Add arcam-av plugin

Added arcam-av control plugin (type "arcam_av") for accessing
Arcam AV amplifier via ALSA mixer interface.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

8 files changed, 1884 insertions, 2 deletions

diff --git a/Makefile.am b/Makefile.am
index aba3ef6..668b1ef 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -21,7 +21,7 @@ if HAVE_SPEEXDSP
 SPEEXDIR = speex
 endif
 
-SUBDIRS = oss mix $(PPHDIR) $(JACKDIR) $(PULSEDIR) $(SAMPLERATEDIR) $(A52DIR) $(LAVCRATEDIR) $(MAEMODIR) $(SPEEXDIR) usb_stream doc
+SUBDIRS = oss mix $(PPHDIR) $(JACKDIR) $(PULSEDIR) $(SAMPLERATEDIR) $(A52DIR) $(LAVCRATEDIR) $(MAEMODIR) $(SPEEXDIR) usb_stream arcam-av doc
 EXTRA_DIST = gitcompile version COPYING.GPL m4/attributes.m4
 AUTOMAKE_OPTIONS = foreign
 ACLOCAL_AMFLAGS = -I m4
diff --git a/arcam-av/Makefile.am b/arcam-av/Makefile.am
new file mode 100644
index 0000000..5c7855f
--- /dev/null
+++ b/arcam-av/Makefile.am
@@ -0,0 +1,9 @@
+asound_module_ctl_arcam_av_LTLIBRARIES = libasound_module_ctl_arcam_av.la
+
+asound_module_ctl_arcam_avdir = @ALSA_PLUGIN_DIR@
+
+AM_CFLAGS = -Wall -g @ALSA_CFLAGS@
+AM_LDFLAGS = -module -avoid-version -export-dynamic -no-undefined
+
+libasound_module_ctl_arcam_av_la_SOURCES = ctl_arcam_av.c arcam_av.c arcam_av.h
+libasound_module_ctl_arcam_av_la_LIBADD = @ALSA_LIBS@
diff --git a/arcam-av/arcam_av.c b/arcam-av/arcam_av.c
new file mode 100644
index 0000000..81e72e9
--- /dev/null
+++ b/arcam-av/arcam_av.c
@@ -0,0 +1,658 @@
+/*
+ * ALSA -> Arcam AV control plugin
+ *
+ * Copyright (c) 2009 by Peter Stokes <linux@dadeos.co.uk>
+ *
+ * This library 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 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+
+#include "arcam_av.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <sys/stat.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#define MIN(a, b)     ((a) < (b) ? (a) : (b))
+#define MAX(a, b)     ((a) > (b) ? (a) : (b))
+
+
+int arcam_av_connect(const char* port)
+{
+	struct termios portsettings;
+
+	int fd = open(port, O_RDWR | O_NOCTTY);
+	if (fd < 0)
+		return -errno;
+
+	bzero(&portsettings, sizeof(portsettings));
+	portsettings.c_cflag = B38400 | CS8 | CLOCAL | CREAD;
+	portsettings.c_iflag = IGNPAR;
+	portsettings.c_oflag = 0;
+	portsettings.c_lflag = 0;
+	portsettings.c_cc[VTIME] = 0;
+	portsettings.c_cc[VMIN] = 5;
+	tcflush(fd, TCIFLUSH);
+	tcsetattr(fd, TCSANOW, &portsettings);
+
+	return fd;
+}
+
+
+int arcam_av_send(int fd, arcam_av_cc_t command, unsigned char param1, unsigned char param2)
+{
+	const char buffer[7] = {'P', 'C', '_', command, param1, param2, 0x0D};
+	const char* cursor = buffer;
+
+	tcdrain(fd);
+
+	do {
+		ssize_t bytes = write(fd, cursor, sizeof buffer - (cursor - buffer));
+
+		if (bytes <= 0)
+			return -errno;
+		
+		cursor += bytes;
+
+	} while (cursor < buffer + sizeof buffer);
+
+	return 0;
+}
+
+
+static int arcam_av_receive(int fd, arcam_av_cc_t* command, unsigned char* param1, unsigned char* param2)
+{
+	static int index = 0;
+	static arcam_av_cc_t received_command;
+	static unsigned char received_param1;
+	static unsigned char received_param2;
+
+	do {
+		static char buffer[8];
+		char* cursor = buffer;
+
+		ssize_t bytes = read(fd, buffer, sizeof buffer - index);
+
+		if (bytes <= 0)
+			return -errno;
+
+		while(bytes > 0) {
+			switch(index++) {
+			case 0:
+				if (*cursor != 'A')
+					index = 0;
+				break;
+
+			case 1:
+				if (*cursor != 'V') {
+					index = 0;
+					continue;
+				}
+				break;
+
+			case 2:
+				if (*cursor != '_') {
+					index = 0;
+					continue;
+				}
+				break;
+
+			case 3:
+				received_command = *cursor;
+				break;
+
+			case 4:
+				if (*cursor != ARCAM_AV_OK) {
+					index = 0;
+					continue;
+				}
+				break;
+
+			case 5:
+				received_param1 = *cursor;
+				break;
+
+			case 6:
+				received_param2 = *cursor;
+				break;
+
+			case 7:
+				if (*cursor != 0x0D) {
+					index = 0;
+					continue;
+				}
+				break;
+			}
+
+			++cursor;
+			--bytes;
+		}
+	} while (index < 8);
+
+	index = 0;
+	*command = received_command;
+	*param1 = received_param1;
+	*param2 = received_param2;
+
+	return 0;
+}
+
+
+static int arcam_av_update(arcam_av_state_t* state, int fd)
+{
+	int result = -1;
+
+	arcam_av_cc_t command = 0;
+	unsigned char param1 = 0;
+	unsigned char param2 = 0;
+
+	while (!arcam_av_receive(fd, &command, &param1, &param2)) {
+		switch(command) {
+		case ARCAM_AV_POWER:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.power = param2;
+				result = 0;
+				break;
+
+			case ARCAM_AV_ZONE2:
+				state->zone2.power = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_VOLUME_CHANGE:
+		case ARCAM_AV_VOLUME_SET:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.volume = param2;
+				result = 0;
+				break;
+
+			case ARCAM_AV_ZONE2:
+				state->zone2.volume = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_MUTE:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.mute = param2;
+				result = 0;
+				break;
+
+			case ARCAM_AV_ZONE2:
+				state->zone2.mute = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_DIRECT:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.direct = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_SOURCE:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.source = param2;
+				result = 0;
+				break;
+
+			case ARCAM_AV_ZONE2:
+				state->zone2.source = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_SOURCE_TYPE:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.source_type = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_STEREO_DECODE:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.stereo_decode = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_STEREO_EFFECT:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.stereo_effect = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		case ARCAM_AV_MULTI_DECODE:
+			switch(param1) {
+			case ARCAM_AV_ZONE1:
+				state->zone1.multi_decode = param2;
+				result = 0;
+				break;
+
+			default:
+				break;
+			}
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	return result;
+}
+
+
+static void arcam_av_state_query(int fd)
+{
+	arcam_av_send(fd, ARCAM_AV_POWER, ARCAM_AV_ZONE1, ARCAM_AV_POWER_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_VOLUME_CHANGE, ARCAM_AV_ZONE1, ARCAM_AV_VOLUME_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_MUTE, ARCAM_AV_ZONE1, ARCAM_AV_MUTE_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_DIRECT, ARCAM_AV_ZONE1, ARCAM_AV_DIRECT_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_SOURCE, ARCAM_AV_ZONE1, ARCAM_AV_SOURCE_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_SOURCE_TYPE, ARCAM_AV_ZONE1, ARCAM_AV_SOURCE_TYPE_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_STEREO_DECODE, ARCAM_AV_ZONE1, ARCAM_AV_STEREO_DECODE_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_MULTI_DECODE, ARCAM_AV_ZONE1, ARCAM_AV_MULTI_DECODE_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_STEREO_EFFECT, ARCAM_AV_ZONE1, ARCAM_AV_STEREO_EFFECT_REQUEST);
+
+	arcam_av_send(fd, ARCAM_AV_POWER, ARCAM_AV_ZONE2, ARCAM_AV_POWER_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_VOLUME_CHANGE, ARCAM_AV_ZONE2, ARCAM_AV_VOLUME_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_MUTE, ARCAM_AV_ZONE2, ARCAM_AV_MUTE_REQUEST);
+	arcam_av_send(fd, ARCAM_AV_SOURCE, ARCAM_AV_ZONE2, ARCAM_AV_SOURCE_REQUEST);
+}
+
+
+static int arcam_av_state_shm_id = -1;
+
+arcam_av_state_t* arcam_av_state_attach(const char* port)
+{
+	arcam_av_state_t* state;
+
+	if (arcam_av_state_shm_id < 0) {
+		struct stat port_stat;
+		key_t ipc_key;
+		int shmflg;
+		struct shmid_ds shm_stat;
+
+		if (stat(port, &port_stat))
+			return NULL;
+
+		ipc_key = ftok(port, 'A');
+		if (ipc_key < 0)
+			return NULL;
+
+		shmflg = IPC_CREAT | (port_stat.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO));
+		arcam_av_state_shm_id = shmget(ipc_key, sizeof(arcam_av_state_t), shmflg);
+		if (arcam_av_state_shm_id < 0)
+			return NULL;
+
+		if (shmctl(arcam_av_state_shm_id, IPC_STAT, &shm_stat))
+			return NULL;
+
+		shm_stat.shm_perm.uid = port_stat.st_uid;
+		shm_stat.shm_perm.gid = port_stat.st_gid;
+		shmctl(arcam_av_state_shm_id, IPC_SET, &shm_stat);
+	}
+
+	state = shmat(arcam_av_state_shm_id, NULL, 0);
+
+	return (state == (void*)-1) ? NULL : state;
+}
+
+
+int arcam_av_state_detach(arcam_av_state_t* state)
+{
+	struct shmid_ds shm_stat;
+
+	if (shmdt(state))
+		return -1;
+
+	if (shmctl(arcam_av_state_shm_id, IPC_STAT, &shm_stat))
+		return -1;
+
+	if (!shm_stat.shm_nattch) {
+		shmctl(arcam_av_state_shm_id, IPC_RMID, NULL);
+		arcam_av_state_shm_id = -1;
+	}
+
+	return 0;
+}
+
+
+static void arcam_av_server_broadcast(fd_set* fds, int fd_max, void* buffer, int bytes)
+{
+	int fd;
+	for (fd = 0; fd <= fd_max; ++fd) {
+		if (FD_ISSET(fd, fds)) {
+			send(fd, buffer, bytes, 0);
+		}
+	}
+}
+
+
+static int arcam_av_server_master(int server_fd)
+{
+	struct sockaddr_un server_address;
+	socklen_t server_address_length;
+	const char* port;
+	int arcam_fd;
+	arcam_av_state_t* state;
+	fd_set all_fds, client_fds, read_fds;
+	int fd, fd_max;
+
+	int result = 0;
+
+	server_address_length = sizeof(server_address) - 1;
+	if (getsockname(server_fd, (struct sockaddr*) &server_address, &server_address_length))
+		return -errno;
+
+	server_address.sun_path[server_address_length - offsetof(struct sockaddr_un, sun_path)] = '\0';
+
+	port = server_address.sun_path + 1;
+
+	arcam_fd = arcam_av_connect(port);
+
+	state = arcam_av_state_attach(port);
+	if (!state) {
+		close(arcam_fd);
+		return -errno;
+	}
+
+	arcam_av_state_query(arcam_fd);
+
+	fcntl(arcam_fd, F_SETFL, O_NONBLOCK);
+
+	FD_ZERO(&all_fds);
+	FD_ZERO(&client_fds);
+	FD_SET(arcam_fd, &all_fds);
+	FD_SET(server_fd, &all_fds);
+	fd_max = MAX(arcam_fd, server_fd);
+
+	for(;;) {
+		read_fds = all_fds;
+
+		if (select(fd_max + 1, &read_fds, NULL, NULL, NULL) < 0) {
+			perror("arcam_av_server_master(): select");
+			result = -errno;
+			break;
+		}
+
+		for(fd = fd_max; fd; --fd) {
+			if (FD_ISSET(fd, &read_fds)) {
+				if (fd == arcam_fd) {
+					if (arcam_av_update(state, arcam_fd))
+						continue;
+
+					arcam_av_server_broadcast(&client_fds, fd_max, "", 1);
+				} else if (fd == server_fd) {
+					struct sockaddr_un client_address;
+					socklen_t client_address_length = sizeof(client_address);
+					int client_fd = accept(server_fd, (struct sockaddr*) &client_address, &client_address_length);
+
+					if (client_fd >= 0) {
+						FD_SET(client_fd, &all_fds);
+						FD_SET(client_fd, &client_fds);
+						fd_max = MAX(fd_max, client_fd);
+					} else {
+						perror("arcam_av_server_master(): accept");
+						result = -errno;
+						goto exit;
+					}
+				} else {
+					pthread_t thread;
+					int bytes = recv(fd, &thread, sizeof(pthread_t), 0);
+
+					if (bytes > 0) {
+						if (bytes == sizeof(pthread_t)) {
+							if (thread == pthread_self())
+								goto exit;
+
+							arcam_av_server_broadcast(&client_fds, fd_max, &thread, sizeof(pthread_t));
+						}
+					} else {
+						close(fd);
+						FD_CLR(fd, &all_fds);
+						FD_CLR(fd, &client_fds);
+						fd_max -= (fd_max == fd);
+					}
+				}
+			}
+		}
+	}
+
+exit:
+
+	for (fd = 0; fd <= fd_max; ++fd) {
+		if (fd != server_fd && FD_ISSET(fd, &all_fds)) {
+			close(fd);
+		}
+	}
+
+	if (state)
+		arcam_av_state_detach(state);
+
+	return result;
+}
+
+
+static int arcam_av_server_slave(int server_fd)
+{
+	for (;;) {
+		pthread_t thread;
+		int bytes = recv(server_fd, &thread, sizeof(pthread_t), 0);
+
+		if (bytes > 0) {
+			if (bytes == sizeof(pthread_t))
+				if (thread == pthread_self())
+					return 0;
+		} else {
+			break;
+		}
+	}
+
+	return -1;
+}
+
+
+static void* arcam_av_server_thread(void* context)
+{
+	struct sockaddr_un address;
+	int size;
+	int quit = 0;
+
+	sem_t* semaphore = context;
+	const char* port = *(const char**)(semaphore + 1);
+
+	address.sun_family = AF_FILE;
+	address.sun_path[0] = '\0';
+	strncpy(&address.sun_path[1], port, sizeof(address.sun_path) - 1);
+	size = offsetof(struct sockaddr_un, sun_path) +
+	       MIN(strlen(port) + 1, sizeof(address.sun_path));
+
+	signal(SIGPIPE, SIG_IGN);
+
+	while (!quit) {
+		int server_fd = socket(PF_UNIX, SOCK_STREAM, 0);
+		if (server_fd < 0) {
+			perror("arcam_av_server_thread(): socket");
+			break;
+		}
+
+		if (!bind(server_fd, (struct sockaddr*) &address, size)) {
+			if (!listen(server_fd, 10)) {
+				if (semaphore) {
+					sem_post(semaphore);
+					semaphore = NULL;
+				}
+				arcam_av_server_master(server_fd);
+			} else {
+				perror("arcam_av_server_master(): listen");
+			}
+			quit = 1;
+		} else if (errno != EADDRINUSE) {
+			perror("arcam_av_server_thread(): bind");
+			quit = 1;
+		} else if (!connect(server_fd, (struct sockaddr*) &address, size)) {
+			if (semaphore) {
+				sem_post(semaphore);
+				semaphore = NULL;
+			}
+			quit = !arcam_av_server_slave(server_fd);
+		} else {
+			perror("arcam_av_server_thread(): connect");
+			quit = 1;
+		}
+
+		close(server_fd);
+	}
+
+	if (semaphore)
+		sem_post(semaphore);
+
+	return NULL;
+}
+
+
+int arcam_av_server_start(pthread_t* thread, const char* port)
+{
+	struct {
+		sem_t		semaphore;
+		const char*	port;
+	} context;
+
+	int result = 0;
+
+	if (sem_init(&context.semaphore, 0, 0))
+		return -1;
+
+	context.port = port;
+
+	if (pthread_create(thread, NULL, arcam_av_server_thread, &context))
+		result = -1;
+	else
+		sem_wait(&context.semaphore);
+
+	sem_destroy(&context.semaphore);
+
+	return result;
+}
+
+
+int arcam_av_server_stop(pthread_t thread, const char* port)
+{
+	int client_fd = arcam_av_client(port);
+	if (client_fd < 0)
+		return -1;
+
+	if (send(client_fd, &thread, sizeof(pthread_t), 0) > 0)
+		pthread_join(thread, NULL);
+
+	close(client_fd);
+	return 0;
+}
+
+
+int arcam_av_client(const char* port)
+{
+	struct sockaddr_un address;
+	int size;
+
+	const int max_retries = 5;
+	int retries = max_retries;
+
+	int client_fd = socket(PF_UNIX, SOCK_STREAM, 0);
+	if (client_fd < 0)
+		return -1;
+
+	address.sun_family = AF_FILE;
+	address.sun_path[0] = '\0';
+	strncpy(&address.sun_path[1], port, sizeof(address.sun_path) - 1);
+	size = offsetof(struct sockaddr_un, sun_path) +
+	       MIN(strlen(port) + 1, sizeof(address.sun_path));
+
+	do {
+		if (!connect(client_fd, (struct sockaddr*) &address, size))
+			return client_fd;
+
+		if (!retries--)
+			break;
+
+		struct timeval sleep = {0, 10 * (max_retries - retries)};
+		
+		select(0, NULL, NULL, NULL, &sleep);
+
+	} while (errno == ECONNREFUSED);
+
+	perror("arcam_av_client(): connect");
+
+	close(client_fd);
+	return -1;
+}
+
diff --git a/arcam-av/arcam_av.h b/arcam-av/arcam_av.h
new file mode 100644
index 0000000..85e9219
--- /dev/null
+++ b/arcam-av/arcam_av.h
@@ -0,0 +1,161 @@
+/*
+ * ALSA -> Arcam AV control plugin
+ *
+ * Copyright (c) 2009 by Peter Stokes <linux@dadeos.co.uk>
+ *
+ * This library 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 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <pthread.h>
+
+typedef enum {
+	ARCAM_AV_ZONE1				= '1',
+	ARCAM_AV_ZONE2				= '2'
+} arcam_av_zone_t;
+
+
+typedef enum {
+	ARCAM_AV_POWER				= '*',
+	ARCAM_AV_VOLUME_CHANGE			= '/',
+	ARCAM_AV_VOLUME_SET			= '0',
+	ARCAM_AV_MUTE				= '.',
+	ARCAM_AV_SOURCE				= '1',
+	ARCAM_AV_SOURCE_TYPE			= '7',
+	ARCAM_AV_DIRECT				= '3',
+	ARCAM_AV_STEREO_DECODE			= '4',
+	ARCAM_AV_MULTI_DECODE			= '5',
+	ARCAM_AV_STEREO_EFFECT			= '6'
+} arcam_av_cc_t;
+
+
+typedef enum {
+	ARCAM_AV_OK				= 'P',
+	ARCAM_AV_ERROR				= 'R'
+} arcam_av_rc_t;
+
+
+typedef enum {
+	ARCAM_AV_POWER_STAND_BY			= '0',
+	ARCAM_AV_POWER_ON			= '1',
+	ARCAM_AV_POWER_REQUEST			= '9'
+} arcam_av_power_t;
+
+
+typedef enum {
+	ARCAM_AV_VOLUME_MIN			= '0',
+	ARCAM_AV_VOLUME_REQUEST			= '9'
+} arcam_av_volume_t;
+
+
+typedef enum {
+	ARCAM_AV_MUTE_ON			= '0',
+	ARCAM_AV_MUTE_OFF			= '1',
+	ARCAM_AV_MUTE_REQUEST			= '9'
+} arcam_av_mute_t;
+
+
+typedef enum {
+	ARCAM_AV_DIRECT_DISABLE			= '0',
+	ARCAM_AV_DIRECT_ENABLE			= '1',
+	ARCAM_AV_DIRECT_REQUEST			= '9'
+} arcam_av_direct_t;
+
+
+typedef enum {
+	ARCAM_AV_SOURCE_DVD 			= '0',
+	ARCAM_AV_SOURCE_SAT			= '1',
+	ARCAM_AV_SOURCE_AV			= '2',
+	ARCAM_AV_SOURCE_PVR			= '3',
+	ARCAM_AV_SOURCE_VCR			= '4',
+	ARCAM_AV_SOURCE_CD			= '5',
+	ARCAM_AV_SOURCE_FM			= '6',
+	ARCAM_AV_SOURCE_AM			= '7',
+	ARCAM_AV_SOURCE_DVDA			= '8',
+	ARCAM_AV_SOURCE_REQUEST			= '9'
+} arcam_av_source_t;
+
+
+typedef enum {
+	ARCAM_AV_SOURCE_TYPE_ANALOGUE 		= '0',
+	ARCAM_AV_SOURCE_TYPE_DIGITAL		= '1',
+	ARCAM_AV_SOURCE_TYPE_REQUEST		= '9'
+} arcam_av_source_type_t;
+
+
+typedef enum {
+	ARCAM_AV_STEREO_DECODE_MONO		= '.',
+	ARCAM_AV_STEREO_DECODE_STEREO		= '/',
+	ARCAM_AV_STEREO_DECODE_PLII_MOVIE	= '0',
+	ARCAM_AV_STEREO_DECODE_PLII_MUSIC	= '1',
+	ARCAM_AV_STEREO_DECODE_PLIIx_MOVIE	= '3',
+	ARCAM_AV_STEREO_DECODE_PLIIx_MUSIC	= '4',
+	ARCAM_AV_STEREO_DECODE_DOLBY_PL		= '6',
+	ARCAM_AV_STEREO_DECODE_NEO6_CINEMA	= '7',
+	ARCAM_AV_STEREO_DECODE_NEO6_MUSIC	= '8',
+	ARCAM_AV_STEREO_DECODE_REQUEST		= '9'
+} arcam_av_stereo_decode_t;
+
+
+typedef enum {
+	ARCAM_AV_MULTI_DECODE_MONO		= '.',
+	ARCAM_AV_MULTI_DECODE_STEREO		= '/',
+	ARCAM_AV_MULTI_DECODE_MULTI_CHANNEL	= '0',
+	ARCAM_AV_MULTI_DECODE_PLIIx		= '2',
+	ARCAM_AV_MULTI_DECODE_REQUEST		= '9'
+} arcam_av_multi_decode_t;
+
+
+typedef enum {
+	ARCAM_AV_STEREO_EFFECT_NONE		= '0',
+	ARCAM_AV_STEREO_EFFECT_MUSIC		= '1',
+	ARCAM_AV_STEREO_EFFECT_PARTY		= '2',
+	ARCAM_AV_STEREO_EFFECT_CLUB		= '3',
+	ARCAM_AV_STEREO_EFFECT_HALL		= '4',
+	ARCAM_AV_STEREO_EFFECT_SPORTS		= '5',
+	ARCAM_AV_STEREO_EFFECT_CHURCH		= '6',
+	ARCAM_AV_STEREO_EFFECT_REQUEST		= '9'
+} arcam_av_stereo_effect_t;
+
+int arcam_av_connect(const char* port);
+int arcam_av_send(int fd, arcam_av_cc_t command, unsigned char param1, unsigned char param2);
+
+
+typedef struct arcam_av_state {
+	struct {
+		arcam_av_power_t		power;
+		unsigned char			volume;
+		arcam_av_mute_t			mute;
+		arcam_av_direct_t		direct;
+		arcam_av_source_t		source;
+		arcam_av_source_type_t		source_type;
+		arcam_av_stereo_decode_t	stereo_decode;
+		arcam_av_stereo_effect_t	stereo_effect;
+		arcam_av_multi_decode_t		multi_decode;
+	} zone1;
+	struct {
+		arcam_av_power_t		power;
+		unsigned char			volume;
+		arcam_av_mute_t			mute;
+		arcam_av_source_t		source;
+	} zone2;
+} arcam_av_state_t;
+
+arcam_av_state_t* arcam_av_state_attach(const char* port);
+int arcam_av_state_detach(arcam_av_state_t* state);
+
+int arcam_av_server_start(pthread_t* thread, const char* port);
+int arcam_av_server_stop(pthread_t thread, const char* port);
+
+int arcam_av_client(const char* port);
diff --git a/arcam-av/ctl_arcam_av.c b/arcam-av/ctl_arcam_av.c
new file mode 100644
index 0000000..c6ca87a
--- /dev/null
+++ b/arcam-av/ctl_arcam_av.c
@@ -0,0 +1,1024 @@
+/*
+ * ALSA -> Arcam AV control plugin
+ *
+ * Copyright (c) 2009 by Peter Stokes <linux@dadeos.co.uk>
+ *
+ * This library 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 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <sys/socket.h>
+#include <alsa/asoundlib.h>
+#include <alsa/control_external.h>
+
+#include "arcam_av.h"
+
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+#define MIN(a, b)     ((a) < (b) ? (a) : (b))
+#define MID(a, b, c)  ((a) < (b) ? ((b) < (c) ? (b) : ((a) < (c) ? (c) : (a))) \
+                                 : ((b) > (c) ? (b) : ((a) > (c) ? (c) : (a))))
+
+
+static const char* arcam_av_name		= "Arcam AV";
+static const char* arcam_av_power_name		= "Power Switch";
+static const char* arcam_av_volume_name		= "Master Playback Volume";
+static const char* arcam_av_mute_name		= "Master Playback Switch";
+static const char* arcam_av_direct_name		= "Direct Playback Switch";
+static const char* arcam_av_source_name		= "Source Playback Route";
+static const char* arcam_av_source_type_name	= "Source Type Playback Route";
+static const char* arcam_av_stereo_decode_name	= "Stereo Decode Playback Route";
+static const char* arcam_av_multi_decode_name	= "Multi-Channel Decode Playback Route";
+static const char* arcam_av_stereo_effect_name	= "Stereo Effect Playback Route";
+
+static const struct {
+	arcam_av_source_t		code;
+	const char*			name;
+} arcam_av_sources[] = {
+	{ARCAM_AV_SOURCE_DVD,			"DVD"			},
+	{ARCAM_AV_SOURCE_SAT,			"SAT"			},
+	{ARCAM_AV_SOURCE_AV,			"AV"			},
+	{ARCAM_AV_SOURCE_PVR,			"PVR"			},
+	{ARCAM_AV_SOURCE_VCR,			"VCR"			},
+	{ARCAM_AV_SOURCE_CD,			"CD"			},
+	{ARCAM_AV_SOURCE_FM,			"FM"			},
+	{ARCAM_AV_SOURCE_AM,			"AM"			},
+	{ARCAM_AV_SOURCE_DVDA,			"DVDA"			}
+};
+
+static const struct {
+	arcam_av_source_type_t		code;
+	const char*			name;
+} arcam_av_source_types[] = {
+	{ARCAM_AV_SOURCE_TYPE_ANALOGUE,		"Analogue"		},
+	{ARCAM_AV_SOURCE_TYPE_DIGITAL,		"Digital"		}
+};
+
+static const struct {
+	arcam_av_direct_t		code;
+	const char*			name;
+} arcam_av_direct[] = {
+	{ARCAM_AV_DIRECT_DISABLE,		"Disable"		},
+	{ARCAM_AV_DIRECT_ENABLE,		"Enable"		}
+};
+
+static const struct {
+	arcam_av_stereo_decode_t	code;
+	const char*			name;
+} arcam_av_stereo_decode_modes[] = {
+	{ARCAM_AV_STEREO_DECODE_MONO,		"Mono"			},
+	{ARCAM_AV_STEREO_DECODE_STEREO,		"Stereo"		},
+	{ARCAM_AV_STEREO_DECODE_PLII_MOVIE,	"Pro Logic II Movie"	},
+	{ARCAM_AV_STEREO_DECODE_PLII_MUSIC,	"Pro Logic II Music"	},
+	{ARCAM_AV_STEREO_DECODE_PLIIx_MOVIE,	"Pro Logic IIx Movie"	},
+	{ARCAM_AV_STEREO_DECODE_PLIIx_MUSIC,	"Pro Logic IIx Music"	},
+	{ARCAM_AV_STEREO_DECODE_DOLBY_PL,	"Dolby Pro Logic"	},
+	{ARCAM_AV_STEREO_DECODE_NEO6_CINEMA,	"Neo:6 Cinema"		},
+	{ARCAM_AV_STEREO_DECODE_NEO6_MUSIC,	"Neo:6 Music"		}
+};
+
+static const struct {
+	arcam_av_multi_decode_t		code;
+	const char*			name;
+} arcam_av_multi_decode_modes[] = {
+	{ARCAM_AV_MULTI_DECODE_MONO,		"Mono down-mix"		},
+	{ARCAM_AV_MULTI_DECODE_STEREO,		"Stereo down-mix"	},
+	{ARCAM_AV_MULTI_DECODE_MULTI_CHANNEL,	"Multi-channel"		},
+	{ARCAM_AV_MULTI_DECODE_PLIIx,		"Pro Logic IIx"		}
+};
+
+static const struct {
+	arcam_av_stereo_effect_t	code;
+	const char*			name;
+} arcam_av_stereo_effects[] = {
+	{ARCAM_AV_STEREO_EFFECT_NONE,		"None"			},
+	{ARCAM_AV_STEREO_EFFECT_MUSIC,		"Music"			},
+	{ARCAM_AV_STEREO_EFFECT_PARTY,		"Party"			},
+	{ARCAM_AV_STEREO_EFFECT_CLUB,		"Club"			},
+	{ARCAM_AV_STEREO_EFFECT_HALL,		"Hall"			},
+	{ARCAM_AV_STEREO_EFFECT_SPORTS,		"Sports"		},
+	{ARCAM_AV_STEREO_EFFECT_CHURCH,		"Church"		}
+};
+
+
+typedef struct snd_ctl_arcam_av {
+	snd_ctl_ext_t		ext;
+	int			port_fd;
+	int			shm_id;
+	const char*		port;
+	arcam_av_zone_t		zone;
+	arcam_av_state_t	local;
+	arcam_av_state_t*	global;
+	pthread_t		server;
+} snd_ctl_arcam_av_t;
+
+static void arcam_av_close(snd_ctl_ext_t *ext)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+
+	if (arcam_av->port_fd >= 0)
+		close(arcam_av->port_fd);
+
+	if (arcam_av->global)
+		arcam_av_state_detach(arcam_av->global);
+
+	if (arcam_av->ext.poll_fd >= 0) {
+		close(arcam_av->ext.poll_fd);
+		arcam_av_server_stop(arcam_av->server, arcam_av->port);
+	}
+
+	free(arcam_av);
+}
+
+static int arcam_av_elem_count(snd_ctl_ext_t *ext)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+
+	return arcam_av->zone == ARCAM_AV_ZONE1 ? 9 : 4;
+}
+
+static int arcam_av_elem_list(snd_ctl_ext_t *ext, unsigned int offset, snd_ctl_elem_id_t *id)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+
+	snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_MIXER);
+	
+	if (arcam_av->zone == ARCAM_AV_ZONE1) {
+		switch(offset) {
+		case 0:
+			snd_ctl_elem_id_set_name(id, arcam_av_power_name);
+			break;
+
+		case 1:
+			snd_ctl_elem_id_set_name(id, arcam_av_volume_name);
+			break;
+
+		case 2:
+			snd_ctl_elem_id_set_name(id, arcam_av_mute_name);
+			break;
+
+		case 3:
+			snd_ctl_elem_id_set_name(id, arcam_av_direct_name);
+			break;
+
+		case 4:
+			snd_ctl_elem_id_set_name(id, arcam_av_source_name);
+			break;
+
+		case 5:
+			snd_ctl_elem_id_set_name(id, arcam_av_source_type_name);
+			break;
+
+		case 6:
+			snd_ctl_elem_id_set_name(id, arcam_av_stereo_decode_name);
+			break;
+
+		case 7:
+			snd_ctl_elem_id_set_name(id, arcam_av_multi_decode_name);
+			break;
+
+		case 8:
+			snd_ctl_elem_id_set_name(id, arcam_av_stereo_effect_name);
+			break;
+		}
+	} else {
+		switch(offset) {
+		case 0:
+			snd_ctl_elem_id_set_name(id, arcam_av_power_name);
+			break;
+
+		case 1:
+			snd_ctl_elem_id_set_name(id, arcam_av_volume_name);
+			break;
+
+		case 2:
+			snd_ctl_elem_id_set_name(id, arcam_av_mute_name);
+			break;
+
+		case 3:
+			snd_ctl_elem_id_set_name(id, arcam_av_source_name);
+			break;
+		}	
+	}
+
+	return 0;
+}
+
+static snd_ctl_ext_key_t arcam_av_find_elem(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
+					    const snd_ctl_elem_id_t *id)
+{
+	const char *name;
+
+	name = snd_ctl_elem_id_get_name(id);
+	if (!strcmp(name, arcam_av_power_name)) {
+		return ARCAM_AV_POWER;
+	} else if (!strcmp(name, arcam_av_volume_name)) {
+		return ARCAM_AV_VOLUME_SET;
+	} else if (!strcmp(name, arcam_av_mute_name)) {
+		return ARCAM_AV_MUTE;
+	} else if (!strcmp(name, arcam_av_direct_name)) {
+		return ARCAM_AV_DIRECT;
+	} else if (!strcmp(name, arcam_av_source_name)) {
+		return ARCAM_AV_SOURCE;
+	} else if (!strcmp(name, arcam_av_source_type_name)) {
+		return ARCAM_AV_SOURCE_TYPE;
+	} else if (!strcmp(name, arcam_av_stereo_decode_name)) {
+		return ARCAM_AV_STEREO_DECODE;
+	} else if (!strcmp(name, arcam_av_multi_decode_name)) {
+		return ARCAM_AV_MULTI_DECODE;
+	} else if (!strcmp(name, arcam_av_stereo_effect_name)) {
+		return ARCAM_AV_STEREO_EFFECT;
+	}
+
+	return SND_CTL_EXT_KEY_NOT_FOUND;
+}
+
+static int arcam_av_get_attribute(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
+				  snd_ctl_ext_key_t key, int *type,
+				  unsigned int *acc, unsigned int *count)
+{
+	switch(key) {
+	case ARCAM_AV_POWER:
+		*type = SND_CTL_ELEM_TYPE_BOOLEAN;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_VOLUME_SET:
+		*type = SND_CTL_ELEM_TYPE_INTEGER;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_MUTE:
+		*type = SND_CTL_ELEM_TYPE_BOOLEAN;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_DIRECT:
+		*type = SND_CTL_ELEM_TYPE_ENUMERATED;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_SOURCE:
+		*type = SND_CTL_ELEM_TYPE_ENUMERATED;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_SOURCE_TYPE:
+		*type = SND_CTL_ELEM_TYPE_ENUMERATED;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_STEREO_DECODE:
+		*type = SND_CTL_ELEM_TYPE_ENUMERATED;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_MULTI_DECODE:
+		*type = SND_CTL_ELEM_TYPE_ENUMERATED;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	case ARCAM_AV_STEREO_EFFECT:
+		*type = SND_CTL_ELEM_TYPE_ENUMERATED;
+		*acc = SND_CTL_EXT_ACCESS_READWRITE;
+		*count = 1;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int arcam_av_get_integer_info(snd_ctl_ext_t *ext,
+				     snd_ctl_ext_key_t key,
+				     long *imin, long *imax, long *istep)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+
+	switch(key) {
+	case ARCAM_AV_VOLUME_SET:
+		*istep = 1;
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			*imin = 0;
+			*imax = 100;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			*imin = 20;
+			*imax = 83;
+			break;
+		}
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int arcam_av_get_enumerated_info(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
+					snd_ctl_ext_key_t key,
+					unsigned int *items)
+{
+	switch(key) {
+	case ARCAM_AV_SOURCE:
+		*items = ARRAY_SIZE(arcam_av_sources);
+		break;
+
+	case ARCAM_AV_SOURCE_TYPE:
+		*items = ARRAY_SIZE(arcam_av_source_types);
+		break;
+
+	case ARCAM_AV_DIRECT:
+		*items = ARRAY_SIZE(arcam_av_direct);
+		break;
+
+	case ARCAM_AV_STEREO_DECODE:
+		*items = ARRAY_SIZE(arcam_av_stereo_decode_modes);
+		break;
+
+	case ARCAM_AV_MULTI_DECODE:
+		*items = ARRAY_SIZE(arcam_av_multi_decode_modes);
+		break;
+
+	case ARCAM_AV_STEREO_EFFECT:
+		*items = ARRAY_SIZE(arcam_av_stereo_effects);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int arcam_av_get_enumerated_name(snd_ctl_ext_t *ext ATTRIBUTE_UNUSED,
+					snd_ctl_ext_key_t key,
+					unsigned int item, char *name,
+					size_t name_max_len)
+{
+	const char* label;
+
+	switch(key) {
+	case ARCAM_AV_SOURCE:
+		if (item >= ARRAY_SIZE(arcam_av_sources))
+			return -EINVAL;
+
+		label = arcam_av_sources[item].name;
+		break;
+
+	case ARCAM_AV_SOURCE_TYPE:
+		if (item >= ARRAY_SIZE(arcam_av_source_types))
+			return -EINVAL;
+
+		label = arcam_av_source_types[item].name;
+		break;
+
+	case ARCAM_AV_DIRECT:
+		if (item >= ARRAY_SIZE(arcam_av_direct))
+			return -EINVAL;
+
+		label = arcam_av_direct[item].name;
+		break;
+
+	case ARCAM_AV_STEREO_DECODE:
+		if (item >= ARRAY_SIZE(arcam_av_stereo_decode_modes))
+			return -EINVAL;
+
+		label = arcam_av_stereo_decode_modes[item].name;
+		break;
+
+	case ARCAM_AV_MULTI_DECODE:
+		if (item >= ARRAY_SIZE(arcam_av_multi_decode_modes))
+			return -EINVAL;
+
+		label = arcam_av_multi_decode_modes[item].name;
+		break;
+
+	case ARCAM_AV_STEREO_EFFECT:
+		if (item >= ARRAY_SIZE(arcam_av_stereo_effects))
+			return -EINVAL;
+
+		label = arcam_av_stereo_effects[item].name;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	strncpy(name, label, name_max_len - 1);
+	name[name_max_len - 1] = '\0';
+
+	return 0;
+}
+
+static int arcam_av_read_integer(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+
+	switch(key) {
+	case ARCAM_AV_POWER:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.power = arcam_av->global->zone1.power;
+			*value = !(arcam_av->local.zone1.power == ARCAM_AV_POWER_STAND_BY);
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.power = arcam_av->global->zone2.power;
+			*value = !(arcam_av->local.zone2.power == ARCAM_AV_POWER_STAND_BY);
+			break;
+		}
+		break;
+
+	case ARCAM_AV_VOLUME_SET:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.volume = arcam_av->global->zone1.volume;
+			*value = MID(0, arcam_av->local.zone1.volume - ARCAM_AV_VOLUME_MIN, 100);
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.volume = arcam_av->global->zone2.volume;
+			*value = MID(20, arcam_av->local.zone2.volume - ARCAM_AV_VOLUME_MIN, 83);
+			break;
+		}
+		break;
+
+	case ARCAM_AV_MUTE:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.mute = arcam_av->global->zone1.mute;
+			*value = !(arcam_av->local.zone1.mute == ARCAM_AV_MUTE_ON);
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.mute = arcam_av->global->zone2.mute;
+			*value = !(arcam_av->local.zone2.mute == ARCAM_AV_MUTE_ON);
+			break;
+		}
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int arcam_av_read_enumerated(snd_ctl_ext_t *ext,
+				    snd_ctl_ext_key_t key,
+				    unsigned int *item)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+	unsigned int i;
+
+	switch(key) {
+	case ARCAM_AV_SOURCE:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.source = arcam_av->global->zone1.source;
+			for (i = 0; i < ARRAY_SIZE(arcam_av_sources); ++i) {
+				if (arcam_av_sources[i].code == arcam_av->local.zone1.source) {
+					*item = i;
+					break;
+				}
+			}
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.source = arcam_av->global->zone2.source;
+			for (i = 0; i < ARRAY_SIZE(arcam_av_sources); ++i) {
+				if (arcam_av_sources[i].code == arcam_av->local.zone2.source) {
+					*item = i;
+					break;
+				}
+			}
+			break;
+		}
+		break;
+
+	case ARCAM_AV_SOURCE_TYPE:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.source_type = arcam_av->global->zone1.source_type;
+			for (i = 0; i < ARRAY_SIZE(arcam_av_source_types); ++i) {
+				if (arcam_av_source_types[i].code == arcam_av->local.zone1.source_type) {
+					*item = i;
+					break;
+				}
+			}
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_DIRECT:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.direct = arcam_av->global->zone1.direct;
+			for (i = 0; i < ARRAY_SIZE(arcam_av_direct); ++i) {
+				if (arcam_av_direct[i].code == arcam_av->local.zone1.direct) {
+					*item = i;
+					break;
+				}
+			}
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_STEREO_DECODE:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.stereo_decode = arcam_av->global->zone1.stereo_decode;
+			for (i = 0; i < ARRAY_SIZE(arcam_av_stereo_decode_modes); ++i) {
+				if (arcam_av_stereo_decode_modes[i].code == arcam_av->local.zone1.stereo_decode) {
+					*item = i;
+					break;
+				}
+			}
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_STEREO_EFFECT:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.stereo_effect = arcam_av->global->zone1.stereo_effect;
+			for (i = 0; i < ARRAY_SIZE(arcam_av_stereo_effects); ++i) {
+				if (arcam_av_stereo_effects[i].code == arcam_av->local.zone1.stereo_effect) {
+					*item = i;
+					break;
+				}
+			}
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_MULTI_DECODE:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.multi_decode = arcam_av->global->zone1.multi_decode;
+			for (i = 0; i < ARRAY_SIZE(arcam_av_multi_decode_modes); ++i) {
+				if (arcam_av_multi_decode_modes[i].code == arcam_av->local.zone1.multi_decode) {
+					*item = i;
+					break;
+				}
+			}
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int arcam_av_write_integer(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+	unsigned char volume = ARCAM_AV_VOLUME_MIN;
+
+	switch(key) {
+	case ARCAM_AV_POWER:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.power = ARCAM_AV_POWER_STAND_BY + *value;
+			if (arcam_av->global->zone1.power == arcam_av->local.zone1.power)
+				return 0;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.power = ARCAM_AV_POWER_STAND_BY + *value;
+			if (arcam_av->global->zone2.power == arcam_av->local.zone2.power)
+				return 0;
+			break;
+		}
+		break;
+
+	case ARCAM_AV_VOLUME_SET:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.volume = ARCAM_AV_VOLUME_MIN + *value;
+			if (arcam_av->global->zone1.volume == arcam_av->local.zone1.volume)
+				return 0;
+
+			if (arcam_av->global->zone1.mute == ARCAM_AV_MUTE_ON) {
+				arcam_av->global->zone1.volume = arcam_av->local.zone1.volume;
+				return 1;
+			}
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.volume = ARCAM_AV_VOLUME_MIN + *value;
+			if (arcam_av->global->zone2.volume == arcam_av->local.zone2.volume)
+				return 0;
+
+			if (arcam_av->global->zone2.mute == ARCAM_AV_MUTE_ON) {
+				arcam_av->global->zone2.volume = arcam_av->local.zone2.volume;
+				return 1;
+			}
+			break;
+		}
+		break;
+
+	case ARCAM_AV_MUTE:
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.mute = ARCAM_AV_MUTE_ON + *value;
+			if (arcam_av->global->zone1.mute == arcam_av->local.zone1.mute)
+				return 0;
+
+			volume = arcam_av->global->zone1.volume;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.mute = ARCAM_AV_MUTE_ON + *value;
+			if (arcam_av->global->zone2.mute == arcam_av->local.zone2.mute)
+				return 0;
+
+			volume = arcam_av->global->zone2.volume;
+			break;
+		}
+
+		if (*value)
+			arcam_av_send(arcam_av->port_fd, ARCAM_AV_VOLUME_SET, arcam_av->zone, volume);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (!arcam_av_send(arcam_av->port_fd, key, arcam_av->zone, '0' + *value))
+		return 1;
+	else
+		return -1;
+}
+
+static int arcam_av_write_enumerated(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *item)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+
+	char code;
+
+	switch(key) {
+	case ARCAM_AV_SOURCE:
+		if (*item >= ARRAY_SIZE(arcam_av_sources))
+			return -EINVAL;
+
+		code = arcam_av_sources[*item].code;
+
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.source = code;
+			if (arcam_av->global->zone1.source == code)
+				return 0;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			arcam_av->local.zone2.source = code;
+			if (arcam_av->global->zone2.source == code)
+				return 0;
+			break;
+		}
+		break;
+
+	case ARCAM_AV_SOURCE_TYPE:
+		if (*item >= ARRAY_SIZE(arcam_av_source_types))
+			return -EINVAL;
+
+		code = arcam_av_source_types[*item].code;
+
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.source_type = code;
+			if (arcam_av->global->zone1.source_type == code)
+				return 0;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_DIRECT:
+		if (*item >= ARRAY_SIZE(arcam_av_direct))
+			return -EINVAL;
+
+		code = arcam_av_direct[*item].code;
+
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.direct = code;
+			if (arcam_av->global->zone1.direct == code)
+				return 0;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_STEREO_DECODE:
+		if (*item >= ARRAY_SIZE(arcam_av_stereo_decode_modes))
+			return -EINVAL;
+
+		code = arcam_av_stereo_decode_modes[*item].code;
+
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.stereo_decode = code;
+			if (arcam_av->global->zone1.stereo_decode == code)
+				return 0;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_STEREO_EFFECT:
+		if (*item >= ARRAY_SIZE(arcam_av_stereo_effects))
+			return -EINVAL;
+
+		code = arcam_av_stereo_effects[*item].code;
+
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.stereo_effect = code;
+			if (arcam_av->global->zone1.stereo_effect == code)
+				return 0;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	case ARCAM_AV_MULTI_DECODE:
+		if (*item >= ARRAY_SIZE(arcam_av_multi_decode_modes))
+			return -EINVAL;
+
+		code = arcam_av_multi_decode_modes[*item].code;
+
+		switch(arcam_av->zone) {
+		case ARCAM_AV_ZONE1:
+			arcam_av->local.zone1.multi_decode = code;
+			if (arcam_av->global->zone1.multi_decode == code)
+				return 0;
+			break;
+
+		case ARCAM_AV_ZONE2:
+			return -EINVAL;
+		}
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (!arcam_av_send(arcam_av->port_fd, key, arcam_av->zone, code))
+		return 1;
+	else
+		return -1;
+}
+
+
+static int arcam_av_read_event(snd_ctl_ext_t *ext, snd_ctl_elem_id_t *id, unsigned int *event_mask)
+{
+	snd_ctl_arcam_av_t *arcam_av = ext->private_data;
+
+	switch(arcam_av->zone) {
+	case ARCAM_AV_ZONE1:
+		if (arcam_av->local.zone1.power != arcam_av->global->zone1.power) {
+			snd_ctl_elem_id_set_name(id, arcam_av_power_name);
+			arcam_av->local.zone1.power = arcam_av->global->zone1.power;
+		} else if (arcam_av->local.zone1.volume != arcam_av->global->zone1.volume) {
+			snd_ctl_elem_id_set_name(id, arcam_av_volume_name);
+			arcam_av->local.zone1.volume = arcam_av->global->zone1.volume;
+		} else if (arcam_av->local.zone1.mute != arcam_av->global->zone1.mute) {
+			snd_ctl_elem_id_set_name(id, arcam_av_mute_name);
+			arcam_av->local.zone1.mute = arcam_av->global->zone1.mute;
+		} else if (arcam_av->local.zone1.direct != arcam_av->global->zone1.direct) {
+			snd_ctl_elem_id_set_name(id, arcam_av_direct_name);
+			arcam_av->local.zone1.direct = arcam_av->global->zone1.direct;
+		} else if (arcam_av->local.zone1.source != arcam_av->global->zone1.source) {
+			snd_ctl_elem_id_set_name(id, arcam_av_source_name);
+			arcam_av->local.zone1.source = arcam_av->global->zone1.source;
+		} else if (arcam_av->local.zone1.source_type != arcam_av->global->zone1.source_type) {
+			snd_ctl_elem_id_set_name(id, arcam_av_source_type_name);
+			arcam_av->local.zone1.source_type = arcam_av->global->zone1.source_type;
+		} else if (arcam_av->local.zone1.stereo_decode != arcam_av->global->zone1.stereo_decode) {
+			snd_ctl_elem_id_set_name(id, arcam_av_stereo_decode_name);
+			arcam_av->local.zone1.stereo_decode = arcam_av->global->zone1.stereo_decode;
+		} else if (arcam_av->local.zone1.stereo_effect != arcam_av->global->zone1.stereo_effect) {
+			snd_ctl_elem_id_set_name(id, arcam_av_stereo_effect_name);
+			arcam_av->local.zone1.stereo_effect = arcam_av->global->zone1.stereo_effect;
+		} else if (arcam_av->local.zone1.multi_decode != arcam_av->global->zone1.multi_decode) {
+			snd_ctl_elem_id_set_name(id, arcam_av_multi_decode_name);
+			arcam_av->local.zone1.multi_decode = arcam_av->global->zone1.multi_decode;
+		} else {
+			char buf[10];
+			if (recv(arcam_av->ext.poll_fd, buf, sizeof(buf), 0) <= 0) {
+				close(arcam_av->ext.poll_fd);
+				arcam_av->ext.poll_fd = arcam_av_client(arcam_av->port);
+				if (arcam_av->ext.poll_fd > 0)
+					fcntl(arcam_av->ext.poll_fd, F_SETFL, O_NONBLOCK);
+			}
+
+			return -EAGAIN;
+		}
+		break;
+
+	case ARCAM_AV_ZONE2:
+		if (arcam_av->local.zone2.power != arcam_av->global->zone2.power) {
+			snd_ctl_elem_id_set_name(id, arcam_av_power_name);
+			arcam_av->local.zone2.power = arcam_av->global->zone2.power;
+		} else if (arcam_av->local.zone2.volume != arcam_av->global->zone2.volume) {
+			snd_ctl_elem_id_set_name(id, arcam_av_volume_name);
+			arcam_av->local.zone2.volume = arcam_av->global->zone2.volume;
+		} else if (arcam_av->local.zone2.mute != arcam_av->global->zone2.mute) {
+			snd_ctl_elem_id_set_name(id, arcam_av_mute_name);
+			arcam_av->local.zone2.mute = arcam_av->global->zone2.mute;
+		} else if (arcam_av->local.zone2.source != arcam_av->global->zone2.source) {
+			snd_ctl_elem_id_set_name(id, arcam_av_source_name);
+			arcam_av->local.zone2.source = arcam_av->global->zone2.source;
+		} else {
+			char buf[10];
+			if (recv(arcam_av->ext.poll_fd, buf, sizeof(buf), 0) <= 0) {
+				close(arcam_av->ext.poll_fd);
+				arcam_av->ext.poll_fd = arcam_av_client(arcam_av->port);
+				if (arcam_av->ext.poll_fd > 0)
+					fcntl(arcam_av->ext.poll_fd, F_SETFL, O_NONBLOCK);
+			}
+
+			return -EAGAIN;
+		}
+		break;
+	}
+
+	snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_MIXER);
+
+	*event_mask = SND_CTL_EVENT_MASK_VALUE;
+
+	return 1;
+}
+
+
+static snd_ctl_ext_callback_t arcam_av_ext_callback = {
+	.close = arcam_av_close,
+	.elem_count = arcam_av_elem_count,
+	.elem_list = arcam_av_elem_list,
+	.find_elem = arcam_av_find_elem,
+	.get_attribute = arcam_av_get_attribute,
+	.get_integer_info = arcam_av_get_integer_info,
+	.get_enumerated_info = arcam_av_get_enumerated_info,
+	.get_enumerated_name = arcam_av_get_enumerated_name,
+	.read_integer = arcam_av_read_integer,
+	.read_enumerated = arcam_av_read_enumerated,
+	.write_integer = arcam_av_write_integer,
+	.write_enumerated = arcam_av_write_enumerated,
+	.read_event = arcam_av_read_event,
+};
+
+
+SND_CTL_PLUGIN_DEFINE_FUNC(arcam_av)
+{
+	snd_config_iterator_t it, next;
+	const char *port = "/dev/ttyS0";
+	long zone = 1;
+	int err;
+	snd_ctl_arcam_av_t *arcam_av = NULL;
+
+	snd_config_for_each(it, next, conf) {
+		snd_config_t *n = snd_config_iterator_entry(it);
+		const char *id;
+		if (snd_config_get_id(n, &id) < 0)
+			continue;
+		if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0)
+			continue;
+		if (strcmp(id, "port") == 0) {
+			if (snd_config_get_string(n, &port) < 0) {
+				SNDERR("Invalid type for %s", id);
+				return -EINVAL;
+			}
+			continue;
+		}
+		if (strcmp(id, "zone") == 0) {
+			if (snd_config_get_integer(n, &zone) < 0) {
+				SNDERR("Invalid type for %s", id);
+				return -EINVAL;
+			}
+			if (zone < 1 || zone > 2) {
+				SNDERR("Invalid value for %s", id);
+				return -EINVAL;
+			}
+			continue;
+		}
+		SNDERR("Unknown field %s", id);
+		return -EINVAL;
+	}
+
+	if (access(port, R_OK | W_OK) < 0) {
+		err = -errno;
+		goto error;
+	}
+
+	arcam_av = calloc(1, sizeof(*arcam_av) + strlen(port) + 1);
+	
+	if (!arcam_av)
+		return -ENOMEM;
+
+	arcam_av->ext.version = SND_CTL_EXT_VERSION;
+	arcam_av->ext.card_idx = 0;
+	strncpy(arcam_av->ext.id, arcam_av_name, sizeof(arcam_av->ext.id) - 1);
+	strncpy(arcam_av->ext.name, arcam_av_name, sizeof(arcam_av->ext.name) - 1);
+	strncpy(arcam_av->ext.longname, arcam_av_name, sizeof(arcam_av->ext.longname) - 1);
+	strncpy(arcam_av->ext.mixername, arcam_av_name, sizeof(arcam_av->ext.mixername) - 1);
+	arcam_av->ext.poll_fd = -1;
+	arcam_av->ext.callback = &arcam_av_ext_callback;
+	arcam_av->ext.private_data = arcam_av;
+
+	arcam_av->shm_id= -1;
+	arcam_av->port_fd = -1;
+	arcam_av->port = strcpy((char*)(arcam_av + 1), port);
+	arcam_av->zone = zone != 2 ? ARCAM_AV_ZONE1 : ARCAM_AV_ZONE2;
+
+	arcam_av->port_fd = arcam_av_connect(arcam_av->port);
+	if (arcam_av->port_fd < 0) {
+		err = -errno;
+		goto error;
+	}
+
+	if (arcam_av_server_start(&arcam_av->server, arcam_av->port)) {
+		err = -errno;
+		goto error;
+	}
+
+	arcam_av->ext.poll_fd = arcam_av_client(arcam_av->port);
+	if (arcam_av->ext.poll_fd < 0) {
+		err = -errno;
+		goto error;
+	}
+
+	fcntl(arcam_av->ext.poll_fd, F_SETFL, O_NONBLOCK);
+
+	arcam_av->global = arcam_av_state_attach(arcam_av->port);
+	if (!arcam_av->global) {
+		err = -errno;
+		goto error;
+	}
+
+	err = snd_ctl_ext_create(&arcam_av->ext, name, mode);
+	if (err < 0)
+		goto error;
+
+	*handlep = arcam_av->ext.handle;
+	return 0;
+
+ error:
+	perror("arcam_av()");
+	arcam_av_close(&arcam_av->ext);
+	return err;
+}
+
+SND_CTL_PLUGIN_SYMBOL(arcam_av);
diff --git a/configure.in b/configure.in
index 12c6f54..072e44d 100644
--- a/configure.in
+++ b/configure.in
@@ -167,6 +167,7 @@ AC_OUTPUT([
 	doc/Makefile
 	usb_stream/Makefile
 	speex/Makefile
+	arcam-av/Makefile
 ])
 
 dnl Show the build conditions
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 3e89be8..19fa0d2 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1,4 +1,4 @@
 EXTRA_DIST = README-pcm-oss README-jack README-pulse README-maemo \
 	upmix.txt vdownmix.txt samplerate.txt a52.txt lavcrate.txt \
-	speexrate.txt speexdsp.txt
+	speexrate.txt speexdsp.txt README-arcam-av
 
diff --git a/doc/README-arcam-av b/doc/README-arcam-av
new file mode 100644
index 0000000..c371cf4
--- /dev/null
+++ b/doc/README-arcam-av
@@ -0,0 +1,29 @@
+Arcam AV Amplifier ALSA Control plugin
+======================================
+
+This plugin exposes the controls for an Arcam AV amplifier
+(see: http://www.arcam.co.uk/) as an ALSA mixer device.
+
+To use this plugin you will need to connect the amplifier
+to the PC using an RS-232 null-modem cable and use the
+following ALSA configuration:
+
+	ctl.arcam_av {
+		type arcam_av
+		port /dev/ttyS0
+	}
+
+The "port" parameter is required and indicates the serial
+port to be used to communicate with the amplifier. There is
+an optional "zone" parameter, which accepts a value of
+either "1" (default) or "2", that indicates which of the
+amplifiers zones should be controlled.
+
+NB: You must ensure that any user accounts that are to use
+this plugin have both read and write access rights for the
+configured serial port.
+
+This plugin was developed and tested using an Arcam AVR 300
+amplifier. I believe most Arcam amplifiers use a sufficiently
+similar control system to be compatible with this plugin but
+your mileage may vary.