Re: [PATCH v6 01/16] dt-bindings: dma: Add YAML schemas for dw-axi-dmac

From: Rob Herring
Date: Mon Dec 14 2020 - 17:53:26 EST


On Fri, Dec 11, 2020 at 08:46:27AM +0800, Sia Jee Heng wrote:
> YAML schemas Device Tree (DT) binding is the new format for DT to replace
> the old format. Introduce YAML schemas DT binding for dw-axi-dmac and
> remove the old version.
>
> Signed-off-by: Sia Jee Heng <jee.heng.sia@xxxxxxxxx>
> ---
> .../bindings/dma/snps,dw-axi-dmac.txt | 39 ------
> .../bindings/dma/snps,dw-axi-dmac.yaml | 125 ++++++++++++++++++
> 2 files changed, 125 insertions(+), 39 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.txt
> create mode 100644 Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml


> diff --git a/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> new file mode 100644
> index 000000000000..61ad37a3f559
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.yaml
> @@ -0,0 +1,125 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/snps,dw-axi-dmac.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synopsys DesignWare AXI DMA Controller
> +
> +maintainers:
> + - Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx>
> +
> +description:
> + Synopsys DesignWare AXI DMA Controller DT Binding

allOf:
- $ref: dma-controller.yaml#

> +
> +properties:
> + compatible:
> + enum:
> + - snps,axi-dma-1.01a
> +
> + reg:
> + items:
> + - description: Address range of the DMAC registers
> +
> + reg-names:
> + items:
> + - const: axidma_ctrl_regs
> +
> + interrupts:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: Bus Clock
> + - description: Module Clock
> +
> + clock-names:
> + items:
> + - const: core-clk
> + - const: cfgr-clk
> +
> + '#dma-cells':
> + const: 1
> +
> + dma-channels:
> + description: |
> + Number of channels supported by hardware.

Already described in dma-controller.yaml

> + minimum: 1
> + maximum: 8
> +
> + snps,dma-masters:
> + description: |
> + Number of AXI masters supported by the hardware.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [1, 2]
> + default: 2
> +
> + snps,data-width:
> + description: |
> + AXI data width supported by hardware.
> + (0 - 8bits, 1 - 16bits, 2 - 32bits, ..., 6 - 512bits)
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [0, 1, 2, 3, 4, 5, 6]
> + default: 4
> +
> + snps,priority:
> + description: |
> + Channel priority specifier associated with the DMA channels.
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + minItems: 1
> + maxItems: 8
> + default: [0, 1, 2, 3]
> +
> + snps,block-size:
> + description: |
> + Channel block size specifier associated with the DMA channels.
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + minItems: 1
> + maxItems: 8
> + default: [4096, 4096, 4096, 4096]
> +
> + snps,axi-max-burst-len:
> + description: |
> + Restrict master AXI burst length by value specified in this property.
> + If this property is missing the maximum AXI burst length supported by
> + DMAC is used.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1
> + maximum: 256
> + default: 16
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - clock-names
> + - interrupts
> + - '#dma-cells'

Already required.

> + - dma-channels
> + - snps,dma-masters
> + - snps,data-width
> + - snps,priority
> + - snps,block-size

How can these be both required and have a default?

> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> + /* example with snps,dw-axi-dmac */
> + dmac: dma-controller@80000 {
> + compatible = "snps,axi-dma-1.01a";
> + reg = <0x80000 0x400>;
> + clocks = <&core_clk>, <&cfgr_clk>;
> + clock-names = "core-clk", "cfgr-clk";
> + interrupt-parent = <&intc>;
> + interrupts = <27>;
> + #dma-cells = <1>;
> + dma-channels = <4>;
> + snps,dma-masters = <2>;
> + snps,data-width = <3>;
> + snps,block-size = <4096 4096 4096 4096>;
> + snps,priority = <0 1 2 3>;
> + snps,axi-max-burst-len = <16>;
> + };
> --
> 2.18.0
>