touch.c

基于s3c44b0的rtc,watchdog,adc,ads的驱动程序

#include <linux/config.h>
#include <linux/utsname.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/spinlock.h>

#include <asm/mach/irq.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>

#include <linux/poll.h>
#include <asm/arch/io.h>
#include "44b.h"

#define TOUCH_MSR_Y   0x9c  //读Y轴坐标命令
#define TOUCH_MSR_X   0xdc  //读X轴坐标命令
#define DEVICE_NAME	"touch"
#define MCLK 64000000

static int delayLoopCount=400;

void Delay(int);
int ReadTouch(unsigned char);
void Test_Touch(void);

typedef struct {
	int  Pressed;
	int  x;
	int  y;
}TOUCHSTATE;

static TOUCHSTATE _State;

int ReadTouch(unsigned char command)
{
	unsigned char temp,i,ack;
	
	ack=0;    
	
	rPDATC &=0xbeff;
	temp=0x80;
	for(i=0;i<8;i++)
	{
		if(command&temp)
			rPDATC |=0x0200;
		else
			rPDATC &=0xfdff;
		rPDATC |=0x4000;
		Delay(3);
		rPDATC &=0xbfff;
		Delay(3);
		temp=temp>>1;
	}
	temp=(unsigned char)((rPDATC&0x0400)>>8);
	while(temp==0)		
		temp=(unsigned char)((rPDATC&0x0400)>>8);
	rPDATC &=0xf7ff;
	rPDATC |=0x4000;
	Delay(3);
	rPDATC &=0xbfff;
	Delay(3);
	for(i=0;i<7;i++)
	{
		rPDATC |=0x4000;//rPDATG |=0x08;	
		temp=(unsigned char)((rPDATC&0x0800)>>8);
		if(temp)		
			ack++;
		ack=ack<<1;
		Delay(3);
		rPDATC &=0xbfff;
		Delay(3);
	}
	rPDATC |=0x4000;	
	temp=(unsigned char)((rPDATC&0x0800)>>8);
	if(temp)		
		ack++;	
	Delay(3);	
	rPDATC &=0xbfff;
	rPDATC |=0x0100;	
        
	return ack;
}
void Test_Touch(void)
{
	_State.x=0;
    	_State.y=0;

	rPCONC =0x1f05ff55;		
	rPUPC  =0x00ff;   
	rPCONG =0x00ff;			
	rPUPG  =0x80;

	if(((rPDATG&0x80)==0)&&(_State.Pressed==0)) 	//有点击
	{
        	_State.Pressed=1;	//设置点击状态存在
		_State.x=ReadTouch(TOUCH_MSR_X);		//读取横坐标
		_State.y=ReadTouch(TOUCH_MSR_Y);		//读取纵坐标
	//	printk("Touch at the point ( %4d, %4d )\n",_State.x,_State.y);
	}
	else if(((rPDATG&0x80)!=0)&&(_State.Pressed==1))	//无点击
		_State.Pressed=0;	//取消点击状态
   	
	Delay(100);
  
}
static int s3c44b0_ts_open(struct inode *inode, struct file *filp)
{
	printk("Open successful\n");
	return 0;
}

static int s3c44b0_ts_release(struct inode *inode, struct file *filp)
{
	printk("Close successful\n");
  	return 0;
}
static int s3c44b0_ts_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	switch(cmd) 
	{
		case 0:
			if(!(rUTRSTAT0 & 0x1)) {
				Test_Touch();	//有点击则调用函数读取坐标
				return 0;
			}
			else
				return 0;
        	default:
                        printk("ERROR\n");
    	}
    	return 0;
}
static int s3c44b0_ts_read(struct file *fp, char *buf, size_t count)
{
    put_user(_State.Pressed, buf);	//将坐标存入缓冲区,以便上层read函数调用
    put_user(_State.x, buf+4);
    put_user(_State.y, buf+8);

    _State.x=0;
    _State.y=0;

    return count;
}
static struct file_operations s3c44b0_fops = {
  	open:	s3c44b0_ts_open,
	ioctl:	s3c44b0_ts_ioctl,
  	release:	s3c44b0_ts_release,
	read:	s3c44b0_ts_read,
};
int s3c44b0_ts_init(void)
{
	int ret;

	ret = register_chrdev(253, DEVICE_NAME, &s3c44b0_fops);
	if (ret < 0) {
		printk(DEVICE_NAME " can't get major number\n");
		return ret;
	}
	else 
		printk("OK\n");	

	return 0;
}
void Delay(int time)	//延时子程序
{
	int i,adjust=0;
	if(time==0)
	{
		time=200;
		adjust=1;
		delayLoopCount=400;
		rWTCON=((MCLK/1000000-1)<<8)|(2<<3);
		rWTDAT=0xffff;
		rWTCNT=0xffff;	 
		rWTCON=((MCLK/1000000-1)<<8)|(2<<3)|(1<<5); 
	}
	for(;time>0;time--)
		for(i=0;i<delayLoopCount;i++);
	if(adjust==1)
	{
		rWTCON=((MCLK/1000000-1)<<8)|(2<<3);
		i=0xffff-rWTCNT;   
		delayLoopCount=8000000/(i*64);	
	}
}