Re: [PATCH v2 12/17] dt-bindings: dma: ti: Add document for K3 BCDMA V2

Rob Herring
2025-06-12T13:20:47Z

On Thu, Jun 12, 2025 at 12:45:16PM +0530, Sai Sree Kartheek Adivi wrote:
> New binding document for
> Texas Instruments K3 Block Copy DMA (BCDMA) V2.

Drop 'document for' in the subject.

>
> BCDMA V2 is introduced as part of AM62L.
>
> Signed-off-by: Sai Sree Kartheek Adivi <s-adivi@ti.com>
> ---
> .../bindings/dma/ti/k3-bcdma-v2.yaml | 97 +++++++++++++++++++
> 1 file changed, 97 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dma/ti/k3-bcdma-v2.yaml
>
> diff --git a/Documentation/devicetree/bindings/dma/ti/k3-bcdma-v2.yaml b/Documentation/devicetree/bindings/dma/ti/k3-bcdma-v2.yaml
> new file mode 100644
> index 0000000000000..9d86e515bdefb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/ti/k3-bcdma-v2.yaml
> @@ -0,0 +1,97 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2024-2025 Texas Instruments Incorporated
> +# Author: Sai Sree Kartheek Adivi <s-adivi@ti.com>

git records the author. Don't need it here.

> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/ti/k3-bcdma-v2.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments K3 DMSS BCDMA V2
> +
> +maintainers:
> + - Sai Sree Kartheek Adivi <s-adivi@ti.com>
> +
> +description: |
> + The BCDMA V2 is intended to perform similar functions as the TR
> + mode channels of K3 UDMA-P.
> + BCDMA V2 includes block copy channels and Split channels.

Is this one paragraph or 2? Either blank line between paragraphs or wrap
at 80 char.

> +
> + 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.
> +
> +allOf:
> + - $ref: /schemas/dma/dma-controller.yaml#
> +
> +properties:
> + compatible:
> + const: ti,am62l-dmss-bcdma
> +
> + reg:
> + items:
> + - description: BCDMA Control /Status
> + - description: Block Copy Channel Realtime
> + - description: Channel Realtime
> + - description: Ring Realtime
> +
> + reg-names:
> + items:
> + - const: gcfg
> + - const: bchanrt
> + - const: chanrt
> + - const: ringrt
> +
> + "#dma-cells":
> + const: 4
> + description: |
> + cell 1: Trigger type for the channel
> + 0 - disable / no trigger
> + 1 - internal channel event
> + 2 - external signal
> + 3 - timer manager event
> +
> + cell 2: parameter for the trigger:
> + if cell 1 is 0 (disable / no trigger):
> + Unused, ignored
> + if cell 1 is 1 (internal channel event):
> + channel number whose TR event should trigger the current channel.
> + if cell 1 is 2 or 3 (external signal or timer manager event):
> + index of global interfaces that come into the DMA.
> +
> + Please refer to the device documentation for global interface indexes.
> +
> + cell 3: Channel number for the peripheral
> +
> + Please refer to the device documentation for the channel map.
> +
> + cell 4: ASEL value for the channel
> +
> +required:
> + - compatible
> + - reg
> + - reg-names
> + - "#dma-cells"
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + cbass_main {

Don't use '_' in node names.

> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + dma-controller@485c4000 {
> + compatible = "ti,dmss-bcdma-v2";
> + reg = <0x00 0x485c4000 0x00 0x4000>,
> + <0x00 0x48880000 0x00 0x10000>,
> + <0x00 0x48800000 0x00 0x80000>,
> + <0x00 0x47000000 0x00 0x200000>;
> + reg-names = "gcfg", "bchanrt", "chanrt", "ringrt";
> + #dma-cells = <4>;
> + };
> + };
> --
> 2.34.1
>