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 * Required method. 17 * 18 * void (*close)(struct tty_struct * tty, struct file * filp); 19 * 20 * This routine is called when a particular tty device is closed. 21 * 22 * Required method. 23 * 24 * int (*write)(struct tty_struct * tty, 25 * const unsigned char *buf, int count); 26 * 27 * This routine is called by the kernel to write a series of 28 * characters to the tty device. The characters may come from 29 * user space or kernel space. This routine will return the 30 * number of characters actually accepted for writing. This 31 * routine is mandatory. 32 * 33 * Optional: Required for writable devices. 34 * 35 * int (*put_char)(struct tty_struct *tty, unsigned char ch); 36 * 37 * This routine is called by the kernel to write a single 38 * character to the tty device. If the kernel uses this routine, 39 * it must call the flush_chars() routine (if defined) when it is 40 * done stuffing characters into the driver. If there is no room 41 * in the queue, the character is ignored. 42 * 43 * Optional: Kernel will use the write method if not provided. 44 * 45 * Note: Do not call this function directly, call tty_put_char 46 * 47 * void (*flush_chars)(struct tty_struct *tty); 48 * 49 * This routine is called by the kernel after it has written a 50 * series of characters to the tty device using put_char(). 51 * 52 * Optional: 53 * 54 * Note: Do not call this function directly, call tty_driver_flush_chars 55 * 56 * int (*write_room)(struct tty_struct *tty); 57 * 58 * This routine returns the numbers of characters the tty driver 59 * will accept for queuing to be written. This number is subject 60 * to change as output buffers get emptied, or if the output flow 61 * control is acted. 62 * 63 * Required if write method is provided else not needed. 64 * 65 * Note: Do not call this function directly, call tty_write_room 66 * 67 * int (*ioctl)(struct tty_struct *tty, struct file * file, 68 * unsigned int cmd, unsigned long arg); 69 * 70 * This routine allows the tty driver to implement 71 * device-specific ioctl's. If the ioctl number passed in cmd 72 * is not recognized by the driver, it should return ENOIOCTLCMD. 73 * 74 * Optional 75 * 76 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file, 77 * unsigned int cmd, unsigned long arg); 78 * 79 * implement ioctl processing for 32 bit process on 64 bit system 80 * 81 * Optional 82 * 83 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 84 * 85 * This routine allows the tty driver to be notified when 86 * device's termios settings have changed. 87 * 88 * Optional: Called under the termios lock 89 * 90 * 91 * void (*set_ldisc)(struct tty_struct *tty); 92 * 93 * This routine allows the tty driver to be notified when the 94 * device's termios settings have changed. 95 * 96 * Optional: Called under BKL (currently) 97 * 98 * void (*throttle)(struct tty_struct * tty); 99 * 100 * This routine notifies the tty driver that input buffers for 101 * the line discipline are close to full, and it should somehow 102 * signal that no more characters should be sent to the tty. 103 * 104 * Optional: Always invoke via tty_throttle(); 105 * 106 * void (*unthrottle)(struct tty_struct * tty); 107 * 108 * This routine notifies the tty drivers that it should signals 109 * that characters can now be sent to the tty without fear of 110 * overrunning the input buffers of the line disciplines. 111 * 112 * Optional: Always invoke via tty_unthrottle(); 113 * 114 * void (*stop)(struct tty_struct *tty); 115 * 116 * This routine notifies the tty driver that it should stop 117 * outputting characters to the tty device. 118 * 119 * Optional: 120 * 121 * Note: Call stop_tty not this method. 122 * 123 * void (*start)(struct tty_struct *tty); 124 * 125 * This routine notifies the tty driver that it resume sending 126 * characters to the tty device. 127 * 128 * Optional: 129 * 130 * Note: Call start_tty not this method. 131 * 132 * void (*hangup)(struct tty_struct *tty); 133 * 134 * This routine notifies the tty driver that it should hangup the 135 * tty device. 136 * 137 * Required: 138 * 139 * void (*break_ctl)(struct tty_stuct *tty, int state); 140 * 141 * This optional routine requests the tty driver to turn on or 142 * off BREAK status on the RS-232 port. If state is -1, 143 * then the BREAK status should be turned on; if state is 0, then 144 * BREAK should be turned off. 145 * 146 * If this routine is implemented, the high-level tty driver will 147 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, 148 * TIOCCBRK. 149 * 150 * Optional: Required for TCSBRK/BRKP/etc handling. 151 * 152 * void (*wait_until_sent)(struct tty_struct *tty, int timeout); 153 * 154 * This routine waits until the device has written out all of the 155 * characters in its transmitter FIFO. 156 * 157 * Optional: If not provided the device is assumed to have no FIFO 158 * 159 * Note: Usually correct to call tty_wait_until_sent 160 * 161 * void (*send_xchar)(struct tty_struct *tty, char ch); 162 * 163 * This routine is used to send a high-priority XON/XOFF 164 * character to the device. 165 * 166 * Optional: If not provided then the write method is called under 167 * the atomic write lock to keep it serialized with the ldisc. 168 */ 169 170 #include <linux/fs.h> 171 #include <linux/list.h> 172 #include <linux/cdev.h> 173 174 struct tty_struct; 175 struct tty_driver; 176 177 struct tty_operations { 178 int (*open)(struct tty_struct * tty, struct file * filp); 179 void (*close)(struct tty_struct * tty, struct file * filp); 180 int (*write)(struct tty_struct * tty, 181 const unsigned char *buf, int count); 182 int (*put_char)(struct tty_struct *tty, unsigned char ch); 183 void (*flush_chars)(struct tty_struct *tty); 184 int (*write_room)(struct tty_struct *tty); 185 int (*chars_in_buffer)(struct tty_struct *tty); 186 int (*ioctl)(struct tty_struct *tty, struct file * file, 187 unsigned int cmd, unsigned long arg); 188 long (*compat_ioctl)(struct tty_struct *tty, struct file * file, 189 unsigned int cmd, unsigned long arg); 190 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 191 void (*throttle)(struct tty_struct * tty); 192 void (*unthrottle)(struct tty_struct * tty); 193 void (*stop)(struct tty_struct *tty); 194 void (*start)(struct tty_struct *tty); 195 void (*hangup)(struct tty_struct *tty); 196 void (*break_ctl)(struct tty_struct *tty, int state); 197 void (*flush_buffer)(struct tty_struct *tty); 198 void (*set_ldisc)(struct tty_struct *tty); 199 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 200 void (*send_xchar)(struct tty_struct *tty, char ch); 201 int (*read_proc)(char *page, char **start, off_t off, 202 int count, int *eof, void *data); 203 int (*tiocmget)(struct tty_struct *tty, struct file *file); 204 int (*tiocmset)(struct tty_struct *tty, struct file *file, 205 unsigned int set, unsigned int clear); 206 #ifdef CONFIG_CONSOLE_POLL 207 int (*poll_init)(struct tty_driver *driver, int line, char *options); 208 int (*poll_get_char)(struct tty_driver *driver, int line); 209 void (*poll_put_char)(struct tty_driver *driver, int line, char ch); 210 #endif 211 }; 212 213 struct tty_driver { 214 int magic; /* magic number for this structure */ 215 struct cdev cdev; 216 struct module *owner; 217 const char *driver_name; 218 const char *name; 219 int name_base; /* offset of printed name */ 220 int major; /* major device number */ 221 int minor_start; /* start of minor device number */ 222 int minor_num; /* number of *possible* devices */ 223 int num; /* number of devices allocated */ 224 short type; /* type of tty driver */ 225 short subtype; /* subtype of tty driver */ 226 struct ktermios init_termios; /* Initial termios */ 227 int flags; /* tty driver flags */ 228 int refcount; /* for loadable tty drivers */ 229 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 230 struct tty_driver *other; /* only used for the PTY driver */ 231 232 /* 233 * Pointer to the tty data structures 234 */ 235 struct tty_struct **ttys; 236 struct ktermios **termios; 237 struct ktermios **termios_locked; 238 void *driver_state; 239 240 /* 241 * Driver methods 242 */ 243 244 const struct tty_operations *ops; 245 struct list_head tty_drivers; 246 }; 247 248 extern struct list_head tty_drivers; 249 250 struct tty_driver *alloc_tty_driver(int lines); 251 void put_tty_driver(struct tty_driver *driver); 252 void tty_set_operations(struct tty_driver *driver, 253 const struct tty_operations *op); 254 extern struct tty_driver *tty_find_polling_driver(char *name, int *line); 255 256 /* tty driver magic number */ 257 #define TTY_DRIVER_MAGIC 0x5402 258 259 /* 260 * tty driver flags 261 * 262 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 263 * termios setting when the last process has closed the device. 264 * Used for PTY's, in particular. 265 * 266 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 267 * guarantee never not to set any special character handling 268 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 269 * !INPCK)). That is, if there is no reason for the driver to 270 * send notifications of parity and break characters up to the 271 * line driver, it won't do so. This allows the line driver to 272 * optimize for this case if this flag is set. (Note that there 273 * is also a promise, if the above case is true, not to signal 274 * overruns, either.) 275 * 276 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need 277 * to be registered with a call to tty_register_driver() when the 278 * device is found in the system and unregistered with a call to 279 * tty_unregister_device() so the devices will be show up 280 * properly in sysfs. If not set, driver->num entries will be 281 * created by the tty core in sysfs when tty_register_driver() is 282 * called. This is to be used by drivers that have tty devices 283 * that can appear and disappear while the main tty driver is 284 * registered with the tty core. 285 * 286 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead 287 * use dynamic memory keyed through the devpts filesystem. This 288 * is only applicable to the pty driver. 289 */ 290 #define TTY_DRIVER_INSTALLED 0x0001 291 #define TTY_DRIVER_RESET_TERMIOS 0x0002 292 #define TTY_DRIVER_REAL_RAW 0x0004 293 #define TTY_DRIVER_DYNAMIC_DEV 0x0008 294 #define TTY_DRIVER_DEVPTS_MEM 0x0010 295 296 /* tty driver types */ 297 #define TTY_DRIVER_TYPE_SYSTEM 0x0001 298 #define TTY_DRIVER_TYPE_CONSOLE 0x0002 299 #define TTY_DRIVER_TYPE_SERIAL 0x0003 300 #define TTY_DRIVER_TYPE_PTY 0x0004 301 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 302 #define TTY_DRIVER_TYPE_SYSCONS 0x0006 303 304 /* system subtypes (magic, used by tty_io.c) */ 305 #define SYSTEM_TYPE_TTY 0x0001 306 #define SYSTEM_TYPE_CONSOLE 0x0002 307 #define SYSTEM_TYPE_SYSCONS 0x0003 308 #define SYSTEM_TYPE_SYSPTMX 0x0004 309 310 /* pty subtypes (magic, used by tty_io.c) */ 311 #define PTY_TYPE_MASTER 0x0001 312 #define PTY_TYPE_SLAVE 0x0002 313 314 /* serial subtype definitions */ 315 #define SERIAL_TYPE_NORMAL 1 316 317 #endif /* #ifdef _LINUX_TTY_DRIVER_H */ 318