use crate::builder::Config;
use crate::driver::EndpointInfo;
use crate::types::{InterfaceNumber, StringIndex};
use crate::CONFIGURATION_VALUE;
#[allow(missing_docs)]
pub mod descriptor_type {
pub const DEVICE: u8 = 1;
pub const CONFIGURATION: u8 = 2;
pub const STRING: u8 = 3;
pub const INTERFACE: u8 = 4;
pub const ENDPOINT: u8 = 5;
pub const IAD: u8 = 11;
pub const BOS: u8 = 15;
pub const CAPABILITY: u8 = 16;
}
pub mod lang_id {
pub const ENGLISH_US: u16 = 0x0409;
}
#[allow(missing_docs)]
pub mod capability_type {
pub const WIRELESS_USB: u8 = 1;
pub const USB_2_0_EXTENSION: u8 = 2;
pub const SS_USB_DEVICE: u8 = 3;
pub const CONTAINER_ID: u8 = 4;
pub const PLATFORM: u8 = 5;
}
pub(crate) struct DescriptorWriter<'a> {
pub buf: &'a mut [u8],
position: usize,
num_interfaces_mark: Option<usize>,
num_endpoints_mark: Option<usize>,
}
impl<'a> DescriptorWriter<'a> {
pub(crate) fn new(buf: &'a mut [u8]) -> Self {
DescriptorWriter {
buf,
position: 0,
num_interfaces_mark: None,
num_endpoints_mark: None,
}
}
pub fn into_buf(self) -> &'a mut [u8] {
&mut self.buf[..self.position]
}
pub const fn position(&self) -> usize {
self.position
}
pub fn write(&mut self, descriptor_type: u8, descriptor: &[u8]) {
let length = descriptor.len();
assert!(
(self.position + 2 + length) <= self.buf.len() && (length + 2) <= 255,
"Descriptor buffer full"
);
self.buf[self.position] = (length + 2) as u8;
self.buf[self.position + 1] = descriptor_type;
let start = self.position + 2;
self.buf[start..start + length].copy_from_slice(descriptor);
self.position = start + length;
}
pub(crate) fn device(&mut self, config: &Config) {
self.write(
descriptor_type::DEVICE,
&[
0x10,
0x02, config.device_class, config.device_sub_class, config.device_protocol, config.max_packet_size_0, config.vendor_id as u8,
(config.vendor_id >> 8) as u8, config.product_id as u8,
(config.product_id >> 8) as u8, config.device_release as u8,
(config.device_release >> 8) as u8, config.manufacturer.map_or(0, |_| 1), config.product.map_or(0, |_| 2), config.serial_number.map_or(0, |_| 3), 1, ],
);
}
pub(crate) fn configuration(&mut self, config: &Config) {
self.num_interfaces_mark = Some(self.position + 4);
self.write(
descriptor_type::CONFIGURATION,
&[
0,
0, 0, CONFIGURATION_VALUE, 0, 0x80 | if config.self_powered { 0x40 } else { 0x00 }
| if config.supports_remote_wakeup { 0x20 } else { 0x00 }, (config.max_power / 2) as u8, ],
);
}
#[allow(unused)]
pub(crate) fn end_class(&mut self) {
self.num_endpoints_mark = None;
}
pub(crate) fn end_configuration(&mut self) {
let position = self.position as u16;
self.buf[2..4].copy_from_slice(&position.to_le_bytes());
}
pub fn iad(
&mut self,
first_interface: InterfaceNumber,
interface_count: u8,
function_class: u8,
function_sub_class: u8,
function_protocol: u8,
) {
self.write(
descriptor_type::IAD,
&[
first_interface.into(), interface_count, function_class,
function_sub_class,
function_protocol,
0,
],
);
}
pub fn interface_alt(
&mut self,
number: InterfaceNumber,
alternate_setting: u8,
interface_class: u8,
interface_sub_class: u8,
interface_protocol: u8,
interface_string: Option<StringIndex>,
) {
if alternate_setting == 0 {
match self.num_interfaces_mark {
Some(mark) => self.buf[mark] += 1,
None => {
panic!("you can only call `interface/interface_alt` after `configuration`.")
}
};
}
let str_index = interface_string.map_or(0, Into::into);
self.num_endpoints_mark = Some(self.position + 4);
self.write(
descriptor_type::INTERFACE,
&[
number.into(), alternate_setting, 0, interface_class, interface_sub_class, interface_protocol, str_index, ],
);
}
pub fn endpoint(&mut self, endpoint: &EndpointInfo) {
match self.num_endpoints_mark {
Some(mark) => self.buf[mark] += 1,
None => panic!("you can only call `endpoint` after `interface/interface_alt`."),
};
self.write(
descriptor_type::ENDPOINT,
&[
endpoint.addr.into(), endpoint.ep_type as u8, endpoint.max_packet_size as u8,
(endpoint.max_packet_size >> 8) as u8, endpoint.interval_ms, ],
);
}
#[allow(unused)]
pub(crate) fn string(&mut self, string: &str) {
let mut pos = self.position;
assert!(pos + 2 <= self.buf.len(), "Descriptor buffer full");
self.buf[pos] = 0; self.buf[pos + 1] = descriptor_type::STRING;
pos += 2;
for c in string.encode_utf16() {
assert!(pos < self.buf.len(), "Descriptor buffer full");
self.buf[pos..pos + 2].copy_from_slice(&c.to_le_bytes());
pos += 2;
}
self.buf[self.position] = (pos - self.position) as u8;
self.position = pos;
}
}
pub struct BosWriter<'a> {
pub(crate) writer: DescriptorWriter<'a>,
num_caps_mark: Option<usize>,
}
impl<'a> BosWriter<'a> {
pub(crate) const fn new(writer: DescriptorWriter<'a>) -> Self {
Self {
writer,
num_caps_mark: None,
}
}
pub(crate) fn bos(&mut self) {
self.num_caps_mark = Some(self.writer.position + 4);
self.writer.write(
descriptor_type::BOS,
&[
0x00, 0x00, 0x00, ],
);
self.capability(capability_type::USB_2_0_EXTENSION, &[0; 4]);
}
pub fn capability(&mut self, capability_type: u8, data: &[u8]) {
match self.num_caps_mark {
Some(mark) => self.writer.buf[mark] += 1,
None => panic!("called `capability` not between `bos` and `end_bos`."),
}
let mut start = self.writer.position;
let blen = data.len();
assert!(
(start + blen + 3) <= self.writer.buf.len() && (blen + 3) <= 255,
"Descriptor buffer full"
);
self.writer.buf[start] = (blen + 3) as u8;
self.writer.buf[start + 1] = descriptor_type::CAPABILITY;
self.writer.buf[start + 2] = capability_type;
start += 3;
self.writer.buf[start..start + blen].copy_from_slice(data);
self.writer.position = start + blen;
}
pub(crate) fn end_bos(&mut self) {
self.num_caps_mark = None;
let position = self.writer.position as u16;
self.writer.buf[2..4].copy_from_slice(&position.to_le_bytes());
}
}