Commit b2993570 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab

[media] doc-rst: add documentation for si4713

Convert it to ReST and add it to the media/v4l-drivers book.
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent b4a41387
Driver for I2C radios for the Silicon Labs Si4713 FM Radio Transmitters
.. include:: <isonum.txt>
The Silicon Labs Si4713 FM Radio Transmitter Driver
===================================================
Copyright |copy| 2009 Nokia Corporation
Copyright (c) 2009 Nokia Corporation
Contact: Eduardo Valentin <eduardo.valentin@nokia.com>
Information about the Device
============================
----------------------------
This chip is a Silicon Labs product. It is a I2C device, currently on 0x63 address.
Basically, it has transmission and signal noise level measurement features.
......@@ -19,7 +24,8 @@ properties which can change the behavior of this chip.
Users must comply with local regulations on radio frequency (RF) transmission.
Device driver description
=========================
-------------------------
There are two modules to handle this device. One is a I2C device driver
and the other is a platform driver.
......@@ -37,12 +43,15 @@ etc. But mostly of its properties will be present in the extended controls.
When the v4l2 mute property is set to 1 (true), the driver will turn the chip off.
Properties description
======================
----------------------
The properties can be accessed using v4l2 extended controls.
Here is an output from v4l2-ctl util:
/ # v4l2-ctl -d /dev/radio0 --all -L
Driver Info:
.. code-block:: none
/ # v4l2-ctl -d /dev/radio0 --all -L
Driver Info:
Driver name : radio-si4713
Card type : Silicon Labs Si4713 Modulator
Bus info :
......@@ -50,20 +59,20 @@ Driver Info:
Capabilities : 0x00080800
RDS Output
Modulator
Audio output: 0 (FM Modulator Audio Out)
Frequency: 1408000 (88.000000 MHz)
Video Standard = 0x00000000
Modulator:
Audio output: 0 (FM Modulator Audio Out)
Frequency: 1408000 (88.000000 MHz)
Video Standard = 0x00000000
Modulator:
Name : FM Modulator
Capabilities : 62.5 Hz stereo rds
Frequency range : 76.0 MHz - 108.0 MHz
Subchannel modulation: stereo+rds
User Controls
User Controls
mute (bool) : default=1 value=0
FM Radio Modulator Controls
FM Radio Modulator Controls
rds_signal_deviation (int) : min=0 max=90000 step=10 default=200 value=200 flags=slider
rds_program_id (int) : min=0 max=65535 step=1 default=0 value=0
......@@ -73,7 +82,7 @@ FM Radio Modulator Controls
audio_limiter_feature_enabled (bool) : default=1 value=1
audio_limiter_release_time (int) : min=250 max=102390 step=50 default=5010 value=5010 flags=slider
audio_limiter_deviation (int) : min=0 max=90000 step=10 default=66250 value=66250 flags=slider
audio_compression_feature_enabl (bool) : default=1 value=1
audio_compression_feature_enabl (bool) : default=1 value=1
audio_compression_gain (int) : min=0 max=20 step=1 default=15 value=15 flags=slider
audio_compression_threshold (int) : min=-40 max=0 step=1 default=-40 value=-40 flags=slider
audio_compression_attack_time (int) : min=0 max=5000 step=500 default=0 value=0 flags=slider
......@@ -84,57 +93,59 @@ audio_compression_feature_enabl (bool) : default=1 value=1
pre_emphasis_settings (menu) : min=0 max=2 default=1 value=1
tune_power_level (int) : min=0 max=120 step=1 default=88 value=88 flags=slider
tune_antenna_capacitor (int) : min=0 max=191 step=1 default=0 value=110 flags=slider
/ #
Here is a summary of them:
* Pilot is an audible tone sent by the device.
pilot_frequency - Configures the frequency of the stereo pilot tone.
pilot_deviation - Configures pilot tone frequency deviation level.
pilot_enabled - Enables or disables the pilot tone feature.
- pilot_frequency - Configures the frequency of the stereo pilot tone.
- pilot_deviation - Configures pilot tone frequency deviation level.
- pilot_enabled - Enables or disables the pilot tone feature.
* The si4713 device is capable of applying audio compression to the transmitted signal.
* The si4713 device is capable of applying audio compression to the
transmitted signal.
acomp_enabled - Enables or disables the audio dynamic range control feature.
acomp_gain - Sets the gain for audio dynamic range control.
acomp_threshold - Sets the threshold level for audio dynamic range control.
acomp_attack_time - Sets the attack time for audio dynamic range control.
acomp_release_time - Sets the release time for audio dynamic range control.
- acomp_enabled - Enables or disables the audio dynamic range control feature.
- acomp_gain - Sets the gain for audio dynamic range control.
- acomp_threshold - Sets the threshold level for audio dynamic range control.
- acomp_attack_time - Sets the attack time for audio dynamic range control.
- acomp_release_time - Sets the release time for audio dynamic range control.
* Limiter setups audio deviation limiter feature. Once a over deviation occurs,
it is possible to adjust the front-end gain of the audio input and always
prevent over deviation.
it is possible to adjust the front-end gain of the audio input and always
prevent over deviation.
limiter_enabled - Enables or disables the limiter feature.
limiter_deviation - Configures audio frequency deviation level.
limiter_release_time - Sets the limiter release time.
- limiter_enabled - Enables or disables the limiter feature.
- limiter_deviation - Configures audio frequency deviation level.
- limiter_release_time - Sets the limiter release time.
* Tuning power
power_level - Sets the output power level for signal transmission.
antenna_capacitor - This selects the value of antenna tuning capacitor manually
or automatically if set to zero.
- power_level - Sets the output power level for signal transmission.
antenna_capacitor - This selects the value of antenna tuning capacitor
manually or automatically if set to zero.
* RDS related
rds_ps_name - Sets the RDS ps name field for transmission.
rds_radio_text - Sets the RDS radio text for transmission.
rds_pi - Sets the RDS PI field for transmission.
rds_pty - Sets the RDS PTY field for transmission.
- rds_ps_name - Sets the RDS ps name field for transmission.
- rds_radio_text - Sets the RDS radio text for transmission.
- rds_pi - Sets the RDS PI field for transmission.
- rds_pty - Sets the RDS PTY field for transmission.
* Region related
preemphasis - sets the preemphasis to be applied for transmission.
- preemphasis - sets the preemphasis to be applied for transmission.
RNL
===
---
This device also has an interface to measure received noise level. To do that, you should
ioctl the device node. Here is an code of example:
int main (int argc, char *argv[])
{
.. code-block:: none
int main (int argc, char *argv[])
{
struct si4713_rnl rnl;
int fd = open("/dev/radio0", O_RDWR);
int rval;
......@@ -154,23 +165,26 @@ int main (int argc, char *argv[])
printf("received noise level: %d\n", rnl.rnl);
close(fd);
}
}
The struct si4713_rnl and SI4713_IOC_MEASURE_RNL are defined under
include/linux/platform_data/media/si4713.h.
Stereo/Mono and RDS subchannels
===============================
-------------------------------
The device can also be configured using the available sub channels for
transmission. To do that use S/G_MODULATOR ioctl and configure txsubchans properly.
Refer to the V4L2 API specification for proper use of this ioctl.
Testing
=======
-------
Testing is usually done with v4l2-ctl utility for managing FM tuner cards.
The tool can be found in v4l-dvb repository under v4l2-apps/util directory.
Example for setting rds ps name:
# v4l2-ctl -d /dev/radio0 --set-ctrl=rds_ps_name="Dummy"
.. code-block:: none
# v4l2-ctl -d /dev/radio0 --set-ctrl=rds_ps_name="Dummy"
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