Subject: Re: [PATCH v5 12/18] dt-bindings: dma: ti: Add K3 BCDMA V2

From: Rob Herring <[email-masked]>
Date: Mon, 23 Feb 2026 12:20:57 -0600

On Thu, Feb 19, 2026 at 05:45:46PM +0530, Sai Sree Kartheek Adivi wrote:
> 
> On 19/02/26 13:13, Krzysztof Kozlowski wrote:
> 
> Hi Krzysztof,
> 
> Thanks for the review.
> > On Wed, Feb 18, 2026 at 03:22:37PM +0530, Sai Sree Kartheek Adivi wrote:
> > > New binding document for
> > Fix wrapping - it's wrapped too early.
> Ack. will fix it in v6.
> > 
> > > Texas Instruments K3 Block Copy DMA (BCDMA) V2.
> > > 
> > > BCDMA V2 is introduced as part of AM62L.
> > > 
> > > Signed-off-by: Sai Sree Kartheek Adivi <[email-masked]>
> > > ---
> > >   .../bindings/dma/ti/ti,am62l-dmss-bcdma.yaml  | 120 ++++++++++++++++++
> > >   1 file changed, 120 insertions(+)
> > >   create mode 100644 Documentation/devicetree/bindings/dma/ti/ti,am62l-dmss-bcdma.yaml
> > > 
> > > diff --git a/Documentation/devicetree/bindings/dma/ti/ti,am62l-dmss-bcdma.yaml b/Documentation/devicetree/bindings/dma/ti/ti,am62l-dmss-bcdma.yaml
> > > new file mode 100644
> > > index 0000000000000..6fa08f22df375
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/dma/ti/ti,am62l-dmss-bcdma.yaml
> > > @@ -0,0 +1,120 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +# Copyright (C) 2024-25 Texas Instruments Incorporated
> > > +# Author: Sai Sree Kartheek Adivi <[email-masked]>
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/dma/ti/ti,am62l-dmss-bcdma.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Texas Instruments K3 DMSS BCDMA V2
> > > +
> > > +maintainers:
> > > +  - Sai Sree Kartheek Adivi <[email-masked]>
> > > +
> > > +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.
> > > +
> > > +  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 Registers region
> > > +      - description: Block Copy Channel Realtime Registers region
> > > +      - description: Channel Realtime Registers region
> > > +      - description: Ring Realtime Registers region
> > > +
> > > +  reg-names:
> > > +    items:
> > > +      - const: gcfg
> > > +      - const: bchanrt
> > > +      - const: chanrt
> > > +      - const: ringrt
> > > +
> > > +  "#address-cells":
> > > +    const: 0
> > > +
> > > +  "#interrupt-cells":
> > > +    const: 1
> > I don't get why this is nexus but not a interrupt-controller.
> > 
> > Can you point me to DTS with complete picture using this?
> 
> Please refer https://github.com/sskartheekadivi/linux/commit/4a7078a6892bfbc4c620b9668e3421b4c7405ca4
> 
> for the dt nodes of AM62L BCDMA and PKTDMA.
> 
> Refer to the below tree for full set of driver, dt-binding and dts changes
> 
> https://github.com/sskartheekadivi/linux/commits/dma-upstream-v5/

Whether this is an interrupt-map or a chained interrupt controller 
entirely depends on whether the interrupts are transparent to the 
DMA controller (i.e. do they have to be acked?). interrupt-map is 
generally for transparent cases.

If not transparent, then just 'interrupts' and 'interrupt-controller' 
should work for you. You can map 'interrupts' entries to channels like 
many other DMA controllers do that have per channel interrupts.

Rob