omap_udc.c g_hid.c hid gadget on beagleboard with angstrom linux

问题

To use the beagleboard xm as an HID peripheral I plan to do the following:

Discover how to build things with angstrom.
Get the kernel source 2.6.32.
Compile omap_udc and g_hid
Insert those modules into the kernel
Compile the example from gadget_hid.txt
Send keyboard commands with hid_gadget_test /dev/hidg0 keyboard

Is that a good way to do what I want?

http://www.edaboard.com/thread145675.html is a somewhat related issue from '09.

Looking for Example Embedded Linux HID Device Code is very similar.

回答1:

I figured I would post this here because I looked and looked for an answer but to no avail so I had to get creative.

First Go here and get the Kernel http://eewiki.net/display/linuxonarm/BeagleBone

Second in The KERNEL/arch/arm/mach-omap2/board-am335xevm.c

Add:

enter code here
#include <linux/usb/g_hid.h>

/* hid descriptor for a keyboard */
static struct hidg_func_descriptor my_hid_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                         */
}
};

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

static void __init am33xx_hidg_init(void)
{
int ret;



ret = platform_device_register(&my_hid);


if (ret)
    printk("HID Gadget registration failed\n");

}

In the:

static void __init am335x_evm_init(void)
{
am33xx_cpuidle_init();
am33xx_mux_init(board_mux);
omap_serial_init();
am335x_rtc_init();
**am33xx_hidg_init();**
clkout2_enable();
}

Build the kernel following the Guide from earlier In the makemenu config section of the kernel build go to the device drivers->usb support-> USB Gadget Support-> USB Gadget Drivers -> Compile HID Gadget as Module ( you may have to hunt for it but it's around this section in a couple more sub menus)

Take the sample code section from the kernel documentation or this page http://www.mjmwired.net/kernel/Documentation/usb/gadget_hid.txt

Compile with GCC

insmod the g_hid.ko driver and then run the compiled sample code

来源：https://stackoverflow.com/questions/9847391/omap-udc-c-g-hid-c-hid-gadget-on-beagleboard-with-angstrom-linux

标签

embedded

kernel-module

hid

beagleboard