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 <sound/core.h>
25 #include "seq_clientmgr.h"
26 #include <sound/initval.h>
27 #include <sound/asoundef.h>
31 Sequencer MIDI-through client
33 This gives a simple midi-through client. All the normal input events
34 are redirected to output port immediately.
35 The routing can be done via aconnect program in alsa-utils.
37 Each client has a static client number 62 (= SNDRV_SEQ_CLIENT_DUMMY).
38 If you want to auto-load this module, you may add the following alias
39 in your /etc/conf.modules file.
41 alias snd-seq-client-62 snd-seq-dummy
43 The module is loaded on demand for client 62, or /proc/asound/seq/
44 is accessed. If you don't need this module to be loaded, alias
45 snd-seq-client-62 as "off". This will help modprobe.
47 The number of ports to be created can be specified via the module
48 parameter "ports". For example, to create four ports, add the
49 following option in /etc/modprobe.conf:
51 option snd-seq-dummy ports=4
53 The modle option "duplex=1" enables duplex operation to the port.
54 In duplex mode, a pair of ports are created instead of single port,
55 and events are tunneled between pair-ports. For example, input to
56 port A is sent to output port of another port B and vice versa.
57 In duplex mode, each port has DUPLEX capability.
62 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
63 MODULE_DESCRIPTION("ALSA sequencer MIDI-through client");
64 MODULE_LICENSE("GPL");
65 MODULE_CLASSES("{sound}");
66 MODULE_SUPPORTED_DEVICE("sound");
67 MODULE_PARM(ports, "i");
68 MODULE_PARM_DESC(ports, "number of ports to be created");
69 MODULE_PARM(duplex, "i");
70 MODULE_PARM_DESC(duplex, "create DUPLEX ports");
74 typedef struct snd_seq_dummy_port {
79 } snd_seq_dummy_port_t;
81 static int my_client = -1;
84 * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events
86 * Note: this callback is called only after all subscribers are removed.
89 dummy_unuse(void *private_data, snd_seq_port_subscribe_t *info)
91 snd_seq_dummy_port_t *p;
95 p = snd_magic_cast(snd_seq_dummy_port_t, private_data, return -EINVAL);
96 memset(&ev, 0, sizeof(ev));
98 ev.source.port = p->connect;
100 ev.source.port = p->port;
101 ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
102 ev.type = SNDRV_SEQ_EVENT_CONTROLLER;
103 for (i = 0; i < 16; i++) {
104 ev.data.control.channel = i;
105 ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF;
106 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
107 ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS;
108 snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0);
114 * event input callback - just redirect events to subscribers
117 dummy_input(snd_seq_event_t *ev, int direct, void *private_data, int atomic, int hop)
119 snd_seq_dummy_port_t *p;
120 snd_seq_event_t tmpev;
122 p = snd_magic_cast(snd_seq_dummy_port_t, private_data, return -EINVAL);
123 if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM ||
124 ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
125 return 0; /* ignore system messages */
126 /* save the original sender */
127 tmpev.type = SNDRV_SEQ_EVENT_KERNEL_QUOTE;
128 tmpev.flags = (ev->flags & ~SNDRV_SEQ_EVENT_LENGTH_MASK)
129 | SNDRV_SEQ_EVENT_LENGTH_FIXED;
131 tmpev.time = ev->time;
132 tmpev.data.quote.origin = ev->source;
133 tmpev.data.quote.event = ev;
135 tmpev.source.port = p->connect;
137 tmpev.source.port = p->port;
138 tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
139 return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop);
143 * free_private callback
146 dummy_free(void *private_data)
148 snd_seq_dummy_port_t *p;
150 p = snd_magic_cast(snd_seq_dummy_port_t, private_data, return);
157 static snd_seq_dummy_port_t __init *
158 create_port(int idx, int type)
160 snd_seq_port_info_t pinfo;
161 snd_seq_port_callback_t pcb;
162 snd_seq_dummy_port_t *rec;
164 if ((rec = snd_magic_kcalloc(snd_seq_dummy_port_t, 0, GFP_KERNEL)) == NULL)
167 rec->client = my_client;
168 rec->duplex = duplex;
170 memset(&pinfo, 0, sizeof(pinfo));
171 pinfo.addr.client = my_client;
173 sprintf(pinfo.name, "Midi Through Port-%d:%c", idx,
176 sprintf(pinfo.name, "Midi Through Port-%d", idx);
177 pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
178 pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
180 pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
181 pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC;
182 memset(&pcb, 0, sizeof(pcb));
183 pcb.owner = THIS_MODULE;
184 pcb.unuse = dummy_unuse;
185 pcb.event_input = dummy_input;
186 pcb.private_free = dummy_free;
187 pcb.private_data = rec;
189 if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) {
190 snd_magic_kfree(rec);
193 rec->port = pinfo.addr.port;
198 * register client and create ports
201 register_client(void)
203 snd_seq_client_callback_t cb;
204 snd_seq_client_info_t cinfo;
205 snd_seq_dummy_port_t *rec1, *rec2;
209 snd_printk(KERN_ERR "invalid number of ports %d\n", ports);
214 memset(&cb, 0, sizeof(cb));
217 my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY, &cb);
221 /* set client name */
222 memset(&cinfo, 0, sizeof(cinfo));
223 cinfo.client = my_client;
224 cinfo.type = KERNEL_CLIENT;
225 strcpy(cinfo.name, "Midi Through");
226 snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, &cinfo);
229 for (i = 0; i < ports; i++) {
230 rec1 = create_port(i, 0);
232 snd_seq_delete_kernel_client(my_client);
236 rec2 = create_port(i, 1);
238 snd_seq_delete_kernel_client(my_client);
241 rec1->connect = rec2->port;
242 rec2->connect = rec1->port;
250 * delete client if exists
256 snd_seq_delete_kernel_client(my_client);
263 static int __init alsa_seq_dummy_init(void)
265 return register_client();
268 static void __exit alsa_seq_dummy_exit(void)
273 module_init(alsa_seq_dummy_init)
274 module_exit(alsa_seq_dummy_exit)