1 files changed, 96 insertions, 0 deletions

diff --git a/embassy-stm32/src/timer/qei.rs b/embassy-stm32/src/timer/qei.rs
new file mode 100644
index 000000000..15f2c3a79
--- /dev/null
+++ b/embassy-stm32/src/timer/qei.rs
@@ -0,0 +1,96 @@
+use core::marker::PhantomData;
+
+use embassy_hal_internal::{into_ref, PeripheralRef};
+
+use super::*;
+use crate::gpio::sealed::AFType;
+use crate::gpio::AnyPin;
+use crate::Peripheral;
+
+pub enum Direction {
+    Upcounting,
+    Downcounting,
+}
+
+pub struct Ch1;
+pub struct Ch2;
+
+pub struct QeiPin<'d, Perip, Channel> {
+    _pin: PeripheralRef<'d, AnyPin>,
+    phantom: PhantomData<(Perip, Channel)>,
+}
+
+macro_rules! channel_impl {
+    ($new_chx:ident, $channel:ident, $pin_trait:ident) => {
+        impl<'d, Perip: CaptureCompare16bitInstance> QeiPin<'d, Perip, $channel> {
+            pub fn $new_chx(pin: impl Peripheral<P = impl $pin_trait<Perip>> + 'd) -> Self {
+                into_ref!(pin);
+                critical_section::with(|_| {
+                    pin.set_low();
+                    pin.set_as_af(pin.af_num(), AFType::Input);
+                    #[cfg(gpio_v2)]
+                    pin.set_speed(crate::gpio::Speed::VeryHigh);
+                });
+                QeiPin {
+                    _pin: pin.map_into(),
+                    phantom: PhantomData,
+                }
+            }
+        }
+    };
+}
+
+channel_impl!(new_ch1, Ch1, Channel1Pin);
+channel_impl!(new_ch2, Ch2, Channel2Pin);
+
+pub struct Qei<'d, T> {
+    _inner: PeripheralRef<'d, T>,
+}
+
+impl<'d, T: CaptureCompare16bitInstance> Qei<'d, T> {
+    pub fn new(tim: impl Peripheral<P = T> + 'd, _ch1: QeiPin<'d, T, Ch1>, _ch2: QeiPin<'d, T, Ch2>) -> Self {
+        Self::new_inner(tim)
+    }
+
+    fn new_inner(tim: impl Peripheral<P = T> + 'd) -> Self {
+        into_ref!(tim);
+
+        T::enable();
+        <T as crate::rcc::sealed::RccPeripheral>::reset();
+
+        // Configure TxC1 and TxC2 as captures
+        T::regs_gp16().ccmr_input(0).modify(|w| {
+            w.set_ccs(0, vals::CcmrInputCcs::TI4);
+            w.set_ccs(1, vals::CcmrInputCcs::TI4);
+        });
+
+        // enable and configure to capture on rising edge
+        T::regs_gp16().ccer().modify(|w| {
+            w.set_cce(0, true);
+            w.set_cce(1, true);
+
+            w.set_ccp(0, false);
+            w.set_ccp(1, false);
+        });
+
+        T::regs_gp16().smcr().modify(|w| {
+            w.set_sms(vals::Sms::ENCODER_MODE_3);
+        });
+
+        T::regs_gp16().arr().modify(|w| w.set_arr(u16::MAX));
+        T::regs_gp16().cr1().modify(|w| w.set_cen(true));
+
+        Self { _inner: tim }
+    }
+
+    pub fn read_direction(&self) -> Direction {
+        match T::regs_gp16().cr1().read().dir() {
+            vals::Dir::DOWN => Direction::Downcounting,
+            vals::Dir::UP => Direction::Upcounting,
+        }
+    }
+
+    pub fn count(&self) -> u16 {
+        T::regs_gp16().cnt().read().cnt()
+    }
+}