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author | Maxime Ripard <maxime.ripard@bootlin.com> | 2019-07-20 12:26:05 +0300 |
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committer | Vinod Koul <vkoul@kernel.org> | 2019-07-29 09:48:49 +0300 |
commit | b37e3534ac4275c1f0d0e08d1b6f672f6cc740c3 (patch) | |
tree | 5bd323424a2b72154a22d23908d8ac6829e367d8 /Documentation/devicetree/bindings/dma/dma.txt | |
parent | aa3c6ce4eab8fb0e967954be1ba1cad3b715f63b (diff) | |
download | linux-b37e3534ac4275c1f0d0e08d1b6f672f6cc740c3.tar.xz |
dt-bindings: dmaengine: Add YAML schemas for the generic DMA bindings
The DMA controllers and consumers have a bunch of generic properties that
are needed in a device tree. Add a YAML schemas for those.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20190720092607.31095-1-maxime.ripard@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'Documentation/devicetree/bindings/dma/dma.txt')
-rw-r--r-- | Documentation/devicetree/bindings/dma/dma.txt | 114 |
1 files changed, 1 insertions, 113 deletions
diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt index eeb4e4d1771e..90a67a016a48 100644 --- a/Documentation/devicetree/bindings/dma/dma.txt +++ b/Documentation/devicetree/bindings/dma/dma.txt @@ -1,113 +1 @@ -* Generic DMA Controller and DMA request bindings - -Generic binding to provide a way for a driver using DMA Engine to retrieve the -DMA request or channel information that goes from a hardware device to a DMA -controller. - - -* DMA controller - -Required property: -- #dma-cells: Must be at least 1. Used to provide DMA controller - specific information. See DMA client binding below for - more details. - -Optional properties: -- dma-channels: Number of DMA channels supported by the controller. -- dma-requests: Number of DMA request signals supported by the - controller. -- dma-channel-mask: Bitmask of available DMA channels in ascending order - that are not reserved by firmware and are available to - the kernel. i.e. first channel corresponds to LSB. - -Example: - - dma: dma@48000000 { - compatible = "ti,omap-sdma"; - reg = <0x48000000 0x1000>; - interrupts = <0 12 0x4 - 0 13 0x4 - 0 14 0x4 - 0 15 0x4>; - #dma-cells = <1>; - dma-channels = <32>; - dma-requests = <127>; - dma-channel-mask = <0xfffe> - }; - -* DMA router - -DMA routers are transparent IP blocks used to route DMA request lines from -devices to the DMA controller. Some SoCs (like TI DRA7x) have more peripherals -integrated with DMA requests than what the DMA controller can handle directly. - -Required property: -- dma-masters: phandle of the DMA controller or list of phandles for - the DMA controllers the router can direct the signal to. -- #dma-cells: Must be at least 1. Used to provide DMA router specific - information. See DMA client binding below for more - details. - -Optional properties: -- dma-requests: Number of incoming request lines the router can handle. -- In the node pointed by the dma-masters: - - dma-requests: The router driver might need to look for this in order - to configure the routing. - -Example: - sdma_xbar: dma-router@4a002b78 { - compatible = "ti,dra7-dma-crossbar"; - reg = <0x4a002b78 0xfc>; - #dma-cells = <1>; - dma-requests = <205>; - ti,dma-safe-map = <0>; - dma-masters = <&sdma>; - }; - -* DMA client - -Client drivers should specify the DMA property using a phandle to the controller -followed by DMA controller specific data. - -Required property: -- dmas: List of one or more DMA specifiers, each consisting of - - A phandle pointing to DMA controller node - - A number of integer cells, as determined by the - #dma-cells property in the node referenced by phandle - containing DMA controller specific information. This - typically contains a DMA request line number or a - channel number, but can contain any data that is - required for configuring a channel. -- dma-names: Contains one identifier string for each DMA specifier in - the dmas property. The specific strings that can be used - are defined in the binding of the DMA client device. - Multiple DMA specifiers can be used to represent - alternatives and in this case the dma-names for those - DMA specifiers must be identical (see examples). - -Examples: - -1. A device with one DMA read channel, one DMA write channel: - - i2c1: i2c@1 { - ... - dmas = <&dma 2 /* read channel */ - &dma 3>; /* write channel */ - dma-names = "rx", "tx"; - ... - }; - -2. A single read-write channel with three alternative DMA controllers: - - dmas = <&dma1 5 - &dma2 7 - &dma3 2>; - dma-names = "rx-tx", "rx-tx", "rx-tx"; - -3. A device with three channels, one of which has two alternatives: - - dmas = <&dma1 2 /* read channel */ - &dma1 3 /* write channel */ - &dma2 0 /* error read */ - &dma3 0>; /* alternative error read */ - dma-names = "rx", "tx", "error", "error"; +This file has been moved to dma-controller.yaml. |