Merge #508

508: STM32 timers + pwm improvements r=matoushybl a=matoushybl



Co-authored-by: Matous Hybl <[email protected]>

10 files changed, 857 insertions, 147 deletions

diff --git a/embassy-stm32/src/lib.rs b/embassy-stm32/src/lib.rs
index 1ed48df3f..dfc027733 100644
--- a/embassy-stm32/src/lib.rs
+++ b/embassy-stm32/src/lib.rs
@@ -20,6 +20,7 @@ pub mod gpio;
 pub mod rcc;
 #[cfg(feature = "_time-driver")]
 mod time_driver;
+pub mod timer;
 
 // Sometimes-present hardware
 
diff --git a/embassy-stm32/src/pwm/mod.rs b/embassy-stm32/src/pwm/mod.rs
index 8357b6cdc..b62a14668 100644
--- a/embassy-stm32/src/pwm/mod.rs
+++ b/embassy-stm32/src/pwm/mod.rs
@@ -1,21 +1,17 @@
-use crate::gpio;
-use crate::rcc::RccPeripheral;
-use crate::time::Hertz;
-use core::marker::PhantomData;
-use embassy::util::Unborrow;
-use embassy_hal_common::unborrow;
-use stm32_metapac::timer::vals::Ocm;
-
-pub struct Pwm<'d, T: Instance> {
-    phantom: PhantomData<&'d mut T>,
-}
+#[cfg(feature = "unstable-pac")]
+#[macro_use]
+pub mod pins;
+
+#[cfg(not(feature = "unstable-pac"))]
+#[macro_use]
+pub(crate) mod pins;
 
-// TIM2
+pub mod simple_pwm;
 
-pub struct Ch1 {}
-pub struct Ch2 {}
-pub struct Ch3 {}
-pub struct Ch4 {}
+#[cfg(feature = "unstable-pac")]
+pub mod low_level {
+    pub use super::sealed::*;
+}
 
 #[derive(Clone, Copy)]
 pub enum Channel {
@@ -25,171 +21,241 @@ pub enum Channel {
     Ch4,
 }
 
-impl<'d, T: Instance> Pwm<'d, T> {
-    pub fn new<F: Into<Hertz>>(
-        _tim: impl Unborrow<Target = T> + 'd,
-        ch1: impl Unborrow<Target = impl PwmPin<T, Ch1>> + 'd,
-        ch2: impl Unborrow<Target = impl PwmPin<T, Ch2>> + 'd,
-        ch3: impl Unborrow<Target = impl PwmPin<T, Ch3>> + 'd,
-        ch4: impl Unborrow<Target = impl PwmPin<T, Ch4>> + 'd,
-        freq: F,
-    ) -> Self {
-        unborrow!(ch1, ch2, ch3, ch4);
-
-        T::enable();
-        T::reset();
-        let r = T::regs();
-
-        let mut this = Pwm {
-            phantom: PhantomData,
-        };
-        unsafe {
-            ch1.configure();
-            ch2.configure();
-            ch3.configure();
-            ch4.configure();
-        }
-
-        unsafe {
-            use stm32_metapac::timer::vals::Dir;
-            this.set_freq(freq);
-            r.cr1().write(|w| {
-                w.set_cen(true);
-                w.set_dir(Dir::UP)
-            });
-
-            this.set_ocm(Channel::Ch1, Ocm::PWMMODE1);
-            this.set_ocm(Channel::Ch2, Ocm::PWMMODE1);
-            this.set_ocm(Channel::Ch3, Ocm::PWMMODE1);
-            this.set_ocm(Channel::Ch4, Ocm::PWMMODE1);
+impl Channel {
+    pub fn raw(&self) -> usize {
+        match self {
+            Channel::Ch1 => 0,
+            Channel::Ch2 => 1,
+            Channel::Ch3 => 2,
+            Channel::Ch4 => 3,
         }
-        this
     }
+}
 
-    unsafe fn set_ocm(&mut self, channel: Channel, mode: Ocm) {
-        let r = T::regs();
-        match channel {
-            Channel::Ch1 => r.ccmr_output(0).modify(|w| w.set_ocm(0, mode)),
-            Channel::Ch2 => r.ccmr_output(0).modify(|w| w.set_ocm(1, mode)),
-            Channel::Ch3 => r.ccmr_output(1).modify(|w| w.set_ocm(0, mode)),
-            Channel::Ch4 => r.ccmr_output(1).modify(|w| w.set_ocm(1, mode)),
-        }
-    }
+#[derive(Clone, Copy)]
+pub enum OutputCompareMode {
+    Frozen,
+    ActiveOnMatch,
+    InactiveOnMatch,
+    Toggle,
+    ForceInactive,
+    ForceActive,
+    PwmMode1,
+    PwmMode2,
+}
 
-    unsafe fn set_enable(&mut self, channel: Channel, enable: bool) {
-        let r = T::regs();
-        match channel {
-            Channel::Ch1 => r.ccer().modify(|w| w.set_cce(0, enable)),
-            Channel::Ch2 => r.ccer().modify(|w| w.set_cce(1, enable)),
-            Channel::Ch3 => r.ccer().modify(|w| w.set_cce(2, enable)),
-            Channel::Ch4 => r.ccer().modify(|w| w.set_cce(3, enable)),
+impl From<OutputCompareMode> for stm32_metapac::timer::vals::Ocm {
+    fn from(mode: OutputCompareMode) -> Self {
+        match mode {
+            OutputCompareMode::Frozen => stm32_metapac::timer::vals::Ocm::FROZEN,
+            OutputCompareMode::ActiveOnMatch => stm32_metapac::timer::vals::Ocm::ACTIVEONMATCH,
+            OutputCompareMode::InactiveOnMatch => stm32_metapac::timer::vals::Ocm::INACTIVEONMATCH,
+            OutputCompareMode::Toggle => stm32_metapac::timer::vals::Ocm::TOGGLE,
+            OutputCompareMode::ForceInactive => stm32_metapac::timer::vals::Ocm::FORCEINACTIVE,
+            OutputCompareMode::ForceActive => stm32_metapac::timer::vals::Ocm::FORCEACTIVE,
+            OutputCompareMode::PwmMode1 => stm32_metapac::timer::vals::Ocm::PWMMODE1,
+            OutputCompareMode::PwmMode2 => stm32_metapac::timer::vals::Ocm::PWMMODE2,
         }
     }
+}
 
-    pub fn enable(&mut self, channel: Channel) {
-        unsafe { self.set_enable(channel, true) }
-    }
+pub(crate) mod sealed {
+    use super::*;
 
-    pub fn disable(&mut self, channel: Channel) {
-        unsafe { self.set_enable(channel, false) }
-    }
+    pub trait CaptureCompareCapable16bitInstance:
+        crate::timer::sealed::GeneralPurpose16bitInstance
+    {
+        unsafe fn set_output_compare_mode(&mut self, channel: Channel, mode: OutputCompareMode);
 
-    pub fn set_freq<F: Into<Hertz>>(&mut self, freq: F) {
-        use core::convert::TryInto;
-        let clk = T::frequency();
-        let r = T::regs();
-        let freq: Hertz = freq.into();
-        let ticks: u32 = clk.0 / freq.0;
-        let psc: u16 = (ticks / (1 << 16)).try_into().unwrap();
-        let arr: u16 = (ticks / (u32::from(psc) + 1)).try_into().unwrap();
-        unsafe {
-            r.psc().write(|w| w.set_psc(psc));
-            r.arr().write(|w| w.set_arr(arr));
-        }
-    }
+        unsafe fn enable_channel(&mut self, channel: Channel, enable: bool);
 
-    pub fn get_max_duty(&self) -> u32 {
-        let r = T::regs();
-        unsafe { r.arr().read().arr() as u32 }
-    }
+        unsafe fn set_compare_value(&mut self, channel: Channel, value: u16);
 
-    pub fn set_duty(&mut self, channel: Channel, duty: u32) {
-        use core::convert::TryInto;
-        assert!(duty < self.get_max_duty());
-        let duty: u16 = duty.try_into().unwrap();
-        let r = T::regs();
-        unsafe {
-            match channel {
-                Channel::Ch1 => r.ccr(0).modify(|w| w.set_ccr(duty)),
-                Channel::Ch2 => r.ccr(1).modify(|w| w.set_ccr(duty)),
-                Channel::Ch3 => r.ccr(2).modify(|w| w.set_ccr(duty)),
-                Channel::Ch4 => r.ccr(3).modify(|w| w.set_ccr(duty)),
-            }
-        }
+        unsafe fn get_max_compare_value(&self) -> u16;
     }
-}
 
-pub(crate) mod sealed {
-    pub trait Instance {
-        fn regs() -> crate::pac::timer::TimGp16;
+    pub trait CaptureCompareCapable32bitInstance:
+        crate::timer::sealed::GeneralPurpose32bitInstance
+    {
+        unsafe fn set_output_compare_mode(&mut self, channel: Channel, mode: OutputCompareMode);
+
+        unsafe fn enable_channel(&mut self, channel: Channel, enable: bool);
+
+        unsafe fn set_compare_value(&mut self, channel: Channel, value: u32);
+
+        unsafe fn get_max_compare_value(&self) -> u32;
     }
 }
 
-pub trait Instance: sealed::Instance + Sized + RccPeripheral + 'static {}
+pub trait CaptureCompareCapable16bitInstance:
+    sealed::CaptureCompareCapable16bitInstance + crate::timer::GeneralPurpose16bitInstance + 'static
+{
+}
+pub trait CaptureCompareCapable32bitInstance:
+    sealed::CaptureCompareCapable32bitInstance + crate::timer::GeneralPurpose32bitInstance + 'static
+{
+}
 
 #[allow(unused)]
-macro_rules! impl_timer {
+macro_rules! impl_compare_capable_16bit {
     ($inst:ident) => {
-        impl crate::pwm::sealed::Instance for crate::peripherals::$inst {
-            fn regs() -> crate::pac::timer::TimGp16 {
-                crate::pac::timer::TimGp16(crate::pac::$inst.0)
+        impl crate::pwm::sealed::CaptureCompareCapable16bitInstance for crate::peripherals::$inst {
+            unsafe fn set_output_compare_mode(
+                &mut self,
+                channel: crate::pwm::Channel,
+                mode: OutputCompareMode,
+            ) {
+                use crate::timer::sealed::GeneralPurpose16bitInstance;
+                let r = self.regs_gp16();
+                let raw_channel: usize = channel.raw();
+                r.ccmr_output(raw_channel / 2)
+                    .modify(|w| w.set_ocm(raw_channel % 2, mode.into()));
             }
-        }
 
-        impl crate::pwm::Instance for crate::peripherals::$inst {}
+            unsafe fn enable_channel(&mut self, channel: Channel, enable: bool) {
+                use crate::timer::sealed::GeneralPurpose16bitInstance;
+                self.regs_gp16()
+                    .ccer()
+                    .modify(|w| w.set_cce(channel.raw(), enable));
+            }
+
+            unsafe fn set_compare_value(&mut self, channel: Channel, value: u16) {
+                use crate::timer::sealed::GeneralPurpose16bitInstance;
+                self.regs_gp16()
+                    .ccr(channel.raw())
+                    .modify(|w| w.set_ccr(value));
+            }
+
+            unsafe fn get_max_compare_value(&self) -> u16 {
+                use crate::timer::sealed::GeneralPurpose16bitInstance;
+                self.regs_gp16().arr().read().arr()
+            }
+        }
     };
 }
 
-pub trait PwmPin<Timer, Channel>: gpio::OptionalPin {
-    unsafe fn configure(&mut self);
-}
+crate::pac::interrupts! {
+    ($inst:ident, timer, TIM_GP16, UP, $irq:ident) => {
+        impl_compare_capable_16bit!($inst);
 
-impl<Timer, Channel> PwmPin<Timer, Channel> for gpio::NoPin {
-    unsafe fn configure(&mut self) {}
-}
+        impl CaptureCompareCapable16bitInstance for crate::peripherals::$inst {
 
-#[allow(unused)]
-macro_rules! impl_pwm_pin {
-    ($timer:ident, $channel:ident, $pin:ident, $af:expr) => {
-        impl crate::pwm::PwmPin<crate::peripherals::$timer, crate::pwm::$channel>
-            for crate::peripherals::$pin
-        {
-            unsafe fn configure(&mut self) {
-                use crate::gpio::sealed::{AFType, Pin};
-                use crate::gpio::Speed;
-                self.set_low();
-                self.set_speed(Speed::VeryHigh);
-                self.set_as_af($af, AFType::OutputPushPull);
+        }
+    };
+
+    ($inst:ident, timer, TIM_GP32, UP, $irq:ident) => {
+        impl_compare_capable_16bit!($inst);
+        impl crate::pwm::sealed::CaptureCompareCapable32bitInstance for crate::peripherals::$inst {
+            unsafe fn set_output_compare_mode(
+                &mut self,
+                channel: crate::pwm::Channel,
+                mode: OutputCompareMode,
+            ) {
+                use crate::timer::sealed::GeneralPurpose32bitInstance;
+                let raw_channel = channel.raw();
+                self.regs_gp32().ccmr_output(raw_channel / 2).modify(|w| w.set_ocm(raw_channel % 2, mode.into()));
             }
+
+            unsafe fn enable_channel(&mut self, channel: Channel, enable: bool) {
+                use crate::timer::sealed::GeneralPurpose32bitInstance;
+                self.regs_gp32().ccer().modify(|w| w.set_cce(channel.raw(), enable));
+            }
+
+            unsafe fn set_compare_value(&mut self, channel: Channel, value: u32) {
+                use crate::timer::sealed::GeneralPurpose32bitInstance;
+                self.regs_gp32().ccr(channel.raw()).modify(|w| w.set_ccr(value));
+            }
+
+            unsafe fn get_max_compare_value(&self) -> u32 {
+                use crate::timer::sealed::GeneralPurpose32bitInstance;
+                self.regs_gp32().arr().read().arr() as u32
+            }
+        }
+        impl CaptureCompareCapable16bitInstance for crate::peripherals::$inst {
+
+        }
+        impl CaptureCompareCapable32bitInstance for crate::peripherals::$inst {
+
+        }
+    };
+
+    ($inst:ident, timer, TIM_ADV, UP, $irq:ident) => {
+        impl_compare_capable_16bit!($inst);
+        impl CaptureCompareCapable16bitInstance for crate::peripherals::$inst {
+
         }
     };
 }
 
+#[allow(unused)]
+macro_rules! impl_pwm_nopin {
+    ($inst:ident) => {
+        impl_no_pin!($inst, Channel1Pin);
+        impl_no_pin!($inst, Channel1ComplementaryPin);
+        impl_no_pin!($inst, Channel2Pin);
+        impl_no_pin!($inst, Channel2ComplementaryPin);
+        impl_no_pin!($inst, Channel3Pin);
+        impl_no_pin!($inst, Channel3ComplementaryPin);
+        impl_no_pin!($inst, Channel4Pin);
+        impl_no_pin!($inst, Channel4ComplementaryPin);
+        impl_no_pin!($inst, ExternalTriggerPin);
+        impl_no_pin!($inst, BreakInputPin);
+        impl_no_pin!($inst, BreakInputComparator1Pin);
+        impl_no_pin!($inst, BreakInputComparator2Pin);
+        impl_no_pin!($inst, BreakInput2Pin);
+        impl_no_pin!($inst, BreakInput2Comparator1Pin);
+        impl_no_pin!($inst, BreakInput2Comparator2Pin);
+    };
+}
+
 crate::pac::peripherals!(
-    (timer, $inst:ident) => { impl_timer!($inst); };
+    (timer, $inst:ident) => { impl_pwm_nopin!($inst); };
 );
 
 crate::pac::peripheral_pins!(
-    ($inst:ident, timer,TIM_GP16, $pin:ident, CH1, $af:expr) => {
-        impl_pwm_pin!($inst, Ch1, $pin, $af);
+    ($inst:ident, timer, $block:ident, $pin:ident, CH1, $af:expr) => {
+        impl_pin!($inst, Channel1Pin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, CH1N, $af:expr) => {
+        impl_pin!($inst, Channel1ComplementaryPin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, CH2, $af:expr) => {
+        impl_pin!($inst, Channel2Pin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, CH2N, $af:expr) => {
+        impl_pin!($inst, Channel2ComplementaryPin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, CH3, $af:expr) => {
+        impl_pin!($inst, Channel3Pin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, CH3N, $af:expr) => {
+        impl_pin!($inst, Channel3ComplementaryPin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, CH4, $af:expr) => {
+        impl_pin!($inst, Channel4Pin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, CH4N, $af:expr) => {
+        impl_pin!($inst, Channel4ComplementaryPin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, ETR, $af:expr) => {
+        impl_pin!($inst, ExternalTriggerPin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, BKIN, $af:expr) => {
+        impl_pin!($inst, BreakInputPin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, BKIN_COMP1, $af:expr) => {
+        impl_pin!($inst, BreakInputComparator1Pin, $pin, $af);
+    };
+    ($inst:ident, timer, $block:ident, $pin:ident, BKIN_COMP2, $af:expr) => {
+        impl_pin!($inst, BreakInputComparator2Pin, $pin, $af);
     };
-    ($inst:ident, timer,TIM_GP16, $pin:ident, CH2, $af:expr) => {
-        impl_pwm_pin!($inst, Ch2, $pin, $af);
+    ($inst:ident, timer, $block:ident, $pin:ident, BKIN2, $af:expr) => {
+        impl_pin!($inst, BreakInput2Pin, $pin, $af);
     };
-    ($inst:ident, timer,TIM_GP16, $pin:ident, CH3, $af:expr) => {
-        impl_pwm_pin!($inst, Ch3, $pin, $af);
+    ($inst:ident, timer, $block:ident, $pin:ident, BKIN2_COMP1, $af:expr) => {
+        impl_pin!($inst, BreakInput2Comparator1Pin, $pin, $af);
     };
-    ($inst:ident, timer,TIM_GP16, $pin:ident, CH4, $af:expr) => {
-        impl_pwm_pin!($inst, Ch4, $pin, $af);
+    ($inst:ident, timer, $block:ident, $pin:ident, BKIN2_COMP2, $af:expr) => {
+        impl_pin!($inst, BreakInput2Comparator2Pin, $pin, $af);
     };
 );
diff --git a/embassy-stm32/src/pwm/pins.rs b/embassy-stm32/src/pwm/pins.rs
new file mode 100644
index 000000000..77ba1f6d5
--- /dev/null
+++ b/embassy-stm32/src/pwm/pins.rs
@@ -0,0 +1,138 @@
+use crate::gpio::OptionalPin;
+
+#[cfg(feature = "unstable-pac")]
+pub mod low_level {
+    pub use super::sealed::*;
+}
+
+pub(crate) mod sealed {
+    use crate::gpio::sealed::OptionalPin;
+
+    pub trait Channel1Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait Channel1ComplementaryPin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+
+    pub trait Channel2Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait Channel2ComplementaryPin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+
+    pub trait Channel3Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait Channel3ComplementaryPin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+
+    pub trait Channel4Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait Channel4ComplementaryPin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+
+    pub trait ExternalTriggerPin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+
+    pub trait BreakInputPin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait BreakInputComparator1Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait BreakInputComparator2Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+
+    pub trait BreakInput2Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait BreakInput2Comparator1Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+    pub trait BreakInput2Comparator2Pin<Timer>: OptionalPin {
+        unsafe fn configure(&mut self);
+    }
+}
+pub trait Channel1Pin<Timer>: sealed::Channel1Pin<Timer> + OptionalPin + 'static {}
+pub trait Channel1ComplementaryPin<Timer>:
+    sealed::Channel1ComplementaryPin<Timer> + OptionalPin + 'static
+{
+}
+
+pub trait Channel2Pin<Timer>: sealed::Channel2Pin<Timer> + 'static {}
+pub trait Channel2ComplementaryPin<Timer>:
+    sealed::Channel2ComplementaryPin<Timer> + OptionalPin + 'static
+{
+}
+
+pub trait Channel3Pin<Timer>: sealed::Channel3Pin<Timer> + 'static {}
+pub trait Channel3ComplementaryPin<Timer>:
+    sealed::Channel3ComplementaryPin<Timer> + OptionalPin + 'static
+{
+}
+
+pub trait Channel4Pin<Timer>: sealed::Channel4Pin<Timer> + 'static {}
+pub trait Channel4ComplementaryPin<Timer>:
+    sealed::Channel4ComplementaryPin<Timer> + OptionalPin + 'static
+{
+}
+
+pub trait ExternalTriggerPin<Timer>:
+    sealed::ExternalTriggerPin<Timer> + OptionalPin + 'static
+{
+}
+
+pub trait BreakInputPin<Timer>: sealed::BreakInputPin<Timer> + OptionalPin + 'static {}
+pub trait BreakInputComparator1Pin<Timer>:
+    sealed::BreakInputComparator1Pin<Timer> + OptionalPin + 'static
+{
+}
+pub trait BreakInputComparator2Pin<Timer>:
+    sealed::BreakInputComparator2Pin<Timer> + OptionalPin + 'static
+{
+}
+
+pub trait BreakInput2Pin<Timer>: sealed::BreakInput2Pin<Timer> + OptionalPin + 'static {}
+pub trait BreakInput2Comparator1Pin<Timer>:
+    sealed::BreakInput2Comparator1Pin<Timer> + OptionalPin + 'static
+{
+}
+pub trait BreakInput2Comparator2Pin<Timer>:
+    sealed::BreakInput2Comparator2Pin<Timer> + OptionalPin + 'static
+{
+}
+
+macro_rules! impl_no_pin {
+    ($timer:ident, $signal:ident) => {
+        impl crate::pwm::pins::sealed::$signal<crate::peripherals::$timer> for crate::gpio::NoPin {
+            unsafe fn configure(&mut self) {}
+        }
+        impl crate::pwm::pins::$signal<crate::peripherals::$timer> for crate::gpio::NoPin {}
+    };
+}
+
+#[allow(unused)]
+macro_rules! impl_pin {
+    ($timer:ident, $signal:ident, $pin:ident, $af:expr) => {
+        impl crate::pwm::pins::sealed::$signal<crate::peripherals::$timer>
+            for crate::peripherals::$pin
+        {
+            unsafe fn configure(&mut self) {
+                use crate::gpio::sealed::{AFType, Pin};
+                use crate::gpio::Speed;
+                self.set_low();
+                self.set_speed(Speed::VeryHigh);
+                self.set_as_af($af, AFType::OutputPushPull);
+            }
+        }
+
+        impl crate::pwm::pins::$signal<crate::peripherals::$timer> for crate::peripherals::$pin {}
+    };
+}
diff --git a/embassy-stm32/src/pwm/simple_pwm.rs b/embassy-stm32/src/pwm/simple_pwm.rs
new file mode 100644
index 000000000..3dc46e6e8
--- /dev/null
+++ b/embassy-stm32/src/pwm/simple_pwm.rs
@@ -0,0 +1,80 @@
+use crate::{
+    pwm::{pins::*, CaptureCompareCapable16bitInstance, Channel, OutputCompareMode},
+    time::Hertz,
+};
+use core::marker::PhantomData;
+use embassy::util::Unborrow;
+use embassy_hal_common::unborrow;
+
+pub struct SimplePwm<'d, T> {
+    phantom: PhantomData<&'d mut T>,
+    inner: T,
+}
+
+impl<'d, T: CaptureCompareCapable16bitInstance> SimplePwm<'d, T> {
+    pub fn new<F: Into<Hertz>>(
+        tim: impl Unborrow<Target = T> + 'd,
+        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
+        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
+        ch3: impl Unborrow<Target = impl Channel3Pin<T>> + 'd,
+        ch4: impl Unborrow<Target = impl Channel4Pin<T>> + 'd,
+        freq: F,
+    ) -> Self {
+        unborrow!(tim, ch1, ch2, ch3, ch4);
+
+        T::enable();
+        <T as crate::rcc::sealed::RccPeripheral>::reset();
+
+        unsafe {
+            ch1.configure();
+            ch2.configure();
+            ch3.configure();
+            ch4.configure();
+        }
+
+        let mut this = Self {
+            inner: tim,
+            phantom: PhantomData,
+        };
+
+        this.inner.set_frequency(freq);
+        this.inner.start();
+
+        unsafe {
+            this.inner
+                .set_output_compare_mode(Channel::Ch1, OutputCompareMode::PwmMode1);
+            this.inner
+                .set_output_compare_mode(Channel::Ch2, OutputCompareMode::PwmMode1);
+            this.inner
+                .set_output_compare_mode(Channel::Ch3, OutputCompareMode::PwmMode1);
+            this.inner
+                .set_output_compare_mode(Channel::Ch4, OutputCompareMode::PwmMode1);
+        }
+        this
+    }
+
+    pub fn enable(&mut self, channel: Channel) {
+        unsafe {
+            self.inner.enable_channel(channel, true);
+        }
+    }
+
+    pub fn disable(&mut self, channel: Channel) {
+        unsafe {
+            self.inner.enable_channel(channel, false);
+        }
+    }
+
+    pub fn set_freq<F: Into<Hertz>>(&mut self, freq: F) {
+        self.inner.set_frequency(freq);
+    }
+
+    pub fn get_max_duty(&self) -> u16 {
+        unsafe { self.inner.get_max_compare_value() }
+    }
+
+    pub fn set_duty(&mut self, channel: Channel, duty: u16) {
+        assert!(duty < self.get_max_duty());
+        unsafe { self.inner.set_compare_value(channel, duty) }
+    }
+}
diff --git a/embassy-stm32/src/rcc/mod.rs b/embassy-stm32/src/rcc/mod.rs
index d0b6e5a18..e5bf15c86 100644
--- a/embassy-stm32/src/rcc/mod.rs
+++ b/embassy-stm32/src/rcc/mod.rs
@@ -85,6 +85,11 @@ pub(crate) unsafe fn get_freqs() -> &'static Clocks {
     &*CLOCK_FREQS.as_ptr()
 }
 
+#[cfg(feature = "unstable-pac")]
+pub mod low_level {
+    pub use super::sealed::*;
+}
+
 pub(crate) mod sealed {
     pub trait RccPeripheral {
         fn frequency() -> crate::time::Hertz;
diff --git a/embassy-stm32/src/timer/mod.rs b/embassy-stm32/src/timer/mod.rs
new file mode 100644
index 000000000..ed2cb2d97
--- /dev/null
+++ b/embassy-stm32/src/timer/mod.rs
@@ -0,0 +1,224 @@
+use embassy::interrupt::Interrupt;
+
+use crate::rcc::{sealed::RccPeripheral as __RccPeri, RccPeripheral};
+use crate::time::Hertz;
+use stm32_metapac::timer::vals;
+
+#[cfg(feature = "unstable-pac")]
+pub mod low_level {
+    pub use super::sealed::*;
+}
+
+pub(crate) mod sealed {
+    use super::*;
+    pub trait Basic16bitInstance: RccPeripheral {
+        type Interrupt: Interrupt;
+
+        fn regs(&self) -> crate::pac::timer::TimBasic;
+
+        fn start(&mut self);
+
+        fn stop(&mut self);
+
+        fn reset(&mut self);
+
+        fn set_frequency<F: Into<Hertz>>(&mut self, frequency: F);
+
+        fn clear_update_interrupt(&mut self) -> bool;
+
+        fn enable_update_interrupt(&mut self, enable: bool);
+    }
+
+    pub trait GeneralPurpose16bitInstance: Basic16bitInstance {
+        fn regs_gp16(&self) -> crate::pac::timer::TimGp16;
+    }
+
+    pub trait GeneralPurpose32bitInstance: GeneralPurpose16bitInstance {
+        fn regs_gp32(&self) -> crate::pac::timer::TimGp32;
+
+        fn set_frequency<F: Into<Hertz>>(&mut self, frequency: F);
+    }
+
+    pub trait AdvancedControlInstance: GeneralPurpose16bitInstance {
+        fn regs_advanced(&self) -> crate::pac::timer::TimAdv;
+    }
+}
+
+pub trait GeneralPurpose16bitInstance: sealed::GeneralPurpose16bitInstance + 'static {}
+
+pub trait GeneralPurpose32bitInstance: sealed::GeneralPurpose32bitInstance + 'static {}
+
+pub trait AdvancedControlInstance: sealed::AdvancedControlInstance + 'static {}
+
+pub trait Basic16bitInstance: sealed::Basic16bitInstance + 'static {}
+
+#[allow(unused)]
+macro_rules! impl_basic_16bit_timer {
+    ($inst:ident, $irq:ident) => {
+        impl sealed::Basic16bitInstance for crate::peripherals::$inst {
+            type Interrupt = crate::interrupt::$irq;
+
+            fn regs(&self) -> crate::pac::timer::TimBasic {
+                crate::pac::timer::TimBasic(crate::pac::$inst.0)
+            }
+
+            fn start(&mut self) {
+                unsafe {
+                    self.regs().cr1().modify(|r| r.set_cen(true));
+                }
+            }
+
+            fn stop(&mut self) {
+                let regs = self.regs();
+                unsafe {
+                    regs.cr1().modify(|r| r.set_cen(false));
+                }
+            }
+
+            fn reset(&mut self) {
+                unsafe {
+                    self.regs().cnt().write(|r| r.set_cnt(0));
+                }
+            }
+
+            fn set_frequency<F: Into<Hertz>>(&mut self, frequency: F) {
+                use core::convert::TryInto;
+                let f = frequency.into().0;
+                let timer_f = Self::frequency().0;
+                let pclk_ticks_per_timer_period = timer_f / f;
+                let psc: u16 = unwrap!(((pclk_ticks_per_timer_period - 1) / (1 << 16)).try_into());
+                let arr: u16 =
+                    unwrap!((pclk_ticks_per_timer_period / (u32::from(psc) + 1)).try_into());
+
+                let regs = self.regs();
+                unsafe {
+                    regs.psc().write(|r| r.set_psc(psc));
+                    regs.arr().write(|r| r.set_arr(arr));
+
+                    regs.cr1().modify(|r| r.set_urs(vals::Urs::COUNTERONLY));
+                    regs.egr().write(|r| r.set_ug(true));
+                    regs.cr1().modify(|r| r.set_urs(vals::Urs::ANYEVENT));
+                }
+            }
+
+            fn clear_update_interrupt(&mut self) -> bool {
+                unsafe {
+                    let sr = self.regs().sr().read();
+                    if sr.uif() {
+                        self.regs().sr().modify(|r| {
+                            r.set_uif(false);
+                        });
+                        true
+                    } else {
+                        false
+                    }
+                }
+            }
+
+            fn enable_update_interrupt(&mut self, enable: bool) {
+                unsafe {
+                    self.regs().dier().write(|r| r.set_uie(enable));
+                }
+            }
+        }
+    };
+}
+
+#[allow(unused)]
+macro_rules! impl_32bit_timer {
+    ($inst:ident) => {
+        impl sealed::GeneralPurpose32bitInstance for crate::peripherals::$inst {
+            fn regs_gp32(&self) -> crate::pac::timer::TimGp32 {
+                crate::pac::$inst
+            }
+
+            fn set_frequency<F: Into<Hertz>>(&mut self, frequency: F) {
+                use core::convert::TryInto;
+                let f = frequency.into().0;
+                let timer_f = Self::frequency().0;
+                let pclk_ticks_per_timer_period = (timer_f / f) as u64;
+                let psc: u16 = unwrap!(((pclk_ticks_per_timer_period - 1) / (1 << 32)).try_into());
+                let arr: u32 =
+                    unwrap!(((pclk_ticks_per_timer_period / (psc as u64 + 1)).try_into()));
+
+                let regs = self.regs_gp32();
+                unsafe {
+                    regs.psc().write(|r| r.set_psc(psc));
+                    regs.arr().write(|r| r.set_arr(arr));
+
+                    regs.cr1().modify(|r| r.set_urs(vals::Urs::COUNTERONLY));
+                    regs.egr().write(|r| r.set_ug(true));
+                    regs.cr1().modify(|r| r.set_urs(vals::Urs::ANYEVENT));
+                }
+            }
+        }
+    };
+}
+
+crate::pac::interrupts! {
+    ($inst:ident, timer, TIM_BASIC, UP, $irq:ident) => {
+        impl_basic_16bit_timer!($inst, $irq);
+
+        impl Basic16bitInstance for crate::peripherals::$inst {
+        }
+    };
+    ($inst:ident, timer, TIM_GP16, UP, $irq:ident) => {
+        impl_basic_16bit_timer!($inst, $irq);
+
+        impl Basic16bitInstance for crate::peripherals::$inst {
+        }
+
+        impl sealed::GeneralPurpose16bitInstance for crate::peripherals::$inst {
+            fn regs_gp16(&self) -> crate::pac::timer::TimGp16 {
+                crate::pac::$inst
+            }
+        }
+
+        impl GeneralPurpose16bitInstance for crate::peripherals::$inst {
+        }
+    };
+
+    ($inst:ident, timer, TIM_GP32, UP, $irq:ident) => {
+        impl_basic_16bit_timer!($inst, $irq);
+
+        impl Basic16bitInstance for crate::peripherals::$inst {
+        }
+
+        impl sealed::GeneralPurpose16bitInstance for crate::peripherals::$inst {
+            fn regs_gp16(&self) -> crate::pac::timer::TimGp16 {
+                crate::pac::timer::TimGp16(crate::pac::$inst.0)
+            }
+        }
+
+        impl GeneralPurpose16bitInstance for crate::peripherals::$inst {
+        }
+
+        impl_32bit_timer!($inst);
+
+        impl GeneralPurpose32bitInstance for crate::peripherals::$inst {
+        }
+    };
+
+    ($inst:ident, timer, TIM_ADV, UP, $irq:ident) => {
+        impl_basic_16bit_timer!($inst, $irq);
+
+        impl Basic16bitInstance for crate::peripherals::$inst {
+        }
+
+        impl sealed::GeneralPurpose16bitInstance for crate::peripherals::$inst {
+            fn regs_gp16(&self) -> crate::pac::timer::TimGp16 {
+                crate::pac::timer::TimGp16(crate::pac::$inst.0)
+            }
+        }
+
+        impl GeneralPurpose16bitInstance for crate::peripherals::$inst {
+        }
+        impl sealed::AdvancedControlInstance for crate::peripherals::$inst {
+            fn regs_advanced(&self) -> crate::pac::timer::TimAdv {
+                crate::pac::$inst
+            }
+        }
+        impl AdvancedControlInstance for crate::peripherals::$inst {
+        }
+    };
+}
diff --git a/examples/stm32g4/src/bin/pwm.rs b/examples/stm32g4/src/bin/pwm.rs
index 1aa7b85f3..3dd45318d 100644
--- a/examples/stm32g4/src/bin/pwm.rs
+++ b/examples/stm32g4/src/bin/pwm.rs
@@ -7,7 +7,7 @@ mod example_common;
 use embassy::executor::Spawner;
 use embassy::time::{Duration, Timer};
 use embassy_stm32::gpio::NoPin;
-use embassy_stm32::pwm::{Channel, Pwm};
+use embassy_stm32::pwm::{simple_pwm::SimplePwm, Channel};
 use embassy_stm32::time::U32Ext;
 use embassy_stm32::Peripherals;
 use example_common::*;
@@ -16,7 +16,7 @@ use example_common::*;
 async fn main(_spawner: Spawner, p: Peripherals) {
     info!("Hello World!");
 
-    let mut pwm = Pwm::new(p.TIM2, p.PA5, NoPin, NoPin, NoPin, 10000.hz());
+    let mut pwm = SimplePwm::new(p.TIM2, p.PA5, NoPin, NoPin, NoPin, 10000.hz());
     let max = pwm.get_max_duty();
     pwm.enable(Channel::Ch1);
 
diff --git a/examples/stm32h7/Cargo.toml b/examples/stm32h7/Cargo.toml
index a34ac6ad9..de294318f 100644
--- a/examples/stm32h7/Cargo.toml
+++ b/examples/stm32h7/Cargo.toml
@@ -10,8 +10,9 @@ resolver = "2"
 [dependencies]
 embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt"] }
 embassy-traits = { version = "0.1.0", path = "../../embassy-traits", features = ["defmt"] }
-embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["defmt", "stm32h743zi", "net", "time-driver-tim2", "exti"] }
+embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["defmt", "stm32h743zi", "net", "time-driver-tim2", "exti", "unstable-pac"] }
 embassy-net = { path = "../../embassy-net", default-features = false, features = ["defmt", "tcp", "medium-ethernet", "pool-16"] }
+embassy-hal-common = { path = "../../embassy-hal-common", default-features = false, features = ["defmt"] }
 
 defmt = "0.3"
 defmt-rtt = "0.3"
diff --git a/examples/stm32h7/src/bin/low_level_timer_api.rs b/examples/stm32h7/src/bin/low_level_timer_api.rs
new file mode 100644
index 000000000..2640f249d
--- /dev/null
+++ b/examples/stm32h7/src/bin/low_level_timer_api.rs
@@ -0,0 +1,147 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use core::marker::PhantomData;
+
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy::util::Unborrow;
+use embassy_hal_common::unborrow;
+use embassy_stm32::gpio::NoPin;
+use embassy_stm32::pwm::{pins::*, Channel, OutputCompareMode};
+use embassy_stm32::time::{Hertz, U32Ext};
+use embassy_stm32::timer::GeneralPurpose32bitInstance;
+use embassy_stm32::{Config, Peripherals};
+use example_common::*;
+
+pub fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.sys_ck = Some(400.mhz().into());
+    config.rcc.hclk = Some(400.mhz().into());
+    config.rcc.pll1.q_ck = Some(100.mhz().into());
+    config.rcc.pclk1 = Some(100.mhz().into());
+    config.rcc.pclk2 = Some(100.mhz().into());
+    config.rcc.pclk3 = Some(100.mhz().into());
+    config.rcc.pclk4 = Some(100.mhz().into());
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    let mut pwm = SimplePwm32::new(p.TIM5, p.PA0, NoPin, NoPin, NoPin, 10000.hz());
+    let max = pwm.get_max_duty();
+    pwm.enable(Channel::Ch1);
+
+    info!("PWM initialized");
+    info!("PWM max duty {}", max);
+
+    loop {
+        pwm.set_duty(Channel::Ch1, 0);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max / 4);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max / 2);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max - 1);
+        Timer::after(Duration::from_millis(300)).await;
+    }
+}
+pub struct SimplePwm32<'d, T: GeneralPurpose32bitInstance> {
+    phantom: PhantomData<&'d mut T>,
+    inner: T,
+}
+
+impl<'d, T: GeneralPurpose32bitInstance> SimplePwm32<'d, T> {
+    pub fn new<F: Into<Hertz>>(
+        tim: impl Unborrow<Target = T> + 'd,
+        ch1: impl Unborrow<Target = impl Channel1Pin<T>> + 'd,
+        ch2: impl Unborrow<Target = impl Channel2Pin<T>> + 'd,
+        ch3: impl Unborrow<Target = impl Channel3Pin<T>> + 'd,
+        ch4: impl Unborrow<Target = impl Channel4Pin<T>> + 'd,
+        freq: F,
+    ) -> Self {
+        unborrow!(tim, ch1, ch2, ch3, ch4);
+
+        T::enable();
+        <T as embassy_stm32::rcc::low_level::RccPeripheral>::reset();
+
+        unsafe {
+            ch1.configure();
+            ch2.configure();
+            ch3.configure();
+            ch4.configure();
+        }
+
+        let mut this = Self {
+            inner: tim,
+            phantom: PhantomData,
+        };
+
+        this.set_freq(freq);
+        this.inner.start();
+
+        unsafe {
+            this.inner
+                .regs_gp32()
+                .ccmr_output(0)
+                .modify(|w| w.set_ocm(0, OutputCompareMode::PwmMode1.into()));
+            this.inner
+                .regs_gp32()
+                .ccmr_output(0)
+                .modify(|w| w.set_ocm(1, OutputCompareMode::PwmMode1.into()));
+            this.inner
+                .regs_gp32()
+                .ccmr_output(1)
+                .modify(|w| w.set_ocm(0, OutputCompareMode::PwmMode1.into()));
+            this.inner
+                .regs_gp32()
+                .ccmr_output(1)
+                .modify(|w| w.set_ocm(1, OutputCompareMode::PwmMode1.into()));
+        }
+        this
+    }
+
+    pub fn enable(&mut self, channel: Channel) {
+        unsafe {
+            self.inner
+                .regs_gp32()
+                .ccer()
+                .modify(|w| w.set_cce(channel.raw(), true));
+        }
+    }
+
+    pub fn disable(&mut self, channel: Channel) {
+        unsafe {
+            self.inner
+                .regs_gp32()
+                .ccer()
+                .modify(|w| w.set_cce(channel.raw(), false));
+        }
+    }
+
+    pub fn set_freq<F: Into<Hertz>>(&mut self, freq: F) {
+        <T as embassy_stm32::timer::low_level::GeneralPurpose32bitInstance>::set_frequency(
+            &mut self.inner,
+            freq,
+        );
+    }
+
+    pub fn get_max_duty(&self) -> u32 {
+        unsafe { self.inner.regs_gp32().arr().read().arr() }
+    }
+
+    pub fn set_duty(&mut self, channel: Channel, duty: u32) {
+        defmt::assert!(duty < self.get_max_duty());
+        unsafe {
+            self.inner
+                .regs_gp32()
+                .ccr(channel.raw())
+                .modify(|w| w.set_ccr(duty))
+        }
+    }
+}
diff --git a/examples/stm32h7/src/bin/pwm.rs b/examples/stm32h7/src/bin/pwm.rs
new file mode 100644
index 000000000..020150a39
--- /dev/null
+++ b/examples/stm32h7/src/bin/pwm.rs
@@ -0,0 +1,48 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_stm32::gpio::NoPin;
+use embassy_stm32::pwm::{simple_pwm::SimplePwm, Channel};
+use embassy_stm32::time::U32Ext;
+use embassy_stm32::{Config, Peripherals};
+use example_common::*;
+
+pub fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.sys_ck = Some(400.mhz().into());
+    config.rcc.hclk = Some(400.mhz().into());
+    config.rcc.pll1.q_ck = Some(100.mhz().into());
+    config.rcc.pclk1 = Some(100.mhz().into());
+    config.rcc.pclk2 = Some(100.mhz().into());
+    config.rcc.pclk3 = Some(100.mhz().into());
+    config.rcc.pclk4 = Some(100.mhz().into());
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    let mut pwm = SimplePwm::new(p.TIM3, p.PA6, NoPin, NoPin, NoPin, 10000.hz());
+    let max = pwm.get_max_duty();
+    pwm.enable(Channel::Ch1);
+
+    info!("PWM initialized");
+    info!("PWM max duty {}", max);
+
+    loop {
+        pwm.set_duty(Channel::Ch1, 0);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max / 4);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max / 2);
+        Timer::after(Duration::from_millis(300)).await;
+        pwm.set_duty(Channel::Ch1, max - 1);
+        Timer::after(Duration::from_millis(300)).await;
+    }
+}