Merge pull request #3653 from fwolter/add-remap

STM32F0/F3 Remap DMA channels

4 files changed, 43 insertions, 4 deletions

diff --git a/embassy-stm32/CHANGELOG.md b/embassy-stm32/CHANGELOG.md
index b6781905e..c4c2cd013 100644
--- a/embassy-stm32/CHANGELOG.md
+++ b/embassy-stm32/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Unreleased
 - Modify BufferedUart initialization to take pins before interrupts ([#3983](https://github.com/embassy-rs/embassy/pull/3983))
 - Added a 'single-bank' and a 'dual-bank' feature so chips with configurable flash bank setups are be supported in embassy ([#4125](https://github.com/embassy-rs/embassy/pull/4125))
+- Add automatic setting of remap bits when using alternate DMA channels on STM32F0 and STM32F3 devices ([#3653](https://github.com/embassy-rs/embassy/pull/3653))
 
 ## 0.2.0 - 2025-01-10
 
diff --git a/embassy-stm32/Cargo.toml b/embassy-stm32/Cargo.toml
index 0266b53b6..d9c5d1dd9 100644
--- a/embassy-stm32/Cargo.toml
+++ b/embassy-stm32/Cargo.toml
@@ -81,7 +81,7 @@ futures-util = { version = "0.3.30", default-features = false }
 sdio-host = "0.9.0"
 critical-section = "1.1"
 #stm32-metapac = { version = "16" }
-stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-f761780b74faf840220b367b15d556b9e10c2334" }
+stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-6e47f105286c0de07f641e22f27db060f1395e86" }
 
 vcell = "0.1.3"
 nb = "1.0.0"
@@ -110,7 +110,7 @@ proc-macro2 = "1.0.36"
 quote = "1.0.15"
 
 #stm32-metapac = { version = "16", default-features = false, features = ["metadata"]}
-stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-f761780b74faf840220b367b15d556b9e10c2334", default-features = false, features = ["metadata"] }
+stm32-metapac = { git = "https://github.com/embassy-rs/stm32-data-generated", tag = "stm32-data-6e47f105286c0de07f641e22f27db060f1395e86", default-features = false, features = ["metadata"] }
 
 [features]
 default = ["rt"]
diff --git a/embassy-stm32/build.rs b/embassy-stm32/build.rs
index 753f241c7..ad07b0269 100644
--- a/embassy-stm32/build.rs
+++ b/embassy-stm32/build.rs
@@ -1551,9 +1551,35 @@ fn main() {
                             quote!(())
                         };
 
+                        let mut remap = quote!();
+                        for remap_info in ch.remap {
+                            let register = format_ident!("{}", remap_info.register.to_lowercase());
+                            let setter = format_ident!("set_{}", remap_info.field.to_lowercase());
+
+                            let field_metadata = METADATA
+                                .peripherals
+                                .iter()
+                                .filter(|p| p.name == "SYSCFG")
+                                .flat_map(|p| p.registers.as_ref().unwrap().ir.fieldsets.iter())
+                                .filter(|f| f.name.eq_ignore_ascii_case(remap_info.register))
+                                .flat_map(|f| f.fields.iter())
+                                .find(|f| f.name.eq_ignore_ascii_case(remap_info.field))
+                                .unwrap();
+
+                            let value = if field_metadata.bit_size == 1 {
+                                let bool_value = format_ident!("{}", remap_info.value > 0);
+                                quote!(#bool_value)
+                            } else {
+                                let value = remap_info.value;
+                                quote!(#value.into())
+                            };
+
+                            remap.extend(quote!(crate::pac::SYSCFG.#register().modify(|w| w.#setter(#value));));
+                        }
+
                         let channel = format_ident!("{}", channel);
                         g.extend(quote! {
-                            dma_trait_impl!(#tr, #peri, #channel, #request);
+                            dma_trait_impl!(#tr, #peri, #channel, #request, {#remap});
                         });
                     }
                 }
diff --git a/embassy-stm32/src/macros.rs b/embassy-stm32/src/macros.rs
index 7526bb180..3a0b490ba 100644
--- a/embassy-stm32/src/macros.rs
+++ b/embassy-stm32/src/macros.rs
@@ -81,17 +81,28 @@ macro_rules! dma_trait {
             /// Note: in some chips, ST calls this the "channel", and calls channels "streams".
             /// `embassy-stm32` always uses the "channel" and "request number" names.
             fn request(&self) -> crate::dma::Request;
+            #[doc = "Remap the DMA channel"]
+            fn remap(&self);
         }
     };
 }
 
 #[allow(unused)]
 macro_rules! dma_trait_impl {
-    (crate::$mod:ident::$trait:ident$(<$mode:ident>)?, $instance:ident, $channel:ident, $request:expr) => {
+    (crate::$mod:ident::$trait:ident$(<$mode:ident>)?, $instance:ident, $channel:ident, $request:expr, $remap:expr) => {
         impl crate::$mod::$trait<crate::peripherals::$instance $(, crate::$mod::$mode)?> for crate::peripherals::$channel {
             fn request(&self) -> crate::dma::Request {
                 $request
             }
+
+            fn remap(&self) {
+                critical_section::with(|_| {
+                    #[allow(unused_unsafe)]
+                    unsafe {
+                        $remap;
+                    }
+                });
+            }
         }
     };
 }
@@ -111,6 +122,7 @@ macro_rules! new_dma_nonopt {
 macro_rules! new_dma {
     ($name:ident) => {{
         let dma = $name;
+        dma.remap();
         let request = dma.request();
         Some(crate::dma::ChannelAndRequest {
             channel: dma.into(),