feat: audio stack working — pulseaudio + x6200_control + voice_rec

- Add pulseaudio in system mode
- Add alsactl restore with correct mixer state from Aether
- Add x6200-control package (I2C hardware control library)
- Audio chain: pulseaudio -> x6200_control_init -> voice_rec -> speaker

br2_external/board/x6200/rootfs-overlay/etc/asound.conf

@@ -0,0 +1,88 @@
+# direct mix for pcm playback
+# aplay -D mixplayback xxx.wav
+pcm.mixout {
+	type dmix
+	ipc_key 1024
+	slave {
+		# slave PCM name
+		pcm "hw:0,0"
+
+		# PCM params
+		format       S16_LE # STR
+		rate         16000  # INT
+		#rate         48000  # INT
+		channels     2      # INT
+
+		# stream params,buffer_size=period x period_size
+		periods      100   # INT,when buffer_size or buffer_time is not specified
+		period_size  1024   # INT,in frames,3 times than app need
+
+		# optional params
+		# period_time  0    # INT,in usec
+		# buffer_time  0    # INT,in usec
+		# buffer_size  65536  #INT,in frames
+	}
+	bindings {
+		0 0 # from 0 -> 0
+		1 1 # from 1 -> 1
+	}
+	# slowptr BOOL # slow but more precise pointer updates
+}
+
+# dsnoop for capture
+# arecord -D mixcapture test.wav
+pcm.mixin {
+	type dsnoop
+	ipc_key 1025 # must be unique for all dmix plugins!!!!
+	# ipc_key_add_uid yes # no need for embedded system
+	slave {
+		# slave PCM name
+		pcm "hw:0,0"
+
+		# PCM params
+		format       S16_LE # STR
+		rate         16000  # INT
+		#rate         48000  # INT
+		channels     2      # INT
+
+		# stream params,buffer_size=period x period_size
+		periods      100   # INT,when buffer_size or buffer_time is not specified
+		period_size  1024   # INT,in frames,3 times than app need
+
+		# optional params
+		# period_time  0    # INT,in usec
+		# buffer_time  0    # INT,in usec
+		# buffer_size  65536  #INT,in frames
+	}
+	bindings {
+		0 0 # from 0 -> 0
+		1 1 # from 1 -> 1
+	}
+ }
+
+# pcm plug for playback
+pcm.mixplayback {
+	type plug
+	slave.pcm "mixout"
+	# A hint is required for listing the device in some GUIs
+	hint {
+		show on
+		description "X6200 playback mixer"
+	}
+}
+
+# pcm plug for capture
+pcm.mixcapture {
+	type plug
+	slave.pcm "mixin"
+	# A hint is required for listing the device in some GUIs
+	hint {
+		show on
+		description "X6200 capture mixer"
+	}
+}
+
+ctl.mixer0 {
+	type hw
+	card 0
+}

br2_external/board/x6200/rootfs-overlay/etc/init.d/S50alsa

@@ -0,0 +1,40 @@
+#!/bin/sh
+#
+# Alsa config
+#
+
+source /etc/profile
+
+start() {
+    printf "Restore alsa"
+    alsactl restore
+    echo "OK"
+}
+
+stop() {
+    printf "Store alsa"
+#   alsactl store
+    echo "OK"
+}
+
+restart() {
+    stop
+    start
+}
+
+case "$1" in
+  start)
+    start
+    ;;
+  stop)
+    stop
+    ;;
+  restart|reload)
+    restart
+    ;;
+  *)
+    echo "Usage: $0 {start|stop|restart}"
+    exit 1
+esac
+
+exit $?

br2_external/board/x6200/rootfs-overlay/etc/init.d/S50pulseaudio

@@ -0,0 +1,45 @@
+#!/bin/sh
+#
+# Starts pulseaudio.
+#
+
+
+start() {
+	printf "Starting pulseaudio: "
+	umask 007
+	/usr/bin/pulseaudio \
+		--system \
+		--daemonize \
+		--disallow-exit \
+		--exit-idle-time=-1 \
+		--use-pid-file \
+		--disable-shm
+	echo "OK"
+}
+stop() {
+	printf "Stopping pulseaudio: "
+	PULSE_RUNTIME_PATH=/var/run/pulse /usr/bin/pulseaudio --kill
+	echo "OK"
+}
+restart() {
+	stop
+	start
+}
+
+case "$1" in
+  start)
+	start
+	;;
+  stop)
+	stop
+	;;
+  restart|reload)
+	restart
+	;;
+  *)
+	echo "Usage: $0 {start|stop|restart}"
+	exit 1
+esac
+
+exit $?
+

br2_external/board/x6200/rootfs-overlay/etc/init.d/S70mestre-audio

@@ -0,0 +1,59 @@
+#!/bin/sh
+# S70mestre-audio — X6200 audio hardware init
+#
+# Initializes the X6200's audio routing via I2C:
+#   1. Calls x6200_control_init() to establish MCU state
+#   2. Sets speaker volume
+#   3. Switches audio routing from RX-radio to SoC DAC (voice_rec)
+#
+# Must run after S50pulseaudio (pulseaudio must hold PCM open first
+# to keep ALSA clocks active).
+#
+# The voice_rec bit (0x00008 in sple_atue_trx register, cmd 12)
+# switches the X6200's internal audio mux from the RF receiver
+# to the SoC DAC — allowing piHPSDR/aplay to be heard in the speaker.
+
+VOLUME=50
+
+do_init() {
+    python3 << EOF
+import ctypes
+lib = ctypes.CDLL("libaether_x6200_control.so")
+lib.x6200_control_init.restype = ctypes.c_bool
+lib.x6200_control_rxvol_set.argtypes = [ctypes.c_uint8]
+lib.x6200_control_spmode_set.argtypes = [ctypes.c_bool]
+
+if not lib.x6200_control_init():
+    raise SystemExit("x6200_control_init() failed")
+
+lib.x6200_control_rxvol_set($VOLUME)
+lib.x6200_control_spmode_set(False)  # Speaker mode (not headphone)
+EOF
+}
+
+do_voice_rec() {
+    # Switch audio routing: RX-radio -> SoC DAC (voice_rec bit = 0x00008)
+    i2ctransfer -y 0 w6@0x72 0x00 0x30 0x08 0x00 0x00 0x00
+}
+
+case "$1" in
+    start)
+        echo "Starting mestre-audio"
+        do_init && do_voice_rec && echo "OK" || echo "FAILED"
+        ;;
+    stop)
+        echo "Stopping mestre-audio"
+        # Switch back to RX-radio audio
+        i2ctransfer -y 0 w6@0x72 0x00 0x30 0x00 0x00 0x00 0x00
+        echo "OK"
+        ;;
+    restart)
+        $0 stop
+        sleep 1
+        $0 start
+        ;;
+    *)
+        echo "Usage: $0 {start|stop|restart}" >&2
+        exit 1
+        ;;
+esac

br2_external/board/x6200/rootfs-overlay/etc/init.d/S96keepalive

@@ -0,0 +1,23 @@
+#!/bin/sh
+# S96keepalive — X6200 PMU keepalive
+#
+# The X6200 powers itself off after ~180s unless the AXP PMU receives
+# periodic I2C traffic. This script starts the keepalive daemon at boot.
+
+case "$1" in
+    start)
+        echo "Starting keepalive"
+        /usr/sbin/i2c_keepalive.sh >/dev/null 2>&1 &
+        ;;
+    stop)
+        echo "Stopping keepalive"
+        killall i2c_keepalive.sh 2>/dev/null || true
+        ;;
+    restart)
+        $0 stop; sleep 1; $0 start
+        ;;
+    *)
+        echo "Usage: $0 {start|stop|restart}" >&2
+        exit 1
+        ;;
+esac

br2_external/board/x6200/rootfs-overlay/etc/pulse/system.pa

@@ -0,0 +1,70 @@
+#!/usr/bin/pulseaudio -nF
+#
+# This file is part of PulseAudio.
+#
+# PulseAudio is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# PulseAudio is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+
+# This startup script is used only if PulseAudio is started in system
+# mode.
+
+### Automatically restore the volume of streams and devices
+load-module module-device-restore
+load-module module-stream-restore
+load-module module-card-restore
+load-module module-switch-on-connect
+load-module module-bluez5-device
+
+### Automatically load driver modules depending on the hardware available
+.ifexists module-udev-detect.so
+load-module module-udev-detect
+.else
+### Use the static hardware detection module (for systems that lack udev/hal support)
+load-module module-detect
+.endif
+
+### Load several protocols
+.ifexists module-esound-protocol-unix.so
+load-module module-esound-protocol-unix
+.endif
+load-module module-native-protocol-unix auth-anonymous=1
+
+### Automatically restore the default sink/source when changed by the user
+### during runtime
+### NOTE: This should be loaded as early as possible so that subsequent modules
+### that look up the default sink/source get the right value
+load-module module-default-device-restore
+
+### Make sure we always have a sink around, even if it is a null sink.
+load-module module-always-sink
+
+### Automatically suspend sinks/sources that become idle for too long
+load-module module-suspend-on-idle
+
+### Enable positioned event sounds
+load-module module-position-event-sounds
+
+### Automatically load driver modules for Bluetooth hardware
+.ifexists module-bluetooth-policy.so
+load-module module-bluetooth-policy
+.endif
+
+.ifexists module-bluetooth-discover.so
+load-module module-bluetooth-discover
+.endif
+
+### Allow including a system.pa.d directory, which if present, can be used
+### for additional configuration snippets.
+### Note that those snippet files must have a .pa file extension, not .conf
+.nofail
+.include /etc/pulse/system.pa.d