xref: /linux/Documentation/userspace-api/media/rc/lirc-set-transmitter-mask.rst (revision cdd38c5f1ce4398ec58fec95904b75824daab7b5)
1.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
2.. c:namespace:: RC
3
4.. _lirc_set_transmitter_mask:
5
6*******************************
7ioctl LIRC_SET_TRANSMITTER_MASK
8*******************************
9
10Name
11====
12
13LIRC_SET_TRANSMITTER_MASK - Enables send codes on a given set of transmitters
14
15Synopsis
16========
17
18.. c:macro:: LIRC_SET_TRANSMITTER_MASK
19
20``int ioctl(int fd, LIRC_SET_TRANSMITTER_MASK, __u32 *mask)``
21
22Arguments
23=========
24
25``fd``
26    File descriptor returned by open().
27
28``mask``
29    Mask with channels to enable tx. Channel 0 is the least significant bit.
30
31Description
32===========
33
34Some IR TX devices have multiple output channels, in such case,
35:ref:`LIRC_CAN_SET_TRANSMITTER_MASK <LIRC-CAN-SET-TRANSMITTER-MASK>` is
36returned via :ref:`LIRC_GET_FEATURES` and this ioctl sets what channels will
37send IR codes.
38
39This ioctl enables the given set of transmitters. The first transmitter is
40encoded by the least significant bit and so on.
41
42When an invalid bit mask is given, i.e. a bit is set, even though the device
43does not have so many transitters, then this ioctl returns the number of
44available transitters and does nothing otherwise.
45
46Return Value
47============
48
49On success 0 is returned, on error -1 and the ``errno`` variable is set
50appropriately. The generic error codes are described at the
51:ref:`Generic Error Codes <gen-errors>` chapter.
52