Messages in this thread Patch in this message | | | From | Paul Cercueil <> | Subject | [PATCH v2 2/6] dt-bindings: dma: ingenic: Support #dma-cells = <3> | Date | Mon, 6 Dec 2021 17:42:55 +0000 |
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Extend the binding to support specifying a different request type for each direction.
Signed-off-by: Paul Cercueil <paul@crapouillou.net> ---
Notes: v2: Enhance documentation
.../devicetree/bindings/dma/ingenic,dma.yaml | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/Documentation/devicetree/bindings/dma/ingenic,dma.yaml b/Documentation/devicetree/bindings/dma/ingenic,dma.yaml index 2607b403277e..3b0b3b919af8 100644 --- a/Documentation/devicetree/bindings/dma/ingenic,dma.yaml +++ b/Documentation/devicetree/bindings/dma/ingenic,dma.yaml @@ -44,13 +44,19 @@ properties: maxItems: 1 "#dma-cells": - const: 2 + enum: [2, 3] description: > DMA clients must use the format described in dma.txt, giving a phandle - to the DMA controller plus the following 2 integer cells: - - - Request type: The DMA request type for transfers to/from the - device on the allocated channel, as defined in the SoC documentation. + to the DMA controller plus the following integer cells: + + - Request type: The DMA request type specifies the device endpoint that + will be the source or destination of the DMA transfer. + If "#dma-cells" is 2, the request type is a single cell, and the + direction will be unidirectional (either RX or TX but not both). + If "#dma-cells" is 3, the request type has two cells; the first + one corresponds to the host to device direction (TX), the second one + corresponds to the device to host direction (RX). The DMA channel is + then bidirectional. - Channel: If set to 0xffffffff, any available channel will be allocated for the client. Otherwise, the exact channel specified will be used. -- 2.33.0
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