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+.. -*- coding: utf-8; mode: rst -*-
+
+.. _lirc_dev_intro:
+
+************
+Introduction
+************
+
+The LIRC device interface is a bi-directional interface for transporting
+raw IR data between userspace and kernelspace. Fundamentally, it is just
+a chardev (/dev/lircX, for X = 0, 1, 2, ...), with a number of standard
+struct file_operations defined on it. With respect to transporting raw
+IR data to and fro, the essential fops are read, write and ioctl.
+
+Example dmesg output upon a driver registering w/LIRC:
+
+.. code-block:: none
+
+    $ dmesg |grep lirc_dev
+    lirc_dev: IR Remote Control driver registered, major 248
+    rc rc0: lirc_dev: driver ir-lirc-codec (mceusb) registered at minor = 0
+
+What you should see for a chardev:
+
+.. code-block:: none
+
+    $ ls -l /dev/lirc*
+    crw-rw---- 1 root root 248, 0 Jul 2 22:20 /dev/lirc0
+
+**********
+LIRC modes
+**********
+
+LIRC supports some modes of receiving and sending IR codes, as shown
+on the following table.
+
+.. _lirc-mode-mode2:
+
+``LIRC_MODE_MODE2``
+
+    The driver returns a sequence of pulse and space codes to userspace.
+
+    This mode is used only for IR receive.
+
+.. _lirc-mode-lirccode:
+
+``LIRC_MODE_LIRCCODE``
+
+    The IR signal is decoded internally by the receiver. The LIRC interface
+    returns the scancode as an integer value. This is the usual mode used
+    by several TV media cards.
+
+    This mode is used only for IR receive.
+
+.. _lirc-mode-pulse:
+
+``LIRC_MODE_PULSE``
+
+    On puse mode, a sequence of pulse/space integer values are written to the
+    lirc device using :Ref:`lirc-write`.
+
+    This mode is used only for IR send.