Documentation/devicetree/bindings/arm/tegra/nvidia,tegra194-cbb.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: "http://devicetree.org/schemas/arm/tegra/nvidia,tegra194-cbb.yaml#"
$schema: "http://devicetree.org/meta-schemas/core.yaml#"

title: NVIDIA Tegra194 CBB 1.0

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 1.0 has
  multiple hierarchical sub-NOCs (Network-on-Chip) and connects various
  initiators and targets using different bridges like AXIP2P, AXI2APB.

  This driver handles errors due to illegal register accesses reported
  by the NOCs inside the CBB. NOCs reporting errors are cluster NOCs
  "AON-NOC, SCE-NOC, RCE-NOC, BPMP-NOC, CV-NOC" and "CBB Central NOC"
  which is the main NOC.

  By default, the access issuing initiator is informed about the error
  using SError or Data Abort exception unless the ERD (Error Response
  Disable) is enabled/set for that initiator. If the ERD is enabled, then
  SError or Data Abort is masked and the error is reported with interrupt.

  - For CCPLEX (CPU Complex) initiator, the driver sets ERD bit. So, the
    errors due to illegal accesses from CCPLEX are reported by interrupts.
    If ERD is not set, then error is reported by SError.
  - For other initiators, the ERD is disabled. So, the access issuing
    initiator is informed about the illegal access by Data Abort exception.
    In addition, an interrupt is also generated to CCPLEX. These initiators
    include all engines using Cortex-R5 (which is ARMv7 CPU cluster) and
    engines like TSEC (Security co-processor), NVDEC (NVIDIA Video Decoder
    engine) etc which can initiate transactions.

  The driver prints relevant debug information like Error Code, Error
  Description, Master, Address, AXI ID, Cache, Protection, Security Group
  etc on receiving error notification.

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

  compatible:
    enum:
      - nvidia,tegra194-cbb-noc
      - nvidia,tegra194-aon-noc
      - nvidia,tegra194-bpmp-noc
      - nvidia,tegra194-rce-noc
      - nvidia,tegra194-sce-noc

  reg:
    maxItems: 1

  interrupts:
    description:
      CCPLEX receives secure or nonsecure interrupt depending on error type.
      A secure interrupt is received for SEC(firewall) & SLV errors and a
      non-secure interrupt is received for TMO & DEC errors.
    items:
      - description: non-secure interrupt
      - description: secure interrupt

  nvidia,axi2apb:
    $ref: '/schemas/types.yaml#/definitions/phandle'
    description:
      Specifies the node having all axi2apb bridges which need to be checked
      for any error logged in their status register.

  nvidia,apbmisc:
    $ref: '/schemas/types.yaml#/definitions/phandle'
    description:
      Specifies the apbmisc node which need to be used for reading the ERD
      register.

additionalProperties: false

required:
  - compatible
  - reg
  - interrupts
  - nvidia,apbmisc

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

    cbb-noc@2300000 {
        compatible = "nvidia,tegra194-cbb-noc";
        reg = <0x02300000 0x1000>;
        interrupts = <GIC_SPI 230 IRQ_TYPE_LEVEL_HIGH>,
                     <GIC_SPI 231 IRQ_TYPE_LEVEL_HIGH>;
        nvidia,axi2apb = <&axi2apb>;
        nvidia,apbmisc = <&apbmisc>;
    };