Re: [PATCH v5 1/2] dt-bindings: dma: Add bindings for intel LGM SOC

From: Rob Herring
Date: Fri Aug 14 2020 - 16:32:29 EST


On Fri, Aug 14, 2020 at 01:26:09PM +0800, Amireddy Mallikarjuna reddy wrote:
> Add DT bindings YAML schema for DMA controller driver
> of Lightning Mountain(LGM) SoC.
>
> Signed-off-by: Amireddy Mallikarjuna reddy <mallikarjunax.reddy@xxxxxxxxxxxxxxx>
> ---
> v1:
> - Initial version.
>
> v2:
> - Fix bot errors.
>
> v3:
> - No change.
>
> v4:
> - Address Thomas langer comments
> - use node name pattern as dma-controller as in common binding.
> - Remove "_" (underscore) in instance name.
> - Remove "port-" and "chan-" in attribute name for both 'dma-ports' & 'dma-channels' child nodes.
>
> v5:
> - Moved some of the attributes in 'dma-ports' & 'dma-channels' child nodes to dma client/consumer side as cells in 'dmas' properties.
> ---
> .../devicetree/bindings/dma/intel,ldma.yaml | 319 +++++++++++++++++++++
> 1 file changed, 319 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dma/intel,ldma.yaml
>
> diff --git a/Documentation/devicetree/bindings/dma/intel,ldma.yaml b/Documentation/devicetree/bindings/dma/intel,ldma.yaml
> new file mode 100644
> index 000000000000..9beaf191a6de
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/intel,ldma.yaml
> @@ -0,0 +1,319 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/intel,ldma.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Lightning Mountain centralized low speed DMA and high speed DMA controllers.
> +
> +maintainers:
> + - chuanhua.lei@xxxxxxxxx
> + - mallikarjunax.reddy@xxxxxxxxx
> +
> +allOf:
> + - $ref: "dma-controller.yaml#"
> +
> +properties:
> + $nodename:
> + pattern: "^dma-controller(@.*)?$"
> +
> + "#dma-cells":
> + const: 1

Example says 3.

> +
> + compatible:
> + anyOf:
> + - const: intel,lgm-cdma
> + - const: intel,lgm-dma2tx
> + - const: intel,lgm-dma1rx
> + - const: intel,lgm-dma1tx
> + - const: intel,lgm-dma0tx
> + - const: intel,lgm-dma3
> + - const: intel,lgm-toe-dma30
> + - const: intel,lgm-toe-dma31

'anyOf' doesn't make sense here. This should be a single 'enum'.

> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> +
> + resets:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + intel,dma-poll-cnt:
> + $ref: /schemas/types.yaml#definitions/uint32
> + description:
> + DMA descriptor polling counter. It may need fine tune according
> + to the system application scenario.
> +
> + intel,dma-byte-en:
> + type: boolean
> + description:
> + DMA byte enable is only valid for DMA write(RX).
> + Byte enable(1) means DMA write will be based on the number of dwords
> + instead of the whole burst.
> +
> + intel,dma-drb:
> + type: boolean
> + description:
> + DMA descriptor read back to make sure data and desc synchronization.
> +
> + intel,dma-burst:
> + $ref: /schemas/types.yaml#definitions/uint32
> + description:
> + Specifiy the DMA burst size(in dwords), the valid value will be 8, 16, 32.
> + Default is 16 for data path dma, 32 is for memcopy DMA.
> +
> + intel,dma-polling-cnt:
> + $ref: /schemas/types.yaml#definitions/uint32
> + description:
> + DMA descriptor polling counter. It may need fine tune according to
> + the system application scenario.
> +
> + intel,dma-desc-in-sram:
> + type: boolean
> + description:
> + DMA descritpors in SRAM or not. Some old controllers descriptors
> + can be in DRAM or SRAM. The new ones are all in SRAM.
> +
> + intel,dma-orrc:
> + $ref: /schemas/types.yaml#definitions/uint32
> + description:
> + DMA outstanding read counter. The maximum value is 16, and it may
> + need fine tune according to the system application scenarios.
> +
> + intel,dma-dburst-wr:
> + type: boolean
> + description:
> + Enable RX dynamic burst write. It only applies to RX DMA and memcopy DMA.
> +
> +
> + dma-ports:
> + type: object
> + description:
> + This sub-node must contain a sub-node for each DMA port.
> + properties:
> + '#address-cells':
> + const: 1
> + '#size-cells':
> + const: 0
> +
> + patternProperties:
> + "^dma-ports@[0-9]+$":
> + type: object
> +
> + properties:
> + reg:
> + items:
> + - enum: [0, 1, 2, 3, 4, 5]
> + description:
> + Which port this node refers to.
> +
> + intel,name:
> + $ref: /schemas/types.yaml#definitions/string-array
> + description:
> + Port name of each DMA port.

No other DMA controller needs this, why do you?

> +
> + intel,chans:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description:
> + The channels included on this port. Format is channel start
> + number and how many channels on this port.

Why does this need to be in DT? This all seems like it can be in the dma
cells for each client.

> +
> + required:
> + - reg
> + - intel,name
> + - intel,chans
> +
> +
> + ldma-channels:
> + type: object
> + description:
> + This sub-node must contain a sub-node for each DMA channel.
> + properties:
> + '#address-cells':
> + const: 1
> + '#size-cells':
> + const: 0
> +
> + patternProperties:
> + "^ldma-channels@[0-15]+$":
> + type: object
> +
> + properties:
> + reg:
> + items:
> + - enum: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
> + description:
> + Which channel this node refers to.
> +
> + intel,desc_num:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Per channel maximum descriptor number. The max value is 255.
> +
> + intel,hdr-mode:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description:
> + The first parameter is header mode size, the second
> + parameter is checksum enable or disable. If enabled,
> + header mode size is ignored. If disabled, header mode
> + size must be provided.
> +
> + intel,hw-desc:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description:
> + Per channel dma hardware descriptor configuration.
> + The first parameter is descriptor physical address and the
> + second parameter hardware descriptor number.

Again, this all seems like per client information for dma cells.

> +
> + required:
> + - reg
> +
> +required:
> + - compatible
> + - reg
> + - '#dma-cells'

Add:

additionalProperties: false

> +
> +examples:
> + - |
> + dma0: dma-controller@e0e00000 {
> + compatible = "intel,lgm-cdma";
> + reg = <0xe0e00000 0x1000>;
> + #dma-cells = <3>;
> + interrupt-parent = <&ioapic1>;
> + interrupts = <82 1>;
> + resets = <&rcu0 0x30 0>;
> + reset-names = "ctrl";

Not documented.

> + clocks = <&cgu0 80>;
> + intel,dma-poll-cnt = <4>;
> + intel,dma-byte-en;
> + intel,dma-drb;
> + dma-ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + dma-ports@0 {
> + reg = <0>;
> + intel,name = "SPI0";
> + intel,chans = <0 2>;
> + };
> + dma-ports@1 {
> + reg = <1>;
> + intel,name = "SPI1";
> + intel,chans = <2 2>;
> + };
> + dma-ports@2 {
> + reg = <2>;
> + intel,name = "SPI2";
> + intel,chans = <4 2>;
> + };
> + dma-ports@3 {
> + reg = <3>;
> + intel,name = "SPI3";
> + intel,chans = <6 2>;
> + };
> + dma-ports@4 {
> + reg = <4>;
> + intel,name = "HSNAND";
> + intel,chans = <8 2>;
> + };
> + dma-ports@5 {
> + reg = <5>;
> + intel,name = "PCM";
> + intel,chans = <10 6>;
> + };
> + };
> + ldma-channels {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + ldma-channels@0 {
> + reg = <0>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@1 {
> + reg = <1>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@2 {
> + reg = <2>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@3 {
> + reg = <3>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@4 {
> + reg = <4>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@5 {
> + reg = <5>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@6 {
> + reg = <6>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@7 {
> + reg = <7>;
> + intel,desc_num = <1>;
> + };
> + ldma-channels@8 {
> + reg = <8>;
> + };
> + ldma-channels@9 {
> + reg = <9>;
> + };
> + ldma-channels@10 {
> + reg = <10>;
> + };
> + ldma-channels@11 {
> + reg = <11>;
> + };
> + ldma-channels@12 {
> + reg = <12>;
> + };
> + ldma-channels@13 {
> + reg = <13>;
> + };
> + ldma-channels@14 {
> + reg = <14>;
> + };
> + ldma-channels@15 {
> + reg = <15>;
> + };
> + };
> + };
> + - |
> + dma3: dma-controller@ec800000 {
> + compatible = "intel,lgm-dma3";
> + reg = <0xec800000 0x1000>;
> + clocks = <&cgu0 71>;
> + resets = <&rcu0 0x10 9>;
> + #dma-cells = <7>;
> + intel,dma-burst = <32>;
> + intel,dma-polling-cnt = <16>;
> + intel,dma-desc-in-sram;
> + intel,dma-orrc = <16>;
> + intel,dma-byte-en;
> + intel,dma-dburst-wr;
> + ldma-channels {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + ldma-channels@12 {
> + reg = <12>;
> + intel,hdr-mode = <128 0>;
> + intel,hw-desc = <0x20000000 8>;
> + };
> + ldma-channels@13 {
> + reg = <13>;
> + intel,hdr-mode = <128 0>;
> + };
> + };
> + };
> --
> 2.11.0
>