led灯闪烁.doc

本人学嵌入式还未到火候，各位有什么好的建议留下，我在此表示感谢，希望多多交流啊。
内核：linux-2.6.23
驱动程序：通过gpio端口点亮at91rm9200开发板上的灯
#include<linux/kernel.h>
#include<linux/module.h>
#include<linux/ioport.h>
#include<asm/io.h>
#include<linux/init.h>
#include<linux/fs.h>
#include<linux/errno.h>
#include<linux/device.h>
#include<mach/gpio.h>
//#include<linux/moduleparam.h>
#include<linux/sched.h>
MODULE_LICENSE("GPL");
#defineDEMO_MAJOR125
#defineCOMMAND11
#defineCOMMAND23
staticunsignedintiovaddr;
staticintdemo_init(void);
staticintdemo_open(structinode*inode,structfile*file);
staticintdemo_close(structinode*inode,structfile*file);
staticssize_tdemo_read(structfile*file,char*buf,size_tcount,loff_t*offset);
staticintdemo_ioctl(structinode*inode,structfile*file,unsignedintcmd,unsignedintarg);
staticvoiddemo_cleanup(void);

intdemo_param=9;
staticintdemo_initialized=0;
staticvolatileintdemo_flag=0;
staticstructfile_operationsdemo_fops={
owner: THIS_MODULE,
llseek: NULL,
read: demo_read,
write: NULL,
ioctl: demo_ioctl,
open: demo_open,
release: demo_close,
};
staticintdemo_init(void)
{
inti;
staticstructclass*my_class;
//printk("1");在运行时，出现问题，可使用printk来检查
my_class=class_create(THIS_MODULE,"demo_drv");
device_create(my_class,NULL,MKDEV(125,0),NULL,"demo_drv");
if(demo_initialized==1)
return0;
//iovaddr=ioremap(0xfffff000,0x10);

//printk("4");
i=register_chrdev(DEMO_MAJOR,"demo_drv",&demo_fops);
//printk("5");
if(i<0)
{
printk(KERN_CRIT"DEMO:i=%d\n",i);
return0;
}
printk(KERN_CRIT"DEMO:demo_drvregisterredsuccessfully:)=\n");
demo_initialized=1;
return0;
}

staticintdemo_open(structinode*inode,structfile*file)
{
//printk("6\n");//必须加上\n，才能显示，
at91_set_GPIO_periph(AT91_PIN_PC15,1);
at91_set_GPIO_periph(AT91_PIN_PC14,1);
at91_set_gpio_output(AT91_PIN_PC15,1);
at91_set_gpio_output(AT91_PIN_PC14,1);
at91_set_gpio_value(AT91_PIN_PC15,0);
at91_set_gpio_value(AT91_PIN_PC14,0);
//printk("7\n");
if(demo_flag==1)
{
return-1;
}
printk(KERN_CRIT"DEMO:demodeviceopen\n");
demo_flag