.. Permission is granted to copy, distribute and/or modify this
.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/userspace-api/media/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections

.. _lirc_get_features:

***********************
ioctl LIRC_GET_FEATURES
***********************

Name
====

LIRC_GET_FEATURES - Get the underlying hardware device's features

Synopsis
========

.. c:function:: int ioctl( int fd, LIRC_GET_FEATURES, __u32 *features)
    :name: LIRC_GET_FEATURES

Arguments
=========

``fd``
    File descriptor returned by open().

``features``
    Bitmask with the LIRC features.


Description
===========


Get the underlying hardware device's features. If a driver does not
announce support of certain features, calling of the corresponding ioctls
is undefined.

LIRC features
=============

.. _LIRC-CAN-REC-RAW:

``LIRC_CAN_REC_RAW``

    Unused. Kept just to avoid breaking uAPI.

.. _LIRC-CAN-REC-PULSE:

``LIRC_CAN_REC_PULSE``

    Unused. Kept just to avoid breaking uAPI.
    :ref:`LIRC_MODE_PULSE <lirc-mode-pulse>` can only be used for transmitting.

.. _LIRC-CAN-REC-MODE2:

``LIRC_CAN_REC_MODE2``

    This is raw IR driver for receiving. This means that
    :ref:`LIRC_MODE_MODE2 <lirc-mode-MODE2>` is used. This also implies
    that :ref:`LIRC_MODE_SCANCODE <lirc-mode-SCANCODE>` is also supported,
    as long as the kernel is recent enough. Use the
    :ref:`lirc_set_rec_mode` to switch modes.

.. _LIRC-CAN-REC-LIRCCODE:

``LIRC_CAN_REC_LIRCCODE``

    Unused. Kept just to avoid breaking uAPI.

.. _LIRC-CAN-REC-SCANCODE:

``LIRC_CAN_REC_SCANCODE``

    This is a scancode driver for receiving. This means that
    :ref:`LIRC_MODE_SCANCODE <lirc-mode-SCANCODE>` is used.

.. _LIRC-CAN-SET-SEND-CARRIER:

``LIRC_CAN_SET_SEND_CARRIER``

    The driver supports changing the modulation frequency via
    :ref:`ioctl LIRC_SET_SEND_CARRIER <LIRC_SET_SEND_CARRIER>`.

.. _LIRC-CAN-SET-SEND-DUTY-CYCLE:

``LIRC_CAN_SET_SEND_DUTY_CYCLE``

    The driver supports changing the duty cycle using
    :ref:`ioctl LIRC_SET_SEND_DUTY_CYCLE <LIRC_SET_SEND_DUTY_CYCLE>`.

.. _LIRC-CAN-SET-TRANSMITTER-MASK:

``LIRC_CAN_SET_TRANSMITTER_MASK``

    The driver supports changing the active transmitter(s) using
    :ref:`ioctl LIRC_SET_TRANSMITTER_MASK <LIRC_SET_TRANSMITTER_MASK>`.

.. _LIRC-CAN-SET-REC-CARRIER:

``LIRC_CAN_SET_REC_CARRIER``

    The driver supports setting the receive carrier frequency using
    :ref:`ioctl LIRC_SET_REC_CARRIER <LIRC_SET_REC_CARRIER>`.

.. _LIRC-CAN-SET-REC-DUTY-CYCLE-RANGE:

``LIRC_CAN_SET_REC_DUTY_CYCLE_RANGE``

    Unused. Kept just to avoid breaking uAPI.

.. _LIRC-CAN-SET-REC-CARRIER-RANGE:

``LIRC_CAN_SET_REC_CARRIER_RANGE``

    The driver supports
    :ref:`ioctl LIRC_SET_REC_CARRIER_RANGE <LIRC_SET_REC_CARRIER_RANGE>`.

.. _LIRC-CAN-GET-REC-RESOLUTION:

``LIRC_CAN_GET_REC_RESOLUTION``

    The driver supports
    :ref:`ioctl LIRC_GET_REC_RESOLUTION <LIRC_GET_REC_RESOLUTION>`.

.. _LIRC-CAN-SET-REC-TIMEOUT:

``LIRC_CAN_SET_REC_TIMEOUT``

    The driver supports
    :ref:`ioctl LIRC_SET_REC_TIMEOUT <LIRC_SET_REC_TIMEOUT>`.

.. _LIRC-CAN-SET-REC-FILTER:

``LIRC_CAN_SET_REC_FILTER``

    Unused. Kept just to avoid breaking uAPI.

.. _LIRC-CAN-MEASURE-CARRIER:

``LIRC_CAN_MEASURE_CARRIER``

    The driver supports measuring of the modulation frequency using
    :ref:`ioctl LIRC_SET_MEASURE_CARRIER_MODE <LIRC_SET_MEASURE_CARRIER_MODE>`.

.. _LIRC-CAN-USE-WIDEBAND-RECEIVER:

``LIRC_CAN_USE_WIDEBAND_RECEIVER``

    The driver supports learning mode using
    :ref:`ioctl LIRC_SET_WIDEBAND_RECEIVER <LIRC_SET_WIDEBAND_RECEIVER>`.

.. _LIRC-CAN-NOTIFY-DECODE:

``LIRC_CAN_NOTIFY_DECODE``

    Unused. Kept just to avoid breaking uAPI.

.. _LIRC-CAN-SEND-RAW:

``LIRC_CAN_SEND_RAW``

    Unused. Kept just to avoid breaking uAPI.

.. _LIRC-CAN-SEND-PULSE:

``LIRC_CAN_SEND_PULSE``

    The driver supports sending (also called as IR blasting or IR TX) using
    :ref:`LIRC_MODE_PULSE <lirc-mode-pulse>`. This implies that
    :ref:`LIRC_MODE_SCANCODE <lirc-mode-SCANCODE>` is also supported for
    transmit, as long as the kernel is recent enough. Use the
    :ref:`lirc_set_send_mode` to switch modes.

.. _LIRC-CAN-SEND-MODE2:

``LIRC_CAN_SEND_MODE2``

    Unused. Kept just to avoid breaking uAPI.
    :ref:`LIRC_MODE_MODE2 <lirc-mode-mode2>` can only be used for receiving.

.. _LIRC-CAN-SEND-LIRCCODE:

``LIRC_CAN_SEND_LIRCCODE``

    Unused. Kept just to avoid breaking uAPI.


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.
