Re: [PATCH v6 04/10] dt-bindings: Add HTE bindings

From: Rob Herring
Date: Mon Apr 25 2022 - 18:24:59 EST


On Fri, Apr 22, 2022 at 01:52:15PM -0700, Dipen Patel wrote:
> 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@xxxxxxxxxx>
> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> Changes in v2:
> - Replace hte with hardware-timestamp for property names
> - Renamed file
> - Removed example from the common dt binding file.
>
> Changes in v3:
> - Addressed grammatical errors.
> - Removed double plural from the respective properties.
> - Added dual license.
> - Prefixed "nvidia" in nvidia specific properties.
>
> Changes in v4:
> - Corrected make dt_binding_check error.
>
> Changes in v5:
> - Addressed review comments.
>
> Changes in v6:
> - Removed hardware prefix from the property as per review comments.
>
> .../hte/hardware-timestamps-common.yaml | 29 ++++++
> .../devicetree/bindings/hte/hte-consumer.yaml | 39 ++++++++
> .../bindings/hte/nvidia,tegra194-hte.yaml | 88 +++++++++++++++++++
> 3 files changed, 156 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hte/hardware-timestamps-common.yaml
> create mode 100644 Documentation/devicetree/bindings/hte/hte-consumer.yaml
> create mode 100644 Documentation/devicetree/bindings/hte/nvidia,tegra194-hte.yaml

'hte' is not obvious what it is, so 'timestamp' for the directory name.

>
> diff --git a/Documentation/devicetree/bindings/hte/hardware-timestamps-common.yaml b/Documentation/devicetree/bindings/hte/hardware-timestamps-common.yaml
> new file mode 100644
> index 000000000000..3e26de605f08
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hte/hardware-timestamps-common.yaml
> @@ -0,0 +1,29 @@
> +# 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@xxxxxxxxxx>
> +
> +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

Define HTE at the 1st use, not the 2nd.

> + 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
> diff --git a/Documentation/devicetree/bindings/hte/hte-consumer.yaml b/Documentation/devicetree/bindings/hte/hte-consumer.yaml
> new file mode 100644
> index 000000000000..68d764ac040a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hte/hte-consumer.yaml
> @@ -0,0 +1,39 @@
> +# 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@xxxxxxxxxx>
> +
> +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:
> + $ref: /schemas/types.yaml#/definitions/string-array
> + description:
> + An optional string property to label each line specifier present in the
> + timestamp property.
> +
> +dependencies:
> + timestamp-names: [ timestamps ]
> +
> +additionalProperties: true
> +
> +examples:
> + - |
> + hte_tegra_consumer {
> + timestamps = <&tegra_hte_aon 0x9>, <&tegra_hte_lic 0x19>;
> + timestamp-names = "hte-gpio", "hte-i2c";
> + };
> diff --git a/Documentation/devicetree/bindings/hte/nvidia,tegra194-hte.yaml b/Documentation/devicetree/bindings/hte/nvidia,tegra194-hte.yaml
> new file mode 100644
> index 000000000000..69e8402d95e5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hte/nvidia,tegra194-hte.yaml
> @@ -0,0 +1,88 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$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@xxxxxxxxxx>
> +
> +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>;
> + };
> +
> +...
> --
> 2.17.1
>
>