hid.c

// vim: tabstop=8 softtabstop=8 shiftwidth=8 noexpandtab
/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2010 Gareth McMullin <gareth@blacksphere.co.nz>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/cm3/systick.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/usb/usbd.h>
#include <libopencm3/usb/hid.h>

#define INCLUDE_PACKET_DESCRIPTOR
#include "hid.h"


static const struct {
	struct usb_hid_descriptor hid_descriptor;
	struct {
		uint8_t bReportDescriptorType;
		uint16_t wDescriptorLength;
	} __attribute__((packed)) hid_report;
} __attribute__((packed)) hid_function = {
	.hid_descriptor = {
		.bLength = sizeof(hid_function),
		.bDescriptorType = USB_DT_HID,
		.bcdHID = 0x0100,
		.bCountryCode = 0,
		.bNumDescriptors = 1,
	},
	.hid_report = {
		.bReportDescriptorType = USB_DT_REPORT,
		.wDescriptorLength = sizeof(hid_report_descriptor),
	}
};


/* Mouse/keyboard interface */
const struct usb_endpoint_descriptor hid_endpoint = {
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,
	.bEndpointAddress = 0x81,
	.bmAttributes = USB_ENDPOINT_ATTR_INTERRUPT,
	.wMaxPacketSize = 9,
	.bInterval = 1,
};

struct usb_interface_descriptor hid_iface = {
	.bLength = USB_DT_INTERFACE_SIZE,
	.bDescriptorType = USB_DT_INTERFACE,
	.bInterfaceNumber = 0,
	.bAlternateSetting = 0,
	.bNumEndpoints = 1,
	.bInterfaceClass = USB_CLASS_HID,
	.bInterfaceSubClass = 1, /* boot */
	.bInterfaceProtocol = 2, /* mouse */
	.iInterface = 0,

	.endpoint = &hid_endpoint,

	.extra = &hid_function,
	.extralen = sizeof(hid_function),
};

static int hid_control_request(usbd_device *dev, struct usb_setup_data *req, uint8_t **buf, uint16_t *len,
			void (**complete)(usbd_device *, struct usb_setup_data *))
{
	(void)complete;
	(void)dev;

	if((req->bmRequestType != 0x81) ||
	   (req->bRequest != USB_REQ_GET_DESCRIPTOR) ||
	   (req->wValue != 0x2200))
		return 0;

	/* Handle the HID report descriptor. */
	*buf = (uint8_t *)hid_report_descriptor;
	*len = sizeof(hid_report_descriptor);

	return 1;
}

void hid_set_config(usbd_device *dev, uint16_t wValue)
{
	(void)wValue;
	(void)dev;

	usbd_ep_setup(dev, 0x81, USB_ENDPOINT_ATTR_INTERRUPT, 4, NULL);

	usbd_register_control_callback(
				dev,
				USB_REQ_TYPE_STANDARD | USB_REQ_TYPE_INTERFACE,
				USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
				hid_control_request);

}