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 * Note: called even if the corresponding open() failed. 44 * 45 * Required method. 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 * 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 hang up the 171 * tty device. 172 * 173 * Optional: 174 * 175 * int (*break_ctl)(struct tty_struct *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 * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount); 229 * 230 * Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel 231 * structure to complete. This method is optional and will only be called 232 * if provided (otherwise EINVAL will be returned). 233 */ 234 235#include <linux/export.h> 236#include <linux/fs.h> 237#include <linux/list.h> 238#include <linux/cdev.h> 239#include <linux/termios.h> 240 241struct tty_struct; 242struct tty_driver; 243struct serial_icounter_struct; 244 245struct tty_operations { 246 struct tty_struct * (*lookup)(struct tty_driver *driver, 247 struct inode *inode, int idx); 248 int (*install)(struct tty_driver *driver, struct tty_struct *tty); 249 void (*remove)(struct tty_driver *driver, struct tty_struct *tty); 250 int (*open)(struct tty_struct * tty, struct file * filp); 251 void (*close)(struct tty_struct * tty, struct file * filp); 252 void (*shutdown)(struct tty_struct *tty); 253 void (*cleanup)(struct tty_struct *tty); 254 int (*write)(struct tty_struct * tty, 255 const unsigned char *buf, int count); 256 int (*put_char)(struct tty_struct *tty, unsigned char ch); 257 void (*flush_chars)(struct tty_struct *tty); 258 int (*write_room)(struct tty_struct *tty); 259 int (*chars_in_buffer)(struct tty_struct *tty); 260 int (*ioctl)(struct tty_struct *tty, 261 unsigned int cmd, unsigned long arg); 262 long (*compat_ioctl)(struct tty_struct *tty, 263 unsigned int cmd, unsigned long arg); 264 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 265 void (*throttle)(struct tty_struct * tty); 266 void (*unthrottle)(struct tty_struct * tty); 267 void (*stop)(struct tty_struct *tty); 268 void (*start)(struct tty_struct *tty); 269 void (*hangup)(struct tty_struct *tty); 270 int (*break_ctl)(struct tty_struct *tty, int state); 271 void (*flush_buffer)(struct tty_struct *tty); 272 void (*set_ldisc)(struct tty_struct *tty); 273 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 274 void (*send_xchar)(struct tty_struct *tty, char ch); 275 int (*tiocmget)(struct tty_struct *tty); 276 int (*tiocmset)(struct tty_struct *tty, 277 unsigned int set, unsigned int clear); 278 int (*resize)(struct tty_struct *tty, struct winsize *ws); 279 int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew); 280 int (*get_icount)(struct tty_struct *tty, 281 struct serial_icounter_struct *icount); 282#ifdef CONFIG_CONSOLE_POLL 283 int (*poll_init)(struct tty_driver *driver, int line, char *options); 284 int (*poll_get_char)(struct tty_driver *driver, int line); 285 void (*poll_put_char)(struct tty_driver *driver, int line, char ch); 286#endif 287 const struct file_operations *proc_fops; 288}; 289 290struct tty_driver { 291 int magic; /* magic number for this structure */ 292 struct kref kref; /* Reference management */ 293 RH_KABI_REPLACE(struct cdev *cdevs, struct cdev **cdevs) 294 struct module *owner; 295 const char *driver_name; 296 const char *name; 297 int name_base; /* offset of printed name */ 298 int major; /* major device number */ 299 int minor_start; /* start of minor device number */ 300 unsigned int num; /* number of devices allocated */ 301 short type; /* type of tty driver */ 302 short subtype; /* subtype of tty driver */ 303 struct ktermios init_termios; /* Initial termios */ 304 unsigned long flags; /* tty driver flags */ 305 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 306 struct tty_driver *other; /* only used for the PTY driver */ 307 308 /* 309 * Pointer to the tty data structures 310 */ 311 struct tty_struct **ttys; 312 struct tty_port **ports; 313 struct ktermios **termios; 314 void *driver_state; 315 316 /* 317 * Driver methods 318 */ 319 320 const struct tty_operations *ops; 321 struct list_head tty_drivers; 322}; 323 324extern struct list_head tty_drivers; 325 326extern struct tty_driver *__tty_alloc_driver(unsigned int lines, 327 struct module *owner, unsigned long flags); 328extern void put_tty_driver(struct tty_driver *driver); 329extern void tty_set_operations(struct tty_driver *driver, 330 const struct tty_operations *op); 331extern struct tty_driver *tty_find_polling_driver(char *name, int *line); 332 333extern void tty_driver_kref_put(struct tty_driver *driver); 334 335/* Use TTY_DRIVER_* flags below */ 336#define tty_alloc_driver(lines, flags) \ 337 __tty_alloc_driver(lines, THIS_MODULE, flags) 338 339/* 340 * DEPRECATED Do not use this in new code, use tty_alloc_driver instead. 341 * (And change the return value checks.) 342 */ 343static inline struct tty_driver *alloc_tty_driver(unsigned int lines) 344{ 345 struct tty_driver *ret = tty_alloc_driver(lines, 0); 346 if (IS_ERR(ret)) 347 return NULL; 348 return ret; 349} 350 351static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) 352{ 353 kref_get(&d->kref); 354 return d; 355} 356 357/* tty driver magic number */ 358#define TTY_DRIVER_MAGIC 0x5402 359 360/* 361 * tty driver flags 362 * 363 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 364 * termios setting when the last process has closed the device. 365 * Used for PTY's, in particular. 366 * 367 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 368 * guarantee never not to set any special character handling 369 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 370 * !INPCK)). That is, if there is no reason for the driver to 371 * send notifications of parity and break characters up to the 372 * line driver, it won't do so. This allows the line driver to 373 * optimize for this case if this flag is set. (Note that there 374 * is also a promise, if the above case is true, not to signal 375 * overruns, either.) 376 * 377 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need 378 * to be registered with a call to tty_register_device() when the 379 * device is found in the system and unregistered with a call to 380 * tty_unregister_device() so the devices will be show up 381 * properly in sysfs. If not set, driver->num entries will be 382 * created by the tty core in sysfs when tty_register_driver() is 383 * called. This is to be used by drivers that have tty devices 384 * that can appear and disappear while the main tty driver is 385 * registered with the tty core. 386 * 387 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead 388 * use dynamic memory keyed through the devpts filesystem. This 389 * is only applicable to the pty driver. 390 * 391 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass 392 * the requested timeout to the caller instead of using a simple 393 * on/off interface. 394 * 395 * TTY_DRIVER_DYNAMIC_ALLOC -- do not allocate structures which are 396 * needed per line for this driver as it would waste memory. 397 * The driver will take care. 398 * 399 * TTY_DRIVER_UNNUMBERED_NODE -- do not create numbered /dev nodes. In 400 * other words create /dev/ttyprintk and not /dev/ttyprintk0. 401 * Applicable only when a driver for a single tty device is 402 * being allocated. 403 */ 404#define TTY_DRIVER_INSTALLED 0x0001 405#define TTY_DRIVER_RESET_TERMIOS 0x0002 406#define TTY_DRIVER_REAL_RAW 0x0004 407#define TTY_DRIVER_DYNAMIC_DEV 0x0008 408#define TTY_DRIVER_DEVPTS_MEM 0x0010 409#define TTY_DRIVER_HARDWARE_BREAK 0x0020 410#define TTY_DRIVER_DYNAMIC_ALLOC 0x0040 411#define TTY_DRIVER_UNNUMBERED_NODE 0x0080 412 413/* tty driver types */ 414#define TTY_DRIVER_TYPE_SYSTEM 0x0001 415#define TTY_DRIVER_TYPE_CONSOLE 0x0002 416#define TTY_DRIVER_TYPE_SERIAL 0x0003 417#define TTY_DRIVER_TYPE_PTY 0x0004 418#define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 419#define TTY_DRIVER_TYPE_SYSCONS 0x0006 420 421/* system subtypes (magic, used by tty_io.c) */ 422#define SYSTEM_TYPE_TTY 0x0001 423#define SYSTEM_TYPE_CONSOLE 0x0002 424#define SYSTEM_TYPE_SYSCONS 0x0003 425#define SYSTEM_TYPE_SYSPTMX 0x0004 426 427/* pty subtypes (magic, used by tty_io.c) */ 428#define PTY_TYPE_MASTER 0x0001 429#define PTY_TYPE_SLAVE 0x0002 430 431/* serial subtype definitions */ 432#define SERIAL_TYPE_NORMAL 1 433 434#endif /* #ifdef _LINUX_TTY_DRIVER_H */ 435