This patch adds the DT binding documentation for the FDMA xbar hw
found on STi based chipsets from STMicroelectronics.
Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
---
Documentation/devicetree/bindings/dma/st_fdma.txt | 24 +++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/Documentation/devicetree/bindings/dma/st_fdma.txt b/Documentation/devicetree/bindings/dma/st_fdma.txt
index 1ec7470..655ee57 100644
--- a/Documentation/devicetree/bindings/dma/st_fdma.txt
+++ b/Documentation/devicetree/bindings/dma/st_fdma.txt
@@ -3,6 +3,24 @@
The FDMA is a general-purpose direct memory access controller capable of
supporting 16 independent DMA channels. It accepts up to 32 DMA requests.
The FDMA is based on a Slim processor which require a firmware.
+To increase the number of peripheral request, the FDMA crossbar can mutiplex
+up to 96 peripheral requests to one of 3 fdma controlers engine.
+
+* FDMA crossbar
+
+Required properties:
+- compatible : Should be "st,fdma-xbar-1.0"
+- reg : Should contain XBAR registers location and length
+- dma-requests : Should contain the number of peripheral request supported
+- #st,fdma-xbar-cells : Must be <1>
+
+Example:
+ xbar0: fdma-xbar-mpe@0 {
+ compatible = "st,fdma-xbar-1.0";
+ reg = <0x8e80000 0x1000>;
+ dma-requests = <79>;
+ #st,fdma-xbar-cells = <1>;
+ };
* FDMA Controller
@@ -18,6 +36,11 @@ Required properties:
See: Documentation/devicetree/bindings/clock/clock-bindings.txt
+Optional properties:
+- st,fdma-xbar : Allow to plug controller behind the crossbar at offset X
+ 1. A phandle pointing to the FDMA crossbar
+ 2. Output offset <2..0>
+
Example:
fdma1: fdma-app@1 {
@@ -26,6 +49,7 @@ Example:
interrupts = <GIC_SPI 7 IRQ_TYPE_NONE>;
dma-channels = <16>;
#dma-cells = <3>;
+ st,fdma-xbar = <&xbar0 0>;
st,fw-name = "fdma_STiH407_1.elf";
clocks = <&CLK_S_C0_FLEXGEN CLK_FDMA>,
<&CLK_S_C0_FLEXGEN CLK_TX_ICN_DMU>,
--
1.9.1
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