mmc: use new-types for the card mode

Adds the `CardMode` enum to represent the device mode for a SD/MMC
perpipheral.

Author: rmsyn

embedded-hal/src/mmc.rs

@@ -1,6 +1,7 @@
 //! Types and traits for SD/MMC peripherals.
 
 mod bus_width;
+mod card_mode;
 mod card_type;
 mod fifo_status;
 mod reset;
@@ -10,6 +11,7 @@ pub mod response;
 pub mod tuning;
 
 pub use bus_width::BusWidth;
+pub use card_mode::CardMode;
 pub use card_type::CardType;
 pub use fifo_status::FifoStatus;
 pub use reset::Reset;
@@ -23,11 +25,11 @@ pub trait MmcOps {
     /// Associated error type for the SD/MMC trait.
     type Error;
 
-    /// Gets whether the device [CardType].
+    /// Gets the device [CardType].
     fn card_type(&self) -> CardType;
 
-    /// Gets whether the device is configured for SPI mode.
-    fn is_spi(&self) -> bool;
+    /// Gets the device [CardMode].
+    fn card_mode(&self) -> CardMode;
 
     /// Performs bus setup for the SD/MMC device.
     fn setup_bus(&mut self) -> Result<(), Self::Error>;

embedded-hal/src/mmc/card_mode.rs

@@ -0,0 +1,39 @@
+/// Represents the card mode of the peripheral.
+#[repr(u8)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum CardMode {
+    /// Represents a device in SD mode.
+    Sd,
+    /// Represents a device in SDIO mode.
+    Sdio,
+    /// Represents a device in SPI mode.
+    Spi,
+}
+
+impl CardMode {
+    /// Creates a new [CardMode].
+    pub const fn new() -> Self {
+        Self::Sd
+    }
+
+    /// Convenience function to get if the [CardMode] is SD.
+    pub const fn is_sd(&self) -> bool {
+        matches!(self, Self::Sd)
+    }
+
+    /// Convenience function to get if the [CardMode] is SDIO.
+    pub const fn is_sdio(&self) -> bool {
+        matches!(self, Self::Sdio)
+    }
+
+    /// Convenience function to get if the [CardMode] is SPI.
+    pub const fn is_spi(&self) -> bool {
+        matches!(self, Self::Spi)
+    }
+}
+
+impl Default for CardMode {
+    fn default() -> Self {
+        Self::new()
+    }
+}