mini 2440 beep驱动代码

今天太晚了,很困,把mini 2440 beep的驱动的代码调试通过之后,开发板成功"滴~"的发出了声音,于是还是挺开心的,在睡觉前把这些代码贴上,择日详解,敬请关注.

首先是驱动代码:beepdriver.c

#include <linux/module.h>
//#include <linux/error.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <mach/irqs.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/device.h>
#include <linux/cdev.h>

#define BEEP_MAGIC 'k'
#define BEEP_START_CMD _IO(BEEP_MAGIC, 1)
#define BEEP_STOP_CMD _IO(BEEP_MAGIC, 2)

MODULE_LICENSE("Dual BSD/GPL");

int major;
int result;
dev_t devno;
static struct cdev beepDev;
struct class *beep_class;

void beep_stop(void) {
	s3c2410_gpio_cfgpin(S3C2410_GPB(0), S3C2410_GPIO_OUTPUT);
	s3c2410_gpio_setpin(S3C2410_GPB(0), 0);
}

void beep_start(void) {
	s3c2410_gpio_pullup(S3C2410_GPB(0), 1);
	s3c2410_gpio_cfgpin(S3C2410_GPB(0), S3C2410_GPIO_OUTPUT);
	s3c2410_gpio_setpin(S3C2410_GPB(0), 1);
}

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



static int beep_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) {
	switch (cmd) {
		case BEEP_START_CMD:
			beep_start();
			break;
		case BEEP_STOP_CMD:
			beep_stop();
			break;
		default:
			break;
	}
	return 0;
}

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

static ssize_t beep_read(struct file *file, char __user *buff, size_t count, loff_t *offp) {
	return 0;
}

ssize_t beep_write(struct file *file, const char __user *buff, size_t count, loff_t *offp)
{
	return 0;
}

static struct file_operations beep_ops = {
	.owner = THIS_MODULE,
	.open = beep_open,
	.read = beep_read,
	.release = beep_release,
	.write = beep_write,
	.ioctl = beep_ioctl,
};

//init beep driver and get major number.
static int beep_init(void) {
	int err;
	char dev_name[] = "beep";
	if (major) {
		devno = MKDEV(major, 0);
		result = register_chrdev_region(devno, 1, dev_name);
	} else {
		//系统自动分配设备号
		result = alloc_chrdev_region(&devno, 0, 1, dev_name);
		major = MAJOR(devno);
	}
	if (result < 0) {
		printk(KERN_WARNING "beep: can't get major %d\n", major);
	}
	
	devno = MKDEV(major, 0);
	cdev_init(&beepDev, &beep_ops);
	beepDev.owner = THIS_MODULE;
	beepDev.ops = &beep_ops;
	err = cdev_add(&beepDev, devno, 1);
	if (err) {
		printk(KERN_NOTICE "Error %d adding beep%d", err, 0);
	}

	beep_class = class_create(THIS_MODULE, "beepdrv");
	if (IS_ERR(beep_class)) {
		printk("Err:failed in creating class.\n");
		return 1;
	}
	device_create(beep_class, NULL, MKDEV(major, 0), NULL, "beep");
	
	printk("beep device installed, with major %d\n", major);
	printk("The device name is: %s\n", dev_name);
	
	return 0;
}



static void beep_exit(void) {
	cdev_del(&beepDev);
	unregister_chrdev_region(MKDEV(major, 0), 1);
	device_destroy(beep_class, MKDEV(major, 0));
	class_destroy(beep_class);
	printk("beep device uninstalled\n");
}

module_init(beep_init);
module_exit(beep_exit);

其次是测试的代码:beeptest.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <linux/ioctl.h>

#define BEEP_MAGIC 'k'
#define BEEP_START_CMD _IO(BEEP_MAGIC, 1)
#define BEEP_STOP_CMD _IO(BEEP_MAGIC, 2)

int main(int argc, char *argv[]) {
	int i = 0;
	int dev_fd;
	dev_fd = open("/dev/beep", O_RDWR | O_NONBLOCK);
	if (dev_fd == -1) {
		printf("Can't open file /dev/beep\n");
		exit(1);
	}
	printf("Start beep\n");
	ioctl(dev_fd, BEEP_START_CMD, 0);
	getchar();
	ioctl(dev_fd, BEEP_STOP_CMD, 0);
	printf("Stop beep and Close device\n");
	close(dev_fd);
	return 0;
}

最后是Makefile:

ifneq ($(KERNELRELEASE),)
	obj-m := beepdriver.o
else
	KERNELDIR ?= /usr/src/linux-2.6.32.2
	PWD := $(shell pwd)
	
defalut:
	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
clean:
	@rm -rf *.ko *.o *.symvers *.order *.mod.c
endif

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