bus

luozhiyong131

1. #include <linux/device.h>
   
2. #include <linux/module.h>
   
3. #include <linux/kernel.h>
   
4. #include <linux/init.h>
   
5. #include <linux/string.h>
   
6. 
   
7. MODULE_AUTHOR("David Xie");
   
8. MODULE_LICENSE("Dual BSD/GPL");
   
9. 
   
10. static char *Version = "$Revision: 1.9 $";
    
11. 
    
12. static int my_match(struct device *dev, struct device_driver *driver)
    
13. {
    
14.     return !strncmp(dev->bus_id, driver->name, strlen(driver->name));
    
15. }
    
16. 
    
17. static void my_bus_release(struct device *dev)
    
18. {
    
19.     printk(KERN_DEBUG "my bus release\n");
    
20. }
    
21.     
    
22. struct device my_bus = {
    
23.     .bus_id = "my_bus0",
    
24.     .release = my_bus_release
    
25. };
    
26. 
    
27. 
    
28. struct bus_type my_bus_type = {
    
29.     .name = "my_bus",
    
30.     .match = my_match,
    
31. };
    
32. 
    
33. EXPORT_SYMBOL(my_bus);
    
34. EXPORT_SYMBOL(my_bus_type);
    
35. 
    
36. 
    
37. /*
    
38.  * Export a simple attribute.
    
39.  */
    
40. static ssize_t show_bus_version(struct bus_type *bus, char *buf)
    
41. {
    
42.     return snprintf(buf, PAGE_SIZE, "%s\n", Version);
    
43. }
    
44. 
    
45. static BUS_ATTR(version, S_IRUGO, show_bus_version, NULL);
    
46. 
    
47. 
    
48. static int __init my_bus_init(void)
    
49. {
    
50.     int ret;
    
51.         
    
52.         /*注册总线*/
    
53.     ret = bus_register(&my_bus_type);
    
54.     if (ret)
    
55.         return ret;
    
56.         
    
57.     /*创建属性文件*/    
    
58.     if (bus_create_file(&my_bus_type, &bus_attr_version))
    
59.         printk(KERN_NOTICE "Fail to create version attribute!\n");
    
60.     
    
61.     /*注册总线设备*/
    
62.     ret = device_register(&my_bus);
    
63.     if (ret)
    
64.         printk(KERN_NOTICE "Fail to register device:my_bus!\n");
    
65.         
    
66.     return ret;
    
67. }
    
68. 
    
69. static void my_bus_exit(void)
    
70. {
    
71.     device_unregister(&my_bus);
    
72.     bus_unregister(&my_bus_type);
    
73. }
    
74. 
    
75. module_init(my_bus_init);
    
76. module_exit(my_bus_exit);