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");
68 static int duplex = 0;
70 module_param(ports, int, 0444);
71 MODULE_PARM_DESC(ports, "number of ports to be created");
72 module_param(duplex, bool, 0444);
73 MODULE_PARM_DESC(duplex, "create DUPLEX ports");
75 typedef struct snd_seq_dummy_port {
80 } snd_seq_dummy_port_t;
82 static int my_client = -1;
85 * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events
87 * Note: this callback is called only after all subscribers are removed.
90 dummy_unuse(void *private_data, snd_seq_port_subscribe_t *info)
92 snd_seq_dummy_port_t *p;
97 memset(&ev, 0, sizeof(ev));
99 ev.source.port = p->connect;
101 ev.source.port = p->port;
102 ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
103 ev.type = SNDRV_SEQ_EVENT_CONTROLLER;
104 for (i = 0; i < 16; i++) {
105 ev.data.control.channel = i;
106 ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF;
107 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
108 ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS;
109 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
115 * event input callback - just redirect events to subscribers
118 dummy_input(snd_seq_event_t *ev, int direct, void *private_data, int atomic, int hop)
120 snd_seq_dummy_port_t *p;
121 snd_seq_event_t tmpev;
124 if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM ||
125 ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
126 return 0; /* ignore system messages */
129 tmpev.source.port = p->connect;
131 tmpev.source.port = p->port;
132 tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
133 return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop);
137 * free_private callback
140 dummy_free(void *private_data)
142 snd_seq_dummy_port_t *p;
151 static snd_seq_dummy_port_t __init *
152 create_port(int idx, int type)
154 snd_seq_port_info_t pinfo;
155 snd_seq_port_callback_t pcb;
156 snd_seq_dummy_port_t *rec;
158 if ((rec = kcalloc(1, sizeof(*rec), GFP_KERNEL)) == NULL)
161 rec->client = my_client;
162 rec->duplex = duplex;
164 memset(&pinfo, 0, sizeof(pinfo));
165 pinfo.addr.client = my_client;
167 sprintf(pinfo.name, "Midi Through Port-%d:%c", idx,
170 sprintf(pinfo.name, "Midi Through Port-%d", idx);
171 pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
172 pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
174 pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
175 pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC;
176 memset(&pcb, 0, sizeof(pcb));
177 pcb.owner = THIS_MODULE;
178 pcb.unuse = dummy_unuse;
179 pcb.event_input = dummy_input;
180 pcb.private_free = dummy_free;
181 pcb.private_data = rec;
183 if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) {
187 rec->port = pinfo.addr.port;
192 * register client and create ports
195 register_client(void)
197 snd_seq_client_callback_t cb;
198 snd_seq_client_info_t cinfo;
199 snd_seq_dummy_port_t *rec1, *rec2;
203 snd_printk(KERN_ERR "invalid number of ports %d\n", ports);
208 memset(&cb, 0, sizeof(cb));
211 my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY, &cb);
215 /* set client name */
216 memset(&cinfo, 0, sizeof(cinfo));
217 cinfo.client = my_client;
218 cinfo.type = KERNEL_CLIENT;
219 strcpy(cinfo.name, "Midi Through");
220 snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, &cinfo);
223 for (i = 0; i < ports; i++) {
224 rec1 = create_port(i, 0);
226 snd_seq_delete_kernel_client(my_client);
230 rec2 = create_port(i, 1);
232 snd_seq_delete_kernel_client(my_client);
235 rec1->connect = rec2->port;
236 rec2->connect = rec1->port;
244 * delete client if exists
250 snd_seq_delete_kernel_client(my_client);
257 static int __init alsa_seq_dummy_init(void)
259 return register_client();
262 static void __exit alsa_seq_dummy_exit(void)
267 module_init(alsa_seq_dummy_init)
268 module_exit(alsa_seq_dummy_exit)