driver-api/hte/hte.rst

1 .. SPDX-License-Identifier: GPL-2.0+
4 The Linux Hardware Timestamping Engine (HTE)
10 ------------
21 engine (HTE) framework. Both consumers and providers must include
22 ``#include <linux/hte.h>``.
24 The HTE framework APIs for the providers
25 ----------------------------------------
27 .. kernel-doc:: drivers/hte/hte.c
30 The HTE framework APIs for the consumers
31 ----------------------------------------
33 .. kernel-doc:: drivers/hte/hte.c
36 The HTE framework public structures
37 -----------------------------------
38 .. kernel-doc:: include/linux/hte.h
40 More on the HTE timestamp data
41 ------------------------------
44 u64. An example of the typical timestamp data life cycle, for the GPIO line is
47  - Monitors GPIO line change.
48  - Detects the state change on GPIO line.
49  - Converts timestamps in nanoseconds.
50  - Stores GPIO raw level in raw_level variable if the provider has that
52  - Pushes this hte_ts_data object to HTE subsystem.
53  - HTE subsystem increments seq counter and invokes consumer provided callback.
54  Based on callback return value, the HTE core invokes secondary callback in
57 HTE subsystem debugfs attributes
58 --------------------------------
59 HTE subsystem creates debugfs attributes at ``/sys/kernel/debug/hte/``.
60 It also creates line/signal-related debugfs attributes at
61 ``/sys/kernel/debug/hte/<provider>/<label or line id>/``. Note that these
62 attributes are read-only.
67 		lines, GPIO, chip signals, buses etc...
69 		``/sys/kernel/debug/hte/<provider>/``.
74 		``/sys/kernel/debug/hte/<provider>/``.
79 		``/sys/kernel/debug/hte/<provider>/<label or line id>/``.