// SPDX-License-Identifier: GPL-2.0-or-later
/*
* MIDI byte <-> sequencer event coder
*
* Copyright (C) 1998,99 Takashi Iwai <[email protected]>,
* Jaroslav Kysela <[email protected]>
*/
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/seq_kernel.h>
#include <sound/seq_midi_event.h>
#include <sound/asoundef.h>
MODULE_AUTHOR("Takashi Iwai <[email protected]>, Jaroslav Kysela <[email protected]>");
MODULE_DESCRIPTION("MIDI byte <-> sequencer event coder");
MODULE_LICENSE("GPL");
/* event type, index into status_event[] */
/* from 0 to 6 are normal commands (note off, on, etc.) for 0x9?-0xe? */
#define ST_INVALID 7
#define ST_SPECIAL 8
#define ST_SYSEX ST_SPECIAL
/* from 8 to 15 are events for 0xf0-0xf7 */
/*
* prototypes
*/
static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
static void note_decode(struct snd_seq_event *ev, unsigned char *buf);
static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf);
static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf);
static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf);
static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf);
/*
* event list
*/
static struct status_event_list {
int event;
int qlen;
void (*encode)(struct snd_midi_event *dev, struct snd_seq_event *ev);
void (*decode)(struct snd_seq_event *ev, unsigned char *buf);
} status_event[] = {
/* 0x80 - 0xef */
{SNDRV_SEQ_EVENT_NOTEOFF, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_NOTEON, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_KEYPRESS, 2, note_event, note_decode},
{SNDRV_SEQ_EVENT_CONTROLLER, 2, two_param_ctrl_event, two_param_decode},
{SNDRV_SEQ_EVENT_PGMCHANGE, 1, one_param_ctrl_event, one_param_decode},
{SNDRV_SEQ_EVENT_CHANPRESS, 1, one_param_ctrl_event, one_param_decode},
{SNDRV_SEQ_EVENT_PITCHBEND, 2, pitchbend_ctrl_event, pitchbend_decode},
/* invalid */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL},
/* 0xf0 - 0xff */
{SNDRV_SEQ_EVENT_SYSEX, 1, NULL, NULL}, /* sysex: 0xf0 */
{SNDRV_SEQ_EVENT_QFRAME, 1, one_param_event, one_param_decode}, /* 0xf1 */
{SNDRV_SEQ_EVENT_SONGPOS, 2, songpos_event, songpos_decode}, /* 0xf2 */
{SNDRV_SEQ_EVENT_SONGSEL, 1, one_param_event, one_param_decode}, /* 0xf3 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf4 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf5 */
{SNDRV_SEQ_EVENT_TUNE_REQUEST, 0, NULL, NULL}, /* 0xf6 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf7 */
{SNDRV_SEQ_EVENT_CLOCK, 0, NULL, NULL}, /* 0xf8 */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf9 */
{SNDRV_SEQ_EVENT_START, 0, NULL, NULL}, /* 0xfa */
{SNDRV_SEQ_EVENT_CONTINUE, 0, NULL, NULL}, /* 0xfb */
{SNDRV_SEQ_EVENT_STOP, 0, NULL, NULL}, /* 0xfc */
{SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xfd */
{SNDRV_SEQ_EVENT_SENSING, 0, NULL, NULL}, /* 0xfe */
{SNDRV_SEQ_EVENT_RESET, 0, NULL, NULL}, /* 0xff */
};
static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf, int len,
struct snd_seq_event *ev);
static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf, int count,
struct snd_seq_event *ev);
static struct extra_event_list {
int event;
int (*decode)(struct snd_midi_event *dev, unsigned char *buf, int len,
struct snd_seq_event *ev);
} extra_event[] = {
{SNDRV_SEQ_EVENT_CONTROL14, extra_decode_ctrl14},
{SNDRV_SEQ_EVENT_NONREGPARAM, extra_decode_xrpn},
{SNDRV_SEQ_EVENT_REGPARAM, extra_decode_xrpn},
};
/*
* new/delete record
*/
int snd_midi_event_new(int bufsize, struct snd_midi_event **rdev)
{
struct snd_midi_event *dev;
*rdev = NULL;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (dev == NULL)
return -ENOMEM;
if (bufsize > 0) {
dev->buf = kmalloc(bufsize, GFP_KERNEL);
if (dev->buf == NULL) {
kfree(dev);
return -ENOMEM;
}
}
dev->bufsize = bufsize;
dev->lastcmd = 0xff;
dev->type = ST_INVALID;
spin_lock_init(&dev->lock);
*rdev = dev;
return 0;
}
EXPORT_SYMBOL(snd_midi_event_new);
void snd_midi_event_free(struct snd_midi_event *dev)
{
if (dev != NULL) {
kfree(dev->buf);
kfree(dev);
}
}
EXPORT_SYMBOL(snd_midi_event_free);
/*
* initialize record
*/
static inline void reset_encode(struct snd_midi_event *dev)
{
dev->read = 0;
dev->qlen = 0;
dev->type = ST_INVALID;
}
void snd_midi_event_reset_encode(struct snd_midi_event *dev)
{
guard(spinlock_irqsave)(&dev->lock);
reset_encode(dev);
}
EXPORT_SYMBOL(snd_midi_event_reset_encode);
void snd_midi_event_reset_decode(struct snd_midi_event *dev)
{
guard(spinlock_irqsave)(&dev->lock);
dev->lastcmd = 0xff;
}
EXPORT_SYMBOL(snd_midi_event_reset_decode);
void snd_midi_event_no_status(struct snd_midi_event *dev, int on)
{
dev->nostat = on ? 1 : 0;
}
EXPORT_SYMBOL(snd_midi_event_no_status);
/*
* read one byte and encode to sequencer event:
* return true if MIDI bytes are encoded to an event
* false data is not finished
*/
bool snd_midi_event_encode_byte(struct snd_midi_event *dev, unsigned char c,
struct snd_seq_event *ev)
{
bool rc = false;
if (c >= MIDI_CMD_COMMON_CLOCK) {
/* real-time event */
ev->type = status_event[ST_SPECIAL + c - 0xf0].event;
ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
return ev->type != SNDRV_SEQ_EVENT_NONE;
}
guard(spinlock_irqsave)(&dev->lock);
if ((c & 0x80) &&
(c != MIDI_CMD_COMMON_SYSEX_END || dev->type != ST_SYSEX)) {
/* new command */
dev->buf[0] = c;
if ((c & 0xf0) == 0xf0) /* system messages */
dev->type = (c & 0x0f) + ST_SPECIAL;
else
dev->type = (c >> 4) & 0x07;
dev->read = 1;
dev->qlen = status_event[dev->type].qlen;
} else {
if (dev->qlen > 0) {
/* rest of command */
dev->buf[dev->read++] = c;
if (dev->type != ST_SYSEX)
dev->qlen--;
} else {
/* running status */
dev->buf[1] = c;
dev->qlen = status_event[dev->type].qlen - 1;
dev->read = 2;
}
}
if (dev->qlen == 0) {
ev->type = status_event[dev->type].event;
ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
if (status_event[dev->type].encode) /* set data values */
status_event[dev->type].encode(dev, ev);
if (dev->type >= ST_SPECIAL)
dev->type = ST_INVALID;
rc = true;
} else if (dev->type == ST_SYSEX) {
if (c == MIDI_CMD_COMMON_SYSEX_END ||
dev->read >= dev->bufsize) {
ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
ev->flags |= SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
ev->type = SNDRV_SEQ_EVENT_SYSEX;
ev->data.ext.len = dev->read;
ev->data.ext.ptr = dev->buf;
if (c != MIDI_CMD_COMMON_SYSEX_END)
dev->read = 0; /* continue to parse */
else
reset_encode(dev); /* all parsed */
rc = true;
}
}
return rc;
}
EXPORT_SYMBOL(snd_midi_event_encode_byte);
/* encode note event */
static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
{
ev->data.note.channel = dev->buf[0] & 0x0f;
ev->data.note.note = dev->buf[1];
ev->data.note.velocity = dev->buf[2];
}
/* encode one parameter controls */
static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
{
ev->data.control.channel = dev->buf[0] & 0x0f;
ev->data.control.value = dev->buf[1];
}
/* encode pitch wheel change */
static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
{
ev->data.control.channel = dev->buf[0] & 0x0f;
ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1] - 8192;
}
/* encode midi control change */
static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
{
ev->data.control.channel = dev->buf[0] & 0x0f;
ev->data.control.param = dev->buf[1];
ev->data.control.value = dev->buf[2];
}
/* encode one parameter value*/
static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
{
ev->data.control.value = dev->buf[1];
}
/* encode song position */
static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
{
ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1];
}
/*
* decode from a sequencer event to midi bytes
* return the size of decoded midi events
*/
long snd_midi_event_decode(struct snd_midi_event *dev, unsigned char *buf, long count,
struct snd_seq_event *ev)
{
unsigned int cmd, type;
if (ev->type == SNDRV_SEQ_EVENT_NONE)
return -ENOENT;
for (type = 0; type < ARRAY_SIZE(status_event); type++) {
if (ev->type == status_event[type].event)
goto __found;
}
for (type = 0; type < ARRAY_SIZE(extra_event); type++) {
if (ev->type == extra_event[type].event)
return extra_event[type].decode(dev, buf, count, ev);
}
return -ENOENT;
__found:
if (type >= ST_SPECIAL)
cmd = 0xf0 + (type - ST_SPECIAL);
else
/* data.note.channel and data.control.channel is identical */
cmd = 0x80 | (type << 4) | (ev->data.note.channel & 0x0f);
if (cmd == MIDI_CMD_COMMON_SYSEX) {
snd_midi_event_reset_decode(dev);
return snd_seq_expand_var_event(ev, count, buf, 1, 0);
} else {
int qlen;
unsigned char xbuf[4];
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd || dev->nostat) {
dev->lastcmd = cmd;
spin_unlock_irqrestore(&dev->lock, flags);
xbuf[0] = cmd;
if (status_event[type].decode)
status_event[type].decode(ev, xbuf + 1);
qlen = status_event[type].qlen + 1;
} else {
spin_unlock_irqrestore(&dev->lock, flags);
if (status_event[type].decode)
status_event[type].decode(ev, xbuf + 0);
qlen = status_event[type].qlen;
}
if (count < qlen)
return -ENOMEM;
memcpy(buf, xbuf, qlen);
return qlen;
}
}
EXPORT_SYMBOL(snd_midi_event_decode);
/* decode note event */
static void note_decode(struct snd_seq_event *ev, unsigned char *buf)
{
buf[0] = ev->data.note.note & 0x7f;
buf[1] = ev->data.note.velocity & 0x7f;
}
/* decode one parameter controls */
static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf)
{
buf[0] = ev->data.control.value & 0x7f;
}
/* decode pitch wheel change */
static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf)
{
int value = ev->data.control.value + 8192;
buf[0] = value & 0x7f;
buf[1] = (value >> 7) & 0x7f;
}
/* decode midi control change */
static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf)
{
buf[0] = ev->data.control.param & 0x7f;
buf[1] = ev->data.control.value & 0x7f;
}
/* decode song position */
static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf)
{
buf[0] = ev->data.control.value & 0x7f;
buf[1] = (ev->data.control.value >> 7) & 0x7f;
}
/* decode 14bit control */
static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf,
int count, struct snd_seq_event *ev)
{
unsigned char cmd;
int idx = 0;
cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
if (ev->data.control.param < 0x20) {
if (count < 4)
return -ENOMEM;
if (dev->nostat && count < 6)
return -ENOMEM;
if (cmd != dev->lastcmd || dev->nostat) {
if (count < 5)
return -ENOMEM;
buf[idx++] = dev->lastcmd = cmd;
}
buf[idx++] = ev->data.control.param;
buf[idx++] = (ev->data.control.value >> 7) & 0x7f;
if (dev->nostat)
buf[idx++] = cmd;
buf[idx++] = ev->data.control.param + 0x20;
buf[idx++] = ev->data.control.value & 0x7f;
} else {
if (count < 2)
return -ENOMEM;
if (cmd != dev->lastcmd || dev->nostat) {
if (count < 3)
return -ENOMEM;
buf[idx++] = dev->lastcmd = cmd;
}
buf[idx++] = ev->data.control.param & 0x7f;
buf[idx++] = ev->data.control.value & 0x7f;
}
return idx;
}
/* decode reg/nonreg param */
static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf,
int count, struct snd_seq_event *ev)
{
unsigned char cmd;
const char *cbytes;
static const char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,
MIDI_CTL_NONREG_PARM_NUM_LSB,
MIDI_CTL_MSB_DATA_ENTRY,
MIDI_CTL_LSB_DATA_ENTRY };
static const char cbytes_rpn[4] = { MIDI_CTL_REGIST_PARM_NUM_MSB,
MIDI_CTL_REGIST_PARM_NUM_LSB,
MIDI_CTL_MSB_DATA_ENTRY,
MIDI_CTL_LSB_DATA_ENTRY };
unsigned char bytes[4];
int idx = 0, i;
if (count < 8)
return -ENOMEM;
if (dev->nostat && count < 12)
return -ENOMEM;
cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
bytes[0] = (ev->data.control.param & 0x3f80) >> 7;
bytes[1] = ev->data.control.param & 0x007f;
bytes[2] = (ev->data.control.value & 0x3f80) >> 7;
bytes[3] = ev->data.control.value & 0x007f;
if (cmd != dev->lastcmd && !dev->nostat) {
if (count < 9)
return -ENOMEM;
buf[idx++] = dev->lastcmd = cmd;
}
cbytes = ev->type == SNDRV_SEQ_EVENT_NONREGPARAM ? cbytes_nrpn : cbytes_rpn;
for (i = 0; i < 4; i++) {
if (dev->nostat)
buf[idx++] = dev->lastcmd = cmd;
buf[idx++] = cbytes[i];
buf[idx++] = bytes[i];
}
return idx;
}
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