spi: Optimize send_slice

Author: GrantM11235

spi/src/lib.rs

@@ -94,6 +94,34 @@ where
 
         err
     }
+
+    #[inline]
+    fn send_slice(
+        &mut self,
+        data_or_command: display_interface::DataOrCommand,
+        slice: &[Self::Word],
+    ) -> Result<(), DisplayError> {
+        // Assert chip select pin
+        self.cs.set_low().map_err(|_| DisplayError::CSError)?;
+
+        // 1 = data, 0 = command
+        match data_or_command {
+            display_interface::DataOrCommand::Data => self.dc.set_high(),
+            display_interface::DataOrCommand::Command => self.dc.set_low(),
+        }
+        .map_err(|_| DisplayError::DCError)?;
+
+        // Send words over SPI
+        let err = self
+            .spi
+            .write(slice)
+            .map_err(|_| DisplayError::BusWriteError);
+
+        // Deassert chip select pin
+        self.cs.set_high().ok();
+
+        err
+    }
 }
 
 /// SPI display interface.
@@ -147,4 +175,23 @@ where
         // Send words over SPI
         send_u8_iter(&mut self.spi, iter)
     }
+
+    #[inline]
+    fn send_slice(
+        &mut self,
+        data_or_command: display_interface::DataOrCommand,
+        slice: &[Self::Word],
+    ) -> Result<(), DisplayError> {
+        // 1 = data, 0 = command
+        match data_or_command {
+            display_interface::DataOrCommand::Data => self.dc.set_high(),
+            display_interface::DataOrCommand::Command => self.dc.set_low(),
+        }
+        .map_err(|_| DisplayError::DCError)?;
+
+        // Send words over SPI
+        self.spi
+            .write(slice)
+            .map_err(|_| DisplayError::BusWriteError)
+    }
 }