ads.c

基于s3c44b0的rtc,watchdog,adc,ads的驱动程序

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

#include "common.h"

#ifdef _ADS_IAL

#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/kd.h>

#include "44b.h"
#include "misc.h"
#include "ial.h"
#include "ads.h"

typedef struct {
    int pressure;
    int x;
    int y;
} TS_EVENT;

static TS_EVENT ts_event;

static int ts = -1;
static int mousex = 0;
static int mousey = 0;

/************************  Low Level Input Operations **********************/
/*
 * Mouse operations -- Event
 */
static int mouse_update(void) //更新鼠标状态
{
    return 1;
}

static void mouse_getxy(int *x, int* y)
{
    *x = mousex;		//最上层通过该函数取得最终的坐标值
    *y = mousey;
}

static int mouse_getbutton(void) //最上层通过该函数,就知道是否有点击
{
    return ts_event.pressure;
}

static int wait_event (int which, fd_set *in, fd_set *out, fd_set *except,
                struct timeval *timeout)
{
    fd_set rfds;
    int    retvalue = 0;
    int    e;

    if (!in) {
        in = &rfds;
        FD_ZERO (in);
    }

    if ((which & IAL_MOUSEEVENT) && ts >= 0) {
        FD_SET (ts, in);
    }
   	
    ioctl(ts,0,0);	//调用驱动程序
 
    e = select (FD_SETSIZE, in, out, except, timeout) ;

    if (e > 0) { 
        if (ts >= 0 && FD_ISSET (ts, in)) {
            FD_CLR (ts, in);
            ts_event.x=0;
            ts_event.y=0;
	    ts_event.pressure=0;

	    read (ts, &ts_event, sizeof (TS_EVENT));	//从缓冲区读取点击状态和坐标值

	    if (ts_event.pressure == 1 && ts_event.x > 0 && ts_event.y > 0) {
	//坐标变换,初始为:右下脚(0,0),左上脚(255,255),因为是八位A/D;转换后的坐标为:左上脚(0,0),右下脚(640,480),符合LCD标准
		mousex=(242-ts_event.x)*640/228;
		mousey=(235-ts_event.y)*480/218;
	//	printf("mousex = %d\n",mousex);
	//	printf("mousey = %d\n",mousey);
	//	printf("ts_event.pressure = %d\n",ts_event.pressure);
		ts_event.pressure = 4;	//相当于鼠标左键按下,最上层的应用程序会作出判断,以便决定是否读取坐标
            }
	    else
            	ts_event.pressure = 0;	//无点击

            retvalue |= IAL_MOUSEEVENT;
		
        }
    } 
    else if (e < 0) {
        return -1;
    }

    return retvalue;
}

BOOL InitADSInput (INPUT* input, const char* mdev, const char* mtype)
{
    ts = open ("/dev/touch", O_RDONLY);
    if (ts < 0) {
        fprintf (stderr, "IAL: Can not open touch screen!\n");
        return FALSE;
    }
 
    input->update_mouse = mouse_update;
    input->get_mouse_xy = mouse_getxy;
    input->set_mouse_xy = NULL;
    input->get_mouse_button = mouse_getbutton;
    input->set_mouse_range = NULL;

    input->wait_event = wait_event;
    mousex = 0;
    mousey = 0;
    ts_event.x = ts_event.y = ts_event.pressure = 0;
    
    return TRUE;
}

void TermADSInput(void) 
{
    if (ts >= 0)
        close(ts);    
}

#endif /* _ADS_IAL */