Merge pull request #4778 from everdrone/stm32_sai_frame_length

allow setting stm32 SAI frame_length to 256

Author: xoviat

embassy-stm32/CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased - ReleaseDate
 
+- fix: Allow setting SAI peripheral `frame_length` to `256`
 - fix: flash erase on dual-bank STM32Gxxx
 - feat: Add support for STM32N657X0
 - feat: timer: Add 32-bit timer support to SimplePwm waveform_up method following waveform pattern ([#4717](https://github.com/embassy-rs/embassy/pull/4717))

embassy-stm32/src/sai/mod.rs

@@ -391,7 +391,7 @@ pub struct Config {
     pub frame_sync_polarity: FrameSyncPolarity,
     pub frame_sync_active_level_length: word::U7,
     pub frame_sync_definition: FrameSyncDefinition,
-    pub frame_length: u8,
+    pub frame_length: u16,
     pub clock_strobe: ClockStrobe,
     pub output_drive: OutputDrive,
     pub master_clock_divider: Option<MasterClockDivider>,
@@ -696,7 +696,7 @@ impl<'d, T: Instance, W: word::Word> Sai<'d, T, W> {
             w.set_fspol(config.frame_sync_polarity.fspol());
             w.set_fsdef(config.frame_sync_definition.fsdef());
             w.set_fsall(config.frame_sync_active_level_length.0 as u8 - 1);
-            w.set_frl(config.frame_length - 1);
+            w.set_frl((config.frame_length - 1).try_into().unwrap());
         });
 
         ch.slotr().modify(|w| {

examples/stm32h723/src/bin/spdifrx.rs

@@ -167,7 +167,7 @@ fn new_sai_transmitter<'d>(
     sai_config.slot_count = hal::sai::word::U4(CHANNEL_COUNT as u8);
     sai_config.slot_enable = 0xFFFF; // All slots
     sai_config.data_size = sai::DataSize::Data32;
-    sai_config.frame_length = (CHANNEL_COUNT * 32) as u8;
+    sai_config.frame_length = (CHANNEL_COUNT * 32) as u16;
     sai_config.master_clock_divider = None;
 
     let (sub_block_tx, _) = hal::sai::split_subblocks(sai);