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 * Note that tty_shutdown() is not called if ops->shutdown is defined. 51 * This means one is responsible to take care of calling ops->remove (e.g. 52 * via tty_driver_remove_tty) and releasing tty->termios. 53 * Note that this hook may be called from *all* the contexts where one 54 * uses tty refcounting (e.g. tty_port_tty_get). 55 * 56 * 57 * void (*cleanup)(struct tty_struct * tty); 58 * 59 * This routine is called asynchronously when a particular tty device 60 * is closed for the last time freeing up the resources. This is 61 * actually the second part of shutdown for routines that might sleep. 62 * 63 * 64 * int (*write)(struct tty_struct * tty, 65 * const unsigned char *buf, int count); 66 * 67 * This routine is called by the kernel to write a series of 68 * characters to the tty device. The characters may come from 69 * user space or kernel space. This routine will return the 70 * number of characters actually accepted for writing. 71 * 72 * Optional: Required for writable devices. 73 * 74 * int (*put_char)(struct tty_struct *tty, unsigned char ch); 75 * 76 * This routine is called by the kernel to write a single 77 * character to the tty device. If the kernel uses this routine, 78 * it must call the flush_chars() routine (if defined) when it is 79 * done stuffing characters into the driver. If there is no room 80 * in the queue, the character is ignored. 81 * 82 * Optional: Kernel will use the write method if not provided. 83 * 84 * Note: Do not call this function directly, call tty_put_char 85 * 86 * void (*flush_chars)(struct tty_struct *tty); 87 * 88 * This routine is called by the kernel after it has written a 89 * series of characters to the tty device using put_char(). 90 * 91 * Optional: 92 * 93 * Note: Do not call this function directly, call tty_driver_flush_chars 94 * 95 * int (*write_room)(struct tty_struct *tty); 96 * 97 * This routine returns the numbers of characters the tty driver 98 * will accept for queuing to be written. This number is subject 99 * to change as output buffers get emptied, or if the output flow 100 * control is acted. 101 * 102 * Required if write method is provided else not needed. 103 * 104 * Note: Do not call this function directly, call tty_write_room 105 * 106 * int (*ioctl)(struct tty_struct *tty, unsigned int cmd, unsigned long arg); 107 * 108 * This routine allows the tty driver to implement 109 * device-specific ioctls. If the ioctl number passed in cmd 110 * is not recognized by the driver, it should return ENOIOCTLCMD. 111 * 112 * Optional 113 * 114 * long (*compat_ioctl)(struct tty_struct *tty,, 115 * unsigned int cmd, unsigned long arg); 116 * 117 * implement ioctl processing for 32 bit process on 64 bit system 118 * 119 * Optional 120 * 121 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 122 * 123 * This routine allows the tty driver to be notified when 124 * device's termios settings have changed. 125 * 126 * Optional: Called under the termios lock 127 * 128 * 129 * void (*set_ldisc)(struct tty_struct *tty); 130 * 131 * This routine allows the tty driver to be notified when the 132 * device's termios settings have changed. 133 * 134 * Optional: Called under BKL (currently) 135 * 136 * void (*throttle)(struct tty_struct * tty); 137 * 138 * This routine notifies the tty driver that input buffers for 139 * the line discipline are close to full, and it should somehow 140 * signal that no more characters should be sent to the tty. 141 * 142 * Optional: Always invoke via tty_throttle(), called under the 143 * termios lock. 144 * 145 * void (*unthrottle)(struct tty_struct * tty); 146 * 147 * This routine notifies the tty drivers that it should signals 148 * that characters can now be sent to the tty without fear of 149 * overrunning the input buffers of the line disciplines. 150 * 151 * Optional: Always invoke via tty_unthrottle(), called under the 152 * termios lock. 153 * 154 * void (*stop)(struct tty_struct *tty); 155 * 156 * This routine notifies the tty driver that it should stop 157 * outputting characters to the tty device. 158 * 159 * Optional: 160 * 161 * Note: Call stop_tty not this method. 162 * 163 * void (*start)(struct tty_struct *tty); 164 * 165 * This routine notifies the tty driver that it resume sending 166 * characters to the tty device. 167 * 168 * Optional: 169 * 170 * Note: Call start_tty not this method. 171 * 172 * void (*hangup)(struct tty_struct *tty); 173 * 174 * This routine notifies the tty driver that it should hang up the 175 * tty device. 176 * 177 * Optional: 178 * 179 * int (*break_ctl)(struct tty_struct *tty, int state); 180 * 181 * This optional routine requests the tty driver to turn on or 182 * off BREAK status on the RS-232 port. If state is -1, 183 * then the BREAK status should be turned on; if state is 0, then 184 * BREAK should be turned off. 185 * 186 * If this routine is implemented, the high-level tty driver will 187 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, 188 * TIOCCBRK. 189 * 190 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface 191 * will also be called with actual times and the hardware is expected 192 * to do the delay work itself. 0 and -1 are still used for on/off. 193 * 194 * Optional: Required for TCSBRK/BRKP/etc handling. 195 * 196 * void (*wait_until_sent)(struct tty_struct *tty, int timeout); 197 * 198 * This routine waits until the device has written out all of the 199 * characters in its transmitter FIFO. 200 * 201 * Optional: If not provided the device is assumed to have no FIFO 202 * 203 * Note: Usually correct to call tty_wait_until_sent 204 * 205 * void (*send_xchar)(struct tty_struct *tty, char ch); 206 * 207 * This routine is used to send a high-priority XON/XOFF 208 * character to the device. 209 * 210 * Optional: If not provided then the write method is called under 211 * the atomic write lock to keep it serialized with the ldisc. 212 * 213 * int (*resize)(struct tty_struct *tty, struct winsize *ws) 214 * 215 * Called when a termios request is issued which changes the 216 * requested terminal geometry. 217 * 218 * Optional: the default action is to update the termios structure 219 * without error. This is usually the correct behaviour. Drivers should 220 * not force errors here if they are not resizable objects (eg a serial 221 * line). See tty_do_resize() if you need to wrap the standard method 222 * in your own logic - the usual case. 223 * 224 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new); 225 * 226 * Called when the device receives a termiox based ioctl. Passes down 227 * the requested data from user space. This method will not be invoked 228 * unless the tty also has a valid tty->termiox pointer. 229 * 230 * Optional: Called under the termios lock 231 * 232 * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount); 233 * 234 * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel 235 * structure to complete. This method is optional and will only be called 236 * if provided (otherwise EINVAL will be returned). 237 */ 238 239#include <linux/export.h> 240#include <linux/fs.h> 241#include <linux/list.h> 242#include <linux/cdev.h> 243#include <linux/termios.h> 244 245struct tty_struct; 246struct tty_driver; 247struct serial_icounter_struct; 248 249struct tty_operations { 250 struct tty_struct * (*lookup)(struct tty_driver *driver, 251 struct inode *inode, int idx); 252 int (*install)(struct tty_driver *driver, struct tty_struct *tty); 253 void (*remove)(struct tty_driver *driver, struct tty_struct *tty); 254 int (*open)(struct tty_struct * tty, struct file * filp); 255 void (*close)(struct tty_struct * tty, struct file * filp); 256 void (*shutdown)(struct tty_struct *tty); 257 void (*cleanup)(struct tty_struct *tty); 258 int (*write)(struct tty_struct * tty, 259 const unsigned char *buf, int count); 260 int (*put_char)(struct tty_struct *tty, unsigned char ch); 261 void (*flush_chars)(struct tty_struct *tty); 262 int (*write_room)(struct tty_struct *tty); 263 int (*chars_in_buffer)(struct tty_struct *tty); 264 int (*ioctl)(struct tty_struct *tty, 265 unsigned int cmd, unsigned long arg); 266 long (*compat_ioctl)(struct tty_struct *tty, 267 unsigned int cmd, unsigned long arg); 268 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 269 void (*throttle)(struct tty_struct * tty); 270 void (*unthrottle)(struct tty_struct * tty); 271 void (*stop)(struct tty_struct *tty); 272 void (*start)(struct tty_struct *tty); 273 void (*hangup)(struct tty_struct *tty); 274 int (*break_ctl)(struct tty_struct *tty, int state); 275 void (*flush_buffer)(struct tty_struct *tty); 276 void (*set_ldisc)(struct tty_struct *tty); 277 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 278 void (*send_xchar)(struct tty_struct *tty, char ch); 279 int (*tiocmget)(struct tty_struct *tty); 280 int (*tiocmset)(struct tty_struct *tty, 281 unsigned int set, unsigned int clear); 282 int (*resize)(struct tty_struct *tty, struct winsize *ws); 283 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew); 284 int (*get_icount)(struct tty_struct *tty, 285 struct serial_icounter_struct *icount); 286#ifdef CONFIG_CONSOLE_POLL 287 int (*poll_init)(struct tty_driver *driver, int line, char *options); 288 int (*poll_get_char)(struct tty_driver *driver, int line); 289 void (*poll_put_char)(struct tty_driver *driver, int line, char ch); 290#endif 291 const struct file_operations *proc_fops; 292}; 293 294struct tty_driver { 295 int magic; /* magic number for this structure */ 296 struct kref kref; /* Reference management */ 297 struct cdev cdev; 298 struct module *owner; 299 const char *driver_name; 300 const char *name; 301 int name_base; /* offset of printed name */ 302 int major; /* major device number */ 303 int minor_start; /* start of minor device number */ 304 int num; /* number of devices allocated */ 305 short type; /* type of tty driver */ 306 short subtype; /* subtype of tty driver */ 307 struct ktermios init_termios; /* Initial termios */ 308 int flags; /* tty driver flags */ 309 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 310 struct tty_driver *other; /* only used for the PTY driver */ 311 312 /* 313 * Pointer to the tty data structures 314 */ 315 struct tty_struct **ttys; 316 struct ktermios **termios; 317 void *driver_state; 318 319 /* 320 * Driver methods 321 */ 322 323 const struct tty_operations *ops; 324 struct list_head tty_drivers; 325}; 326 327extern struct list_head tty_drivers; 328 329extern struct tty_driver *__alloc_tty_driver(int lines, struct module *owner); 330extern void put_tty_driver(struct tty_driver *driver); 331extern void tty_set_operations(struct tty_driver *driver, 332 const struct tty_operations *op); 333extern struct tty_driver *tty_find_polling_driver(char *name, int *line); 334 335extern void tty_driver_kref_put(struct tty_driver *driver); 336 337#define alloc_tty_driver(lines) __alloc_tty_driver(lines, THIS_MODULE) 338 339static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) 340{ 341 kref_get(&d->kref); 342 return d; 343} 344 345/* tty driver magic number */ 346#define TTY_DRIVER_MAGIC 0x5402 347 348/* 349 * tty driver flags 350 * 351 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 352 * termios setting when the last process has closed the device. 353 * Used for PTY's, in particular. 354 * 355 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 356 * guarantee never not to set any special character handling 357 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 358 * !INPCK)). That is, if there is no reason for the driver to 359 * send notifications of parity and break characters up to the 360 * line driver, it won't do so. This allows the line driver to 361 * optimize for this case if this flag is set. (Note that there 362 * is also a promise, if the above case is true, not to signal 363 * overruns, either.) 364 * 365 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need 366 * to be registered with a call to tty_register_device() when the 367 * device is found in the system and unregistered with a call to 368 * tty_unregister_device() so the devices will be show up 369 * properly in sysfs. If not set, driver->num entries will be 370 * created by the tty core in sysfs when tty_register_driver() is 371 * called. This is to be used by drivers that have tty devices 372 * that can appear and disappear while the main tty driver is 373 * registered with the tty core. 374 * 375 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead 376 * use dynamic memory keyed through the devpts filesystem. This 377 * is only applicable to the pty driver. 378 * 379 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass 380 * the requested timeout to the caller instead of using a simple 381 * on/off interface. 382 * 383 */ 384#define TTY_DRIVER_INSTALLED 0x0001 385#define TTY_DRIVER_RESET_TERMIOS 0x0002 386#define TTY_DRIVER_REAL_RAW 0x0004 387#define TTY_DRIVER_DYNAMIC_DEV 0x0008 388#define TTY_DRIVER_DEVPTS_MEM 0x0010 389#define TTY_DRIVER_HARDWARE_BREAK 0x0020 390 391/* tty driver types */ 392#define TTY_DRIVER_TYPE_SYSTEM 0x0001 393#define TTY_DRIVER_TYPE_CONSOLE 0x0002 394#define TTY_DRIVER_TYPE_SERIAL 0x0003 395#define TTY_DRIVER_TYPE_PTY 0x0004 396#define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 397#define TTY_DRIVER_TYPE_SYSCONS 0x0006 398 399/* system subtypes (magic, used by tty_io.c) */ 400#define SYSTEM_TYPE_TTY 0x0001 401#define SYSTEM_TYPE_CONSOLE 0x0002 402#define SYSTEM_TYPE_SYSCONS 0x0003 403#define SYSTEM_TYPE_SYSPTMX 0x0004 404 405/* pty subtypes (magic, used by tty_io.c) */ 406#define PTY_TYPE_MASTER 0x0001 407#define PTY_TYPE_SLAVE 0x0002 408 409/* serial subtype definitions */ 410#define SERIAL_TYPE_NORMAL 1 411 412#endif /* #ifdef _LINUX_TTY_DRIVER_H */ 413