s3c2410-adc.c~

本驱动是LINUX下开发的S3C2410的8通道的ADC驱动.可以直接insmod使用.包含测试程序TEST.

/*
 * s3c2410-adc.c
 *
 * S3C2410 ADC 
 *  exclusive with s3c2410-ts.c
 *
 * Author: SeonKon Choi <[e-mail]>
 * Date  : $Date: 2003/01/20 14:24:49 $ 
 *
 * $Revision: 1.1.2.6 $
 *

   Fri Dec 03 2002 SeonKon Choi <[e-mail]>
   - initial

 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/proc_fs.h>

#include <linux/sched.h>
#include <linux/irq.h>
#include <linux/delay.h>

#include <asm/hardware.h>
#include <asm/semaphore.h>
#include <asm/uaccess.h>
#include <asm/arch/cpu_s3c2410.h>

//#undef DEBUG
//#define DEBUG

#define	ADC_MINOR	251

#define	ADC_INx 	ADC_IN1
#define PCLK		s3c2410_get_bus_clk(GET_PCLK)//50000000
#define ADC_FREQ	2500000 // max freq: 2500000(2.5MHz)
#define vPRSCVL 	(PCLK/ADC_FREQ -1)

#ifdef DEBUG
#define DPRINTK(x...) {printk(__FUNCTION__"(%d): ",__LINE__);printk(##x);}
#else
#define DPRINTK(x...) (void)(0)
#endif

#define START_ADC_AIN(x) \
	{ \
		ADCCON = PRESCALE_EN | PRSCVL(vPRSCVL) | ADC_INPUT((x)) ; \
		ADCCON |= ADC_START; \
		while(!(ADCCON & 0x8000));\
	}

static struct semaphore adc_lock;

int s3c2410_adc_read(int ain, int a)
{
	int tmpp,ret = 0;

	down(&adc_lock);

	START_ADC_AIN(ain);
	ret = ADCDAT0 ;

	up(&adc_lock);

	DPRINTK("AIN[%d]=0x%04x, ADCCON=0x%x 0x%x\n", ain, ret, ADCCON, GPCON(PORTG_OFS));

	return (ret & 0x3ff);
}
/*
static int adc_open(struct inode *inode, struct file *file)
{	
    int i;

	ADCCON |= ADC_START;

	DPRINTK("ADCCON=0x%x 0x%x\n", ADCCON, GPCON(PORTG_OFS));

	return 0;
}

static int adc_close(struct inode *inode, struct file *file)
{
	
	ADCCON &= ~ADC_START;

	return 0;
}
*/

ssize_t adc_read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
	unsigned long i,data;
	ssize_t retval;

	data = s3c2410_adc_read(ADC_INx,1);
		
	retval = put_user(data, (unsigned long *)buf);
	if (!retval)
		retval = count;
//	retval = copy_to_user(buf, &data, count) ? -EFAULT : count;
	
	return retval;
}

static struct file_operations adc_fops = {
	owner:		THIS_MODULE,
	read:		adc_read,
//	open:		adc_open,
//	release:	adc_close,
};

static struct miscdevice adc_dev=
{
	ADC_MINOR,
	"adc",
	&adc_fops
};

int __init s3c2410_adc_init(void)
{
	int ret,nPreScaler;

	init_MUTEX(&adc_lock);

	misc_register(&adc_dev);

	/* normal ADC */
	ADCTSC = 0; //XP_PST(NOP_MODE);
	/* add by R.X Huang */
//	nPreScaler = PCLK/ADC_FREQ -1;	
//  ADCCON=(1<<14)|(nPreScaler<<6)|ADC_INPUT(ADC_INx)|(0<<2)|(1<<1);//enable prescaler,ain2,normal,start by read

	return 0;

irq_err:
	return 1;
}


module_init(s3c2410_adc_init);

#ifdef MODULE
void __exit s3c2410_adc_exit(void)
{
#ifdef CONFIG_PROC_FS
	remove_proc_entry("driver/adc", NULL);
#endif

	misc_deregister(&adc_dev);
}

module_exit(s3c2410_adc_exit);
MODULE_LICENSE("GPL");
#endif