Merge pull request #113 from hardfau18/dac

added dac support

Author: hannobraun

Cargo.toml

@@ -25,7 +25,7 @@ micromath = "1.0.0"
 synopsys-usb-otg = { version = "0.2.3", features = ["cortex-m"], optional = true }
 stm32-fmc = { version = "0.2.0", features = ["sdram"], optional = true }
 rand_core = "0.5.1"
-bxcan = "0.4"
+bxcan = "0.5"
 
 [dependencies.bare-metal]
 version = "0.2.4"

src/dac.rs

@@ -0,0 +1,103 @@
+use crate::gpio::{
+    gpioa::{PA4, PA5},
+    Analog,
+};
+use crate::pac::{DAC, RCC};
+
+/// DAC Errors
+#[derive(Debug)]
+pub enum Error {
+    /// general
+    error,
+}
+
+use core::mem;
+
+pub struct C1;
+pub struct C2;
+
+pub trait DacOut<V> {
+    fn set_value(&mut self, val: V);
+    fn get_value(&mut self) -> V;
+}
+
+pub trait DacPin {
+    fn enable(&mut self);
+}
+
+pub trait Pins<DAC> {
+    type Output;
+}
+
+impl Pins<DAC> for PA4<Analog> {
+    type Output = C1;
+}
+
+impl Pins<DAC> for PA5<Analog> {
+    type Output = C2;
+}
+
+impl Pins<DAC> for (PA4<Analog>, PA5<Analog>) {
+    type Output = (C1, C2);
+}
+
+pub fn dac<PINS>(_dac: DAC, _pins: PINS) -> PINS::Output
+where
+    PINS: Pins<DAC>,
+{
+    unsafe {
+        // NOTE(unsafe) this reference will only be used for atomic writes with no side effects.
+        let rcc = &(*RCC::ptr());
+        rcc.apb1enr.modify(|_, w| w.dacen().set_bit());
+
+        // Stall the pipeline to work around erratum 2.1.13 (DM00037591)
+        cortex_m::asm::dsb();
+
+        rcc.apb1rstr.write(|w| w.dacrst().set_bit());
+        rcc.apb1rstr.write(|w| w.dacrst().clear_bit());
+
+        // NOTE(unsafe) ZST, doesn't need initialization.
+        mem::MaybeUninit::uninit().assume_init()
+    }
+}
+
+macro_rules! dac {
+    ($CX:ident, $en:ident, $cen:ident, $cal_flag:ident, $trim:ident, $mode:ident, $dhrx:ident, $dac_dor:ident, $daccxdhr:ident) => {
+        impl DacPin for $CX {
+            fn enable(&mut self) {
+                let dac = unsafe { &(*DAC::ptr()) };
+                dac.cr.modify(|_, w| w.$en().set_bit());
+            }
+        }
+
+        impl DacOut<u16> for $CX {
+            fn set_value(&mut self, val: u16) {
+                let dac = unsafe { &(*DAC::ptr()) };
+                dac.$dhrx.write(|w| unsafe { w.bits(val as u32) });
+            }
+
+            fn get_value(&mut self) -> u16 {
+                let dac = unsafe { &(*DAC::ptr()) };
+                dac.$dac_dor.read().bits() as u16
+            }
+        }
+    };
+}
+
+pub trait DacExt {
+    fn constrain<PINS>(self, pins: PINS) -> PINS::Output
+    where
+        PINS: Pins<DAC>;
+}
+
+impl DacExt for DAC {
+    fn constrain<PINS>(self, pins: PINS) -> PINS::Output
+    where
+        PINS: Pins<DAC>,
+    {
+        dac(self, pins)
+    }
+}
+
+dac!(C1, en1, cen1, cal_flag1, otrim1, mode1, dhr12r1, dor1, dacc1dhr);
+dac!(C2, en2, cen2, cal_flag2, otrim2, mode2, dhr12r2, dor2, dacc2dhr);

src/lib.rs

@@ -86,6 +86,9 @@ pub mod fmc;
 #[cfg(feature = "device-selected")]
 pub mod gpio;
 
+#[cfg(feature = "device-selected")]
+pub mod dac;
+
 #[cfg(all(
     feature = "usb_fs",
     any(