From fa45dcd0348379e7b9714f9b845fa3eb75671890 Mon Sep 17 00:00:00 2001 From: Adam Greig Date: Sun, 5 Nov 2023 15:41:31 +0000 Subject: [PATCH] Add raw USB example using control transfers --- examples/stm32f4/src/bin/usb_raw.rs | 201 ++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) create mode 100644 examples/stm32f4/src/bin/usb_raw.rs diff --git a/examples/stm32f4/src/bin/usb_raw.rs b/examples/stm32f4/src/bin/usb_raw.rs new file mode 100644 index 00000000..8d4e6c7d --- /dev/null +++ b/examples/stm32f4/src/bin/usb_raw.rs @@ -0,0 +1,201 @@ +//! Example of using USB without a pre-defined class, but instead responding to +//! raw USB control requests. +//! +//! The host computer can either: +//! * send a command, with a 16-bit request ID, a 16-bit value, and an optional data buffer +//! * request some data, with a 16-bit request ID, a 16-bit value, and a length of data to receive +//! +//! For higher throughput data, you can add some bulk endpoints after creating the alternate, +//! but for low rate command/response, plain control transfers can be very simple and effective. +//! +//! Example code to send/receive data using `nusb`: +//! +//! ```ignore +//! use futures_lite::future::block_on; +//! use nusb::transfer::{ControlIn, ControlOut, ControlType, Recipient}; +//! +//! fn main() { +//! let di = nusb::list_devices() +//! .unwrap() +//! .find(|d| d.vendor_id() == 0xc0de && d.product_id() == 0xcafe) +//! .expect("no device found"); +//! let device = di.open().expect("error opening device"); +//! let interface = device.claim_interface(0).expect("error claiming interface"); +//! +//! // Send "hello world" to device +//! let result = block_on(interface.control_out(ControlOut { +//! control_type: ControlType::Vendor, +//! recipient: Recipient::Interface, +//! request: 100, +//! value: 200, +//! index: 0, +//! data: b"hello world", +//! })); +//! println!("{result:?}"); +//! +//! // Receive "hello" from device +//! let result = block_on(interface.control_in(ControlIn { +//! control_type: ControlType::Vendor, +//! recipient: Recipient::Interface, +//! request: 101, +//! value: 201, +//! index: 0, +//! length: 5, +//! })); +//! println!("{result:?}"); +//! } +//! ``` + +#![no_std] +#![no_main] +#![feature(type_alias_impl_trait)] + +use defmt::*; +use embassy_executor::Spawner; +use embassy_stm32::time::Hertz; +use embassy_stm32::usb_otg::Driver; +use embassy_stm32::{bind_interrupts, peripherals, usb_otg, Config}; +use embassy_usb::control::{InResponse, OutResponse, Recipient, Request, RequestType}; +use embassy_usb::types::InterfaceNumber; +use embassy_usb::{Builder, Handler}; +use {defmt_rtt as _, panic_probe as _}; + +bind_interrupts!(struct Irqs { + OTG_FS => usb_otg::InterruptHandler; +}); + +#[embassy_executor::main] +async fn main(_spawner: Spawner) { + info!("Hello World!"); + + let mut config = Config::default(); + { + use embassy_stm32::rcc::*; + config.rcc.hse = Some(Hse { + freq: Hertz(8_000_000), + mode: HseMode::Bypass, + }); + config.rcc.pll_src = PllSource::HSE; + config.rcc.pll = Some(Pll { + prediv: PllPreDiv::DIV4, + mul: PllMul::MUL168, + divp: Some(Pllp::DIV2), // 8mhz / 4 * 168 / 2 = 168Mhz. + divq: Some(Pllq::DIV7), // 8mhz / 4 * 168 / 7 = 48Mhz. + divr: None, + }); + config.rcc.ahb_pre = AHBPrescaler::DIV1; + config.rcc.apb1_pre = APBPrescaler::DIV4; + config.rcc.apb2_pre = APBPrescaler::DIV2; + config.rcc.sys = Sysclk::PLL1_P; + } + let p = embassy_stm32::init(config); + + // Create the driver, from the HAL. + let mut ep_out_buffer = [0u8; 256]; + let mut config = embassy_stm32::usb_otg::Config::default(); + config.vbus_detection = true; + let driver = Driver::new_fs(p.USB_OTG_FS, Irqs, p.PA12, p.PA11, &mut ep_out_buffer, config); + + // Create embassy-usb Config + let mut config = embassy_usb::Config::new(0xc0de, 0xcafe); + config.manufacturer = Some("Embassy"); + config.product = Some("USB-raw example"); + config.serial_number = Some("12345678"); + + // Required for windows compatibility. + // https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.9.1/kconfig/CONFIG_CDC_ACM_IAD.html#help + config.device_class = 0xEF; + config.device_sub_class = 0x02; + config.device_protocol = 0x01; + config.composite_with_iads = true; + + // Create embassy-usb DeviceBuilder using the driver and config. + // It needs some buffers for building the descriptors. + let mut device_descriptor = [0; 256]; + let mut config_descriptor = [0; 256]; + let mut bos_descriptor = [0; 256]; + let mut control_buf = [0; 64]; + + let mut handler = ControlHandler { + if_num: InterfaceNumber(0), + }; + + let mut builder = Builder::new( + driver, + config, + &mut device_descriptor, + &mut config_descriptor, + &mut bos_descriptor, + &mut control_buf, + ); + + // Add a vendor-specific function (class 0xFF), and corresponding interface, + // that uses our custom handler. + let mut function = builder.function(0xFF, 0, 0); + let mut interface = function.interface(); + let _alternate = interface.alt_setting(0xFF, 0, 0, None); + handler.if_num = interface.interface_number(); + drop(function); + builder.handler(&mut handler); + + // Build the builder. + let mut usb = builder.build(); + + // Run the USB device. + usb.run().await; +} + +/// Handle CONTROL endpoint requests and responses. For many simple requests and responses +/// you can get away with only using the control endpoint. +struct ControlHandler { + if_num: InterfaceNumber, +} + +impl Handler for ControlHandler { + /// Respond to HostToDevice control messages, where the host sends us a command and + /// optionally some data, and we can only acknowledge or reject it. + fn control_out<'a>(&'a mut self, req: Request, buf: &'a [u8]) -> Option { + // Log the request before filtering to help with debugging. + info!("Got control_out, request={}, buf={:a}", req, buf); + + // Only handle Vendor request types to an Interface. + if req.request_type != RequestType::Vendor || req.recipient != Recipient::Interface { + return None; + } + + // Ignore requests to other interfaces. + if req.index != self.if_num.0 as u16 { + return None; + } + + // Accept request 100, value 200, reject others. + if req.request == 100 && req.value == 200 { + Some(OutResponse::Accepted) + } else { + Some(OutResponse::Rejected) + } + } + + /// Respond to DeviceToHost control messages, where the host requests some data from us. + fn control_in<'a>(&'a mut self, req: Request, buf: &'a mut [u8]) -> Option> { + info!("Got control_in, request={}", req); + + // Only handle Vendor request types to an Interface. + if req.request_type != RequestType::Vendor || req.recipient != Recipient::Interface { + return None; + } + + // Ignore requests to other interfaces. + if req.index != self.if_num.0 as u16 { + return None; + } + + // Respond "hello" to request 101, value 201, when asked for 5 bytes, otherwise reject. + if req.request == 101 && req.value == 201 && req.length == 5 { + buf[..5].copy_from_slice(b"hello"); + Some(InResponse::Accepted(&buf[..5])) + } else { + Some(InResponse::Rejected) + } + } +}