|  | /* | 
|  | * ALSA sequencer MIDI-through client | 
|  | * Copyright (c) 1999-2000 by Takashi Iwai <tiwai@suse.de> | 
|  | * | 
|  | *   This program is free software; you can redistribute it and/or modify | 
|  | *   it under the terms of the GNU General Public License as published by | 
|  | *   the Free Software Foundation; either version 2 of the License, or | 
|  | *   (at your option) any later version. | 
|  | * | 
|  | *   This program is distributed in the hope that it will be useful, | 
|  | *   but WITHOUT ANY WARRANTY; without even the implied warranty of | 
|  | *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
|  | *   GNU General Public License for more details. | 
|  | * | 
|  | *   You should have received a copy of the GNU General Public License | 
|  | *   along with this program; if not, write to the Free Software | 
|  | *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA | 
|  | * | 
|  | */ | 
|  |  | 
|  | #include <linux/init.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/moduleparam.h> | 
|  | #include <sound/core.h> | 
|  | #include "seq_clientmgr.h" | 
|  | #include <sound/initval.h> | 
|  | #include <sound/asoundef.h> | 
|  |  | 
|  | /* | 
|  |  | 
|  | Sequencer MIDI-through client | 
|  |  | 
|  | This gives a simple midi-through client.  All the normal input events | 
|  | are redirected to output port immediately. | 
|  | The routing can be done via aconnect program in alsa-utils. | 
|  |  | 
|  | Each client has a static client number 62 (= SNDRV_SEQ_CLIENT_DUMMY). | 
|  | If you want to auto-load this module, you may add the following alias | 
|  | in your /etc/conf.modules file. | 
|  |  | 
|  | alias snd-seq-client-62  snd-seq-dummy | 
|  |  | 
|  | The module is loaded on demand for client 62, or /proc/asound/seq/ | 
|  | is accessed.  If you don't need this module to be loaded, alias | 
|  | snd-seq-client-62 as "off".  This will help modprobe. | 
|  |  | 
|  | The number of ports to be created can be specified via the module | 
|  | parameter "ports".  For example, to create four ports, add the | 
|  | following option in /etc/modprobe.conf: | 
|  |  | 
|  | option snd-seq-dummy ports=4 | 
|  |  | 
|  | The modle option "duplex=1" enables duplex operation to the port. | 
|  | In duplex mode, a pair of ports are created instead of single port, | 
|  | and events are tunneled between pair-ports.  For example, input to | 
|  | port A is sent to output port of another port B and vice versa. | 
|  | In duplex mode, each port has DUPLEX capability. | 
|  |  | 
|  | */ | 
|  |  | 
|  |  | 
|  | MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); | 
|  | MODULE_DESCRIPTION("ALSA sequencer MIDI-through client"); | 
|  | MODULE_LICENSE("GPL"); | 
|  | MODULE_ALIAS("snd-seq-client-" __stringify(SNDRV_SEQ_CLIENT_DUMMY)); | 
|  |  | 
|  | static int ports = 1; | 
|  | static int duplex; | 
|  |  | 
|  | module_param(ports, int, 0444); | 
|  | MODULE_PARM_DESC(ports, "number of ports to be created"); | 
|  | module_param(duplex, bool, 0444); | 
|  | MODULE_PARM_DESC(duplex, "create DUPLEX ports"); | 
|  |  | 
|  | struct snd_seq_dummy_port { | 
|  | int client; | 
|  | int port; | 
|  | int duplex; | 
|  | int connect; | 
|  | }; | 
|  |  | 
|  | static int my_client = -1; | 
|  |  | 
|  | /* | 
|  | * unuse callback - send ALL_SOUNDS_OFF and RESET_CONTROLLERS events | 
|  | * to subscribers. | 
|  | * Note: this callback is called only after all subscribers are removed. | 
|  | */ | 
|  | static int | 
|  | dummy_unuse(void *private_data, struct snd_seq_port_subscribe *info) | 
|  | { | 
|  | struct snd_seq_dummy_port *p; | 
|  | int i; | 
|  | struct snd_seq_event ev; | 
|  |  | 
|  | p = private_data; | 
|  | memset(&ev, 0, sizeof(ev)); | 
|  | if (p->duplex) | 
|  | ev.source.port = p->connect; | 
|  | else | 
|  | ev.source.port = p->port; | 
|  | ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; | 
|  | ev.type = SNDRV_SEQ_EVENT_CONTROLLER; | 
|  | for (i = 0; i < 16; i++) { | 
|  | ev.data.control.channel = i; | 
|  | ev.data.control.param = MIDI_CTL_ALL_SOUNDS_OFF; | 
|  | snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0); | 
|  | ev.data.control.param = MIDI_CTL_RESET_CONTROLLERS; | 
|  | snd_seq_kernel_client_dispatch(p->client, &ev, 0, 0); | 
|  | } | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * event input callback - just redirect events to subscribers | 
|  | */ | 
|  | static int | 
|  | dummy_input(struct snd_seq_event *ev, int direct, void *private_data, | 
|  | int atomic, int hop) | 
|  | { | 
|  | struct snd_seq_dummy_port *p; | 
|  | struct snd_seq_event tmpev; | 
|  |  | 
|  | p = private_data; | 
|  | if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM || | 
|  | ev->type == SNDRV_SEQ_EVENT_KERNEL_ERROR) | 
|  | return 0; /* ignore system messages */ | 
|  | tmpev = *ev; | 
|  | if (p->duplex) | 
|  | tmpev.source.port = p->connect; | 
|  | else | 
|  | tmpev.source.port = p->port; | 
|  | tmpev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; | 
|  | return snd_seq_kernel_client_dispatch(p->client, &tmpev, atomic, hop); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * free_private callback | 
|  | */ | 
|  | static void | 
|  | dummy_free(void *private_data) | 
|  | { | 
|  | kfree(private_data); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * create a port | 
|  | */ | 
|  | static struct snd_seq_dummy_port __init * | 
|  | create_port(int idx, int type) | 
|  | { | 
|  | struct snd_seq_port_info pinfo; | 
|  | struct snd_seq_port_callback pcb; | 
|  | struct snd_seq_dummy_port *rec; | 
|  |  | 
|  | if ((rec = kzalloc(sizeof(*rec), GFP_KERNEL)) == NULL) | 
|  | return NULL; | 
|  |  | 
|  | rec->client = my_client; | 
|  | rec->duplex = duplex; | 
|  | rec->connect = 0; | 
|  | memset(&pinfo, 0, sizeof(pinfo)); | 
|  | pinfo.addr.client = my_client; | 
|  | if (duplex) | 
|  | sprintf(pinfo.name, "Midi Through Port-%d:%c", idx, | 
|  | (type ? 'B' : 'A')); | 
|  | else | 
|  | sprintf(pinfo.name, "Midi Through Port-%d", idx); | 
|  | pinfo.capability = SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ; | 
|  | pinfo.capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE; | 
|  | if (duplex) | 
|  | pinfo.capability |= SNDRV_SEQ_PORT_CAP_DUPLEX; | 
|  | pinfo.type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC | 
|  | | SNDRV_SEQ_PORT_TYPE_SOFTWARE | 
|  | | SNDRV_SEQ_PORT_TYPE_PORT; | 
|  | memset(&pcb, 0, sizeof(pcb)); | 
|  | pcb.owner = THIS_MODULE; | 
|  | pcb.unuse = dummy_unuse; | 
|  | pcb.event_input = dummy_input; | 
|  | pcb.private_free = dummy_free; | 
|  | pcb.private_data = rec; | 
|  | pinfo.kernel = &pcb; | 
|  | if (snd_seq_kernel_client_ctl(my_client, SNDRV_SEQ_IOCTL_CREATE_PORT, &pinfo) < 0) { | 
|  | kfree(rec); | 
|  | return NULL; | 
|  | } | 
|  | rec->port = pinfo.addr.port; | 
|  | return rec; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * register client and create ports | 
|  | */ | 
|  | static int __init | 
|  | register_client(void) | 
|  | { | 
|  | struct snd_seq_dummy_port *rec1, *rec2; | 
|  | int i; | 
|  |  | 
|  | if (ports < 1) { | 
|  | snd_printk(KERN_ERR "invalid number of ports %d\n", ports); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | /* create client */ | 
|  | my_client = snd_seq_create_kernel_client(NULL, SNDRV_SEQ_CLIENT_DUMMY, | 
|  | "Midi Through"); | 
|  | if (my_client < 0) | 
|  | return my_client; | 
|  |  | 
|  | /* create ports */ | 
|  | for (i = 0; i < ports; i++) { | 
|  | rec1 = create_port(i, 0); | 
|  | if (rec1 == NULL) { | 
|  | snd_seq_delete_kernel_client(my_client); | 
|  | return -ENOMEM; | 
|  | } | 
|  | if (duplex) { | 
|  | rec2 = create_port(i, 1); | 
|  | if (rec2 == NULL) { | 
|  | snd_seq_delete_kernel_client(my_client); | 
|  | return -ENOMEM; | 
|  | } | 
|  | rec1->connect = rec2->port; | 
|  | rec2->connect = rec1->port; | 
|  | } | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * delete client if exists | 
|  | */ | 
|  | static void __exit | 
|  | delete_client(void) | 
|  | { | 
|  | if (my_client >= 0) | 
|  | snd_seq_delete_kernel_client(my_client); | 
|  | } | 
|  |  | 
|  | /* | 
|  | *  Init part | 
|  | */ | 
|  |  | 
|  | static int __init alsa_seq_dummy_init(void) | 
|  | { | 
|  | int err; | 
|  | snd_seq_autoload_lock(); | 
|  | err = register_client(); | 
|  | snd_seq_autoload_unlock(); | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static void __exit alsa_seq_dummy_exit(void) | 
|  | { | 
|  | delete_client(); | 
|  | } | 
|  |  | 
|  | module_init(alsa_seq_dummy_init) | 
|  | module_exit(alsa_seq_dummy_exit) |