embassy/embassy-usb/src/lib.rs

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2022-03-09 00:34:35 +00:00
#![no_std]
#![feature(generic_associated_types)]
// This mod MUST go first, so that the others see its macros.
pub(crate) mod fmt;
mod builder;
mod control;
pub mod descriptor;
pub mod driver;
pub mod types;
use self::control::*;
use self::descriptor::*;
use self::driver::*;
use self::types::*;
pub use self::builder::Config;
pub use self::builder::UsbDeviceBuilder;
/// The global state of the USB device.
///
/// In general class traffic is only possible in the `Configured` state.
#[repr(u8)]
#[derive(PartialEq, Eq, Copy, Clone, Debug)]
pub enum UsbDeviceState {
/// The USB device has just been created or reset.
Default,
/// The USB device has received an address from the host.
Addressed,
/// The USB device has been configured and is fully functional.
Configured,
/// The USB device has been suspended by the host or it has been unplugged from the USB bus.
Suspend,
}
/// The bConfiguration value for the not configured state.
pub const CONFIGURATION_NONE: u8 = 0;
/// The bConfiguration value for the single configuration supported by this device.
pub const CONFIGURATION_VALUE: u8 = 1;
/// The default value for bAlternateSetting for all interfaces.
pub const DEFAULT_ALTERNATE_SETTING: u8 = 0;
pub struct UsbDevice<'d, D: Driver<'d>> {
driver: D::Bus,
control_in: D::EndpointIn,
control_out: D::EndpointOut,
config: Config<'d>,
device_descriptor: &'d [u8],
config_descriptor: &'d [u8],
bos_descriptor: &'d [u8],
device_state: UsbDeviceState,
remote_wakeup_enabled: bool,
self_powered: bool,
pending_address: u8,
}
impl<'d, D: Driver<'d>> UsbDevice<'d, D> {
pub(crate) fn build(
mut driver: D,
config: Config<'d>,
device_descriptor: &'d [u8],
config_descriptor: &'d [u8],
bos_descriptor: &'d [u8],
) -> Self {
let control_out = driver
.alloc_endpoint_out(
Some(0x00.into()),
EndpointType::Control,
config.max_packet_size_0 as u16,
0,
)
.expect("failed to alloc control endpoint");
let control_in = driver
.alloc_endpoint_in(
Some(0x80.into()),
EndpointType::Control,
config.max_packet_size_0 as u16,
0,
)
.expect("failed to alloc control endpoint");
// Enable the USB bus.
// This prevent further allocation by consuming the driver.
let driver = driver.enable();
Self {
driver,
config,
control_in,
control_out,
device_descriptor,
config_descriptor,
bos_descriptor,
device_state: UsbDeviceState::Default,
remote_wakeup_enabled: false,
self_powered: false,
pending_address: 0,
}
}
pub async fn run(&mut self) {
loop {
let mut buf = [0; 8];
let n = self.control_out.read(&mut buf).await.unwrap();
assert_eq!(n, 8);
let req = Request::parse(&buf).unwrap();
info!("setup request: {:x}", req);
// Now that we have properly parsed the setup packet, ensure the end-point is no longer in
// a stalled state.
self.control_out.set_stalled(false);
match req.direction {
UsbDirection::In => self.handle_control_in(req).await,
UsbDirection::Out => self.handle_control_out(req).await,
}
}
}
async fn write_chunked(&mut self, data: &[u8]) -> Result<(), driver::WriteError> {
for c in data.chunks(8) {
self.control_in.write(c).await?;
}
if data.len() % 8 == 0 {
self.control_in.write(&[]).await?;
}
Ok(())
}
async fn control_out_accept(&mut self, req: Request) {
info!("control out accept");
// status phase
// todo: cleanup
self.control_out.read(&mut []).await.unwrap();
}
async fn control_in_accept(&mut self, req: Request, data: &[u8]) {
info!("control accept {:x}", data);
let len = data.len().min(req.length as _);
if let Err(e) = self.write_chunked(&data[..len]).await {
info!("write_chunked failed: {:?}", e);
}
// status phase
// todo: cleanup
self.control_out.read(&mut []).await.unwrap();
}
async fn control_in_accept_writer(
&mut self,
req: Request,
f: impl FnOnce(&mut DescriptorWriter),
) {
let mut buf = [0; 256];
let mut w = DescriptorWriter::new(&mut buf);
f(&mut w);
let pos = w.position();
self.control_in_accept(req, &buf[..pos]).await;
}
fn control_reject(&mut self, req: Request) {
self.control_out.set_stalled(true);
}
async fn handle_control_out(&mut self, req: Request) {
// TODO actually read the data if there's an OUT data phase.
const CONFIGURATION_NONE_U16: u16 = CONFIGURATION_NONE as u16;
const CONFIGURATION_VALUE_U16: u16 = CONFIGURATION_VALUE as u16;
const DEFAULT_ALTERNATE_SETTING_U16: u16 = DEFAULT_ALTERNATE_SETTING as u16;
match req.request_type {
RequestType::Standard => match (req.recipient, req.request, req.value) {
(
Recipient::Device,
Request::CLEAR_FEATURE,
Request::FEATURE_DEVICE_REMOTE_WAKEUP,
) => {
self.remote_wakeup_enabled = false;
self.control_out_accept(req).await;
}
(Recipient::Endpoint, Request::CLEAR_FEATURE, Request::FEATURE_ENDPOINT_HALT) => {
//self.bus.set_stalled(((req.index as u8) & 0x8f).into(), false);
self.control_out_accept(req).await;
}
(
Recipient::Device,
Request::SET_FEATURE,
Request::FEATURE_DEVICE_REMOTE_WAKEUP,
) => {
self.remote_wakeup_enabled = true;
self.control_out_accept(req).await;
}
(Recipient::Endpoint, Request::SET_FEATURE, Request::FEATURE_ENDPOINT_HALT) => {
//self.bus.set_stalled(((req.index as u8) & 0x8f).into(), true);
self.control_out_accept(req).await;
}
(Recipient::Device, Request::SET_ADDRESS, 1..=127) => {
self.pending_address = req.value as u8;
// on NRF the hardware auto-handles SET_ADDRESS.
self.control_out_accept(req).await;
}
(Recipient::Device, Request::SET_CONFIGURATION, CONFIGURATION_VALUE_U16) => {
self.device_state = UsbDeviceState::Configured;
self.control_out_accept(req).await;
}
(Recipient::Device, Request::SET_CONFIGURATION, CONFIGURATION_NONE_U16) => {
match self.device_state {
UsbDeviceState::Default => {
self.control_out_accept(req).await;
}
_ => {
self.device_state = UsbDeviceState::Addressed;
self.control_out_accept(req).await;
}
}
}
(Recipient::Interface, Request::SET_INTERFACE, DEFAULT_ALTERNATE_SETTING_U16) => {
// TODO: do something when alternate settings are implemented
self.control_out_accept(req).await;
}
_ => self.control_reject(req),
},
_ => self.control_reject(req),
}
}
async fn handle_control_in(&mut self, req: Request) {
match req.request_type {
RequestType::Standard => match (req.recipient, req.request) {
(Recipient::Device, Request::GET_STATUS) => {
let mut status: u16 = 0x0000;
if self.self_powered {
status |= 0x0001;
}
if self.remote_wakeup_enabled {
status |= 0x0002;
}
self.control_in_accept(req, &status.to_le_bytes()).await;
}
(Recipient::Interface, Request::GET_STATUS) => {
let status: u16 = 0x0000;
self.control_in_accept(req, &status.to_le_bytes()).await;
}
(Recipient::Endpoint, Request::GET_STATUS) => {
let ep_addr: EndpointAddress = ((req.index as u8) & 0x8f).into();
let mut status: u16 = 0x0000;
if self.driver.is_stalled(ep_addr) {
status |= 0x0001;
}
self.control_in_accept(req, &status.to_le_bytes()).await;
}
(Recipient::Device, Request::GET_DESCRIPTOR) => {
self.handle_get_descriptor(req).await;
}
(Recipient::Device, Request::GET_CONFIGURATION) => {
let status = match self.device_state {
UsbDeviceState::Configured => CONFIGURATION_VALUE,
_ => CONFIGURATION_NONE,
};
self.control_in_accept(req, &status.to_le_bytes()).await;
}
(Recipient::Interface, Request::GET_INTERFACE) => {
// TODO: change when alternate settings are implemented
let status = DEFAULT_ALTERNATE_SETTING;
self.control_in_accept(req, &status.to_le_bytes()).await;
}
_ => self.control_reject(req),
},
_ => self.control_reject(req),
}
}
async fn handle_get_descriptor(&mut self, req: Request) {
let (dtype, index) = req.descriptor_type_index();
let config = self.config.clone();
match dtype {
descriptor_type::BOS => self.control_in_accept(req, self.bos_descriptor).await,
descriptor_type::DEVICE => self.control_in_accept(req, self.device_descriptor).await,
descriptor_type::CONFIGURATION => {
self.control_in_accept(req, self.config_descriptor).await
}
descriptor_type::STRING => {
if index == 0 {
self.control_in_accept_writer(req, |w| {
w.write(descriptor_type::STRING, &lang_id::ENGLISH_US.to_le_bytes())
.unwrap();
})
.await
} else {
let s = match index {
1 => self.config.manufacturer,
2 => self.config.product,
3 => self.config.serial_number,
_ => {
let index = StringIndex::new(index);
let lang_id = req.index;
None
//classes
// .iter()
// .filter_map(|cls| cls.get_string(index, lang_id))
// .nth(0)
}
};
if let Some(s) = s {
self.control_in_accept_writer(req, |w| w.string(s).unwrap())
.await;
} else {
self.control_reject(req)
}
}
}
_ => self.control_reject(req),
}
}
}