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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/dma/brcm,bcm2835-dma.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: BCM2835 DMA controller
maintainers:
- Nicolas Saenz Julienne <nsaenz@kernel.org>
description:
The BCM2835 DMA controller has 16 channels in total. Only the lower
13 channels have an associated IRQ. Some arbitrary channels are used by the
VideoCore firmware (1,3,6,7 in the current firmware version). The channels
0, 2 and 3 have special functionality and should not be used by the driver.
allOf:
- $ref: dma-controller.yaml#
properties:
compatible:
const: brcm,bcm2835-dma
reg:
maxItems: 1
interrupts:
description:
Should contain the DMA interrupts associated to the DMA channels in
ascending order.
minItems: 1
maxItems: 16
interrupt-names:
minItems: 1
maxItems: 16
'#dma-cells':
description: The single cell represents the DREQ number.
const: 1
brcm,dma-channel-mask:
$ref: /schemas/types.yaml#/definitions/uint32
description:
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.
unevaluatedProperties: false
required:
- compatible
- reg
- interrupts
- "#dma-cells"
- brcm,dma-channel-mask
examples:
- |
dma-controller@7e007000 {
compatible = "brcm,bcm2835-dma";
reg = <0x7e007000 0xf00>;
interrupts = <1 16>,
<1 17>,
<1 18>,
<1 19>,
<1 20>,
<1 21>,
<1 22>,
<1 23>,
<1 24>,
<1 25>,
<1 26>,
/* dma channel 11-14 share one irq */
<1 27>,
<1 27>,
<1 27>,
<1 27>,
/* unused shared irq for all channels */
<1 28>;
interrupt-names = "dma0",
"dma1",
"dma2",
"dma3",
"dma4",
"dma5",
"dma6",
"dma7",
"dma8",
"dma9",
"dma10",
"dma11",
"dma12",
"dma13",
"dma14",
"dma-shared-all";
#dma-cells = <1>;
brcm,dma-channel-mask = <0x7f35>;
};
...
|
