media: docs: move uAPI book to userspace-api/media

Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").

As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.

Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/userspace-api/media/rc/lirc-get-features.rst

@@ -0,0 +1,200 @@
+.. 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.