Add a binding document for the IMG Multi-threaded DMA Controller (MDC)
present on the MIPS-based Pistachio and other IMG SoCs.
Signed-off-by: Andrew Bresticker <abres...@chromium.org>
---
.../devicetree/bindings/dma/img-mdc-dma.txt | 57 ++++++++++++++++++++++
1 file changed, 57 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dma/img-mdc-dma.txt
diff --git a/Documentation/devicetree/bindings/dma/img-mdc-dma.txt
b/Documentation/devicetree/bindings/dma/img-mdc-dma.txt
new file mode 100644
index 0000000..28c1341
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/img-mdc-dma.txt
@@ -0,0 +1,57 @@
+* IMG Multi-threaded DMA Controller (MDC)
+
+Required properties:
+- compatible: Must be "img,pistachio-mdc-dma".
+- reg: Must contain the base address and length of the MDC registers.
+- interrupts: Must contain all the per-channel DMA interrupts.
+- clocks: Must contain an entry for each entry in clock-names.
+ See ../clock/clock-bindings.txt for details.
+- clock-names: Must include the following entries:
+ - sys: MDC system interface clock.
+- img,cr-periph: Must contain a phandle to the peripheral control syscon
+ node which contains the DMA request to channel mapping registers.
+- img,max-burst-multiplier: Must be the maximum supported burst size
multiplier.
+ The maximum burst size is this value multiplied by the hardware-reported bus
+ width.
+- #dma-cells: Must be 3:
+ - The first cell is the peripheral's DMA request line.
+ - The second cell is a bitmap specifying to which channels the DMA request
+ line may be mapped (i.e. bit N set indicates channel N is usable).
+ - The third cell is the thread ID to be used by the channel.
+
+Optional properties:
+- dma-channels: Number of supported DMA channels, up to 32. If not specified
+ the number reported by the hardware is used.
+
+Example:
+
+mdc: dma-controller@18143000 {
+ compatible = "img,pistachio-mdc-dma";
+ reg = <0x18143000 0x1000>;
+ interrupts = <GIC_SHARED 27 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 28 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 29 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 30 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 31 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 32 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 33 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 34 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 35 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 36 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 37 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 38 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&system_clk>;
+ clock-names = "sys";
+
+ img,max-burst-multiplier = <16>;
+ img,cr-periph = <&cr_periph>;
+
+ #dma-cells = <3>;
+};
+
+spi@18100f00 {
+ ...
+ dmas = <&mdc 9 0xffffffff 0>, <&mdc 10 0xffffffff 0>;
+ dma-names = "tx", "rx";
+ ...
+};
--
2.1.0.rc2.206.gedb03e5
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