Moved BFPOWER drivers to Physical

node/src/lib.rs

@@ -2,7 +2,11 @@
 
 #[cfg(feature = "comms")]
 pub mod comms;
+pub mod spi;
 #[cfg(feature = "stm32")]
 pub mod stm32;
 
-pub use physical::CriticalError;
+pub use physical::CriticalError;
+
+pub const GPIO_ERROR_MSG: &'static str =
+    "Driver does not support GPIO pins with expected failure states";

node/src/spi.rs

@@ -0,0 +1,52 @@
+use crate::GPIO_ERROR_MSG;
+use embedded_hal::digital::OutputPin;
+use embedded_hal::spi;
+use embedded_hal::spi::SpiBus;
+
+/// End the SPI operation if the result was an error.
+/// This function will attempt to flush the SPI bus if the result being inspected was an error.
+/// If the flush fails, the flush error will be ignored and the original error will be returned.
+#[inline]
+pub fn end_spi_if_err<OkT, SpiT: SpiBus>(
+    slave_select: &mut impl OutputPin,
+    spi: &mut SpiT,
+    result: Result<OkT, <SpiT as spi::ErrorType>::Error>,
+) -> Result<OkT, <SpiT as spi::ErrorType>::Error> {
+    match result {
+        Ok(_) => result,
+        Err(_) => {
+            // Ignore flush error and return the original error
+            slave_select.set_high().expect(GPIO_ERROR_MSG);
+            let _ = spi.flush();
+            result
+        },
+    }
+}
+
+/// End the series of SPI operations and forward the error of the final operation if there was
+/// one. Error handling:
+/// * If there was an error in the SPI operation and an error flushing the bus, returns the original
+///   SPI error, not the bus error.
+/// * If there was not an error in the SPI operation but was an error flushing the bus, returns the
+///   bus flush error.
+/// * If there was an error in the SPI operation and no error flushing the bus, returns the original
+///   SPI error.
+#[inline]
+pub fn end_spi<OkT, SpiT: SpiBus>(
+    slave_select: &mut impl OutputPin,
+    spi: &mut SpiT,
+    result: Result<OkT, <SpiT as spi::ErrorType>::Error>,
+) -> Result<OkT, <SpiT as spi::ErrorType>::Error> {
+    match result {
+        Ok(_) => {
+            slave_select.set_high().expect(GPIO_ERROR_MSG);
+            spi.flush()?;
+            result
+        },
+        Err(_) => {
+            slave_select.set_high().expect(GPIO_ERROR_MSG);
+            let _ = spi.flush();
+            result
+        },
+    }
+}