linedisc(9) [netbsd man page]

LINEDISC(9)						   BSD Kernel Developer's Manual					       LINEDISC(9)

NAME

     linedisc, ttyldisc_add, ttyldisc_lookup, ttyldisc_remove -- extensible line discipline framework

SYNOPSIS

     #include <sys/conf.h>

     int
     ttyldisc_add(struct linesw *disc, int no);

     struct linesw *
     ttyldisc_remove(const char *name);

     struct linesw *
     ttyldisc_lookup(const char *name);

DESCRIPTION

     The NetBSD TTY line discipline framework allows extensibility.  Modules that need special line disciplines can add them as convenient and do
     not need to modify tty_conf.c.  Line disciplines are now managed by a string, rather than number.

     Once the framework has been initialized, a new line discipline can be added by creating and initializing a struct linesw and calling
     ttyldisc_add().

     The following is a brief description of each function in the framework:

     ttyldisc_add()	Register a line discipline.  The l_name field of the struct linesw should point to a string which is to be the symbolic
			name of that line discipline.  For compatibility purposes, a line discipline number can be passed in no, but for new dis-
			ciplines this should be set to -1.

     ttyldisc_lookup()	Look up a line discipline by name.  NULL is returned if it can not be found.

     ttyldisc_remove()	Remove a line discipline called name and return a pointer to it.  If the discipline cannot be found or removed
			ttyldisc_remove() will return NULL.

SEE ALSO

     tty(4)

HISTORY

     The linedisc functions were added in NetBSD 1.6.

AUTHORS

     The NetBSD extensible line discipline framework was created by Eduardo Horvath <eeh@NetBSD.org>.

BSD
								 November 1, 2000							       BSD

TB(4)							     Kernel Interfaces Manual							     TB(4)

NAME

       tb - line discipline for digitizing devices

SYNOPSIS

       /sys/conf/SYSTEM:
	    NTB  1    # RS232 interface for Genisco/Hitachi tablets

DESCRIPTION

       This  line  discipline  provides  a polled interface to many common digitizing devices which are connected to a host through a serial line.
       When these devices stream data at high speed, the use of the line discipline is critical in minimizing the number  of  samples  that  would
       otherwise be lost due to buffer exhaustion in the tty(4) handler.

       The line discipline is enabled by a sequence:

	    #include <sys/tablet.h>
	    int ldisc = TBLDISC, fildes; ...
	    ioctl(fildes, TIOCSETD, &ldisc);

       A typical application program then polls the digitizing device by reading a binary data structure which contains: the current X and Y posi-
       tions (in the device coordinate space), up-down status of the buttons or pen stylus, proximity information (when available), and a count of
       the  number  of samples received from the input device since it was opened.  In addition, devices such as the GTCO append tilt and pressure
       information to the end of the aforementioned structure.	For the Polhemus 3-D digitizer the structure read is completely  different.  Refer
       to the include file for a complete description.

       While  in  tablet mode, normal teletype input and output functions take place.  Thus, if an 8 bit output data path is desired, it is neces-
       sary to prepare the output line by putting it into RAW mode using ioctl(2).  This must be done before changing the  discipline  with  TIOC-
       SETD, as most ioctl(2) calls are disabled while in tablet line-discipline mode.

       The  line  discipline supports ioctl(2) requests to get/set the operating mode, and to get/set the tablet type and operating mode by or-ing
       the two values together.

       The line discipline supports digitizing devices which are compatible with Hitachi, GTCO, or Polhemus protocol formats.  For  Hitachi  there
       are several formats with that used in the newer model HDG-1111B the most common.

SEE ALSO

       tty(4)

DIAGNOSTICS

       None.

3rd Berkeley Distribution					  August 1, 1987							     TB(4)