target/linux/layerscape/patches-5.4/806-dma-0018-dma-imx-add-the-32bit-dma-limitation.patch

From bd7176b9cb91671b248fbdef0c65d2893fd78226 Mon Sep 17 00:00:00 2001
From: Richard Zhu <hongxing.zhu@nxp.com>
Date: Fri, 25 Jan 2019 18:02:22 +0800
Subject: [PATCH] dma: imx: add the 32bit dma limitation

Since the imx8qm/qxp hsio only supports up to 32bit
dma capability.
Add the 32bit dma limitation into dma binding document.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
 Documentation/devicetree/bindings/dma/fsl-imx-dma.txt | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

--- a/Documentation/devicetree/bindings/dma/fsl-imx-dma.txt
+++ b/Documentation/devicetree/bindings/dma/fsl-imx-dma.txt
@@ -16,6 +16,21 @@ Optional properties:
 - #dma-channels : Number of DMA channels supported. Should be 16.
 - #dma-requests : Number of DMA requests supported.
 
+* DMA capability limitation
+
+Specify the DMA capability limitations.
+For example, some SoCs only support up to 32bit DMA capability, although
+they are 64bit SoCs.
+
+- only-dma-mask32: 1 means that the SoCs only suppot up to 32bit DMA
+  capability.
+
+Example:
+	dma_cap: dma_cap {
+		compatible = "dma-capability";
+		only-dma-mask32 = <1>;
+	};
+
 Example:
 
 	dma: dma@10001000 {