dog.c

s3c2410的很多驱动实验

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <asm-arm/arch-s3c2410/S3C2410.h>

#include "directio.h"

#define PCLK (50*1024*1024)

static int fd = -1;

int port_init()
{
	fd = open("/dev/directio",O_NONBLOCK,0);
	
	if(fd<0)
	{
		printf("Can't open directio device\n");
		return -1;
	}
	return 0;
}

unsigned char port_inb(unsigned int port)
{
	struct port_data data;	//端口结构的定义
	
	data.cmd       = CMD_PORT;
	data.startaddr = port;
	data.nums      = 1;
	data.opts      = PORT_BYTE;
	
	ioctl(fd, IOCTL_GET_MSG, &data);	//调用ioctl()访问内核
	
	return data.value;
}

unsigned short port_inw(unsigned int port)
{
	struct port_data data;
	
	data.cmd       = CMD_PORT;
	data.startaddr = port;
	data.nums      = 2;
	data.opts      = PORT_HWORD;
	
	ioctl(fd, IOCTL_GET_MSG, &data);

	return data.value;
}

unsigned int port_inl(unsigned int port)
{
	struct port_data data;
	
	data.cmd       = CMD_PORT;
	data.startaddr = port;
	data.nums      = 4;
	data.opts      = PORT_WORD;

	ioctl(fd, IOCTL_GET_MSG, &data);
	
	return data.value;
}

int port_outb(unsigned int port, unsigned char value)
{
	struct port_data data;

	data.cmd       = CMD_PORT;
	data.startaddr = port;
	data.nums      = 1;
	data.opts      = PORT_BYTE;
	data.value     = value;
	
	ioctl(fd, IOCTL_SET_MSG, &data);
}

int port_outw(unsigned int port, unsigned short value)
{
	struct port_data data;

	data.cmd       = CMD_PORT;
	data.startaddr = port;
	data.nums      = 2;
	data.opts      = PORT_HWORD;
	data.value     = value;
	
	ioctl(fd, IOCTL_SET_MSG, &data);
}

int port_outl(unsigned int port, unsigned int value)
{
	struct port_data data;
	
	data.cmd       = CMD_PORT;
	data.startaddr = port;
	data.nums      = 4;
	data.opts      = PORT_WORD;
	data.value     = value;
	
	ioctl(fd, IOCTL_SET_MSG, &data);
}

void port_uninit()
{
	if(fd >= 0)
		close(fd);
}

int main(int argc, char **argv)
{
	/*
	*	2410看门狗测试程序,定时器时钟周期的计算:
	*	t_watchdog 	= 1 / (PCLK / (Prescaler value + 1 ) / Division_factor)
	*				= 0.000001*Division_factor(秒)
	*	显然: WTCNT寄存器每减一个数相当于0.000001*Division_factor(秒)
	*	则:减到来则需要 WTCNT*0.000001*Division_factor秒
	*	WTCNT寄存器为零时将会产生一个复位信号
	*/
	printf("WatchDog TimerTest!\n");
	printf("t_watchdog = 1/(PCLK*1000000/(Prescaler value + 1)/Division_factor)\n");
	
	if(port_init() != 0)	//如果端口初始化不成功
	{
		printf("port open error\n");
		printf("Please follow me:\n");
		printf("    #insmod directio\n");
		printf("    #mknod /dev/directio c 199 0\n");
		printf("    #./watchdog\n");
        return -1;
	}

	port_outl(rWTCON, ((PCLK/1000000-1)<<8) | (3<<3) | (1)); 
		//Prescaler=0x31(49),Clock division 128,Interrupt disable,Watch-dog timer enable
	printf("    PCLK = %dMHz\n", PCLK/1024/1024);
	printf("    Prescaler value = %d\n", (PCLK/1000000-1));
	printf("    Clock division = %d\n", 128);
	printf("t_watchdog = %f\n", 1.0 / (PCLK / (((PCLK/1000000-1)) + 1) / (128)));

	port_outl(rWTCNT, 16896); 
	//计数值大概相当于16896(或0x4200)*0.000001*128 = 2.16秒

	printf("Please feed the dog every %f sec, if not System will restart.\n", (8448 * 2) * 1.0 / (PCLK / (((PCLK/1000000-1)) + 1) / (128)));
	
	port_outl(rWTCON, port_inl(rWTCON) | (1 << 5));//打开看门狗
	//port_outl(0xf3000000, port_inl(rWTCON) | (1 << 5));//直接用虚拟地址也可以
	//用ioremap()
	while(1)
	{
		printf("Feed the dog\n");
		
		port_outl(rWTCNT,16896); //计数值大概相当于16896*0.000001*128 = 2.16秒
		
		sleep(2);		//2秒钟休眠
	}
	
	port_uninit();	//移除端口
}