十、编写LED混杂设备驱动

led.c修改为：

 1 #include <linux/init.h>
 2 #include <linux/module.h>
 3 #include <linux/miscdevice.h>
 4 #include <linux/fs.h>
 5 #include <linux/io.h>
 6 
 7 
 8 #define GPMCON    0x7F008820
 9 #define GPMDAT    0x7F008824
10 
11 static int * __gp_gpmdat;
12 
13 static int led_open (struct inode *p_inode, struct file *p_file)
14 {
15     int *p_gpmcon = NULL;
16 
17     p_gpmcon = ioremap(GPMCON, 4);
18     writel(0x1111, p_gpmcon);
19 
20     __gp_gpmdat = ioremap(GPMDAT, 4);
21 
22     return 0;
23 }
24 
25 static long led_ioctl (struct file *p_file, unsigned int cmd, unsigned long arg)
26 {
27     switch (cmd) {
28     case 0:
29         writel(0x0, __gp_gpmdat);
30         break;
31     
32     case 1:
33         writel(0xF, __gp_gpmdat);
34         break;
35 
36     default:
37         return -1;
38     }
39     return 0;
40 }
41 
42 static struct file_operations fops = {
43     .owner = THIS_MODULE,
44     .open = led_open,
45     .unlocked_ioctl = led_ioctl,
46 };
47 
48 
49 static struct miscdevice led_dev = {
50     .minor = MISC_DYNAMIC_MINOR,
51     .name = "myled",
52     .fops = &fops,
53 };
54 
55 static __init int led_init (void)
56 {
57     misc_register(&led_dev);
58 
59     return 0;
60 }
61 
62 static __exit void led_exit (void)
63 {
64     misc_deregister(&led_dev);
65 }
66 
67 module_init(led_init);
68 module_exit(led_exit);
69 
70 MODULE_LICENSE("GPL");

其他文件同上一章一样，但是使用led时只需要先insmod led.ko，不需要再创建设备节点便可以使用led_app控制led