userspace-api/gpio/gpio-lineevent-data-read.rst

1 .. SPDX-License-Identifier: GPL-2.0
11     gpio-v2-line-event-read.rst.
16 GPIO_LINEEVENT_DATA_READ - Read edge detection events from a line event.
28     :c:type:`request.fd<gpioevent_request>` by gpio-get-lineevent-ioctl.rst.
40 Read edge detection events for a line from a line event.
56 The source of the clock for :c:type:`event.timestamp<gpioevent_data>` is
57 ``CLOCK_MONOTONIC``, except for kernels earlier than Linux 5.7 when it was
65 The size of the kernel event buffer is fixed at 16 events.
68 by userspace. If an overflow occurs then the most recent event is discarded.
76 The `read()` will block if no event is available and the ``event_fd`` has not
79 The presence of an event can be tested for by checking that the ``event_fd`` is
86 a :c:type:`gpio_lineevent_data` event.
88 On error -1 and the ``errno`` variable is set appropriately.
89 Common error codes are described in error-codes.rst.