hte: Re-phrase tegra API document

Make Tegra194 API document generic to make it applicable for
current and future tegra hte providers.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>

diff --git a/Documentation/driver-api/hte/index.rst b/Documentation/driver-api/hte/index.rst
index 9f43301c05dcfde6cf13904a3a2a135ecc17ff8a..29011de9a4b856800165373bdaba217b193d08d2 100644 (file)
--- a/Documentation/driver-api/hte/index.rst
+++ b/Documentation/driver-api/hte/index.rst
@@ -18,5 +18,5 @@ HTE Tegra Provider
 .. toctree::
    :maxdepth: 1
 
-   tegra194-hte
+   tegra-hte
 

diff --git a/Documentation/driver-api/hte/tegra-hte.rst b/Documentation/driver-api/hte/tegra-hte.rst
new file mode 100644 (file)
index 0000000..85e6547
--- /dev/null
+++ b/Documentation/driver-api/hte/tegra-hte.rst
@@ -0,0 +1,47 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+HTE Kernel provider driver
+==========================
+
+Description
+-----------
+The Nvidia tegra HTE provider also known as GTE (Generic Timestamping Engine)
+driver implements two GTE instances: 1) GPIO GTE and 2) LIC
+(Legacy Interrupt Controller) IRQ GTE. Both GTE instances get the timestamp
+from the system counter TSC which has 31.25MHz clock rate, and the driver
+converts clock tick rate to nanoseconds before storing it as timestamp value.
+
+GPIO GTE
+--------
+
+This GTE instance timestamps GPIO in real time. For that to happen GPIO
+needs to be configured as input. Only the always on (AON) GPIO controller
+instance supports timestamping GPIOs in real time as it is tightly coupled with
+the GPIO GTE. To support this, GPIOLIB adds two optional APIs as mentioned
+below. The GPIO GTE code supports both kernel and userspace consumers. The
+kernel space consumers can directly talk to HTE subsystem while userspace
+consumers timestamp requests go through GPIOLIB CDEV framework to HTE
+subsystem. The hte devicetree binding described at
+``Documentation/devicetree/bindings/timestamp`` provides an example of how a
+consumer can request an GPIO line.
+
+See gpiod_enable_hw_timestamp_ns() and gpiod_disable_hw_timestamp_ns().
+
+For userspace consumers, GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE flag must be
+specified during IOCTL calls. Refer to ``tools/gpio/gpio-event-mon.c``, which
+returns the timestamp in nanoseconds.
+
+LIC (Legacy Interrupt Controller) IRQ GTE
+-----------------------------------------
+
+This GTE instance timestamps LIC IRQ lines in real time. The hte devicetree
+binding described at ``Documentation/devicetree/bindings/timestamp``
+provides an example of how a consumer can request an IRQ line. Since it is a
+one-to-one mapping with IRQ GTE provider, consumers can simply specify the IRQ
+number that they are interested in. There is no userspace consumer support for
+this GTE instance in the HTE framework.
+
+The provider source code of both IRQ and GPIO GTE instances is located at
+``drivers/hte/hte-tegra194.c``. The test driver
+``drivers/hte/hte-tegra194-test.c`` demonstrates HTE API usage for both IRQ
+and GPIO GTE.

diff --git a/Documentation/driver-api/hte/tegra194-hte.rst b/Documentation/driver-api/hte/tegra194-hte.rst
deleted file mode 100644 (file)
index f2d6172..0000000
--- a/Documentation/driver-api/hte/tegra194-hte.rst
+++ /dev/null
@@ -1,48 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0+
-
-HTE Kernel provider driver
-==========================
-
-Description
------------
-The Nvidia tegra194 HTE provider driver implements two GTE
-(Generic Timestamping Engine) instances: 1) GPIO GTE and 2) LIC
-(Legacy Interrupt Controller) IRQ GTE. Both GTE instances get the
-timestamp from the system counter TSC which has 31.25MHz clock rate, and the
-driver converts clock tick rate to nanoseconds before storing it as timestamp
-value.
-
-GPIO GTE
---------
-
-This GTE instance timestamps GPIO in real time. For that to happen GPIO
-needs to be configured as input. The always on (AON) GPIO controller instance
-supports timestamping GPIOs in real time and it has 39 GPIO lines. The GPIO GTE
-and AON GPIO controller are tightly coupled as it requires very specific bits
-to be set in GPIO config register before GPIO GTE can be used, for that GPIOLIB
-adds two optional APIs as below. The GPIO GTE code supports both kernel
-and userspace consumers. The kernel space consumers can directly talk to HTE
-subsystem while userspace consumers timestamp requests go through GPIOLIB CDEV
-framework to HTE subsystem.
-
-See gpiod_enable_hw_timestamp_ns() and gpiod_disable_hw_timestamp_ns().
-
-For userspace consumers, GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE flag must be
-specified during IOCTL calls. Refer to ``tools/gpio/gpio-event-mon.c``, which
-returns the timestamp in nanoseconds.
-
-LIC (Legacy Interrupt Controller) IRQ GTE
------------------------------------------
-
-This GTE instance timestamps LIC IRQ lines in real time. There are 352 IRQ
-lines which this instance can add timestamps to in real time. The hte
-devicetree binding described at ``Documentation/devicetree/bindings/timestamp``
-provides an example of how a consumer can request an IRQ line. Since it is a
-one-to-one mapping with IRQ GTE provider, consumers can simply specify the IRQ
-number that they are interested in. There is no userspace consumer support for
-this GTE instance in the HTE framework.
-
-The provider source code of both IRQ and GPIO GTE instances is located at
-``drivers/hte/hte-tegra194.c``. The test driver
-``drivers/hte/hte-tegra194-test.c`` demonstrates HTE API usage for both IRQ
-and GPIO GTE.