// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   *   ALSA modem driver for VIA VT82xx (South Bridge)
   *
   *   VT82C686A/B/C, VT8233A/C, VT8235
   *

   *	Copyright (c) 2000 Jaroslav Kysela <perex@perex.cz>

   *	                   Tjeerd.Mulder <Tjeerd.Mulder@fujitsu-siemens.com>
   *                    2002 Takashi Iwai <tiwai@suse.de>

   */
  
  /*
   * Changes:
   *

   * Sep. 2,  2004  Sasha Khapyorsky <sashak@alsa-project.org>

   *      Modified from original audio driver 'via82xx.c' to support AC97
   *      modems.
   */

  #include <linux/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 <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>
  
  #if 0
  #define POINTER_DEBUG
  #endif

  MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");

  MODULE_DESCRIPTION("VIA VT82xx modem");
  MODULE_LICENSE("GPL");
  MODULE_SUPPORTED_DEVICE("{{VIA,VT82C686A/B/C modem,pci}}");

  static int index = -2; /* Exclude the first card */
  static char *id = SNDRV_DEFAULT_STR1;	/* ID for this card */
  static int ac97_clock = 48000;

  module_param(index, int, 0444);

  MODULE_PARM_DESC(index, "Index value for VIA 82xx bridge.");

  module_param(id, charp, 0444);

  MODULE_PARM_DESC(id, "ID string for VIA 82xx bridge.");

  module_param(ac97_clock, int, 0444);

  MODULE_PARM_DESC(ac97_clock, "AC'97 codec clock (default 48000Hz).");

  /* just for backward compatibility */

  static bool enable;

  module_param(enable, bool, 0444);

  
  /*
   *  Direct registers
   */
  
  #define VIAREG(via, x) ((via)->port + VIA_REG_##x)
  #define VIADEV_REG(viadev, x) ((viadev)->port + VIA_REG_##x)
  
  /* common offsets */
  #define VIA_REG_OFFSET_STATUS		0x00	/* byte - channel status */
  #define   VIA_REG_STAT_ACTIVE		0x80	/* RO */
  #define   VIA_REG_STAT_PAUSED		0x40	/* RO */
  #define   VIA_REG_STAT_TRIGGER_QUEUED	0x08	/* RO */
  #define   VIA_REG_STAT_STOPPED		0x04	/* RWC */
  #define   VIA_REG_STAT_EOL		0x02	/* RWC */
  #define   VIA_REG_STAT_FLAG		0x01	/* RWC */
  #define VIA_REG_OFFSET_CONTROL		0x01	/* byte - channel control */
  #define   VIA_REG_CTRL_START		0x80	/* WO */
  #define   VIA_REG_CTRL_TERMINATE	0x40	/* WO */
  #define   VIA_REG_CTRL_AUTOSTART	0x20
  #define   VIA_REG_CTRL_PAUSE		0x08	/* RW */
  #define   VIA_REG_CTRL_INT_STOP		0x04		
  #define   VIA_REG_CTRL_INT_EOL		0x02
  #define   VIA_REG_CTRL_INT_FLAG		0x01
  #define   VIA_REG_CTRL_RESET		0x01	/* RW - probably reset? undocumented */
  #define   VIA_REG_CTRL_INT (VIA_REG_CTRL_INT_FLAG | VIA_REG_CTRL_INT_EOL | VIA_REG_CTRL_AUTOSTART)
  #define VIA_REG_OFFSET_TYPE		0x02	/* byte - channel type (686 only) */
  #define   VIA_REG_TYPE_AUTOSTART	0x80	/* RW - autostart at EOL */
  #define   VIA_REG_TYPE_16BIT		0x20	/* RW */
  #define   VIA_REG_TYPE_STEREO		0x10	/* RW */
  #define   VIA_REG_TYPE_INT_LLINE	0x00
  #define   VIA_REG_TYPE_INT_LSAMPLE	0x04
  #define   VIA_REG_TYPE_INT_LESSONE	0x08
  #define   VIA_REG_TYPE_INT_MASK		0x0c
  #define   VIA_REG_TYPE_INT_EOL		0x02
  #define   VIA_REG_TYPE_INT_FLAG		0x01
  #define VIA_REG_OFFSET_TABLE_PTR	0x04	/* dword - channel table pointer */
  #define VIA_REG_OFFSET_CURR_PTR		0x04	/* dword - channel current pointer */
  #define VIA_REG_OFFSET_STOP_IDX		0x08	/* dword - stop index, channel type, sample rate */
  #define VIA_REG_OFFSET_CURR_COUNT	0x0c	/* dword - channel current count (24 bit) */
  #define VIA_REG_OFFSET_CURR_INDEX	0x0f	/* byte - channel current index (for via8233 only) */
  
  #define DEFINE_VIA_REGSET(name,val) \
  enum {\
  	VIA_REG_##name##_STATUS		= (val),\
  	VIA_REG_##name##_CONTROL	= (val) + 0x01,\
  	VIA_REG_##name##_TYPE		= (val) + 0x02,\
  	VIA_REG_##name##_TABLE_PTR	= (val) + 0x04,\
  	VIA_REG_##name##_CURR_PTR	= (val) + 0x04,\
  	VIA_REG_##name##_STOP_IDX	= (val) + 0x08,\
  	VIA_REG_##name##_CURR_COUNT	= (val) + 0x0c,\
  }
  
  /* modem block */
  DEFINE_VIA_REGSET(MO, 0x40);
  DEFINE_VIA_REGSET(MI, 0x50);
  
  /* AC'97 */
  #define VIA_REG_AC97			0x80	/* dword */
  #define   VIA_REG_AC97_CODEC_ID_MASK	(3<<30)
  #define   VIA_REG_AC97_CODEC_ID_SHIFT	30
  #define   VIA_REG_AC97_CODEC_ID_PRIMARY	0x00
  #define   VIA_REG_AC97_CODEC_ID_SECONDARY 0x01
  #define   VIA_REG_AC97_SECONDARY_VALID	(1<<27)
  #define   VIA_REG_AC97_PRIMARY_VALID	(1<<25)
  #define   VIA_REG_AC97_BUSY		(1<<24)
  #define   VIA_REG_AC97_READ		(1<<23)
  #define   VIA_REG_AC97_CMD_SHIFT	16
  #define   VIA_REG_AC97_CMD_MASK		0x7e
  #define   VIA_REG_AC97_DATA_SHIFT	0
  #define   VIA_REG_AC97_DATA_MASK	0xffff
  
  #define VIA_REG_SGD_SHADOW		0x84	/* dword */
  #define   VIA_REG_SGD_STAT_PB_FLAG	(1<<0)
  #define   VIA_REG_SGD_STAT_CP_FLAG	(1<<1)
  #define   VIA_REG_SGD_STAT_FM_FLAG	(1<<2)
  #define   VIA_REG_SGD_STAT_PB_EOL	(1<<4)
  #define   VIA_REG_SGD_STAT_CP_EOL	(1<<5)
  #define   VIA_REG_SGD_STAT_FM_EOL	(1<<6)
  #define   VIA_REG_SGD_STAT_PB_STOP	(1<<8)
  #define   VIA_REG_SGD_STAT_CP_STOP	(1<<9)
  #define   VIA_REG_SGD_STAT_FM_STOP	(1<<10)
  #define   VIA_REG_SGD_STAT_PB_ACTIVE	(1<<12)
  #define   VIA_REG_SGD_STAT_CP_ACTIVE	(1<<13)
  #define   VIA_REG_SGD_STAT_FM_ACTIVE	(1<<14)
  #define   VIA_REG_SGD_STAT_MR_FLAG      (1<<16)
  #define   VIA_REG_SGD_STAT_MW_FLAG      (1<<17)
  #define   VIA_REG_SGD_STAT_MR_EOL       (1<<20)
  #define   VIA_REG_SGD_STAT_MW_EOL       (1<<21)
  #define   VIA_REG_SGD_STAT_MR_STOP      (1<<24)
  #define   VIA_REG_SGD_STAT_MW_STOP      (1<<25)
  #define   VIA_REG_SGD_STAT_MR_ACTIVE    (1<<28)
  #define   VIA_REG_SGD_STAT_MW_ACTIVE    (1<<29)
  
  #define VIA_REG_GPI_STATUS		0x88
  #define VIA_REG_GPI_INTR		0x8c
  
  #define VIA_TBL_BIT_FLAG	0x40000000
  #define VIA_TBL_BIT_EOL		0x80000000
  
  /* pci space */
  #define VIA_ACLINK_STAT		0x40
  #define  VIA_ACLINK_C11_READY	0x20
  #define  VIA_ACLINK_C10_READY	0x10
  #define  VIA_ACLINK_C01_READY	0x04 /* secondary codec ready */
  #define  VIA_ACLINK_LOWPOWER	0x02 /* low-power state */
  #define  VIA_ACLINK_C00_READY	0x01 /* primary codec ready */
  #define VIA_ACLINK_CTRL		0x41
  #define  VIA_ACLINK_CTRL_ENABLE	0x80 /* 0: disable, 1: enable */
  #define  VIA_ACLINK_CTRL_RESET	0x40 /* 0: assert, 1: de-assert */
  #define  VIA_ACLINK_CTRL_SYNC	0x20 /* 0: release SYNC, 1: force SYNC hi */
  #define  VIA_ACLINK_CTRL_SDO	0x10 /* 0: release SDO, 1: force SDO hi */
  #define  VIA_ACLINK_CTRL_VRA	0x08 /* 0: disable VRA, 1: enable VRA */
  #define  VIA_ACLINK_CTRL_PCM	0x04 /* 0: disable PCM, 1: enable PCM */
  #define  VIA_ACLINK_CTRL_FM	0x02 /* via686 only */
  #define  VIA_ACLINK_CTRL_SB	0x01 /* via686 only */
  #define  VIA_ACLINK_CTRL_INIT	(VIA_ACLINK_CTRL_ENABLE|\
  				 VIA_ACLINK_CTRL_RESET|\
  				 VIA_ACLINK_CTRL_PCM)
  #define VIA_FUNC_ENABLE		0x42
  #define  VIA_FUNC_MIDI_PNP	0x80 /* FIXME: it's 0x40 in the datasheet! */
  #define  VIA_FUNC_MIDI_IRQMASK	0x40 /* FIXME: not documented! */
  #define  VIA_FUNC_RX2C_WRITE	0x20
  #define  VIA_FUNC_SB_FIFO_EMPTY	0x10
  #define  VIA_FUNC_ENABLE_GAME	0x08
  #define  VIA_FUNC_ENABLE_FM	0x04
  #define  VIA_FUNC_ENABLE_MIDI	0x02
  #define  VIA_FUNC_ENABLE_SB	0x01
  #define VIA_PNP_CONTROL		0x43
  #define VIA_MC97_CTRL		0x44
  #define  VIA_MC97_CTRL_ENABLE   0x80
  #define  VIA_MC97_CTRL_SECONDARY 0x40
  #define  VIA_MC97_CTRL_INIT     (VIA_MC97_CTRL_ENABLE|\
                                   VIA_MC97_CTRL_SECONDARY)

  /*
   * pcm stream
   */
  
  struct snd_via_sg_table {
  	unsigned int offset;
  	unsigned int size;
  } ;
  
  #define VIA_TABLE_SIZE	255

  struct viadev {

  	unsigned int reg_offset;
  	unsigned long port;
  	int direction;	/* playback = 0, capture = 1 */

          struct snd_pcm_substream *substream;

  	int running;
  	unsigned int tbl_entries; /* # descriptors */
  	struct snd_dma_buffer table;
  	struct snd_via_sg_table *idx_table;
  	/* for recovery from the unexpected pointer */
  	unsigned int lastpos;
  	unsigned int bufsize;
  	unsigned int bufsize2;
  };
  
  enum { TYPE_CARD_VIA82XX_MODEM = 1 };
  
  #define VIA_MAX_MODEM_DEVS	2

  struct via82xx_modem {

  	int irq;
  
  	unsigned long port;
  
  	unsigned int intr_mask; /* SGD_SHADOW mask to check interrupts */
  
  	struct pci_dev *pci;

  	struct snd_card *card;

  
  	unsigned int num_devs;
  	unsigned int playback_devno, capture_devno;

  	struct viadev devs[VIA_MAX_MODEM_DEVS];

  	struct snd_pcm *pcms[2];

  	struct snd_ac97_bus *ac97_bus;
  	struct snd_ac97 *ac97;

  	unsigned int ac97_clock;
  	unsigned int ac97_secondary;	/* secondary AC'97 codec is present */
  
  	spinlock_t reg_lock;

  	struct snd_info_entry *proc_entry;

  };

  static const struct pci_device_id snd_via82xx_modem_ids[] = {

  	{ PCI_VDEVICE(VIA, 0x3068), TYPE_CARD_VIA82XX_MODEM, },

  	{ 0, }
  };
  
  MODULE_DEVICE_TABLE(pci, snd_via82xx_modem_ids);
  
  /*
   */
  
  /*
   * allocate and initialize the descriptor buffers
   * periods = number of periods
   * fragsize = period size in bytes
   */

  static int build_via_table(struct viadev *dev, struct snd_pcm_substream *substream,

  			   struct pci_dev *pci,
  			   unsigned int periods, unsigned int fragsize)
  {
  	unsigned int i, idx, ofs, rest;

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);

  	__le32 *pgtbl;

  
  	if (dev->table.area == NULL) {
  		/* the start of each lists must be aligned to 8 bytes,
  		 * but the kernel pages are much bigger, so we don't care
  		 */

  		if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, &chip->pci->dev,

  					PAGE_ALIGN(VIA_TABLE_SIZE * 2 * 8),
  					&dev->table) < 0)
  			return -ENOMEM;
  	}
  	if (! dev->idx_table) {

  		dev->idx_table = kmalloc_array(VIA_TABLE_SIZE,
  					       sizeof(*dev->idx_table),
  					       GFP_KERNEL);

  		if (! dev->idx_table)
  			return -ENOMEM;
  	}
  
  	/* fill the entries */
  	idx = 0;
  	ofs = 0;

  	pgtbl = (__le32 *)dev->table.area;

  	for (i = 0; i < periods; i++) {
  		rest = fragsize;
  		/* fill descriptors for a period.
  		 * a period can be split to several descriptors if it's
  		 * over page boundary.
  		 */
  		do {
  			unsigned int r;
  			unsigned int flag;

  			unsigned int addr;

  
  			if (idx >= VIA_TABLE_SIZE) {

  				dev_err(&pci->dev, "too much table size!
  ");

  				return -EINVAL;
  			}

  			addr = snd_pcm_sgbuf_get_addr(substream, ofs);

  			pgtbl[idx << 1] = cpu_to_le32(addr);

  			r = PAGE_SIZE - (ofs % PAGE_SIZE);
  			if (rest < r)
  				r = rest;
  			rest -= r;
  			if (! rest) {
  				if (i == periods - 1)
  					flag = VIA_TBL_BIT_EOL; /* buffer boundary */
  				else
  					flag = VIA_TBL_BIT_FLAG; /* period boundary */
  			} else
  				flag = 0; /* period continues to the next */

  			/*

  			dev_dbg(&pci->dev,
  				"tbl %d: at %d  size %d (rest %d)
  ",
  				idx, ofs, r, rest);

  			*/

  			pgtbl[(idx<<1) + 1] = cpu_to_le32(r | flag);

  			dev->idx_table[idx].offset = ofs;
  			dev->idx_table[idx].size = r;
  			ofs += r;
  			idx++;
  		} while (rest > 0);
  	}
  	dev->tbl_entries = idx;
  	dev->bufsize = periods * fragsize;
  	dev->bufsize2 = dev->bufsize / 2;
  	return 0;
  }

  static int clean_via_table(struct viadev *dev, struct snd_pcm_substream *substream,

  			   struct pci_dev *pci)
  {
  	if (dev->table.area) {
  		snd_dma_free_pages(&dev->table);
  		dev->table.area = NULL;
  	}

  	kfree(dev->idx_table);
  	dev->idx_table = NULL;

  	return 0;
  }
  
  /*
   *  Basic I/O
   */

  static inline unsigned int snd_via82xx_codec_xread(struct via82xx_modem *chip)

  {
  	return inl(VIAREG(chip, AC97));
  }
   

  static inline void snd_via82xx_codec_xwrite(struct via82xx_modem *chip, unsigned int val)

  {
  	outl(val, VIAREG(chip, AC97));
  }
   

  static int snd_via82xx_codec_ready(struct via82xx_modem *chip, int secondary)

  {
  	unsigned int timeout = 1000;	/* 1ms */
  	unsigned int val;
  	
  	while (timeout-- > 0) {
  		udelay(1);
  		if (!((val = snd_via82xx_codec_xread(chip)) & VIA_REG_AC97_BUSY))
  			return val & 0xffff;
  	}

  	dev_err(chip->card->dev, "codec_ready: codec %i is not ready [0x%x]
  ",

  		   secondary, snd_via82xx_codec_xread(chip));

  	return -EIO;
  }
   

  static int snd_via82xx_codec_valid(struct via82xx_modem *chip, int secondary)

  {
  	unsigned int timeout = 1000;	/* 1ms */
  	unsigned int val, val1;
  	unsigned int stat = !secondary ? VIA_REG_AC97_PRIMARY_VALID :
  					 VIA_REG_AC97_SECONDARY_VALID;
  	
  	while (timeout-- > 0) {
  		val = snd_via82xx_codec_xread(chip);
  		val1 = val & (VIA_REG_AC97_BUSY | stat);
  		if (val1 == stat)
  			return val & 0xffff;
  		udelay(1);
  	}
  	return -EIO;
  }
   

  static void snd_via82xx_codec_wait(struct snd_ac97 *ac97)

  {

  	struct via82xx_modem *chip = ac97->private_data;

  	__always_unused int err;

  	err = snd_via82xx_codec_ready(chip, ac97->num);
  	/* here we need to wait fairly for long time.. */

  	msleep(500);

  }

  static void snd_via82xx_codec_write(struct snd_ac97 *ac97,

  				    unsigned short reg,
  				    unsigned short val)
  {

  	struct via82xx_modem *chip = ac97->private_data;

  	unsigned int xval;

  	if(reg == AC97_GPIO_STATUS) {
  		outl(val, VIAREG(chip, GPI_STATUS));
  		return;
  	}	

  	xval = !ac97->num ? VIA_REG_AC97_CODEC_ID_PRIMARY : VIA_REG_AC97_CODEC_ID_SECONDARY;
  	xval <<= VIA_REG_AC97_CODEC_ID_SHIFT;
  	xval |= reg << VIA_REG_AC97_CMD_SHIFT;
  	xval |= val << VIA_REG_AC97_DATA_SHIFT;
  	snd_via82xx_codec_xwrite(chip, xval);
  	snd_via82xx_codec_ready(chip, ac97->num);
  }

  static unsigned short snd_via82xx_codec_read(struct snd_ac97 *ac97, unsigned short reg)

  {

  	struct via82xx_modem *chip = ac97->private_data;

  	unsigned int xval, val = 0xffff;
  	int again = 0;
  
  	xval = ac97->num << VIA_REG_AC97_CODEC_ID_SHIFT;
  	xval |= ac97->num ? VIA_REG_AC97_SECONDARY_VALID : VIA_REG_AC97_PRIMARY_VALID;
  	xval |= VIA_REG_AC97_READ;
  	xval |= (reg & 0x7f) << VIA_REG_AC97_CMD_SHIFT;
        	while (1) {
        		if (again++ > 3) {

  			dev_err(chip->card->dev,
  				"codec_read: codec %i is not valid [0x%x]
  ",

  				   ac97->num, snd_via82xx_codec_xread(chip));

  		      	return 0xffff;
  		}
  		snd_via82xx_codec_xwrite(chip, xval);
  		udelay (20);
  		if (snd_via82xx_codec_valid(chip, ac97->num) >= 0) {
  			udelay(25);
  			val = snd_via82xx_codec_xread(chip);
  			break;
  		}
  	}
  	return val & 0xffff;
  }

  static void snd_via82xx_channel_reset(struct via82xx_modem *chip, struct viadev *viadev)

  {
  	outb(VIA_REG_CTRL_PAUSE | VIA_REG_CTRL_TERMINATE | VIA_REG_CTRL_RESET,
  	     VIADEV_REG(viadev, OFFSET_CONTROL));
  	inb(VIADEV_REG(viadev, OFFSET_CONTROL));
  	udelay(50);
  	/* disable interrupts */
  	outb(0x00, VIADEV_REG(viadev, OFFSET_CONTROL));
  	/* clear interrupts */
  	outb(0x03, VIADEV_REG(viadev, OFFSET_STATUS));
  	outb(0x00, VIADEV_REG(viadev, OFFSET_TYPE)); /* for via686 */
  	// outl(0, VIADEV_REG(viadev, OFFSET_CURR_PTR));
  	viadev->lastpos = 0;
  }
  
  
  /*
   *  Interrupt handler
   */

  static irqreturn_t snd_via82xx_interrupt(int irq, void *dev_id)

  {

  	struct via82xx_modem *chip = dev_id;

  	unsigned int status;
  	unsigned int i;
  
  	status = inl(VIAREG(chip, SGD_SHADOW));
  	if (! (status & chip->intr_mask)) {
  		return IRQ_NONE;
  	}
  // _skip_sgd:
  
  	/* check status for each stream */
  	spin_lock(&chip->reg_lock);
  	for (i = 0; i < chip->num_devs; i++) {

  		struct viadev *viadev = &chip->devs[i];

  		unsigned char c_status = inb(VIADEV_REG(viadev, OFFSET_STATUS));
  		c_status &= (VIA_REG_STAT_EOL|VIA_REG_STAT_FLAG|VIA_REG_STAT_STOPPED);
  		if (! c_status)
  			continue;
  		if (viadev->substream && viadev->running) {
  			spin_unlock(&chip->reg_lock);
  			snd_pcm_period_elapsed(viadev->substream);
  			spin_lock(&chip->reg_lock);
  		}
  		outb(c_status, VIADEV_REG(viadev, OFFSET_STATUS)); /* ack */
  	}
  	spin_unlock(&chip->reg_lock);
  	return IRQ_HANDLED;
  }
  
  /*
   *  PCM callbacks
   */
  
  /*
   * trigger callback
   */

  static int snd_via82xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)

  {

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
  	struct viadev *viadev = substream->runtime->private_data;

  	unsigned char val = 0;
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:

  	case SNDRV_PCM_TRIGGER_SUSPEND:

  		val |= VIA_REG_CTRL_START;
  		viadev->running = 1;
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  		val = VIA_REG_CTRL_TERMINATE;
  		viadev->running = 0;
  		break;
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		val |= VIA_REG_CTRL_PAUSE;
  		viadev->running = 0;
  		break;
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		viadev->running = 1;
  		break;
  	default:
  		return -EINVAL;
  	}
  	outb(val, VIADEV_REG(viadev, OFFSET_CONTROL));
  	if (cmd == SNDRV_PCM_TRIGGER_STOP)
  		snd_via82xx_channel_reset(chip, viadev);
  	return 0;
  }

  /*
   * pointer callbacks
   */
  
  /*
   * calculate the linear position at the given sg-buffer index and the rest count
   */
  
  #define check_invalid_pos(viadev,pos) \

  	((pos) < viadev->lastpos && ((pos) >= viadev->bufsize2 ||\
  				     viadev->lastpos < viadev->bufsize2))

  static inline unsigned int calc_linear_pos(struct via82xx_modem *chip,
  					   struct viadev *viadev,
  					   unsigned int idx,

  					   unsigned int count)

  {
  	unsigned int size, res;
  
  	size = viadev->idx_table[idx].size;
  	res = viadev->idx_table[idx].offset + size - count;
  
  	/* check the validity of the calculated position */
  	if (size < count) {

  		dev_err(chip->card->dev,
  			"invalid via82xx_cur_ptr (size = %d, count = %d)
  ",

  			   (int)size, (int)count);

  		res = viadev->lastpos;
  	} else if (check_invalid_pos(viadev, res)) {
  #ifdef POINTER_DEBUG

  		dev_dbg(chip->card->dev,
  			"fail: idx = %i/%i, lastpos = 0x%x, bufsize2 = 0x%x, offsize = 0x%x, size = 0x%x, count = 0x%x
  ",
  			idx, viadev->tbl_entries, viadev->lastpos,

  		       viadev->bufsize2, viadev->idx_table[idx].offset,
  		       viadev->idx_table[idx].size, count);

  #endif
  		if (count && size < count) {

  			dev_dbg(chip->card->dev,
  				"invalid via82xx_cur_ptr, using last valid pointer
  ");

  			res = viadev->lastpos;
  		} else {
  			if (! count)
  				/* bogus count 0 on the DMA boundary? */
  				res = viadev->idx_table[idx].offset;
  			else

  				/* count register returns full size
  				 * when end of buffer is reached
  				 */

  				res = viadev->idx_table[idx].offset + size;
  			if (check_invalid_pos(viadev, res)) {

  				dev_dbg(chip->card->dev,
  					"invalid via82xx_cur_ptr (2), using last valid pointer
  ");

  				res = viadev->lastpos;
  			}
  		}
  	}
  	viadev->lastpos = res; /* remember the last position */
  	if (res >= viadev->bufsize)
  		res -= viadev->bufsize;
  	return res;
  }
  
  /*
   * get the current pointer on via686
   */

  static snd_pcm_uframes_t snd_via686_pcm_pointer(struct snd_pcm_substream *substream)

  {

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
  	struct viadev *viadev = substream->runtime->private_data;

  	unsigned int idx, ptr, count, res;

  	if (snd_BUG_ON(!viadev->tbl_entries))
  		return 0;

  	if (!(inb(VIADEV_REG(viadev, OFFSET_STATUS)) & VIA_REG_STAT_ACTIVE))
  		return 0;
  
  	spin_lock(&chip->reg_lock);
  	count = inl(VIADEV_REG(viadev, OFFSET_CURR_COUNT)) & 0xffffff;
  	/* The via686a does not have the current index register,
  	 * so we need to calculate the index from CURR_PTR.
  	 */
  	ptr = inl(VIADEV_REG(viadev, OFFSET_CURR_PTR));
  	if (ptr <= (unsigned int)viadev->table.addr)
  		idx = 0;
  	else /* CURR_PTR holds the address + 8 */

  		idx = ((ptr - (unsigned int)viadev->table.addr) / 8 - 1) %
  			viadev->tbl_entries;

  	res = calc_linear_pos(chip, viadev, idx, count);

  	spin_unlock(&chip->reg_lock);
  
  	return bytes_to_frames(substream->runtime, res);
  }
  
  /*
   * hw_params callback:
   * allocate the buffer and build up the buffer description table
   */

  static int snd_via82xx_hw_params(struct snd_pcm_substream *substream,
  				 struct snd_pcm_hw_params *hw_params)

  {

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
  	struct viadev *viadev = substream->runtime->private_data;

  	int err;

  	err = build_via_table(viadev, substream, chip->pci,
  			      params_periods(hw_params),
  			      params_period_bytes(hw_params));
  	if (err < 0)
  		return err;
  
  	snd_ac97_write(chip->ac97, AC97_LINE1_RATE, params_rate(hw_params));
  	snd_ac97_write(chip->ac97, AC97_LINE1_LEVEL, 0);
  
  	return 0;
  }
  
  /*
   * hw_free callback:
   * clean up the buffer description table and release the buffer
   */

  static int snd_via82xx_hw_free(struct snd_pcm_substream *substream)

  {

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
  	struct viadev *viadev = substream->runtime->private_data;

  
  	clean_via_table(viadev, substream, chip->pci);

  	return 0;
  }
  
  
  /*
   * set up the table pointer
   */

  static void snd_via82xx_set_table_ptr(struct via82xx_modem *chip, struct viadev *viadev)

  {
  	snd_via82xx_codec_ready(chip, chip->ac97_secondary);
  	outl((u32)viadev->table.addr, VIADEV_REG(viadev, OFFSET_TABLE_PTR));
  	udelay(20);
  	snd_via82xx_codec_ready(chip, chip->ac97_secondary);
  }
  
  /*
   * prepare callback for playback and capture
   */

  static int snd_via82xx_pcm_prepare(struct snd_pcm_substream *substream)

  {

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
  	struct viadev *viadev = substream->runtime->private_data;

  
  	snd_via82xx_channel_reset(chip, viadev);
  	/* this must be set after channel_reset */
  	snd_via82xx_set_table_ptr(chip, viadev);
  	outb(VIA_REG_TYPE_AUTOSTART|VIA_REG_TYPE_INT_EOL|VIA_REG_TYPE_INT_FLAG,
  	     VIADEV_REG(viadev, OFFSET_TYPE));
  	return 0;
  }
  
  /*
   * pcm hardware definition, identical for both playback and capture
   */

  static const struct snd_pcm_hardware snd_via82xx_hw =

  {
  	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
  				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
  				 SNDRV_PCM_INFO_MMAP_VALID |

  				 /* SNDRV_PCM_INFO_RESUME | */

  				 SNDRV_PCM_INFO_PAUSE),
  	.formats =		SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
  	.rates =		SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_KNOT,
  	.rate_min =		8000,
  	.rate_max =		16000,
  	.channels_min =		1,
  	.channels_max =		1,
  	.buffer_bytes_max =	128 * 1024,
  	.period_bytes_min =	32,
  	.period_bytes_max =	128 * 1024,
  	.periods_min =		2,
  	.periods_max =		VIA_TABLE_SIZE / 2,
  	.fifo_size =		0,
  };
  
  
  /*
   * open callback skeleton
   */

  static int snd_via82xx_modem_pcm_open(struct via82xx_modem *chip, struct viadev *viadev,
  				      struct snd_pcm_substream *substream)

  {

  	struct snd_pcm_runtime *runtime = substream->runtime;

  	int err;

  	static const unsigned int rates[] = { 8000,  9600, 12000, 16000 };
  	static const struct snd_pcm_hw_constraint_list hw_constraints_rates = {

                  .count = ARRAY_SIZE(rates),
                  .list = rates,
                  .mask = 0,
          };
  
  	runtime->hw = snd_via82xx_hw;
  	

          if ((err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
  					      &hw_constraints_rates)) < 0)

                  return err;
  
  	/* we may remove following constaint when we modify table entries
  	   in interrupt */
  	if ((err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS)) < 0)
  		return err;
  
  	runtime->private_data = viadev;
  	viadev->substream = substream;
  
  	return 0;
  }
  
  
  /*
   * open callback for playback
   */

  static int snd_via82xx_playback_open(struct snd_pcm_substream *substream)

  {

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
  	struct viadev *viadev = &chip->devs[chip->playback_devno + substream->number];

  
  	return snd_via82xx_modem_pcm_open(chip, viadev, substream);
  }
  
  /*
   * open callback for capture
   */

  static int snd_via82xx_capture_open(struct snd_pcm_substream *substream)

  {

  	struct via82xx_modem *chip = snd_pcm_substream_chip(substream);
  	struct viadev *viadev = &chip->devs[chip->capture_devno + substream->pcm->device];

  
  	return snd_via82xx_modem_pcm_open(chip, viadev, substream);
  }
  
  /*
   * close callback
   */

  static int snd_via82xx_pcm_close(struct snd_pcm_substream *substream)

  {

  	struct viadev *viadev = substream->runtime->private_data;

  
  	viadev->substream = NULL;
  	return 0;
  }
  
  
  /* via686 playback callbacks */

  static const struct snd_pcm_ops snd_via686_playback_ops = {

  	.open =		snd_via82xx_playback_open,
  	.close =	snd_via82xx_pcm_close,

  	.hw_params =	snd_via82xx_hw_params,
  	.hw_free =	snd_via82xx_hw_free,
  	.prepare =	snd_via82xx_pcm_prepare,

  	.trigger =	snd_via82xx_pcm_trigger,

  	.pointer =	snd_via686_pcm_pointer,

  };
  
  /* via686 capture callbacks */

  static const struct snd_pcm_ops snd_via686_capture_ops = {

  	.open =		snd_via82xx_capture_open,
  	.close =	snd_via82xx_pcm_close,

  	.hw_params =	snd_via82xx_hw_params,
  	.hw_free =	snd_via82xx_hw_free,
  	.prepare =	snd_via82xx_pcm_prepare,

  	.trigger =	snd_via82xx_pcm_trigger,

  	.pointer =	snd_via686_pcm_pointer,

  };

  static void init_viadev(struct via82xx_modem *chip, int idx, unsigned int reg_offset,
  			int direction)

  {
  	chip->devs[idx].reg_offset = reg_offset;
  	chip->devs[idx].direction = direction;
  	chip->devs[idx].port = chip->port + reg_offset;
  }
  
  /*
   * create a pcm instance for via686a/b
   */

  static int snd_via686_pcm_new(struct via82xx_modem *chip)

  {

  	struct snd_pcm *pcm;

  	int err;
  
  	chip->playback_devno = 0;
  	chip->capture_devno = 1;
  	chip->num_devs = 2;
  	chip->intr_mask = 0x330000; /* FLAGS | EOL for MR, MW */
  
  	err = snd_pcm_new(chip->card, chip->card->shortname, 0, 1, 1, &pcm);
  	if (err < 0)
  		return err;
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_via686_playback_ops);
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_via686_capture_ops);

  	pcm->dev_class = SNDRV_PCM_CLASS_MODEM;

  	pcm->private_data = chip;
  	strcpy(pcm->name, chip->card->shortname);
  	chip->pcms[0] = pcm;
  	init_viadev(chip, 0, VIA_REG_MO_STATUS, 0);
  	init_viadev(chip, 1, VIA_REG_MI_STATUS, 1);

  	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_SG,
  				       &chip->pci->dev, 64*1024, 128*1024);

  	return 0;
  }
  
  
  /*
   *  Mixer part
   */

  static void snd_via82xx_mixer_free_ac97_bus(struct snd_ac97_bus *bus)

  {

  	struct via82xx_modem *chip = bus->private_data;

  	chip->ac97_bus = NULL;
  }

  static void snd_via82xx_mixer_free_ac97(struct snd_ac97 *ac97)

  {

  	struct via82xx_modem *chip = ac97->private_data;

  	chip->ac97 = NULL;
  }

  static int snd_via82xx_mixer_new(struct via82xx_modem *chip)

  {

  	struct snd_ac97_template ac97;

  	int err;

  	static const struct snd_ac97_bus_ops ops = {

  		.write = snd_via82xx_codec_write,
  		.read = snd_via82xx_codec_read,
  		.wait = snd_via82xx_codec_wait,
  	};
  
  	if ((err = snd_ac97_bus(chip->card, 0, &ops, chip, &chip->ac97_bus)) < 0)
  		return err;
  	chip->ac97_bus->private_free = snd_via82xx_mixer_free_ac97_bus;
  	chip->ac97_bus->clock = chip->ac97_clock;

  
  	memset(&ac97, 0, sizeof(ac97));
  	ac97.private_data = chip;
  	ac97.private_free = snd_via82xx_mixer_free_ac97;
  	ac97.pci = chip->pci;

  	ac97.scaps = AC97_SCAP_SKIP_AUDIO | AC97_SCAP_POWER_SAVE;

  	ac97.num = chip->ac97_secondary;
  
  	if ((err = snd_ac97_mixer(chip->ac97_bus, &ac97, &chip->ac97)) < 0)
  		return err;
  
  	return 0;
  }
  
  
  /*
   * proc interface
   */

  static void snd_via82xx_proc_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)

  {

  	struct via82xx_modem *chip = entry->private_data;

  	int i;
  	
  	snd_iprintf(buffer, "%s
  
  ", chip->card->longname);
  	for (i = 0; i < 0xa0; i += 4) {
  		snd_iprintf(buffer, "%02x: %08x
  ", i, inl(chip->port + i));
  	}
  }

  static void snd_via82xx_proc_init(struct via82xx_modem *chip)

  {

  	snd_card_ro_proc_new(chip->card, "via82xx", chip,
  			     snd_via82xx_proc_read);

  }
  
  /*
   *
   */

  static int snd_via82xx_chip_init(struct via82xx_modem *chip)

  {
  	unsigned int val;

  	unsigned long end_time;

  	unsigned char pval;
  
  	pci_read_config_byte(chip->pci, VIA_MC97_CTRL, &pval);
  	if((pval & VIA_MC97_CTRL_INIT) != VIA_MC97_CTRL_INIT) {
  		pci_write_config_byte(chip->pci, 0x44, pval|VIA_MC97_CTRL_INIT);
  		udelay(100);
  	}
  
  	pci_read_config_byte(chip->pci, VIA_ACLINK_STAT, &pval);
  	if (! (pval & VIA_ACLINK_C00_READY)) { /* codec not ready? */
  		/* deassert ACLink reset, force SYNC */
  		pci_write_config_byte(chip->pci, VIA_ACLINK_CTRL,
  				      VIA_ACLINK_CTRL_ENABLE |
  				      VIA_ACLINK_CTRL_RESET |
  				      VIA_ACLINK_CTRL_SYNC);
  		udelay(100);
  #if 1 /* FIXME: should we do full reset here for all chip models? */
  		pci_write_config_byte(chip->pci, VIA_ACLINK_CTRL, 0x00);
  		udelay(100);
  #else
  		/* deassert ACLink reset, force SYNC (warm AC'97 reset) */
  		pci_write_config_byte(chip->pci, VIA_ACLINK_CTRL,
  				      VIA_ACLINK_CTRL_RESET|VIA_ACLINK_CTRL_SYNC);
  		udelay(2);
  #endif
  		/* ACLink on, deassert ACLink reset, VSR, SGD data out */
  		pci_write_config_byte(chip->pci, VIA_ACLINK_CTRL, VIA_ACLINK_CTRL_INIT);
  		udelay(100);
  	}
  	
  	pci_read_config_byte(chip->pci, VIA_ACLINK_CTRL, &pval);
  	if ((pval & VIA_ACLINK_CTRL_INIT) != VIA_ACLINK_CTRL_INIT) {
  		/* ACLink on, deassert ACLink reset, VSR, SGD data out */
  		pci_write_config_byte(chip->pci, VIA_ACLINK_CTRL, VIA_ACLINK_CTRL_INIT);
  		udelay(100);
  	}
  
  	/* wait until codec ready */

  	end_time = jiffies + msecs_to_jiffies(750);

  	do {
  		pci_read_config_byte(chip->pci, VIA_ACLINK_STAT, &pval);
  		if (pval & VIA_ACLINK_C00_READY) /* primary codec ready */
  			break;

  		schedule_timeout_uninterruptible(1);

  	} while (time_before(jiffies, end_time));

  
  	if ((val = snd_via82xx_codec_xread(chip)) & VIA_REG_AC97_BUSY)

  		dev_err(chip->card->dev,
  			"AC'97 codec is not ready [0x%x]
  ", val);

  
  	snd_via82xx_codec_xwrite(chip, VIA_REG_AC97_READ |
  				 VIA_REG_AC97_SECONDARY_VALID |
  				 (VIA_REG_AC97_CODEC_ID_SECONDARY << VIA_REG_AC97_CODEC_ID_SHIFT));

  	end_time = jiffies + msecs_to_jiffies(750);

  	snd_via82xx_codec_xwrite(chip, VIA_REG_AC97_READ |
  				 VIA_REG_AC97_SECONDARY_VALID |
  				 (VIA_REG_AC97_CODEC_ID_SECONDARY << VIA_REG_AC97_CODEC_ID_SHIFT));
  	do {
  		if ((val = snd_via82xx_codec_xread(chip)) & VIA_REG_AC97_SECONDARY_VALID) {
  			chip->ac97_secondary = 1;
  			goto __ac97_ok2;
  		}

  		schedule_timeout_uninterruptible(1);

  	} while (time_before(jiffies, end_time));

  	/* This is ok, the most of motherboards have only one codec */
  
        __ac97_ok2:
  
  	/* route FM trap to IRQ, disable FM trap */
  	// pci_write_config_byte(chip->pci, VIA_FM_NMI_CTRL, 0);
  	/* disable all GPI interrupts */
  	outl(0, VIAREG(chip, GPI_INTR));
  
  	return 0;
  }

  #ifdef CONFIG_PM_SLEEP

  /*
   * power management
   */

  static int snd_via82xx_suspend(struct device *dev)

  {

  	struct snd_card *card = dev_get_drvdata(dev);

  	struct via82xx_modem *chip = card->private_data;

  	int i;

  	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);

  	for (i = 0; i < chip->num_devs; i++)
  		snd_via82xx_channel_reset(chip, &chip->devs[i]);

  	snd_ac97_suspend(chip->ac97);

  	return 0;
  }

  static int snd_via82xx_resume(struct device *dev)

  {

  	struct snd_card *card = dev_get_drvdata(dev);

  	struct via82xx_modem *chip = card->private_data;

  	int i;

  	snd_via82xx_chip_init(chip);
  
  	snd_ac97_resume(chip->ac97);
  
  	for (i = 0; i < chip->num_devs; i++)
  		snd_via82xx_channel_reset(chip, &chip->devs[i]);

  	snd_power_change_state(card, SNDRV_CTL_POWER_D0);

  	return 0;
  }

  
  static SIMPLE_DEV_PM_OPS(snd_via82xx_pm, snd_via82xx_suspend, snd_via82xx_resume);
  #define SND_VIA82XX_PM_OPS	&snd_via82xx_pm
  #else
  #define SND_VIA82XX_PM_OPS	NULL

  #endif /* CONFIG_PM_SLEEP */

  static int snd_via82xx_free(struct via82xx_modem *chip)

  {
  	unsigned int i;
  
  	if (chip->irq < 0)
  		goto __end_hw;
  	/* disable interrupts */
  	for (i = 0; i < chip->num_devs; i++)
  		snd_via82xx_channel_reset(chip, &chip->devs[i]);

        __end_hw:
  	if (chip->irq >= 0)

  		free_irq(chip->irq, chip);

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

  static int snd_via82xx_dev_free(struct snd_device *device)

  {

  	struct via82xx_modem *chip = device->device_data;

  	return snd_via82xx_free(chip);
  }

  static int snd_via82xx_create(struct snd_card *card,
  			      struct pci_dev *pci,
  			      int chip_type,
  			      int revision,
  			      unsigned int ac97_clock,
  			      struct via82xx_modem **r_via)

  {

  	struct via82xx_modem *chip;

  	int err;

  	static const struct snd_device_ops ops = {

  		.dev_free =	snd_via82xx_dev_free,
          };
  
  	if ((err = pci_enable_device(pci)) < 0)
  		return err;

  	if ((chip = kzalloc(sizeof(*chip), GFP_KERNEL)) == NULL) {

  		pci_disable_device(pci);
  		return -ENOMEM;
  	}
  
  	spin_lock_init(&chip->reg_lock);
  	chip->card = card;
  	chip->pci = pci;
  	chip->irq = -1;
  
  	if ((err = pci_request_regions(pci, card->driver)) < 0) {
  		kfree(chip);
  		pci_disable_device(pci);
  		return err;
  	}
  	chip->port = pci_resource_start(pci, 0);

  	if (request_irq(pci->irq, snd_via82xx_interrupt, IRQF_SHARED,

  			KBUILD_MODNAME, chip)) {

  		dev_err(card->dev, "unable to grab IRQ %d
  ", pci->irq);

  		snd_via82xx_free(chip);
  		return -EBUSY;
  	}
  	chip->irq = pci->irq;

  	card->sync_irq = chip->irq;

  	if (ac97_clock >= 8000 && ac97_clock <= 48000)
  		chip->ac97_clock = ac97_clock;

  
  	if ((err = snd_via82xx_chip_init(chip)) < 0) {
  		snd_via82xx_free(chip);
  		return err;
  	}
  
  	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
  		snd_via82xx_free(chip);
  		return err;
  	}
  
  	/* The 8233 ac97 controller does not implement the master bit
  	 * in the pci command register. IMHO this is a violation of the PCI spec.
  	 * We call pci_set_master here because it does not hurt. */
  	pci_set_master(pci);

  	*r_via = chip;
  	return 0;
  }

  static int snd_via82xx_probe(struct pci_dev *pci,
  			     const struct pci_device_id *pci_id)

  {

  	struct snd_card *card;
  	struct via82xx_modem *chip;

  	int chip_type = 0, card_type;
  	unsigned int i;
  	int err;

  	err = snd_card_new(&pci->dev, index, id, THIS_MODULE, 0, &card);

  	if (err < 0)
  		return err;

  
  	card_type = pci_id->driver_data;

  	switch (card_type) {
  	case TYPE_CARD_VIA82XX_MODEM:
  		strcpy(card->driver, "VIA82XX-MODEM");
  		sprintf(card->shortname, "VIA 82XX modem");
  		break;
  	default:

  		dev_err(card->dev, "invalid card type %d
  ", card_type);

  		err = -EINVAL;
  		goto __error;
  	}
  		

  	if ((err = snd_via82xx_create(card, pci, chip_type, pci->revision,

  				      ac97_clock, &chip)) < 0)

  		goto __error;

  	card->private_data = chip;

  	if ((err = snd_via82xx_mixer_new(chip)) < 0)
  		goto __error;
  
  	if ((err = snd_via686_pcm_new(chip)) < 0 )
  		goto __error;

  	/* disable interrupts */
  	for (i = 0; i < chip->num_devs; i++)
  		snd_via82xx_channel_reset(chip, &chip->devs[i]);
  
  	sprintf(card->longname, "%s at 0x%lx, irq %d",
  		card->shortname, chip->port, chip->irq);
  
  	snd_via82xx_proc_init(chip);
  
  	if ((err = snd_card_register(card)) < 0) {
  		snd_card_free(card);
  		return err;
  	}
  	pci_set_drvdata(pci, card);

  	return 0;
  
   __error:
  	snd_card_free(card);
  	return err;
  }

  static void snd_via82xx_remove(struct pci_dev *pci)

  {
  	snd_card_free(pci_get_drvdata(pci));

  }

  static struct pci_driver via82xx_modem_driver = {

  	.name = KBUILD_MODNAME,

  	.id_table = snd_via82xx_modem_ids,
  	.probe = snd_via82xx_probe,

  	.remove = snd_via82xx_remove,

  	.driver = {
  		.pm = SND_VIA82XX_PM_OPS,
  	},

  };

  module_pci_driver(via82xx_modem_driver);