7 files changed, 334 insertions, 251 deletions

diff --git a/embassy-stm32/src/timer/complementary_pwm.rs b/embassy-stm32/src/timer/complementary_pwm.rs
index 8eec6c0c7..b00cc18ad 100644
--- a/embassy-stm32/src/timer/complementary_pwm.rs
+++ b/embassy-stm32/src/timer/complementary_pwm.rs
@@ -5,14 +5,12 @@ use core::marker::PhantomData;
 use stm32_metapac::timer::vals::Ckd;
 
 use super::low_level::{CountingMode, OutputPolarity, Timer};
-use super::simple_pwm::{Ch1, Ch2, Ch3, Ch4, PwmPin};
-use super::{
-    AdvancedInstance4Channel, Channel, Channel1ComplementaryPin, Channel2ComplementaryPin, Channel3ComplementaryPin,
-    Channel4ComplementaryPin,
-};
+use super::simple_pwm::PwmPin;
+use super::{AdvancedInstance4Channel, Ch1, Ch2, Ch3, Ch4, Channel, TimerComplementaryPin};
 use crate::gpio::{AnyPin, OutputType};
 use crate::time::Hertz;
 use crate::timer::low_level::OutputCompareMode;
+use crate::timer::TimerChannel;
 use crate::Peri;
 
 /// Complementary PWM pin wrapper.
@@ -23,32 +21,23 @@ pub struct ComplementaryPwmPin<'d, T, C> {
     phantom: PhantomData<(T, C)>,
 }
 
-macro_rules! complementary_channel_impl {
-    ($new_chx:ident, $channel:ident, $pin_trait:ident) => {
-        impl<'d, T: AdvancedInstance4Channel> ComplementaryPwmPin<'d, T, $channel> {
-            #[doc = concat!("Create a new ", stringify!($channel), " complementary PWM pin instance.")]
-            pub fn $new_chx(pin: Peri<'d, impl $pin_trait<T>>, output_type: OutputType) -> Self {
-                critical_section::with(|_| {
-                    pin.set_low();
-                    pin.set_as_af(
-                        pin.af_num(),
-                        crate::gpio::AfType::output(output_type, crate::gpio::Speed::VeryHigh),
-                    );
-                });
-                ComplementaryPwmPin {
-                    _pin: pin.into(),
-                    phantom: PhantomData,
-                }
-            }
+impl<'d, T: AdvancedInstance4Channel, C: TimerChannel> ComplementaryPwmPin<'d, T, C> {
+    /// Create a new  complementary PWM pin instance.
+    pub fn new(pin: Peri<'d, impl TimerComplementaryPin<T, C>>, output_type: OutputType) -> Self {
+        critical_section::with(|_| {
+            pin.set_low();
+            pin.set_as_af(
+                pin.af_num(),
+                crate::gpio::AfType::output(output_type, crate::gpio::Speed::VeryHigh),
+            );
+        });
+        ComplementaryPwmPin {
+            _pin: pin.into(),
+            phantom: PhantomData,
         }
-    };
+    }
 }
 
-complementary_channel_impl!(new_ch1, Ch1, Channel1ComplementaryPin);
-complementary_channel_impl!(new_ch2, Ch2, Channel2ComplementaryPin);
-complementary_channel_impl!(new_ch3, Ch3, Channel3ComplementaryPin);
-complementary_channel_impl!(new_ch4, Ch4, Channel4ComplementaryPin);
-
 /// PWM driver with support for standard and complementary outputs.
 pub struct ComplementaryPwm<'d, T: AdvancedInstance4Channel> {
     inner: Timer<'d, T>,
@@ -88,6 +77,7 @@ impl<'d, T: AdvancedInstance4Channel> ComplementaryPwm<'d, T> {
                 this.inner.set_output_compare_mode(channel, OutputCompareMode::PwmMode1);
                 this.inner.set_output_compare_preload(channel, true);
             });
+        this.inner.set_autoreload_preload(true);
 
         this
     }
@@ -121,7 +111,11 @@ impl<'d, T: AdvancedInstance4Channel> ComplementaryPwm<'d, T> {
     ///
     /// This value depends on the configured frequency and the timer's clock rate from RCC.
     pub fn get_max_duty(&self) -> u16 {
-        self.inner.get_max_compare_value() as u16 + 1
+        if self.inner.get_counting_mode().is_center_aligned() {
+            self.inner.get_max_compare_value() as u16
+        } else {
+            self.inner.get_max_compare_value() as u16 + 1
+        }
     }
 
     /// Set the duty for a given channel.
@@ -171,7 +165,11 @@ impl<'d, T: AdvancedInstance4Channel> embedded_hal_02::Pwm for ComplementaryPwm<
     }
 
     fn get_max_duty(&self) -> Self::Duty {
-        self.inner.get_max_compare_value() as u16 + 1
+        if self.inner.get_counting_mode().is_center_aligned() {
+            self.inner.get_max_compare_value() as u16
+        } else {
+            self.inner.get_max_compare_value() as u16 + 1
+        }
     }
 
     fn set_duty(&mut self, channel: Self::Channel, duty: Self::Duty) {
diff --git a/embassy-stm32/src/timer/input_capture.rs b/embassy-stm32/src/timer/input_capture.rs
index ec8b1ddf1..dda33e7f1 100644
--- a/embassy-stm32/src/timer/input_capture.rs
+++ b/embassy-stm32/src/timer/input_capture.rs
@@ -6,14 +6,12 @@ use core::pin::Pin;
 use core::task::{Context, Poll};
 
 use super::low_level::{CountingMode, FilterValue, InputCaptureMode, InputTISelection, Timer};
-use super::{
-    CaptureCompareInterruptHandler, Channel, Channel1Pin, Channel2Pin, Channel3Pin, Channel4Pin,
-    GeneralInstance4Channel,
-};
+use super::{CaptureCompareInterruptHandler, Channel, GeneralInstance4Channel, TimerPin};
 pub use super::{Ch1, Ch2, Ch3, Ch4};
 use crate::gpio::{AfType, AnyPin, Pull};
 use crate::interrupt::typelevel::{Binding, Interrupt};
 use crate::time::Hertz;
+use crate::timer::TimerChannel;
 use crate::Peri;
 
 /// Capture pin wrapper.
@@ -23,27 +21,17 @@ pub struct CapturePin<'d, T, C> {
     _pin: Peri<'d, AnyPin>,
     phantom: PhantomData<(T, C)>,
 }
-
-macro_rules! channel_impl {
-    ($new_chx:ident, $channel:ident, $pin_trait:ident) => {
-        impl<'d, T: GeneralInstance4Channel> CapturePin<'d, T, $channel> {
-            #[doc = concat!("Create a new ", stringify!($channel), " capture pin instance.")]
-            pub fn $new_chx(pin: Peri<'d, impl $pin_trait<T>>, pull: Pull) -> Self {
-                pin.set_as_af(pin.af_num(), AfType::input(pull));
-                CapturePin {
-                    _pin: pin.into(),
-                    phantom: PhantomData,
-                }
-            }
+impl<'d, T: GeneralInstance4Channel, C: TimerChannel> CapturePin<'d, T, C> {
+    /// Create a new capture pin instance.
+    pub fn new(pin: Peri<'d, impl TimerPin<T, C>>, pull: Pull) -> Self {
+        pin.set_as_af(pin.af_num(), AfType::input(pull));
+        CapturePin {
+            _pin: pin.into(),
+            phantom: PhantomData,
         }
-    };
+    }
 }
 
-channel_impl!(new_ch1, Ch1, Channel1Pin);
-channel_impl!(new_ch2, Ch2, Channel2Pin);
-channel_impl!(new_ch3, Ch3, Channel3Pin);
-channel_impl!(new_ch4, Ch4, Channel4Pin);
-
 /// Input capture driver.
 pub struct InputCapture<'d, T: GeneralInstance4Channel> {
     inner: Timer<'d, T>,
diff --git a/embassy-stm32/src/timer/mod.rs b/embassy-stm32/src/timer/mod.rs
index b29382fc8..7062f5f4c 100644
--- a/embassy-stm32/src/timer/mod.rs
+++ b/embassy-stm32/src/timer/mod.rs
@@ -51,6 +51,80 @@ pub enum Ch3 {}
 /// Channel 4 marker type.
 pub enum Ch4 {}
 
+/// Timer channel trait.
+#[allow(private_bounds)]
+pub trait TimerChannel: SealedTimerChannel {
+    /// The runtime channel.
+    const CHANNEL: Channel;
+}
+
+trait SealedTimerChannel {}
+
+impl TimerChannel for Ch1 {
+    const CHANNEL: Channel = Channel::Ch1;
+}
+
+impl TimerChannel for Ch2 {
+    const CHANNEL: Channel = Channel::Ch2;
+}
+
+impl TimerChannel for Ch3 {
+    const CHANNEL: Channel = Channel::Ch3;
+}
+
+impl TimerChannel for Ch4 {
+    const CHANNEL: Channel = Channel::Ch4;
+}
+
+impl SealedTimerChannel for Ch1 {}
+impl SealedTimerChannel for Ch2 {}
+impl SealedTimerChannel for Ch3 {}
+impl SealedTimerChannel for Ch4 {}
+
+/// Timer break input.
+#[derive(Clone, Copy)]
+pub enum BkIn {
+    /// Break input 1.
+    BkIn1,
+    /// Break input 2.
+    BkIn2,
+}
+
+impl BkIn {
+    /// Get the channel index (0..3)
+    pub fn index(&self) -> usize {
+        match self {
+            BkIn::BkIn1 => 0,
+            BkIn::BkIn2 => 1,
+        }
+    }
+}
+
+/// Break input 1 marker type.
+pub enum BkIn1 {}
+/// Break input 2 marker type.
+pub enum BkIn2 {}
+
+/// Timer channel trait.
+#[allow(private_bounds)]
+pub trait BreakInput: SealedBreakInput {
+    /// The runtim timer channel.
+    const INPUT: BkIn;
+}
+
+trait SealedBreakInput {}
+
+impl BreakInput for BkIn1 {
+    const INPUT: BkIn = BkIn::BkIn1;
+}
+
+impl BreakInput for BkIn2 {
+    const INPUT: BkIn = BkIn::BkIn2;
+}
+
+impl SealedBreakInput for BkIn1 {}
+impl SealedBreakInput for BkIn2 {}
+
 /// Amount of bits of a timer.
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -149,33 +223,20 @@ pub trait AdvancedInstance2Channel: BasicInstance + GeneralInstance2Channel + Ad
 /// Advanced 16-bit timer with 4 channels instance.
 pub trait AdvancedInstance4Channel: AdvancedInstance2Channel + GeneralInstance4Channel {}
 
-pin_trait!(Channel1Pin, GeneralInstance4Channel);
-pin_trait!(Channel2Pin, GeneralInstance4Channel);
-pin_trait!(Channel3Pin, GeneralInstance4Channel);
-pin_trait!(Channel4Pin, GeneralInstance4Channel);
+pin_trait!(TimerPin, GeneralInstance4Channel, TimerChannel);
 pin_trait!(ExternalTriggerPin, GeneralInstance4Channel);
 
-pin_trait!(Channel1ComplementaryPin, AdvancedInstance4Channel);
-pin_trait!(Channel2ComplementaryPin, AdvancedInstance4Channel);
-pin_trait!(Channel3ComplementaryPin, AdvancedInstance4Channel);
-pin_trait!(Channel4ComplementaryPin, AdvancedInstance4Channel);
-
-pin_trait!(BreakInputPin, AdvancedInstance4Channel);
-pin_trait!(BreakInput2Pin, AdvancedInstance4Channel);
+pin_trait!(TimerComplementaryPin, AdvancedInstance4Channel, TimerChannel);
 
-pin_trait!(BreakInputComparator1Pin, AdvancedInstance4Channel);
-pin_trait!(BreakInputComparator2Pin, AdvancedInstance4Channel);
+pin_trait!(BreakInputPin, AdvancedInstance4Channel, BreakInput);
 
-pin_trait!(BreakInput2Comparator1Pin, AdvancedInstance4Channel);
-pin_trait!(BreakInput2Comparator2Pin, AdvancedInstance4Channel);
+pin_trait!(BreakInputComparator1Pin, AdvancedInstance4Channel, BreakInput);
+pin_trait!(BreakInputComparator2Pin, AdvancedInstance4Channel, BreakInput);
 
 // Update Event trigger DMA for every timer
 dma_trait!(UpDma, BasicInstance);
 
-dma_trait!(Ch1Dma, GeneralInstance4Channel);
-dma_trait!(Ch2Dma, GeneralInstance4Channel);
-dma_trait!(Ch3Dma, GeneralInstance4Channel);
-dma_trait!(Ch4Dma, GeneralInstance4Channel);
+dma_trait!(Dma, GeneralInstance4Channel, TimerChannel);
 
 #[allow(unused)]
 macro_rules! impl_core_timer {
diff --git a/embassy-stm32/src/timer/one_pulse.rs b/embassy-stm32/src/timer/one_pulse.rs
index 933165ef9..498d9c082 100644
--- a/embassy-stm32/src/timer/one_pulse.rs
+++ b/embassy-stm32/src/timer/one_pulse.rs
@@ -7,11 +7,9 @@ use core::pin::Pin;
 use core::task::{Context, Poll};
 
 use super::low_level::{
-    CountingMode, FilterValue, InputCaptureMode, InputTISelection, SlaveMode, Timer, TriggerSource,
-};
-use super::{
-    CaptureCompareInterruptHandler, Channel, Channel1Pin, Channel2Pin, ExternalTriggerPin, GeneralInstance4Channel,
+    CountingMode, FilterValue, InputCaptureMode, InputTISelection, SlaveMode, Timer, TriggerSource as Ts,
 };
+use super::{CaptureCompareInterruptHandler, Channel, ExternalTriggerPin, GeneralInstance4Channel, TimerPin};
 pub use super::{Ch1, Ch2};
 use crate::gpio::{AfType, AnyPin, Pull};
 use crate::interrupt::typelevel::{Binding, Interrupt};
@@ -48,24 +46,78 @@ pub struct TriggerPin<'d, T, C> {
     phantom: PhantomData<(T, C)>,
 }
 
-macro_rules! channel_impl {
-    ($new_chx:ident, $channel:ident, $pin_trait:ident) => {
-        impl<'d, T: GeneralInstance4Channel> TriggerPin<'d, T, $channel> {
-            #[doc = concat!("Create a new ", stringify!($channel), " trigger pin instance.")]
-            pub fn $new_chx(pin: Peri<'d, impl $pin_trait<T>>, pull: Pull) -> Self {
-                pin.set_as_af(pin.af_num(), AfType::input(pull));
-                TriggerPin {
-                    _pin: pin.into(),
-                    phantom: PhantomData,
-                }
-            }
-        }
-    };
+trait SealedTriggerSource {}
+
+/// Marker trait for a trigger source.
+#[expect(private_bounds)]
+pub trait TriggerSource: SealedTriggerSource {}
+
+impl TriggerSource for Ch1 {}
+impl TriggerSource for Ch2 {}
+impl TriggerSource for Ext {}
+
+impl SealedTriggerSource for Ch1 {}
+impl SealedTriggerSource for Ch2 {}
+impl SealedTriggerSource for Ext {}
+
+trait SealedTimerTriggerPin<T, S>: crate::gpio::Pin {}
+
+/// Marker trait for a trigger pin.
+#[expect(private_bounds)]
+// TODO: find better naming scheme than prefixing all pin traits with "Timer".
+// The trait name cannot conflict with the corresponding type's name.
+// Applies to other timer submodules as well.
+pub trait TimerTriggerPin<T, S>: SealedTimerTriggerPin<T, S> {
+    /// Get the AF number needed to use this pin as a trigger source.
+    fn af_num(&self) -> u8;
+}
+
+impl<T, P, C> TimerTriggerPin<T, C> for P
+where
+    T: GeneralInstance4Channel,
+    P: TimerPin<T, C>,
+    C: super::TimerChannel + TriggerSource,
+{
+    fn af_num(&self) -> u8 {
+        TimerPin::af_num(self)
+    }
+}
+
+impl<T, P> TimerTriggerPin<T, Ext> for P
+where
+    T: GeneralInstance4Channel,
+    P: ExternalTriggerPin<T>,
+{
+    fn af_num(&self) -> u8 {
+        ExternalTriggerPin::af_num(self)
+    }
+}
+
+impl<T, P, C> SealedTimerTriggerPin<T, C> for P
+where
+    T: GeneralInstance4Channel,
+    P: TimerPin<T, C>,
+    C: super::TimerChannel + TriggerSource,
+{
 }
 
-channel_impl!(new_ch1, Ch1, Channel1Pin);
-channel_impl!(new_ch2, Ch2, Channel2Pin);
-channel_impl!(new_ext, Ext, ExternalTriggerPin);
+impl<T, P> SealedTimerTriggerPin<T, Ext> for P
+where
+    T: GeneralInstance4Channel,
+    P: ExternalTriggerPin<T>,
+{
+}
+
+impl<'d, T: GeneralInstance4Channel, C: TriggerSource> TriggerPin<'d, T, C> {
+    /// "Create a new Ch1 trigger pin instance.
+    pub fn new(pin: Peri<'d, impl TimerTriggerPin<T, C>>, pull: Pull) -> Self {
+        pin.set_as_af(pin.af_num(), AfType::input(pull));
+        TriggerPin {
+            _pin: pin.into(),
+            phantom: PhantomData,
+        }
+    }
+}
 
 /// One pulse driver.
 ///
@@ -89,7 +141,7 @@ impl<'d, T: GeneralInstance4Channel> OnePulse<'d, T> {
     ) -> Self {
         let mut this = Self { inner: Timer::new(tim) };
 
-        this.inner.set_trigger_source(TriggerSource::TI1F_ED);
+        this.inner.set_trigger_source(Ts::TI1F_ED);
         this.inner
             .set_input_ti_selection(Channel::Ch1, InputTISelection::Normal);
         this.inner
@@ -114,7 +166,7 @@ impl<'d, T: GeneralInstance4Channel> OnePulse<'d, T> {
     ) -> Self {
         let mut this = Self { inner: Timer::new(tim) };
 
-        this.inner.set_trigger_source(TriggerSource::TI1FP1);
+        this.inner.set_trigger_source(Ts::TI1FP1);
         this.inner
             .set_input_ti_selection(Channel::Ch1, InputTISelection::Normal);
         this.inner
@@ -131,7 +183,7 @@ impl<'d, T: GeneralInstance4Channel> OnePulse<'d, T> {
     /// as an output.
     pub fn new_ch2(
         tim: Peri<'d, T>,
-        _pin: TriggerPin<'d, T, Ch1>,
+        _pin: TriggerPin<'d, T, Ch2>,
         _irq: impl Binding<T::CaptureCompareInterrupt, CaptureCompareInterruptHandler<T>> + 'd,
         freq: Hertz,
         pulse_end: u32,
@@ -140,7 +192,7 @@ impl<'d, T: GeneralInstance4Channel> OnePulse<'d, T> {
     ) -> Self {
         let mut this = Self { inner: Timer::new(tim) };
 
-        this.inner.set_trigger_source(TriggerSource::TI2FP2);
+        this.inner.set_trigger_source(Ts::TI2FP2);
         this.inner
             .set_input_ti_selection(Channel::Ch2, InputTISelection::Normal);
         this.inner
@@ -172,7 +224,7 @@ impl<'d, T: GeneralInstance4Channel> OnePulse<'d, T> {
             // No filtering
             r.set_etf(FilterValue::NO_FILTER);
         });
-        this.inner.set_trigger_source(TriggerSource::ETRF);
+        this.inner.set_trigger_source(Ts::ETRF);
         this.new_inner(freq, pulse_end, counting_mode);
 
         this
diff --git a/embassy-stm32/src/timer/pwm_input.rs b/embassy-stm32/src/timer/pwm_input.rs
index 98b798634..1e55f2919 100644
--- a/embassy-stm32/src/timer/pwm_input.rs
+++ b/embassy-stm32/src/timer/pwm_input.rs
@@ -1,12 +1,16 @@
 //! PWM Input driver.
 
 use super::low_level::{CountingMode, InputCaptureMode, InputTISelection, SlaveMode, Timer, TriggerSource};
-use super::{Channel, Channel1Pin, Channel2Pin, GeneralInstance4Channel};
+use super::{Ch1, Ch2, Channel, GeneralInstance4Channel, TimerPin};
 use crate::gpio::{AfType, Pull};
 use crate::time::Hertz;
 use crate::Peri;
 
 /// PWM Input driver.
+///
+/// Only works with CH1 or CH2
+/// Note: Not all timer peripherals are supported
+/// Double check your chips reference manual
 pub struct PwmInput<'d, T: GeneralInstance4Channel> {
     channel: Channel,
     inner: Timer<'d, T>,
@@ -14,14 +18,14 @@ pub struct PwmInput<'d, T: GeneralInstance4Channel> {
 
 impl<'d, T: GeneralInstance4Channel> PwmInput<'d, T> {
     /// Create a new PWM input driver.
-    pub fn new(tim: Peri<'d, T>, pin: Peri<'d, impl Channel1Pin<T>>, pull: Pull, freq: Hertz) -> Self {
+    pub fn new_ch1(tim: Peri<'d, T>, pin: Peri<'d, impl TimerPin<T, Ch1>>, pull: Pull, freq: Hertz) -> Self {
         pin.set_as_af(pin.af_num(), AfType::input(pull));
 
         Self::new_inner(tim, freq, Channel::Ch1, Channel::Ch2)
     }
 
     /// Create a new PWM input driver.
-    pub fn new_alt(tim: Peri<'d, T>, pin: Peri<'d, impl Channel2Pin<T>>, pull: Pull, freq: Hertz) -> Self {
+    pub fn new_ch2(tim: Peri<'d, T>, pin: Peri<'d, impl TimerPin<T, Ch2>>, pull: Pull, freq: Hertz) -> Self {
         pin.set_as_af(pin.af_num(), AfType::input(pull));
 
         Self::new_inner(tim, freq, Channel::Ch2, Channel::Ch1)
@@ -37,6 +41,7 @@ impl<'d, T: GeneralInstance4Channel> PwmInput<'d, T> {
 
         // Configuration steps from ST RM0390 (STM32F446) chapter 17.3.6
         // or ST RM0008 (STM32F103) chapter 15.3.6 Input capture mode
+        // or ST RM0440 (STM32G4) chapter 30.4.8 PWM input mode
         inner.set_input_ti_selection(ch1, InputTISelection::Normal);
         inner.set_input_capture_mode(ch1, InputCaptureMode::Rising);
 
diff --git a/embassy-stm32/src/timer/qei.rs b/embassy-stm32/src/timer/qei.rs
index f3c81667c..eabe1b22a 100644
--- a/embassy-stm32/src/timer/qei.rs
+++ b/embassy-stm32/src/timer/qei.rs
@@ -6,8 +6,9 @@ use stm32_metapac::timer::vals;
 
 use super::low_level::Timer;
 pub use super::{Ch1, Ch2};
-use super::{Channel1Pin, Channel2Pin, GeneralInstance4Channel};
+use super::{GeneralInstance4Channel, TimerPin};
 use crate::gpio::{AfType, AnyPin, Pull};
+use crate::timer::TimerChannel;
 use crate::Peri;
 
 /// Counting direction
@@ -24,26 +25,31 @@ pub struct QeiPin<'d, T, Channel> {
     phantom: PhantomData<(T, Channel)>,
 }
 
-macro_rules! channel_impl {
-    ($new_chx:ident, $channel:ident, $pin_trait:ident) => {
-        impl<'d, T: GeneralInstance4Channel> QeiPin<'d, T, $channel> {
-            #[doc = concat!("Create a new ", stringify!($channel), " QEI pin instance.")]
-            pub fn $new_chx(pin: Peri<'d, impl $pin_trait<T>>) -> Self {
-                critical_section::with(|_| {
-                    pin.set_low();
-                    pin.set_as_af(pin.af_num(), AfType::input(Pull::None));
-                });
-                QeiPin {
-                    _pin: pin.into(),
-                    phantom: PhantomData,
-                }
-            }
+impl<'d, T: GeneralInstance4Channel, C: QeiChannel> QeiPin<'d, T, C> {
+    /// Create a new  QEI pin instance.
+    pub fn new(pin: Peri<'d, impl TimerPin<T, C>>) -> Self {
+        critical_section::with(|_| {
+            pin.set_low();
+            pin.set_as_af(pin.af_num(), AfType::input(Pull::None));
+        });
+        QeiPin {
+            _pin: pin.into(),
+            phantom: PhantomData,
         }
-    };
+    }
 }
 
-channel_impl!(new_ch1, Ch1, Channel1Pin);
-channel_impl!(new_ch2, Ch2, Channel2Pin);
+trait SealedQeiChannel: TimerChannel {}
+
+/// Marker trait for a timer channel eligible for use with QEI.
+#[expect(private_bounds)]
+pub trait QeiChannel: SealedQeiChannel {}
+
+impl QeiChannel for Ch1 {}
+impl QeiChannel for Ch2 {}
+
+impl SealedQeiChannel for Ch1 {}
+impl SealedQeiChannel for Ch2 {}
 
 /// Quadrature decoder driver.
 pub struct Qei<'d, T: GeneralInstance4Channel> {
diff --git a/embassy-stm32/src/timer/simple_pwm.rs b/embassy-stm32/src/timer/simple_pwm.rs
index f7f433154..c04b1ab97 100644
--- a/embassy-stm32/src/timer/simple_pwm.rs
+++ b/embassy-stm32/src/timer/simple_pwm.rs
@@ -4,22 +4,13 @@ use core::marker::PhantomData;
 use core::mem::ManuallyDrop;
 
 use super::low_level::{CountingMode, OutputCompareMode, OutputPolarity, Timer};
-use super::{Channel, Channel1Pin, Channel2Pin, Channel3Pin, Channel4Pin, GeneralInstance4Channel, TimerBits};
+use super::{Ch1, Ch2, Ch3, Ch4, Channel, GeneralInstance4Channel, TimerBits, TimerChannel, TimerPin};
 #[cfg(gpio_v2)]
 use crate::gpio::Pull;
 use crate::gpio::{AfType, AnyPin, OutputType, Speed};
 use crate::time::Hertz;
 use crate::Peri;
 
-/// Channel 1 marker type.
-pub enum Ch1 {}
-/// Channel 2 marker type.
-pub enum Ch2 {}
-/// Channel 3 marker type.
-pub enum Ch3 {}
-/// Channel 4 marker type.
-pub enum Ch4 {}
-
 /// PWM pin wrapper.
 ///
 /// This wraps a pin to make it usable with PWM.
@@ -43,46 +34,37 @@ pub struct PwmPinConfig {
     pub pull: Pull,
 }
 
-macro_rules! channel_impl {
-    ($new_chx:ident, $new_chx_with_config:ident, $channel:ident, $pin_trait:ident) => {
-        impl<'d, T: GeneralInstance4Channel> PwmPin<'d, T, $channel> {
-            #[doc = concat!("Create a new ", stringify!($channel), " PWM pin instance.")]
-            pub fn $new_chx(pin: Peri<'d, impl $pin_trait<T>>, output_type: OutputType) -> Self {
-                critical_section::with(|_| {
-                    pin.set_low();
-                    pin.set_as_af(pin.af_num(), AfType::output(output_type, Speed::VeryHigh));
-                });
-                PwmPin {
-                    _pin: pin.into(),
-                    phantom: PhantomData,
-                }
-            }
-
-            #[doc = concat!("Create a new ", stringify!($channel), " PWM pin instance with config.")]
-            pub fn $new_chx_with_config(pin: Peri<'d, impl $pin_trait<T>>, pin_config: PwmPinConfig) -> Self {
-                critical_section::with(|_| {
-                    pin.set_low();
-                    pin.set_as_af(
-                        pin.af_num(),
-                        #[cfg(gpio_v1)]
-                        AfType::output(pin_config.output_type, pin_config.speed),
-                        #[cfg(gpio_v2)]
-                        AfType::output_pull(pin_config.output_type, pin_config.speed, pin_config.pull),
-                    );
-                });
-                PwmPin {
-                    _pin: pin.into(),
-                    phantom: PhantomData,
-                }
-            }
+impl<'d, T: GeneralInstance4Channel, C: TimerChannel> PwmPin<'d, T, C> {
+    /// Create a new PWM pin instance.
+    pub fn new(pin: Peri<'d, impl TimerPin<T, C>>, output_type: OutputType) -> Self {
+        critical_section::with(|_| {
+            pin.set_low();
+            pin.set_as_af(pin.af_num(), AfType::output(output_type, Speed::VeryHigh));
+        });
+        PwmPin {
+            _pin: pin.into(),
+            phantom: PhantomData,
         }
-    };
-}
+    }
 
-channel_impl!(new_ch1, new_ch1_with_config, Ch1, Channel1Pin);
-channel_impl!(new_ch2, new_ch2_with_config, Ch2, Channel2Pin);
-channel_impl!(new_ch3, new_ch3_with_config, Ch3, Channel3Pin);
-channel_impl!(new_ch4, new_ch4_with_config, Ch4, Channel4Pin);
+    /// Create a new PWM pin instance with config.
+    pub fn new_with_config(pin: Peri<'d, impl TimerPin<T, C>>, pin_config: PwmPinConfig) -> Self {
+        critical_section::with(|_| {
+            pin.set_low();
+            pin.set_as_af(
+                pin.af_num(),
+                #[cfg(gpio_v1)]
+                AfType::output(pin_config.output_type, pin_config.speed),
+                #[cfg(gpio_v2)]
+                AfType::output_pull(pin_config.output_type, pin_config.speed, pin_config.pull),
+            );
+        });
+        PwmPin {
+            _pin: pin.into(),
+            phantom: PhantomData,
+        }
+    }
+}
 
 /// A single channel of a pwm, obtained from [`SimplePwm::split`],
 /// [`SimplePwm::channel`], [`SimplePwm::ch1`], etc.
@@ -466,107 +448,98 @@ impl<'d, T: GeneralInstance4Channel> SimplePwm<'d, T> {
     }
 }
 
-macro_rules! impl_waveform_chx {
-    ($fn_name:ident, $dma_ch:ident, $cc_ch:ident) => {
-        impl<'d, T: GeneralInstance4Channel> SimplePwm<'d, T> {
-            /// Generate a sequence of PWM waveform
-            pub async fn $fn_name(&mut self, dma: Peri<'_, impl super::$dma_ch<T>>, duty: &[u16]) {
-                use crate::pac::timer::vals::Ccds;
+impl<'d, T: GeneralInstance4Channel> SimplePwm<'d, T> {
+    /// Generate a sequence of PWM waveform
+    pub async fn waveform<C: TimerChannel>(&mut self, dma: Peri<'_, impl super::Dma<T, C>>, duty: &[u16]) {
+        use crate::pac::timer::vals::Ccds;
+
+        #[allow(clippy::let_unit_value)] // eg. stm32f334
+        let req = dma.request();
 
-                #[allow(clippy::let_unit_value)] // eg. stm32f334
-                let req = dma.request();
+        let cc_channel = C::CHANNEL;
 
-                let cc_channel = Channel::$cc_ch;
+        let original_duty_state = self.channel(cc_channel).current_duty_cycle();
+        let original_enable_state = self.channel(cc_channel).is_enabled();
+        let original_cc_dma_on_update = self.inner.get_cc_dma_selection() == Ccds::ON_UPDATE;
+        let original_cc_dma_enabled = self.inner.get_cc_dma_enable_state(cc_channel);
 
-                let original_duty_state = self.channel(cc_channel).current_duty_cycle();
-                let original_enable_state = self.channel(cc_channel).is_enabled();
-                let original_cc_dma_on_update = self.inner.get_cc_dma_selection() == Ccds::ON_UPDATE;
-                let original_cc_dma_enabled = self.inner.get_cc_dma_enable_state(cc_channel);
+        // redirect CC DMA request onto Update Event
+        if !original_cc_dma_on_update {
+            self.inner.set_cc_dma_selection(Ccds::ON_UPDATE)
+        }
 
-                // redirect CC DMA request onto Update Event
-                if !original_cc_dma_on_update {
-                    self.inner.set_cc_dma_selection(Ccds::ON_UPDATE)
-                }
+        if !original_cc_dma_enabled {
+            self.inner.set_cc_dma_enable_state(cc_channel, true);
+        }
 
-                if !original_cc_dma_enabled {
-                    self.inner.set_cc_dma_enable_state(cc_channel, true);
-                }
+        if !original_enable_state {
+            self.channel(cc_channel).enable();
+        }
 
-                if !original_enable_state {
-                    self.channel(cc_channel).enable();
-                }
+        unsafe {
+            #[cfg(not(any(bdma, gpdma)))]
+            use crate::dma::{Burst, FifoThreshold};
+            use crate::dma::{Transfer, TransferOptions};
 
-                unsafe {
+            let dma_transfer_option = TransferOptions {
+                #[cfg(not(any(bdma, gpdma)))]
+                fifo_threshold: Some(FifoThreshold::Full),
+                #[cfg(not(any(bdma, gpdma)))]
+                mburst: Burst::Incr8,
+                ..Default::default()
+            };
+
+            match self.inner.bits() {
+                TimerBits::Bits16 => {
+                    Transfer::new_write(
+                        dma,
+                        req,
+                        duty,
+                        self.inner.regs_gp16().ccr(cc_channel.index()).as_ptr() as *mut u16,
+                        dma_transfer_option,
+                    )
+                    .await
+                }
+                #[cfg(not(any(stm32l0)))]
+                TimerBits::Bits32 => {
                     #[cfg(not(any(bdma, gpdma)))]
-                    use crate::dma::{Burst, FifoThreshold};
-                    use crate::dma::{Transfer, TransferOptions};
-
-                    let dma_transfer_option = TransferOptions {
-                        #[cfg(not(any(bdma, gpdma)))]
-                        fifo_threshold: Some(FifoThreshold::Full),
-                        #[cfg(not(any(bdma, gpdma)))]
-                        mburst: Burst::Incr8,
-                        ..Default::default()
-                    };
-
-                    match self.inner.bits() {
-                        TimerBits::Bits16 => {
-                            Transfer::new_write(
-                                dma,
-                                req,
-                                duty,
-                                self.inner.regs_gp16().ccr(cc_channel.index()).as_ptr() as *mut u16,
-                                dma_transfer_option,
-                            )
-                            .await
-                        }
-                        #[cfg(not(any(stm32l0)))]
-                        TimerBits::Bits32 => {
-                            #[cfg(not(any(bdma, gpdma)))]
-                            panic!("unsupported timer bits");
-
-                            #[cfg(any(bdma, gpdma))]
-                            Transfer::new_write(
-                                dma,
-                                req,
-                                duty,
-                                self.inner.regs_gp16().ccr(cc_channel.index()).as_ptr() as *mut u32,
-                                dma_transfer_option,
-                            )
-                            .await
-                        }
-                    };
-                };
-
-                // restore output compare state
-                if !original_enable_state {
-                    self.channel(cc_channel).disable();
+                    panic!("unsupported timer bits");
+
+                    #[cfg(any(bdma, gpdma))]
+                    Transfer::new_write(
+                        dma,
+                        req,
+                        duty,
+                        self.inner.regs_gp16().ccr(cc_channel.index()).as_ptr() as *mut u32,
+                        dma_transfer_option,
+                    )
+                    .await
                 }
+            };
+        };
+
+        // restore output compare state
+        if !original_enable_state {
+            self.channel(cc_channel).disable();
+        }
 
-                self.channel(cc_channel).set_duty_cycle(original_duty_state);
+        self.channel(cc_channel).set_duty_cycle(original_duty_state);
 
-                // Since DMA is closed before timer Capture Compare Event trigger DMA is turn off,
-                // this can almost always trigger a DMA FIFO error.
-                //
-                // optional TODO:
-                // clean FEIF after disable UDE
-                if !original_cc_dma_enabled {
-                    self.inner.set_cc_dma_enable_state(cc_channel, false);
-                }
+        // Since DMA is closed before timer Capture Compare Event trigger DMA is turn off,
+        // this can almost always trigger a DMA FIFO error.
+        //
+        // optional TODO:
+        // clean FEIF after disable UDE
+        if !original_cc_dma_enabled {
+            self.inner.set_cc_dma_enable_state(cc_channel, false);
+        }
 
-                if !original_cc_dma_on_update {
-                    self.inner.set_cc_dma_selection(Ccds::ON_COMPARE)
-                }
-            }
+        if !original_cc_dma_on_update {
+            self.inner.set_cc_dma_selection(Ccds::ON_COMPARE)
         }
-    };
+    }
 }
 
-impl_waveform_chx!(waveform_ch1, Ch1Dma, Ch1);
-impl_waveform_chx!(waveform_ch2, Ch2Dma, Ch2);
-impl_waveform_chx!(waveform_ch3, Ch3Dma, Ch3);
-impl_waveform_chx!(waveform_ch4, Ch4Dma, Ch4);
-
 impl<'d, T: GeneralInstance4Channel> embedded_hal_1::pwm::ErrorType for SimplePwmChannel<'d, T> {
     type Error = core::convert::Infallible;
 }