eh: update set_config and add get_config

embassy-embedded-hal/src/lib.rs

@@ -26,6 +26,18 @@ pub trait SetConfig {
     /// The configuration type used by this driver.
     type Config;
 
+    /// The error type that can occur if `set_config` fails.
+    type ConfigError;
+
     /// Set the configuration of the driver.
-    fn set_config(&mut self, config: &Self::Config);
+    fn set_config(&mut self, config: &Self::Config) -> Result<(), Self::ConfigError>;
+}
+
+/// Get the configuration of a peripheral driver.
+pub trait GetConfig {
+    /// The configuration type used by this driver.
+    type Config;
+
+    /// Get the configuration of the driver.
+    fn get_config(&self) -> Self::Config;
 }

embassy-embedded-hal/src/shared_bus/asynch/i2c.rs

@@ -125,14 +125,14 @@ where
 {
     async fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
         let mut bus = self.bus.lock().await;
-        bus.set_config(&self.config);
+        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
         bus.read(address, buffer).await.map_err(I2cDeviceError::I2c)?;
         Ok(())
     }
 
     async fn write(&mut self, address: u8, bytes: &[u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
         let mut bus = self.bus.lock().await;
-        bus.set_config(&self.config);
+        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
         bus.write(address, bytes).await.map_err(I2cDeviceError::I2c)?;
         Ok(())
     }
@@ -144,7 +144,7 @@ where
         rd_buffer: &mut [u8],
     ) -> Result<(), I2cDeviceError<BUS::Error>> {
         let mut bus = self.bus.lock().await;
-        bus.set_config(&self.config);
+        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
         bus.write_read(address, wr_buffer, rd_buffer)
             .await
             .map_err(I2cDeviceError::I2c)?;
@@ -153,7 +153,7 @@ where
 
     async fn transaction(&mut self, address: u8, operations: &mut [i2c::Operation<'_>]) -> Result<(), Self::Error> {
         let mut bus = self.bus.lock().await;
-        bus.set_config(&self.config);
+        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
         bus.transaction(address, operations)
             .await
             .map_err(I2cDeviceError::I2c)?;

embassy-embedded-hal/src/shared_bus/asynch/spi.rs

@@ -130,7 +130,7 @@ where
 {
     async fn transaction(&mut self, operations: &mut [spi::Operation<'_, u8>]) -> Result<(), Self::Error> {
         let mut bus = self.bus.lock().await;
-        bus.set_config(&self.config);
+        bus.set_config(&self.config).map_err(|_| SpiDeviceError::Config)?;
         self.cs.set_low().map_err(SpiDeviceError::Cs)?;
 
         let op_res: Result<(), BUS::Error> = try {

embassy-embedded-hal/src/shared_bus/blocking/i2c.rs

@@ -148,7 +148,7 @@ where
     fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), Self::Error> {
         self.bus.lock(|bus| {
             let mut bus = bus.borrow_mut();
-            bus.set_config(&self.config);
+            bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
             bus.read(address, buffer).map_err(I2cDeviceError::I2c)
         })
     }
@@ -156,7 +156,7 @@ where
     fn write(&mut self, address: u8, bytes: &[u8]) -> Result<(), Self::Error> {
         self.bus.lock(|bus| {
             let mut bus = bus.borrow_mut();
-            bus.set_config(&self.config);
+            bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
             bus.write(address, bytes).map_err(I2cDeviceError::I2c)
         })
     }
@@ -164,7 +164,7 @@ where
     fn write_read(&mut self, address: u8, wr_buffer: &[u8], rd_buffer: &mut [u8]) -> Result<(), Self::Error> {
         self.bus.lock(|bus| {
             let mut bus = bus.borrow_mut();
-            bus.set_config(&self.config);
+            bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
             bus.write_read(address, wr_buffer, rd_buffer)
                 .map_err(I2cDeviceError::I2c)
         })

embassy-embedded-hal/src/shared_bus/blocking/spi.rs

@@ -163,7 +163,7 @@ where
     fn transaction(&mut self, operations: &mut [Operation<'_, u8>]) -> Result<(), Self::Error> {
         self.bus.lock(|bus| {
             let mut bus = bus.borrow_mut();
-            bus.set_config(&self.config);
+            bus.set_config(&self.config).map_err(|_| SpiDeviceError::Config)?;
             self.cs.set_low().map_err(SpiDeviceError::Cs)?;
 
             let op_res = operations.iter_mut().try_for_each(|op| match op {

embassy-embedded-hal/src/shared_bus/mod.rs

@@ -14,6 +14,8 @@ pub mod blocking;
 pub enum I2cDeviceError<BUS> {
     /// An operation on the inner I2C bus failed.
     I2c(BUS),
+    /// Configuration of the inner I2C bus failed.
+    Config,
 }
 
 impl<BUS> i2c::Error for I2cDeviceError<BUS>
@@ -23,6 +25,7 @@ where
     fn kind(&self) -> i2c::ErrorKind {
         match self {
             Self::I2c(e) => e.kind(),
+            Self::Config => i2c::ErrorKind::Other,
         }
     }
 }
@@ -38,6 +41,8 @@ pub enum SpiDeviceError<BUS, CS> {
     Cs(CS),
     /// DelayUs operations are not supported when the `time` Cargo feature is not enabled.
     DelayUsNotSupported,
+    /// The SPI bus could not be configured.
+    Config,
 }
 
 impl<BUS, CS> spi::Error for SpiDeviceError<BUS, CS>
@@ -50,6 +55,7 @@ where
             Self::Spi(e) => e.kind(),
             Self::Cs(_) => spi::ErrorKind::Other,
             Self::DelayUsNotSupported => spi::ErrorKind::Other,
+            Self::Config => spi::ErrorKind::Other,
         }
     }
 }