Pre-release docs tweaks

Cargo.toml

@@ -1,7 +1,9 @@
 [package]
 name = "nusb"
 version = "0.1.0"
-description = "Low-level access to USB devices in pure Rust"
+description = "Cross-platform low-level access to USB devices in pure Rust"
+categories = ["hardware-support"]
+keywords = ["usb", "hardware"]
 authors = ["Kevin Mehall <km@kevinmehall.net>"]
 edition = "2021"
 license = "Apache-2.0 OR MIT"

README.md

@@ -3,6 +3,8 @@ nusb
 
 A new pure-Rust library for cross-platform low-level access to USB devices.
 
+[Documentation](https://docs.rs/nusb)
+
 ### Compared to [rusb](https://docs.rs/rusb/latest/rusb/) and libusb
 
 * Pure Rust, no dependency on libusb or any other C library.
@@ -11,14 +13,13 @@ A new pure-Rust library for cross-platform low-level access to USB devices.
   `futures_lite::block_on`.
 * No context object. You just open a device. There is a global event loop thread
   that is started when opening the first device.
-* Doesn't try to paper over OS differences. For example, on Windows, you must open
-  a specific interface, not a device as a whole. `nusb`'s API makes working with interfaces
-  a required step so that it can map directly to Windows APIs.
+* Thinner layer over OS APIs, with less internal state.
 
 ### :construction: Current status
 
 * Linux:  Control, bulk and interrupt transfers work, minimally tested
 * Windows:  Control, bulk and interrupt transfers work, minimally tested
+* macOS : Not yet implemented
 
 ### License
 MIT or Apache 2.0, at your option

src/device.rs

@@ -8,7 +8,17 @@ use crate::{
 
 /// An opened USB device.
 ///
-/// Obtain a `Device` by calling [`DeviceInfo::open`].
+/// Obtain a `Device` by calling [`DeviceInfo::open`]:
+///
+/// ```no_run
+/// use nusb;
+/// let device_info = nusb::list_devices().unwrap()
+///     .find(|dev| dev.vendor_id() == 0xAAAA && dev.product_id() == 0xBBBB)
+///     .expect("device not connected");
+///
+/// let device = device_info.open().expect("failed to open device");
+/// let interface = device.claim_interface(0);
+/// ```
 ///
 /// This type is reference-counted with an [`Arc`] internally, and can be cloned cheaply for
 /// use in multiple places in your program. The device is closed when all clones and all
@@ -74,6 +84,27 @@ impl Interface {
     }
 
     /// Submit a single **IN (device-to-host)** transfer on the default **control** endpoint.
+    ///
+    /// ### Example
+    ///
+    /// ```no_run
+    /// use futures_lite::future::block_on;
+    /// use nusb::transfer::{ ControlIn, ControlType, Recipient };
+    /// # fn main() -> Result<(), std::io::Error> {
+    /// # let di = nusb::list_devices().unwrap().next().unwrap();
+    /// # let device = di.open().unwrap();
+    /// # let interface = device.claim_interface(0).unwrap();
+    ///
+    /// let data: Vec<u8> = block_on(interface.control_in(ControlIn {
+    ///     control_type: ControlType::Vendor,
+    ///     recipient: Recipient::Device,
+    ///     request: 0x30,
+    ///     value: 0x0,
+    ///     index: 0x0,
+    ///     length: 64,
+    /// })).into_result()?;
+    /// # Ok(()) }
+    /// ```
     pub fn control_in(&self, data: ControlIn) -> TransferFuture<ControlIn> {
         let mut t = self.backend.make_transfer(0, EndpointType::Control);
         t.submit::<ControlIn>(data);
@@ -81,6 +112,27 @@ impl Interface {
     }
 
     /// Submit a single **OUT (host-to-device)** transfer on the default **control** endpoint.
+    ///
+    /// ### Example
+    ///
+    /// ```no_run
+    /// use futures_lite::future::block_on;
+    /// use nusb::transfer::{ ControlOut, ControlType, Recipient };
+    /// # fn main() -> Result<(), std::io::Error> {
+    /// # let di = nusb::list_devices().unwrap().next().unwrap();
+    /// # let device = di.open().unwrap();
+    /// # let interface = device.claim_interface(0).unwrap();
+    ///
+    /// block_on(interface.control_out(ControlOut {
+    ///     control_type: ControlType::Vendor,
+    ///     recipient: Recipient::Device,
+    ///     request: 0x32,
+    ///     value: 0x0,
+    ///     index: 0x0,
+    ///     data: &[0x01, 0x02, 0x03, 0x04],
+    /// })).into_result()?;
+    /// # Ok(()) }
+    /// ```
     pub fn control_out(&self, data: ControlOut) -> TransferFuture<ControlOut> {
         let mut t = self.backend.make_transfer(0, EndpointType::Control);
         t.submit::<ControlOut>(data);

src/lib.rs

@@ -32,10 +32,10 @@
 //! device. To open an interface, call [`Device::claim_interface`]. Only one
 //! program (or kernel driver) may claim an interface at a time.
 //!
-//! Use the resulting [`Interface`] struct to transfer data on the device's
-//! control, bulk or interrupt endpoints. Transfers are async by default, and
-//! can be awaited as individual `Future`s, or use a [`transfer::Queue`] to
-//! manage streams of data.
+//! Use the resulting [`Interface`] to transfer data on the device's control,
+//! bulk or interrupt endpoints. Transfers are async by default, and can be
+//! awaited as individual [`Future`][`transfer::TransferFuture`]s, or use a
+//! [`Queue`][`transfer::Queue`] to manage streams of data.
 //!
 //! *For more details on how USB works, [USB in a
 //! Nutshell](https://beyondlogic.org/usbnutshell/usb1.shtml) is a good
@@ -44,10 +44,14 @@
 //! ## Logging
 //!
 //! `nusb` uses the [`log`](https://docs.rs/log) crate to log debug and error
-//! information. When submitting a bug report, please include the logs: include
-//! a logging backend like [`env_logger`](https://docs.rs/env_logger) and
-//! configure it to enable log output for this crate (for `env_logger` set
-//! environment variable `RUST_LOG=nusb=debug`.)
+//! information.
+//!
+//! When [submitting a bug report][gh-issues], please include the logs: use a
+//! `log` backend like [`env_logger`](https://docs.rs/env_logger) and configure
+//! it to enable log output for this crate (for `env_logger` set environment
+//! variable `RUST_LOG=nusb=debug`.)
+//!
+//! [gh-issues]: https://github.com/kevinmehall/nusb/issues
 //!
 //! ## Platform support
 //!
@@ -78,7 +82,7 @@
 //!
 //! ### Windows
 //!
-//! `nusb` uses [SetupAPI] to find devices and [WinUSB] to access them.
+//! `nusb` uses [WinUSB] on Windows.
 //!
 //! On Windows, devices are associated with a particular driver, which persists
 //! across connections and reboots. Composite devices appear as multiple devices
@@ -86,11 +90,11 @@
 //! separate driver.
 //!
 //! To use `nusb`, your device or interface must be associated with the `WinUSB`
-//! driver. The recommended way to this if you control the device firmware is to
-//! use a [WCID] descriptor to tell Windows to install the WinUSB driver
-//! automatically when the device is first connected. Alternatively [Zadig]
-//! (GUI) or [libwdi] (CLI / C library) can be used to manually install the
-//! WinUSB driver for a device.
+//! driver. If you control the device firmware, the recommended way is to use a
+//! [WCID] descriptor to tell Windows to install the WinUSB driver automatically
+//! when the device is first connected. Alternatively [Zadig] (GUI) or [libwdi]
+//! (CLI / C library) can be used to manually install the WinUSB driver for a
+//! device.
 //!
 //! [SetupAPI]:
 //!     https://learn.microsoft.com/en-us/windows-hardware/drivers/install/setupapi

src/platform/linux_usbfs/device.rs

@@ -132,7 +132,10 @@ impl LinuxInterface {
     }
 
     pub fn set_alt_setting(&self, alt_setting: u8) -> Result<(), Error> {
-        debug!("Set interface {} alt setting to {alt_setting}", self.interface);
+        debug!(
+            "Set interface {} alt setting to {alt_setting}",
+            self.interface
+        );
         Ok(usbfs::set_interface(
             &self.device.fd,
             self.interface,

src/platform/linux_usbfs/usbfs.rs

@@ -1,5 +1,6 @@
 //! Wrappers for the [usbfs] character device ioctls, translated from the
 //! [C structures and ioctl definitions][uapi].
+//!
 //! [usbfs]: https://www.kernel.org/doc/html/latest/driver-api/usb/usb.html#the-usb-character-device-nodes
 //! [uapi]: https://github.com/torvalds/linux/blob/master/tools/include/uapi/linux/usbdevice_fs.h
 #![allow(dead_code)]

src/platform/windows_winusb/device.rs

@@ -8,7 +8,9 @@ use std::{
 
 use log::{debug, error};
 use windows_sys::Win32::{
-    Devices::Usb::{WinUsb_Free, WinUsb_Initialize, WINUSB_INTERFACE_HANDLE, WinUsb_SetCurrentAlternateSetting},
+    Devices::Usb::{
+        WinUsb_Free, WinUsb_Initialize, WinUsb_SetCurrentAlternateSetting, WINUSB_INTERFACE_HANDLE,
+    },
     Foundation::{FALSE, TRUE},
 };
 

src/transfer/mod.rs

@@ -1,12 +1,14 @@
 //! Transfer-related types.
-//! 
+//!
 //! Use the methods on an [`Interface`][`super::Interface`] to make individual
 //! transfers or obtain a [`Queue`] to manage multiple transfers.
 
 use std::{
+    fmt::Display,
     future::Future,
+    io,
     marker::PhantomData,
-    task::{Context, Poll}, io, fmt::Display,
+    task::{Context, Poll},
 };
 
 use crate::platform;

src/transfer/queue.rs

@@ -10,17 +10,17 @@ use crate::platform;
 use super::{Completion, EndpointType, PlatformSubmit, TransferHandle, TransferRequest};
 
 /// Manages a stream of transfers on an endpoint.
-/// 
+///
 /// A `Queue` optimizes a common pattern when streaming data to or from a USB
 /// endpoint: To maximize throughput and minimize latency, the host controller
 /// needs to attempt a transfer in every possible frame. That requires always
 /// having a transfer request pending with the kernel by submitting multiple
 /// transfer requests and re-submitting them as they complete.
-/// 
+///
 /// When the `Queue` is dropped, all pending transfers are cancelled.
-/// 
-/// ### Why use a `Queue` instead of submitting multiple transfers individually
-/// with the methods on [`Interface`][`crate::Interface`]?
+///
+/// ### Why use a `Queue` instead of submitting multiple transfers individually with the methods on [`Interface`][`crate::Interface`]?
+///
 ///  * Individual transfers give you individual `Future`s, which you then have
 ///    to keep track of and poll using something like `FuturesUnordered`.
 ///  * A `Queue` provides better cancellation semantics than `Future`'s
@@ -36,9 +36,9 @@ use super::{Completion, EndpointType, PlatformSubmit, TransferHandle, TransferRe
 ///  * A queue caches the internal transfer data structures of the last
 ///    completed transfer, meaning that if you re-use the data buffer there is
 ///    no memory allocation involved in continued streaming.
-/// 
+///
 /// ### Example (read from an endpoint)
-/// 
+///
 /// ```no_run
 /// use futures_lite::future::block_on;
 /// use nusb::transfer::RequestBuffer;
@@ -47,18 +47,18 @@ use super::{Completion, EndpointType, PlatformSubmit, TransferHandle, TransferRe
 /// # let interface = device.claim_interface(0).unwrap();
 /// # fn handle_data(_: &[u8]) {}
 /// let mut queue = interface.bulk_in_queue(0x81);
-/// 
+///
 /// let n_transfers = 8;
 /// let transfer_size = 256;
 ///
 /// while queue.pending() < n_transfers {
 ///     queue.submit(RequestBuffer::new(transfer_size));
 /// }
-/// 
+///
 /// loop {
 ///     let completion = block_on(queue.next_complete());
 ///     handle_data(&completion.data); // your function
-/// 
+///
 ///     if completion.status.is_err() {
 ///         break;
 ///     }
@@ -66,7 +66,7 @@ use super::{Completion, EndpointType, PlatformSubmit, TransferHandle, TransferRe
 ///     queue.submit(RequestBuffer::reuse(completion.data, transfer_size))
 /// }
 /// ```
-/// 
+///
 /// ### Example (write to an endpoint)
 /// ```no_run
 /// use std::mem;
@@ -77,18 +77,18 @@ use super::{Completion, EndpointType, PlatformSubmit, TransferHandle, TransferRe
 /// # fn fill_data(_: &mut Vec<u8>) {}
 /// # fn data_confirmed_sent(_: usize) {}
 /// let mut queue = interface.bulk_out_queue(0x02);
-/// 
+///
 /// let n_transfers = 8;
 ///
 /// let mut next_buf = Vec::new();
-/// 
+///
 /// loop {
 ///     while queue.pending() < n_transfers {
 ///         let mut buf = mem::replace(&mut next_buf, Vec::new());
 ///         fill_data(&mut buf); // your function
 ///         queue.submit(buf);
 ///     }
-/// 
+///
 ///     let completion = block_on(queue.next_complete());
 ///     data_confirmed_sent(completion.data.actual_length()); // your function
 ///     next_buf = completion.data.reuse();
@@ -133,7 +133,7 @@ where
     }
 
     /// Submit a new transfer on the endpoint.
-    /// 
+    ///
     /// For an `IN` endpoint, pass a [`RequestBuffer`][`super::RequestBuffer`].\
     /// For an `OUT` endpoint, pass a [`Vec<u8>`].
     pub fn submit(&mut self, data: R) {
@@ -147,7 +147,7 @@ where
 
     /// Return a `Future` that waits for the next pending transfer to complete, and yields its
     /// buffer and status.
-    /// 
+    ///
     /// For an `IN` endpoint, the completion contains a [`Vec<u8>`].\
     /// For an `OUT` endpoint, the completion contains a [`ResponseBuffer`][`super::ResponseBuffer`].
     ///
@@ -173,7 +173,7 @@ where
     }
 
     /// Cancel all pending transfers.
-    /// 
+    ///
     /// They will still be returned from subsequent calls to `next_complete` so
     /// you can tell which were completed, partially-completed, or cancelled.
     pub fn cancel_all(&mut self) {