Files
libopencm3/lib/usb/usb_microsoft.c

116 lines
3.9 KiB
C

/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2022 Rachel Mant <git@dragonmux.network>
*
* 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 <string.h>
#include <libopencm3/usb/usbd.h>
#include <libopencm3/usb/microsoft.h>
#include "usb_private.h"
static uint16_t build_function_subset(const microsoft_os_descriptor_function_subset_header *const subset,
uint8_t *const buf, uint16_t len)
{
uint16_t count = MIN(len, subset->wLength);
memcpy(buf, subset, count);
uint16_t total_length = subset->wLength;
((microsoft_os_descriptor_function_subset_header *)buf)->wTotalLength = total_length;
return total_length;
}
static uint16_t build_config_subset(const microsoft_os_descriptor_config_subset_header *const subset,
uint8_t *const buf, uint16_t len)
{
uint16_t total = 0;
uint16_t count = MIN(len, subset->wLength);
memcpy(buf, subset, count);
len -= count;
total += count;
uint16_t total_length = subset->wLength;
for (size_t i = 0; i < subset->num_function_subset_headers; ++i) {
const uint16_t subset_header_len = build_function_subset(&subset->function_subset_headers[i],
buf + total, len);
count = MIN(len, subset_header_len);
len -= count;
total += count;
total_length += subset_header_len;
}
((microsoft_os_descriptor_config_subset_header *)buf)->wTotalLength = total_length;
return total_length;
}
static uint16_t build_descriptor_set(const microsoft_os_descriptor_set_header *const set,
uint8_t *const buf, uint16_t len)
{
uint16_t count = MIN(len, set->wLength);
memcpy(buf, set, count);
len -= count;
uint16_t total = count;
uint16_t total_length = set->wLength;
for (size_t i = 0; i < set->num_config_subset_headers; ++i) {
const uint16_t subset_header_len = build_config_subset(&set->config_subset_headers[i], buf + total, len);
count = MIN(len, subset_header_len);
len -= count;
total += count;
total_length += subset_header_len;
}
((microsoft_os_descriptor_set_header *)buf)->wTotalLength = total_length;
return total;
}
static enum usbd_request_return_codes microsoft_os_get_descriptor_set(usbd_device *const usbd_dev,
struct usb_setup_data *const req, uint8_t **const buf, uint16_t *const len)
{
if (req->wValue != 0)
return USBD_REQ_NOTSUPP;
const microsoft_os_descriptor_set_header *const sets = usbd_dev->microsoft_os_descriptor_sets;
for (size_t i = 0; i < usbd_dev->num_microsoft_os_descriptor_sets; ++i) {
if (sets[i].vendor_code == req->bRequest) {
*buf = usbd_dev->ctrl_buf;
*len = build_descriptor_set(&sets[i], *buf, *len);
return USBD_REQ_HANDLED;
}
}
return USBD_REQ_NOTSUPP;
}
static enum usbd_request_return_codes microsoft_os_control_request(usbd_device *const usbd_dev,
struct usb_setup_data *const req, uint8_t **const buf, uint16_t *const len)
{
switch (req->wIndex) {
case MICROSOFT_GET_DESCRIPTOR_SET:
return microsoft_os_get_descriptor_set(usbd_dev, req, buf, len);
case MICROSOFT_SET_ALTERNATE_ENUM:
return USBD_REQ_NOTSUPP;
}
return USBD_REQ_NEXT_CALLBACK;
}
void microsoft_os_register_descriptor_sets(usbd_device *const dev,
const microsoft_os_descriptor_set_header *const sets, const uint8_t num_sets)
{
dev->microsoft_os_req_callback = microsoft_os_control_request;
dev->microsoft_os_descriptor_sets = sets;
dev->num_microsoft_os_descriptor_sets = num_sets;
}