xf86-input-synaptics/test/test-pad.c

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

int getbyte(int fd, unsigned char *b)
{
	return(read(fd, b, 1) == 1);
}

int putbyte(int fd, unsigned char b)
{
	unsigned char ack;

printf("write %02X\n", b);
	if(write(fd, &b, 1) != 1)
	{
		fprintf(stderr, "error write: %s\n", strerror(errno));
		return 0;
	}

	if(!getbyte(fd, &ack))
	{
		fprintf(stderr, "error read: %s\n", strerror(errno));
		return 0;
	}
printf("read %02X\n", ack);

	if(ack != 0xFA)
	{
		fprintf(stderr, "error ack\n");
		return 0;
	}

	return 1;
}

int special_cmd(int fd, unsigned char cmd)
{
	int i;

	if(putbyte(fd, 0xE6))
		for(i=0; i<4; i++)
		{
printf("special_cmd %i\n", i);
			if((!putbyte(fd, 0xE8)) || (!putbyte(fd, (cmd>>6)&0x3)))
				return 0;
			cmd<<=2;
		}
	else
		return 0;
	return 1;
}

int send_cmd(int fd, unsigned char cmd)
{
	return(special_cmd(fd, cmd) && putbyte(fd, 0xE9));
}

int identify(int fd, unsigned long int *ident)
{
	unsigned char id[3];

	if(send_cmd(fd, 0x00) && getbyte(fd, &id[0]) && getbyte(fd, &id[1]) && getbyte(fd, &id[2]))
	{
		*ident = (id[0]<<16)|(id[1]<<8)|id[2];
		printf("ident %06X\n", *ident);
		return 1;
	} else {
		fprintf(stderr, "error identify\n");
		return 0;
	}
}

int reset(int fd)
{
	unsigned char r[2];

	if(!putbyte(fd, 0xFF))
	{
		fprintf(stderr, "error reset\n");
		return 0;
	}

	sleep(5);

	if(getbyte(fd, &r[0]) && getbyte(fd, &r[1]))
		if(r[0] == 0xAA && r[1] == 0x00)
		{
			fprintf(stderr, "reset done\n");
			return 1;
		}
	fprintf(stderr, "error reset ack\n");
	return 0;
}




int main(int argc, char* argv[])
{
	int fd;
	unsigned long int ident;

	fd = open("/dev/psaux", O_RDWR);
	if(fd == -1)
	{
		fprintf(stderr, "error open: %s\n", strerror(errno));
		exit(0);
	}

	reset(fd);
	identify(fd, &ident);

	close(fd);

	exit(0);
}