Merge pull request #4970 from beeelias/feature/spi-bidi

Feature SPI Bidirectional Mode

2 files changed, 49 insertions, 0 deletions

diff --git a/embassy-stm32/CHANGELOG.md b/embassy-stm32/CHANGELOG.md
index 70c46b025..851c22afd 100644
--- a/embassy-stm32/CHANGELOG.md
+++ b/embassy-stm32/CHANGELOG.md
@@ -86,6 +86,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - fix: build script ensures EXTI2_TSC is listed as the IRQ of EXTI2 even if the PAC doesn't
 - feat: stm32/lcd: added implementation
 - change: add error messages to can timing calculations ([#4961](https://github.com/embassy-rs/embassy/pull/4961))
+- feat: stm32/spi bidirectional mode 
 - fix: stm32/i2c v2: add stop flag on stop received
 - fix: stm32l47*/stm32l48* adc analog pin setup
 
diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index abb80ed26..0048d5d21 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -54,6 +54,16 @@ pub enum BitOrder {
     MsbFirst,
 }
 
+/// SPI Direction.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Direction {
+    /// Transmit
+    Transmit,
+    /// Receive
+    Receive,
+}
+
 /// SPI configuration.
 #[non_exhaustive]
 #[derive(Copy, Clone)]
@@ -348,6 +358,20 @@ impl<'d, M: PeriMode, CM: CommunicationMode> Spi<'d, M, CM> {
         Ok(())
     }
 
+    /// Set SPI direction
+    #[cfg(any(spi_v1, spi_v2, spi_v3))]
+    pub fn set_direction(&mut self, dir: Option<Direction>) {
+        let (bidimode, bidioe) = match dir {
+            Some(Direction::Transmit) => (vals::Bidimode::BIDIRECTIONAL, vals::Bidioe::TRANSMIT),
+            Some(Direction::Receive) => (vals::Bidimode::BIDIRECTIONAL, vals::Bidioe::RECEIVE),
+            None => (vals::Bidimode::UNIDIRECTIONAL, vals::Bidioe::TRANSMIT),
+        };
+        self.info.regs.cr1().modify(|w| {
+            w.set_bidimode(bidimode);
+            w.set_bidioe(bidioe);
+        });
+    }
+
     /// Get current SPI configuration.
     pub fn get_current_config(&self) -> Config {
         #[cfg(any(spi_v1, spi_v2, spi_v3))]
@@ -708,6 +732,30 @@ impl<'d> Spi<'d, Async, Master> {
         )
     }
 
+    /// Create a new SPI driver, in bidirectional mode, specifically in tranmit mode    
+    #[cfg(any(spi_v1, spi_v2, spi_v3))]
+    pub fn new_bidi<T: Instance, #[cfg(afio)] A>(
+        peri: Peri<'d, T>,
+        sck: Peri<'d, if_afio!(impl SckPin<T, A>)>,
+        sdio: Peri<'d, if_afio!(impl MosiPin<T, A>)>,
+        tx_dma: Peri<'d, impl TxDma<T>>,
+        rx_dma: Peri<'d, impl RxDma<T>>,
+        config: Config,
+    ) -> Self {
+        let mut this = Self::new_inner(
+            peri,
+            new_pin!(sck, config.sck_af()),
+            new_pin!(sdio, AfType::output(OutputType::PushPull, config.gpio_speed)),
+            None,
+            None,
+            new_dma!(tx_dma),
+            new_dma!(rx_dma),
+            config,
+        );
+        this.set_direction(Some(Direction::Transmit));
+        this
+    }
+
     /// Create a new SPI driver, in TX-only mode, without SCK pin.
     ///
     /// This can be useful for bit-banging non-SPI protocols.