s3c2410_adc中断方式实现

/*

* HLG442-S3C2410-ADC_DRV

*/26/03/2008 AUTHOR "machuanlong"

*/

#include

#include

#include

#include

#include

#include

#include

#include

#include ccess.h>

#include /* printk() */

#include /* kmalloc() */

#include /* everything... */

#include /* error codes */

#include /* size_t */

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include adc.h>

#include

#include

#include "s3c2410-adc.h"

#include

#include

#define DEVICE_NAME"adc"

static int adc_major = 0;

typedef struct {

struct semaphore lock;

wait_queue_head_t wait;

int channel;

int prescale;

}ADC_DEV;

static ADC_DEV adcdev;

static irqreturn_t adcdone_int_handler(int irq,void *dev_id,struct pt_regs *regs)

{

wake_up(&adcdev.wait);

return IRQ_HANDLED ;

}

static ssize_t s3c2410_adc_write(struct file *file, const char *buffer, size_t count, loff_t * ppos)

{

return 0;

}

static ssize_t s3c2410_adc_read(struct file *filp, char *buffer, size_t count, loff_t *ppos)

{

int ret = 0;

if (down_interruptible(&adcdev.lock))

return -ERESTARTSYS;

writel((readl(S3C2410_CLKCON) | S3C2410_CLKCON_ADC),S3C2410_CLKCON);

writel((1<<14) | PRSCVL(adcdev.prescale) | ADC_INPUT(adcdev.channel) | 0x01 | 0x01, S3C2410_ADCCON);

interruptible_sleep_on(&adcdev.wait);

ret = readl(S3C2410_ADCDAT0);

ret &= 0x3ff;

copy_to_user(buffer, (char *)&ret, sizeof(ret));

up(&adcdev.lock);

return sizeof(ret);

}

static int s3c2410_adc_open(struct inode *inode, struct file *filp)

{

int ret;

ret = request_irq(IRQ_ADC, adcdone_int_handler, SA_INTERRUPT, DEVICE_NAME, NULL);

if (ret) {

return ret;

}

init_MUTEX(&adcdev.lock);

init_waitqueue_head(&(adcdev.wait));

adcdev.channel=0;

adcdev.prescale=255;

return 0;

}

static int s3c2410_adc_release(struct inode *inode, struct file *filp)

{

free_irq(IRQ_ADC, NULL);

printk( "adc closedn");

return 0;

}

static void adc_setup_cdev(struct cdev *dev, int minor,

struct file_operations *fops)

{

int err, devno = MKDEV(adc_major, minor);

cdev_init(dev, fops);

dev->owner = THIS_MODULE;

dev->ops = fops;

err = cdev_add (dev, devno, 1);

/* Fail gracefully if need be */

if (err)

printk (KERN_NOTICE "Error %d adding adc %d", err, minor);

}

static struct cdev AdcDevs;

static struct file_operations adc_remap_ops = {

.owner =THIS_MODULE,

.open =s3c2410_adc_open,

.read =s3c2410_adc_read,

.write = s3c2410_adc_write,

.release =s3c2410_adc_release,

};

int __init adc_init(void)

{

/* normal ADC */

writel(0,S3C2410_ADCTSC); //XP_PST(NOP_MODE);

int result;

dev_t dev = MKDEV(adc_major, 0);

/* Figure out our device number. */

if (adc_major)

result = register_chrdev_region(dev, 1, "adc");

else {

result = alloc_chrdev_region(&dev, 0, 1, "adc");

adc_major = MAJOR(dev);

}

if (result < 0) {

printk(KERN_WARNING "adc: unable to get major %dn", adc_major);

return result;

}

if (adc_major == 0)

adc_major = result;

adc_setup_cdev(&AdcDevs, 0, &adc_remap_ops);

printk("adc device installed, with major %dn", adc_major);

return 0;

}

static void adc_cleanup(void)

{

cdev_del(&AdcDevs);

unregister_chrdev_region(MKDEV(adc_major, 0), 1);

printk("adc device uninstalledn");

}

module_init(adc_init);

module_exit(adc_cleanup);

MODULE_AUTHOR("Machuanlong");

MODULE_LICENSE("Dual BSD/GPL");

///////////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////////

Makefile(驱动的)

///////////////////////////////////////////////////////////////////////////////////

ifeq ($(KERNELRELEASE),)

#KERNELDIR ?= /source/kernel/linux-2.6.8.1-farsight

KERNELDIR ?= /disk2/linux-2.6.14

PWD := $(shell pwd)

modules:

$(MAKE) -C $(KERNELDIR) M=$(PWD) modules

modules_install:

$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install

clean:

rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions

.PHONY: modules modules_install clean

else

obj-m := s3c2410_adc.o

endif

///////////////////////////////////////////////////////////////////////////////////

s3c2410-adc.h

///////////////////////////////////////////////////////////////////////////////////

#ifndef _S3C2410_ADC_H_

#define _S3C2410_ADC_H_

#define ADC_WRITE(ch, prescale)((ch)<<16|(prescale))

#define ADC_WRITE_GETCH(data)(((data)>>16)&0x7)

#define ADC_WRITE_GETPRE(data)((data)&0xff)

#define ADC_INPUT(x)(x<<3)

#define PRSCVL(x)(x<<6)

#endif /* _S3C2410_ADC_H_ */

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

测试程序:

main.c

///////////////////////////////////////////////////////////////////////////////////

/************************************************

**HLG442 ADC-TEST

/26/3/2008

Author machuanlong

**

***********************************************/

#include

#include

#include

#include

#include

#include

#include

#include "s3c2410-adc.h"

#define ADC_DEV"/dev/adc"

static int adc_fd=-1;

static int GetADresult()

{

int data;

read(adc_fd, &data, sizeof(data));

return data;

}

static int stop=0;

int main(void)

{

int i;

float d;

if((adc_fd=open(ADC_DEV, O_RDWR))<0){

printf("Error opening %s adc devicen", ADC_DEV);

return -1;

}

while(1){

d=((float)GetADresult()*3.3)/1024.0;

printf("a%d=%8.4ft",0,d);

printf("n");

sleep(1);

printf("r");

}

close(adc_fd);

return 0;

}

这两个都是字符型驱动希望对初学者用所帮助