LCOV - code coverage report
Current view: top level - include/linux - tty_driver.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 2 2 100.0 %
Date: 2017-01-25 Functions: 0 0 -

          Line data    Source code
       1             : #ifndef _LINUX_TTY_DRIVER_H
       2             : #define _LINUX_TTY_DRIVER_H
       3             : 
       4             : /*
       5             :  * This structure defines the interface between the low-level tty
       6             :  * driver and the tty routines.  The following routines can be
       7             :  * defined; unless noted otherwise, they are optional, and can be
       8             :  * filled in with a null pointer.
       9             :  *
      10             :  * struct tty_struct * (*lookup)(struct tty_driver *self, int idx)
      11             :  *
      12             :  *      Return the tty device corresponding to idx, NULL if there is not
      13             :  *      one currently in use and an ERR_PTR value on error. Called under
      14             :  *      tty_mutex (for now!)
      15             :  *
      16             :  *      Optional method. Default behaviour is to use the ttys array
      17             :  *
      18             :  * int (*install)(struct tty_driver *self, struct tty_struct *tty)
      19             :  *
      20             :  *      Install a new tty into the tty driver internal tables. Used in
      21             :  *      conjunction with lookup and remove methods.
      22             :  *
      23             :  *      Optional method. Default behaviour is to use the ttys array
      24             :  *
      25             :  * void (*remove)(struct tty_driver *self, struct tty_struct *tty)
      26             :  *
      27             :  *      Remove a closed tty from the tty driver internal tables. Used in
      28             :  *      conjunction with lookup and remove methods.
      29             :  *
      30             :  *      Optional method. Default behaviour is to use the ttys array
      31             :  *
      32             :  * int  (*open)(struct tty_struct * tty, struct file * filp);
      33             :  *
      34             :  *      This routine is called when a particular tty device is opened.
      35             :  *      This routine is mandatory; if this routine is not filled in,
      36             :  *      the attempted open will fail with ENODEV.
      37             :  *
      38             :  *      Required method.
      39             :  *     
      40             :  * void (*close)(struct tty_struct * tty, struct file * filp);
      41             :  *
      42             :  *      This routine is called when a particular tty device is closed.
      43             :  *
      44             :  *      Required method.
      45             :  *
      46             :  * void (*shutdown)(struct tty_struct * tty);
      47             :  *
      48             :  *      This routine is called synchronously when a particular tty device
      49             :  *      is closed for the last time freeing up the resources.
      50             :  *
      51             :  *
      52             :  * void (*cleanup)(struct tty_struct * tty);
      53             :  *
      54             :  *      This routine is called asynchronously when a particular tty device
      55             :  *      is closed for the last time freeing up the resources. This is
      56             :  *      actually the second part of shutdown for routines that might sleep.
      57             :  *
      58             :  *
      59             :  * int (*write)(struct tty_struct * tty,
      60             :  *               const unsigned char *buf, int count);
      61             :  *
      62             :  *      This routine is called by the kernel to write a series of
      63             :  *      characters to the tty device.  The characters may come from
      64             :  *      user space or kernel space.  This routine will return the
      65             :  *      number of characters actually accepted for writing.
      66             :  *
      67             :  *      Optional: Required for writable devices.
      68             :  *
      69             :  * int (*put_char)(struct tty_struct *tty, unsigned char ch);
      70             :  *
      71             :  *      This routine is called by the kernel to write a single
      72             :  *      character to the tty device.  If the kernel uses this routine,
      73             :  *      it must call the flush_chars() routine (if defined) when it is
      74             :  *      done stuffing characters into the driver.  If there is no room
      75             :  *      in the queue, the character is ignored.
      76             :  *
      77             :  *      Optional: Kernel will use the write method if not provided.
      78             :  *
      79             :  *      Note: Do not call this function directly, call tty_put_char
      80             :  *
      81             :  * void (*flush_chars)(struct tty_struct *tty);
      82             :  *
      83             :  *      This routine is called by the kernel after it has written a
      84             :  *      series of characters to the tty device using put_char().  
      85             :  *
      86             :  *      Optional:
      87             :  *
      88             :  *      Note: Do not call this function directly, call tty_driver_flush_chars
      89             :  * 
      90             :  * int  (*write_room)(struct tty_struct *tty);
      91             :  *
      92             :  *      This routine returns the numbers of characters the tty driver
      93             :  *      will accept for queuing to be written.  This number is subject
      94             :  *      to change as output buffers get emptied, or if the output flow
      95             :  *      control is acted.
      96             :  *
      97             :  *      Required if write method is provided else not needed.
      98             :  *
      99             :  *      Note: Do not call this function directly, call tty_write_room
     100             :  * 
     101             :  * int  (*ioctl)(struct tty_struct *tty, struct file * file,
     102             :  *          unsigned int cmd, unsigned long arg);
     103             :  *
     104             :  *      This routine allows the tty driver to implement
     105             :  *      device-specific ioctl's.  If the ioctl number passed in cmd
     106             :  *      is not recognized by the driver, it should return ENOIOCTLCMD.
     107             :  *
     108             :  *      Optional
     109             :  *
     110             :  * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
     111             :  *                      unsigned int cmd, unsigned long arg);
     112             :  *
     113             :  *      implement ioctl processing for 32 bit process on 64 bit system
     114             :  *
     115             :  *      Optional
     116             :  * 
     117             :  * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
     118             :  *
     119             :  *      This routine allows the tty driver to be notified when
     120             :  *      device's termios settings have changed.
     121             :  *
     122             :  *      Optional: Called under the termios lock
     123             :  *
     124             :  *
     125             :  * void (*set_ldisc)(struct tty_struct *tty);
     126             :  *
     127             :  *      This routine allows the tty driver to be notified when the
     128             :  *      device's termios settings have changed.
     129             :  *
     130             :  *      Optional: Called under BKL (currently)
     131             :  * 
     132             :  * void (*throttle)(struct tty_struct * tty);
     133             :  *
     134             :  *      This routine notifies the tty driver that input buffers for
     135             :  *      the line discipline are close to full, and it should somehow
     136             :  *      signal that no more characters should be sent to the tty.
     137             :  *
     138             :  *      Optional: Always invoke via tty_throttle(), called under the
     139             :  *      termios lock.
     140             :  * 
     141             :  * void (*unthrottle)(struct tty_struct * tty);
     142             :  *
     143             :  *      This routine notifies the tty drivers that it should signals
     144             :  *      that characters can now be sent to the tty without fear of
     145             :  *      overrunning the input buffers of the line disciplines.
     146             :  * 
     147             :  *      Optional: Always invoke via tty_unthrottle(), called under the
     148             :  *      termios lock.
     149             :  *
     150             :  * void (*stop)(struct tty_struct *tty);
     151             :  *
     152             :  *      This routine notifies the tty driver that it should stop
     153             :  *      outputting characters to the tty device.  
     154             :  *
     155             :  *      Optional:
     156             :  *
     157             :  *      Note: Call stop_tty not this method.
     158             :  * 
     159             :  * void (*start)(struct tty_struct *tty);
     160             :  *
     161             :  *      This routine notifies the tty driver that it resume sending
     162             :  *      characters to the tty device.
     163             :  *
     164             :  *      Optional:
     165             :  *
     166             :  *      Note: Call start_tty not this method.
     167             :  * 
     168             :  * void (*hangup)(struct tty_struct *tty);
     169             :  *
     170             :  *      This routine notifies the tty driver that it should hangup the
     171             :  *      tty device.
     172             :  *
     173             :  *      Optional:
     174             :  *
     175             :  * int (*break_ctl)(struct tty_stuct *tty, int state);
     176             :  *
     177             :  *      This optional routine requests the tty driver to turn on or
     178             :  *      off BREAK status on the RS-232 port.  If state is -1,
     179             :  *      then the BREAK status should be turned on; if state is 0, then
     180             :  *      BREAK should be turned off.
     181             :  *
     182             :  *      If this routine is implemented, the high-level tty driver will
     183             :  *      handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
     184             :  *      TIOCCBRK.
     185             :  *
     186             :  *      If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface
     187             :  *      will also be called with actual times and the hardware is expected
     188             :  *      to do the delay work itself. 0 and -1 are still used for on/off.
     189             :  *
     190             :  *      Optional: Required for TCSBRK/BRKP/etc handling.
     191             :  *
     192             :  * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
     193             :  * 
     194             :  *      This routine waits until the device has written out all of the
     195             :  *      characters in its transmitter FIFO.
     196             :  *
     197             :  *      Optional: If not provided the device is assumed to have no FIFO
     198             :  *
     199             :  *      Note: Usually correct to call tty_wait_until_sent
     200             :  *
     201             :  * void (*send_xchar)(struct tty_struct *tty, char ch);
     202             :  *
     203             :  *      This routine is used to send a high-priority XON/XOFF
     204             :  *      character to the device.
     205             :  *
     206             :  *      Optional: If not provided then the write method is called under
     207             :  *      the atomic write lock to keep it serialized with the ldisc.
     208             :  *
     209             :  * int (*resize)(struct tty_struct *tty, struct winsize *ws)
     210             :  *
     211             :  *      Called when a termios request is issued which changes the
     212             :  *      requested terminal geometry.
     213             :  *
     214             :  *      Optional: the default action is to update the termios structure
     215             :  *      without error. This is usually the correct behaviour. Drivers should
     216             :  *      not force errors here if they are not resizable objects (eg a serial
     217             :  *      line). See tty_do_resize() if you need to wrap the standard method
     218             :  *      in your own logic - the usual case.
     219             :  *
     220             :  * void (*set_termiox)(struct tty_struct *tty, struct termiox *new);
     221             :  *
     222             :  *      Called when the device receives a termiox based ioctl. Passes down
     223             :  *      the requested data from user space. This method will not be invoked
     224             :  *      unless the tty also has a valid tty->termiox pointer.
     225             :  *
     226             :  *      Optional: Called under the termios lock
     227             :  */
     228             : 
     229             : #include <linux/fs.h>
     230             : #include <linux/list.h>
     231             : #include <linux/cdev.h>
     232             : 
     233             : struct tty_struct;
     234             : struct tty_driver;
     235             : 
     236             : struct tty_operations {
     237             :         struct tty_struct * (*lookup)(struct tty_driver *driver,
     238             :                         struct inode *inode, int idx);
     239             :         int  (*install)(struct tty_driver *driver, struct tty_struct *tty);
     240             :         void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
     241             :         int  (*open)(struct tty_struct * tty, struct file * filp);
     242             :         void (*close)(struct tty_struct * tty, struct file * filp);
     243             :         void (*shutdown)(struct tty_struct *tty);
     244             :         void (*cleanup)(struct tty_struct *tty);
     245             :         int  (*write)(struct tty_struct * tty,
     246             :                       const unsigned char *buf, int count);
     247             :         int  (*put_char)(struct tty_struct *tty, unsigned char ch);
     248             :         void (*flush_chars)(struct tty_struct *tty);
     249             :         int  (*write_room)(struct tty_struct *tty);
     250             :         int  (*chars_in_buffer)(struct tty_struct *tty);
     251             :         int  (*ioctl)(struct tty_struct *tty, struct file * file,
     252             :                     unsigned int cmd, unsigned long arg);
     253             :         long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
     254             :                              unsigned int cmd, unsigned long arg);
     255             :         void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
     256             :         void (*throttle)(struct tty_struct * tty);
     257             :         void (*unthrottle)(struct tty_struct * tty);
     258             :         void (*stop)(struct tty_struct *tty);
     259             :         void (*start)(struct tty_struct *tty);
     260             :         void (*hangup)(struct tty_struct *tty);
     261             :         int (*break_ctl)(struct tty_struct *tty, int state);
     262             :         void (*flush_buffer)(struct tty_struct *tty);
     263             :         void (*set_ldisc)(struct tty_struct *tty);
     264             :         void (*wait_until_sent)(struct tty_struct *tty, int timeout);
     265             :         void (*send_xchar)(struct tty_struct *tty, char ch);
     266             :         int (*tiocmget)(struct tty_struct *tty, struct file *file);
     267             :         int (*tiocmset)(struct tty_struct *tty, struct file *file,
     268             :                         unsigned int set, unsigned int clear);
     269             :         int (*resize)(struct tty_struct *tty, struct winsize *ws);
     270             :         int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
     271             : #ifdef CONFIG_CONSOLE_POLL
     272             :         int (*poll_init)(struct tty_driver *driver, int line, char *options);
     273             :         int (*poll_get_char)(struct tty_driver *driver, int line);
     274             :         void (*poll_put_char)(struct tty_driver *driver, int line, char ch);
     275             : #endif
     276             :         const struct file_operations *proc_fops;
     277             : };
     278           2 : 
     279             : struct tty_driver {
     280             :         int     magic;          /* magic number for this structure */
     281             :         struct kref kref;       /* Reference management */
     282             :         struct cdev cdev;
     283             :         struct module   *owner;
     284             :         const char      *driver_name;
     285             :         const char      *name;
     286             :         int     name_base;      /* offset of printed name */
     287             :         int     major;          /* major device number */
     288             :         int     minor_start;    /* start of minor device number */
     289             :         int     minor_num;      /* number of *possible* devices */
     290             :         int     num;            /* number of devices allocated */
     291             :         short   type;           /* type of tty driver */
     292             :         short   subtype;        /* subtype of tty driver */
     293             :         struct ktermios init_termios; /* Initial termios */
     294             :         int     flags;          /* tty driver flags */
     295             :         struct proc_dir_entry *proc_entry; /* /proc fs entry */
     296             :         struct tty_driver *other; /* only used for the PTY driver */
     297             : 
     298             :         /*
     299             :          * Pointer to the tty data structures
     300             :          */
     301             :         struct tty_struct **ttys;
     302             :         struct ktermios **termios;
     303             :         struct ktermios **termios_locked;
     304             :         void *driver_state;
     305             : 
     306             :         /*
     307             :          * Driver methods
     308             :          */
     309             : 
     310             :         const struct tty_operations *ops;
     311             :         struct list_head tty_drivers;
     312             : };
     313             : 
     314             : extern struct list_head tty_drivers;
     315             : 
     316             : extern struct tty_driver *alloc_tty_driver(int lines);
     317             : extern void put_tty_driver(struct tty_driver *driver);
     318             : extern void tty_set_operations(struct tty_driver *driver,
     319             :                         const struct tty_operations *op);
     320             : extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
     321             : 
     322             : extern void tty_driver_kref_put(struct tty_driver *driver);
     323             : 
     324             : static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
     325             : {
     326             :         kref_get(&d->kref);
     327             :         return d;
     328             : }
     329           1 : 
     330             : /* tty driver magic number */
     331             : #define TTY_DRIVER_MAGIC                0x5402
     332             : 
     333             : /*
     334             :  * tty driver flags
     335             :  * 
     336             :  * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
     337             :  *      termios setting when the last process has closed the device.
     338             :  *      Used for PTY's, in particular.
     339             :  * 
     340             :  * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
     341             :  *      guarantee never not to set any special character handling
     342             :  *      flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
     343             :  *      !INPCK)).  That is, if there is no reason for the driver to
     344             :  *      send notifications of parity and break characters up to the
     345             :  *      line driver, it won't do so.  This allows the line driver to
     346             :  *      optimize for this case if this flag is set.  (Note that there
     347             :  *      is also a promise, if the above case is true, not to signal
     348             :  *      overruns, either.)
     349             :  *
     350             :  * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
     351             :  *      to be registered with a call to tty_register_driver() when the
     352             :  *      device is found in the system and unregistered with a call to
     353             :  *      tty_unregister_device() so the devices will be show up
     354             :  *      properly in sysfs.  If not set, driver->num entries will be
     355             :  *      created by the tty core in sysfs when tty_register_driver() is
     356             :  *      called.  This is to be used by drivers that have tty devices
     357             :  *      that can appear and disappear while the main tty driver is
     358             :  *      registered with the tty core.
     359             :  *
     360             :  * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
     361             :  *      use dynamic memory keyed through the devpts filesystem.  This
     362             :  *      is only applicable to the pty driver.
     363             :  *
     364             :  * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass
     365             :  *      the requested timeout to the caller instead of using a simple
     366             :  *      on/off interface.
     367             :  *
     368             :  */
     369             : #define TTY_DRIVER_INSTALLED            0x0001
     370             : #define TTY_DRIVER_RESET_TERMIOS        0x0002
     371             : #define TTY_DRIVER_REAL_RAW             0x0004
     372             : #define TTY_DRIVER_DYNAMIC_DEV          0x0008
     373             : #define TTY_DRIVER_DEVPTS_MEM           0x0010
     374             : #define TTY_DRIVER_HARDWARE_BREAK       0x0020
     375             : 
     376             : /* tty driver types */
     377             : #define TTY_DRIVER_TYPE_SYSTEM          0x0001
     378             : #define TTY_DRIVER_TYPE_CONSOLE         0x0002
     379             : #define TTY_DRIVER_TYPE_SERIAL          0x0003
     380             : #define TTY_DRIVER_TYPE_PTY             0x0004
     381             : #define TTY_DRIVER_TYPE_SCC             0x0005  /* scc driver */
     382             : #define TTY_DRIVER_TYPE_SYSCONS         0x0006
     383             : 
     384             : /* system subtypes (magic, used by tty_io.c) */
     385             : #define SYSTEM_TYPE_TTY                 0x0001
     386             : #define SYSTEM_TYPE_CONSOLE             0x0002
     387             : #define SYSTEM_TYPE_SYSCONS             0x0003
     388             : #define SYSTEM_TYPE_SYSPTMX             0x0004
     389             : 
     390             : /* pty subtypes (magic, used by tty_io.c) */
     391             : #define PTY_TYPE_MASTER                 0x0001
     392             : #define PTY_TYPE_SLAVE                  0x0002
     393             : 
     394             : /* serial subtype definitions */
     395             : #define SERIAL_TYPE_NORMAL      1
     396             : 
     397             : #endif /* #ifdef _LINUX_TTY_DRIVER_H */

Generated by: LCOV version 1.10