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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /Documentation/devicetree/bindings/dma/jz4780-dma.txt
parentInitial commit. (diff)
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Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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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.
+- 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";
+ ...
+};