Feature gate embedded-hal-bus atomic impls

Author: 9names

embedded-hal-bus/Cargo.toml

@@ -16,6 +16,7 @@ version = "0.2.0"
 
 [features]
 std = []
+atomic-device = []
 async = ["dep:embedded-hal-async"]
 defmt-03 = ["dep:defmt-03", "embedded-hal/defmt-03", "embedded-hal-async?/defmt-03"]
 
@@ -27,5 +28,5 @@ defmt-03 = { package = "defmt", version = "0.3", optional = true }
 portable-atomic = {version = "1", default-features = false}
 
 [package.metadata.docs.rs]
-features = ["std", "async"]
+features = ["std", "async", "atomic-device"]
 rustdoc-args = ["--cfg", "docsrs"]

embedded-hal-bus/src/i2c/mod.rs

@@ -8,5 +8,7 @@ mod mutex;
 pub use mutex::*;
 mod critical_section;
 pub use self::critical_section::*;
+#[cfg(feature = "atomic-device")]
 mod atomic;
+#[cfg(feature = "atomic-device")]
 pub use atomic::*;

embedded-hal-bus/src/spi/mod.rs

@@ -11,9 +11,11 @@ pub use refcell::*;
 mod mutex;
 #[cfg(feature = "std")]
 pub use mutex::*;
+#[cfg(feature = "atomic-device")]
 mod atomic;
 mod critical_section;
 mod shared;
+#[cfg(feature = "atomic-device")]
 pub use atomic::*;
 
 pub use self::critical_section::*;

embedded-hal-bus/src/util.rs

@@ -1,7 +1,9 @@
 //! Utilities shared by all bus types.
 
+#[allow(unused_imports)]
 use core::cell::UnsafeCell;
 
+#[cfg(feature = "atomic-device")]
 /// Cell type used by [`spi::AtomicDevice`](crate::spi::AtomicDevice) and [`i2c::AtomicDevice`](crate::i2c::AtomicDevice).
 ///
 /// To use `AtomicDevice`, you must wrap the bus with this struct, and then
@@ -10,10 +12,12 @@ pub struct AtomicCell<BUS> {
     pub(crate) bus: UnsafeCell<BUS>,
     pub(crate) busy: portable_atomic::AtomicBool,
 }
-
+#[cfg(feature = "atomic-device")]
 unsafe impl<BUS: Send> Send for AtomicCell<BUS> {}
+#[cfg(feature = "atomic-device")]
 unsafe impl<BUS: Send> Sync for AtomicCell<BUS> {}
 
+#[cfg(feature = "atomic-device")]
 impl<BUS> AtomicCell<BUS> {
     /// Create a new `AtomicCell`
     pub fn new(bus: BUS) -> Self {