感謝TI社區提供的好幫助啊！http://e2e.ti.com/support/arm/sitara_arm/f/791/p/571771/2103409?pi316653=2
雖然海思平台和TI平台不一樣 ，但也大同小異。
具體的步驟如下：
轉到內核目錄：
//加載配置文件
cp xxx .config 修改配置 make xxxx menuconfig -> Device Drivers -> USB support -> USB Gadget Support 添加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
打開自動切換！！！！
需要注意的是gadget子項的驅動依賴於udc模塊和composite模塊，而composite模塊又依賴於udc模塊，udc是硬件接口模塊，直接操作USB寄存器等。composite為上層驅動提供操作UDC。
所以加載順序必要是udc-hisi.ko 、libcomposite.ko 、g_hid.ko
加載發現出現問題，某些函數不能用，經過研究要打開
File systems > Pseudo filesystems
+ {*} Userspace-driven configuration filesystem
即可，加載g_hid.ko后出現：
insmod: can’t insert ‘g_hid.ko’: No such device
原因在於沒有注冊設備報告描述符！！！修改hid.c文件
頭文件：
+#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 */ +}; 定義鍵盤設備： +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)函數開始處注冊鍵盤設備
+status = platform_device_register(&keyboard_device); + if (status < 0) { + printk("____ reg failed\n"); + platform_device_unregister(&keyboard_device); + return status; + }
在驅動卸載處釋放鍵盤設備
platform_driver_unregister(&hidg_plat_driver); +platform_device_unregister(&keyboard_device); usb_composite_unregister(&hidg_driver);
添加后即可識別為鍵盤設別如下圖所示： 單個鍵盤和鼠標沒有任何問題，然而同時設置鼠標和鍵盤加載后出現如下錯誤： ------------[ 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相同了沖突了！！
經過這樣子做，鼠標鍵盤在dev對應的是hidg0(鍵盤id 0) hidg1(鼠標id 1),只要打開這兩個設備，往這兩個設備發送鍵盤和鼠標報告就可以了
經過如此的配置只要按照順序加載udc-hisi.ko、libcomposite.ko、以及g_hid.ko即可使用gadget鼠標鍵盤設備了，卸載這些驅動后，host又可以正常使用。