diff options
Diffstat (limited to 'sound/core/seq/seq_dummy.c')
| -rw-r--r-- | sound/core/seq/seq_dummy.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c new file mode 100644 index 000000000..d3a2ec4f0 --- /dev/null +++ b/sound/core/seq/seq_dummy.c @@ -0,0 +1,226 @@ +/* + * 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/module.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 a configuration file under /etc/modprobe.d/: + + option snd-seq-dummy ports=4 + + The model 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 bool 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; + +/* + * 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.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) { + pr_err("ALSA: seq_dummy: 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) +{ + return register_client(); +} + +static void __exit alsa_seq_dummy_exit(void) +{ + delete_client(); +} + +module_init(alsa_seq_dummy_init) +module_exit(alsa_seq_dummy_exit) |