main.c

AD转换器TLC3544在Linux2.6内核中的驱动程序 本人已经调试过 可以成功运行

/*
 * FileName 	tlc3544a.h
 * Author 	wangzhenhui
 * Date 	09/21/06
 * Board	SESI_AT91RM9200EDUKIT
 * A/D driver
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>

#include <linux/kernel.h>	/* printk() */
#include <linux/slab.h>	/* kmalloc() */
#include <linux/fs.h>	/* everything... */
#include <linux/errno.h>	/* error codes */
#include <linux/types.h>	/* size_t */
#include <linux/proc_fs.h>
#include <linux/fcntl.h>	/* O_ACCMODE */
#include <linux/seq_file.h>
#include <linux/cdev.h>

#include <linux/delay.h>


#include <asm/system.h>	/* cli(), *_flags */
#include <asm/uaccess.h>	/* copy_*_user */
#include <asm/arch/board.h>
#include <asm/arch/gpio.h>
#include <asm/hardware.h>
#include <linux/interrupt.h>
#include <asm/irq.h>

#include "tlc3544.h"

static int tlc3544_open(struct inode *, struct file *);
static int tlc3544_close(struct inode *, struct file *);
static int tlc3544_read(struct file *, int *, size_t, loff_t *);
static int tlc3544_write(struct file *, const char *, size_t, loff_t *);


static void tlc3544_hardware_init(void);
static void Command(int);
static int ReadData(int);
static void InitAD(void);
static int Cal(int);
 

int tlc3544_major =   0;
int tlc3544_minor =   0;
struct tlc3544_dev *tlc3544_device;
int first=0;
int channel=0;

static struct file_operations tlc3544_fops = {
	open:           tlc3544_open,
	read:		tlc3544_read,
	write:          tlc3544_write,
	release:        tlc3544_close,
};

static void Command(int command)
{
	int i,SDIdata;
	
	long int mask;
	at91_set_gpio_value(CS,1);
	at91_set_gpio_value(CS,0);
	//ÉèÖÃÃüÁSDI bit[15:12]=1010b
	for(i=0,mask=0x8000;i<16;i++,mask=mask>>1)
	{
		SDIdata=command&mask;
		if(SDIdata==mask)
		at91_set_gpio_value(SDI,1);
		else
		at91_set_gpio_value(SDI,0);
		
		at91_set_gpio_value(SCLK,1);
		at91_set_gpio_value(SCLK,0);
		udelay(10);

	}
	
}


static int ReadData(int command)
{
int i,j,result,SDIdata;
	
	long int mask;
	at91_set_gpio_value(CS,1);
	at91_set_gpio_value(CS,0);
	
	//¶ÁÈ¡žß12λµÄ×ÖœÚÊýŸÝ
	for(i=0,mask=0x8000;i<16;i++,mask=mask>>1)
	{
		SDIdata=command&mask;
		if(SDIdata==mask)
		at91_set_gpio_value(SDI,1);
		else
		at91_set_gpio_value(SDI,0);
		at91_set_gpio_value(SCLK,1);
		at91_set_gpio_value(SCLK,0);
		
		j=at91_get_gpio_value(SDO);
		result+=j;
		result=result<<1;
		udelay(10);
	}
	result=result>>1;
	return (result&0xFFFC);
}

static void InitAD(void)
{
    
	Command(0xa204);   // user internal reference 0xa204 ueser external referencd 

	ReadData(0x1000);
}


static int Cal(int result)
{
	int v;
	v=0;
	v=(result>>2)*4000/16383;
	return v;
}


static void tlc3544_hardware_init (void)
{
	printk("tlc3544_hardware_init\n");

	at91_set_gpio_output(CS,1);
	at91_set_gpio_output(SDI,1);
	at91_set_gpio_output(SCLK,1);

	at91_set_gpio_input(SDO,1);
       at91_set_gpio_input(EOC,1);

	at91_set_gpio_value(CS,0);
	at91_set_gpio_value(SDI,0);
	at91_set_gpio_value(SCLK,0);
	
         InitAD();
	
}



static int tlc3544_open (struct inode *inode, struct file *file)
{
	printk("tlc3544_open\n");
	tlc3544_device->use_count++;
	if(tlc3544_device->use_count==1)file->private_data = tlc3544_device;
	return 0;
}

static int tlc3544_close (struct inode *inode, struct file *file)
{
	printk("tlc3544_close\n");
	tlc3544_device->use_count--;	
	return 0;
}

static int tlc3544_read (struct file *file, int *buf, size_t count, loff_t *ppos)
{      
       int result=0;
       int tmp=0;
       char data;
       first++;
       if(channel==0)
       tmp=ReadData(0x0000);
       if(channel==3)
       tmp=ReadData(0x3000);
       if(first!=1)       
        {  
          result=Cal(tmp);
//printk("result: %d\n",result);
           //data=result;
	   put_user(result,buf);
        }
       
return count;
}

static int tlc3544_write (struct file *file, const char *buf, size_t count, loff_t *ppos)
{   char data;

   get_user(data, buf);
   if(data==0)
   channel=0;
   if(data==3)
   channel=3;
     // printk("channel: %d\n", channel);
	
	return count;
	
}


void  tlc3544_cleanup_module(void)
{
	dev_t devno = MKDEV(tlc3544_major, tlc3544_minor);
	printk("tlc3544 module cleanup.\n");
	cdev_del(&tlc3544_device->cdev);
	kfree(tlc3544_device);
	unregister_chrdev_region(devno, 1);
	
}
int  tlc3544_init_module(void)
{
	int result,dev_no;
	dev_t dev = 0;
	tlc3544_hardware_init ();
	/* ask for a dynamic major */
	result = alloc_chrdev_region(&dev, tlc3544_minor, 0,
				"tlc3544");
	tlc3544_major = MAJOR(dev);
	
	if (result < 0) {
		printk(KERN_WARNING "tlc3544: can't get major %d\n", tlc3544_major);
		return result;
	}
	/* mem alloc for device */
	tlc3544_device = kmalloc(sizeof(struct tlc3544_dev), GFP_KERNEL);
	if (!tlc3544_device) {
		result = -ENOMEM;
		printk(KERN_WARNING "ads 7843 memory alloc failed.\n");
		goto fail;  /* Make this more graceful */
	}
	memset(tlc3544_device, 0, sizeof(struct tlc3544_dev));
	/* init mutex */
	init_MUTEX(&(tlc3544_device->sem));
	/* reg device */
	dev_no = MKDEV(tlc3544_major, tlc3544_minor);
	cdev_init(&tlc3544_device->cdev, &tlc3544_fops);
	tlc3544_device->cdev.owner = THIS_MODULE;
	tlc3544_device->cdev.ops = &tlc3544_fops;
	result = cdev_add (&tlc3544_device->cdev, dev_no, 1);
	/* Fail gracefully if need be */
	if (result){
		printk(KERN_NOTICE "Error %d adding tlc3544.\n", result);
		goto fail;
	}
	
	printk("tlc3544 module init major:%d.\n",tlc3544_major);
	return 0;
fail:
	tlc3544_cleanup_module();
	return result;
}

module_init(tlc3544_init_module);
module_exit(tlc3544_cleanup_module);
MODULE_AUTHOR("Zhenhui wang, [e-mail]");
MODULE_LICENSE("GPL");