Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 2803 insertions, 0 deletions

diff --git a/sound/drivers/opl3/Makefile b/sound/drivers/opl3/Makefile
new file mode 100644
index 000000000..83bca9f1f
--- /dev/null
+++ b/sound/drivers/opl3/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for ALSA
+# Copyright (c) 2001 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-opl3-lib-objs := opl3_lib.o opl3_synth.o
+snd-opl3-synth-y := opl3_seq.o opl3_midi.o opl3_drums.o
+ifneq ($(CONFIG_SND_SEQUENCER_OSS),)
+snd-opl3-synth-y += opl3_oss.o
+endif
+
+obj-$(CONFIG_SND_OPL3_LIB) += snd-opl3-lib.o
+obj-$(CONFIG_SND_OPL4_LIB) += snd-opl3-lib.o
+obj-$(CONFIG_SND_OPL3_LIB_SEQ) += snd-opl3-synth.o
diff --git a/sound/drivers/opl3/opl3_drums.c b/sound/drivers/opl3/opl3_drums.c
new file mode 100644
index 000000000..ccc49f394
--- /dev/null
+++ b/sound/drivers/opl3/opl3_drums.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
+ *
+ *   OPL2/OPL3/OPL4 FM routines for internal percussion channels
+ */
+
+#include "opl3_voice.h"
+
+static const char snd_opl3_drum_table[47] =
+{
+	OPL3_BASSDRUM_ON,  OPL3_BASSDRUM_ON,  OPL3_HIHAT_ON,	/* 35 - 37 */
+	OPL3_SNAREDRUM_ON, OPL3_HIHAT_ON,     OPL3_SNAREDRUM_ON, /* 38 - 40 */
+	OPL3_BASSDRUM_ON,  OPL3_HIHAT_ON,     OPL3_BASSDRUM_ON,	/* 41 - 43 */
+	OPL3_HIHAT_ON,     OPL3_TOMTOM_ON,    OPL3_HIHAT_ON,	/* 44 - 46 */
+	OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,    OPL3_CYMBAL_ON,	/* 47 - 49 */
+
+	OPL3_TOMTOM_ON,    OPL3_CYMBAL_ON,    OPL3_CYMBAL_ON,	/* 50 - 52 */
+	OPL3_CYMBAL_ON,    OPL3_CYMBAL_ON,    OPL3_CYMBAL_ON,	/* 53 - 55 */
+	OPL3_HIHAT_ON,     OPL3_CYMBAL_ON,    OPL3_TOMTOM_ON,	/* 56 - 58 */
+	OPL3_CYMBAL_ON,    OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,	/* 59 - 61 */
+	OPL3_HIHAT_ON,     OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,	/* 62 - 64 */
+
+	OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,	/* 65 - 67 */
+	OPL3_TOMTOM_ON,    OPL3_HIHAT_ON,     OPL3_HIHAT_ON,	/* 68 - 70 */
+	OPL3_HIHAT_ON,     OPL3_HIHAT_ON,     OPL3_TOMTOM_ON,	/* 71 - 73 */
+	OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,	/* 74 - 76 */
+	OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,    OPL3_TOMTOM_ON,	/* 77 - 79 */
+	OPL3_CYMBAL_ON,    OPL3_CYMBAL_ON			/* 80 - 81 */
+};
+
+struct snd_opl3_drum_voice {
+	int voice;
+	int op;
+	unsigned char am_vib;
+	unsigned char ksl_level;
+	unsigned char attack_decay;
+	unsigned char sustain_release;
+	unsigned char feedback_connection;
+	unsigned char wave_select;
+};
+
+struct snd_opl3_drum_note {
+	int voice;
+	unsigned char fnum;
+	unsigned char octave_f;
+	unsigned char feedback_connection;
+};
+
+static const struct snd_opl3_drum_voice bass_op0 = {6, 0, 0x00, 0x32, 0xf8, 0x66, 0x30, 0x00};
+static const struct snd_opl3_drum_voice bass_op1 = {6, 1, 0x00, 0x03, 0xf6, 0x57, 0x30, 0x00};
+static const struct snd_opl3_drum_note bass_note = {6, 0x90, 0x09};
+
+static const struct snd_opl3_drum_voice hihat = {7, 0, 0x00, 0x03, 0xf0, 0x06, 0x20, 0x00};
+
+static const struct snd_opl3_drum_voice snare = {7, 1, 0x00, 0x03, 0xf0, 0x07, 0x20, 0x02};
+static const struct snd_opl3_drum_note snare_note = {7, 0xf4, 0x0d};
+
+static const struct snd_opl3_drum_voice tomtom = {8, 0, 0x02, 0x03, 0xf0, 0x06, 0x10, 0x00};
+static const struct snd_opl3_drum_note tomtom_note = {8, 0xf4, 0x09};
+
+static const struct snd_opl3_drum_voice cymbal = {8, 1, 0x04, 0x03, 0xf0, 0x06, 0x10, 0x00};
+
+/*
+ * set drum voice characteristics
+ */
+static void snd_opl3_drum_voice_set(struct snd_opl3 *opl3,
+				    const struct snd_opl3_drum_voice *data)
+{
+	unsigned char op_offset = snd_opl3_regmap[data->voice][data->op];
+	unsigned char voice_offset = data->voice;
+	unsigned short opl3_reg;
+	
+	/* Set OPL3 AM_VIB register */ 
+	opl3_reg = OPL3_LEFT | (OPL3_REG_AM_VIB + op_offset);
+	opl3->command(opl3, opl3_reg, data->am_vib);
+
+	/* Set OPL3 KSL_LEVEL register */ 
+	opl3_reg = OPL3_LEFT | (OPL3_REG_KSL_LEVEL + op_offset);
+	opl3->command(opl3, opl3_reg, data->ksl_level);
+
+	/* Set OPL3 ATTACK_DECAY register */ 
+	opl3_reg = OPL3_LEFT | (OPL3_REG_ATTACK_DECAY + op_offset);
+	opl3->command(opl3, opl3_reg, data->attack_decay);
+
+	/* Set OPL3 SUSTAIN_RELEASE register */ 
+	opl3_reg = OPL3_LEFT | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
+	opl3->command(opl3, opl3_reg, data->sustain_release);
+
+	/* Set OPL3 FEEDBACK_CONNECTION register */ 
+	opl3_reg = OPL3_LEFT | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
+	opl3->command(opl3, opl3_reg, data->feedback_connection);
+
+	/* Select waveform */
+	opl3_reg = OPL3_LEFT | (OPL3_REG_WAVE_SELECT + op_offset);
+	opl3->command(opl3, opl3_reg, data->wave_select);
+}
+
+/*
+ * Set drum voice pitch
+ */
+static void snd_opl3_drum_note_set(struct snd_opl3 *opl3,
+				   const struct snd_opl3_drum_note *data)
+{
+	unsigned char voice_offset = data->voice;
+	unsigned short opl3_reg;
+
+	/* Set OPL3 FNUM_LOW register */ 
+	opl3_reg = OPL3_LEFT | (OPL3_REG_FNUM_LOW + voice_offset);
+	opl3->command(opl3, opl3_reg, data->fnum);
+
+	/* Set OPL3 KEYON_BLOCK register */ 
+	opl3_reg = OPL3_LEFT | (OPL3_REG_KEYON_BLOCK + voice_offset);
+	opl3->command(opl3, opl3_reg, data->octave_f);
+}
+
+/*
+ * Set drum voice volume and position
+ */
+static void snd_opl3_drum_vol_set(struct snd_opl3 *opl3,
+				  const struct snd_opl3_drum_voice *data,
+				  int vel, struct snd_midi_channel *chan)
+{
+	unsigned char op_offset = snd_opl3_regmap[data->voice][data->op];
+	unsigned char voice_offset = data->voice;
+	unsigned char reg_val;
+	unsigned short opl3_reg;
+
+	/* Set OPL3 KSL_LEVEL register */ 
+	reg_val = data->ksl_level;
+	snd_opl3_calc_volume(&reg_val, vel, chan);
+	opl3_reg = OPL3_LEFT | (OPL3_REG_KSL_LEVEL + op_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	/* Set OPL3 FEEDBACK_CONNECTION register */ 
+	/* Set output voice connection */
+	reg_val = data->feedback_connection | OPL3_STEREO_BITS;
+	if (chan->gm_pan < 43)
+		reg_val &= ~OPL3_VOICE_TO_RIGHT;
+	if (chan->gm_pan > 85)
+		reg_val &= ~OPL3_VOICE_TO_LEFT;
+	opl3_reg = OPL3_LEFT | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+}
+
+/*
+ * Loads drum voices at init time
+ */
+void snd_opl3_load_drums(struct snd_opl3 *opl3)
+{
+	snd_opl3_drum_voice_set(opl3, &bass_op0);
+	snd_opl3_drum_voice_set(opl3, &bass_op1);
+	snd_opl3_drum_note_set(opl3, &bass_note);
+
+	snd_opl3_drum_voice_set(opl3, &hihat);
+
+	snd_opl3_drum_voice_set(opl3, &snare);
+	snd_opl3_drum_note_set(opl3, &snare_note);
+
+	snd_opl3_drum_voice_set(opl3, &tomtom);
+	snd_opl3_drum_note_set(opl3, &tomtom_note);
+
+	snd_opl3_drum_voice_set(opl3, &cymbal);
+}
+
+/*
+ * Switch drum voice on or off
+ */
+void snd_opl3_drum_switch(struct snd_opl3 *opl3, int note, int vel, int on_off,
+			  struct snd_midi_channel *chan)
+{
+	unsigned char drum_mask;
+	const struct snd_opl3_drum_voice *drum_voice;
+
+	if (!(opl3->drum_reg & OPL3_PERCUSSION_ENABLE))
+		return;
+
+	if ((note < 35) || (note > 81))
+		return;
+	drum_mask = snd_opl3_drum_table[note - 35];
+
+	if (on_off) {
+		switch (drum_mask) {
+		case OPL3_BASSDRUM_ON:
+			drum_voice = &bass_op1;
+			break;
+		case OPL3_HIHAT_ON:
+			drum_voice = &hihat;
+			break;
+		case OPL3_SNAREDRUM_ON:
+			drum_voice = &snare;
+			break;
+		case OPL3_TOMTOM_ON:
+			drum_voice = &tomtom;
+			break;
+		case OPL3_CYMBAL_ON:
+			drum_voice = &cymbal;
+			break;
+		default:
+			drum_voice = &tomtom;
+		}
+
+		snd_opl3_drum_vol_set(opl3, drum_voice, vel, chan);
+		opl3->drum_reg |= drum_mask;
+	} else {
+		opl3->drum_reg &= ~drum_mask;
+	}
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION,
+			 opl3->drum_reg);
+}
diff --git a/sound/drivers/opl3/opl3_lib.c b/sound/drivers/opl3/opl3_lib.c
new file mode 100644
index 000000000..6c1f1cc09
--- /dev/null
+++ b/sound/drivers/opl3/opl3_lib.c
@@ -0,0 +1,538 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>,
+ *                   Hannu Savolainen 1993-1996,
+ *                   Rob Hooft
+ *                   
+ *  Routines for control of AdLib FM cards (OPL2/OPL3/OPL4 chips)
+ *
+ *  Most if code is ported from OSS/Lite.
+ */
+
+#include <sound/opl3.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <sound/minors.h>
+#include "opl3_voice.h"
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Hannu Savolainen 1993-1996, Rob Hooft");
+MODULE_DESCRIPTION("Routines for control of AdLib FM cards (OPL2/OPL3/OPL4 chips)");
+MODULE_LICENSE("GPL");
+
+static void snd_opl2_command(struct snd_opl3 * opl3, unsigned short cmd, unsigned char val)
+{
+	unsigned long flags;
+	unsigned long port;
+
+	/*
+	 * The original 2-OP synth requires a quite long delay
+	 * after writing to a register.
+	 */
+
+	port = (cmd & OPL3_RIGHT) ? opl3->r_port : opl3->l_port;
+
+	spin_lock_irqsave(&opl3->reg_lock, flags);
+
+	outb((unsigned char) cmd, port);
+	udelay(10);
+
+	outb((unsigned char) val, port + 1);
+	udelay(30);
+
+	spin_unlock_irqrestore(&opl3->reg_lock, flags);
+}
+
+static void snd_opl3_command(struct snd_opl3 * opl3, unsigned short cmd, unsigned char val)
+{
+	unsigned long flags;
+	unsigned long port;
+
+	/*
+	 * The OPL-3 survives with just two INBs
+	 * after writing to a register.
+	 */
+
+	port = (cmd & OPL3_RIGHT) ? opl3->r_port : opl3->l_port;
+
+	spin_lock_irqsave(&opl3->reg_lock, flags);
+
+	outb((unsigned char) cmd, port);
+	inb(opl3->l_port);
+	inb(opl3->l_port);
+
+	outb((unsigned char) val, port + 1);
+	inb(opl3->l_port);
+	inb(opl3->l_port);
+
+	spin_unlock_irqrestore(&opl3->reg_lock, flags);
+}
+
+static int snd_opl3_detect(struct snd_opl3 * opl3)
+{
+	/*
+	 * This function returns 1 if the FM chip is present at the given I/O port
+	 * The detection algorithm plays with the timer built in the FM chip and
+	 * looks for a change in the status register.
+	 *
+	 * Note! The timers of the FM chip are not connected to AdLib (and compatible)
+	 * boards.
+	 *
+	 * Note2! The chip is initialized if detected.
+	 */
+
+	unsigned char stat1, stat2, signature;
+
+	/* Reset timers 1 and 2 */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, OPL3_TIMER1_MASK | OPL3_TIMER2_MASK);
+	/* Reset the IRQ of the FM chip */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, OPL3_IRQ_RESET);
+	signature = stat1 = inb(opl3->l_port);	/* Status register */
+	if ((stat1 & 0xe0) != 0x00) {	/* Should be 0x00 */
+		snd_printd("OPL3: stat1 = 0x%x\n", stat1);
+		return -ENODEV;
+	}
+	/* Set timer1 to 0xff */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER1, 0xff);
+	/* Unmask and start timer 1 */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, OPL3_TIMER2_MASK | OPL3_TIMER1_START);
+	/* Now we have to delay at least 80us */
+	udelay(200);
+	/* Read status after timers have expired */
+	stat2 = inb(opl3->l_port);
+	/* Stop the timers */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, OPL3_TIMER1_MASK | OPL3_TIMER2_MASK);
+	/* Reset the IRQ of the FM chip */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, OPL3_IRQ_RESET);
+	if ((stat2 & 0xe0) != 0xc0) {	/* There is no YM3812 */
+		snd_printd("OPL3: stat2 = 0x%x\n", stat2);
+		return -ENODEV;
+	}
+
+	/* If the toplevel code knows exactly the type of chip, don't try
+	   to detect it. */
+	if (opl3->hardware != OPL3_HW_AUTO)
+		return 0;
+
+	/* There is a FM chip on this address. Detect the type (OPL2 to OPL4) */
+	if (signature == 0x06) {	/* OPL2 */
+		opl3->hardware = OPL3_HW_OPL2;
+	} else {
+		/*
+		 * If we had an OPL4 chip, opl3->hardware would have been set
+		 * by the OPL4 driver; so we can assume OPL3 here.
+		 */
+		if (snd_BUG_ON(!opl3->r_port))
+			return -ENODEV;
+		opl3->hardware = OPL3_HW_OPL3;
+	}
+	return 0;
+}
+
+/*
+ *  AdLib timers
+ */
+
+/*
+ *  Timer 1 - 80us
+ */
+
+static int snd_opl3_timer1_start(struct snd_timer * timer)
+{
+	unsigned long flags;
+	unsigned char tmp;
+	unsigned int ticks;
+	struct snd_opl3 *opl3;
+
+	opl3 = snd_timer_chip(timer);
+	spin_lock_irqsave(&opl3->timer_lock, flags);
+	ticks = timer->sticks;
+	tmp = (opl3->timer_enable | OPL3_TIMER1_START) & ~OPL3_TIMER1_MASK;
+	opl3->timer_enable = tmp;
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER1, 256 - ticks);	/* timer 1 count */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, tmp);	/* enable timer 1 IRQ */
+	spin_unlock_irqrestore(&opl3->timer_lock, flags);
+	return 0;
+}
+
+static int snd_opl3_timer1_stop(struct snd_timer * timer)
+{
+	unsigned long flags;
+	unsigned char tmp;
+	struct snd_opl3 *opl3;
+
+	opl3 = snd_timer_chip(timer);
+	spin_lock_irqsave(&opl3->timer_lock, flags);
+	tmp = (opl3->timer_enable | OPL3_TIMER1_MASK) & ~OPL3_TIMER1_START;
+	opl3->timer_enable = tmp;
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, tmp);	/* disable timer #1 */
+	spin_unlock_irqrestore(&opl3->timer_lock, flags);
+	return 0;
+}
+
+/*
+ *  Timer 2 - 320us
+ */
+
+static int snd_opl3_timer2_start(struct snd_timer * timer)
+{
+	unsigned long flags;
+	unsigned char tmp;
+	unsigned int ticks;
+	struct snd_opl3 *opl3;
+
+	opl3 = snd_timer_chip(timer);
+	spin_lock_irqsave(&opl3->timer_lock, flags);
+	ticks = timer->sticks;
+	tmp = (opl3->timer_enable | OPL3_TIMER2_START) & ~OPL3_TIMER2_MASK;
+	opl3->timer_enable = tmp;
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER2, 256 - ticks);	/* timer 1 count */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, tmp);	/* enable timer 1 IRQ */
+	spin_unlock_irqrestore(&opl3->timer_lock, flags);
+	return 0;
+}
+
+static int snd_opl3_timer2_stop(struct snd_timer * timer)
+{
+	unsigned long flags;
+	unsigned char tmp;
+	struct snd_opl3 *opl3;
+
+	opl3 = snd_timer_chip(timer);
+	spin_lock_irqsave(&opl3->timer_lock, flags);
+	tmp = (opl3->timer_enable | OPL3_TIMER2_MASK) & ~OPL3_TIMER2_START;
+	opl3->timer_enable = tmp;
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TIMER_CONTROL, tmp);	/* disable timer #1 */
+	spin_unlock_irqrestore(&opl3->timer_lock, flags);
+	return 0;
+}
+
+/*
+
+ */
+
+static const struct snd_timer_hardware snd_opl3_timer1 =
+{
+	.flags =	SNDRV_TIMER_HW_STOP,
+	.resolution =	80000,
+	.ticks =	256,
+	.start =	snd_opl3_timer1_start,
+	.stop =		snd_opl3_timer1_stop,
+};
+
+static const struct snd_timer_hardware snd_opl3_timer2 =
+{
+	.flags =	SNDRV_TIMER_HW_STOP,
+	.resolution =	320000,
+	.ticks =	256,
+	.start =	snd_opl3_timer2_start,
+	.stop =		snd_opl3_timer2_stop,
+};
+
+static int snd_opl3_timer1_init(struct snd_opl3 * opl3, int timer_no)
+{
+	struct snd_timer *timer = NULL;
+	struct snd_timer_id tid;
+	int err;
+
+	tid.dev_class = SNDRV_TIMER_CLASS_CARD;
+	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	tid.card = opl3->card->number;
+	tid.device = timer_no;
+	tid.subdevice = 0;
+	err = snd_timer_new(opl3->card, "AdLib timer #1", &tid, &timer);
+	if (err >= 0) {
+		strcpy(timer->name, "AdLib timer #1");
+		timer->private_data = opl3;
+		timer->hw = snd_opl3_timer1;
+	}
+	opl3->timer1 = timer;
+	return err;
+}
+
+static int snd_opl3_timer2_init(struct snd_opl3 * opl3, int timer_no)
+{
+	struct snd_timer *timer = NULL;
+	struct snd_timer_id tid;
+	int err;
+
+	tid.dev_class = SNDRV_TIMER_CLASS_CARD;
+	tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
+	tid.card = opl3->card->number;
+	tid.device = timer_no;
+	tid.subdevice = 0;
+	err = snd_timer_new(opl3->card, "AdLib timer #2", &tid, &timer);
+	if (err >= 0) {
+		strcpy(timer->name, "AdLib timer #2");
+		timer->private_data = opl3;
+		timer->hw = snd_opl3_timer2;
+	}
+	opl3->timer2 = timer;
+	return err;
+}
+
+/*
+
+ */
+
+void snd_opl3_interrupt(struct snd_hwdep * hw)
+{
+	unsigned char status;
+	struct snd_opl3 *opl3;
+	struct snd_timer *timer;
+
+	if (hw == NULL)
+		return;
+
+	opl3 = hw->private_data;
+	status = inb(opl3->l_port);
+#if 0
+	snd_printk(KERN_DEBUG "AdLib IRQ status = 0x%x\n", status);
+#endif
+	if (!(status & 0x80))
+		return;
+
+	if (status & 0x40) {
+		timer = opl3->timer1;
+		snd_timer_interrupt(timer, timer->sticks);
+	}
+	if (status & 0x20) {
+		timer = opl3->timer2;
+		snd_timer_interrupt(timer, timer->sticks);
+	}
+}
+
+EXPORT_SYMBOL(snd_opl3_interrupt);
+
+/*
+
+ */
+
+static int snd_opl3_free(struct snd_opl3 *opl3)
+{
+	if (snd_BUG_ON(!opl3))
+		return -ENXIO;
+	if (opl3->private_free)
+		opl3->private_free(opl3);
+	snd_opl3_clear_patches(opl3);
+	release_and_free_resource(opl3->res_l_port);
+	release_and_free_resource(opl3->res_r_port);
+	kfree(opl3);
+	return 0;
+}
+
+static int snd_opl3_dev_free(struct snd_device *device)
+{
+	struct snd_opl3 *opl3 = device->device_data;
+	return snd_opl3_free(opl3);
+}
+
+int snd_opl3_new(struct snd_card *card,
+		 unsigned short hardware,
+		 struct snd_opl3 **ropl3)
+{
+	static const struct snd_device_ops ops = {
+		.dev_free = snd_opl3_dev_free,
+	};
+	struct snd_opl3 *opl3;
+	int err;
+
+	*ropl3 = NULL;
+	opl3 = kzalloc(sizeof(*opl3), GFP_KERNEL);
+	if (!opl3)
+		return -ENOMEM;
+
+	opl3->card = card;
+	opl3->hardware = hardware;
+	spin_lock_init(&opl3->reg_lock);
+	spin_lock_init(&opl3->timer_lock);
+
+	err = snd_device_new(card, SNDRV_DEV_CODEC, opl3, &ops);
+	if (err < 0) {
+		snd_opl3_free(opl3);
+		return err;
+	}
+
+	*ropl3 = opl3;
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_opl3_new);
+
+int snd_opl3_init(struct snd_opl3 *opl3)
+{
+	if (! opl3->command) {
+		printk(KERN_ERR "snd_opl3_init: command not defined!\n");
+		return -EINVAL;
+	}
+
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TEST, OPL3_ENABLE_WAVE_SELECT);
+	/* Melodic mode */
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, 0x00);
+
+	switch (opl3->hardware & OPL3_HW_MASK) {
+	case OPL3_HW_OPL2:
+		opl3->max_voices = MAX_OPL2_VOICES;
+		break;
+	case OPL3_HW_OPL3:
+	case OPL3_HW_OPL4:
+		opl3->max_voices = MAX_OPL3_VOICES;
+		/* Enter OPL3 mode */
+		opl3->command(opl3, OPL3_RIGHT | OPL3_REG_MODE, OPL3_OPL3_ENABLE);
+	}
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_opl3_init);
+
+int snd_opl3_create(struct snd_card *card,
+		    unsigned long l_port,
+		    unsigned long r_port,
+		    unsigned short hardware,
+		    int integrated,
+		    struct snd_opl3 ** ropl3)
+{
+	struct snd_opl3 *opl3;
+	int err;
+
+	*ropl3 = NULL;
+	err = snd_opl3_new(card, hardware, &opl3);
+	if (err < 0)
+		return err;
+	if (! integrated) {
+		opl3->res_l_port = request_region(l_port, 2, "OPL2/3 (left)");
+		if (!opl3->res_l_port) {
+			snd_printk(KERN_ERR "opl3: can't grab left port 0x%lx\n", l_port);
+			snd_device_free(card, opl3);
+			return -EBUSY;
+		}
+		if (r_port != 0) {
+			opl3->res_r_port = request_region(r_port, 2, "OPL2/3 (right)");
+			if (!opl3->res_r_port) {
+				snd_printk(KERN_ERR "opl3: can't grab right port 0x%lx\n", r_port);
+				snd_device_free(card, opl3);
+				return -EBUSY;
+			}
+		}
+	}
+	opl3->l_port = l_port;
+	opl3->r_port = r_port;
+
+	switch (opl3->hardware) {
+	/* some hardware doesn't support timers */
+	case OPL3_HW_OPL3_SV:
+	case OPL3_HW_OPL3_CS:
+	case OPL3_HW_OPL3_FM801:
+		opl3->command = &snd_opl3_command;
+		break;
+	default:
+		opl3->command = &snd_opl2_command;
+		err = snd_opl3_detect(opl3);
+		if (err < 0) {
+			snd_printd("OPL2/3 chip not detected at 0x%lx/0x%lx\n",
+				   opl3->l_port, opl3->r_port);
+			snd_device_free(card, opl3);
+			return err;
+		}
+		/* detect routine returns correct hardware type */
+		switch (opl3->hardware & OPL3_HW_MASK) {
+		case OPL3_HW_OPL3:
+		case OPL3_HW_OPL4:
+			opl3->command = &snd_opl3_command;
+		}
+	}
+
+	snd_opl3_init(opl3);
+
+	*ropl3 = opl3;
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_opl3_create);
+
+int snd_opl3_timer_new(struct snd_opl3 * opl3, int timer1_dev, int timer2_dev)
+{
+	int err;
+
+	if (timer1_dev >= 0) {
+		err = snd_opl3_timer1_init(opl3, timer1_dev);
+		if (err < 0)
+			return err;
+	}
+	if (timer2_dev >= 0) {
+		err = snd_opl3_timer2_init(opl3, timer2_dev);
+		if (err < 0) {
+			snd_device_free(opl3->card, opl3->timer1);
+			opl3->timer1 = NULL;
+			return err;
+		}
+	}
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_opl3_timer_new);
+
+int snd_opl3_hwdep_new(struct snd_opl3 * opl3,
+		       int device, int seq_device,
+		       struct snd_hwdep ** rhwdep)
+{
+	struct snd_hwdep *hw;
+	struct snd_card *card = opl3->card;
+	int err;
+
+	if (rhwdep)
+		*rhwdep = NULL;
+
+	/* create hardware dependent device (direct FM) */
+
+	err = snd_hwdep_new(card, "OPL2/OPL3", device, &hw);
+	if (err < 0) {
+		snd_device_free(card, opl3);
+		return err;
+	}
+	hw->private_data = opl3;
+	hw->exclusive = 1;
+#ifdef CONFIG_SND_OSSEMUL
+	if (device == 0)
+		hw->oss_type = SNDRV_OSS_DEVICE_TYPE_DMFM;
+#endif
+	strcpy(hw->name, hw->id);
+	switch (opl3->hardware & OPL3_HW_MASK) {
+	case OPL3_HW_OPL2:
+		strcpy(hw->name, "OPL2 FM");
+		hw->iface = SNDRV_HWDEP_IFACE_OPL2;
+		break;
+	case OPL3_HW_OPL3:
+		strcpy(hw->name, "OPL3 FM");
+		hw->iface = SNDRV_HWDEP_IFACE_OPL3;
+		break;
+	case OPL3_HW_OPL4:
+		strcpy(hw->name, "OPL4 FM");
+		hw->iface = SNDRV_HWDEP_IFACE_OPL4;
+		break;
+	}
+
+	/* operators - only ioctl */
+	hw->ops.open = snd_opl3_open;
+	hw->ops.ioctl = snd_opl3_ioctl;
+	hw->ops.write = snd_opl3_write;
+	hw->ops.release = snd_opl3_release;
+
+	opl3->hwdep = hw;
+	opl3->seq_dev_num = seq_device;
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+	if (snd_seq_device_new(card, seq_device, SNDRV_SEQ_DEV_ID_OPL3,
+			       sizeof(struct snd_opl3 *), &opl3->seq_dev) >= 0) {
+		strcpy(opl3->seq_dev->name, hw->name);
+		*(struct snd_opl3 **)SNDRV_SEQ_DEVICE_ARGPTR(opl3->seq_dev) = opl3;
+	}
+#endif
+	if (rhwdep)
+		*rhwdep = hw;
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_opl3_hwdep_new);
diff --git a/sound/drivers/opl3/opl3_midi.c b/sound/drivers/opl3/opl3_midi.c
new file mode 100644
index 000000000..e2b7be67f
--- /dev/null
+++ b/sound/drivers/opl3/opl3_midi.c
@@ -0,0 +1,855 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
+ *
+ *  Midi synth routines for OPL2/OPL3/OPL4 FM
+ */
+
+#undef DEBUG_ALLOC
+#undef DEBUG_MIDI
+
+#include "opl3_voice.h"
+#include <sound/asoundef.h>
+
+static void snd_opl3_note_off_unsafe(void *p, int note, int vel,
+				     struct snd_midi_channel *chan);
+/*
+ * The next table looks magical, but it certainly is not. Its values have
+ * been calculated as table[i]=8*log(i/64)/log(2) with an obvious exception
+ * for i=0. This log-table converts a linear volume-scaling (0..127) to a
+ * logarithmic scaling as present in the FM-synthesizer chips. so :    Volume
+ * 64 =  0 db = relative volume  0 and:    Volume 32 = -6 db = relative
+ * volume -8 it was implemented as a table because it is only 128 bytes and
+ * it saves a lot of log() calculations. (Rob Hooft <hooft@chem.ruu.nl>)
+ */
+
+static const char opl3_volume_table[128] =
+{
+	-63, -48, -40, -35, -32, -29, -27, -26,
+	-24, -23, -21, -20, -19, -18, -18, -17,
+	-16, -15, -15, -14, -13, -13, -12, -12,
+	-11, -11, -10, -10, -10, -9, -9, -8,
+	-8, -8, -7, -7, -7, -6, -6, -6,
+	-5, -5, -5, -5, -4, -4, -4, -4,
+	-3, -3, -3, -3, -2, -2, -2, -2,
+	-2, -1, -1, -1, -1, 0, 0, 0,
+	0, 0, 0, 1, 1, 1, 1, 1,
+	1, 2, 2, 2, 2, 2, 2, 2,
+	3, 3, 3, 3, 3, 3, 3, 4,
+	4, 4, 4, 4, 4, 4, 4, 5,
+	5, 5, 5, 5, 5, 5, 5, 5,
+	6, 6, 6, 6, 6, 6, 6, 6,
+	6, 7, 7, 7, 7, 7, 7, 7,
+	7, 7, 7, 8, 8, 8, 8, 8
+};
+
+void snd_opl3_calc_volume(unsigned char *volbyte, int vel,
+			  struct snd_midi_channel *chan)
+{
+	int oldvol, newvol, n;
+	int volume;
+
+	volume = (vel * chan->gm_volume * chan->gm_expression) / (127*127);
+	if (volume > 127)
+		volume = 127;
+
+	oldvol = OPL3_TOTAL_LEVEL_MASK - (*volbyte & OPL3_TOTAL_LEVEL_MASK);
+
+	newvol = opl3_volume_table[volume] + oldvol;
+	if (newvol > OPL3_TOTAL_LEVEL_MASK)
+		newvol = OPL3_TOTAL_LEVEL_MASK;
+	else if (newvol < 0)
+		newvol = 0;
+
+	n = OPL3_TOTAL_LEVEL_MASK - (newvol & OPL3_TOTAL_LEVEL_MASK);
+
+	*volbyte = (*volbyte & OPL3_KSL_MASK) | (n & OPL3_TOTAL_LEVEL_MASK);
+}
+
+/*
+ * Converts the note frequency to block and fnum values for the FM chip
+ */
+static const short opl3_note_table[16] =
+{
+	305, 323,	/* for pitch bending, -2 semitones */
+	343, 363, 385, 408, 432, 458, 485, 514, 544, 577, 611, 647,
+	686, 726	/* for pitch bending, +2 semitones */
+};
+
+static void snd_opl3_calc_pitch(unsigned char *fnum, unsigned char *blocknum,
+				int note, struct snd_midi_channel *chan)
+{
+	int block = ((note / 12) & 0x07) - 1;
+	int idx = (note % 12) + 2;
+	int freq;
+
+	if (chan->midi_pitchbend) {
+		int pitchbend = chan->midi_pitchbend;
+		int segment;
+
+		if (pitchbend < -0x2000)
+			pitchbend = -0x2000;
+		if (pitchbend > 0x1FFF)
+			pitchbend = 0x1FFF;
+
+		segment = pitchbend / 0x1000;
+		freq = opl3_note_table[idx+segment];
+		freq += ((opl3_note_table[idx+segment+1] - freq) *
+			 (pitchbend % 0x1000)) / 0x1000;
+	} else {
+		freq = opl3_note_table[idx];
+	}
+
+	*fnum = (unsigned char) freq;
+	*blocknum = ((freq >> 8) & OPL3_FNUM_HIGH_MASK) |
+		((block << 2) & OPL3_BLOCKNUM_MASK);
+}
+
+
+#ifdef DEBUG_ALLOC
+static void debug_alloc(struct snd_opl3 *opl3, char *s, int voice) {
+	int i;
+	char *str = "x.24";
+
+	printk(KERN_DEBUG "time %.5i: %s [%.2i]: ", opl3->use_time, s, voice);
+	for (i = 0; i < opl3->max_voices; i++)
+		printk(KERN_CONT "%c", *(str + opl3->voices[i].state + 1));
+	printk(KERN_CONT "\n");
+}
+#endif
+
+/*
+ * Get a FM voice (channel) to play a note on.
+ */
+static int opl3_get_voice(struct snd_opl3 *opl3, int instr_4op,
+			  struct snd_midi_channel *chan) {
+	int chan_4op_1;		/* first voice for 4op instrument */
+	int chan_4op_2;		/* second voice for 4op instrument */
+
+	struct snd_opl3_voice *vp, *vp2;
+	unsigned int voice_time;
+	int i;
+
+#ifdef DEBUG_ALLOC
+	char *alloc_type[3] = { "FREE     ", "CHEAP    ", "EXPENSIVE" };
+#endif
+
+	/* This is our "allocation cost" table */
+	enum {
+		FREE = 0, CHEAP, EXPENSIVE, END
+	};
+
+	/* Keeps track of what we are finding */
+	struct best {
+		unsigned int time;
+		int voice;
+	} best[END];
+	struct best *bp;
+
+	for (i = 0; i < END; i++) {
+		best[i].time = (unsigned int)(-1); /* XXX MAX_?INT really */
+		best[i].voice = -1;
+	}
+
+	/* Look through all the channels for the most suitable. */
+	for (i = 0; i < opl3->max_voices; i++) {
+		vp = &opl3->voices[i];
+
+		if (vp->state == SNDRV_OPL3_ST_NOT_AVAIL)
+		  /* skip unavailable channels, allocated by
+		     drum voices or by bounded 4op voices) */
+			continue;
+
+		voice_time = vp->time;
+		bp = best;
+
+		chan_4op_1 = ((i < 3) || (i > 8 && i < 12));
+		chan_4op_2 = ((i > 2 && i < 6) || (i > 11 && i < 15));
+		if (instr_4op) {
+			/* allocate 4op voice */
+			/* skip channels unavailable to 4op instrument */
+			if (!chan_4op_1)
+				continue;
+
+			if (vp->state)
+				/* kill one voice, CHEAP */
+				bp++;
+			/* get state of bounded 2op channel
+			   to be allocated for 4op instrument */
+			vp2 = &opl3->voices[i + 3];
+			if (vp2->state == SNDRV_OPL3_ST_ON_2OP) {
+				/* kill two voices, EXPENSIVE */
+				bp++;
+				voice_time = max(voice_time, vp2->time);
+			}
+		} else {
+			/* allocate 2op voice */
+			if ((chan_4op_1) || (chan_4op_2))
+				/* use bounded channels for 2op, CHEAP */
+				bp++;
+			else if (vp->state)
+				/* kill one voice on 2op channel, CHEAP */
+				bp++;
+			/* raise kill cost to EXPENSIVE for all channels */
+			if (vp->state)
+				bp++;
+		}
+		if (voice_time < bp->time) {
+			bp->time = voice_time;
+			bp->voice = i;
+		}
+	}
+
+	for (i = 0; i < END; i++) {
+		if (best[i].voice >= 0) {
+#ifdef DEBUG_ALLOC
+			printk(KERN_DEBUG "%s %iop allocation on voice %i\n",
+			       alloc_type[i], instr_4op ? 4 : 2,
+			       best[i].voice);
+#endif
+			return best[i].voice;
+		}
+	}
+	/* not found */
+	return -1;
+}
+
+/* ------------------------------ */
+
+/*
+ * System timer interrupt function
+ */
+void snd_opl3_timer_func(struct timer_list *t)
+{
+
+	struct snd_opl3 *opl3 = from_timer(opl3, t, tlist);
+	unsigned long flags;
+	int again = 0;
+	int i;
+
+	spin_lock_irqsave(&opl3->voice_lock, flags);
+	for (i = 0; i < opl3->max_voices; i++) {
+		struct snd_opl3_voice *vp = &opl3->voices[i];
+		if (vp->state > 0 && vp->note_off_check) {
+			if (vp->note_off == jiffies)
+				snd_opl3_note_off_unsafe(opl3, vp->note, 0,
+							 vp->chan);
+			else
+				again++;
+		}
+	}
+	spin_unlock_irqrestore(&opl3->voice_lock, flags);
+
+	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
+	if (again)
+		mod_timer(&opl3->tlist, jiffies + 1);	/* invoke again */
+	else
+		opl3->sys_timer_status = 0;
+	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
+}
+
+/*
+ * Start system timer
+ */
+static void snd_opl3_start_timer(struct snd_opl3 *opl3)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
+	if (! opl3->sys_timer_status) {
+		mod_timer(&opl3->tlist, jiffies + 1);
+		opl3->sys_timer_status = 1;
+	}
+	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
+}
+
+/* ------------------------------ */
+
+
+static const int snd_opl3_oss_map[MAX_OPL3_VOICES] = {
+	0, 1, 2, 9, 10, 11, 6, 7, 8, 15, 16, 17, 3, 4 ,5, 12, 13, 14
+};
+
+/*
+ * Start a note.
+ */
+void snd_opl3_note_on(void *p, int note, int vel, struct snd_midi_channel *chan)
+{
+	struct snd_opl3 *opl3;
+	int instr_4op;
+
+	int voice;
+	struct snd_opl3_voice *vp, *vp2;
+	unsigned short connect_mask;
+	unsigned char connection;
+	unsigned char vol_op[4];
+
+	int extra_prg = 0;
+
+	unsigned short reg_side;
+	unsigned char op_offset;
+	unsigned char voice_offset;
+	unsigned short opl3_reg;
+	unsigned char reg_val;
+	unsigned char prg, bank;
+
+	int key = note;
+	unsigned char fnum, blocknum;
+	int i;
+
+	struct fm_patch *patch;
+	struct fm_instrument *fm;
+	unsigned long flags;
+
+	opl3 = p;
+
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "Note on, ch %i, inst %i, note %i, vel %i\n",
+		   chan->number, chan->midi_program, note, vel);
+#endif
+
+	/* in SYNTH mode, application takes care of voices */
+	/* in SEQ mode, drum voice numbers are notes on drum channel */
+	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
+		if (chan->drum_channel) {
+			/* percussion instruments are located in bank 128 */
+			bank = 128;
+			prg = note;
+		} else {
+			bank = chan->gm_bank_select;
+			prg = chan->midi_program;
+		}
+	} else {
+		/* Prepare for OSS mode */
+		if (chan->number >= MAX_OPL3_VOICES)
+			return;
+
+		/* OSS instruments are located in bank 127 */
+		bank = 127;
+		prg = chan->midi_program;
+	}
+
+	spin_lock_irqsave(&opl3->voice_lock, flags);
+
+	if (use_internal_drums) {
+		snd_opl3_drum_switch(opl3, note, vel, 1, chan);
+		spin_unlock_irqrestore(&opl3->voice_lock, flags);
+		return;
+	}
+
+ __extra_prg:
+	patch = snd_opl3_find_patch(opl3, prg, bank, 0);
+	if (!patch) {
+		spin_unlock_irqrestore(&opl3->voice_lock, flags);
+		return;
+	}
+
+	fm = &patch->inst;
+	switch (patch->type) {
+	case FM_PATCH_OPL2:
+		instr_4op = 0;
+		break;
+	case FM_PATCH_OPL3:
+		if (opl3->hardware >= OPL3_HW_OPL3) {
+			instr_4op = 1;
+			break;
+		}
+		fallthrough;
+	default:
+		spin_unlock_irqrestore(&opl3->voice_lock, flags);
+		return;
+	}
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "  --> OPL%i instrument: %s\n",
+		   instr_4op ? 3 : 2, patch->name);
+#endif
+	/* in SYNTH mode, application takes care of voices */
+	/* in SEQ mode, allocate voice on free OPL3 channel */
+	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
+		voice = opl3_get_voice(opl3, instr_4op, chan);
+	} else {
+		/* remap OSS voice */
+		voice = snd_opl3_oss_map[chan->number];		
+	}
+
+	if (voice < 0) {
+		spin_unlock_irqrestore(&opl3->voice_lock, flags);
+		return;
+	}
+
+	if (voice < MAX_OPL2_VOICES) {
+		/* Left register block for voices 0 .. 8 */
+		reg_side = OPL3_LEFT;
+		voice_offset = voice;
+		connect_mask = (OPL3_LEFT_4OP_0 << voice_offset) & 0x07;
+	} else {
+		/* Right register block for voices 9 .. 17 */
+		reg_side = OPL3_RIGHT;
+		voice_offset = voice - MAX_OPL2_VOICES;
+		connect_mask = (OPL3_RIGHT_4OP_0 << voice_offset) & 0x38;
+	}
+
+	/* kill voice on channel */
+	vp = &opl3->voices[voice];
+	if (vp->state > 0) {
+		opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+		reg_val = vp->keyon_reg & ~OPL3_KEYON_BIT;
+		opl3->command(opl3, opl3_reg, reg_val);
+	}
+	if (instr_4op) {
+		vp2 = &opl3->voices[voice + 3];
+		if (vp2->state > 0) {
+			opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK +
+					       voice_offset + 3);
+			reg_val = vp->keyon_reg & ~OPL3_KEYON_BIT;
+			opl3->command(opl3, opl3_reg, reg_val);
+		}
+	}
+
+	/* set connection register */
+	if (instr_4op) {
+		if ((opl3->connection_reg ^ connect_mask) & connect_mask) {
+			opl3->connection_reg |= connect_mask;
+			/* set connection bit */
+			opl3_reg = OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT;
+			opl3->command(opl3, opl3_reg, opl3->connection_reg);
+		}
+	} else {
+		if ((opl3->connection_reg ^ ~connect_mask) & connect_mask) {
+			opl3->connection_reg &= ~connect_mask;
+			/* clear connection bit */
+			opl3_reg = OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT;
+			opl3->command(opl3, opl3_reg, opl3->connection_reg);
+		}
+	}
+
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "  --> setting OPL3 connection: 0x%x\n",
+		   opl3->connection_reg);
+#endif
+	/*
+	 * calculate volume depending on connection
+	 * between FM operators (see include/opl3.h)
+	 */
+	for (i = 0; i < (instr_4op ? 4 : 2); i++)
+		vol_op[i] = fm->op[i].ksl_level;
+
+	connection = fm->feedback_connection[0] & 0x01;
+	if (instr_4op) {
+		connection <<= 1;
+		connection |= fm->feedback_connection[1] & 0x01;
+
+		snd_opl3_calc_volume(&vol_op[3], vel, chan);
+		switch (connection) {
+		case 0x03:
+			snd_opl3_calc_volume(&vol_op[2], vel, chan);
+			fallthrough;
+		case 0x02:
+			snd_opl3_calc_volume(&vol_op[0], vel, chan);
+			break;
+		case 0x01:
+			snd_opl3_calc_volume(&vol_op[1], vel, chan);
+		}
+	} else {
+		snd_opl3_calc_volume(&vol_op[1], vel, chan);
+		if (connection)
+			snd_opl3_calc_volume(&vol_op[0], vel, chan);
+	}
+
+	/* Program the FM voice characteristics */
+	for (i = 0; i < (instr_4op ? 4 : 2); i++) {
+#ifdef DEBUG_MIDI
+		snd_printk(KERN_DEBUG "  --> programming operator %i\n", i);
+#endif
+		op_offset = snd_opl3_regmap[voice_offset][i];
+
+		/* Set OPL3 AM_VIB register of requested voice/operator */ 
+		reg_val = fm->op[i].am_vib;
+		opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
+		opl3->command(opl3, opl3_reg, reg_val);
+
+		/* Set OPL3 KSL_LEVEL register of requested voice/operator */ 
+		reg_val = vol_op[i];
+		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
+		opl3->command(opl3, opl3_reg, reg_val);
+
+		/* Set OPL3 ATTACK_DECAY register of requested voice/operator */ 
+		reg_val = fm->op[i].attack_decay;
+		opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
+		opl3->command(opl3, opl3_reg, reg_val);
+
+		/* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */ 
+		reg_val = fm->op[i].sustain_release;
+		opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
+		opl3->command(opl3, opl3_reg, reg_val);
+
+		/* Select waveform */
+		reg_val = fm->op[i].wave_select;
+		opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
+		opl3->command(opl3, opl3_reg, reg_val);
+	}
+
+	/* Set operator feedback and 2op inter-operator connection */
+	reg_val = fm->feedback_connection[0];
+	/* Set output voice connection */
+	reg_val |= OPL3_STEREO_BITS;
+	if (chan->gm_pan < 43)
+		reg_val &= ~OPL3_VOICE_TO_RIGHT;
+	if (chan->gm_pan > 85)
+		reg_val &= ~OPL3_VOICE_TO_LEFT;
+	opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	if (instr_4op) {
+		/* Set 4op inter-operator connection */
+		reg_val = fm->feedback_connection[1] & OPL3_CONNECTION_BIT;
+		/* Set output voice connection */
+		reg_val |= OPL3_STEREO_BITS;
+		if (chan->gm_pan < 43)
+			reg_val &= ~OPL3_VOICE_TO_RIGHT;
+		if (chan->gm_pan > 85)
+			reg_val &= ~OPL3_VOICE_TO_LEFT;
+		opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION +
+				       voice_offset + 3);
+		opl3->command(opl3, opl3_reg, reg_val);
+	}
+
+	/*
+	 * Special treatment of percussion notes for fm:
+	 * Requested pitch is really program, and pitch for
+	 * device is whatever was specified in the patch library.
+	 */
+	if (fm->fix_key)
+		note = fm->fix_key;
+	/*
+	 * use transpose if defined in patch library
+	 */
+	if (fm->trnsps)
+		note += (fm->trnsps - 64);
+
+	snd_opl3_calc_pitch(&fnum, &blocknum, note, chan);
+
+	/* Set OPL3 FNUM_LOW register of requested voice */
+	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
+	opl3->command(opl3, opl3_reg, fnum);
+
+	opl3->voices[voice].keyon_reg = blocknum;
+
+	/* Set output sound flag */
+	blocknum |= OPL3_KEYON_BIT;
+
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "  --> trigger voice %i\n", voice);
+#endif
+	/* Set OPL3 KEYON_BLOCK register of requested voice */ 
+	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+	opl3->command(opl3, opl3_reg, blocknum);
+
+	/* kill note after fixed duration (in centiseconds) */
+	if (fm->fix_dur) {
+		opl3->voices[voice].note_off = jiffies +
+			(fm->fix_dur * HZ) / 100;
+		snd_opl3_start_timer(opl3);
+		opl3->voices[voice].note_off_check = 1;
+	} else
+		opl3->voices[voice].note_off_check = 0;
+
+	/* get extra pgm, but avoid possible loops */
+	extra_prg = (extra_prg) ? 0 : fm->modes;
+
+	/* do the bookkeeping */
+	vp->time = opl3->use_time++;
+	vp->note = key;
+	vp->chan = chan;
+
+	if (instr_4op) {
+		vp->state = SNDRV_OPL3_ST_ON_4OP;
+
+		vp2 = &opl3->voices[voice + 3];
+		vp2->time = opl3->use_time++;
+		vp2->note = key;
+		vp2->chan = chan;
+		vp2->state = SNDRV_OPL3_ST_NOT_AVAIL;
+	} else {
+		if (vp->state == SNDRV_OPL3_ST_ON_4OP) {
+			/* 4op killed by 2op, release bounded voice */
+			vp2 = &opl3->voices[voice + 3];
+			vp2->time = opl3->use_time++;
+			vp2->state = SNDRV_OPL3_ST_OFF;
+		}
+		vp->state = SNDRV_OPL3_ST_ON_2OP;
+	}
+
+#ifdef DEBUG_ALLOC
+	debug_alloc(opl3, "note on ", voice);
+#endif
+
+	/* allocate extra program if specified in patch library */
+	if (extra_prg) {
+		if (extra_prg > 128) {
+			bank = 128;
+			/* percussions start at 35 */
+			prg = extra_prg - 128 + 35 - 1;
+		} else {
+			bank = 0;
+			prg = extra_prg - 1;
+		}
+#ifdef DEBUG_MIDI
+		snd_printk(KERN_DEBUG " *** allocating extra program\n");
+#endif
+		goto __extra_prg;
+	}
+	spin_unlock_irqrestore(&opl3->voice_lock, flags);
+}
+
+static void snd_opl3_kill_voice(struct snd_opl3 *opl3, int voice)
+{
+	unsigned short reg_side;
+	unsigned char voice_offset;
+	unsigned short opl3_reg;
+
+	struct snd_opl3_voice *vp, *vp2;
+
+	if (snd_BUG_ON(voice >= MAX_OPL3_VOICES))
+		return;
+
+	vp = &opl3->voices[voice];
+	if (voice < MAX_OPL2_VOICES) {
+		/* Left register block for voices 0 .. 8 */
+		reg_side = OPL3_LEFT;
+		voice_offset = voice;
+	} else {
+		/* Right register block for voices 9 .. 17 */
+		reg_side = OPL3_RIGHT;
+		voice_offset = voice - MAX_OPL2_VOICES;
+	}
+
+	/* kill voice */
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "  --> kill voice %i\n", voice);
+#endif
+	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+	/* clear Key ON bit */
+	opl3->command(opl3, opl3_reg, vp->keyon_reg);
+
+	/* do the bookkeeping */
+	vp->time = opl3->use_time++;
+
+	if (vp->state == SNDRV_OPL3_ST_ON_4OP) {
+		vp2 = &opl3->voices[voice + 3];
+
+		vp2->time = opl3->use_time++;
+		vp2->state = SNDRV_OPL3_ST_OFF;
+	}
+	vp->state = SNDRV_OPL3_ST_OFF;
+#ifdef DEBUG_ALLOC
+	debug_alloc(opl3, "note off", voice);
+#endif
+
+}
+
+/*
+ * Release a note in response to a midi note off.
+ */
+static void snd_opl3_note_off_unsafe(void *p, int note, int vel,
+				     struct snd_midi_channel *chan)
+{
+  	struct snd_opl3 *opl3;
+
+	int voice;
+	struct snd_opl3_voice *vp;
+
+	opl3 = p;
+
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "Note off, ch %i, inst %i, note %i\n",
+		   chan->number, chan->midi_program, note);
+#endif
+
+	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
+		if (chan->drum_channel && use_internal_drums) {
+			snd_opl3_drum_switch(opl3, note, vel, 0, chan);
+			return;
+		}
+		/* this loop will hopefully kill all extra voices, because
+		   they are grouped by the same channel and note values */
+		for (voice = 0; voice < opl3->max_voices; voice++) {
+			vp = &opl3->voices[voice];
+			if (vp->state > 0 && vp->chan == chan && vp->note == note) {
+				snd_opl3_kill_voice(opl3, voice);
+			}
+		}
+	} else {
+		/* remap OSS voices */
+		if (chan->number < MAX_OPL3_VOICES) {
+			voice = snd_opl3_oss_map[chan->number];		
+			snd_opl3_kill_voice(opl3, voice);
+		}
+	}
+}
+
+void snd_opl3_note_off(void *p, int note, int vel,
+		       struct snd_midi_channel *chan)
+{
+	struct snd_opl3 *opl3 = p;
+	unsigned long flags;
+
+	spin_lock_irqsave(&opl3->voice_lock, flags);
+	snd_opl3_note_off_unsafe(p, note, vel, chan);
+	spin_unlock_irqrestore(&opl3->voice_lock, flags);
+}
+
+/*
+ * key pressure change
+ */
+void snd_opl3_key_press(void *p, int note, int vel, struct snd_midi_channel *chan)
+{
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "Key pressure, ch#: %i, inst#: %i\n",
+		   chan->number, chan->midi_program);
+#endif
+}
+
+/*
+ * terminate note
+ */
+void snd_opl3_terminate_note(void *p, int note, struct snd_midi_channel *chan)
+{
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "Terminate note, ch#: %i, inst#: %i\n",
+		   chan->number, chan->midi_program);
+#endif
+}
+
+static void snd_opl3_update_pitch(struct snd_opl3 *opl3, int voice)
+{
+	unsigned short reg_side;
+	unsigned char voice_offset;
+	unsigned short opl3_reg;
+
+	unsigned char fnum, blocknum;
+
+	struct snd_opl3_voice *vp;
+
+	if (snd_BUG_ON(voice >= MAX_OPL3_VOICES))
+		return;
+
+	vp = &opl3->voices[voice];
+	if (vp->chan == NULL)
+		return; /* not allocated? */
+
+	if (voice < MAX_OPL2_VOICES) {
+		/* Left register block for voices 0 .. 8 */
+		reg_side = OPL3_LEFT;
+		voice_offset = voice;
+	} else {
+		/* Right register block for voices 9 .. 17 */
+		reg_side = OPL3_RIGHT;
+		voice_offset = voice - MAX_OPL2_VOICES;
+	}
+
+	snd_opl3_calc_pitch(&fnum, &blocknum, vp->note, vp->chan);
+
+	/* Set OPL3 FNUM_LOW register of requested voice */
+	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
+	opl3->command(opl3, opl3_reg, fnum);
+
+	vp->keyon_reg = blocknum;
+
+	/* Set output sound flag */
+	blocknum |= OPL3_KEYON_BIT;
+
+	/* Set OPL3 KEYON_BLOCK register of requested voice */ 
+	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+	opl3->command(opl3, opl3_reg, blocknum);
+
+	vp->time = opl3->use_time++;
+}
+
+/*
+ * Update voice pitch controller
+ */
+static void snd_opl3_pitch_ctrl(struct snd_opl3 *opl3, struct snd_midi_channel *chan)
+{
+	int voice;
+	struct snd_opl3_voice *vp;
+
+	unsigned long flags;
+
+	spin_lock_irqsave(&opl3->voice_lock, flags);
+
+	if (opl3->synth_mode == SNDRV_OPL3_MODE_SEQ) {
+		for (voice = 0; voice < opl3->max_voices; voice++) {
+			vp = &opl3->voices[voice];
+			if (vp->state > 0 && vp->chan == chan) {
+				snd_opl3_update_pitch(opl3, voice);
+			}
+		}
+	} else {
+		/* remap OSS voices */
+		if (chan->number < MAX_OPL3_VOICES) {
+			voice = snd_opl3_oss_map[chan->number];		
+			snd_opl3_update_pitch(opl3, voice);
+		}
+	}
+	spin_unlock_irqrestore(&opl3->voice_lock, flags);
+}
+
+/*
+ * Deal with a controller type event.  This includes all types of
+ * control events, not just the midi controllers
+ */
+void snd_opl3_control(void *p, int type, struct snd_midi_channel *chan)
+{
+  	struct snd_opl3 *opl3;
+
+	opl3 = p;
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "Controller, TYPE = %i, ch#: %i, inst#: %i\n",
+		   type, chan->number, chan->midi_program);
+#endif
+
+	switch (type) {
+	case MIDI_CTL_MSB_MODWHEEL:
+		if (chan->control[MIDI_CTL_MSB_MODWHEEL] > 63)
+			opl3->drum_reg |= OPL3_VIBRATO_DEPTH;
+		else 
+			opl3->drum_reg &= ~OPL3_VIBRATO_DEPTH;
+		opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION,
+				 opl3->drum_reg);
+		break;
+	case MIDI_CTL_E2_TREMOLO_DEPTH:
+		if (chan->control[MIDI_CTL_E2_TREMOLO_DEPTH] > 63)
+			opl3->drum_reg |= OPL3_TREMOLO_DEPTH;
+		else 
+			opl3->drum_reg &= ~OPL3_TREMOLO_DEPTH;
+		opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION,
+				 opl3->drum_reg);
+		break;
+	case MIDI_CTL_PITCHBEND:
+		snd_opl3_pitch_ctrl(opl3, chan);
+		break;
+	}
+}
+
+/*
+ * NRPN events
+ */
+void snd_opl3_nrpn(void *p, struct snd_midi_channel *chan,
+		   struct snd_midi_channel_set *chset)
+{
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "NRPN, ch#: %i, inst#: %i\n",
+		   chan->number, chan->midi_program);
+#endif
+}
+
+/*
+ * receive sysex
+ */
+void snd_opl3_sysex(void *p, unsigned char *buf, int len,
+		    int parsed, struct snd_midi_channel_set *chset)
+{
+#ifdef DEBUG_MIDI
+	snd_printk(KERN_DEBUG "SYSEX\n");
+#endif
+}
diff --git a/sound/drivers/opl3/opl3_oss.c b/sound/drivers/opl3/opl3_oss.c
new file mode 100644
index 000000000..7645365ee
--- /dev/null
+++ b/sound/drivers/opl3/opl3_oss.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Interface for OSS sequencer emulation
+ *
+ *  Copyright (C) 2000 Uros Bizjak <uros@kss-loka.si>
+ */
+
+#include <linux/export.h>
+#include "opl3_voice.h"
+
+static int snd_opl3_open_seq_oss(struct snd_seq_oss_arg *arg, void *closure);
+static int snd_opl3_close_seq_oss(struct snd_seq_oss_arg *arg);
+static int snd_opl3_ioctl_seq_oss(struct snd_seq_oss_arg *arg, unsigned int cmd, unsigned long ioarg);
+static int snd_opl3_load_patch_seq_oss(struct snd_seq_oss_arg *arg, int format, const char __user *buf, int offs, int count);
+static int snd_opl3_reset_seq_oss(struct snd_seq_oss_arg *arg);
+
+/* operators */
+
+static const struct snd_seq_oss_callback oss_callback = {
+	.owner = 	THIS_MODULE,
+	.open =		snd_opl3_open_seq_oss,
+	.close =	snd_opl3_close_seq_oss,
+	.ioctl =	snd_opl3_ioctl_seq_oss,
+	.load_patch =	snd_opl3_load_patch_seq_oss,
+	.reset =	snd_opl3_reset_seq_oss,
+};
+
+static int snd_opl3_oss_event_input(struct snd_seq_event *ev, int direct,
+				    void *private_data, int atomic, int hop)
+{
+	struct snd_opl3 *opl3 = private_data;
+
+	if (ev->type != SNDRV_SEQ_EVENT_OSS)
+		snd_midi_process_event(&opl3_ops, ev, opl3->oss_chset);
+	return 0;
+}
+
+/* ------------------------------ */
+
+static void snd_opl3_oss_free_port(void *private_data)
+{
+	struct snd_opl3 *opl3 = private_data;
+
+	snd_midi_channel_free_set(opl3->oss_chset);
+}
+
+static int snd_opl3_oss_create_port(struct snd_opl3 * opl3)
+{
+	struct snd_seq_port_callback callbacks;
+	char name[32];
+	int voices, opl_ver;
+
+	voices = (opl3->hardware < OPL3_HW_OPL3) ?
+		MAX_OPL2_VOICES : MAX_OPL3_VOICES;
+	opl3->oss_chset = snd_midi_channel_alloc_set(voices);
+	if (opl3->oss_chset == NULL)
+		return -ENOMEM;
+	opl3->oss_chset->private_data = opl3;
+
+	memset(&callbacks, 0, sizeof(callbacks));
+	callbacks.owner = THIS_MODULE;
+	callbacks.event_input = snd_opl3_oss_event_input;
+	callbacks.private_free = snd_opl3_oss_free_port;
+	callbacks.private_data = opl3;
+
+	opl_ver = (opl3->hardware & OPL3_HW_MASK) >> 8;
+	sprintf(name, "OPL%i OSS Port", opl_ver);
+
+	opl3->oss_chset->client = opl3->seq_client;
+	opl3->oss_chset->port = snd_seq_event_port_attach(opl3->seq_client, &callbacks,
+							  SNDRV_SEQ_PORT_CAP_WRITE,
+							  SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
+							  SNDRV_SEQ_PORT_TYPE_MIDI_GM |
+							  SNDRV_SEQ_PORT_TYPE_HARDWARE |
+							  SNDRV_SEQ_PORT_TYPE_SYNTHESIZER,
+							  voices, voices,
+							  name);
+	if (opl3->oss_chset->port < 0) {
+		int port;
+		port = opl3->oss_chset->port;
+		snd_midi_channel_free_set(opl3->oss_chset);
+		return port;
+	}
+	return 0;
+}
+
+/* ------------------------------ */
+
+/* register OSS synth */
+void snd_opl3_init_seq_oss(struct snd_opl3 *opl3, char *name)
+{
+	struct snd_seq_oss_reg *arg;
+	struct snd_seq_device *dev;
+
+	if (snd_seq_device_new(opl3->card, 0, SNDRV_SEQ_DEV_ID_OSS,
+			       sizeof(struct snd_seq_oss_reg), &dev) < 0)
+		return;
+
+	opl3->oss_seq_dev = dev;
+	strscpy(dev->name, name, sizeof(dev->name));
+	arg = SNDRV_SEQ_DEVICE_ARGPTR(dev);
+	arg->type = SYNTH_TYPE_FM;
+	if (opl3->hardware < OPL3_HW_OPL3) {
+		arg->subtype = FM_TYPE_ADLIB;
+		arg->nvoices = MAX_OPL2_VOICES;
+	} else {
+		arg->subtype = FM_TYPE_OPL3;
+		arg->nvoices = MAX_OPL3_VOICES;
+	}
+	arg->oper = oss_callback;
+	arg->private_data = opl3;
+
+	if (snd_opl3_oss_create_port(opl3)) {
+		/* register to OSS synth table */
+		snd_device_register(opl3->card, dev);
+	}
+}
+
+/* unregister */
+void snd_opl3_free_seq_oss(struct snd_opl3 *opl3)
+{
+	if (opl3->oss_seq_dev) {
+		/* The instance should have been released in prior */
+		opl3->oss_seq_dev = NULL;
+	}
+}
+
+/* ------------------------------ */
+
+/* open OSS sequencer */
+static int snd_opl3_open_seq_oss(struct snd_seq_oss_arg *arg, void *closure)
+{
+	struct snd_opl3 *opl3 = closure;
+	int err;
+
+	if (snd_BUG_ON(!arg))
+		return -ENXIO;
+
+	err = snd_opl3_synth_setup(opl3);
+	if (err < 0)
+		return err;
+
+	/* fill the argument data */
+	arg->private_data = opl3;
+	arg->addr.client = opl3->oss_chset->client;
+	arg->addr.port = opl3->oss_chset->port;
+
+	err = snd_opl3_synth_use_inc(opl3);
+	if (err < 0)
+		return err;
+
+	opl3->synth_mode = SNDRV_OPL3_MODE_SYNTH;
+	return 0;
+}
+
+/* close OSS sequencer */
+static int snd_opl3_close_seq_oss(struct snd_seq_oss_arg *arg)
+{
+	struct snd_opl3 *opl3;
+
+	if (snd_BUG_ON(!arg))
+		return -ENXIO;
+	opl3 = arg->private_data;
+
+	snd_opl3_synth_cleanup(opl3);
+
+	snd_opl3_synth_use_dec(opl3);
+	return 0;
+}
+
+/* load patch */
+
+/* from sound_config.h */
+#define SBFM_MAXINSTR	256
+
+static int snd_opl3_load_patch_seq_oss(struct snd_seq_oss_arg *arg, int format,
+				       const char __user *buf, int offs, int count)
+{
+	struct snd_opl3 *opl3;
+	struct sbi_instrument sbi;
+	char name[32];
+	int err, type;
+
+	if (snd_BUG_ON(!arg))
+		return -ENXIO;
+	opl3 = arg->private_data;
+
+	if (format == FM_PATCH)
+		type = FM_PATCH_OPL2;
+	else if (format == OPL3_PATCH)
+		type = FM_PATCH_OPL3;
+	else
+		return -EINVAL;
+
+	if (count < (int)sizeof(sbi)) {
+		snd_printk(KERN_ERR "FM Error: Patch record too short\n");
+		return -EINVAL;
+	}
+	if (copy_from_user(&sbi, buf, sizeof(sbi)))
+		return -EFAULT;
+
+	if (sbi.channel < 0 || sbi.channel >= SBFM_MAXINSTR) {
+		snd_printk(KERN_ERR "FM Error: Invalid instrument number %d\n",
+			   sbi.channel);
+		return -EINVAL;
+	}
+
+	memset(name, 0, sizeof(name));
+	sprintf(name, "Chan%d", sbi.channel);
+
+	err = snd_opl3_load_patch(opl3, sbi.channel, 127, type, name, NULL,
+				  sbi.operators);
+	if (err < 0)
+		return err;
+
+	return sizeof(sbi);
+}
+
+/* ioctl */
+static int snd_opl3_ioctl_seq_oss(struct snd_seq_oss_arg *arg, unsigned int cmd,
+				  unsigned long ioarg)
+{
+	if (snd_BUG_ON(!arg))
+		return -ENXIO;
+	switch (cmd) {
+		case SNDCTL_FM_LOAD_INSTR:
+			snd_printk(KERN_ERR "OPL3: "
+				   "Obsolete ioctl(SNDCTL_FM_LOAD_INSTR) used. "
+				   "Fix the program.\n");
+			return -EINVAL;
+
+		case SNDCTL_SYNTH_MEMAVL:
+			return 0x7fffffff;
+
+		case SNDCTL_FM_4OP_ENABLE:
+			// handled automatically by OPL instrument type
+			return 0;
+
+		default:
+			return -EINVAL;
+	}
+	return 0;
+}
+
+/* reset device */
+static int snd_opl3_reset_seq_oss(struct snd_seq_oss_arg *arg)
+{
+	if (snd_BUG_ON(!arg))
+		return -ENXIO;
+
+	return 0;
+}
diff --git a/sound/drivers/opl3/opl3_seq.c b/sound/drivers/opl3/opl3_seq.c
new file mode 100644
index 000000000..75de1299c
--- /dev/null
+++ b/sound/drivers/opl3/opl3_seq.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
+ *
+ *  Midi Sequencer interface routines for OPL2/OPL3/OPL4 FM
+ *
+ *  OPL2/3 FM instrument loader:
+ *   alsa-tools/seq/sbiload/
+ */
+
+#include "opl3_voice.h"
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/module.h>
+#include <sound/initval.h>
+
+MODULE_AUTHOR("Uros Bizjak <uros@kss-loka.si>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ALSA driver for OPL3 FM synth");
+
+bool use_internal_drums = 0;
+module_param(use_internal_drums, bool, 0444);
+MODULE_PARM_DESC(use_internal_drums, "Enable internal OPL2/3 drums.");
+
+int snd_opl3_synth_use_inc(struct snd_opl3 * opl3)
+{
+	if (!try_module_get(opl3->card->module))
+		return -EFAULT;
+	return 0;
+
+}
+
+void snd_opl3_synth_use_dec(struct snd_opl3 * opl3)
+{
+	module_put(opl3->card->module);
+}
+
+int snd_opl3_synth_setup(struct snd_opl3 * opl3)
+{
+	int idx;
+	struct snd_hwdep *hwdep = opl3->hwdep;
+
+	mutex_lock(&hwdep->open_mutex);
+	if (hwdep->used) {
+		mutex_unlock(&hwdep->open_mutex);
+		return -EBUSY;
+	}
+	hwdep->used++;
+	mutex_unlock(&hwdep->open_mutex);
+
+	snd_opl3_reset(opl3);
+
+	for (idx = 0; idx < MAX_OPL3_VOICES; idx++) {
+		opl3->voices[idx].state = SNDRV_OPL3_ST_OFF;
+		opl3->voices[idx].time = 0;
+		opl3->voices[idx].keyon_reg = 0x00;
+	}
+	opl3->use_time = 0;
+	opl3->connection_reg = 0x00;
+	if (opl3->hardware >= OPL3_HW_OPL3) {
+		/* Clear 4-op connections */
+		opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT,
+				 opl3->connection_reg);
+		opl3->max_voices = MAX_OPL3_VOICES;
+	}
+	return 0;
+}
+
+void snd_opl3_synth_cleanup(struct snd_opl3 * opl3)
+{
+	unsigned long flags;
+	struct snd_hwdep *hwdep;
+
+	/* Stop system timer */
+	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
+	if (opl3->sys_timer_status) {
+		del_timer(&opl3->tlist);
+		opl3->sys_timer_status = 0;
+	}
+	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
+
+	snd_opl3_reset(opl3);
+	hwdep = opl3->hwdep;
+	mutex_lock(&hwdep->open_mutex);
+	hwdep->used--;
+	mutex_unlock(&hwdep->open_mutex);
+	wake_up(&hwdep->open_wait);
+}
+
+static int snd_opl3_synth_use(void *private_data, struct snd_seq_port_subscribe * info)
+{
+	struct snd_opl3 *opl3 = private_data;
+	int err;
+
+	err = snd_opl3_synth_setup(opl3);
+	if (err < 0)
+		return err;
+
+	if (use_internal_drums) {
+		/* Percussion mode */
+		opl3->voices[6].state = opl3->voices[7].state = 
+			opl3->voices[8].state = SNDRV_OPL3_ST_NOT_AVAIL;
+		snd_opl3_load_drums(opl3);
+		opl3->drum_reg = OPL3_PERCUSSION_ENABLE;
+		opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, opl3->drum_reg);
+	} else {
+		opl3->drum_reg = 0x00;
+	}
+
+	if (info->sender.client != SNDRV_SEQ_CLIENT_SYSTEM) {
+		err = snd_opl3_synth_use_inc(opl3);
+		if (err < 0)
+			return err;
+	}
+	opl3->synth_mode = SNDRV_OPL3_MODE_SEQ;
+	return 0;
+}
+
+static int snd_opl3_synth_unuse(void *private_data, struct snd_seq_port_subscribe * info)
+{
+	struct snd_opl3 *opl3 = private_data;
+
+	snd_opl3_synth_cleanup(opl3);
+
+	if (info->sender.client != SNDRV_SEQ_CLIENT_SYSTEM)
+		snd_opl3_synth_use_dec(opl3);
+	return 0;
+}
+
+/*
+ * MIDI emulation operators
+ */
+const struct snd_midi_op opl3_ops = {
+	.note_on =		snd_opl3_note_on,
+	.note_off =		snd_opl3_note_off,
+	.key_press =		snd_opl3_key_press,
+	.note_terminate =	snd_opl3_terminate_note,
+	.control =		snd_opl3_control,
+	.nrpn =			snd_opl3_nrpn,
+	.sysex =		snd_opl3_sysex,
+};
+
+static int snd_opl3_synth_event_input(struct snd_seq_event * ev, int direct,
+				      void *private_data, int atomic, int hop)
+{
+	struct snd_opl3 *opl3 = private_data;
+
+	snd_midi_process_event(&opl3_ops, ev, opl3->chset);
+	return 0;
+}
+
+/* ------------------------------ */
+
+static void snd_opl3_synth_free_port(void *private_data)
+{
+	struct snd_opl3 *opl3 = private_data;
+
+	snd_midi_channel_free_set(opl3->chset);
+}
+
+static int snd_opl3_synth_create_port(struct snd_opl3 * opl3)
+{
+	struct snd_seq_port_callback callbacks;
+	char name[32];
+	int voices, opl_ver;
+
+	voices = (opl3->hardware < OPL3_HW_OPL3) ?
+		MAX_OPL2_VOICES : MAX_OPL3_VOICES;
+	opl3->chset = snd_midi_channel_alloc_set(16);
+	if (opl3->chset == NULL)
+		return -ENOMEM;
+	opl3->chset->private_data = opl3;
+
+	memset(&callbacks, 0, sizeof(callbacks));
+	callbacks.owner = THIS_MODULE;
+	callbacks.use = snd_opl3_synth_use;
+	callbacks.unuse = snd_opl3_synth_unuse;
+	callbacks.event_input = snd_opl3_synth_event_input;
+	callbacks.private_free = snd_opl3_synth_free_port;
+	callbacks.private_data = opl3;
+
+	opl_ver = (opl3->hardware & OPL3_HW_MASK) >> 8;
+	sprintf(name, "OPL%i FM Port", opl_ver);
+
+	opl3->chset->client = opl3->seq_client;
+	opl3->chset->port = snd_seq_event_port_attach(opl3->seq_client, &callbacks,
+						      SNDRV_SEQ_PORT_CAP_WRITE |
+						      SNDRV_SEQ_PORT_CAP_SUBS_WRITE,
+						      SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
+						      SNDRV_SEQ_PORT_TYPE_MIDI_GM |
+						      SNDRV_SEQ_PORT_TYPE_DIRECT_SAMPLE |
+						      SNDRV_SEQ_PORT_TYPE_HARDWARE |
+						      SNDRV_SEQ_PORT_TYPE_SYNTHESIZER,
+						      16, voices,
+						      name);
+	if (opl3->chset->port < 0) {
+		int port;
+		port = opl3->chset->port;
+		snd_midi_channel_free_set(opl3->chset);
+		return port;
+	}
+	return 0;
+}
+
+/* ------------------------------ */
+
+static int snd_opl3_seq_probe(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	struct snd_opl3 *opl3;
+	int client, err;
+	char name[32];
+	int opl_ver;
+
+	opl3 = *(struct snd_opl3 **)SNDRV_SEQ_DEVICE_ARGPTR(dev);
+	if (opl3 == NULL)
+		return -EINVAL;
+
+	spin_lock_init(&opl3->voice_lock);
+
+	opl3->seq_client = -1;
+
+	/* allocate new client */
+	opl_ver = (opl3->hardware & OPL3_HW_MASK) >> 8;
+	sprintf(name, "OPL%i FM synth", opl_ver);
+	client = opl3->seq_client =
+		snd_seq_create_kernel_client(opl3->card, opl3->seq_dev_num,
+					     name);
+	if (client < 0)
+		return client;
+
+	err = snd_opl3_synth_create_port(opl3);
+	if (err < 0) {
+		snd_seq_delete_kernel_client(client);
+		opl3->seq_client = -1;
+		return err;
+	}
+
+	/* setup system timer */
+	timer_setup(&opl3->tlist, snd_opl3_timer_func, 0);
+	spin_lock_init(&opl3->sys_timer_lock);
+	opl3->sys_timer_status = 0;
+
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
+	snd_opl3_init_seq_oss(opl3, name);
+#endif
+	return 0;
+}
+
+static int snd_opl3_seq_remove(struct device *_dev)
+{
+	struct snd_seq_device *dev = to_seq_dev(_dev);
+	struct snd_opl3 *opl3;
+
+	opl3 = *(struct snd_opl3 **)SNDRV_SEQ_DEVICE_ARGPTR(dev);
+	if (opl3 == NULL)
+		return -EINVAL;
+
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
+	snd_opl3_free_seq_oss(opl3);
+#endif
+	if (opl3->seq_client >= 0) {
+		snd_seq_delete_kernel_client(opl3->seq_client);
+		opl3->seq_client = -1;
+	}
+	return 0;
+}
+
+static struct snd_seq_driver opl3_seq_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.probe = snd_opl3_seq_probe,
+		.remove = snd_opl3_seq_remove,
+	},
+	.id = SNDRV_SEQ_DEV_ID_OPL3,
+	.argsize = sizeof(struct snd_opl3 *),
+};
+
+module_snd_seq_driver(opl3_seq_driver);
diff --git a/sound/drivers/opl3/opl3_synth.c b/sound/drivers/opl3/opl3_synth.c
new file mode 100644
index 000000000..97d30a833
--- /dev/null
+++ b/sound/drivers/opl3/opl3_synth.c
@@ -0,0 +1,608 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Uros Bizjak <uros@kss-loka.si>
+ *                   
+ *  Routines for OPL2/OPL3/OPL4 control
+ */
+
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/nospec.h>
+#include <sound/opl3.h>
+#include <sound/asound_fm.h>
+#include "opl3_voice.h"
+
+#if IS_ENABLED(CONFIG_SND_SEQUENCER)
+#define OPL3_SUPPORT_SYNTH
+#endif
+
+/*
+ *    There is 18 possible 2 OP voices
+ *      (9 in the left and 9 in the right).
+ *      The first OP is the modulator and 2nd is the carrier.
+ *
+ *      The first three voices in the both sides may be connected
+ *      with another voice to a 4 OP voice. For example voice 0
+ *      can be connected with voice 3. The operators of voice 3 are
+ *      used as operators 3 and 4 of the new 4 OP voice.
+ *      In this case the 2 OP voice number 0 is the 'first half' and
+ *      voice 3 is the second.
+ */
+
+
+/*
+ *    Register offset table for OPL2/3 voices,
+ *    OPL2 / one OPL3 register array side only
+ */
+
+char snd_opl3_regmap[MAX_OPL2_VOICES][4] =
+{
+/*	  OP1   OP2   OP3   OP4		*/
+/*	 ------------------------	*/
+	{ 0x00, 0x03, 0x08, 0x0b },
+	{ 0x01, 0x04, 0x09, 0x0c },
+	{ 0x02, 0x05, 0x0a, 0x0d },
+
+	{ 0x08, 0x0b, 0x00, 0x00 },
+	{ 0x09, 0x0c, 0x00, 0x00 },
+	{ 0x0a, 0x0d, 0x00, 0x00 },
+
+	{ 0x10, 0x13, 0x00, 0x00 },	/* used by percussive voices */
+	{ 0x11, 0x14, 0x00, 0x00 },	/* if the percussive mode */
+	{ 0x12, 0x15, 0x00, 0x00 }	/* is selected (only left reg block) */
+};
+
+EXPORT_SYMBOL(snd_opl3_regmap);
+
+/*
+ * prototypes
+ */
+static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note);
+static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice);
+static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params);
+static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode);
+static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection);
+
+/* ------------------------------ */
+
+/*
+ * open the device exclusively
+ */
+int snd_opl3_open(struct snd_hwdep * hw, struct file *file)
+{
+	return 0;
+}
+
+/*
+ * ioctl for hwdep device:
+ */
+int snd_opl3_ioctl(struct snd_hwdep * hw, struct file *file,
+		   unsigned int cmd, unsigned long arg)
+{
+	struct snd_opl3 *opl3 = hw->private_data;
+	void __user *argp = (void __user *)arg;
+
+	if (snd_BUG_ON(!opl3))
+		return -EINVAL;
+
+	switch (cmd) {
+		/* get information */
+	case SNDRV_DM_FM_IOCTL_INFO:
+		{
+			struct snd_dm_fm_info info;
+
+			memset(&info, 0, sizeof(info));
+
+			info.fm_mode = opl3->fm_mode;
+			info.rhythm = opl3->rhythm;
+			if (copy_to_user(argp, &info, sizeof(struct snd_dm_fm_info)))
+				return -EFAULT;
+			return 0;
+		}
+
+	case SNDRV_DM_FM_IOCTL_RESET:
+#ifdef CONFIG_SND_OSSEMUL
+	case SNDRV_DM_FM_OSS_IOCTL_RESET:
+#endif
+		snd_opl3_reset(opl3);
+		return 0;
+
+	case SNDRV_DM_FM_IOCTL_PLAY_NOTE:
+#ifdef CONFIG_SND_OSSEMUL
+	case SNDRV_DM_FM_OSS_IOCTL_PLAY_NOTE:
+#endif
+		{
+			struct snd_dm_fm_note note;
+			if (copy_from_user(&note, argp, sizeof(struct snd_dm_fm_note)))
+				return -EFAULT;
+			return snd_opl3_play_note(opl3, &note);
+		}
+
+	case SNDRV_DM_FM_IOCTL_SET_VOICE:
+#ifdef CONFIG_SND_OSSEMUL
+	case SNDRV_DM_FM_OSS_IOCTL_SET_VOICE:
+#endif
+		{
+			struct snd_dm_fm_voice voice;
+			if (copy_from_user(&voice, argp, sizeof(struct snd_dm_fm_voice)))
+				return -EFAULT;
+			return snd_opl3_set_voice(opl3, &voice);
+		}
+
+	case SNDRV_DM_FM_IOCTL_SET_PARAMS:
+#ifdef CONFIG_SND_OSSEMUL
+	case SNDRV_DM_FM_OSS_IOCTL_SET_PARAMS:
+#endif
+		{
+			struct snd_dm_fm_params params;
+			if (copy_from_user(&params, argp, sizeof(struct snd_dm_fm_params)))
+				return -EFAULT;
+			return snd_opl3_set_params(opl3, &params);
+		}
+
+	case SNDRV_DM_FM_IOCTL_SET_MODE:
+#ifdef CONFIG_SND_OSSEMUL
+	case SNDRV_DM_FM_OSS_IOCTL_SET_MODE:
+#endif
+		return snd_opl3_set_mode(opl3, (int) arg);
+
+	case SNDRV_DM_FM_IOCTL_SET_CONNECTION:
+#ifdef CONFIG_SND_OSSEMUL
+	case SNDRV_DM_FM_OSS_IOCTL_SET_OPL:
+#endif
+		return snd_opl3_set_connection(opl3, (int) arg);
+
+#ifdef OPL3_SUPPORT_SYNTH
+	case SNDRV_DM_FM_IOCTL_CLEAR_PATCHES:
+		snd_opl3_clear_patches(opl3);
+		return 0;
+#endif
+
+#ifdef CONFIG_SND_DEBUG
+	default:
+		snd_printk(KERN_WARNING "unknown IOCTL: 0x%x\n", cmd);
+#endif
+	}
+	return -ENOTTY;
+}
+
+/*
+ * close the device
+ */
+int snd_opl3_release(struct snd_hwdep * hw, struct file *file)
+{
+	struct snd_opl3 *opl3 = hw->private_data;
+
+	snd_opl3_reset(opl3);
+	return 0;
+}
+
+#ifdef OPL3_SUPPORT_SYNTH
+/*
+ * write the device - load patches
+ */
+long snd_opl3_write(struct snd_hwdep *hw, const char __user *buf, long count,
+		    loff_t *offset)
+{
+	struct snd_opl3 *opl3 = hw->private_data;
+	long result = 0;
+	int err = 0;
+	struct sbi_patch inst;
+
+	while (count >= sizeof(inst)) {
+		unsigned char type;
+		if (copy_from_user(&inst, buf, sizeof(inst)))
+			return -EFAULT;
+		if (!memcmp(inst.key, FM_KEY_SBI, 4) ||
+		    !memcmp(inst.key, FM_KEY_2OP, 4))
+			type = FM_PATCH_OPL2;
+		else if (!memcmp(inst.key, FM_KEY_4OP, 4))
+			type = FM_PATCH_OPL3;
+		else /* invalid type */
+			break;
+		err = snd_opl3_load_patch(opl3, inst.prog, inst.bank, type,
+					  inst.name, inst.extension,
+					  inst.data);
+		if (err < 0)
+			break;
+		result += sizeof(inst);
+		count -= sizeof(inst);
+	}
+	return result > 0 ? result : err;
+}
+
+
+/*
+ * Patch management
+ */
+
+/* offsets for SBI params */
+#define AM_VIB		0
+#define KSL_LEVEL	2
+#define ATTACK_DECAY	4
+#define SUSTAIN_RELEASE	6
+#define WAVE_SELECT	8
+
+/* offset for SBI instrument */
+#define CONNECTION	10
+#define OFFSET_4OP	11
+
+/*
+ * load a patch, obviously.
+ *
+ * loaded on the given program and bank numbers with the given type
+ * (FM_PATCH_OPLx).
+ * data is the pointer of SBI record _without_ header (key and name).
+ * name is the name string of the patch.
+ * ext is the extension data of 7 bytes long (stored in name of SBI
+ * data up to offset 25), or NULL to skip.
+ * return 0 if successful or a negative error code.
+ */
+int snd_opl3_load_patch(struct snd_opl3 *opl3,
+			int prog, int bank, int type,
+			const char *name,
+			const unsigned char *ext,
+			const unsigned char *data)
+{
+	struct fm_patch *patch;
+	int i;
+
+	patch = snd_opl3_find_patch(opl3, prog, bank, 1);
+	if (!patch)
+		return -ENOMEM;
+
+	patch->type = type;
+
+	for (i = 0; i < 2; i++) {
+		patch->inst.op[i].am_vib = data[AM_VIB + i];
+		patch->inst.op[i].ksl_level = data[KSL_LEVEL + i];
+		patch->inst.op[i].attack_decay = data[ATTACK_DECAY + i];
+		patch->inst.op[i].sustain_release = data[SUSTAIN_RELEASE + i];
+		patch->inst.op[i].wave_select = data[WAVE_SELECT + i];
+	}
+	patch->inst.feedback_connection[0] = data[CONNECTION];
+
+	if (type == FM_PATCH_OPL3) {
+		for (i = 0; i < 2; i++) {
+			patch->inst.op[i+2].am_vib =
+				data[OFFSET_4OP + AM_VIB + i];
+			patch->inst.op[i+2].ksl_level =
+				data[OFFSET_4OP + KSL_LEVEL + i];
+			patch->inst.op[i+2].attack_decay =
+				data[OFFSET_4OP + ATTACK_DECAY + i];
+			patch->inst.op[i+2].sustain_release =
+				data[OFFSET_4OP + SUSTAIN_RELEASE + i];
+			patch->inst.op[i+2].wave_select =
+				data[OFFSET_4OP + WAVE_SELECT + i];
+		}
+		patch->inst.feedback_connection[1] =
+			data[OFFSET_4OP + CONNECTION];
+	}
+
+	if (ext) {
+		patch->inst.echo_delay = ext[0];
+		patch->inst.echo_atten = ext[1];
+		patch->inst.chorus_spread = ext[2];
+		patch->inst.trnsps = ext[3];
+		patch->inst.fix_dur = ext[4];
+		patch->inst.modes = ext[5];
+		patch->inst.fix_key = ext[6];
+	}
+
+	if (name)
+		strscpy(patch->name, name, sizeof(patch->name));
+
+	return 0;
+}
+EXPORT_SYMBOL(snd_opl3_load_patch);
+
+/*
+ * find a patch with the given program and bank numbers, returns its pointer
+ * if no matching patch is found and create_patch is set, it creates a
+ * new patch object.
+ */
+struct fm_patch *snd_opl3_find_patch(struct snd_opl3 *opl3, int prog, int bank,
+				     int create_patch)
+{
+	/* pretty dumb hash key */
+	unsigned int key = (prog + bank) % OPL3_PATCH_HASH_SIZE;
+	struct fm_patch *patch;
+
+	for (patch = opl3->patch_table[key]; patch; patch = patch->next) {
+		if (patch->prog == prog && patch->bank == bank)
+			return patch;
+	}
+	if (!create_patch)
+		return NULL;
+
+	patch = kzalloc(sizeof(*patch), GFP_KERNEL);
+	if (!patch)
+		return NULL;
+	patch->prog = prog;
+	patch->bank = bank;
+	patch->next = opl3->patch_table[key];
+	opl3->patch_table[key] = patch;
+	return patch;
+}
+EXPORT_SYMBOL(snd_opl3_find_patch);
+
+/*
+ * Clear all patches of the given OPL3 instance
+ */
+void snd_opl3_clear_patches(struct snd_opl3 *opl3)
+{
+	int i;
+	for (i = 0; i <  OPL3_PATCH_HASH_SIZE; i++) {
+		struct fm_patch *patch, *next;
+		for (patch = opl3->patch_table[i]; patch; patch = next) {
+			next = patch->next;
+			kfree(patch);
+		}
+	}
+	memset(opl3->patch_table, 0, sizeof(opl3->patch_table));
+}
+#endif /* OPL3_SUPPORT_SYNTH */
+
+/* ------------------------------ */
+
+void snd_opl3_reset(struct snd_opl3 * opl3)
+{
+	unsigned short opl3_reg;
+
+	unsigned short reg_side;
+	unsigned char voice_offset;
+
+	int max_voices, i;
+
+	max_voices = (opl3->hardware < OPL3_HW_OPL3) ?
+		MAX_OPL2_VOICES : MAX_OPL3_VOICES;
+
+	for (i = 0; i < max_voices; i++) {
+		/* Get register array side and offset of voice */
+		if (i < MAX_OPL2_VOICES) {
+			/* Left register block for voices 0 .. 8 */
+			reg_side = OPL3_LEFT;
+			voice_offset = i;
+		} else {
+			/* Right register block for voices 9 .. 17 */
+			reg_side = OPL3_RIGHT;
+			voice_offset = i - MAX_OPL2_VOICES;
+		}
+		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][0]);
+		opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 1 volume */
+		opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + snd_opl3_regmap[voice_offset][1]);
+		opl3->command(opl3, opl3_reg, OPL3_TOTAL_LEVEL_MASK); /* Operator 2 volume */
+
+		opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+		opl3->command(opl3, opl3_reg, 0x00);	/* Note off */
+	}
+
+	opl3->max_voices = MAX_OPL2_VOICES;
+	opl3->fm_mode = SNDRV_DM_FM_MODE_OPL2;
+
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_TEST, OPL3_ENABLE_WAVE_SELECT);
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, 0x00);	/* Melodic mode */
+	opl3->rhythm = 0;
+}
+
+EXPORT_SYMBOL(snd_opl3_reset);
+
+static int snd_opl3_play_note(struct snd_opl3 * opl3, struct snd_dm_fm_note * note)
+{
+	unsigned short reg_side;
+	unsigned char voice_offset;
+
+	unsigned short opl3_reg;
+	unsigned char reg_val;
+
+	/* Voices 0 -  8 in OPL2 mode */
+	/* Voices 0 - 17 in OPL3 mode */
+	if (note->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
+			    MAX_OPL3_VOICES : MAX_OPL2_VOICES))
+		return -EINVAL;
+
+	/* Get register array side and offset of voice */
+	if (note->voice < MAX_OPL2_VOICES) {
+		/* Left register block for voices 0 .. 8 */
+		reg_side = OPL3_LEFT;
+		voice_offset = note->voice;
+	} else {
+		/* Right register block for voices 9 .. 17 */
+		reg_side = OPL3_RIGHT;
+		voice_offset = note->voice - MAX_OPL2_VOICES;
+	}
+
+	/* Set lower 8 bits of note frequency */
+	reg_val = (unsigned char) note->fnum;
+	opl3_reg = reg_side | (OPL3_REG_FNUM_LOW + voice_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+	
+	reg_val = 0x00;
+	/* Set output sound flag */
+	if (note->key_on)
+		reg_val |= OPL3_KEYON_BIT;
+	/* Set octave */
+	reg_val |= (note->octave << 2) & OPL3_BLOCKNUM_MASK;
+	/* Set higher 2 bits of note frequency */
+	reg_val |= (unsigned char) (note->fnum >> 8) & OPL3_FNUM_HIGH_MASK;
+
+	/* Set OPL3 KEYON_BLOCK register of requested voice */ 
+	opl3_reg = reg_side | (OPL3_REG_KEYON_BLOCK + voice_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	return 0;
+}
+
+
+static int snd_opl3_set_voice(struct snd_opl3 * opl3, struct snd_dm_fm_voice * voice)
+{
+	unsigned short reg_side;
+	unsigned char op_offset;
+	unsigned char voice_offset, voice_op;
+
+	unsigned short opl3_reg;
+	unsigned char reg_val;
+
+	/* Only operators 1 and 2 */
+	if (voice->op > 1)
+		return -EINVAL;
+	/* Voices 0 -  8 in OPL2 mode */
+	/* Voices 0 - 17 in OPL3 mode */
+	if (voice->voice >= ((opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) ?
+			     MAX_OPL3_VOICES : MAX_OPL2_VOICES))
+		return -EINVAL;
+
+	/* Get register array side and offset of voice */
+	if (voice->voice < MAX_OPL2_VOICES) {
+		/* Left register block for voices 0 .. 8 */
+		reg_side = OPL3_LEFT;
+		voice_offset = voice->voice;
+	} else {
+		/* Right register block for voices 9 .. 17 */
+		reg_side = OPL3_RIGHT;
+		voice_offset = voice->voice - MAX_OPL2_VOICES;
+	}
+	/* Get register offset of operator */
+	voice_offset = array_index_nospec(voice_offset, MAX_OPL2_VOICES);
+	voice_op = array_index_nospec(voice->op, 4);
+	op_offset = snd_opl3_regmap[voice_offset][voice_op];
+
+	reg_val = 0x00;
+	/* Set amplitude modulation (tremolo) effect */
+	if (voice->am)
+		reg_val |= OPL3_TREMOLO_ON;
+	/* Set vibrato effect */
+	if (voice->vibrato)
+		reg_val |= OPL3_VIBRATO_ON;
+	/* Set sustaining sound phase */
+	if (voice->do_sustain)
+		reg_val |= OPL3_SUSTAIN_ON;
+	/* Set keyboard scaling bit */ 
+	if (voice->kbd_scale)
+		reg_val |= OPL3_KSR;
+	/* Set harmonic or frequency multiplier */
+	reg_val |= voice->harmonic & OPL3_MULTIPLE_MASK;
+
+	/* Set OPL3 AM_VIB register of requested voice/operator */ 
+	opl3_reg = reg_side | (OPL3_REG_AM_VIB + op_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	/* Set decreasing volume of higher notes */
+	reg_val = (voice->scale_level << 6) & OPL3_KSL_MASK;
+	/* Set output volume */
+	reg_val |= ~voice->volume & OPL3_TOTAL_LEVEL_MASK;
+
+	/* Set OPL3 KSL_LEVEL register of requested voice/operator */ 
+	opl3_reg = reg_side | (OPL3_REG_KSL_LEVEL + op_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	/* Set attack phase level */
+	reg_val = (voice->attack << 4) & OPL3_ATTACK_MASK;
+	/* Set decay phase level */
+	reg_val |= voice->decay & OPL3_DECAY_MASK;
+
+	/* Set OPL3 ATTACK_DECAY register of requested voice/operator */ 
+	opl3_reg = reg_side | (OPL3_REG_ATTACK_DECAY + op_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	/* Set sustain phase level */
+	reg_val = (voice->sustain << 4) & OPL3_SUSTAIN_MASK;
+	/* Set release phase level */
+	reg_val |= voice->release & OPL3_RELEASE_MASK;
+
+	/* Set OPL3 SUSTAIN_RELEASE register of requested voice/operator */ 
+	opl3_reg = reg_side | (OPL3_REG_SUSTAIN_RELEASE + op_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	/* Set inter-operator feedback */
+	reg_val = (voice->feedback << 1) & OPL3_FEEDBACK_MASK;
+	/* Set inter-operator connection */
+	if (voice->connection)
+		reg_val |= OPL3_CONNECTION_BIT;
+	/* OPL-3 only */
+	if (opl3->fm_mode == SNDRV_DM_FM_MODE_OPL3) {
+		if (voice->left)
+			reg_val |= OPL3_VOICE_TO_LEFT;
+		if (voice->right)
+			reg_val |= OPL3_VOICE_TO_RIGHT;
+	}
+	/* Feedback/connection bits are applicable to voice */
+	opl3_reg = reg_side | (OPL3_REG_FEEDBACK_CONNECTION + voice_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	/* Select waveform */
+	reg_val = voice->waveform & OPL3_WAVE_SELECT_MASK;
+	opl3_reg = reg_side | (OPL3_REG_WAVE_SELECT + op_offset);
+	opl3->command(opl3, opl3_reg, reg_val);
+
+	return 0;
+}
+
+static int snd_opl3_set_params(struct snd_opl3 * opl3, struct snd_dm_fm_params * params)
+{
+	unsigned char reg_val;
+
+	reg_val = 0x00;
+	/* Set keyboard split method */
+	if (params->kbd_split)
+		reg_val |= OPL3_KEYBOARD_SPLIT;
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_KBD_SPLIT, reg_val);
+
+	reg_val = 0x00;
+	/* Set amplitude modulation (tremolo) depth */
+	if (params->am_depth)
+		reg_val |= OPL3_TREMOLO_DEPTH;
+	/* Set vibrato depth */
+	if (params->vib_depth)
+		reg_val |= OPL3_VIBRATO_DEPTH;
+	/* Set percussion mode */
+	if (params->rhythm) {
+		reg_val |= OPL3_PERCUSSION_ENABLE;
+		opl3->rhythm = 1;
+	} else {
+		opl3->rhythm = 0;
+	}
+	/* Play percussion instruments */
+	if (params->bass)
+		reg_val |= OPL3_BASSDRUM_ON;
+	if (params->snare)
+		reg_val |= OPL3_SNAREDRUM_ON;
+	if (params->tomtom)
+		reg_val |= OPL3_TOMTOM_ON;
+	if (params->cymbal)
+		reg_val |= OPL3_CYMBAL_ON;
+	if (params->hihat)
+		reg_val |= OPL3_HIHAT_ON;
+
+	opl3->command(opl3, OPL3_LEFT | OPL3_REG_PERCUSSION, reg_val);
+	return 0;
+}
+
+static int snd_opl3_set_mode(struct snd_opl3 * opl3, int mode)
+{
+	if ((mode == SNDRV_DM_FM_MODE_OPL3) && (opl3->hardware < OPL3_HW_OPL3))
+		return -EINVAL;
+
+	opl3->fm_mode = mode;
+	if (opl3->hardware >= OPL3_HW_OPL3)
+		opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, 0x00);	/* Clear 4-op connections */
+
+	return 0;
+}
+
+static int snd_opl3_set_connection(struct snd_opl3 * opl3, int connection)
+{
+	unsigned char reg_val;
+
+	/* OPL-3 only */
+	if (opl3->fm_mode != SNDRV_DM_FM_MODE_OPL3)
+		return -EINVAL;
+
+	reg_val = connection & (OPL3_RIGHT_4OP_0 | OPL3_RIGHT_4OP_1 | OPL3_RIGHT_4OP_2 |
+				OPL3_LEFT_4OP_0 | OPL3_LEFT_4OP_1 | OPL3_LEFT_4OP_2);
+	/* Set 4-op connections */
+	opl3->command(opl3, OPL3_RIGHT | OPL3_REG_CONNECTION_SELECT, reg_val);
+
+	return 0;
+}
+
diff --git a/sound/drivers/opl3/opl3_voice.h b/sound/drivers/opl3/opl3_voice.h
new file mode 100644
index 000000000..be9ccca2d
--- /dev/null
+++ b/sound/drivers/opl3/opl3_voice.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __OPL3_VOICE_H
+#define __OPL3_VOICE_H
+
+/*
+ *  Copyright (c) 2000 Uros Bizjak <uros@kss-loka.si>
+ */
+
+#include <sound/opl3.h>
+
+/* Prototypes for opl3_seq.c */
+int snd_opl3_synth_use_inc(struct snd_opl3 * opl3);
+void snd_opl3_synth_use_dec(struct snd_opl3 * opl3);
+int snd_opl3_synth_setup(struct snd_opl3 * opl3);
+void snd_opl3_synth_cleanup(struct snd_opl3 * opl3);
+
+/* Prototypes for opl3_midi.c */
+void snd_opl3_note_on(void *p, int note, int vel, struct snd_midi_channel *chan);
+void snd_opl3_note_off(void *p, int note, int vel, struct snd_midi_channel *chan);
+void snd_opl3_key_press(void *p, int note, int vel, struct snd_midi_channel *chan);
+void snd_opl3_terminate_note(void *p, int note, struct snd_midi_channel *chan);
+void snd_opl3_control(void *p, int type, struct snd_midi_channel *chan);
+void snd_opl3_nrpn(void *p, struct snd_midi_channel *chan, struct snd_midi_channel_set *chset);
+void snd_opl3_sysex(void *p, unsigned char *buf, int len, int parsed, struct snd_midi_channel_set *chset);
+
+void snd_opl3_calc_volume(unsigned char *reg, int vel, struct snd_midi_channel *chan);
+void snd_opl3_timer_func(struct timer_list *t);
+
+/* Prototypes for opl3_drums.c */
+void snd_opl3_load_drums(struct snd_opl3 *opl3);
+void snd_opl3_drum_switch(struct snd_opl3 *opl3, int note, int vel, int on_off, struct snd_midi_channel *chan);
+
+/* Prototypes for opl3_oss.c */
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
+void snd_opl3_init_seq_oss(struct snd_opl3 *opl3, char *name);
+void snd_opl3_free_seq_oss(struct snd_opl3 *opl3);
+#else
+#define snd_opl3_init_seq_oss(opl3, name) /* NOP */
+#define snd_opl3_free_seq_oss(opl3) /* NOP */
+#endif
+
+extern char snd_opl3_regmap[MAX_OPL2_VOICES][4];
+extern bool use_internal_drums;
+extern const struct snd_midi_op opl3_ops;
+
+#endif