summaryrefslogtreecommitdiffstats
path: root/sound/core/seq/seq_midi.c
blob: 5dd0ee2583592e156f5822c2aa56e83c4c41c97d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
/*
 *   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(&params, 0, sizeof(params));
	params.avail_min = 1;
	params.buffer_size = input_buffer_size;
	if ((err = snd_rawmidi_input_params(msynth->input_rfile.input, &params)) < 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(&params, 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, &params)) < 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(&register_mutex);
	client = synths[card->number];
	if (client == NULL) {
		newclient = 1;
		client = kzalloc(sizeof(*client), GFP_KERNEL);
		if (client == NULL) {
			mutex_unlock(&register_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(&register_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(&register_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(&register_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(&register_mutex);
	client = synths[card->number];
	if (client == NULL || client->ports[device] == NULL) {
		mutex_unlock(&register_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(&register_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);
OpenPOWER on IntegriCloud