2 * ALSA sequencer MIDI-through client
3 * Copyright (c) 1999-2000 by Takashi Iwai <tiwai@suse.de>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <sound/driver.h>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/moduleparam.h>
25 #include <sound/core.h>
26 #include "seq_clientmgr.h"
27 #include <sound/initval.h>
28 #include <sound/asoundef.h>
32 Sequencer MIDI-through client
34 This gives a simple midi-through client. All the normal input events
35 are redirected to output port immediately.
36 The routing can be done via aconnect program in alsa-utils.
38 Each client has a static client number 62 (= SNDRV_SEQ_CLIENT_DUMMY).
39 If you want to auto-load this module, you may add the following alias
40 in your /etc/conf.modules file.
42 alias snd-seq-client-62 snd-seq-dummy
44 The module is loaded on demand for client 62, or /proc/asound/seq/
45 is accessed. If you don't need this module to be loaded, alias
46 snd-seq-client-62 as "off". This will help modprobe.
48 The number of ports to be created can be specified via the module
49 parameter "ports". For example, to create four ports, add the
50 following option in /etc/modprobe.conf:
52 option snd-seq-dummy ports=4
54 The modle option "duplex=1" enables duplex operation to the port.
55 In duplex mode, a pair of ports are created instead of single port,
56 and events are tunneled between pair-ports. For example, input to
57 port A is sent to output port of another port B and vice versa.
58 In duplex mode, each port has DUPLEX capability.
63 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
64 MODULE_DESCRIPTION("ALSA sequencer MIDI-through client");
65 MODULE_LICENSE("GPL");
66 MODULE_ALIAS("snd-seq-client-" __stringify(SNDRV_SEQ_CLIENT_DUMMY));
69 static int duplex = 0;
71 module_param(ports, int, 0444);
72 MODULE_PARM_DESC(ports, "number of ports to be created");
73 module_param(duplex, bool, 0444);
74 MODULE_PARM_DESC(duplex, "create DUPLEX ports");
76 struct snd_seq_dummy_port {
83 static int my_client = -1;
86 * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events
88 * Note: this callback is called only after all subscribers are removed.
91 dummy_unuse(void *private_data, struct snd_seq_port_subscribe *info)
93 struct snd_seq_dummy_port *p;
95 struct snd_seq_event ev;
98 memset(&ev, 0, sizeof(ev));
100 ev.source.port = p->connect;
102 ev.source.port = p->port;
103 ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
104 ev.type = SNDRV_SEQ_EVENT_CONTROLLER;
105 for (i = 0; i < 16; i++) {
106 ev.data.control.channel = i;
107 ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF;
108 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
109 ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS;
110 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
116 * event input callback - just redirect events to subscribers
119 dummy_input(struct snd_seq_event *ev, int direct, void *private_data,
122 struct snd_seq_dummy_port *p;
123 struct snd_seq_event tmpev;
126 if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM ||
127 ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
128 return 0; /* ignore system messages */
131 tmpev.source.port = p->connect;
133 tmpev.source.port = p->port;
134 tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
135 return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop);
139 * free_private callback
142 dummy_free(void *private_data)
150 static struct snd_seq_dummy_port __init *
151 create_port(int idx, int type)
153 struct snd_seq_port_info pinfo;
154 struct snd_seq_port_callback pcb;
155 struct snd_seq_dummy_port *rec;
157 if ((rec = kzalloc(sizeof(*rec), GFP_KERNEL)) == NULL)
160 rec->client = my_client;
161 rec->duplex = duplex;
163 memset(&pinfo, 0, sizeof(pinfo));
164 pinfo.addr.client = my_client;
166 sprintf(pinfo.name, "Midi Through Port-%d:%c", idx,
169 sprintf(pinfo.name, "Midi Through Port-%d", idx);
170 pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
171 pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
173 pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
174 pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC;
175 memset(&pcb, 0, sizeof(pcb));
176 pcb.owner = THIS_MODULE;
177 pcb.unuse = dummy_unuse;
178 pcb.event_input = dummy_input;
179 pcb.private_free = dummy_free;
180 pcb.private_data = rec;
182 if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) {
186 rec->port = pinfo.addr.port;
191 * register client and create ports
194 register_client(void)
196 struct snd_seq_client_info cinfo;
197 struct snd_seq_dummy_port *rec1, *rec2;
201 snd_printk(KERN_ERR "invalid number of ports %d\n", ports);
206 my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY);
210 /* set client name */
211 memset(&cinfo, 0, sizeof(cinfo));
212 cinfo.client = my_client;
213 cinfo.type = KERNEL_CLIENT;
214 strcpy(cinfo.name, "Midi Through");
215 snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, &cinfo);
218 for (i = 0; i < ports; i++) {
219 rec1 = create_port(i, 0);
221 snd_seq_delete_kernel_client(my_client);
225 rec2 = create_port(i, 1);
227 snd_seq_delete_kernel_client(my_client);
230 rec1->connect = rec2->port;
231 rec2->connect = rec1->port;
239 * delete client if exists
245 snd_seq_delete_kernel_client(my_client);
252 static int __init alsa_seq_dummy_init(void)
255 snd_seq_autoload_lock();
256 err = register_client();
257 snd_seq_autoload_unlock();
261 static void __exit alsa_seq_dummy_exit(void)
266 module_init(alsa_seq_dummy_init)
267 module_exit(alsa_seq_dummy_exit)