/* 
 * Driver for NeoMagic 256AV and 256ZX chipsets.
 * Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>
 *
 * Based on nm256_audio.c OSS driver in linux kernel.
 * The original author of OSS nm256 driver wishes to remain anonymous,
 * so I just put my acknoledgment to him/her here.
 * The original author's web page is found at
 *      http://www.uglx.org/sony.html
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */
  
#include <asm/io.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>

#include <sound/core.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/ac97_codec.h>
#include <sound/initval.h>

#define CARD_NAME "NeoMagic 256AV/ZX"
#define DRIVER_NAME "NM256"

MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
MODULE_DESCRIPTION("NeoMagic NM256AV/ZX");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{NeoMagic,NM256AV},"
                "{NeoMagic,NM256ZX}}");

/*
 * some compile conditions.
 */

static int index = SNDRV_DEFAULT_IDX1;  /* Index */
static char *id = SNDRV_DEFAULT_STR1;   /* ID for this card */
static int playback_bufsize = 16;
static int capture_bufsize = 16;
static int force_ac97;                  /* disabled as default */
static int buffer_top;                  /* not specified */
static int use_cache;                   /* disabled */
static int vaio_hack;                   /* disabled */
static int reset_workaround;
static int reset_workaround_2;

module_param(index, int, 0444);
MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard.");
module_param(id, charp, 0444);
MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard.");
module_param(playback_bufsize, int, 0444);
MODULE_PARM_DESC(playback_bufsize, "DAC frame size in kB for " CARD_NAME " soundcard.");
module_param(capture_bufsize, int, 0444);
MODULE_PARM_DESC(capture_bufsize, "ADC frame size in kB for " CARD_NAME " soundcard.");
module_param(force_ac97, bool, 0444);
MODULE_PARM_DESC(force_ac97, "Force to use AC97 codec for " CARD_NAME " soundcard.");
module_param(buffer_top, int, 0444);
MODULE_PARM_DESC(buffer_top, "Set the top address of audio buffer for " CARD_NAME " soundcard.");
module_param(use_cache, bool, 0444);
MODULE_PARM_DESC(use_cache, "Enable the cache for coefficient table access.");
module_param(vaio_hack, bool, 0444);
MODULE_PARM_DESC(vaio_hack, "Enable workaround for Sony VAIO notebooks.");
module_param(reset_workaround, bool, 0444);
MODULE_PARM_DESC(reset_workaround, "Enable AC97 RESET workaround for some laptops.");
module_param(reset_workaround_2, bool, 0444);
MODULE_PARM_DESC(reset_workaround_2, "Enable extended AC97 RESET workaround for some other laptops.");

/* just for backward compatibility */
static int enable;
module_param(enable, bool, 0444);



/*
 * hw definitions
 */

/* The BIOS signature. */
#define NM_SIGNATURE 0x4e4d0000
/* Signature mask. */
#define NM_SIG_MASK 0xffff0000

/* Size of the second memory area. */
#define NM_PORT2_SIZE 4096

/* The base offset of the mixer in the second memory area. */
#define NM_MIXER_OFFSET 0x600

/* The maximum size of a coefficient entry. */
#define NM_MAX_PLAYBACK_COEF_SIZE       0x5000
#define NM_MAX_RECORD_COEF_SIZE         0x1260

/* The interrupt register. */
#define NM_INT_REG 0xa04
/* And its bits. */
#define NM_PLAYBACK_INT 0x40
#define NM_RECORD_INT 0x100
#define NM_MISC_INT_1 0x4000
#define NM_MISC_INT_2 0x1
#define NM_ACK_INT(chip, X) snd_nm256_writew(chip, NM_INT_REG, (X) << 1)

/* The AV's "mixer ready" status bit and location. */
#define NM_MIXER_STATUS_OFFSET 0xa04
#define NM_MIXER_READY_MASK 0x0800
#define NM_MIXER_PRESENCE 0xa06
#define NM_PRESENCE_MASK 0x0050
#define NM_PRESENCE_VALUE 0x0040

/*
 * For the ZX.  It uses the same interrupt register, but it holds 32
 * bits instead of 16.
 */
#define NM2_PLAYBACK_INT 0x10000
#define NM2_RECORD_INT 0x80000
#define NM2_MISC_INT_1 0x8
#define NM2_MISC_INT_2 0x2
#define NM2_ACK_INT(chip, X) snd_nm256_writel(chip, NM_INT_REG, (X))

/* The ZX's "mixer ready" status bit and location. */
#define NM2_MIXER_STATUS_OFFSET 0xa06
#define NM2_MIXER_READY_MASK 0x0800

/* The playback registers start from here. */
#define NM_PLAYBACK_REG_OFFSET 0x0
/* The record registers start from here. */
#define NM_RECORD_REG_OFFSET 0x200

/* The rate register is located 2 bytes from the start of the register area. */
#define NM_RATE_REG_OFFSET 2

/* Mono/stereo flag, number of bits on playback, and rate mask. */
#define NM_RATE_STEREO 1
#define NM_RATE_BITS_16 2
#define NM_RATE_MASK 0xf0

/* Playback enable register. */
#define NM_PLAYBACK_ENABLE_REG (NM_PLAYBACK_REG_OFFSET + 0x1)
#define NM_PLAYBACK_ENABLE_FLAG 1
#define NM_PLAYBACK_ONESHOT 2
#define NM_PLAYBACK_FREERUN 4

/* Mutes the audio output. */
#define NM_AUDIO_MUTE_REG (NM_PLAYBACK_REG_OFFSET + 0x18)
#define NM_AUDIO_MUTE_LEFT 0x8000
#define NM_AUDIO_MUTE_RIGHT 0x0080

/* Recording enable register. */
#define NM_RECORD_ENABLE_REG (NM_RECORD_REG_OFFSET + 0)
#define NM_RECORD_ENABLE_FLAG 1
#define NM_RECORD_FREERUN 2

/* coefficient buffer pointer */
#define NM_COEFF_START_OFFSET   0x1c
#define NM_COEFF_END_OFFSET     0x20

/* DMA buffer offsets */
#define NM_RBUFFER_START (NM_RECORD_REG_OFFSET + 0x4)
#define NM_RBUFFER_END   (NM_RECORD_REG_OFFSET + 0x10)
#define NM_RBUFFER_WMARK (NM_RECORD_REG_OFFSET + 0xc)
#define NM_RBUFFER_CURRP (NM_RECORD_REG_OFFSET + 0x8)

#define NM_PBUFFER_START (NM_PLAYBACK_REG_OFFSET + 0x4)
#define NM_PBUFFER_END   (NM_PLAYBACK_REG_OFFSET + 0x14)
#define NM_PBUFFER_WMARK (NM_PLAYBACK_REG_OFFSET + 0xc)
#define NM_PBUFFER_CURRP (NM_PLAYBACK_REG_OFFSET + 0x8)

struct nm256_stream {

        struct nm256 *chip;
        struct snd_pcm_substream *substream;
        int running;
        int suspended;
        
        u32 buf;        /* offset from chip->buffer */
        int bufsize;    /* buffer size in bytes */
        void __iomem *bufptr;           /* mapped pointer */
        unsigned long bufptr_addr;      /* physical address of the mapped pointer */

        int dma_size;           /* buffer size of the substream in bytes */
        int period_size;        /* period size in bytes */
        int periods;            /* # of periods */
        int shift;              /* bit shifts */
        int cur_period;         /* current period # */

};

struct nm256 {
        
        struct snd_card *card;

        void __iomem *cport;            /* control port */
        struct resource *res_cport;     /* its resource */
        unsigned long cport_addr;       /* physical address */

        void __iomem *buffer;           /* buffer */
        struct resource *res_buffer;    /* its resource */
        unsigned long buffer_addr;      /* buffer phyiscal address */

        u32 buffer_start;               /* start offset from pci resource 0 */
        u32 buffer_end;                 /* end offset */
        u32 buffer_size;                /* total buffer size */

        u32 all_coeff_buf;              /* coefficient buffer */
        u32 coeff_buf[2];               /* coefficient buffer for each stream */

        unsigned int coeffs_current: 1; /* coeff. table is loaded? */
        unsigned int use_cache: 1;      /* use one big coef. table */
        unsigned int reset_workaround: 1; /* Workaround for some laptops to avoid freeze */
        unsigned int reset_workaround_2: 1; /* Extended workaround for some other laptops to avoid freeze */
        unsigned int in_resume: 1;

        int mixer_base;                 /* register offset of ac97 mixer */
        int mixer_status_offset;        /* offset of mixer status reg. */
        int mixer_status_mask;          /* bit mask to test the mixer status */

        int irq;
        int irq_acks;
        irq_handler_t interrupt;
        int badintrcount;               /* counter to check bogus interrupts */
        struct mutex irq_mutex;

        struct nm256_stream streams[2];

        struct snd_ac97 *ac97;
        unsigned short *ac97_regs; /* register caches, only for valid regs */

        struct snd_pcm *pcm;

        struct pci_dev *pci;

        spinlock_t reg_lock;

};


/*
 * include coefficient table
 */
#include "nm256_coef.c"


/*
 * PCI ids
 */
static struct pci_device_id snd_nm256_ids[] = {
        {PCI_VDEVICE(NEOMAGIC, PCI_DEVICE_ID_NEOMAGIC_NM256AV_AUDIO), 0},
        {PCI_VDEVICE(NEOMAGIC, PCI_DEVICE_ID_NEOMAGIC_NM256ZX_AUDIO), 0},
        {PCI_VDEVICE(NEOMAGIC, PCI_DEVICE_ID_NEOMAGIC_NM256XL_PLUS_AUDIO), 0},
        {0,},
};

MODULE_DEVICE_TABLE(pci, snd_nm256_ids);


/*
 * lowlvel stuffs
 */

static inline u8
snd_nm256_readb(struct nm256 *chip, int offset)
{
        return readb(chip->cport + offset);
}

static inline u16
snd_nm256_readw(struct nm256 *chip, int offset)
{
        return readw(chip->cport + offset);
}

static inline u32
snd_nm256_readl(struct nm256 *chip, int offset)
{
        return readl(chip->cport + offset);
}

static inline void
snd_nm256_writeb(struct nm256 *chip, int offset, u8 val)
{
        writeb(val, chip->cport + offset);
}

static inline void
snd_nm256_writew(struct nm256 *chip, int offset, u16 val)
{
        writew(val, chip->cport + offset);
}

static inline void
snd_nm256_writel(struct nm256 *chip, int offset, u32 val)
{
        writel(val, chip->cport + offset);
}

static inline void
snd_nm256_write_buffer(struct nm256 *chip, void *src, int offset, int size)
{
        offset -= chip->buffer_start;
#ifdef CONFIG_SND_DEBUG
        if (offset < 0 || offset >= chip->buffer_size) {
                snd_printk(KERN_ERR "write_buffer invalid offset = %d size = %d\n",
                           offset, size);
                return;
        }
#endif
        memcpy_toio(chip->buffer + offset, src, size);
}

/*
 * coefficient handlers -- what a magic!
 */

static u16
snd_nm256_get_start_offset(int which)
{
        u16 offset = 0;
        while (which-- > 0)
                offset += coefficient_sizes[which];
        return offset;
}

static void
snd_nm256_load_one_coefficient(struct nm256 *chip, int stream, u32 port, int which)
{
        u32 coeff_buf = chip->coeff_buf[stream];
        u16 offset = snd_nm256_get_start_offset(which);
        u16 size = coefficient_sizes[which];

        snd_nm256_write_buffer(chip, coefficients + offset, coeff_buf, size);
        snd_nm256_writel(chip, port, coeff_buf);
        /* ???  Record seems to behave differently than playback.  */
        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                size--;
        snd_nm256_writel(chip, port + 4, coeff_buf + size);
}

static void
snd_nm256_load_coefficient(struct nm256 *chip, int stream, int number)
{
        /* The enable register for the specified engine.  */
        u32 poffset = (stream == SNDRV_PCM_STREAM_CAPTURE ?
                       NM_RECORD_ENABLE_REG : NM_PLAYBACK_ENABLE_REG);
        u32 addr = NM_COEFF_START_OFFSET;

        addr += (stream == SNDRV_PCM_STREAM_CAPTURE ?
                 NM_RECORD_REG_OFFSET : NM_PLAYBACK_REG_OFFSET);

        if (snd_nm256_readb(chip, poffset) & 1) {
                snd_printd("NM256: Engine was enabled while loading coefficients!\n");
                return;
        }

        /* The recording engine uses coefficient values 8-15.  */
        number &= 7;
        if (stream == SNDRV_PCM_STREAM_CAPTURE)
                number += 8;

        if (! chip->use_cache) {
                snd_nm256_load_one_coefficient(chip, stream, addr, number);
                return;
        }
        if (! chip->coeffs_current) {
                snd_nm256_write_buffer(chip, coefficients, chip->all_coeff_buf,
                                       NM_TOTAL_COEFF_COUNT * 4);
                chip->coeffs_current = 1;
        } else {
                u32 base = chip->all_coeff_buf;
                u32 offset = snd_nm256_get_start_offset(number);
                u32 end_offset = offset + coefficient_sizes[number];
                snd_nm256_writel(chip, addr, base + offset);
                if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                        end_offset--;
                snd_nm256_writel(chip, addr + 4, base + end_offset);
        }
}


/* The actual rates supported by the card. */
static unsigned int samplerates[8] = {
        8000, 11025, 16000, 22050, 24000, 32000, 44100, 48000,
};
static struct snd_pcm_hw_constraint_list constraints_rates = {
        .count = ARRAY_SIZE(samplerates), 
        .list = samplerates,
        .mask = 0,
};

/*
 * return the index of the target rate
 */
static int
snd_nm256_fixed_rate(unsigned int rate)
{
        unsigned int i;
        for (i = 0; i < ARRAY_SIZE(samplerates); i++) {
                if (rate == samplerates[i])
                        return i;
        }
        snd_BUG();
        return 0;
}

/*
 * set sample rate and format
 */
static void
snd_nm256_set_format(struct nm256 *chip, struct nm256_stream *s,
                     struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        int rate_index = snd_nm256_fixed_rate(runtime->rate);
        unsigned char ratebits = (rate_index << 4) & NM_RATE_MASK;

        s->shift = 0;
        if (snd_pcm_format_width(runtime->format) == 16) {
                ratebits |= NM_RATE_BITS_16;
                s->shift++;
        }
        if (runtime->channels > 1) {
                ratebits |= NM_RATE_STEREO;
                s->shift++;
        }

        runtime->rate = samplerates[rate_index];

        switch (substream->stream) {
        case SNDRV_PCM_STREAM_PLAYBACK:
                snd_nm256_load_coefficient(chip, 0, rate_index); /* 0 = playback */
                snd_nm256_writeb(chip,
                                 NM_PLAYBACK_REG_OFFSET + NM_RATE_REG_OFFSET,
                                 ratebits);
                break;
        case SNDRV_PCM_STREAM_CAPTURE:
                snd_nm256_load_coefficient(chip, 1, rate_index); /* 1 = record */
                snd_nm256_writeb(chip,
                                 NM_RECORD_REG_OFFSET + NM_RATE_REG_OFFSET,
                                 ratebits);
                break;
        }
}

/* acquire interrupt */
static int snd_nm256_acquire_irq(struct nm256 *chip)
{
        mutex_lock(&chip->irq_mutex);
        if (chip->irq < 0) {
                if (request_irq(chip->pci->irq, chip->interrupt, IRQF_SHARED,
                                chip->card->driver, chip)) {
                        snd_printk(KERN_ERR "unable to grab IRQ %d\n", chip->pci->irq);
                        mutex_unlock(&chip->irq_mutex);
                        return -EBUSY;
                }
                chip->irq = chip->pci->irq;
        }
        chip->irq_acks++;
        mutex_unlock(&chip->irq_mutex);
        return 0;
}

/* release interrupt */
static void snd_nm256_release_irq(struct nm256 *chip)
{
        mutex_lock(&chip->irq_mutex);
        if (chip->irq_acks > 0)
                chip->irq_acks--;
        if (chip->irq_acks == 0 && chip->irq >= 0) {
                free_irq(chip->irq, chip);
                chip->irq = -1;
        }
        mutex_unlock(&chip->irq_mutex);
}

/*
 * start / stop
 */

/* update the watermark (current period) */
static void snd_nm256_pcm_mark(struct nm256 *chip, struct nm256_stream *s, int reg)
{
        s->cur_period++;
        s->cur_period %= s->periods;
        snd_nm256_writel(chip, reg, s->buf + s->cur_period * s->period_size);
}

#define snd_nm256_playback_mark(chip, s) snd_nm256_pcm_mark(chip, s, NM_PBUFFER_WMARK)
#define snd_nm256_capture_mark(chip, s)  snd_nm256_pcm_mark(chip, s, NM_RBUFFER_WMARK)

static void
snd_nm256_playback_start(struct nm256 *chip, struct nm256_stream *s,
                         struct snd_pcm_substream *substream)
{
        /* program buffer pointers */
        snd_nm256_writel(chip, NM_PBUFFER_START, s->buf);
        snd_nm256_writel(chip, NM_PBUFFER_END, s->buf + s->dma_size - (1 << s->shift));
        snd_nm256_writel(chip, NM_PBUFFER_CURRP, s->buf);
        snd_nm256_playback_mark(chip, s);

        /* Enable playback engine and interrupts. */
        snd_nm256_writeb(chip, NM_PLAYBACK_ENABLE_REG,
                         NM_PLAYBACK_ENABLE_FLAG | NM_PLAYBACK_FREERUN);
        /* Enable both channels. */
        snd_nm256_writew(chip, NM_AUDIO_MUTE_REG, 0x0);
}

static void
snd_nm256_capture_start(struct nm256 *chip, struct nm256_stream *s,
                        struct snd_pcm_substream *substream)
{
        /* program buffer pointers */
        snd_nm256_writel(chip, NM_RBUFFER_START, s->buf);
        snd_nm256_writel(chip, NM_RBUFFER_END, s->buf + s->dma_size);
        snd_nm256_writel(chip, NM_RBUFFER_CURRP, s->buf);
        snd_nm256_capture_mark(chip, s);

        /* Enable playback engine and interrupts. */
        snd_nm256_writeb(chip, NM_RECORD_ENABLE_REG,
                         NM_RECORD_ENABLE_FLAG | NM_RECORD_FREERUN);
}

/* Stop the play engine. */
static void
snd_nm256_playback_stop(struct nm256 *chip)
{
        /* Shut off sound from both channels. */
        snd_nm256_writew(chip, NM_AUDIO_MUTE_REG,
                         NM_AUDIO_MUTE_LEFT | NM_AUDIO_MUTE_RIGHT);
        /* Disable play engine. */
        snd_nm256_writeb(chip, NM_PLAYBACK_ENABLE_REG, 0);
}

static void
snd_nm256_capture_stop(struct nm256 *chip)
{
        /* Disable recording engine. */
        snd_nm256_writeb(chip, NM_RECORD_ENABLE_REG, 0);
}

static int
snd_nm256_playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);
        struct nm256_stream *s = substream->runtime->private_data;
        int err = 0;

        if (snd_BUG_ON(!s))
                return -ENXIO;

        spin_lock(&chip->reg_lock);
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_RESUME:
                s->suspended = 0;
                /* fallthru */
        case SNDRV_PCM_TRIGGER_START:
                if (! s->running) {
                        snd_nm256_playback_start(chip, s, substream);
                        s->running = 1;
                }
                break;
        case SNDRV_PCM_TRIGGER_SUSPEND:
                s->suspended = 1;
                /* fallthru */
        case SNDRV_PCM_TRIGGER_STOP:
                if (s->running) {
                        snd_nm256_playback_stop(chip);
                        s->running = 0;
                }
                break;
        default:
                err = -EINVAL;
                break;
        }
        spin_unlock(&chip->reg_lock);
        return err;
}

static int
snd_nm256_capture_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);
        struct nm256_stream *s = substream->runtime->private_data;
        int err = 0;

        if (snd_BUG_ON(!s))
                return -ENXIO;

        spin_lock(&chip->reg_lock);
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
                if (! s->running) {
                        snd_nm256_capture_start(chip, s, substream);
                        s->running = 1;
                }
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
                if (s->running) {
                        snd_nm256_capture_stop(chip);
                        s->running = 0;
                }
                break;
        default:
                err = -EINVAL;
                break;
        }
        spin_unlock(&chip->reg_lock);
        return err;
}


/*
 * prepare playback/capture channel
 */
static int snd_nm256_pcm_prepare(struct snd_pcm_substream *substream)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct nm256_stream *s = runtime->private_data;

        if (snd_BUG_ON(!s))
                return -ENXIO;
        s->dma_size = frames_to_bytes(runtime, substream->runtime->buffer_size);
        s->period_size = frames_to_bytes(runtime, substream->runtime->period_size);
        s->periods = substream->runtime->periods;
        s->cur_period = 0;

        spin_lock_irq(&chip->reg_lock);
        s->running = 0;
        snd_nm256_set_format(chip, s, substream);
        spin_unlock_irq(&chip->reg_lock);

        return 0;
}


/*
 * get the current pointer
 */
static snd_pcm_uframes_t
snd_nm256_playback_pointer(struct snd_pcm_substream *substream)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);
        struct nm256_stream *s = substream->runtime->private_data;
        unsigned long curp;

        if (snd_BUG_ON(!s))
                return 0;
        curp = snd_nm256_readl(chip, NM_PBUFFER_CURRP) - (unsigned long)s->buf;
        curp %= s->dma_size;
        return bytes_to_frames(substream->runtime, curp);
}

static snd_pcm_uframes_t
snd_nm256_capture_pointer(struct snd_pcm_substream *substream)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);
        struct nm256_stream *s = substream->runtime->private_data;
        unsigned long curp;

        if (snd_BUG_ON(!s))
                return 0;
        curp = snd_nm256_readl(chip, NM_RBUFFER_CURRP) - (unsigned long)s->buf;
        curp %= s->dma_size;    
        return bytes_to_frames(substream->runtime, curp);
}

/* Remapped I/O space can be accessible as pointer on i386 */
/* This might be changed in the future */
#ifndef __i386__
/*
 * silence / copy for playback
 */
static int
snd_nm256_playback_silence(struct snd_pcm_substream *substream,
                           int channel, /* not used (interleaved data) */
                           snd_pcm_uframes_t pos,
                           snd_pcm_uframes_t count)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct nm256_stream *s = runtime->private_data;
        count = frames_to_bytes(runtime, count);
        pos = frames_to_bytes(runtime, pos);
        memset_io(s->bufptr + pos, 0, count);
        return 0;
}

static int
snd_nm256_playback_copy(struct snd_pcm_substream *substream,
                        int channel, /* not used (interleaved data) */
                        snd_pcm_uframes_t pos,
                        void __user *src,
                        snd_pcm_uframes_t count)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct nm256_stream *s = runtime->private_data;
        count = frames_to_bytes(runtime, count);
        pos = frames_to_bytes(runtime, pos);
        if (copy_from_user_toio(s->bufptr + pos, src, count))
                return -EFAULT;
        return 0;
}

/*
 * copy to user
 */
static int
snd_nm256_capture_copy(struct snd_pcm_substream *substream,
                       int channel, /* not used (interleaved data) */
                       snd_pcm_uframes_t pos,
                       void __user *dst,
                       snd_pcm_uframes_t count)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct nm256_stream *s = runtime->private_data;
        count = frames_to_bytes(runtime, count);
        pos = frames_to_bytes(runtime, pos);
        if (copy_to_user_fromio(dst, s->bufptr + pos, count))
                return -EFAULT;
        return 0;
}

#endif /* !__i386__ */


/*
 * update playback/capture watermarks
 */

/* spinlock held! */
static void
snd_nm256_playback_update(struct nm256 *chip)
{
        struct nm256_stream *s;

        s = &chip->streams[SNDRV_PCM_STREAM_PLAYBACK];
        if (s->running && s->substream) {
                spin_unlock(&chip->reg_lock);
                snd_pcm_period_elapsed(s->substream);
                spin_lock(&chip->reg_lock);
                snd_nm256_playback_mark(chip, s);
        }
}

/* spinlock held! */
static void
snd_nm256_capture_update(struct nm256 *chip)
{
        struct nm256_stream *s;

        s = &chip->streams[SNDRV_PCM_STREAM_CAPTURE];
        if (s->running && s->substream) {
                spin_unlock(&chip->reg_lock);
                snd_pcm_period_elapsed(s->substream);
                spin_lock(&chip->reg_lock);
                snd_nm256_capture_mark(chip, s);
        }
}

/*
 * hardware info
 */
static struct snd_pcm_hardware snd_nm256_playback =
{
        .info =                 SNDRV_PCM_INFO_MMAP_IOMEM |SNDRV_PCM_INFO_MMAP_VALID |
                                SNDRV_PCM_INFO_INTERLEAVED |
                                /*SNDRV_PCM_INFO_PAUSE |*/
                                SNDRV_PCM_INFO_RESUME,
        .formats =              SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
        .rates =                SNDRV_PCM_RATE_KNOT/*24k*/ | SNDRV_PCM_RATE_8000_48000,
        .rate_min =             8000,
        .rate_max =             48000,
        .channels_min =         1,
        .channels_max =         2,
        .periods_min =          2,
        .periods_max =          1024,
        .buffer_bytes_max =     128 * 1024,
        .period_bytes_min =     256,
        .period_bytes_max =     128 * 1024,
};

static struct snd_pcm_hardware snd_nm256_capture =
{
        .info =                 SNDRV_PCM_INFO_MMAP_IOMEM | SNDRV_PCM_INFO_MMAP_VALID |
                                SNDRV_PCM_INFO_INTERLEAVED |
                                /*SNDRV_PCM_INFO_PAUSE |*/
                                SNDRV_PCM_INFO_RESUME,
        .formats =              SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
        .rates =                SNDRV_PCM_RATE_KNOT/*24k*/ | SNDRV_PCM_RATE_8000_48000,
        .rate_min =             8000,
        .rate_max =             48000,
        .channels_min =         1,
        .channels_max =         2,
        .periods_min =          2,
        .periods_max =          1024,
        .buffer_bytes_max =     128 * 1024,
        .period_bytes_min =     256,
        .period_bytes_max =     128 * 1024,
};


/* set dma transfer size */
static int snd_nm256_pcm_hw_params(struct snd_pcm_substream *substream,
                                   struct snd_pcm_hw_params *hw_params)
{
        /* area and addr are already set and unchanged */
        substream->runtime->dma_bytes = params_buffer_bytes(hw_params);
        return 0;
}

/*
 * open
 */
static void snd_nm256_setup_stream(struct nm256 *chip, struct nm256_stream *s,
                                   struct snd_pcm_substream *substream,
                                   struct snd_pcm_hardware *hw_ptr)
{
        struct snd_pcm_runtime *runtime = substream->runtime;

        s->running = 0;
        runtime->hw = *hw_ptr;
        runtime->hw.buffer_bytes_max = s->bufsize;
        runtime->hw.period_bytes_max = s->bufsize / 2;
        runtime->dma_area = (void __force *) s->bufptr;
        runtime->dma_addr = s->bufptr_addr;
        runtime->dma_bytes = s->bufsize;
        runtime->private_data = s;
        s->substream = substream;

        snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                                   &constraints_rates);
}

static int
snd_nm256_playback_open(struct snd_pcm_substream *substream)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);

        if (snd_nm256_acquire_irq(chip) < 0)
                return -EBUSY;
        snd_nm256_setup_stream(chip, &chip->streams[SNDRV_PCM_STREAM_PLAYBACK],
                               substream, &snd_nm256_playback);
        return 0;
}

static int
snd_nm256_capture_open(struct snd_pcm_substream *substream)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);

        if (snd_nm256_acquire_irq(chip) < 0)
                return -EBUSY;
        snd_nm256_setup_stream(chip, &chip->streams[SNDRV_PCM_STREAM_CAPTURE],
                               substream, &snd_nm256_capture);
        return 0;
}

/*
 * close - we don't have to do special..
 */
static int
snd_nm256_playback_close(struct snd_pcm_substream *substream)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);

        snd_nm256_release_irq(chip);
        return 0;
}


static int
snd_nm256_capture_close(struct snd_pcm_substream *substream)
{
        struct nm256 *chip = snd_pcm_substream_chip(substream);

        snd_nm256_release_irq(chip);
        return 0;
}

/*
 * create a pcm instance
 */
static struct snd_pcm_ops snd_nm256_playback_ops = {
        .open =         snd_nm256_playback_open,
        .close =        snd_nm256_playback_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .hw_params =    snd_nm256_pcm_hw_params,
        .prepare =      snd_nm256_pcm_prepare,
        .trigger =      snd_nm256_playback_trigger,
        .pointer =      snd_nm256_playback_pointer,
#ifndef __i386__
        .copy =         snd_nm256_playback_copy,
        .silence =      snd_nm256_playback_silence,
#endif
        .mmap =         snd_pcm_lib_mmap_iomem,
};

static struct snd_pcm_ops snd_nm256_capture_ops = {
        .open =         snd_nm256_capture_open,
        .close =        snd_nm256_capture_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .hw_params =    snd_nm256_pcm_hw_params,
        .prepare =      snd_nm256_pcm_prepare,
        .trigger =      snd_nm256_capture_trigger,
        .pointer =      snd_nm256_capture_pointer,
#ifndef __i386__
        .copy =         snd_nm256_capture_copy,
#endif
        .mmap =         snd_pcm_lib_mmap_iomem,
};

static int __devinit
snd_nm256_pcm(struct nm256 *chip, int device)
{
        struct snd_pcm *pcm;
        int i, err;

        for (i = 0; i < 2; i++) {
                struct nm256_stream *s = &chip->streams[i];
                s->bufptr = chip->buffer + (s->buf - chip->buffer_start);
                s->bufptr_addr = chip->buffer_addr + (s->buf - chip->buffer_start);
        }

        err = snd_pcm_new(chip->card, chip->card->driver, device,
                          1, 1, &pcm);
        if (err < 0)
                return err;

        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_nm256_playback_ops);
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_nm256_capture_ops);

        pcm->private_data = chip;
        pcm->info_flags = 0;
        chip->pcm = pcm;

        return 0;
}


/* 
 * Initialize the hardware. 
 */
static void
snd_nm256_init_chip(struct nm256 *chip)
{
        /* Reset everything. */
        snd_nm256_writeb(chip, 0x0, 0x11);
        snd_nm256_writew(chip, 0x214, 0);
        /* stop sounds.. */
        //snd_nm256_playback_stop(chip);
        //snd_nm256_capture_stop(chip);
}


static irqreturn_t
snd_nm256_intr_check(struct nm256 *chip)
{
        if (chip->badintrcount++ > 1000) {
                /*
                 * I'm not sure if the best thing is to stop the card from
                 * playing or just release the interrupt (after all, we're in
                 * a bad situation, so doing fancy stuff may not be such a good
                 * idea).
                 *
                 * I worry about the card engine continuing to play noise
                 * over and over, however--that could become a very
                 * obnoxious problem.  And we know that when this usually
                 * happens things are fairly safe, it just means the user's
                 * inserted a PCMCIA card and someone's spamming us with IRQ 9s.
                 */
                if (chip->streams[SNDRV_PCM_STREAM_PLAYBACK].running)
                        snd_nm256_playback_stop(chip);
                if (chip->streams[SNDRV_PCM_STREAM_CAPTURE].running)
                        snd_nm256_capture_stop(chip);
                chip->badintrcount = 0;
                return IRQ_HANDLED;
        }
        return IRQ_NONE;
}

/* 

 * Handle a potential interrupt for the device referred to by DEV_ID. 
 *
 * I don't like the cut-n-paste job here either between the two routines,
 * but there are sufficient differences between the two interrupt handlers
 * that parameterizing it isn't all that great either.  (Could use a macro,
 * I suppose...yucky bleah.)
 */

static irqreturn_t
snd_nm256_interrupt(int irq, void *dev_id)
{
        struct nm256 *chip = dev_id;
        u16 status;
        u8 cbyte;

        status = snd_nm256_readw(chip, NM_INT_REG);

        /* Not ours. */
        if (status == 0)
                return snd_nm256_intr_check(chip);

        chip->badintrcount = 0;

        /* Rather boring; check for individual interrupts and process them. */

        spin_lock(&chip->reg_lock);
        if (status & NM_PLAYBACK_INT) {
                status &= ~NM_PLAYBACK_INT;
                NM_ACK_INT(chip, NM_PLAYBACK_INT);
                snd_nm256_playback_update(chip);
        }

        if (status & NM_RECORD_INT) {
                status &= ~NM_RECORD_INT;
                NM_ACK_INT(chip, NM_RECORD_INT);
                snd_nm256_capture_update(chip);
        }

        if (status & NM_MISC_INT_1) {
                status &= ~NM_MISC_INT_1;
                NM_ACK_INT(chip, NM_MISC_INT_1);
                snd_printd("NM256: Got misc interrupt #1\n");
                snd_nm256_writew(chip, NM_INT_REG, 0x8000);
                cbyte = snd_nm256_readb(chip, 0x400);
                snd_nm256_writeb(chip, 0x400, cbyte | 2);
        }

        if (status & NM_MISC_INT_2) {
                status &= ~NM_MISC_INT_2;
                NM_ACK_INT(chip, NM_MISC_INT_2);
                snd_printd("NM256: Got misc interrupt #2\n");
                cbyte = snd_nm256_readb(chip, 0x400);
                snd_nm256_writeb(chip, 0x400, cbyte & ~2);
        }

        /* Unknown interrupt. */
        if (status) {
                snd_printd("NM256: Fire in the hole! Unknown status 0x%x\n",
                           status);
                /* Pray. */
                NM_ACK_INT(chip, status);
        }

        spin_unlock(&chip->reg_lock);
        return IRQ_HANDLED;
}

/*
 * Handle a potential interrupt for the device referred to by DEV_ID.
 * This handler is for the 256ZX, and is very similar to the non-ZX
 * routine.
 */

static irqreturn_t
snd_nm256_interrupt_zx(int irq, void *dev_id)
{
        struct nm256 *chip = dev_id;
        u32 status;
        u8 cbyte;

        status = snd_nm256_readl(chip, NM_INT_REG);

        /* Not ours. */
        if (status == 0)
                return snd_nm256_intr_check(chip);

        chip->badintrcount = 0;

        /* Rather boring; check for individual interrupts and process them. */

        spin_lock(&chip->reg_lock);
        if (status & NM2_PLAYBACK_INT) {
                status &= ~NM2_PLAYBACK_INT;
                NM2_ACK_INT(chip, NM2_PLAYBACK_INT);
                snd_nm256_playback_update(chip);
        }

        if (status & NM2_RECORD_INT) {
                status &= ~NM2_RECORD_INT;
                NM2_ACK_INT(chip, NM2_RECORD_INT);
                snd_nm256_capture_update(chip);
        }

        if (status & NM2_MISC_INT_1) {
                status &= ~NM2_MISC_INT_1;
                NM2_ACK_INT(chip, NM2_MISC_INT_1);
                snd_printd("NM256: Got misc interrupt #1\n");
                cbyte = snd_nm256_readb(chip, 0x400);
                snd_nm256_writeb(chip, 0x400, cbyte | 2);
        }

        if (status & NM2_MISC_INT_2) {
                status &= ~NM2_MISC_INT_2;
                NM2_ACK_INT(chip, NM2_MISC_INT_2);
                snd_printd("NM256: Got misc interrupt #2\n");
                cbyte = snd_nm256_readb(chip, 0x400);
                snd_nm256_writeb(chip, 0x400, cbyte & ~2);
        }

        /* Unknown interrupt. */
        if (status) {
                snd_printd("NM256: Fire in the hole! Unknown status 0x%x\n",
                           status);
                /* Pray. */
                NM2_ACK_INT(chip, status);
        }

        spin_unlock(&chip->reg_lock);
        return IRQ_HANDLED;
}

/*
 * AC97 interface
 */

/*
 * Waits for the mixer to become ready to be written; returns a zero value
 * if it timed out.
 */
static int
snd_nm256_ac97_ready(struct nm256 *chip)
{
        int timeout = 10;
        u32 testaddr;
        u16 testb;

        testaddr = chip->mixer_status_offset;
        testb = chip->mixer_status_mask;

        /* 
         * Loop around waiting for the mixer to become ready. 
         */
        while (timeout-- > 0) {
                if ((snd_nm256_readw(chip, testaddr) & testb) == 0)
                        return 1;
                udelay(100);
        }
        return 0;
}

/* 
 * Initial register values to be written to the AC97 mixer.
 * While most of these are identical to the reset values, we do this
 * so that we have most of the register contents cached--this avoids
 * reading from the mixer directly (which seems to be problematic,
 * probably due to ignorance).
 */

struct initialValues {
        unsigned short reg;
        unsigned short value;
};

static struct initialValues nm256_ac97_init_val[] =
{
        { AC97_MASTER,          0x8000 },
        { AC97_HEADPHONE,       0x8000 },
        { AC97_MASTER_MONO,     0x8000 },
        { AC97_PC_BEEP,         0x8000 },
        { AC97_PHONE,           0x8008 },
        { AC97_MIC,             0x8000 },
        { AC97_LINE,            0x8808 },
        { AC97_CD,              0x8808 },
        { AC97_VIDEO,           0x8808 },
        { AC97_AUX,             0x8808 },
        { AC97_PCM,             0x8808 },
        { AC97_REC_SEL,         0x0000 },
        { AC97_REC_GAIN,        0x0B0B },
        { AC97_GENERAL_PURPOSE, 0x0000 },
        { AC97_3D_CONTROL,      0x8000 }, 
        { AC97_VENDOR_ID1,      0x8384 },
        { AC97_VENDOR_ID2,      0x7609 },
};

static int nm256_ac97_idx(unsigned short reg)
{
        int i;
        for (i = 0; i < ARRAY_SIZE(nm256_ac97_init_val); i++)
                if (nm256_ac97_init_val[i].reg == reg)
                        return i;
        return -1;
}

/*
 * some nm256 easily crash when reading from mixer registers
 * thus we're treating it as a write-only mixer and cache the
 * written values
 */
static unsigned short
snd_nm256_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
{
        struct nm256 *chip = ac97->private_data;
        int idx = nm256_ac97_idx(reg);

        if (idx < 0)
                return 0;
        return chip->ac97_regs[idx];
}

/* 
 */
static void
snd_nm256_ac97_write(struct snd_ac97 *ac97,
                     unsigned short reg, unsigned short val)
{
        struct nm256 *chip = ac97->private_data;
        int tries = 2;
        int idx = nm256_ac97_idx(reg);
        u32 base;

        if (idx < 0)
                return;

        base = chip->mixer_base;

        snd_nm256_ac97_ready(chip);

        /* Wait for the write to take, too. */
        while (tries-- > 0) {
                snd_nm256_writew(chip, base + reg, val);
                msleep(1);  /* a little delay here seems better.. */
                if (snd_nm256_ac97_ready(chip)) {
                        /* successful write: set cache */
                        chip->ac97_regs[idx] = val;
                        return;
                }
        }
        snd_printd("nm256: ac97 codec not ready..\n");
}

/* static resolution table */
static struct snd_ac97_res_table nm256_res_table[] = {
        { AC97_MASTER, 0x1f1f },
        { AC97_HEADPHONE, 0x1f1f },
        { AC97_MASTER_MONO, 0x001f },
        { AC97_PC_BEEP, 0x001f },
        { AC97_PHONE, 0x001f },
        { AC97_MIC, 0x001f },
        { AC97_LINE, 0x1f1f },
        { AC97_CD, 0x1f1f },
        { AC97_VIDEO, 0x1f1f },
        { AC97_AUX, 0x1f1f },
        { AC97_PCM, 0x1f1f },
        { AC97_REC_GAIN, 0x0f0f },
        { } /* terminator */
};

/* initialize the ac97 into a known state */
static void
snd_nm256_ac97_reset(struct snd_ac97 *ac97)
{
        struct nm256 *chip = ac97->private_data;

        /* Reset the mixer.  'Tis magic!  */
        snd_nm256_writeb(chip, 0x6c0, 1);
        if (! chip->reset_workaround) {
                /* Dell latitude LS will lock up by this */
                snd_nm256_writeb(chip, 0x6cc, 0x87);
        }
        if (! chip->reset_workaround_2) {
                /* Dell latitude CSx will lock up by this */
                snd_nm256_writeb(chip, 0x6cc, 0x80);
                snd_nm256_writeb(chip, 0x6cc, 0x0);
        }
        if (! chip->in_resume) {
                int i;
                for (i = 0; i < ARRAY_SIZE(nm256_ac97_init_val); i++) {
                        /* preload the cache, so as to avoid even a single
                         * read of the mixer regs
                         */
                        snd_nm256_ac97_write(ac97, nm256_ac97_init_val[i].reg,
                                             nm256_ac97_init_val[i].value);
                }
        }
}

/* create an ac97 mixer interface */
static int __devinit
snd_nm256_mixer(struct nm256 *chip)
{
        struct snd_ac97_bus *pbus;
        struct snd_ac97_template ac97;
        int err;
        static struct snd_ac97_bus_ops ops = {
                .reset = snd_nm256_ac97_reset,
                .write = snd_nm256_ac97_write,
                .read = snd_nm256_ac97_read,
        };

        chip->ac97_regs = kcalloc(ARRAY_SIZE(nm256_ac97_init_val),
                                  sizeof(short), GFP_KERNEL);
        if (! chip->ac97_regs)
                return -ENOMEM;

        if ((err = snd_ac97_bus(chip->card, 0, &ops, NULL, &pbus)) < 0)
                return err;

        memset(&ac97, 0, sizeof(ac97));
        ac97.scaps = AC97_SCAP_AUDIO; /* we support audio! */
        ac97.private_data = chip;
        ac97.res_table = nm256_res_table;
        pbus->no_vra = 1;
        err = snd_ac97_mixer(pbus, &ac97, &chip->ac97);
        if (err < 0)
                return err;
        if (! (chip->ac97->id & (0xf0000000))) {
                /* looks like an invalid id */
                sprintf(chip->card->mixername, "%s AC97", chip->card->driver);
        }
        return 0;
}

/* 
 * See if the signature left by the NM256 BIOS is intact; if so, we use
 * the associated address as the end of our audio buffer in the video
 * RAM.
 */

static int __devinit
snd_nm256_peek_for_sig(struct nm256 *chip)
{
        /* The signature is located 1K below the end of video RAM.  */
        void __iomem *temp;
        /* Default buffer end is 5120 bytes below the top of RAM.  */
        unsigned long pointer_found = chip->buffer_end - 0x1400;
        u32 sig;

        temp = ioremap_nocache(chip->buffer_addr + chip->buffer_end - 0x400, 16);
        if (temp == NULL) {
                snd_printk(KERN_ERR "Unable to scan for card signature in video RAM\n");
                return -EBUSY;
        }

        sig = readl(temp);
        if ((sig & NM_SIG_MASK) == NM_SIGNATURE) {
                u32 pointer = readl(temp + 4);

                /*
                 * If it's obviously invalid, don't use it
                 */
                if (pointer == 0xffffffff ||
                    pointer < chip->buffer_size ||
                    pointer > chip->buffer_end) {
                        snd_printk(KERN_ERR "invalid signature found: 0x%x\n", pointer);
                        iounmap(temp);
                        return -ENODEV;
                } else {
                        pointer_found = pointer;
                        printk(KERN_INFO "nm256: found card signature in video RAM: 0x%x\n",
                               pointer);
                }
        }

        iounmap(temp);
        chip->buffer_end = pointer_found;

        return 0;
}

#ifdef CONFIG_PM
/*
 * APM event handler, so the card is properly reinitialized after a power
 * event.
 */
static int nm256_suspend(struct pci_dev *pci, pm_message_t state)
{
        struct snd_card *card = pci_get_drvdata(pci);
        struct nm256 *chip = card->private_data;

        snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
        snd_pcm_suspend_all(chip->pcm);
        snd_ac97_suspend(chip->ac97);
        chip->coeffs_current = 0;
        pci_disable_device(pci);
        pci_save_state(pci);
        pci_set_power_state(pci, pci_choose_state(pci, state));
        return 0;
}

static int nm256_resume(struct pci_dev *pci)
{
        struct snd_card *card = pci_get_drvdata(pci);
        struct nm256 *chip = card->private_data;
        int i;

        /* Perform a full reset on the hardware */
        chip->in_resume = 1;

        pci_set_power_state(pci, PCI_D0);
        pci_restore_state(pci);
        if (pci_enable_device(pci) < 0) {
                printk(KERN_ERR "nm256: pci_enable_device failed, "
                       "disabling device\n");
                snd_card_disconnect(card);
                return -EIO;
        }
        pci_set_master(pci);

        snd_nm256_init_chip(chip);

        /* restore ac97 */
        snd_ac97_resume(chip->ac97);

        for (i = 0; i < 2; i++) {
                struct nm256_stream *s = &chip->streams[i];
                if (s->substream && s->suspended) {
                        spin_lock_irq(&chip->reg_lock);
                        snd_nm256_set_format(chip, s, s->substream);
                        spin_unlock_irq(&chip->reg_lock);
                }
        }

        snd_power_change_state(card, SNDRV_CTL_POWER_D0);
        chip->in_resume = 0;
        return 0;
}
#endif /* CONFIG_PM */

static int snd_nm256_free(struct nm256 *chip)
{
        if (chip->streams[SNDRV_PCM_STREAM_PLAYBACK].running)
                snd_nm256_playback_stop(chip);
        if (chip->streams[SNDRV_PCM_STREAM_CAPTURE].running)
                snd_nm256_capture_stop(chip);

        if (chip->irq >= 0)
                free_irq(chip->irq, chip);

        if (chip->cport)
                iounmap(chip->cport);
        if (chip->buffer)
                iounmap(chip->buffer);
        release_and_free_resource(chip->res_cport);
        release_and_free_resource(chip->res_buffer);

        pci_disable_device(chip->pci);
        kfree(chip->ac97_regs);
        kfree(chip);
        return 0;
}

static int snd_nm256_dev_free(struct snd_device *device)
{
        struct nm256 *chip = device->device_data;
        return snd_nm256_free(chip);
}

static int __devinit
snd_nm256_create(struct snd_card *card, struct pci_dev *pci,
                 struct nm256 **chip_ret)
{
        struct nm256 *chip;
        int err, pval;
        static struct snd_device_ops ops = {
                .dev_free =     snd_nm256_dev_free,
        };
        u32 addr;

        *chip_ret = NULL;

        if ((err = pci_enable_device(pci)) < 0)
                return err;

        chip = kzalloc(sizeof(*chip), GFP_KERNEL);
        if (chip == NULL) {
                pci_disable_device(pci);
                return -ENOMEM;
        }

        chip->card = card;
        chip->pci = pci;
        chip->use_cache = use_cache;
        spin_lock_init(&chip->reg_lock);
        chip->irq = -1;
        mutex_init(&chip->irq_mutex);

        /* store buffer sizes in bytes */
        chip->streams[SNDRV_PCM_STREAM_PLAYBACK].bufsize = playback_bufsize * 1024;
        chip->streams[SNDRV_PCM_STREAM_CAPTURE].bufsize = capture_bufsize * 1024;

        /* 
         * The NM256 has two memory ports.  The first port is nothing
         * more than a chunk of video RAM, which is used as the I/O ring
         * buffer.  The second port has the actual juicy stuff (like the
         * mixer and the playback engine control registers).
         */

        chip->buffer_addr = pci_resource_start(pci, 0);
        chip->cport_addr = pci_resource_start(pci, 1);

        /* Init the memory port info.  */
        /* remap control port (#2) */
        chip->res_cport = request_mem_region(chip->cport_addr, NM_PORT2_SIZE,
                                             card->driver);
        if (chip->res_cport == NULL) {
                snd_printk(KERN_ERR "memory region 0x%lx (size 0x%x) busy\n",
                           chip->cport_addr, NM_PORT2_SIZE);
                err = -EBUSY;
                goto __error;
        }
        chip->cport = ioremap_nocache(chip->cport_addr, NM_PORT2_SIZE);
        if (chip->cport == NULL) {
                snd_printk(KERN_ERR "unable to map control port %lx\n", chip->cport_addr);
                err = -ENOMEM;
                goto __error;
        }

        if (!strcmp(card->driver, "NM256AV")) {
                /* Ok, try to see if this is a non-AC97 version of the hardware. */
                pval = snd_nm256_readw(chip, NM_MIXER_PRESENCE);
                if ((pval & NM_PRESENCE_MASK) != NM_PRESENCE_VALUE) {
                        if (! force_ac97) {
                                printk(KERN_ERR "nm256: no ac97 is found!\n");
                                printk(KERN_ERR "  force the driver to load by "
                                       "passing in the module parameter\n");
                                printk(KERN_ERR "    force_ac97=1\n");
                                printk(KERN_ERR "  or try sb16, opl3sa2, or "
                                       "cs423x drivers instead.\n");
                                err = -ENXIO;
                                goto __error;
                        }
                }
                chip->buffer_end = 2560 * 1024;
                chip->interrupt = snd_nm256_interrupt;
                chip->mixer_status_offset = NM_MIXER_STATUS_OFFSET;
                chip->mixer_status_mask = NM_MIXER_READY_MASK;
        } else {
                /* Not sure if there is any relevant detect for the ZX or not.  */
                if (snd_nm256_readb(chip, 0xa0b) != 0)
                        chip->buffer_end = 6144 * 1024;
                else
                        chip->buffer_end = 4096 * 1024;

                chip->interrupt = snd_nm256_interrupt_zx;
                chip->mixer_status_offset = NM2_MIXER_STATUS_OFFSET;
                chip->mixer_status_mask = NM2_MIXER_READY_MASK;
        }
        
        chip->buffer_size = chip->streams[SNDRV_PCM_STREAM_PLAYBACK].bufsize +
                chip->streams[SNDRV_PCM_STREAM_CAPTURE].bufsize;
        if (chip->use_cache)
                chip->buffer_size += NM_TOTAL_COEFF_COUNT * 4;
        else
                chip->buffer_size += NM_MAX_PLAYBACK_COEF_SIZE + NM_MAX_RECORD_COEF_SIZE;

        if (buffer_top >= chip->buffer_size && buffer_top < chip->buffer_end)
                chip->buffer_end = buffer_top;
        else {
                /* get buffer end pointer from signature */
                if ((err = snd_nm256_peek_for_sig(chip)) < 0)
                        goto __error;
        }

        chip->buffer_start = chip->buffer_end - chip->buffer_size;
        chip->buffer_addr += chip->buffer_start;

        printk(KERN_INFO "nm256: Mapping port 1 from 0x%x - 0x%x\n",
               chip->buffer_start, chip->buffer_end);

        chip->res_buffer = request_mem_region(chip->buffer_addr,
                                              chip->buffer_size,
                                              card->driver);
        if (chip->res_buffer == NULL) {
                snd_printk(KERN_ERR "nm256: buffer 0x%lx (size 0x%x) busy\n",
                           chip->buffer_addr, chip->buffer_size);
                err = -EBUSY;
                goto __error;
        }
        chip->buffer = ioremap_nocache(chip->buffer_addr, chip->buffer_size);
        if (chip->buffer == NULL) {
                err = -ENOMEM;
                snd_printk(KERN_ERR "unable to map ring buffer at %lx\n", chip->buffer_addr);
                goto __error;
        }

        /* set offsets */
        addr = chip->buffer_start;
        chip->streams[SNDRV_PCM_STREAM_PLAYBACK].buf = addr;
        addr += chip->streams[SNDRV_PCM_STREAM_PLAYBACK].bufsize;
        chip->streams[SNDRV_PCM_STREAM_CAPTURE].buf = addr;
        addr += chip->streams[SNDRV_PCM_STREAM_CAPTURE].bufsize;
        if (chip->use_cache) {
                chip->all_coeff_buf = addr;
        } else {
                chip->coeff_buf[SNDRV_PCM_STREAM_PLAYBACK] = addr;
                addr += NM_MAX_PLAYBACK_COEF_SIZE;
                chip->coeff_buf[SNDRV_PCM_STREAM_CAPTURE] = addr;
        }

        /* Fixed setting. */
        chip->mixer_base = NM_MIXER_OFFSET;

        chip->coeffs_current = 0;

        snd_nm256_init_chip(chip);

        // pci_set_master(pci); /* needed? */
        
        if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0)
                goto __error;

        snd_card_set_dev(card, &pci->dev);

        *chip_ret = chip;
        return 0;

__error:
        snd_nm256_free(chip);
        return err;
}


enum { NM_BLACKLISTED, NM_RESET_WORKAROUND, NM_RESET_WORKAROUND_2 };

static struct snd_pci_quirk nm256_quirks[] __devinitdata = {
        /* HP omnibook 4150 has cs4232 codec internally */
        SND_PCI_QUIRK(0x103c, 0x0007, "HP omnibook 4150", NM_BLACKLISTED),
        /* Reset workarounds to avoid lock-ups */
        SND_PCI_QUIRK(0x104d, 0x8041, "Sony PCG-F305", NM_RESET_WORKAROUND),
        SND_PCI_QUIRK(0x1028, 0x0080, "Dell Latitude LS", NM_RESET_WORKAROUND),
        SND_PCI_QUIRK(0x1028, 0x0091, "Dell Latitude CSx", NM_RESET_WORKAROUND_2),
        { } /* terminator */
};


static int __devinit snd_nm256_probe(struct pci_dev *pci,
                                     const struct pci_device_id *pci_id)
{
        struct snd_card *card;
        struct nm256 *chip;
        int err;
        const struct snd_pci_quirk *q;

        q = snd_pci_quirk_lookup(pci, nm256_quirks);
        if (q) {
                snd_printdd(KERN_INFO "nm256: Enabled quirk for %s.\n", q->name);
                switch (q->value) {
                case NM_BLACKLISTED:
                        printk(KERN_INFO "nm256: The device is blacklisted. "
                               "Loading stopped\n");
                        return -ENODEV;
                case NM_RESET_WORKAROUND_2:
                        reset_workaround_2 = 1;
                        /* Fall-through */
                case NM_RESET_WORKAROUND:
                        reset_workaround = 1;
                        break;
                }
        }

        err = snd_card_create(index, id, THIS_MODULE, 0, &card);
        if (err < 0)
                return err;

        switch (pci->device) {
        case PCI_DEVICE_ID_NEOMAGIC_NM256AV_AUDIO:
                strcpy(card->driver, "NM256AV");
                break;
        case PCI_DEVICE_ID_NEOMAGIC_NM256ZX_AUDIO:
                strcpy(card->driver, "NM256ZX");
                break;
        case PCI_DEVICE_ID_NEOMAGIC_NM256XL_PLUS_AUDIO:
                strcpy(card->driver, "NM256XL+");
                break;
        default:
                snd_printk(KERN_ERR "invalid device id 0x%x\n", pci->device);
                snd_card_free(card);
                return -EINVAL;
        }

        if (vaio_hack)
                buffer_top = 0x25a800;  /* this avoids conflicts with XFree86 server */

        if (playback_bufsize < 4)
                playback_bufsize = 4;
        if (playback_bufsize > 128)
                playback_bufsize = 128;
        if (capture_bufsize < 4)
                capture_bufsize = 4;
        if (capture_bufsize > 128)
                capture_bufsize = 128;
        if ((err = snd_nm256_create(card, pci, &chip)) < 0) {
                snd_card_free(card);
                return err;
        }
        card->private_data = chip;

        if (reset_workaround) {
                snd_printdd(KERN_INFO "nm256: reset_workaround activated\n");
                chip->reset_workaround = 1;
        }

        if (reset_workaround_2) {
                snd_printdd(KERN_INFO "nm256: reset_workaround_2 activated\n");
                chip->reset_workaround_2 = 1;
        }

        if ((err = snd_nm256_pcm(chip, 0)) < 0 ||
            (err = snd_nm256_mixer(chip)) < 0) {
                snd_card_free(card);
                return err;
        }

        sprintf(card->shortname, "NeoMagic %s", card->driver);
        sprintf(card->longname, "%s at 0x%lx & 0x%lx, irq %d",
                card->shortname,
                chip->buffer_addr, chip->cport_addr, chip->irq);

        if ((err = snd_card_register(card)) < 0) {
                snd_card_free(card);
                return err;
        }

        pci_set_drvdata(pci, card);
        return 0;
}

static void __devexit snd_nm256_remove(struct pci_dev *pci)
{
        snd_card_free(pci_get_drvdata(pci));
        pci_set_drvdata(pci, NULL);
}


static struct pci_driver driver = {
        .name = "NeoMagic 256",
        .id_table = snd_nm256_ids,
        .probe = snd_nm256_probe,
        .remove = __devexit_p(snd_nm256_remove),
#ifdef CONFIG_PM
        .suspend = nm256_suspend,
        .resume = nm256_resume,
#endif
};


static int __init alsa_card_nm256_init(void)
{
        return pci_register_driver(&driver);
}

static void __exit alsa_card_nm256_exit(void)
{
        pci_unregister_driver(&driver);
}

module_init(alsa_card_nm256_init)
module_exit(alsa_card_nm256_exit)