Commit dfcfe386 authored by Stefan Wahren's avatar Stefan Wahren Committed by Vinod Koul

dt-bindings: dma: convert bcm2835-dma bindings to YAML

Convert the DT binding document for bcm2835-dma from .txt to YAML.
Signed-off-by: default avatarStefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230617133620.53129-3-stefan.wahren@i2se.comSigned-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent fbac8ceb
* BCM2835 DMA controller
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 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.
Required properties:
- compatible: Should be "brcm,bcm2835-dma".
- reg: Should contain DMA registers location and length.
- interrupts: Should contain the DMA interrupts associated
to the DMA channels in ascending order.
- interrupt-names: Should contain the names of the interrupt
in the form "dmaXX".
Use "dma-shared-all" for the common interrupt line
that is shared by all dma channels.
- #dma-cells: Must be <1>, the cell in the dmas property of the
client device represents the DREQ number.
- brcm,dma-channel-mask: Bit mask representing the channels
not used by the firmware in ascending order,
i.e. first channel corresponds to LSB.
Example:
dma: dma@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>;
};
DMA clients connected to the BCM2835 DMA controller must use the format
described in the dma.txt file, using a two-cell specifier for each channel.
Example:
bcm2835_i2s: i2s@7e203000 {
compatible = "brcm,bcm2835-i2s";
reg = < 0x7e203000 0x24>;
clocks = <&clocks BCM2835_CLOCK_PCM>;
dmas = <&dma 2>,
<&dma 3>;
dma-names = "tx", "rx";
};
# 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>;
};
...
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