蜂鸣器驱动（s3c3440）

buzzer_mwm.c

#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/gpio.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <asm/unistd.h>



#define DEVICE_NAME     "pwm"

#define PWM_IOCTL_SET_FREQ		1
#define PWM_IOCTL_STOP			0
#define BUZZER_MINORS	       109
volatile unsigned long *gpbcon = NULL;
volatile unsigned long *gpbdat = NULL;

static struct class *buzzerdrv_class;


static int mini2440_pwm_mwm_open(struct inode *inode, struct file *file)
{
	*gpbcon |= (0x1<<(0*2));
	return 0;
}

static int mini2440_pwm_mwm_close(struct inode *inode, struct file *file)
{
	
    return 0;
}

static ssize_t mini2440_pwm_mwm_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
{
	int val;
	copy_from_user(&val,buf,count);
	if(val)
	{
		*gpbdat &= ~(1<<0);
	}
	else
	{
		*gpbdat |= (1<<0);
	}
	return 0;
}

static struct file_operations dev_fops = {
    .owner   =   THIS_MODULE,
    .open    =   mini2440_pwm_mwm_open,
    .release =   mini2440_pwm_mwm_close, 
    .write   =   mini2440_pwm_mwm_write,
};

static int __init dev_init(void)
{
	int res;
	res = register_chrdev(BUZZER_MINORS,"buzzer_drv",&dev_fops);
	if (res)		
		goto out;
		buzzerdrv_class = class_create(THIS_MODULE, "buzzer_drv");	//
		device_create(buzzerdrv_class, NULL, MKDEV(BUZZER_MINORS,0),"%s","buzzer_drv");

		gpbcon = (volatile unsigned long *)ioremap(0x56000010, 16);	
		gpbdat = gpbcon + 1;

	return 0;
out:
	printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
	return res;
}

static void __exit dev_exit(void)
{
	iounmap(gpbcon);
	device_destroy(buzzerdrv_class,MKDEV(BUZZER_MINORS,0));
	class_destroy(buzzerdrv_class);
	unregister_chrdev(BUZZER_MINORS, "buzzer_drv");
}

module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("FriendlyARM Inc.");

Makefile

KERN_DIR = /home/mao/work0630/linux-2.6.32.2
all:
	     make -C $(KERN_DIR) M=`pwd` modules
clean:
	     make -C $(KERN_DIR) M=`pwd` modules clean
	     rm -rf modules.order
obj-m += buzzer_mwm.o

buzzertest.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(int argc,char **argv)
{   
    int fd;
    int val = 1;
    fd = open("/dev/buzzer_drv",O_RDWR);
    if (fd <0)
    {
        printf("can't open ! \n");
    }
    if (argc != 2)
    {
        printf("Usage :\n");
        printf("%s <on|off> \n");
        return 0;
    }
    if(strcmp(argv[1],"on") == 0)
    {
        val = 1;
    }
    else
        val = 0;

    write(fd,&val,4);
    return 0;
}

本文地址：https://blog.csdn.net/laomao_mwm/article/details/107568846