xref: /linux/Documentation/userspace-api/media/rc/lirc-set-rec-carrier-range.rst (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
1.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
2.. c:namespace:: RC
3
4.. _lirc_set_rec_carrier_range:
5
6********************************
7ioctl LIRC_SET_REC_CARRIER_RANGE
8********************************
9
10Name
11====
12
13LIRC_SET_REC_CARRIER_RANGE - Set lower bound of the carrier used to modulate
14IR receive.
15
16Synopsis
17========
18
19.. c:macro:: LIRC_SET_REC_CARRIER_RANGE
20
21``int ioctl(int fd, LIRC_SET_REC_CARRIER_RANGE, __u32 *frequency)``
22
23Arguments
24=========
25
26``fd``
27    File descriptor returned by open().
28
29``frequency``
30    Frequency of the carrier that modulates PWM data, in Hz.
31
32Description
33===========
34
35This ioctl sets the upper range of carrier frequency that will be recognized
36by the IR receiver.
37
38.. note::
39
40   To set a range use :ref:`LIRC_SET_REC_CARRIER_RANGE
41   <LIRC_SET_REC_CARRIER_RANGE>` with the lower bound first and later call
42   :ref:`LIRC_SET_REC_CARRIER <LIRC_SET_REC_CARRIER>` with the upper bound.
43
44Return Value
45============
46
47On success 0 is returned, on error -1 and the ``errno`` variable is set
48appropriately. The generic error codes are described at the
49:ref:`Generic Error Codes <gen-errors>` chapter.
50