Created a first draft of the I3C trait.

Cargo.toml

@@ -6,6 +6,7 @@ members = [
     "embedded-hal-async",
     "embedded-hal-nb",
     "embedded-hal-bus",
+    "embedded-hal-i3c",
     "embedded-can",
     "embedded-io",
     "embedded-io-async",

embedded-hal-i3c/Cargo.toml

@@ -0,0 +1,30 @@
+
+[package]
+authors = [
+  "The Embedded HAL Team and Contributors <embedded-hal@teams.rust-embedded.org>",
+]
+categories = ["embedded", "hardware-support", "no-std"]
+description = "Traits for abstracting I3C Databusses"
+documentation = "https://docs.rs/embedded-hal-i3c"
+edition = "2021"
+rust-version = "1.81"
+keywords = ["hal", "IO"]
+license = "MIT OR Apache-2.0"
+name = "embedded-hal-i3c"
+readme = "README.md"
+repository = "https://github.com/rust-embedded/embedded-hal"
+version = "0.1.0"
+
+[features]
+async = ["dep:embedded-hal-async"]
+# Derive `defmt::Format` from `defmt` 0.3 for enums and structs. See https://github.com/knurling-rs/defmt for more info
+defmt-03 = ["dep:defmt-03", "embedded-hal/defmt-03", "embedded-hal-async?/defmt-03"]
+
+[dependencies]
+embedded-hal = { version = "1.0.0", path = "../embedded-hal" }
+embedded-hal-async = { version = "1.0.0", path = "../embedded-hal-async", optional = true }
+defmt-03 = { package = "defmt", version = "0.3", optional = true }
+
+[package.metadata.docs.rs]
+features = ["async"]
+rustdoc-args = ["--cfg", "docsrs"]

embedded-hal-i3c/src/lib.rs

@@ -0,0 +1,80 @@
+pub use embedded_hal::i2c::Operation;
+
+/// I3C error.
+pub trait Error: core::fmt::Debug {
+    /// Convert error to a generic I3C error kind.
+    ///
+    /// By using this method, I3C errors freely defined by HAL implementations
+    /// can be converted to a set of generic I3C errors upon which generic
+    /// code can act.
+    fn kind(&self) -> ErrorKind;
+}
+
+impl Error for core::convert::Infallible {
+    #[inline]
+    fn kind(&self) -> ErrorKind {
+        match *self {}
+    }
+}
+
+#[non_exhaustive]
+pub enum ErrorKind {
+    Bus,
+    ArbitrationLoss,
+    Ovverun,
+    Other,
+}
+
+/// I3C error type trait.
+///
+/// This just defines the error type, to be used by the other traits.
+pub trait ErrorType {
+    type Error: Error;
+}
+
+impl<T: ErrorType + ?Sized> ErrorType for &mut T {
+    type Error = T::Error;
+}
+
+pub trait I3c<S: SpeedMode = Sdr>: ErrorType {
+    // Here we also add read, write read_write like I2C removed for brevity
+
+    /// Execute the provided operations on the I3C bus.
+    ///
+    /// Transaction contract:
+    /// - Before executing the first operation an ST is sent automatically. This is followed by SAD+R/W as appropriate.
+    /// - After the first time the address is send the bus switches to the specified speed
+    /// - Data from adjacent operations of the same type are sent after each other without an SP or SR.
+    /// - Between adjacent operations of a different type an SR and SAD+R/W is sent.
+    /// - After executing the last operation an SP is sent automatically.
+    /// - If the last operation is a `Read` the master does not send an acknowledge for the last byte.
+    ///
+    /// - `ST` = start condition
+    /// - `SAD+R/W` = slave address followed by bit 1 to indicate reading or 0 to indicate writing
+    /// - `SR` = repeated start condition
+    /// - `SP` = stop condition
+    fn transaction(
+        &mut self,
+        address: u8,
+        operations: &mut [Operation<'_>],
+    ) -> Result<(), Self::Error>;
+}
+
+trait Sealed {}
+
+#[allow(private_bounds)]
+pub trait SpeedMode: Sealed + 'static {}
+
+/// Single data rate
+pub struct Sdr {}
+
+impl Sealed for Sdr {}
+
+impl SpeedMode for Sdr {}
+
+/// Double data rate
+pub struct Ddr {}
+
+impl Sealed for Ddr {}
+
+impl SpeedMode for Ddr {}