pine64-pinephone: reset modem after applying configuration

The datasheet says that the AT+QDAI audio routing configuration is saved
to non-volatile memory directly, and therefore needs a modem reset to be
applied.

This commits changes the audio routing configuration script to first
check for the current configuration, and only change it if it is
different from the one wanted.

The new configuration is then sent, and modem is reset to apply
configuration.

device/device-pine64-pinephone/setup-modem-audio.sh

 #!/bin/sh
 
-RET=$(echo "AT+QDAI=1,0,0,2,0,1,1,1" | atinout - /dev/EG25.AT -)
+# Current modem routing
+#
+#  1 - Digital PCM
+#  0 - I2S master
+#  0 - Primary mode (short sync)
+#  2 - 512kHz clock (512kHz / 16bit = 32k samples/s)
+#  0 - 16bit linear format
+#  1 - 16k sample/s
+#  1 - 1 slot
+#  1 - map to first slot (the only slot)
+#
+QDAI_CONFIG="1,0,0,2,0,1,1,1"
 
-if echo $RET | grep -q OK; then
+DEV=/dev/EG25.AT
+
+# Read current config
+RET=$(echo "AT+QDAI?" | atinout - $DEV -)
+
+if echo $RET | grep -q $QDAI_CONFIG
+then
+	echo "Modem audio already configured"
+	exit 0
+fi
+
+
+# Modem not configured, we need to send it the digital interface configuration,
+# then reboot it
+RET=$(echo "AT+QDAI=$QDAI_CONFIG" | atinout - $DEV -)
+
+if echo $RET | grep -q OK
+then
 	echo "Successfully configured modem audio"
 else
 	echo "Failed to set modem audio up: $RET"
 	exit 1
 fi
+
+# Reset module
+# 1 Set the mode to full functionality (vs 4: no RF, and 1: min functionality)
+# 1 Reset the modem before changing mode (only available with 1 above)
+#
+RET=$(echo "AT+CFUN=1,1" | atinout - $DEV -)
+
+if echo $RET | grep -q OK
+then
+	echo "Successfully reset the modem to apply audio configuration"
+else
+	echo "Failed to reset the modem to apply audio configuration: $RET"
+fi