Merge #827

827: Fix PWM for advanced timers r=Dirbaio a=chemicstry

Advanced timers have additional BDTR register, which has a global output enable bit and it is disabled by default.

Also added an example for F4, but it will only work once https://github.com/embassy-rs/stm32-data/pull/149 is merged. We can also move it to some other chip, but I don't have anything else to test on atm.

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

3 files changed, 49 insertions, 32 deletions

diff --git a/embassy-stm32/src/pwm/mod.rs b/embassy-stm32/src/pwm/mod.rs
index bd8358563..674740cc5 100644
--- a/embassy-stm32/src/pwm/mod.rs
+++ b/embassy-stm32/src/pwm/mod.rs
@@ -55,6 +55,9 @@ pub(crate) mod sealed {
     use super::*;
 
     pub trait CaptureCompare16bitInstance: crate::timer::sealed::Basic16bitInstance {
+        /// Global output enable. Does not do anything on non-advanced timers.
+        unsafe fn enable_outputs(&mut self, enable: bool);
+
         unsafe fn set_output_compare_mode(&mut self, channel: Channel, mode: OutputCompareMode);
 
         unsafe fn enable_channel(&mut self, channel: Channel, enable: bool);
@@ -88,6 +91,8 @@ pub trait CaptureCompare32bitInstance:
 macro_rules! impl_compare_capable_16bit {
     ($inst:ident) => {
         impl crate::pwm::sealed::CaptureCompare16bitInstance for crate::peripherals::$inst {
+            unsafe fn enable_outputs(&mut self, _enable: bool) {}
+
             unsafe fn set_output_compare_mode(&mut self, channel: crate::pwm::Channel, mode: OutputCompareMode) {
                 use crate::timer::sealed::GeneralPurpose16bitInstance;
                 let r = Self::regs_gp16();
@@ -118,38 +123,7 @@ macro_rules! impl_compare_capable_16bit {
 
 foreach_interrupt! {
     ($inst:ident, timer, TIM_GP16, UP, $irq:ident) => {
-        impl crate::pwm::sealed::CaptureCompare16bitInstance for crate::peripherals::$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()));
-            }
-
-            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()
-            }
-        }
+        impl_compare_capable_16bit!($inst);
 
         impl CaptureCompare16bitInstance for crate::peripherals::$inst {
 
@@ -194,6 +168,12 @@ foreach_interrupt! {
 
     ($inst:ident, timer, TIM_ADV, UP, $irq:ident) => {
         impl crate::pwm::sealed::CaptureCompare16bitInstance for crate::peripherals::$inst {
+            unsafe fn enable_outputs(&mut self, enable: bool) {
+                use crate::timer::sealed::AdvancedControlInstance;
+                let r = Self::regs_advanced();
+                r.bdtr().modify(|w| w.set_moe(enable));
+            }
+
             unsafe fn set_output_compare_mode(
                 &mut self,
                 channel: crate::pwm::Channel,
diff --git a/embassy-stm32/src/pwm/simple_pwm.rs b/embassy-stm32/src/pwm/simple_pwm.rs
index a475f3f70..049a64027 100644
--- a/embassy-stm32/src/pwm/simple_pwm.rs
+++ b/embassy-stm32/src/pwm/simple_pwm.rs
@@ -92,6 +92,8 @@ impl<'d, T: CaptureCompare16bitInstance> SimplePwm<'d, T> {
         this.inner.start();
 
         unsafe {
+            this.inner.enable_outputs(true);
+
             this.inner
                 .set_output_compare_mode(Channel::Ch1, OutputCompareMode::PwmMode1);
             this.inner
diff --git a/examples/stm32f4/src/bin/pwm.rs b/examples/stm32f4/src/bin/pwm.rs
new file mode 100644
index 000000000..cd20c68bb
--- /dev/null
+++ b/examples/stm32f4/src/bin/pwm.rs
@@ -0,0 +1,35 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_stm32::pwm::simple_pwm::SimplePwm;
+use embassy_stm32::pwm::Channel;
+use embassy_stm32::time::U32Ext;
+use embassy_stm32::Peripherals;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    let mut pwm = SimplePwm::new_1ch(p.TIM1, p.PE9, 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;
+    }
+}