335xGPIO型蜂鸣器控制

来源：互联网发布：关宁军知乎编辑：程序博客网时间：2024/05/21 04:20

转自：http://bbs.elecfans.com/jishu_903104_1_1.html

buzzer_drv.h

#ifndef _BUZZER_DRV_H#define _BUZZER_DRV_H#define BUZZER_IOC_MAGIC 'B'#define BUZZER_ON _IO(BUZZER_IOC_MAGIC, 1)#define BUZZER_OFF _IO(BUZZER_IOC_MAGIC, 0)#define BUZZER_IOCTL_MAXNR 2#endif /*_BUZZER_DRV_H*/~

buzzer_drv.c:

#include <linux/init.h>#include <linux/module.h>#include <linux/fs.h>#include <linux/cdev.h>#include <linux/device.h>#include <linux/version.h>#include <asm/mach/arch.h>#include <mach/hardware.h>#include <mach/gpio.h>#include <asm/gpio.h>#include "buzzer_drv.h"static int major;static int minor;struct cdev *buzzer; /* cdev 数据结构 */static dev_t devno; /* 设备编号 */static struct class *buzzer_class;#define DEVICE_NAME "buzzer"#define GPIO_BUZZER_PIN_NUM (0*32 + 2) /*gpio0_2 */static int buzzer_open(struct inode *inode,struct file *file ){      try_module_get(THIS_MODULE);      gpio_direction_output(GPIO_BUZZER_PIN_NUM, 1);      return 0;}static int buzzer_release(struct inode*inode, struct file *file ){      module_put(THIS_MODULE);      gpio_direction_output(GPIO_BUZZER_PIN_NUM, 1);      return 0;}static int buzzer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg){      if(_IOC_TYPE(cmd) != BUZZER_IOC_MAGIC) {             return -ENOTTY;      }      if(_IOC_NR(cmd) > BUZZER_IOCTL_MAXNR) {             return -ENOTTY;      }      switch(cmd){             case BUZZER_ON:             gpio_set_value(GPIO_BUZZER_PIN_NUM, 1);             break;             case BUZZER_OFF:             gpio_set_value(GPIO_BUZZER_PIN_NUM, 0);             break;             default:             break;      }      return 0;  }struct file_operations buzzer_fops = {      .owner = THIS_MODULE,      .open = buzzer_open,      .release = buzzer_release,      .unlocked_ioctl = buzzer_ioctl,};static int __init buzzer_init(void){      int ret;      gpio_free(GPIO_BUZZER_PIN_NUM);      if(gpio_request(GPIO_BUZZER_PIN_NUM, "buzzer_bee")) {             printk("request %s gpio faile \n", "buzzer");             return -1;      }      ret = alloc_chrdev_region(&devno, minor, 1, "buzzer"); /* 从系统获取主设备号 */             major= MAJOR(devno);             if(ret < 0) {             printk(KERN_ERR"cannot get major %d \n", major);             return -1;      }      buzzer = cdev_alloc(); /* 分配 buzzer 结构 */      if(buzzer != NULL) {             cdev_init(buzzer,&buzzer_fops); /* 初始化 buzzer 结构 */             buzzer->owner = THIS_MODULE;             if(cdev_add(buzzer, devno, 1) != 0) { /* 增加 buzzer 到系统中 */                    printk(KERN_ERR"add cdev error!\n");             goto error;      }      }else {             printk(KERN_ERR"cdev_alloc error!\n");             return -1;      }      buzzer_class = class_create(THIS_MODULE, "buzzer_class");      if(IS_ERR(buzzer_class)) {             printk(KERN_INFO"create class error\n");             return -1;      }      device_create(buzzer_class,NULL, devno, NULL, "buzzer");      return 0;      error:      unregister_chrdev_region(devno,1); /* 释放已经获得的设备号 */      return ret;}static void __exit buzzer_exit(void){      cdev_del(buzzer);/* 移除字符设备 */      unregister_chrdev_region(devno,1); /* 释放设备号 */      device_destroy(buzzer_class,devno);      class_destroy(buzzer_class);}MODULE_LICENSE("GPL");module_init(buzzer_init);module_exit(buzzer_exit);MODULE_AUTHOR("Xiaoxin");

Makefile:

PWD := $(shell pwd)ARCH=armCROSS_COMPILE=/home/goembed/B1/335x-B1-CROSS_COMPILE/usr/bin/arm-linux-gnueabihf-obj-m += buzzer_drv.oKDIR = /home/goembed/B4/project_kernel/335x-B1-LINUX/all:        make -C $(KDIR) M=$(PWD) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) modules        arm-linux-gcc buzzer_test.c -o buzzer_testclean:        make -C $(KDIR) M=$(PWD) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE)  clean        rm buzzer_test

buzzer_test.c

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/ioctl.h>#include <errno.h>#include <fcntl.h>#include "buzzer_drv.h"#define DEV_NAME "/dev/buzzer"int main(int argc, char *argv[]){      int i;      int fd = 0;      fd = open (DEV_NAME, O_RDONLY);             if(fd < 0) {             perror("Open"DEV_NAME" Failed!\n");             exit(1);      }      while(1){             ioctl(fd,BUZZER_ON);       printf("BUZZER_ON\n");              sleep(1);             ioctl(fd,BUZZER_OFF);        printf("BUZZER_OFF\n");             sleep(1);      }      close(fd);      return 0;}~

加载驱动: insmod buzzer_drv.ko

查看是否加载成功： ls /dev/buzz* 如果有buzzer（节点名），则加载成功

卸载： rmmod buzzer_drv 注意不要后缀名.ko

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