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_CLASSES("{sound}");
67 MODULE_SUPPORTED_DEVICE("sound");
70 static int duplex = 0;
72 module_param(ports, int, 0444);
73 MODULE_PARM_DESC(ports, "number of ports to be created");
74 module_param(duplex, bool, 0444);
75 MODULE_PARM_DESC(duplex, "create DUPLEX ports");
77 typedef struct snd_seq_dummy_port {
82 } snd_seq_dummy_port_t;
84 static int my_client = -1;
87 * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events
89 * Note: this callback is called only after all subscribers are removed.
92 dummy_unuse(void *private_data, snd_seq_port_subscribe_t *info)
94 snd_seq_dummy_port_t *p;
98 p = snd_magic_cast(snd_seq_dummy_port_t, private_data, return -EINVAL);
99 memset(&ev, 0, sizeof(ev));
101 ev.source.port = p->connect;
103 ev.source.port = p->port;
104 ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
105 ev.type = SNDRV_SEQ_EVENT_CONTROLLER;
106 for (i = 0; i < 16; i++) {
107 ev.data.control.channel = i;
108 ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF;
109 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
110 ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS;
111 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
117 * event input callback - just redirect events to subscribers
120 dummy_input(snd_seq_event_t *ev, int direct, void *private_data, int atomic, int hop)
122 snd_seq_dummy_port_t *p;
123 snd_seq_event_t tmpev;
125 p = snd_magic_cast(snd_seq_dummy_port_t, private_data, return -EINVAL);
126 if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM ||
127 ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
128 return 0; /* ignore system messages */
129 /* save the original sender */
130 tmpev.type = SNDRV_SEQ_EVENT_KERNEL_QUOTE;
131 tmpev.flags = (ev->flags & ~SNDRV_SEQ_EVENT_LENGTH_MASK)
132 | SNDRV_SEQ_EVENT_LENGTH_FIXED;
134 tmpev.time = ev->time;
135 tmpev.data.quote.origin = ev->source;
136 tmpev.data.quote.event = ev;
138 tmpev.source.port = p->connect;
140 tmpev.source.port = p->port;
141 tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
142 return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop);
146 * free_private callback
149 dummy_free(void *private_data)
151 snd_seq_dummy_port_t *p;
153 p = snd_magic_cast(snd_seq_dummy_port_t, private_data, return);
160 static snd_seq_dummy_port_t __init *
161 create_port(int idx, int type)
163 snd_seq_port_info_t pinfo;
164 snd_seq_port_callback_t pcb;
165 snd_seq_dummy_port_t *rec;
167 if ((rec = snd_magic_kcalloc(snd_seq_dummy_port_t, 0, GFP_KERNEL)) == NULL)
170 rec->client = my_client;
171 rec->duplex = duplex;
173 memset(&pinfo, 0, sizeof(pinfo));
174 pinfo.addr.client = my_client;
176 sprintf(pinfo.name, "Midi Through Port-%d:%c", idx,
179 sprintf(pinfo.name, "Midi Through Port-%d", idx);
180 pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
181 pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
183 pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
184 pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC;
185 memset(&pcb, 0, sizeof(pcb));
186 pcb.owner = THIS_MODULE;
187 pcb.unuse = dummy_unuse;
188 pcb.event_input = dummy_input;
189 pcb.private_free = dummy_free;
190 pcb.private_data = rec;
192 if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) {
193 snd_magic_kfree(rec);
196 rec->port = pinfo.addr.port;
201 * register client and create ports
204 register_client(void)
206 snd_seq_client_callback_t cb;
207 snd_seq_client_info_t cinfo;
208 snd_seq_dummy_port_t *rec1, *rec2;
212 snd_printk(KERN_ERR "invalid number of ports %d\n", ports);
217 memset(&cb, 0, sizeof(cb));
220 my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY, &cb);
224 /* set client name */
225 memset(&cinfo, 0, sizeof(cinfo));
226 cinfo.client = my_client;
227 cinfo.type = KERNEL_CLIENT;
228 strcpy(cinfo.name, "Midi Through");
229 snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, &cinfo);
232 for (i = 0; i < ports; i++) {
233 rec1 = create_port(i, 0);
235 snd_seq_delete_kernel_client(my_client);
239 rec2 = create_port(i, 1);
241 snd_seq_delete_kernel_client(my_client);
244 rec1->connect = rec2->port;
245 rec2->connect = rec1->port;
253 * delete client if exists
259 snd_seq_delete_kernel_client(my_client);
266 static int __init alsa_seq_dummy_init(void)
268 return register_client();
271 static void __exit alsa_seq_dummy_exit(void)
276 module_init(alsa_seq_dummy_init)
277 module_exit(alsa_seq_dummy_exit)