linux/linux-5.18.11/Documentation/userspace-api/media/rc/lirc-set-send-duty-cycle.rst

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2024-03-22 18:12:32 +00:00
.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
.. c:namespace:: RC
.. _lirc_set_send_duty_cycle:
******************************
ioctl LIRC_SET_SEND_DUTY_CYCLE
******************************
Name
====
LIRC_SET_SEND_DUTY_CYCLE - Set the duty cycle of the carrier signal for
IR transmit.
Synopsis
========
.. c:macro:: LIRC_SET_SEND_DUTY_CYCLE
``int ioctl(int fd, LIRC_SET_SEND_DUTY_CYCLE, __u32 *duty_cycle)``
Arguments
=========
``fd``
File descriptor returned by open().
``duty_cycle``
Duty cicle, describing the pulse width in percent (from 1 to 99) of
the total cycle. Values 0 and 100 are reserved.
Description
===========
Get/set the duty cycle of the carrier signal for IR transmit.
Currently, no special meaning is defined for 0 or 100, but this
could be used to switch off carrier generation in the future, so
these values should be reserved.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.