驱动中IO端口申请代码
时间: 2024-04-29 10:22:59 浏览: 8
这是一个简单的驱动程序的IO端口申请代码示例:
```
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ioport.h>
#define PORT_START 0x1000
#define PORT_END 0x2000
#define PORT_SIZE (PORT_END - PORT_START + 1)
static unsigned long port_base;
static int __init my_driver_init(void)
{
int ret;
ret = check_region(PORT_START, PORT_SIZE);
if (ret) {
printk(KERN_ERR "Port range is already in use\n");
return ret;
}
request_region(PORT_START, PORT_SIZE, "my_driver");
port_base = (unsigned long)ioremap(PORT_START, PORT_SIZE);
if (!port_base) {
release_region(PORT_START, PORT_SIZE);
printk(KERN_ERR "Unable to map IO region\n");
return -EIO;
}
// Now you can use `inb` and `outb` to access the IO port
return 0;
}
static void __exit my_driver_exit(void)
{
iounmap((void *)port_base);
release_region(PORT_START, PORT_SIZE);
}
module_init(my_driver_init);
module_exit(my_driver_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name <you@example.com>");
MODULE_DESCRIPTION("My Driver");
```
此代码将请求从0x1000到0x2000的IO端口范围,并将其映射到内核空间中的指针`port_base`。您可以使用`inb`和`outb`来访问这些端口。在模块退出时,使用`release_region`和`iounmap`释放资源。