Add support for USB classes handling control requests.

This commit is contained in:
alexmoon
2022-03-25 16:46:14 -04:00
committed by Dario Nieuwenhuis
parent 5c0db627fe
commit bdc6e0481c
8 changed files with 703 additions and 291 deletions

View File

@ -1,5 +1,8 @@
use core::convert::TryInto;
use core::future::Future;
use core::mem;
use defmt::info;
use embassy_usb::class::{ControlInRequestStatus, RequestStatus, UsbClass};
use embassy_usb::control::{self, Request};
use embassy_usb::driver::{Endpoint, EndpointIn, EndpointOut, ReadError, WriteError};
use embassy_usb::{driver::Driver, types::*, UsbDeviceBuilder};
@ -39,16 +42,107 @@ const REQ_SET_CONTROL_LINE_STATE: u8 = 0x22;
/// terminated with a short packet, even if the bulk endpoint is used for stream-like data.
pub struct CdcAcmClass<'d, D: Driver<'d>> {
// TODO not pub
pub comm_if: InterfaceNumber,
pub comm_ep: D::EndpointIn,
pub data_if: InterfaceNumber,
pub read_ep: D::EndpointOut,
pub write_ep: D::EndpointIn,
pub control: CdcAcmControl,
}
pub struct CdcAcmControl {
pub comm_if: InterfaceNumber,
pub line_coding: LineCoding,
pub dtr: bool,
pub rts: bool,
}
impl<'d, D: Driver<'d>> UsbClass<'d, D> for CdcAcmControl {
type ControlOutFuture<'a> = impl Future<Output = RequestStatus> + 'a where Self: 'a, 'd: 'a, D: 'a;
type ControlInFuture<'a> = impl Future<Output = ControlInRequestStatus> + 'a where Self: 'a, 'd: 'a, D: 'a;
fn reset(&mut self) {
self.line_coding = LineCoding::default();
self.dtr = false;
self.rts = false;
}
fn control_out<'a>(
&'a mut self,
req: control::Request,
data: &'a [u8],
) -> Self::ControlOutFuture<'a>
where
'd: 'a,
D: 'a,
{
async move {
if !(req.request_type == control::RequestType::Class
&& req.recipient == control::Recipient::Interface
&& req.index == u8::from(self.comm_if) as u16)
{
return RequestStatus::Unhandled;
}
match req.request {
REQ_SEND_ENCAPSULATED_COMMAND => {
// We don't actually support encapsulated commands but pretend we do for standards
// compatibility.
RequestStatus::Accepted
}
REQ_SET_LINE_CODING if data.len() >= 7 => {
self.line_coding.data_rate = u32::from_le_bytes(data[0..4].try_into().unwrap());
self.line_coding.stop_bits = data[4].into();
self.line_coding.parity_type = data[5].into();
self.line_coding.data_bits = data[6];
info!("Set line coding to: {:?}", self.line_coding);
RequestStatus::Accepted
}
REQ_SET_CONTROL_LINE_STATE => {
self.dtr = (req.value & 0x0001) != 0;
self.rts = (req.value & 0x0002) != 0;
info!("Set dtr {}, rts {}", self.dtr, self.rts);
RequestStatus::Accepted
}
_ => RequestStatus::Rejected,
}
}
}
fn control_in<'a>(
&'a mut self,
req: Request,
control: embassy_usb::class::ControlIn<'a, 'd, D>,
) -> Self::ControlInFuture<'a>
where
'd: 'a,
{
async move {
if !(req.request_type == control::RequestType::Class
&& req.recipient == control::Recipient::Interface
&& req.index == u8::from(self.comm_if) as u16)
{
return control.ignore();
}
match req.request {
// REQ_GET_ENCAPSULATED_COMMAND is not really supported - it will be rejected below.
REQ_GET_LINE_CODING if req.length == 7 => {
info!("Sending line coding");
let mut data = [0; 7];
data[0..4].copy_from_slice(&self.line_coding.data_rate.to_le_bytes());
data[4] = self.line_coding.stop_bits as u8;
data[5] = self.line_coding.parity_type as u8;
data[6] = self.line_coding.data_bits;
control.accept(&data).await
}
_ => control.reject(),
}
}
}
}
impl<'d, D: Driver<'d>> CdcAcmClass<'d, D> {
/// Creates a new CdcAcmClass with the provided UsbBus and max_packet_size in bytes. For
/// full-speed devices, max_packet_size has to be one of 8, 16, 32 or 64.
@ -133,19 +227,21 @@ impl<'d, D: Driver<'d>> CdcAcmClass<'d, D> {
builder.config_descriptor.endpoint(read_ep.info()).unwrap();
CdcAcmClass {
comm_if,
comm_ep,
data_if,
read_ep,
write_ep,
line_coding: LineCoding {
stop_bits: StopBits::One,
data_bits: 8,
parity_type: ParityType::None,
data_rate: 8_000,
control: CdcAcmControl {
comm_if,
dtr: false,
rts: false,
line_coding: LineCoding {
stop_bits: StopBits::One,
data_bits: 8,
parity_type: ParityType::None,
data_rate: 8_000,
},
},
dtr: false,
rts: false,
}
}
@ -158,17 +254,17 @@ impl<'d, D: Driver<'d>> CdcAcmClass<'d, D> {
/// Gets the current line coding. The line coding contains information that's mainly relevant
/// for USB to UART serial port emulators, and can be ignored if not relevant.
pub fn line_coding(&self) -> &LineCoding {
&self.line_coding
&self.control.line_coding
}
/// Gets the DTR (data terminal ready) state
pub fn dtr(&self) -> bool {
self.dtr
self.control.dtr
}
/// Gets the RTS (request to send) state
pub fn rts(&self) -> bool {
self.rts
self.control.rts
}
/// Writes a single packet into the IN endpoint.
@ -270,7 +366,7 @@ impl<B: UsbBus> UsbClass<B> for CdcAcmClass<'_, B> {
*/
/// Number of stop bits for LineCoding
#[derive(Copy, Clone, PartialEq, Eq)]
#[derive(Copy, Clone, PartialEq, Eq, defmt::Format)]
pub enum StopBits {
/// 1 stop bit
One = 0,
@ -293,7 +389,7 @@ impl From<u8> for StopBits {
}
/// Parity for LineCoding
#[derive(Copy, Clone, PartialEq, Eq)]
#[derive(Copy, Clone, PartialEq, Eq, defmt::Format)]
pub enum ParityType {
None = 0,
Odd = 1,
@ -316,6 +412,7 @@ impl From<u8> for ParityType {
///
/// This is provided by the host for specifying the standard UART parameters such as baud rate. Can
/// be ignored if you don't plan to interface with a physical UART.
#[derive(defmt::Format)]
pub struct LineCoding {
stop_bits: StopBits,
data_bits: u8,

View File

@ -1,5 +1,6 @@
#![no_std]
#![no_main]
#![feature(generic_associated_types)]
#![feature(type_alias_impl_trait)]
#[path = "../../example_common.rs"]
@ -58,7 +59,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
let mut class = CdcAcmClass::new(&mut builder, 64);
// Build the builder.
let mut usb = builder.build();
let mut usb = builder.build(class.control);
// Run the USB device.
let fut1 = usb.run();