Program: CWE-119
Project: CVE-2011-1477
Buggy source:
/*
 * sound/oss/opl3.c
 *
 * A low level driver for Yamaha YM3812 and OPL-3 -chips
 *
 *
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 *
 *
 * Changes
 *	Thomas Sailer   	ioctl code reworked (vmalloc/vfree removed)
 *	Alan Cox		modularisation, fixed sound_mem allocs.
 *	Christoph Hellwig	Adapted to module_init/module_exit
 *	Arnaldo C. de Melo	get rid of check_region, use request_region for
 *				OPL4, release it on exit, some cleanups.
 *
 * Status
 *	Believed to work. Badly needs rewriting a bit to support multiple
 *	OPL3 devices.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/delay.h>

/*
 * Major improvements to the FM handling 30AUG92 by Rob Hooft,
 * hooft@chem.ruu.nl
 */

#include "sound_config.h"

#include "opl3_hw.h"

#define MAX_VOICE	18
#define OFFS_4OP	11

struct voice_info
{
	unsigned char   keyon_byte;
	long            bender;
	long            bender_range;
	unsigned long   orig_freq;
	unsigned long   current_freq;
	int             volume;
	int             mode;
	int             panning;	/* 0xffff means not set */
};

typedef struct opl_devinfo
{
	int             base;
	int             left_io, right_io;
	int             nr_voice;
	int             lv_map[MAX_VOICE];

	struct voice_info voc[MAX_VOICE];
	struct voice_alloc_info *v_alloc;
	struct channel_info *chn_info;

	struct sbi_instrument i_map[SBFM_MAXINSTR];
	struct sbi_instrument *act_i[MAX_VOICE];

	struct synth_info fm_info;

	int             busy;
	int             model;
	unsigned char   cmask;

	int             is_opl4;
} opl_devinfo;

static struct opl_devinfo *devc = NULL;

static int      detected_model;

static int      store_instr(int instr_no, struct sbi_instrument *instr);
static void     freq_to_fnum(int freq, int *block, int *fnum);
static void     opl3_command(int io_addr, unsigned int addr, unsigned int val);
static int      opl3_kill_note(int dev, int voice, int note, int velocity);

static void enter_4op_mode(void)
{
	int i;
	static int v4op[MAX_VOICE] = {
		0, 1, 2, 9, 10, 11, 6, 7, 8, 15, 16, 17
	};

	devc->cmask = 0x3f;	/* Connect all possible 4 OP voice operators */
	opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, 0x3f);

	for (i = 0; i < 3; i++)
		pv_map[i].voice_mode = 4;
	for (i = 3; i < 6; i++)
		pv_map[i].voice_mode = 0;

	for (i = 9; i < 12; i++)
		pv_map[i].voice_mode = 4;
	for (i = 12; i < 15; i++)
		pv_map[i].voice_mode = 0;

	for (i = 0; i < 12; i++)
		devc->lv_map[i] = v4op[i];
	devc->v_alloc->max_voice = devc->nr_voice = 12;
}

static int opl3_ioctl(int dev, unsigned int cmd, void __user * arg)
{
	struct sbi_instrument ins;
	
	switch (cmd) {
		case SNDCTL_FM_LOAD_INSTR:
			printk(KERN_WARNING "Warning: Obsolete ioctl(SNDCTL_FM_LOAD_INSTR) used. Fix the program.\n");
			if (copy_from_user(&ins, arg, sizeof(ins)))
				return -EFAULT;
			if (ins.channel < 0 || ins.channel >= SBFM_MAXINSTR) {
				printk(KERN_WARNING "FM Error: Invalid instrument number %d\n", ins.channel);
				return -EINVAL;
			}
			return store_instr(ins.channel, &ins);

		case SNDCTL_SYNTH_INFO:
			devc->fm_info.nr_voices = (devc->nr_voice == 12) ? 6 : devc->nr_voice;
			if (copy_to_user(arg, &devc->fm_info, sizeof(devc->fm_info)))
				return -EFAULT;
			return 0;

		case SNDCTL_SYNTH_MEMAVL:
			return 0x7fffffff;

		case SNDCTL_FM_4OP_ENABLE:
			if (devc->model == 2)
				enter_4op_mode();
			return 0;

		default:
			return -EINVAL;
	}
}

static int opl3_detect(int ioaddr)
{
	/*
	 * 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, signature;
	int i;

	if (devc != NULL)
	{
		printk(KERN_ERR "opl3: Only one OPL3 supported.\n");
		return 0;
	}

	devc = kzalloc(sizeof(*devc), GFP_KERNEL);

	if (devc == NULL)
	{
		printk(KERN_ERR "opl3: Can't allocate memory for the device control "
			"structure \n ");
		return 0;
	}

	strcpy(devc->fm_info.name, "OPL2");

	if (!request_region(ioaddr, 4, devc->fm_info.name)) {
		printk(KERN_WARNING "opl3: I/O port 0x%x already in use\n", ioaddr);
		goto cleanup_devc;
	}

	devc->base = ioaddr;

	/* Reset timers 1 and 2 */
	opl3_command(ioaddr, TIMER_CONTROL_REGISTER, TIMER1_MASK | TIMER2_MASK);

	/* Reset the IRQ of the FM chip */
	opl3_command(ioaddr, TIMER_CONTROL_REGISTER, IRQ_RESET);

	signature = stat1 = inb(ioaddr);	/* Status register */

	if (signature != 0x00 && signature != 0x06 && signature != 0x02 &&
		signature != 0x0f)
	{
		MDB(printk(KERN_INFO "OPL3 not detected %x\n", signature));
		goto cleanup_region;
	}

	if (signature == 0x06)		/* OPL2 */
	{
		detected_model = 2;
	}
	else if (signature == 0x00 || signature == 0x0f)	/* OPL3 or OPL4 */
	{
		unsigned char tmp;

		detected_model = 3;

		/*
		 * Detect availability of OPL4 (_experimental_). Works probably
		 * only after a cold boot. In addition the OPL4 port
		 * of the chip may not be connected to the PC bus at all.
		 */

		opl3_command(ioaddr + 2, OPL3_MODE_REGISTER, 0x00);
		opl3_command(ioaddr + 2, OPL3_MODE_REGISTER, OPL3_ENABLE | OPL4_ENABLE);

		if ((tmp = inb(ioaddr)) == 0x02)	/* Have a OPL4 */
		{
			detected_model = 4;
		}

		if (request_region(ioaddr - 8, 2, "OPL4"))	/* OPL4 port was free */
		{
			int tmp;

			outb((0x02), ioaddr - 8);	/* Select OPL4 ID register */
			udelay(10);
			tmp = inb(ioaddr - 7);		/* Read it */
			udelay(10);

			if (tmp == 0x20)	/* OPL4 should return 0x20 here */
			{
				detected_model = 4;
				outb((0xF8), ioaddr - 8);	/* Select OPL4 FM mixer control */
				udelay(10);
				outb((0x1B), ioaddr - 7);	/* Write value */
				udelay(10);
			}
			else
			{ /* release OPL4 port */
				release_region(ioaddr - 8, 2);
				detected_model = 3;
			}
		}
		opl3_command(ioaddr + 2, OPL3_MODE_REGISTER, 0);
	}
	for (i = 0; i < 9; i++)
		opl3_command(ioaddr, KEYON_BLOCK + i, 0);	/*
								 * Note off
								 */

	opl3_command(ioaddr, TEST_REGISTER, ENABLE_WAVE_SELECT);
	opl3_command(ioaddr, PERCOSSION_REGISTER, 0x00);	/*
								 * Melodic mode.
								 */
	return 1;
cleanup_region:
	release_region(ioaddr, 4);
cleanup_devc:
	kfree(devc);
	devc = NULL;
	return 0;
}

static int opl3_kill_note  (int devno, int voice, int note, int velocity)
{
	 struct physical_voice_info *map;

	 if (voice < 0 || voice >= devc->nr_voice)
		 return 0;

	 devc->v_alloc->map[voice] = 0;

	 map = &pv_map[devc->lv_map[voice]];
	 DEB(printk("Kill note %d\n", voice));

	 if (map->voice_mode == 0)
		 return 0;

	 opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, devc->voc[voice].keyon_byte & ~0x20);
	 devc->voc[voice].keyon_byte = 0;
	 devc->voc[voice].bender = 0;
	 devc->voc[voice].volume = 64;
	 devc->voc[voice].panning = 0xffff;	/* Not set */
	 devc->voc[voice].bender_range = 200;
	 devc->voc[voice].orig_freq = 0;
	 devc->voc[voice].current_freq = 0;
	 devc->voc[voice].mode = 0;
	 return 0;
}

#define HIHAT			0
#define CYMBAL			1
#define TOMTOM			2
#define SNARE			3
#define BDRUM			4
#define UNDEFINED		TOMTOM
#define DEFAULT			TOMTOM

static int store_instr(int instr_no, struct sbi_instrument *instr)
{
	if (instr->key != FM_PATCH && (instr->key != OPL3_PATCH || devc->model != 2))
		printk(KERN_WARNING "FM warning: Invalid patch format field (key) 0x%x\n", instr->key);
	memcpy((char *) &(devc->i_map[instr_no]), (char *) instr, sizeof(*instr));
	return 0;
}

static int opl3_set_instr  (int dev, int voice, int instr_no)
{
	if (voice < 0 || voice >= devc->nr_voice)
		return 0;
	if (instr_no < 0 || instr_no >= SBFM_MAXINSTR)
		instr_no = 0;	/* Acoustic piano (usually) */

	devc->act_i[voice] = &devc->i_map[instr_no];
	return 0;
}

/*
 * 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. (RH)
 */

static char fm_volume_table[128] =
{
	-64, -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
};

static void calc_vol(unsigned char *regbyte, int volume, int main_vol)
{
	int level = (~*regbyte & 0x3f);

	if (main_vol > 127)
		main_vol = 127;
	volume = (volume * main_vol) / 127;

	if (level)
		level += fm_volume_table[volume];

	if (level > 0x3f)
		level = 0x3f;
	if (level < 0)
		level = 0;

	*regbyte = (*regbyte & 0xc0) | (~level & 0x3f);
}

static void set_voice_volume(int voice, int volume, int main_vol)
{
	unsigned char vol1, vol2, vol3, vol4;
	struct sbi_instrument *instr;
	struct physical_voice_info *map;

	if (voice < 0 || voice >= devc->nr_voice)
		return;

	map = &pv_map[devc->lv_map[voice]];
	instr = devc->act_i[voice];

	if (!instr)
		instr = &devc->i_map[0];

	if (instr->channel < 0)
		return;

	if (devc->voc[voice].mode == 0)
		return;

	if (devc->voc[voice].mode == 2)
	{
		vol1 = instr->operators[2];
		vol2 = instr->operators[3];
		if ((instr->operators[10] & 0x01))
		{
			calc_vol(&vol1, volume, main_vol);
			calc_vol(&vol2, volume, main_vol);
		}
		else
		{
			calc_vol(&vol2, volume, main_vol);
		}
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[0], vol1);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[1], vol2);
	}
	else
	{	/*
		 * 4 OP voice
		 */
		int connection;

		vol1 = instr->operators[2];
		vol2 = instr->operators[3];
		vol3 = instr->operators[OFFS_4OP + 2];
		vol4 = instr->operators[OFFS_4OP + 3];

		/*
		 * The connection method for 4 OP devc->voc is defined by the rightmost
		 * bits at the offsets 10 and 10+OFFS_4OP
		 */

		connection = ((instr->operators[10] & 0x01) << 1) | (instr->operators[10 + OFFS_4OP] & 0x01);

		switch (connection)
		{
			case 0:
				calc_vol(&vol4, volume, main_vol);
				break;

			case 1:
				calc_vol(&vol2, volume, main_vol);
				calc_vol(&vol4, volume, main_vol);
				break;

			case 2:
				calc_vol(&vol1, volume, main_vol);
				calc_vol(&vol4, volume, main_vol);
				break;

			case 3:
				calc_vol(&vol1, volume, main_vol);
				calc_vol(&vol3, volume, main_vol);
				calc_vol(&vol4, volume, main_vol);
				break;

			default:
				;
		}
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[0], vol1);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[1], vol2);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[2], vol3);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[3], vol4);
	}
}

static int opl3_start_note (int dev, int voice, int note, int volume)
{
	unsigned char data, fpc;
	int block, fnum, freq, voice_mode, pan;
	struct sbi_instrument *instr;
	struct physical_voice_info *map;

	if (voice < 0 || voice >= devc->nr_voice)
		return 0;

	map = &pv_map[devc->lv_map[voice]];
	pan = devc->voc[voice].panning;

	if (map->voice_mode == 0)
		return 0;

	if (note == 255)	/*
				 * Just change the volume
				 */
	{
		set_voice_volume(voice, volume, devc->voc[voice].volume);
		return 0;
	}

	/*
	 * Kill previous note before playing
	 */
	
	opl3_command(map->ioaddr, KSL_LEVEL + map->op[1], 0xff);	/*
									 * Carrier
									 * volume to
									 * min
									 */
	opl3_command(map->ioaddr, KSL_LEVEL + map->op[0], 0xff);	/*
									 * Modulator
									 * volume to
									 */

	if (map->voice_mode == 4)
	{
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[2], 0xff);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[3], 0xff);
	}

	opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, 0x00);	/*
									 * Note
									 * off
									 */

	instr = devc->act_i[voice];
	
	if (!instr)
		instr = &devc->i_map[0];

	if (instr->channel < 0)
	{
		printk(KERN_WARNING "opl3: Initializing voice %d with undefined instrument\n", voice);
		return 0;
	}

	if (map->voice_mode == 2 && instr->key == OPL3_PATCH)
		return 0;	/*
				 * Cannot play
				 */

	voice_mode = map->voice_mode;

	if (voice_mode == 4)
	{
		int voice_shift;

		voice_shift = (map->ioaddr == devc->left_io) ? 0 : 3;
		voice_shift += map->voice_num;

		if (instr->key != OPL3_PATCH)	/*
						 * Just 2 OP patch
						 */
		{
			voice_mode = 2;
			devc->cmask &= ~(1 << voice_shift);
		}
		else
		{
			devc->cmask |= (1 << voice_shift);
		}

		opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, devc->cmask);
	}

	/*
	 * Set Sound Characteristics
	 */
	
	opl3_command(map->ioaddr, AM_VIB + map->op[0], instr->operators[0]);
	opl3_command(map->ioaddr, AM_VIB + map->op[1], instr->operators[1]);

	/*
	 * Set Attack/Decay
	 */
	
	opl3_command(map->ioaddr, ATTACK_DECAY + map->op[0], instr->operators[4]);
	opl3_command(map->ioaddr, ATTACK_DECAY + map->op[1], instr->operators[5]);

	/*
	 * Set Sustain/Release
	 */
	
	opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[0], instr->operators[6]);
	opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[1], instr->operators[7]);

	/*
	 * Set Wave Select
	 */

	opl3_command(map->ioaddr, WAVE_SELECT + map->op[0], instr->operators[8]);
	opl3_command(map->ioaddr, WAVE_SELECT + map->op[1], instr->operators[9]);

	/*
	 * Set Feedback/Connection
	 */
	
	fpc = instr->operators[10];

	if (pan != 0xffff)
	{
		fpc &= ~STEREO_BITS;
		if (pan < -64)
			fpc |= VOICE_TO_LEFT;
		else
			if (pan > 64)
				fpc |= VOICE_TO_RIGHT;
			else
				fpc |= (VOICE_TO_LEFT | VOICE_TO_RIGHT);
	}

	if (!(fpc & 0x30))
		fpc |= 0x30;	/*
				 * Ensure that at least one chn is enabled
				 */
	opl3_command(map->ioaddr, FEEDBACK_CONNECTION + map->voice_num, fpc);

	/*
	 * If the voice is a 4 OP one, initialize the operators 3 and 4 also
	 */

	if (voice_mode == 4)
	{
		/*
		 * Set Sound Characteristics
		 */
	
		opl3_command(map->ioaddr, AM_VIB + map->op[2], instr->operators[OFFS_4OP + 0]);
		opl3_command(map->ioaddr, AM_VIB + map->op[3], instr->operators[OFFS_4OP + 1]);

		/*
		 * Set Attack/Decay
		 */
		
		opl3_command(map->ioaddr, ATTACK_DECAY + map->op[2], instr->operators[OFFS_4OP + 4]);
		opl3_command(map->ioaddr, ATTACK_DECAY + map->op[3], instr->operators[OFFS_4OP + 5]);

		/*
		 * Set Sustain/Release
		 */
		
		opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[2], instr->operators[OFFS_4OP + 6]);
		opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[3], instr->operators[OFFS_4OP + 7]);

		/*
		 * Set Wave Select
		 */
		
		opl3_command(map->ioaddr, WAVE_SELECT + map->op[2], instr->operators[OFFS_4OP + 8]);
		opl3_command(map->ioaddr, WAVE_SELECT + map->op[3], instr->operators[OFFS_4OP + 9]);

		/*
		 * Set Feedback/Connection
		 */
		
		fpc = instr->operators[OFFS_4OP + 10];
		if (!(fpc & 0x30))
			 fpc |= 0x30;	/*
					 * Ensure that at least one chn is enabled
					 */
		opl3_command(map->ioaddr, FEEDBACK_CONNECTION + map->voice_num + 3, fpc);
	}

	devc->voc[voice].mode = voice_mode;
	set_voice_volume(voice, volume, devc->voc[voice].volume);

	freq = devc->voc[voice].orig_freq = note_to_freq(note) / 1000;

	/*
	 * Since the pitch bender may have been set before playing the note, we
	 * have to calculate the bending now.
	 */

	freq = compute_finetune(devc->voc[voice].orig_freq, devc->voc[voice].bender, devc->voc[voice].bender_range, 0);
	devc->voc[voice].current_freq = freq;

	freq_to_fnum(freq, &block, &fnum);

	/*
	 * Play note
	 */

	data = fnum & 0xff;	/*
				 * Least significant bits of fnumber
				 */
	opl3_command(map->ioaddr, FNUM_LOW + map->voice_num, data);

	data = 0x20 | ((block & 0x7) << 2) | ((fnum >> 8) & 0x3);
		 devc->voc[voice].keyon_byte = data;
	opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, data);
	if (voice_mode == 4)
		opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num + 3, data);

	return 0;
}

static void freq_to_fnum    (int freq, int *block, int *fnum)
{
	int f, octave;

	/*
	 * Converts the note frequency to block and fnum values for the FM chip
	 */
	/*
	 * First try to compute the block -value (octave) where the note belongs
	 */

	f = freq;

	octave = 5;

	if (f == 0)
		octave = 0;
	else if (f < 261)
	{
		while (f < 261)
		{
			octave--;
			f <<= 1;
		}
	}
	else if (f > 493)
	{
		while (f > 493)
		{
			 octave++;
			 f >>= 1;
		}
	}

	if (octave > 7)
		octave = 7;

	*fnum = freq * (1 << (20 - octave)) / 49716;
	*block = octave;
}

static void opl3_command    (int io_addr, unsigned int addr, unsigned int val)
{
	 int i;

	/*
	 * The original 2-OP synth requires a quite long delay after writing to a
	 * register. The OPL-3 survives with just two INBs
	 */

	outb(((unsigned char) (addr & 0xff)), io_addr);

	if (devc->model != 2)
		udelay(10);
	else
		for (i = 0; i < 2; i++)
			inb(io_addr);

	outb(((unsigned char) (val & 0xff)), io_addr + 1);

	if (devc->model != 2)
		udelay(30);
	else
		for (i = 0; i < 2; i++)
			inb(io_addr);
}

static void opl3_reset(int devno)
{
	int i;

	for (i = 0; i < 18; i++)
		devc->lv_map[i] = i;

	for (i = 0; i < devc->nr_voice; i++)
	{
		opl3_command(pv_map[devc->lv_map[i]].ioaddr,
			KSL_LEVEL + pv_map[devc->lv_map[i]].op[0], 0xff);

		opl3_command(pv_map[devc->lv_map[i]].ioaddr,
			KSL_LEVEL + pv_map[devc->lv_map[i]].op[1], 0xff);

		if (pv_map[devc->lv_map[i]].voice_mode == 4)
		{
			opl3_command(pv_map[devc->lv_map[i]].ioaddr,
				KSL_LEVEL + pv_map[devc->lv_map[i]].op[2], 0xff);

			opl3_command(pv_map[devc->lv_map[i]].ioaddr,
				KSL_LEVEL + pv_map[devc->lv_map[i]].op[3], 0xff);
		}

		opl3_kill_note(devno, i, 0, 64);
	}

	if (devc->model == 2)
	{
		devc->v_alloc->max_voice = devc->nr_voice = 18;

		for (i = 0; i < 18; i++)
			pv_map[i].voice_mode = 2;

	}
}

static int opl3_open(int dev, int mode)
{
	int i;

	if (devc->busy)
		return -EBUSY;
	devc->busy = 1;

	devc->v_alloc->max_voice = devc->nr_voice = (devc->model == 2) ? 18 : 9;
	devc->v_alloc->timestamp = 0;

	for (i = 0; i < 18; i++)
	{
		devc->v_alloc->map[i] = 0;
		devc->v_alloc->alloc_times[i] = 0;
	}

	devc->cmask = 0x00;	/*
				 * Just 2 OP mode
				 */
	if (devc->model == 2)
		opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, devc->cmask);
	return 0;
}

static void opl3_close(int dev)
{
	devc->busy = 0;
	devc->v_alloc->max_voice = devc->nr_voice = (devc->model == 2) ? 18 : 9;

	devc->fm_info.nr_drums = 0;
	devc->fm_info.perc_mode = 0;

	opl3_reset(dev);
}

static void opl3_hw_control(int dev, unsigned char *event)
{
}

static int opl3_load_patch(int dev, int format, const char __user *addr,
		int count, int pmgr_flag)
{
	struct sbi_instrument ins;

	if (count <sizeof(ins))
	{
		printk(KERN_WARNING "FM Error: Patch record too short\n");
		return -EINVAL;
	}

	if (copy_from_user(&ins, addr, sizeof(ins)))
		return -EFAULT;

	if (ins.channel < 0 || ins.channel >= SBFM_MAXINSTR)
	{
		printk(KERN_WARNING "FM Error: Invalid instrument number %d\n", ins.channel);
		return -EINVAL;
	}
	ins.key = format;

	return store_instr(ins.channel, &ins);
}

static void opl3_panning(int dev, int voice, int value)
{
	devc->voc[voice].panning = value;
}

static void opl3_volume_method(int dev, int mode)
{
}

#define SET_VIBRATO(cell) { \
	tmp = instr->operators[(cell-1)+(((cell-1)/2)*OFFS_4OP)]; \
	if (pressure > 110) \
		tmp |= 0x40;		/* Vibrato on */ \
	opl3_command (map->ioaddr, AM_VIB + map->op[cell-1], tmp);}

static void opl3_aftertouch(int dev, int voice, int pressure)
{
	int tmp;
	struct sbi_instrument *instr;
	struct physical_voice_info *map;

	if (voice < 0 || voice >= devc->nr_voice)
		return;

	map = &pv_map[devc->lv_map[voice]];

	DEB(printk("Aftertouch %d\n", voice));

	if (map->voice_mode == 0)
		return;

	/*
	 * Adjust the amount of vibrato depending the pressure
	 */

	instr = devc->act_i[voice];

	if (!instr)
		instr = &devc->i_map[0];

	if (devc->voc[voice].mode == 4)
	{
		int connection = ((instr->operators[10] & 0x01) << 1) | (instr->operators[10 + OFFS_4OP] & 0x01);

		switch (connection)
		{
			case 0:
				SET_VIBRATO(4);
				break;

			case 1:
				SET_VIBRATO(2);
				SET_VIBRATO(4);
				break;

			case 2:
				SET_VIBRATO(1);
				SET_VIBRATO(4);
				break;

			case 3:
				SET_VIBRATO(1);
				SET_VIBRATO(3);
				SET_VIBRATO(4);
				break;

		}
		/*
		 * Not implemented yet
		 */
	}
	else
	{
		SET_VIBRATO(1);

		if ((instr->operators[10] & 0x01))	/*
							 * Additive synthesis
							 */
			SET_VIBRATO(2);
	}
}

#undef SET_VIBRATO

static void bend_pitch(int dev, int voice, int value)
{
	unsigned char data;
	int block, fnum, freq;
	struct physical_voice_info *map;

	map = &pv_map[devc->lv_map[voice]];

	if (map->voice_mode == 0)
		return;

	devc->voc[voice].bender = value;
	if (!value)
		return;
	if (!(devc->voc[voice].keyon_byte & 0x20))
		return;	/*
			 * Not keyed on
			 */

	freq = compute_finetune(devc->voc[voice].orig_freq, devc->voc[voice].bender, devc->voc[voice].bender_range, 0);
	devc->voc[voice].current_freq = freq;

	freq_to_fnum(freq, &block, &fnum);

	data = fnum & 0xff;	/*
				 * Least significant bits of fnumber
				 */
	opl3_command(map->ioaddr, FNUM_LOW + map->voice_num, data);

	data = 0x20 | ((block & 0x7) << 2) | ((fnum >> 8) & 0x3);
	devc->voc[voice].keyon_byte = data;
	opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, data);
}

static void opl3_controller (int dev, int voice, int ctrl_num, int value)
{
	if (voice < 0 || voice >= devc->nr_voice)
		return;

	switch (ctrl_num)
	{
		case CTRL_PITCH_BENDER:
			bend_pitch(dev, voice, value);
			break;

		case CTRL_PITCH_BENDER_RANGE:
			devc->voc[voice].bender_range = value;
			break;

		case CTL_MAIN_VOLUME:
			devc->voc[voice].volume = value / 128;
			break;

		case CTL_PAN:
			devc->voc[voice].panning = (value * 2) - 128;
			break;
	}
}

static void opl3_bender(int dev, int voice, int value)
{
	if (voice < 0 || voice >= devc->nr_voice)
		return;

	bend_pitch(dev, voice, value - 8192);
}

static int opl3_alloc_voice(int dev, int chn, int note, struct voice_alloc_info *alloc)
{
	int i, p, best, first, avail, best_time = 0x7fffffff;
	struct sbi_instrument *instr;
	int is4op;
	int instr_no;

	if (chn < 0 || chn > 15)
		instr_no = 0;
	else
		instr_no = devc->chn_info[chn].pgm_num;

	instr = &devc->i_map[instr_no];
	if (instr->channel < 0 ||	/* Instrument not loaded */
		devc->nr_voice != 12)	/* Not in 4 OP mode */
		is4op = 0;
	else if (devc->nr_voice == 12)	/* 4 OP mode */
		is4op = (instr->key == OPL3_PATCH);
	else
		is4op = 0;

	if (is4op)
	{
		first = p = 0;
		avail = 6;
	}
	else
	{
		if (devc->nr_voice == 12)	/* 4 OP mode. Use the '2 OP only' operators first */
			first = p = 6;
		else
			first = p = 0;
		avail = devc->nr_voice;
	}

	/*
	 *    Now try to find a free voice
	 */
	best = first;

	for (i = 0; i < avail; i++)
	{
		if (alloc->map[p] == 0)
		{
			return p;
		}
		if (alloc->alloc_times[p] < best_time)		/* Find oldest playing note */
		{
			best_time = alloc->alloc_times[p];
			best = p;
		}
		p = (p + 1) % avail;
	}

	/*
	 *    Insert some kind of priority mechanism here.
	 */

	if (best < 0)
		best = 0;
	if (best > devc->nr_voice)
		best -= devc->nr_voice;

	return best;	/* All devc->voc in use. Select the first one. */
}

static void opl3_setup_voice(int dev, int voice, int chn)
{
	struct channel_info *info =
	&synth_devs[dev]->chn_info[chn];

	opl3_set_instr(dev, voice, info->pgm_num);

	devc->voc[voice].bender = 0;
	devc->voc[voice].bender_range = info->bender_range;
	devc->voc[voice].volume = info->controllers[CTL_MAIN_VOLUME];
	devc->voc[voice].panning = (info->controllers[CTL_PAN] * 2) - 128;
}

static struct synth_operations opl3_operations =
{
	.owner		= THIS_MODULE,
	.id		= "OPL",
	.info		= NULL,
	.midi_dev	= 0,
	.synth_type	= SYNTH_TYPE_FM,
	.synth_subtype	= FM_TYPE_ADLIB,
	.open		= opl3_open,
	.close		= opl3_close,
	.ioctl		= opl3_ioctl,
	.kill_note	= opl3_kill_note,
	.start_note	= opl3_start_note,
	.set_instr	= opl3_set_instr,
	.reset		= opl3_reset,
	.hw_control	= opl3_hw_control,
	.load_patch	= opl3_load_patch,
	.aftertouch	= opl3_aftertouch,
	.controller	= opl3_controller,
	.panning	= opl3_panning,
	.volume_method	= opl3_volume_method,
	.bender		= opl3_bender,
	.alloc_voice	= opl3_alloc_voice,
	.setup_voice	= opl3_setup_voice
};

static int opl3_init(int ioaddr, struct module *owner)
{
	int i;
	int me;

	if (devc == NULL)
	{
		printk(KERN_ERR "opl3: Device control structure not initialized.\n");
		return -1;
	}

	if ((me = sound_alloc_synthdev()) == -1)
	{
		printk(KERN_WARNING "opl3: Too many synthesizers\n");
		return -1;
	}

	devc->nr_voice = 9;

	devc->fm_info.device = 0;
	devc->fm_info.synth_type = SYNTH_TYPE_FM;
	devc->fm_info.synth_subtype = FM_TYPE_ADLIB;
	devc->fm_info.perc_mode = 0;
	devc->fm_info.nr_voices = 9;
	devc->fm_info.nr_drums = 0;
	devc->fm_info.instr_bank_size = SBFM_MAXINSTR;
	devc->fm_info.capabilities = 0;
	devc->left_io = ioaddr;
	devc->right_io = ioaddr + 2;

	if (detected_model <= 2)
		devc->model = 1;
	else
	{
		devc->model = 2;
		if (detected_model == 4)
			devc->is_opl4 = 1;
	}

	opl3_operations.info = &devc->fm_info;

	synth_devs[me] = &opl3_operations;

	if (owner)
		synth_devs[me]->owner = owner;
	
	sequencer_init();
	devc->v_alloc = &opl3_operations.alloc;
	devc->chn_info = &opl3_operations.chn_info[0];

	if (devc->model == 2)
	{
		if (devc->is_opl4) 
			strcpy(devc->fm_info.name, "Yamaha OPL4/OPL3 FM");
		else 
			strcpy(devc->fm_info.name, "Yamaha OPL3");

		devc->v_alloc->max_voice = devc->nr_voice = 18;
		devc->fm_info.nr_drums = 0;
		devc->fm_info.synth_subtype = FM_TYPE_OPL3;
		devc->fm_info.capabilities |= SYNTH_CAP_OPL3;

		for (i = 0; i < 18; i++)
		{
			if (pv_map[i].ioaddr == USE_LEFT)
				pv_map[i].ioaddr = devc->left_io;
			else
				pv_map[i].ioaddr = devc->right_io;
		}
		opl3_command(devc->right_io, OPL3_MODE_REGISTER, OPL3_ENABLE);
		opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, 0x00);
	}
	else
	{
		strcpy(devc->fm_info.name, "Yamaha OPL2");
		devc->v_alloc->max_voice = devc->nr_voice = 9;
		devc->fm_info.nr_drums = 0;

		for (i = 0; i < 18; i++)
			pv_map[i].ioaddr = devc->left_io;
	};
	conf_printf2(devc->fm_info.name, ioaddr, 0, -1, -1);

	for (i = 0; i < SBFM_MAXINSTR; i++)
		devc->i_map[i].channel = -1;

	return me;
}

static int me;

static int io = -1;

module_param(io, int, 0);

static int __init init_opl3 (void)
{
	printk(KERN_INFO "YM3812 and OPL-3 driver Copyright (C) by Hannu Savolainen, Rob Hooft 1993-1996\n");

	if (io != -1)	/* User loading pure OPL3 module */
	{
		if (!opl3_detect(io))
		{
			return -ENODEV;
		}

		me = opl3_init(io, THIS_MODULE);
	}

	return 0;
}

static void __exit cleanup_opl3(void)
{
	if (devc && io != -1)
	{
		if (devc->base) {
			release_region(devc->base,4);
			if (devc->is_opl4)
				release_region(devc->base - 8, 2);
		}
		kfree(devc);
		devc = NULL;
		sound_unload_synthdev(me);
	}
}

module_init(init_opl3);
module_exit(cleanup_opl3);

#ifndef MODULE
static int __init setup_opl3(char *str)
{
        /* io  */
	int ints[2];
	
	str = get_options(str, ARRAY_SIZE(ints), ints);
	
	io = ints[1];

	return 1;
}

__setup("opl3=", setup_opl3);
#endif
MODULE_LICENSE("GPL");


Fixed version (ground truth):
/*
 * sound/oss/opl3.c
 *
 * A low level driver for Yamaha YM3812 and OPL-3 -chips
 *
 *
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 *
 *
 * Changes
 *	Thomas Sailer   	ioctl code reworked (vmalloc/vfree removed)
 *	Alan Cox		modularisation, fixed sound_mem allocs.
 *	Christoph Hellwig	Adapted to module_init/module_exit
 *	Arnaldo C. de Melo	get rid of check_region, use request_region for
 *				OPL4, release it on exit, some cleanups.
 *
 * Status
 *	Believed to work. Badly needs rewriting a bit to support multiple
 *	OPL3 devices.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/delay.h>

/*
 * Major improvements to the FM handling 30AUG92 by Rob Hooft,
 * hooft@chem.ruu.nl
 */

#include "sound_config.h"

#include "opl3_hw.h"

#define MAX_VOICE	18
#define OFFS_4OP	11

struct voice_info
{
	unsigned char   keyon_byte;
	long            bender;
	long            bender_range;
	unsigned long   orig_freq;
	unsigned long   current_freq;
	int             volume;
	int             mode;
	int             panning;	/* 0xffff means not set */
};

typedef struct opl_devinfo
{
	int             base;
	int             left_io, right_io;
	int             nr_voice;
	int             lv_map[MAX_VOICE];

	struct voice_info voc[MAX_VOICE];
	struct voice_alloc_info *v_alloc;
	struct channel_info *chn_info;

	struct sbi_instrument i_map[SBFM_MAXINSTR];
	struct sbi_instrument *act_i[MAX_VOICE];

	struct synth_info fm_info;

	int             busy;
	int             model;
	unsigned char   cmask;

	int             is_opl4;
} opl_devinfo;

static struct opl_devinfo *devc = NULL;

static int      detected_model;

static int      store_instr(int instr_no, struct sbi_instrument *instr);
static void     freq_to_fnum(int freq, int *block, int *fnum);
static void     opl3_command(int io_addr, unsigned int addr, unsigned int val);
static int      opl3_kill_note(int dev, int voice, int note, int velocity);

static void enter_4op_mode(void)
{
	int i;
	static int v4op[MAX_VOICE] = {
		0, 1, 2, 9, 10, 11, 6, 7, 8, 15, 16, 17
	};

	devc->cmask = 0x3f;	/* Connect all possible 4 OP voice operators */
	opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, 0x3f);

	for (i = 0; i < 3; i++)
		pv_map[i].voice_mode = 4;
	for (i = 3; i < 6; i++)
		pv_map[i].voice_mode = 0;

	for (i = 9; i < 12; i++)
		pv_map[i].voice_mode = 4;
	for (i = 12; i < 15; i++)
		pv_map[i].voice_mode = 0;

	for (i = 0; i < 12; i++)
		devc->lv_map[i] = v4op[i];
	devc->v_alloc->max_voice = devc->nr_voice = 12;
}

static int opl3_ioctl(int dev, unsigned int cmd, void __user * arg)
{
	struct sbi_instrument ins;
	
	switch (cmd) {
		case SNDCTL_FM_LOAD_INSTR:
			printk(KERN_WARNING "Warning: Obsolete ioctl(SNDCTL_FM_LOAD_INSTR) used. Fix the program.\n");
			if (copy_from_user(&ins, arg, sizeof(ins)))
				return -EFAULT;
			if (ins.channel < 0 || ins.channel >= SBFM_MAXINSTR) {
				printk(KERN_WARNING "FM Error: Invalid instrument number %d\n", ins.channel);
				return -EINVAL;
			}
			return store_instr(ins.channel, &ins);

		case SNDCTL_SYNTH_INFO:
			devc->fm_info.nr_voices = (devc->nr_voice == 12) ? 6 : devc->nr_voice;
			if (copy_to_user(arg, &devc->fm_info, sizeof(devc->fm_info)))
				return -EFAULT;
			return 0;

		case SNDCTL_SYNTH_MEMAVL:
			return 0x7fffffff;

		case SNDCTL_FM_4OP_ENABLE:
			if (devc->model == 2)
				enter_4op_mode();
			return 0;

		default:
			return -EINVAL;
	}
}

static int opl3_detect(int ioaddr)
{
	/*
	 * 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, signature;
	int i;

	if (devc != NULL)
	{
		printk(KERN_ERR "opl3: Only one OPL3 supported.\n");
		return 0;
	}

	devc = kzalloc(sizeof(*devc), GFP_KERNEL);

	if (devc == NULL)
	{
		printk(KERN_ERR "opl3: Can't allocate memory for the device control "
			"structure \n ");
		return 0;
	}

	strcpy(devc->fm_info.name, "OPL2");

	if (!request_region(ioaddr, 4, devc->fm_info.name)) {
		printk(KERN_WARNING "opl3: I/O port 0x%x already in use\n", ioaddr);
		goto cleanup_devc;
	}

	devc->base = ioaddr;

	/* Reset timers 1 and 2 */
	opl3_command(ioaddr, TIMER_CONTROL_REGISTER, TIMER1_MASK | TIMER2_MASK);

	/* Reset the IRQ of the FM chip */
	opl3_command(ioaddr, TIMER_CONTROL_REGISTER, IRQ_RESET);

	signature = stat1 = inb(ioaddr);	/* Status register */

	if (signature != 0x00 && signature != 0x06 && signature != 0x02 &&
		signature != 0x0f)
	{
		MDB(printk(KERN_INFO "OPL3 not detected %x\n", signature));
		goto cleanup_region;
	}

	if (signature == 0x06)		/* OPL2 */
	{
		detected_model = 2;
	}
	else if (signature == 0x00 || signature == 0x0f)	/* OPL3 or OPL4 */
	{
		unsigned char tmp;

		detected_model = 3;

		/*
		 * Detect availability of OPL4 (_experimental_). Works probably
		 * only after a cold boot. In addition the OPL4 port
		 * of the chip may not be connected to the PC bus at all.
		 */

		opl3_command(ioaddr + 2, OPL3_MODE_REGISTER, 0x00);
		opl3_command(ioaddr + 2, OPL3_MODE_REGISTER, OPL3_ENABLE | OPL4_ENABLE);

		if ((tmp = inb(ioaddr)) == 0x02)	/* Have a OPL4 */
		{
			detected_model = 4;
		}

		if (request_region(ioaddr - 8, 2, "OPL4"))	/* OPL4 port was free */
		{
			int tmp;

			outb((0x02), ioaddr - 8);	/* Select OPL4 ID register */
			udelay(10);
			tmp = inb(ioaddr - 7);		/* Read it */
			udelay(10);

			if (tmp == 0x20)	/* OPL4 should return 0x20 here */
			{
				detected_model = 4;
				outb((0xF8), ioaddr - 8);	/* Select OPL4 FM mixer control */
				udelay(10);
				outb((0x1B), ioaddr - 7);	/* Write value */
				udelay(10);
			}
			else
			{ /* release OPL4 port */
				release_region(ioaddr - 8, 2);
				detected_model = 3;
			}
		}
		opl3_command(ioaddr + 2, OPL3_MODE_REGISTER, 0);
	}
	for (i = 0; i < 9; i++)
		opl3_command(ioaddr, KEYON_BLOCK + i, 0);	/*
								 * Note off
								 */

	opl3_command(ioaddr, TEST_REGISTER, ENABLE_WAVE_SELECT);
	opl3_command(ioaddr, PERCOSSION_REGISTER, 0x00);	/*
								 * Melodic mode.
								 */
	return 1;
cleanup_region:
	release_region(ioaddr, 4);
cleanup_devc:
	kfree(devc);
	devc = NULL;
	return 0;
}

static int opl3_kill_note  (int devno, int voice, int note, int velocity)
{
	 struct physical_voice_info *map;

	 if (voice < 0 || voice >= devc->nr_voice)
		 return 0;

	 devc->v_alloc->map[voice] = 0;

	 map = &pv_map[devc->lv_map[voice]];
	 DEB(printk("Kill note %d\n", voice));

	 if (map->voice_mode == 0)
		 return 0;

	 opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, devc->voc[voice].keyon_byte & ~0x20);
	 devc->voc[voice].keyon_byte = 0;
	 devc->voc[voice].bender = 0;
	 devc->voc[voice].volume = 64;
	 devc->voc[voice].panning = 0xffff;	/* Not set */
	 devc->voc[voice].bender_range = 200;
	 devc->voc[voice].orig_freq = 0;
	 devc->voc[voice].current_freq = 0;
	 devc->voc[voice].mode = 0;
	 return 0;
}

#define HIHAT			0
#define CYMBAL			1
#define TOMTOM			2
#define SNARE			3
#define BDRUM			4
#define UNDEFINED		TOMTOM
#define DEFAULT			TOMTOM

static int store_instr(int instr_no, struct sbi_instrument *instr)
{
	if (instr->key != FM_PATCH && (instr->key != OPL3_PATCH || devc->model != 2))
		printk(KERN_WARNING "FM warning: Invalid patch format field (key) 0x%x\n", instr->key);
	memcpy((char *) &(devc->i_map[instr_no]), (char *) instr, sizeof(*instr));
	return 0;
}

static int opl3_set_instr  (int dev, int voice, int instr_no)
{
	if (voice < 0 || voice >= devc->nr_voice)
		return 0;
	if (instr_no < 0 || instr_no >= SBFM_MAXINSTR)
		instr_no = 0;	/* Acoustic piano (usually) */

	devc->act_i[voice] = &devc->i_map[instr_no];
	return 0;
}

/*
 * 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. (RH)
 */

static char fm_volume_table[128] =
{
	-64, -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
};

static void calc_vol(unsigned char *regbyte, int volume, int main_vol)
{
	int level = (~*regbyte & 0x3f);

	if (main_vol > 127)
		main_vol = 127;
	volume = (volume * main_vol) / 127;

	if (level)
		level += fm_volume_table[volume];

	if (level > 0x3f)
		level = 0x3f;
	if (level < 0)
		level = 0;

	*regbyte = (*regbyte & 0xc0) | (~level & 0x3f);
}

static void set_voice_volume(int voice, int volume, int main_vol)
{
	unsigned char vol1, vol2, vol3, vol4;
	struct sbi_instrument *instr;
	struct physical_voice_info *map;

	if (voice < 0 || voice >= devc->nr_voice)
		return;

	map = &pv_map[devc->lv_map[voice]];
	instr = devc->act_i[voice];

	if (!instr)
		instr = &devc->i_map[0];

	if (instr->channel < 0)
		return;

	if (devc->voc[voice].mode == 0)
		return;

	if (devc->voc[voice].mode == 2)
	{
		vol1 = instr->operators[2];
		vol2 = instr->operators[3];
		if ((instr->operators[10] & 0x01))
		{
			calc_vol(&vol1, volume, main_vol);
			calc_vol(&vol2, volume, main_vol);
		}
		else
		{
			calc_vol(&vol2, volume, main_vol);
		}
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[0], vol1);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[1], vol2);
	}
	else
	{	/*
		 * 4 OP voice
		 */
		int connection;

		vol1 = instr->operators[2];
		vol2 = instr->operators[3];
		vol3 = instr->operators[OFFS_4OP + 2];
		vol4 = instr->operators[OFFS_4OP + 3];

		/*
		 * The connection method for 4 OP devc->voc is defined by the rightmost
		 * bits at the offsets 10 and 10+OFFS_4OP
		 */

		connection = ((instr->operators[10] & 0x01) << 1) | (instr->operators[10 + OFFS_4OP] & 0x01);

		switch (connection)
		{
			case 0:
				calc_vol(&vol4, volume, main_vol);
				break;

			case 1:
				calc_vol(&vol2, volume, main_vol);
				calc_vol(&vol4, volume, main_vol);
				break;

			case 2:
				calc_vol(&vol1, volume, main_vol);
				calc_vol(&vol4, volume, main_vol);
				break;

			case 3:
				calc_vol(&vol1, volume, main_vol);
				calc_vol(&vol3, volume, main_vol);
				calc_vol(&vol4, volume, main_vol);
				break;

			default:
				;
		}
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[0], vol1);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[1], vol2);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[2], vol3);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[3], vol4);
	}
}

static int opl3_start_note (int dev, int voice, int note, int volume)
{
	unsigned char data, fpc;
	int block, fnum, freq, voice_mode, pan;
	struct sbi_instrument *instr;
	struct physical_voice_info *map;

	if (voice < 0 || voice >= devc->nr_voice)
		return 0;

	map = &pv_map[devc->lv_map[voice]];
	pan = devc->voc[voice].panning;

	if (map->voice_mode == 0)
		return 0;

	if (note == 255)	/*
				 * Just change the volume
				 */
	{
		set_voice_volume(voice, volume, devc->voc[voice].volume);
		return 0;
	}

	/*
	 * Kill previous note before playing
	 */
	
	opl3_command(map->ioaddr, KSL_LEVEL + map->op[1], 0xff);	/*
									 * Carrier
									 * volume to
									 * min
									 */
	opl3_command(map->ioaddr, KSL_LEVEL + map->op[0], 0xff);	/*
									 * Modulator
									 * volume to
									 */

	if (map->voice_mode == 4)
	{
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[2], 0xff);
		opl3_command(map->ioaddr, KSL_LEVEL + map->op[3], 0xff);
	}

	opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, 0x00);	/*
									 * Note
									 * off
									 */

	instr = devc->act_i[voice];
	
	if (!instr)
		instr = &devc->i_map[0];

	if (instr->channel < 0)
	{
		printk(KERN_WARNING "opl3: Initializing voice %d with undefined instrument\n", voice);
		return 0;
	}

	if (map->voice_mode == 2 && instr->key == OPL3_PATCH)
		return 0;	/*
				 * Cannot play
				 */

	voice_mode = map->voice_mode;

	if (voice_mode == 4)
	{
		int voice_shift;

		voice_shift = (map->ioaddr == devc->left_io) ? 0 : 3;
		voice_shift += map->voice_num;

		if (instr->key != OPL3_PATCH)	/*
						 * Just 2 OP patch
						 */
		{
			voice_mode = 2;
			devc->cmask &= ~(1 << voice_shift);
		}
		else
		{
			devc->cmask |= (1 << voice_shift);
		}

		opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, devc->cmask);
	}

	/*
	 * Set Sound Characteristics
	 */
	
	opl3_command(map->ioaddr, AM_VIB + map->op[0], instr->operators[0]);
	opl3_command(map->ioaddr, AM_VIB + map->op[1], instr->operators[1]);

	/*
	 * Set Attack/Decay
	 */
	
	opl3_command(map->ioaddr, ATTACK_DECAY + map->op[0], instr->operators[4]);
	opl3_command(map->ioaddr, ATTACK_DECAY + map->op[1], instr->operators[5]);

	/*
	 * Set Sustain/Release
	 */
	
	opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[0], instr->operators[6]);
	opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[1], instr->operators[7]);

	/*
	 * Set Wave Select
	 */

	opl3_command(map->ioaddr, WAVE_SELECT + map->op[0], instr->operators[8]);
	opl3_command(map->ioaddr, WAVE_SELECT + map->op[1], instr->operators[9]);

	/*
	 * Set Feedback/Connection
	 */
	
	fpc = instr->operators[10];

	if (pan != 0xffff)
	{
		fpc &= ~STEREO_BITS;
		if (pan < -64)
			fpc |= VOICE_TO_LEFT;
		else
			if (pan > 64)
				fpc |= VOICE_TO_RIGHT;
			else
				fpc |= (VOICE_TO_LEFT | VOICE_TO_RIGHT);
	}

	if (!(fpc & 0x30))
		fpc |= 0x30;	/*
				 * Ensure that at least one chn is enabled
				 */
	opl3_command(map->ioaddr, FEEDBACK_CONNECTION + map->voice_num, fpc);

	/*
	 * If the voice is a 4 OP one, initialize the operators 3 and 4 also
	 */

	if (voice_mode == 4)
	{
		/*
		 * Set Sound Characteristics
		 */
	
		opl3_command(map->ioaddr, AM_VIB + map->op[2], instr->operators[OFFS_4OP + 0]);
		opl3_command(map->ioaddr, AM_VIB + map->op[3], instr->operators[OFFS_4OP + 1]);

		/*
		 * Set Attack/Decay
		 */
		
		opl3_command(map->ioaddr, ATTACK_DECAY + map->op[2], instr->operators[OFFS_4OP + 4]);
		opl3_command(map->ioaddr, ATTACK_DECAY + map->op[3], instr->operators[OFFS_4OP + 5]);

		/*
		 * Set Sustain/Release
		 */
		
		opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[2], instr->operators[OFFS_4OP + 6]);
		opl3_command(map->ioaddr, SUSTAIN_RELEASE + map->op[3], instr->operators[OFFS_4OP + 7]);

		/*
		 * Set Wave Select
		 */
		
		opl3_command(map->ioaddr, WAVE_SELECT + map->op[2], instr->operators[OFFS_4OP + 8]);
		opl3_command(map->ioaddr, WAVE_SELECT + map->op[3], instr->operators[OFFS_4OP + 9]);

		/*
		 * Set Feedback/Connection
		 */
		
		fpc = instr->operators[OFFS_4OP + 10];
		if (!(fpc & 0x30))
			 fpc |= 0x30;	/*
					 * Ensure that at least one chn is enabled
					 */
		opl3_command(map->ioaddr, FEEDBACK_CONNECTION + map->voice_num + 3, fpc);
	}

	devc->voc[voice].mode = voice_mode;
	set_voice_volume(voice, volume, devc->voc[voice].volume);

	freq = devc->voc[voice].orig_freq = note_to_freq(note) / 1000;

	/*
	 * Since the pitch bender may have been set before playing the note, we
	 * have to calculate the bending now.
	 */

	freq = compute_finetune(devc->voc[voice].orig_freq, devc->voc[voice].bender, devc->voc[voice].bender_range, 0);
	devc->voc[voice].current_freq = freq;

	freq_to_fnum(freq, &block, &fnum);

	/*
	 * Play note
	 */

	data = fnum & 0xff;	/*
				 * Least significant bits of fnumber
				 */
	opl3_command(map->ioaddr, FNUM_LOW + map->voice_num, data);

	data = 0x20 | ((block & 0x7) << 2) | ((fnum >> 8) & 0x3);
		 devc->voc[voice].keyon_byte = data;
	opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, data);
	if (voice_mode == 4)
		opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num + 3, data);

	return 0;
}

static void freq_to_fnum    (int freq, int *block, int *fnum)
{
	int f, octave;

	/*
	 * Converts the note frequency to block and fnum values for the FM chip
	 */
	/*
	 * First try to compute the block -value (octave) where the note belongs
	 */

	f = freq;

	octave = 5;

	if (f == 0)
		octave = 0;
	else if (f < 261)
	{
		while (f < 261)
		{
			octave--;
			f <<= 1;
		}
	}
	else if (f > 493)
	{
		while (f > 493)
		{
			 octave++;
			 f >>= 1;
		}
	}

	if (octave > 7)
		octave = 7;

	*fnum = freq * (1 << (20 - octave)) / 49716;
	*block = octave;
}

static void opl3_command    (int io_addr, unsigned int addr, unsigned int val)
{
	 int i;

	/*
	 * The original 2-OP synth requires a quite long delay after writing to a
	 * register. The OPL-3 survives with just two INBs
	 */

	outb(((unsigned char) (addr & 0xff)), io_addr);

	if (devc->model != 2)
		udelay(10);
	else
		for (i = 0; i < 2; i++)
			inb(io_addr);

	outb(((unsigned char) (val & 0xff)), io_addr + 1);

	if (devc->model != 2)
		udelay(30);
	else
		for (i = 0; i < 2; i++)
			inb(io_addr);
}

static void opl3_reset(int devno)
{
	int i;

	for (i = 0; i < 18; i++)
		devc->lv_map[i] = i;

	for (i = 0; i < devc->nr_voice; i++)
	{
		opl3_command(pv_map[devc->lv_map[i]].ioaddr,
			KSL_LEVEL + pv_map[devc->lv_map[i]].op[0], 0xff);

		opl3_command(pv_map[devc->lv_map[i]].ioaddr,
			KSL_LEVEL + pv_map[devc->lv_map[i]].op[1], 0xff);

		if (pv_map[devc->lv_map[i]].voice_mode == 4)
		{
			opl3_command(pv_map[devc->lv_map[i]].ioaddr,
				KSL_LEVEL + pv_map[devc->lv_map[i]].op[2], 0xff);

			opl3_command(pv_map[devc->lv_map[i]].ioaddr,
				KSL_LEVEL + pv_map[devc->lv_map[i]].op[3], 0xff);
		}

		opl3_kill_note(devno, i, 0, 64);
	}

	if (devc->model == 2)
	{
		devc->v_alloc->max_voice = devc->nr_voice = 18;

		for (i = 0; i < 18; i++)
			pv_map[i].voice_mode = 2;

	}
}

static int opl3_open(int dev, int mode)
{
	int i;

	if (devc->busy)
		return -EBUSY;
	devc->busy = 1;

	devc->v_alloc->max_voice = devc->nr_voice = (devc->model == 2) ? 18 : 9;
	devc->v_alloc->timestamp = 0;

	for (i = 0; i < 18; i++)
	{
		devc->v_alloc->map[i] = 0;
		devc->v_alloc->alloc_times[i] = 0;
	}

	devc->cmask = 0x00;	/*
				 * Just 2 OP mode
				 */
	if (devc->model == 2)
		opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, devc->cmask);
	return 0;
}

static void opl3_close(int dev)
{
	devc->busy = 0;
	devc->v_alloc->max_voice = devc->nr_voice = (devc->model == 2) ? 18 : 9;

	devc->fm_info.nr_drums = 0;
	devc->fm_info.perc_mode = 0;

	opl3_reset(dev);
}

static void opl3_hw_control(int dev, unsigned char *event)
{
}

static int opl3_load_patch(int dev, int format, const char __user *addr,
		int count, int pmgr_flag)
{
	struct sbi_instrument ins;

	if (count <sizeof(ins))
	{
		printk(KERN_WARNING "FM Error: Patch record too short\n");
		return -EINVAL;
	}

	if (copy_from_user(&ins, addr, sizeof(ins)))
		return -EFAULT;

	if (ins.channel < 0 || ins.channel >= SBFM_MAXINSTR)
	{
		printk(KERN_WARNING "FM Error: Invalid instrument number %d\n", ins.channel);
		return -EINVAL;
	}
	ins.key = format;

	return store_instr(ins.channel, &ins);
}

static void opl3_panning(int dev, int voice, int value)
{

	if (voice < 0 || voice >= devc->nr_voice)
		return;

	devc->voc[voice].panning = value;
}

static void opl3_volume_method(int dev, int mode)
{
}

#define SET_VIBRATO(cell) { \
	tmp = instr->operators[(cell-1)+(((cell-1)/2)*OFFS_4OP)]; \
	if (pressure > 110) \
		tmp |= 0x40;		/* Vibrato on */ \
	opl3_command (map->ioaddr, AM_VIB + map->op[cell-1], tmp);}

static void opl3_aftertouch(int dev, int voice, int pressure)
{
	int tmp;
	struct sbi_instrument *instr;
	struct physical_voice_info *map;

	if (voice < 0 || voice >= devc->nr_voice)
		return;

	map = &pv_map[devc->lv_map[voice]];

	DEB(printk("Aftertouch %d\n", voice));

	if (map->voice_mode == 0)
		return;

	/*
	 * Adjust the amount of vibrato depending the pressure
	 */

	instr = devc->act_i[voice];

	if (!instr)
		instr = &devc->i_map[0];

	if (devc->voc[voice].mode == 4)
	{
		int connection = ((instr->operators[10] & 0x01) << 1) | (instr->operators[10 + OFFS_4OP] & 0x01);

		switch (connection)
		{
			case 0:
				SET_VIBRATO(4);
				break;

			case 1:
				SET_VIBRATO(2);
				SET_VIBRATO(4);
				break;

			case 2:
				SET_VIBRATO(1);
				SET_VIBRATO(4);
				break;

			case 3:
				SET_VIBRATO(1);
				SET_VIBRATO(3);
				SET_VIBRATO(4);
				break;

		}
		/*
		 * Not implemented yet
		 */
	}
	else
	{
		SET_VIBRATO(1);

		if ((instr->operators[10] & 0x01))	/*
							 * Additive synthesis
							 */
			SET_VIBRATO(2);
	}
}

#undef SET_VIBRATO

static void bend_pitch(int dev, int voice, int value)
{
	unsigned char data;
	int block, fnum, freq;
	struct physical_voice_info *map;

	map = &pv_map[devc->lv_map[voice]];

	if (map->voice_mode == 0)
		return;

	devc->voc[voice].bender = value;
	if (!value)
		return;
	if (!(devc->voc[voice].keyon_byte & 0x20))
		return;	/*
			 * Not keyed on
			 */

	freq = compute_finetune(devc->voc[voice].orig_freq, devc->voc[voice].bender, devc->voc[voice].bender_range, 0);
	devc->voc[voice].current_freq = freq;

	freq_to_fnum(freq, &block, &fnum);

	data = fnum & 0xff;	/*
				 * Least significant bits of fnumber
				 */
	opl3_command(map->ioaddr, FNUM_LOW + map->voice_num, data);

	data = 0x20 | ((block & 0x7) << 2) | ((fnum >> 8) & 0x3);
	devc->voc[voice].keyon_byte = data;
	opl3_command(map->ioaddr, KEYON_BLOCK + map->voice_num, data);
}

static void opl3_controller (int dev, int voice, int ctrl_num, int value)
{
	if (voice < 0 || voice >= devc->nr_voice)
		return;

	switch (ctrl_num)
	{
		case CTRL_PITCH_BENDER:
			bend_pitch(dev, voice, value);
			break;

		case CTRL_PITCH_BENDER_RANGE:
			devc->voc[voice].bender_range = value;
			break;

		case CTL_MAIN_VOLUME:
			devc->voc[voice].volume = value / 128;
			break;

		case CTL_PAN:
			devc->voc[voice].panning = (value * 2) - 128;
			break;
	}
}

static void opl3_bender(int dev, int voice, int value)
{
	if (voice < 0 || voice >= devc->nr_voice)
		return;

	bend_pitch(dev, voice, value - 8192);
}

static int opl3_alloc_voice(int dev, int chn, int note, struct voice_alloc_info *alloc)
{
	int i, p, best, first, avail, best_time = 0x7fffffff;
	struct sbi_instrument *instr;
	int is4op;
	int instr_no;

	if (chn < 0 || chn > 15)
		instr_no = 0;
	else
		instr_no = devc->chn_info[chn].pgm_num;

	instr = &devc->i_map[instr_no];
	if (instr->channel < 0 ||	/* Instrument not loaded */
		devc->nr_voice != 12)	/* Not in 4 OP mode */
		is4op = 0;
	else if (devc->nr_voice == 12)	/* 4 OP mode */
		is4op = (instr->key == OPL3_PATCH);
	else
		is4op = 0;

	if (is4op)
	{
		first = p = 0;
		avail = 6;
	}
	else
	{
		if (devc->nr_voice == 12)	/* 4 OP mode. Use the '2 OP only' operators first */
			first = p = 6;
		else
			first = p = 0;
		avail = devc->nr_voice;
	}

	/*
	 *    Now try to find a free voice
	 */
	best = first;

	for (i = 0; i < avail; i++)
	{
		if (alloc->map[p] == 0)
		{
			return p;
		}
		if (alloc->alloc_times[p] < best_time)		/* Find oldest playing note */
		{
			best_time = alloc->alloc_times[p];
			best = p;
		}
		p = (p + 1) % avail;
	}

	/*
	 *    Insert some kind of priority mechanism here.
	 */

	if (best < 0)
		best = 0;
	if (best > devc->nr_voice)
		best -= devc->nr_voice;

	return best;	/* All devc->voc in use. Select the first one. */
}

static void opl3_setup_voice(int dev, int voice, int chn)
{
	struct channel_info *info;

	if (voice < 0 || voice >= devc->nr_voice)
		return;

	if (chn < 0 || chn > 15)
		return;

	info = &synth_devs[dev]->chn_info[chn];

	opl3_set_instr(dev, voice, info->pgm_num);

	devc->voc[voice].bender = 0;
	devc->voc[voice].bender_range = info->bender_range;
	devc->voc[voice].volume = info->controllers[CTL_MAIN_VOLUME];
	devc->voc[voice].panning = (info->controllers[CTL_PAN] * 2) - 128;
}

static struct synth_operations opl3_operations =
{
	.owner		= THIS_MODULE,
	.id		= "OPL",
	.info		= NULL,
	.midi_dev	= 0,
	.synth_type	= SYNTH_TYPE_FM,
	.synth_subtype	= FM_TYPE_ADLIB,
	.open		= opl3_open,
	.close		= opl3_close,
	.ioctl		= opl3_ioctl,
	.kill_note	= opl3_kill_note,
	.start_note	= opl3_start_note,
	.set_instr	= opl3_set_instr,
	.reset		= opl3_reset,
	.hw_control	= opl3_hw_control,
	.load_patch	= opl3_load_patch,
	.aftertouch	= opl3_aftertouch,
	.controller	= opl3_controller,
	.panning	= opl3_panning,
	.volume_method	= opl3_volume_method,
	.bender		= opl3_bender,
	.alloc_voice	= opl3_alloc_voice,
	.setup_voice	= opl3_setup_voice
};

static int opl3_init(int ioaddr, struct module *owner)
{
	int i;
	int me;

	if (devc == NULL)
	{
		printk(KERN_ERR "opl3: Device control structure not initialized.\n");
		return -1;
	}

	if ((me = sound_alloc_synthdev()) == -1)
	{
		printk(KERN_WARNING "opl3: Too many synthesizers\n");
		return -1;
	}

	devc->nr_voice = 9;

	devc->fm_info.device = 0;
	devc->fm_info.synth_type = SYNTH_TYPE_FM;
	devc->fm_info.synth_subtype = FM_TYPE_ADLIB;
	devc->fm_info.perc_mode = 0;
	devc->fm_info.nr_voices = 9;
	devc->fm_info.nr_drums = 0;
	devc->fm_info.instr_bank_size = SBFM_MAXINSTR;
	devc->fm_info.capabilities = 0;
	devc->left_io = ioaddr;
	devc->right_io = ioaddr + 2;

	if (detected_model <= 2)
		devc->model = 1;
	else
	{
		devc->model = 2;
		if (detected_model == 4)
			devc->is_opl4 = 1;
	}

	opl3_operations.info = &devc->fm_info;

	synth_devs[me] = &opl3_operations;

	if (owner)
		synth_devs[me]->owner = owner;
	
	sequencer_init();
	devc->v_alloc = &opl3_operations.alloc;
	devc->chn_info = &opl3_operations.chn_info[0];

	if (devc->model == 2)
	{
		if (devc->is_opl4) 
			strcpy(devc->fm_info.name, "Yamaha OPL4/OPL3 FM");
		else 
			strcpy(devc->fm_info.name, "Yamaha OPL3");

		devc->v_alloc->max_voice = devc->nr_voice = 18;
		devc->fm_info.nr_drums = 0;
		devc->fm_info.synth_subtype = FM_TYPE_OPL3;
		devc->fm_info.capabilities |= SYNTH_CAP_OPL3;

		for (i = 0; i < 18; i++)
		{
			if (pv_map[i].ioaddr == USE_LEFT)
				pv_map[i].ioaddr = devc->left_io;
			else
				pv_map[i].ioaddr = devc->right_io;
		}
		opl3_command(devc->right_io, OPL3_MODE_REGISTER, OPL3_ENABLE);
		opl3_command(devc->right_io, CONNECTION_SELECT_REGISTER, 0x00);
	}
	else
	{
		strcpy(devc->fm_info.name, "Yamaha OPL2");
		devc->v_alloc->max_voice = devc->nr_voice = 9;
		devc->fm_info.nr_drums = 0;

		for (i = 0; i < 18; i++)
			pv_map[i].ioaddr = devc->left_io;
	};
	conf_printf2(devc->fm_info.name, ioaddr, 0, -1, -1);

	for (i = 0; i < SBFM_MAXINSTR; i++)
		devc->i_map[i].channel = -1;

	return me;
}

static int me;

static int io = -1;

module_param(io, int, 0);

static int __init init_opl3 (void)
{
	printk(KERN_INFO "YM3812 and OPL-3 driver Copyright (C) by Hannu Savolainen, Rob Hooft 1993-1996\n");

	if (io != -1)	/* User loading pure OPL3 module */
	{
		if (!opl3_detect(io))
		{
			return -ENODEV;
		}

		me = opl3_init(io, THIS_MODULE);
	}

	return 0;
}

static void __exit cleanup_opl3(void)
{
	if (devc && io != -1)
	{
		if (devc->base) {
			release_region(devc->base,4);
			if (devc->is_opl4)
				release_region(devc->base - 8, 2);
		}
		kfree(devc);
		devc = NULL;
		sound_unload_synthdev(me);
	}
}

module_init(init_opl3);
module_exit(cleanup_opl3);

#ifndef MODULE
static int __init setup_opl3(char *str)
{
        /* io  */
	int ints[2];
	
	str = get_options(str, ARRAY_SIZE(ints), ints);
	
	io = ints[1];

	return 1;
}

__setup("opl3=", setup_opl3);
#endif
MODULE_LICENSE("GPL");