Documentation/media/v4l-drivers/si476x.rst

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