Documentation/devicetree/bindings/arm/tegra/nvidia,tegra234-cbb.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/arm/tegra/nvidia,tegra234-cbb.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: NVIDIA Tegra CBB 2.0

maintainers:
  - Sumit Gupta <sumitg@nvidia.com>

description: |+
  The Control Backbone (CBB) is comprised of the physical path from an
  initiator to a target's register configuration space. CBB 2.0 consists
  of multiple sub-blocks connected to each other to create a topology.
  The Tegra234 SoC has different fabrics based on CBB 2.0 architecture
  which include cluster fabrics BPMP, AON, PSC, SCE, RCE, DCE, FSI and
  "CBB central fabric".

  In CBB 2.0, each initiator which can issue transactions connects to a
  Root Master Node (MN) before it connects to any other element of the
  fabric. Each Root MN contains a Error Monitor (EM) which detects and
  logs error. Interrupts from various EM blocks are collated by Error
  Notifier (EN) which is per fabric and presents a single interrupt from
  fabric to the SoC interrupt controller.

  The driver handles errors from CBB due to illegal register accesses
  and prints debug information about failed transaction on receiving
  the interrupt from EN. Debug information includes Error Code, Error
  Description, MasterID, Fabric, SlaveID, Address, Cache, Protection,
  Security Group etc on receiving error notification.

  If the Error Response Disable (ERD) is set/enabled for an initiator,
  then SError or Data abort exception error response is masked and an
  interrupt is used for reporting errors due to illegal accesses from
  that initiator. The value returned on read failures is '0xFFFFFFFF'
  for compatibility with PCIE.

properties:
  $nodename:
    pattern: "^[a-z]+-fabric@[0-9a-f]+$"

  compatible:
    enum:
      - nvidia,tegra234-aon-fabric
      - nvidia,tegra234-bpmp-fabric
      - nvidia,tegra234-cbb-fabric
      - nvidia,tegra234-dce-fabric
      - nvidia,tegra234-rce-fabric
      - nvidia,tegra234-sce-fabric

  reg:
    maxItems: 1

  interrupts:
    items:
      - description: secure interrupt from error notifier

additionalProperties: false

required:
  - compatible
  - reg
  - interrupts

examples:
  - |
    #include <dt-bindings/interrupt-controller/arm-gic.h>

    cbb-fabric@1300000 {
      compatible = "nvidia,tegra234-cbb-fabric";
      reg = <0x13a00000 0x400000>;
      interrupts = <GIC_SPI 231 IRQ_TYPE_LEVEL_HIGH>;
    };