感謝TI社群提供的好幫助啊！http://e2e.ti.com/support/arm/sitara_arm/f/791/p/571771/2103409?pi316653=2
雖然海思平臺和TI平臺不一樣 ，但也大同小異。

具體的步驟如下：
轉到核心目錄：
//載入配置檔案

cp xxx .config 
修改配置 
make xxxx menuconfig 
-> Device Drivers -> USB support -> USB Gadget Support 新增gadget， HID Gadget 
進到： 
-> Device Drivers -> USB support > USB Gadget Support-> USB Peripheral Controller 
 
->Device Drivers ->USB support > USB Gadget Support -> USB Peripheral Controller -> Hisilicon USB2.0 Device Controller SUPPORT 
+ [*] Hisilicon USB2.0 Device auto switch

開啟自動切換！！！！
需要注意的是gadget子項的驅動依賴於udc模組和composite模組，而composite模組又依賴於udc模組，udc是硬體介面模組，直接操作USB暫存器等。composite為上層驅動提供操作UDC。

所以載入順序必要是udc-hisi.ko 、libcomposite.ko 、g_hid.ko
載入發現出現問題，某些函式不能用，經過研究要開啟

File systems > Pseudo filesystems 
+ {*} Userspace-driven configuration filesystem 

即可，載入g_hid.ko後出現： 
insmod: can’t insert ‘g_hid.ko’: No such device 
原因在於沒有註冊裝置報告描述符！！！修改hid.c檔案 
標頭檔案：

+#include <linux/usb/g_hid.h>

+static struct hidg_func_descriptor keyboard_report_data =
+{
+   .subclass       = 0, /* No subclass */  
+   .protocol       = 1, /* Keyboard */
+   .report_length      = 8,
+   .report_desc_length = 63,
+   .report_desc        = {
+   0x05, 0x01, /* USAGE_PAGE (Generic Desktop)           */
+       0x09, 0x06, /* USAGE (Keyboard)                       */
+       0xa1, 0x01, /* COLLECTION (Application)               */
+       0x05, 0x07, /*   USAGE_PAGE (Keyboard)                */
+       0x19, 0xe0, /*   USAGE_MINIMUM (Keyboard LeftControl) */
+       0x29, 0xe7, /*   USAGE_MAXIMUM (Keyboard Right GUI)   */
+       0x15, 0x00, /*   LOGICAL_MINIMUM (0)                  */
+       0x25, 0x01, /*   LOGICAL_MAXIMUM (1)                  */
+       0x75, 0x01, /*   REPORT_SIZE (1)                      */
+       0x95, 0x08, /*   REPORT_COUNT (8)                     */
+       0x81, 0x02, /*   INPUT (Data,Var,Abs)                 */
    +   0x95, 0x01, /*   REPORT_COUNT (1)                     */
    +   0x75, 0x08, /*   REPORT_SIZE (8)                      */
    +   0x81, 0x03, /*   INPUT (Cnst,Var,Abs)                 */
    +   0x95, 0x05, /*   REPORT_COUNT (5)                     */
    +   0x75, 0x01, /*   REPORT_SIZE (1)                      */
    +   0x05, 0x08, /*   USAGE_PAGE (LEDs)                    */
    +   0x19, 0x01, /*   USAGE_MINIMUM (Num Lock)             */
    +   0x29, 0x05, /*   USAGE_MAXIMUM (Kana)                 */
    +   0x91, 0x02, /*   OUTPUT (Data,Var,Abs)                */
    +   0x95, 0x01, /*   REPORT_COUNT (1)                     */
    +   0x75, 0x03, /*   REPORT_SIZE (3)                      */
    +   0x91, 0x03, /*   OUTPUT (Cnst,Var,Abs)                */
    +   0x95, 0x06, /*   REPORT_COUNT (6)                     */
    +   0x75, 0x08, /*   REPORT_SIZE (8)                      */
    +   0x15, 0x00, /*   LOGICAL_MINIMUM (0)                  */
    +   0x25, 0x65, /*   LOGICAL_MAXIMUM (101)                */
    +   0x05, 0x07, /*   USAGE_PAGE (Keyboard)                */
    +   0x19, 0x00, /*   USAGE_MINIMUM (Reserved)             */
    +   0x29, 0x65, /*   USAGE_MAXIMUM (Keyboard Application) */
    +   0x81, 0x00, /*   INPUT (Data,Ary,Abs)                 */
    +   0xc0        /* END_COLLECTION                         */  
+};

定義鍵盤裝置：
+static struct platform_device keyboard_device = {  
+   .name           = "hidg",  
+   .id         = 0,  
+   .num_resources      = 0,  
+   .resource       = 0,  
+   .dev.platform_data  = &keyboard_report_data,  
+};  

在static int __init hidg_init(void)函式開始處註冊鍵盤裝置

+status = platform_device_register(&keyboard_device);  
+   if (status < 0) {
+       printk("____ reg failed\n");
+       platform_device_unregister(&keyboard_device);
+       return status;  
+   }   

在驅動解除安裝處釋放鍵盤裝置

platform_driver_unregister(&hidg_plat_driver); 
+platform_device_unregister(&keyboard_device); 
usb_composite_unregister(&hidg_driver);

新增後即可識別為鍵盤設別如下圖所示：



單個鍵盤和滑鼠沒有任何問題，然而同時設定滑鼠和鍵盤載入後出現如下錯誤：
------------[ cut here ]------------
WARNING: CPU: 1 PID: 139 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x60/0x70()
sysfs: cannot create duplicate filename '/devices/platform/hidg.0'
Modules linked in: g_hid(+) libcomposite udc_hisi [last unloaded: g_hid]
CPU: 1 PID: 139 Comm: insmod Tainted: G        W      3.18.20 #14
[<c001487c>] (unwind_backtrace) from [<c0011964>] (show_stack+0x10/0x14)
[<c0011964>] (show_stack) from [<c041e220>] (dump_stack+0x88/0x98)
[<c041e220>] (dump_stack) from [<c001e2d0>] (warn_slowpath_common+0x6c/0x88)
[<c001e2d0>] (warn_slowpath_common) from [<c001e31c>] (warn_slowpath_fmt+0x30/0x40)
[<c001e31c>] (warn_slowpath_fmt) from [<c012b4b8>] (sysfs_warn_dup+0x60/0x70)
[<c012b4b8>] (sysfs_warn_dup) from [<c012b550>] (sysfs_create_dir_ns+0x88/0x98)
[<c012b550>] (sysfs_create_dir_ns) from [<c01f94b0>] (kobject_add_internal+0xb0/0x300)
[<c01f94b0>] (kobject_add_internal) from [<c01f98bc>] (kobject_add+0x48/0x94)
[<c01f98bc>] (kobject_add) from [<c024eac4>] (device_add+0xd8/0x53c)
[<c024eac4>] (device_add) from [<c0252924>] (platform_device_add+0xb4/0x21c)
[<c0252924>] (platform_device_add) from [<bf0625bc>] (hidg_init+0x38/0xc8 [g_hid])
[<bf0625bc>] (hidg_init [g_hid]) from [<c00088d0>] (do_one_initcall+0x8c/0x1c8)
[<c00088d0>] (do_one_initcall) from [<c0085298>] (load_module+0x1740/0x1e88)
[<c0085298>] (load_module) from [<c0085ab8>] (SyS_init_module+0xd8/0xec)
[<c0085ab8>] (SyS_init_module) from [<c000e4a0>] (ret_fast_syscall+0x0/0x38)
---[ end trace c7b2846a724052eb ]---

static struct platform_device mouse_device = {  
   .name           = "hidg",  
   .id         = 0,  
   .num_resources      = 0,  
   .resource       = 0,  
   .dev.platform_data  = &mouse_report_desc,  
};

id和keyboard的id相同了衝突了！！
經過這樣子做，滑鼠鍵盤在dev對應的是hidg0(鍵盤id 0) hidg1(滑鼠id 1),只要開啟這兩個裝置，往這兩個裝置傳送鍵盤和滑鼠報告就可以了

經過如此的配置只要按照順序載入udc-hisi.ko、libcomposite.ko、以及g_hid.ko即可使用gadget滑鼠鍵盤裝置了，解除安裝這些驅動後，host又可以正常使用。