On Saturday 25 July 2009 15:48:58 Eduardo Valentin wrote:
> On Sat, Jul 25, 2009 at 03:17:05PM +0200, Valentin Eduardo (Nokia-D/Helsinki)
> wrote:
> > On Sat, Jul 25, 2009 at 03:25:25PM +0200, ext Hans Verkuil wrote:
> > > On Friday 24 July 2009 18:37:28 Eduardo Valentin wrote:
> > > > This patch adds a document file for si4713 device driver.
> > > > It describes the driver interfaces and organization.
> > > >
> > > > Signed-off-by: Eduardo Valentin <[email protected]>
> > > > ---
> > > > linux/Documentation/video4linux/si4713.txt | 175
> > > > ++++++++++++++++++++++++++++
> > > > 1 files changed, 175 insertions(+), 0 deletions(-)
> > > > create mode 100644 linux/Documentation/video4linux/si4713.txt
> > > >
> > > > diff --git a/linux/Documentation/video4linux/si4713.txt
> > > > b/linux/Documentation/video4linux/si4713.txt
> > > > new file mode 100644
> > > > index 0000000..3843af5
> > > > --- /dev/null
> > > > +++ b/linux/Documentation/video4linux/si4713.txt
> > > > @@ -0,0 +1,175 @@
> > > > +Driver for I2C radios for the Silicon Labs Si4713 FM Radio Transmitters
> > > > +
> > > > +Copyright (c) 2009 Nokia Corporation
> > > > +Contact: Eduardo Valentin <[email protected]>
> > > > +
> > > > +
> > > > +Information about the Device
> > > > +============================
> > > > +This chip is a Silicon Labs product. It is a I2C device, currently on
> > > > 0×63 address.
> > > > +Basically, it has transmission and signal noise level measurement
> > > > features.
> > > > +
> > > > +The Si4713 integrates transmit functions for FM broadcast stereo
> > > > transmission.
> > > > +The chip also allows integrated receive power scanning to identify low
> > > > signal
> > > > +power FM channels.
> > > > +
> > > > +The chip is programmed using commands and responses. There are also
> > > > several
> > > > +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.
> > > > +
> > > > +The I2C device driver exports a v4l2-subdev interface to the kernel.
> > > > +All properties can also be accessed by v4l2 extended controls
> > > > interface, by
> > > > +using the v4l2-subdev calls (g_ext_ctrls, s_ext_ctrls).
> > > > +
> > > > +The platform device driver exports a v4l2 radio device interface to
> > > > user land.
> > > > +So, it uses the I2C device driver as a sub device in order to send the
> > > > user
> > > > +commands to the actual device. Basically it is a wrapper to the I2C
> > > > device driver.
> > > > +
> > > > +Applications can use v4l2 radio API to specify frequency of operation,
> > > > mute state,
> > > > +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:
> > > > + Driver name : radio-si4713
> > > > + Card type : Silicon Labs Si4713 Modulator
> > > > + Bus info :
> > > > + Driver version: 0
> > > > + Capabilities : 0x00080800
> > > > + RDS Output
> > > > + Modulator
> > > > +Audio output: 0 (FM Modulator Audio Out)
> > > > +Frequency: 1545600 (96.600000 MHz)
> > > > +Video Standard = 0x00000000
> > > > +Modulator:
> > > > + Name : FM Modulator
> > > > + Capabilities : 62.5 Hz stereo rds
> > > > + Frequency range : 76.0 MHz - 108.0 MHz
> > > > + Available subchannels: mono rds
> > > > +
> > > > +User Controls
> > > > +
> > > > + mute (bool) : default=1 value=0
> > > > +
> > > > +FM Radio Modulator Controls
> > > > +
> > > > + rds_program_id (int) : min=0 max=65535 step=1
> > > > default=0 value=0
> > > > + rds_program_type (int) : min=0 max=31 step=1 default=0
> > > > value=0
> > > > + rds_ps_name (str) : value='Si4713 ' len=1024
> > > > +' len=1024 rds_radio_text (str) : value='Si4713
> > >
> > > This doesn't look right. I think this output is from an old v4l2-ctl
> > > version.
> > > I'd like to see this output anyway using the latest v4l2-ctl version as I
> > > haven't been able to test it myself.
> >
> > Yeah. My bad, forgot to update here. This is the output from the older
> > version.
>
>
> I've just checked that now v4l2-ctl does not report rds subchannel for
> txsubchannel.
> Just to confirm this is something which is missing right?
Yes, that was missing. I've just added it to my tree. Thanks for the report.
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG Telecom
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