DAC Improvements - Dual DAC support and DMA

Cargo.toml

@@ -17,7 +17,7 @@ stm32g4 = { version = "0.16.0", features = ["atomics"] }
 paste = "1.0"
 fugit = "0.3.7"
 stm32-usbd = { version = "0.7.0", optional = true }
-fixed = { version = "1.28.0", optional = true }
+fixed = { version = "1.28.0" }
 embedded-io = "0.6"
 
 [dependencies.cortex-m]
@@ -106,7 +106,7 @@ defmt = [
     "embedded-io/defmt-03",
     "embedded-test/defmt",
 ]
-cordic = ["dep:fixed"]
+cordic = []
 adc3 = []
 adc4 = []
 adc5 = []

src/dac.rs

@@ -9,12 +9,27 @@ use core::marker::PhantomData;
 use core::mem::MaybeUninit;
 use core::ops::Deref;
 
+use crate::dac::trigger::DacTriggerSource;
+use crate::dma::mux::DmaMuxResources;
+use crate::dma::traits::TargetAddress;
+use crate::dma::MemoryToPeripheral;
 use crate::gpio::{Analog, PA4, PA5, PA6};
 use crate::pac;
 use crate::rcc::{self, *};
 use crate::stm32::dac1::mcr::HFSEL;
 use embedded_hal::delay::DelayNs;
 
+pub mod dual;
+pub mod format;
+pub mod trigger;
+
+/// DAC Channel identifier
+#[repr(u8)]
+pub enum DacChannel {
+    Ch1 = 0,
+    Ch2 = 1,
+}
+
 pub trait DacOut<V> {
     fn get_value(&mut self) -> V;
     fn set_value(&mut self, val: V);
@@ -137,6 +152,7 @@ impl SawtoothConfig {
 
 /// Enabled DAC (type state)
 pub struct Enabled;
+pub struct EnabledDma;
 // / Enabled DAC without output buffer (type state)
 //pub struct EnabledUnbuffered;
 /// Enabled DAC wave generator for triangle or noise wave form (type state)
@@ -282,6 +298,43 @@ impl<DAC: Instance, const CH: u8, const MODE_BITS: u8> DacCh<DAC, CH, MODE_BITS,
         DacCh::new()
     }
 
+    /// Enable trigger for the channel using the trigger source provided as a generic type parameter.
+    ///
+    /// This will cause the DAC to copy the hold register to the output register
+    /// when the trigger is raised by a timer signal or external interrupt,
+    /// and issue a new DMA request if DMA is enabled.
+    #[inline(always)]
+    pub fn enable_trigger<Source>(&mut self)
+    where
+        Source: DacTriggerSource<DAC>,
+    {
+        // Set the TSELx bits to the trigger signal identifier from the DacTriggerSource impl
+        let dac = unsafe { &(*DAC::ptr()) };
+        if CH == DacChannel::Ch1 as u8 {
+            unsafe { dac.cr().modify(|_, w| w.tsel1().bits(Source::SIGNAL)) };
+        }
+        if CH == DacChannel::Ch2 as u8 {
+            unsafe { dac.cr().modify(|_, w| w.tsel2().bits(Source::SIGNAL)) };
+        }
+
+        // Enable the TENx flag in DAC CR
+        dac.cr().modify(|_, w| w.ten(CH).set_bit());
+    }
+
+    pub fn enable_dma(self, rcc: &mut Rcc) -> DacCh<DAC, CH, MODE_BITS, EnabledDma> {
+        let dac = unsafe { &(*DAC::ptr()) };
+
+        dac.mcr()
+            .modify(|_, w| unsafe { w.hfsel().variant(hfsel(rcc)).mode(CH).bits(MODE_BITS) });
+
+        dac.cr()
+            .modify(|_, w| w.dmaen(CH).set_bit().en(CH).set_bit());
+
+        dac.dhr12r(CH as usize).write(|w| unsafe { w.bits(0) });
+
+        DacCh::new()
+    }
+
     pub fn enable_generator(
         self,
         config: GeneratorConfig,
@@ -450,7 +503,16 @@ impl<DAC: Instance, const CH: u8, const MODE_BITS: u8>
     }
 }
 
-pub trait DacExt: Sized {
+/// DMA state implementation
+impl<DAC: Instance, const CH: u8, const MODE_BITS: u8> DacCh<DAC, CH, MODE_BITS, EnabledDma> {
+    pub fn start(&mut self, val: u16) {
+        let dac = unsafe { &(*DAC::ptr()) };
+        dac.dhr12r(CH as usize)
+            .write(|w| unsafe { w.bits(val as u32) });
+    }
+}
+
+pub trait DacExt: Instance + Sized {
     fn constrain<PINS>(self, pins: PINS, rcc: &mut Rcc) -> PINS::Output
     where
         PINS: Pins<Self>;
@@ -478,3 +540,28 @@ macro_rules! impl_dac_ext {
 }
 
 impl_dac_ext!(pac::DAC1, pac::DAC2, pac::DAC3, pac::DAC4,);
+
+macro_rules! impl_dac_dma {
+    ($($DAC:ty, $channel:expr, $dmamux:ident)+) => {$(
+        unsafe impl<const MODE_BITS: u8, ED> TargetAddress<MemoryToPeripheral>
+            for DacCh<$DAC, $channel, MODE_BITS, ED>
+            where $DAC: Instance
+        {
+            type MemSize = u32;
+            const REQUEST_LINE: Option<u8> = Some(DmaMuxResources::$dmamux as u8);
+
+            fn address(&self) -> u32 {
+                let dac = unsafe { &(*<$DAC>::ptr()) };
+                dac.dhr12r($channel as usize) as *const _ as u32
+            }
+        }
+    )+};
+}
+
+impl_dac_dma!(pac::DAC1, 0, DAC1_CH1);
+impl_dac_dma!(pac::DAC1, 1, DAC1_CH2);
+impl_dac_dma!(pac::DAC2, 0, DAC2_CH1);
+impl_dac_dma!(pac::DAC3, 0, DAC3_CH1);
+impl_dac_dma!(pac::DAC3, 1, DAC3_CH2);
+impl_dac_dma!(pac::DAC4, 0, DAC4_CH1);
+impl_dac_dma!(pac::DAC4, 1, DAC4_CH2);

src/dac/dual.rs

@@ -0,0 +1,191 @@
+#![deny(missing_docs)]
+
+//! Dual DAC
+//!
+//! This module provides access to the dual DAC channels of the STM32G4 series microcontrollers.
+//! It allows for simultaneous access to both DAC channels and supports DMA transfers.
+//!
+
+use core::marker::PhantomData;
+
+use embedded_hal::delay::DelayNs;
+
+use crate::dac::{
+    format::SampleFormat, trigger::DacTriggerSource, DacCh, DacChannel, Disabled, Enabled,
+    Instance, M_EXT_PIN,
+};
+use crate::dac::{hfsel, DacExt as _, Pins};
+
+use crate::dac::format::{self, ToDac as _};
+use crate::dma::mux::DmaMuxResources;
+use crate::dma::traits::TargetAddress;
+use crate::dma::MemoryToPeripheral;
+use crate::rcc::Rcc;
+
+/// Extension trait for [`Instance`] to create a [`DualDac`] from the given pins and RCC.
+pub trait DualDacExt: Instance + Sized {
+    /// Create a dual DAC instance from the given pins and RCC.
+    ///
+    /// DAC calibration is performed before enabling the DAC, so
+    /// a DelayNs implementation is required.
+    ///
+    /// This uses the dual hold registers (DHR12xD, DHR8RD) and
+    /// can write to both DAC channels simultaneously with DMA support.
+    fn into_dual<F: SampleFormat, PINS>(
+        self,
+        pins: PINS,
+        rcc: &mut Rcc,
+        delay: &mut impl DelayNs,
+    ) -> DualDac<Self, F, Disabled>
+    where
+        PINS: Pins<
+            Self,
+            Output = (
+                DacCh<Self, 0, M_EXT_PIN, Disabled>,
+                DacCh<Self, 1, M_EXT_PIN, Disabled>,
+            ),
+        >;
+}
+
+/// Dual DAC handle
+pub struct DualDac<DAC: Instance, F: SampleFormat, State> {
+    _ch1: DacCh<DAC, 0, M_EXT_PIN, State>,
+    _ch2: DacCh<DAC, 1, M_EXT_PIN, State>,
+    _phantom: PhantomData<F>,
+}
+
+impl<DAC: Instance, F: SampleFormat> DualDac<DAC, F, Disabled> {
+    /// Enable DMA double mode for the specified channel.
+    /// This creates a single DMA request for every
+    /// two external hardware triggers (excluding software triggers).
+    #[inline(always)]
+    pub fn enable_dma_double(&mut self, channel: u8, enable: bool) {
+        let dac = unsafe { &(*DAC::ptr()) };
+        dac.mcr().modify(|_, w| w.dmadouble(channel).bit(enable));
+    }
+
+    /// Enable DMA for the specified channel
+    #[inline(always)]
+    pub fn enable_dma(&mut self, channel: DacChannel, enable: bool) {
+        let dac = unsafe { &(*DAC::ptr()) };
+        dac.cr().modify(|_, w| w.dmaen(channel as u8).bit(enable));
+    }
+
+    /// Enable trigger for the specified channel and the [`DacTriggerSource`]
+    /// provided as a generic type parameter.
+    ///
+    /// This will cause the DAC to copy the hold register to the output register
+    /// when the trigger is raised by a timer signal or external interrupt,
+    /// and issue a new DMA request if DMA is enabled.
+    #[inline(always)]
+    pub fn enable_trigger<Source>(&mut self, channel: DacChannel)
+    where
+        Source: DacTriggerSource<DAC>,
+    {
+        // Set the TSELx bits to the trigger signal identifier from the DacTriggerSource impl
+        let dac = unsafe { &(*DAC::ptr()) };
+        match channel {
+            DacChannel::Ch1 => {
+                unsafe { dac.cr().modify(|_, w| w.tsel1().bits(Source::SIGNAL)) };
+            }
+            DacChannel::Ch2 => {
+                unsafe { dac.cr().modify(|_, w| w.tsel2().bits(Source::SIGNAL)) };
+            }
+        }
+
+        // Enable the TENx flag in DAC CR
+        dac.cr().modify(|_, w| w.ten(channel as u8).set_bit());
+    }
+
+    /// Enable both DAC channels
+    #[inline(always)]
+    pub fn enable(self) -> DualDac<DAC, F, Enabled> {
+        let dac = unsafe { &(*DAC::ptr()) };
+
+        dac.cr().modify(|_, w| w.en(0).set_bit().en(1).set_bit());
+        DualDac {
+            _ch1: DacCh::new(),
+            _ch2: DacCh::new(),
+            _phantom: PhantomData,
+        }
+    }
+}
+
+impl<DAC: Instance, F: SampleFormat> DualDac<DAC, F, Enabled> {
+    /// Write to both DAC channels simultaneously.
+    #[inline(always)]
+    pub fn set_channels(&mut self, ch1: F::Scalar, ch2: F::Scalar) {
+        let dac = unsafe { &(*DAC::ptr()) };
+
+        let bits = (ch2.to_dac() as u32) << F::CH2_SHIFT | (ch1.to_dac() as u32) & F::CH1_MASK;
+
+        match F::DEPTH {
+            format::SampleDepth::Bits12(alignment) => match alignment {
+                format::Alignment::Left => {
+                    dac.dhr12ld().write(|w| unsafe { w.bits(bits) });
+                }
+                format::Alignment::Right => {
+                    dac.dhr12rd().write(|w| unsafe { w.bits(bits) });
+                }
+            },
+            format::SampleDepth::Bits8 => {
+                // NOTE: 8-bit is always right aligned
+                dac.dhr8rd().write(|w| unsafe { w.bits(bits) });
+            }
+        }
+    }
+}
+
+impl<DAC: Instance> DualDacExt for DAC {
+    fn into_dual<F: SampleFormat, PINS>(
+        self,
+        pins: PINS,
+        rcc: &mut Rcc,
+        delay: &mut impl DelayNs,
+    ) -> DualDac<DAC, F, Disabled>
+    where
+        PINS: Pins<
+            Self,
+            Output = (
+                DacCh<Self, 0, M_EXT_PIN, Disabled>,
+                DacCh<Self, 1, M_EXT_PIN, Disabled>,
+            ),
+        >,
+    {
+        let (ch1, ch2) = self.constrain(pins, rcc);
+
+        let ch1 = ch1.calibrate_buffer(delay);
+        let ch2 = ch2.calibrate_buffer(delay);
+
+        // Configure HFSEL
+        let dac = unsafe { &(*DAC::ptr()) };
+        let hfsel = hfsel(rcc);
+        dac.mcr().modify(|_, w| w.hfsel().variant(hfsel));
+
+        // Apply the format configuration to both channels
+        for channel in 0..2 {
+            dac.mcr().modify(|_, w| w.sinformat(channel).bit(F::SIGNED));
+        }
+
+        DualDac {
+            _ch1: ch1,
+            _ch2: ch2,
+            _phantom: PhantomData,
+        }
+    }
+}
+
+unsafe impl<DAC: Instance, F: SampleFormat, State> TargetAddress<MemoryToPeripheral>
+    for DualDac<DAC, F, State>
+{
+    type MemSize = u32;
+    const REQUEST_LINE: Option<u8> = Some(DmaMuxResources::DAC1_CH1 as u8);
+
+    fn address(&self) -> u32 {
+        let dac = unsafe { &(*DAC::ptr()) };
+        match F::SIGNED {
+            true => dac.dhr12ld() as *const _ as u32,
+            false => dac.dhr12rd() as *const _ as u32,
+        }
+    }
+}