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use crate::descriptor::descriptor_type;
use crate::driver::EndpointAddress;
use crate::types::InterfaceNumber;
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct ReadError;
pub struct Reader<'a> {
data: &'a [u8],
}
impl<'a> Reader<'a> {
pub const fn new(data: &'a [u8]) -> Self {
Self { data }
}
pub const fn eof(&self) -> bool {
self.data.is_empty()
}
pub fn read<const N: usize>(&mut self) -> Result<[u8; N], ReadError> {
let n = self.data.get(0..N).ok_or(ReadError)?;
self.data = &self.data[N..];
Ok(n.try_into().unwrap())
}
pub fn read_u8(&mut self) -> Result<u8, ReadError> {
Ok(u8::from_le_bytes(self.read()?))
}
pub fn read_u16(&mut self) -> Result<u16, ReadError> {
Ok(u16::from_le_bytes(self.read()?))
}
pub fn read_slice(&mut self, len: usize) -> Result<&'a [u8], ReadError> {
let res = self.data.get(0..len).ok_or(ReadError)?;
self.data = &self.data[len..];
Ok(res)
}
pub fn read_descriptors(&mut self) -> DescriptorIter<'_, 'a> {
DescriptorIter { r: self }
}
}
pub struct DescriptorIter<'a, 'b> {
r: &'a mut Reader<'b>,
}
impl<'a, 'b> Iterator for DescriptorIter<'a, 'b> {
type Item = Result<(u8, Reader<'a>), ReadError>;
fn next(&mut self) -> Option<Self::Item> {
if self.r.eof() {
return None;
}
let len = match self.r.read_u8() {
Ok(x) => x,
Err(e) => return Some(Err(e)),
};
let type_ = match self.r.read_u8() {
Ok(x) => x,
Err(e) => return Some(Err(e)),
};
let data = match self.r.read_slice(len as usize - 2) {
Ok(x) => x,
Err(e) => return Some(Err(e)),
};
Some(Ok((type_, Reader::new(data))))
}
}
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct EndpointInfo {
pub configuration: u8,
pub interface: InterfaceNumber,
pub interface_alt: u8,
pub ep_address: EndpointAddress,
}
pub fn foreach_endpoint(data: &[u8], mut f: impl FnMut(EndpointInfo)) -> Result<(), ReadError> {
let mut ep = EndpointInfo {
configuration: 0,
interface: InterfaceNumber(0),
interface_alt: 0,
ep_address: EndpointAddress::from(0),
};
for res in Reader::new(data).read_descriptors() {
let (kind, mut r) = res?;
match kind {
descriptor_type::CONFIGURATION => {
let _total_length = r.read_u16()?;
let _total_length = r.read_u8()?;
ep.configuration = r.read_u8()?;
}
descriptor_type::INTERFACE => {
ep.interface = InterfaceNumber(r.read_u8()?);
ep.interface_alt = r.read_u8()?;
}
descriptor_type::ENDPOINT => {
ep.ep_address = EndpointAddress::from(r.read_u8()?);
f(ep);
}
_ => {}
}
}
Ok(())
}
|
