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 * 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 * 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. Note that a 60 * well-designed tty driver should be prepared to accept the case 61 * where old == NULL, and try to do something rational. 62 * 63 * void (*set_ldisc)(struct tty_struct *tty); 64 * 65 * This routine allows the tty driver to be notified when the 66 * device's termios settings have changed. 67 * 68 * void (*throttle)(struct tty_struct * tty); 69 * 70 * This routine notifies the tty driver that input buffers for 71 * the line discipline are close to full, and it should somehow 72 * signal that no more characters should be sent to the tty. 73 * 74 * void (*unthrottle)(struct tty_struct * tty); 75 * 76 * This routine notifies the tty drivers that it should signals 77 * that characters can now be sent to the tty without fear of 78 * overrunning the input buffers of the line disciplines. 79 * 80 * void (*stop)(struct tty_struct *tty); 81 * 82 * This routine notifies the tty driver that it should stop 83 * outputting characters to the tty device. 84 * 85 * void (*start)(struct tty_struct *tty); 86 * 87 * This routine notifies the tty driver that it resume sending 88 * characters to the tty device. 89 * 90 * void (*hangup)(struct tty_struct *tty); 91 * 92 * This routine notifies the tty driver that it should hangup the 93 * tty device. 94 * 95 * void (*break_ctl)(struct tty_stuct *tty, int state); 96 * 97 * This optional routine requests the tty driver to turn on or 98 * off BREAK status on the RS-232 port. If state is -1, 99 * then the BREAK status should be turned on; if state is 0, then 100 * BREAK should be turned off. 101 * 102 * If this routine is implemented, the high-level tty driver will 103 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, 104 * TIOCCBRK. Otherwise, these ioctls will be passed down to the 105 * driver to handle. 106 * 107 * void (*wait_until_sent)(struct tty_struct *tty, int timeout); 108 * 109 * This routine waits until the device has written out all of the 110 * characters in its transmitter FIFO. 111 * 112 * void (*send_xchar)(struct tty_struct *tty, char ch); 113 * 114 * This routine is used to send a high-priority XON/XOFF 115 * character to the device. 116 */ 117 118#include <linux/fs.h> 119 120struct tty_driver { 121 int magic; /* magic number for this structure */ 122 const char *driver_name; 123 const char *name; 124 int name_base; /* offset of printed name */ 125 short major; /* major device number */ 126 short minor_start; /* start of minor device number*/ 127 short num; /* number of devices */ 128 short type; /* type of tty driver */ 129 short subtype; /* subtype of tty driver */ 130 struct termios init_termios; /* Initial termios */ 131 int flags; /* tty driver flags */ 132 int *refcount; /* for loadable tty drivers */ 133 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 134 struct tty_driver *other; /* only used for the PTY driver */ 135 136 /* 137 * Pointer to the tty data structures 138 */ 139 struct tty_struct **table; 140 struct termios **termios; 141 struct termios **termios_locked; 142 void *driver_state; /* only used for the PTY driver */ 143 144 /* 145 * Interface routines from the upper tty layer to the tty 146 * driver. 147 */ 148 int (*open)(struct tty_struct * tty, struct file * filp); 149 void (*close)(struct tty_struct * tty, struct file * filp); 150 int (*write)(struct tty_struct * tty, int from_user, 151 const unsigned char *buf, int count); 152 void (*put_char)(struct tty_struct *tty, unsigned char ch); 153 void (*flush_chars)(struct tty_struct *tty); 154 int (*write_room)(struct tty_struct *tty); 155 int (*chars_in_buffer)(struct tty_struct *tty); 156 int (*ioctl)(struct tty_struct *tty, struct file * file, 157 unsigned int cmd, unsigned long arg); 158 void (*set_termios)(struct tty_struct *tty, struct termios * old); 159 void (*throttle)(struct tty_struct * tty); 160 void (*unthrottle)(struct tty_struct * tty); 161 void (*stop)(struct tty_struct *tty); 162 void (*start)(struct tty_struct *tty); 163 void (*hangup)(struct tty_struct *tty); 164 void (*break_ctl)(struct tty_struct *tty, int state); 165 void (*flush_buffer)(struct tty_struct *tty); 166 void (*set_ldisc)(struct tty_struct *tty); 167 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 168 void (*send_xchar)(struct tty_struct *tty, char ch); 169 int (*read_proc)(char *page, char **start, off_t off, 170 int count, int *eof, void *data); 171 int (*write_proc)(struct file *file, const char *buffer, 172 unsigned long count, void *data); 173 174 /* 175 * linked list pointers 176 */ 177 struct tty_driver *next; 178 struct tty_driver *prev; 179}; 180 181/* tty driver magic number */ 182#define TTY_DRIVER_MAGIC 0x5402 183 184/* 185 * tty driver flags 186 * 187 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 188 * termios setting when the last process has closed the device. 189 * Used for PTY's, in particular. 190 * 191 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 192 * guarantee never not to set any special character handling 193 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 194 * !INPCK)). That is, if there is no reason for the driver to 195 * send notifications of parity and break characters up to the 196 * line driver, it won't do so. This allows the line driver to 197 * optimize for this case if this flag is set. (Note that there 198 * is also a promise, if the above case is true, not to signal 199 * overruns, either.) 200 * 201 * TTY_DRIVER_NO_DEVFS --- if set, do not create devfs entries. This 202 * is only used by tty_register_driver(). 203 * 204 */ 205#define TTY_DRIVER_INSTALLED 0x0001 206#define TTY_DRIVER_RESET_TERMIOS 0x0002 207#define TTY_DRIVER_REAL_RAW 0x0004 208#define TTY_DRIVER_NO_DEVFS 0x0008 209 210/* tty driver types */ 211#define TTY_DRIVER_TYPE_SYSTEM 0x0001 212#define TTY_DRIVER_TYPE_CONSOLE 0x0002 213#define TTY_DRIVER_TYPE_SERIAL 0x0003 214#define TTY_DRIVER_TYPE_PTY 0x0004 215#define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 216#define TTY_DRIVER_TYPE_SYSCONS 0x0006 217 218/* system subtypes (magic, used by tty_io.c) */ 219#define SYSTEM_TYPE_TTY 0x0001 220#define SYSTEM_TYPE_CONSOLE 0x0002 221#define SYSTEM_TYPE_SYSCONS 0x0003 222#define SYSTEM_TYPE_SYSPTMX 0x0004 223 224/* pty subtypes (magic, used by tty_io.c) */ 225#define PTY_TYPE_MASTER 0x0001 226#define PTY_TYPE_SLAVE 0x0002 227 228/* serial subtype definitions */ 229#define SERIAL_TYPE_NORMAL 1 230#define SERIAL_TYPE_CALLOUT 2 231 232#endif /* #ifdef _LINUX_TTY_DRIVER_H */ 233