求一个2440可用的DS18B20温度传感器的驱动

  自己写了一个....各种参考以前大神发在网上的2440的ds18b20的驱动，最后能装上，就是最后读不出来温度。全是0，一个星期了....求大神们给个调试好的ds18b20驱动，我来研究下，我写的那个到底错在哪里！！

/*#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/uaccess.h>
#include <linux/clk.h>
#include <mach/regs-gpio.h>
#include <mach/io.h>
#include <mach/map.h>
#include <mach/regs-clock.h>*/


#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/miscdevice.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <mach/regs-clock.h>
#include <plat/regs-timer.h>
#include <mach/regs-gpio.h>
#include <mach/gpio.h>
#include <linux/cdev.h>

#define   DQ             S3C2410_GPG11
#define   CPG_IN         S3C2410_GPG11_INP
#define   CPG_OUT        S3C2410_GPG11_OUTP

#define DEVICE_NAME "ds18b20"  //自定义驱动称为“ds18b20”。
#define DS18B20_MAJOR 210
static int opencount = 0;
static char data[2];
//ds18b20复位，返回0成功，返回1失败
static unsigned char init_ds18b20(void)
{
  unsigned char ret = 0;

  s3c2410_gpio_cfgpin(DQ, CPG_OUT);   
  //s3c2410_gpio_pullup(DQ, 0);
  s3c2410_gpio_setpin(DQ, 1);
  udelay(100);
  s3c2410_gpio_setpin(DQ, 0);
  udelay(600);

  s3c2410_gpio_setpin(DQ, 1);
  udelay(50);

  s3c2410_gpio_cfgpin(DQ, CPG_IN);

  ret = s3c2410_gpio_getpin(DQ);   
  udelay(200);
  return ret;
}


static void write_onechar(char data)
{
unsigned char i;
s3c2410_gpio_cfgpin(DQ, CPG_OUT);
s3c2410_gpio_pullup(DQ, 1);
for(i=0; i<8; i++)
{
s3c2410_gpio_setpin(DQ, 0);   
udelay(15);   
s3c2410_gpio_setpin(DQ, data&0x01);  
udelay(60);
s3c2410_gpio_setpin(DQ, 1);
udelay(2);
data >>= 1;
  }
}


static unsigned char read_onechar(void)
{
  unsigned char i;
  unsigned char data=0;
  for(i=0; i<8; i++)
    {

   s3c2410_gpio_cfgpin(DQ, CPG_OUT);
      s3c2410_gpio_setpin(DQ, 0);   
      udelay(1);
      data >>= 1;
      s3c2410_gpio_setpin(DQ, 1);
      s3c2410_gpio_cfgpin(DQ, CPG_IN);   
      if(s3c2410_gpio_getpin(DQ))   
   data |= 0x80;
      udelay(50);
    }
  return data;
}


static ssize_t read_ds18b20(struct file *filp, char *buffer,
             size_t count, loff_t *ppos)
{
  if(init_ds18b20())
    return -1;

  write_onechar(0x0cc);
  write_onechar(0x44);
  udelay(5);
  while(init_ds18b20());
  udelay(200);
  write_onechar(0x0cc);
  write_onechar(0x0be);

  data[0] = read_onechar();
  data[1] = read_onechar();
// copy_to_user(buffer, &data, 2);
  buffer[0]=data[0];
  buffer[1]=data[1];
  return 1;
}


static int open_ds18b20(struct inode *node, struct file *file)
{
  unsigned char flag;

  if(opencount == 1)
    return -EBUSY;

  flag = init_ds18b20();

  if(flag&0x01)
    {
      printk("uable to open device!\n");
      return -1;
    }
  else
   {
      opencount++;
      printk("device opened!\n");
      return 0;
   }
}

static int release_ds18b20(struct inode *node, struct file *file)
{
  opencount--;
  printk("device released!\n");
  return 0;
}

static struct file_operations ds18b20_fops = {
.owner = THIS_MODULE,
  .read = read_ds18b20,
  .release = release_ds18b20,
  .open = open_ds18b20,
};

static char __initdata banner[] = "TQ2440/SKY2440 ds18b20\n";
static struct class *ds18b20_class;
static int __init ds18b20_init(void)
{
int ret;
printk(banner);
ret = register_chrdev(DS18B20_MAJOR, DEVICE_NAME, &ds18b20_fops);
if (ret < 0)
{
  printk(DEVICE_NAME " can't register major number\n");
  return ret;
}

ds18b20_class = class_create(THIS_MODULE, DEVICE_NAME);
if(IS_ERR(ds18b20_class))
{
  printk("Err: failed in tope-leds class. \n");
  return -1;
}
device_create(ds18b20_class, NULL, MKDEV(DS18B20_MAJOR, 0), NULL, DEVICE_NAME);
printk(DEVICE_NAME " initialized\n");
return 0;
}
static void __exit ds18b20_exit(void)
{
printk(DEVICE_NAME " exit\n");
unregister_chrdev(DS18B20_MAJOR, DEVICE_NAME);
device_destroy(ds18b20_class, MKDEV(DS18B20_MAJOR, 0));
class_destroy(ds18b20_class);     
}
module_init(ds18b20_init);
module_exit(ds18b20_exit);
MODULE_LICENSE("GPL");



这是我修改后的驱动代码，  读不出温度数据来。

我写了个可用的

zjhsucceed_329 发表于 2014-5-9 18:13
我写了个可用的

嗯嗯~  我看看

这个驱动可以用吗