6410上DS18B20驱动_ds16b20 linux驱动-优快云博客

本文介绍了一种基于S3C6410平台的DS18b20温度传感器驱动程序的设计与实现，通过GPIO接口进行数据交换，并提供了测试应用程序以读取温度数据。

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#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <mach/hardware.h>
#include <linux/gpio.h>
#include <plat/gpio-cfg.h>


#define DEVICE_NAME "6410ds18"
#define DPRINTK(x...) printk(x);
//#define DPRINTK(x...)
#define DS18_PIN S3C64XX_GPB(1)


typedefunsignedchar U8;

void ds18_reset(void)
{
    s3c_gpio_cfgpin(DS18_PIN, S3C_GPIO_SFN(1));
    gpio_set_value(DS18_PIN, 0);
    udelay(600);
    gpio_set_value(DS18_PIN, 1);
    udelay(55);
    s3c_gpio_cfgpin(DS18_PIN, S3C_GPIO_SFN(0));
    while(gpio_get_value(DS18_PIN));
    while(! (gpio_get_value(DS18_PIN)) );
}

void ds18_write(U8 data)
{
    U8 i;
    s3c_gpio_cfgpin(DS18_PIN, S3C_GPIO_SFN(1));
    for(i=0;i<8;i++){
    gpio_set_value(DS18_PIN, 0);
    udelay(10);
    if((data&0x01)==1)
    gpio_set_value(DS18_PIN, 1);
    else
    gpio_set_value(DS18_PIN, 0);
    udelay(40);
    gpio_set_value(DS18_PIN, 1);
    udelay(1);
    data = data >> 1;
    } 
}

U8 ds18_read(void)
{
    U8 i; 
    U8 comdata=0x00;
    for(i=0;i<8;i++){
    comdata >>= 1;
    s3c_gpio_cfgpin(DS18_PIN, S3C_GPIO_SFN(1));
    gpio_set_value(DS18_PIN, 0);
    udelay(1);
    s3c_gpio_cfgpin(DS18_PIN, S3C_GPIO_SFN(0));
    //udelay(10);
    if( gpio_get_value(DS18_PIN))
    comdata = comdata | 0x80;
    udelay(40); 
    } 
return comdata;
}


static int dht_read(struct file *file,char * buffer,size_t count,loff_t * ppos)
{
    U8 data[2];
    ds18_reset(); 
    ds18_write(0xcc);
    ds18_write(0x44);
    ds18_reset();
    ds18_write(0xcc);
    ds18_write(0xbe);
    data[0] = ds18_read();
    data[1] = ds18_read();
    ds18_reset(); 
    count = copy_to_user(buffer, data, 2); 
    return count;
}


staticstruct file_operations dht_fops={
    read:dht_read,
};

staticstruct miscdevice misc = {
    .minor = MISC_DYNAMIC_MINOR,
    .name = DEVICE_NAME,
    .fops = &dht_fops,
};

static int __initmy_dht_init(void)
{
    int ret;
    s3c_gpio_setpull(DS18_PIN, S3C_GPIO_PULL_UP);
    ret = misc_register(&misc);
    printk(DEVICE_NAME " 6410_DS18b20 Pull_up initialized\n");
    return0;
}

static void __exitmy_dht_exit(void)
{
    misc_deregister(&misc);
}

module_init(my_dht_init);
module_exit(my_dht_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("TONY");


//===================测试应用程序===================
//ds18_test.c

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

intmain(void)
{
    int s,ret;
    int fd;
    unsignedchar data[5];
    unsignedint temp;
    float data_rh,data_t;
    if((fd = open("/dev/6410ds18", O_RDONLY)) <0)
    return -1;
    printf("DS18B20 Get Data:\n");
    while(1){
    bzero(data,5);
    read(fd,data,2);
    printf("\nGet data-->");
    for(s=0;s<2;s++) printf("%x ",data[s]);
    printf("\n");
    temp = (data[0]|data[1]<<8)*6.25;
    data_t = (float)temp/100;
    printf("temp=%4.2f\n",data_t);
    sleep(3); 
    } 
close(fd);
return 0;
}