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 <eduardo.valentin@xxxxxxxxx> > > > > --- > > > > 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 <eduardo.valentin@xxxxxxxxx> > > > > + > > > > + > > > > +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 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
