1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Generic MIDI synth driver for ALSA sequencer 4 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl> 5 * Jaroslav Kysela <perex@perex.cz> 6 */ 7 8/* 9Possible options for midisynth module: 10 - automatic opening of midi ports on first received event or subscription 11 (close will be performed when client leaves) 12*/ 13 14 15#include <linux/init.h> 16#include <linux/slab.h> 17#include <linux/errno.h> 18#include <linux/string.h> 19#include <linux/module.h> 20#include <linux/mutex.h> 21#include <sound/core.h> 22#include <sound/rawmidi.h> 23#include <sound/seq_kernel.h> 24#include <sound/seq_device.h> 25#include <sound/seq_midi_event.h> 26#include <sound/initval.h> 27 28MODULE_AUTHOR("Frank van de Pol <fvdpol@coil.demon.nl>, Jaroslav Kysela <perex@perex.cz>"); 29MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer MIDI synth."); 30MODULE_LICENSE("GPL"); 31static int output_buffer_size = PAGE_SIZE; 32module_param(output_buffer_size, int, 0644); 33MODULE_PARM_DESC(output_buffer_size, "Output buffer size in bytes."); 34static int input_buffer_size = PAGE_SIZE; 35module_param(input_buffer_size, int, 0644); 36MODULE_PARM_DESC(input_buffer_size, "Input buffer size in bytes."); 37 38/* data for this midi synth driver */ 39struct seq_midisynth { 40 struct snd_card *card; 41 struct snd_rawmidi *rmidi; 42 int device; 43 int subdevice; 44 struct snd_rawmidi_file input_rfile; 45 struct snd_rawmidi_file output_rfile; 46 int seq_client; 47 int seq_port; 48 struct snd_midi_event *parser; 49}; 50 51struct seq_midisynth_client { 52 int seq_client; 53 int num_ports; 54 int ports_per_device[SNDRV_RAWMIDI_DEVICES]; 55 struct seq_midisynth *ports[SNDRV_RAWMIDI_DEVICES]; 56}; 57 58static struct seq_midisynth_client *synths[SNDRV_CARDS]; 59static DEFINE_MUTEX(register_mutex); 60 61/* handle rawmidi input event (MIDI v1.0 stream) */ 62static void snd_midi_input_event(struct snd_rawmidi_substream *substream) 63{ 64 struct snd_rawmidi_runtime *runtime; 65 struct seq_midisynth *msynth; 66 struct snd_seq_event ev; 67 char buf[16], *pbuf; 68 long res; 69 70 if (substream == NULL) 71 return; 72 runtime = substream->runtime; 73 msynth = runtime->private_data; 74 if (msynth == NULL) 75 return; 76 memset(&ev, 0, sizeof(ev)); 77 while (runtime->avail > 0) { 78 res = snd_rawmidi_kernel_read(substream, buf, sizeof(buf)); 79 if (res <= 0) 80 continue; 81 if (msynth->parser == NULL) 82 continue; 83 pbuf = buf; 84 while (res-- > 0) { 85 if (!snd_midi_event_encode_byte(msynth->parser, 86 *pbuf++, &ev)) 87 continue; 88 ev.source.port = msynth->seq_port; 89 ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS; 90 snd_seq_kernel_client_dispatch(msynth->seq_client, &ev, 1, 0); 91 /* clear event and reset header */ 92 memset(&ev, 0, sizeof(ev)); 93 } 94 } 95} 96 97static int dump_midi(struct snd_rawmidi_substream *substream, const char *buf, int count) 98{ 99 struct snd_rawmidi_runtime *runtime; 100 int tmp; 101 102 if (snd_BUG_ON(!substream || !buf)) 103 return -EINVAL; 104 runtime = substream->runtime; 105 tmp = runtime->avail; 106 if (tmp < count) { 107 if (printk_ratelimit()) 108 pr_err("ALSA: seq_midi: MIDI output buffer overrun\n"); 109 return -ENOMEM; 110 } 111 if (snd_rawmidi_kernel_write(substream, buf, count) < count) 112 return -EINVAL; 113 return 0; 114} 115 116/* callback for snd_seq_dump_var_event(), bridging to dump_midi() */ 117static int __dump_midi(void *ptr, void *buf, int count) 118{ 119 return dump_midi(ptr, buf, count); 120} 121 122static int event_process_midi(struct snd_seq_event *ev, int direct, 123 void *private_data, int atomic, int hop) 124{ 125 struct seq_midisynth *msynth = private_data; 126 unsigned char msg[10]; /* buffer for constructing midi messages */ 127 struct snd_rawmidi_substream *substream; 128 int len; 129 130 if (snd_BUG_ON(!msynth)) 131 return -EINVAL; 132 substream = msynth->output_rfile.output; 133 if (substream == NULL) 134 return -ENODEV; 135 if (ev->type == SNDRV_SEQ_EVENT_SYSEX) { /* special case, to save space */ 136 if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) { 137 /* invalid event */ 138 pr_debug("ALSA: seq_midi: invalid sysex event flags = 0x%x\n", ev->flags); 139 return 0; 140 } 141 snd_seq_dump_var_event(ev, __dump_midi, substream); 142 snd_midi_event_reset_decode(msynth->parser); 143 } else { 144 if (msynth->parser == NULL) 145 return -EIO; 146 len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev); 147 if (len < 0) 148 return 0; 149 if (dump_midi(substream, msg, len) < 0) 150 snd_midi_event_reset_decode(msynth->parser); 151 } 152 return 0; 153} 154 155 156static int snd_seq_midisynth_new(struct seq_midisynth *msynth, 157 struct snd_card *card, 158 int device, 159 int subdevice) 160{ 161 if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &msynth->parser) < 0) 162 return -ENOMEM; 163 msynth->card = card; 164 msynth->device = device; 165 msynth->subdevice = subdevice; 166 return 0; 167} 168 169/* open associated midi device for input */ 170static int midisynth_subscribe(void *private_data, struct snd_seq_port_subscribe *info) 171{ 172 int err; 173 struct seq_midisynth *msynth = private_data; 174 struct snd_rawmidi_runtime *runtime; 175 struct snd_rawmidi_params params; 176 177 /* open midi port */ 178 err = snd_rawmidi_kernel_open(msynth->rmidi, msynth->subdevice, 179 SNDRV_RAWMIDI_LFLG_INPUT, 180 &msynth->input_rfile); 181 if (err < 0) { 182 pr_debug("ALSA: seq_midi: midi input open failed!!!\n"); 183 return err; 184 } 185 runtime = msynth->input_rfile.input->runtime; 186 memset(¶ms, 0, sizeof(params)); 187 params.avail_min = 1; 188 params.buffer_size = input_buffer_size; 189 err = snd_rawmidi_input_params(msynth->input_rfile.input, ¶ms); 190 if (err < 0) { 191 snd_rawmidi_kernel_release(&msynth->input_rfile); 192 return err; 193 } 194 snd_midi_event_reset_encode(msynth->parser); 195 runtime->event = snd_midi_input_event; 196 runtime->private_data = msynth; 197 snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0); 198 return 0; 199} 200 201/* close associated midi device for input */ 202static int midisynth_unsubscribe(void *private_data, struct snd_seq_port_subscribe *info) 203{ 204 int err; 205 struct seq_midisynth *msynth = private_data; 206 207 if (snd_BUG_ON(!msynth->input_rfile.input)) 208 return -EINVAL; 209 err = snd_rawmidi_kernel_release(&msynth->input_rfile); 210 return err; 211} 212 213/* open associated midi device for output */ 214static int midisynth_use(void *private_data, struct snd_seq_port_subscribe *info) 215{ 216 int err; 217 struct seq_midisynth *msynth = private_data; 218 struct snd_rawmidi_params params; 219 220 /* open midi port */ 221 err = snd_rawmidi_kernel_open(msynth->rmidi, msynth->subdevice, 222 SNDRV_RAWMIDI_LFLG_OUTPUT, 223 &msynth->output_rfile); 224 if (err < 0) { 225 pr_debug("ALSA: seq_midi: midi output open failed!!!\n"); 226 return err; 227 } 228 memset(¶ms, 0, sizeof(params)); 229 params.avail_min = 1; 230 params.buffer_size = output_buffer_size; 231 params.no_active_sensing = 1; 232 err = snd_rawmidi_output_params(msynth->output_rfile.output, ¶ms); 233 if (err < 0) { 234 snd_rawmidi_kernel_release(&msynth->output_rfile); 235 return err; 236 } 237 snd_midi_event_reset_decode(msynth->parser); 238 return 0; 239} 240 241/* close associated midi device for output */ 242static int midisynth_unuse(void *private_data, struct snd_seq_port_subscribe *info) 243{ 244 struct seq_midisynth *msynth = private_data; 245 246 if (snd_BUG_ON(!msynth->output_rfile.output)) 247 return -EINVAL; 248 snd_rawmidi_drain_output(msynth->output_rfile.output); 249 return snd_rawmidi_kernel_release(&msynth->output_rfile); 250} 251 252/* delete given midi synth port */ 253static void snd_seq_midisynth_delete(struct seq_midisynth *msynth) 254{ 255 if (msynth == NULL) 256 return; 257 258 if (msynth->seq_client > 0) { 259 /* delete port */ 260 snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port); 261 } 262 263 snd_midi_event_free(msynth->parser); 264} 265 266/* register new midi synth port */ 267static int 268snd_seq_midisynth_probe(struct device *_dev) 269{ 270 struct snd_seq_device *dev = to_seq_dev(_dev); 271 struct seq_midisynth_client *client; 272 struct seq_midisynth *msynth, *ms; 273 struct snd_seq_port_info *port __free(kfree) = NULL; 274 struct snd_rawmidi_info *info __free(kfree) = NULL; 275 struct snd_rawmidi *rmidi = dev->private_data; 276 int newclient = 0; 277 unsigned int p, ports; 278 struct snd_seq_port_callback pcallbacks; 279 struct snd_card *card = dev->card; 280 int device = dev->device; 281 unsigned int input_count = 0, output_count = 0; 282 283 if (snd_BUG_ON(!card || device < 0 || device >= SNDRV_RAWMIDI_DEVICES)) 284 return -EINVAL; 285 info = kmalloc(sizeof(*info), GFP_KERNEL); 286 if (! info) 287 return -ENOMEM; 288 info->device = device; 289 info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT; 290 info->subdevice = 0; 291 if (snd_rawmidi_info_select(card, info) >= 0) 292 output_count = info->subdevices_count; 293 info->stream = SNDRV_RAWMIDI_STREAM_INPUT; 294 if (snd_rawmidi_info_select(card, info) >= 0) { 295 input_count = info->subdevices_count; 296 } 297 ports = output_count; 298 if (ports < input_count) 299 ports = input_count; 300 if (ports == 0) 301 return -ENODEV; 302 if (ports > (256 / SNDRV_RAWMIDI_DEVICES)) 303 ports = 256 / SNDRV_RAWMIDI_DEVICES; 304 305 guard(mutex)(®ister_mutex); 306 client = synths[card->number]; 307 if (client == NULL) { 308 newclient = 1; 309 client = kzalloc(sizeof(*client), GFP_KERNEL); 310 if (client == NULL) 311 return -ENOMEM; 312 client->seq_client = 313 snd_seq_create_kernel_client( 314 card, 0, "%s", card->shortname[0] ? 315 (const char *)card->shortname : "External MIDI"); 316 if (client->seq_client < 0) { 317 kfree(client); 318 return -ENOMEM; 319 } 320 } 321 322 msynth = kcalloc(ports, sizeof(struct seq_midisynth), GFP_KERNEL); 323 port = kmalloc(sizeof(*port), GFP_KERNEL); 324 if (msynth == NULL || port == NULL) 325 goto __nomem; 326 327 for (p = 0; p < ports; p++) { 328 ms = &msynth[p]; 329 ms->rmidi = rmidi; 330 331 if (snd_seq_midisynth_new(ms, card, device, p) < 0) 332 goto __nomem; 333 334 /* declare port */ 335 memset(port, 0, sizeof(*port)); 336 port->addr.client = client->seq_client; 337 port->addr.port = device * (256 / SNDRV_RAWMIDI_DEVICES) + p; 338 port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT; 339 memset(info, 0, sizeof(*info)); 340 info->device = device; 341 if (p < output_count) 342 info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT; 343 else 344 info->stream = SNDRV_RAWMIDI_STREAM_INPUT; 345 info->subdevice = p; 346 if (snd_rawmidi_info_select(card, info) >= 0) 347 strcpy(port->name, info->subname); 348 if (! port->name[0]) { 349 if (info->name[0]) { 350 if (ports > 1) 351 scnprintf(port->name, sizeof(port->name), "%s-%u", info->name, p); 352 else 353 scnprintf(port->name, sizeof(port->name), "%s", info->name); 354 } else { 355 /* last resort */ 356 if (ports > 1) 357 sprintf(port->name, "MIDI %d-%d-%u", card->number, device, p); 358 else 359 sprintf(port->name, "MIDI %d-%d", card->number, device); 360 } 361 } 362 if ((info->flags & SNDRV_RAWMIDI_INFO_OUTPUT) && p < output_count) 363 port->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE; 364 if ((info->flags & SNDRV_RAWMIDI_INFO_INPUT) && p < input_count) 365 port->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ; 366 if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) && 367 info->flags & SNDRV_RAWMIDI_INFO_DUPLEX) 368 port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX; 369 if (port->capability & SNDRV_SEQ_PORT_CAP_READ) 370 port->direction |= SNDRV_SEQ_PORT_DIR_INPUT; 371 if (port->capability & SNDRV_SEQ_PORT_CAP_WRITE) 372 port->direction |= SNDRV_SEQ_PORT_DIR_OUTPUT; 373 port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC 374 | SNDRV_SEQ_PORT_TYPE_HARDWARE 375 | SNDRV_SEQ_PORT_TYPE_PORT; 376 port->midi_channels = 16; 377 memset(&pcallbacks, 0, sizeof(pcallbacks)); 378 pcallbacks.owner = THIS_MODULE; 379 pcallbacks.private_data = ms; 380 pcallbacks.subscribe = midisynth_subscribe; 381 pcallbacks.unsubscribe = midisynth_unsubscribe; 382 pcallbacks.use = midisynth_use; 383 pcallbacks.unuse = midisynth_unuse; 384 pcallbacks.event_input = event_process_midi; 385 port->kernel = &pcallbacks; 386 if (rmidi->ops && rmidi->ops->get_port_info) 387 rmidi->ops->get_port_info(rmidi, p, port); 388 if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0) 389 goto __nomem; 390 ms->seq_client = client->seq_client; 391 ms->seq_port = port->addr.port; 392 } 393 client->ports_per_device[device] = ports; 394 client->ports[device] = msynth; 395 client->num_ports++; 396 if (newclient) 397 synths[card->number] = client; 398 return 0; /* success */ 399 400 __nomem: 401 if (msynth != NULL) { 402 for (p = 0; p < ports; p++) 403 snd_seq_midisynth_delete(&msynth[p]); 404 kfree(msynth); 405 } 406 if (newclient) { 407 snd_seq_delete_kernel_client(client->seq_client); 408 kfree(client); 409 } 410 return -ENOMEM; 411} 412 413/* release midi synth port */ 414static int 415snd_seq_midisynth_remove(struct device *_dev) 416{ 417 struct snd_seq_device *dev = to_seq_dev(_dev); 418 struct seq_midisynth_client *client; 419 struct seq_midisynth *msynth; 420 struct snd_card *card = dev->card; 421 int device = dev->device, p, ports; 422 423 guard(mutex)(®ister_mutex); 424 client = synths[card->number]; 425 if (client == NULL || client->ports[device] == NULL) 426 return -ENODEV; 427 ports = client->ports_per_device[device]; 428 client->ports_per_device[device] = 0; 429 msynth = client->ports[device]; 430 client->ports[device] = NULL; 431 for (p = 0; p < ports; p++) 432 snd_seq_midisynth_delete(&msynth[p]); 433 kfree(msynth); 434 client->num_ports--; 435 if (client->num_ports <= 0) { 436 snd_seq_delete_kernel_client(client->seq_client); 437 synths[card->number] = NULL; 438 kfree(client); 439 } 440 return 0; 441} 442 443static struct snd_seq_driver seq_midisynth_driver = { 444 .driver = { 445 .name = KBUILD_MODNAME, 446 .probe = snd_seq_midisynth_probe, 447 .remove = snd_seq_midisynth_remove, 448 }, 449 .id = SNDRV_SEQ_DEV_ID_MIDISYNTH, 450 .argsize = 0, 451}; 452 453module_snd_seq_driver(seq_midisynth_driver); 454