The dma-cell values for the stm32-dmamux are used to craft the DMA spec for the actual controller. These values are currently undocumented leaving the user to reverse engineer the driver in order to determine their meaning. Add a basic description, while avoiding duplicating information by pointing the user to the associated DMA docs that describe the fields in depth. Signed-off-by: Ken Sloat <ksloat@xxxxxxxxxxxxxxxxxxxxxxx> --- .../bindings/dma/stm32/st,stm32-dmamux.yaml | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dmamux.yaml b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dmamux.yaml index f26c914a3a9a..aa2e52027ee6 100644 --- a/Documentation/devicetree/bindings/dma/stm32/st,stm32-dmamux.yaml +++ b/Documentation/devicetree/bindings/dma/stm32/st,stm32-dmamux.yaml @@ -15,6 +15,17 @@ allOf: properties: "#dma-cells": const: 3 + description: | + Should be set to <3> with each cell representing the following: + 1. The mux input number/line for the request + 2. Bitfield representing DMA channel configuration that is passed + to the real DMA controller + 3. Bitfield representing device dependent DMA features passed to + the real DMA controller + + For bitfield definitions of cells 2 and 3, see the associated + bindings doc for the actual DMA controller the mux is connected + to. compatible: const: st,stm32h7-dmamux -- 2.34.1
