1 files changed, 190 insertions, 0 deletions

diff --git a/sound/core/seq/seq_system.c b/sound/core/seq/seq_system.c
new file mode 100644
index 00000000000..e8f0a6683d5
--- /dev/null
+++ b/sound/core/seq/seq_system.c
@@ -0,0 +1,190 @@
+/*
+ *   ALSA sequencer System services Client
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <sound/driver.h>
+#include <linux/init.h>
+#include <sound/core.h>
+#include "seq_system.h"
+#include "seq_timer.h"
+#include "seq_queue.h"
+
+/* internal client that provide system services, access to timer etc. */
+
+/*
+ * Port "Timer"
+ *      - send tempo /start/stop etc. events to this port to manipulate the 
+ *        queue's timer. The queue address is specified in
+ *        data.queue.queue.
+ *      - this port supports subscription. The received timer events are 
+ *        broadcasted to all subscribed clients. The modified tempo
+ *        value is stored on data.queue.value.
+ *        The modifier client/port is not send.
+ *
+ * Port "Announce"
+ *      - does not receive message
+ *      - supports supscription. For each client or port attaching to or 
+ *        detaching from the system an announcement is send to the subscribed
+ *        clients.
+ *
+ * Idea: the subscription mechanism might also work handy for distributing 
+ * synchronisation and timing information. In this case we would ideally have
+ * a list of subscribers for each type of sync (time, tick), for each timing
+ * queue.
+ *
+ * NOTE: the queue to be started, stopped, etc. must be specified
+ *       in data.queue.addr.queue field.  queue is used only for
+ *       scheduling, and no longer referred as affected queue.
+ *       They are used only for timer broadcast (see above).
+ *                                                      -- iwai
+ */
+
+
+/* client id of our system client */
+static int sysclient = -1;
+
+/* port id numbers for this client */
+static int announce_port = -1;
+
+
+
+/* fill standard header data, source port & channel are filled in */
+static int setheader(snd_seq_event_t * ev, int client, int port)
+{
+        if (announce_port < 0)
+                return -ENODEV;
+
+        memset(ev, 0, sizeof(snd_seq_event_t));
+
+        ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
+        ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
+
+        ev->source.client = sysclient;
+        ev->source.port = announce_port;
+        ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+
+        /* fill data */
+        /*ev->data.addr.queue = SNDRV_SEQ_ADDRESS_UNKNOWN;*/
+        ev->data.addr.client = client;
+        ev->data.addr.port = port;
+
+        return 0;
+}
+
+
+/* entry points for broadcasting system events */
+void snd_seq_system_broadcast(int client, int port, int type)
+{
+        snd_seq_event_t ev;
+        
+        if (setheader(&ev, client, port) < 0)
+                return;
+        ev.type = type;
+        snd_seq_kernel_client_dispatch(sysclient, &ev, 0, 0);
+}
+
+/* entry points for broadcasting system events */
+int snd_seq_system_notify(int client, int port, snd_seq_event_t *ev)
+{
+        ev->flags = SNDRV_SEQ_EVENT_LENGTH_FIXED;
+        ev->source.client = sysclient;
+        ev->source.port = announce_port;
+        ev->dest.client = client;
+        ev->dest.port = port;
+        return snd_seq_kernel_client_dispatch(sysclient, ev, 0, 0);
+}
+
+/* call-back handler for timer events */
+static int event_input_timer(snd_seq_event_t * ev, int direct, void *private_data, int atomic, int hop)
+{
+        return snd_seq_control_queue(ev, atomic, hop);
+}
+
+/* register our internal client */
+int __init snd_seq_system_client_init(void)
+{
+
+        snd_seq_client_callback_t callbacks;
+        snd_seq_port_callback_t pcallbacks;
+        snd_seq_client_info_t *inf;
+        snd_seq_port_info_t *port;
+
+        inf = kcalloc(1, sizeof(*inf), GFP_KERNEL);
+        port = kcalloc(1, sizeof(*port), GFP_KERNEL);
+        if (! inf || ! port) {
+                kfree(inf);
+                kfree(port);
+                return -ENOMEM;
+        }
+
+        memset(&callbacks, 0, sizeof(callbacks));
+        memset(&pcallbacks, 0, sizeof(pcallbacks));
+        pcallbacks.owner = THIS_MODULE;
+        pcallbacks.event_input = event_input_timer;
+
+        /* register client */
+        callbacks.allow_input = callbacks.allow_output = 1;
+        sysclient = snd_seq_create_kernel_client(NULL, 0, &callbacks);
+
+        /* set our name */
+        inf->client = 0;
+        inf->type = KERNEL_CLIENT;
+        strcpy(inf->name, "System");
+        snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, inf);
+
+        /* register timer */
+        strcpy(port->name, "Timer");
+        port->capability = SNDRV_SEQ_PORT_CAP_WRITE; /* accept queue control */
+        port->capability |= SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast */
+        port->kernel = &pcallbacks;
+        port->type = 0;
+        port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+        port->addr.client = sysclient;
+        port->addr.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
+        snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT, port);
+
+        /* register announcement port */
+        strcpy(port->name, "Announce");
+        port->capability = SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ; /* for broadcast only */
+        port->kernel = NULL;
+        port->type = 0;
+        port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
+        port->addr.client = sysclient;
+        port->addr.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
+        snd_seq_kernel_client_ctl(sysclient, SNDRV_SEQ_IOCTL_CREATE_PORT, port);
+        announce_port = port->addr.port;
+
+        kfree(inf);
+        kfree(port);
+        return 0;
+}
+
+
+/* unregister our internal client */
+void __exit snd_seq_system_client_done(void)
+{
+        int oldsysclient = sysclient;
+
+        if (oldsysclient >= 0) {
+                sysclient = -1;
+                announce_port = -1;
+                snd_seq_delete_kernel_client(oldsysclient);
+        }
+}