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 * int (*open)(struct tty_struct * tty, struct file * filp); 11 * 12 * This routine is called when a particular tty device is opened. 13 * This routine is mandatory; if this routine is not filled in, 14 * the attempted open will fail with ENODEV. 15 * 16 * Required method. 17 * 18 * void (*close)(struct tty_struct * tty, struct file * filp); 19 * 20 * This routine is called when a particular tty device is closed. 21 * 22 * Required method. 23 * 24 * int (*write)(struct tty_struct * tty, 25 * const unsigned char *buf, int count); 26 * 27 * This routine is called by the kernel to write a series of 28 * characters to the tty device. The characters may come from 29 * user space or kernel space. This routine will return the 30 * number of characters actually accepted for writing. 31 * 32 * Optional: Required for writable devices. 33 * 34 * int (*put_char)(struct tty_struct *tty, unsigned char ch); 35 * 36 * This routine is called by the kernel to write a single 37 * character to the tty device. If the kernel uses this routine, 38 * it must call the flush_chars() routine (if defined) when it is 39 * done stuffing characters into the driver. If there is no room 40 * in the queue, the character is ignored. 41 * 42 * Optional: Kernel will use the write method if not provided. 43 * 44 * Note: Do not call this function directly, call tty_put_char 45 * 46 * void (*flush_chars)(struct tty_struct *tty); 47 * 48 * This routine is called by the kernel after it has written a 49 * series of characters to the tty device using put_char(). 50 * 51 * Optional: 52 * 53 * Note: Do not call this function directly, call tty_driver_flush_chars 54 * 55 * int (*write_room)(struct tty_struct *tty); 56 * 57 * This routine returns the numbers of characters the tty driver 58 * will accept for queuing to be written. This number is subject 59 * to change as output buffers get emptied, or if the output flow 60 * control is acted. 61 * 62 * Required if write method is provided else not needed. 63 * 64 * Note: Do not call this function directly, call tty_write_room 65 * 66 * int (*ioctl)(struct tty_struct *tty, struct file * file, 67 * unsigned int cmd, unsigned long arg); 68 * 69 * This routine allows the tty driver to implement 70 * device-specific ioctl's. If the ioctl number passed in cmd 71 * is not recognized by the driver, it should return ENOIOCTLCMD. 72 * 73 * Optional 74 * 75 * long (*compat_ioctl)(struct tty_struct *tty, struct file * file, 76 * unsigned int cmd, unsigned long arg); 77 * 78 * implement ioctl processing for 32 bit process on 64 bit system 79 * 80 * Optional 81 * 82 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 83 * 84 * This routine allows the tty driver to be notified when 85 * device's termios settings have changed. 86 * 87 * Optional: Called under the termios lock 88 * 89 * 90 * void (*set_ldisc)(struct tty_struct *tty); 91 * 92 * This routine allows the tty driver to be notified when the 93 * device's termios settings have changed. 94 * 95 * Optional: Called under BKL (currently) 96 * 97 * void (*throttle)(struct tty_struct * tty); 98 * 99 * This routine notifies the tty driver that input buffers for 100 * the line discipline are close to full, and it should somehow 101 * signal that no more characters should be sent to the tty. 102 * 103 * Optional: Always invoke via tty_throttle(); 104 * 105 * void (*unthrottle)(struct tty_struct * tty); 106 * 107 * This routine notifies the tty drivers that it should signals 108 * that characters can now be sent to the tty without fear of 109 * overrunning the input buffers of the line disciplines. 110 * 111 * Optional: Always invoke via tty_unthrottle(); 112 * 113 * void (*stop)(struct tty_struct *tty); 114 * 115 * This routine notifies the tty driver that it should stop 116 * outputting characters to the tty device. 117 * 118 * Optional: 119 * 120 * Note: Call stop_tty not this method. 121 * 122 * void (*start)(struct tty_struct *tty); 123 * 124 * This routine notifies the tty driver that it resume sending 125 * characters to the tty device. 126 * 127 * Optional: 128 * 129 * Note: Call start_tty not this method. 130 * 131 * void (*hangup)(struct tty_struct *tty); 132 * 133 * This routine notifies the tty driver that it should hangup the 134 * tty device. 135 * 136 * Optional: 137 * 138 * int (*break_ctl)(struct tty_stuct *tty, int state); 139 * 140 * This optional routine requests the tty driver to turn on or 141 * off BREAK status on the RS-232 port. If state is -1, 142 * then the BREAK status should be turned on; if state is 0, then 143 * BREAK should be turned off. 144 * 145 * If this routine is implemented, the high-level tty driver will 146 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, 147 * TIOCCBRK. 148 * 149 * If the driver sets TTY_DRIVER_HARDWARE_BREAK then the interface 150 * will also be called with actual times and the hardware is expected 151 * to do the delay work itself. 0 and -1 are still used for on/off. 152 * 153 * Optional: Required for TCSBRK/BRKP/etc handling. 154 * 155 * void (*wait_until_sent)(struct tty_struct *tty, int timeout); 156 * 157 * This routine waits until the device has written out all of the 158 * characters in its transmitter FIFO. 159 * 160 * Optional: If not provided the device is assumed to have no FIFO 161 * 162 * Note: Usually correct to call tty_wait_until_sent 163 * 164 * void (*send_xchar)(struct tty_struct *tty, char ch); 165 * 166 * This routine is used to send a high-priority XON/XOFF 167 * character to the device. 168 * 169 * Optional: If not provided then the write method is called under 170 * the atomic write lock to keep it serialized with the ldisc. 171 * 172 * int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty, 173 * unsigned int rows, unsigned int cols); 174 * 175 * Called when a termios request is issued which changes the 176 * requested terminal geometry. 177 * 178 * Optional: the default action is to update the termios structure 179 * without error. This is usually the correct behaviour. Drivers should 180 * not force errors here if they are not resizable objects (eg a serial 181 * line). See tty_do_resize() if you need to wrap the standard method 182 * in your own logic - the usual case. 183 */ 184 185 #include <linux/fs.h> 186 #include <linux/list.h> 187 #include <linux/cdev.h> 188 189 struct tty_struct; 190 struct tty_driver; 191 192 struct tty_operations { 193 int (*open)(struct tty_struct * tty, struct file * filp); 194 void (*close)(struct tty_struct * tty, struct file * filp); 195 int (*write)(struct tty_struct * tty, 196 const unsigned char *buf, int count); 197 int (*put_char)(struct tty_struct *tty, unsigned char ch); 198 void (*flush_chars)(struct tty_struct *tty); 199 int (*write_room)(struct tty_struct *tty); 200 int (*chars_in_buffer)(struct tty_struct *tty); 201 int (*ioctl)(struct tty_struct *tty, struct file * file, 202 unsigned int cmd, unsigned long arg); 203 long (*compat_ioctl)(struct tty_struct *tty, struct file * file, 204 unsigned int cmd, unsigned long arg); 205 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 206 void (*throttle)(struct tty_struct * tty); 207 void (*unthrottle)(struct tty_struct * tty); 208 void (*stop)(struct tty_struct *tty); 209 void (*start)(struct tty_struct *tty); 210 void (*hangup)(struct tty_struct *tty); 211 int (*break_ctl)(struct tty_struct *tty, int state); 212 void (*flush_buffer)(struct tty_struct *tty); 213 void (*set_ldisc)(struct tty_struct *tty); 214 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 215 void (*send_xchar)(struct tty_struct *tty, char ch); 216 int (*read_proc)(char *page, char **start, off_t off, 217 int count, int *eof, void *data); 218 int (*tiocmget)(struct tty_struct *tty, struct file *file); 219 int (*tiocmset)(struct tty_struct *tty, struct file *file, 220 unsigned int set, unsigned int clear); 221 int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty, 222 struct winsize *ws); 223 #ifdef CONFIG_CONSOLE_POLL 224 int (*poll_init)(struct tty_driver *driver, int line, char *options); 225 int (*poll_get_char)(struct tty_driver *driver, int line); 226 void (*poll_put_char)(struct tty_driver *driver, int line, char ch); 227 #endif 228 }; 229 230 struct tty_driver { 231 int magic; /* magic number for this structure */ 232 struct cdev cdev; 233 struct module *owner; 234 const char *driver_name; 235 const char *name; 236 int name_base; /* offset of printed name */ 237 int major; /* major device number */ 238 int minor_start; /* start of minor device number */ 239 int minor_num; /* number of *possible* devices */ 240 int num; /* number of devices allocated */ 241 short type; /* type of tty driver */ 242 short subtype; /* subtype of tty driver */ 243 struct ktermios init_termios; /* Initial termios */ 244 int flags; /* tty driver flags */ 245 int refcount; /* for loadable tty drivers */ 246 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 247 struct tty_driver *other; /* only used for the PTY driver */ 248 249 /* 250 * Pointer to the tty data structures 251 */ 252 struct tty_struct **ttys; 253 struct ktermios **termios; 254 struct ktermios **termios_locked; 255 void *driver_state; 256 257 /* 258 * Driver methods 259 */ 260 261 const struct tty_operations *ops; 262 struct list_head tty_drivers; 263 }; 264 265 extern struct list_head tty_drivers; 266 267 struct tty_driver *alloc_tty_driver(int lines); 268 void put_tty_driver(struct tty_driver *driver); 269 void tty_set_operations(struct tty_driver *driver, 270 const struct tty_operations *op); 271 extern struct tty_driver *tty_find_polling_driver(char *name, int *line); 272 273 /* tty driver magic number */ 274 #define TTY_DRIVER_MAGIC 0x5402 275 276 /* 277 * tty driver flags 278 * 279 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 280 * termios setting when the last process has closed the device. 281 * Used for PTY's, in particular. 282 * 283 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 284 * guarantee never not to set any special character handling 285 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 286 * !INPCK)). That is, if there is no reason for the driver to 287 * send notifications of parity and break characters up to the 288 * line driver, it won't do so. This allows the line driver to 289 * optimize for this case if this flag is set. (Note that there 290 * is also a promise, if the above case is true, not to signal 291 * overruns, either.) 292 * 293 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need 294 * to be registered with a call to tty_register_driver() when the 295 * device is found in the system and unregistered with a call to 296 * tty_unregister_device() so the devices will be show up 297 * properly in sysfs. If not set, driver->num entries will be 298 * created by the tty core in sysfs when tty_register_driver() is 299 * called. This is to be used by drivers that have tty devices 300 * that can appear and disappear while the main tty driver is 301 * registered with the tty core. 302 * 303 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead 304 * use dynamic memory keyed through the devpts filesystem. This 305 * is only applicable to the pty driver. 306 * 307 * TTY_DRIVER_HARDWARE_BREAK -- hardware handles break signals. Pass 308 * the requested timeout to the caller instead of using a simple 309 * on/off interface. 310 * 311 */ 312 #define TTY_DRIVER_INSTALLED 0x0001 313 #define TTY_DRIVER_RESET_TERMIOS 0x0002 314 #define TTY_DRIVER_REAL_RAW 0x0004 315 #define TTY_DRIVER_DYNAMIC_DEV 0x0008 316 #define TTY_DRIVER_DEVPTS_MEM 0x0010 317 #define TTY_DRIVER_HARDWARE_BREAK 0x0020 318 319 /* tty driver types */ 320 #define TTY_DRIVER_TYPE_SYSTEM 0x0001 321 #define TTY_DRIVER_TYPE_CONSOLE 0x0002 322 #define TTY_DRIVER_TYPE_SERIAL 0x0003 323 #define TTY_DRIVER_TYPE_PTY 0x0004 324 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 325 #define TTY_DRIVER_TYPE_SYSCONS 0x0006 326 327 /* system subtypes (magic, used by tty_io.c) */ 328 #define SYSTEM_TYPE_TTY 0x0001 329 #define SYSTEM_TYPE_CONSOLE 0x0002 330 #define SYSTEM_TYPE_SYSCONS 0x0003 331 #define SYSTEM_TYPE_SYSPTMX 0x0004 332 333 /* pty subtypes (magic, used by tty_io.c) */ 334 #define PTY_TYPE_MASTER 0x0001 335 #define PTY_TYPE_SLAVE 0x0002 336 337 /* serial subtype definitions */ 338 #define SERIAL_TYPE_NORMAL 1 339 340 #endif /* #ifdef _LINUX_TTY_DRIVER_H */ 341