Documentation/video4linux/si476x.txt

   1 SI476x Driver Readme
   2 ------------------------------------------------
   3         Copyright (C) 2013 Andrey Smirnov <andrew.smirnov@gmail.com>
   4
   5 TODO for the driver
   6 ------------------------------
   7
   8 - According to the SiLabs' datasheet it is possible to update the
   9   firmware of the radio chip in the run-time, thus bringing it to the
  10   most recent version. Unfortunately I couldn't find any mentioning of
  11   the said firmware update for the old chips that I tested the driver
  12   against, so for chips like that the driver only exposes the old
  13   functionality.
  14
  15
  16 Parameters exposed over debugfs
  17 -------------------------------
  18 SI476x allow user to get multiple characteristics that can be very
  19 useful for EoL testing/RF performance estimation, parameters that have
  20 very little to do with V4L2 subsystem. Such parameters are exposed via
  21 debugfs and can be accessed via regular file I/O operations.
  22
  23 The drivers exposes following files:
  24
  25 * /sys/kernel/debug/<device-name>/acf
  26   This file contains ACF(Automatically Controlled Features) status
  27   information. The contents of the file is binary data of the
  28   following layout:
  29
  30   Offset        | Name          | Description
  31   ====================================================================
  32   0x00          | blend_int     | Flag, set when stereo separation has
  33                 |               | crossed below the blend threshold
  34   --------------------------------------------------------------------
  35   0x01          | hblend_int    | Flag, set when HiBlend cutoff
  36                 |               | frequency is lower than threshold
  37   --------------------------------------------------------------------
  38   0x02          | hicut_int     | Flag, set when HiCut cutoff
  39                 |               | frequency is lower than threshold
  40   --------------------------------------------------------------------
  41   0x03          | chbw_int      | Flag, set when channel filter
  42                 |               | bandwidth is less than threshold
  43   --------------------------------------------------------------------
  44   0x04          | softmute_int  | Flag indicating that softmute
  45                 |               | attenuation has increased above
  46                 |               | softmute threshold
  47   --------------------------------------------------------------------
  48   0x05          | smute         | 0 - Audio is not soft muted
  49                 |               | 1 - Audio is soft muted
  50   --------------------------------------------------------------------
  51   0x06          | smattn        | Soft mute attenuation level in dB
  52   --------------------------------------------------------------------
  53   0x07          | chbw          | Channel filter bandwidth in kHz
  54   --------------------------------------------------------------------
  55   0x08          | hicut         | HiCut cutoff frequency in units of
  56                 |               | 100Hz
  57   --------------------------------------------------------------------
  58   0x09          | hiblend       | HiBlend cutoff frequency in units
  59                 |               | of 100 Hz
  60   --------------------------------------------------------------------
  61   0x10          | pilot         | 0 - Stereo pilot is not present
  62                 |               | 1 - Stereo pilot is present
  63   --------------------------------------------------------------------
  64   0x11          | stblend       | Stereo blend in %
  65   --------------------------------------------------------------------
  66
  67
  68 * /sys/kernel/debug/<device-name>/rds_blckcnt
  69   This file contains statistics about RDS receptions. It's binary data
  70   has the following layout:
  71
  72   Offset        | Name          | Description
  73   ====================================================================
  74   0x00          | expected      | Number of expected RDS blocks
  75   --------------------------------------------------------------------
  76   0x02          | received      | Number of received RDS blocks
  77   --------------------------------------------------------------------
  78   0x04          | uncorrectable | Number of uncorrectable RDS blocks
  79   --------------------------------------------------------------------
  80
  81 * /sys/kernel/debug/<device-name>/agc
  82   This file contains information about parameters pertaining to
  83   AGC(Automatic Gain Control)
  84
  85   The layout is:
  86   Offset        | Name          | Description
  87   ====================================================================
  88   0x00          | mxhi          | 0 - FM Mixer PD high threshold is
  89                 |               | not tripped
  90                 |               | 1 - FM Mixer PD high threshold is
  91                 |               | tripped
  92   --------------------------------------------------------------------
  93   0x01          | mxlo          | ditto for FM Mixer PD low
  94   --------------------------------------------------------------------
  95   0x02          | lnahi         | ditto for FM LNA PD high
  96   --------------------------------------------------------------------
  97   0x03          | lnalo         | ditto for FM LNA PD low
  98   --------------------------------------------------------------------
  99   0x04          | fmagc1        | FMAGC1 attenuator resistance
 100                 |               | (see datasheet for more detail)
 101   --------------------------------------------------------------------
 102   0x05          | fmagc2        | ditto for FMAGC2
 103   --------------------------------------------------------------------
 104   0x06          | pgagain       | PGA gain in dB
 105   --------------------------------------------------------------------
 106   0x07          | fmwblang      | FM/WB LNA Gain in dB
 107   --------------------------------------------------------------------
 108
 109 * /sys/kernel/debug/<device-name>/rsq
 110   This file contains information about parameters pertaining to
 111   RSQ(Received Signal Quality)
 112
 113   The layout is:
 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   --------------------------------------------------------------------
 121   0x01          | multlint      | ditto for Multipath low threshold
 122   --------------------------------------------------------------------
 123   0x02          | snrhint       | 0 - received signal's SNR has not
 124                 |               | crossed high threshold
 125                 |               | 1 - received signal's SNR has
 126                 |               | crossed high threshold
 127   --------------------------------------------------------------------
 128   0x03          | snrlint       | ditto for low threshold
 129   --------------------------------------------------------------------
 130   0x04          | rssihint      | ditto for RSSI high threshold
 131   --------------------------------------------------------------------
 132   0x05          | rssilint      | ditto for RSSI low threshold
 133   --------------------------------------------------------------------
 134   0x06          | bltf          | Flag indicating if seek command
 135                 |               | reached/wrapped seek band limit
 136   --------------------------------------------------------------------
 137   0x07          | snr_ready     | Indicates that SNR metrics is ready
 138   --------------------------------------------------------------------
 139   0x08          | rssiready     | ditto for RSSI metrics
 140   --------------------------------------------------------------------
 141   0x09          | injside       | 0 - Low-side injection is being used
 142                 |               | 1 - High-side injection is used
 143   --------------------------------------------------------------------
 144   0x10          | afcrl         | Flag indicating if AFC rails
 145   --------------------------------------------------------------------
 146   0x11          | valid         | Flag indicating if channel is valid
 147   --------------------------------------------------------------------
 148   0x12          | readfreq      | Current tuned frequency
 149   --------------------------------------------------------------------
 150   0x14          | freqoff       | Singed frequency offset in units of
 151                 |               | 2ppm
 152   --------------------------------------------------------------------
 153   0x15          | rssi          | Signed value of RSSI in dBuV
 154   --------------------------------------------------------------------
 155   0x16          | snr           | Signed RF SNR in dB
 156   --------------------------------------------------------------------
 157   0x17          | issi          | Signed Image Strength Signal
 158                 |               | indicator
 159   --------------------------------------------------------------------
 160   0x18          | lassi         | Signed Low side adjacent Channel
 161                 |               | Strength indicator
 162   --------------------------------------------------------------------
 163   0x19          | hassi         | ditto fpr High side
 164   --------------------------------------------------------------------
 165   0x20          | mult          | Multipath indicator
 166   --------------------------------------------------------------------
 167   0x21          | dev           | Frequency deviation
 168   --------------------------------------------------------------------
 169   0x24          | assi          | Adjacent channel SSI
 170   --------------------------------------------------------------------
 171   0x25          | usn           | Ultrasonic noise indicator
 172   --------------------------------------------------------------------
 173   0x26          | pilotdev      | Pilot deviation in units of 100 Hz
 174   --------------------------------------------------------------------
 175   0x27          | rdsdev        | ditto for RDS
 176   --------------------------------------------------------------------
 177   0x28          | assidev       | ditto for ASSI
 178   --------------------------------------------------------------------
 179   0x29          | strongdev     | Frequency deviation
 180   --------------------------------------------------------------------
 181   0x30          | rdspi         | RDS PI code
 182   --------------------------------------------------------------------
 183
 184 * /sys/kernel/debug/<device-name>/rsq_primary
 185   This file contains information about parameters pertaining to
 186   RSQ(Received Signal Quality) for primary tuner only. Layout is as
 187   the one above.