Add EH 0.2 impls + example docs

1 files changed, 60 insertions, 0 deletions

diff --git a/embassy-embedded-hal/src/shared_bus/blocking/spi.rs b/embassy-embedded-hal/src/shared_bus/blocking/spi.rs
index c08bcbf62..81cf97457 100644
--- a/embassy-embedded-hal/src/shared_bus/blocking/spi.rs
+++ b/embassy-embedded-hal/src/shared_bus/blocking/spi.rs
@@ -1,4 +1,23 @@
 //! Blocking shared SPI bus
+//!
+//! # Example (nrf52)
+//!
+//! ```rust
+//! use embassy_embedded_hal::shared_bus::blocking::spi::SpiBusDevice;
+//! use embassy::blocking_mutex::{NoopMutex, raw::NoopRawMutex};
+//!
+//! static SPI_BUS: Forever<NoopMutex<RefCell<Spim<SPI3>>>> = Forever::new();
+//! let irq = interrupt::take!(SPIM3);
+//! let spi = Spim::new_txonly(p.SPI3, irq, p.P0_15, p.P0_18, Config::default());
+//! let spi_bus = NoopMutex::new(RefCell::new(spi));
+//! let spi_bus = SPI_BUS.put(spi_bus);
+//!
+//! // Device 1, using embedded-hal compatible driver for ST7735 LCD display
+//! let cs_pin1 = Output::new(p.P0_24, Level::Low, OutputDrive::Standard);
+//! let spi_dev1 = SpiBusDevice::new(spi_bus, cs_pin1);
+//! let display1 = ST7735::new(spi_dev1, dc1, rst1, Default::default(), false, 160, 128);
+//! ```
+
 use core::cell::RefCell;
 
 use embassy::blocking_mutex::raw::RawMutex;
@@ -55,3 +74,44 @@ where
         })
     }
 }
+
+impl<'d, M, BUS, CS, BusErr, CsErr> embedded_hal_02::blocking::spi::Transfer<u8> for SpiBusDevice<'_, M, BUS, CS>
+where
+    M: RawMutex,
+    BUS: embedded_hal_02::blocking::spi::Transfer<u8, Error = BusErr>,
+    CS: OutputPin<Error = CsErr>,
+{
+    type Error = SpiBusDeviceError<BusErr, CsErr>;
+    fn transfer<'w>(&mut self, words: &'w mut [u8]) -> Result<&'w [u8], Self::Error> {
+        self.bus.lock(|bus| {
+            let mut bus = bus.borrow_mut();
+            self.cs.set_low().map_err(SpiBusDeviceError::Cs)?;
+            let f_res = bus.transfer(words);
+            let cs_res = self.cs.set_high();
+            let f_res = f_res.map_err(SpiBusDeviceError::Spi)?;
+            cs_res.map_err(SpiBusDeviceError::Cs)?;
+            Ok(f_res)
+        })
+    }
+}
+
+impl<'d, M, BUS, CS, BusErr, CsErr> embedded_hal_02::blocking::spi::Write<u8> for SpiBusDevice<'_, M, BUS, CS>
+where
+    M: RawMutex,
+    BUS: embedded_hal_02::blocking::spi::Write<u8, Error = BusErr>,
+    CS: OutputPin<Error = CsErr>,
+{
+    type Error = SpiBusDeviceError<BusErr, CsErr>;
+
+    fn write(&mut self, words: &[u8]) -> Result<(), Self::Error> {
+        self.bus.lock(|bus| {
+            let mut bus = bus.borrow_mut();
+            self.cs.set_low().map_err(SpiBusDeviceError::Cs)?;
+            let f_res = bus.write(words);
+            let cs_res = self.cs.set_high();
+            let f_res = f_res.map_err(SpiBusDeviceError::Spi)?;
+            cs_res.map_err(SpiBusDeviceError::Cs)?;
+            Ok(f_res)
+        })
+    }
+}