diff options
Diffstat (limited to 'linux/Documentation')
| -rw-r--r-- | linux/Documentation/video4linux/README.cx88 | 12 | ||||
| -rw-r--r-- | linux/Documentation/video4linux/si470x.txt | 118 |
2 files changed, 123 insertions, 7 deletions
diff --git a/linux/Documentation/video4linux/README.cx88 b/linux/Documentation/video4linux/README.cx88 index 06a33a4f5..35fae23f8 100644 --- a/linux/Documentation/video4linux/README.cx88 +++ b/linux/Documentation/video4linux/README.cx88 @@ -1,4 +1,3 @@ - cx8800 release notes ==================== @@ -10,25 +9,24 @@ current status video - Basically works. - - Some minor image quality glitches. - - For now only capture, overlay support isn't completed yet. + - For now, only capture and read(). Overlay isn't supported. audio - The chip specs for the on-chip TV sound decoder are next to useless :-/ - Neverless the builtin TV sound decoder starts working now, - at least for PAL-BG. Other TV norms need other code ... + at least for some standards. FOR ANY REPORTS ON THIS PLEASE MENTION THE TV NORM YOU ARE USING. - Most tuner chips do provide mono sound, which may or may not be useable depending on the board design. With the Hauppauge cards it works, so there is mono sound available as fallback. - audio data dma (i.e. recording without loopback cable to the - sound card) should be possible, but there is no code yet ... + sound card) is supported via cx88-alsa. vbi - - some code present. Doesn't crash any more, but also doesn't - work yet ... + - Code present. Works for NTSC closed caption. PAL and other + TV norms may or may not work. how to add support for new cards diff --git a/linux/Documentation/video4linux/si470x.txt b/linux/Documentation/video4linux/si470x.txt new file mode 100644 index 000000000..11c5fd22a --- /dev/null +++ b/linux/Documentation/video4linux/si470x.txt @@ -0,0 +1,118 @@ +Driver for USB radios for the Silicon Labs Si470x FM Radio Receivers + +Copyright (c) 2008 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, +together with a small microcontroller C8051F321, to form a USB radio. +Part of this reference design is also a radio application in binary and source +code. The software also contains an automatic firmware upgrade to the most +current version. Information on these can be downloaded here: +http://www.silabs.com/usbradio + + +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 +- Si4703: FM radio receiver, RDS Support +- Si4704: FM radio receiver, no external antenna required +- Si4705: FM radio receiver, no external antenna required, RDS support, Dig I/O +- Si4706: Enhanced FM RDS/TMC radio receiver, no external antenna required, RDS + Support +- 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 +- kradio - Comfortable Radio Application for KDE +- radio - ncurses-based radio application + +There is also a library libv4l, which can be used. It's going to have a function +for frequency seeking, either by using hardware functionality as in radio-si470x +or by implementing a function as we currently have in every of the mentioned +programs. Somewhen the radio programs should make use of libv4l. + +For processing RDS information, there is a project ongoing at: +http://rdsd.berlios.de/ + +There is currently no project for making TMC sentences human readable. + + +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. + +If you just want to test audio (very poor quality): +cat /dev/dsp1 > /dev/dsp + +If you use OSS try: +sox -2 --endian little -r 96000 -t oss /dev/dsp1 -t oss /dev/dsp + +If you use arts try: +arecord -D hw:1,0 -r96000 -c2 -f S16_LE | artsdsp aplay -B - + + +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 +video controls. The others are runtime changeable. + + +Errors +====== +Increase tune_timeout, if you often get -EIO errors. + +When timed out or band limit is reached, hw_freq_seek returns -EAGAIN. + +If you get any errors from snd_usb_audio, please report them to the ALSA people. + + +Open Issues +=========== +V4L minor device allocation and parameter setting is not perfect. A solution is +currently under discussion. + +There is an USB interface for downloading/uploading new firmware images. Support +for it can be implemented using the request_firmware interface. + +There is a RDS interrupt mode. The driver is already using the same interface +for polling RDS information, but is currently not using the interrupt mode. + +There is a LED interface, which can be used to override the LED control +programmed in the firmware. This can be made available using the LED support +functions in the kernel. + + +Other useful information and links +================================== +http://www.silabs.com/usbradio |