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, int from_user, 21 * 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 queueing to be writen. 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 iotctl's. If the ioctl number passed in cmd 54 * is not recognized by the driver, it should return ENOIOCTLCMD. 55 * 56 * void (*set_termios)(struct tty_struct *tty, struct termios * old); 57 * 58 * This routine allows the tty driver to be notified when 59 * device's termios settings have changed. 60 * 61 * void (*throttle)(struct tty_struct * tty); 62 * 63 * This routine notifies the tty driver that input buffers for 64 * the line discpline are close to full, and it should somehow 65 * signal that no more characters should be sent to the tty. 66 * 67 * void (*unthrottle)(struct tty_struct * tty); 68 * 69 * This routine notifies the tty drivers that it should signals 70 * that characters can now be sent to the tty without fear of 71 * overrunning the input buffers of the line discplines. 72 * 73 * void (*stop)(struct tty_struct *tty); 74 * 75 * This routine notfies the tty driver that it should stop 76 * outputting characters to the tty device. 77 * 78 * void (*start)(struct tty_struct *tty); 79 * 80 * This routine notifies the tty driver that it resume sending 81 * characters to the tty device. 82 * 83 * void (*hangup)(struct tty_struct *tty); 84 * 85 * This routine notifies the tty driver that it should hangup the 86 * tty device. 87 * 88 */ 89 90 #include <linux/fs.h> 91 92 struct tty_driver { 93 int magic; /* magic number for this structure */ 94 char *name; 95 int name_base; /* offset of printed name */ 96 short major; /* major device number */ 97 short minor_start; /* start of minor device number*/ 98 short num; /* number of devices */ 99 short type; /* type of tty driver */ 100 short subtype; /* subtype of tty driver */ 101 struct termios init_termios; /* Initial termios */ 102 int flags; /* tty driver flags */ 103 int *refcount; /* for loadable tty drivers */ 104 struct tty_driver *other; /* only used for the PTY driver */ 105 106 /* 107 * Pointer to the tty data structures 108 */ 109 struct tty_struct **table; 110 struct termios **termios; 111 struct termios **termios_locked; 112 113 /* 114 * Interface routines from the upper tty layer to the tty 115 * driver. 116 */ 117 int (*open)(struct tty_struct * tty, struct file * filp); 118 void (*close)(struct tty_struct * tty, struct file * filp); 119 int (*write)(struct tty_struct * tty, int from_user, 120 unsigned char *buf, int count); 121 void (*put_char)(struct tty_struct *tty, unsigned char ch); 122 void (*flush_chars)(struct tty_struct *tty); 123 int (*write_room)(struct tty_struct *tty); 124 int (*chars_in_buffer)(struct tty_struct *tty); 125 int (*ioctl)(struct tty_struct *tty, struct file * file, 126 unsigned int cmd, unsigned long arg); 127 void (*set_termios)(struct tty_struct *tty, struct termios * old); 128 void (*throttle)(struct tty_struct * tty); 129 void (*unthrottle)(struct tty_struct * tty); 130 void (*stop)(struct tty_struct *tty); 131 void (*start)(struct tty_struct *tty); 132 void (*hangup)(struct tty_struct *tty); 133 void (*flush_buffer)(struct tty_struct *tty); 134 135 /* 136 * linked list pointers 137 */ 138 struct tty_driver *next; 139 struct tty_driver *prev; 140 }; 141 142 /* tty driver magic number */ 143 #define TTY_DRIVER_MAGIC 0x5402 144 145 /* 146 * tty driver flags 147 * 148 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 149 * termios setting when the last process has closed the device. 150 * Used for PTY's, in particular. 151 * 152 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 153 * guarantee never not to set any special character handling 154 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 155 * !INPCK)). That is, if there is no reason for the driver to 156 * send notifications of parity and break characters up to the 157 * line driver, it won't do so. This allows the line driver to 158 * optimize for this case if this flag is set. (Note that there 159 * is also a promise, if the above case is true, not to signal 160 * overruns, either.) 161 */ 162 #define TTY_DRIVER_INSTALLED 0x0001 163 #define TTY_DRIVER_RESET_TERMIOS 0x0002 164 #define TTY_DRIVER_REAL_RAW 0x0004 165 166 /* tty driver types */ 167 #define TTY_DRIVER_TYPE_SYSTEM 0x0001 168 #define TTY_DRIVER_TYPE_CONSOLE 0x0002 169 #define TTY_DRIVER_TYPE_SERIAL 0x0003 170 #define TTY_DRIVER_TYPE_PTY 0x0004 171 172 /* system subtypes (magic, used by tty_io.c) */ 173 #define SYSTEM_TYPE_TTY 0x0001 174 #define SYSTEM_TYPE_CONSOLE 0x0002 175 176 /* pty subtypes (magic, used by tty_io.c) */ 177 #define PTY_TYPE_MASTER 0x0001 178 #define PTY_TYPE_SLAVE 0x0002 179 180 #endif /* #ifdef _LINUX_TTY_DRIVER_H */