Add a dummy usb bus implementation

Author: sourcebox

CHANGELOG.md

@@ -7,37 +7,48 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Added
+
+* `DummyUsbBus` without functionality to allow examples that actually compile (but not run).
+
 ### Changed
+
 * [breaking] The control pipe is now provided in the `UsbDeviceBuilder` API to allow for user-provided control
 pipes. This makes it so that control pipes have configurable sizing.
 
 ## [0.3.2] - 2024-03-06
 
 ### Added
+
 * A new `log` feature can be enabled to provide logging and tracing information about the USB
 interface.
 
 ### Changed
+
 * [breaking] LangIDs no longer implement `TryFromPrimitive`. The minor version has not been bumped
 as this was not intended to be used in the public API.
-    - If this is problematic, please open an issue in the main `usb-device` repository.
+  * If this is problematic, please open an issue in the main `usb-device` repository.
 * Changed handling of EP0 state to eliminate unexpected issues with device enumeration
 
 ## [0.3.1] - 2023-11-15
 
 ### Added
+
 * `BuilderError`, `LangID`, `StringDescriptors` now in `prelude`
 * `LangID` now in `class_prelude`
 
 ### Changed
+
 * Updated documentation, including example code
 
 ## [0.3.0] - 2023-11-13
 
 ### Fixed
+
 * Fixed a defect where enumeration may fail due to timing-related issues ([#128](https://github.com/rust-embedded-community/usb-device/issues/128))
 
 ### Added
+
 * New enums and allocators for Isochronous endpoints ([#60](https://github.com/rust-embedded-community/usb-device/pull/60)).
 * Ability to select USB revision ([#116](https://github.com/rust-embedded-community/usb-device/pull/116)).
 * Added support for alternate settings on interfaces ([#114](https://github.com/rust-embedded-community/usb-device/pull/114)).
@@ -46,22 +57,26 @@ as this was not intended to be used in the public API.
   * `UsbDeviceBuilder` has a public `.extra_lang_ids()` method to specify LANGIDs besides ENGLISH_US(0x0409)
 
 ### Breaking
+
 * Acess numeric form of `EndpointType` variants now require a `.to_bm_attributes()`. ([#60](https://github.com/rust-embedded-community/usb-device/pull/60))
 * `DescriptorWriter::iad()` now requires a `Option<StringIndex>` to optionally specify a string for describing the function ([#121](https://github.com/rust-embedded-community/usb-device/pull/121))
 * `.manufacturer()`, `.product()` and `.serial_number()` of `UsbDeviceBuilder` are now replaced with the `strings()` function that accepts a `StringDescriptor` list to allow multilanguage support ([#122](https://github.com/rust-embedded-community/usb-device/pull/122))
 * Various methods of the `UsbDeviceBuilder` now return `Result<>` types instead of internally panicking.
 
 ### Changed
+
 * `EndpointType` enum now has fields for isochronous synchronization and usage ([#60](https://github.com/rust-embedded-community/usb-device/pull/60)).
 * `descriptor_type::STRING` of `fn get_descriptor()` will send the LANGIDs supported by device, and respond STRING Request with specified LANGID. ([#122](https://github.com/rust-embedded-community/usb-device/pull/122))
 * `UsbError` is now copyable and comparable ([#127](https://github.com/rust-embedded-community/usb-device/pull/127))
 
 ## [0.2.9] - 2022-08-02
 
 ### Added
+
 * Optional support for defmt ([#76](https://github.com/rust-embedded-community/usb-device/pull/76)).
 
 ### Fixed
+
 * Fixed an issue where USB devices were not enumerating on Windows ([#32](https://github.com/rust-embedded-community/usb-device/issues/82))
 * Fixed Suspend state transition so it goes back to the previous state, not just Default ([#97](https://github.com/rust-embedded-community/usb-device/pull/97))
 

src/dummy_bus.rs

@@ -0,0 +1,86 @@
+#![allow(unused_variables)]
+
+use crate::bus::UsbBus;
+
+/// Dummy bus implementation with no functionality.
+///
+/// Examples can create an instance of this bus just to make them compile.
+pub struct DummyUsbBus;
+
+impl DummyUsbBus {
+    /// Creates a new `DummyUsbBus`.
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl Default for DummyUsbBus {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl UsbBus for DummyUsbBus {
+    fn alloc_ep(
+        &mut self,
+        ep_dir: crate::UsbDirection,
+        ep_addr: Option<crate::class_prelude::EndpointAddress>,
+        ep_type: crate::class_prelude::EndpointType,
+        max_packet_size: u16,
+        interval: u8,
+    ) -> crate::Result<crate::class_prelude::EndpointAddress> {
+        unimplemented!()
+    }
+
+    fn enable(&mut self) {
+        unimplemented!()
+    }
+
+    fn force_reset(&self) -> crate::Result<()> {
+        unimplemented!()
+    }
+
+    fn is_stalled(&self, ep_addr: crate::class_prelude::EndpointAddress) -> bool {
+        unimplemented!()
+    }
+
+    fn poll(&self) -> crate::bus::PollResult {
+        unimplemented!()
+    }
+
+    fn read(
+        &self,
+        ep_addr: crate::class_prelude::EndpointAddress,
+        buf: &mut [u8],
+    ) -> crate::Result<usize> {
+        unimplemented!()
+    }
+
+    fn reset(&self) {
+        unimplemented!()
+    }
+
+    fn resume(&self) {
+        unimplemented!()
+    }
+
+    fn set_device_address(&self, addr: u8) {
+        unimplemented!()
+    }
+
+    fn set_stalled(&self, ep_addr: crate::class_prelude::EndpointAddress, stalled: bool) {
+        unimplemented!()
+    }
+
+    fn suspend(&self) {
+        unimplemented!()
+    }
+
+    fn write(
+        &self,
+        ep_addr: crate::class_prelude::EndpointAddress,
+        buf: &[u8],
+    ) -> crate::Result<usize> {
+        unimplemented!()
+    }
+}

src/lib.rs

@@ -184,6 +184,19 @@ pub use descriptor::lang_id::LangID;
 /// driver to be tested with the test_class_host example in this crate.
 pub mod test_class;
 
+/// Dummy bus with no functionality.
+///
+/// Examples can create an instance of this bus so they can be compile-checked.
+/// Note that the lack of functionality does not allow to run the examples.
+///
+/// ```
+/// use usb_device::dummy_bus::DummyUsbBus;
+/// use usb_device::class_prelude::UsbBusAllocator;
+///
+/// let usb_bus = UsbBusAllocator::new(DummyUsbBus::new());
+/// ```
+pub mod dummy_bus;
+
 mod control_pipe;
 
 mod device_builder;