Merge #1330

1330: stm32/pwm: add complementary pwm r=Dirbaio a=xoviat

This implements complementary PWM with dead time on many supported targets. The specific dead-time programming functions are passed through directly to the user, which is a bit ugly but the best compromise I could reach for now.

Co-authored-by: xoviat <[email protected]>

3 files changed, 241 insertions, 0 deletions

diff --git a/embassy-stm32/src/pwm/complementary_pwm.rs b/embassy-stm32/src/pwm/complementary_pwm.rs
new file mode 100644
index 000000000..13edfbaa3
--- /dev/null
+++ b/embassy-stm32/src/pwm/complementary_pwm.rs
@@ -0,0 +1,124 @@
+use core::marker::PhantomData;
+
+use embassy_hal_common::{into_ref, PeripheralRef};
+pub use stm32_metapac::timer::vals::Ckd;
+
+use super::simple_pwm::*;
+use super::*;
+#[allow(unused_imports)]
+use crate::gpio::sealed::{AFType, Pin};
+use crate::gpio::AnyPin;
+use crate::time::Hertz;
+use crate::Peripheral;
+
+pub struct ComplementaryPwmPin<'d, Perip, Channel> {
+    _pin: PeripheralRef<'d, AnyPin>,
+    phantom: PhantomData<(Perip, Channel)>,
+}
+
+macro_rules! complementary_channel_impl {
+    ($new_chx:ident, $channel:ident, $pin_trait:ident, $complementary_pin_trait:ident) => {
+        impl<'d, Perip: CaptureCompare16bitInstance> ComplementaryPwmPin<'d, Perip, $channel> {
+            pub fn $new_chx(pin: impl Peripheral<P = impl $complementary_pin_trait<Perip>> + 'd) -> Self {
+                into_ref!(pin);
+                critical_section::with(|_| unsafe {
+                    pin.set_low();
+                    pin.set_as_af(pin.af_num(), AFType::OutputPushPull);
+                    #[cfg(gpio_v2)]
+                    pin.set_speed(crate::gpio::Speed::VeryHigh);
+                });
+                ComplementaryPwmPin {
+                    _pin: pin.map_into(),
+                    phantom: PhantomData,
+                }
+            }
+        }
+    };
+}
+
+complementary_channel_impl!(new_ch1, Ch1, Channel1Pin, Channel1ComplementaryPin);
+complementary_channel_impl!(new_ch2, Ch2, Channel2Pin, Channel2ComplementaryPin);
+complementary_channel_impl!(new_ch3, Ch3, Channel3Pin, Channel3ComplementaryPin);
+complementary_channel_impl!(new_ch4, Ch4, Channel4Pin, Channel4ComplementaryPin);
+
+pub struct ComplementaryPwm<'d, T> {
+    inner: PeripheralRef<'d, T>,
+}
+
+impl<'d, T: ComplementaryCaptureCompare16bitInstance> ComplementaryPwm<'d, T> {
+    pub fn new(
+        tim: impl Peripheral<P = T> + 'd,
+        _ch1: Option<PwmPin<'d, T, Ch1>>,
+        _ch1n: Option<ComplementaryPwmPin<'d, T, Ch1>>,
+        _ch2: Option<PwmPin<'d, T, Ch2>>,
+        _ch2n: Option<ComplementaryPwmPin<'d, T, Ch2>>,
+        _ch3: Option<PwmPin<'d, T, Ch3>>,
+        _ch3n: Option<ComplementaryPwmPin<'d, T, Ch3>>,
+        _ch4: Option<PwmPin<'d, T, Ch4>>,
+        _ch4n: Option<ComplementaryPwmPin<'d, T, Ch4>>,
+        freq: Hertz,
+    ) -> Self {
+        Self::new_inner(tim, freq)
+    }
+
+    fn new_inner(tim: impl Peripheral<P = T> + 'd, freq: Hertz) -> Self {
+        into_ref!(tim);
+
+        T::enable();
+        <T as crate::rcc::sealed::RccPeripheral>::reset();
+
+        let mut this = Self { inner: tim };
+
+        this.inner.set_frequency(freq);
+        this.inner.start();
+
+        unsafe {
+            this.inner.enable_outputs(true);
+
+            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);
+            self.inner.enable_complementary_channel(channel, true);
+        }
+    }
+
+    pub fn disable(&mut self, channel: Channel) {
+        unsafe {
+            self.inner.enable_complementary_channel(channel, false);
+            self.inner.enable_channel(channel, false);
+        }
+    }
+
+    pub fn set_freq(&mut self, freq: Hertz) {
+        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) }
+    }
+
+    pub fn set_dead_time_clock_division(&mut self, value: Ckd) {
+        unsafe { self.inner.set_dead_time_clock_division(value) }
+    }
+
+    pub fn set_dead_time_value(&mut self, value: u8) {
+        unsafe { self.inner.set_dead_time_value(value) }
+    }
+}
diff --git a/embassy-stm32/src/pwm/mod.rs b/embassy-stm32/src/pwm/mod.rs
index d3713391c..0bef07089 100644
--- a/embassy-stm32/src/pwm/mod.rs
+++ b/embassy-stm32/src/pwm/mod.rs
@@ -1,5 +1,8 @@
+pub mod complementary_pwm;
 pub mod simple_pwm;
 
+use stm32_metapac::timer::vals::Ckd;
+
 #[cfg(feature = "unstable-pac")]
 pub mod low_level {
     pub use super::sealed::*;
@@ -67,6 +70,14 @@ pub(crate) mod sealed {
         unsafe fn get_max_compare_value(&self) -> u16;
     }
 
+    pub trait ComplementaryCaptureCompare16bitInstance: CaptureCompare16bitInstance {
+        unsafe fn set_dead_time_clock_division(&mut self, value: Ckd);
+
+        unsafe fn set_dead_time_value(&mut self, value: u8);
+
+        unsafe fn enable_complementary_channel(&mut self, channel: Channel, enable: bool);
+    }
+
     pub trait CaptureCompare32bitInstance: crate::timer::sealed::GeneralPurpose32bitInstance {
         unsafe fn set_output_compare_mode(&mut self, channel: Channel, mode: OutputCompareMode);
 
@@ -82,6 +93,12 @@ pub trait CaptureCompare16bitInstance:
     sealed::CaptureCompare16bitInstance + crate::timer::GeneralPurpose16bitInstance + 'static
 {
 }
+
+pub trait ComplementaryCaptureCompare16bitInstance:
+    sealed::ComplementaryCaptureCompare16bitInstance + crate::timer::AdvancedControlInstance + 'static
+{
+}
+
 pub trait CaptureCompare32bitInstance:
     sealed::CaptureCompare32bitInstance + CaptureCompare16bitInstance + crate::timer::GeneralPurpose32bitInstance + 'static
 {
@@ -209,6 +226,29 @@ foreach_interrupt! {
         impl CaptureCompare16bitInstance for crate::peripherals::$inst {
 
         }
+
+        impl crate::pwm::sealed::ComplementaryCaptureCompare16bitInstance for crate::peripherals::$inst {
+            unsafe fn set_dead_time_clock_division(&mut self, value: Ckd) {
+                use crate::timer::sealed::AdvancedControlInstance;
+                Self::regs_advanced().cr1().modify(|w| w.set_ckd(value));
+            }
+
+            unsafe fn set_dead_time_value(&mut self, value: u8) {
+                use crate::timer::sealed::AdvancedControlInstance;
+                Self::regs_advanced().bdtr().modify(|w| w.set_dtg(value));
+            }
+
+            unsafe fn enable_complementary_channel(&mut self, channel: Channel, enable: bool) {
+                use crate::timer::sealed::AdvancedControlInstance;
+                Self::regs_advanced()
+                    .ccer()
+                    .modify(|w| w.set_ccne(channel.raw(), enable));
+            }
+        }
+
+        impl ComplementaryCaptureCompare16bitInstance for crate::peripherals::$inst {
+
+        }
     };
 }
 
diff --git a/examples/stm32f4/src/bin/pwm_complementary.rs b/examples/stm32f4/src/bin/pwm_complementary.rs
new file mode 100644
index 000000000..6e17f3fd3
--- /dev/null
+++ b/examples/stm32f4/src/bin/pwm_complementary.rs
@@ -0,0 +1,77 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::pwm::complementary_pwm::{Ckd, ComplementaryPwm, ComplementaryPwmPin};
+use embassy_stm32::pwm::simple_pwm::PwmPin;
+use embassy_stm32::pwm::Channel;
+use embassy_stm32::time::khz;
+use embassy_time::{Duration, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello World!");
+
+    let ch1 = PwmPin::new_ch1(p.PE9);
+    let ch1n = ComplementaryPwmPin::new_ch1(p.PA7);
+    let mut pwm = ComplementaryPwm::new(
+        p.TIM1,
+        Some(ch1),
+        Some(ch1n),
+        None,
+        None,
+        None,
+        None,
+        None,
+        None,
+        khz(10),
+    );
+
+    /*
+        Dead-time = T_clk * T_dts * T_dtg
+
+        T_dts:
+        This bit-field indicates the division ratio between the timer clock (CK_INT) frequency and the
+        dead-time and sampling clock (tDTS)used by the dead-time generators and the digital filters
+        (ETR, TIx),
+        00: tDTS=tCK_INT
+        01: tDTS=2*tCK_INT
+        10: tDTS=4*tCK_INT
+
+        T_dtg:
+        This bit-field defines the duration of the dead-time inserted between the complementary
+        outputs. DT correspond to this duration.
+        DTG[7:5]=0xx => DT=DTG[7:0]x tdtg with tdtg=tDTS.
+        DTG[7:5]=10x => DT=(64+DTG[5:0])xtdtg with Tdtg=2xtDTS.
+        DTG[7:5]=110 => DT=(32+DTG[4:0])xtdtg with Tdtg=8xtDTS.
+        DTG[7:5]=111 => DT=(32+DTG[4:0])xtdtg with Tdtg=16xtDTS.
+        Example if TDTS=125ns (8MHz), dead-time possible values are:
+        0 to 15875 ns by 125 ns steps,
+        16 us to 31750 ns by 250 ns steps,
+        32 us to 63us by 1 us steps,
+        64 us to 126 us by 2 us steps
+    */
+    pwm.set_dead_time_clock_division(Ckd::DIV1);
+    pwm.set_dead_time_value(0);
+
+    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;
+    }
+}