Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 1 | Driver for USB radios for the Silicon Labs Si470x FM Radio Receivers |
| 2 | |
Tobias Lorenz | 00ec8d0 | 2009-02-12 14:55:45 -0300 | [diff] [blame] | 3 | Copyright (c) 2009 Tobias Lorenz <tobias.lorenz@gmx.net> |
Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 4 | |
| 5 | |
| 6 | Information from Silicon Labs |
| 7 | ============================= |
| 8 | Silicon Laboratories is the manufacturer of the radio ICs, that nowadays are the |
| 9 | most often used radio receivers in cell phones. Usually they are connected with |
| 10 | I2C. But SiLabs also provides a reference design, which integrates this IC, |
| 11 | together with a small microcontroller C8051F321, to form a USB radio. |
| 12 | Part of this reference design is also a radio application in binary and source |
| 13 | code. The software also contains an automatic firmware upgrade to the most |
| 14 | current version. Information on these can be downloaded here: |
| 15 | http://www.silabs.com/usbradio |
| 16 | |
| 17 | |
| 18 | Supported ICs |
| 19 | ============= |
| 20 | The following ICs have a very similar register set, so that they are or will be |
| 21 | supported somewhen by the driver: |
| 22 | - Si4700: FM radio receiver |
| 23 | - Si4701: FM radio receiver, RDS Support |
| 24 | - Si4702: FM radio receiver |
| 25 | - Si4703: FM radio receiver, RDS Support |
| 26 | - Si4704: FM radio receiver, no external antenna required |
| 27 | - Si4705: FM radio receiver, no external antenna required, RDS support, Dig I/O |
| 28 | - Si4706: Enhanced FM RDS/TMC radio receiver, no external antenna required, RDS |
| 29 | Support |
| 30 | - Si4707: Dedicated weather band radio receiver with SAME decoder, RDS Support |
| 31 | - Si4708: Smallest FM receivers |
| 32 | - Si4709: Smallest FM receivers, RDS Support |
| 33 | More information on these can be downloaded here: |
| 34 | http://www.silabs.com/products/mcu/Pages/USBFMRadioRD.aspx |
| 35 | |
| 36 | |
| 37 | Supported USB devices |
| 38 | ===================== |
| 39 | Currently the following USB radios (vendor:product) with the Silicon Labs si470x |
| 40 | chips are known to work: |
| 41 | - 10c4:818a: Silicon Labs USB FM Radio Reference Design |
| 42 | - 06e1:a155: ADS/Tech FM Radio Receiver (formerly Instant FM Music) (RDX-155-EF) |
| 43 | - 1b80:d700: KWorld USB FM Radio SnapMusic Mobile 700 (FM700) |
Tobias Lorenz | 00ec8d0 | 2009-02-12 14:55:45 -0300 | [diff] [blame] | 44 | - 10c5:819a: Sanei Electric, Inc. FM USB Radio (sold as DealExtreme.com PCear) |
Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 45 | |
| 46 | |
| 47 | Software |
| 48 | ======== |
| 49 | Testing is usually done with most application under Debian/testing: |
| 50 | - fmtools - Utility for managing FM tuner cards |
| 51 | - gnomeradio - FM-radio tuner for the GNOME desktop |
| 52 | - gradio - GTK FM radio tuner |
| 53 | - kradio - Comfortable Radio Application for KDE |
| 54 | - radio - ncurses-based radio application |
Tobias Lorenz | 00ec8d0 | 2009-02-12 14:55:45 -0300 | [diff] [blame] | 55 | - mplayer - The Ultimate Movie Player For Linux |
Alexey Klimov | 4db45af | 2013-02-11 19:04:51 -0300 | [diff] [blame^] | 56 | - v4l2-ctl - Collection of command line video4linux utilities |
| 57 | For example, you can use: |
| 58 | v4l2-ctl -d /dev/radio0 --set-ctrl=volume=10,mute=0 --set-freq=95.21 --all |
Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 59 | |
| 60 | There is also a library libv4l, which can be used. It's going to have a function |
| 61 | for frequency seeking, either by using hardware functionality as in radio-si470x |
| 62 | or by implementing a function as we currently have in every of the mentioned |
| 63 | programs. Somewhen the radio programs should make use of libv4l. |
| 64 | |
| 65 | For processing RDS information, there is a project ongoing at: |
| 66 | http://rdsd.berlios.de/ |
| 67 | |
| 68 | There is currently no project for making TMC sentences human readable. |
| 69 | |
| 70 | |
| 71 | Audio Listing |
| 72 | ============= |
| 73 | USB Audio is provided by the ALSA snd_usb_audio module. It is recommended to |
| 74 | also select SND_USB_AUDIO, as this is required to get sound from the radio. For |
| 75 | listing you have to redirect the sound, for example using one of the following |
Tobias Lorenz | 00ec8d0 | 2009-02-12 14:55:45 -0300 | [diff] [blame] | 76 | commands. Please adjust the audio devices to your needs (/dev/dsp* and hw:x,x). |
Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 77 | |
| 78 | If you just want to test audio (very poor quality): |
| 79 | cat /dev/dsp1 > /dev/dsp |
| 80 | |
Alexey Klimov | 4db45af | 2013-02-11 19:04:51 -0300 | [diff] [blame^] | 81 | If you use sox + OSS try: |
Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 82 | sox -2 --endian little -r 96000 -t oss /dev/dsp1 -t oss /dev/dsp |
Alexey Klimov | 4db45af | 2013-02-11 19:04:51 -0300 | [diff] [blame^] | 83 | or using sox + alsa: |
| 84 | sox --endian little -c 2 -S -r 96000 -t alsa hw:1 -t alsa -r 96000 hw:0 |
Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 85 | |
| 86 | If you use arts try: |
| 87 | arecord -D hw:1,0 -r96000 -c2 -f S16_LE | artsdsp aplay -B - |
| 88 | |
Tobias Lorenz | 00ec8d0 | 2009-02-12 14:55:45 -0300 | [diff] [blame] | 89 | If you use mplayer try: |
| 90 | mplayer -radio adevice=hw=1.0:arate=96000 \ |
| 91 | -rawaudio rate=96000 \ |
| 92 | radio://<frequency>/capture |
Tobias Lorenz | 6aadf82 | 2008-10-28 08:48:27 -0300 | [diff] [blame] | 93 | |
| 94 | Module Parameters |
| 95 | ================= |
| 96 | After loading the module, you still have access to some of them in the sysfs |
| 97 | mount under /sys/module/radio_si470x/parameters. The contents of read-only files |
| 98 | (0444) are not updated, even if space, band and de are changed using private |
| 99 | video controls. The others are runtime changeable. |
| 100 | |
| 101 | |
| 102 | Errors |
| 103 | ====== |
| 104 | Increase tune_timeout, if you often get -EIO errors. |
| 105 | |
| 106 | When timed out or band limit is reached, hw_freq_seek returns -EAGAIN. |
| 107 | |
| 108 | If you get any errors from snd_usb_audio, please report them to the ALSA people. |
| 109 | |
| 110 | |
| 111 | Open Issues |
| 112 | =========== |
| 113 | V4L minor device allocation and parameter setting is not perfect. A solution is |
| 114 | currently under discussion. |
| 115 | |
| 116 | There is an USB interface for downloading/uploading new firmware images. Support |
| 117 | for it can be implemented using the request_firmware interface. |
| 118 | |
| 119 | There is a RDS interrupt mode. The driver is already using the same interface |
| 120 | for polling RDS information, but is currently not using the interrupt mode. |
| 121 | |
| 122 | There is a LED interface, which can be used to override the LED control |
| 123 | programmed in the firmware. This can be made available using the LED support |
| 124 | functions in the kernel. |
| 125 | |
| 126 | |
| 127 | Other useful information and links |
| 128 | ================================== |
| 129 | http://www.silabs.com/usbradio |