dts/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.yaml

# Copyright (c) 2026 Jonathan Elliot Peace <jep@alphabetiq.com>
# SPDX-License-Identifier: Apache-2.0

description: |
  BCM2835 ARMC peripheral interrupt controller -- the "GPU IRQ" side
  of the BCM283x family (Pi 1 / Pi 2 / Pi 3 / Pi Zero family).

  Hangs off the BCM2836 ARM-local intc as a child. Aggregates 64 GPU
  IRQs (PEND1 + PEND2 banks) plus 8 ARMC "basic" IRQs into the GPU
  cascade line of its parent.

  Zephyr exposes this controller's IRQs in a flat range offset by 32
  (the L1 ARM-local intc occupies 0..31, only 0..9 used):
    32..39   = basic bank   (IRQ_BASIC_PENDING bits 0..7)
    64..95   = GPU PEND1    (PEND1 bits 0..31)
    96..127  = GPU PEND2    (PEND2 bits 0..31)
  (See <zephyr/dt-bindings/interrupt-controller/bcm2835-armctrl.h>
  for the symbolic constants, and soc/brcm/bcm2710/soc_irq.c +
  drivers/interrupt_controller/intc_bcm2835_armctrl.c for the
  decode that maps these numbers to the bank-0 shortcut bits +
  PEND1 / PEND2 registers.)

compatible: "brcm,bcm2835-armctrl-ic"

include: [interrupt-controller.yaml, base.yaml]

properties:
  reg:
    required: true

  interrupts:
    description: |
      The single GPU-cascade IRQ on the parent BCM2836 ARM-local intc.
      Present only when this controller is cascaded (BCM2836 / Pi 2+).
      On the BCM2835 (Pi 1 / Zero / Zero W) the ARMC is the root
      interrupt controller, wired directly to the ARM core IRQ line, so
      it has no parent interrupt and this property is omitted.

  interrupt-controller:
    required: true

  "#interrupt-cells":
    const: 3
    description: |
      Cell 0: flat IRQ number from the offset-by-32 ARMC space
              (32..39 basic / 64..95 PEND1 / 96..127 PEND2).
      Cell 1: trigger-type flags (IRQ_TYPE_LEVEL / IRQ_TYPE_EDGE).
      Cell 2: priority -- unused by this controller, kept as a
              fixed third cell for parity with the parent
              brcm,bcm2836-l1-intc binding (see its rationale).

interrupt-cells:
  - irq
  - flags
  - priority