DMA-350 can be integrated with either one interrupt per channel or a
single combined interrupt for all channels. This series adds support
for the combined IRQ topology while keeping compatibility with the
per-channel topology.

Patch 1 updates the DT binding to describe both interrupt topologies
(1 combined IRQ or 8 per-channel IRQs) and keeps "arm,dma-350" as the
generic compatible, with optional SoC-specific fallback compatible.

Patch 2 updates the driver to detect IRQ topology at runtime using
platform_irq_count(), handles both modes in one code path, and enables
DMANSECCTRL.INTREN_ANYCHINTR only when combined IRQ mode is used.

Patch 3 adds the Sky1 DMA DT node using the combined IRQ topology.

Tested on CIX SKY1 with dmatest:
  % echo 2000 > /sys/module/dmatest/parameters/timeout
  % echo 1 > /sys/module/dmatest/parameters/iterations
  % echo "" > /sys/module/dmatest/parameters/channel
  % echo 1 > /sys/module/dmatest/parameters/run

Changes in v4:
- Reword binding text to align with kernel style.
- Revise the AI attribution to the standard format.
- Remove redundant links from the commit log.

Changes in v3:
- Rework binding compatible description to match generic-first model.
- Keep interrupts schema support for both 1-IRQ and 8-IRQ topologies.
- Drop SoC match-data dependency for IRQ mode selection.
- Detect IRQ topology via platform_irq_count() in probe path.
- Refactor IRQ handling into a shared channel handler.
- Enable DMANSECCTRL.INTREN_ANYCHINTR only in combined IRQ mode.

Changes in v2:
- Update to kernel standards, enhance patch description, and refactor
 driver to use match data for hardware differentiation instead of
 compatible strings.

Jun Guo (3):
  dt-bindings: dma: arm-dma350: document generic and combined IRQ
    topologies
  dma: arm-dma350: support combined IRQ mode with runtime IRQ topology
    detection
  arm64: dts: cix: add DT nodes for DMA

 .../devicetree/bindings/dma/arm,dma-350.yaml  |  34 ++--
 arch/arm64/boot/dts/cix/sky1.dtsi             |   7 +
 drivers/dma/arm-dma350.c                      | 165 +++++++++++++++---
 3 files changed, 170 insertions(+), 36 deletions(-)

-- 
2.34.1