1 files changed, 459 insertions, 0 deletions

diff --git a/sound/core/seq/seq_midi_event.c b/sound/core/seq/seq_midi_event.c
new file mode 100644
index 000000000..7511462fe
--- /dev/null
+++ b/sound/core/seq/seq_midi_event.c
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  MIDI byte <-> sequencer event coder
+ *
+ *  Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>,
+ *                        Jaroslav Kysela <perex@perex.cz>
+ */
+
+#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 <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>");
+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)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	reset_encode(dev);
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+EXPORT_SYMBOL(snd_midi_event_reset_encode);
+
+void snd_midi_event_reset_decode(struct snd_midi_event *dev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	dev->lastcmd = 0xff;
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+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;
+	unsigned long flags;
+
+	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;
+	}
+
+	spin_lock_irqsave(&dev->lock, flags);
+	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;
+		}
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+	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;
+}