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 }; 278 279 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 } 329 330 /* 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 */ 398