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authorLinus Torvalds <torvalds@linux-foundation.org>2022-06-05 19:12:28 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-06-05 19:12:28 +0300
commit2981436374177f78539b026ce5bcbab8c251818e (patch)
treed9d7c4854d4461bec86ca9c0695617a2baeb8e81 /Documentation/devicetree
parent71e80720dbf0f08c6979e54f21ddaa5735ce742d (diff)
parent5dad4eccd2b4316a84209603a28d34c6346392bb (diff)
downloadlinux-2981436374177f78539b026ce5bcbab8c251818e.tar.xz
Merge tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux
Pull hardware timestamping subsystem from Thierry Reding: "This contains the new HTE (hardware timestamping engine) subsystem that has been in the works for a couple of months now. The infrastructure provided allows for drivers to register as hardware timestamp providers, while consumers will be able to request events that they are interested in (such as GPIOs and IRQs) to be timestamped by the hardware providers. Note that this currently supports only one provider, but there seems to be enough interest in this functionality and we expect to see more drivers added once this is merged" [ Linus Walleij mentions the Intel PMC in the Elkhart and Tiger Lake platforms as another future timestamp provider ] * tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux: dt-bindings: timestamp: Correct id path dt-bindings: Renamed hte directory to timestamp hte: Uninitialized variable in hte_ts_get() hte: Fix off by one in hte_push_ts_ns() hte: Fix possible use-after-free in tegra_hte_test_remove() hte: Remove unused including <linux/version.h> MAINTAINERS: Add HTE Subsystem hte: Add Tegra HTE test driver tools: gpio: Add new hardware clock type gpiolib: cdev: Add hardware timestamp clock type gpio: tegra186: Add HTE support gpiolib: Add HTE support dt-bindings: Add HTE bindings hte: Add Tegra194 HTE kernel provider drivers: Add hardware timestamp engine (HTE) subsystem Documentation: Add HTE subsystem guide
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/timestamp/hardware-timestamps-common.yaml29
-rw-r--r--Documentation/devicetree/bindings/timestamp/hte-consumer.yaml39
-rw-r--r--Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml88
3 files changed, 156 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/timestamp/hardware-timestamps-common.yaml b/Documentation/devicetree/bindings/timestamp/hardware-timestamps-common.yaml
new file mode 100644
index 000000000000..fd6a7b51f571
--- /dev/null
+++ b/Documentation/devicetree/bindings/timestamp/hardware-timestamps-common.yaml
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timestamp/hardware-timestamps-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Hardware timestamp providers
+
+maintainers:
+ - Dipen Patel <dipenp@nvidia.com>
+
+description:
+ Some devices/SoCs have hardware timestamp engines (HTE) 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 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
diff --git a/Documentation/devicetree/bindings/timestamp/hte-consumer.yaml b/Documentation/devicetree/bindings/timestamp/hte-consumer.yaml
new file mode 100644
index 000000000000..6456515c3d26
--- /dev/null
+++ b/Documentation/devicetree/bindings/timestamp/hte-consumer.yaml
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timestamp/hte-consumer.yaml#
+$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:
+ $ref: /schemas/types.yaml#/definitions/string-array
+ description:
+ An optional string property to label each line specifier present in the
+ timestamp property.
+
+dependencies:
+ timestamp-names: [ timestamps ]
+
+additionalProperties: true
+
+examples:
+ - |
+ hte_tegra_consumer {
+ timestamps = <&tegra_hte_aon 0x9>, <&tegra_hte_lic 0x19>;
+ timestamp-names = "hte-gpio", "hte-i2c";
+ };
diff --git a/Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml b/Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml
new file mode 100644
index 000000000000..c31e207d1652
--- /dev/null
+++ b/Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml
@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timestamp/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>;
+ };
+
+...