Linux Gadget的一点研究之HID设备

接上文，配置编译gadget HID模块

make modules后在driver/usb/gadget目录下生成g_hid.ko

执行加载命令：

1. root@XXX:/mnt# insmod g_hid.ko   
2. insmod: can't insert 'g_hid.ko': No such device  

提示错误。

在TI 技术论坛上看到相关技术回复：

• The error message you had before 'error inserting 'g_hid.ko': -1 No such device.' is due to incomplete hid gadget driver. You can followDocumentation/usb/gadget_hid.txt to add your own platform device portion.

  For your reference, the following patch is what I tried and it works with the 3.3 kernel from the link I provided above with SD card boot.

下载提及的补丁

1. From 6363b29be2c2b477a723b74e52025511be280979 Mon Sep 17 00:00:00 2001  
2. From: Bin Liu   
3. Date: Fri, 18 Jan 2013 10:27:57 -0600  
4. Subject: [PATCH] patched hid gadget  
5.   
6. ---  
7.  drivers/usb/gadget/hid.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++  
8.  1 files changed, 61 insertions(+), 0 deletions(-)  
9.   
10. diff --git a/drivers/usb/gadget/hid.c b/drivers/usb/gadget/hid.c  
11. index f888c3e..c037039 100644  
12. --- a/drivers/usb/gadget/hid.c  
13. +++ b/drivers/usb/gadget/hid.c  
14. @@ -16,6 +16,8 @@  
15.  #include   
16.  #include   
17.    
18. +#include   
19. +  
20.  #define DRIVER_DESC        "HID Gadget"  
21.  #define DRIVER_VERSION     "2010/03/16"  
22.    
23. @@ -49,6 +51,57 @@ struct hidg_func_node {  
24.    
25.  static LIST_HEAD(hidg_func_list);  
26.    
27. +  
28. +/* hid descriptor for a keyboard */  
29. +static struct hidg_func_descriptor my_hid_data = {  
30. +   .subclass       = 0, /* No subclass */  
31. +   .protocol       = 1, /* Keyboard */  
32. +   .report_length      = 8,  
33. +   .report_desc_length = 63,  
34. +   .report_desc        = {  
35. +       0x05, 0x01, /* USAGE_PAGE (Generic Desktop)           */  
36. +       0x09, 0x06, /* USAGE (Keyboard)                       */  
37. +       0xa1, 0x01, /* COLLECTION (Application)               */  
38. +       0x05, 0x07, /*   USAGE_PAGE (Keyboard)                */  
39. +       0x19, 0xe0, /*   USAGE_MINIMUM (Keyboard LeftControl) */  
40. +       0x29, 0xe7, /*   USAGE_MAXIMUM (Keyboard Right GUI)   */  
41. +       0x15, 0x00, /*   LOGICAL_MINIMUM (0)                  */  
42. +       0x25, 0x01, /*   LOGICAL_MAXIMUM (1)                  */  
43. +       0x75, 0x01, /*   REPORT_SIZE (1)                      */  
44. +       0x95, 0x08, /*   REPORT_COUNT (8)                     */  
45. +       0x81, 0x02, /*   INPUT (Data,Var,Abs)                 */  
46. +       0x95, 0x01, /*   REPORT_COUNT (1)                     */  
47. +       0x75, 0x08, /*   REPORT_SIZE (8)                      */  
48. +       0x81, 0x03, /*   INPUT (Cnst,Var,Abs)                 */  
49. +       0x95, 0x05, /*   REPORT_COUNT (5)                     */  
50. +       0x75, 0x01, /*   REPORT_SIZE (1)                      */  
51. +       0x05, 0x08, /*   USAGE_PAGE (LEDs)                    */  
52. +       0x19, 0x01, /*   USAGE_MINIMUM (Num Lock)             */  
53. +       0x29, 0x05, /*   USAGE_MAXIMUM (Kana)                 */  
54. +       0x91, 0x02, /*   OUTPUT (Data,Var,Abs)                */  
55. +       0x95, 0x01, /*   REPORT_COUNT (1)                     */  
56. +       0x75, 0x03, /*   REPORT_SIZE (3)                      */  
57. +       0x91, 0x03, /*   OUTPUT (Cnst,Var,Abs)                */  
58. +       0x95, 0x06, /*   REPORT_COUNT (6)                     */  
59. +       0x75, 0x08, /*   REPORT_SIZE (8)                      */  
60. +       0x15, 0x00, /*   LOGICAL_MINIMUM (0)                  */  
61. +       0x25, 0x65, /*   LOGICAL_MAXIMUM (101)                */  
62. +       0x05, 0x07, /*   USAGE_PAGE (Keyboard)                */  
63. +       0x19, 0x00, /*   USAGE_MINIMUM (Reserved)             */  
64. +       0x29, 0x65, /*   USAGE_MAXIMUM (Keyboard Application) */  
65. +       0x81, 0x00, /*   INPUT (Data,Ary,Abs)                 */  
66. +       0xc0        /* END_COLLECTION                         */  
67. +   }  
68. +};  
69. +  
70. +static struct platform_device my_hid = {  
71. +   .name           = "hidg",  
72. +   .id         = 0,  
73. +   .num_resources      = 0,  
74. +   .resource       = 0,  
75. +   .dev.platform_data  = &my_hid_data,  
76. +};  
77. +  
78.  /*-------------------------------------------------------------------------*/  
79.    
80.  static struct usb_device_descriptor device_desc = {  
81. @@ -267,6 +320,13 @@ static int __init hidg_init(void)  
82.  {  
83.     int status;  
84.    
85. +   status = platform_device_register(&my_hid);  
86. +   if (status < 0) {  
87. +       printk("____ reg failed\n");  
88. +       platform_device_unregister(&my_hid);  
89. +       return status;  
90. +   }  
91. +  
92.     status = platform_driver_probe(&hidg_plat_driver,  
93.                 hidg_plat_driver_probe);  
94.     if (status < 0)  
95. @@ -283,6 +343,7 @@ module_init(hidg_init);  
96.  static void __exit hidg_cleanup(void)  
97.  {  
98.     platform_driver_unregister(&hidg_plat_driver);  
99. +   platform_device_unregister(&my_hid);  
100.     usb_composite_unregister(&hidg_driver);  
101.  }  
102.  module_exit(hidg_cleanup);  
103. --   
104. 1.7.0.4  

继续尝试。。。