1 .. SPDX-License-Identifier: GPL-2.0
2
3 .. include:: <isonum.txt>
4
5
6 The SI476x Driver
7 =================
8
9 Copyright |copy| 2013 Andrey Smirnov <andrew.smirnov@gmail.com>
10
11 TODO for the driver
12 -------------------
13
14 - According to the SiLabs' datasheet it is possible to update the
15 firmware of the radio chip in the run-time, thus bringing it to the
16 most recent version. Unfortunately I couldn't find any mentioning of
17 the said firmware update for the old chips that I tested the driver
18 against, so for chips like that the driver only exposes the old
19 functionality.
20
21
22 Parameters exposed over debugfs
23 -------------------------------
24 SI476x allow user to get multiple characteristics that can be very
25 useful for EoL testing/RF performance estimation, parameters that have
26 very little to do with V4L2 subsystem. Such parameters are exposed via
27 debugfs and can be accessed via regular file I/O operations.
28
29 The drivers exposes following files:
30
31 * /sys/kernel/debug/<device-name>/acf
32 This file contains ACF(Automatically Controlled Features) status
33 information. The contents of the file is binary data of the
34 following layout:
35
36 .. tabularcolumns:: |p{7ex}|p{12ex}|L|
37
38 ============= ============== ====================================
39 Offset Name Description
40 ============= ============== ====================================
41 0x00 blend_int Flag, set when stereo separation has
42 crossed below the blend threshold
43 0x01 hblend_int Flag, set when HiBlend cutoff
44 frequency is lower than threshold
45 0x02 hicut_int Flag, set when HiCut cutoff
46 frequency is lower than threshold
47 0x03 chbw_int Flag, set when channel filter
48 bandwidth is less than threshold
49 0x04 softmute_int Flag indicating that softmute
50 attenuation has increased above
51 softmute threshold
52 0x05 smute 0 - Audio is not soft muted
53 1 - Audio is soft muted
54 0x06 smattn Soft mute attenuation level in dB
55 0x07 chbw Channel filter bandwidth in kHz
56 0x08 hicut HiCut cutoff frequency in units of
57 100Hz
58 0x09 hiblend HiBlend cutoff frequency in units
59 of 100 Hz
60 0x10 pilot 0 - Stereo pilot is not present
61 1 - Stereo pilot is present
62 0x11 stblend Stereo blend in %
63 ============= ============== ====================================
64
65
66 * /sys/kernel/debug/<device-name>/rds_blckcnt
67 This file contains statistics about RDS receptions. It's binary data
68 has the following layout:
69
70 .. tabularcolumns:: |p{7ex}|p{12ex}|L|
71
72 ============= ============== ====================================
73 Offset Name Description
74 ============= ============== ====================================
75 0x00 expected Number of expected RDS blocks
76 0x02 received Number of received RDS blocks
77 0x04 uncorrectable Number of uncorrectable RDS blocks
78 ============= ============== ====================================
79
80 * /sys/kernel/debug/<device-name>/agc
81 This file contains information about parameters pertaining to
82 AGC(Automatic Gain Control)
83
84 The layout is:
85
86 .. tabularcolumns:: |p{7ex}|p{12ex}|L|
87
88 ============= ============== ====================================
89 Offset Name Description
90 ============= ============== ====================================
91 0x00 mxhi 0 - FM Mixer PD high threshold is
92 not tripped
93 1 - FM Mixer PD high threshold is
94 tripped
95 0x01 mxlo ditto for FM Mixer PD low
96 0x02 lnahi ditto for FM LNA PD high
97 0x03 lnalo ditto for FM LNA PD low
98 0x04 fmagc1 FMAGC1 attenuator resistance
99 (see datasheet for more detail)
100 0x05 fmagc2 ditto for FMAGC2
101 0x06 pgagain PGA gain in dB
102 0x07 fmwblang FM/WB LNA Gain in dB
103 ============= ============== ====================================
104
105 * /sys/kernel/debug/<device-name>/rsq
106 This file contains information about parameters pertaining to
107 RSQ(Received Signal Quality)
108
109 The layout is:
110
111 .. tabularcolumns:: |p{7ex}|p{12ex}|p{60ex}|
112
113 ============= ============== ====================================
114 Offset Name Description
115 ============= ============== ====================================
116 0x00 multhint 0 - multipath value has not crossed
117 the Multipath high threshold
118 1 - multipath value has crossed
119 the Multipath high threshold
120 0x01 multlint ditto for Multipath low threshold
121 0x02 snrhint 0 - received signal's SNR has not
122 crossed high threshold
123 1 - received signal's SNR has
124 crossed high threshold
125 0x03 snrlint ditto for low threshold
126 0x04 rssihint ditto for RSSI high threshold
127 0x05 rssilint ditto for RSSI low threshold
128 0x06 bltf Flag indicating if seek command
129 reached/wrapped seek band limit
130 0x07 snr_ready Indicates that SNR metrics is ready
131 0x08 rssiready ditto for RSSI metrics
132 0x09 injside 0 - Low-side injection is being used
133 1 - High-side injection is used
134 0x10 afcrl Flag indicating if AFC rails
135 0x11 valid Flag indicating if channel is valid
136 0x12 readfreq Current tuned frequency
137 0x14 freqoff Signed frequency offset in units of
138 2ppm
139 0x15 rssi Signed value of RSSI in dBuV
140 0x16 snr Signed RF SNR in dB
141 0x17 issi Signed Image Strength Signal
142 indicator
143 0x18 lassi Signed Low side adjacent Channel
144 Strength indicator
145 0x19 hassi ditto for High side
146 0x20 mult Multipath indicator
147 0x21 dev Frequency deviation
148 0x24 assi Adjacent channel SSI
149 0x25 usn Ultrasonic noise indicator
150 0x26 pilotdev Pilot deviation in units of 100 Hz
151 0x27 rdsdev ditto for RDS
152 0x28 assidev ditto for ASSI
153 0x29 strongdev Frequency deviation
154 0x30 rdspi RDS PI code
155 ============= ============== ====================================
156
157 * /sys/kernel/debug/<device-name>/rsq_primary
158 This file contains information about parameters pertaining to
159 RSQ(Received Signal Quality) for primary tuner only. Layout is as
160 the one above.
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