badges

.gitignore

@@ -1 +1,3 @@
 /target
+.zed
+.gdbinit

.pre-commit-config.yaml

@@ -0,0 +1,27 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.5.0
+    hooks:
+      - id: fix-byte-order-marker
+      - id: check-case-conflict
+      - id: check-merge-conflict
+      - id: check-symlinks
+      - id: check-yaml
+      - id: end-of-file-fixer
+      - id: mixed-line-ending
+      - id: trailing-whitespace
+  - repo: https://github.com/pre-commit/pre-commit
+    rev: v3.6.2
+    hooks:
+      - id: validate_manifest
+  - repo: https://github.com/jorisroovers/gitlint
+    rev: v0.19.1
+    hooks:
+      - id: gitlint
+  - repo: https://github.com/FeryET/pre-commit-rust
+    rev: v1.2.1
+    hooks:
+      - id: fmt
+      - id: cargo-check
+      - id: clippy
+      - id: build

Cargo.toml

@@ -12,10 +12,16 @@ usbd-uac2 = { path = "." }
 [package]
 name = "usbd-uac2"
 description = "USB Audio Class 2.0 for usb-device"
+readme = "README.md"
 authors = ["Keenan Tims <ktims@gotroot.ca>"]
+repository = "https://github.com/ktims/usbd-uac2"
 version = "0.1.0"
 edition = "2024"
+license = "MIT"
 keywords = ["no-std", "usb-device", "audio"]
+exclude = [
+    "examples/**"
+]
 
 [features]
 defmt = ["dep:defmt", "usb-device/defmt"]
@@ -27,3 +33,9 @@ embedded-io = "0.7.1"
 modular-bitfield = "0.13.1"
 num-traits = { version = "0.2.19", default-features = false }
 usb-device.workspace = true
+
+[profile.release]
+opt-level = "z"
+lto = true
+debug = true
+codegen-units = 1

LICENSE

@@ -0,0 +1,18 @@
+Copyright 2026 Keenan Tims
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the “Software”), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -0,0 +1,47 @@
+![Crates.io Version](https://img.shields.io/crates/v/usbd-uac2) ![docs.rs](https://img.shields.io/docsrs/usbd-uac2)
+
+# usbd-uac2
+
+USB Audio Class 2.0
+
+This crate provides a USB Audio Class 2.0 implementation for
+[usb-device](https://crates.io/crates/usb-device). It implements all
+required elements of the specification, however many controls are not
+implemented (e.g. mixers, effects).
+
+Device behaviour is driven by implementing the `ClockSource` and
+`AudioHandler` traits to configure the audio pipeline and source/sink data
+to/from USB.
+
+Example (creates a UAC2 device with in and out streams):
+
+```rust
+let mut audio = YourTraitImpl {...};
+
+let config = UsbAudioClassConfig::new(usb_speed, FunctionCode::IoBox, &mut audio)
+    // base_id is USB entity ID, id 1 is always taken by the clock source, and each stream builds 2 entities
+    .with_output_config(TerminalConfig::builder().base_id(2).build())
+    .with_input_config(TerminalConfig::builder().base_id(4).build());
+
+let mut uac2 = config.build(&usb_bus).unwrap();
+
+let mut usb_dev = usbd_uac2::builder(&usb_bus, UsbVidPid(0x1209, 0x0001))
+    .strings(&[StringDescriptors::default()
+        .manufacturer("usbd_uac2")
+        .product("example")])
+    .unwrap()
+    .max_packet_size_0(64) // Required to be 64 on HS
+    .unwrap()
+    .build();
+```
+
+No work needs to be done in the poll loop, the class implementation will
+call your trait callbacks as required, just call the usb poll as usual:
+
+```rust
+loop {
+    usb_dev.poll(&mut [&mut uac2]);
+}
+```
+
+See the trait documentation or examples for additional details.

examples/README.md

@@ -3,7 +3,7 @@ Two example backends are provided, both based on the LPCXpresso55S28 demo board,
 ## LPC55S28 (LPCXpresso55S28)
 
 These examples work on the
-(LPCXpresso55S28)[https://www.nxp.com/design/design-center/software/development-software/mcuxpresso-software-and-tools-/lpcxpresso-boards/lpcxpresso55s28-development-board:LPC55S28-EVK]
+[LPCXpresso55S28](https://www.nxp.com/design/design-center/software/development-software/mcuxpresso-software-and-tools-/lpcxpresso-boards/lpcxpresso55s28-development-board:LPC55S28-EVK)
 development board. They use the onboard WM8904 codec, so don't require any
 additional hardware for audio I/O.
 

examples/lpc55s28-evk-dma/.cargo/config.toml

@@ -1,10 +1,3 @@
-[target.thumbv8m.main-none-eabi]
-rustflags = [
-  "-C", "link-arg=-Tlink.x",
-  "-C", "link-arg=-Tdefmt.x",
-  "-C", "debug-assertions",
-]
-
 [target.thumbv8m.main-none-eabihf]
 rustflags = [
   "-C", "link-arg=-Tlink.x",

examples/lpc55s28-evk-dma/Cargo.toml

@@ -24,9 +24,3 @@ static_cell = "2.1.1"
 lpc55-hal = { git = "https://github.com/ktims/lpc55-hal", branch = "main" }
 usb-device.workspace = true
 usbd-uac2 = { workspace = true, features = ["defmt"] }
-
-[profile.release]
-opt-level = "z"
-lto = true
-debug = true
-codegen-units = 1

examples/lpc55s28-evk-dma/src/main.rs

@@ -38,7 +38,7 @@ use pac::interrupt;
 use static_cell::StaticCell;
 use usb_device::{
     bus::{self},
-    device::{StringDescriptors, UsbDeviceBuilder, UsbVidPid},
+    device::{StringDescriptors, UsbVidPid},
 };
 use usbd_uac2::TerminalConfig;
 use usbd_uac2::{
@@ -53,6 +53,12 @@ mod dma;
 mod hw;
 mod wm8904;
 
+// pid.codes test IDs
+const USB_VID: u16 = 0x1209;
+const USB_PID: u16 = 0x0001;
+const USB_MANUFACTURER: &str = "usbd_uac2";
+const USB_PRODUCT: &str = "DMA example device";
+
 const CODEC_I2C_ADDR: u8 = 0b0011010;
 const MCLK_FREQ: u32 = 12288000;
 
@@ -199,6 +205,11 @@ impl<const N: usize, const MAX_SLOT_BYTES: usize, B: bus::UsbBus> AudioHandler<'
             self.running.store(true, Ordering::Relaxed)
         }
     }
+    fn audio_data_tx(
+        &mut self,
+        _ep: &usb_device::endpoint::Endpoint<'_, B, usb_device::endpoint::In>,
+    ) {
+    }
 
     /// Provide rate feedback to the host. P-only is stable and works fine, with
     /// most hosts. The host can either filter it internally or treat it
@@ -229,7 +240,7 @@ impl<const N: usize, const MAX_SLOT_BYTES: usize, B: bus::UsbBus> AudioHandler<'
         // 0.2% which is a huge clock error
         let max_allowed_deviation = nominal_v / 500;
 
-        let p_term = -(error_permille * nominal_v) / 256000; // this works reasonably well to keep the buffer 
+        let p_term = -(error_permille * nominal_v) / 256000; // this works reasonably well to keep the buffer
         let i_term = 0; // placeholder
 
         let mut v = nominal_v + p_term + i_term;
@@ -379,18 +390,13 @@ fn main() -> ! {
         .with_output_config(TerminalConfig::builder().base_id(2).build());
     let mut uac2 = config.build(&usb_bus).unwrap();
 
-    let mut usb_dev = UsbDeviceBuilder::new(&usb_bus, UsbVidPid(0x1209, 0xcc1d))
+    let mut usb_dev = usbd_uac2::builder(&usb_bus, UsbVidPid(USB_VID, USB_PID))
-        .composite_with_iads()
         .strings(&[StringDescriptors::default()
-            .manufacturer("Generic")
+            .manufacturer(USB_MANUFACTURER)
-            .product("usbd_uac2 device")
+            .product(USB_PRODUCT)])
-            .serial_number("123456789")])
         .unwrap()
-        .max_packet_size_0(64)
+        .max_packet_size_0(64) // Required to be 64 on HS, allowed on FS
         .unwrap()
-        .device_class(0xef)
-        .device_sub_class(0x02)
-        .device_protocol(0x01)
         .build();
 
     defmt::info!("main loop");

examples/lpc55s28-evk/.cargo/config.toml

@@ -1,10 +1,3 @@
-[target.thumbv8m.main-none-eabi]
-rustflags = [
-  "-C", "link-arg=-Tlink.x",
-  "-C", "link-arg=-Tdefmt.x",
-  "-C", "debug-assertions",
-]
-
 [target.thumbv8m.main-none-eabihf]
 rustflags = [
   "-C", "link-arg=-Tlink.x",

examples/lpc55s28-evk/Cargo.toml

@@ -23,9 +23,3 @@ panic-probe = { version = "1.0.0", features = ["print-defmt"] }
 lpc55-hal = { git = "https://github.com/ktims/lpc55-hal", branch = "main" }
 usb-device.workspace = true
 usbd-uac2 = { workspace = true, features = ["defmt"] }
-
-[profile.release]
-opt-level = "z"
-lto = true
-debug = true
-codegen-units = 1

src/lib.rs

@@ -1,3 +1,47 @@
+//! USB Audio Class 2.0
+//!
+//! This crate provides a USB Audio Class 2.0 implementation for
+//! [usb-device](https://crates.io/crates/usb-device). It implements all
+//! required elements of the specification, however many controls are not
+//! implemented (e.g. mixers, effects).
+//!
+//! Device behaviour is driven by implementing the `ClockSource` and
+//! `AudioHandler` traits to configure the audio pipeline and source/sink data
+//! to/from USB.
+//!
+//! Example (creates a UAC2 device with in and out streams):
+//!
+//! ```ignore
+//! let mut audio = YourTraitImpl {...};
+//!
+//! let config = UsbAudioClassConfig::new(usb_speed, FunctionCode::IoBox, &mut audio)
+//!     // base_id is USB entity ID, id 1 is always taken by the clock source, and each stream builds 2 entities
+//!     .with_output_config(TerminalConfig::builder().base_id(2).build())
+//!     .with_input_config(TerminalConfig::builder().base_id(4).build());
+//!
+//! let mut uac2 = config.build(&usb_bus).unwrap();
+//!
+//! let mut usb_dev = usbd_uac2::builder(&usb_bus, UsbVidPid(0x1209, 0x0001))
+//!     .strings(&[StringDescriptors::default()
+//!         .manufacturer("usbd_uac2")
+//!         .product("example")])
+//!     .unwrap()
+//!     .max_packet_size_0(64) // Required to be 64 on HS
+//!     .unwrap()
+//!     .build();
+//! ```
+//!
+//! No work needs to be done in the poll loop, the class implementation will
+//! call your trait callbacks as required, just call the usb poll as usual:
+//!
+//! ```ignore
+//! loop {
+//!     usb_dev.poll(&mut [&mut uac2]);
+//! }
+//! ```
+//!
+//! See the trait documentation or examples for additional details.
+
 #![no_std]
 #![allow(dead_code)]
 
@@ -9,11 +53,12 @@ mod log;
 use core::cmp::Ordering;
 use core::marker::PhantomData;
 
-use byteorder_embedded_io::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use constants::*;
 use descriptors::*;
+#[allow(unused_imports)]
 use log::*;
 
+use byteorder_embedded_io::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use num_traits::{ConstZero, ToPrimitive};
 use usb_device::control::{Recipient, Request, RequestType};
 use usb_device::device::{DEFAULT_ALTERNATE_SETTING, UsbDeviceBuilder, UsbVidPid};
@@ -936,8 +981,8 @@ impl<'a, B: UsbBus, AU: AudioHandler<'a, B> + ClockSource> UsbClass<B>
                         break;
                     }
                     Err(UsbError::WouldBlock) => break,
-                    Err(err) => {
+                    Err(_err) => {
-                        debug!("EP OUT error {:?}", err);
+                        debug!("EP OUT error {:?}", _err);
                     }
                 }
             }
@@ -962,8 +1007,8 @@ impl<'a, B: UsbBus, AU: AudioHandler<'a, B> + ClockSource> UsbAudioClass<'a, B,
                     UsbSpeed::Low | UsbSpeed::Full => fb_ep.write(&fb.to_bytes_10_14()),
                     UsbSpeed::High | UsbSpeed::Super => fb_ep.write(&fb.to_bytes_12_13()),
                 };
-                if let Err(e) = r {
+                if let Err(_e) = r {
-                    warn!("  feedback IN failed {:?}", e);
+                    warn!("  feedback IN failed {:?}", _e);
                 }
             } else {
                 debug!("  feedback callback returned None");

src/log.rs

@@ -7,25 +7,36 @@ pub use defmt::{debug, error, info, trace, warn};
 mod no_defmt {
     #[macro_export]
     macro_rules! trace {
-        ($($t:tt)*) => {};
+        ($($t:tt)*) => {
+            ()
+        };
     }
     #[macro_export]
     macro_rules! debug {
-        ($($t:tt)*) => {};
+        ($($t:tt)*) => {
+            ()
+        };
     }
     #[macro_export]
     macro_rules! info {
-        ($($t:tt)*) => {};
+        ($($t:tt)*) => {
+            ()
+        };
     }
     #[macro_export]
     macro_rules! warn {
-        ($($t:tt)*) => {};
+        ($($t:tt)*) => {
+            ()
+        };
     }
     #[macro_export]
     macro_rules! error {
-        ($($t:tt)*) => {};
+        ($($t:tt)*) => {
+            ()
+        };
     }
 }
 
+#[allow(unused_imports)]
 #[cfg(not(feature = "defmt"))]
 pub use no_defmt::*;