- 根目录:
- sound
- core
- seq
- seq_midi.c
/*
* Generic MIDI synth driver for ALSA sequencer
* Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
* 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
*
*/
/*
Possible options for midisynth module:
- automatic opening of midi ports on first received event or subscription
(close will be performed when client leaves)
*/
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <sound/core.h>
#include <sound/rawmidi.h>
#include <sound/seq_kernel.h>
#include <sound/seq_device.h>
#include <sound/seq_midi_event.h>
#include <sound/initval.h>
MODULE_AUTHOR("Frank van de Pol <fvdpol@coil.demon.nl>, Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer MIDI synth.");
MODULE_LICENSE("GPL");
static int output_buffer_size = PAGE_SIZE;
module_param(output_buffer_size, int, 0644);
MODULE_PARM_DESC(output_buffer_size, "Output buffer size in bytes.");
static int input_buffer_size = PAGE_SIZE;
module_param(input_buffer_size, int, 0644);
MODULE_PARM_DESC(input_buffer_size, "Input buffer size in bytes.");
/* data for this midi synth driver */
struct seq_midisynth {
struct snd_card *card;
int device;
int subdevice;
struct snd_rawmidi_file input_rfile;
struct snd_rawmidi_file output_rfile;
int seq_client;
int seq_port;
struct snd_midi_event *parser;
};
struct seq_midisynth_client {
int seq_client;
int num_ports;
int ports_per_device[SNDRV_RAWMIDI_DEVICES];
struct seq_midisynth *ports[SNDRV_RAWMIDI_DEVICES];
};
static struct seq_midisynth_client *synths[SNDRV_CARDS];
static DEFINE_MUTEX(register_mutex);
/* handle rawmidi input event (MIDI v1.0 stream) */
static void snd_midi_input_event(struct snd_rawmidi_substream *substream)
{
struct snd_rawmidi_runtime *runtime;
struct seq_midisynth *msynth;
struct snd_seq_event ev;
char buf[16], *pbuf;
long res, count;
if (substream == NULL)
return;
runtime = substream->runtime;
msynth = runtime->private_data;
if (msynth == NULL)
return;
memset(&ev, 0, sizeof(ev));
while (runtime->avail > 0) {
res = snd_rawmidi_kernel_read(substream, buf, sizeof(buf));
if (res <= 0)
continue;
if (msynth->parser == NULL)
continue;
pbuf = buf;
while (res > 0) {
count = snd_midi_event_encode(msynth->parser, pbuf, res, &ev);
if (count < 0)
break;
pbuf += count;
res -= count;
if (ev.type != SNDRV_SEQ_EVENT_NONE) {
ev.source.port = msynth->seq_port;
ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
snd_seq_kernel_client_dispatch(msynth->seq_client, &ev, 1, 0);
/* clear event and reset header */
memset(&ev, 0, sizeof(ev));
}
}
}
}
static int dump_midi(struct snd_rawmidi_substream *substream, const char *buf, int count)
{
struct snd_rawmidi_runtime *runtime;
int tmp;
if (snd_BUG_ON(!substream || !buf))
return -EINVAL;
runtime = substream->runtime;
if ((tmp = runtime->avail) < count) {
if (printk_ratelimit())
pr_err("ALSA: seq_midi: MIDI output buffer overrun\n");
return -ENOMEM;
}
if (snd_rawmidi_kernel_write(substream, buf, count) < count)
return -EINVAL;
return 0;
}
static int event_process_midi(struct snd_seq_event *ev, int direct,
void *private_data, int atomic, int hop)
{
struct seq_midisynth *msynth = private_data;
unsigned char msg[10]; /* buffer for constructing midi messages */
struct snd_rawmidi_substream *substream;
int len;
if (snd_BUG_ON(!msynth))
return -EINVAL;
substream = msynth->output_rfile.output;
if (substream == NULL)
return -ENODEV;
if (ev->type == SNDRV_SEQ_EVENT_SYSEX) { /* special case, to save space */
if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) {
/* invalid event */
pr_debug("ALSA: seq_midi: invalid sysex event flags = 0x%x\n", ev->flags);
return 0;
}
snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
snd_midi_event_reset_decode(msynth->parser);
} else {
if (msynth->parser == NULL)
return -EIO;
len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev);
if (len < 0)
return 0;
if (dump_midi(substream, msg, len) < 0)
snd_midi_event_reset_decode(msynth->parser);
}
return 0;
}
static int snd_seq_midisynth_new(struct seq_midisynth *msynth,
struct snd_card *card,
int device,
int subdevice)
{
if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &msynth->parser) < 0)
return -ENOMEM;
msynth->card = card;
msynth->device = device;
msynth->subdevice = subdevice;
return 0;
}
/* open associated midi device for input */
static int midisynth_subscribe(void *private_data, struct snd_seq_port_subscribe *info)
{
int err;
struct seq_midisynth *msynth = private_data;
struct snd_rawmidi_runtime *runtime;
struct snd_rawmidi_params params;
/* open midi port */
if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
msynth->subdevice,
SNDRV_RAWMIDI_LFLG_INPUT,
&msynth->input_rfile)) < 0) {
pr_debug("ALSA: seq_midi: midi input open failed!!!\n");
return err;
}
runtime = msynth->input_rfile.input->runtime;
memset(¶ms, 0, sizeof(params));
params.avail_min = 1;
params.buffer_size = input_buffer_size;
if ((err = snd_rawmidi_input_params(msynth->input_rfile.input, ¶ms)) < 0) {
snd_rawmidi_kernel_release(&msynth->input_rfile);
return err;
}
snd_midi_event_reset_encode(msynth->parser);
runtime->event = snd_midi_input_event;
runtime->private_data = msynth;
snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0);
return 0;
}
/* close associated midi device for input */
static int midisynth_unsubscribe(void *private_data, struct snd_seq_port_subscribe *info)
{
int err;
struct seq_midisynth *msynth = private_data;
if (snd_BUG_ON(!msynth->input_rfile.input))
return -EINVAL;
err = snd_rawmidi_kernel_release(&msynth->input_rfile);
return err;
}
/* open associated midi device for output */
static int midisynth_use(void *private_data, struct snd_seq_port_subscribe *info)
{
int err;
struct seq_midisynth *msynth = private_data;
struct snd_rawmidi_params params;
/* open midi port */
if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
msynth->subdevice,
SNDRV_RAWMIDI_LFLG_OUTPUT,
&msynth->output_rfile)) < 0) {
pr_debug("ALSA: seq_midi: midi output open failed!!!\n");
return err;
}
memset(¶ms, 0, sizeof(params));
params.avail_min = 1;
params.buffer_size = output_buffer_size;
params.no_active_sensing = 1;
if ((err = snd_rawmidi_output_params(msynth->output_rfile.output, ¶ms)) < 0) {
snd_rawmidi_kernel_release(&msynth->output_rfile);
return err;
}
snd_midi_event_reset_decode(msynth->parser);
return 0;
}
/* close associated midi device for output */
static int midisynth_unuse(void *private_data, struct snd_seq_port_subscribe *info)
{
struct seq_midisynth *msynth = private_data;
if (snd_BUG_ON(!msynth->output_rfile.output))
return -EINVAL;
snd_rawmidi_drain_output(msynth->output_rfile.output);
return snd_rawmidi_kernel_release(&msynth->output_rfile);
}
/* delete given midi synth port */
static void snd_seq_midisynth_delete(struct seq_midisynth *msynth)
{
if (msynth == NULL)
return;
if (msynth->seq_client > 0) {
/* delete port */
snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port);
}
snd_midi_event_free(msynth->parser);
}
/* register new midi synth port */
static int
snd_seq_midisynth_probe(struct device *_dev)
{
struct snd_seq_device *dev = to_seq_dev(_dev);
struct seq_midisynth_client *client;
struct seq_midisynth *msynth, *ms;
struct snd_seq_port_info *port;
struct snd_rawmidi_info *info;
struct snd_rawmidi *rmidi = dev->private_data;
int newclient = 0;
unsigned int p, ports;
struct snd_seq_port_callback pcallbacks;
struct snd_card *card = dev->card;
int device = dev->device;
unsigned int input_count = 0, output_count = 0;
if (snd_BUG_ON(!card || device < 0 || device >= SNDRV_RAWMIDI_DEVICES))
return -EINVAL;
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (! info)
return -ENOMEM;
info->device = device;
info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
info->subdevice = 0;
if (snd_rawmidi_info_select(card, info) >= 0)
output_count = info->subdevices_count;
info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
if (snd_rawmidi_info_select(card, info) >= 0) {
input_count = info->subdevices_count;
}
ports = output_count;
if (ports < input_count)
ports = input_count;
if (ports == 0) {
kfree(info);
return -ENODEV;
}
if (ports > (256 / SNDRV_RAWMIDI_DEVICES))
ports = 256 / SNDRV_RAWMIDI_DEVICES;
mutex_lock(®ister_mutex);
client = synths[card->number];
if (client == NULL) {
newclient = 1;
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (client == NULL) {
mutex_unlock(®ister_mutex);
kfree(info);
return -ENOMEM;
}
client->seq_client =
snd_seq_create_kernel_client(
card, 0, "%s", card->shortname[0] ?
(const char *)card->shortname : "External MIDI");
if (client->seq_client < 0) {
kfree(client);
mutex_unlock(®ister_mutex);
kfree(info);
return -ENOMEM;
}
}
msynth = kcalloc(ports, sizeof(struct seq_midisynth), GFP_KERNEL);
port = kmalloc(sizeof(*port), GFP_KERNEL);
if (msynth == NULL || port == NULL)
goto __nomem;
for (p = 0; p < ports; p++) {
ms = &msynth[p];
if (snd_seq_midisynth_new(ms, card, device, p) < 0)
goto __nomem;
/* declare port */
memset(port, 0, sizeof(*port));
port->addr.client = client->seq_client;
port->addr.port = device * (256 / SNDRV_RAWMIDI_DEVICES) + p;
port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
memset(info, 0, sizeof(*info));
info->device = device;
if (p < output_count)
info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
else
info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
info->subdevice = p;
if (snd_rawmidi_info_select(card, info) >= 0)
strcpy(port->name, info->subname);
if (! port->name[0]) {
if (info->name[0]) {
if (ports > 1)
snprintf(port->name, sizeof(port->name), "%s-%u", info->name, p);
else
snprintf(port->name, sizeof(port->name), "%s", info->name);
} else {
/* last resort */
if (ports > 1)
sprintf(port->name, "MIDI %d-%d-%u", card->number, device, p);
else
sprintf(port->name, "MIDI %d-%d", card->number, device);
}
}
if ((info->flags & SNDRV_RAWMIDI_INFO_OUTPUT) && p < output_count)
port->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
if ((info->flags & SNDRV_RAWMIDI_INFO_INPUT) && p < input_count)
port->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) &&
info->flags & SNDRV_RAWMIDI_INFO_DUPLEX)
port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
| SNDRV_SEQ_PORT_TYPE_HARDWARE
| SNDRV_SEQ_PORT_TYPE_PORT;
port->midi_channels = 16;
memset(&pcallbacks, 0, sizeof(pcallbacks));
pcallbacks.owner = THIS_MODULE;
pcallbacks.private_data = ms;
pcallbacks.subscribe = midisynth_subscribe;
pcallbacks.unsubscribe = midisynth_unsubscribe;
pcallbacks.use = midisynth_use;
pcallbacks.unuse = midisynth_unuse;
pcallbacks.event_input = event_process_midi;
port->kernel = &pcallbacks;
if (rmidi->ops && rmidi->ops->get_port_info)
rmidi->ops->get_port_info(rmidi, p, port);
if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0)
goto __nomem;
ms->seq_client = client->seq_client;
ms->seq_port = port->addr.port;
}
client->ports_per_device[device] = ports;
client->ports[device] = msynth;
client->num_ports++;
if (newclient)
synths[card->number] = client;
mutex_unlock(®ister_mutex);
kfree(info);
kfree(port);
return 0; /* success */
__nomem:
if (msynth != NULL) {
for (p = 0; p < ports; p++)
snd_seq_midisynth_delete(&msynth[p]);
kfree(msynth);
}
if (newclient) {
snd_seq_delete_kernel_client(client->seq_client);
kfree(client);
}
kfree(info);
kfree(port);
mutex_unlock(®ister_mutex);
return -ENOMEM;
}
/* release midi synth port */
static int
snd_seq_midisynth_remove(struct device *_dev)
{
struct snd_seq_device *dev = to_seq_dev(_dev);
struct seq_midisynth_client *client;
struct seq_midisynth *msynth;
struct snd_card *card = dev->card;
int device = dev->device, p, ports;
mutex_lock(®ister_mutex);
client = synths[card->number];
if (client == NULL || client->ports[device] == NULL) {
mutex_unlock(®ister_mutex);
return -ENODEV;
}
ports = client->ports_per_device[device];
client->ports_per_device[device] = 0;
msynth = client->ports[device];
client->ports[device] = NULL;
for (p = 0; p < ports; p++)
snd_seq_midisynth_delete(&msynth[p]);
kfree(msynth);
client->num_ports--;
if (client->num_ports <= 0) {
snd_seq_delete_kernel_client(client->seq_client);
synths[card->number] = NULL;
kfree(client);
}
mutex_unlock(®ister_mutex);
return 0;
}
static struct snd_seq_driver seq_midisynth_driver = {
.driver = {
.name = KBUILD_MODNAME,
.probe = snd_seq_midisynth_probe,
.remove = snd_seq_midisynth_remove,
},
.id = SNDRV_SEQ_DEV_ID_MIDISYNTH,
.argsize = 0,
};
module_snd_seq_driver(seq_midisynth_driver);