HRTIM: Add capture.rs

Author: usbalbin

src/hrtim/capture.rs

@@ -0,0 +1,120 @@
+use core::marker::PhantomData;
+
+use stm32g4::stm32g474::{
+    HRTIM_TIMA,
+    HRTIM_TIMB,
+    HRTIM_TIMC,
+    HRTIM_TIMD,
+    HRTIM_TIME,
+    HRTIM_TIMF,
+};
+
+
+pub struct Ch1;
+pub struct Ch2;
+
+pub struct HrCapt<TIM, PSCL, CH> {
+    _x: PhantomData<(TIM, PSCL, CH)>
+}
+
+pub enum CountingDirection {
+    Up = 0,
+    Down = 1,
+}
+
+pub trait CaptureEvent<TIM, PSCL> {
+    const BITS: u32;
+}
+
+trait HrCapture {
+    fn get(&self) -> (u16, CountingDirection);
+
+    /// Get number of ticks relative to beginning of upcounting
+    /// 
+    /// where captures during down counting count as negative (before the upcount)
+    fn get_signed(&self) -> i32 {
+        let (value, dir) = self.get();
+        let dir_bit = dir as i32;
+        dir_bit << 31 | i32::from(value)
+    }
+
+    /// Get number of ticks relative to beginning of upcounting
+    /// 
+    /// where captures during down counting count as larger (after upcount)
+    fn get_unsigned(&self) -> u32 {
+        let (value, dir) = self.get();
+        let dir_bit = dir as u32;
+        dir_bit << 16 | u32::from(value)
+    }
+}
+
+macro_rules! impl_capture {
+    ($($TIMX:ident, $CH:ident, $cptXYr:ident, $cptXYcr:ident, $cptXx:ident),+) => {
+        $(impl<PSCL> HrCapt<$TIMX, PSCL, $CH> {
+            /// Add event to capture
+            /// 
+            /// If multiple events are added, they will be ORed together meaning
+            /// that a capture will be trigger if any one of the events triggers
+            pub fn add_event<E: CaptureEvent<$TIMX, PSCL>>(&mut self, _event: &E) {
+                let tim = unsafe { &*$TIMX::ptr() };
+                
+                // SAFETY: We are the only one with access to cptXYcr
+                unsafe {
+                    tim.$cptXYcr.modify(|r, w| w.bits(r.bits() | E::BITS));
+                }
+            }
+
+            /// Remove event to capture
+            pub fn remove_event<E: CaptureEvent<$TIMX, PSCL>>(&mut self, _event: &E) {
+                let tim = unsafe { &*$TIMX::ptr() };
+                
+                // SAFETY: We are the only one with access to cptXYcr
+                unsafe {
+                    tim.$cptXYcr.modify(|r, w| w.bits(r.bits() & !E::BITS));
+                }
+            }
+
+            /// Force capture trigger now
+            pub fn trigger_now(&mut self) {
+                // SAFETY: We are the only one with access to cptXYcr
+                let tim = unsafe { &*$TIMX::ptr() };
+                
+                tim.$cptXYcr.modify(|_, w| w.swcpt().set_bit());
+            }
+        }
+
+        impl<PSCL> HrCapture for HrCapt<$TIMX, PSCL, $CH> {
+            fn get(&self) -> (u16, CountingDirection) {
+                let tim = unsafe { &*$TIMX::ptr() };
+                let data = tim.$cptXYr.read();
+                let dir = match data.dir().bit() {
+                    true => CountingDirection::Down,
+                    false => CountingDirection::Up,
+                };
+                let value = data.$cptXx().bits();
+
+                (value, dir)
+            }
+        })+
+    };
+}
+
+impl_capture!(
+    HRTIM_TIMA, Ch1, cpt1ar, cpt1acr, cpt1x,
+    HRTIM_TIMA, Ch2, cpt2ar, cpt2acr, cpt2x,
+
+    HRTIM_TIMB, Ch1, cpt1br, cpt1bcr, cpt1x,
+    HRTIM_TIMB, Ch2, cpt2br, cpt2bcr, cpt2x,
+
+    HRTIM_TIMC, Ch1, cpt1cr, cpt1ccr, cpt1x,
+    HRTIM_TIMC, Ch2, cpt2cr, cpt2ccr, cpt2x,
+
+    HRTIM_TIMD, Ch1, cpt1dr, cpt1dcr, cpt1x,
+    HRTIM_TIMD, Ch2, cpt2dr, cpt2dcr, cpt2x,
+
+    HRTIM_TIME, Ch1, cpt1er, cpt1ecr, cpt1x,
+    HRTIM_TIME, Ch2, cpt2er, cpt2ecr, cpt2x,
+
+    HRTIM_TIMF, Ch1, cpt1fr, cpt1fcr, cpt1x,
+    HRTIM_TIMF, Ch2, cpt2fr, cpt2fcr, cpt2x
+);