Beginning of OSS4 support

9 files changed, 1062 insertions, 3 deletions

diff --git a/backends/Makefile.am b/backends/Makefile.am
index 8ca01bd..0cf8dd4 100644
--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -12,4 +12,8 @@ if HAVE_OSS
 SUBDIRS += oss
 endif
 
+if HAVE_OSS4
+SUBDIRS += oss4
+endif
+
 -include $(top_srcdir)/git.mk
diff --git a/backends/oss4/Makefile.am b/backends/oss4/Makefile.am
new file mode 100644
index 0000000..cca8723
--- /dev/null
+++ b/backends/oss4/Makefile.am
@@ -0,0 +1,29 @@
+backenddir = $(libdir)/libmatemixer
+
+backend_LTLIBRARIES = libmatemixer-oss4.la
+
+AM_CPPFLAGS =                                                   \
+        -I$(top_srcdir)                                         \
+        -DG_LOG_DOMAIN=\"libmatemixer-oss4\"
+
+libmatemixer_oss4_la_CFLAGS =                                   \
+        $(GLIB_CFLAGS)                                          \
+        $(OSS4_CFLAGS)
+
+libmatemixer_oss4_la_SOURCES =                                  \
+        oss4-common.h                                           \
+        oss4-backend.c                                          \
+        oss4-backend.h                                          \
+        oss4-device.c                                           \
+        oss4-device.h
+
+libmatemixer_oss4_la_LIBADD =                                   \
+        $(GLIB_LIBS)
+
+libmatemixer_oss4_la_LDFLAGS =                                  \
+        -avoid-version                                          \
+        -no-undefined                                           \
+        -export-dynamic                                         \
+        -module
+
+-include $(top_srcdir)/git.mk
diff --git a/backends/oss4/oss4-backend.c b/backends/oss4/oss4-backend.c
new file mode 100644
index 0000000..bd79fdf
--- /dev/null
+++ b/backends/oss4/oss4-backend.c
@@ -0,0 +1,487 @@
+/*
+ * Copyright (C) 2014 Michal Ratajsky <[email protected]>
+ *
+ * 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 of the licence, or (at your option) any later version.
+ *
+ * This library 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <glib.h>
+#include <glib-object.h>
+#include <glib/gstdio.h>
+#include <glib/gprintf.h>
+#include <glib/gi18n.h>
+#include <gio/gio.h>
+
+#include <libmatemixer/matemixer-backend.h>
+#include <libmatemixer/matemixer-backend-module.h>
+#include <libmatemixer/matemixer-enums.h>
+#include <libmatemixer/matemixer-stream.h>
+
+#include "oss4-backend.h"
+#include "oss4-common.h"
+#include "oss4-device.h"
+
+#define BACKEND_NAME      "OSS4"
+#define BACKEND_PRIORITY  8
+
+#define PATH_SNDSTAT      "/dev/sndstat"
+
+struct _Oss4BackendPrivate
+{
+    gint fd;
+    gchar           *sndstat;
+    GHashTable      *devices;
+    GHashTable      *streams;
+    MateMixerStream *default_input;
+    MateMixerStream *default_output;
+    MateMixerState   state;
+};
+
+enum {
+    PROP_0,
+    PROP_STATE,
+    PROP_DEFAULT_INPUT,
+    PROP_DEFAULT_OUTPUT
+};
+
+static void mate_mixer_backend_interface_init (MateMixerBackendInterface *iface);
+
+static void oss4_backend_class_init     (Oss4BackendClass *klass);
+static void oss4_backend_class_finalize (Oss4BackendClass *klass);
+
+static void oss4_backend_get_property   (GObject         *object,
+                                         guint            param_id,
+                                         GValue          *value,
+                                         GParamSpec      *pspec);
+
+static void oss4_backend_init           (Oss4Backend     *oss);
+static void oss4_backend_dispose        (GObject         *object);
+static void oss4_backend_finalize       (GObject         *object);
+
+G_DEFINE_DYNAMIC_TYPE_EXTENDED (Oss4Backend, oss4_backend,
+                                G_TYPE_OBJECT, 0,
+                                G_IMPLEMENT_INTERFACE_DYNAMIC (MATE_MIXER_TYPE_BACKEND,
+                                                               mate_mixer_backend_interface_init))
+
+static gboolean oss4_backend_open         (MateMixerBackend  *backend);
+static void     oss4_backend_close        (MateMixerBackend  *backend);
+static GList *  oss4_backend_list_devices (MateMixerBackend  *backend);
+static GList *  oss4_backend_list_streams (MateMixerBackend  *backend);
+
+static void     change_state                    (Oss4Backend       *oss,
+                                                 MateMixerState     state);
+
+static gboolean read_device (Oss4Backend *oss, gint index);
+
+static gchar *  read_device_sndstat_description (Oss4Backend *oss,
+                                                 const gchar *prefix);
+
+static void     add_device      (Oss4Backend *oss, Oss4Device *device);
+static void     remove_device   (Oss4Backend *oss, Oss4Device *device);
+
+static MateMixerBackendInfo info;
+
+void
+backend_module_init (GTypeModule *module)
+{
+    oss4_backend_register_type (module);
+
+    info.name         = BACKEND_NAME;
+    info.priority     = BACKEND_PRIORITY;
+    info.g_type       = OSS4_TYPE_BACKEND;
+    info.backend_type = MATE_MIXER_BACKEND_OSS4;
+}
+
+const MateMixerBackendInfo *backend_module_get_info (void)
+{
+    return &info;
+}
+
+static void
+mate_mixer_backend_interface_init (MateMixerBackendInterface *iface)
+{
+    iface->open         = oss4_backend_open;
+    iface->close        = oss4_backend_close;
+    iface->list_devices = oss4_backend_list_devices;
+    iface->list_streams = oss4_backend_list_streams;
+}
+
+static void
+oss4_backend_class_init (Oss4BackendClass *klass)
+{
+    GObjectClass *object_class;
+
+    object_class = G_OBJECT_CLASS (klass);
+    object_class->dispose      = oss4_backend_dispose;
+    object_class->finalize     = oss4_backend_finalize;
+    object_class->get_property = oss4_backend_get_property;
+
+    g_object_class_override_property (object_class, PROP_STATE, "state");
+    g_object_class_override_property (object_class, PROP_DEFAULT_INPUT, "default-input");
+    g_object_class_override_property (object_class, PROP_DEFAULT_OUTPUT, "default-output");
+
+    g_type_class_add_private (object_class, sizeof (Oss4BackendPrivate));
+}
+
+/* Called in the code generated by G_DEFINE_DYNAMIC_TYPE_EXTENDED() */
+static void
+oss4_backend_class_finalize (Oss4BackendClass *klass)
+{
+}
+
+static void
+oss4_backend_get_property (GObject    *object,
+                           guint       param_id,
+                           GValue     *value,
+                           GParamSpec *pspec)
+{
+    Oss4Backend *oss;
+
+    oss = OSS4_BACKEND (object);
+
+    switch (param_id) {
+    case PROP_STATE:
+        g_value_set_enum (value, oss->priv->state);
+        break;
+    case PROP_DEFAULT_INPUT:
+        g_value_set_object (value, oss->priv->default_input);
+        break;
+    case PROP_DEFAULT_OUTPUT:
+        g_value_set_object (value, oss->priv->default_output);
+        break;
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
+        break;
+    }
+}
+
+static void
+oss4_backend_init (Oss4Backend *oss)
+{
+    oss->priv = G_TYPE_INSTANCE_GET_PRIVATE (oss,
+                                             OSS4_TYPE_BACKEND,
+                                             Oss4BackendPrivate);
+
+    oss->priv->devices = g_hash_table_new_full (g_direct_hash,
+                                                g_direct_equal,
+                                                NULL,
+                                                g_object_unref);
+
+    oss->priv->streams = g_hash_table_new_full (g_str_hash,
+                                                g_str_equal,
+                                                g_free,
+                                                g_object_unref);
+}
+
+static void
+oss4_backend_dispose (GObject *object)
+{
+    oss4_backend_close (MATE_MIXER_BACKEND (object));
+}
+
+static void
+oss4_backend_finalize (GObject *object)
+{
+    Oss4Backend *oss;
+
+    oss = OSS4_BACKEND (object);
+
+    g_hash_table_destroy (oss->priv->devices);
+    g_hash_table_destroy (oss->priv->streams);
+}
+
+static gboolean
+oss4_backend_open (MateMixerBackend *backend)
+{
+    Oss4Backend       *oss;
+    gint               fd;
+    gint               i;
+    gint               ret;
+    struct oss_sysinfo info;
+
+    g_return_val_if_fail (OSS4_IS_BACKEND (backend), FALSE);
+
+    oss = OSS4_BACKEND (backend);
+
+    fd = g_open ("/dev/mixer", O_RDONLY, 0);
+    if (fd == -1)
+        fd = g_open ("/dev/mixer0", O_RDONLY, 0);
+    if (fd == -1) {
+        change_state (oss, MATE_MIXER_STATE_FAILED);
+        return FALSE;
+    }
+
+    /* Query the number of mixer devices */
+    ret = ioctl (fd, OSS_SYSINFO, &info);
+    if (ret == -1) {
+        close (fd);
+        change_state (oss, MATE_MIXER_STATE_FAILED);
+        return FALSE;
+    }
+
+    g_debug ("The sound system is %s version %s",
+             info.product,
+             info.version);
+
+#if !defined(__linux__)
+    /* At least on systems based on FreeBSD we will need to read devices names
+     * from the sndstat file, but avoid even trying that on systems where this
+     * is not needed and the file is not present */
+    oss->priv->sndstat = PATH_SNDSTAT;
+#endif
+
+    oss->priv->fd = fd;
+
+    for (i = 0; i < info.nummixers; i++)
+        read_device (oss, i);
+
+    change_state (oss, MATE_MIXER_STATE_READY);
+    return TRUE;
+}
+
+void
+oss4_backend_close (MateMixerBackend *backend)
+{
+    Oss4Backend *oss;
+
+    g_return_if_fail (OSS4_IS_BACKEND (backend));
+
+    oss = OSS4_BACKEND (backend);
+
+    g_clear_object (&oss->priv->default_input);
+    g_clear_object (&oss->priv->default_output);
+
+    g_hash_table_remove_all (oss->priv->streams);
+    g_hash_table_remove_all (oss->priv->devices);
+}
+
+static GList *
+oss4_backend_list_devices (MateMixerBackend *backend)
+{
+    GList *list;
+
+    g_return_val_if_fail (OSS4_IS_BACKEND (backend), NULL);
+
+    /* Convert the hash table to a sorted linked list, this list is expected
+     * to be cached in the main library */
+    list = g_hash_table_get_values (OSS4_BACKEND (backend)->priv->devices);
+    if (list != NULL) {
+        g_list_foreach (list, (GFunc) g_object_ref, NULL);
+
+        return list;
+    }
+    return NULL;
+}
+
+static GList *
+oss4_backend_list_streams (MateMixerBackend *backend)
+{
+    GList *list;
+
+    g_return_val_if_fail (OSS4_IS_BACKEND (backend), NULL);
+
+    /* Convert the hash table to a sorted linked list, this list is expected
+     * to be cached in the main library */
+    list = g_hash_table_get_values (OSS4_BACKEND (backend)->priv->streams);
+    if (list != NULL) {
+        g_list_foreach (list, (GFunc) g_object_ref, NULL);
+
+        return list;
+    }
+    return NULL;
+}
+
+static void
+change_state (Oss4Backend *oss, MateMixerState state)
+{
+    if (oss->priv->state == state)
+        return;
+
+    oss->priv->state = state;
+
+    g_object_notify (G_OBJECT (oss), "state");
+}
+
+static gboolean
+read_device (Oss4Backend *oss, gint index)
+{
+    Oss4Device          *device;
+    gboolean             ret;
+    gchar               *description = NULL;
+    struct oss_mixerinfo info;
+
+    /* We assume that the name and capabilities of a device do not change */
+    device = g_hash_table_lookup (oss->priv->devices, GINT_TO_POINTER (index));
+    if (G_UNLIKELY (device != NULL)) {
+        g_debug ("Attempt to re-read already know device with index %d", index);
+        return TRUE;
+    }
+
+    info.dev = index;
+    ret = ioctl (oss->priv->fd, SNDCTL_MIXERINFO, &info);
+    if (ret == -1) {
+        g_debug ("Failed to read mixer info: %s", g_strerror (errno));
+        return FALSE;
+    }
+
+    if (info.enabled == 0)
+        return TRUE;
+
+    /* Use the id as the device name and try to figure out the name of the
+     * sound card from the sndstat file if it is available, otherwise use
+     * the name from the mixer info */
+    if (oss->priv->sndstat != NULL &&
+        g_str_has_prefix (info.name, "pcm") == TRUE)
+        description = read_device_sndstat_description (oss, info.name);
+
+    if (description == NULL)
+        description = g_strdup (info.name);
+
+    device = oss4_device_new (info.id, description, oss->priv->fd, index);
+
+    ret = oss4_device_read (device);
+    if (ret == TRUE)
+        add_device (oss, device);
+
+    g_object_unref (device);
+    g_free (description);
+
+    return ret;
+}
+
+static gchar *
+read_device_sndstat_description (Oss4Backend *oss, const gchar *prefix)
+{
+    FILE  *fp;
+    gchar  line[256];
+    gchar *description = NULL;
+
+    g_debug ("reading prefix %s", prefix);
+
+    fp = fopen (oss->priv->sndstat, "r");
+    if (fp == NULL) {
+        g_warning ("Failed to read %s: %s", oss->priv->sndstat, g_strerror (errno));
+        return FALSE;
+    }
+
+    while (fgets (line, sizeof (line), fp) != NULL) {
+        gchar *p;
+
+        if (g_str_has_prefix (line, prefix) == FALSE)
+            continue;
+
+        /* Example line:
+         * pcm0: <ATI R6xx (HDMI)> (play) default */
+        p = strchr (line, '<');
+        if (p != NULL && *p && *(++p)) {
+            gchar *end = strchr (p, '>');
+
+            if (end != NULL)
+                description = g_strndup (p, end - p);
+        }
+
+        // XXX we can also read "default" at the end of the line
+        // XXX http://ashish.is.lostca.se/2011/05/23/default-sound-device-in-freebsd/
+        if (g_str_has_suffix (line, "default") ||
+            g_str_has_suffix (line, "default)"))
+            ;
+
+        if (description != NULL)
+            break;
+    }
+
+    fclose (fp);
+    return description;
+}
+
+static void
+add_device (Oss4Backend *oss, Oss4Device *device)
+{
+    MateMixerStream *stream;
+
+    /* Add device, file path is used as the key rather than the name, because
+     * the name is not known until an OssDevice instance is created */
+    g_hash_table_insert (oss->priv->devices,
+                         GINT_TO_POINTER (oss4_device_get_index (device)),
+                         g_object_ref (device));
+
+    g_signal_emit_by_name (G_OBJECT (oss),
+                           "device-added",
+                           mate_mixer_device_get_name (MATE_MIXER_DEVICE (device)));
+
+    /* Add streams if they exist */
+    stream = oss4_device_get_input_stream (device);
+    if (stream != NULL) {
+        g_hash_table_insert (oss->priv->streams,
+                             g_strdup (mate_mixer_stream_get_name (stream)),
+                             g_object_ref (stream));
+
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-added",
+                               mate_mixer_stream_get_name (stream));
+    }
+
+    stream = oss4_device_get_output_stream (device);
+    if (stream != NULL) {
+        g_hash_table_insert (oss->priv->streams,
+                             g_strdup (mate_mixer_stream_get_name (stream)),
+                             g_object_ref (stream));
+
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-added",
+                               mate_mixer_stream_get_name (stream));
+    }
+}
+
+static void
+remove_device (Oss4Backend *oss, Oss4Device *device)
+{
+    MateMixerStream *stream;
+
+    /* Remove the device streams first as they are a part of the device */
+    stream = oss4_device_get_input_stream (device);
+    if (stream != NULL) {
+        const gchar *name = mate_mixer_stream_get_name (stream);
+
+        g_hash_table_remove (oss->priv->streams, name);
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-removed",
+                               name);
+    }
+
+    stream = oss4_device_get_output_stream (device);
+    if (stream != NULL) {
+        const gchar *name = mate_mixer_stream_get_name (stream);
+
+        g_hash_table_remove (oss->priv->streams, stream);
+        g_signal_emit_by_name (G_OBJECT (oss),
+                               "stream-removed",
+                               name);
+    }
+
+    /* Remove the device */
+    g_object_ref (device);
+
+    g_hash_table_remove (oss->priv->devices,
+                         GINT_TO_POINTER (oss4_device_get_index (device)));
+
+    g_signal_emit_by_name (G_OBJECT (oss),
+                           "device-removed",
+                           mate_mixer_device_get_name (MATE_MIXER_DEVICE (device)));
+
+    g_object_unref (device);
+}
diff --git a/backends/oss4/oss4-backend.h b/backends/oss4/oss4-backend.h
new file mode 100644
index 0000000..bc89e72
--- /dev/null
+++ b/backends/oss4/oss4-backend.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2014 Michal Ratajsky <[email protected]>
+ *
+ * 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 of the licence, or (at your option) any later version.
+ *
+ * This library 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef OSS4_BACKEND_H
+#define OSS4_BACKEND_H
+
+#include <glib.h>
+#include <glib-object.h>
+
+#include <libmatemixer/matemixer-backend-module.h>
+
+#define OSS4_TYPE_BACKEND                       \
+        (oss4_backend_get_type ())
+#define OSS4_BACKEND(o)                         \
+        (G_TYPE_CHECK_INSTANCE_CAST ((o), OSS4_TYPE_BACKEND, Oss4Backend))
+#define OSS4_IS_BACKEND(o)                      \
+        (G_TYPE_CHECK_INSTANCE_TYPE ((o), OSS4_TYPE_BACKEND))
+#define OSS4_BACKEND_CLASS(k)                   \
+        (G_TYPE_CHECK_CLASS_CAST ((k), OSS4_TYPE_BACKEND, Oss4BackendClass))
+#define OSS4_IS_BACKEND_CLASS(k)                \
+        (G_TYPE_CHECK_CLASS_TYPE ((k), OSS4_TYPE_BACKEND))
+#define OSS4_BACKEND_GET_CLASS(o)               \
+        (G_TYPE_INSTANCE_GET_CLASS ((o), OSS4_TYPE_BACKEND, Oss4BackendClass))
+
+typedef struct _Oss4Backend         Oss4Backend;
+typedef struct _Oss4BackendClass    Oss4BackendClass;
+typedef struct _Oss4BackendPrivate  Oss4BackendPrivate;
+
+struct _Oss4Backend
+{
+    GObject parent;
+
+    /*< private >*/
+    Oss4BackendPrivate *priv;
+};
+
+struct _Oss4BackendClass
+{
+    GObjectClass parent_class;
+};
+
+GType                       oss4_backend_get_type   (void) G_GNUC_CONST;
+
+/* Support function for dynamic loading of the backend module */
+void                        backend_module_init     (GTypeModule *module);
+const MateMixerBackendInfo *backend_module_get_info (void);
+
+#endif /* OSS4_BACKEND_H */
diff --git a/backends/oss4/oss4-common.h b/backends/oss4/oss4-common.h
new file mode 100644
index 0000000..fe55b2b
--- /dev/null
+++ b/backends/oss4/oss4-common.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2014 Michal Ratajsky <[email protected]>
+ *
+ * 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 of the licence, or (at your option) any later version.
+ *
+ * This library 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef OSS4_COMMON_H
+#define OSS4_COMMON_H
+
+#include "config.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+
+#ifdef HAVE_SYS_SOUNDCARD_H
+#  include <sys/soundcard.h>
+#elif HAVE_SOUNDCARD_H
+#  include <soundcard.h>
+#elif HAVE_MACHINE_SOUNDCARD_H
+#  include <machine/soundcard.h>
+#else
+#  error "No OSS4 header file present"
+#endif
+
+#endif /* OSS4_COMMON_H */
diff --git a/backends/oss4/oss4-device.c b/backends/oss4/oss4-device.c
new file mode 100644
index 0000000..b68648b
--- /dev/null
+++ b/backends/oss4/oss4-device.c
@@ -0,0 +1,328 @@
+/*
+ * Copyright (C) 2014 Michal Ratajsky <[email protected]>
+ *
+ * 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 of the licence, or (at your option) any later version.
+ *
+ * This library 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <unistd.h>
+#include <glib.h>
+#include <glib/gi18n.h>
+#include <glib/gstdio.h>
+#include <glib-object.h>
+
+#include <libmatemixer/matemixer-device.h>
+#include <libmatemixer/matemixer-enums.h>
+#include <libmatemixer/matemixer-port.h>
+#include <libmatemixer/matemixer-port-private.h>
+#include <libmatemixer/matemixer-stream.h>
+#include <libmatemixer/matemixer-stream-control.h>
+
+#include "oss4-common.h"
+#include "oss4-device.h"
+
+#define OSS4_DEVICE_ICON "audio-card"
+
+struct _Oss4DevicePrivate
+{
+    gint             fd;
+    gint             index;
+    gchar           *name;
+    gchar           *description;
+    gchar           *icon;
+    MateMixerStream *input;
+    MateMixerStream *output;
+};
+
+enum {
+    PROP_0,
+    PROP_NAME,
+    PROP_DESCRIPTION,
+    PROP_ICON,
+    PROP_ACTIVE_PROFILE,
+    PROP_FD,
+    PROP_INDEX
+};
+
+static void mate_mixer_device_interface_init (MateMixerDeviceInterface *iface);
+
+static void oss4_device_class_init   (Oss4DeviceClass *klass);
+
+static void oss4_device_get_property (GObject        *object,
+                                      guint           param_id,
+                                      GValue         *value,
+                                      GParamSpec     *pspec);
+static void oss4_device_set_property (GObject        *object,
+                                      guint           param_id,
+                                      const GValue   *value,
+                                      GParamSpec     *pspec);
+
+static void oss4_device_init         (Oss4Device     *device);
+static void oss4_device_finalize     (GObject        *object);
+
+G_DEFINE_TYPE_WITH_CODE (Oss4Device, oss4_device, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (MATE_MIXER_TYPE_DEVICE,
+                                                mate_mixer_device_interface_init))
+
+static const gchar *oss4_device_get_name        (MateMixerDevice *device);
+static const gchar *oss4_device_get_description (MateMixerDevice *device);
+static const gchar *oss4_device_get_icon        (MateMixerDevice *device);
+
+static gboolean     read_mixer_devices          (Oss4Device      *device);
+
+static void
+mate_mixer_device_interface_init (MateMixerDeviceInterface *iface)
+{
+    iface->get_name        = oss4_device_get_name;
+    iface->get_description = oss4_device_get_description;
+    iface->get_icon        = oss4_device_get_icon;
+}
+
+static void
+oss4_device_class_init (Oss4DeviceClass *klass)
+{
+    GObjectClass *object_class;
+
+    object_class = G_OBJECT_CLASS (klass);
+    object_class->finalize     = oss4_device_finalize;
+    object_class->get_property = oss4_device_get_property;
+    object_class->set_property = oss4_device_set_property;
+
+    g_object_class_install_property (object_class,
+                                     PROP_FD,
+                                     g_param_spec_int ("fd",
+                                                       "File descriptor",
+                                                       "File descriptor of the device",
+                                                       G_MININT,
+                                                       G_MAXINT,
+                                                       -1,
+                                                       G_PARAM_CONSTRUCT_ONLY |
+                                                       G_PARAM_READWRITE |
+                                                       G_PARAM_STATIC_STRINGS));
+
+    g_object_class_install_property (object_class,
+                                     PROP_INDEX,
+                                     g_param_spec_int ("index",
+                                                       "Index",
+                                                       "Index of the device",
+                                                       G_MININT,
+                                                       G_MAXINT,
+                                                       0,
+                                                       G_PARAM_CONSTRUCT_ONLY |
+                                                       G_PARAM_READWRITE |
+                                                       G_PARAM_STATIC_STRINGS));
+
+    g_object_class_override_property (object_class, PROP_NAME, "name");
+    g_object_class_override_property (object_class, PROP_DESCRIPTION, "description");
+    g_object_class_override_property (object_class, PROP_ICON, "icon");
+    g_object_class_override_property (object_class, PROP_ACTIVE_PROFILE, "active-profile");
+
+    g_type_class_add_private (object_class, sizeof (Oss4DevicePrivate));
+}
+
+static void
+oss4_device_get_property (GObject    *object,
+                         guint       param_id,
+                         GValue     *value,
+                         GParamSpec *pspec)
+{
+    Oss4Device *device;
+
+    device = OSS4_DEVICE (object);
+
+    switch (param_id) {
+    case PROP_NAME:
+        g_value_set_string (value, device->priv->name);
+        break;
+    case PROP_DESCRIPTION:
+        g_value_set_string (value, device->priv->description);
+        break;
+    case PROP_ICON:
+        g_value_set_string (value, OSS4_DEVICE_ICON);
+        break;
+    case PROP_ACTIVE_PROFILE:
+        /* Not supported */
+        g_value_set_object (value, NULL);
+        break;
+    case PROP_FD:
+        g_value_set_int (value, device->priv->fd);
+        break;
+    case PROP_INDEX:
+        g_value_set_int (value, device->priv->index);
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
+        break;
+    }
+}
+
+static void
+oss4_device_set_property (GObject      *object,
+                         guint         param_id,
+                         const GValue *value,
+                         GParamSpec   *pspec)
+{
+    Oss4Device *device;
+
+    device = OSS4_DEVICE (object);
+
+    switch (param_id) {
+    case PROP_NAME:
+        /* Construct-only string */
+        device->priv->name = g_strdup (g_value_get_string (value));
+        break;
+    case PROP_DESCRIPTION:
+        /* Construct-only string */
+        device->priv->description = g_strdup (g_value_get_string (value));
+        break;
+    case PROP_ICON:
+        /* Construct-only string */
+        device->priv->icon = g_strdup (g_value_get_string (value));
+        break;
+    case PROP_FD:
+        device->priv->fd = dup (g_value_get_int (value));
+        break;
+    case PROP_INDEX:
+        device->priv->index = g_value_get_int (value);
+        break;
+    default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, param_id, pspec);
+        break;
+    }
+}
+
+static void
+oss4_device_init (Oss4Device *device)
+{
+    device->priv = G_TYPE_INSTANCE_GET_PRIVATE (device,
+                                                OSS4_TYPE_DEVICE,
+                                                Oss4DevicePrivate);
+}
+
+static void
+oss4_device_finalize (GObject *object)
+{
+    Oss4Device *device;
+
+    device = OSS4_DEVICE (object);
+
+    g_free (device->priv->name);
+    g_free (device->priv->description);
+
+    if (device->priv->fd != -1)
+        g_close (device->priv->fd, NULL);
+
+    G_OBJECT_CLASS (oss4_device_parent_class)->finalize (object);
+}
+
+Oss4Device *
+oss4_device_new (const gchar *name,
+                 const gchar *description,
+                 gint         fd,
+                 gint         index)
+{
+    Oss4Device *device;
+
+    device = g_object_new (OSS4_TYPE_DEVICE,
+                           "name", name,
+                           "description", description,
+                           "fd", fd,
+                           "index", index,
+                           NULL);
+
+    return device;
+}
+
+gboolean
+oss4_device_read (Oss4Device *odevice)
+{
+    gint exts;
+    gint ret;
+    gint i;
+
+    ret = ioctl (odevice->priv->fd, SNDCTL_MIX_NREXT, &exts);
+    if (ret == -1)
+        return FALSE;
+
+    for (i = 0; i < exts; i++) {
+        oss_mixext ext;
+
+        ext.dev  = odevice->priv->index;
+        ext.ctrl = i;
+        ret = ioctl (odevice->priv->fd, SNDCTL_MIX_EXTINFO, &ext);
+        if (ret == -1)
+            continue;
+
+        g_debug ("Mixer control %d type %d\n"
+                 " min %d max %d\n"
+                 " id %s\n"
+                 " extname %s",
+                 i,ext.type, ext.minvalue, ext.maxvalue, ext.id, ext.extname);
+    }
+
+    return TRUE;
+}
+
+gint
+oss4_device_get_index (Oss4Device *odevice)
+{
+    g_return_val_if_fail (OSS4_IS_DEVICE (odevice), FALSE);
+
+    return odevice->priv->index;
+}
+
+MateMixerStream *
+oss4_device_get_input_stream (Oss4Device *odevice)
+{
+    g_return_val_if_fail (OSS4_IS_DEVICE (odevice), FALSE);
+
+    return odevice->priv->input;
+}
+
+MateMixerStream *
+oss4_device_get_output_stream (Oss4Device *odevice)
+{
+    g_return_val_if_fail (OSS4_IS_DEVICE (odevice), FALSE);
+
+    return odevice->priv->output;
+}
+
+static gboolean
+read_mixer_devices (Oss4Device *device)
+{
+}
+
+static const gchar *
+oss4_device_get_name (MateMixerDevice *device)
+{
+    g_return_val_if_fail (OSS4_IS_DEVICE (device), NULL);
+
+    return OSS4_DEVICE (device)->priv->name;
+}
+
+static const gchar *
+oss4_device_get_description (MateMixerDevice *device)
+{
+    g_return_val_if_fail (OSS4_IS_DEVICE (device), NULL);
+
+    return OSS4_DEVICE (device)->priv->description;
+}
+
+static const gchar *
+oss4_device_get_icon (MateMixerDevice *device)
+{
+    g_return_val_if_fail (OSS4_IS_DEVICE (device), NULL);
+
+    return OSS4_DEVICE_ICON;
+}
diff --git a/backends/oss4/oss4-device.h b/backends/oss4/oss4-device.h
new file mode 100644
index 0000000..3ec72e7
--- /dev/null
+++ b/backends/oss4/oss4-device.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2014 Michal Ratajsky <[email protected]>
+ *
+ * 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 of the licence, or (at your option) any later version.
+ *
+ * This library 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef OSS4_DEVICE_H
+#define OSS4_DEVICE_H
+
+#include <glib.h>
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#define OSS4_TYPE_DEVICE                        \
+        (oss4_device_get_type ())
+#define OSS4_DEVICE(o)                          \
+        (G_TYPE_CHECK_INSTANCE_CAST ((o), OSS4_TYPE_DEVICE, Oss4Device))
+#define OSS4_IS_DEVICE(o)                       \
+        (G_TYPE_CHECK_INSTANCE_TYPE ((o), OSS4_TYPE_DEVICE))
+#define OSS4_DEVICE_CLASS(k)                    \
+        (G_TYPE_CHECK_CLASS_CAST ((k), OSS4_TYPE_DEVICE, Oss4DeviceClass))
+#define OSS4_IS_DEVICE_CLASS(k)                 \
+        (G_TYPE_CHECK_CLASS_TYPE ((k), OSS4_TYPE_DEVICE))
+#define OSS4_DEVICE_GET_CLASS(o)                \
+        (G_TYPE_INSTANCE_GET_CLASS ((o), OSS4_TYPE_DEVICE, Oss4DeviceClass))
+
+typedef struct _Oss4Device         Oss4Device;
+typedef struct _Oss4DeviceClass    Oss4DeviceClass;
+typedef struct _Oss4DevicePrivate  Oss4DevicePrivate;
+
+struct _Oss4Device
+{
+    GObject parent;
+
+    /*< private >*/
+    Oss4DevicePrivate *priv;
+};
+
+struct _Oss4DeviceClass
+{
+    GObjectClass parent;
+};
+
+GType            oss4_device_get_type          (void) G_GNUC_CONST;
+
+Oss4Device *     oss4_device_new (const gchar *name,
+                                  const gchar *description,
+                                  gint         fd,
+                                  gint         index);
+
+gboolean         oss4_device_read              (Oss4Device   *device);
+
+gint             oss4_device_get_index         (Oss4Device *odevice);
+
+MateMixerStream *oss4_device_get_input_stream  (Oss4Device   *odevice);
+MateMixerStream *oss4_device_get_output_stream (Oss4Device   *odevice);
+
+G_END_DECLS
+
+#endif /* OSS_DEVICE_H */
diff --git a/configure.ac b/configure.ac
index 65e06e0..b618913 100644
--- a/configure.ac
+++ b/configure.ac
@@ -155,6 +155,40 @@ AC_SUBST(HAVE_OSS)
 AC_SUBST(OSS_CFLAGS)
 AC_SUBST(OSS_LIBS)
 
+# -----------------------------------------------------------------------
+# OSS4
+# -----------------------------------------------------------------------
+AC_ARG_ENABLE([oss4],
+              AS_HELP_STRING([--enable-oss4],
+                             [Enable OSS4 backend module @<:@default=no@:>@]),
+              enable_oss4=$enableval, enable_oss4=no)
+
+if test "x$enable_oss4" != "xno"; then
+  AC_CHECK_HEADERS([soundcard.h sys/soundcard.h machine/soundcard.h])
+  if test "x$ac_cv_header_soundcard_h" = "xyes" -o \
+          "x$ac_cv_header_sys_soundcard_h" = "xyes" -o \
+          "x$ac_cv_header_machine_soundcard_h" = "xyes"; then
+    have_oss4=yes
+  else
+    have_oss4=no
+  fi
+
+  if test "x$enable_oss4" = "xyes" -a "x$have_oss4" = "xno"; then
+    AC_MSG_ERROR([OSS4 support explicitly requested but dependencies not found])
+  fi
+
+  if test "x$have_oss4" = "xyes" ; then
+    AC_DEFINE(HAVE_OSS4, [], [Define if we have OSS support])
+  fi
+else
+  have_oss4=no
+fi
+
+AM_CONDITIONAL(HAVE_OSS4, test "x$have_oss4" = "xyes")
+
+AC_SUBST(HAVE_OSS4)
+AC_SUBST(OSS4_CFLAGS)
+
 # =======================================================================
 # Compiler warnings
 # =======================================================================
@@ -207,6 +241,7 @@ libmatemixer/Makefile
 backends/Makefile
 backends/null/Makefile
 backends/oss/Makefile
+backends/oss4/Makefile
 backends/pulse/Makefile
 data/Makefile
 data/libmatemixer.pc
@@ -232,5 +267,6 @@ echo "
         Build Null module:           $have_null
         Build PulseAudio module:     $have_pulseaudio
         Build OSS module:            $have_oss
+        Build OSS4 module:           $have_oss4
 
 "
diff --git a/libmatemixer/matemixer-device.c b/libmatemixer/matemixer-device.c
index 0406709..87517d6 100644
--- a/libmatemixer/matemixer-device.c
+++ b/libmatemixer/matemixer-device.c
@@ -38,7 +38,8 @@ mate_mixer_device_default_init (MateMixerDeviceInterface *iface)
                                                               "Name",
                                                               "Name of the device",
                                                               NULL,
-                                                              G_PARAM_READABLE |
+                                                              G_PARAM_READWRITE |
+                                                              G_PARAM_CONSTRUCT_ONLY |
                                                               G_PARAM_STATIC_STRINGS));
 
     g_object_interface_install_property (iface,
@@ -46,7 +47,8 @@ mate_mixer_device_default_init (MateMixerDeviceInterface *iface)
                                                               "Description",
                                                               "Description of the device",
                                                               NULL,
-                                                              G_PARAM_READABLE |
+                                                              G_PARAM_READWRITE |
+                                                              G_PARAM_CONSTRUCT_ONLY |
                                                               G_PARAM_STATIC_STRINGS));
 
     g_object_interface_install_property (iface,
@@ -54,7 +56,8 @@ mate_mixer_device_default_init (MateMixerDeviceInterface *iface)
                                                               "Icon",
                                                               "Name of the sound device icon",
                                                               NULL,
-                                                              G_PARAM_READABLE |
+                                                              G_PARAM_READWRITE |
+                                                              G_PARAM_CONSTRUCT_ONLY |
                                                               G_PARAM_STATIC_STRINGS));
 
     g_object_interface_install_property (iface,