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Message-Id: <20260211-b4-imx95-v2x-v4-1-10852754b267@nxp.com>
Date: Wed, 11 Feb 2026 17:28:24 +0800
From: Joy Zou <joy.zou@....com>
To: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>, Shawn Guo <shawnguo@...nel.org>,
Sascha Hauer <s.hauer@...gutronix.de>,
Pengutronix Kernel Team <kernel@...gutronix.de>,
Fabio Estevam <festevam@...il.com>, Frank Li <Frank.Li@....com>,
Peng Fan <peng.fan@....com>, Ye Li <ye.li@....com>
Cc: devicetree@...r.kernel.org, imx@...ts.linux.dev,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
Joy Zou <joy.zou@....com>
Subject: [PATCH v4 1/3] dt-bindings: dma: fsl-edma: add dma-channel-mask
property description
Add documentation for the dma-channel-mask property in the fsl-edma
binding. This property uses an inverted bit definition: bit value 0
indicates the channel is available, while bit value 1 indicates
unavailable.
That was already used widely for i.MX8, i.MX9. Correcting the definition
will break backward compatibility. This reversal only impacts the eDMA
dts node and driver, and doesn't impact DMA consumer. Therefore,
keep the inverted definition.
Also add a note at the top of the binding to highlight this inverted
definition to prevent confusion.
Signed-off-by: Joy Zou <joy.zou@....com>
---
Documentation/devicetree/bindings/dma/fsl,edma.yaml | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/Documentation/devicetree/bindings/dma/fsl,edma.yaml b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
index fa4248e2f1b9cecd00f1535744bfe6d9ecdba613..f609038e35ae1836b89c5b4d8a095b15a882fb87 100644
--- a/Documentation/devicetree/bindings/dma/fsl,edma.yaml
+++ b/Documentation/devicetree/bindings/dma/fsl,edma.yaml
@@ -12,6 +12,9 @@ description: |
DMAMUX0 and DMAMUX1, specific DMA request source can only be multiplexed
by any channel of certain group, DMAMUX0 or DMAMUX1, but not both.
+ This binding has an inverted dma-channel-mask definition compared to
+ the common DMA binding for historical reasons.
+
maintainers:
- Peng Fan <peng.fan@....com>
@@ -95,6 +98,12 @@ properties:
eDMA are implemented in big endian mode, otherwise in little mode.
type: boolean
+ dma-channel-mask:
+ description: |
+ Bitmask of available DMA channels (inverted definition).
+ Bit semantics: 0 means channel available, 1 means channel unavailable
+ default: 0
+
required:
- "#dma-cells"
- compatible
--
2.37.1
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