1 files changed, 273 insertions, 0 deletions
diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c
new file mode 100644
index 000000000000..e88967c5b93d
--- /dev/null
+++ b/sound/core/seq/seq_dummy.c
@@ -0,0 +1,273 @@
+/*
+ * ALSA sequencer MIDI-through client
+ * Copyright (c) 1999-2000 by Takashi Iwai <tiwai@suse.de>
+ *
+ *   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 <linux/slab.h>
+#include <linux/moduleparam.h>
+#include <sound/core.h>
+#include "seq_clientmgr.h"
+#include <sound/initval.h>
+#include <sound/asoundef.h>
+
+/*
+
+  Sequencer MIDI-through client
+
+  This gives a simple midi-through client.  All the normal input events
+  are redirected to output port immediately.
+  The routing can be done via aconnect program in alsa-utils.
+
+  Each client has a static client number 62 (= SNDRV_SEQ_CLIENT_DUMMY).
+  If you want to auto-load this module, you may add the following alias
+  in your /etc/conf.modules file.
+
+	alias snd-seq-client-62  snd-seq-dummy
+
+  The module is loaded on demand for client 62, or /proc/asound/seq/
+  is accessed.  If you don't need this module to be loaded, alias
+  snd-seq-client-62 as "off".  This will help modprobe.
+
+  The number of ports to be created can be specified via the module
+  parameter "ports".  For example, to create four ports, add the
+  following option in /etc/modprobe.conf:
+
+	option snd-seq-dummy ports=4
+
+  The modle option "duplex=1" enables duplex operation to the port.
+  In duplex mode, a pair of ports are created instead of single port,
+  and events are tunneled between pair-ports.  For example, input to
+  port A is sent to output port of another port B and vice versa.
+  In duplex mode, each port has DUPLEX capability.
+
+ */
+
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("ALSA sequencer MIDI-through client");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("snd-seq-client-" __stringify(SNDRV_SEQ_CLIENT_DUMMY));
+
+static int ports = 1;
+static int duplex = 0;
+
+module_param(ports, int, 0444);
+MODULE_PARM_DESC(ports, "number of ports to be created");
+module_param(duplex, bool, 0444);
+MODULE_PARM_DESC(duplex, "create DUPLEX ports");
+
+typedef struct snd_seq_dummy_port {
+	int client;
+	int port;
+	int duplex;
+	int connect;
+} snd_seq_dummy_port_t;
+
+static int my_client = -1;
+
+/*
+ * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events
+ * to subscribers.
+ * Note: this callback is called only after all subscribers are removed.
+ */
+static int
+dummy_unuse(void *private_data, snd_seq_port_subscribe_t *info)
+{
+	snd_seq_dummy_port_t *p;
+	int i;
+	snd_seq_event_t ev;
+
+	p = private_data;
+	memset(&ev, 0, sizeof(ev));
+	if (p->duplex)
+		ev.source.port = p->connect;
+	else
+		ev.source.port = p->port;
+	ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+	ev.type = SNDRV_SEQ_EVENT_CONTROLLER;
+	for (i = 0; i < 16; i++) {
+		ev.data.control.channel = i;
+		ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF;
+		snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
+		ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS;
+		snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
+	}
+	return 0;
+}
+
+/*
+ * event input callback - just redirect events to subscribers
+ */
+static int
+dummy_input(snd_seq_event_t *ev, int direct, void *private_data, int atomic, int hop)
+{
+	snd_seq_dummy_port_t *p;
+	snd_seq_event_t tmpev;
+
+	p = private_data;
+	if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM ||
+	    ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
+		return 0; /* ignore system messages */
+	tmpev = *ev;
+	if (p->duplex)
+		tmpev.source.port = p->connect;
+	else
+		tmpev.source.port = p->port;
+	tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
+	return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop);
+}
+
+/*
+ * free_private callback
+ */
+static void
+dummy_free(void *private_data)
+{
+	snd_seq_dummy_port_t *p;
+
+	p = private_data;
+	kfree(p);
+}
+
+/*
+ * create a port
+ */
+static snd_seq_dummy_port_t __init *
+create_port(int idx, int type)
+{
+	snd_seq_port_info_t pinfo;
+	snd_seq_port_callback_t pcb;
+	snd_seq_dummy_port_t *rec;
+
+	if ((rec = kcalloc(1, sizeof(*rec), GFP_KERNEL)) == NULL)
+		return NULL;
+
+	rec->client = my_client;
+	rec->duplex = duplex;
+	rec->connect = 0;
+	memset(&pinfo, 0, sizeof(pinfo));
+	pinfo.addr.client = my_client;
+	if (duplex)
+		sprintf(pinfo.name, "Midi Through Port-%d:%c", idx,
+			(type ? 'B' : 'A'));
+	else
+		sprintf(pinfo.name, "Midi Through Port-%d", idx);
+	pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
+	pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
+	if (duplex)
+		pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
+	pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC;
+	memset(&pcb, 0, sizeof(pcb));
+	pcb.owner = THIS_MODULE;
+	pcb.unuse = dummy_unuse;
+	pcb.event_input = dummy_input;
+	pcb.private_free = dummy_free;
+	pcb.private_data = rec;
+	pinfo.kernel = &pcb;
+	if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) {
+		kfree(rec);
+		return NULL;
+	}
+	rec->port = pinfo.addr.port;
+	return rec;
+}
+
+/*
+ * register client and create ports
+ */
+static int __init
+register_client(void)
+{
+	snd_seq_client_callback_t cb;
+	snd_seq_client_info_t cinfo;
+	snd_seq_dummy_port_t *rec1, *rec2;
+	int i;
+
+	if (ports < 1) {
+		snd_printk(KERN_ERR "invalid number of ports %d\n", ports);
+		return -EINVAL;
+	}
+
+	/* create client */
+	memset(&cb, 0, sizeof(cb));
+	cb.allow_input = 1;
+	cb.allow_output = 1;
+	my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY, &cb);
+	if (my_client < 0)
+		return my_client;
+
+	/* set client name */
+	memset(&cinfo, 0, sizeof(cinfo));
+	cinfo.client = my_client;
+	cinfo.type = KERNEL_CLIENT;
+	strcpy(cinfo.name, "Midi Through");
+	snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, &cinfo);
+
+	/* create ports */
+	for (i = 0; i < ports; i++) {
+		rec1 = create_port(i, 0);
+		if (rec1 == NULL) {
+			snd_seq_delete_kernel_client(my_client);
+			return -ENOMEM;
+		}
+		if (duplex) {
+			rec2 = create_port(i, 1);
+			if (rec2 == NULL) {
+				snd_seq_delete_kernel_client(my_client);
+				return -ENOMEM;
+			}
+			rec1->connect = rec2->port;
+			rec2->connect = rec1->port;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * delete client if exists
+ */
+static void __exit
+delete_client(void)
+{
+	if (my_client >= 0)
+		snd_seq_delete_kernel_client(my_client);
+}
+
+/*
+ *  Init part
+ */
+
+static int __init alsa_seq_dummy_init(void)
+{
+	int err;
+	snd_seq_autoload_lock();
+	err = register_client();
+	snd_seq_autoload_unlock();
+	return err;
+}
+
+static void __exit alsa_seq_dummy_exit(void)
+{
+	delete_client();
+}
+
+module_init(alsa_seq_dummy_init)
+module_exit(alsa_seq_dummy_exit)