ds18b20/t224.c

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/cdev.h>

#include <linux/gpio.h>
#include <linux/of_gpio.h>

#include <asm/uaccess.h>
#include "ds18b20.h"

#define DEVICE_NAME "ds18b20-224"
#define NODE_NAME "ds18b20-224"

#define gpio_num 224

static int ds18b20_open(struct inode *inode, struct file *filp)
{
    //printk (KERN_INFO "Device opened\n");
    int flag = initDs18b20(gpio_num);
    if(flag & 0x01)
        return -1;
    return 0;
}

 /*读取数据*/
static int ds18b20_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos)
{
    unsigned char tmp[2];
    readDs18b20Data(tmp);
	return copy_to_user(buffer, &tmp, sizeof(tmp));
}


static struct file_operations ds18b20_fops = {
    .owner  = THIS_MODULE,
    .open   = ds18b20_open,
    .read   = ds18b20_read,
};

static struct miscdevice ds18b20_dev = {
    .minor           = MISC_DYNAMIC_MINOR,
    .name            = DEVICE_NAME,
    .nodename        = NODE_NAME,
    .fops            = &ds18b20_fops,
};

static int __init ds18b20_dev_init(void) {
    int ret;
    ret = gpio_request(gpio_num, DEVICE_NAME);
    if (ret) {
        printk("%s: request GPIO %d for GPE0 failed, ret = %d\n", DEVICE_NAME, gpio_num, ret);
        return ret;
    }
    ret = misc_register(&ds18b20_dev);//注册杂设备驱动
    printk(DEVICE_NAME"\tinitialized\n");
    return ret;
}

static void __exit ds18b20_dev_exit(void) {
    freeDs18b20();
    misc_deregister(&ds18b20_dev);
}

module_init(ds18b20_dev_init);
module_exit(ds18b20_dev_exit);

MODULE_LICENSE("GPL");
MODULE_VERSION("1.0");
MODULE_AUTHOR("shuixx.");