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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/video4linux/si476x.txt | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/Documentation/video4linux/si476x.txt b/Documentation/video4linux/si476x.txt new file mode 100644 index 000000000000..d1a08db2cbd9 --- /dev/null +++ b/Documentation/video4linux/si476x.txt @@ -0,0 +1,187 @@ +SI476x Driver Readme +------------------------------------------------ + Copyright (C) 2013 Andrey Smirnov <andrew.smirnov@gmail.com> + +TODO for the driver +------------------------------ + +- According to the SiLabs' datasheet it is possible to update the + firmware of the radio chip in the run-time, thus bringing it to the + most recent version. Unfortunately I couldn't find any mentioning of + the said firmware update for the old chips that I tested the driver + against, so for chips like that the driver only exposes the old + functionality. + + +Parameters exposed over debugfs +------------------------------- +SI476x allow user to get multiple characteristics that can be very +useful for EoL testing/RF performance estimation, parameters that have +very little to do with V4L2 subsystem. Such parameters are exposed via +debugfs and can be accessed via regular file I/O operations. + +The drivers exposes following files: + +* /sys/kernel/debug/<device-name>/acf + This file contains ACF(Automatically Controlled Features) status + information. The contents of the file is binary data of the + following layout: + + Offset | Name | Description + ==================================================================== + 0x00 | blend_int | Flag, set when stereo separation has + | | crossed below the blend threshold + -------------------------------------------------------------------- + 0x01 | hblend_int | Flag, set when HiBlend cutoff + | | frequency is lower than threshold + -------------------------------------------------------------------- + 0x02 | hicut_int | Flag, set when HiCut cutoff + | | frequency is lower than threshold + -------------------------------------------------------------------- + 0x03 | chbw_int | Flag, set when channel filter + | | bandwidth is less than threshold + -------------------------------------------------------------------- + 0x04 | softmute_int | Flag indicating that softmute + | | attenuation has increased above + | | softmute threshold + -------------------------------------------------------------------- + 0x05 | smute | 0 - Audio is not soft muted + | | 1 - Audio is soft muted + -------------------------------------------------------------------- + 0x06 | smattn | Soft mute attenuation level in dB + -------------------------------------------------------------------- + 0x07 | chbw | Channel filter bandwidth in kHz + -------------------------------------------------------------------- + 0x08 | hicut | HiCut cutoff frequency in units of + | | 100Hz + -------------------------------------------------------------------- + 0x09 | hiblend | HiBlend cutoff frequency in units + | | of 100 Hz + -------------------------------------------------------------------- + 0x10 | pilot | 0 - Stereo pilot is not present + | | 1 - Stereo pilot is present + -------------------------------------------------------------------- + 0x11 | stblend | Stereo blend in % + -------------------------------------------------------------------- + + +* /sys/kernel/debug/<device-name>/rds_blckcnt + This file contains statistics about RDS receptions. It's binary data + has the following layout: + + Offset | Name | Description + ==================================================================== + 0x00 | expected | Number of expected RDS blocks + -------------------------------------------------------------------- + 0x02 | received | Number of received RDS blocks + -------------------------------------------------------------------- + 0x04 | uncorrectable | Number of uncorrectable RDS blocks + -------------------------------------------------------------------- + +* /sys/kernel/debug/<device-name>/agc + This file contains information about parameters pertaining to + AGC(Automatic Gain Control) + + The layout is: + Offset | Name | Description + ==================================================================== + 0x00 | mxhi | 0 - FM Mixer PD high threshold is + | | not tripped + | | 1 - FM Mixer PD high threshold is + | | tripped + -------------------------------------------------------------------- + 0x01 | mxlo | ditto for FM Mixer PD low + -------------------------------------------------------------------- + 0x02 | lnahi | ditto for FM LNA PD high + -------------------------------------------------------------------- + 0x03 | lnalo | ditto for FM LNA PD low + -------------------------------------------------------------------- + 0x04 | fmagc1 | FMAGC1 attenuator resistance + | | (see datasheet for more detail) + -------------------------------------------------------------------- + 0x05 | fmagc2 | ditto for FMAGC2 + -------------------------------------------------------------------- + 0x06 | pgagain | PGA gain in dB + -------------------------------------------------------------------- + 0x07 | fmwblang | FM/WB LNA Gain in dB + -------------------------------------------------------------------- + +* /sys/kernel/debug/<device-name>/rsq + This file contains information about parameters pertaining to + RSQ(Received Signal Quality) + + The layout is: + Offset | Name | Description + ==================================================================== + 0x00 | multhint | 0 - multipath value has not crossed + | | the Multipath high threshold + | | 1 - multipath value has crossed + | | the Multipath high threshold + -------------------------------------------------------------------- + 0x01 | multlint | ditto for Multipath low threshold + -------------------------------------------------------------------- + 0x02 | snrhint | 0 - received signal's SNR has not + | | crossed high threshold + | | 1 - received signal's SNR has + | | crossed high threshold + -------------------------------------------------------------------- + 0x03 | snrlint | ditto for low threshold + -------------------------------------------------------------------- + 0x04 | rssihint | ditto for RSSI high threshold + -------------------------------------------------------------------- + 0x05 | rssilint | ditto for RSSI low threshold + -------------------------------------------------------------------- + 0x06 | bltf | Flag indicating if seek command + | | reached/wrapped seek band limit + -------------------------------------------------------------------- + 0x07 | snr_ready | Indicates that SNR metrics is ready + -------------------------------------------------------------------- + 0x08 | rssiready | ditto for RSSI metrics + -------------------------------------------------------------------- + 0x09 | injside | 0 - Low-side injection is being used + | | 1 - High-side injection is used + -------------------------------------------------------------------- + 0x10 | afcrl | Flag indicating if AFC rails + -------------------------------------------------------------------- + 0x11 | valid | Flag indicating if channel is valid + -------------------------------------------------------------------- + 0x12 | readfreq | Current tuned frequency + -------------------------------------------------------------------- + 0x14 | freqoff | Singed frequency offset in units of + | | 2ppm + -------------------------------------------------------------------- + 0x15 | rssi | Signed value of RSSI in dBuV + -------------------------------------------------------------------- + 0x16 | snr | Signed RF SNR in dB + -------------------------------------------------------------------- + 0x17 | issi | Signed Image Strength Signal + | | indicator + -------------------------------------------------------------------- + 0x18 | lassi | Signed Low side adjacent Channel + | | Strength indicator + -------------------------------------------------------------------- + 0x19 | hassi | ditto fpr High side + -------------------------------------------------------------------- + 0x20 | mult | Multipath indicator + -------------------------------------------------------------------- + 0x21 | dev | Frequency deviation + -------------------------------------------------------------------- + 0x24 | assi | Adjascent channel SSI + -------------------------------------------------------------------- + 0x25 | usn | Ultrasonic noise indicator + -------------------------------------------------------------------- + 0x26 | pilotdev | Pilot deviation in units of 100 Hz + -------------------------------------------------------------------- + 0x27 | rdsdev | ditto for RDS + -------------------------------------------------------------------- + 0x28 | assidev | ditto for ASSI + -------------------------------------------------------------------- + 0x29 | strongdev | Frequency deviation + -------------------------------------------------------------------- + 0x30 | rdspi | RDS PI code + -------------------------------------------------------------------- + +* /sys/kernel/debug/<device-name>/rsq_primary + This file contains information about parameters pertaining to + RSQ(Received Signal Quality) for primary tuner only. Layout is as + the one above. |