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