Re: [PATCH 2/5] dt-bindings: dma: ingenic: Support #dma-cells = <3>
From: Vinod Koul <vkoul@kernel.org>
Date: 2021-10-18 06:28:45
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dmaengine, linux-mips, lkml
On 11-10-21, 16:36, Paul Cercueil wrote:
quoted hunk ↗ jump to hunk
Extend the binding to support specifying a different request type for each direction. Signed-off-by: Paul Cercueil <paul@crapouillou.net> --- Documentation/devicetree/bindings/dma/ingenic,dma.yaml | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)diff --git a/Documentation/devicetree/bindings/dma/ingenic,dma.yaml b/Documentation/devicetree/bindings/dma/ingenic,dma.yaml index f45fd5235879..51b41e4795a2 100644 --- a/Documentation/devicetree/bindings/dma/ingenic,dma.yaml +++ b/Documentation/devicetree/bindings/dma/ingenic,dma.yaml@@ -44,13 +44,17 @@ 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: + to the DMA controller plus the following integer cells: - Request type: The DMA request type for transfers to/from the device on the allocated channel, as defined in the SoC documentation. + If "#dma-cells" is 2, the request type is a single cell. If + "#dma-cells" is 3, the request type has two cells; the first one + corresponds to the host to device direction, the second one corresponds + to the device to host direction.
Why would you need the direction here, that should be a runtime parameter and not a DT one?
- 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-- ~Vinod