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authorAlex Smith <alex.smith@imgtec.com>2015-03-18 19:16:35 +0300
committerVinod Koul <vinod.koul@intel.com>2015-04-01 06:13:33 +0300
commitc8307106f5fa53b8fe8763b488d629e3cce9fae3 (patch)
treee1348e8e38562e15ae7167c6402802108a8d3fba /Documentation/devicetree/bindings/dma/jz4780-dma.txt
parent381a3c4a33bf33943ed3791bd8797d8d8490b4fd (diff)
downloadlinux-c8307106f5fa53b8fe8763b488d629e3cce9fae3.tar.xz
dt-bindings: dma: Add binding for jz4780-dma
Add device tree bindings for the DMA controller on JZ4780 SoCs, used by the dma-jz4780 driver. Signed-off-by: Alex Smith <alex.smith@imgtec.com> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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+* Ingenic JZ4780 DMA Controller
+
+Required properties:
+
+- compatible: Should be "ingenic,jz4780-dma"
+- reg: Should contain the DMA controller registers location and length.
+- interrupts: Should contain the interrupt specifier of the DMA controller.
+- interrupt-parent: Should be the phandle of the interrupt controller that
+- clocks: Should contain a clock specifier for the JZ4780 PDMA clock.
+- #dma-cells: Must be <2>. Number of integer cells in the dmas property of
+ DMA clients (see below).
+
+Optional properties:
+
+- ingenic,reserved-channels: Bitmask of channels to reserve for devices that
+ need a specific channel. These channels will only be assigned when explicitly
+ requested by a client. The primary use for this is channels 0 and 1, which
+ can be configured to have special behaviour for NAND/BCH when using
+ programmable firmware.
+
+Example:
+
+dma: dma@13420000 {
+ compatible = "ingenic,jz4780-dma";
+ reg = <0x13420000 0x10000>;
+
+ interrupt-parent = <&intc>;
+ interrupts = <10>;
+
+ clocks = <&cgu JZ4780_CLK_PDMA>;
+
+ #dma-cells = <2>;
+
+ ingenic,reserved-channels = <0x3>;
+};
+
+DMA clients must use the format described in dma.txt, giving a phandle to the
+DMA controller plus the following 2 integer cells:
+
+1. Request type: The DMA request type for transfers to/from the device on
+ the allocated channel, as defined in the SoC documentation.
+
+2. Channel: If set to 0xffffffff, any available channel will be allocated for
+ the client. Otherwise, the exact channel specified will be used. The channel
+ should be reserved on the DMA controller using the ingenic,reserved-channels
+ property.
+
+Example:
+
+uart0: serial@10030000 {
+ ...
+ dmas = <&dma 0x14 0xffffffff
+ &dma 0x15 0xffffffff>;
+ dma-names = "tx", "rx";
+ ...
+};