mspm0: blocking uart driver

embassy-mspm0/Cargo.toml

@@ -39,6 +39,7 @@ embedded-hal = { version = "1.0" }
 embedded-hal-async = { version = "1.0" }
 
 defmt = { version = "0.3", optional = true }
+fixed = "1.29"
 log = { version = "0.4.14", optional = true }
 cortex-m-rt = ">=0.6.15,<0.8"
 cortex-m = "0.7.6"

embassy-mspm0/build.rs

@@ -381,7 +381,7 @@ fn generate_peripheral_instances() -> TokenStream {
         // Will be filled in when uart implementation is finished
         let _ = peri;
         let tokens = match peripheral.kind {
-            // "uart" => Some(quote! { impl_uart_instance!(#peri); }),
+            "uart" => Some(quote! { impl_uart_instance!(#peri); }),
             _ => None,
         };
 
@@ -412,10 +412,10 @@ fn generate_pin_trait_impls() -> TokenStream {
             let _ = pf;
 
             let tokens = match key {
-                // ("uart", "TX") => Some(quote! { impl_uart_tx_pin!(#peri, #pin_name, #pf); }),
-                // ("uart", "RX") => Some(quote! { impl_uart_rx_pin!(#peri, #pin_name, #pf); }),
-                // ("uart", "CTS") => Some(quote! { impl_uart_cts_pin!(#peri, #pin_name, #pf); }),
-                // ("uart", "RTS") => Some(quote! { impl_uart_rts_pin!(#peri, #pin_name, #pf); }),
+                ("uart", "TX") => Some(quote! { impl_uart_tx_pin!(#peri, #pin_name, #pf); }),
+                ("uart", "RX") => Some(quote! { impl_uart_rx_pin!(#peri, #pin_name, #pf); }),
+                ("uart", "CTS") => Some(quote! { impl_uart_cts_pin!(#peri, #pin_name, #pf); }),
+                ("uart", "RTS") => Some(quote! { impl_uart_rts_pin!(#peri, #pin_name, #pf); }),
                 _ => None,
             };
 

embassy-mspm0/src/gpio.rs

@@ -836,6 +836,31 @@ impl<'d> embedded_hal_async::digital::Wait for OutputOpenDrain<'d> {
     }
 }
 
+#[derive(Copy, Clone)]
+pub struct PfType {
+    pull: Pull,
+    input: bool,
+    invert: bool,
+}
+
+impl PfType {
+    pub const fn input(pull: Pull, invert: bool) -> Self {
+        Self {
+            pull,
+            input: true,
+            invert,
+        }
+    }
+
+    pub const fn output(pull: Pull, invert: bool) -> Self {
+        Self {
+            pull,
+            input: false,
+            invert,
+        }
+    }
+}
+
 /// The pin function to disconnect peripherals from the pin.
 ///
 /// This is also the pin function used to connect to analog peripherals, such as an ADC.
@@ -907,6 +932,40 @@ pub(crate) trait SealedPin {
         (self.pin_port() % 32) as usize
     }
 
+    #[inline]
+    fn set_as_analog(&self) {
+        let pincm = pac::IOMUX.pincm(self._pin_cm() as usize);
+
+        pincm.modify(|w| {
+            w.set_pf(DISCONNECT_PF);
+            w.set_pipu(false);
+            w.set_pipd(false);
+        });
+    }
+
+    fn update_pf(&self, ty: PfType) {
+        let pincm = pac::IOMUX.pincm(self._pin_cm() as usize);
+        let pf = pincm.read().pf();
+
+        set_pf(self._pin_cm() as usize, pf, ty);
+    }
+
+    fn set_as_pf(&self, pf: u8, ty: PfType) {
+        set_pf(self._pin_cm() as usize, pf, ty)
+    }
+
+    /// Set the pin as "disconnected", ie doing nothing and consuming the lowest
+    /// amount of power possible.
+    ///
+    /// This is currently the same as [`Self::set_as_analog()`] but is semantically different
+    /// really. Drivers should `set_as_disconnected()` pins when dropped.
+    ///
+    /// Note that this also disables the internal weak pull-up and pull-down resistors.
+    #[inline]
+    fn set_as_disconnected(&self) {
+        self.set_as_analog();
+    }
+
     #[inline]
     fn block(&self) -> gpio::Gpio {
         match self.pin_port() / 32 {
@@ -920,6 +979,18 @@ pub(crate) trait SealedPin {
     }
 }
 
+#[inline(never)]
+fn set_pf(pincm: usize, pf: u8, ty: PfType) {
+    pac::IOMUX.pincm(pincm).modify(|w| {
+        w.set_pf(pf);
+        w.set_pc(true);
+        w.set_pipu(ty.pull == Pull::Up);
+        w.set_pipd(ty.pull == Pull::Down);
+        w.set_inena(ty.input);
+        w.set_inv(ty.invert);
+    });
+}
+
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 struct InputFuture<'d> {
     pin: Peri<'d, AnyPin>,

embassy-mspm0/src/lib.rs

@@ -5,8 +5,12 @@
 // This mod MUST go first, so that the others see its macros.
 pub(crate) mod fmt;
 
+// This must be declared early as well for
+mod macros;
+
 pub mod gpio;
 pub mod timer;
+pub mod uart;
 
 /// Operating modes for peripherals.
 pub mod mode {

embassy-mspm0/src/macros.rs

@@ -0,0 +1,9 @@
+#![macro_use]
+
+macro_rules! new_pin {
+    ($name: ident, $pf_type: expr) => {{
+        let pin = $name;
+        pin.set_as_pf(pin.pf_num(), $pf_type);
+        Some(pin.into())
+    }};
+}