Create DMA fn to select peripheral based on channel number

embassy-stm32/gen.py

@@ -75,6 +75,7 @@ for chip in chips.values():
         # ========= peripherals
 
         peripheral_names.extend((f'EXTI{x}' for x in range(16)))
+        num_dmas = 0
 
         for (name, peri) in chip['peripherals'].items():
             if 'block' not in peri:
@@ -147,11 +148,14 @@ for chip in chips.values():
 
             if block_mod == 'dma':
                 custom_singletons = True
+                num_dmas += 1
                 dma_num = int(name[3:])-1  # substract 1 because we want DMA1=0, DMA2=1
+
                 for ch_num in range(8):
                     channel = f'{name}_CH{ch_num}'
                     peripheral_names.append(channel)
-                    f.write(f'impl_dma_channel!({name}, {channel}, {dma_num}, {ch_num});')
+
+                    f.write(f'impl_dma_channel!({channel}, {dma_num}, {ch_num});')
 
             if peri['block'] == 'sdmmc_v2/SDMMC':
                 f.write(f'impl_sdmmc!({name});')
@@ -198,6 +202,19 @@ for chip in chips.values():
         """)
 
 
+        # ========= DMA peripherals
+        if num_dmas > 0:
+            f.write(f"""
+                pub fn DMA(n: u8) -> dma::Dma {{
+                    match n {{
+            """)
+            for n in range(num_dmas - 1):
+                f.write(f'{n} => DMA{n + 1},')
+            f.write(f"""
+                        _ => DMA{num_dmas},
+                    }}
+                }}
+            """)
 
         # ========= exti interrupts
 

embassy-stm32/src/dma/mod.rs

@@ -20,24 +20,22 @@ pub(crate) mod sealed {
         fn ch_num(&self) -> u8 {
             self.num() % 8
         }
-        fn regs(&self) -> pac::dma::Dma;
+        fn regs(&self) -> pac::dma::Dma {
+            pac::DMA(self.num())
+        }
     }
 }
 
 pub trait Channel: sealed::Channel + Sized {}
 
 macro_rules! impl_dma_channel {
-    ($name:ident, $type:ident, $dma_num:expr, $ch_num:expr) => {
+    ($type:ident, $dma_num:expr, $ch_num:expr) => {
         impl crate::dma::Channel for peripherals::$type {}
         impl crate::dma::sealed::Channel for peripherals::$type {
             #[inline]
             fn num(&self) -> u8 {
                 $dma_num * 8 + $ch_num
             }
-
-            fn regs(&self) -> dma::Dma {
-                $name
-            }
         }
     };
 }