linux/Documentation/devicetree/bindings/dma/mmp-dma.txt
Robert Jarzmik 9ab9ae55fd dma: mmp_pdma: Add the #dma-requests DT property documentation
For pxa based platforms, the number of requestor lines should be
specified, so that the driver can check if the flow control should be
activated (when a requestor line is asked for) or not.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Rob Herring <robh@kernel.org>
2016-02-26 22:56:23 +01:00

80 lines
2.3 KiB
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* MARVELL MMP DMA controller
Marvell Peripheral DMA Controller
Used platforms: pxa688, pxa910, pxa3xx, etc
Required properties:
- compatible: Should be "marvell,pdma-1.0"
- reg: Should contain DMA registers location and length.
- interrupts: Either contain all of the per-channel DMA interrupts
or one irq for pdma device
Optional properties:
- #dma-channels: Number of DMA channels supported by the controller (defaults
to 32 when not specified)
- #dma-requests: Number of DMA requestor lines supported by the controller
(defaults to 32 when not specified)
"marvell,pdma-1.0"
Used platforms: pxa25x, pxa27x, pxa3xx, pxa93x, pxa168, pxa910, pxa688.
Examples:
/*
* Each channel has specific irq
* ICU parse out irq channel from ICU register,
* while DMA controller may not able to distinguish the irq channel
* Using this method, interrupt-parent is required as demuxer
* For example, pxa688 icu register 0x128, bit 0~15 is PDMA channel irq,
* 18~21 is ADMA irq
*/
pdma: dma-controller@d4000000 {
compatible = "marvell,pdma-1.0";
reg = <0xd4000000 0x10000>;
interrupts = <0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15>;
interrupt-parent = <&intcmux32>;
#dma-channels = <16>;
};
/*
* One irq for all channels
* Dmaengine driver (DMA controller) distinguish irq channel via
* parsing internal register
*/
pdma: dma-controller@d4000000 {
compatible = "marvell,pdma-1.0";
reg = <0xd4000000 0x10000>;
interrupts = <47>;
#dma-channels = <16>;
};
Marvell Two Channel DMA Controller used specifically for audio
Used platforms: pxa688, pxa910
Required properties:
- compatible: Should be "marvell,adma-1.0" or "marvell,pxa910-squ"
- reg: Should contain DMA registers location and length.
- interrupts: Either contain all of the per-channel DMA interrupts
or one irq for dma device
"marvell,adma-1.0" used on pxa688
"marvell,pxa910-squ" used on pxa910
Examples:
/* each channel has specific irq */
adma0: dma-controller@d42a0800 {
compatible = "marvell,adma-1.0";
reg = <0xd42a0800 0x100>;
interrupts = <18 19>;
interrupt-parent = <&intcmux32>;
};
/* One irq for all channels */
squ: dma-controller@d42a0800 {
compatible = "marvell,pxa910-squ";
reg = <0xd42a0800 0x100>;
interrupts = <46>;
};