ()(struct tty_struct *tty)``
*
- * This optional routine requests the tty driver to turn on or
- * off BREAK status on the RS-232 port. If state is -1,
- * then the BREAK status should be turned on; if state is 0, then
- * BREAK should be turned off.
+ * This routine notifies the @tty driver that it should hang up the @tty
+ * device.
*
- * If this routine is implemented, the high-level tty driver will
- * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
- * TIOCCBRK.
+ * Optional. Called with tty lock held.
*
- * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
- * will also be called with actual times and the hardware is expected
- * to do the delay work itself. 0 and -1 are still used for on/off.
+ * @break_ctl: ``int ()(struct tty_struct *tty, int state)``
*
- * Optional: Required for TCSBRK/BRKP/etc handling.
+ * This optional routine requests the @tty driver to turn on or off BREAK
+ * status on the RS-232 port. If @state is -1, then the BREAK status
+ * should be turned on; if @state is 0, then BREAK should be turned off.
*
- * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
- *
- * This routine waits until the device has written out all of the
- * characters in its transmitter FIFO.
+ * If this routine is implemented, the high-level tty driver will handle
+ * the following ioctls: %TCSBRK, %TCSBRKP, %TIOCSBRK, %TIOCCBRK.
+ *
+ * If the driver sets %TTY_DRIVER_HARDWARE_BREAK in tty_alloc_driver(),
+ * then the interface will also be called with actual times and the
+ * hardware is expected to do the delay work itself. 0 and -1 are still
+ * used for on/off.
+ *
+ * Optional: Required for %TCSBRK/%BRKP/etc. handling.
+ *
+ * @flush_buffer: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine discards device private output buffer. Invoked on close,
+ * hangup, to implement %TCOFLUSH ioctl and similar.
+ *
+ * Optional: if not provided, it is assumed there is no queue on the
+ * device. Do not call this function directly, call
+ * tty_driver_flush_buffer().
+ *
+ * @wait_until_sent: ``void ()(struct tty_struct *tty, int timeout)``
+ *
+ * This routine waits until the device has written out all of the
+ * characters in its transmitter FIFO. Or until @timeout (in jiffies) is
+ * reached.
+ *
+ * Optional: If not provided, the device is assumed to have no FIFO.
+ * Usually correct to invoke via tty_wait_until_sent().
+ *
+ * @send_xchar: ``void ()(struct tty_struct *tty, char ch)``
+ *
+ * This routine is used to send a high-priority XON/XOFF character (@ch)
+ * to the @tty device.
*
- * Optional: If not provided the device is assumed to have no FIFO
+ * Optional: If not provided, then the @write method is called under
+ * the @tty->atomic_write_lock to keep it serialized with the ldisc.
*
- * Note: Usually correct to call tty_wait_until_sent
+ * @tiocmget: ``int ()(struct tty_struct *tty)``
*
- * void (*send_xchar)(struct tty_struct *tty, char ch);
+ * This routine is used to obtain the modem status bits from the @tty
+ * driver.
*
- * This routine is used to send a high-priority XON/XOFF
- * character to the device.
+ * Optional: If not provided, then %ENOTTY is returned from the %TIOCMGET
+ * ioctl. Do not call this function directly, call tty_tiocmget().
*
- * Optional: If not provided then the write method is called under
- * the atomic write lock to keep it serialized with the ldisc.
+ * @tiocmset: ``int ()(struct tty_struct *tty,
+ * unsigned int set, unsigned int clear)``
*
- * int (*resize)(struct tty_struct *tty, struct winsize *ws)
+ * This routine is used to set the modem status bits to the @tty driver.
+ * First, @clear bits should be cleared, then @set bits set.
*
- * Called when a termios request is issued which changes the
- * requested terminal geometry.
+ * Optional: If not provided, then %ENOTTY is returned from the %TIOCMSET
+ * ioctl. Do not call this function directly, call tty_tiocmset().
+ *
+ * @resize: ``int ()(struct tty_struct *tty, struct winsize *ws)``
+ *
+ * Called when a termios request is issued which changes the requested
+ * terminal geometry to @ws.
*
* Optional: the default action is to update the termios structure
* without error. This is usually the correct behaviour. Drivers should
- * not force errors here if they are not resizable objects (eg a serial
+ * not force errors here if they are not resizable objects (e.g. a serial
* line). See tty_do_resize() if you need to wrap the standard method
- * in your own logic - the usual case.
+ * in your own logic -- the usual case.
+ *
+ * @get_icount: ``int ()(struct tty_struct *tty,
+ * struct serial_icounter *icount)``
+ *
+ * Called when the @tty device receives a %TIOCGICOUNT ioctl. Passed a
+ * kernel structure @icount to complete.
+ *
+ * Optional: called only if provided, otherwise %ENOTTY will be returned.
+ *
+ * @get_serial: ``int ()(struct tty_struct *tty, struct serial_struct *p)``
+ *
+ * Called when the @tty device receives a %TIOCGSERIAL ioctl. Passed a
+ * kernel structure @p (&struct serial_struct) to complete.
+ *
+ * Optional: called only if provided, otherwise %ENOTTY will be returned.
+ * Do not call this function directly, call tty_tiocgserial().
+ *
+ * @set_serial: ``int ()(struct tty_struct *tty, struct serial_struct *p)``
+ *
+ * Called when the @tty device receives a %TIOCSSERIAL ioctl. Passed a
+ * kernel structure @p (&struct serial_struct) to set the values from.
+ *
+ * Optional: called only if provided, otherwise %ENOTTY will be returned.
+ * Do not call this function directly, call tty_tiocsserial().
+ *
+ * @show_fdinfo: ``void ()(struct tty_struct *tty, struct seq_file *m)``
+ *
+ * Called when the @tty device file descriptor receives a fdinfo request
+ * from VFS (to show in /proc/<pid>/fdinfo/). @m should be filled with
+ * information.
+ *
+ * Optional: called only if provided, otherwise nothing is written to @m.
+ * Do not call this function directly, call tty_show_fdinfo().
+ *
+ * @poll_init: ``int ()(struct tty_driver *driver, int line, char *options)``
+ *
+ * kgdboc support (Documentation/dev-tools/kgdb.rst). This routine is
+ * called to initialize the HW for later use by calling @poll_get_char or
+ * @poll_put_char.
+ *
+ * Optional: called only if provided, otherwise skipped as a non-polling
+ * driver.
+ *
+ * @poll_get_char: ``int ()(struct tty_driver *driver, int line)``
+ *
+ * kgdboc support (see @poll_init). @driver should read a character from a
+ * tty identified by @line and return it.
+ *
+ * Optional: called only if @poll_init provided.
*
- * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount);
+ * @poll_put_char: ``void ()(struct tty_driver *driver, int line, char ch)``
*
- * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
- * structure to complete. This method is optional and will only be called
- * if provided (otherwise ENOTTY will be returned).
+ * kgdboc support (see @poll_init). @driver should write character @ch to
+ * a tty identified by @line.
+ *
+ * Optional: called only if @poll_init provided.
+ *
+ * @proc_show: ``int ()(struct seq_file *m, void *driver)``
+ *
+ * Driver @driver (cast to &struct tty_driver) can show additional info in
+ * /proc/tty/driver/<driver_name>. It is enough to fill in the information
+ * into @m.
+ *
+ * Optional: called only if provided, otherwise no /proc entry created.
+ *
+ * This structure defines the interface between the low-level tty driver and
+ * the tty routines. These routines can be defined. Unless noted otherwise,
+ * they are optional, and can be filled in with a %NULL pointer.
*/
-
-#include <linux/export.h>
-#include <linux/fs.h>
-#include <linux/kref.h>
-#include <linux/list.h>
-#include <linux/cdev.h>
-#include <linux/termios.h>
-#include <linux/seq_file.h>
-
-struct tty_struct;
-struct tty_driver;
-struct serial_icounter_struct;
-struct serial_struct;
-
struct tty_operations {
struct tty_struct * (*lookup)(struct tty_driver *driver,
struct file *filp, int idx);
int (*poll_get_char)(struct tty_driver *driver, int line);
void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
#endif
- int (*proc_show)(struct seq_file *, void *);
+ int (*proc_show)(struct seq_file *m, void *driver);
} __randomize_layout;
/**
git.samba.org / sfrench / cifs-2.6.git / commitdiff