[media] doc-rst: add documentation for si470x

	radiotrack

	saa7134

	sh_mobile_ceu_camera

	si470x

	zr364xx

Driver for USB radios for the Silicon Labs Si470x FM Radio Receivers

.. include:: <isonum.txt>

Copyright (c) 2009 Tobias Lorenz <tobias.lorenz@gmx.net>

The Silicon Labs Si470x FM Radio Receivers driver

=================================================

Copyright |copy| 2009 Tobias Lorenz <tobias.lorenz@gmx.net>

Information from Silicon Labs

=============================

-----------------------------

Silicon Laboratories is the manufacturer of the radio ICs, that nowadays are the

most often used radio receivers in cell phones. Usually they are connected with

I2C. But SiLabs also provides a reference design, which integrates this IC,

Supported ICs

=============

-------------

The following ICs have a very similar register set, so that they are or will be

supported somewhen by the driver:

- Si4700: FM radio receiver

- Si4701: FM radio receiver, RDS Support

- Si4702: FM radio receiver

- Si4707: Dedicated weather band radio receiver with SAME decoder, RDS Support

- Si4708: Smallest FM receivers

- Si4709: Smallest FM receivers, RDS Support

More information on these can be downloaded here:

http://www.silabs.com/products/mcu/Pages/USBFMRadioRD.aspx

Supported USB devices

=====================

---------------------

Currently the following USB radios (vendor:product) with the Silicon Labs si470x

chips are known to work:

- 10c4:818a: Silicon Labs USB FM Radio Reference Design

- 06e1:a155: ADS/Tech FM Radio Receiver (formerly Instant FM Music) (RDX-155-EF)

- 1b80:d700: KWorld USB FM Radio SnapMusic Mobile 700 (FM700)

Software

========

--------

Testing is usually done with most application under Debian/testing:

- fmtools - Utility for managing FM tuner cards

- gnomeradio - FM-radio tuner for the GNOME desktop

- gradio - GTK FM radio tuner

- radio - ncurses-based radio application

- mplayer - The Ultimate Movie Player For Linux

- v4l2-ctl - Collection of command line video4linux utilities

For example, you can use:

.. code-block:: none

	v4l2-ctl -d /dev/radio0 --set-ctrl=volume=10,mute=0 --set-freq=95.21 --all

There is also a library libv4l, which can be used. It's going to have a function

Audio Listing

=============

-------------

USB Audio is provided by the ALSA snd_usb_audio module. It is recommended to

also select SND_USB_AUDIO, as this is required to get sound from the radio. For

listing you have to redirect the sound, for example using one of the following

commands. Please adjust the audio devices to your needs (/dev/dsp* and hw:x,x).

If you just want to test audio (very poor quality):

.. code-block:: none

	cat /dev/dsp1 > /dev/dsp

If you use sox + OSS try:

.. code-block:: none

	sox -2 --endian little -r 96000 -t oss /dev/dsp1 -t oss /dev/dsp

or using sox + alsa:

.. code-block:: none

	sox --endian little -c 2 -S -r 96000 -t alsa hw:1 -t alsa -r 96000 hw:0

If you use arts try:

.. code-block:: none

	arecord -D hw:1,0 -r96000 -c2 -f S16_LE | artsdsp aplay -B -

If you use mplayer try:

.. code-block:: none

	mplayer -radio adevice=hw=1.0:arate=96000 \

		-rawaudio rate=96000 \

		radio://<frequency>/capture

Module Parameters

=================

-----------------

After loading the module, you still have access to some of them in the sysfs

mount under /sys/module/radio_si470x/parameters. The contents of read-only files

(0444) are not updated, even if space, band and de are changed using private

Errors

======

------

Increase tune_timeout, if you often get -EIO errors.

When timed out or band limit is reached, hw_freq_seek returns -EAGAIN.

Open Issues

===========

-----------

V4L minor device allocation and parameter setting is not perfect. A solution is

currently under discussion.

Other useful information and links

==================================

----------------------------------

http://www.silabs.com/usbradio