xref: /linux/sound/core/seq/seq_ump_client.c (revision dd4d315f38272688edea0611a11cadf6a445f61a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* ALSA sequencer binding for UMP device */
3 
4 #include <linux/init.h>
5 #include <linux/slab.h>
6 #include <linux/errno.h>
7 #include <linux/mutex.h>
8 #include <linux/string.h>
9 #include <linux/module.h>
10 #include <asm/byteorder.h>
11 #include <sound/core.h>
12 #include <sound/ump.h>
13 #include <sound/seq_kernel.h>
14 #include <sound/seq_device.h>
15 #include "seq_clientmgr.h"
16 #include "seq_system.h"
17 
18 struct seq_ump_client;
19 struct seq_ump_group;
20 
21 enum {
22 	STR_IN = SNDRV_RAWMIDI_STREAM_INPUT,
23 	STR_OUT = SNDRV_RAWMIDI_STREAM_OUTPUT
24 };
25 
26 /* context for UMP input parsing, per EP */
27 struct seq_ump_input_buffer {
28 	unsigned char len;		/* total length in words */
29 	unsigned char pending;		/* pending words */
30 	unsigned char type;		/* parsed UMP packet type */
31 	unsigned char group;		/* parsed UMP packet group */
32 	u32 buf[4];			/* incoming UMP packet */
33 };
34 
35 /* sequencer client, per UMP EP (rawmidi) */
36 struct seq_ump_client {
37 	struct snd_ump_endpoint *ump;	/* assigned endpoint */
38 	int seq_client;			/* sequencer client id */
39 	int opened[2];			/* current opens for each direction */
40 	struct snd_rawmidi_file out_rfile; /* rawmidi for output */
41 	struct seq_ump_input_buffer input; /* input parser context */
42 	void *ump_info[SNDRV_UMP_MAX_BLOCKS + 1]; /* shadow of seq client ump_info */
43 	struct work_struct group_notify_work; /* FB change notification */
44 };
45 
46 /* number of 32bit words for each UMP message type */
47 static unsigned char ump_packet_words[0x10] = {
48 	1, 1, 1, 2, 2, 4, 1, 1, 2, 2, 2, 3, 3, 4, 4, 4
49 };
50 
51 /* conversion between UMP group and seq port;
52  * assume the port number is equal with UMP group number (1-based)
53  */
54 static unsigned char ump_group_to_seq_port(unsigned char group)
55 {
56 	return group + 1;
57 }
58 
59 /* process the incoming rawmidi stream */
60 static void seq_ump_input_receive(struct snd_ump_endpoint *ump,
61 				  const u32 *val, int words)
62 {
63 	struct seq_ump_client *client = ump->seq_client;
64 	struct snd_seq_ump_event ev = {};
65 
66 	if (!client->opened[STR_IN])
67 		return;
68 
69 	if (ump_is_groupless_msg(ump_message_type(*val)))
70 		ev.source.port = 0; /* UMP EP port */
71 	else
72 		ev.source.port = ump_group_to_seq_port(ump_message_group(*val));
73 	ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
74 	ev.flags = SNDRV_SEQ_EVENT_UMP;
75 	memcpy(ev.ump, val, words << 2);
76 	snd_seq_kernel_client_dispatch(client->seq_client,
77 				       (struct snd_seq_event *)&ev,
78 				       true, 0);
79 }
80 
81 /* process an input sequencer event; only deal with UMP types */
82 static int seq_ump_process_event(struct snd_seq_event *ev, int direct,
83 				 void *private_data, int atomic, int hop)
84 {
85 	struct seq_ump_client *client = private_data;
86 	struct snd_rawmidi_substream *substream;
87 	struct snd_seq_ump_event *ump_ev;
88 	unsigned char type;
89 	int len;
90 
91 	substream = client->out_rfile.output;
92 	if (!substream)
93 		return -ENODEV;
94 	if (!snd_seq_ev_is_ump(ev))
95 		return 0; /* invalid event, skip */
96 	ump_ev = (struct snd_seq_ump_event *)ev;
97 	type = ump_message_type(ump_ev->ump[0]);
98 	len = ump_packet_words[type];
99 	if (len > 4)
100 		return 0; // invalid - skip
101 	snd_rawmidi_kernel_write(substream, ev->data.raw8.d, len << 2);
102 	return 0;
103 }
104 
105 /* open the rawmidi */
106 static int seq_ump_client_open(struct seq_ump_client *client, int dir)
107 {
108 	struct snd_ump_endpoint *ump = client->ump;
109 	int err;
110 
111 	guard(mutex)(&ump->open_mutex);
112 	if (dir == STR_OUT && !client->opened[dir]) {
113 		err = snd_rawmidi_kernel_open(&ump->core, 0,
114 					      SNDRV_RAWMIDI_LFLG_OUTPUT |
115 					      SNDRV_RAWMIDI_LFLG_APPEND,
116 					      &client->out_rfile);
117 		if (err < 0)
118 			return err;
119 	}
120 	client->opened[dir]++;
121 	return 0;
122 }
123 
124 /* close the rawmidi */
125 static int seq_ump_client_close(struct seq_ump_client *client, int dir)
126 {
127 	struct snd_ump_endpoint *ump = client->ump;
128 
129 	guard(mutex)(&ump->open_mutex);
130 	if (!--client->opened[dir])
131 		if (dir == STR_OUT)
132 			snd_rawmidi_kernel_release(&client->out_rfile);
133 	return 0;
134 }
135 
136 /* sequencer subscription ops for each client */
137 static int seq_ump_subscribe(void *pdata, struct snd_seq_port_subscribe *info)
138 {
139 	struct seq_ump_client *client = pdata;
140 
141 	return seq_ump_client_open(client, STR_IN);
142 }
143 
144 static int seq_ump_unsubscribe(void *pdata, struct snd_seq_port_subscribe *info)
145 {
146 	struct seq_ump_client *client = pdata;
147 
148 	return seq_ump_client_close(client, STR_IN);
149 }
150 
151 static int seq_ump_use(void *pdata, struct snd_seq_port_subscribe *info)
152 {
153 	struct seq_ump_client *client = pdata;
154 
155 	return seq_ump_client_open(client, STR_OUT);
156 }
157 
158 static int seq_ump_unuse(void *pdata, struct snd_seq_port_subscribe *info)
159 {
160 	struct seq_ump_client *client = pdata;
161 
162 	return seq_ump_client_close(client, STR_OUT);
163 }
164 
165 /* fill port_info from the given UMP EP and group info */
166 static void fill_port_info(struct snd_seq_port_info *port,
167 			   struct seq_ump_client *client,
168 			   struct snd_ump_group *group)
169 {
170 	unsigned int rawmidi_info = client->ump->core.info_flags;
171 
172 	port->addr.client = client->seq_client;
173 	port->addr.port = ump_group_to_seq_port(group->group);
174 	port->capability = 0;
175 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT)
176 		port->capability |= SNDRV_SEQ_PORT_CAP_WRITE |
177 			SNDRV_SEQ_PORT_CAP_SYNC_WRITE |
178 			SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
179 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT)
180 		port->capability |= SNDRV_SEQ_PORT_CAP_READ |
181 			SNDRV_SEQ_PORT_CAP_SYNC_READ |
182 			SNDRV_SEQ_PORT_CAP_SUBS_READ;
183 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_DUPLEX)
184 		port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
185 	if (group->dir_bits & (1 << STR_IN))
186 		port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
187 	if (group->dir_bits & (1 << STR_OUT))
188 		port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
189 	port->ump_group = group->group + 1;
190 	if (!group->active)
191 		port->capability |= SNDRV_SEQ_PORT_CAP_INACTIVE;
192 	if (group->is_midi1)
193 		port->flags |= SNDRV_SEQ_PORT_FLG_IS_MIDI1;
194 	port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
195 		SNDRV_SEQ_PORT_TYPE_MIDI_UMP |
196 		SNDRV_SEQ_PORT_TYPE_HARDWARE |
197 		SNDRV_SEQ_PORT_TYPE_PORT;
198 	port->midi_channels = 16;
199 	if (*group->name)
200 		snprintf(port->name, sizeof(port->name), "Group %d (%.53s)",
201 			 group->group + 1, group->name);
202 	else
203 		sprintf(port->name, "Group %d", group->group + 1);
204 }
205 
206 /* skip non-existing group for static blocks */
207 static bool skip_group(struct seq_ump_client *client, struct snd_ump_group *group)
208 {
209 	return !group->valid &&
210 		(client->ump->info.flags & SNDRV_UMP_EP_INFO_STATIC_BLOCKS);
211 }
212 
213 /* create a new sequencer port per UMP group */
214 static int seq_ump_group_init(struct seq_ump_client *client, int group_index)
215 {
216 	struct snd_ump_group *group = &client->ump->groups[group_index];
217 	struct snd_seq_port_info *port __free(kfree) = NULL;
218 	struct snd_seq_port_callback pcallbacks;
219 
220 	if (skip_group(client, group))
221 		return 0;
222 
223 	port = kzalloc(sizeof(*port), GFP_KERNEL);
224 	if (!port)
225 		return -ENOMEM;
226 
227 	fill_port_info(port, client, group);
228 	port->flags |= SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
229 	memset(&pcallbacks, 0, sizeof(pcallbacks));
230 	pcallbacks.owner = THIS_MODULE;
231 	pcallbacks.private_data = client;
232 	pcallbacks.subscribe = seq_ump_subscribe;
233 	pcallbacks.unsubscribe = seq_ump_unsubscribe;
234 	pcallbacks.use = seq_ump_use;
235 	pcallbacks.unuse = seq_ump_unuse;
236 	pcallbacks.event_input = seq_ump_process_event;
237 	port->kernel = &pcallbacks;
238 	return snd_seq_kernel_client_ctl(client->seq_client,
239 					 SNDRV_SEQ_IOCTL_CREATE_PORT,
240 					 port);
241 }
242 
243 /* update the sequencer ports; called from notify_fb_change callback */
244 static void update_port_infos(struct seq_ump_client *client)
245 {
246 	struct snd_seq_port_info *old __free(kfree) = NULL;
247 	struct snd_seq_port_info *new __free(kfree) = NULL;
248 	int i, err;
249 
250 	old = kzalloc(sizeof(*old), GFP_KERNEL);
251 	new = kzalloc(sizeof(*new), GFP_KERNEL);
252 	if (!old || !new)
253 		return;
254 
255 	for (i = 0; i < SNDRV_UMP_MAX_GROUPS; i++) {
256 		if (skip_group(client, &client->ump->groups[i]))
257 			continue;
258 
259 		old->addr.client = client->seq_client;
260 		old->addr.port = ump_group_to_seq_port(i);
261 		err = snd_seq_kernel_client_ctl(client->seq_client,
262 						SNDRV_SEQ_IOCTL_GET_PORT_INFO,
263 						old);
264 		if (err < 0)
265 			continue;
266 		fill_port_info(new, client, &client->ump->groups[i]);
267 		if (old->capability == new->capability &&
268 		    !strcmp(old->name, new->name))
269 			continue;
270 		err = snd_seq_kernel_client_ctl(client->seq_client,
271 						SNDRV_SEQ_IOCTL_SET_PORT_INFO,
272 						new);
273 		if (err < 0)
274 			continue;
275 		/* notify to system port */
276 		snd_seq_system_client_ev_port_change(client->seq_client, i);
277 	}
278 }
279 
280 /* create a UMP Endpoint port */
281 static int create_ump_endpoint_port(struct seq_ump_client *client)
282 {
283 	struct snd_seq_port_info *port __free(kfree) = NULL;
284 	struct snd_seq_port_callback pcallbacks;
285 	unsigned int rawmidi_info = client->ump->core.info_flags;
286 	int err;
287 
288 	port = kzalloc(sizeof(*port), GFP_KERNEL);
289 	if (!port)
290 		return -ENOMEM;
291 
292 	port->addr.client = client->seq_client;
293 	port->addr.port = 0; /* fixed */
294 	port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
295 	port->capability = SNDRV_SEQ_PORT_CAP_UMP_ENDPOINT;
296 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT) {
297 		port->capability |= SNDRV_SEQ_PORT_CAP_READ |
298 			SNDRV_SEQ_PORT_CAP_SYNC_READ |
299 			SNDRV_SEQ_PORT_CAP_SUBS_READ;
300 		port->direction |= SNDRV_SEQ_PORT_DIR_INPUT;
301 	}
302 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT) {
303 		port->capability |= SNDRV_SEQ_PORT_CAP_WRITE |
304 			SNDRV_SEQ_PORT_CAP_SYNC_WRITE |
305 			SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
306 		port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT;
307 	}
308 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_DUPLEX)
309 		port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
310 	port->ump_group = 0; /* no associated group, no conversion */
311 	port->type = SNDRV_SEQ_PORT_TYPE_MIDI_UMP |
312 		SNDRV_SEQ_PORT_TYPE_HARDWARE |
313 		SNDRV_SEQ_PORT_TYPE_PORT;
314 	port->midi_channels = 16;
315 	strcpy(port->name, "MIDI 2.0");
316 	memset(&pcallbacks, 0, sizeof(pcallbacks));
317 	pcallbacks.owner = THIS_MODULE;
318 	pcallbacks.private_data = client;
319 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_INPUT) {
320 		pcallbacks.subscribe = seq_ump_subscribe;
321 		pcallbacks.unsubscribe = seq_ump_unsubscribe;
322 	}
323 	if (rawmidi_info & SNDRV_RAWMIDI_INFO_OUTPUT) {
324 		pcallbacks.use = seq_ump_use;
325 		pcallbacks.unuse = seq_ump_unuse;
326 		pcallbacks.event_input = seq_ump_process_event;
327 	}
328 	port->kernel = &pcallbacks;
329 	err = snd_seq_kernel_client_ctl(client->seq_client,
330 					SNDRV_SEQ_IOCTL_CREATE_PORT,
331 					port);
332 	return err;
333 }
334 
335 /* release the client resources */
336 static void seq_ump_client_free(struct seq_ump_client *client)
337 {
338 	cancel_work_sync(&client->group_notify_work);
339 
340 	if (client->seq_client >= 0)
341 		snd_seq_delete_kernel_client(client->seq_client);
342 
343 	client->ump->seq_ops = NULL;
344 	client->ump->seq_client = NULL;
345 
346 	kfree(client);
347 }
348 
349 /* update the MIDI version for the given client */
350 static void setup_client_midi_version(struct seq_ump_client *client)
351 {
352 	struct snd_seq_client *cptr;
353 
354 	cptr = snd_seq_kernel_client_get(client->seq_client);
355 	if (!cptr)
356 		return;
357 	if (client->ump->info.protocol & SNDRV_UMP_EP_INFO_PROTO_MIDI2)
358 		cptr->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_2_0;
359 	else
360 		cptr->midi_version = SNDRV_SEQ_CLIENT_UMP_MIDI_1_0;
361 	snd_seq_kernel_client_put(cptr);
362 }
363 
364 /* set up client's group_filter bitmap */
365 static void setup_client_group_filter(struct seq_ump_client *client)
366 {
367 	struct snd_seq_client *cptr;
368 	unsigned int filter;
369 	int p;
370 
371 	cptr = snd_seq_kernel_client_get(client->seq_client);
372 	if (!cptr)
373 		return;
374 	filter = ~(1U << 0); /* always allow groupless messages */
375 	for (p = 0; p < SNDRV_UMP_MAX_GROUPS; p++) {
376 		if (client->ump->groups[p].active)
377 			filter &= ~(1U << (p + 1));
378 	}
379 	cptr->group_filter = filter;
380 	snd_seq_kernel_client_put(cptr);
381 }
382 
383 /* UMP group change notification */
384 static void handle_group_notify(struct work_struct *work)
385 {
386 	struct seq_ump_client *client =
387 		container_of(work, struct seq_ump_client, group_notify_work);
388 
389 	update_port_infos(client);
390 	setup_client_group_filter(client);
391 }
392 
393 /* UMP FB change notification */
394 static int seq_ump_notify_fb_change(struct snd_ump_endpoint *ump,
395 				    struct snd_ump_block *fb)
396 {
397 	struct seq_ump_client *client = ump->seq_client;
398 
399 	if (!client)
400 		return -ENODEV;
401 	schedule_work(&client->group_notify_work);
402 	return 0;
403 }
404 
405 /* UMP protocol change notification; just update the midi_version field */
406 static int seq_ump_switch_protocol(struct snd_ump_endpoint *ump)
407 {
408 	if (!ump->seq_client)
409 		return -ENODEV;
410 	setup_client_midi_version(ump->seq_client);
411 	return 0;
412 }
413 
414 static const struct snd_seq_ump_ops seq_ump_ops = {
415 	.input_receive = seq_ump_input_receive,
416 	.notify_fb_change = seq_ump_notify_fb_change,
417 	.switch_protocol = seq_ump_switch_protocol,
418 };
419 
420 /* create a sequencer client and ports for the given UMP endpoint */
421 static int snd_seq_ump_probe(struct device *_dev)
422 {
423 	struct snd_seq_device *dev = to_seq_dev(_dev);
424 	struct snd_ump_endpoint *ump = dev->private_data;
425 	struct snd_card *card = dev->card;
426 	struct seq_ump_client *client;
427 	struct snd_ump_block *fb;
428 	struct snd_seq_client *cptr;
429 	int p, err;
430 
431 	client = kzalloc(sizeof(*client), GFP_KERNEL);
432 	if (!client)
433 		return -ENOMEM;
434 
435 	INIT_WORK(&client->group_notify_work, handle_group_notify);
436 	client->ump = ump;
437 
438 	client->seq_client =
439 		snd_seq_create_kernel_client(card, ump->core.device,
440 					     ump->core.name);
441 	if (client->seq_client < 0) {
442 		err = client->seq_client;
443 		goto error;
444 	}
445 
446 	client->ump_info[0] = &ump->info;
447 	list_for_each_entry(fb, &ump->block_list, list)
448 		client->ump_info[fb->info.block_id + 1] = &fb->info;
449 
450 	setup_client_midi_version(client);
451 
452 	for (p = 0; p < SNDRV_UMP_MAX_GROUPS; p++) {
453 		err = seq_ump_group_init(client, p);
454 		if (err < 0)
455 			goto error;
456 	}
457 
458 	setup_client_group_filter(client);
459 
460 	err = create_ump_endpoint_port(client);
461 	if (err < 0)
462 		goto error;
463 
464 	cptr = snd_seq_kernel_client_get(client->seq_client);
465 	if (!cptr) {
466 		err = -EINVAL;
467 		goto error;
468 	}
469 	cptr->ump_info = client->ump_info;
470 	snd_seq_kernel_client_put(cptr);
471 
472 	ump->seq_client = client;
473 	ump->seq_ops = &seq_ump_ops;
474 	return 0;
475 
476  error:
477 	seq_ump_client_free(client);
478 	return err;
479 }
480 
481 /* remove a sequencer client */
482 static int snd_seq_ump_remove(struct device *_dev)
483 {
484 	struct snd_seq_device *dev = to_seq_dev(_dev);
485 	struct snd_ump_endpoint *ump = dev->private_data;
486 
487 	if (ump->seq_client)
488 		seq_ump_client_free(ump->seq_client);
489 	return 0;
490 }
491 
492 static struct snd_seq_driver seq_ump_driver = {
493 	.driver = {
494 		.name = KBUILD_MODNAME,
495 		.probe = snd_seq_ump_probe,
496 		.remove = snd_seq_ump_remove,
497 	},
498 	.id = SNDRV_SEQ_DEV_ID_UMP,
499 	.argsize = 0,
500 };
501 
502 module_snd_seq_driver(seq_ump_driver);
503 
504 MODULE_DESCRIPTION("ALSA sequencer client for UMP rawmidi");
505 MODULE_LICENSE("GPL");
506