dt-bindings: dma: stm32-dma3: prevent additional transfers

Some devices require a single transfer. For example, reading FMC ECC status
registers does not support multiple transfers.
Add the possibility to prevent additional transfers, by setting bit 17 of
the 'DMA transfer requirements' bit mask.

Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20241016-dma3-mp25-updates-v3-4-8311fe6f228d@foss.st.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
index 5484848..36f9fe8 100644 (file)
--- a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
+++ b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dma3.yaml
@@ -99,6 +99,9 @@ properties:
         -bit 16: Prevent packing/unpacking mode
           0x0: pack/unpack enabled when source data width/burst != destination data width/burst
           0x1: memory data width/burst forced to peripheral data width/burst to prevent pack/unpack
+        -bit 17: Prevent additional transfers due to linked-list refactoring
+          0x0: don't prevent additional transfers for optimal performance
+          0x1: prevent additional transfer to accommodate user constraints such as single transfer
 
 required:
   - compatible