Linux下CPLD驱动程序
static unsigned cpld_drv_poll(struct file *file, poll_table *wait)
{
unsigned int mask = 0;
poll_wait(file, eint1_waitq, wait); //不会立即休眠
if (ev_eint1)
mask |= POLLIN | POLLRDNORM; //若产生中断，mask赋值，表示有数据可读
return mask;
}
static int cpld_drv_fasync (int fd, struct file *filp, int on)
{
//printk(driver: cpld_drv_fasyncn);
return fasync_helper (fd, filp, on, eint1_async);
}
int cpld_drv_close(struct inode *inode, struct file *file)
{
free_irq(IRQ_EINT1, 1); //释放中断
return 0;
}
static struct file_operations cpld_drv_fops = {
.owner = THIS_MODULE,
.write = cpld_drv_write,
.read = cpld_drv_read,
.open = cpld_drv_open,
.release = cpld_drv_close,
.poll = cpld_drv_poll,
.fasync = cpld_drv_fasync,
};
int major;
static int cpld_drv_init(void)
{
major = register_chrdev(0, cpld_drv, cpld_drv_fops); //注册设备
cpld_class = class_create(THIS_MODULE, cplddrv); //创建类
cpld_class_dev = device_create(cpld_class, NULL, MKDEV(major, 0), NULL, cpld_drv); //自动创建设备文件 /dev/cpld_drv
cpld_data = (volatile unsigned long *)ioremap(0x08000000,4); //映射CPLD物理地址到虚拟地址
gpfcon = (volatile unsigned long *)ioremap(0x56000050, 8); //映射GPF寄存器物理地址到虚拟地址
gpfdat = gpfcon+1;
*gpfcon =~((0x30) | (0x3(2*2)));
*gpfcon |=((0x10) | (0x01(2*2))); //设置GPF0、2为输出
*gpfdat |=0x1; //将使能位置1，加载驱动时CPLD不输出PWM
printk(cpld_drv initialized!n);
return 0;
}
static void cpld_drv_exit(void)
{
*gpfdat |=0x1; //将使能位置1，卸载驱动后CPLD不输出PWM
unregister_chrdev(major, cpld_drv); //注销驱动
device_unregister(cpld_class_dev); //注销设备
class_destroy(cpld_class); //注销类
iounmap(cpld_data); //取消映射
iounmap(gpfcon);
}
module_init(cpld_drv_init);
module_exit(cpld_drv_exit);
MODULE_LICENSE(GPL);
评论