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 when a particular tty device is closed for 49 * the last time freeing up the resources. 50 * 51 * int (*write)(struct tty_struct * tty, 52 * const unsigned char *buf, int count); 53 * 54 * This routine is called by the kernel to write a series of 55 * characters to the tty device. The characters may come from 56 * user space or kernel space. This routine will return the 57 * number of characters actually accepted for writing. 58 * 59 * Optional: Required for writable devices. 60 * 61 * int (*put_char)(struct tty_struct *tty, unsigned char ch); 62 * 63 * This routine is called by the kernel to write a single 64 * character to the tty device. If the kernel uses this routine, 65 * it must call the flush_chars() routine (if defined) when it is 66 * done stuffing characters into the driver. If there is no room 67 * in the queue, the character is ignored. 68 * 69 * Optional: Kernel will use the write method if not provided. 70 * 71 * Note: Do not call this function directly, call tty_put_char 72 * 73 * void (*flush_chars)(struct tty_struct *tty); 74 * 75 * This routine is called by the kernel after it has written a 76 * series of characters to the tty device using put_char(). 77 * 78 * Optional: 79 * 80 * Note: Do not call this function directly, call tty_driver_flush_chars 81 * 82 * int (*write_room)(struct tty_struct *tty); 83 * 84 * This routine returns the numbers of characters the tty driver 85 * will accept for queuing to be written. This number is subject 86 * to change as output buffers get emptied, or if the output flow 87 * control is acted. 88 * 89 * Required if write method is provided else not needed. 90 * 91 * Note: Do not call this function directly, call tty_write_room 92 * 93 * int (*ioctl)(struct tty_struct *tty, struct file * file, 94 * unsigned int cmd, unsigned long arg); 95 * 96 * This routine allows the tty driver to implement 97 * device-specific ioctl's. If the ioctl number passed in cmd 98 * is not recognized by the driver, it should return ENOIOCTLCMD. 99 * 100 * Optional 101 * 102 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file, 103 * unsigned int cmd, unsigned long arg); 104 * 105 * implement ioctl processing for 32 bit process on 64 bit system 106 * 107 * Optional 108 * 109 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 110 * 111 * This routine allows the tty driver to be notified when 112 * device's termios settings have changed. 113 * 114 * Optional: Called under the termios lock 115 * 116 * 117 * void (*set_ldisc)(struct tty_struct *tty); 118 * 119 * This routine allows the tty driver to be notified when the 120 * device's termios settings have changed. 121 * 122 * Optional: Called under BKL (currently) 123 * 124 * void (*throttle)(struct tty_struct * tty); 125 * 126 * This routine notifies the tty driver that input buffers for 127 * the line discipline are close to full, and it should somehow 128 * signal that no more characters should be sent to the tty. 129 * 130 * Optional: Always invoke via tty_throttle(); 131 * 132 * void (*unthrottle)(struct tty_struct * tty); 133 * 134 * This routine notifies the tty drivers that it should signals 135 * that characters can now be sent to the tty without fear of 136 * overrunning the input buffers of the line disciplines. 137 * 138 * Optional: Always invoke via tty_unthrottle(); 139 * 140 * void (*stop)(struct tty_struct *tty); 141 * 142 * This routine notifies the tty driver that it should stop 143 * outputting characters to the tty device. 144 * 145 * Optional: 146 * 147 * Note: Call stop_tty not this method. 148 * 149 * void (*start)(struct tty_struct *tty); 150 * 151 * This routine notifies the tty driver that it resume sending 152 * characters to the tty device. 153 * 154 * Optional: 155 * 156 * Note: Call start_tty not this method. 157 * 158 * void (*hangup)(struct tty_struct *tty); 159 * 160 * This routine notifies the tty driver that it should hangup the 161 * tty device. 162 * 163 * Optional: 164 * 165 * int (*break_ctl)(struct tty_stuct *tty, int state); 166 * 167 * This optional routine requests the tty driver to turn on or 168 * off BREAK status on the RS-232 port. If state is -1, 169 * then the BREAK status should be turned on; if state is 0, then 170 * BREAK should be turned off. 171 * 172 * If this routine is implemented, the high-level tty driver will 173 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, 174 * TIOCCBRK. 175 * 176 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface 177 * will also be called with actual times and the hardware is expected 178 * to do the delay work itself. 0 and -1 are still used for on/off. 179 * 180 * Optional: Required for TCSBRK/BRKP/etc handling. 181 * 182 * void (*wait_until_sent)(struct tty_struct *tty, int timeout); 183 * 184 * This routine waits until the device has written out all of the 185 * characters in its transmitter FIFO. 186 * 187 * Optional: If not provided the device is assumed to have no FIFO 188 * 189 * Note: Usually correct to call tty_wait_until_sent 190 * 191 * void (*send_xchar)(struct tty_struct *tty, char ch); 192 * 193 * This routine is used to send a high-priority XON/XOFF 194 * character to the device. 195 * 196 * Optional: If not provided then the write method is called under 197 * the atomic write lock to keep it serialized with the ldisc. 198 * 199 * int (*resize)(struct tty_struct *tty, struct winsize *ws) 200 * 201 * Called when a termios request is issued which changes the 202 * requested terminal geometry. 203 * 204 * Optional: the default action is to update the termios structure 205 * without error. This is usually the correct behaviour. Drivers should 206 * not force errors here if they are not resizable objects (eg a serial 207 * line). See tty_do_resize() if you need to wrap the standard method 208 * in your own logic - the usual case. 209 * 210 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new); 211 * 212 * Called when the device receives a termiox based ioctl. Passes down 213 * the requested data from user space. This method will not be invoked 214 * unless the tty also has a valid tty->termiox pointer. 215 * 216 * Optional: Called under the termios lock 217 */ 218 219 #include <linux/fs.h> 220 #include <linux/list.h> 221 #include <linux/cdev.h> 222 223 struct tty_struct; 224 struct tty_driver; 225 226 struct tty_operations { 227 struct tty_struct * (*lookup)(struct tty_driver *driver, 228 struct inode *inode, int idx); 229 int (*install)(struct tty_driver *driver, struct tty_struct *tty); 230 void (*remove)(struct tty_driver *driver, struct tty_struct *tty); 231 int (*open)(struct tty_struct * tty, struct file * filp); 232 void (*close)(struct tty_struct * tty, struct file * filp); 233 void (*shutdown)(struct tty_struct *tty); 234 int (*write)(struct tty_struct * tty, 235 const unsigned char *buf, int count); 236 int (*put_char)(struct tty_struct *tty, unsigned char ch); 237 void (*flush_chars)(struct tty_struct *tty); 238 int (*write_room)(struct tty_struct *tty); 239 int (*chars_in_buffer)(struct tty_struct *tty); 240 int (*ioctl)(struct tty_struct *tty, struct file * file, 241 unsigned int cmd, unsigned long arg); 242 long (*compat_ioctl)(struct tty_struct *tty, struct file * file, 243 unsigned int cmd, unsigned long arg); 244 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 245 void (*throttle)(struct tty_struct * tty); 246 void (*unthrottle)(struct tty_struct * tty); 247 void (*stop)(struct tty_struct *tty); 248 void (*start)(struct tty_struct *tty); 249 void (*hangup)(struct tty_struct *tty); 250 int (*break_ctl)(struct tty_struct *tty, int state); 251 void (*flush_buffer)(struct tty_struct *tty); 252 void (*set_ldisc)(struct tty_struct *tty); 253 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 254 void (*send_xchar)(struct tty_struct *tty, char ch); 255 int (*read_proc)(char *page, char **start, off_t off, 256 int count, int *eof, void *data); 257 int (*tiocmget)(struct tty_struct *tty, struct file *file); 258 int (*tiocmset)(struct tty_struct *tty, struct file *file, 259 unsigned int set, unsigned int clear); 260 int (*resize)(struct tty_struct *tty, struct winsize *ws); 261 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew); 262 #ifdef CONFIG_CONSOLE_POLL 263 int (*poll_init)(struct tty_driver *driver, int line, char *options); 264 int (*poll_get_char)(struct tty_driver *driver, int line); 265 void (*poll_put_char)(struct tty_driver *driver, int line, char ch); 266 #endif 267 }; 268 269 struct tty_driver { 270 int magic; /* magic number for this structure */ 271 struct kref kref; /* Reference management */ 272 struct cdev cdev; 273 struct module *owner; 274 const char *driver_name; 275 const char *name; 276 int name_base; /* offset of printed name */ 277 int major; /* major device number */ 278 int minor_start; /* start of minor device number */ 279 int minor_num; /* number of *possible* devices */ 280 int num; /* number of devices allocated */ 281 short type; /* type of tty driver */ 282 short subtype; /* subtype of tty driver */ 283 struct ktermios init_termios; /* Initial termios */ 284 int flags; /* tty driver flags */ 285 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 286 struct tty_driver *other; /* only used for the PTY driver */ 287 288 /* 289 * Pointer to the tty data structures 290 */ 291 struct tty_struct **ttys; 292 struct ktermios **termios; 293 struct ktermios **termios_locked; 294 void *driver_state; 295 296 /* 297 * Driver methods 298 */ 299 300 const struct tty_operations *ops; 301 struct list_head tty_drivers; 302 }; 303 304 extern struct list_head tty_drivers; 305 306 extern struct tty_driver *alloc_tty_driver(int lines); 307 extern void put_tty_driver(struct tty_driver *driver); 308 extern void tty_set_operations(struct tty_driver *driver, 309 const struct tty_operations *op); 310 extern struct tty_driver *tty_find_polling_driver(char *name, int *line); 311 312 extern void tty_driver_kref_put(struct tty_driver *driver); 313 extern inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) 314 { 315 kref_get(&d->kref); 316 return d; 317 } 318 319 /* tty driver magic number */ 320 #define TTY_DRIVER_MAGIC 0x5402 321 322 /* 323 * tty driver flags 324 * 325 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 326 * termios setting when the last process has closed the device. 327 * Used for PTY's, in particular. 328 * 329 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 330 * guarantee never not to set any special character handling 331 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 332 * !INPCK)). That is, if there is no reason for the driver to 333 * send notifications of parity and break characters up to the 334 * line driver, it won't do so. This allows the line driver to 335 * optimize for this case if this flag is set. (Note that there 336 * is also a promise, if the above case is true, not to signal 337 * overruns, either.) 338 * 339 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need 340 * to be registered with a call to tty_register_driver() when the 341 * device is found in the system and unregistered with a call to 342 * tty_unregister_device() so the devices will be show up 343 * properly in sysfs. If not set, driver->num entries will be 344 * created by the tty core in sysfs when tty_register_driver() is 345 * called. This is to be used by drivers that have tty devices 346 * that can appear and disappear while the main tty driver is 347 * registered with the tty core. 348 * 349 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead 350 * use dynamic memory keyed through the devpts filesystem. This 351 * is only applicable to the pty driver. 352 * 353 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass 354 * the requested timeout to the caller instead of using a simple 355 * on/off interface. 356 * 357 */ 358 #define TTY_DRIVER_INSTALLED 0x0001 359 #define TTY_DRIVER_RESET_TERMIOS 0x0002 360 #define TTY_DRIVER_REAL_RAW 0x0004 361 #define TTY_DRIVER_DYNAMIC_DEV 0x0008 362 #define TTY_DRIVER_DEVPTS_MEM 0x0010 363 #define TTY_DRIVER_HARDWARE_BREAK 0x0020 364 365 /* tty driver types */ 366 #define TTY_DRIVER_TYPE_SYSTEM 0x0001 367 #define TTY_DRIVER_TYPE_CONSOLE 0x0002 368 #define TTY_DRIVER_TYPE_SERIAL 0x0003 369 #define TTY_DRIVER_TYPE_PTY 0x0004 370 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 371 #define TTY_DRIVER_TYPE_SYSCONS 0x0006 372 373 /* system subtypes (magic, used by tty_io.c) */ 374 #define SYSTEM_TYPE_TTY 0x0001 375 #define SYSTEM_TYPE_CONSOLE 0x0002 376 #define SYSTEM_TYPE_SYSCONS 0x0003 377 #define SYSTEM_TYPE_SYSPTMX 0x0004 378 379 /* pty subtypes (magic, used by tty_io.c) */ 380 #define PTY_TYPE_MASTER 0x0001 381 #define PTY_TYPE_SLAVE 0x0002 382 383 /* serial subtype definitions */ 384 #define SERIAL_TYPE_NORMAL 1 385 386 #endif /* #ifdef _LINUX_TTY_DRIVER_H */ 387