[Patch v3 6/9] dt-bindings: arm: tegra: Add NVIDIA Tegra234 CBB2.0 binding

Sumit Gupta
2021-12-21T12:51:57Z

Add device-tree binding documentation to represent CBB2.0 (Control
Backbone) error handling driver. The driver prints debug information
about failed transaction on receiving interrupt from CBB2.0.

Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---
.../arm/tegra/nvidia,tegra234-cbb.yaml | 70 +++++++++++++++++++
1 file changed, 70 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/tegra/nvidia,tegra234-cbb.yaml

diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra234-cbb.yaml b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra234-cbb.yaml
new file mode 100644
index 000000000000..fa4383be19d8
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra234-cbb.yaml
@@ -0,0 +1,70 @@
+# 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 Error handling driver device tree bindings
+
+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 CBB2.0 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: true
+
+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>;
+ status = "okay";
+ };
--
2.17.1