# HG changeset patch # User Mychaela Falconia # Date 1633821600 0 # Node ID 82fb5a70c9fd24b6d8da9f5d2871974e46d24803 # Parent 34490934ff0281b50d91eb0cdc6985db4340df52 compal/audio: results of simple experiments diff -r 34490934ff02 -r 82fb5a70c9fd compal/audio/tfc139-headset-entry --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/compal/audio/tfc139-headset-entry Sat Oct 09 23:20:00 2021 +0000 @@ -0,0 +1,49 @@ +The following results have been obtained by connecting to a C139 phone via the +headset jack, switching to "Trace On" via the **16379# hidden menu, breaking in +with tfc139, then running the new tfc139-audio-dump command in fc-loadtool: + +d_aec_ctrl: 0x03C7 +New AEC params: 0x0001 0x0014 0x4CCC 0x59AD 0x7500 0x0000 0x1000 0x1000 + +Uplink FIR coefficients: + +0x4000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 +0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 +0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 +0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 + +Downlink FIR coefficients: + +0x7FFF 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 +0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 +0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 +0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 + +VBCTRL1: 0x004 +VBCTRL2: 0x007 +VBPOP: 0x004 +VBUCTRL: 0x1B2 +VBDCTRL: 0x069 + +Commentary: the values read out of VBCTRL1 and VBCTRL2 registers are consistent +with the headset audio channel being selected for both input and output, leading +to the suspicion that the firmware probably switched the audio path to headset +mode even though the **16379# hidden menu selection was set to "Trace On". The +Mother's primary interest here is to see the official C139 fw settings for the +handheld audio mode (built-in earpiece and mic) rather than the headset mode, +but it now appears that such capture won't be possible except maybe by +connecting to the production test pads inside the battery compartment, +bypassing the headset jack. + +Looking at what appears to be C139 headset mode audio config, we see that +HSMICBIAS voltage is set to 2.0 V, the uplink gain is set to 8 dB, and the +sidetone level is set to -23 dB: we get this info from the MICBIAS bit in +VBCTRL1 and the VBUCTRL setting. Decoding VBDCTRL, we see that the volume +control is set to -6 dB and the PGA gain is set to 3 dB. However, these +VBDCTRL settings don't tell us much: see the volume-ctrl article. + +Also note the FIR coefficient oddity: no frequency curve-transforming FIR +filters are being set up, neither UL nor DL, but DL FIR coefficient 0 is set to +0x7FFF instead of 0x4000. This oddity means that Calypso DL FIR block is +producing a 6 dB gain (doubling of the samples) purely on the digital side, +before DL audio passes to the ABB - certainly a noteworthy hack. diff -r 34490934ff02 -r 82fb5a70c9fd compal/audio/volume-ctrl --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/compal/audio/volume-ctrl Sat Oct 09 23:20:00 2021 +0000 @@ -0,0 +1,20 @@ +It appears that the only way to bring up audio volume control (as opposed to +ringer volume) on a C139 phone running Mot official fw is to be in active call, +implying the need for a valid SIM, a GSM network, working service with that +SIM+network combination and a party one can test-call. When you do get into +the necessary active call state, navigation left and right buttons bring up the +audio volume control screen and move this volume up or down. However, instead +of seeing just 5 possible volume levels as would be available if Iota ABB +downlink volume controls were used in TI's simple way, we see 8 possible volume +levels being offered by Motorola's fw, numbered from 0 through 7. Level 0 is +not mute - downlink audio is still present in the earpiece speaker, albeit +quiet. + +It appears that Compal did something similar to Foxconn/Pirelli, probably +manipulating both volume and PGA gain settings in Iota VBDCTRL in order to +offer more than 5 possible volume levels to the user. However, because Compal +firmwares don't have ETM and their oabbr TM3 command is broken (returns +garbage), we don't have a way to just read out the register settings for each +volume level. Furthermore, because the audio volume setting is so difficult to +get to (requiring not only a SIM, but also network registration and a call), +doing a tfc139 break-in for each possible volume level would be too much work.