From 36f4075b9054576ccf6dba2dedb08c62484a0599 Mon Sep 17 00:00:00 2001
From: Eicke Hecht <eicke.hecht@outlook.de>
Date: Sun, 23 Nov 2025 12:29:56 +0100
Subject: fix: Fix waveform for channels > 1 and disallow for unsupported dmas

---
 embassy-stm32/src/timer/low_level.rs | 12 +++++--
 examples/stm32f7/src/bin/pwm.rs      | 65 ++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+), 3 deletions(-)
 create mode 100644 examples/stm32f7/src/bin/pwm.rs

diff --git a/embassy-stm32/src/timer/low_level.rs b/embassy-stm32/src/timer/low_level.rs
index 670298d23..307d614bf 100644
--- a/embassy-stm32/src/timer/low_level.rs
+++ b/embassy-stm32/src/timer/low_level.rs
@@ -781,7 +781,7 @@ impl<'d, T: GeneralInstance4Channel> Timer<'d, T> {
         let cc_channel = C::CHANNEL;
 
         let original_cc_dma_on_update = self.get_cc_dma_selection() == Ccds::ON_UPDATE;
-        let original_cc_dma_enabled = self.get_c fsc_dma_enable_state(cc_channel);
+        let original_cc_dma_enabled = self.get_cc_dma_enable_state(cc_channel);
 
         // redirect CC DMA request onto Update Event
         if !original_cc_dma_on_update {
@@ -810,7 +810,12 @@ impl<'d, T: GeneralInstance4Channel> Timer<'d, T> {
 
     /// Generate a sequence of PWM waveform that will run continously
     /// You may want to start this in a new thread as this will block forever
+
     pub async fn waveform_continuous<C: TimerChannel>(&mut self, dma: Peri<'_, impl super::Dma<T, C>>, duty: &[u16]) {
+
+        #[cfg(any(bdma, gpdma))]
+        panic!("unsupported DMA");
+
         use crate::pac::timer::vals::Ccds;
 
         #[allow(clippy::let_unit_value)] // eg. stm32f334
@@ -871,6 +876,7 @@ impl<'d, T: GeneralInstance4Channel> Timer<'d, T> {
                 fifo_threshold: Some(FifoThreshold::Full),
                 #[cfg(not(any(bdma, gpdma)))]
                 mburst: Burst::Incr8,
+                #[cfg(not(any(bdma, gpdma)))]
                 circular: circular,
                 ..Default::default()
             };
@@ -881,7 +887,7 @@ impl<'d, T: GeneralInstance4Channel> Timer<'d, T> {
                         dma,
                         req,
                         duty,
-                        self.regs_1ch().ccr(channel.index()).as_ptr() as *mut u16,
+                        self.regs_gp16().ccr(channel.index()).as_ptr() as *mut u16,
                         dma_transfer_option,
                     )
                     .await
@@ -896,7 +902,7 @@ impl<'d, T: GeneralInstance4Channel> Timer<'d, T> {
                         dma,
                         req,
                         duty,
-                        self.regs_1ch().ccr(channel.index()).as_ptr() as *mut u32,
+                        self.regs_gp16().ccr(channel.index()).as_ptr() as *mut u32,
                         dma_transfer_option,
                     )
                     .await
diff --git a/examples/stm32f7/src/bin/pwm.rs b/examples/stm32f7/src/bin/pwm.rs
new file mode 100644
index 000000000..872d99859
--- /dev/null
+++ b/examples/stm32f7/src/bin/pwm.rs
@@ -0,0 +1,65 @@
+#![no_std]
+#![no_main]
+
+use defmt::{panic, *};
+use embassy_executor::Spawner;
+use embassy_futures::join::join;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::{Config, peripherals};
+use embassy_stm32::gpio::OutputType;
+use embassy_stm32::time::mhz;
+use embassy_stm32::timer::simple_pwm::{PwmPin, SimplePwm};
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+// If you are trying this and your USB device doesn't connect, the most
+// common issues are the RCC config and vbus_detection
+//
+// See https://embassy.dev/book/#_the_usb_examples_are_not_working_on_my_board_is_there_anything_else_i_need_to_configure
+// for more information.
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    info!("Hello World!");
+
+    let mut config = Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hse = Some(Hse {
+            freq: Hertz(8_000_000),
+            mode: HseMode::Bypass,
+        });
+        config.rcc.pll_src = PllSource::HSE;
+        config.rcc.pll = Some(Pll {
+            prediv: PllPreDiv::DIV4,
+            mul: PllMul::MUL200,
+            divp: Some(PllPDiv::DIV2), // 8mhz / 4 * 200 / 2 = 200Mhz
+            divq: Some(PllQDiv::DIV4), // 8mhz / 4 * 200 / 4 = 100Mhz
+            divr: None,
+        });
+        config.rcc.ahb_pre = AHBPrescaler::DIV1;
+        config.rcc.apb1_pre = APBPrescaler::DIV4;
+        config.rcc.apb2_pre = APBPrescaler::DIV2;
+        config.rcc.sys = Sysclk::PLL1_P;
+    }
+    let p = embassy_stm32::init(config);
+    let ch1_pin = PwmPin::new(p.PE9, OutputType::PushPull);
+    let ch2_pin = PwmPin::new(p.PE11, OutputType::PushPull);
+    let mut pwm = SimplePwm::new(p.TIM1, Some(ch1_pin), Some(ch2_pin), None, None, mhz(1), Default::default());
+    let mut ch1 = pwm.ch1();
+    ch1.enable();
+    info!("PWM initialized");
+    info!("PWM max duty {}", ch1.max_duty_cycle());
+
+    info!("PWM duty on channel 1 (D6) 50%");
+    ch1.set_duty_cycle_fraction(1, 2);
+    info!("PWM waveform on channel 2 (D5)");
+    const max_duty: usize = 200;
+    let mut duty = [0u16;max_duty];
+    for i in 0..max_duty {
+        duty[i] = i as u16;
+    }
+    pwm.waveform_continuous::<embassy_stm32::timer::Ch2>(p.DMA2_CH6, &duty).await;
+
+
+}
+
-- 
cgit