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

* 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>;

    };

...