atiixp.c

Go to the documentation of this file.

/*
 *   ALSA driver for ATI IXP 150/200/250/300 AC97 controllers
 *
 *  Copyright (c) 2004 Takashi Iwai <[email protected]>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <asm/io.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/info.h>
#include <sound/ac97_codec.h>
#include <sound/initval.h>

MODULE_AUTHOR("Takashi Iwai <[email protected]>");
MODULE_DESCRIPTION("ATI IXP AC97 controller");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{ATI,IXP150/200/250/300/400/600}}");

static int index = SNDRV_DEFAULT_IDX1;  /* Index 0-MAX */
static char *id = SNDRV_DEFAULT_STR1;   /* ID for this card */
static int ac97_clock = 48000;
static char *ac97_quirk;
static bool spdif_aclink = 1;
static int ac97_codec = -1;

module_param(index, int, 0444);
MODULE_PARM_DESC(index, "Index value for ATI IXP controller.");
module_param(id, charp, 0444);
MODULE_PARM_DESC(id, "ID string for ATI IXP controller.");
module_param(ac97_clock, int, 0444);
MODULE_PARM_DESC(ac97_clock, "AC'97 codec clock (default 48000Hz).");
module_param(ac97_quirk, charp, 0444);
MODULE_PARM_DESC(ac97_quirk, "AC'97 workaround for strange hardware.");
module_param(ac97_codec, int, 0444);
MODULE_PARM_DESC(ac97_codec, "Specify codec instead of probing.");
module_param(spdif_aclink, bool, 0444);
MODULE_PARM_DESC(spdif_aclink, "S/PDIF over AC-link.");

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


/*
 */

#define ATI_REG_ISR         0x00    /* interrupt source */
#define  ATI_REG_ISR_IN_XRUN        (1U<<0)
#define  ATI_REG_ISR_IN_STATUS      (1U<<1)
#define  ATI_REG_ISR_OUT_XRUN       (1U<<2)
#define  ATI_REG_ISR_OUT_STATUS     (1U<<3)
#define  ATI_REG_ISR_SPDF_XRUN      (1U<<4)
#define  ATI_REG_ISR_SPDF_STATUS    (1U<<5)
#define  ATI_REG_ISR_PHYS_INTR      (1U<<8)
#define  ATI_REG_ISR_PHYS_MISMATCH  (1U<<9)
#define  ATI_REG_ISR_CODEC0_NOT_READY   (1U<<10)
#define  ATI_REG_ISR_CODEC1_NOT_READY   (1U<<11)
#define  ATI_REG_ISR_CODEC2_NOT_READY   (1U<<12)
#define  ATI_REG_ISR_NEW_FRAME      (1U<<13)

#define ATI_REG_IER         0x04    /* interrupt enable */
#define  ATI_REG_IER_IN_XRUN_EN     (1U<<0)
#define  ATI_REG_IER_IO_STATUS_EN   (1U<<1)
#define  ATI_REG_IER_OUT_XRUN_EN    (1U<<2)
#define  ATI_REG_IER_OUT_XRUN_COND  (1U<<3)
#define  ATI_REG_IER_SPDF_XRUN_EN   (1U<<4)
#define  ATI_REG_IER_SPDF_STATUS_EN (1U<<5)
#define  ATI_REG_IER_PHYS_INTR_EN   (1U<<8)
#define  ATI_REG_IER_PHYS_MISMATCH_EN   (1U<<9)
#define  ATI_REG_IER_CODEC0_INTR_EN (1U<<10)
#define  ATI_REG_IER_CODEC1_INTR_EN (1U<<11)
#define  ATI_REG_IER_CODEC2_INTR_EN (1U<<12)
#define  ATI_REG_IER_NEW_FRAME_EN   (1U<<13)    /* (RO */
#define  ATI_REG_IER_SET_BUS_BUSY   (1U<<14)    /* (WO) audio is running */

#define ATI_REG_CMD         0x08    /* command */
#define  ATI_REG_CMD_POWERDOWN      (1U<<0)
#define  ATI_REG_CMD_RECEIVE_EN     (1U<<1)
#define  ATI_REG_CMD_SEND_EN        (1U<<2)
#define  ATI_REG_CMD_STATUS_MEM     (1U<<3)
#define  ATI_REG_CMD_SPDF_OUT_EN    (1U<<4)
#define  ATI_REG_CMD_SPDF_STATUS_MEM    (1U<<5)
#define  ATI_REG_CMD_SPDF_THRESHOLD (3U<<6)
#define  ATI_REG_CMD_SPDF_THRESHOLD_SHIFT   6
#define  ATI_REG_CMD_IN_DMA_EN      (1U<<8)
#define  ATI_REG_CMD_OUT_DMA_EN     (1U<<9)
#define  ATI_REG_CMD_SPDF_DMA_EN    (1U<<10)
#define  ATI_REG_CMD_SPDF_OUT_STOPPED   (1U<<11)
#define  ATI_REG_CMD_SPDF_CONFIG_MASK   (7U<<12)
#define   ATI_REG_CMD_SPDF_CONFIG_34    (1U<<12)
#define   ATI_REG_CMD_SPDF_CONFIG_78    (2U<<12)
#define   ATI_REG_CMD_SPDF_CONFIG_69    (3U<<12)
#define   ATI_REG_CMD_SPDF_CONFIG_01    (4U<<12)
#define  ATI_REG_CMD_INTERLEAVE_SPDF    (1U<<16)
#define  ATI_REG_CMD_AUDIO_PRESENT  (1U<<20)
#define  ATI_REG_CMD_INTERLEAVE_IN  (1U<<21)
#define  ATI_REG_CMD_INTERLEAVE_OUT (1U<<22)
#define  ATI_REG_CMD_LOOPBACK_EN    (1U<<23)
#define  ATI_REG_CMD_PACKED_DIS     (1U<<24)
#define  ATI_REG_CMD_BURST_EN       (1U<<25)
#define  ATI_REG_CMD_PANIC_EN       (1U<<26)
#define  ATI_REG_CMD_MODEM_PRESENT  (1U<<27)
#define  ATI_REG_CMD_ACLINK_ACTIVE  (1U<<28)
#define  ATI_REG_CMD_AC_SOFT_RESET  (1U<<29)
#define  ATI_REG_CMD_AC_SYNC        (1U<<30)
#define  ATI_REG_CMD_AC_RESET       (1U<<31)

#define ATI_REG_PHYS_OUT_ADDR       0x0c
#define  ATI_REG_PHYS_OUT_CODEC_MASK    (3U<<0)
#define  ATI_REG_PHYS_OUT_RW        (1U<<2)
#define  ATI_REG_PHYS_OUT_ADDR_EN   (1U<<8)
#define  ATI_REG_PHYS_OUT_ADDR_SHIFT    9
#define  ATI_REG_PHYS_OUT_DATA_SHIFT    16

#define ATI_REG_PHYS_IN_ADDR        0x10
#define  ATI_REG_PHYS_IN_READ_FLAG  (1U<<8)
#define  ATI_REG_PHYS_IN_ADDR_SHIFT 9
#define  ATI_REG_PHYS_IN_DATA_SHIFT 16

#define ATI_REG_SLOTREQ         0x14

#define ATI_REG_COUNTER         0x18
#define  ATI_REG_COUNTER_SLOT       (3U<<0) /* slot # */
#define  ATI_REG_COUNTER_BITCLOCK   (31U<<8)

#define ATI_REG_IN_FIFO_THRESHOLD   0x1c

#define ATI_REG_IN_DMA_LINKPTR      0x20
#define ATI_REG_IN_DMA_DT_START     0x24    /* RO */
#define ATI_REG_IN_DMA_DT_NEXT      0x28    /* RO */
#define ATI_REG_IN_DMA_DT_CUR       0x2c    /* RO */
#define ATI_REG_IN_DMA_DT_SIZE      0x30

#define ATI_REG_OUT_DMA_SLOT        0x34
#define  ATI_REG_OUT_DMA_SLOT_BIT(x)    (1U << ((x) - 3))
#define  ATI_REG_OUT_DMA_SLOT_MASK  0x1ff
#define  ATI_REG_OUT_DMA_THRESHOLD_MASK 0xf800
#define  ATI_REG_OUT_DMA_THRESHOLD_SHIFT    11

#define ATI_REG_OUT_DMA_LINKPTR     0x38
#define ATI_REG_OUT_DMA_DT_START    0x3c    /* RO */
#define ATI_REG_OUT_DMA_DT_NEXT     0x40    /* RO */
#define ATI_REG_OUT_DMA_DT_CUR      0x44    /* RO */
#define ATI_REG_OUT_DMA_DT_SIZE     0x48

#define ATI_REG_SPDF_CMD        0x4c
#define  ATI_REG_SPDF_CMD_LFSR      (1U<<4)
#define  ATI_REG_SPDF_CMD_SINGLE_CH (1U<<5)
#define  ATI_REG_SPDF_CMD_LFSR_ACC  (0xff<<8)   /* RO */

#define ATI_REG_SPDF_DMA_LINKPTR    0x50
#define ATI_REG_SPDF_DMA_DT_START   0x54    /* RO */
#define ATI_REG_SPDF_DMA_DT_NEXT    0x58    /* RO */
#define ATI_REG_SPDF_DMA_DT_CUR     0x5c    /* RO */
#define ATI_REG_SPDF_DMA_DT_SIZE    0x60

#define ATI_REG_MODEM_MIRROR        0x7c
#define ATI_REG_AUDIO_MIRROR        0x80

#define ATI_REG_6CH_REORDER     0x84    /* reorder slots for 6ch */
#define  ATI_REG_6CH_REORDER_EN     (1U<<0) /* 3,4,7,8,6,9 -> 3,4,6,9,7,8 */

#define ATI_REG_FIFO_FLUSH      0x88
#define  ATI_REG_FIFO_OUT_FLUSH     (1U<<0)
#define  ATI_REG_FIFO_IN_FLUSH      (1U<<1)

/* LINKPTR */
#define  ATI_REG_LINKPTR_EN     (1U<<0)

/* [INT|OUT|SPDIF]_DMA_DT_SIZE */
#define  ATI_REG_DMA_DT_SIZE        (0xffffU<<0)
#define  ATI_REG_DMA_FIFO_USED      (0x1fU<<16)
#define  ATI_REG_DMA_FIFO_FREE      (0x1fU<<21)
#define  ATI_REG_DMA_STATE      (7U<<26)


#define ATI_MAX_DESCRIPTORS 256 /* max number of descriptor packets */


struct atiixp;

/*
 * DMA packate descriptor
 */

struct atiixp_dma_desc {
    u32 addr;   /* DMA buffer address */
    u16 status; /* status bits */
    u16 size;   /* size of the packet in dwords */
    u32 next;   /* address of the next packet descriptor */
};

/*
 * stream enum
 */
enum { ATI_DMA_PLAYBACK, ATI_DMA_CAPTURE, ATI_DMA_SPDIF, NUM_ATI_DMAS }; /* DMAs */
enum { ATI_PCM_OUT, ATI_PCM_IN, ATI_PCM_SPDIF, NUM_ATI_PCMS }; /* AC97 pcm slots */
enum { ATI_PCMDEV_ANALOG, ATI_PCMDEV_DIGITAL, NUM_ATI_PCMDEVS }; /* pcm devices */

#define NUM_ATI_CODECS  3


/*
 * constants and callbacks for each DMA type
 */
struct atiixp_dma_ops {
    int type;           /* ATI_DMA_XXX */
    unsigned int llp_offset;    /* LINKPTR offset */
    unsigned int dt_cur;        /* DT_CUR offset */
    /* called from open callback */
    void (*enable_dma)(struct atiixp *chip, int on);
    /* called from trigger (START/STOP) */
    void (*enable_transfer)(struct atiixp *chip, int on);
    /* called from trigger (STOP only) */
    void (*flush_dma)(struct atiixp *chip);
};

/*
 * DMA stream
 */
struct atiixp_dma {
    const struct atiixp_dma_ops *ops;
    struct snd_dma_buffer desc_buf;
    struct snd_pcm_substream *substream;    /* assigned PCM substream */
    unsigned int buf_addr, buf_bytes;   /* DMA buffer address, bytes */
    unsigned int period_bytes, periods;
    int opened;
    int running;
    int suspended;
    int pcm_open_flag;
    int ac97_pcm_type;  /* index # of ac97_pcm to access, -1 = not used */
    unsigned int saved_curptr;
};

/*
 * ATI IXP chip
 */
struct atiixp {
    struct snd_card *card;
    struct pci_dev *pci;

    unsigned long addr;
    void __iomem *remap_addr;
    int irq;
    
    struct snd_ac97_bus *ac97_bus;
    struct snd_ac97 *ac97[NUM_ATI_CODECS];

    spinlock_t reg_lock;

    struct atiixp_dma dmas[NUM_ATI_DMAS];
    struct ac97_pcm *pcms[NUM_ATI_PCMS];
    struct snd_pcm *pcmdevs[NUM_ATI_PCMDEVS];

    int max_channels;       /* max. channels for PCM out */

    unsigned int codec_not_ready_bits;  /* for codec detection */

    int spdif_over_aclink;      /* passed from the module option */
    struct mutex open_mutex;    /* playback open mutex */
};


/*
 */
static DEFINE_PCI_DEVICE_TABLE(snd_atiixp_ids) = {
    { PCI_VDEVICE(ATI, 0x4341), 0 }, /* SB200 */
    { PCI_VDEVICE(ATI, 0x4361), 0 }, /* SB300 */
    { PCI_VDEVICE(ATI, 0x4370), 0 }, /* SB400 */
    { PCI_VDEVICE(ATI, 0x4382), 0 }, /* SB600 */
    { 0, }
};

MODULE_DEVICE_TABLE(pci, snd_atiixp_ids);

static struct snd_pci_quirk atiixp_quirks[] __devinitdata = {
    SND_PCI_QUIRK(0x105b, 0x0c81, "Foxconn RC4107MA-RS2", 0),
    SND_PCI_QUIRK(0x15bd, 0x3100, "DFI RS482", 0),
    { } /* terminator */
};

/*
 * lowlevel functions
 */

/*
 * update the bits of the given register.
 * return 1 if the bits changed.
 */
static int snd_atiixp_update_bits(struct atiixp *chip, unsigned int reg,
                 unsigned int mask, unsigned int value)
{
    void __iomem *addr = chip->remap_addr + reg;
    unsigned int data, old_data;
    old_data = data = readl(addr);
    data &= ~mask;
    data |= value;
    if (old_data == data)
        return 0;
    writel(data, addr);
    return 1;
}

/*
 * macros for easy use
 */
#define atiixp_write(chip,reg,value) \
    writel(value, chip->remap_addr + ATI_REG_##reg)
#define atiixp_read(chip,reg) \
    readl(chip->remap_addr + ATI_REG_##reg)
#define atiixp_update(chip,reg,mask,val) \
    snd_atiixp_update_bits(chip, ATI_REG_##reg, mask, val)

/*
 * handling DMA packets
 *
 * we allocate a linear buffer for the DMA, and split it to  each packet.
 * in a future version, a scatter-gather buffer should be implemented.
 */

#define ATI_DESC_LIST_SIZE \
    PAGE_ALIGN(ATI_MAX_DESCRIPTORS * sizeof(struct atiixp_dma_desc))

/*
 * build packets ring for the given buffer size.
 *
 * IXP handles the buffer descriptors, which are connected as a linked
 * list.  although we can change the list dynamically, in this version,
 * a static RING of buffer descriptors is used.
 *
 * the ring is built in this function, and is set up to the hardware. 
 */
static int atiixp_build_dma_packets(struct atiixp *chip, struct atiixp_dma *dma,
                    struct snd_pcm_substream *substream,
                    unsigned int periods,
                    unsigned int period_bytes)
{
    unsigned int i;
    u32 addr, desc_addr;
    unsigned long flags;

    if (periods > ATI_MAX_DESCRIPTORS)
        return -ENOMEM;

    if (dma->desc_buf.area == NULL) {
        if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
                    snd_dma_pci_data(chip->pci),
                    ATI_DESC_LIST_SIZE,
                    &dma->desc_buf) < 0)
            return -ENOMEM;
        dma->period_bytes = dma->periods = 0; /* clear */
    }

    if (dma->periods == periods && dma->period_bytes == period_bytes)
        return 0;

    /* reset DMA before changing the descriptor table */
    spin_lock_irqsave(&chip->reg_lock, flags);
    writel(0, chip->remap_addr + dma->ops->llp_offset);
    dma->ops->enable_dma(chip, 0);
    dma->ops->enable_dma(chip, 1);
    spin_unlock_irqrestore(&chip->reg_lock, flags);

    /* fill the entries */
    addr = (u32)substream->runtime->dma_addr;
    desc_addr = (u32)dma->desc_buf.addr;
    for (i = 0; i < periods; i++) {
        struct atiixp_dma_desc *desc;
        desc = &((struct atiixp_dma_desc *)dma->desc_buf.area)[i];
        desc->addr = cpu_to_le32(addr);
        desc->status = 0;
        desc->size = period_bytes >> 2; /* in dwords */
        desc_addr += sizeof(struct atiixp_dma_desc);
        if (i == periods - 1)
            desc->next = cpu_to_le32((u32)dma->desc_buf.addr);
        else
            desc->next = cpu_to_le32(desc_addr);
        addr += period_bytes;
    }

    writel((u32)dma->desc_buf.addr | ATI_REG_LINKPTR_EN,
           chip->remap_addr + dma->ops->llp_offset);

    dma->period_bytes = period_bytes;
    dma->periods = periods;

    return 0;
}

/*
 * remove the ring buffer and release it if assigned
 */
static void atiixp_clear_dma_packets(struct atiixp *chip, struct atiixp_dma *dma,
                     struct snd_pcm_substream *substream)
{
    if (dma->desc_buf.area) {
        writel(0, chip->remap_addr + dma->ops->llp_offset);
        snd_dma_free_pages(&dma->desc_buf);
        dma->desc_buf.area = NULL;
    }
}

/*
 * AC97 interface
 */
static int snd_atiixp_acquire_codec(struct atiixp *chip)
{
    int timeout = 1000;

    while (atiixp_read(chip, PHYS_OUT_ADDR) & ATI_REG_PHYS_OUT_ADDR_EN) {
        if (! timeout--) {
            snd_printk(KERN_WARNING "atiixp: codec acquire timeout\n");
            return -EBUSY;
        }
        udelay(1);
    }
    return 0;
}

static unsigned short snd_atiixp_codec_read(struct atiixp *chip, unsigned short codec, unsigned short reg)
{
    unsigned int data;
    int timeout;

    if (snd_atiixp_acquire_codec(chip) < 0)
        return 0xffff;
    data = (reg << ATI_REG_PHYS_OUT_ADDR_SHIFT) |
        ATI_REG_PHYS_OUT_ADDR_EN |
        ATI_REG_PHYS_OUT_RW |
        codec;
    atiixp_write(chip, PHYS_OUT_ADDR, data);
    if (snd_atiixp_acquire_codec(chip) < 0)
        return 0xffff;
    timeout = 1000;
    do {
        data = atiixp_read(chip, PHYS_IN_ADDR);
        if (data & ATI_REG_PHYS_IN_READ_FLAG)
            return data >> ATI_REG_PHYS_IN_DATA_SHIFT;
        udelay(1);
    } while (--timeout);
    /* time out may happen during reset */
    if (reg < 0x7c)
        snd_printk(KERN_WARNING "atiixp: codec read timeout (reg %x)\n", reg);
    return 0xffff;
}


static void snd_atiixp_codec_write(struct atiixp *chip, unsigned short codec,
                   unsigned short reg, unsigned short val)
{
    unsigned int data;
    
    if (snd_atiixp_acquire_codec(chip) < 0)
        return;
    data = ((unsigned int)val << ATI_REG_PHYS_OUT_DATA_SHIFT) |
        ((unsigned int)reg << ATI_REG_PHYS_OUT_ADDR_SHIFT) |
        ATI_REG_PHYS_OUT_ADDR_EN | codec;
    atiixp_write(chip, PHYS_OUT_ADDR, data);
}


static unsigned short snd_atiixp_ac97_read(struct snd_ac97 *ac97,
                       unsigned short reg)
{
    struct atiixp *chip = ac97->private_data;
    return snd_atiixp_codec_read(chip, ac97->num, reg);
    
}

static void snd_atiixp_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
                  unsigned short val)
{
    struct atiixp *chip = ac97->private_data;
    snd_atiixp_codec_write(chip, ac97->num, reg, val);
}

/*
 * reset AC link
 */
static int snd_atiixp_aclink_reset(struct atiixp *chip)
{
    int timeout;

    /* reset powerdoewn */
    if (atiixp_update(chip, CMD, ATI_REG_CMD_POWERDOWN, 0))
        udelay(10);

    /* perform a software reset */
    atiixp_update(chip, CMD, ATI_REG_CMD_AC_SOFT_RESET, ATI_REG_CMD_AC_SOFT_RESET);
    atiixp_read(chip, CMD);
    udelay(10);
    atiixp_update(chip, CMD, ATI_REG_CMD_AC_SOFT_RESET, 0);
    
    timeout = 10;
    while (! (atiixp_read(chip, CMD) & ATI_REG_CMD_ACLINK_ACTIVE)) {
        /* do a hard reset */
        atiixp_update(chip, CMD, ATI_REG_CMD_AC_SYNC|ATI_REG_CMD_AC_RESET,
                  ATI_REG_CMD_AC_SYNC);
        atiixp_read(chip, CMD);
        mdelay(1);
        atiixp_update(chip, CMD, ATI_REG_CMD_AC_RESET, ATI_REG_CMD_AC_RESET);
        if (!--timeout) {
            snd_printk(KERN_ERR "atiixp: codec reset timeout\n");
            break;
        }
    }

    /* deassert RESET and assert SYNC to make sure */
    atiixp_update(chip, CMD, ATI_REG_CMD_AC_SYNC|ATI_REG_CMD_AC_RESET,
              ATI_REG_CMD_AC_SYNC|ATI_REG_CMD_AC_RESET);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int snd_atiixp_aclink_down(struct atiixp *chip)
{
    // if (atiixp_read(chip, MODEM_MIRROR) & 0x1) /* modem running, too? */
    //  return -EBUSY;
    atiixp_update(chip, CMD,
             ATI_REG_CMD_POWERDOWN | ATI_REG_CMD_AC_RESET,
             ATI_REG_CMD_POWERDOWN);
    return 0;
}
#endif

/*
 * auto-detection of codecs
 *
 * the IXP chip can generate interrupts for the non-existing codecs.
 * NEW_FRAME interrupt is used to make sure that the interrupt is generated
 * even if all three codecs are connected.
 */

#define ALL_CODEC_NOT_READY \
        (ATI_REG_ISR_CODEC0_NOT_READY |\
         ATI_REG_ISR_CODEC1_NOT_READY |\
         ATI_REG_ISR_CODEC2_NOT_READY)
#define CODEC_CHECK_BITS (ALL_CODEC_NOT_READY|ATI_REG_ISR_NEW_FRAME)

static int __devinit ac97_probing_bugs(struct pci_dev *pci)
{
    const struct snd_pci_quirk *q;

    q = snd_pci_quirk_lookup(pci, atiixp_quirks);
    if (q) {
        snd_printdd(KERN_INFO "Atiixp quirk for %s.  "
                "Forcing codec %d\n", q->name, q->value);
        return q->value;
    }
    /* this hardware doesn't need workarounds.  Probe for codec */
    return -1;
}

static int __devinit snd_atiixp_codec_detect(struct atiixp *chip)
{
    int timeout;

    chip->codec_not_ready_bits = 0;
    if (ac97_codec == -1)
        ac97_codec = ac97_probing_bugs(chip->pci);
    if (ac97_codec >= 0) {
        chip->codec_not_ready_bits |= 
            CODEC_CHECK_BITS ^ (1 << (ac97_codec + 10));
        return 0;
    }

    atiixp_write(chip, IER, CODEC_CHECK_BITS);
    /* wait for the interrupts */
    timeout = 50;
    while (timeout-- > 0) {
        mdelay(1);
        if (chip->codec_not_ready_bits)
            break;
    }
    atiixp_write(chip, IER, 0); /* disable irqs */

    if ((chip->codec_not_ready_bits & ALL_CODEC_NOT_READY) == ALL_CODEC_NOT_READY) {
        snd_printk(KERN_ERR "atiixp: no codec detected!\n");
        return -ENXIO;
    }
    return 0;
}


/*
 * enable DMA and irqs
 */
static int snd_atiixp_chip_start(struct atiixp *chip)
{
    unsigned int reg;

    /* set up spdif, enable burst mode */
    reg = atiixp_read(chip, CMD);
    reg |= 0x02 << ATI_REG_CMD_SPDF_THRESHOLD_SHIFT;
    reg |= ATI_REG_CMD_BURST_EN;
    atiixp_write(chip, CMD, reg);

    reg = atiixp_read(chip, SPDF_CMD);
    reg &= ~(ATI_REG_SPDF_CMD_LFSR|ATI_REG_SPDF_CMD_SINGLE_CH);
    atiixp_write(chip, SPDF_CMD, reg);

    /* clear all interrupt source */
    atiixp_write(chip, ISR, 0xffffffff);
    /* enable irqs */
    atiixp_write(chip, IER,
             ATI_REG_IER_IO_STATUS_EN |
             ATI_REG_IER_IN_XRUN_EN |
             ATI_REG_IER_OUT_XRUN_EN |
             ATI_REG_IER_SPDF_XRUN_EN |
             ATI_REG_IER_SPDF_STATUS_EN);
    return 0;
}


/*
 * disable DMA and IRQs
 */
static int snd_atiixp_chip_stop(struct atiixp *chip)
{
    /* clear interrupt source */
    atiixp_write(chip, ISR, atiixp_read(chip, ISR));
    /* disable irqs */
    atiixp_write(chip, IER, 0);
    return 0;
}


/*
 * PCM section
 */

/*
 * pointer callback simplly reads XXX_DMA_DT_CUR register as the current
 * position.  when SG-buffer is implemented, the offset must be calculated
 * correctly...
 */
static snd_pcm_uframes_t snd_atiixp_pcm_pointer(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct atiixp_dma *dma = runtime->private_data;
    unsigned int curptr;
    int timeout = 1000;

    while (timeout--) {
        curptr = readl(chip->remap_addr + dma->ops->dt_cur);
        if (curptr < dma->buf_addr)
            continue;
        curptr -= dma->buf_addr;
        if (curptr >= dma->buf_bytes)
            continue;
        return bytes_to_frames(runtime, curptr);
    }
    snd_printd("atiixp: invalid DMA pointer read 0x%x (buf=%x)\n",
           readl(chip->remap_addr + dma->ops->dt_cur), dma->buf_addr);
    return 0;
}

/*
 * XRUN detected, and stop the PCM substream
 */
static void snd_atiixp_xrun_dma(struct atiixp *chip, struct atiixp_dma *dma)
{
    if (! dma->substream || ! dma->running)
        return;
    snd_printdd("atiixp: XRUN detected (DMA %d)\n", dma->ops->type);
    snd_pcm_stop(dma->substream, SNDRV_PCM_STATE_XRUN);
}

/*
 * the period ack.  update the substream.
 */
static void snd_atiixp_update_dma(struct atiixp *chip, struct atiixp_dma *dma)
{
    if (! dma->substream || ! dma->running)
        return;
    snd_pcm_period_elapsed(dma->substream);
}

/* set BUS_BUSY interrupt bit if any DMA is running */
/* call with spinlock held */
static void snd_atiixp_check_bus_busy(struct atiixp *chip)
{
    unsigned int bus_busy;
    if (atiixp_read(chip, CMD) & (ATI_REG_CMD_SEND_EN |
                      ATI_REG_CMD_RECEIVE_EN |
                      ATI_REG_CMD_SPDF_OUT_EN))
        bus_busy = ATI_REG_IER_SET_BUS_BUSY;
    else
        bus_busy = 0;
    atiixp_update(chip, IER, ATI_REG_IER_SET_BUS_BUSY, bus_busy);
}

/* common trigger callback
 * calling the lowlevel callbacks in it
 */
static int snd_atiixp_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    struct atiixp_dma *dma = substream->runtime->private_data;
    int err = 0;

    if (snd_BUG_ON(!dma->ops->enable_transfer ||
               !dma->ops->flush_dma))
        return -EINVAL;

    spin_lock(&chip->reg_lock);
    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
    case SNDRV_PCM_TRIGGER_RESUME:
        dma->ops->enable_transfer(chip, 1);
        dma->running = 1;
        dma->suspended = 0;
        break;
    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
    case SNDRV_PCM_TRIGGER_SUSPEND:
        dma->ops->enable_transfer(chip, 0);
        dma->running = 0;
        dma->suspended = cmd == SNDRV_PCM_TRIGGER_SUSPEND;
        break;
    default:
        err = -EINVAL;
        break;
    }
    if (! err) {
        snd_atiixp_check_bus_busy(chip);
        if (cmd == SNDRV_PCM_TRIGGER_STOP) {
            dma->ops->flush_dma(chip);
            snd_atiixp_check_bus_busy(chip);
        }
    }
    spin_unlock(&chip->reg_lock);
    return err;
}


/*
 * lowlevel callbacks for each DMA type
 *
 * every callback is supposed to be called in chip->reg_lock spinlock
 */

/* flush FIFO of analog OUT DMA */
static void atiixp_out_flush_dma(struct atiixp *chip)
{
    atiixp_write(chip, FIFO_FLUSH, ATI_REG_FIFO_OUT_FLUSH);
}

/* enable/disable analog OUT DMA */
static void atiixp_out_enable_dma(struct atiixp *chip, int on)
{
    unsigned int data;
    data = atiixp_read(chip, CMD);
    if (on) {
        if (data & ATI_REG_CMD_OUT_DMA_EN)
            return;
        atiixp_out_flush_dma(chip);
        data |= ATI_REG_CMD_OUT_DMA_EN;
    } else
        data &= ~ATI_REG_CMD_OUT_DMA_EN;
    atiixp_write(chip, CMD, data);
}

/* start/stop transfer over OUT DMA */
static void atiixp_out_enable_transfer(struct atiixp *chip, int on)
{
    atiixp_update(chip, CMD, ATI_REG_CMD_SEND_EN,
              on ? ATI_REG_CMD_SEND_EN : 0);
}

/* enable/disable analog IN DMA */
static void atiixp_in_enable_dma(struct atiixp *chip, int on)
{
    atiixp_update(chip, CMD, ATI_REG_CMD_IN_DMA_EN,
              on ? ATI_REG_CMD_IN_DMA_EN : 0);
}

/* start/stop analog IN DMA */
static void atiixp_in_enable_transfer(struct atiixp *chip, int on)
{
    if (on) {
        unsigned int data = atiixp_read(chip, CMD);
        if (! (data & ATI_REG_CMD_RECEIVE_EN)) {
            data |= ATI_REG_CMD_RECEIVE_EN;
#if 0 /* FIXME: this causes the endless loop */
            /* wait until slot 3/4 are finished */
            while ((atiixp_read(chip, COUNTER) &
                ATI_REG_COUNTER_SLOT) != 5)
                ;
#endif
            atiixp_write(chip, CMD, data);
        }
    } else
        atiixp_update(chip, CMD, ATI_REG_CMD_RECEIVE_EN, 0);
}

/* flush FIFO of analog IN DMA */
static void atiixp_in_flush_dma(struct atiixp *chip)
{
    atiixp_write(chip, FIFO_FLUSH, ATI_REG_FIFO_IN_FLUSH);
}

/* enable/disable SPDIF OUT DMA */
static void atiixp_spdif_enable_dma(struct atiixp *chip, int on)
{
    atiixp_update(chip, CMD, ATI_REG_CMD_SPDF_DMA_EN,
              on ? ATI_REG_CMD_SPDF_DMA_EN : 0);
}

/* start/stop SPDIF OUT DMA */
static void atiixp_spdif_enable_transfer(struct atiixp *chip, int on)
{
    unsigned int data;
    data = atiixp_read(chip, CMD);
    if (on)
        data |= ATI_REG_CMD_SPDF_OUT_EN;
    else
        data &= ~ATI_REG_CMD_SPDF_OUT_EN;
    atiixp_write(chip, CMD, data);
}

/* flush FIFO of SPDIF OUT DMA */
static void atiixp_spdif_flush_dma(struct atiixp *chip)
{
    int timeout;

    /* DMA off, transfer on */
    atiixp_spdif_enable_dma(chip, 0);
    atiixp_spdif_enable_transfer(chip, 1);
    
    timeout = 100;
    do {
        if (! (atiixp_read(chip, SPDF_DMA_DT_SIZE) & ATI_REG_DMA_FIFO_USED))
            break;
        udelay(1);
    } while (timeout-- > 0);

    atiixp_spdif_enable_transfer(chip, 0);
}

/* set up slots and formats for SPDIF OUT */
static int snd_atiixp_spdif_prepare(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);

    spin_lock_irq(&chip->reg_lock);
    if (chip->spdif_over_aclink) {
        unsigned int data;
        /* enable slots 10/11 */
        atiixp_update(chip, CMD, ATI_REG_CMD_SPDF_CONFIG_MASK,
                  ATI_REG_CMD_SPDF_CONFIG_01);
        data = atiixp_read(chip, OUT_DMA_SLOT) & ~ATI_REG_OUT_DMA_SLOT_MASK;
        data |= ATI_REG_OUT_DMA_SLOT_BIT(10) |
            ATI_REG_OUT_DMA_SLOT_BIT(11);
        data |= 0x04 << ATI_REG_OUT_DMA_THRESHOLD_SHIFT;
        atiixp_write(chip, OUT_DMA_SLOT, data);
        atiixp_update(chip, CMD, ATI_REG_CMD_INTERLEAVE_OUT,
                  substream->runtime->format == SNDRV_PCM_FORMAT_S16_LE ?
                  ATI_REG_CMD_INTERLEAVE_OUT : 0);
    } else {
        atiixp_update(chip, CMD, ATI_REG_CMD_SPDF_CONFIG_MASK, 0);
        atiixp_update(chip, CMD, ATI_REG_CMD_INTERLEAVE_SPDF, 0);
    }
    spin_unlock_irq(&chip->reg_lock);
    return 0;
}

/* set up slots and formats for analog OUT */
static int snd_atiixp_playback_prepare(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    unsigned int data;

    spin_lock_irq(&chip->reg_lock);
    data = atiixp_read(chip, OUT_DMA_SLOT) & ~ATI_REG_OUT_DMA_SLOT_MASK;
    switch (substream->runtime->channels) {
    case 8:
        data |= ATI_REG_OUT_DMA_SLOT_BIT(10) |
            ATI_REG_OUT_DMA_SLOT_BIT(11);
        /* fallthru */
    case 6:
        data |= ATI_REG_OUT_DMA_SLOT_BIT(7) |
            ATI_REG_OUT_DMA_SLOT_BIT(8);
        /* fallthru */
    case 4:
        data |= ATI_REG_OUT_DMA_SLOT_BIT(6) |
            ATI_REG_OUT_DMA_SLOT_BIT(9);
        /* fallthru */
    default:
        data |= ATI_REG_OUT_DMA_SLOT_BIT(3) |
            ATI_REG_OUT_DMA_SLOT_BIT(4);
        break;
    }

    /* set output threshold */
    data |= 0x04 << ATI_REG_OUT_DMA_THRESHOLD_SHIFT;
    atiixp_write(chip, OUT_DMA_SLOT, data);

    atiixp_update(chip, CMD, ATI_REG_CMD_INTERLEAVE_OUT,
              substream->runtime->format == SNDRV_PCM_FORMAT_S16_LE ?
              ATI_REG_CMD_INTERLEAVE_OUT : 0);

    /*
     * enable 6 channel re-ordering bit if needed
     */
    atiixp_update(chip, 6CH_REORDER, ATI_REG_6CH_REORDER_EN,
              substream->runtime->channels >= 6 ? ATI_REG_6CH_REORDER_EN: 0);
    
    spin_unlock_irq(&chip->reg_lock);
    return 0;
}

/* set up slots and formats for analog IN */
static int snd_atiixp_capture_prepare(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);

    spin_lock_irq(&chip->reg_lock);
    atiixp_update(chip, CMD, ATI_REG_CMD_INTERLEAVE_IN,
              substream->runtime->format == SNDRV_PCM_FORMAT_S16_LE ?
              ATI_REG_CMD_INTERLEAVE_IN : 0);
    spin_unlock_irq(&chip->reg_lock);
    return 0;
}

/*
 * hw_params - allocate the buffer and set up buffer descriptors
 */
static int snd_atiixp_pcm_hw_params(struct snd_pcm_substream *substream,
                    struct snd_pcm_hw_params *hw_params)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    struct atiixp_dma *dma = substream->runtime->private_data;
    int err;

    err = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
    if (err < 0)
        return err;
    dma->buf_addr = substream->runtime->dma_addr;
    dma->buf_bytes = params_buffer_bytes(hw_params);

    err = atiixp_build_dma_packets(chip, dma, substream,
                       params_periods(hw_params),
                       params_period_bytes(hw_params));
    if (err < 0)
        return err;

    if (dma->ac97_pcm_type >= 0) {
        struct ac97_pcm *pcm = chip->pcms[dma->ac97_pcm_type];
        /* PCM is bound to AC97 codec(s)
         * set up the AC97 codecs
         */
        if (dma->pcm_open_flag) {
            snd_ac97_pcm_close(pcm);
            dma->pcm_open_flag = 0;
        }
        err = snd_ac97_pcm_open(pcm, params_rate(hw_params),
                    params_channels(hw_params),
                    pcm->r[0].slots);
        if (err >= 0)
            dma->pcm_open_flag = 1;
    }

    return err;
}

static int snd_atiixp_pcm_hw_free(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    struct atiixp_dma *dma = substream->runtime->private_data;

    if (dma->pcm_open_flag) {
        struct ac97_pcm *pcm = chip->pcms[dma->ac97_pcm_type];
        snd_ac97_pcm_close(pcm);
        dma->pcm_open_flag = 0;
    }
    atiixp_clear_dma_packets(chip, dma, substream);
    snd_pcm_lib_free_pages(substream);
    return 0;
}


/*
 * pcm hardware definition, identical for all DMA types
 */
static struct snd_pcm_hardware snd_atiixp_pcm_hw =
{
    .info =         (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
                 SNDRV_PCM_INFO_BLOCK_TRANSFER |
                 SNDRV_PCM_INFO_PAUSE |
                 SNDRV_PCM_INFO_RESUME |
                 SNDRV_PCM_INFO_MMAP_VALID),
    .formats =      SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE,
    .rates =        SNDRV_PCM_RATE_48000,
    .rate_min =     48000,
    .rate_max =     48000,
    .channels_min =     2,
    .channels_max =     2,
    .buffer_bytes_max = 256 * 1024,
    .period_bytes_min = 32,
    .period_bytes_max = 128 * 1024,
    .periods_min =      2,
    .periods_max =      ATI_MAX_DESCRIPTORS,
};

static int snd_atiixp_pcm_open(struct snd_pcm_substream *substream,
                   struct atiixp_dma *dma, int pcm_type)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    struct snd_pcm_runtime *runtime = substream->runtime;
    int err;

    if (snd_BUG_ON(!dma->ops || !dma->ops->enable_dma))
        return -EINVAL;

    if (dma->opened)
        return -EBUSY;
    dma->substream = substream;
    runtime->hw = snd_atiixp_pcm_hw;
    dma->ac97_pcm_type = pcm_type;
    if (pcm_type >= 0) {
        runtime->hw.rates = chip->pcms[pcm_type]->rates;
        snd_pcm_limit_hw_rates(runtime);
    } else {
        /* direct SPDIF */
        runtime->hw.formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE;
    }
    if ((err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS)) < 0)
        return err;
    runtime->private_data = dma;

    /* enable DMA bits */
    spin_lock_irq(&chip->reg_lock);
    dma->ops->enable_dma(chip, 1);
    spin_unlock_irq(&chip->reg_lock);
    dma->opened = 1;

    return 0;
}

static int snd_atiixp_pcm_close(struct snd_pcm_substream *substream,
                struct atiixp_dma *dma)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    /* disable DMA bits */
    if (snd_BUG_ON(!dma->ops || !dma->ops->enable_dma))
        return -EINVAL;
    spin_lock_irq(&chip->reg_lock);
    dma->ops->enable_dma(chip, 0);
    spin_unlock_irq(&chip->reg_lock);
    dma->substream = NULL;
    dma->opened = 0;
    return 0;
}

/*
 */
static int snd_atiixp_playback_open(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    int err;

    mutex_lock(&chip->open_mutex);
    err = snd_atiixp_pcm_open(substream, &chip->dmas[ATI_DMA_PLAYBACK], 0);
    mutex_unlock(&chip->open_mutex);
    if (err < 0)
        return err;
    substream->runtime->hw.channels_max = chip->max_channels;
    if (chip->max_channels > 2)
        /* channels must be even */
        snd_pcm_hw_constraint_step(substream->runtime, 0,
                       SNDRV_PCM_HW_PARAM_CHANNELS, 2);
    return 0;
}

static int snd_atiixp_playback_close(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    int err;
    mutex_lock(&chip->open_mutex);
    err = snd_atiixp_pcm_close(substream, &chip->dmas[ATI_DMA_PLAYBACK]);
    mutex_unlock(&chip->open_mutex);
    return err;
}

static int snd_atiixp_capture_open(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    return snd_atiixp_pcm_open(substream, &chip->dmas[ATI_DMA_CAPTURE], 1);
}

static int snd_atiixp_capture_close(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    return snd_atiixp_pcm_close(substream, &chip->dmas[ATI_DMA_CAPTURE]);
}

static int snd_atiixp_spdif_open(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    int err;
    mutex_lock(&chip->open_mutex);
    if (chip->spdif_over_aclink) /* share DMA_PLAYBACK */
        err = snd_atiixp_pcm_open(substream, &chip->dmas[ATI_DMA_PLAYBACK], 2);
    else
        err = snd_atiixp_pcm_open(substream, &chip->dmas[ATI_DMA_SPDIF], -1);
    mutex_unlock(&chip->open_mutex);
    return err;
}

static int snd_atiixp_spdif_close(struct snd_pcm_substream *substream)
{
    struct atiixp *chip = snd_pcm_substream_chip(substream);
    int err;
    mutex_lock(&chip->open_mutex);
    if (chip->spdif_over_aclink)
        err = snd_atiixp_pcm_close(substream, &chip->dmas[ATI_DMA_PLAYBACK]);
    else
        err = snd_atiixp_pcm_close(substream, &chip->dmas[ATI_DMA_SPDIF]);
    mutex_unlock(&chip->open_mutex);
    return err;
}

/* AC97 playback */
static struct snd_pcm_ops snd_atiixp_playback_ops = {
    .open =     snd_atiixp_playback_open,
    .close =    snd_atiixp_playback_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    snd_atiixp_pcm_hw_params,
    .hw_free =  snd_atiixp_pcm_hw_free,
    .prepare =  snd_atiixp_playback_prepare,
    .trigger =  snd_atiixp_pcm_trigger,
    .pointer =  snd_atiixp_pcm_pointer,
};

/* AC97 capture */
static struct snd_pcm_ops snd_atiixp_capture_ops = {
    .open =     snd_atiixp_capture_open,
    .close =    snd_atiixp_capture_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    snd_atiixp_pcm_hw_params,
    .hw_free =  snd_atiixp_pcm_hw_free,
    .prepare =  snd_atiixp_capture_prepare,
    .trigger =  snd_atiixp_pcm_trigger,
    .pointer =  snd_atiixp_pcm_pointer,
};

/* SPDIF playback */
static struct snd_pcm_ops snd_atiixp_spdif_ops = {
    .open =     snd_atiixp_spdif_open,
    .close =    snd_atiixp_spdif_close,
    .ioctl =    snd_pcm_lib_ioctl,
    .hw_params =    snd_atiixp_pcm_hw_params,
    .hw_free =  snd_atiixp_pcm_hw_free,
    .prepare =  snd_atiixp_spdif_prepare,
    .trigger =  snd_atiixp_pcm_trigger,
    .pointer =  snd_atiixp_pcm_pointer,
};

static struct ac97_pcm atiixp_pcm_defs[] __devinitdata = {
    /* front PCM */
    {
        .exclusive = 1,
        .r = {  {
                .slots = (1 << AC97_SLOT_PCM_LEFT) |
                     (1 << AC97_SLOT_PCM_RIGHT) |
                     (1 << AC97_SLOT_PCM_CENTER) |
                     (1 << AC97_SLOT_PCM_SLEFT) |
                     (1 << AC97_SLOT_PCM_SRIGHT) |
                     (1 << AC97_SLOT_LFE)
            }
        }
    },
    /* PCM IN #1 */
    {
        .stream = 1,
        .exclusive = 1,
        .r = {  {
                .slots = (1 << AC97_SLOT_PCM_LEFT) |
                     (1 << AC97_SLOT_PCM_RIGHT)
            }
        }
    },
    /* S/PDIF OUT (optional) */
    {
        .exclusive = 1,
        .spdif = 1,
        .r = {  {
                .slots = (1 << AC97_SLOT_SPDIF_LEFT2) |
                     (1 << AC97_SLOT_SPDIF_RIGHT2)
            }
        }
    },
};

static struct atiixp_dma_ops snd_atiixp_playback_dma_ops = {
    .type = ATI_DMA_PLAYBACK,
    .llp_offset = ATI_REG_OUT_DMA_LINKPTR,
    .dt_cur = ATI_REG_OUT_DMA_DT_CUR,
    .enable_dma = atiixp_out_enable_dma,
    .enable_transfer = atiixp_out_enable_transfer,
    .flush_dma = atiixp_out_flush_dma,
};
    
static struct atiixp_dma_ops snd_atiixp_capture_dma_ops = {
    .type = ATI_DMA_CAPTURE,
    .llp_offset = ATI_REG_IN_DMA_LINKPTR,
    .dt_cur = ATI_REG_IN_DMA_DT_CUR,
    .enable_dma = atiixp_in_enable_dma,
    .enable_transfer = atiixp_in_enable_transfer,
    .flush_dma = atiixp_in_flush_dma,
};
    
static struct atiixp_dma_ops snd_atiixp_spdif_dma_ops = {
    .type = ATI_DMA_SPDIF,
    .llp_offset = ATI_REG_SPDF_DMA_LINKPTR,
    .dt_cur = ATI_REG_SPDF_DMA_DT_CUR,
    .enable_dma = atiixp_spdif_enable_dma,
    .enable_transfer = atiixp_spdif_enable_transfer,
    .flush_dma = atiixp_spdif_flush_dma,
};
    

static int __devinit snd_atiixp_pcm_new(struct atiixp *chip)
{
    struct snd_pcm *pcm;
    struct snd_pcm_chmap *chmap;
    struct snd_ac97_bus *pbus = chip->ac97_bus;
    int err, i, num_pcms;

    /* initialize constants */
    chip->dmas[ATI_DMA_PLAYBACK].ops = &snd_atiixp_playback_dma_ops;
    chip->dmas[ATI_DMA_CAPTURE].ops = &snd_atiixp_capture_dma_ops;
    if (! chip->spdif_over_aclink)
        chip->dmas[ATI_DMA_SPDIF].ops = &snd_atiixp_spdif_dma_ops;

    /* assign AC97 pcm */
    if (chip->spdif_over_aclink)
        num_pcms = 3;
    else
        num_pcms = 2;
    err = snd_ac97_pcm_assign(pbus, num_pcms, atiixp_pcm_defs);
    if (err < 0)
        return err;
    for (i = 0; i < num_pcms; i++)
        chip->pcms[i] = &pbus->pcms[i];

    chip->max_channels = 2;
    if (pbus->pcms[ATI_PCM_OUT].r[0].slots & (1 << AC97_SLOT_PCM_SLEFT)) {
        if (pbus->pcms[ATI_PCM_OUT].r[0].slots & (1 << AC97_SLOT_LFE))
            chip->max_channels = 6;
        else
            chip->max_channels = 4;
    }

    /* PCM #0: analog I/O */
    err = snd_pcm_new(chip->card, "ATI IXP AC97",
              ATI_PCMDEV_ANALOG, 1, 1, &pcm);
    if (err < 0)
        return err;
    snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_atiixp_playback_ops);
    snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_atiixp_capture_ops);
    pcm->private_data = chip;
    strcpy(pcm->name, "ATI IXP AC97");
    chip->pcmdevs[ATI_PCMDEV_ANALOG] = pcm;

    snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
                          snd_dma_pci_data(chip->pci),
                          64*1024, 128*1024);

    err = snd_pcm_add_chmap_ctls(pcm, SNDRV_PCM_STREAM_PLAYBACK,
                     snd_pcm_alt_chmaps, chip->max_channels, 0,
                     &chmap);
    if (err < 0)
        return err;
    chmap->channel_mask = SND_PCM_CHMAP_MASK_2468;
    chip->ac97[0]->chmaps[SNDRV_PCM_STREAM_PLAYBACK] = chmap;

    /* no SPDIF support on codec? */
    if (chip->pcms[ATI_PCM_SPDIF] && ! chip->pcms[ATI_PCM_SPDIF]->rates)
        return 0;
        
    /* FIXME: non-48k sample rate doesn't work on my test machine with AD1888 */
    if (chip->pcms[ATI_PCM_SPDIF])
        chip->pcms[ATI_PCM_SPDIF]->rates = SNDRV_PCM_RATE_48000;

    /* PCM #1: spdif playback */
    err = snd_pcm_new(chip->card, "ATI IXP IEC958",
              ATI_PCMDEV_DIGITAL, 1, 0, &pcm);
    if (err < 0)
        return err;
    snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_atiixp_spdif_ops);
    pcm->private_data = chip;
    if (chip->spdif_over_aclink)
        strcpy(pcm->name, "ATI IXP IEC958 (AC97)");
    else
        strcpy(pcm->name, "ATI IXP IEC958 (Direct)");
    chip->pcmdevs[ATI_PCMDEV_DIGITAL] = pcm;

    snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
                          snd_dma_pci_data(chip->pci),
                          64*1024, 128*1024);

    /* pre-select AC97 SPDIF slots 10/11 */
    for (i = 0; i < NUM_ATI_CODECS; i++) {
        if (chip->ac97[i])
            snd_ac97_update_bits(chip->ac97[i],
                         AC97_EXTENDED_STATUS,
                         0x03 << 4, 0x03 << 4);
    }

    return 0;
}



/*
 * interrupt handler
 */
static irqreturn_t snd_atiixp_interrupt(int irq, void *dev_id)
{
    struct atiixp *chip = dev_id;
    unsigned int status;

    status = atiixp_read(chip, ISR);

    if (! status)
        return IRQ_NONE;

    /* process audio DMA */
    if (status & ATI_REG_ISR_OUT_XRUN)
        snd_atiixp_xrun_dma(chip,  &chip->dmas[ATI_DMA_PLAYBACK]);
    else if (status & ATI_REG_ISR_OUT_STATUS)
        snd_atiixp_update_dma(chip, &chip->dmas[ATI_DMA_PLAYBACK]);
    if (status & ATI_REG_ISR_IN_XRUN)
        snd_atiixp_xrun_dma(chip,  &chip->dmas[ATI_DMA_CAPTURE]);
    else if (status & ATI_REG_ISR_IN_STATUS)
        snd_atiixp_update_dma(chip, &chip->dmas[ATI_DMA_CAPTURE]);
    if (! chip->spdif_over_aclink) {
        if (status & ATI_REG_ISR_SPDF_XRUN)
            snd_atiixp_xrun_dma(chip,  &chip->dmas[ATI_DMA_SPDIF]);
        else if (status & ATI_REG_ISR_SPDF_STATUS)
            snd_atiixp_update_dma(chip, &chip->dmas[ATI_DMA_SPDIF]);
    }

    /* for codec detection */
    if (status & CODEC_CHECK_BITS) {
        unsigned int detected;
        detected = status & CODEC_CHECK_BITS;
        spin_lock(&chip->reg_lock);
        chip->codec_not_ready_bits |= detected;
        atiixp_update(chip, IER, detected, 0); /* disable the detected irqs */
        spin_unlock(&chip->reg_lock);
    }

    /* ack */
    atiixp_write(chip, ISR, status);

    return IRQ_HANDLED;
}


/*
 * ac97 mixer section
 */

static struct ac97_quirk ac97_quirks[] __devinitdata = {
    {
        .subvendor = 0x103c,
        .subdevice = 0x006b,
        .name = "HP Pavilion ZV5030US",
        .type = AC97_TUNE_MUTE_LED
    },
    {
        .subvendor = 0x103c,
        .subdevice = 0x308b,
        .name = "HP nx6125",
        .type = AC97_TUNE_MUTE_LED
    },
    {
        .subvendor = 0x103c,
        .subdevice = 0x3091,
        .name = "unknown HP",
        .type = AC97_TUNE_MUTE_LED
    },
    { } /* terminator */
};

static int __devinit snd_atiixp_mixer_new(struct atiixp *chip, int clock,
                      const char *quirk_override)
{
    struct snd_ac97_bus *pbus;
    struct snd_ac97_template ac97;
    int i, err;
    int codec_count;
    static struct snd_ac97_bus_ops ops = {
        .write = snd_atiixp_ac97_write,
        .read = snd_atiixp_ac97_read,
    };
    static unsigned int codec_skip[NUM_ATI_CODECS] = {
        ATI_REG_ISR_CODEC0_NOT_READY,
        ATI_REG_ISR_CODEC1_NOT_READY,
        ATI_REG_ISR_CODEC2_NOT_READY,
    };

    if (snd_atiixp_codec_detect(chip) < 0)
        return -ENXIO;

    if ((err = snd_ac97_bus(chip->card, 0, &ops, chip, &pbus)) < 0)
        return err;
    pbus->clock = clock;
    chip->ac97_bus = pbus;

    codec_count = 0;
    for (i = 0; i < NUM_ATI_CODECS; i++) {
        if (chip->codec_not_ready_bits & codec_skip[i])
            continue;
        memset(&ac97, 0, sizeof(ac97));
        ac97.private_data = chip;
        ac97.pci = chip->pci;
        ac97.num = i;
        ac97.scaps = AC97_SCAP_SKIP_MODEM | AC97_SCAP_POWER_SAVE;
        if (! chip->spdif_over_aclink)
            ac97.scaps |= AC97_SCAP_NO_SPDIF;
        if ((err = snd_ac97_mixer(pbus, &ac97, &chip->ac97[i])) < 0) {
            chip->ac97[i] = NULL; /* to be sure */
            snd_printdd("atiixp: codec %d not available for audio\n", i);
            continue;
        }
        codec_count++;
    }

    if (! codec_count) {
        snd_printk(KERN_ERR "atiixp: no codec available\n");
        return -ENODEV;
    }

    snd_ac97_tune_hardware(chip->ac97[0], ac97_quirks, quirk_override);

    return 0;
}


#ifdef CONFIG_PM_SLEEP
/*
 * power management
 */
static int snd_atiixp_suspend(struct device *dev)
{
    struct pci_dev *pci = to_pci_dev(dev);
    struct snd_card *card = dev_get_drvdata(dev);
    struct atiixp *chip = card->private_data;
    int i;

    snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
    for (i = 0; i < NUM_ATI_PCMDEVS; i++)
        if (chip->pcmdevs[i]) {
            struct atiixp_dma *dma = &chip->dmas[i];
            if (dma->substream && dma->running)
                dma->saved_curptr = readl(chip->remap_addr +
                              dma->ops->dt_cur);
            snd_pcm_suspend_all(chip->pcmdevs[i]);
        }
    for (i = 0; i < NUM_ATI_CODECS; i++)
        snd_ac97_suspend(chip->ac97[i]);
    snd_atiixp_aclink_down(chip);
    snd_atiixp_chip_stop(chip);

    pci_disable_device(pci);
    pci_save_state(pci);
    pci_set_power_state(pci, PCI_D3hot);
    return 0;
}

static int snd_atiixp_resume(struct device *dev)
{
    struct pci_dev *pci = to_pci_dev(dev);
    struct snd_card *card = dev_get_drvdata(dev);
    struct atiixp *chip = card->private_data;
    int i;

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

    snd_atiixp_aclink_reset(chip);
    snd_atiixp_chip_start(chip);

    for (i = 0; i < NUM_ATI_CODECS; i++)
        snd_ac97_resume(chip->ac97[i]);

    for (i = 0; i < NUM_ATI_PCMDEVS; i++)
        if (chip->pcmdevs[i]) {
            struct atiixp_dma *dma = &chip->dmas[i];
            if (dma->substream && dma->suspended) {
                dma->ops->enable_dma(chip, 1);
                dma->substream->ops->prepare(dma->substream);
                writel((u32)dma->desc_buf.addr | ATI_REG_LINKPTR_EN,
                       chip->remap_addr + dma->ops->llp_offset);
                writel(dma->saved_curptr, chip->remap_addr +
                       dma->ops->dt_cur);
            }
        }

    snd_power_change_state(card, SNDRV_CTL_POWER_D0);
    return 0;
}

static SIMPLE_DEV_PM_OPS(snd_atiixp_pm, snd_atiixp_suspend, snd_atiixp_resume);
#define SND_ATIIXP_PM_OPS   &snd_atiixp_pm
#else
#define SND_ATIIXP_PM_OPS   NULL
#endif /* CONFIG_PM_SLEEP */


#ifdef CONFIG_PROC_FS
/*
 * proc interface for register dump
 */

static void snd_atiixp_proc_read(struct snd_info_entry *entry,
                 struct snd_info_buffer *buffer)
{
    struct atiixp *chip = entry->private_data;
    int i;

    for (i = 0; i < 256; i += 4)
        snd_iprintf(buffer, "%02x: %08x\n", i, readl(chip->remap_addr + i));
}

static void __devinit snd_atiixp_proc_init(struct atiixp *chip)
{
    struct snd_info_entry *entry;

    if (! snd_card_proc_new(chip->card, "atiixp", &entry))
        snd_info_set_text_ops(entry, chip, snd_atiixp_proc_read);
}
#else /* !CONFIG_PROC_FS */
#define snd_atiixp_proc_init(chip)
#endif


/*
 * destructor
 */

static int snd_atiixp_free(struct atiixp *chip)
{
    if (chip->irq < 0)
        goto __hw_end;
    snd_atiixp_chip_stop(chip);

      __hw_end:
    if (chip->irq >= 0)
        free_irq(chip->irq, chip);
    if (chip->remap_addr)
        iounmap(chip->remap_addr);
    pci_release_regions(chip->pci);
    pci_disable_device(chip->pci);
    kfree(chip);
    return 0;
}

static int snd_atiixp_dev_free(struct snd_device *device)
{
    struct atiixp *chip = device->device_data;
    return snd_atiixp_free(chip);
}

/*
 * constructor for chip instance
 */
static int __devinit snd_atiixp_create(struct snd_card *card,
                      struct pci_dev *pci,
                      struct atiixp **r_chip)
{
    static struct snd_device_ops ops = {
        .dev_free = snd_atiixp_dev_free,
    };
    struct atiixp *chip;
    int err;

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

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

    spin_lock_init(&chip->reg_lock);
    mutex_init(&chip->open_mutex);
    chip->card = card;
    chip->pci = pci;
    chip->irq = -1;
    if ((err = pci_request_regions(pci, "ATI IXP AC97")) < 0) {
        pci_disable_device(pci);
        kfree(chip);
        return err;
    }
    chip->addr = pci_resource_start(pci, 0);
    chip->remap_addr = pci_ioremap_bar(pci, 0);
    if (chip->remap_addr == NULL) {
        snd_printk(KERN_ERR "AC'97 space ioremap problem\n");
        snd_atiixp_free(chip);
        return -EIO;
    }

    if (request_irq(pci->irq, snd_atiixp_interrupt, IRQF_SHARED,
            KBUILD_MODNAME, chip)) {
        snd_printk(KERN_ERR "unable to grab IRQ %d\n", pci->irq);
        snd_atiixp_free(chip);
        return -EBUSY;
    }
    chip->irq = pci->irq;
    pci_set_master(pci);
    synchronize_irq(chip->irq);

    if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
        snd_atiixp_free(chip);
        return err;
    }

    snd_card_set_dev(card, &pci->dev);

    *r_chip = chip;
    return 0;
}


static int __devinit snd_atiixp_probe(struct pci_dev *pci,
                     const struct pci_device_id *pci_id)
{
    struct snd_card *card;
    struct atiixp *chip;
    int err;

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

    strcpy(card->driver, spdif_aclink ? "ATIIXP" : "ATIIXP-SPDMA");
    strcpy(card->shortname, "ATI IXP");
    if ((err = snd_atiixp_create(card, pci, &chip)) < 0)
        goto __error;
    card->private_data = chip;

    if ((err = snd_atiixp_aclink_reset(chip)) < 0)
        goto __error;

    chip->spdif_over_aclink = spdif_aclink;

    if ((err = snd_atiixp_mixer_new(chip, ac97_clock, ac97_quirk)) < 0)
        goto __error;

    if ((err = snd_atiixp_pcm_new(chip)) < 0)
        goto __error;
    
    snd_atiixp_proc_init(chip);

    snd_atiixp_chip_start(chip);

    snprintf(card->longname, sizeof(card->longname),
         "%s rev %x with %s at %#lx, irq %i", card->shortname,
         pci->revision,
         chip->ac97[0] ? snd_ac97_get_short_name(chip->ac97[0]) : "?",
         chip->addr, chip->irq);

    if ((err = snd_card_register(card)) < 0)
        goto __error;

    pci_set_drvdata(pci, card);
    return 0;

 __error:
    snd_card_free(card);
    return err;
}

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

static struct pci_driver atiixp_driver = {
    .name = KBUILD_MODNAME,
    .id_table = snd_atiixp_ids,
    .probe = snd_atiixp_probe,
    .remove = __devexit_p(snd_atiixp_remove),
    .driver = {
        .pm = SND_ATIIXP_PM_OPS,
    },
};

module_pci_driver(atiixp_driver);