//mdelay(1);
//ds18b20_set_input(index);
//mdelay(1);
mdelay(800);
ds18b20_reset();
ds18b20_write_byte(SKIP_ROM); /*skip ROM operation*/
ds18b20_write_byte(READ_TEMP); /*start read temperature*/
data[0]=ds18b20_read_byte();
data[1]=ds18b20_read_byte();
printk("%x,%x \n",data[1],data[0]);
ds18b20_set_output(HIGH);
return 0;
}
static int ds18b20_open(struct inode * s_node,struct file * s_file)
{
return 0;
}
static ssize_t ds18b20_read(struct file *DS1820_file,char * buf, size_t count, loff_t * l)
{
ds18b20_read_temp();
buf[0] = data[0];
buf[1] = data[1];
return 0;
}
struct file_operations ds18b20_fops =
{
.owner = THIS_MODULE,
.open=ds18b20_open,
.read=ds18b20_read,
};
struct class *myclass ;
static int __init ds18b20_init(void)
{
int ret;
ret = register_chrdev(char_major,DEV_NAME, &ds18b20_fops);
myclass = class_create(THIS_MODULE,DEV_NAME);
device_create(myclass, NULL, MKDEV(char_major, 0), NULL, DEV_NAME);
if(ret<0)
{
printk(KERN_ALERT "DS18b20 REG FAIL!\n");
}
else
{
printk(KERN_ALERT "MAJOR = %d\n",char_major);
}
printk(KERN_INFO "Temperature Sensor Driver For ds18b20\n");
ds18b20_reset();
return ret;
}
static void __exit ds18b20_exit(void)
{
unregister_chrdev(char_major,DEV_NAME);
class_destroy(myclass);
printk(KERN_INFO PFX "ds18b20 dirver removed\n");
}
module_init(ds18b20_init);
module_exit(ds18b20_exit);
MODULE_AUTHOR("St.Dickens");
MODULE_DESCRIPTION("temperature sensor driver for ds18b20");
MODULE_LICENSE("Dual BSD/GPL");
===================================makefile========================================
# Makefile2.6
ifneq ($(KERNELRELEASE),)
#kbuild syntax. dependency relationshsip of files and target modules are listed here.
obj-m := ds18b20.o
else
PWD := $(shell pwd)
KVER = 2.6.27
KDIR := /home/dickens/linux-2.6.27
all:
$(MAKE) -C $(KDIR) M=$(PWD) modules
clean:
rm -rf .*.cmd *.o *.mod.c *.ko .tmp_versions
endif
==============================随便写了个测试程序=======================================
#include "stdio.h"
#include "sys/types.h"
#include "sys/ioctl.h"
#include "stdlib.h"
#include "termios.h"
#include "sys/stat.h"
#include "fcntl.h"
#include "sys/time.h"
#define DEV_NAME "/dev/ds18b20"
void delay(unsigned int time)
{
while(time>0)
time--;
}
int main()
{
int fd;
unsigned char buf[2];
float result;
int times=5;
//打开设备文件
fd=open(DEV_NAME,O_RDWR | O_NDELAY | O_NOCTTY);
if(fd<0)
{
printf("Open Device Fail!\n");
return -1;
}
//读取当前设备数值
else
{
printf("OPEND!\n");
}
while(times>0)
{
read(fd, buf, 1);
result = (float)buf[0];
result /= 16;
result += ((float)buf[1] * 16);
printf("%.1f `C\r\n", result);
times--;
sleep(5);
}
close(fd);
}