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| author | Paul Cercueil <paul@crapouillou.net> | 2021-12-06 17:42:55 +0000 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2021-12-17 21:39:27 +0530 |
| commit | dafa79a10ed70683811295cb68deca2d30c22ef4 (patch) | |
| tree | 699e5302a63bb08c84d5f6ad70e89350502a185d /Documentation | |
| parent | e0699a75955dabac1e2edcf67d74b9998fe9d42c (diff) | |
| download | linux-dafa79a10ed70683811295cb68deca2d30c22ef4.tar.gz | |
dt-bindings: dma: ingenic: Support #dma-cells = <3>
Extend the binding to support specifying a different request type for
each direction.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20211206174259.68133-3-paul@crapouillou.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/dma/ingenic,dma.yaml | 16 |
1 files 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. |