#include <stdio.h>#include <unistd.h>#include <fcntl.h>              /* 文件操作 */#define PEN_UP	        0		/* 觸摸筆抬筆，即觸摸屏不被壓下 */#define PEN_DOWN		1		/* 觸摸筆下筆，即觸摸屏被壓下 */#define PEN_FLEETING	2		/* 觸摸筆拖動 */typedef struct {  unsigned short pressure;		/* 觸摸筆動作 */  unsigned short x;				/* 觸點x座標值 */  unsigned short y;				/* 觸點y座標值 */  unsigned short pad;}TS_RET;int main(){    int fd,ret,i;    unsigned char suba;    TS_RET tsret;   	fd = open("/dev/touchscreen/0", O_RDWR);         /* 打開設備 */    if(fd == -1)    {        printf("\nCan't open I2C device!\n");        exit(-1);    }   	while(1)  	{  		ret = read(fd, (char *)&tsret, sizeof(TS_RET));  		if (ret != sizeof(TS_RET))  		{  			printf("read touch screen error!");  			close(fd);  			exit(-1);  		}	  		else  		{  			printf("pressure is: %d\n", tsret.pressure);  			printf("x is: %d\n", tsret.x);  			printf("y is: %d\n", tsret.y);  		}  	}	close(fd);      return 0;}/****************************************************************************                            End Of File**************************************************************************/