11a59d1b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
21da177e4SLinus Torvalds /*
31da177e4SLinus Torvalds * ALSA sequencer MIDI-through client
41da177e4SLinus Torvalds * Copyright (c) 1999-2000 by Takashi Iwai <tiwai@suse.de>
51da177e4SLinus Torvalds */
61da177e4SLinus Torvalds
71da177e4SLinus Torvalds #include <linux/init.h>
81da177e4SLinus Torvalds #include <linux/slab.h>
965a77217SPaul Gortmaker #include <linux/module.h>
101da177e4SLinus Torvalds #include <sound/core.h>
111da177e4SLinus Torvalds #include "seq_clientmgr.h"
121da177e4SLinus Torvalds #include <sound/initval.h>
131da177e4SLinus Torvalds #include <sound/asoundef.h>
141da177e4SLinus Torvalds
151da177e4SLinus Torvalds /*
161da177e4SLinus Torvalds
171da177e4SLinus Torvalds Sequencer MIDI-through client
181da177e4SLinus Torvalds
191da177e4SLinus Torvalds This gives a simple midi-through client. All the normal input events
201da177e4SLinus Torvalds are redirected to output port immediately.
211da177e4SLinus Torvalds The routing can be done via aconnect program in alsa-utils.
221da177e4SLinus Torvalds
23c5aa8277STakashi Iwai Each client has a static client number 14 (= SNDRV_SEQ_CLIENT_DUMMY).
241da177e4SLinus Torvalds If you want to auto-load this module, you may add the following alias
251da177e4SLinus Torvalds in your /etc/conf.modules file.
261da177e4SLinus Torvalds
27c5aa8277STakashi Iwai alias snd-seq-client-14 snd-seq-dummy
281da177e4SLinus Torvalds
29c5aa8277STakashi Iwai The module is loaded on demand for client 14, or /proc/asound/seq/
301da177e4SLinus Torvalds is accessed. If you don't need this module to be loaded, alias
31c5aa8277STakashi Iwai snd-seq-client-14 as "off". This will help modprobe.
321da177e4SLinus Torvalds
331da177e4SLinus Torvalds The number of ports to be created can be specified via the module
341da177e4SLinus Torvalds parameter "ports". For example, to create four ports, add the
35970e2486SLucas De Marchi following option in a configuration file under /etc/modprobe.d/:
361da177e4SLinus Torvalds
371da177e4SLinus Torvalds option snd-seq-dummy ports=4
381da177e4SLinus Torvalds
3925985edcSLucas De Marchi The model option "duplex=1" enables duplex operation to the port.
401da177e4SLinus Torvalds In duplex mode, a pair of ports are created instead of single port,
411da177e4SLinus Torvalds and events are tunneled between pair-ports. For example, input to
421da177e4SLinus Torvalds port A is sent to output port of another port B and vice versa.
431da177e4SLinus Torvalds In duplex mode, each port has DUPLEX capability.
441da177e4SLinus Torvalds
451da177e4SLinus Torvalds */
461da177e4SLinus Torvalds
471da177e4SLinus Torvalds
481da177e4SLinus Torvalds MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
491da177e4SLinus Torvalds MODULE_DESCRIPTION("ALSA sequencer MIDI-through client");
501da177e4SLinus Torvalds MODULE_LICENSE("GPL");
511da177e4SLinus Torvalds MODULE_ALIAS("snd-seq-client-" __stringify(SNDRV_SEQ_CLIENT_DUMMY));
521da177e4SLinus Torvalds
531da177e4SLinus Torvalds static int ports = 1;
54a67ff6a5SRusty Russell static bool duplex;
551da177e4SLinus Torvalds
561da177e4SLinus Torvalds module_param(ports, int, 0444);
571da177e4SLinus Torvalds MODULE_PARM_DESC(ports, "number of ports to be created");
581da177e4SLinus Torvalds module_param(duplex, bool, 0444);
591da177e4SLinus Torvalds MODULE_PARM_DESC(duplex, "create DUPLEX ports");
601da177e4SLinus Torvalds
61*32cb23a0STakashi Iwai #if IS_ENABLED(CONFIG_SND_SEQ_UMP)
62*32cb23a0STakashi Iwai static int ump;
63*32cb23a0STakashi Iwai module_param(ump, int, 0444);
64*32cb23a0STakashi Iwai MODULE_PARM_DESC(ump, "UMP conversion (0: no convert, 1: MIDI 1.0, 2: MIDI 2.0)");
65*32cb23a0STakashi Iwai #endif
66*32cb23a0STakashi Iwai
67c7e0b5bfSTakashi Iwai struct snd_seq_dummy_port {
681da177e4SLinus Torvalds int client;
691da177e4SLinus Torvalds int port;
701da177e4SLinus Torvalds int duplex;
711da177e4SLinus Torvalds int connect;
72c7e0b5bfSTakashi Iwai };
731da177e4SLinus Torvalds
741da177e4SLinus Torvalds static int my_client = -1;
751da177e4SLinus Torvalds
761da177e4SLinus Torvalds /*
771da177e4SLinus Torvalds * event input callback - just redirect events to subscribers
781da177e4SLinus Torvalds */
791da177e4SLinus Torvalds static int
dummy_input(struct snd_seq_event * ev,int direct,void * private_data,int atomic,int hop)80c7e0b5bfSTakashi Iwai dummy_input(struct snd_seq_event *ev, int direct, void *private_data,
81c7e0b5bfSTakashi Iwai int atomic, int hop)
821da177e4SLinus Torvalds {
83c7e0b5bfSTakashi Iwai struct snd_seq_dummy_port *p;
84c7e0b5bfSTakashi Iwai struct snd_seq_event tmpev;
851da177e4SLinus Torvalds
861da177e4SLinus Torvalds p = private_data;
871da177e4SLinus Torvalds if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM ||
881da177e4SLinus Torvalds ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR)
891da177e4SLinus Torvalds return 0; /* ignore system messages */
901da177e4SLinus Torvalds tmpev = *ev;
911da177e4SLinus Torvalds if (p->duplex)
921da177e4SLinus Torvalds tmpev.source.port = p->connect;
931da177e4SLinus Torvalds else
941da177e4SLinus Torvalds tmpev.source.port = p->port;
951da177e4SLinus Torvalds tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
961da177e4SLinus Torvalds return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop);
971da177e4SLinus Torvalds }
981da177e4SLinus Torvalds
991da177e4SLinus Torvalds /*
1001da177e4SLinus Torvalds * free_private callback
1011da177e4SLinus Torvalds */
1021da177e4SLinus Torvalds static void
dummy_free(void * private_data)1031da177e4SLinus Torvalds dummy_free(void *private_data)
1041da177e4SLinus Torvalds {
1054d572776SJesper Juhl kfree(private_data);
1061da177e4SLinus Torvalds }
1071da177e4SLinus Torvalds
1081da177e4SLinus Torvalds /*
1091da177e4SLinus Torvalds * create a port
1101da177e4SLinus Torvalds */
111c7e0b5bfSTakashi Iwai static struct snd_seq_dummy_port __init *
create_port(int idx,int type)1121da177e4SLinus Torvalds create_port(int idx, int type)
1131da177e4SLinus Torvalds {
114c7e0b5bfSTakashi Iwai struct snd_seq_port_info pinfo;
115c7e0b5bfSTakashi Iwai struct snd_seq_port_callback pcb;
116c7e0b5bfSTakashi Iwai struct snd_seq_dummy_port *rec;
1171da177e4SLinus Torvalds
118f9a6bb84STakashi Iwai rec = kzalloc(sizeof(*rec), GFP_KERNEL);
119f9a6bb84STakashi Iwai if (!rec)
1201da177e4SLinus Torvalds return NULL;
1211da177e4SLinus Torvalds
1221da177e4SLinus Torvalds rec->client = my_client;
1231da177e4SLinus Torvalds rec->duplex = duplex;
1241da177e4SLinus Torvalds rec->connect = 0;
1251da177e4SLinus Torvalds memset(&pinfo, 0, sizeof(pinfo));
1261da177e4SLinus Torvalds pinfo.addr.client = my_client;
1271da177e4SLinus Torvalds if (duplex)
1281da177e4SLinus Torvalds sprintf(pinfo.name, "Midi Through Port-%d:%c", idx,
1291da177e4SLinus Torvalds (type ? 'B' : 'A'));
1301da177e4SLinus Torvalds else
1311da177e4SLinus Torvalds sprintf(pinfo.name, "Midi Through Port-%d", idx);
1321da177e4SLinus Torvalds pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
1331da177e4SLinus Torvalds pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
1341da177e4SLinus Torvalds if (duplex)
1351da177e4SLinus Torvalds pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
136ff166a9dSTakashi Iwai pinfo.direction = SNDRV_SEQ_PORT_DIR_BIDIRECTION;
137450047a7SClemens Ladisch pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
138450047a7SClemens Ladisch | SNDRV_SEQ_PORT_TYPE_SOFTWARE
139450047a7SClemens Ladisch | SNDRV_SEQ_PORT_TYPE_PORT;
1401da177e4SLinus Torvalds memset(&pcb, 0, sizeof(pcb));
1411da177e4SLinus Torvalds pcb.owner = THIS_MODULE;
1421da177e4SLinus Torvalds pcb.event_input = dummy_input;
1431da177e4SLinus Torvalds pcb.private_free = dummy_free;
1441da177e4SLinus Torvalds pcb.private_data = rec;
1451da177e4SLinus Torvalds pinfo.kernel = &pcb;
1461da177e4SLinus Torvalds if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) {
1471da177e4SLinus Torvalds kfree(rec);
1481da177e4SLinus Torvalds return NULL;
1491da177e4SLinus Torvalds }
1501da177e4SLinus Torvalds rec->port = pinfo.addr.port;
1511da177e4SLinus Torvalds return rec;
1521da177e4SLinus Torvalds }
1531da177e4SLinus Torvalds
1541da177e4SLinus Torvalds /*
1551da177e4SLinus Torvalds * register client and create ports
1561da177e4SLinus Torvalds */
1571da177e4SLinus Torvalds static int __init
register_client(void)1581da177e4SLinus Torvalds register_client(void)
1591da177e4SLinus Torvalds {
160c7e0b5bfSTakashi Iwai struct snd_seq_dummy_port *rec1, *rec2;
161*32cb23a0STakashi Iwai #if IS_ENABLED(CONFIG_SND_SEQ_UMP)
162329ffe11STakashi Iwai struct snd_seq_client *client;
163*32cb23a0STakashi Iwai #endif
1641da177e4SLinus Torvalds int i;
1651da177e4SLinus Torvalds
1661da177e4SLinus Torvalds if (ports < 1) {
16704cc79a0STakashi Iwai pr_err("ALSA: seq_dummy: invalid number of ports %d\n", ports);
1681da177e4SLinus Torvalds return -EINVAL;
1691da177e4SLinus Torvalds }
1701da177e4SLinus Torvalds
1711da177e4SLinus Torvalds /* create client */
1727b6d9245SClemens Ladisch my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY,
1737b6d9245SClemens Ladisch "Midi Through");
1741da177e4SLinus Torvalds if (my_client < 0)
1751da177e4SLinus Torvalds return my_client;
1761da177e4SLinus Torvalds
177*32cb23a0STakashi Iwai #if IS_ENABLED(CONFIG_SND_SEQ_UMP)
178329ffe11STakashi Iwai client = snd_seq_kernel_client_get(my_client);
179329ffe11STakashi Iwai if (!client)
180329ffe11STakashi Iwai return -EINVAL;
181*32cb23a0STakashi Iwai switch (ump) {
182*32cb23a0STakashi Iwai case 1:
183*32cb23a0STakashi Iwai client->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_1_0;
184*32cb23a0STakashi Iwai break;
185*32cb23a0STakashi Iwai case 2:
186*32cb23a0STakashi Iwai client->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_2_0;
187*32cb23a0STakashi Iwai break;
188*32cb23a0STakashi Iwai default:
189*32cb23a0STakashi Iwai /* don't convert events but just pass-through */
190329ffe11STakashi Iwai client->filter = SNDRV_SEQ_FILTER_NO_CONVERT;
191*32cb23a0STakashi Iwai break;
192*32cb23a0STakashi Iwai }
193329ffe11STakashi Iwai snd_seq_kernel_client_put(client);
194*32cb23a0STakashi Iwai #endif
195329ffe11STakashi Iwai
1961da177e4SLinus Torvalds /* create ports */
1971da177e4SLinus Torvalds for (i = 0; i < ports; i++) {
1981da177e4SLinus Torvalds rec1 = create_port(i, 0);
1991da177e4SLinus Torvalds if (rec1 == NULL) {
2001da177e4SLinus Torvalds snd_seq_delete_kernel_client(my_client);
2011da177e4SLinus Torvalds return -ENOMEM;
2021da177e4SLinus Torvalds }
2031da177e4SLinus Torvalds if (duplex) {
2041da177e4SLinus Torvalds rec2 = create_port(i, 1);
2051da177e4SLinus Torvalds if (rec2 == NULL) {
2061da177e4SLinus Torvalds snd_seq_delete_kernel_client(my_client);
2071da177e4SLinus Torvalds return -ENOMEM;
2081da177e4SLinus Torvalds }
2091da177e4SLinus Torvalds rec1->connect = rec2->port;
2101da177e4SLinus Torvalds rec2->connect = rec1->port;
2111da177e4SLinus Torvalds }
2121da177e4SLinus Torvalds }
2131da177e4SLinus Torvalds
2141da177e4SLinus Torvalds return 0;
2151da177e4SLinus Torvalds }
2161da177e4SLinus Torvalds
2171da177e4SLinus Torvalds /*
2181da177e4SLinus Torvalds * delete client if exists
2191da177e4SLinus Torvalds */
2201da177e4SLinus Torvalds static void __exit
delete_client(void)2211da177e4SLinus Torvalds delete_client(void)
2221da177e4SLinus Torvalds {
2231da177e4SLinus Torvalds if (my_client >= 0)
2241da177e4SLinus Torvalds snd_seq_delete_kernel_client(my_client);
2251da177e4SLinus Torvalds }
2261da177e4SLinus Torvalds
2271da177e4SLinus Torvalds /*
2281da177e4SLinus Torvalds * Init part
2291da177e4SLinus Torvalds */
2301da177e4SLinus Torvalds
alsa_seq_dummy_init(void)2311da177e4SLinus Torvalds static int __init alsa_seq_dummy_init(void)
2321da177e4SLinus Torvalds {
23354a721abSTakashi Iwai return register_client();
2341da177e4SLinus Torvalds }
2351da177e4SLinus Torvalds
alsa_seq_dummy_exit(void)2361da177e4SLinus Torvalds static void __exit alsa_seq_dummy_exit(void)
2371da177e4SLinus Torvalds {
2381da177e4SLinus Torvalds delete_client();
2391da177e4SLinus Torvalds }
2401da177e4SLinus Torvalds
2411da177e4SLinus Torvalds module_init(alsa_seq_dummy_init)
2421da177e4SLinus Torvalds module_exit(alsa_seq_dummy_exit)
243