/*
 * Support for VIA 82Cxxx Audio Codecs
 * Copyright 1999,2000 Jeff Garzik
 *
 * Updated to support the VIA 8233/8235 audio subsystem
 * Alan Cox <alan@redhat.com> (C) Copyright 2002, 2003 Red Hat Inc
 *
 * Distributed under the GNU GENERAL PUBLIC LICENSE (GPL) Version 2.
 * See the "COPYING" file distributed with this software for more info.
 * NO WARRANTY
 *
 * For a list of known bugs (errata) and documentation,
 * see via-audio.pdf in linux/Documentation/DocBook.
 * If this documentation does not exist, run "make pdfdocs".
 */


#define VIA_VERSION     "1.9.1-ac3"


#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/sound.h>
#include <linux/poll.h>
#include <linux/soundcard.h>
#include <linux/ac97_codec.h>
#include <linux/smp_lock.h>
#include <linux/ioport.h>
#include <linux/wrapper.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/hardirq.h>
#include <asm/semaphore.h>
#include "sound_config.h"
#include "dev_table.h"
#include "mpu401.h"


#undef VIA_DEBUG        /* define to enable debugging output and checks */
#ifdef VIA_DEBUG
/* note: prints function name for you */
#define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __FUNCTION__ , ## args)
#else
#define DPRINTK(fmt, args...)
#endif

#undef VIA_NDEBUG       /* define to disable lightweight runtime checks */
#ifdef VIA_NDEBUG
#define assert(expr)
#else
#define assert(expr) \
        if(!(expr)) {                                   \
        printk( "Assertion failed! %s,%s,%s,line=%d\n", \
        #expr,__FILE__,__FUNCTION__,__LINE__);          \
        }
#endif

#define VIA_SUPPORT_MMAP 1 /* buggy, for now... */

#define MAX_CARDS       1

#define VIA_CARD_NAME   "VIA 82Cxxx Audio driver " VIA_VERSION
#define VIA_MODULE_NAME "via82cxxx"
#define PFX             VIA_MODULE_NAME ": "

#define VIA_COUNTER_LIMIT       100000

/* size of DMA buffers */
#define VIA_MAX_BUFFER_DMA_PAGES        32

/* buffering default values in ms */
#define VIA_DEFAULT_FRAG_TIME           20
#define VIA_DEFAULT_BUFFER_TIME         500

/* the hardware has a 256 fragment limit */
#define VIA_MIN_FRAG_NUMBER             2
#define VIA_MAX_FRAG_NUMBER             128

#define VIA_MAX_FRAG_SIZE               PAGE_SIZE
#define VIA_MIN_FRAG_SIZE               (VIA_MAX_BUFFER_DMA_PAGES * PAGE_SIZE / VIA_MAX_FRAG_NUMBER)


/* 82C686 function 5 (audio codec) PCI configuration registers */
#define VIA_ACLINK_STATUS       0x40
#define VIA_ACLINK_CTRL         0x41
#define VIA_FUNC_ENABLE         0x42
#define VIA_PNP_CONTROL         0x43
#define VIA_FM_NMI_CTRL         0x48

/*
 * controller base 0 (scatter-gather) registers
 *
 * NOTE: Via datasheet lists first channel as "read"
 * channel and second channel as "write" channel.
 * I changed the naming of the constants to be more
 * clear than I felt the datasheet to be.
 */

#define VIA_BASE0_PCM_OUT_CHAN  0x00 /* output PCM to user */
#define VIA_BASE0_PCM_OUT_CHAN_STATUS 0x00
#define VIA_BASE0_PCM_OUT_CHAN_CTRL     0x01
#define VIA_BASE0_PCM_OUT_CHAN_TYPE     0x02

#define VIA_BASE0_PCM_IN_CHAN           0x10 /* input PCM from user */
#define VIA_BASE0_PCM_IN_CHAN_STATUS    0x10
#define VIA_BASE0_PCM_IN_CHAN_CTRL      0x11
#define VIA_BASE0_PCM_IN_CHAN_TYPE      0x12

/* offsets from base */
#define VIA_PCM_STATUS                  0x00
#define VIA_PCM_CONTROL                 0x01
#define VIA_PCM_TYPE                    0x02
#define VIA_PCM_LEFTVOL                 0x02
#define VIA_PCM_RIGHTVOL                0x03
#define VIA_PCM_TABLE_ADDR              0x04
#define VIA_PCM_STOPRATE                0x08    /* 8233+ */
#define VIA_PCM_BLOCK_COUNT             0x0C

/* XXX unused DMA channel for FM PCM data */
#define VIA_BASE0_FM_OUT_CHAN           0x20
#define VIA_BASE0_FM_OUT_CHAN_STATUS    0x20
#define VIA_BASE0_FM_OUT_CHAN_CTRL      0x21
#define VIA_BASE0_FM_OUT_CHAN_TYPE      0x22

/* Six channel audio output on 8233 */
#define VIA_BASE0_MULTI_OUT_CHAN                0x40
#define VIA_BASE0_MULTI_OUT_CHAN_STATUS         0x40
#define VIA_BASE0_MULTI_OUT_CHAN_CTRL           0x41
#define VIA_BASE0_MULTI_OUT_CHAN_TYPE           0x42

#define VIA_BASE0_AC97_CTRL             0x80
#define VIA_BASE0_SGD_STATUS_SHADOW     0x84
#define VIA_BASE0_GPI_INT_ENABLE        0x8C
#define VIA_INTR_OUT                    ((1<<0) |  (1<<4) |  (1<<8))
#define VIA_INTR_IN                     ((1<<1) |  (1<<5) |  (1<<9))
#define VIA_INTR_FM                     ((1<<2) |  (1<<6) | (1<<10))
#define VIA_INTR_MASK           (VIA_INTR_OUT | VIA_INTR_IN | VIA_INTR_FM)

/* Newer VIA we need to monitor the low 3 bits of each channel. This
   mask covers the channels we don't yet use as well 
 */
 
#define VIA_NEW_INTR_MASK               0x77077777UL

/* VIA_BASE0_AUDIO_xxx_CHAN_TYPE bits */
#define VIA_IRQ_ON_FLAG                 (1<<0)  /* int on each flagged scatter block */
#define VIA_IRQ_ON_EOL                  (1<<1)  /* int at end of scatter list */
#define VIA_INT_SEL_PCI_LAST_LINE_READ  (0)     /* int at PCI read of last line */
#define VIA_INT_SEL_LAST_SAMPLE_SENT    (1<<2)  /* int at last sample sent */
#define VIA_INT_SEL_ONE_LINE_LEFT       (1<<3)  /* int at less than one line to send */
#define VIA_PCM_FMT_STEREO              (1<<4)  /* PCM stereo format (bit clear == mono) */
#define VIA_PCM_FMT_16BIT               (1<<5)  /* PCM 16-bit format (bit clear == 8-bit) */
#define VIA_PCM_REC_FIFO                (1<<6)  /* PCM Recording FIFO */
#define VIA_RESTART_SGD_ON_EOL          (1<<7)  /* restart scatter-gather at EOL */
#define VIA_PCM_FMT_MASK                (VIA_PCM_FMT_STEREO|VIA_PCM_FMT_16BIT)
#define VIA_CHAN_TYPE_MASK              (VIA_RESTART_SGD_ON_EOL | \
                                         VIA_IRQ_ON_FLAG | \
                                         VIA_IRQ_ON_EOL)
#define VIA_CHAN_TYPE_INT_SELECT        (VIA_INT_SEL_LAST_SAMPLE_SENT)

/* PCI configuration register bits and masks */
#define VIA_CR40_AC97_READY     0x01
#define VIA_CR40_AC97_LOW_POWER 0x02
#define VIA_CR40_SECONDARY_READY 0x04

#define VIA_CR41_AC97_ENABLE    0x80 /* enable AC97 codec */
#define VIA_CR41_AC97_RESET     0x40 /* clear bit to reset AC97 */
#define VIA_CR41_AC97_WAKEUP    0x20 /* wake up from power-down mode */
#define VIA_CR41_AC97_SDO       0x10 /* force Serial Data Out (SDO) high */
#define VIA_CR41_VRA            0x08 /* enable variable sample rate */
#define VIA_CR41_PCM_ENABLE     0x04 /* AC Link SGD Read Channel PCM Data Output */
#define VIA_CR41_FM_PCM_ENABLE  0x02 /* AC Link FM Channel PCM Data Out */
#define VIA_CR41_SB_PCM_ENABLE  0x01 /* AC Link SB PCM Data Output */
#define VIA_CR41_BOOT_MASK      (VIA_CR41_AC97_ENABLE | \
                                 VIA_CR41_AC97_WAKEUP | \
                                 VIA_CR41_AC97_SDO)
#define VIA_CR41_RUN_MASK       (VIA_CR41_AC97_ENABLE | \
                                 VIA_CR41_AC97_RESET | \
                                 VIA_CR41_VRA | \
                                 VIA_CR41_PCM_ENABLE)

#define VIA_CR42_SB_ENABLE      0x01
#define VIA_CR42_MIDI_ENABLE    0x02
#define VIA_CR42_FM_ENABLE      0x04
#define VIA_CR42_GAME_ENABLE    0x08
#define VIA_CR42_MIDI_IRQMASK   0x40
#define VIA_CR42_MIDI_PNP       0x80

#define VIA_CR44_SECOND_CODEC_SUPPORT   (1 << 6)
#define VIA_CR44_AC_LINK_ACCESS         (1 << 7)

#define VIA_CR48_FM_TRAP_TO_NMI         (1 << 2)

/* controller base 0 register bitmasks */
#define VIA_INT_DISABLE_MASK            (~(0x01|0x02))
#define VIA_SGD_STOPPED                 (1 << 2)
#define VIA_SGD_PAUSED                  (1 << 6)
#define VIA_SGD_ACTIVE                  (1 << 7)
#define VIA_SGD_TERMINATE               (1 << 6)
#define VIA_SGD_FLAG                    (1 << 0)
#define VIA_SGD_EOL                     (1 << 1)
#define VIA_SGD_START                   (1 << 7)

#define VIA_CR80_FIRST_CODEC            0
#define VIA_CR80_SECOND_CODEC           (1 << 30)
#define VIA_CR80_FIRST_CODEC_VALID      (1 << 25)
#define VIA_CR80_VALID                  (1 << 25)
#define VIA_CR80_SECOND_CODEC_VALID     (1 << 27)
#define VIA_CR80_BUSY                   (1 << 24)
#define VIA_CR83_BUSY                   (1)
#define VIA_CR83_FIRST_CODEC_VALID      (1 << 1)
#define VIA_CR80_READ                   (1 << 23)
#define VIA_CR80_WRITE_MODE             0
#define VIA_CR80_REG_IDX(idx)           ((((idx) & 0xFF) >> 1) << 16)

/* capabilities we announce */
#ifdef VIA_SUPPORT_MMAP
#define VIA_DSP_CAP (DSP_CAP_REVISION | DSP_CAP_DUPLEX | DSP_CAP_MMAP | \
                     DSP_CAP_TRIGGER | DSP_CAP_REALTIME)
#else
#define VIA_DSP_CAP (DSP_CAP_REVISION | DSP_CAP_DUPLEX | \
                     DSP_CAP_TRIGGER | DSP_CAP_REALTIME)
#endif

/* scatter-gather DMA table entry, exactly as passed to hardware */
struct via_sgd_table {
        u32 addr;
        u32 count;      /* includes additional VIA_xxx bits also */
};

#define VIA_EOL (1 << 31)
#define VIA_FLAG (1 << 30)
#define VIA_STOP (1 << 29)


enum via_channel_states {
        sgd_stopped = 0,
        sgd_in_progress = 1,
};


struct via_buffer_pgtbl {
        dma_addr_t handle;
        void *cpuaddr;
};


struct via_channel {
        atomic_t n_frags;
        atomic_t hw_ptr;
        wait_queue_head_t wait;

        unsigned int sw_ptr;
        unsigned int slop_len;
        unsigned int n_irqs;
        int bytes;

        unsigned is_active : 1;
        unsigned is_record : 1;
        unsigned is_mapped : 1;
        unsigned is_enabled : 1;
        unsigned is_multi: 1;   /* 8233 6 channel */
        u8 pcm_fmt;             /* VIA_PCM_FMT_xxx */
        u8 channels;            /* Channel count */

        unsigned rate;          /* sample rate */
        unsigned int frag_size;
        unsigned int frag_number;
        
        unsigned char intmask;

        volatile struct via_sgd_table *sgtable;
        dma_addr_t sgt_handle;

        unsigned int page_number;
        struct via_buffer_pgtbl pgtbl[VIA_MAX_BUFFER_DMA_PAGES];

        long iobase;

        const char *name;
};


/* data stored for each chip */
struct via_info {
        struct pci_dev *pdev;
        long baseaddr;

        struct ac97_codec *ac97;
        spinlock_t ac97_lock;
        spinlock_t lock;
        int card_num;           /* unique card number, from 0 */

        int dev_dsp;            /* /dev/dsp index from register_sound_dsp() */

        unsigned rev_h : 1;
        unsigned legacy: 1;     /* Has legacy ports */
        unsigned intmask: 1;    /* Needs int bits */
        unsigned sixchannel: 1; /* 8233/35 with 6 channel support */
        unsigned volume: 1;

        int locked_rate : 1;
        
        int mixer_vol;          /* 8233/35 volume  - not yet implemented */

        struct semaphore syscall_sem;
        struct semaphore open_sem;

        /* The 8233/8235 have 4 DX audio channels, two record and
           one six channel out. We bind ch_in to DX 1, ch_out to multichannel
           and ch_fm to DX 2. DX 3 and REC0/REC1 are unused at the
           moment */
           
        struct via_channel ch_in;
        struct via_channel ch_out;
        struct via_channel ch_fm;

#ifdef CONFIG_MIDI_VIA82CXXX
        void *midi_devc;
        struct address_info midi_info;
#endif
};


/* number of cards, used for assigning unique numbers to cards */
static unsigned via_num_cards = 0;



/****************************************************************
 *
 * prototypes
 *
 *
 */

static int via_init_one (struct pci_dev *dev, const struct pci_device_id *id);
static void __devexit via_remove_one (struct pci_dev *pdev);

static ssize_t via_dsp_read(struct file *file, char *buffer, size_t count, loff_t *ppos);
static ssize_t via_dsp_write(struct file *file, const char *buffer, size_t count, loff_t *ppos);
static unsigned int via_dsp_poll(struct file *file, struct poll_table_struct *wait);
static int via_dsp_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
static int via_dsp_open (struct inode *inode, struct file *file);
static int via_dsp_release(struct inode *inode, struct file *file);
static int via_dsp_mmap(struct file *file, struct vm_area_struct *vma);

static u16 via_ac97_read_reg (struct ac97_codec *codec, u8 reg);
static void via_ac97_write_reg (struct ac97_codec *codec, u8 reg, u16 value);
static u8 via_ac97_wait_idle (struct via_info *card);

static void via_chan_free (struct via_info *card, struct via_channel *chan);
static void via_chan_clear (struct via_info *card, struct via_channel *chan);
static void via_chan_pcm_fmt (struct via_channel *chan, int reset);
static void via_chan_buffer_free (struct via_info *card, struct via_channel *chan);

#ifdef CONFIG_PROC_FS
static int via_init_proc (void);
static void via_cleanup_proc (void);
static int via_card_init_proc (struct via_info *card);
static void via_card_cleanup_proc (struct via_info *card);
#else
static inline int via_init_proc (void) { return 0; }
static inline void via_cleanup_proc (void) {}
static inline int via_card_init_proc (struct via_info *card) { return 0; }
static inline void via_card_cleanup_proc (struct via_info *card) {}
#endif


/****************************************************************
 *
 * Various data the driver needs
 *
 *
 */


static struct pci_device_id via_pci_tbl[] __initdata = {
        { PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_5,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
        { PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_5,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 1},
        { 0, }
};
MODULE_DEVICE_TABLE(pci,via_pci_tbl);


static struct pci_driver via_driver = {
        name:           VIA_MODULE_NAME,
        id_table:       via_pci_tbl,
        probe:          via_init_one,
        remove:         __devexit_p(via_remove_one),
};


/****************************************************************
 *
 * Low-level base 0 register read/write helpers
 *
 *
 */

/**
 *      via_chan_stop - Terminate DMA on specified PCM channel
 *      @iobase: PCI base address for SGD channel registers
 *
 *      Terminate scatter-gather DMA operation for given
 *      channel (derived from @iobase), if DMA is active.
 *
 *      Note that @iobase is not the PCI base address,
 *      but the PCI base address plus an offset to
 *      one of three PCM channels supported by the chip.
 *
 */

static inline void via_chan_stop (long iobase)
{
        if (inb (iobase + VIA_PCM_STATUS) & VIA_SGD_ACTIVE)
                outb (VIA_SGD_TERMINATE, iobase + VIA_PCM_CONTROL);
}


/**
 *      via_chan_status_clear - Clear status flags on specified DMA channel
 *      @iobase: PCI base address for SGD channel registers
 *
 *      Clear any pending status flags for the given
 *      DMA channel (derived from @iobase), if any
 *      flags are asserted.
 *
 *      Note that @iobase is not the PCI base address,
 *      but the PCI base address plus an offset to
 *      one of three PCM channels supported by the chip.
 *
 */

static inline void via_chan_status_clear (long iobase)
{
        u8 tmp = inb (iobase + VIA_PCM_STATUS);

        if (tmp != 0)
                outb (tmp, iobase + VIA_PCM_STATUS);
}


/**
 *      sg_begin - Begin recording or playback on a PCM channel
 *      @chan: Channel for which DMA operation shall begin
 *
 *      Start scatter-gather DMA for the given channel.
 *
 */

static inline void sg_begin (struct via_channel *chan)
{
        DPRINTK("Start with intmask %d\n", chan->intmask);
        DPRINTK("About to start from %d to %d\n", 
                inl(chan->iobase + VIA_PCM_BLOCK_COUNT),
                inb(chan->iobase + VIA_PCM_STOPRATE + 3));
        outb (VIA_SGD_START|chan->intmask, chan->iobase + VIA_PCM_CONTROL);
        DPRINTK("Status is now %02X\n", inb(chan->iobase + VIA_PCM_STATUS));
        DPRINTK("Control is now %02X\n", inb(chan->iobase + VIA_PCM_CONTROL));
}


static int sg_active (long iobase)
{
        u8 tmp = inb (iobase + VIA_PCM_STATUS);
        if ((tmp & VIA_SGD_STOPPED) || (tmp & VIA_SGD_PAUSED)) {
                printk(KERN_WARNING "via82cxxx warning: SG stopped or paused\n");
                return 0;
        }
        if (tmp & VIA_SGD_ACTIVE)
                return 1;
        return 0;
}

static int via_sg_offset(struct via_channel *chan)
{
        return inl (chan->iobase + VIA_PCM_BLOCK_COUNT) & 0x00FFFFFF;
}

/****************************************************************
 *
 * Miscellaneous debris
 *
 *
 */


/**
 *      via_syscall_down - down the card-specific syscell semaphore
 *      @card: Private info for specified board
 *      @nonblock: boolean, non-zero if O_NONBLOCK is set
 *
 *      Encapsulates standard method of acquiring the syscall sem.
 *
 *      Returns negative errno on error, or zero for success.
 */

static inline int via_syscall_down (struct via_info *card, int nonblock)
{
        /* Thomas Sailer:
         * EAGAIN is supposed to be used if IO is pending,
         * not if there is contention on some internal
         * synchronization primitive which should be
         * held only for a short time anyway
         */
        nonblock = 0;

        if (nonblock) {
                if (down_trylock (&card->syscall_sem))
                        return -EAGAIN;
        } else {
                if (down_interruptible (&card->syscall_sem))
                        return -ERESTARTSYS;
        }

        return 0;
}


/**
 *      via_stop_everything - Stop all audio operations
 *      @card: Private info for specified board
 *
 *      Stops all DMA operations and interrupts, and clear
 *      any pending status bits resulting from those operations.
 */

static void via_stop_everything (struct via_info *card)
{
        u8 tmp, new_tmp;

        DPRINTK ("ENTER\n");

        assert (card != NULL);

        /*
         * terminate any existing operations on audio read/write channels
         */
        via_chan_stop (card->baseaddr + VIA_BASE0_PCM_OUT_CHAN);
        via_chan_stop (card->baseaddr + VIA_BASE0_PCM_IN_CHAN);
        via_chan_stop (card->baseaddr + VIA_BASE0_FM_OUT_CHAN);
        if(card->sixchannel)
                via_chan_stop (card->baseaddr + VIA_BASE0_MULTI_OUT_CHAN);

        /*
         * clear any existing stops / flags (sanity check mainly)
         */
        via_chan_status_clear (card->baseaddr + VIA_BASE0_PCM_OUT_CHAN);
        via_chan_status_clear (card->baseaddr + VIA_BASE0_PCM_IN_CHAN);
        via_chan_status_clear (card->baseaddr + VIA_BASE0_FM_OUT_CHAN);
        if(card->sixchannel)
                via_chan_status_clear (card->baseaddr + VIA_BASE0_MULTI_OUT_CHAN);

        /*
         * clear any enabled interrupt bits
         */
        tmp = inb (card->baseaddr + VIA_BASE0_PCM_OUT_CHAN_TYPE);
        new_tmp = tmp & ~(VIA_IRQ_ON_FLAG|VIA_IRQ_ON_EOL|VIA_RESTART_SGD_ON_EOL);
        if (tmp != new_tmp)
                outb (0, card->baseaddr + VIA_BASE0_PCM_OUT_CHAN_TYPE);

        tmp = inb (card->baseaddr + VIA_BASE0_PCM_IN_CHAN_TYPE);
        new_tmp = tmp & ~(VIA_IRQ_ON_FLAG|VIA_IRQ_ON_EOL|VIA_RESTART_SGD_ON_EOL);
        if (tmp != new_tmp)
                outb (0, card->baseaddr + VIA_BASE0_PCM_IN_CHAN_TYPE);

        tmp = inb (card->baseaddr + VIA_BASE0_FM_OUT_CHAN_TYPE);
        new_tmp = tmp & ~(VIA_IRQ_ON_FLAG|VIA_IRQ_ON_EOL|VIA_RESTART_SGD_ON_EOL);
        if (tmp != new_tmp)
                outb (0, card->baseaddr + VIA_BASE0_FM_OUT_CHAN_TYPE);

        if(card->sixchannel)
        {
                tmp = inb (card->baseaddr + VIA_BASE0_MULTI_OUT_CHAN_TYPE);
                new_tmp = tmp & ~(VIA_IRQ_ON_FLAG|VIA_IRQ_ON_EOL|VIA_RESTART_SGD_ON_EOL);
                if (tmp != new_tmp)
                        outb (0, card->baseaddr + VIA_BASE0_MULTI_OUT_CHAN_TYPE);
        }

        udelay(10);

        /*
         * clear any existing flags
         */
        via_chan_status_clear (card->baseaddr + VIA_BASE0_PCM_OUT_CHAN);
        via_chan_status_clear (card->baseaddr + VIA_BASE0_PCM_IN_CHAN);
        via_chan_status_clear (card->baseaddr + VIA_BASE0_FM_OUT_CHAN);

        DPRINTK ("EXIT\n");
}


/**
 *      via_set_rate - Set PCM rate for given channel
 *      @ac97: Pointer to generic codec info struct
 *      @chan: Private info for specified channel
 *      @rate: Desired PCM sample rate, in Khz
 *
 *      Sets the PCM sample rate for a channel.
 *
 *      Values for @rate are clamped to a range of 4000 Khz through 48000 Khz,
 *      due to hardware constraints.
 */

static int via_set_rate (struct ac97_codec *ac97,
                         struct via_channel *chan, unsigned rate)
{
        struct via_info *card = ac97->private_data;
        int rate_reg;
        u32 dacp;
        u32 mast_vol, phone_vol, mono_vol, pcm_vol;
        u32 mute_vol = 0x8000;  /* The mute volume? -- Seems to work! */

        DPRINTK ("ENTER, rate = %d\n", rate);

        if (chan->rate == rate)
                goto out;
        if (card->locked_rate) {
                chan->rate = 48000;
                goto out;
        }

        if (rate > 48000)               rate = 48000;
        if (rate < 4000)                rate = 4000;

        rate_reg = chan->is_record ? AC97_PCM_LR_ADC_RATE :
                            AC97_PCM_FRONT_DAC_RATE;

        /* Save current state */
        dacp=via_ac97_read_reg(ac97, AC97_POWER_CONTROL);
        mast_vol = via_ac97_read_reg(ac97, AC97_MASTER_VOL_STEREO);
        mono_vol = via_ac97_read_reg(ac97, AC97_MASTER_VOL_MONO);
        phone_vol = via_ac97_read_reg(ac97, AC97_HEADPHONE_VOL);
        pcm_vol = via_ac97_read_reg(ac97, AC97_PCMOUT_VOL);
        /* Mute - largely reduces popping */
        via_ac97_write_reg(ac97, AC97_MASTER_VOL_STEREO, mute_vol);
        via_ac97_write_reg(ac97, AC97_MASTER_VOL_MONO, mute_vol);
        via_ac97_write_reg(ac97, AC97_HEADPHONE_VOL, mute_vol);
        via_ac97_write_reg(ac97, AC97_PCMOUT_VOL, mute_vol);
        /* Power down the DAC */
        via_ac97_write_reg(ac97, AC97_POWER_CONTROL, dacp|0x0200);

        /* Set new rate */
        via_ac97_write_reg (ac97, rate_reg, rate);

        /* Power DAC back up */
        via_ac97_write_reg(ac97, AC97_POWER_CONTROL, dacp);
        udelay (200); /* reduces popping */

        /* Restore volumes */
        via_ac97_write_reg(ac97, AC97_MASTER_VOL_STEREO, mast_vol);
        via_ac97_write_reg(ac97, AC97_MASTER_VOL_MONO, mono_vol);
        via_ac97_write_reg(ac97, AC97_HEADPHONE_VOL, phone_vol);
        via_ac97_write_reg(ac97, AC97_PCMOUT_VOL, pcm_vol);

        /* the hardware might return a value different than what we
         * passed to it, so read the rate value back from hardware
         * to see what we came up with
         */
        chan->rate = via_ac97_read_reg (ac97, rate_reg);

        if (chan->rate == 0) {
                card->locked_rate = 1;
                chan->rate = 48000;
                printk (KERN_WARNING PFX "Codec rate locked at 48Khz\n");
        }

out:
        DPRINTK ("EXIT, returning rate %d Hz\n", chan->rate);
        return chan->rate;
}


/****************************************************************
 *
 * Channel-specific operations
 *
 *
 */


/**
 *      via_chan_init_defaults - Initialize a struct via_channel
 *      @card: Private audio chip info
 *      @chan: Channel to be initialized
 *
 *      Zero @chan, and then set all static defaults for the structure.
 */

static void via_chan_init_defaults (struct via_info *card, struct via_channel *chan)
{
        memset (chan, 0, sizeof (*chan));

        if(card->intmask)
                chan->intmask = 0x23;   /* Turn on the IRQ bits */
                
        if (chan == &card->ch_out) {
                chan->name = "PCM-OUT";
                if(card->sixchannel)
                {
                        chan->iobase = card->baseaddr + VIA_BASE0_MULTI_OUT_CHAN;
                        chan->is_multi = 1;
                        DPRINTK("Using multichannel for pcm out\n");
                }
                else
                        chan->iobase = card->baseaddr + VIA_BASE0_PCM_OUT_CHAN;
        } else if (chan == &card->ch_in) {
                chan->name = "PCM-IN";
                chan->iobase = card->baseaddr + VIA_BASE0_PCM_IN_CHAN;
                chan->is_record = 1;
        } else if (chan == &card->ch_fm) {
                chan->name = "PCM-OUT-FM";
                chan->iobase = card->baseaddr + VIA_BASE0_FM_OUT_CHAN;
        } else {
                BUG();
        }

        init_waitqueue_head (&chan->wait);

        chan->pcm_fmt = VIA_PCM_FMT_MASK;
        chan->is_enabled = 1;

        chan->frag_number = 0;
        chan->frag_size = 0;
        atomic_set(&chan->n_frags, 0);
        atomic_set (&chan->hw_ptr, 0);
}

/**
 *      via_chan_init - Initialize PCM channel
 *      @card: Private audio chip info
 *      @chan: Channel to be initialized
 *
 *      Performs some of the preparations necessary to begin
 *      using a PCM channel.
 *
 *      Currently the preparations consist of
 *      setting the PCM channel to a known state.
 */


static void via_chan_init (struct via_info *card, struct via_channel *chan)
{

        DPRINTK ("ENTER\n");

        /* bzero channel structure, and init members to defaults */
        via_chan_init_defaults (card, chan);

        /* stop any existing channel output */
        via_chan_clear (card, chan);
        via_chan_status_clear (chan->iobase);
        via_chan_pcm_fmt (chan, 1);

        DPRINTK ("EXIT\n");
}

/**
 *      via_chan_buffer_init - Initialize PCM channel buffer
 *      @card: Private audio chip info
 *      @chan: Channel to be initialized
 *
 *      Performs some of the preparations necessary to begin
 *      using a PCM channel.
 *
 *      Currently the preparations include allocating the
 *      scatter-gather DMA table and buffers,
 *      and passing the
 *      address of the DMA table to the hardware.
 *
 *      Note that special care is taken when passing the
 *      DMA table address to hardware, because it was found
 *      during driver development that the hardware did not
 *      always "take" the address.
 */

static int via_chan_buffer_init (struct via_info *card, struct via_channel *chan)
{
        int page, offset;
        int i;

        DPRINTK ("ENTER\n");


        chan->intmask = 0;
        if(card->intmask)
                chan->intmask = 0x23;   /* Turn on the IRQ bits */
                
        if (chan->sgtable != NULL) {
                DPRINTK ("EXIT\n");
                return 0;
        }

        /* alloc DMA-able memory for scatter-gather table */
        chan->sgtable = pci_alloc_consistent (card->pdev,
                (sizeof (struct via_sgd_table) * chan->frag_number),
                &chan->sgt_handle);
        if (!chan->sgtable) {
                printk (KERN_ERR PFX "DMA table alloc fail, aborting\n");
                DPRINTK ("EXIT\n");
                return -ENOMEM;
        }

        memset ((void*)chan->sgtable, 0,
                (sizeof (struct via_sgd_table) * chan->frag_number));

        /* alloc DMA-able memory for scatter-gather buffers */

        chan->page_number = (chan->frag_number * chan->frag_size) / PAGE_SIZE +
                            (((chan->frag_number * chan->frag_size) % PAGE_SIZE) ? 1 : 0);

        for (i = 0; i < chan->page_number; i++) {
                chan->pgtbl[i].cpuaddr = pci_alloc_consistent (card->pdev, PAGE_SIZE,
                                              &chan->pgtbl[i].handle);

                if (!chan->pgtbl[i].cpuaddr) {
                        chan->page_number = i;
                        goto err_out_nomem;
                }

#ifndef VIA_NDEBUG
                memset (chan->pgtbl[i].cpuaddr, 0xBC, chan->frag_size);
#endif

#if 1
                DPRINTK ("dmabuf_pg #%d (h=%lx, v2p=%lx, a=%p)\n",
                        i, (long)chan->pgtbl[i].handle,
                        virt_to_phys(chan->pgtbl[i].cpuaddr),
                        chan->pgtbl[i].cpuaddr);
#endif
        }

        for (i = 0; i < chan->frag_number; i++) {

                page = i / (PAGE_SIZE / chan->frag_size);
                offset = (i % (PAGE_SIZE / chan->frag_size)) * chan->frag_size;

                chan->sgtable[i].count = cpu_to_le32 (chan->frag_size | VIA_FLAG);
                chan->sgtable[i].addr = cpu_to_le32 (chan->pgtbl[page].handle + offset);

#if 1
                DPRINTK ("dmabuf #%d (32(h)=%lx)\n",
                         i,
                         (long)chan->sgtable[i].addr);
#endif
        }

        /* overwrite the last buffer information */
        chan->sgtable[chan->frag_number - 1].count = cpu_to_le32 (chan->frag_size | VIA_EOL);

        /* set location of DMA-able scatter-gather info table */
        DPRINTK ("outl (0x%X, 0x%04lX)\n",
                chan->sgt_handle, chan->iobase + VIA_PCM_TABLE_ADDR);

        via_ac97_wait_idle (card);
        outl (chan->sgt_handle, chan->iobase + VIA_PCM_TABLE_ADDR);
        udelay (20);
        via_ac97_wait_idle (card);
        /* load no rate adaption, stereo 16bit, set up ring slots */
        if(card->sixchannel)
        {
                if(!chan->is_multi)
                {
                        outl (0xFFFFF | (0x3 << 20) | (chan->frag_number << 24), chan->iobase + VIA_PCM_STOPRATE);
                        udelay (20);
                        via_ac97_wait_idle (card);
                }
        }

        DPRINTK ("inl (0x%lX) = %x\n",
                chan->iobase + VIA_PCM_TABLE_ADDR,
                inl(chan->iobase + VIA_PCM_TABLE_ADDR));

        DPRINTK ("EXIT\n");
        return 0;

err_out_nomem:
        printk (KERN_ERR PFX "DMA buffer alloc fail, aborting\n");
        via_chan_buffer_free (card, chan);
        DPRINTK ("EXIT\n");
        return -ENOMEM;
}


/**
 *      via_chan_free - Release a PCM channel
 *      @card: Private audio chip info
 *      @chan: Channel to be released
 *
 *      Performs all the functions necessary to clean up
 *      an initialized channel.
 *
 *      Currently these functions include disabled any
 *      active DMA operations, setting the PCM channel
 *      back to a known state, and releasing any allocated
 *      sound buffers.
 */

static void via_chan_free (struct via_info *card, struct via_channel *chan)
{
        DPRINTK ("ENTER\n");

        spin_lock_irq (&card->lock);

        /* stop any existing channel output */
        via_chan_status_clear (chan->iobase);
        via_chan_stop (chan->iobase);
        via_chan_status_clear (chan->iobase);

        spin_unlock_irq (&card->lock);

        synchronize_irq();

        DPRINTK ("EXIT\n");
}

static void via_chan_buffer_free (struct via_info *card, struct via_channel *chan)
{
        int i;

        DPRINTK ("ENTER\n");

        /* zero location of DMA-able scatter-gather info table */
        via_ac97_wait_idle(card);
        outl (0, chan->iobase + VIA_PCM_TABLE_ADDR);

        for (i = 0; i < chan->page_number; i++)
                if (chan->pgtbl[i].cpuaddr) {
                        pci_free_consistent (card->pdev, PAGE_SIZE,
                                             chan->pgtbl[i].cpuaddr,
                                             chan->pgtbl[i].handle);
                        chan->pgtbl[i].cpuaddr = NULL;
                        chan->pgtbl[i].handle = 0;
                }

        chan->page_number = 0;

        if (chan->sgtable) {
                pci_free_consistent (card->pdev,
                        (sizeof (struct via_sgd_table) * chan->frag_number),
                        (void*)chan->sgtable, chan->sgt_handle);
                chan->sgtable = NULL;
        }

        DPRINTK ("EXIT\n");
}


/**
 *      via_chan_pcm_fmt - Update PCM channel settings
 *      @chan: Channel to be updated
 *      @reset: Boolean.  If non-zero, channel will be reset
 *              to 8-bit mono mode.
 *
 *      Stores the settings of the current PCM format,
 *      8-bit or 16-bit, and mono/stereo, into the
 *      hardware settings for the specified channel.
 *      If @reset is non-zero, the channel is reset
 *      to 8-bit mono mode.  Otherwise, the channel
 *      is set to the values stored in the channel
 *      information struct @chan.
 */

static void via_chan_pcm_fmt (struct via_channel *chan, int reset)
{
        DPRINTK ("ENTER, pcm_fmt=0x%02X, reset=%s\n",
                 chan->pcm_fmt, reset ? "yes" : "no");

        assert (chan != NULL);

        if (reset)
        {
                /* reset to 8-bit mono mode */
                chan->pcm_fmt = 0;
                chan->channels = 1;
        }

        /* enable interrupts on FLAG and EOL */
        chan->pcm_fmt |= VIA_CHAN_TYPE_MASK;

        /* if we are recording, enable recording fifo bit */
        if (chan->is_record)
                chan->pcm_fmt |= VIA_PCM_REC_FIFO;
        /* set interrupt select bits where applicable (PCM in & out channels) */
        if (!chan->is_record)
                chan->pcm_fmt |= VIA_CHAN_TYPE_INT_SELECT;
        
        DPRINTK("SET FMT - %02x %02x\n", chan->intmask , chan->is_multi);
        

        if(chan->intmask)
        {
                u32 m;

                /*
                 *      Channel 0x4 is up to 6 x 16bit and has to be
                 *      programmed differently 
                 */
                                
                if(chan->is_multi)
                {
                        u8 c = 0;
                        
                        /*
                         *      Load the type bit for num channels
                         *      and 8/16bit
                         */
                         
                        if(chan->pcm_fmt & VIA_PCM_FMT_16BIT)
                                c = 1 << 7;
                        if(chan->pcm_fmt & VIA_PCM_FMT_STEREO)
                                c |= (2<<4);
                        else
                                c |= (1<<4);
                                
                        outb(c, chan->iobase + VIA_PCM_TYPE);
                        
                        /*
                         *      Set the channel steering
                         *      Mono
                         *              Channel 0 to slot 3
                         *              Channel 0 to slot 4
                         *      Stereo
                         *              Channel 0 to slot 3
                         *              Channel 1 to slot 4
                         */
                         
                        switch(chan->channels)
                        {
                                case 1:
                                        outl(0xFF000000 | (1<<0) | (1<<4) , chan->iobase + VIA_PCM_STOPRATE);
                                        break;
                                case 2:
                                        outl(0xFF000000 | (1<<0) | (2<<4) , chan->iobase + VIA_PCM_STOPRATE);
                                        break;
                                case 4:
                                        outl(0xFF000000 | (1<<0) | (2<<4) | (3<<8) | (4<<12), chan->iobase + VIA_PCM_STOPRATE);
                                        break;
                                case 6:
                                        outl(0xFF000000 | (1<<0) | (2<<4) | (5<<8) | (6<<12) | (3<<16) | (4<<20), chan->iobase + VIA_PCM_STOPRATE);
                                        break;
                        }                               
                }
                else
                {
                        /*
                         *      New style, turn off channel volume
                         *      control, set bits in the right register
                         */     
                        outb(0x0, chan->iobase + VIA_PCM_LEFTVOL);
                        outb(0x0, chan->iobase + VIA_PCM_RIGHTVOL);

                        m = inl(chan->iobase + VIA_PCM_STOPRATE);
                        m &= ~(3<<20);
                        if(chan->pcm_fmt & VIA_PCM_FMT_STEREO)
                                m |= (1 << 20);
                        if(chan->pcm_fmt & VIA_PCM_FMT_16BIT)
                                m |= (1 << 21);
                        outl(m, chan->iobase + VIA_PCM_STOPRATE);
                }               
        }
        else
                outb (chan->pcm_fmt, chan->iobase + VIA_PCM_TYPE);


        DPRINTK ("EXIT, pcm_fmt = 0x%02X, reg = 0x%02X\n",
                 chan->pcm_fmt,
                 inb (chan->iobase + VIA_PCM_TYPE));
}


/**
 *      via_chan_clear - Stop DMA channel operation, and reset pointers
 *      @card: the chip to accessed
 *      @chan: Channel to be cleared
 *
 *      Call via_chan_stop to halt DMA operations, and then resets
 *      all software pointers which track DMA operation.
 */

static void via_chan_clear (struct via_info *card, struct via_channel *chan)
{
        DPRINTK ("ENTER\n");
        via_chan_stop (chan->iobase);
        via_chan_buffer_free(card, chan);
        chan->is_active = 0;
        chan->is_mapped = 0;
        chan->is_enabled = 1;
        chan->slop_len = 0;
        chan->sw_ptr = 0;
        chan->n_irqs = 0;
        atomic_set (&chan->hw_ptr, 0);
        DPRINTK ("EXIT\n");
}


/**
 *      via_chan_set_speed - Set PCM sample rate for given channel
 *      @card: Private info for specified board
 *      @chan: Channel whose sample rate will be adjusted
 *      @val: New sample rate, in Khz
 *
 *      Helper function for the %SNDCTL_DSP_SPEED ioctl.  OSS semantics
 *      demand that all audio operations halt (if they are not already
 *      halted) when the %SNDCTL_DSP_SPEED is given.
 *
 *      This function halts all audio operations for the given channel
 *      @chan, and then calls via_set_rate to set the audio hardware
 *      to the new rate.
 */

static int via_chan_set_speed (struct via_info *card,
                               struct via_channel *chan, int val)
{
        DPRINTK ("ENTER, requested rate = %d\n", val);

        via_chan_clear (card, chan);

        val = via_set_rate (card->ac97, chan, val);

        DPRINTK ("EXIT, returning %d\n", val);
        return val;
}


/**
 *      via_chan_set_fmt - Set PCM sample size for given channel
 *      @card: Private info for specified board
 *      @chan: Channel whose sample size will be adjusted
 *      @val: New sample size, use the %AFMT_xxx constants
 *
 *      Helper function for the %SNDCTL_DSP_SETFMT ioctl.  OSS semantics
 *      demand that all audio operations halt (if they are not already
 *      halted) when the %SNDCTL_DSP_SETFMT is given.
 *
 *      This function halts all audio operations for the given channel
 *      @chan, and then calls via_chan_pcm_fmt to set the audio hardware
 *      to the new sample size, either 8-bit or 16-bit.
 */

static int via_chan_set_fmt (struct via_info *card,
                             struct via_channel *chan, int val)
{
        DPRINTK ("ENTER, val=%s\n",
                 val == AFMT_U8 ? "AFMT_U8" :
                 val == AFMT_S16_LE ? "AFMT_S16_LE" :
                 "unknown");

        via_chan_clear (card, chan);

        assert (val != AFMT_QUERY); /* this case is handled elsewhere */

        switch (val) {
        case AFMT_S16_LE:
                if ((chan->pcm_fmt & VIA_PCM_FMT_16BIT) == 0) {
                        chan->pcm_fmt |= VIA_PCM_FMT_16BIT;
                        via_chan_pcm_fmt (chan, 0);
                }
                break;

        case AFMT_U8:
                if (chan->pcm_fmt & VIA_PCM_FMT_16BIT) {
                        chan->pcm_fmt &= ~VIA_PCM_FMT_16BIT;
                        via_chan_pcm_fmt (chan, 0);
                }
                break;

        default:
                DPRINTK ("unknown AFMT: 0x%X\n", val);
                val = AFMT_S16_LE;
        }

        DPRINTK ("EXIT\n");
        return val;
}


/**
 *      via_chan_set_stereo - Enable or disable stereo for a DMA channel
 *      @card: Private info for specified board
 *      @chan: Channel whose stereo setting will be adjusted
 *      @val: New sample size, use the %AFMT_xxx constants
 *
 *      Helper function for the %SNDCTL_DSP_CHANNELS and %SNDCTL_DSP_STEREO ioctls.  OSS semantics
 *      demand that all audio operations halt (if they are not already
 *      halted) when %SNDCTL_DSP_CHANNELS or SNDCTL_DSP_STEREO is given.
 *
 *      This function halts all audio operations for the given channel
 *      @chan, and then calls via_chan_pcm_fmt to set the audio hardware
 *      to enable or disable stereo.
 */

static int via_chan_set_stereo (struct via_info *card,
                                struct via_channel *chan, int val)
{
        DPRINTK ("ENTER, channels = %d\n", val);

        via_chan_clear (card, chan);

        switch (val) {

        /* mono */
        case 1:
                chan->pcm_fmt &= ~VIA_PCM_FMT_STEREO;
                chan->channels = 1;
                via_chan_pcm_fmt (chan, 0);
                break;

        /* stereo */
        case 2:
                chan->pcm_fmt |= VIA_PCM_FMT_STEREO;
                chan->channels = 2;
                via_chan_pcm_fmt (chan, 0);
                break;

        case 4:
        case 6:
                if(chan->is_multi)
                {
                        chan->pcm_fmt |= VIA_PCM_FMT_STEREO;
                        chan->channels = val;
                        break;
                }
        /* unknown */
        default:
                val = -EINVAL;
                break;
        }

        DPRINTK ("EXIT, returning %d\n", val);
        return val;
}

static int via_chan_set_buffering (struct via_info *card,
                                struct via_channel *chan, int val)
{
        int shift;

        DPRINTK ("ENTER\n");

        /* in both cases the buffer cannot be changed */
        if (chan->is_active || chan->is_mapped) {
                DPRINTK ("EXIT\n");
                return -EINVAL;
        }

        /* called outside SETFRAGMENT */
        /* set defaults or do nothing */
        if (val < 0) {

                if (chan->frag_size && chan->frag_number)
                        goto out;

                DPRINTK ("\n");

                chan->frag_size = (VIA_DEFAULT_FRAG_TIME * chan->rate * chan->channels
                                   * ((chan->pcm_fmt & VIA_PCM_FMT_16BIT) ? 2 : 1)) / 1000 - 1;

                shift = 0;
                while (chan->frag_size) {
                        chan->frag_size >>= 1;
                        shift++;
                }
                chan->frag_size = 1 << shift;

                chan->frag_number = (VIA_DEFAULT_BUFFER_TIME / VIA_DEFAULT_FRAG_TIME);

                DPRINTK ("setting default values %d %d\n", chan->frag_size, chan->frag_number);
        } else {
                chan->frag_size = 1 << (val & 0xFFFF);
                chan->frag_number = (val >> 16) & 0xFFFF;

                DPRINTK ("using user values %d %d\n", chan->frag_size, chan->frag_number);
        }

        /* quake3 wants frag_number to be a power of two */
        shift = 0;
        while (chan->frag_number) {
                chan->frag_number >>= 1;
                shift++;
        }
        chan->frag_number = 1 << shift;

        if (chan->frag_size > VIA_MAX_FRAG_SIZE)
                chan->frag_size = VIA_MAX_FRAG_SIZE;
        else if (chan->frag_size < VIA_MIN_FRAG_SIZE)
                chan->frag_size = VIA_MIN_FRAG_SIZE;

        if (chan->frag_number < VIA_MIN_FRAG_NUMBER)
                chan->frag_number = VIA_MIN_FRAG_NUMBER;
        if (chan->frag_number > VIA_MAX_FRAG_NUMBER)
                chan->frag_number = VIA_MAX_FRAG_NUMBER;

        if ((chan->frag_number * chan->frag_size) / PAGE_SIZE > VIA_MAX_BUFFER_DMA_PAGES)
                chan->frag_number = (VIA_MAX_BUFFER_DMA_PAGES * PAGE_SIZE) / chan->frag_size;

out:
        if (chan->is_record)
                atomic_set (&chan->n_frags, 0);
        else
                atomic_set (&chan->n_frags, chan->frag_number);

        DPRINTK ("EXIT\n");

        return 0;
}

#ifdef VIA_CHAN_DUMP_BUFS
/**
 *      via_chan_dump_bufs - Display DMA table contents
 *      @chan: Channel whose DMA table will be displayed
 *
 *      Debugging function which displays the contents of the
 *      scatter-gather DMA table for the given channel @chan.
 */

static void via_chan_dump_bufs (struct via_channel *chan)
{
        int i;

        for (i = 0; i < chan->frag_number; i++) {
                DPRINTK ("#%02d: addr=%x, count=%u, flag=%d, eol=%d\n",
                         i, chan->sgtable[i].addr,
                         chan->sgtable[i].count & 0x00FFFFFF,
                         chan->sgtable[i].count & VIA_FLAG ? 1 : 0,
                         chan->sgtable[i].count & VIA_EOL ? 1 : 0);
        }
        DPRINTK ("buf_in_use = %d, nextbuf = %d\n",
                 atomic_read (&chan->buf_in_use),
                 atomic_read (&chan->sw_ptr));
}
#endif /* VIA_CHAN_DUMP_BUFS */


/**
 *      via_chan_flush_frag - Flush partially-full playback buffer to hardware
 *      @chan: Channel whose DMA table will be flushed
 *
 *      Flushes partially-full playback buffer to hardware.
 */

static void via_chan_flush_frag (struct via_channel *chan)
{
        DPRINTK ("ENTER\n");

        assert (chan->slop_len > 0);

        if (chan->sw_ptr == (chan->frag_number - 1))
                chan->sw_ptr = 0;
        else
                chan->sw_ptr++;

        chan->slop_len = 0;

        assert (atomic_read (&chan->n_frags) > 0);
        atomic_dec (&chan->n_frags);

        DPRINTK ("EXIT\n");
}



/**
 *      via_chan_maybe_start - Initiate audio hardware DMA operation
 *      @chan: Channel whose DMA is to be started
 *
 *      Initiate DMA operation, if the DMA engine for the given
 *      channel @chan is not already active.
 */

static inline void via_chan_maybe_start (struct via_channel *chan)
{
        assert (chan->is_active == sg_active(chan->iobase));

        DPRINTK ("MAYBE START %s\n", chan->name);
        if (!chan->is_active && chan->is_enabled) {
                chan->is_active = 1;
                sg_begin (chan);
                DPRINTK ("starting channel %s\n", chan->name);
        }
}


/****************************************************************
 *
 * Interface to ac97-codec module
 *
 *
 */

/**
 *      via_ac97_wait_idle - Wait until AC97 codec is not busy
 *      @card: Private info for specified board
 *
 *      Sleep until the AC97 codec is no longer busy.
 *      Returns the final value read from the SGD
 *      register being polled.
 */

static u8 via_ac97_wait_idle (struct via_info *card)
{
        u8 tmp8;
        int counter = VIA_COUNTER_LIMIT;

        DPRINTK ("ENTER/EXIT\n");

        assert (card != NULL);
        assert (card->pdev != NULL);

        do {
                udelay (15);

                tmp8 = inb (card->baseaddr + 0x83);
        } while ((tmp8 & VIA_CR83_BUSY) && (counter-- > 0));

        if (tmp8 & VIA_CR83_BUSY)
                printk (KERN_WARNING PFX "timeout waiting on AC97 codec\n");
        return tmp8;
}


/**
 *      via_ac97_read_reg - Read AC97 standard register
 *      @codec: Pointer to generic AC97 codec info
 *      @reg: Index of AC97 register to be read
 *
 *      Read the value of a single AC97 codec register,
 *      as defined by the Intel AC97 specification.
 *
 *      Defines the standard AC97 read-register operation
 *      required by the kernel's ac97_codec interface.
 *
 *      Returns the 16-bit value stored in the specified
 *      register.
 */

static u16 via_ac97_read_reg (struct ac97_codec *codec, u8 reg)
{
        unsigned long data;
        struct via_info *card;
        int counter;

        DPRINTK ("ENTER\n");

        assert (codec != NULL);
        assert (codec->private_data != NULL);

        card = codec->private_data;
        
        spin_lock(&card->ac97_lock);

        /* Every time we write to register 80 we cause a transaction.
           The only safe way to clear the valid bit is to write it at
           the same time as the command */
        data = (reg << 16) | VIA_CR80_READ | VIA_CR80_VALID;

        outl (data, card->baseaddr + VIA_BASE0_AC97_CTRL);
        udelay (20);

        for (counter = VIA_COUNTER_LIMIT; counter > 0; counter--) {
                udelay (1);
                if ((((data = inl(card->baseaddr + VIA_BASE0_AC97_CTRL)) &
                      (VIA_CR80_VALID|VIA_CR80_BUSY)) == VIA_CR80_VALID))
                        goto out;
        }

        printk (KERN_WARNING PFX "timeout while reading AC97 codec (0x%lX)\n", data);
        goto err_out;

out:
        /* Once the valid bit has become set, we must wait a complete AC97
           frame before the data has settled. */
        udelay(25);
        data = (unsigned long) inl (card->baseaddr + VIA_BASE0_AC97_CTRL);

        outb (0x02, card->baseaddr + 0x83);

        if (((data & 0x007F0000) >> 16) == reg) {
                DPRINTK ("EXIT, success, data=0x%lx, retval=0x%lx\n",
                         data, data & 0x0000FFFF);
                spin_unlock(&card->ac97_lock);
                return data & 0x0000FFFF;
        }

        printk (KERN_WARNING "via82cxxx_audio: not our index: reg=0x%x, newreg=0x%lx\n",
                reg, ((data & 0x007F0000) >> 16));

err_out:
        spin_unlock(&card->ac97_lock);
        DPRINTK ("EXIT, returning 0\n");
        return 0;
}


/**
 *      via_ac97_write_reg - Write AC97 standard register
 *      @codec: Pointer to generic AC97 codec info
 *      @reg: Index of AC97 register to be written
 *      @value: Value to be written to AC97 register
 *
 *      Write the value of a single AC97 codec register,
 *      as defined by the Intel AC97 specification.
 *
 *      Defines the standard AC97 write-register operation
 *      required by the kernel's ac97_codec interface.
 */

static void via_ac97_write_reg (struct ac97_codec *codec, u8 reg, u16 value)
{
        u32 data;
        struct via_info *card;
        int counter;

        DPRINTK ("ENTER\n");

        assert (codec != NULL);
        assert (codec->private_data != NULL);

        card = codec->private_data;

        spin_lock(&card->ac97_lock);
        
        data = (reg << 16) + value;
        outl (data, card->baseaddr + VIA_BASE0_AC97_CTRL);
        udelay (10);

        for (counter = VIA_COUNTER_LIMIT; counter > 0; counter--) {
                if ((inb (card->baseaddr + 0x83) & VIA_CR83_BUSY) == 0)
                        goto out;

                udelay (15);
        }

        printk (KERN_WARNING PFX "timeout after AC97 codec write (0x%X, 0x%X)\n", reg, value);

out:
        spin_unlock(&card->ac97_lock);
        DPRINTK ("EXIT\n");
}


static int via_mixer_open (struct inode *inode, struct file *file)
{
        int minor = MINOR(inode->i_rdev);
        struct via_info *card;
        struct pci_dev *pdev;
        struct pci_driver *drvr;

        DPRINTK ("ENTER\n");

        pci_for_each_dev(pdev) {
                drvr = pci_dev_driver (pdev);
                if (drvr == &via_driver) {
                        assert (pci_get_drvdata (pdev) != NULL);

                        card = pci_get_drvdata (pdev);
                        if (card->ac97->dev_mixer == minor)
                                goto match;
                }
        }

        DPRINTK ("EXIT, returning -ENODEV\n");
        return -ENODEV;

match:
        file->private_data = card->ac97;

        DPRINTK ("EXIT, returning 0\n");
        return 0;
}

static int via_mixer_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
                            unsigned long arg)
{
        struct ac97_codec *codec = file->private_data;
        struct via_info *card;
        int nonblock = (file->f_flags & O_NONBLOCK);
        int rc;

        DPRINTK ("ENTER\n");

        assert (codec != NULL);
        card = codec->private_data;
        assert (card != NULL);

        rc = via_syscall_down (card, nonblock);
        if (rc) goto out;
        
#if 0
        /*
         *      Intercept volume control on 8233 and 8235
         */
        if(card->volume)
        {
                switch(cmd)
                {
                        case SOUND_MIXER_READ_VOLUME:
                                return card->mixer_vol;
                        case SOUND_MIXER_WRITE_VOLUME:
                        {
                                int v;
                                if(get_user(v, (int *)arg))
                                {
                                        rc = -EFAULT;
                                        goto out;
                                }
                                card->mixer_vol = v;
                        }
                }
        }               
#endif
        rc = codec->mixer_ioctl(codec, cmd, arg);

        up (&card->syscall_sem);

out:
        DPRINTK ("EXIT, returning %d\n", rc);
        return rc;
}


static struct file_operations via_mixer_fops = {
        owner:          THIS_MODULE,
        open:           via_mixer_open,
        llseek:         no_llseek,
        ioctl:          via_mixer_ioctl,
};


static int __init via_ac97_reset (struct via_info *card)
{
        struct pci_dev *pdev = card->pdev;
        u8 tmp8;
        u16 tmp16;

        DPRINTK ("ENTER\n");

        assert (pdev != NULL);

#ifndef NDEBUG
        {
                u8 r40,r41,r42,r43,r44,r48;
                pci_read_config_byte (card->pdev, 0x40, &r40);
                pci_read_config_byte (card->pdev, 0x41, &r41);
                pci_read_config_byte (card->pdev, 0x42, &r42);
                pci_read_config_byte (card->pdev, 0x43, &r43);
                pci_read_config_byte (card->pdev, 0x44, &r44);
                pci_read_config_byte (card->pdev, 0x48, &r48);
                DPRINTK ("PCI config: %02X %02X %02X %02X %02X %02X\n",
                        r40,r41,r42,r43,r44,r48);

                spin_lock_irq (&card->lock);
                DPRINTK ("regs==%02X %02X %02X %08X %08X %08X %08X\n",
                         inb (card->baseaddr + 0x00),
                         inb (card->baseaddr + 0x01),
                         inb (card->baseaddr + 0x02),
                         inl (card->baseaddr + 0x04),
                         inl (card->baseaddr + 0x0C),
                         inl (card->baseaddr + 0x80),
                         inl (card->baseaddr + 0x84));
                spin_unlock_irq (&card->lock);

        }
#endif

        /*
         * Reset AC97 controller: enable, disable, enable,
         * pausing after each command for good luck.  Only
         * do this if the codec is not ready, because it causes
         * loud pops and such due to such a hard codec reset.
         */
        pci_read_config_byte (pdev, VIA_ACLINK_STATUS, &tmp8);
        if ((tmp8 & VIA_CR40_AC97_READY) == 0) {
                pci_write_config_byte (pdev, VIA_ACLINK_CTRL,
                                       VIA_CR41_AC97_ENABLE |
                                       VIA_CR41_AC97_RESET |
                                       VIA_CR41_AC97_WAKEUP);
                udelay (100);

                pci_write_config_byte (pdev, VIA_ACLINK_CTRL, 0);
                udelay (100);

                pci_write_config_byte (pdev, VIA_ACLINK_CTRL,
                                       VIA_CR41_AC97_ENABLE |
                                       VIA_CR41_PCM_ENABLE |
                                       VIA_CR41_VRA | VIA_CR41_AC97_RESET);
                udelay (100);
        }

        /* Make sure VRA is enabled, in case we didn't do a
         * complete codec reset, above
         */
        pci_read_config_byte (pdev, VIA_ACLINK_CTRL, &tmp8);
        if (((tmp8 & VIA_CR41_VRA) == 0) ||
            ((tmp8 & VIA_CR41_AC97_ENABLE) == 0) ||
            ((tmp8 & VIA_CR41_PCM_ENABLE) == 0) ||
            ((tmp8 & VIA_CR41_AC97_RESET) == 0)) {
                pci_write_config_byte (pdev, VIA_ACLINK_CTRL,
                                       VIA_CR41_AC97_ENABLE |
                                       VIA_CR41_PCM_ENABLE |
                                       VIA_CR41_VRA | VIA_CR41_AC97_RESET);
                udelay (100);
        }

        if(card->legacy)
        {
#if 0 /* this breaks on K7M */
                /* disable legacy stuff */
                pci_write_config_byte (pdev, 0x42, 0x00);
                udelay(10);
#endif

                /* route FM trap to IRQ, disable FM trap */
                pci_write_config_byte (pdev, 0x48, 0x05);
                udelay(10);
        }
        
        /* disable all codec GPI interrupts */
        outl (0, pci_resource_start (pdev, 0) + 0x8C);

        /* WARNING: this line is magic.  Remove this
         * and things break. */
        /* enable variable rate */
        tmp16 = via_ac97_read_reg (card->ac97, AC97_EXTENDED_STATUS);
        if ((tmp16 & 1) == 0)
                via_ac97_write_reg (card->ac97, AC97_EXTENDED_STATUS, tmp16 | 1);

        DPRINTK ("EXIT, returning 0\n");
        return 0;
}


static void via_ac97_codec_wait (struct ac97_codec *codec)
{
        assert (codec->private_data != NULL);
        via_ac97_wait_idle (codec->private_data);
}


static int __init via_ac97_init (struct via_info *card)
{
        int rc;
        u16 tmp16;

        DPRINTK ("ENTER\n");

        assert (card != NULL);

        card->ac97 = ac97_alloc_codec();
        if(card->ac97 == NULL)
                return -ENOMEM;
                
        card->ac97->private_data = card;
        card->ac97->codec_read = via_ac97_read_reg;
        card->ac97->codec_write = via_ac97_write_reg;
        card->ac97->codec_wait = via_ac97_codec_wait;

        card->ac97->dev_mixer = register_sound_mixer (&via_mixer_fops, -1);
        if (card->ac97->dev_mixer < 0) {
                printk (KERN_ERR PFX "unable to register AC97 mixer, aborting\n");
                DPRINTK ("EXIT, returning -EIO\n");
                ac97_release_codec(card->ac97);
                return -EIO;
        }

        rc = via_ac97_reset (card);
        if (rc) {
                printk (KERN_ERR PFX "unable to reset AC97 codec, aborting\n");
                goto err_out;
        }
        
        mdelay(10);
        
        if (ac97_probe_codec (card->ac97) == 0) {
                printk (KERN_ERR PFX "unable to probe AC97 codec, aborting\n");
                rc = -EIO;
                goto err_out;
        }

        /* enable variable rate */
        tmp16 = via_ac97_read_reg (card->ac97, AC97_EXTENDED_STATUS);
        via_ac97_write_reg (card->ac97, AC97_EXTENDED_STATUS, tmp16 | 1);

        /*
         * If we cannot enable VRA, we have a locked-rate codec.
         * We try again to enable VRA before assuming so, however.
         */
        tmp16 = via_ac97_read_reg (card->ac97, AC97_EXTENDED_STATUS);
        if ((tmp16 & 1) == 0) {
                via_ac97_write_reg (card->ac97, AC97_EXTENDED_STATUS, tmp16 | 1);
                tmp16 = via_ac97_read_reg (card->ac97, AC97_EXTENDED_STATUS);
                if ((tmp16 & 1) == 0) {
                        card->locked_rate = 1;
                        printk (KERN_WARNING PFX "Codec rate locked at 48Khz\n");
                }
        }

        DPRINTK ("EXIT, returning 0\n");
        return 0;

err_out:
        unregister_sound_mixer (card->ac97->dev_mixer);
        DPRINTK ("EXIT, returning %d\n", rc);
        ac97_release_codec(card->ac97);
        return rc;
}


static void via_ac97_cleanup (struct via_info *card)
{
        DPRINTK ("ENTER\n");

        assert (card != NULL);
        assert (card->ac97->dev_mixer >= 0);

        unregister_sound_mixer (card->ac97->dev_mixer);
        ac97_release_codec(card->ac97);

        DPRINTK ("EXIT\n");
}



/****************************************************************
 *
 * Interrupt-related code
 *
 */

/**
 *      via_intr_channel - handle an interrupt for a single channel
 *      @chan: handle interrupt for this channel
 *
 *      This is the "meat" of the interrupt handler,
 *      containing the actions taken each time an interrupt
 *      occurs.  All communication and coordination with
 *      userspace takes place here.
 *
 *      Locking: inside card->lock
 */

static void via_intr_channel (struct via_info *card, struct via_channel *chan)
{
        u8 status;
        int n;
        
        /* check pertinent bits of status register for action bits */
        status = inb (chan->iobase) & (VIA_SGD_FLAG | VIA_SGD_EOL | VIA_SGD_STOPPED);
        if (!status)
                return;

        /* acknowledge any flagged bits ASAP */
        outb (status, chan->iobase);

        if (!chan->sgtable) /* XXX: temporary solution */
                return;

        /* grab current h/w ptr value */
        n = atomic_read (&chan->hw_ptr);

        /* sanity check: make sure our h/w ptr doesn't have a weird value */
        assert (n >= 0);
        assert (n < chan->frag_number);

        
        /* reset SGD data structure in memory to reflect a full buffer,
         * and advance the h/w ptr, wrapping around to zero if needed
         */
        if (n == (chan->frag_number - 1)) {
                chan->sgtable[n].count = cpu_to_le32(chan->frag_size | VIA_EOL);
                atomic_set (&chan->hw_ptr, 0);
        } else {
                chan->sgtable[n].count = cpu_to_le32(chan->frag_size | VIA_FLAG);
                atomic_inc (&chan->hw_ptr);
        }

        /* accounting crap for SNDCTL_DSP_GETxPTR */
        chan->n_irqs++;
        chan->bytes += chan->frag_size;
        /* FIXME - signed overflow is undefined */
        if (chan->bytes < 0) /* handle overflow of 31-bit value */
                chan->bytes = chan->frag_size;
        /* all following checks only occur when not in mmap(2) mode */
        if (!chan->is_mapped)
        {
                /* If we are recording, then n_frags represents the number
                 * of fragments waiting to be handled by userspace.
                 * If we are playback, then n_frags represents the number
                 * of fragments remaining to be filled by userspace.
                 * We increment here.  If we reach max number of fragments,
                 * this indicates an underrun/overrun.  For this case under OSS,
                 * we stop the record/playback process.
                 */
                if (atomic_read (&chan->n_frags) < chan->frag_number)
                        atomic_inc (&chan->n_frags);
                assert (atomic_read (&chan->n_frags) <= chan->frag_number);
                if (atomic_read (&chan->n_frags) == chan->frag_number) {
                        chan->is_active = 0;
                        via_chan_stop (chan->iobase);
                }
        }
        /* wake up anyone listening to see when interrupts occur */
        wake_up_all (&chan->wait);

        DPRINTK ("%s intr, status=0x%02X, hwptr=0x%lX, chan->hw_ptr=%d\n",
                 chan->name, status, (long) inl (chan->iobase + 0x04),
                 atomic_read (&chan->hw_ptr));

        DPRINTK ("%s intr, channel n_frags == %d, missed %d\n", chan->name,
                 atomic_read (&chan->n_frags), missed);
}


static void via_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        struct via_info *card = dev_id;
        u32 status32;

        /* to minimize interrupt sharing costs, we use the SGD status
         * shadow register to check the status of all inputs and
         * outputs with a single 32-bit bus read.  If no interrupt
         * conditions are flagged, we exit immediately
         */
        status32 = inl (card->baseaddr + VIA_BASE0_SGD_STATUS_SHADOW);
        if (!(status32 & VIA_INTR_MASK))
        {
#ifdef CONFIG_MIDI_VIA82CXXX
                 if (card->midi_devc)
                        uart401intr(irq, card->midi_devc, regs);
#endif
                return;
        }
        DPRINTK ("intr, status32 == 0x%08X\n", status32);

        /* synchronize interrupt handling under SMP.  this spinlock
         * goes away completely on UP
         */
        spin_lock (&card->lock);

        if (status32 & VIA_INTR_OUT)
                via_intr_channel (card, &card->ch_out);
        if (status32 & VIA_INTR_IN)
                via_intr_channel (card, &card->ch_in);
        if (status32 & VIA_INTR_FM)
                via_intr_channel (card, &card->ch_fm);

        spin_unlock (&card->lock);
}

static void via_new_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        struct via_info *card = dev_id;
        u32 status32;

        /* to minimize interrupt sharing costs, we use the SGD status
         * shadow register to check the status of all inputs and
         * outputs with a single 32-bit bus read.  If no interrupt
         * conditions are flagged, we exit immediately
         */
        status32 = inl (card->baseaddr + VIA_BASE0_SGD_STATUS_SHADOW);
        if (!(status32 & VIA_NEW_INTR_MASK))
                return;
        /*
         * goes away completely on UP
         */
        spin_lock (&card->lock);

        via_intr_channel (card, &card->ch_out);
        via_intr_channel (card, &card->ch_in);
        via_intr_channel (card, &card->ch_fm);

        spin_unlock (&card->lock);
}


/**
 *      via_interrupt_init - Initialize interrupt handling
 *      @card: Private info for specified board
 *
 *      Obtain and reserve IRQ for using in handling audio events.
 *      Also, disable any IRQ-generating resources, to make sure
 *      we don't get interrupts before we want them.
 */

static int via_interrupt_init (struct via_info *card)
{
        u8 tmp8;

        DPRINTK ("ENTER\n");

        assert (card != NULL);
        assert (card->pdev != NULL);

        /* check for sane IRQ number. can this ever happen? */
        if (card->pdev->irq < 2) {
                printk (KERN_ERR PFX "insane IRQ %d, aborting\n",
                        card->pdev->irq);
                DPRINTK ("EXIT, returning -EIO\n");
                return -EIO;
        }

        /* VIA requires this is done */
        pci_write_config_byte(card->pdev, PCI_INTERRUPT_LINE, card->pdev->irq);
        
        if(card->legacy)
        {
                /* make sure FM irq is not routed to us */
                pci_read_config_byte (card->pdev, VIA_FM_NMI_CTRL, &tmp8);
                if ((tmp8 & VIA_CR48_FM_TRAP_TO_NMI) == 0) {
                        tmp8 |= VIA_CR48_FM_TRAP_TO_NMI;
                        pci_write_config_byte (card->pdev, VIA_FM_NMI_CTRL, tmp8);
                }
                if (request_irq (card->pdev->irq, via_interrupt, SA_SHIRQ, VIA_MODULE_NAME, card)) {
                        printk (KERN_ERR PFX "unable to obtain IRQ %d, aborting\n",
                                card->pdev->irq);
                        DPRINTK ("EXIT, returning -EBUSY\n");
                        return -EBUSY;
                }
        }
        else 
        {
                if (request_irq (card->pdev->irq, via_new_interrupt, SA_SHIRQ, VIA_MODULE_NAME, card)) {
                        printk (KERN_ERR PFX "unable to obtain IRQ %d, aborting\n",
                                card->pdev->irq);
                        DPRINTK ("EXIT, returning -EBUSY\n");
                        return -EBUSY;
                }
        }

        DPRINTK ("EXIT, returning 0\n");
        return 0;
}


/****************************************************************
 *
 * OSS DSP device
 *
 */

static struct file_operations via_dsp_fops = {
        owner:          THIS_MODULE,
        open:           via_dsp_open,
        release:        via_dsp_release,
        read:           via_dsp_read,
        write:          via_dsp_write,
        poll:           via_dsp_poll,
        llseek:         no_llseek,
        ioctl:          via_dsp_ioctl,
        mmap:           via_dsp_mmap,
};


static int __init via_dsp_init (struct via_info *card)
{
        u8 tmp8;

        DPRINTK ("ENTER\n");

        assert (card != NULL);

        if(card->legacy)
        {
                /* turn off legacy features, if not already */
                pci_read_config_byte (card->pdev, VIA_FUNC_ENABLE, &tmp8);
                if (tmp8 & (VIA_CR42_SB_ENABLE |  VIA_CR42_FM_ENABLE)) {
                        tmp8 &= ~(VIA_CR42_SB_ENABLE | VIA_CR42_FM_ENABLE);
                        pci_write_config_byte (card->pdev, VIA_FUNC_ENABLE, tmp8);
                }
        }

        via_stop_everything (card);

        card->dev_dsp = register_sound_dsp (&via_dsp_fops, -1);
        if (card->dev_dsp < 0) {
                DPRINTK ("EXIT, returning -ENODEV\n");
                return -ENODEV;
        }
        DPRINTK ("EXIT, returning 0\n");
        return 0;
}


static void via_dsp_cleanup (struct via_info *card)
{
        DPRINTK ("ENTER\n");

        assert (card != NULL);
        assert (card->dev_dsp >= 0);

        via_stop_everything (card);

        unregister_sound_dsp (card->dev_dsp);

        DPRINTK ("EXIT\n");
}


static struct page * via_mm_nopage (struct vm_area_struct * vma,
                                    unsigned long address, int write_access)
{
        struct via_info *card = vma->vm_private_data;
        struct via_channel *chan = &card->ch_out;
        struct page *dmapage;
        unsigned long pgoff;
        int rd, wr;

        DPRINTK ("ENTER, start %lXh, ofs %lXh, pgoff %ld, addr %lXh, wr %d\n",
                 vma->vm_start,
                 address - vma->vm_start,
                 (address - vma->vm_start) >> PAGE_SHIFT,
                 address,
                 write_access);

        if (address > vma->vm_end) {
                DPRINTK ("EXIT, returning NOPAGE_SIGBUS\n");
                return NOPAGE_SIGBUS; /* Disallow mremap */
        }
        if (!card) {
                DPRINTK ("EXIT, returning NOPAGE_OOM\n");
                return NOPAGE_OOM;      /* Nothing allocated */
        }

        pgoff = vma->vm_pgoff + ((address - vma->vm_start) >> PAGE_SHIFT);
        rd = card->ch_in.is_mapped;
        wr = card->ch_out.is_mapped;

#ifndef VIA_NDEBUG
        {
        unsigned long max_bufs = chan->frag_number;
        if (rd && wr) max_bufs *= 2;
        /* via_dsp_mmap() should ensure this */
        assert (pgoff < max_bufs);
        }
#endif

        /* if full-duplex (read+write) and we have two sets of bufs,
         * then the playback buffers come first, sez soundcard.c */
        if (pgoff >= chan->page_number) {
                pgoff -= chan->page_number;
                chan = &card->ch_in;
        } else if (!wr)
                chan = &card->ch_in;

        assert ((((unsigned long)chan->pgtbl[pgoff].cpuaddr) % PAGE_SIZE) == 0);

        dmapage = virt_to_page (chan->pgtbl[pgoff].cpuaddr);
        DPRINTK ("EXIT, returning page %p for cpuaddr %lXh\n",
                 dmapage, (unsigned long) chan->pgtbl[pgoff].cpuaddr);
        get_page (dmapage);
        return dmapage;
}


#ifndef VM_RESERVED
static int via_mm_swapout (struct page *page, struct file *filp)
{
        return 0;
}
#endif /* VM_RESERVED */


struct vm_operations_struct via_mm_ops = {
        nopage:         via_mm_nopage,

#ifndef VM_RESERVED
        swapout:        via_mm_swapout,
#endif
};


static int via_dsp_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct via_info *card;
        int nonblock = (file->f_flags & O_NONBLOCK);
        int rc = -EINVAL, rd=0, wr=0;
        unsigned long max_size, size, start, offset;

        assert (file != NULL);
        assert (vma != NULL);
        card = file->private_data;
        assert (card != NULL);

        DPRINTK ("ENTER, start %lXh, size %ld, pgoff %ld\n",
                 vma->vm_start,
                 vma->vm_end - vma->vm_start,
                 vma->vm_pgoff);

        max_size = 0;
        if (vma->vm_flags & VM_READ) {
                rd = 1;
                via_chan_set_buffering(card, &card->ch_in, -1);
                via_chan_buffer_init (card, &card->ch_in);
                max_size += card->ch_in.page_number << PAGE_SHIFT;
        }
        if (vma->vm_flags & VM_WRITE) {
                wr = 1;
                via_chan_set_buffering(card, &card->ch_out, -1);
                via_chan_buffer_init (card, &card->ch_out);
                max_size += card->ch_out.page_number << PAGE_SHIFT;
        }

        start = vma->vm_start;
        offset = (vma->vm_pgoff << PAGE_SHIFT);
        size = vma->vm_end - vma->vm_start;

        /* some basic size/offset sanity checks */
        if (size > max_size)
                goto out;
        if (offset > max_size - size)
                goto out;

        rc = via_syscall_down (card, nonblock);
        if (rc) goto out;

        vma->vm_ops = &via_mm_ops;
        vma->vm_private_data = card;

#ifdef VM_RESERVED
        vma->vm_flags |= VM_RESERVED;
#endif

        if (rd)
                card->ch_in.is_mapped = 1;
        if (wr)
                card->ch_out.is_mapped = 1;

        up (&card->syscall_sem);
        rc = 0;

out:
        DPRINTK ("EXIT, returning %d\n", rc);
        return rc;
}


static ssize_t via_dsp_do_read (struct via_info *card,
                                char *userbuf, size_t count,
                                int nonblock)
{
        DECLARE_WAITQUEUE(wait, current);
        const char *orig_userbuf = userbuf;
        struct via_channel *chan = &card->ch_in;
        size_t size;
        int n, tmp;
        ssize_t ret = 0;

        /* if SGD has not yet been started, start it */
        via_chan_maybe_start (chan);

handle_one_block:
        /* just to be a nice neighbor */
        /* Thomas Sailer:
         * But also to ourselves, release semaphore if we do so */
        if (current->need_resched) {
                up(&card->syscall_sem);
                schedule ();
                ret = via_syscall_down (card, nonblock);
                if (ret)
                        goto out;
        }

        /* grab current channel software pointer.  In the case of
         * recording, this is pointing to the next buffer that
         * will receive data from the audio hardware.
         */
        n = chan->sw_ptr;

        /* n_frags represents the number of fragments waiting
         * to be copied to userland.  sleep until at least
         * one buffer has been read from the audio hardware.
         */
        add_wait_queue(&chan->wait, &wait);
        for (;;) {
                __set_current_state(TASK_INTERRUPTIBLE);
                tmp = atomic_read (&chan->n_frags);
                assert (tmp >= 0);
                assert (tmp <= chan->frag_number);
                if (tmp)
                        break;
                if (nonblock || !chan->is_active) {
                        ret = -EAGAIN;
                        break;
                }

                up(&card->syscall_sem);

                DPRINTK ("Sleeping on block %d\n", n);
                schedule();

                ret = via_syscall_down (card, nonblock);
                if (ret)
                        break;

                if (signal_pending (current)) {
                        ret = -ERESTARTSYS;
                        break;
                }
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&chan->wait, &wait);
        if (ret)
                goto out;

        /* Now that we have a buffer we can read from, send
         * as much as sample data possible to userspace.
         */
        while ((count > 0) && (chan->slop_len < chan->frag_size)) {
                size_t slop_left = chan->frag_size - chan->slop_len;
                void *base = chan->pgtbl[n / (PAGE_SIZE / chan->frag_size)].cpuaddr;
                unsigned ofs = (n % (PAGE_SIZE / chan->frag_size)) * chan->frag_size;

                size = (count < slop_left) ? count : slop_left;
                if (copy_to_user (userbuf,
                                  base + ofs + chan->slop_len,
                                  size)) {
                        ret = -EFAULT;
                        goto out;
                }

                count -= size;
                chan->slop_len += size;
                userbuf += size;
        }

        /* If we didn't copy the buffer completely to userspace,
         * stop now.
         */
        if (chan->slop_len < chan->frag_size)
                goto out;

        /*
         * If we get to this point, we copied one buffer completely
         * to userspace, give the buffer back to the hardware.
         */

        /* advance channel software pointer to point to
         * the next buffer from which we will copy
         */
        if (chan->sw_ptr == (chan->frag_number - 1))
                chan->sw_ptr = 0;
        else
                chan->sw_ptr++;

        /* mark one less buffer waiting to be processed */
        assert (atomic_read (&chan->n_frags) > 0);
        atomic_dec (&chan->n_frags);

        /* we are at a block boundary, there is no fragment data */
        chan->slop_len = 0;

        DPRINTK ("Flushed block %u, sw_ptr now %u, n_frags now %d\n",
                n, chan->sw_ptr, atomic_read (&chan->n_frags));

        DPRINTK ("regs==%02X %02X %02X %08X %08X %08X %08X\n",
                 inb (card->baseaddr + 0x00),
                 inb (card->baseaddr + 0x01),
                 inb (card->baseaddr + 0x02),
                 inl (card->baseaddr + 0x04),
                 inl (card->baseaddr + 0x0C),
                 inl (card->baseaddr + 0x80),
                 inl (card->baseaddr + 0x84));

        if (count > 0)
                goto handle_one_block;

out:
        return (userbuf != orig_userbuf) ? (userbuf - orig_userbuf) : ret;
}


static ssize_t via_dsp_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
{
        struct via_info *card;
        int nonblock = (file->f_flags & O_NONBLOCK);
        int rc;

        DPRINTK ("ENTER, file=%p, buffer=%p, count=%u, ppos=%lu\n",
                 file, buffer, count, ppos ? ((unsigned long)*ppos) : 0);

        assert (file != NULL);
        card = file->private_data;
        assert (card != NULL);

        if (ppos != &file->f_pos) {
                DPRINTK ("EXIT, returning -ESPIPE\n");
                return -ESPIPE;
        }

        rc = via_syscall_down (card, nonblock);
        if (rc) goto out;

        if (card->ch_in.is_mapped) {
                rc = -ENXIO;
                goto out_up;
        }

        via_chan_set_buffering(card, &card->ch_in, -1);
        rc = via_chan_buffer_init (card, &card->ch_in);

        if (rc)
                goto out_up;

        rc = via_dsp_do_read (card, buffer, count, nonblock);

out_up:
        up (&card->syscall_sem);
out:
        DPRINTK ("EXIT, returning %ld\n",(long) rc);
        return rc;
}


static ssize_t via_dsp_do_write (struct via_info *card,
                                 const char *userbuf, size_t count,
                                 int nonblock)
{
        DECLARE_WAITQUEUE(wait, current);
        const char *orig_userbuf = userbuf;
        struct via_channel *chan = &card->ch_out;
        volatile struct via_sgd_table *sgtable = chan->sgtable;
        size_t size;
        int n, tmp;
        ssize_t ret = 0;

handle_one_block:
        /* just to be a nice neighbor */
        /* Thomas Sailer:
         * But also to ourselves, release semaphore if we do so */
        if (current->need_resched) {
                up(&card->syscall_sem);
                schedule ();
                ret = via_syscall_down (card, nonblock);
                if (ret)
                        goto out;
        }

        /* grab current channel fragment pointer.  In the case of
         * playback, this is pointing to the next fragment that
         * should receive data from userland.
         */
        n = chan->sw_ptr;

        /* n_frags represents the number of fragments remaining
         * to be filled by userspace.  Sleep until
         * at least one fragment is available for our use.
         */
        add_wait_queue(&chan->wait, &wait);
        for (;;) {
                __set_current_state(TASK_INTERRUPTIBLE);
                tmp = atomic_read (&chan->n_frags);
                assert (tmp >= 0);
                assert (tmp <= chan->frag_number);
                if (tmp)
                        break;
                if (nonblock || !chan->is_active) {
                        ret = -EAGAIN;
                        break;
                }

                up(&card->syscall_sem);

                DPRINTK ("Sleeping on page %d, tmp==%d, ir==%d\n", n, tmp, chan->is_record);
                schedule();

                ret = via_syscall_down (card, nonblock);
                if (ret)
                        break;

                if (signal_pending (current)) {
                        ret = -ERESTARTSYS;
                        break;
                }
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&chan->wait, &wait);
        if (ret)
                goto out;

        /* Now that we have at least one fragment we can write to, fill the buffer
         * as much as possible with data from userspace.
         */
        while ((count > 0) && (chan->slop_len < chan->frag_size)) {
                size_t slop_left = chan->frag_size - chan->slop_len;

                size = (count < slop_left) ? count : slop_left;
                if (copy_from_user (chan->pgtbl[n / (PAGE_SIZE / chan->frag_size)].cpuaddr + (n % (PAGE_SIZE / chan->frag_size)) * chan->frag_size + chan->slop_len,
                                    userbuf, size)) {
                        ret = -EFAULT;
                        goto out;
                }

                count -= size;
                chan->slop_len += size;
                userbuf += size;
        }

        /* If we didn't fill up the buffer with data, stop now.
         * Put a 'stop' marker in the DMA table too, to tell the
         * audio hardware to stop if it gets here.
         */
        if (chan->slop_len < chan->frag_size) {
                sgtable[n].count = cpu_to_le32 (chan->slop_len | VIA_EOL | VIA_STOP);
                goto out;
        }

        /*
         * If we get to this point, we have filled a buffer with
         * audio data, flush the buffer to audio hardware.
         */

        /* Record the true size for the audio hardware to notice */
        if (n == (chan->frag_number - 1))
                sgtable[n].count = cpu_to_le32 (chan->frag_size | VIA_EOL);
        else
                sgtable[n].count = cpu_to_le32 (chan->frag_size | VIA_FLAG);

        /* advance channel software pointer to point to
         * the next buffer we will fill with data
         */
        if (chan->sw_ptr == (chan->frag_number - 1))
                chan->sw_ptr = 0;
        else
                chan->sw_ptr++;

        /* mark one less buffer as being available for userspace consumption */
        assert (atomic_read (&chan->n_frags) > 0);
        atomic_dec (&chan->n_frags);

        /* we are at a block boundary, there is no fragment data */
        chan->slop_len = 0;

        /* if SGD has not yet been started, start it */
        via_chan_maybe_start (chan);

        DPRINTK ("Flushed block %u, sw_ptr now %u, n_frags now %d\n",
                n, chan->sw_ptr, atomic_read (&chan->n_frags));

        DPRINTK ("regs==S=%02X C=%02X TP=%02X BP=%08X RT=%08X SG=%08X CC=%08X SS=%08X\n",
                 inb (card->baseaddr + 0x00),
                 inb (card->baseaddr + 0x01),
                 inb (card->baseaddr + 0x02),
                 inl (card->baseaddr + 0x04),
                 inl (card->baseaddr + 0x08),
                 inl (card->baseaddr + 0x0C),
                 inl (card->baseaddr + 0x80),
                 inl (card->baseaddr + 0x84));

        if (count > 0)
                goto handle_one_block;

out:
        if (userbuf - orig_userbuf)
                return userbuf - orig_userbuf;
        else
                return ret;
}


static ssize_t via_dsp_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
{
        struct via_info *card;
        ssize_t rc;
        int nonblock = (file->f_flags & O_NONBLOCK);

        DPRINTK ("ENTER, file=%p, buffer=%p, count=%u, ppos=%lu\n",
                 file, buffer, count, ppos ? ((unsigned long)*ppos) : 0);

        assert (file != NULL);
        card = file->private_data;
        assert (card != NULL);

        if (ppos != &file->f_pos) {
                DPRINTK ("EXIT, returning -ESPIPE\n");
                return -ESPIPE;
        }

        rc = via_syscall_down (card, nonblock);
        if (rc) goto out;

        if (card->ch_out.is_mapped) {
                rc = -ENXIO;
                goto out_up;
        }

        via_chan_set_buffering(card, &card->ch_out, -1);
        rc = via_chan_buffer_init (card, &card->ch_out);

        if (rc)
                goto out_up;

        rc = via_dsp_do_write (card, buffer, count, nonblock);

out_up:
        up (&card->syscall_sem);
out:
        DPRINTK ("EXIT, returning %ld\n",(long) rc);
        return rc;
}


static unsigned int via_dsp_poll(struct file *file, struct poll_table_struct *wait)
{
        struct via_info *card;
        struct via_channel *chan;
        unsigned int mask = 0;

        DPRINTK ("ENTER\n");

        assert (file != NULL);
        card = file->private_data;
        assert (card != NULL);

        if (file->f_mode & FMODE_READ) {
                chan = &card->ch_in;
                if (sg_active (chan->iobase))
                        poll_wait(file, &chan->wait, wait);
                if (atomic_read (&chan->n_frags) > 0)
                        mask |= POLLIN | POLLRDNORM;
        }

        if (file->f_mode & FMODE_WRITE) {
                chan = &card->ch_out;
                if (sg_active (chan->iobase))
                        poll_wait(file, &chan->wait, wait);
                if (atomic_read (&chan->n_frags) > 0)
                        mask |= POLLOUT | POLLWRNORM;
        }

        DPRINTK ("EXIT, returning %u\n", mask);
        return mask;
}


/**
 *      via_dsp_drain_playback - sleep until all playback samples are flushed
 *      @card: Private info for specified board
 *      @chan: Channel to drain
 *      @nonblock: boolean, non-zero if O_NONBLOCK is set
 *
 *      Sleeps until all playback has been flushed to the audio
 *      hardware.
 *
 *      Locking: inside card->syscall_sem
 */

static int via_dsp_drain_playback (struct via_info *card,
                                   struct via_channel *chan, int nonblock)
{
        DECLARE_WAITQUEUE(wait, current);
        int ret = 0;

        DPRINTK ("ENTER, nonblock = %d\n", nonblock);

        if (chan->slop_len > 0)
                via_chan_flush_frag (chan);

        if (atomic_read (&chan->n_frags) == chan->frag_number)
                goto out;

        via_chan_maybe_start (chan);

        add_wait_queue(&chan->wait, &wait);
        for (;;) {
                DPRINTK ("FRAGS %d FRAGNUM %d\n", atomic_read(&chan->n_frags), chan->frag_number);
                __set_current_state(TASK_INTERRUPTIBLE);
                if (atomic_read (&chan->n_frags) >= chan->frag_number)
                        break;

                if (nonblock) {
                        DPRINTK ("EXIT, returning -EAGAIN\n");
                        ret = -EAGAIN;
                        break;
                }

#ifdef VIA_DEBUG
                {
                u8 r40,r41,r42,r43,r44,r48;
                pci_read_config_byte (card->pdev, 0x40, &r40);
                pci_read_config_byte (card->pdev, 0x41, &r41);
                pci_read_config_byte (card->pdev, 0x42, &r42);
                pci_read_config_byte (card->pdev, 0x43, &r43);
                pci_read_config_byte (card->pdev, 0x44, &r44);
                pci_read_config_byte (card->pdev, 0x48, &r48);
                DPRINTK ("PCI config: %02X %02X %02X %02X %02X %02X\n",
                        r40,r41,r42,r43,r44,r48);

                DPRINTK ("regs==%02X %02X %02X %08X %08X %08X %08X\n",
                         inb (card->baseaddr + 0x00),
                         inb (card->baseaddr + 0x01),
                         inb (card->baseaddr + 0x02),
                         inl (card->baseaddr + 0x04),
                         inl (card->baseaddr + 0x0C),
                         inl (card->baseaddr + 0x80),
                         inl (card->baseaddr + 0x84));
                }

                if (!chan->is_active)
                        printk (KERN_ERR "sleeping but not active\n");
#endif

                up(&card->syscall_sem);

                DPRINTK ("sleeping, nbufs=%d\n", atomic_read (&chan->n_frags));
                schedule();

                if ((ret = via_syscall_down (card, nonblock)))
                        break;

                if (signal_pending (current)) {
                        DPRINTK ("EXIT, returning -ERESTARTSYS\n");
                        ret = -ERESTARTSYS;
                        break;
                }
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&chan->wait, &wait);

#ifdef VIA_DEBUG
        {
                u8 r40,r41,r42,r43,r44,r48;
                pci_read_config_byte (card->pdev, 0x40, &r40);
                pci_read_config_byte (card->pdev, 0x41, &r41);
                pci_read_config_byte (card->pdev, 0x42, &r42);
                pci_read_config_byte (card->pdev, 0x43, &r43);
                pci_read_config_byte (card->pdev, 0x44, &r44);
                pci_read_config_byte (card->pdev, 0x48, &r48);
                DPRINTK ("PCI config: %02X %02X %02X %02X %02X %02X\n",
                        r40,r41,r42,r43,r44,r48);

                DPRINTK ("regs==%02X %02X %02X %08X %08X %08X %08X\n",
                         inb (card->baseaddr + 0x00),
                         inb (card->baseaddr + 0x01),
                         inb (card->baseaddr + 0x02),
                         inl (card->baseaddr + 0x04),
                         inl (card->baseaddr + 0x0C),
                         inl (card->baseaddr + 0x80),
                         inl (card->baseaddr + 0x84));

                DPRINTK ("final nbufs=%d\n", atomic_read (&chan->n_frags));
        }
#endif

out:
        DPRINTK ("EXIT, returning %d\n", ret);
        return ret;
}


/**
 *      via_dsp_ioctl_space - get information about channel buffering
 *      @card: Private info for specified board
 *      @chan: pointer to channel-specific info
 *      @arg: user buffer for returned information
 *
 *      Handles SNDCTL_DSP_GETISPACE and SNDCTL_DSP_GETOSPACE.
 *
 *      Locking: inside card->syscall_sem
 */

static int via_dsp_ioctl_space (struct via_info *card,
                                struct via_channel *chan,
                                void *arg)
{
        audio_buf_info info;

        via_chan_set_buffering(card, chan, -1);

        info.fragstotal = chan->frag_number;
        info.fragsize = chan->frag_size;

        /* number of full fragments we can read/write without blocking */
        info.fragments = atomic_read (&chan->n_frags);

        if ((chan->slop_len % chan->frag_size > 0) && (info.fragments > 0))
                info.fragments--;

        /* number of bytes that can be read or written immediately
         * without blocking.
         */
        info.bytes = (info.fragments * chan->frag_size);
        if (chan->slop_len % chan->frag_size > 0)
                info.bytes += chan->frag_size - (chan->slop_len % chan->frag_size);

        DPRINTK ("EXIT, returning fragstotal=%d, fragsize=%d, fragments=%d, bytes=%d\n",
                info.fragstotal,
                info.fragsize,
                info.fragments,
                info.bytes);

        return copy_to_user (arg, &info, sizeof (info))?-EFAULT:0;
}


/**
 *      via_dsp_ioctl_ptr - get information about hardware buffer ptr
 *      @card: Private info for specified board
 *      @chan: pointer to channel-specific info
 *      @arg: user buffer for returned information
 *
 *      Handles SNDCTL_DSP_GETIPTR and SNDCTL_DSP_GETOPTR.
 *
 *      Locking: inside card->syscall_sem
 */

static int via_dsp_ioctl_ptr (struct via_info *card,
                                struct via_channel *chan,
                                void *arg)
{
        count_info info;

        spin_lock_irq (&card->lock);

        info.bytes = chan->bytes;
        info.blocks = chan->n_irqs;
        chan->n_irqs = 0;

        spin_unlock_irq (&card->lock);

        if (chan->is_active) {
                unsigned long extra;
                info.ptr = atomic_read (&chan->hw_ptr) * chan->frag_size;
                extra = chan->frag_size - via_sg_offset(chan);
                info.ptr += extra;
                info.bytes += extra;
        } else {
                info.ptr = 0;
        }

        DPRINTK ("EXIT, returning bytes=%d, blocks=%d, ptr=%d\n",
                info.bytes,
                info.blocks,
                info.ptr);

        return copy_to_user (arg, &info, sizeof (info))?-EFAULT:0;
}


static int via_dsp_ioctl_trigger (struct via_channel *chan, int val)
{
        int enable, do_something;

        if (chan->is_record)
                enable = (val & PCM_ENABLE_INPUT);
        else
                enable = (val & PCM_ENABLE_OUTPUT);

        if (!chan->is_enabled && enable) {
                do_something = 1;
        } else if (chan->is_enabled && !enable) {
                do_something = -1;
        } else {
                do_something = 0;
        }

        DPRINTK ("enable=%d, do_something=%d\n",
                 enable, do_something);

        if (chan->is_active && do_something)
                return -EINVAL;

        if (do_something == 1) {
                chan->is_enabled = 1;
                via_chan_maybe_start (chan);
                DPRINTK ("Triggering input\n");
        }

        else if (do_something == -1) {
                chan->is_enabled = 0;
                DPRINTK ("Setup input trigger\n");
        }

        return 0;
}


static int via_dsp_ioctl (struct inode *inode, struct file *file,
                          unsigned int cmd, unsigned long arg)
{
        int rc, rd=0, wr=0, val=0;
        struct via_info *card;
        struct via_channel *chan;
        int nonblock = (file->f_flags & O_NONBLOCK);

        assert (file != NULL);
        card = file->private_data;
        assert (card != NULL);

        if (file->f_mode & FMODE_WRITE)
                wr = 1;
        if (file->f_mode & FMODE_READ)
                rd = 1;

        rc = via_syscall_down (card, nonblock);
        if (rc)
                return rc;
        rc = -EINVAL;

        switch (cmd) {

        /* OSS API version.  XXX unverified */
        case OSS_GETVERSION:
                DPRINTK ("ioctl OSS_GETVERSION, EXIT, returning SOUND_VERSION\n");
                rc = put_user (SOUND_VERSION, (int *)arg);
                break;

        /* list of supported PCM data formats */
        case SNDCTL_DSP_GETFMTS:
                DPRINTK ("DSP_GETFMTS, EXIT, returning AFMT U8|S16_LE\n");
                rc = put_user (AFMT_U8 | AFMT_S16_LE, (int *)arg);
                break;

        /* query or set current channel's PCM data format */
        case SNDCTL_DSP_SETFMT:
                if (get_user(val, (int *)arg)) {
                        rc = -EFAULT;
                        break;
                }
                DPRINTK ("DSP_SETFMT, val==%d\n", val);
                if (val != AFMT_QUERY) {
                        rc = 0;

                        if (rd)
                                rc = via_chan_set_fmt (card, &card->ch_in, val);

                        if (rc >= 0 && wr)
                                rc = via_chan_set_fmt (card, &card->ch_out, val);

                        if (rc < 0)
                                break;

                        val = rc;
                } else {
                        if ((rd && (card->ch_in.pcm_fmt & VIA_PCM_FMT_16BIT)) ||
                            (wr && (card->ch_out.pcm_fmt & VIA_PCM_FMT_16BIT)))
                                val = AFMT_S16_LE;
                        else
                                val = AFMT_U8;
                }
                DPRINTK ("SETFMT EXIT, returning %d\n", val);
                rc = put_user (val, (int *)arg);
                break;

        /* query or set number of channels (1=mono, 2=stereo, 4/6 for multichannel) */
        case SNDCTL_DSP_CHANNELS:
                if (get_user(val, (int *)arg)) {
                        rc = -EFAULT;
                        break;
                }
                DPRINTK ("DSP_CHANNELS, val==%d\n", val);
                if (val != 0) {
                        rc = 0;

                        if (rd)
                                rc = via_chan_set_stereo (card, &card->ch_in, val);

                        if (rc >= 0 && wr)
                                rc = via_chan_set_stereo (card, &card->ch_out, val);

                        if (rc < 0)
                                break;

                        val = rc;
                } else {
                        if (rd)
                                val = card->ch_in.channels;
                        else
                                val = card->ch_out.channels;
                }
                DPRINTK ("CHANNELS EXIT, returning %d\n", val);
                rc = put_user (val, (int *)arg);
                break;

        /* enable (val is not zero) or disable (val == 0) stereo */
        case SNDCTL_DSP_STEREO:
                if (get_user(val, (int *)arg)) {
                        rc = -EFAULT;
                        break;
                }
                DPRINTK ("DSP_STEREO, val==%d\n", val);
                rc = 0;

                if (rd)
                        rc = via_chan_set_stereo (card, &card->ch_in, val ? 2 : 1);
                if (rc >= 0 && wr)
                        rc = via_chan_set_stereo (card, &card->ch_out, val ? 2 : 1);

                if (rc < 0)
                        break;