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. Called with tty lock held. 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 * Note: called even if the corresponding open() failed. 44 * 45 * Required method. Called with tty lock held. 46 * 47 * void (*shutdown)(struct tty_struct * tty); 48 * 49 * This routine is called under the tty lock when a particular tty device 50 * is closed for the last time. It executes before the tty resources 51 * are freed so may execute while another function holds a tty kref. 52 * 53 * void (*cleanup)(struct tty_struct * tty); 54 * 55 * This routine is called asynchronously when a particular tty device 56 * is closed for the last time freeing up the resources. This is 57 * actually the second part of shutdown for routines that might sleep. 58 * 59 * 60 * int (*write)(struct tty_struct * tty, 61 * const unsigned char *buf, int count); 62 * 63 * This routine is called by the kernel to write a series of 64 * characters to the tty device. The characters may come from 65 * user space or kernel space. This routine will return the 66 * number of characters actually accepted for writing. 67 * 68 * Optional: Required for writable devices. 69 * 70 * int (*put_char)(struct tty_struct *tty, unsigned char ch); 71 * 72 * This routine is called by the kernel to write a single 73 * character to the tty device. If the kernel uses this routine, 74 * it must call the flush_chars() routine (if defined) when it is 75 * done stuffing characters into the driver. If there is no room 76 * in the queue, the character is ignored. 77 * 78 * Optional: Kernel will use the write method if not provided. 79 * 80 * Note: Do not call this function directly, call tty_put_char 81 * 82 * void (*flush_chars)(struct tty_struct *tty); 83 * 84 * This routine is called by the kernel after it has written a 85 * series of characters to the tty device using put_char(). 86 * 87 * Optional: 88 * 89 * Note: Do not call this function directly, call tty_driver_flush_chars 90 * 91 * int (*write_room)(struct tty_struct *tty); 92 * 93 * This routine returns the numbers of characters the tty driver 94 * will accept for queuing to be written. This number is subject 95 * to change as output buffers get emptied, or if the output flow 96 * control is acted. 97 * 98 * Required if write method is provided else not needed. 99 * 100 * Note: Do not call this function directly, call tty_write_room 101 * 102 * int (*ioctl)(struct tty_struct *tty, unsigned int cmd, unsigned long arg); 103 * 104 * This routine allows the tty driver to implement 105 * device-specific ioctls. 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,, 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 * Called with ->flow_lock held. Serialized with start() method. 156 * 157 * Optional: 158 * 159 * Note: Call stop_tty not this method. 160 * 161 * void (*start)(struct tty_struct *tty); 162 * 163 * This routine notifies the tty driver that it resume sending 164 * characters to the tty device. 165 * 166 * Called with ->flow_lock held. Serialized with stop() method. 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 * Called with tty lock held. 180 * 181 * int (*break_ctl)(struct tty_struct *tty, int state); 182 * 183 * This optional routine requests the tty driver to turn on or 184 * off BREAK status on the RS-232 port. If state is -1, 185 * then the BREAK status should be turned on; if state is 0, then 186 * BREAK should be turned off. 187 * 188 * If this routine is implemented, the high-level tty driver will 189 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, 190 * TIOCCBRK. 191 * 192 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface 193 * will also be called with actual times and the hardware is expected 194 * to do the delay work itself. 0 and -1 are still used for on/off. 195 * 196 * Optional: Required for TCSBRK/BRKP/etc handling. 197 * 198 * void (*wait_until_sent)(struct tty_struct *tty, int timeout); 199 * 200 * This routine waits until the device has written out all of the 201 * characters in its transmitter FIFO. 202 * 203 * Optional: If not provided the device is assumed to have no FIFO 204 * 205 * Note: Usually correct to call tty_wait_until_sent 206 * 207 * void (*send_xchar)(struct tty_struct *tty, char ch); 208 * 209 * This routine is used to send a high-priority XON/XOFF 210 * character to the device. 211 * 212 * Optional: If not provided then the write method is called under 213 * the atomic write lock to keep it serialized with the ldisc. 214 * 215 * int (*resize)(struct tty_struct *tty, struct winsize *ws) 216 * 217 * Called when a termios request is issued which changes the 218 * requested terminal geometry. 219 * 220 * Optional: the default action is to update the termios structure 221 * without error. This is usually the correct behaviour. Drivers should 222 * not force errors here if they are not resizable objects (eg a serial 223 * line). See tty_do_resize() if you need to wrap the standard method 224 * in your own logic - the usual case. 225 * 226 * void (*set_termiox)(struct tty_struct *tty, struct termiox *new); 227 * 228 * Called when the device receives a termiox based ioctl. Passes down 229 * the requested data from user space. This method will not be invoked 230 * unless the tty also has a valid tty->termiox pointer. 231 * 232 * Optional: Called under the termios lock 233 * 234 * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount); 235 * 236 * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel 237 * structure to complete. This method is optional and will only be called 238 * if provided (otherwise EINVAL will be returned). 239 */ 240 241#include <linux/export.h> 242#include <linux/fs.h> 243#include <linux/list.h> 244#include <linux/cdev.h> 245#include <linux/termios.h> 246 247struct tty_struct; 248struct tty_driver; 249struct serial_icounter_struct; 250 251struct tty_operations { 252 struct tty_struct * (*lookup)(struct tty_driver *driver, 253 struct inode *inode, int idx); 254 int (*install)(struct tty_driver *driver, struct tty_struct *tty); 255 void (*remove)(struct tty_driver *driver, struct tty_struct *tty); 256 int (*open)(struct tty_struct * tty, struct file * filp); 257 void (*close)(struct tty_struct * tty, struct file * filp); 258 void (*shutdown)(struct tty_struct *tty); 259 void (*cleanup)(struct tty_struct *tty); 260 int (*write)(struct tty_struct * tty, 261 const unsigned char *buf, int count); 262 int (*put_char)(struct tty_struct *tty, unsigned char ch); 263 void (*flush_chars)(struct tty_struct *tty); 264 int (*write_room)(struct tty_struct *tty); 265 int (*chars_in_buffer)(struct tty_struct *tty); 266 int (*ioctl)(struct tty_struct *tty, 267 unsigned int cmd, unsigned long arg); 268 long (*compat_ioctl)(struct tty_struct *tty, 269 unsigned int cmd, unsigned long arg); 270 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 271 void (*throttle)(struct tty_struct * tty); 272 void (*unthrottle)(struct tty_struct * tty); 273 void (*stop)(struct tty_struct *tty); 274 void (*start)(struct tty_struct *tty); 275 void (*hangup)(struct tty_struct *tty); 276 int (*break_ctl)(struct tty_struct *tty, int state); 277 void (*flush_buffer)(struct tty_struct *tty); 278 void (*set_ldisc)(struct tty_struct *tty); 279 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 280 void (*send_xchar)(struct tty_struct *tty, char ch); 281 int (*tiocmget)(struct tty_struct *tty); 282 int (*tiocmset)(struct tty_struct *tty, 283 unsigned int set, unsigned int clear); 284 int (*resize)(struct tty_struct *tty, struct winsize *ws); 285 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew); 286 int (*get_icount)(struct tty_struct *tty, 287 struct serial_icounter_struct *icount); 288#ifdef CONFIG_CONSOLE_POLL 289 int (*poll_init)(struct tty_driver *driver, int line, char *options); 290 int (*poll_get_char)(struct tty_driver *driver, int line); 291 void (*poll_put_char)(struct tty_driver *driver, int line, char ch); 292#endif 293 const struct file_operations *proc_fops; 294}; 295 296struct tty_driver { 297 int magic; /* magic number for this structure */ 298 struct kref kref; /* Reference management */ 299 struct cdev **cdevs; 300 struct module *owner; 301 const char *driver_name; 302 const char *name; 303 int name_base; /* offset of printed name */ 304 int major; /* major device number */ 305 int minor_start; /* start of minor device number */ 306 unsigned int num; /* number of devices allocated */ 307 short type; /* type of tty driver */ 308 short subtype; /* subtype of tty driver */ 309 struct ktermios init_termios; /* Initial termios */ 310 unsigned long flags; /* tty driver flags */ 311 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 312 struct tty_driver *other; /* only used for the PTY driver */ 313 314 /* 315 * Pointer to the tty data structures 316 */ 317 struct tty_struct **ttys; 318 struct tty_port **ports; 319 struct ktermios **termios; 320 void *driver_state; 321 322 /* 323 * Driver methods 324 */ 325 326 const struct tty_operations *ops; 327 struct list_head tty_drivers; 328}; 329 330extern struct list_head tty_drivers; 331 332extern struct tty_driver *__tty_alloc_driver(unsigned int lines, 333 struct module *owner, unsigned long flags); 334extern void put_tty_driver(struct tty_driver *driver); 335extern void tty_set_operations(struct tty_driver *driver, 336 const struct tty_operations *op); 337extern struct tty_driver *tty_find_polling_driver(char *name, int *line); 338 339extern void tty_driver_kref_put(struct tty_driver *driver); 340 341/* Use TTY_DRIVER_* flags below */ 342#define tty_alloc_driver(lines, flags) \ 343 __tty_alloc_driver(lines, THIS_MODULE, flags) 344 345/* 346 * DEPRECATED Do not use this in new code, use tty_alloc_driver instead. 347 * (And change the return value checks.) 348 */ 349static inline struct tty_driver *alloc_tty_driver(unsigned int lines) 350{ 351 struct tty_driver *ret = tty_alloc_driver(lines, 0); 352 if (IS_ERR(ret)) 353 return NULL; 354 return ret; 355} 356 357static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) 358{ 359 kref_get(&d->kref); 360 return d; 361} 362 363/* tty driver magic number */ 364#define TTY_DRIVER_MAGIC 0x5402 365 366/* 367 * tty driver flags 368 * 369 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 370 * termios setting when the last process has closed the device. 371 * Used for PTY's, in particular. 372 * 373 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 374 * guarantee never not to set any special character handling 375 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 376 * !INPCK)). That is, if there is no reason for the driver to 377 * send notifications of parity and break characters up to the 378 * line driver, it won't do so. This allows the line driver to 379 * optimize for this case if this flag is set. (Note that there 380 * is also a promise, if the above case is true, not to signal 381 * overruns, either.) 382 * 383 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need 384 * to be registered with a call to tty_register_device() when the 385 * device is found in the system and unregistered with a call to 386 * tty_unregister_device() so the devices will be show up 387 * properly in sysfs. If not set, driver->num entries will be 388 * created by the tty core in sysfs when tty_register_driver() is 389 * called. This is to be used by drivers that have tty devices 390 * that can appear and disappear while the main tty driver is 391 * registered with the tty core. 392 * 393 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead 394 * use dynamic memory keyed through the devpts filesystem. This 395 * is only applicable to the pty driver. 396 * 397 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass 398 * the requested timeout to the caller instead of using a simple 399 * on/off interface. 400 * 401 * TTY_DRIVER_DYNAMIC_ALLOC -- do not allocate structures which are 402 * needed per line for this driver as it would waste memory. 403 * The driver will take care. 404 * 405 * TTY_DRIVER_UNNUMBERED_NODE -- do not create numbered /dev nodes. In 406 * other words create /dev/ttyprintk and not /dev/ttyprintk0. 407 * Applicable only when a driver for a single tty device is 408 * being allocated. 409 */ 410#define TTY_DRIVER_INSTALLED 0x0001 411#define TTY_DRIVER_RESET_TERMIOS 0x0002 412#define TTY_DRIVER_REAL_RAW 0x0004 413#define TTY_DRIVER_DYNAMIC_DEV 0x0008 414#define TTY_DRIVER_DEVPTS_MEM 0x0010 415#define TTY_DRIVER_HARDWARE_BREAK 0x0020 416#define TTY_DRIVER_DYNAMIC_ALLOC 0x0040 417#define TTY_DRIVER_UNNUMBERED_NODE 0x0080 418 419/* tty driver types */ 420#define TTY_DRIVER_TYPE_SYSTEM 0x0001 421#define TTY_DRIVER_TYPE_CONSOLE 0x0002 422#define TTY_DRIVER_TYPE_SERIAL 0x0003 423#define TTY_DRIVER_TYPE_PTY 0x0004 424#define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 425#define TTY_DRIVER_TYPE_SYSCONS 0x0006 426 427/* system subtypes (magic, used by tty_io.c) */ 428#define SYSTEM_TYPE_TTY 0x0001 429#define SYSTEM_TYPE_CONSOLE 0x0002 430#define SYSTEM_TYPE_SYSCONS 0x0003 431#define SYSTEM_TYPE_SYSPTMX 0x0004 432 433/* pty subtypes (magic, used by tty_io.c) */ 434#define PTY_TYPE_MASTER 0x0001 435#define PTY_TYPE_SLAVE 0x0002 436 437/* serial subtype definitions */ 438#define SERIAL_TYPE_NORMAL 1 439 440#endif /* #ifdef _LINUX_TTY_DRIVER_H */ 441