1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 .. include:: <isonum.txt> 3 .. include:: <isonum.txt>
4 4
5 The Silicon Labs Si470x FM Radio Receivers dri 5 The Silicon Labs Si470x FM Radio Receivers driver
6 ============================================== 6 =================================================
7 7
8 Copyright |copy| 2009 Tobias Lorenz <tobias.lor 8 Copyright |copy| 2009 Tobias Lorenz <tobias.lorenz@gmx.net>
9 9
10 10
11 Information from Silicon Labs 11 Information from Silicon Labs
12 ----------------------------- 12 -----------------------------
13 13
14 Silicon Laboratories is the manufacturer of th 14 Silicon Laboratories is the manufacturer of the radio ICs, that nowadays are the
15 most often used radio receivers in cell phones 15 most often used radio receivers in cell phones. Usually they are connected with
16 I2C. But SiLabs also provides a reference desi 16 I2C. But SiLabs also provides a reference design, which integrates this IC,
17 together with a small microcontroller C8051F32 17 together with a small microcontroller C8051F321, to form a USB radio.
18 Part of this reference design is also a radio 18 Part of this reference design is also a radio application in binary and source
19 code. The software also contains an automatic 19 code. The software also contains an automatic firmware upgrade to the most
20 current version. Information on these can be d 20 current version. Information on these can be downloaded here:
21 http://www.silabs.com/usbradio 21 http://www.silabs.com/usbradio
22 22
23 23
24 Supported ICs 24 Supported ICs
25 ------------- 25 -------------
26 26
27 The following ICs have a very similar register 27 The following ICs have a very similar register set, so that they are or will be
28 supported somewhen by the driver: 28 supported somewhen by the driver:
29 29
30 - Si4700: FM radio receiver 30 - Si4700: FM radio receiver
31 - Si4701: FM radio receiver, RDS Support 31 - Si4701: FM radio receiver, RDS Support
32 - Si4702: FM radio receiver 32 - Si4702: FM radio receiver
33 - Si4703: FM radio receiver, RDS Support 33 - Si4703: FM radio receiver, RDS Support
34 - Si4704: FM radio receiver, no external anten 34 - Si4704: FM radio receiver, no external antenna required
35 - Si4705: FM radio receiver, no external anten 35 - Si4705: FM radio receiver, no external antenna required, RDS support, Dig I/O
36 - Si4706: Enhanced FM RDS/TMC radio receiver, 36 - Si4706: Enhanced FM RDS/TMC radio receiver, no external antenna required, RDS
37 Support 37 Support
38 - Si4707: Dedicated weather band radio receive 38 - Si4707: Dedicated weather band radio receiver with SAME decoder, RDS Support
39 - Si4708: Smallest FM receivers 39 - Si4708: Smallest FM receivers
40 - Si4709: Smallest FM receivers, RDS Support 40 - Si4709: Smallest FM receivers, RDS Support
41 41
42 More information on these can be downloaded he 42 More information on these can be downloaded here:
43 http://www.silabs.com/products/mcu/Pages/USBFM 43 http://www.silabs.com/products/mcu/Pages/USBFMRadioRD.aspx
44 44
45 45
46 Supported USB devices 46 Supported USB devices
47 --------------------- 47 ---------------------
48 48
49 Currently the following USB radios (vendor:pro 49 Currently the following USB radios (vendor:product) with the Silicon Labs si470x
50 chips are known to work: 50 chips are known to work:
51 51
52 - 10c4:818a: Silicon Labs USB FM Radio Referen 52 - 10c4:818a: Silicon Labs USB FM Radio Reference Design
53 - 06e1:a155: ADS/Tech FM Radio Receiver (forme 53 - 06e1:a155: ADS/Tech FM Radio Receiver (formerly Instant FM Music) (RDX-155-EF)
54 - 1b80:d700: KWorld USB FM Radio SnapMusic Mob 54 - 1b80:d700: KWorld USB FM Radio SnapMusic Mobile 700 (FM700)
55 - 10c5:819a: Sanei Electric, Inc. FM USB Radio 55 - 10c5:819a: Sanei Electric, Inc. FM USB Radio (sold as DealExtreme.com PCear)
56 56
57 57
58 Software 58 Software
59 -------- 59 --------
60 60
61 Testing is usually done with most application 61 Testing is usually done with most application under Debian/testing:
62 62
63 - fmtools - Utility for managing FM tuner card 63 - fmtools - Utility for managing FM tuner cards
64 - gnomeradio - FM-radio tuner for the GNOME de 64 - gnomeradio - FM-radio tuner for the GNOME desktop
65 - gradio - GTK FM radio tuner 65 - gradio - GTK FM radio tuner
66 - kradio - Comfortable Radio Application for K 66 - kradio - Comfortable Radio Application for KDE
67 - radio - ncurses-based radio application 67 - radio - ncurses-based radio application
68 - mplayer - The Ultimate Movie Player For Linu 68 - mplayer - The Ultimate Movie Player For Linux
69 - v4l2-ctl - Collection of command line video4 69 - v4l2-ctl - Collection of command line video4linux utilities
70 70
71 For example, you can use: 71 For example, you can use:
72 72
73 .. code-block:: none 73 .. code-block:: none
74 74
75 v4l2-ctl -d /dev/radio0 --set-ctrl=vol 75 v4l2-ctl -d /dev/radio0 --set-ctrl=volume=10,mute=0 --set-freq=95.21 --all
76 76
77 There is also a library libv4l, which can be u 77 There is also a library libv4l, which can be used. It's going to have a function
78 for frequency seeking, either by using hardwar 78 for frequency seeking, either by using hardware functionality as in radio-si470x
79 or by implementing a function as we currently 79 or by implementing a function as we currently have in every of the mentioned
80 programs. Somewhen the radio programs should m 80 programs. Somewhen the radio programs should make use of libv4l.
81 81
82 For processing RDS information, there is a pro 82 For processing RDS information, there is a project ongoing at:
83 http://rdsd.berlios.de/ 83 http://rdsd.berlios.de/
84 84
85 There is currently no project for making TMC s 85 There is currently no project for making TMC sentences human readable.
86 86
87 87
88 Audio Listing 88 Audio Listing
89 ------------- 89 -------------
90 90
91 USB Audio is provided by the ALSA snd_usb_audi 91 USB Audio is provided by the ALSA snd_usb_audio module. It is recommended to
92 also select SND_USB_AUDIO, as this is required 92 also select SND_USB_AUDIO, as this is required to get sound from the radio. For
93 listing you have to redirect the sound, for ex 93 listing you have to redirect the sound, for example using one of the following
94 commands. Please adjust the audio devices to y 94 commands. Please adjust the audio devices to your needs (/dev/dsp* and hw:x,x).
95 95
96 If you just want to test audio (very poor qual 96 If you just want to test audio (very poor quality):
97 97
98 .. code-block:: none 98 .. code-block:: none
99 99
100 cat /dev/dsp1 > /dev/dsp 100 cat /dev/dsp1 > /dev/dsp
101 101
102 If you use sox + OSS try: 102 If you use sox + OSS try:
103 103
104 .. code-block:: none 104 .. code-block:: none
105 105
106 sox -2 --endian little -r 96000 -t oss 106 sox -2 --endian little -r 96000 -t oss /dev/dsp1 -t oss /dev/dsp
107 107
108 or using sox + alsa: 108 or using sox + alsa:
109 109
110 .. code-block:: none 110 .. code-block:: none
111 111
112 sox --endian little -c 2 -S -r 96000 - 112 sox --endian little -c 2 -S -r 96000 -t alsa hw:1 -t alsa -r 96000 hw:0
113 113
114 If you use arts try: 114 If you use arts try:
115 115
116 .. code-block:: none 116 .. code-block:: none
117 117
118 arecord -D hw:1,0 -r96000 -c2 -f S16_L 118 arecord -D hw:1,0 -r96000 -c2 -f S16_LE | artsdsp aplay -B -
119 119
120 If you use mplayer try: 120 If you use mplayer try:
121 121
122 .. code-block:: none 122 .. code-block:: none
123 123
124 mplayer -radio adevice=hw=1.0:arate=96 124 mplayer -radio adevice=hw=1.0:arate=96000 \
125 -rawaudio rate=96000 \ 125 -rawaudio rate=96000 \
126 radio://<frequency>/capture 126 radio://<frequency>/capture
127 127
128 Module Parameters 128 Module Parameters
129 ----------------- 129 -----------------
130 130
131 After loading the module, you still have acces 131 After loading the module, you still have access to some of them in the sysfs
132 mount under /sys/module/radio_si470x/parameter 132 mount under /sys/module/radio_si470x/parameters. The contents of read-only files
133 (0444) are not updated, even if space, band an 133 (0444) are not updated, even if space, band and de are changed using private
134 video controls. The others are runtime changea 134 video controls. The others are runtime changeable.
135 135
136 136
137 Errors 137 Errors
138 ------ 138 ------
139 139
140 Increase tune_timeout, if you often get -EIO e 140 Increase tune_timeout, if you often get -EIO errors.
141 141
142 When timed out or band limit is reached, hw_fr 142 When timed out or band limit is reached, hw_freq_seek returns -EAGAIN.
143 143
144 If you get any errors from snd_usb_audio, plea 144 If you get any errors from snd_usb_audio, please report them to the ALSA people.
145 145
146 146
147 Open Issues 147 Open Issues
148 ----------- 148 -----------
149 149
150 V4L minor device allocation and parameter sett 150 V4L minor device allocation and parameter setting is not perfect. A solution is
151 currently under discussion. 151 currently under discussion.
152 152
153 There is an USB interface for downloading/uplo 153 There is an USB interface for downloading/uploading new firmware images. Support
154 for it can be implemented using the request_fi 154 for it can be implemented using the request_firmware interface.
155 155
156 There is a RDS interrupt mode. The driver is a 156 There is a RDS interrupt mode. The driver is already using the same interface
157 for polling RDS information, but is currently 157 for polling RDS information, but is currently not using the interrupt mode.
158 158
159 There is a LED interface, which can be used to 159 There is a LED interface, which can be used to override the LED control
160 programmed in the firmware. This can be made a 160 programmed in the firmware. This can be made available using the LED support
161 functions in the kernel. 161 functions in the kernel.
162 162
163 163
164 Other useful information and links 164 Other useful information and links
165 ---------------------------------- 165 ----------------------------------
166 166
167 http://www.silabs.com/usbradio 167 http://www.silabs.com/usbradio
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