1/*
2 *  Virtual Raw MIDI client on Sequencer
3 *
4 *  Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>,
5 *                        Jaroslav Kysela <perex@perex.cz>
6 *
7 *   This program is free software; you can redistribute it and/or modify
8 *   it under the terms of the GNU General Public License as published by
9 *   the Free Software Foundation; either version 2 of the License, or
10 *   (at your option) any later version.
11 *
12 *   This program is distributed in the hope that it will be useful,
13 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 *   GNU General Public License for more details.
16 *
17 *   You should have received a copy of the GNU General Public License
18 *   along with this program; if not, write to the Free Software
19 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20 *
21 */
22
23/*
24 * Virtual Raw MIDI client
25 *
26 * The virtual rawmidi client is a sequencer client which associate
27 * a rawmidi device file.  The created rawmidi device file can be
28 * accessed as a normal raw midi, but its MIDI source and destination
29 * are arbitrary.  For example, a user-client software synth connected
30 * to this port can be used as a normal midi device as well.
31 *
32 * The virtual rawmidi device accepts also multiple opens.  Each file
33 * has its own input buffer, so that no conflict would occur.  The drain
34 * of input/output buffer acts only to the local buffer.
35 *
36 */
37
38#include <linux/init.h>
39#include <linux/wait.h>
40#include <linux/module.h>
41#include <linux/slab.h>
42#include <sound/core.h>
43#include <sound/rawmidi.h>
44#include <sound/info.h>
45#include <sound/control.h>
46#include <sound/minors.h>
47#include <sound/seq_kernel.h>
48#include <sound/seq_midi_event.h>
49#include <sound/seq_virmidi.h>
50
51MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
52MODULE_DESCRIPTION("Virtual Raw MIDI client on Sequencer");
53MODULE_LICENSE("GPL");
54
55/*
56 * initialize an event record
57 */
58static void snd_virmidi_init_event(struct snd_virmidi *vmidi,
59				   struct snd_seq_event *ev)
60{
61	memset(ev, 0, sizeof(*ev));
62	ev->source.port = vmidi->port;
63	switch (vmidi->seq_mode) {
64	case SNDRV_VIRMIDI_SEQ_DISPATCH:
65		ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
66		break;
67	case SNDRV_VIRMIDI_SEQ_ATTACH:
68		/* FIXME: source and destination are same - not good.. */
69		ev->dest.client = vmidi->client;
70		ev->dest.port = vmidi->port;
71		break;
72	}
73	ev->type = SNDRV_SEQ_EVENT_NONE;
74}
75
76/*
77 * decode input event and put to read buffer of each opened file
78 */
79static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev,
80					 struct snd_seq_event *ev)
81{
82	struct snd_virmidi *vmidi;
83	unsigned char msg[4];
84	int len;
85
86	read_lock(&rdev->filelist_lock);
87	list_for_each_entry(vmidi, &rdev->filelist, list) {
88		if (!vmidi->trigger)
89			continue;
90		if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
91			if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
92				continue;
93			snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
94		} else {
95			len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
96			if (len > 0)
97				snd_rawmidi_receive(vmidi->substream, msg, len);
98		}
99	}
100	read_unlock(&rdev->filelist_lock);
101
102	return 0;
103}
104
105/*
106 * receive an event from the remote virmidi port
107 *
108 * for rawmidi inputs, you can call this function from the event
109 * handler of a remote port which is attached to the virmidi via
110 * SNDRV_VIRMIDI_SEQ_ATTACH.
111 */
112#if 0
113int snd_virmidi_receive(struct snd_rawmidi *rmidi, struct snd_seq_event *ev)
114{
115	struct snd_virmidi_dev *rdev;
116
117	rdev = rmidi->private_data;
118	return snd_virmidi_dev_receive_event(rdev, ev);
119}
120#endif  /*  0  */
121
122/*
123 * event handler of virmidi port
124 */
125static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct,
126				   void *private_data, int atomic, int hop)
127{
128	struct snd_virmidi_dev *rdev;
129
130	rdev = private_data;
131	if (!(rdev->flags & SNDRV_VIRMIDI_USE))
132		return 0; /* ignored */
133	return snd_virmidi_dev_receive_event(rdev, ev);
134}
135
136/*
137 * trigger rawmidi stream for input
138 */
139static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
140{
141	struct snd_virmidi *vmidi = substream->runtime->private_data;
142
143	if (up) {
144		vmidi->trigger = 1;
145	} else {
146		vmidi->trigger = 0;
147	}
148}
149
150/*
151 * trigger rawmidi stream for output
152 */
153static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
154{
155	struct snd_virmidi *vmidi = substream->runtime->private_data;
156	int count, res;
157	unsigned char buf[32], *pbuf;
158	unsigned long flags;
159
160	if (up) {
161		vmidi->trigger = 1;
162		if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
163		    !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
164			while (snd_rawmidi_transmit(substream, buf,
165						    sizeof(buf)) > 0) {
166				/* ignored */
167			}
168			return;
169		}
170		if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
171			if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
172				return;
173			vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
174		}
175		spin_lock_irqsave(&substream->runtime->lock, flags);
176		while (1) {
177			count = __snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
178			if (count <= 0)
179				break;
180			pbuf = buf;
181			while (count > 0) {
182				res = snd_midi_event_encode(vmidi->parser, pbuf, count, &vmidi->event);
183				if (res < 0) {
184					snd_midi_event_reset_encode(vmidi->parser);
185					continue;
186				}
187				__snd_rawmidi_transmit_ack(substream, res);
188				pbuf += res;
189				count -= res;
190				if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
191					if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
192						goto out;
193					vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
194				}
195			}
196		}
197	out:
198		spin_unlock_irqrestore(&substream->runtime->lock, flags);
199	} else {
200		vmidi->trigger = 0;
201	}
202}
203
204/*
205 * open rawmidi handle for input
206 */
207static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
208{
209	struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
210	struct snd_rawmidi_runtime *runtime = substream->runtime;
211	struct snd_virmidi *vmidi;
212	unsigned long flags;
213
214	vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
215	if (vmidi == NULL)
216		return -ENOMEM;
217	vmidi->substream = substream;
218	if (snd_midi_event_new(0, &vmidi->parser) < 0) {
219		kfree(vmidi);
220		return -ENOMEM;
221	}
222	vmidi->seq_mode = rdev->seq_mode;
223	vmidi->client = rdev->client;
224	vmidi->port = rdev->port;
225	runtime->private_data = vmidi;
226	write_lock_irqsave(&rdev->filelist_lock, flags);
227	list_add_tail(&vmidi->list, &rdev->filelist);
228	write_unlock_irqrestore(&rdev->filelist_lock, flags);
229	vmidi->rdev = rdev;
230	return 0;
231}
232
233/*
234 * open rawmidi handle for output
235 */
236static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
237{
238	struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
239	struct snd_rawmidi_runtime *runtime = substream->runtime;
240	struct snd_virmidi *vmidi;
241
242	vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
243	if (vmidi == NULL)
244		return -ENOMEM;
245	vmidi->substream = substream;
246	if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
247		kfree(vmidi);
248		return -ENOMEM;
249	}
250	vmidi->seq_mode = rdev->seq_mode;
251	vmidi->client = rdev->client;
252	vmidi->port = rdev->port;
253	snd_virmidi_init_event(vmidi, &vmidi->event);
254	vmidi->rdev = rdev;
255	runtime->private_data = vmidi;
256	return 0;
257}
258
259/*
260 * close rawmidi handle for input
261 */
262static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
263{
264	struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
265	struct snd_virmidi *vmidi = substream->runtime->private_data;
266
267	write_lock_irq(&rdev->filelist_lock);
268	list_del(&vmidi->list);
269	write_unlock_irq(&rdev->filelist_lock);
270	snd_midi_event_free(vmidi->parser);
271	substream->runtime->private_data = NULL;
272	kfree(vmidi);
273	return 0;
274}
275
276/*
277 * close rawmidi handle for output
278 */
279static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
280{
281	struct snd_virmidi *vmidi = substream->runtime->private_data;
282	snd_midi_event_free(vmidi->parser);
283	substream->runtime->private_data = NULL;
284	kfree(vmidi);
285	return 0;
286}
287
288/*
289 * subscribe callback - allow output to rawmidi device
290 */
291static int snd_virmidi_subscribe(void *private_data,
292				 struct snd_seq_port_subscribe *info)
293{
294	struct snd_virmidi_dev *rdev;
295
296	rdev = private_data;
297	if (!try_module_get(rdev->card->module))
298		return -EFAULT;
299	rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
300	return 0;
301}
302
303/*
304 * unsubscribe callback - disallow output to rawmidi device
305 */
306static int snd_virmidi_unsubscribe(void *private_data,
307				   struct snd_seq_port_subscribe *info)
308{
309	struct snd_virmidi_dev *rdev;
310
311	rdev = private_data;
312	rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
313	module_put(rdev->card->module);
314	return 0;
315}
316
317
318/*
319 * use callback - allow input to rawmidi device
320 */
321static int snd_virmidi_use(void *private_data,
322			   struct snd_seq_port_subscribe *info)
323{
324	struct snd_virmidi_dev *rdev;
325
326	rdev = private_data;
327	if (!try_module_get(rdev->card->module))
328		return -EFAULT;
329	rdev->flags |= SNDRV_VIRMIDI_USE;
330	return 0;
331}
332
333/*
334 * unuse callback - disallow input to rawmidi device
335 */
336static int snd_virmidi_unuse(void *private_data,
337			     struct snd_seq_port_subscribe *info)
338{
339	struct snd_virmidi_dev *rdev;
340
341	rdev = private_data;
342	rdev->flags &= ~SNDRV_VIRMIDI_USE;
343	module_put(rdev->card->module);
344	return 0;
345}
346
347
348/*
349 *  Register functions
350 */
351
352static struct snd_rawmidi_ops snd_virmidi_input_ops = {
353	.open = snd_virmidi_input_open,
354	.close = snd_virmidi_input_close,
355	.trigger = snd_virmidi_input_trigger,
356};
357
358static struct snd_rawmidi_ops snd_virmidi_output_ops = {
359	.open = snd_virmidi_output_open,
360	.close = snd_virmidi_output_close,
361	.trigger = snd_virmidi_output_trigger,
362};
363
364/*
365 * create a sequencer client and a port
366 */
367static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
368{
369	int client;
370	struct snd_seq_port_callback pcallbacks;
371	struct snd_seq_port_info *pinfo;
372	int err;
373
374	if (rdev->client >= 0)
375		return 0;
376
377	pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
378	if (!pinfo) {
379		err = -ENOMEM;
380		goto __error;
381	}
382
383	client = snd_seq_create_kernel_client(rdev->card, rdev->device,
384					      "%s %d-%d", rdev->rmidi->name,
385					      rdev->card->number,
386					      rdev->device);
387	if (client < 0) {
388		err = client;
389		goto __error;
390	}
391	rdev->client = client;
392
393	/* create a port */
394	pinfo->addr.client = client;
395	sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
396	/* set all capabilities */
397	pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
398	pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
399	pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
400	pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
401		| SNDRV_SEQ_PORT_TYPE_SOFTWARE
402		| SNDRV_SEQ_PORT_TYPE_PORT;
403	pinfo->midi_channels = 16;
404	memset(&pcallbacks, 0, sizeof(pcallbacks));
405	pcallbacks.owner = THIS_MODULE;
406	pcallbacks.private_data = rdev;
407	pcallbacks.subscribe = snd_virmidi_subscribe;
408	pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
409	pcallbacks.use = snd_virmidi_use;
410	pcallbacks.unuse = snd_virmidi_unuse;
411	pcallbacks.event_input = snd_virmidi_event_input;
412	pinfo->kernel = &pcallbacks;
413	err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
414	if (err < 0) {
415		snd_seq_delete_kernel_client(client);
416		rdev->client = -1;
417		goto __error;
418	}
419
420	rdev->port = pinfo->addr.port;
421	err = 0; /* success */
422
423 __error:
424	kfree(pinfo);
425	return err;
426}
427
428
429/*
430 * release the sequencer client
431 */
432static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
433{
434	if (rdev->client >= 0) {
435		snd_seq_delete_kernel_client(rdev->client);
436		rdev->client = -1;
437	}
438}
439
440/*
441 * register the device
442 */
443static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
444{
445	struct snd_virmidi_dev *rdev = rmidi->private_data;
446	int err;
447
448	switch (rdev->seq_mode) {
449	case SNDRV_VIRMIDI_SEQ_DISPATCH:
450		err = snd_virmidi_dev_attach_seq(rdev);
451		if (err < 0)
452			return err;
453		break;
454	case SNDRV_VIRMIDI_SEQ_ATTACH:
455		if (rdev->client == 0)
456			return -EINVAL;
457		/* should check presence of port more strictly.. */
458		break;
459	default:
460		pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
461		return -EINVAL;
462	}
463	return 0;
464}
465
466
467/*
468 * unregister the device
469 */
470static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
471{
472	struct snd_virmidi_dev *rdev = rmidi->private_data;
473
474	if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
475		snd_virmidi_dev_detach_seq(rdev);
476	return 0;
477}
478
479/*
480 *
481 */
482static struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
483	.dev_register = snd_virmidi_dev_register,
484	.dev_unregister = snd_virmidi_dev_unregister,
485};
486
487/*
488 * free device
489 */
490static void snd_virmidi_free(struct snd_rawmidi *rmidi)
491{
492	struct snd_virmidi_dev *rdev = rmidi->private_data;
493	kfree(rdev);
494}
495
496/*
497 * create a new device
498 *
499 */
500/* exported */
501int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
502{
503	struct snd_rawmidi *rmidi;
504	struct snd_virmidi_dev *rdev;
505	int err;
506
507	*rrmidi = NULL;
508	if ((err = snd_rawmidi_new(card, "VirMidi", device,
509				   16,	/* may be configurable */
510				   16,	/* may be configurable */
511				   &rmidi)) < 0)
512		return err;
513	strcpy(rmidi->name, rmidi->id);
514	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
515	if (rdev == NULL) {
516		snd_device_free(card, rmidi);
517		return -ENOMEM;
518	}
519	rdev->card = card;
520	rdev->rmidi = rmidi;
521	rdev->device = device;
522	rdev->client = -1;
523	rwlock_init(&rdev->filelist_lock);
524	INIT_LIST_HEAD(&rdev->filelist);
525	rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
526	rmidi->private_data = rdev;
527	rmidi->private_free = snd_virmidi_free;
528	rmidi->ops = &snd_virmidi_global_ops;
529	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
530	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
531	rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
532			    SNDRV_RAWMIDI_INFO_OUTPUT |
533			    SNDRV_RAWMIDI_INFO_DUPLEX;
534	*rrmidi = rmidi;
535	return 0;
536}
537
538/*
539 *  ENTRY functions
540 */
541
542static int __init alsa_virmidi_init(void)
543{
544	return 0;
545}
546
547static void __exit alsa_virmidi_exit(void)
548{
549}
550
551module_init(alsa_virmidi_init)
552module_exit(alsa_virmidi_exit)
553
554EXPORT_SYMBOL(snd_virmidi_new);
555