549 lines
19 KiB
Rust
549 lines
19 KiB
Rust
//! USB HID (Human Interface Device) class implementation.
|
|
|
|
use core::mem::MaybeUninit;
|
|
use core::ops::Range;
|
|
use core::sync::atomic::{AtomicUsize, Ordering};
|
|
|
|
#[cfg(feature = "usbd-hid")]
|
|
use ssmarshal::serialize;
|
|
#[cfg(feature = "usbd-hid")]
|
|
use usbd_hid::descriptor::AsInputReport;
|
|
|
|
use crate::control::{InResponse, OutResponse, Recipient, Request, RequestType};
|
|
use crate::driver::{Driver, Endpoint, EndpointError, EndpointIn, EndpointOut};
|
|
use crate::types::InterfaceNumber;
|
|
use crate::{Builder, Handler};
|
|
|
|
const USB_CLASS_HID: u8 = 0x03;
|
|
const USB_SUBCLASS_NONE: u8 = 0x00;
|
|
const USB_PROTOCOL_NONE: u8 = 0x00;
|
|
|
|
// HID
|
|
const HID_DESC_DESCTYPE_HID: u8 = 0x21;
|
|
const HID_DESC_DESCTYPE_HID_REPORT: u8 = 0x22;
|
|
const HID_DESC_SPEC_1_10: [u8; 2] = [0x10, 0x01];
|
|
const HID_DESC_COUNTRY_UNSPEC: u8 = 0x00;
|
|
|
|
const HID_REQ_SET_IDLE: u8 = 0x0a;
|
|
const HID_REQ_GET_IDLE: u8 = 0x02;
|
|
const HID_REQ_GET_REPORT: u8 = 0x01;
|
|
const HID_REQ_SET_REPORT: u8 = 0x09;
|
|
const HID_REQ_GET_PROTOCOL: u8 = 0x03;
|
|
const HID_REQ_SET_PROTOCOL: u8 = 0x0b;
|
|
|
|
/// Configuration for the HID class.
|
|
pub struct Config<'d> {
|
|
/// HID report descriptor.
|
|
pub report_descriptor: &'d [u8],
|
|
|
|
/// Handler for control requests.
|
|
pub request_handler: Option<&'d dyn RequestHandler>,
|
|
|
|
/// Configures how frequently the host should poll for reading/writing HID reports.
|
|
///
|
|
/// A lower value means better throughput & latency, at the expense
|
|
/// of CPU on the device & bandwidth on the bus. A value of 10 is reasonable for
|
|
/// high performance uses, and a value of 255 is good for best-effort usecases.
|
|
pub poll_ms: u8,
|
|
|
|
/// Max packet size for both the IN and OUT endpoints.
|
|
pub max_packet_size: u16,
|
|
}
|
|
|
|
/// Report ID
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
|
|
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
|
|
pub enum ReportId {
|
|
/// IN report
|
|
In(u8),
|
|
/// OUT report
|
|
Out(u8),
|
|
/// Feature report
|
|
Feature(u8),
|
|
}
|
|
|
|
impl ReportId {
|
|
fn try_from(value: u16) -> Result<Self, ()> {
|
|
match value >> 8 {
|
|
1 => Ok(ReportId::In(value as u8)),
|
|
2 => Ok(ReportId::Out(value as u8)),
|
|
3 => Ok(ReportId::Feature(value as u8)),
|
|
_ => Err(()),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Internal state for USB HID.
|
|
pub struct State<'d> {
|
|
control: MaybeUninit<Control<'d>>,
|
|
out_report_offset: AtomicUsize,
|
|
}
|
|
|
|
impl<'d> State<'d> {
|
|
/// Create a new `State`.
|
|
pub fn new() -> Self {
|
|
State {
|
|
control: MaybeUninit::uninit(),
|
|
out_report_offset: AtomicUsize::new(0),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// USB HID reader/writer.
|
|
pub struct HidReaderWriter<'d, D: Driver<'d>, const READ_N: usize, const WRITE_N: usize> {
|
|
reader: HidReader<'d, D, READ_N>,
|
|
writer: HidWriter<'d, D, WRITE_N>,
|
|
}
|
|
|
|
fn build<'d, D: Driver<'d>>(
|
|
builder: &mut Builder<'d, D>,
|
|
state: &'d mut State<'d>,
|
|
config: Config<'d>,
|
|
with_out_endpoint: bool,
|
|
) -> (Option<D::EndpointOut>, D::EndpointIn, &'d AtomicUsize) {
|
|
let len = config.report_descriptor.len();
|
|
|
|
let mut func = builder.function(USB_CLASS_HID, USB_SUBCLASS_NONE, USB_PROTOCOL_NONE);
|
|
let mut iface = func.interface();
|
|
let if_num = iface.interface_number();
|
|
let mut alt = iface.alt_setting(USB_CLASS_HID, USB_SUBCLASS_NONE, USB_PROTOCOL_NONE, None);
|
|
|
|
// HID descriptor
|
|
alt.descriptor(
|
|
HID_DESC_DESCTYPE_HID,
|
|
&[
|
|
// HID Class spec version
|
|
HID_DESC_SPEC_1_10[0],
|
|
HID_DESC_SPEC_1_10[1],
|
|
// Country code not supported
|
|
HID_DESC_COUNTRY_UNSPEC,
|
|
// Number of following descriptors
|
|
1,
|
|
// We have a HID report descriptor the host should read
|
|
HID_DESC_DESCTYPE_HID_REPORT,
|
|
// HID report descriptor size,
|
|
(len & 0xFF) as u8,
|
|
(len >> 8 & 0xFF) as u8,
|
|
],
|
|
);
|
|
|
|
let ep_in = alt.endpoint_interrupt_in(config.max_packet_size, config.poll_ms);
|
|
let ep_out = if with_out_endpoint {
|
|
Some(alt.endpoint_interrupt_out(config.max_packet_size, config.poll_ms))
|
|
} else {
|
|
None
|
|
};
|
|
|
|
drop(func);
|
|
|
|
let control = state.control.write(Control::new(
|
|
if_num,
|
|
config.report_descriptor,
|
|
config.request_handler,
|
|
&state.out_report_offset,
|
|
));
|
|
builder.handler(control);
|
|
|
|
(ep_out, ep_in, &state.out_report_offset)
|
|
}
|
|
|
|
impl<'d, D: Driver<'d>, const READ_N: usize, const WRITE_N: usize> HidReaderWriter<'d, D, READ_N, WRITE_N> {
|
|
/// Creates a new HidReaderWriter.
|
|
///
|
|
/// This will allocate one IN and one OUT endpoints. If you only need writing (sending)
|
|
/// HID reports, consider using [`HidWriter::new`] instead, which allocates an IN endpoint only.
|
|
///
|
|
pub fn new(builder: &mut Builder<'d, D>, state: &'d mut State<'d>, config: Config<'d>) -> Self {
|
|
let (ep_out, ep_in, offset) = build(builder, state, config, true);
|
|
|
|
Self {
|
|
reader: HidReader {
|
|
ep_out: ep_out.unwrap(),
|
|
offset,
|
|
},
|
|
writer: HidWriter { ep_in },
|
|
}
|
|
}
|
|
|
|
/// Splits into seperate readers/writers for input and output reports.
|
|
pub fn split(self) -> (HidReader<'d, D, READ_N>, HidWriter<'d, D, WRITE_N>) {
|
|
(self.reader, self.writer)
|
|
}
|
|
|
|
/// Waits for both IN and OUT endpoints to be enabled.
|
|
pub async fn ready(&mut self) -> () {
|
|
self.reader.ready().await;
|
|
self.writer.ready().await;
|
|
}
|
|
|
|
/// Writes an input report by serializing the given report structure.
|
|
#[cfg(feature = "usbd-hid")]
|
|
pub async fn write_serialize<IR: AsInputReport>(&mut self, r: &IR) -> Result<(), EndpointError> {
|
|
self.writer.write_serialize(r).await
|
|
}
|
|
|
|
/// Writes `report` to its interrupt endpoint.
|
|
pub async fn write(&mut self, report: &[u8]) -> Result<(), EndpointError> {
|
|
self.writer.write(report).await
|
|
}
|
|
|
|
/// Reads an output report from the Interrupt Out pipe.
|
|
///
|
|
/// See [`HidReader::read`].
|
|
pub async fn read(&mut self, buf: &mut [u8]) -> Result<usize, ReadError> {
|
|
self.reader.read(buf).await
|
|
}
|
|
}
|
|
|
|
/// USB HID writer.
|
|
///
|
|
/// You can obtain a `HidWriter` using [`HidReaderWriter::split`].
|
|
pub struct HidWriter<'d, D: Driver<'d>, const N: usize> {
|
|
ep_in: D::EndpointIn,
|
|
}
|
|
|
|
/// USB HID reader.
|
|
///
|
|
/// You can obtain a `HidReader` using [`HidReaderWriter::split`].
|
|
pub struct HidReader<'d, D: Driver<'d>, const N: usize> {
|
|
ep_out: D::EndpointOut,
|
|
offset: &'d AtomicUsize,
|
|
}
|
|
|
|
/// Error when reading a HID report.
|
|
#[derive(Debug, Clone, PartialEq, Eq)]
|
|
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
|
|
pub enum ReadError {
|
|
/// The given buffer was too small to read the received report.
|
|
BufferOverflow,
|
|
/// The endpoint is disabled.
|
|
Disabled,
|
|
/// The report was only partially read. See [`HidReader::read`] for details.
|
|
Sync(Range<usize>),
|
|
}
|
|
|
|
impl From<EndpointError> for ReadError {
|
|
fn from(val: EndpointError) -> Self {
|
|
use EndpointError::*;
|
|
match val {
|
|
BufferOverflow => ReadError::BufferOverflow,
|
|
Disabled => ReadError::Disabled,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'d, D: Driver<'d>, const N: usize> HidWriter<'d, D, N> {
|
|
/// Creates a new HidWriter.
|
|
///
|
|
/// This will allocate one IN endpoint only, so the host won't be able to send
|
|
/// reports to us. If you need that, consider using [`HidReaderWriter::new`] instead.
|
|
///
|
|
/// poll_ms configures how frequently the host should poll for reading/writing
|
|
/// HID reports. A lower value means better throughput & latency, at the expense
|
|
/// of CPU on the device & bandwidth on the bus. A value of 10 is reasonable for
|
|
/// high performance uses, and a value of 255 is good for best-effort usecases.
|
|
pub fn new(builder: &mut Builder<'d, D>, state: &'d mut State<'d>, config: Config<'d>) -> Self {
|
|
let (ep_out, ep_in, _offset) = build(builder, state, config, false);
|
|
|
|
assert!(ep_out.is_none());
|
|
|
|
Self { ep_in }
|
|
}
|
|
|
|
/// Waits for the interrupt in endpoint to be enabled.
|
|
pub async fn ready(&mut self) -> () {
|
|
self.ep_in.wait_enabled().await
|
|
}
|
|
|
|
/// Writes an input report by serializing the given report structure.
|
|
#[cfg(feature = "usbd-hid")]
|
|
pub async fn write_serialize<IR: AsInputReport>(&mut self, r: &IR) -> Result<(), EndpointError> {
|
|
let mut buf: [u8; N] = [0; N];
|
|
let size = match serialize(&mut buf, r) {
|
|
Ok(size) => size,
|
|
Err(_) => return Err(EndpointError::BufferOverflow),
|
|
};
|
|
self.write(&buf[0..size]).await
|
|
}
|
|
|
|
/// Writes `report` to its interrupt endpoint.
|
|
pub async fn write(&mut self, report: &[u8]) -> Result<(), EndpointError> {
|
|
assert!(report.len() <= N);
|
|
|
|
let max_packet_size = usize::from(self.ep_in.info().max_packet_size);
|
|
let zlp_needed = report.len() < N && (report.len() % max_packet_size == 0);
|
|
for chunk in report.chunks(max_packet_size) {
|
|
self.ep_in.write(chunk).await?;
|
|
}
|
|
|
|
if zlp_needed {
|
|
self.ep_in.write(&[]).await?;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
impl<'d, D: Driver<'d>, const N: usize> HidReader<'d, D, N> {
|
|
/// Waits for the interrupt out endpoint to be enabled.
|
|
pub async fn ready(&mut self) -> () {
|
|
self.ep_out.wait_enabled().await
|
|
}
|
|
|
|
/// Delivers output reports from the Interrupt Out pipe to `handler`.
|
|
///
|
|
/// If `use_report_ids` is true, the first byte of the report will be used as
|
|
/// the `ReportId` value. Otherwise the `ReportId` value will be 0.
|
|
pub async fn run<T: RequestHandler>(mut self, use_report_ids: bool, handler: &T) -> ! {
|
|
let offset = self.offset.load(Ordering::Acquire);
|
|
assert!(offset == 0);
|
|
let mut buf = [0; N];
|
|
loop {
|
|
match self.read(&mut buf).await {
|
|
Ok(len) => {
|
|
let id = if use_report_ids { buf[0] } else { 0 };
|
|
handler.set_report(ReportId::Out(id), &buf[..len]);
|
|
}
|
|
Err(ReadError::BufferOverflow) => warn!(
|
|
"Host sent output report larger than the configured maximum output report length ({})",
|
|
N
|
|
),
|
|
Err(ReadError::Disabled) => self.ep_out.wait_enabled().await,
|
|
Err(ReadError::Sync(_)) => unreachable!(),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Reads an output report from the Interrupt Out pipe.
|
|
///
|
|
/// **Note:** Any reports sent from the host over the control pipe will be
|
|
/// passed to [`RequestHandler::set_report()`] for handling. The application
|
|
/// is responsible for ensuring output reports from both pipes are handled
|
|
/// correctly.
|
|
///
|
|
/// **Note:** If `N` > the maximum packet size of the endpoint (i.e. output
|
|
/// reports may be split across multiple packets) and this method's future
|
|
/// is dropped after some packets have been read, the next call to `read()`
|
|
/// will return a [`ReadError::Sync`]. The range in the sync error
|
|
/// indicates the portion `buf` that was filled by the current call to
|
|
/// `read()`. If the dropped future used the same `buf`, then `buf` will
|
|
/// contain the full report.
|
|
pub async fn read(&mut self, buf: &mut [u8]) -> Result<usize, ReadError> {
|
|
assert!(N != 0);
|
|
assert!(buf.len() >= N);
|
|
|
|
// Read packets from the endpoint
|
|
let max_packet_size = usize::from(self.ep_out.info().max_packet_size);
|
|
let starting_offset = self.offset.load(Ordering::Acquire);
|
|
let mut total = starting_offset;
|
|
loop {
|
|
for chunk in buf[starting_offset..N].chunks_mut(max_packet_size) {
|
|
match self.ep_out.read(chunk).await {
|
|
Ok(size) => {
|
|
total += size;
|
|
if size < max_packet_size || total == N {
|
|
self.offset.store(0, Ordering::Release);
|
|
break;
|
|
} else {
|
|
self.offset.store(total, Ordering::Release);
|
|
}
|
|
}
|
|
Err(err) => {
|
|
self.offset.store(0, Ordering::Release);
|
|
return Err(err.into());
|
|
}
|
|
}
|
|
}
|
|
|
|
// Some hosts may send ZLPs even when not required by the HID spec, so we'll loop as long as total == 0.
|
|
if total > 0 {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if starting_offset > 0 {
|
|
Err(ReadError::Sync(starting_offset..total))
|
|
} else {
|
|
Ok(total)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Handler for HID-related control requests.
|
|
pub trait RequestHandler {
|
|
/// Reads the value of report `id` into `buf` returning the size.
|
|
///
|
|
/// Returns `None` if `id` is invalid or no data is available.
|
|
fn get_report(&self, id: ReportId, buf: &mut [u8]) -> Option<usize> {
|
|
let _ = (id, buf);
|
|
None
|
|
}
|
|
|
|
/// Sets the value of report `id` to `data`.
|
|
fn set_report(&self, id: ReportId, data: &[u8]) -> OutResponse {
|
|
let _ = (id, data);
|
|
OutResponse::Rejected
|
|
}
|
|
|
|
/// Get the idle rate for `id`.
|
|
///
|
|
/// If `id` is `None`, get the idle rate for all reports. Returning `None`
|
|
/// will reject the control request. Any duration at or above 1.024 seconds
|
|
/// or below 4ms will be returned as an indefinite idle rate.
|
|
fn get_idle_ms(&self, id: Option<ReportId>) -> Option<u32> {
|
|
let _ = id;
|
|
None
|
|
}
|
|
|
|
/// Set the idle rate for `id` to `dur`.
|
|
///
|
|
/// If `id` is `None`, set the idle rate of all input reports to `dur`. If
|
|
/// an indefinite duration is requested, `dur` will be set to `u32::MAX`.
|
|
fn set_idle_ms(&self, id: Option<ReportId>, duration_ms: u32) {
|
|
let _ = (id, duration_ms);
|
|
}
|
|
}
|
|
|
|
struct Control<'d> {
|
|
if_num: InterfaceNumber,
|
|
report_descriptor: &'d [u8],
|
|
request_handler: Option<&'d dyn RequestHandler>,
|
|
out_report_offset: &'d AtomicUsize,
|
|
hid_descriptor: [u8; 9],
|
|
}
|
|
|
|
impl<'d> Control<'d> {
|
|
fn new(
|
|
if_num: InterfaceNumber,
|
|
report_descriptor: &'d [u8],
|
|
request_handler: Option<&'d dyn RequestHandler>,
|
|
out_report_offset: &'d AtomicUsize,
|
|
) -> Self {
|
|
Control {
|
|
if_num,
|
|
report_descriptor,
|
|
request_handler,
|
|
out_report_offset,
|
|
hid_descriptor: [
|
|
// Length of buf inclusive of size prefix
|
|
9,
|
|
// Descriptor type
|
|
HID_DESC_DESCTYPE_HID,
|
|
// HID Class spec version
|
|
HID_DESC_SPEC_1_10[0],
|
|
HID_DESC_SPEC_1_10[1],
|
|
// Country code not supported
|
|
HID_DESC_COUNTRY_UNSPEC,
|
|
// Number of following descriptors
|
|
1,
|
|
// We have a HID report descriptor the host should read
|
|
HID_DESC_DESCTYPE_HID_REPORT,
|
|
// HID report descriptor size,
|
|
(report_descriptor.len() & 0xFF) as u8,
|
|
(report_descriptor.len() >> 8 & 0xFF) as u8,
|
|
],
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'d> Handler for Control<'d> {
|
|
fn reset(&mut self) {
|
|
self.out_report_offset.store(0, Ordering::Release);
|
|
}
|
|
|
|
fn control_out(&mut self, req: Request, data: &[u8]) -> Option<OutResponse> {
|
|
if (req.request_type, req.recipient, req.index)
|
|
!= (RequestType::Class, Recipient::Interface, self.if_num.0 as u16)
|
|
{
|
|
return None;
|
|
}
|
|
|
|
// This uses a defmt-specific formatter that causes use of the `log`
|
|
// feature to fail to build, so leave it defmt-specific for now.
|
|
#[cfg(feature = "defmt")]
|
|
trace!("HID control_out {:?} {=[u8]:x}", req, data);
|
|
match req.request {
|
|
HID_REQ_SET_IDLE => {
|
|
if let Some(handler) = self.request_handler {
|
|
let id = req.value as u8;
|
|
let id = (id != 0).then(|| ReportId::In(id));
|
|
let dur = u32::from(req.value >> 8);
|
|
let dur = if dur == 0 { u32::MAX } else { 4 * dur };
|
|
handler.set_idle_ms(id, dur);
|
|
}
|
|
Some(OutResponse::Accepted)
|
|
}
|
|
HID_REQ_SET_REPORT => match (ReportId::try_from(req.value), self.request_handler) {
|
|
(Ok(id), Some(handler)) => Some(handler.set_report(id, data)),
|
|
_ => Some(OutResponse::Rejected),
|
|
},
|
|
HID_REQ_SET_PROTOCOL => {
|
|
if req.value == 1 {
|
|
Some(OutResponse::Accepted)
|
|
} else {
|
|
warn!("HID Boot Protocol is unsupported.");
|
|
Some(OutResponse::Rejected) // UNSUPPORTED: Boot Protocol
|
|
}
|
|
}
|
|
_ => Some(OutResponse::Rejected),
|
|
}
|
|
}
|
|
|
|
fn control_in<'a>(&'a mut self, req: Request, buf: &'a mut [u8]) -> Option<InResponse<'a>> {
|
|
if req.index != self.if_num.0 as u16 {
|
|
return None;
|
|
}
|
|
|
|
match (req.request_type, req.recipient) {
|
|
(RequestType::Standard, Recipient::Interface) => match req.request {
|
|
Request::GET_DESCRIPTOR => match (req.value >> 8) as u8 {
|
|
HID_DESC_DESCTYPE_HID_REPORT => Some(InResponse::Accepted(self.report_descriptor)),
|
|
HID_DESC_DESCTYPE_HID => Some(InResponse::Accepted(&self.hid_descriptor)),
|
|
_ => Some(InResponse::Rejected),
|
|
},
|
|
|
|
_ => Some(InResponse::Rejected),
|
|
},
|
|
(RequestType::Class, Recipient::Interface) => {
|
|
trace!("HID control_in {:?}", req);
|
|
match req.request {
|
|
HID_REQ_GET_REPORT => {
|
|
let size = match ReportId::try_from(req.value) {
|
|
Ok(id) => self.request_handler.and_then(|x| x.get_report(id, buf)),
|
|
Err(_) => None,
|
|
};
|
|
|
|
if let Some(size) = size {
|
|
Some(InResponse::Accepted(&buf[0..size]))
|
|
} else {
|
|
Some(InResponse::Rejected)
|
|
}
|
|
}
|
|
HID_REQ_GET_IDLE => {
|
|
if let Some(handler) = self.request_handler {
|
|
let id = req.value as u8;
|
|
let id = (id != 0).then(|| ReportId::In(id));
|
|
if let Some(dur) = handler.get_idle_ms(id) {
|
|
let dur = u8::try_from(dur / 4).unwrap_or(0);
|
|
buf[0] = dur;
|
|
Some(InResponse::Accepted(&buf[0..1]))
|
|
} else {
|
|
Some(InResponse::Rejected)
|
|
}
|
|
} else {
|
|
Some(InResponse::Rejected)
|
|
}
|
|
}
|
|
HID_REQ_GET_PROTOCOL => {
|
|
// UNSUPPORTED: Boot Protocol
|
|
buf[0] = 1;
|
|
Some(InResponse::Accepted(&buf[0..1]))
|
|
}
|
|
_ => Some(InResponse::Rejected),
|
|
}
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
}
|