DM816X 实现 USB HID Gadget 鼠标键盘功能

开发环境：
平台： DM8168
内核 ：linux 2.6.32
RDK：DVRRDK_04.00.00.03
USB口：DM8168有两个USB口可供选择，因为特殊原因我选择的是USB1，请根据实际需要选择USB口
，下面的配置会稍微有些不同。

1配置内核

依据参照http://processors.wiki.ti.com/index.php/DM81xx_AM38XX_USB_User_Guide#Introduction
http://processors.wiki.ti.com/index.php/Usbgeneralpage#One_port_as_host_and_other_port_as_Gadget_.28for_DM81XX.29。
摘录如下：

1) Select host and gadget support

Menuconfig->Device Drviers->USB Support

      <*>   Support for Host-side USB  
      [ ]     USB verbose debug messages   
      [*]     USB announce new devices     
      *** Miscellaneous USB options ***   
      ......
      <*>   USB Gadget Support  --->

2) Select USB OTG support (for TI816X)

Menuconfig->Device Drviers->USB Support

      <*>   Inventra Highspeed Dual Role Controller (TI, ADI, ...)  
                   *** Platform Glue Layer *** 
      < >     TUSB6010                                                           
      < >     OMAP2430 and onwards                                               
      < >     AM35x                                                             
      <*>     TI81XX                                                            
              TI816X usb connector's ID pin control (from software setting)  ---> 
                        Force TI816X USB0 to  (Host mode)  ---> 
                        Force TI816X USB1 to  (Host mode)  --->                 
              Driver Mode (Both host and peripheral:  USB OTG (On The Go) Device)  --->  
      [ ]   Disable DMA (always use PIO)                                          
      [*]   Enable debugging messages

3) Select Gadget device controller and gadget driver as modules

Menuconfig->Device Drviers->USB Support

      <*>   USB Gadget Support  --->
            --- USB Gadget Support                                
            [ ]   Debugging messages (DEVELOPMENT) (NEW)           
            [ ]   Debugging information files (DEVELOPMENT) (NEW)  
            [ ]   Debugging information files in debugfs (DEVELOPMENT) (NEW)
            (2)   Maximum VBUS Power usage (2-500 mA) (NEW)                 
            USB Peripheral Controller (Inventra HDRC USB Peripheral (TI, ADI, ...))  --->
           <M>   USB Gadget Drivers                                                          
           <M>     Gadget Zero (DEVELOPMENT)                                                 
           [ ]       HNP Test Device (NEW)                                                   
           < >     Audio Gadget (EXPERIMENTAL) (NEW)                                         
           <M>     Ethernet Gadget (with CDC Ethernet support)                               
           [*]       RNDIS support (NEW)                                                     
           [ ]       Ethernet Emulation Model (EEM) support (NEW)                            
           < >     Gadget Filesystem (EXPERIMENTAL) (NEW)                                    
           < >     Function Filesystem (EXPERIMENTAL) (NEW)                                  
           <M>     File-backed Storage Gadget                                                
           [*]       File-backed Storage Gadget testing version

4) Unselect the OTG Targeted Peripherals list

Menuconfig->Device Drviers->USB Support

      <*>   Support for Host-side USB
            ....
           [*] USB runtime power management (autosuspend) and wakeup  
           -*- OTG support  
           [ ]   Rely on OTG Targeted Peripherals List 
           [ ]   Disable external hubs

完成以上步骤，先保存退出。

2设备注册

为了实现设备被识别，需加入设备注册。修改hid.c 路径： DVRRDK_04.00.00.03/ti_tools/linux_lsp/kernel/linux-dvr-rdk/drivers/usb/gadget。
由于鼠标键盘为常见USB设备，设备描述符很好得到，如果是要自定义hid设备请参照usb协议.pdf(网络上很容易找到)。
修改如下

#include <linux/usb/g_hid.h>

/* hid descriptor for a keyboard */
static struct hidg_func_descriptor pcdm8168_keyboard_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 */
    }
};
/*hid descriptor for a mouse*/
static struct hidg_func_descriptor pcdm8168_mouse_data = {
    .subclass = 0,  /*NO SubClass*/
    .protocol = 2,  /*Mouse*/
    .report_length = 4,
    .report_desc_length = 52,
    .report_desc={
        0x05,0x01,  /*Usage Page (Generic Desktop Controls)*/
        0x09,0x02,  /*Usage (Mouse)*/
        0xa1,0x01,  /*Collction (Application)*/
        0x09,0x01,  /*Usage (pointer)*/
        0xa1,0x00,  /*Collction (Physical)*/
        0x05,0x09,  /*Usage Page (Button)*/
        0x19,0x01,  /*Usage Minimum(1)*/
        0x29,0x03,  /*Usage Maximum(3) */ 
        0x15,0x00,  /*Logical Minimum(1)*/
        0x25,0x01,  /*Logical Maximum(1)*/
        0x95,0x03,  /*Report Count(5)  */
        0x75,0x01,  /*Report Size(1)*/
        0x81,0x02,  /*Input(Data,Variable,Absolute,BitFiled)*/
        0x95,0x01,  /*Report Count(1)*/
        0x75,0x05,  /*Report Size(5) */
        0x81,0x01,  /*Input(Constant,Array,Absolute,BitFiled) */
        0x05,0x01,  /*Usage Page (Generic Desktop Controls)*/
        0x09,0x30,  /*Usage(x)*/
        0x09,0x31,  /*Usage(y)*/
        0x09,0x38,  /*Usage(Wheel)*/
        0x15,0x81,  /*Logical Minimum(-127)*/
        0x25,0x7f,  /*Logical Maximum(127)*/
        0x75,0x08,  /*Report Size(8)*/
        0x95,0x02,  /*Report Count(2)  */
        0x81,0x06,  /*Input(Data,Variable,Relative,BitFiled)*/
        0xc0,   /*End Collection*/
        0xc0    /*End Collection*/
    }
};

static struct platform_device pcdm8168_hid_keyboard = {
    .name = "hidg",
    .id            = 0,
    .num_resources = 0,
    .resource    = 0,
    .dev.platform_data = &pcdm8168_keyboard_data,
};

static struct platform_device pcdm8168_hid_mouse = {
    .name = "hidg",
    .id            = 1,
    .num_resources = 0,
    .resource    = 0,
    .dev.platform_data = &pcdm8168_mouse_data,
};

static int __init hidg_init(void)
{
    int status;

    status = platform_device_register(&pcdm8168_hid_keyboard);
    if (status < 0)
    {
        printk("platform_driver hid keyboard:*****wrong\n");
        platform_device_unregister(&pcdm8168_hid_keyboard);
        return status;
    }

    status = platform_device_register(&pcdm8168_hid_mouse);
    if (status < 0)
    {
        printk("platform_driver hid mouse:*****wrong\n");       
        platform_device_unregister(&pcdm8168_hid_mouse);    
        return status;
    }

    status = platform_driver_probe(&hidg_plat_driver,
                hidg_plat_driver_probe);
    if (status < 0)
    {
            printk("platform_driver_probe:*****wrong\n");
            return status;
    }
    status = usb_composite_probe(&hidg_driver, hid_bind);
    if (status < 0)
        platform_driver_unregister(&hidg_plat_driver);

    return status;
}
static void __exit hidg_cleanup(void)
{
    platform_driver_unregister(&hidg_plat_driver);
    platform_device_unregister(&pcdm8168_hid_keyboard);
    platform_device_unregister(&pcdm8168_hid_mouse);
    usb_composite_unregister(&hidg_driver);
}

3编译

继续完成内核配置的后续操作
1）Build uImage and usb gadget modules

Build the kernel image and the two usb gadget as modules (like
g_ether.ko, g_file_storage.ko, g_mass_storage.ko or g_zero.ko ..etc).

编译内核 以及 上方修改的代码 ，根据自己的开发环境编译
我的是 make lsp

4测试

通过USB线把8168板子和PC机 连接接起来。
1）Insert the two gadget modules

Load the kernel image and Make sure above setup is done before insert
the modules. Insert the gadget modules for usb0 port.

insmod .ko (eg: #insert g_ether.ko) Insert the gadget

module for usb1 port.

insmod .ko (eg: #insert g_file_storage.kofile= stall=0 buflen=65536)

8168上电，进入工作目录，make init 和 make load（个人需要）
由于我所用板子使用的是USB1，没有使用USB0，但是由于8168的特性，USB0也必须进行配置，
我的配置如下：
insmod g_ether.ko
insmod g_hid.ko

这时打开PC的设别管理器会发现，8168已经被识别成鼠标和键盘。
为了测试其功能是否正常需要写一小测试程序，
如下：

#include <pthread.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>

#define BUF_LEN 512

struct options{
    const char *opt;
    unsigned char val;
};

static struct options kmod[] = {
    {.opt = "--left-ctrl",        .val = 0x01},
    {.opt = "--right-ctrl",        .val = 0x10},
    {.opt = "--left-shift",        .val = 0x02},
    {.opt = "--right-shift",    .val = 0x20},
    {.opt = "--left-alt",        .val = 0x04},
    {.opt = "--right-alt",        .val = 0x40},
    {.opt = "--left-meta",        .val = 0x08},
    {.opt = "--right-meta",        .val = 0x80},
    {.opt = NULL}
};

static struct options kval[] = {
    {.opt = "--return",    .val = 0x28},
    {.opt = "--esc",    .val = 0x29},
    {.opt = "--bckspc",    .val = 0x2a},
    {.opt = "--tab",    .val = 0x2b},
    {.opt = "--spacebar",    .val = 0x2c},
    {.opt = "--caps-lock",    .val = 0x39},
    {.opt = "--f1",        .val = 0x3a},
    {.opt = "--f2",        .val = 0x3b},
    {.opt = "--f3",        .val = 0x3c},
    {.opt = "--f4",        .val = 0x3d},
    {.opt = "--f5",        .val = 0x3e},
    {.opt = "--f6",        .val = 0x3f},
    {.opt = "--f7",        .val = 0x40},
    {.opt = "--f8",        .val = 0x41},
    {.opt = "--f9",        .val = 0x42},
    {.opt = "--f10",    .val = 0x43},
    {.opt = "--f11",    .val = 0x44},
    {.opt = "--f12",    .val = 0x45},
    {.opt = "--insert",    .val = 0x49},
    {.opt = "--home",    .val = 0x4a},
    {.opt = "--pageup",    .val = 0x4b},
    {.opt = "--del",    .val = 0x4c},
    {.opt = "--end",    .val = 0x4d},
    {.opt = "--pagedown",    .val = 0x4e},
    {.opt = "--right",    .val = 0x4f},
    {.opt = "--left",    .val = 0x50},
    {.opt = "--down",    .val = 0x51},
    {.opt = "--kp-enter",    .val = 0x58},
    {.opt = "--up",        .val = 0x52},
    {.opt = "--num-lock",    .val = 0x53},
    {.opt = NULL}
};

int keyboard_fill_report(char report[8],char buf[BUF_LEN],int *hold)
{
    char *tok = strtok(buf, " ");
    int key = 0;
    int i = 0;

    for (; tok != NULL; tok = strtok(NULL, " ")) {

        if (strcmp(tok, "--quit") == 0)
            return -1;

        if (strcmp(tok, "--hold") == 0) {
            *hold = 1;
            continue;
        }

        if (key < 6) {
            for (i = 0; kval[i].opt != NULL; i++)
                if (strcmp(tok, kval[i].opt) == 0) {
                    report[2 + key++] = kval[i].val;
                    break;
                }
            if (kval[i].opt != NULL)
                continue;
        }

        if (key < 6)
            if (islower(tok[0])) {
                report[2 + key++] = (tok[0] - ('a' - 0x04));
                continue;
            }

        for (i = 0; kmod[i].opt != NULL; i++)
            if (strcmp(tok, kmod[i].opt) == 0) {
                report[0] = report[0] | kmod[i].val;
                break;
            }
        if (kmod[i].opt != NULL)
            continue;

        if (key < 6)
            fprintf(stderr, "unknown option: %s\n", tok);
    }
    return 8;
}

static struct options mmod[] = {
    {.opt = "--b1", .val = 0x01},
    {.opt = "--b2", .val = 0x02},
    {.opt = "--b3", .val = 0x04},
    {.opt = NULL}
};


int mouse_fill_report(char report[8],char buf[BUF_LEN],int *hold)
{
    char *tok = strtok(buf, " ");
    int mvt = 0;
    int i = 0;
    for (; tok != NULL; tok = strtok(NULL, " ")) {

        if (strcmp(tok, "--quit") == 0)
            return -1;

        if (strcmp(tok, "--hold") == 0) {
            *hold = 1;
            continue;
        }

        for (i = 0; mmod[i].opt != NULL; i++)
            if (strcmp(tok, mmod[i].opt) == 0) 
            {
                report[0] = report[0] | mmod[i].val;
                break;
            }
        if (mmod[i].opt != NULL)
            continue;

        if (!(tok[0] == '-' && tok[1] == '-') && mvt < 2) 
        {
            errno = 0;
            report[1 + mvt++] = (char)strtol(tok, NULL, 0);
            if (errno != 0) 
            {
                fprintf(stderr, "Bad value:'%s'\n", tok);
                report[1 + mvt--] = 0;
            }
            continue;
        }

        fprintf(stderr, "unknown option: %s\n", tok);
    }
    return 3;
}



void print_options(char c)
{
    int i = 0;

    if (c == 'k') {
        printf("    keyboard options:\n"
         "        --hold\n");

        for (i = 0; kmod[i].opt != NULL; i++)
            printf("\t\t%s\n", kmod[i].opt);


        printf("\n    keyboard values:\n"
         "        [a-z] or\n");

        for (i = 0; kval[i].opt != NULL; i++)
            printf("\t\t%-8s%s", kval[i].opt, i % 2 ? "\n" : "");

        printf( "    --quit to close\n");
        printf("\n");
    } 
    else if (c == 'm') 
        {
            printf("    mouse options:\n"
             "        --hold\n");

            for (i = 0; mmod[i].opt != NULL; i++)
                printf("\t\t%s\n", mmod[i].opt);

            printf("\n    mouse values:\n"
             "        Two signed numbers\n"
             "   --quit to close\n");
        } 
}

int main(int argc,const char *argv[])
{
    const char *filename = NULL;
    int fd = 0;
    char buf[BUF_LEN];
    int cmd_len;
    char report[8];
    int to_send = 8;
    int hold = 0;
    fd_set rfds;
    int retval,i;

    if (argc < 3) {
        fprintf(stderr, "Usage: %s devname mouse|keyboard\n",
            argv[0]);
        return 1;
    }

    if(argv[2][0] != 'k' && argv[2][0] != 'm')
    {
        return 2;
    }

    filename = argv[1];
    if ((fd = open(filename, O_RDWR, 0666)) == -1) {
        perror(filename);
        return 3;
    }

    print_options(argv[2][0]);

    while (42) {

        FD_ZERO(&rfds);
        FD_SET(STDIN_FILENO, &rfds);
        FD_SET(fd, &rfds);

        retval = select(fd + 1, &rfds, NULL, NULL, NULL);
        if (retval == -1 && errno == EINTR)
            continue;
        if (retval < 0) {
            perror("select()");
            return 4;
        }

        if (FD_ISSET(fd, &rfds)) {
            cmd_len = read(fd, buf, BUF_LEN - 1);
            printf("recv report:");
            for (i = 0; i < cmd_len; i++)
                printf(" %02x", buf[i]);
            printf("\n");
        }

        if (FD_ISSET(STDIN_FILENO, &rfds)) {
            memset(report, 0x0, sizeof(report));
            cmd_len = read(STDIN_FILENO, buf, BUF_LEN - 1);

            if (cmd_len == 0)
                break;

            buf[cmd_len - 1] = '\0';
            hold = 0;

            memset(report, 0x0, sizeof(report));
            if (argv[2][0] == 'k')
                to_send = keyboard_fill_report(report, buf, &hold);
            else if (argv[2][0] == 'm')
                to_send = mouse_fill_report(report, buf, &hold);

            if (to_send == -1)
                break;

            if (write(fd, report, to_send) != to_send) {
                perror(filename);
                return 5;
            }
            if (!hold) {
                memset(report, 0x0, sizeof(report));
                if (write(fd, report, to_send) != to_send) {
                    perror(filename);
                    return 6;
                }
            }
        }
    }

    close(fd);
    return 0;
}

需要交叉编译器进行编译，我使用的是arm-none-linux-gnueabi-gcc-4.3.3

编译完成后，把生成的执行文件cp到设备中分别执行
./pcdm8168_hid /dev/hidg0 k和./pcdm8168_hid /dev/hidg1 m
根据提示进行操作即可。

声明:上文是参考http://www.oschina.net/question/1174645_135969完成的，思路和代码大体是按其思路，只有修改了个别设备描述符。