0001 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/timestamp/nvidia,tegra194-hte.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: Tegra194 on chip generic hardware timestamping engine (HTE)
0008
0009 maintainers:
0010 - Dipen Patel <dipenp@nvidia.com>
0011
0012 description:
0013 Tegra SoC has two instances of generic hardware timestamping engines (GTE)
0014 known as GTE GPIO and GTE IRQ, which can monitor subset of GPIO and on chip
0015 IRQ lines for the state change respectively, upon detection it will record
0016 timestamp (taken from system counter) in its internal hardware FIFO. It has
0017 a bitmap array arranged in 32bit slices where each bit represent signal/line
0018 to enable or disable for the hardware timestamping. The GTE GPIO monitors
0019 GPIO lines from the AON (always on) GPIO controller.
0020
0021 properties:
0022 compatible:
0023 enum:
0024 - nvidia,tegra194-gte-aon
0025 - nvidia,tegra194-gte-lic
0026
0027 reg:
0028 maxItems: 1
0029
0030 interrupts:
0031 maxItems: 1
0032
0033 nvidia,int-threshold:
0034 $ref: /schemas/types.yaml#/definitions/uint32
0035 description:
0036 HTE device generates its interrupt based on this u32 FIFO threshold
0037 value. The recommended value is 1.
0038 minimum: 1
0039 maximum: 256
0040
0041 nvidia,slices:
0042 $ref: /schemas/types.yaml#/definitions/uint32
0043 description:
0044 HTE lines are arranged in 32 bit slice where each bit represents different
0045 line/signal that it can enable/configure for the timestamp. It is u32
0046 property and depends on the HTE instance in the chip. The value 3 is for
0047 GPIO GTE and 11 for IRQ GTE.
0048 enum: [3, 11]
0049
0050 '#timestamp-cells':
0051 description:
0052 This represents number of line id arguments as specified by the
0053 consumers. For the GTE IRQ, this is IRQ number as mentioned in the
0054 SoC technical reference manual. For the GTE GPIO, its value is same as
0055 mentioned in the nvidia GPIO device tree binding document.
0056 const: 1
0057
0058 required:
0059 - compatible
0060 - reg
0061 - interrupts
0062 - nvidia,slices
0063 - "#timestamp-cells"
0064
0065 additionalProperties: false
0066
0067 examples:
0068 - |
0069 tegra_hte_aon: timestamp@c1e0000 {
0070 compatible = "nvidia,tegra194-gte-aon";
0071 reg = <0xc1e0000 0x10000>;
0072 interrupts = <0 13 0x4>;
0073 nvidia,int-threshold = <1>;
0074 nvidia,slices = <3>;
0075 #timestamp-cells = <1>;
0076 };
0077
0078 - |
0079 tegra_hte_lic: timestamp@3aa0000 {
0080 compatible = "nvidia,tegra194-gte-lic";
0081 reg = <0x3aa0000 0x10000>;
0082 interrupts = <0 11 0x4>;
0083 nvidia,int-threshold = <1>;
0084 nvidia,slices = <11>;
0085 #timestamp-cells = <1>;
0086 };
0087
0088 ...
