mirror of
https://github.com/torvalds/linux.git
synced 2024-12-27 21:33:00 +00:00
77da5d19af
The driver now expects the devicetree to supply a second memory resource. This resource is mandatory on the newly supported SoCs. For the JZ4780, new devicetree code must also provide it, although the driver is still compatible with older devicetree binaries. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Tested-by: Mathieu Malaterre <malat@debian.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Vinod Koul <vkoul@kernel.org>
62 lines
1.8 KiB
Plaintext
62 lines
1.8 KiB
Plaintext
* Ingenic JZ4780 DMA Controller
|
|
|
|
Required properties:
|
|
|
|
- compatible: Should be one of:
|
|
* ingenic,jz4740-dma
|
|
* ingenic,jz4725b-dma
|
|
* ingenic,jz4770-dma
|
|
* ingenic,jz4780-dma
|
|
- reg: Should contain the DMA channel registers location and length, followed
|
|
by 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-controller@13420000 {
|
|
compatible = "ingenic,jz4780-dma";
|
|
reg = <0x13420000 0x400
|
|
0x13421000 0x40>;
|
|
|
|
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";
|
|
...
|
|
};
|