File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/Documentation/video4linux/si476x.txt b/Documentation/video4linux/si476x.txt
new file mode 100644
index 0000000..6166079
--- /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 | Signed 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 | Adjacent 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.