Linux 下串口驱动头文件之tty_driver.h

#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.
 *
 * struct tty_struct * (*lookup)(struct tty_driver *self, 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!)
 *
 * Optional method. Default behaviour is to use the ttys array
 *
 * int (*install)(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.
 *
 * Optional method. Default behaviour is to use the ttys array
 *
 * void (*remove)(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.
 *
 * Optional method. Default behaviour is to use the ttys array
 *
 * int  (*open)(struct tty_struct * tty, struct file * filp);
 *
 *  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.
 *     
 * void (*close)(struct tty_struct * tty, struct file * filp);
 *
 *  This routine is called when a particular tty device is closed.
 *
 * Required method.
 *
 * void (*shutdown)(struct tty_struct * tty);
 *
 *  This routine is called when a particular tty device is closed for
 * the last time freeing up the resources.
 *
 * 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
 * number of characters actually accepted for writing.
 *
 * Optional: Required for writable devices.
 *
 * int (*put_char)(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.
 *
 * Optional: Kernel will use the write method if not provided.
 *
 * Note: Do not call this function directly, call tty_put_char
 *
 * 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().  
 *
 * Optional:
 *
 * Note: Do not call this function directly, call tty_driver_flush_chars
 * 
 * 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
 * control is acted.
 *
 * Required if write method is provided else not needed.
 *
 * Note: Do not call this function directly, call tty_write_room
 * 
 * int  (*ioctl)(struct tty_struct *tty, struct file * file,
 *      unsigned int cmd, unsigned long arg);
 *
 *  This routine allows the tty driver to implement
 * device-specific ioctl's.  If the ioctl number passed in cmd
 *  is not recognized by the driver, it should return ENOIOCTLCMD.
 *
 * Optional
 *
 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
 *                  unsigned int cmd, unsigned long arg);
 *
 *  implement ioctl processing for 32 bit process on 64 bit system
 *
 * Optional
 * 
 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
 *
 *  This routine allows the tty driver to be notified when
 *  device's termios settings have changed.
 *
 * Optional: Called under the termios lock
 *
 *
 * void (*set_ldisc)(struct tty_struct *tty);
 *
 *  This routine allows the tty driver to be notified when the
 *  device's termios settings have changed.
 *
 * Optional: Called under BKL (currently)
 * 
 * void (*throttle)(struct tty_struct * tty);
 *
 *  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.
 *
 * Optional: Always invoke via tty_throttle();
 * 
 * void (*unthrottle)(struct tty_struct * tty);
 *
 *  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();
 *
 * void (*stop)(struct tty_struct *tty);
 *
 *  This routine notifies the tty driver that it should stop
 *  outputting characters to the tty device.  
 *
 * Optional:
 *
 * Note: Call stop_tty not this method.
 * 
 * void (*start)(struct tty_struct *tty);
 *
 *  This routine notifies the tty driver that it resume sending
 * characters to the tty device.
 *
 * Optional:
 *
 * Note: Call start_tty not this method.
 * 
 * void (*hangup)(struct tty_struct *tty);
 *
 *  This routine notifies the tty driver that it should hangup the
 *  tty device.
 *
 * Optional:
 *
 * int (*break_ctl)(struct tty_stuct *tty, int state);
 *
 *  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.
 *
 *  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 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.
 *
 * 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.
 *
 * Optional: If not provided the device is assumed to have no FIFO
 *
 * Note: Usually correct to call tty_wait_until_sent
 *
 * void (*send_xchar)(struct tty_struct *tty, char ch);
 *
 *  This routine is used to send a high-priority XON/XOFF
 *  character to the device.
 *
 * Optional: If not provided then the write method is called under
 * the atomic write lock to keep it serialized with the ldisc.
 *
 * int (*resize)(struct tty_struct *tty, struct winsize *ws)
 *
 * Called when a termios request is issued which changes the
 * requested terminal geometry.
 *
 * 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
 * line). See tty_do_resize() if you need to wrap the standard method
 * in your own logic - the usual case.
 *
 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
 *
 * Called when the device receives a termiox based ioctl. Passes down
 * the requested data from user space. This method will not be invoked
 * unless the tty also has a valid tty->termiox pointer.
 *
 * Optional: Called under the termios lock
 */#include <linux/fs.h>
#include <linux/list.h>
#include <linux/cdev.h>struct tty_struct;
struct tty_driver;struct tty_operations {
 struct tty_struct * (*lookup)(struct tty_driver *driver,
   struct inode *inode, int idx);
 int  (*install)(struct tty_driver *driver, struct tty_struct *tty);
 void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
 int  (*open)(struct tty_struct * tty, struct file * filp);
 void (*close)(struct tty_struct * tty, struct file * filp);
 void (*shutdown)(struct tty_struct *tty);
 int  (*write)(struct tty_struct * tty,
        const unsigned char *buf, int count);
 int  (*put_char)(struct tty_struct *tty, unsigned char ch);
 void (*flush_chars)(struct tty_struct *tty);
 int  (*write_room)(struct tty_struct *tty);
 int  (*chars_in_buffer)(struct tty_struct *tty);
 int  (*ioctl)(struct tty_struct *tty, struct file * file,
      unsigned int cmd, unsigned long arg);
 long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
        unsigned int cmd, unsigned long arg);
 void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
 void (*throttle)(struct tty_struct * tty);
 void (*unthrottle)(struct tty_struct * tty);
 void (*stop)(struct tty_struct *tty);
 void (*start)(struct tty_struct *tty);
 void (*hangup)(struct tty_struct *tty);
 int (*break_ctl)(struct tty_struct *tty, int state);
 void (*flush_buffer)(struct tty_struct *tty);
 void (*set_ldisc)(struct tty_struct *tty);
 void (*wait_until_sent)(struct tty_struct *tty, int timeout);
 void (*send_xchar)(struct tty_struct *tty, char ch);
 int (*read_proc)(char *page, char **start, off_t off,
     int count, int *eof, void *data);
 int (*tiocmget)(struct tty_struct *tty, struct file *file);
 int (*tiocmset)(struct tty_struct *tty, struct file *file,
   unsigned int set, unsigned int clear);
 int (*resize)(struct tty_struct *tty, struct winsize *ws);
 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
#ifdef CONFIG_CONSOLE_POLL
 int (*poll_init)(struct tty_driver *driver, int line, char *options);
 int (*poll_get_char)(struct tty_driver *driver, int line);
 void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
#endif
};struct tty_driver {
 int magic;  /* magic number for this structure */
 struct kref kref; /* Reference management */
 struct cdev cdev;
 struct module *owner;
 const char *driver_name;
 const char *name;
 int name_base; /* offset of printed name */
 int major;  /* major device number */
 int minor_start; /* start of minor device number */
 int minor_num; /* number of *possible* devices */
 int num;  /* number of devices allocated */
 short type;  /* type of tty driver */
 short subtype; /* subtype of tty driver */
 struct ktermios init_termios; /* Initial termios */
 int flags;  /* tty driver flags */
 struct proc_dir_entry *proc_entry; /* /proc fs entry */
 struct tty_driver *other; /* only used for the PTY driver */ /*
  * Pointer to the tty data structures
  */
 struct tty_struct **ttys;
 struct ktermios **termios;
 struct ktermios **termios_locked;
 void *driver_state; /*
  * Driver methods
  */ const struct tty_operations *ops;
 struct list_head tty_drivers;
};extern struct list_head tty_drivers;
extern struct tty_driver *alloc_tty_driver(int lines);
extern void put_tty_driver(struct tty_driver *driver);
extern void tty_set_operations(struct tty_driver *driver,
   const struct tty_operations *op);
extern struct tty_driver *tty_find_polling_driver(char *name, int *line);extern void tty_driver_kref_put(struct tty_driver *driver);
extern inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
{
 kref_get(&d->kref);
 return d;
}/* tty driver magic number */
#define TTY_DRIVER_MAGIC  0x5402/*
 * tty driver flags
 * 
 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
 *  termios setting when the last process has closed the device.
 *  Used for PTY's, in particular.
 * 
 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
 *  guarantee never not to set any special character handling
 *  flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
 *  !INPCK)).  That is, if there is no reason for the driver to
 *  send notifications of parity and break characters up to the
 *  line driver, it won't do so.  This allows the line driver to
 * optimize for this case if this flag is set.  (Note that there
 *  is also a promise, if the above case is true, not to signal
 *  overruns, either.)
 *
 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
 * to be registered with a call to tty_register_driver() when the
 * device is found in the system and unregistered with a call to
 * tty_unregister_device() so the devices will be show up
 * properly in sysfs.  If not set, driver->num entries will be
 * created by the tty core in sysfs when tty_register_driver() is
 * called.  This is to be used by drivers that have tty devices
 * that can appear and disappear while the main tty driver is
 * registered with the tty core.
 *
 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
 * use dynamic memory keyed through the devpts filesystem.  This
 * is only applicable to the pty driver.
 *
 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
 * the requested timeout to the caller instead of using a simple
 * on/off interface.
 *
 */
#define TTY_DRIVER_INSTALLED  0x0001
#define TTY_DRIVER_RESET_TERMIOS 0x0002
#define TTY_DRIVER_REAL_RAW  0x0004
#define TTY_DRIVER_DYNAMIC_DEV  0x0008
#define TTY_DRIVER_DEVPTS_MEM  0x0010
#define TTY_DRIVER_HARDWARE_BREAK 0x0020/* tty driver types */
#define TTY_DRIVER_TYPE_SYSTEM  0x0001
#define TTY_DRIVER_TYPE_CONSOLE  0x0002
#define TTY_DRIVER_TYPE_SERIAL  0x0003
#define TTY_DRIVER_TYPE_PTY  0x0004
#define TTY_DRIVER_TYPE_SCC  0x0005 /* scc driver */
#define TTY_DRIVER_TYPE_SYSCONS  0x0006/* system subtypes (magic, used by tty_io.c) */
#define SYSTEM_TYPE_TTY   0x0001
#define SYSTEM_TYPE_CONSOLE  0x0002
#define SYSTEM_TYPE_SYSCONS  0x0003
#define SYSTEM_TYPE_SYSPTMX  0x0004/* pty subtypes (magic, used by tty_io.c) */
#define PTY_TYPE_MASTER   0x0001
#define PTY_TYPE_SLAVE   0x0002/* serial subtype definitions */
#define SERIAL_TYPE_NORMAL 1#endif /* #ifdef _LINUX_TTY_DRIVER_H */