Linux下CPLD驅動(dòng)程序

int major;
static int cpld_drv_init(void)
{
major = register_chrdev(0, cpld_drv, cpld_drv_fops); //注冊設備
cpld_class = class_create(THIS_MODULE, cplddrv); //創(chuàng )建類(lèi)
cpld_class_dev = device_create(cpld_class, NULL, MKDEV(major, 0), NULL, cpld_drv); //自動(dòng)創(chuàng )建設備文件 /dev/cpld_drv
cpld_data = (volatile unsigned long *)ioremap(0x08000000,4); //映射CPLD物理地址到虛擬地址
gpfcon = (volatile unsigned long *)ioremap(0x56000050, 8); //映射GPF寄存器物理地址到虛擬地址
gpfdat = gpfcon+1;
*gpfcon =~((0x30) | (0x3(2*2)));
*gpfcon |=((0x10) | (0x01(2*2))); //設置GPF0、2為輸出
*gpfdat |=0x1; //將使能位置1，加載驅動(dòng)時(shí)CPLD不輸出PWM
printk(cpld_drv initialized!n);
return 0;
}

static void cpld_drv_exit(void)
{
*gpfdat |=0x1; //將使能位置1，卸載驅動(dòng)后CPLD不輸出PWM
unregister_chrdev(major, cpld_drv); //注銷(xiāo)驅動(dòng)
device_unregister(cpld_class_dev); //注銷(xiāo)設備
class_destroy(cpld_class); //注銷(xiāo)類(lèi)
iounmap(cpld_data); //取消映射
iounmap(gpfcon);
}

module_init(cpld_drv_init);
module_exit(cpld_drv_exit);

MODULE_LICENSE(GPL);