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 * void (*close)(struct tty_struct * tty, struct file * filp); 17 * 18 * This routine is called when a particular tty device is closed. 19 * 20 * int (*write)(struct tty_struct * tty, 21 * const unsigned char *buf, int count); 22 * 23 * This routine is called by the kernel to write a series of 24 * characters to the tty device. The characters may come from 25 * user space or kernel space. This routine will return the 26 * number of characters actually accepted for writing. This 27 * routine is mandatory. 28 * 29 * void (*put_char)(struct tty_struct *tty, unsigned char ch); 30 * 31 * This routine is called by the kernel to write a single 32 * character to the tty device. If the kernel uses this routine, 33 * it must call the flush_chars() routine (if defined) when it is 34 * done stuffing characters into the driver. If there is no room 35 * in the queue, the character is ignored. 36 * 37 * void (*flush_chars)(struct tty_struct *tty); 38 * 39 * This routine is called by the kernel after it has written a 40 * series of characters to the tty device using put_char(). 41 * 42 * int (*write_room)(struct tty_struct *tty); 43 * 44 * This routine returns the numbers of characters the tty driver 45 * will accept for queuing to be written. This number is subject 46 * to change as output buffers get emptied, or if the output flow 47 * control is acted. 48 * 49 * int (*ioctl)(struct tty_struct *tty, struct file * file, 50 * unsigned int cmd, unsigned long arg); 51 * 52 * This routine allows the tty driver to implement 53 * device-specific ioctl's. If the ioctl number passed in cmd 54 * is not recognized by the driver, it should return ENOIOCTLCMD. 55 * 56 * void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 57 * 58 * This routine allows the tty driver to be notified when 59 * device's termios settings have changed. Note that a 60 * well-designed tty driver should be prepared to accept the case 61 * where old == NULL, and try to do something rational. 62 * 63 * void (*set_ldisc)(struct tty_struct *tty); 64 * 65 * This routine allows the tty driver to be notified when the 66 * device's termios settings have changed. 67 * 68 * void (*throttle)(struct tty_struct * tty); 69 * 70 * This routine notifies the tty driver that input buffers for 71 * the line discipline are close to full, and it should somehow 72 * signal that no more characters should be sent to the tty. 73 * 74 * void (*unthrottle)(struct tty_struct * tty); 75 * 76 * This routine notifies the tty drivers that it should signals 77 * that characters can now be sent to the tty without fear of 78 * overrunning the input buffers of the line disciplines. 79 * 80 * void (*stop)(struct tty_struct *tty); 81 * 82 * This routine notifies the tty driver that it should stop 83 * outputting characters to the tty device. 84 * 85 * void (*start)(struct tty_struct *tty); 86 * 87 * This routine notifies the tty driver that it resume sending 88 * characters to the tty device. 89 * 90 * void (*hangup)(struct tty_struct *tty); 91 * 92 * This routine notifies the tty driver that it should hangup the 93 * tty device. 94 * 95 * void (*break_ctl)(struct tty_stuct *tty, int state); 96 * 97 * This optional routine requests the tty driver to turn on or 98 * off BREAK status on the RS-232 port. If state is -1, 99 * then the BREAK status should be turned on; if state is 0, then 100 * BREAK should be turned off. 101 * 102 * If this routine is implemented, the high-level tty driver will 103 * handle the following ioctls: TCSBRK, TCSBRKP, TIOCSBRK, 104 * TIOCCBRK. Otherwise, these ioctls will be passed down to the 105 * driver to handle. 106 * 107 * void (*wait_until_sent)(struct tty_struct *tty, int timeout); 108 * 109 * This routine waits until the device has written out all of the 110 * characters in its transmitter FIFO. 111 * 112 * void (*send_xchar)(struct tty_struct *tty, char ch); 113 * 114 * This routine is used to send a high-priority XON/XOFF 115 * character to the device. 116 */ 117 118 #include <linux/fs.h> 119 #include <linux/list.h> 120 #include <linux/cdev.h> 121 122 struct tty_struct; 123 124 struct tty_operations { 125 int (*open)(struct tty_struct * tty, struct file * filp); 126 void (*close)(struct tty_struct * tty, struct file * filp); 127 int (*write)(struct tty_struct * tty, 128 const unsigned char *buf, int count); 129 void (*put_char)(struct tty_struct *tty, unsigned char ch); 130 void (*flush_chars)(struct tty_struct *tty); 131 int (*write_room)(struct tty_struct *tty); 132 int (*chars_in_buffer)(struct tty_struct *tty); 133 int (*ioctl)(struct tty_struct *tty, struct file * file, 134 unsigned int cmd, unsigned long arg); 135 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 136 void (*throttle)(struct tty_struct * tty); 137 void (*unthrottle)(struct tty_struct * tty); 138 void (*stop)(struct tty_struct *tty); 139 void (*start)(struct tty_struct *tty); 140 void (*hangup)(struct tty_struct *tty); 141 void (*break_ctl)(struct tty_struct *tty, int state); 142 void (*flush_buffer)(struct tty_struct *tty); 143 void (*set_ldisc)(struct tty_struct *tty); 144 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 145 void (*send_xchar)(struct tty_struct *tty, char ch); 146 int (*read_proc)(char *page, char **start, off_t off, 147 int count, int *eof, void *data); 148 int (*write_proc)(struct file *file, const char __user *buffer, 149 unsigned long count, void *data); 150 int (*tiocmget)(struct tty_struct *tty, struct file *file); 151 int (*tiocmset)(struct tty_struct *tty, struct file *file, 152 unsigned int set, unsigned int clear); 153 }; 154 155 struct tty_driver { 156 int magic; /* magic number for this structure */ 157 struct cdev cdev; 158 struct module *owner; 159 const char *driver_name; 160 const char *name; 161 int name_base; /* offset of printed name */ 162 int major; /* major device number */ 163 int minor_start; /* start of minor device number */ 164 int minor_num; /* number of *possible* devices */ 165 int num; /* number of devices allocated */ 166 short type; /* type of tty driver */ 167 short subtype; /* subtype of tty driver */ 168 struct ktermios init_termios; /* Initial termios */ 169 int flags; /* tty driver flags */ 170 int refcount; /* for loadable tty drivers */ 171 struct proc_dir_entry *proc_entry; /* /proc fs entry */ 172 struct tty_driver *other; /* only used for the PTY driver */ 173 174 /* 175 * Pointer to the tty data structures 176 */ 177 struct tty_struct **ttys; 178 struct ktermios **termios; 179 struct ktermios **termios_locked; 180 void *driver_state; /* only used for the PTY driver */ 181 182 /* 183 * Interface routines from the upper tty layer to the tty 184 * driver. Will be replaced with struct tty_operations. 185 */ 186 int (*open)(struct tty_struct * tty, struct file * filp); 187 void (*close)(struct tty_struct * tty, struct file * filp); 188 int (*write)(struct tty_struct * tty, 189 const unsigned char *buf, int count); 190 void (*put_char)(struct tty_struct *tty, unsigned char ch); 191 void (*flush_chars)(struct tty_struct *tty); 192 int (*write_room)(struct tty_struct *tty); 193 int (*chars_in_buffer)(struct tty_struct *tty); 194 int (*ioctl)(struct tty_struct *tty, struct file * file, 195 unsigned int cmd, unsigned long arg); 196 void (*set_termios)(struct tty_struct *tty, struct ktermios * old); 197 void (*throttle)(struct tty_struct * tty); 198 void (*unthrottle)(struct tty_struct * tty); 199 void (*stop)(struct tty_struct *tty); 200 void (*start)(struct tty_struct *tty); 201 void (*hangup)(struct tty_struct *tty); 202 void (*break_ctl)(struct tty_struct *tty, int state); 203 void (*flush_buffer)(struct tty_struct *tty); 204 void (*set_ldisc)(struct tty_struct *tty); 205 void (*wait_until_sent)(struct tty_struct *tty, int timeout); 206 void (*send_xchar)(struct tty_struct *tty, char ch); 207 int (*read_proc)(char *page, char **start, off_t off, 208 int count, int *eof, void *data); 209 int (*write_proc)(struct file *file, const char __user *buffer, 210 unsigned long count, void *data); 211 int (*tiocmget)(struct tty_struct *tty, struct file *file); 212 int (*tiocmset)(struct tty_struct *tty, struct file *file, 213 unsigned int set, unsigned int clear); 214 215 struct list_head tty_drivers; 216 }; 217 218 extern struct list_head tty_drivers; 219 220 struct tty_driver *alloc_tty_driver(int lines); 221 void put_tty_driver(struct tty_driver *driver); 222 void tty_set_operations(struct tty_driver *driver, 223 const struct tty_operations *op); 224 225 /* tty driver magic number */ 226 #define TTY_DRIVER_MAGIC 0x5402 227 228 /* 229 * tty driver flags 230 * 231 * TTY_DRIVER_RESET_TERMIOS --- requests the tty layer to reset the 232 * termios setting when the last process has closed the device. 233 * Used for PTY's, in particular. 234 * 235 * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will 236 * guarantee never not to set any special character handling 237 * flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR || 238 * !INPCK)). That is, if there is no reason for the driver to 239 * send notifications of parity and break characters up to the 240 * line driver, it won't do so. This allows the line driver to 241 * optimize for this case if this flag is set. (Note that there 242 * is also a promise, if the above case is true, not to signal 243 * overruns, either.) 244 * 245 * TTY_DRIVER_DYNAMIC_DEV --- if set, the individual tty devices need 246 * to be registered with a call to tty_register_driver() when the 247 * device is found in the system and unregistered with a call to 248 * tty_unregister_device() so the devices will be show up 249 * properly in sysfs. If not set, driver->num entries will be 250 * created by the tty core in sysfs when tty_register_driver() is 251 * called. This is to be used by drivers that have tty devices 252 * that can appear and disappear while the main tty driver is 253 * registered with the tty core. 254 * 255 * TTY_DRIVER_DEVPTS_MEM -- don't use the standard arrays, instead 256 * use dynamic memory keyed through the devpts filesystem. This 257 * is only applicable to the pty driver. 258 */ 259 #define TTY_DRIVER_INSTALLED 0x0001 260 #define TTY_DRIVER_RESET_TERMIOS 0x0002 261 #define TTY_DRIVER_REAL_RAW 0x0004 262 #define TTY_DRIVER_DYNAMIC_DEV 0x0008 263 #define TTY_DRIVER_DEVPTS_MEM 0x0010 264 265 /* tty driver types */ 266 #define TTY_DRIVER_TYPE_SYSTEM 0x0001 267 #define TTY_DRIVER_TYPE_CONSOLE 0x0002 268 #define TTY_DRIVER_TYPE_SERIAL 0x0003 269 #define TTY_DRIVER_TYPE_PTY 0x0004 270 #define TTY_DRIVER_TYPE_SCC 0x0005 /* scc driver */ 271 #define TTY_DRIVER_TYPE_SYSCONS 0x0006 272 273 /* system subtypes (magic, used by tty_io.c) */ 274 #define SYSTEM_TYPE_TTY 0x0001 275 #define SYSTEM_TYPE_CONSOLE 0x0002 276 #define SYSTEM_TYPE_SYSCONS 0x0003 277 #define SYSTEM_TYPE_SYSPTMX 0x0004 278 279 /* pty subtypes (magic, used by tty_io.c) */ 280 #define PTY_TYPE_MASTER 0x0001 281 #define PTY_TYPE_SLAVE 0x0002 282 283 /* serial subtype definitions */ 284 #define SERIAL_TYPE_NORMAL 1 285 286 #endif /* #ifdef _LINUX_TTY_DRIVER_H */ 287