1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * MIDI byte <-> sequencer event coder |
4 | * |
5 | * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>, |
6 | * Jaroslav Kysela <perex@perex.cz> |
7 | */ |
8 | |
9 | #include <linux/slab.h> |
10 | #include <linux/errno.h> |
11 | #include <linux/string.h> |
12 | #include <linux/module.h> |
13 | #include <sound/core.h> |
14 | #include <sound/seq_kernel.h> |
15 | #include <sound/seq_midi_event.h> |
16 | #include <sound/asoundef.h> |
17 | |
18 | MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>" ); |
19 | MODULE_DESCRIPTION("MIDI byte <-> sequencer event coder" ); |
20 | MODULE_LICENSE("GPL" ); |
21 | |
22 | /* event type, index into status_event[] */ |
23 | /* from 0 to 6 are normal commands (note off, on, etc.) for 0x9?-0xe? */ |
24 | #define ST_INVALID 7 |
25 | #define ST_SPECIAL 8 |
26 | #define ST_SYSEX ST_SPECIAL |
27 | /* from 8 to 15 are events for 0xf0-0xf7 */ |
28 | |
29 | |
30 | /* |
31 | * prototypes |
32 | */ |
33 | static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev); |
34 | static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev); |
35 | static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev); |
36 | static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev); |
37 | static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev); |
38 | static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev); |
39 | static void note_decode(struct snd_seq_event *ev, unsigned char *buf); |
40 | static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf); |
41 | static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf); |
42 | static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf); |
43 | static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf); |
44 | |
45 | /* |
46 | * event list |
47 | */ |
48 | static struct status_event_list { |
49 | int event; |
50 | int qlen; |
51 | void (*encode)(struct snd_midi_event *dev, struct snd_seq_event *ev); |
52 | void (*decode)(struct snd_seq_event *ev, unsigned char *buf); |
53 | } status_event[] = { |
54 | /* 0x80 - 0xef */ |
55 | {SNDRV_SEQ_EVENT_NOTEOFF, 2, note_event, note_decode}, |
56 | {SNDRV_SEQ_EVENT_NOTEON, 2, note_event, note_decode}, |
57 | {SNDRV_SEQ_EVENT_KEYPRESS, 2, note_event, note_decode}, |
58 | {SNDRV_SEQ_EVENT_CONTROLLER, 2, two_param_ctrl_event, two_param_decode}, |
59 | {SNDRV_SEQ_EVENT_PGMCHANGE, 1, one_param_ctrl_event, one_param_decode}, |
60 | {SNDRV_SEQ_EVENT_CHANPRESS, 1, one_param_ctrl_event, one_param_decode}, |
61 | {SNDRV_SEQ_EVENT_PITCHBEND, 2, pitchbend_ctrl_event, pitchbend_decode}, |
62 | /* invalid */ |
63 | {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, |
64 | /* 0xf0 - 0xff */ |
65 | {SNDRV_SEQ_EVENT_SYSEX, 1, NULL, NULL}, /* sysex: 0xf0 */ |
66 | {SNDRV_SEQ_EVENT_QFRAME, 1, one_param_event, one_param_decode}, /* 0xf1 */ |
67 | {SNDRV_SEQ_EVENT_SONGPOS, 2, songpos_event, songpos_decode}, /* 0xf2 */ |
68 | {SNDRV_SEQ_EVENT_SONGSEL, 1, one_param_event, one_param_decode}, /* 0xf3 */ |
69 | {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf4 */ |
70 | {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf5 */ |
71 | {SNDRV_SEQ_EVENT_TUNE_REQUEST, 0, NULL, NULL}, /* 0xf6 */ |
72 | {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf7 */ |
73 | {SNDRV_SEQ_EVENT_CLOCK, 0, NULL, NULL}, /* 0xf8 */ |
74 | {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf9 */ |
75 | {SNDRV_SEQ_EVENT_START, 0, NULL, NULL}, /* 0xfa */ |
76 | {SNDRV_SEQ_EVENT_CONTINUE, 0, NULL, NULL}, /* 0xfb */ |
77 | {SNDRV_SEQ_EVENT_STOP, 0, NULL, NULL}, /* 0xfc */ |
78 | {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xfd */ |
79 | {SNDRV_SEQ_EVENT_SENSING, 0, NULL, NULL}, /* 0xfe */ |
80 | {SNDRV_SEQ_EVENT_RESET, 0, NULL, NULL}, /* 0xff */ |
81 | }; |
82 | |
83 | static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf, int len, |
84 | struct snd_seq_event *ev); |
85 | static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf, int count, |
86 | struct snd_seq_event *ev); |
87 | |
88 | static struct { |
89 | int ; |
90 | int (*)(struct snd_midi_event *dev, unsigned char *buf, int len, |
91 | struct snd_seq_event *ev); |
92 | } [] = { |
93 | {SNDRV_SEQ_EVENT_CONTROL14, extra_decode_ctrl14}, |
94 | {SNDRV_SEQ_EVENT_NONREGPARAM, extra_decode_xrpn}, |
95 | {SNDRV_SEQ_EVENT_REGPARAM, extra_decode_xrpn}, |
96 | }; |
97 | |
98 | /* |
99 | * new/delete record |
100 | */ |
101 | |
102 | int snd_midi_event_new(int bufsize, struct snd_midi_event **rdev) |
103 | { |
104 | struct snd_midi_event *dev; |
105 | |
106 | *rdev = NULL; |
107 | dev = kzalloc(size: sizeof(*dev), GFP_KERNEL); |
108 | if (dev == NULL) |
109 | return -ENOMEM; |
110 | if (bufsize > 0) { |
111 | dev->buf = kmalloc(size: bufsize, GFP_KERNEL); |
112 | if (dev->buf == NULL) { |
113 | kfree(objp: dev); |
114 | return -ENOMEM; |
115 | } |
116 | } |
117 | dev->bufsize = bufsize; |
118 | dev->lastcmd = 0xff; |
119 | dev->type = ST_INVALID; |
120 | spin_lock_init(&dev->lock); |
121 | *rdev = dev; |
122 | return 0; |
123 | } |
124 | EXPORT_SYMBOL(snd_midi_event_new); |
125 | |
126 | void snd_midi_event_free(struct snd_midi_event *dev) |
127 | { |
128 | if (dev != NULL) { |
129 | kfree(objp: dev->buf); |
130 | kfree(objp: dev); |
131 | } |
132 | } |
133 | EXPORT_SYMBOL(snd_midi_event_free); |
134 | |
135 | /* |
136 | * initialize record |
137 | */ |
138 | static inline void reset_encode(struct snd_midi_event *dev) |
139 | { |
140 | dev->read = 0; |
141 | dev->qlen = 0; |
142 | dev->type = ST_INVALID; |
143 | } |
144 | |
145 | void snd_midi_event_reset_encode(struct snd_midi_event *dev) |
146 | { |
147 | guard(spinlock_irqsave)(l: &dev->lock); |
148 | reset_encode(dev); |
149 | } |
150 | EXPORT_SYMBOL(snd_midi_event_reset_encode); |
151 | |
152 | void snd_midi_event_reset_decode(struct snd_midi_event *dev) |
153 | { |
154 | guard(spinlock_irqsave)(l: &dev->lock); |
155 | dev->lastcmd = 0xff; |
156 | } |
157 | EXPORT_SYMBOL(snd_midi_event_reset_decode); |
158 | |
159 | void snd_midi_event_no_status(struct snd_midi_event *dev, int on) |
160 | { |
161 | dev->nostat = on ? 1 : 0; |
162 | } |
163 | EXPORT_SYMBOL(snd_midi_event_no_status); |
164 | |
165 | /* |
166 | * read one byte and encode to sequencer event: |
167 | * return true if MIDI bytes are encoded to an event |
168 | * false data is not finished |
169 | */ |
170 | bool snd_midi_event_encode_byte(struct snd_midi_event *dev, unsigned char c, |
171 | struct snd_seq_event *ev) |
172 | { |
173 | bool rc = false; |
174 | |
175 | if (c >= MIDI_CMD_COMMON_CLOCK) { |
176 | /* real-time event */ |
177 | ev->type = status_event[ST_SPECIAL + c - 0xf0].event; |
178 | ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK; |
179 | ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED; |
180 | return ev->type != SNDRV_SEQ_EVENT_NONE; |
181 | } |
182 | |
183 | guard(spinlock_irqsave)(l: &dev->lock); |
184 | if ((c & 0x80) && |
185 | (c != MIDI_CMD_COMMON_SYSEX_END || dev->type != ST_SYSEX)) { |
186 | /* new command */ |
187 | dev->buf[0] = c; |
188 | if ((c & 0xf0) == 0xf0) /* system messages */ |
189 | dev->type = (c & 0x0f) + ST_SPECIAL; |
190 | else |
191 | dev->type = (c >> 4) & 0x07; |
192 | dev->read = 1; |
193 | dev->qlen = status_event[dev->type].qlen; |
194 | } else { |
195 | if (dev->qlen > 0) { |
196 | /* rest of command */ |
197 | dev->buf[dev->read++] = c; |
198 | if (dev->type != ST_SYSEX) |
199 | dev->qlen--; |
200 | } else { |
201 | /* running status */ |
202 | dev->buf[1] = c; |
203 | dev->qlen = status_event[dev->type].qlen - 1; |
204 | dev->read = 2; |
205 | } |
206 | } |
207 | if (dev->qlen == 0) { |
208 | ev->type = status_event[dev->type].event; |
209 | ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK; |
210 | ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED; |
211 | if (status_event[dev->type].encode) /* set data values */ |
212 | status_event[dev->type].encode(dev, ev); |
213 | if (dev->type >= ST_SPECIAL) |
214 | dev->type = ST_INVALID; |
215 | rc = true; |
216 | } else if (dev->type == ST_SYSEX) { |
217 | if (c == MIDI_CMD_COMMON_SYSEX_END || |
218 | dev->read >= dev->bufsize) { |
219 | ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK; |
220 | ev->flags |= SNDRV_SEQ_EVENT_LENGTH_VARIABLE; |
221 | ev->type = SNDRV_SEQ_EVENT_SYSEX; |
222 | ev->data.ext.len = dev->read; |
223 | ev->data.ext.ptr = dev->buf; |
224 | if (c != MIDI_CMD_COMMON_SYSEX_END) |
225 | dev->read = 0; /* continue to parse */ |
226 | else |
227 | reset_encode(dev); /* all parsed */ |
228 | rc = true; |
229 | } |
230 | } |
231 | |
232 | return rc; |
233 | } |
234 | EXPORT_SYMBOL(snd_midi_event_encode_byte); |
235 | |
236 | /* encode note event */ |
237 | static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev) |
238 | { |
239 | ev->data.note.channel = dev->buf[0] & 0x0f; |
240 | ev->data.note.note = dev->buf[1]; |
241 | ev->data.note.velocity = dev->buf[2]; |
242 | } |
243 | |
244 | /* encode one parameter controls */ |
245 | static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev) |
246 | { |
247 | ev->data.control.channel = dev->buf[0] & 0x0f; |
248 | ev->data.control.value = dev->buf[1]; |
249 | } |
250 | |
251 | /* encode pitch wheel change */ |
252 | static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev) |
253 | { |
254 | ev->data.control.channel = dev->buf[0] & 0x0f; |
255 | ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1] - 8192; |
256 | } |
257 | |
258 | /* encode midi control change */ |
259 | static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev) |
260 | { |
261 | ev->data.control.channel = dev->buf[0] & 0x0f; |
262 | ev->data.control.param = dev->buf[1]; |
263 | ev->data.control.value = dev->buf[2]; |
264 | } |
265 | |
266 | /* encode one parameter value*/ |
267 | static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev) |
268 | { |
269 | ev->data.control.value = dev->buf[1]; |
270 | } |
271 | |
272 | /* encode song position */ |
273 | static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev) |
274 | { |
275 | ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1]; |
276 | } |
277 | |
278 | /* |
279 | * decode from a sequencer event to midi bytes |
280 | * return the size of decoded midi events |
281 | */ |
282 | long snd_midi_event_decode(struct snd_midi_event *dev, unsigned char *buf, long count, |
283 | struct snd_seq_event *ev) |
284 | { |
285 | unsigned int cmd, type; |
286 | |
287 | if (ev->type == SNDRV_SEQ_EVENT_NONE) |
288 | return -ENOENT; |
289 | |
290 | for (type = 0; type < ARRAY_SIZE(status_event); type++) { |
291 | if (ev->type == status_event[type].event) |
292 | goto __found; |
293 | } |
294 | for (type = 0; type < ARRAY_SIZE(extra_event); type++) { |
295 | if (ev->type == extra_event[type].event) |
296 | return extra_event[type].decode(dev, buf, count, ev); |
297 | } |
298 | return -ENOENT; |
299 | |
300 | __found: |
301 | if (type >= ST_SPECIAL) |
302 | cmd = 0xf0 + (type - ST_SPECIAL); |
303 | else |
304 | /* data.note.channel and data.control.channel is identical */ |
305 | cmd = 0x80 | (type << 4) | (ev->data.note.channel & 0x0f); |
306 | |
307 | |
308 | if (cmd == MIDI_CMD_COMMON_SYSEX) { |
309 | snd_midi_event_reset_decode(dev); |
310 | return snd_seq_expand_var_event(event: ev, count, buf, in_kernel: 1, size_aligned: 0); |
311 | } else { |
312 | int qlen; |
313 | unsigned char xbuf[4]; |
314 | unsigned long flags; |
315 | |
316 | spin_lock_irqsave(&dev->lock, flags); |
317 | if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd || dev->nostat) { |
318 | dev->lastcmd = cmd; |
319 | spin_unlock_irqrestore(lock: &dev->lock, flags); |
320 | xbuf[0] = cmd; |
321 | if (status_event[type].decode) |
322 | status_event[type].decode(ev, xbuf + 1); |
323 | qlen = status_event[type].qlen + 1; |
324 | } else { |
325 | spin_unlock_irqrestore(lock: &dev->lock, flags); |
326 | if (status_event[type].decode) |
327 | status_event[type].decode(ev, xbuf + 0); |
328 | qlen = status_event[type].qlen; |
329 | } |
330 | if (count < qlen) |
331 | return -ENOMEM; |
332 | memcpy(buf, xbuf, qlen); |
333 | return qlen; |
334 | } |
335 | } |
336 | EXPORT_SYMBOL(snd_midi_event_decode); |
337 | |
338 | |
339 | /* decode note event */ |
340 | static void note_decode(struct snd_seq_event *ev, unsigned char *buf) |
341 | { |
342 | buf[0] = ev->data.note.note & 0x7f; |
343 | buf[1] = ev->data.note.velocity & 0x7f; |
344 | } |
345 | |
346 | /* decode one parameter controls */ |
347 | static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf) |
348 | { |
349 | buf[0] = ev->data.control.value & 0x7f; |
350 | } |
351 | |
352 | /* decode pitch wheel change */ |
353 | static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf) |
354 | { |
355 | int value = ev->data.control.value + 8192; |
356 | buf[0] = value & 0x7f; |
357 | buf[1] = (value >> 7) & 0x7f; |
358 | } |
359 | |
360 | /* decode midi control change */ |
361 | static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf) |
362 | { |
363 | buf[0] = ev->data.control.param & 0x7f; |
364 | buf[1] = ev->data.control.value & 0x7f; |
365 | } |
366 | |
367 | /* decode song position */ |
368 | static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf) |
369 | { |
370 | buf[0] = ev->data.control.value & 0x7f; |
371 | buf[1] = (ev->data.control.value >> 7) & 0x7f; |
372 | } |
373 | |
374 | /* decode 14bit control */ |
375 | static int (struct snd_midi_event *dev, unsigned char *buf, |
376 | int count, struct snd_seq_event *ev) |
377 | { |
378 | unsigned char cmd; |
379 | int idx = 0; |
380 | |
381 | cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f); |
382 | if (ev->data.control.param < 0x20) { |
383 | if (count < 4) |
384 | return -ENOMEM; |
385 | if (dev->nostat && count < 6) |
386 | return -ENOMEM; |
387 | if (cmd != dev->lastcmd || dev->nostat) { |
388 | if (count < 5) |
389 | return -ENOMEM; |
390 | buf[idx++] = dev->lastcmd = cmd; |
391 | } |
392 | buf[idx++] = ev->data.control.param; |
393 | buf[idx++] = (ev->data.control.value >> 7) & 0x7f; |
394 | if (dev->nostat) |
395 | buf[idx++] = cmd; |
396 | buf[idx++] = ev->data.control.param + 0x20; |
397 | buf[idx++] = ev->data.control.value & 0x7f; |
398 | } else { |
399 | if (count < 2) |
400 | return -ENOMEM; |
401 | if (cmd != dev->lastcmd || dev->nostat) { |
402 | if (count < 3) |
403 | return -ENOMEM; |
404 | buf[idx++] = dev->lastcmd = cmd; |
405 | } |
406 | buf[idx++] = ev->data.control.param & 0x7f; |
407 | buf[idx++] = ev->data.control.value & 0x7f; |
408 | } |
409 | return idx; |
410 | } |
411 | |
412 | /* decode reg/nonreg param */ |
413 | static int (struct snd_midi_event *dev, unsigned char *buf, |
414 | int count, struct snd_seq_event *ev) |
415 | { |
416 | unsigned char cmd; |
417 | const char *cbytes; |
418 | static const char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB, |
419 | MIDI_CTL_NONREG_PARM_NUM_LSB, |
420 | MIDI_CTL_MSB_DATA_ENTRY, |
421 | MIDI_CTL_LSB_DATA_ENTRY }; |
422 | static const char cbytes_rpn[4] = { MIDI_CTL_REGIST_PARM_NUM_MSB, |
423 | MIDI_CTL_REGIST_PARM_NUM_LSB, |
424 | MIDI_CTL_MSB_DATA_ENTRY, |
425 | MIDI_CTL_LSB_DATA_ENTRY }; |
426 | unsigned char bytes[4]; |
427 | int idx = 0, i; |
428 | |
429 | if (count < 8) |
430 | return -ENOMEM; |
431 | if (dev->nostat && count < 12) |
432 | return -ENOMEM; |
433 | cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f); |
434 | bytes[0] = (ev->data.control.param & 0x3f80) >> 7; |
435 | bytes[1] = ev->data.control.param & 0x007f; |
436 | bytes[2] = (ev->data.control.value & 0x3f80) >> 7; |
437 | bytes[3] = ev->data.control.value & 0x007f; |
438 | if (cmd != dev->lastcmd && !dev->nostat) { |
439 | if (count < 9) |
440 | return -ENOMEM; |
441 | buf[idx++] = dev->lastcmd = cmd; |
442 | } |
443 | cbytes = ev->type == SNDRV_SEQ_EVENT_NONREGPARAM ? cbytes_nrpn : cbytes_rpn; |
444 | for (i = 0; i < 4; i++) { |
445 | if (dev->nostat) |
446 | buf[idx++] = dev->lastcmd = cmd; |
447 | buf[idx++] = cbytes[i]; |
448 | buf[idx++] = bytes[i]; |
449 | } |
450 | return idx; |
451 | } |
452 | |