GEC2440A实现蜂鸣器唱歌linux驱动程序实现

/*====================================================================== A beep_driver driver as an example of char device drivers The initial developer of the original code is Baohua Song <author@linuxdriver.cn>. All Rights Reserved. ======================================================================*/ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/init.h> #include <linux/kernel.h> /* printk() */ #include <linux/slab.h> /* kmalloc() */ #include <linux/fs.h> /* everything... */ #include <linux/errno.h> /* error codes */ #include <linux/types.h> /* size_t */ #include <linux/proc_fs.h> #include <linux/fcntl.h> /* O_ACCMODE */ #include <linux/seq_file.h> #include <linux/cdev.h> #include <linux/sched.h> #include <asm/hardware.h> #include <asm/system.h> /* cli(), *_flags */ #include <asm/uaccess.h> /* copy_*_user */ #include <asm/semaphore.h> /*信号量*/ #include<linux/delay.h> #include"beep_driver.h" int beep_dev_num=DEV_NUM; /*申请设备的个数*/ static int beep_major = BEEP_MAJOR; /*beep设备结构体*/ struct cdev beep_dev; /*cdev结构体*/ int temp=0; //struct cdev *beep_devp; /*设备结构体指针*/ struct semaphore sem; /*开发板寄存器初始化*/ void beep(unsigned int freq) { /*蜂鸣器初始化*/ //设置引脚GPB2为Timer功能引 volatile unsigned int temp=0; temp=__raw_readl(rGPBCON); temp &=~((1<<2) | (1<<3)); temp |=(1<<3); __raw_writel(temp,rGPBCON); temp=__raw_readl(rGPBUP); temp |=(1<<1); __raw_writel(temp,rGPBUP); //定时器配置寄存器0的前8位置一 //预分频器Prescaler 0配置成255 temp=__raw_readl(rTCFG0); temp |=0xff; __raw_writel(temp,rTCFG0); //定时器配置寄存器0的前8位置一 //预分频器Prescaler 0配置成255 temp=__raw_readl(rTCFG1); temp &=~((1<<4) | (1<<5) | (1<<6) | (1<<7)); temp |=(1<<5); __raw_writel(temp,rTCFG1); //定时器配置寄存器0的前8位置一 //预分频器Prescaler 0配置成255 temp=__raw_readl(rTCNTB1); temp=((50000000/freq)>>11); __raw_writel( temp,rTCNTB1); //当定时器数到总数的一半时电平翻转 temp=__raw_readl(rTCMPB1); temp=((50000000/freq)>>12); __raw_writel(temp, rTCMPB1); //BIT[11]:Timer 1 auto reload on/off = Interval mode (auto reload) //BIT[10]:Timer 1 output inverter on/off = Inverter off //BIT[9]:Timer 1 manual update = Update TCNTB1 & TCMPB1 //BIT[8]:Timer 1 start/stop = Stop temp=__raw_readl(rTCON); temp &=~((1<<8) | (1<<9) | (1<<10) | (1<<11)); temp |=(1<<9); __raw_writel(temp,rTCON); //设置为auto reload并且Start for Timer 1 //open [9] [8] temp = __raw_readl(rTCON); temp &= ~(0xf<<8); temp |= (1<<11)|(1<<8); __raw_writel(temp,rTCON); temp = __raw_readl(rTCON); temp &=(~(1<<9)); __raw_writel(temp,rTCON); printk("<0>" "----------beep_init scuessful\n"); } /*动态分配设备号码*/ void stop_buzzer(void) { volatile unsigned int temp=0; temp = __raw_readl(rTCON); temp &= ~(1<<8); __raw_writel(temp,rTCON); } /*文件打开函数*/ int beep_open(struct inode *inode, struct file *filp) { beep(1); return 0; } /*文件释放函数*/ int beep_release(struct inode *inode, struct file *filp) { return 0; } /* ioctl设备控制函数 */ static int beep_ioctl(struct inode *inodep, struct file *filp, unsigned int cmd, unsigned long arg) { return 0; } /*读函数*/ static ssize_t beep_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) { return 0; } /*写函数*/ static ssize_t beep_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) { struct songdata { unsigned int time; unsigned short tonefreq; }bjhyn[1]; down_interruptible(&sem); temp++; copy_from_user(&bjhyn,buf,count); beep(bjhyn[0].tonefreq); msleep((bjhyn[0].time)*60); up(&sem); return 0; } /* seek文件定位函数 */ static loff_t beep_llseek(struct file *filp, loff_t offset, int orig) { return 0; } /*文件操作结构体*/ struct file_operations beep_fops = { .owner = THIS_MODULE, .llseek = beep_llseek, .read = beep_read, .write = beep_write, .ioctl = beep_ioctl, .open = beep_open, .release = beep_release, }; /*初始化并注册cdev*/ static void beep_setup_cdev(struct cdev *beep_dev, int index) { int err=0, devno = MKDEV(beep_major, index); beep_dev = cdev_alloc();/*申请设备空间*/ cdev_init(beep_dev, &beep_fops); beep_dev->owner = THIS_MODULE; beep_dev->ops = &beep_fops; err = cdev_add(beep_dev, devno, 1); if (err) { printk(KERN_NOTICE "Error %d adding LED%d", err, index); } } /*关闭蜂鸣器*/ void buzzer_stop(void) { volatile unsigned int temp=0; temp = __raw_readl(rTCON); temp &=(~(1<<8)); __raw_writel(temp,rTCON); } /*开发板寄存器初始化完毕*/ /*设备驱动模块加载函数*/ static int __init beep_init(void) { int result=0; dev_t devno = MKDEV(beep_major, 0); struct cdev beep_dev; /* 申请设备号*/ if (beep_major) result = register_chrdev_region(devno, beep_dev_num, "beep_driver"); else /* 动态申请设备号 */ { result = alloc_chrdev_region(&devno, 0, beep_dev_num, "beep_driver"); beep_major = MAJOR(devno); printk("<0>" "device number is %d.\n",beep_major); } if (result < 0) { return result; } beep_setup_cdev(&beep_dev, 0); /*注册设备号*/ sema_init(& sem , 1); /*初始化信号量*/ return result; } /*模块卸载函数*/ static void __exit beep_exit(void) { cdev_del(&beep_dev); /*注销cdev*/ buzzer_stop();/*停止蜂鸣器*/ unregister_chrdev_region(MKDEV(beep_major, 0), beep_dev_num); /*释放设备号*/ } MODULE_AUTHOR("Song Baohua"); MODULE_LICENSE("Dual BSD/GPL"); module_param(beep_major, int, S_IRUGO); module_init(beep_init); module_exit(beep_exit);