dt-bindings: Add HTE bindings

Introduces HTE devicetree binding details for the HTE subsystem. It
includes examples for the consumers, binding details for the providers
and specific binding details for the Tegra194 based HTE providers.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Dipen Patel 2022-04-22 13:52:15 -07:00 committed by Thierry Reding
parent 09574cca6a
commit e6a3a65be8
3 changed files with 156 additions and 0 deletions

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/hte/hardware-timestamps-common.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Hardware timestamp providers
maintainers:
- Dipen Patel <dipenp@nvidia.com>
description:
Some devices/SoCs have hardware time stamping engines which can use hardware
means to timestamp entity in realtime. The entity could be anything from
GPIOs, IRQs, Bus and so on. The hardware timestamp engine (HTE) present
itself as a provider with the bindings described in this document.
properties:
$nodename:
pattern: "^timestamp(@.*|-[0-9a-f])?$"
"#timestamp-cells":
description:
Number of cells in a HTE specifier.
required:
- "#timestamp-cells"
additionalProperties: true

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/hte/hte-consumer.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: HTE Consumer Device Tree Bindings
maintainers:
- Dipen Patel <dipenp@nvidia.com>
select: true
properties:
timestamps:
$ref: /schemas/types.yaml#/definitions/phandle-array
description:
The list of HTE provider phandle. The first cell must represent the
provider phandle followed by the line identifiers. The meaning of the
line identifier and exact number of arguments must be specified in the
HTE provider device tree binding document.
timestamp-names:
$ref: /schemas/types.yaml#/definitions/string-array
description:
An optional string property to label each line specifier present in the
timestamp property.
dependencies:
timestamp-names: [ timestamps ]
additionalProperties: true
examples:
- |
hte_tegra_consumer {
timestamps = <&tegra_hte_aon 0x9>, <&tegra_hte_lic 0x19>;
timestamp-names = "hte-gpio", "hte-i2c";
};

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/hte/nvidia,tegra194-hte.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Tegra194 on chip generic hardware timestamping engine (HTE)
maintainers:
- Dipen Patel <dipenp@nvidia.com>
description:
Tegra SoC has two instances of generic hardware timestamping engines (GTE)
known as GTE GPIO and GTE IRQ, which can monitor subset of GPIO and on chip
IRQ lines for the state change respectively, upon detection it will record
timestamp (taken from system counter) in its internal hardware FIFO. It has
a bitmap array arranged in 32bit slices where each bit represent signal/line
to enable or disable for the hardware timestamping. The GTE GPIO monitors
GPIO lines from the AON (always on) GPIO controller.
properties:
compatible:
enum:
- nvidia,tegra194-gte-aon
- nvidia,tegra194-gte-lic
reg:
maxItems: 1
interrupts:
maxItems: 1
nvidia,int-threshold:
$ref: /schemas/types.yaml#/definitions/uint32
description:
HTE device generates its interrupt based on this u32 FIFO threshold
value. The recommended value is 1.
minimum: 1
maximum: 256
nvidia,slices:
$ref: /schemas/types.yaml#/definitions/uint32
description:
HTE lines are arranged in 32 bit slice where each bit represents different
line/signal that it can enable/configure for the timestamp. It is u32
property and depends on the HTE instance in the chip. The value 3 is for
GPIO GTE and 11 for IRQ GTE.
enum: [3, 11]
'#timestamp-cells':
description:
This represents number of line id arguments as specified by the
consumers. For the GTE IRQ, this is IRQ number as mentioned in the
SoC technical reference manual. For the GTE GPIO, its value is same as
mentioned in the nvidia GPIO device tree binding document.
const: 1
required:
- compatible
- reg
- interrupts
- nvidia,slices
- "#timestamp-cells"
additionalProperties: false
examples:
- |
tegra_hte_aon: timestamp@c1e0000 {
compatible = "nvidia,tegra194-gte-aon";
reg = <0xc1e0000 0x10000>;
interrupts = <0 13 0x4>;
nvidia,int-threshold = <1>;
nvidia,slices = <3>;
#timestamp-cells = <1>;
};
- |
tegra_hte_lic: timestamp@3aa0000 {
compatible = "nvidia,tegra194-gte-lic";
reg = <0x3aa0000 0x10000>;
interrupts = <0 11 0x4>;
nvidia,int-threshold = <1>;
nvidia,slices = <11>;
#timestamp-cells = <1>;
};
...