Merge pull request #4847 from yannick818/stm32-dsi-cmd

stm32/dsi: support short write without parameters

2 files changed, 6 insertions, 7 deletions

diff --git a/embassy-stm32/CHANGELOG.md b/embassy-stm32/CHANGELOG.md
index 2a7a89bc9..df1d909b7 100644
--- a/embassy-stm32/CHANGELOG.md
+++ b/embassy-stm32/CHANGELOG.md
@@ -44,6 +44,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - feat: Added RTC low-power support for STM32WLEx ([#4716](https://github.com/embassy-rs/embassy/pull/4716))
 - fix: Correct STM32WBA VREFBUFTRIM values
 - low_power: remove stop_with rtc and initialize in init if low-power feature enabled.
+- feat: stm32/dsi support zero parameter commands in `write_cmd` ([#4847](https://github.com/embassy-rs/embassy/pull/4847))
 - feat: stm32/spi: added support for slave mode ([#4388](https://github.com/embassy-rs/embassy/pull/4388))
 
 ## 0.4.0 - 2025-08-26
diff --git a/embassy-stm32/src/dsihost.rs b/embassy-stm32/src/dsihost.rs
index fd1682d2b..59a2cbcdb 100644
--- a/embassy-stm32/src/dsihost.rs
+++ b/embassy-stm32/src/dsihost.rs
@@ -121,17 +121,15 @@ impl<'d, T: Instance> DsiHost<'d, T> {
 
     /// DCS or Generic short/long write command
     pub fn write_cmd(&mut self, channel_id: u8, address: u8, data: &[u8]) -> Result<(), Error> {
-        assert!(data.len() > 0);
-
-        if data.len() == 1 {
-            self.short_write(channel_id, PacketType::DcsShortPktWriteP1, address, data[0])
-        } else {
-            self.long_write(
+        match data.len() {
+            0 => self.short_write(channel_id, PacketType::DcsShortPktWriteP0, address, 0),
+            1 => self.short_write(channel_id, PacketType::DcsShortPktWriteP1, address, data[0]),
+            _ => self.long_write(
                 channel_id,
                 PacketType::DcsLongPktWrite, // FIXME: This might be a generic long packet, as well...
                 address,
                 data,
-            )
+            ),
         }
     }