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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * MIDI byte <-> sequencer event coder4 *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 18MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>");19MODULE_DESCRIPTION("MIDI byte <-> sequencer event coder");20MODULE_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 725#define ST_SPECIAL 826#define ST_SYSEX ST_SPECIAL27/* from 8 to 15 are events for 0xf0-0xf7 */28 29 30/*31 * prototypes32 */33static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev);34static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);35static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);36static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);37static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev);38static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev);39static void note_decode(struct snd_seq_event *ev, unsigned char *buf);40static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf);41static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf);42static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf);43static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf);44 45/*46 * event list47 */48static 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 83static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf, int len,84 struct snd_seq_event *ev);85static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf, int count,86 struct snd_seq_event *ev);87 88static struct extra_event_list {89 int event;90 int (*decode)(struct snd_midi_event *dev, unsigned char *buf, int len,91 struct snd_seq_event *ev);92} extra_event[] = {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 record100 */101 102int 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(sizeof(*dev), GFP_KERNEL);108 if (dev == NULL)109 return -ENOMEM;110 if (bufsize > 0) {111 dev->buf = kmalloc(bufsize, GFP_KERNEL);112 if (dev->buf == NULL) {113 kfree(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}124EXPORT_SYMBOL(snd_midi_event_new);125 126void snd_midi_event_free(struct snd_midi_event *dev)127{128 if (dev != NULL) {129 kfree(dev->buf);130 kfree(dev);131 }132}133EXPORT_SYMBOL(snd_midi_event_free);134 135/*136 * initialize record137 */138static 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 145void snd_midi_event_reset_encode(struct snd_midi_event *dev)146{147 guard(spinlock_irqsave)(&dev->lock);148 reset_encode(dev);149}150EXPORT_SYMBOL(snd_midi_event_reset_encode);151 152void snd_midi_event_reset_decode(struct snd_midi_event *dev)153{154 guard(spinlock_irqsave)(&dev->lock);155 dev->lastcmd = 0xff;156}157EXPORT_SYMBOL(snd_midi_event_reset_decode);158 159void snd_midi_event_no_status(struct snd_midi_event *dev, int on)160{161 dev->nostat = on ? 1 : 0;162}163EXPORT_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 event168 * false data is not finished169 */170bool 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)(&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 else191 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 else227 reset_encode(dev); /* all parsed */228 rc = true;229 }230 }231 232 return rc;233}234EXPORT_SYMBOL(snd_midi_event_encode_byte);235 236/* encode note event */237static 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 */245static 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 */252static 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 */259static 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*/267static 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 */273static 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 bytes280 * return the size of decoded midi events281 */282long 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 else304 /* 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(ev, count, buf, 1, 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(&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(&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}336EXPORT_SYMBOL(snd_midi_event_decode);337 338 339/* decode note event */340static 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 */347static 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 */353static 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 */361static 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 */368static 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 */375static int extra_decode_ctrl14(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 */413static int extra_decode_xrpn(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