platform设备驱动框架

驱动框架

通过使用platform设备驱动框架，实现led驱动与设备操作的分离。

 
 

我们关注led_drv里面的 struct platform_driver led_drv里面的.probe函数，当有同名的device注册到内核，将运行这个driver的probe函数（同名的：led_dev里面的struct platform_device led_dev里面的.name与 struct platform_driver led_drv里面的.name一一对应）。

 
 

led_dev.c

1

5

20

21         []                 .start                          .end                          .flags                 },
27

28         []                 .start                          .end                          .flags                 }
33 };
34

35 {
37

38 }
39

40         .name                                  .id                                  .num_resources                  .resource                         .dev                 .release         }
48 };
49

50

51 {
53         platform_device_register(         ;
55 }
56

57

58 {
60         platform_device_unregister(          }
63

64 module_init(led_dev_init);
65 module_exit(led_dev_exit);
66 MODULE_LICENSE("GPL");

 
 

 
 

led_drv.c

1

5

20

21

22

24

27

30

32

33 {
35                                    ;
39 }
40

41
{
44         

46         copy_from_user(                  {
49                          }
51                                   }
54         ;
55 }
56

57         .owner                  .open                  .write         };
62

63 {
65         

67         printk(         
69                  res );
71         gpioctl         gpiodat

74         res );
75         led_pin

77                  major ,

80         led_class

82                  led_class_dev ),

85         ;
86 }
87

88 {
90         printk(         

93                  unregister_chrdev(major,         class_device_unregister(led_class_dev);
96         class_destroy(led_class);
97

98                  iounmap(gpioctl);
100

101         ;
102 }
103

104         .probe                  .remove         .driver                 .name                  }
110 };
111

112 {
114         platform_driver_register(         ;
116 }
117

118 {
120         platform_driver_unregister(          }
123

124 module_init(led_drv_init);
125 module_exit(led_drv_exit);
126 MODULE_LICENSE("GPL");

 
 

app.c

1

6 {
8                                    
12         printf(                  {
15                 printf(                          }
18         
19         filename ];
20         
21         printf(         
23         fd                  {
26                 printf(                          }
29         
30                  ]))
32         {
33                 val                 write(fd, );
35         }
36                  ]))
38         {        
39                 val                 write(fd, );
41         }
42         ;        
43 }

 
 

Makefile

1

3         make -C

6         make -C         rm -rf modules.order
9

10 obj-m += led_drv.o
11 obj-m +=
led_dev.o