include/linux/tty_driver.h

   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  * int  (*open)(struct tty_struct * tty, struct file * filp);
  11  *
  12  *      This routine is called when a particular tty device is opened.
  13  *      This routine is mandatory; if this routine is not filled in,
  14  *      the attempted open will fail with ENODEV.
  15  *
  16  * void (*close)(struct tty_struct * tty, struct file * filp);
  17  *
  18  *      This routine is called when a particular tty device is closed.
  19  *
  20  * int (*write)(struct tty_struct * tty,
  21  *               const unsigned char *buf, int count);
  22  *
  23  *      This routine is called by the kernel to write a series of
  24  *      characters to the tty device.  The characters may come from
  25  *      user space or kernel space.  This routine will return the
  26  *      number of characters actually accepted for writing.  This
  27  *      routine is mandatory.
  28  *
  29  * void (*put_char)(struct tty_struct *tty, unsigned char ch);
  30  *
  31  *      This routine is called by the kernel to write a single
  32  *      character to the tty device.  If the kernel uses this routine,
  33  *      it must call the flush_chars() routine (if defined) when it is
  34  *      done stuffing characters into the driver.  If there is no room
  35  *      in the queue, the character is ignored.
  36  *
  37  * void (*flush_chars)(struct tty_struct *tty);
  38  *
  39  *      This routine is called by the kernel after it has written a
  40  *      series of characters to the tty device using put_char().
  41  *
  42  * int  (*write_room)(struct tty_struct *tty);
  43  *
  44  *      This routine returns the numbers of characters the tty driver
  45  *      will accept for queuing to be written.  This number is subject
  46  *      to change as output buffers get emptied, or if the output flow
  47  *      control is acted.
  48  *
  49  * int  (*ioctl)(struct tty_struct *tty, struct file * file,
  50  *          unsigned int cmd, unsigned long arg);
  51  *
  52  *      This routine allows the tty driver to implement
  53  *      device-specific ioctl's.  If the ioctl number passed in cmd
  54  *      is not recognized by the driver, it should return ENOIOCTLCMD.
  55  *
  56  * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
  57  *                      unsigned int cmd, unsigned long arg);
  58  *
  59  *      implement ioctl processing for 32 bit process on 64 bit system
  60  *
  61  * void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
  62  *
  63  *      This routine allows the tty driver to be notified when
  64  *      device's termios settings have changed.  Note that a
  65  *      well-designed tty driver should be prepared to accept the case
  66  *      where old == NULL, and try to do something rational.
  67  *
  68  * void (*set_ldisc)(struct tty_struct *tty);
  69  *
  70  *      This routine allows the tty driver to be notified when the
  71  *      device's termios settings have changed.
  72  *
  73  * void (*throttle)(struct tty_struct * tty);
  74  *
  75  *      This routine notifies the tty driver that input buffers for
  76  *      the line discipline are close to full, and it should somehow
  77  *      signal that no more characters should be sent to the tty.
  78  *
  79  * void (*unthrottle)(struct tty_struct * tty);
  80  *
  81  *      This routine notifies the tty drivers that it should signals
  82  *      that characters can now be sent to the tty without fear of
  83  *      overrunning the input buffers of the line disciplines.
  84  *
  85  * void (*stop)(struct tty_struct *tty);
  86  *
  87  *      This routine notifies the tty driver that it should stop
  88  *      outputting characters to the tty device.
  89  *
  90  * void (*start)(struct tty_struct *tty);
  91  *
  92  *      This routine notifies the tty driver that it resume sending
  93  *      characters to the tty device.
  94  *
  95  * void (*hangup)(struct tty_struct *tty);
  96  *
  97  *      This routine notifies the tty driver that it should hangup the
  98  *      tty device.
  99  *
 100  * void (*break_ctl)(struct tty_stuct *tty, int state);
 101  *
 102  *      This optional routine requests the tty driver to turn on or
 103  *      off BREAK status on the RS-232 port.  If state is -1,
 104  *      then the BREAK status should be turned on; if state is 0, then
 105  *      BREAK should be turned off.
 106  *
 107  *      If this routine is implemented, the high-level tty driver will
 108  *      handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK,
 109  *      TIOCCBRK.  Otherwise, these ioctls will be passed down to the
 110  *      driver to handle.
 111  *
 112  * void (*wait_until_sent)(struct tty_struct *tty, int timeout);
 113  *
 114  *      This routine waits until the device has written out all of the
 115  *      characters in its transmitter FIFO.
 116  *
 117  * void (*send_xchar)(struct tty_struct *tty, char ch);
 118  *
 119  *      This routine is used to send a high-priority XON/XOFF
 120  *      character to the device.
 121  */
 122
 123 #include <linux/fs.h>
 124 #include <linux/list.h>
 125 #include <linux/cdev.h>
 126
 127 struct tty_struct;
 128
 129 struct tty_operations {
 130         int  (*open)(struct tty_struct * tty, struct file * filp);
 131         void (*close)(struct tty_struct * tty, struct file * filp);
 132         int  (*write)(struct tty_struct * tty,
 133                       const unsigned char *buf, int count);
 134         void (*put_char)(struct tty_struct *tty, unsigned char ch);
 135         void (*flush_chars)(struct tty_struct *tty);
 136         int  (*write_room)(struct tty_struct *tty);
 137         int  (*chars_in_buffer)(struct tty_struct *tty);
 138         int  (*ioctl)(struct tty_struct *tty, struct file * file,
 139                     unsigned int cmd, unsigned long arg);
 140         long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
 141                              unsigned int cmd, unsigned long arg);
 142         void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
 143         void (*throttle)(struct tty_struct * tty);
 144         void (*unthrottle)(struct tty_struct * tty);
 145         void (*stop)(struct tty_struct *tty);
 146         void (*start)(struct tty_struct *tty);
 147         void (*hangup)(struct tty_struct *tty);
 148         void (*break_ctl)(struct tty_struct *tty, int state);
 149         void (*flush_buffer)(struct tty_struct *tty);
 150         void (*set_ldisc)(struct tty_struct *tty);
 151         void (*wait_until_sent)(struct tty_struct *tty, int timeout);
 152         void (*send_xchar)(struct tty_struct *tty, char ch);
 153         int (*read_proc)(char *page, char **start, off_t off,
 154                           int count, int *eof, void *data);
 155         int (*write_proc)(struct file *file, const char __user *buffer,
 156                           unsigned long count, void *data);
 157         int (*tiocmget)(struct tty_struct *tty, struct file *file);
 158         int (*tiocmset)(struct tty_struct *tty, struct file *file,
 159                         unsigned int set, unsigned int clear);
 160 };
 161
 162 struct tty_driver {
 163         int     magic;          /* magic number for this structure */
 164         struct cdev cdev;
 165         struct module   *owner;
 166         const char      *driver_name;
 167         const char      *name;
 168         int     name_base;      /* offset of printed name */
 169         int     major;          /* major device number */
 170         int     minor_start;    /* start of minor device number */
 171         int     minor_num;      /* number of *possible* devices */
 172         int     num;            /* number of devices allocated */
 173         short   type;           /* type of tty driver */
 174         short   subtype;        /* subtype of tty driver */
 175         struct ktermios init_termios; /* Initial termios */
 176         int     flags;          /* tty driver flags */
 177         int     refcount;       /* for loadable tty drivers */
 178         struct proc_dir_entry *proc_entry; /* /proc fs entry */
 179         struct tty_driver *other; /* only used for the PTY driver */
 180
 181         /*
 182          * Pointer to the tty data structures
 183          */
 184         struct tty_struct **ttys;
 185         struct ktermios **termios;
 186         struct ktermios **termios_locked;
 187         void *driver_state;     /* only used for the PTY driver */
 188
 189         /*
 190          * Interface routines from the upper tty layer to the tty
 191          * driver.      Will be replaced with struct tty_operations.
 192          */
 193         int  (*open)(struct tty_struct * tty, struct file * filp);
 194         void (*close)(struct tty_struct * tty, struct file * filp);
 195         int  (*write)(struct tty_struct * tty,
 196                       const unsigned char *buf, int count);
 197         void (*put_char)(struct tty_struct *tty, unsigned char ch);
 198         void (*flush_chars)(struct tty_struct *tty);
 199         int  (*write_room)(struct tty_struct *tty);
 200         int  (*chars_in_buffer)(struct tty_struct *tty);
 201         int  (*ioctl)(struct tty_struct *tty, struct file * file,
 202                     unsigned int cmd, unsigned long arg);
 203         long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
 204                              unsigned int cmd, unsigned long arg);
 205         void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
 206         void (*throttle)(struct tty_struct * tty);
 207         void (*unthrottle)(struct tty_struct * tty);
 208         void (*stop)(struct tty_struct *tty);
 209         void (*start)(struct tty_struct *tty);
 210         void (*hangup)(struct tty_struct *tty);
 211         void (*break_ctl)(struct tty_struct *tty, int state);
 212         void (*flush_buffer)(struct tty_struct *tty);
 213         void (*set_ldisc)(struct tty_struct *tty);
 214         void (*wait_until_sent)(struct tty_struct *tty, int timeout);
 215         void (*send_xchar)(struct tty_struct *tty, char ch);
 216         int (*read_proc)(char *page, char **start, off_t off,
 217                           int count, int *eof, void *data);
 218         int (*write_proc)(struct file *file, const char __user *buffer,
 219                           unsigned long count, void *data);
 220         int (*tiocmget)(struct tty_struct *tty, struct file *file);
 221         int (*tiocmset)(struct tty_struct *tty, struct file *file,
 222                         unsigned int set, unsigned int clear);
 223
 224         struct list_head tty_drivers;
 225 };
 226
 227 extern struct list_head tty_drivers;
 228
 229 struct tty_driver *alloc_tty_driver(int lines);
 230 void put_tty_driver(struct tty_driver *driver);
 231 void tty_set_operations(struct tty_driver *driver,
 232                         const struct tty_operations *op);
 233
 234 /* tty driver magic number */
 235 #define TTY_DRIVER_MAGIC                0x5402
 236
 237 /*
 238  * tty driver flags
 239  *
 240  * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the
 241  *      termios setting when the last process has closed the device.
 242  *      Used for PTY's, in particular.
 243  *
 244  * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
 245  *      guarantee never not to set any special character handling
 246  *      flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
 247  *      !INPCK)).  That is, if there is no reason for the driver to
 248  *      send notifications of parity and break characters up to the
 249  *      line driver, it won't do so.  This allows the line driver to
 250  *      optimize for this case if this flag is set.  (Note that there
 251  *      is also a promise, if the above case is true, not to signal
 252  *      overruns, either.)
 253  *
 254  * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need
 255  *      to be registered with a call to tty_register_driver() when the
 256  *      device is found in the system and unregistered with a call to
 257  *      tty_unregister_device() so the devices will be show up
 258  *      properly in sysfs.  If not set, driver->num entries will be
 259  *      created by the tty core in sysfs when tty_register_driver() is
 260  *      called.  This is to be used by drivers that have tty devices
 261  *      that can appear and disappear while the main tty driver is
 262  *      registered with the tty core.
 263  *
 264  * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead
 265  *      use dynamic memory keyed through the devpts filesystem.  This
 266  *      is only applicable to the pty driver.
 267  */
 268 #define TTY_DRIVER_INSTALLED            0x0001
 269 #define TTY_DRIVER_RESET_TERMIOS        0x0002
 270 #define TTY_DRIVER_REAL_RAW             0x0004
 271 #define TTY_DRIVER_DYNAMIC_DEV          0x0008
 272 #define TTY_DRIVER_DEVPTS_MEM           0x0010
 273
 274 /* tty driver types */
 275 #define TTY_DRIVER_TYPE_SYSTEM          0x0001
 276 #define TTY_DRIVER_TYPE_CONSOLE         0x0002
 277 #define TTY_DRIVER_TYPE_SERIAL          0x0003
 278 #define TTY_DRIVER_TYPE_PTY             0x0004
 279 #define TTY_DRIVER_TYPE_SCC             0x0005  /* scc driver */
 280 #define TTY_DRIVER_TYPE_SYSCONS         0x0006
 281
 282 /* system subtypes (magic, used by tty_io.c) */
 283 #define SYSTEM_TYPE_TTY                 0x0001
 284 #define SYSTEM_TYPE_CONSOLE             0x0002
 285 #define SYSTEM_TYPE_SYSCONS             0x0003
 286 #define SYSTEM_TYPE_SYSPTMX             0x0004
 287
 288 /* pty subtypes (magic, used by tty_io.c) */
 289 #define PTY_TYPE_MASTER                 0x0001
 290 #define PTY_TYPE_SLAVE                  0x0002
 291
 292 /* serial subtype definitions */
 293 #define SERIAL_TYPE_NORMAL      1
 294
 295 #endif /* #ifdef _LINUX_TTY_DRIVER_H */