diff options
Diffstat (limited to 'sound/core/seq/seq_virmidi.c')
| -rw-r--r-- | sound/core/seq/seq_virmidi.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c new file mode 100644 index 000000000..af9af89a4 --- /dev/null +++ b/sound/core/seq/seq_virmidi.c @@ -0,0 +1,531 @@ +/* + * Virtual Raw MIDI client on Sequencer + * + * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>, + * Jaroslav Kysela <perex@perex.cz> + * + * 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 + * + */ + +/* + * Virtual Raw MIDI client + * + * The virtual rawmidi client is a sequencer client which associate + * a rawmidi device file. The created rawmidi device file can be + * accessed as a normal raw midi, but its MIDI source and destination + * are arbitrary. For example, a user-client software synth connected + * to this port can be used as a normal midi device as well. + * + * The virtual rawmidi device accepts also multiple opens. Each file + * has its own input buffer, so that no conflict would occur. The drain + * of input/output buffer acts only to the local buffer. + * + */ + +#include <linux/init.h> +#include <linux/wait.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <sound/core.h> +#include <sound/rawmidi.h> +#include <sound/info.h> +#include <sound/control.h> +#include <sound/minors.h> +#include <sound/seq_kernel.h> +#include <sound/seq_midi_event.h> +#include <sound/seq_virmidi.h> + +MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); +MODULE_DESCRIPTION("Virtual Raw MIDI client on Sequencer"); +MODULE_LICENSE("GPL"); + +/* + * initialize an event record + */ +static void snd_virmidi_init_event(struct snd_virmidi *vmidi, + struct snd_seq_event *ev) +{ + memset(ev, 0, sizeof(*ev)); + ev->source.port = vmidi->port; + switch (vmidi->seq_mode) { + case SNDRV_VIRMIDI_SEQ_DISPATCH: + ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; + break; + case SNDRV_VIRMIDI_SEQ_ATTACH: + /* FIXME: source and destination are same - not good.. */ + ev->dest.client = vmidi->client; + ev->dest.port = vmidi->port; + break; + } + ev->type = SNDRV_SEQ_EVENT_NONE; +} + +/* + * decode input event and put to read buffer of each opened file + */ +static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev, + struct snd_seq_event *ev, + bool atomic) +{ + struct snd_virmidi *vmidi; + unsigned char msg[4]; + int len; + + if (atomic) + read_lock(&rdev->filelist_lock); + else + down_read(&rdev->filelist_sem); + list_for_each_entry(vmidi, &rdev->filelist, list) { + if (!READ_ONCE(vmidi->trigger)) + continue; + if (ev->type == SNDRV_SEQ_EVENT_SYSEX) { + if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) + continue; + snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream); + snd_midi_event_reset_decode(vmidi->parser); + } else { + len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev); + if (len > 0) + snd_rawmidi_receive(vmidi->substream, msg, len); + } + } + if (atomic) + read_unlock(&rdev->filelist_lock); + else + up_read(&rdev->filelist_sem); + + return 0; +} + +/* + * event handler of virmidi port + */ +static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct, + void *private_data, int atomic, int hop) +{ + struct snd_virmidi_dev *rdev; + + rdev = private_data; + if (!(rdev->flags & SNDRV_VIRMIDI_USE)) + return 0; /* ignored */ + return snd_virmidi_dev_receive_event(rdev, ev, atomic); +} + +/* + * trigger rawmidi stream for input + */ +static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, int up) +{ + struct snd_virmidi *vmidi = substream->runtime->private_data; + + WRITE_ONCE(vmidi->trigger, !!up); +} + +/* process rawmidi bytes and send events; + * we need no lock here for vmidi->event since it's handled only in this work + */ +static void snd_vmidi_output_work(struct work_struct *work) +{ + struct snd_virmidi *vmidi; + struct snd_rawmidi_substream *substream; + unsigned char input; + int ret; + + vmidi = container_of(work, struct snd_virmidi, output_work); + substream = vmidi->substream; + + /* discard the outputs in dispatch mode unless subscribed */ + if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH && + !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) { + char buf[32]; + while (snd_rawmidi_transmit(substream, buf, sizeof(buf)) > 0) + ; /* ignored */ + return; + } + + while (READ_ONCE(vmidi->trigger)) { + if (snd_rawmidi_transmit(substream, &input, 1) != 1) + break; + if (!snd_midi_event_encode_byte(vmidi->parser, input, + &vmidi->event)) + continue; + if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) { + ret = snd_seq_kernel_client_dispatch(vmidi->client, + &vmidi->event, + false, 0); + vmidi->event.type = SNDRV_SEQ_EVENT_NONE; + if (ret < 0) + break; + } + /* rawmidi input might be huge, allow to have a break */ + cond_resched(); + } +} + +/* + * trigger rawmidi stream for output + */ +static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, int up) +{ + struct snd_virmidi *vmidi = substream->runtime->private_data; + + WRITE_ONCE(vmidi->trigger, !!up); + if (up) + queue_work(system_highpri_wq, &vmidi->output_work); +} + +/* + * open rawmidi handle for input + */ +static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream) +{ + struct snd_virmidi_dev *rdev = substream->rmidi->private_data; + struct snd_rawmidi_runtime *runtime = substream->runtime; + struct snd_virmidi *vmidi; + + vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL); + if (vmidi == NULL) + return -ENOMEM; + vmidi->substream = substream; + if (snd_midi_event_new(0, &vmidi->parser) < 0) { + kfree(vmidi); + return -ENOMEM; + } + vmidi->seq_mode = rdev->seq_mode; + vmidi->client = rdev->client; + vmidi->port = rdev->port; + runtime->private_data = vmidi; + down_write(&rdev->filelist_sem); + write_lock_irq(&rdev->filelist_lock); + list_add_tail(&vmidi->list, &rdev->filelist); + write_unlock_irq(&rdev->filelist_lock); + up_write(&rdev->filelist_sem); + vmidi->rdev = rdev; + return 0; +} + +/* + * open rawmidi handle for output + */ +static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream) +{ + struct snd_virmidi_dev *rdev = substream->rmidi->private_data; + struct snd_rawmidi_runtime *runtime = substream->runtime; + struct snd_virmidi *vmidi; + + vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL); + if (vmidi == NULL) + return -ENOMEM; + vmidi->substream = substream; + if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) { + kfree(vmidi); + return -ENOMEM; + } + vmidi->seq_mode = rdev->seq_mode; + vmidi->client = rdev->client; + vmidi->port = rdev->port; + snd_virmidi_init_event(vmidi, &vmidi->event); + vmidi->rdev = rdev; + INIT_WORK(&vmidi->output_work, snd_vmidi_output_work); + runtime->private_data = vmidi; + return 0; +} + +/* + * close rawmidi handle for input + */ +static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream) +{ + struct snd_virmidi_dev *rdev = substream->rmidi->private_data; + struct snd_virmidi *vmidi = substream->runtime->private_data; + + down_write(&rdev->filelist_sem); + write_lock_irq(&rdev->filelist_lock); + list_del(&vmidi->list); + write_unlock_irq(&rdev->filelist_lock); + up_write(&rdev->filelist_sem); + snd_midi_event_free(vmidi->parser); + substream->runtime->private_data = NULL; + kfree(vmidi); + return 0; +} + +/* + * close rawmidi handle for output + */ +static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream) +{ + struct snd_virmidi *vmidi = substream->runtime->private_data; + + WRITE_ONCE(vmidi->trigger, false); /* to be sure */ + cancel_work_sync(&vmidi->output_work); + snd_midi_event_free(vmidi->parser); + substream->runtime->private_data = NULL; + kfree(vmidi); + return 0; +} + +/* + * subscribe callback - allow output to rawmidi device + */ +static int snd_virmidi_subscribe(void *private_data, + struct snd_seq_port_subscribe *info) +{ + struct snd_virmidi_dev *rdev; + + rdev = private_data; + if (!try_module_get(rdev->card->module)) + return -EFAULT; + rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE; + return 0; +} + +/* + * unsubscribe callback - disallow output to rawmidi device + */ +static int snd_virmidi_unsubscribe(void *private_data, + struct snd_seq_port_subscribe *info) +{ + struct snd_virmidi_dev *rdev; + + rdev = private_data; + rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE; + module_put(rdev->card->module); + return 0; +} + + +/* + * use callback - allow input to rawmidi device + */ +static int snd_virmidi_use(void *private_data, + struct snd_seq_port_subscribe *info) +{ + struct snd_virmidi_dev *rdev; + + rdev = private_data; + if (!try_module_get(rdev->card->module)) + return -EFAULT; + rdev->flags |= SNDRV_VIRMIDI_USE; + return 0; +} + +/* + * unuse callback - disallow input to rawmidi device + */ +static int snd_virmidi_unuse(void *private_data, + struct snd_seq_port_subscribe *info) +{ + struct snd_virmidi_dev *rdev; + + rdev = private_data; + rdev->flags &= ~SNDRV_VIRMIDI_USE; + module_put(rdev->card->module); + return 0; +} + + +/* + * Register functions + */ + +static const struct snd_rawmidi_ops snd_virmidi_input_ops = { + .open = snd_virmidi_input_open, + .close = snd_virmidi_input_close, + .trigger = snd_virmidi_input_trigger, +}; + +static const struct snd_rawmidi_ops snd_virmidi_output_ops = { + .open = snd_virmidi_output_open, + .close = snd_virmidi_output_close, + .trigger = snd_virmidi_output_trigger, +}; + +/* + * create a sequencer client and a port + */ +static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev) +{ + int client; + struct snd_seq_port_callback pcallbacks; + struct snd_seq_port_info *pinfo; + int err; + + if (rdev->client >= 0) + return 0; + + pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL); + if (!pinfo) { + err = -ENOMEM; + goto __error; + } + + client = snd_seq_create_kernel_client(rdev->card, rdev->device, + "%s %d-%d", rdev->rmidi->name, + rdev->card->number, + rdev->device); + if (client < 0) { + err = client; + goto __error; + } + rdev->client = client; + + /* create a port */ + pinfo->addr.client = client; + sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device); + /* set all capabilities */ + pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE; + pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ; + 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; + pinfo->midi_channels = 16; + memset(&pcallbacks, 0, sizeof(pcallbacks)); + pcallbacks.owner = THIS_MODULE; + pcallbacks.private_data = rdev; + pcallbacks.subscribe = snd_virmidi_subscribe; + pcallbacks.unsubscribe = snd_virmidi_unsubscribe; + pcallbacks.use = snd_virmidi_use; + pcallbacks.unuse = snd_virmidi_unuse; + pcallbacks.event_input = snd_virmidi_event_input; + pinfo->kernel = &pcallbacks; + err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo); + if (err < 0) { + snd_seq_delete_kernel_client(client); + rdev->client = -1; + goto __error; + } + + rdev->port = pinfo->addr.port; + err = 0; /* success */ + + __error: + kfree(pinfo); + return err; +} + + +/* + * release the sequencer client + */ +static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev) +{ + if (rdev->client >= 0) { + snd_seq_delete_kernel_client(rdev->client); + rdev->client = -1; + } +} + +/* + * register the device + */ +static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi) +{ + struct snd_virmidi_dev *rdev = rmidi->private_data; + int err; + + switch (rdev->seq_mode) { + case SNDRV_VIRMIDI_SEQ_DISPATCH: + err = snd_virmidi_dev_attach_seq(rdev); + if (err < 0) + return err; + break; + case SNDRV_VIRMIDI_SEQ_ATTACH: + if (rdev->client == 0) + return -EINVAL; + /* should check presence of port more strictly.. */ + break; + default: + pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode); + return -EINVAL; + } + return 0; +} + + +/* + * unregister the device + */ +static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi) +{ + struct snd_virmidi_dev *rdev = rmidi->private_data; + + if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH) + snd_virmidi_dev_detach_seq(rdev); + return 0; +} + +/* + * + */ +static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = { + .dev_register = snd_virmidi_dev_register, + .dev_unregister = snd_virmidi_dev_unregister, +}; + +/* + * free device + */ +static void snd_virmidi_free(struct snd_rawmidi *rmidi) +{ + struct snd_virmidi_dev *rdev = rmidi->private_data; + kfree(rdev); +} + +/* + * create a new device + * + */ +/* exported */ +int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi) +{ + struct snd_rawmidi *rmidi; + struct snd_virmidi_dev *rdev; + int err; + + *rrmidi = NULL; + if ((err = snd_rawmidi_new(card, "VirMidi", device, + 16, /* may be configurable */ + 16, /* may be configurable */ + &rmidi)) < 0) + return err; + strcpy(rmidi->name, rmidi->id); + rdev = kzalloc(sizeof(*rdev), GFP_KERNEL); + if (rdev == NULL) { + snd_device_free(card, rmidi); + return -ENOMEM; + } + rdev->card = card; + rdev->rmidi = rmidi; + rdev->device = device; + rdev->client = -1; + init_rwsem(&rdev->filelist_sem); + rwlock_init(&rdev->filelist_lock); + INIT_LIST_HEAD(&rdev->filelist); + rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH; + rmidi->private_data = rdev; + rmidi->private_free = snd_virmidi_free; + rmidi->ops = &snd_virmidi_global_ops; + snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops); + snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops); + rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT | + SNDRV_RAWMIDI_INFO_OUTPUT | + SNDRV_RAWMIDI_INFO_DUPLEX; + *rrmidi = rmidi; + return 0; +} +EXPORT_SYMBOL(snd_virmidi_new); |