mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-28 13:34:38 +08:00
bd6a63f2e6
Reorganize the LIRC rst files, using "-" instead of "_" on their names, and creating a separate chapter for syscalls. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
63 lines
1.6 KiB
ReStructuredText
63 lines
1.6 KiB
ReStructuredText
.. -*- 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.
|