#	include	<stdio.h>
#	include	<unistd.h>
#	include	<fcntl.h>

// This code is free, as in beer


// This program is based on some information at:
// http://www.synaptics.com/support/dev_support.cfm
//
// as well as the program tpconfig from
// http://www.compass.com/synaptics
//

/* WHY
 *
 * I *hate* the tapping feature on my Sony Z505. Alps completly Foobared it's design
 * and it makes random taps all over the place.  With windows I had tapping disabled,
 * but when I switched to Linux it really wanted to tap.  The program "tpconfig"
 * is out there and it will disable tapping when you have X stopped and gpm stopped
 * and are sitting at a root console window.  However, I really wanted the ability
 * to put my laptop to sleep and be able to wake it back up in X and keep working.
 * Thus was born this hack.
 *
 * WHAT
 *
 * This program will open /dev/psaux (which is hopefully your glidepoint mouse!) and
 * send it its special sequence of keys to disable tapping.  It will do this regardless
 * of whether you are in X or not and it wont mess up X if you are.  Note that the
 * sequence of bytes it sends to disable tapping has this nasty side effect of
 * setting your resolution really low.  So it also turns up the reosolution to a
 * "suitable" value.  You can change this if you like (see note below)
 *
 * HOW
 *
 * Dont' ask how.  Apparently the PS/2 protocol is a total hack.  It does not support
 * in a clean way "vendor extensions".  Thus if you want to control things that
 * are special about mice (such as tapping on the glide point) you send the mouse
 * clean looking commands that are within protocol spec for PS/2 mice, *but* on 
 * the correct hardware are interpreted as special and do something magical.  This
 * by the way is NOT the way to design hardware and software interfaces....
 * So you see the string "magic" down below.  That is the magic sequence of
 * bytes that make it work.  The technical document available from synaptics has
 * a nice write up all about this.
 *
 */

// Here are some random notes about the PS/2 protocol
//
// Resend fe
// ACK fa
// Reset ff
// Set defaults f6
// disable stream mode f5
// enable stream mode f4
// set sampling rate f3 followed by 10,20,40,60,80,100,200
// read device type f2
// set remote mode f0
// set wrap mode ee
// reset wrap mode ec
// read data eb
// set stream mode ea
// status request e9
// set resolution e8
//
int
main(int	argc,
	char	*argv[])
		{
		int	mode;
		int	fd;

		// NOTE the last byte of this string.  It is the resolution your mouse will end up in 
		// after you run this.  Legal values are 0x00, 0x01, 0x02, and 0x03 that correspond
		// to (if you believe the documentation), 1, 2, 4, and 8 counts per mm.  Ofcourse,
		// YMMV.
		//
		// The first 10 bytes of this "magic" are a hack.  See discussion above.
		//
		// The byte 0xeb is there just to make me feel better.  The 10 byte prefix is a special
		// sequence for the Glidepoint, so the 11'th byte is there to make sure they stop
		// interpreting the sequnce.
		//
		// Final note.  You may be able to tune the 10 byte sequence to work better and
		// not mess up your mouse resolution.  I have no real glide point documentation
		// so I just acquired this sequence from the sources listed above.  If you do
		// get a better sequence, do share.
		char	magic[]		=	{	0xe9, 0xf5, 0xf5, 0xe8, 0x00, 0xf5, 0xf5, 0xf5, 0xe9, 0xf4,0xeb,0xe8,0x02	};

		// when all else fails, send your mouse a reset!
		char	reset[]		=	{	0xff	};

		if ( argc != 2 )
				{
				printf("usage: %s reset|disable\n", argv[0]);
				return(1);
				}

		if ( !strcmp(argv[1], "reset"))
				mode = 0;
		else
		if ( !strcmp(argv[1], "disable"))
				mode = 1;
		else
			{
			printf("usage: %s reset|disable\n", argv[0]);
			return(2);
			}

		fd = open("/dev/psaux", O_RDWR);

		if(fd<0)
				{
				printf("error opening device\n");
				return(1);
				}

		if(mode == 0)
			write(fd, reset, 1);
		else
		if(mode == 1)
			write(fd, magic, 13);
		close(fd);
		return(0);
		}