[WIP][RFC] Test-case: Set PGAs to unity gain in script check-alsabat.sh

This patch adds find of volume controls for used playback and capture
devices and sets them to unity gain (0 dB). The alsabat test fails
if e.g. capture PGA is set to their maximum value that can be up
to +30 dB. The test sine wave distorts and causes test fail.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu

test-case/check-alsabat.sh

@@ -20,7 +20,11 @@ set -e
 # remove the existing alsabat wav files
 rm -f /tmp/bat.wav.*
 
-source $(dirname ${BASH_SOURCE[0]})/../case-lib/lib.sh
+TESTDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+TPLGREADER="$TESTDIR"/tools/sof-tplgreader.py
+
+# shellcheck source=case-lib/lib.sh
+source "$TESTDIR/case-lib/lib.sh"
 
 OPT_OPT_lst['p']='pcm_p'     	OPT_DESC_lst['p']='pcm for playback. Example: hw:0,0'
 OPT_PARM_lst['p']=1          	OPT_VALUE_lst['p']=''
@@ -37,12 +41,16 @@ OPT_PARM_lst['n']=1             OPT_VALUE_lst['n']=240000
 OPT_OPT_lst['s']='sof-logger'   OPT_DESC_lst['s']="Open sof-logger trace the data will store at $LOG_ROOT"
 OPT_PARM_lst['s']=0             OPT_VALUE_lst['s']=1
 
+OPT_OPT_lst['t']='tplg'     OPT_DESC_lst['t']='tplg file, default value is env TPLG: $''TPLG'
+OPT_PARM_lst['t']=1         OPT_VALUE_lst['t']="$TPLG"
+
 func_opt_parse_option "$@"
 
 pcm_p=${OPT_VALUE_lst['p']}
 pcm_c=${OPT_VALUE_lst['c']}
 frequency=${OPT_VALUE_lst['f']}
 frames=${OPT_VALUE_lst['n']}
+tplg=${OPT_VALUE_lst['t']}
 
 if [ "$pcm_p" = "" ]||[ "$pcm_c" = "" ];
 then
@@ -64,11 +72,84 @@ function __upload_wav_file
     done
 }
 
+function set_pga_to_unity_gain ()
+{
+    tmp=$(amixer controls | grep "$pga" | grep Volume)
+    search="name="
+    cname=${tmp#*$search}
+
+    # Get volume min and step to compute value for cset
+    # for 0 dB gain. The amixer line looks like
+    # "| dBscale-min=-50.00dB,step=1.00dB,mute=1"
+    scale=$(amixer cget name="$cname" | grep "dBscale" || true)
+    search="dBscale-min="
+    tmp=${scale#*$search}
+    min_db="${tmp%%dB*}"
+    search="step="
+    tmp=${scale#*$search}
+    step_db="${tmp%%dB*}"
+
+    # Get multiplied by 100 values by removing decimal dot
+    min_x100="${min_db//.}"
+    step_x100="${step_db//.}"
+    val=$(printf %d "$(((-min_x100) / step_x100))")
+
+    # Apply the computed value for requested gain
+    amixer cset name="$cname" "$val"
+}
+
+function set_pgas_list_to_unity_gain ()
+{
+    if [[ -z "$1" ]]; then
+	return
+    fi
+
+    for pga in $1; do
+	dlogi "Set $pga"
+	set_pga_to_unity_gain "$pga"
+    done
+}
+
+function get_snd_base ()
+{
+    tmp=${1#*"hw:"}
+    ncard="${tmp%%,*}"
+    ndevice="${tmp#*,}"
+    echo "/dev/snd/pcmC${ncard}D${ndevice}"
+}
+
+function get_play_snd ()
+{
+    tmp=$(get_snd_base $1)
+    echo ${tmp}p
+}
+
+function get_capture_snd ()
+{
+    tmp=$(get_snd_base $1)
+    echo ${tmp}c
+}
+
 # check the PCMs before alsabat test
 dlogi "check the PCMs before alsabat test"
 [[ $(aplay -Dplug$pcm_p -d 1 /dev/zero -q) ]] && die "Failed to play on PCM: $pcm_p"
 [[ $(arecord -Dplug$pcm_c -d 1 /dev/null -q) ]] && die "Failed to capture on PCM: $pcm_c"
 
+# Set PGAs for PCMs to 0 dB value
+test -n "$(command -v $TPLGREADER)" || {
+    die "Command $TPLGREADER is not available."
+}
+
+test -n "$tplg" || die "Use -t or set environment variable TPLG to current topology"
+dlogi "Getting playback PGA information"
+play_snd=$(get_play_snd "$pcm_p")
+PLAY_PGA=$($TPLGREADER "$tplg" -f "snd:$play_snd" -d pga -v)
+set_pgas_list_to_unity_gain "$PLAY_PGA"
+dlogi "Getting capture PGA information"
+cap_snd=$(get_capture_snd "$pcm_c")
+CAP_PGA=$($TPLGREADER "$tplg" -f "snd:$cap_snd" -d pga -v)
+set_pgas_list_to_unity_gain "$CAP_PGA"
+
 # alsabat test
 # different PCMs may support different audio formats(like samplerate, channel-counting, etc.).
 # use plughw to do the audio format conversions. So we don't need to specify them for each PCM.