linux.git/include/uapi/linux/gpio.h, branch v6.18.21

gpio: uapi: clarify default_values being logical

2024-02-15T07:44:57+00:00

The documentation for default_values mentions high/low which can be
confusing, particularly when the ACTIVE_LOW flag is set.

Replace high/low with active/inactive to clarify that the values are
logical not physical.

Similarly, clarify the interpretation of values in struct gpiohandle_data.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Acked-by: Linus Walleij 
Signed-off-by: Bartosz Golaszewski

gpio: uapi: clarify using v2 rather than v1

2024-01-22T08:53:12+00:00

The documentation contains notes like
 This struct is part of ABI v1 and is deprecated.
 Use struct gpio_v2_line_info instead.

This could be interpreted to mean the structs can be directly
substituted in v1 calls.  Clarify that the user should use the
corresponding v2 ioctl() and structs.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpio: uapi: document possible values of gpioevent_data.id

2024-01-22T08:52:15+00:00

Clarify the possible values of event id, rather than requiring the
reader to infer.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpio: uapi: drop trailing period from one sentence descriptions

2024-01-22T08:52:08+00:00

Make documentation more consistent by using trailing periods only for
multi-sentence field descriptions, not single sentence descriptions.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpio: uapi: clarify hte references

2024-01-22T08:51:48+00:00

The full name of the HTE subsystem is "hardware timestamping engine",
so correct references and highlight that this refers to the HTE
subsystem.

Extend the description of struct gpio_v2_line_event to clarify that
the timestamp_ns is sourced from the HTE if the
GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE is set.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpio: uapi: improve description of fd fields

2024-01-22T08:51:02+00:00

Only a successful operation modifies fd fields, but the current
documentation wording could be taken to imply that a positive fd
value after an ioctl() returns indicates a success.

Reword documentation to clarify that the fd is only valid after a
successful operation.

Signed-off-by: Kent Gibson 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: Add hardware timestamp clock type

2022-05-04T09:06:13+00:00

This patch adds new clock type for the GPIO controller which can
timestamp gpio lines in using hardware means. To expose such
functionalities to the userspace, code has been added where
during line create or set config API calls, it checks for new
clock type and if requested, calls HTE API. During line change
event, the HTE subsystem pushes timestamp data to userspace
through gpiolib-cdev.

Signed-off-by: Dipen Patel 
Acked-by: Linus Walleij 
Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
Signed-off-by: Thierry Reding

gpio: uapi: use the preferred SPDX license identifier

2021-02-15T10:43:33+00:00

GPL-2.0 license identifier is deprecated. User-space projects that want
to include the kernel header with their source-code will be unable to
become fully REUSE compliant due to the reuse tool complaining about
deprecated licenses. Change the SPDX identifier to GPL-2.0-only.

Signed-off-by: Bartosz Golaszewski

gpio: uapi: fix line info flags description

2021-02-15T10:43:29+00:00

The description of the flags field of the struct gpio_v2_line_info
mentions "the GPIO lines" while the info only applies to an individual
GPIO line.  This was accidentally changed from "the GPIO line" during
formatting improvements.

Reword to "this GPIO line" to clarify and to be consistent with other
struct gpio_v2_line_info fields.

Fixes: 2cc522d3931b ("gpio: uapi: kernel-doc formatting improvements")
Signed-off-by: Kent Gibson 
Signed-off-by: Bartosz Golaszewski

gpiolib: cdev: allow edge event timestamps to be configured as REALTIME

2020-12-05T22:22:47+00:00

Using CLOCK_REALTIME as the source for event timestamps is crucial for
some specific applications, particularly those requiring timetamps
relative to a PTP clock, so provide an option to switch the event
timestamp source from the default CLOCK_MONOTONIC to CLOCK_REALTIME.

Note that CLOCK_REALTIME was the default source clock for GPIO until
Linux 5.7 when it was changed to CLOCK_MONOTONIC due to issues with the
shifting of the realtime clock.
Providing this option maintains the CLOCK_MONOTONIC as the default,
while also providing a path forward for those dependent on the pre-5.7
behaviour.

Suggested-by: Jack Winch 
Signed-off-by: Kent Gibson 
Link: https://lore.kernel.org/r/20201014231158.34117-2-warthog618@gmail.com
Signed-off-by: Linus Walleij