Re: [PATCH v2 10/19] dt-bindings: dma: ti: Add document for K3 BCDMA

Rob Herring
2020-12-07T19:43:18Z

On Tue, Nov 17, 2020 at 12:56:47PM +0200, Peter Ujfalusi wrote:
> New binding document for
> Texas Instruments K3 Block Copy DMA (BCDMA).
>
> BCDMA is introduced as part of AM64.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> ---
> .../devicetree/bindings/dma/ti/k3-bcdma.yaml | 175 ++++++++++++++++++
> 1 file changed, 175 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
>
> diff --git a/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
> new file mode 100644
> index 000000000000..c6d76641ebec
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
> @@ -0,0 +1,175 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/ti/k3-bcdma.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments K3 DMSS BCDMA Device Tree Bindings
> +
> +maintainers:
> + - Peter Ujfalusi <peter.ujfalusi@ti.com>
> +
> +description: |
> + The Block Copy DMA (BCDMA) is intended to perform similar functions as the TR
> + mode channels of K3 UDMA-P.
> + BCDMA includes block copy channels and Split channels.
> +
> + Block copy channels mainly used for memory to memory transfers, but with
> + optional triggers a block copy channel can service peripherals by accessing
> + directly to memory mapped registers or area.
> +
> + Split channels can be used to service PSI-L based peripherals.
> + The peripherals can be PSI-L native or legacy, non PSI-L native peripherals
> + with PDMAs. PDMA is tasked to act as a bridge between the PSI-L fabric and the
> + legacy peripheral.
> +
> + PDMAs can be configured via BCDMA split channel's peer registers to match with
> + the configuration of the legacy peripheral.
> +
> +allOf:
> + - $ref: /schemas/dma/dma-controller.yaml#
> +
> +properties:
> + "#dma-cells":
> + const: 3
> + description: |
> + cell 1: type of the BCDMA channel to be used to service the peripheral:
> + 0 - split channel
> + 1 - block copy channel using global trigger 1
> + 2 - block copy channel using global trigger 2
> + 3 - block copy channel using local trigger
> +
> + cell 2: parameter for the channel:
> + if cell 1 is 0 (split channel):
> + PSI-L thread ID of the remote (to BCDMA) end.
> + Valid ranges for thread ID depends on the data movement direction:
> + for source thread IDs (rx): 0 - 0x7fff
> + for destination thread IDs (tx): 0x8000 - 0xffff
> +
> + Please refer to the device documentation for the PSI-L thread map and
> + also the PSI-L peripheral chapter for the correct thread ID.
> + if cell 1 is 1 or 2 (block copy channel using global trigger):
> + Unused, ignored
> +
> + The trigger must be configured for the channel externally to BCDMA,
> + channels using global triggers should not be requested directly, but
> + via DMA event router.
> + if cell 1 is 3 (block copy channel using local trigger):
> + bchan number of the locally triggered channel
> +
> + cell 3: ASEL value for the channel
> +
> + compatible:
> + enum:
> + - ti,am64-dmss-bcdma

Typically, we put 'compatible' first.

> + "#address-cells":
> + const: 2
> +
> + "#size-cells":
> + const: 2

These apply to child nodes, but you don't have any.

> +
> + reg:
> + maxItems: 5
> +
> + reg-names:
> + items:
> + - const: gcfg
> + - const: bchanrt
> + - const: rchanrt
> + - const: tchanrt
> + - const: ringrt
> +
> + msi-parent: true
> +
> + ti,asel:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: ASEL value for non slave channels
> +
> + ti,sci-rm-range-bchan:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description: |
> + Array of BCDMA block-copy channel resource subtypes for resource
> + allocation for this host
> + minItems: 1
> + # Should be enough
> + maxItems: 255
> + items:
> + maximum: 0x3f
> +
> + ti,sci-rm-range-tchan:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description: |
> + Array of BCDMA split tx channel resource subtypes for resource allocation
> + for this host
> + minItems: 1
> + # Should be enough
> + maxItems: 255
> + items:
> + maximum: 0x3f
> +
> + ti,sci-rm-range-rchan:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description: |
> + Array of BCDMA split rx channel resource subtypes for resource allocation
> + for this host
> + minItems: 1
> + # Should be enough
> + maxItems: 255
> + items:
> + maximum: 0x3f
> +
> +required:
> + - compatible
> + - "#address-cells"
> + - "#size-cells"
> + - "#dma-cells"
> + - reg
> + - reg-names
> + - msi-parent
> + - ti,sci
> + - ti,sci-dev-id
> + - ti,sci-rm-range-bchan
> + - ti,sci-rm-range-tchan
> + - ti,sci-rm-range-rchan
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |+
> + cbass_main {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + main_dmss {
> + compatible = "simple-mfd";
> + #address-cells = <2>;
> + #size-cells = <2>;
> + dma-ranges;
> + ranges;
> +
> + ti,sci-dev-id = <25>;
> +
> + main_bcdma: dma-controller@485c0100 {
> + compatible = "ti,am64-dmss-bcdma";
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + reg = <0x0 0x485c0100 0x0 0x100>,
> + <0x0 0x4c000000 0x0 0x20000>,
> + <0x0 0x4a820000 0x0 0x20000>,
> + <0x0 0x4aa40000 0x0 0x20000>,
> + <0x0 0x4bc00000 0x0 0x100000>;
> + reg-names = "gcfg", "bchanrt", "rchanrt", "tchanrt", "ringrt";
> + msi-parent = <&inta_main_dmss>;
> + #dma-cells = <3>;
> +
> + ti,sci = <&dmsc>;
> + ti,sci-dev-id = <26>;
> +
> + ti,sci-rm-range-bchan = <0x20>; /* BLOCK_COPY_CHAN */
> + ti,sci-rm-range-rchan = <0x21>; /* SPLIT_TR_RX_CHAN */
> + ti,sci-rm-range-tchan = <0x22>; /* SPLIT_TR_TX_CHAN */
> + };
> + };
> + };
> --
> Peter
>
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>