/*
   *  Driver for Cirrus Logic CS4281 based PCI soundcard

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

   *
   *
   *   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/gameport.h>

  #include <linux/module.h>

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

  #include <sound/tlv.h>

  #include <sound/opl3.h>
  #include <sound/initval.h>

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

  MODULE_DESCRIPTION("Cirrus Logic CS4281");
  MODULE_LICENSE("GPL");
  MODULE_SUPPORTED_DEVICE("{{Cirrus Logic,CS4281}}");
  
  static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
  static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */

  static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;	/* Enable switches */
  static bool dual_codec[SNDRV_CARDS];	/* dual codec */

  
  module_param_array(index, int, NULL, 0444);
  MODULE_PARM_DESC(index, "Index value for CS4281 soundcard.");
  module_param_array(id, charp, NULL, 0444);
  MODULE_PARM_DESC(id, "ID string for CS4281 soundcard.");
  module_param_array(enable, bool, NULL, 0444);
  MODULE_PARM_DESC(enable, "Enable CS4281 soundcard.");
  module_param_array(dual_codec, bool, NULL, 0444);
  MODULE_PARM_DESC(dual_codec, "Secondary Codec ID (0 = disabled).");
  
  /*

   *  Direct registers
   */
  
  #define CS4281_BA0_SIZE		0x1000
  #define CS4281_BA1_SIZE		0x10000
  
  /*
   *  BA0 registers
   */
  #define BA0_HISR		0x0000	/* Host Interrupt Status Register */
  #define BA0_HISR_INTENA		(1<<31)	/* Internal Interrupt Enable Bit */
  #define BA0_HISR_MIDI		(1<<22)	/* MIDI port interrupt */
  #define BA0_HISR_FIFOI		(1<<20)	/* FIFO polled interrupt */
  #define BA0_HISR_DMAI		(1<<18)	/* DMA interrupt (half or end) */
  #define BA0_HISR_FIFO(c)	(1<<(12+(c))) /* FIFO channel interrupt */
  #define BA0_HISR_DMA(c)		(1<<(8+(c)))  /* DMA channel interrupt */
  #define BA0_HISR_GPPI		(1<<5)	/* General Purpose Input (Primary chip) */
  #define BA0_HISR_GPSI		(1<<4)	/* General Purpose Input (Secondary chip) */
  #define BA0_HISR_GP3I		(1<<3)	/* GPIO3 pin Interrupt */
  #define BA0_HISR_GP1I		(1<<2)	/* GPIO1 pin Interrupt */
  #define BA0_HISR_VUPI		(1<<1)	/* VOLUP pin Interrupt */
  #define BA0_HISR_VDNI		(1<<0)	/* VOLDN pin Interrupt */
  
  #define BA0_HICR		0x0008	/* Host Interrupt Control Register */
  #define BA0_HICR_CHGM		(1<<1)	/* INTENA Change Mask */
  #define BA0_HICR_IEV		(1<<0)	/* INTENA Value */
  #define BA0_HICR_EOI		(3<<0)	/* End of Interrupt command */
  
  #define BA0_HIMR		0x000c	/* Host Interrupt Mask Register */
  					/* Use same contants as for BA0_HISR */
  
  #define BA0_IIER		0x0010	/* ISA Interrupt Enable Register */
  
  #define BA0_HDSR0		0x00f0	/* Host DMA Engine 0 Status Register */
  #define BA0_HDSR1		0x00f4	/* Host DMA Engine 1 Status Register */
  #define BA0_HDSR2		0x00f8	/* Host DMA Engine 2 Status Register */
  #define BA0_HDSR3		0x00fc	/* Host DMA Engine 3 Status Register */
  
  #define BA0_HDSR_CH1P		(1<<25)	/* Channel 1 Pending */
  #define BA0_HDSR_CH2P		(1<<24)	/* Channel 2 Pending */
  #define BA0_HDSR_DHTC		(1<<17)	/* DMA Half Terminal Count */
  #define BA0_HDSR_DTC		(1<<16)	/* DMA Terminal Count */
  #define BA0_HDSR_DRUN		(1<<15)	/* DMA Running */
  #define BA0_HDSR_RQ		(1<<7)	/* Pending Request */
  
  #define BA0_DCA0		0x0110	/* Host DMA Engine 0 Current Address */
  #define BA0_DCC0		0x0114	/* Host DMA Engine 0 Current Count */
  #define BA0_DBA0		0x0118	/* Host DMA Engine 0 Base Address */
  #define BA0_DBC0		0x011c	/* Host DMA Engine 0 Base Count */
  #define BA0_DCA1		0x0120	/* Host DMA Engine 1 Current Address */
  #define BA0_DCC1		0x0124	/* Host DMA Engine 1 Current Count */
  #define BA0_DBA1		0x0128	/* Host DMA Engine 1 Base Address */
  #define BA0_DBC1		0x012c	/* Host DMA Engine 1 Base Count */
  #define BA0_DCA2		0x0130	/* Host DMA Engine 2 Current Address */
  #define BA0_DCC2		0x0134	/* Host DMA Engine 2 Current Count */
  #define BA0_DBA2		0x0138	/* Host DMA Engine 2 Base Address */
  #define BA0_DBC2		0x013c	/* Host DMA Engine 2 Base Count */
  #define BA0_DCA3		0x0140	/* Host DMA Engine 3 Current Address */
  #define BA0_DCC3		0x0144	/* Host DMA Engine 3 Current Count */
  #define BA0_DBA3		0x0148	/* Host DMA Engine 3 Base Address */
  #define BA0_DBC3		0x014c	/* Host DMA Engine 3 Base Count */
  #define BA0_DMR0		0x0150	/* Host DMA Engine 0 Mode */
  #define BA0_DCR0		0x0154	/* Host DMA Engine 0 Command */
  #define BA0_DMR1		0x0158	/* Host DMA Engine 1 Mode */
  #define BA0_DCR1		0x015c	/* Host DMA Engine 1 Command */
  #define BA0_DMR2		0x0160	/* Host DMA Engine 2 Mode */
  #define BA0_DCR2		0x0164	/* Host DMA Engine 2 Command */
  #define BA0_DMR3		0x0168	/* Host DMA Engine 3 Mode */
  #define BA0_DCR3		0x016c	/* Host DMA Engine 3 Command */
  
  #define BA0_DMR_DMA		(1<<29)	/* Enable DMA mode */
  #define BA0_DMR_POLL		(1<<28)	/* Enable poll mode */
  #define BA0_DMR_TBC		(1<<25)	/* Transfer By Channel */
  #define BA0_DMR_CBC		(1<<24)	/* Count By Channel (0 = frame resolution) */
  #define BA0_DMR_SWAPC		(1<<22)	/* Swap Left/Right Channels */
  #define BA0_DMR_SIZE20		(1<<20)	/* Sample is 20-bit */
  #define BA0_DMR_USIGN		(1<<19)	/* Unsigned */
  #define BA0_DMR_BEND		(1<<18)	/* Big Endian */
  #define BA0_DMR_MONO		(1<<17)	/* Mono */
  #define BA0_DMR_SIZE8		(1<<16)	/* Sample is 8-bit */
  #define BA0_DMR_TYPE_DEMAND	(0<<6)
  #define BA0_DMR_TYPE_SINGLE	(1<<6)
  #define BA0_DMR_TYPE_BLOCK	(2<<6)
  #define BA0_DMR_TYPE_CASCADE	(3<<6)	/* Not supported */
  #define BA0_DMR_DEC		(1<<5)	/* Access Increment (0) or Decrement (1) */
  #define BA0_DMR_AUTO		(1<<4)	/* Auto-Initialize */
  #define BA0_DMR_TR_VERIFY	(0<<2)	/* Verify Transfer */
  #define BA0_DMR_TR_WRITE	(1<<2)	/* Write Transfer */
  #define BA0_DMR_TR_READ		(2<<2)	/* Read Transfer */
  
  #define BA0_DCR_HTCIE		(1<<17)	/* Half Terminal Count Interrupt */
  #define BA0_DCR_TCIE		(1<<16)	/* Terminal Count Interrupt */
  #define BA0_DCR_MSK		(1<<0)	/* DMA Mask bit */
  
  #define BA0_FCR0		0x0180	/* FIFO Control 0 */
  #define BA0_FCR1		0x0184	/* FIFO Control 1 */
  #define BA0_FCR2		0x0188	/* FIFO Control 2 */
  #define BA0_FCR3		0x018c	/* FIFO Control 3 */
  
  #define BA0_FCR_FEN		(1<<31)	/* FIFO Enable bit */
  #define BA0_FCR_DACZ		(1<<30)	/* DAC Zero */
  #define BA0_FCR_PSH		(1<<29)	/* Previous Sample Hold */
  #define BA0_FCR_RS(x)		(((x)&0x1f)<<24) /* Right Slot Mapping */
  #define BA0_FCR_LS(x)		(((x)&0x1f)<<16) /* Left Slot Mapping */
  #define BA0_FCR_SZ(x)		(((x)&0x7f)<<8)	/* FIFO buffer size (in samples) */
  #define BA0_FCR_OF(x)		(((x)&0x7f)<<0)	/* FIFO starting offset (in samples) */
  
  #define BA0_FPDR0		0x0190	/* FIFO Polled Data 0 */
  #define BA0_FPDR1		0x0194	/* FIFO Polled Data 1 */
  #define BA0_FPDR2		0x0198	/* FIFO Polled Data 2 */
  #define BA0_FPDR3		0x019c	/* FIFO Polled Data 3 */
  
  #define BA0_FCHS		0x020c	/* FIFO Channel Status */
  #define BA0_FCHS_RCO(x)		(1<<(7+(((x)&3)<<3))) /* Right Channel Out */
  #define BA0_FCHS_LCO(x)		(1<<(6+(((x)&3)<<3))) /* Left Channel Out */
  #define BA0_FCHS_MRP(x)		(1<<(5+(((x)&3)<<3))) /* Move Read Pointer */
  #define BA0_FCHS_FE(x)		(1<<(4+(((x)&3)<<3))) /* FIFO Empty */
  #define BA0_FCHS_FF(x)		(1<<(3+(((x)&3)<<3))) /* FIFO Full */
  #define BA0_FCHS_IOR(x)		(1<<(2+(((x)&3)<<3))) /* Internal Overrun Flag */
  #define BA0_FCHS_RCI(x)		(1<<(1+(((x)&3)<<3))) /* Right Channel In */
  #define BA0_FCHS_LCI(x)		(1<<(0+(((x)&3)<<3))) /* Left Channel In */
  
  #define BA0_FSIC0		0x0210	/* FIFO Status and Interrupt Control 0 */
  #define BA0_FSIC1		0x0214	/* FIFO Status and Interrupt Control 1 */
  #define BA0_FSIC2		0x0218	/* FIFO Status and Interrupt Control 2 */
  #define BA0_FSIC3		0x021c	/* FIFO Status and Interrupt Control 3 */
  
  #define BA0_FSIC_FIC(x)		(((x)&0x7f)<<24) /* FIFO Interrupt Count */
  #define BA0_FSIC_FORIE		(1<<23) /* FIFO OverRun Interrupt Enable */
  #define BA0_FSIC_FURIE		(1<<22) /* FIFO UnderRun Interrupt Enable */
  #define BA0_FSIC_FSCIE		(1<<16)	/* FIFO Sample Count Interrupt Enable */
  #define BA0_FSIC_FSC(x)		(((x)&0x7f)<<8) /* FIFO Sample Count */
  #define BA0_FSIC_FOR		(1<<7)	/* FIFO OverRun */
  #define BA0_FSIC_FUR		(1<<6)	/* FIFO UnderRun */
  #define BA0_FSIC_FSCR		(1<<0)	/* FIFO Sample Count Reached */
  
  #define BA0_PMCS		0x0344	/* Power Management Control/Status */
  #define BA0_CWPR		0x03e0	/* Configuration Write Protect */

  #define BA0_EPPMC		0x03e4	/* Extended PCI Power Management Control */

  #define BA0_EPPMC_FPDN		(1<<14) /* Full Power DowN */

  #define BA0_GPIOR		0x03e8	/* GPIO Pin Interface Register */
  
  #define BA0_SPMC		0x03ec	/* Serial Port Power Management Control (& ASDIN2 enable) */
  #define BA0_SPMC_GIPPEN		(1<<15)	/* GP INT Primary PME# Enable */
  #define BA0_SPMC_GISPEN		(1<<14)	/* GP INT Secondary PME# Enable */
  #define BA0_SPMC_EESPD		(1<<9)	/* EEPROM Serial Port Disable */
  #define BA0_SPMC_ASDI2E		(1<<8)	/* ASDIN2 Enable */
  #define BA0_SPMC_ASDO		(1<<7)	/* Asynchronous ASDOUT Assertion */
  #define BA0_SPMC_WUP2		(1<<3)	/* Wakeup for Secondary Input */
  #define BA0_SPMC_WUP1		(1<<2)	/* Wakeup for Primary Input */
  #define BA0_SPMC_ASYNC		(1<<1)	/* Asynchronous ASYNC Assertion */
  #define BA0_SPMC_RSTN		(1<<0)	/* Reset Not! */
  
  #define BA0_CFLR		0x03f0	/* Configuration Load Register (EEPROM or BIOS) */
  #define BA0_CFLR_DEFAULT	0x00000001 /* CFLR must be in AC97 link mode */
  #define BA0_IISR		0x03f4	/* ISA Interrupt Select */
  #define BA0_TMS			0x03f8	/* Test Register */
  #define BA0_SSVID		0x03fc	/* Subsystem ID register */
  
  #define BA0_CLKCR1		0x0400	/* Clock Control Register 1 */
  #define BA0_CLKCR1_CLKON	(1<<25)	/* Read Only */
  #define BA0_CLKCR1_DLLRDY	(1<<24)	/* DLL Ready */
  #define BA0_CLKCR1_DLLOS	(1<<6)	/* DLL Output Select */
  #define BA0_CLKCR1_SWCE		(1<<5)	/* Clock Enable */
  #define BA0_CLKCR1_DLLP		(1<<4)	/* DLL PowerUp */
  #define BA0_CLKCR1_DLLSS	(((x)&3)<<3) /* DLL Source Select */
  
  #define BA0_FRR			0x0410	/* Feature Reporting Register */
  #define BA0_SLT12O		0x041c	/* Slot 12 GPIO Output Register for AC-Link */
  
  #define BA0_SERMC		0x0420	/* Serial Port Master Control */
  #define BA0_SERMC_FCRN		(1<<27)	/* Force Codec Ready Not */
  #define BA0_SERMC_ODSEN2	(1<<25)	/* On-Demand Support Enable ASDIN2 */
  #define BA0_SERMC_ODSEN1	(1<<24)	/* On-Demand Support Enable ASDIN1 */
  #define BA0_SERMC_SXLB		(1<<21)	/* ASDIN2 to ASDOUT Loopback */
  #define BA0_SERMC_SLB		(1<<20)	/* ASDOUT to ASDIN2 Loopback */
  #define BA0_SERMC_LOVF		(1<<19)	/* Loopback Output Valid Frame bit */
  #define BA0_SERMC_TCID(x)	(((x)&3)<<16) /* Target Secondary Codec ID */
  #define BA0_SERMC_PXLB		(5<<1)	/* Primary Port External Loopback */
  #define BA0_SERMC_PLB		(4<<1)	/* Primary Port Internal Loopback */
  #define BA0_SERMC_PTC		(7<<1)	/* Port Timing Configuration */
  #define BA0_SERMC_PTC_AC97	(1<<1)	/* AC97 mode */
  #define BA0_SERMC_MSPE		(1<<0)	/* Master Serial Port Enable */
  
  #define BA0_SERC1		0x0428	/* Serial Port Configuration 1 */
  #define BA0_SERC1_SO1F(x)	(((x)&7)>>1) /* Primary Output Port Format */
  #define BA0_SERC1_AC97		(1<<1)
  #define BA0_SERC1_SO1EN		(1<<0)	/* Primary Output Port Enable */
  
  #define BA0_SERC2		0x042c	/* Serial Port Configuration 2 */
  #define BA0_SERC2_SI1F(x)	(((x)&7)>>1) /* Primary Input Port Format */
  #define BA0_SERC2_AC97		(1<<1)
  #define BA0_SERC2_SI1EN		(1<<0)	/* Primary Input Port Enable */
  
  #define BA0_SLT12M		0x045c	/* Slot 12 Monitor Register for Primary AC-Link */
  
  #define BA0_ACCTL		0x0460	/* AC'97 Control */
  #define BA0_ACCTL_TC		(1<<6)	/* Target Codec */
  #define BA0_ACCTL_CRW		(1<<4)	/* 0=Write, 1=Read Command */
  #define BA0_ACCTL_DCV		(1<<3)	/* Dynamic Command Valid */
  #define BA0_ACCTL_VFRM		(1<<2)	/* Valid Frame */
  #define BA0_ACCTL_ESYN		(1<<1)	/* Enable Sync */
  
  #define BA0_ACSTS		0x0464	/* AC'97 Status */
  #define BA0_ACSTS_VSTS		(1<<1)	/* Valid Status */
  #define BA0_ACSTS_CRDY		(1<<0)	/* Codec Ready */
  
  #define BA0_ACOSV		0x0468	/* AC'97 Output Slot Valid */
  #define BA0_ACOSV_SLV(x)	(1<<((x)-3))
  
  #define BA0_ACCAD		0x046c	/* AC'97 Command Address */
  #define BA0_ACCDA		0x0470	/* AC'97 Command Data */
  
  #define BA0_ACISV		0x0474	/* AC'97 Input Slot Valid */
  #define BA0_ACISV_SLV(x)	(1<<((x)-3))
  
  #define BA0_ACSAD		0x0478	/* AC'97 Status Address */
  #define BA0_ACSDA		0x047c	/* AC'97 Status Data */
  #define BA0_JSPT		0x0480	/* Joystick poll/trigger */
  #define BA0_JSCTL		0x0484	/* Joystick control */
  #define BA0_JSC1		0x0488	/* Joystick control */
  #define BA0_JSC2		0x048c	/* Joystick control */
  #define BA0_JSIO		0x04a0
  
  #define BA0_MIDCR		0x0490	/* MIDI Control */
  #define BA0_MIDCR_MRST		(1<<5)	/* Reset MIDI Interface */
  #define BA0_MIDCR_MLB		(1<<4)	/* MIDI Loop Back Enable */
  #define BA0_MIDCR_TIE		(1<<3)	/* MIDI Transmuit Interrupt Enable */
  #define BA0_MIDCR_RIE		(1<<2)	/* MIDI Receive Interrupt Enable */
  #define BA0_MIDCR_RXE		(1<<1)	/* MIDI Receive Enable */
  #define BA0_MIDCR_TXE		(1<<0)	/* MIDI Transmit Enable */
  
  #define BA0_MIDCMD		0x0494	/* MIDI Command (wo) */
  
  #define BA0_MIDSR		0x0494	/* MIDI Status (ro) */
  #define BA0_MIDSR_RDA		(1<<15)	/* Sticky bit (RBE 1->0) */
  #define BA0_MIDSR_TBE		(1<<14) /* Sticky bit (TBF 0->1) */
  #define BA0_MIDSR_RBE		(1<<7)	/* Receive Buffer Empty */
  #define BA0_MIDSR_TBF		(1<<6)	/* Transmit Buffer Full */
  
  #define BA0_MIDWP		0x0498	/* MIDI Write */
  #define BA0_MIDRP		0x049c	/* MIDI Read (ro) */
  
  #define BA0_AODSD1		0x04a8	/* AC'97 On-Demand Slot Disable for primary link (ro) */
  #define BA0_AODSD1_NDS(x)	(1<<((x)-3))
  
  #define BA0_AODSD2		0x04ac	/* AC'97 On-Demand Slot Disable for secondary link (ro) */
  #define BA0_AODSD2_NDS(x)	(1<<((x)-3))
  
  #define BA0_CFGI		0x04b0	/* Configure Interface (EEPROM interface) */
  #define BA0_SLT12M2		0x04dc	/* Slot 12 Monitor Register 2 for secondary AC-link */
  #define BA0_ACSTS2		0x04e4	/* AC'97 Status Register 2 */
  #define BA0_ACISV2		0x04f4	/* AC'97 Input Slot Valid Register 2 */
  #define BA0_ACSAD2		0x04f8	/* AC'97 Status Address Register 2 */
  #define BA0_ACSDA2		0x04fc	/* AC'97 Status Data Register 2 */
  #define BA0_FMSR		0x0730	/* FM Synthesis Status (ro) */
  #define BA0_B0AP		0x0730	/* FM Bank 0 Address Port (wo) */
  #define BA0_FMDP		0x0734	/* FM Data Port */
  #define BA0_B1AP		0x0738	/* FM Bank 1 Address Port */
  #define BA0_B1DP		0x073c	/* FM Bank 1 Data Port */
  
  #define BA0_SSPM		0x0740	/* Sound System Power Management */
  #define BA0_SSPM_MIXEN		(1<<6)	/* Playback SRC + FM/Wavetable MIX */
  #define BA0_SSPM_CSRCEN		(1<<5)	/* Capture Sample Rate Converter Enable */
  #define BA0_SSPM_PSRCEN		(1<<4)	/* Playback Sample Rate Converter Enable */
  #define BA0_SSPM_JSEN		(1<<3)	/* Joystick Enable */
  #define BA0_SSPM_ACLEN		(1<<2)	/* Serial Port Engine and AC-Link Enable */
  #define BA0_SSPM_FMEN		(1<<1)	/* FM Synthesis Block Enable */
  
  #define BA0_DACSR		0x0744	/* DAC Sample Rate - Playback SRC */
  #define BA0_ADCSR		0x0748	/* ADC Sample Rate - Capture SRC */
  
  #define BA0_SSCR		0x074c	/* Sound System Control Register */
  #define BA0_SSCR_HVS1		(1<<23)	/* Hardwave Volume Step (0=1,1=2) */
  #define BA0_SSCR_MVCS		(1<<19)	/* Master Volume Codec Select */
  #define BA0_SSCR_MVLD		(1<<18)	/* Master Volume Line Out Disable */
  #define BA0_SSCR_MVAD		(1<<17)	/* Master Volume Alternate Out Disable */
  #define BA0_SSCR_MVMD		(1<<16)	/* Master Volume Mono Out Disable */
  #define BA0_SSCR_XLPSRC		(1<<8)	/* External SRC Loopback Mode */
  #define BA0_SSCR_LPSRC		(1<<7)	/* SRC Loopback Mode */
  #define BA0_SSCR_CDTX		(1<<5)	/* CD Transfer Data */
  #define BA0_SSCR_HVC		(1<<3)	/* Harware Volume Control Enable */
  
  #define BA0_FMLVC		0x0754	/* FM Synthesis Left Volume Control */
  #define BA0_FMRVC		0x0758	/* FM Synthesis Right Volume Control */
  #define BA0_SRCSA		0x075c	/* SRC Slot Assignments */
  #define BA0_PPLVC		0x0760	/* PCM Playback Left Volume Control */
  #define BA0_PPRVC		0x0764	/* PCM Playback Right Volume Control */
  #define BA0_PASR		0x0768	/* playback sample rate */
  #define BA0_CASR		0x076C	/* capture sample rate */
  
  /* Source Slot Numbers - Playback */
  #define SRCSLOT_LEFT_PCM_PLAYBACK		0
  #define SRCSLOT_RIGHT_PCM_PLAYBACK		1
  #define SRCSLOT_PHONE_LINE_1_DAC		2
  #define SRCSLOT_CENTER_PCM_PLAYBACK		3
  #define SRCSLOT_LEFT_SURROUND_PCM_PLAYBACK	4
  #define SRCSLOT_RIGHT_SURROUND_PCM_PLAYBACK	5
  #define SRCSLOT_LFE_PCM_PLAYBACK		6
  #define SRCSLOT_PHONE_LINE_2_DAC		7
  #define SRCSLOT_HEADSET_DAC			8
  #define SRCSLOT_LEFT_WT				29  /* invalid for BA0_SRCSA */
  #define SRCSLOT_RIGHT_WT			30  /* invalid for BA0_SRCSA */
  
  /* Source Slot Numbers - Capture */
  #define SRCSLOT_LEFT_PCM_RECORD			10
  #define SRCSLOT_RIGHT_PCM_RECORD		11
  #define SRCSLOT_PHONE_LINE_1_ADC		12
  #define SRCSLOT_MIC_ADC				13
  #define SRCSLOT_PHONE_LINE_2_ADC		17
  #define SRCSLOT_HEADSET_ADC			18
  #define SRCSLOT_SECONDARY_LEFT_PCM_RECORD	20
  #define SRCSLOT_SECONDARY_RIGHT_PCM_RECORD	21
  #define SRCSLOT_SECONDARY_PHONE_LINE_1_ADC	22
  #define SRCSLOT_SECONDARY_MIC_ADC		23
  #define SRCSLOT_SECONDARY_PHONE_LINE_2_ADC	27
  #define SRCSLOT_SECONDARY_HEADSET_ADC		28
  
  /* Source Slot Numbers - Others */
  #define SRCSLOT_POWER_DOWN			31
  
  /* MIDI modes */
  #define CS4281_MODE_OUTPUT		(1<<0)
  #define CS4281_MODE_INPUT		(1<<1)
  
  /* joystick bits */
  /* Bits for JSPT */
  #define JSPT_CAX                                0x00000001
  #define JSPT_CAY                                0x00000002
  #define JSPT_CBX                                0x00000004
  #define JSPT_CBY                                0x00000008
  #define JSPT_BA1                                0x00000010
  #define JSPT_BA2                                0x00000020
  #define JSPT_BB1                                0x00000040
  #define JSPT_BB2                                0x00000080
  
  /* Bits for JSCTL */
  #define JSCTL_SP_MASK                           0x00000003
  #define JSCTL_SP_SLOW                           0x00000000
  #define JSCTL_SP_MEDIUM_SLOW                    0x00000001
  #define JSCTL_SP_MEDIUM_FAST                    0x00000002
  #define JSCTL_SP_FAST                           0x00000003
  #define JSCTL_ARE                               0x00000004
  
  /* Data register pairs masks */
  #define JSC1_Y1V_MASK                           0x0000FFFF
  #define JSC1_X1V_MASK                           0xFFFF0000
  #define JSC1_Y1V_SHIFT                          0
  #define JSC1_X1V_SHIFT                          16
  #define JSC2_Y2V_MASK                           0x0000FFFF
  #define JSC2_X2V_MASK                           0xFFFF0000
  #define JSC2_Y2V_SHIFT                          0
  #define JSC2_X2V_SHIFT                          16
  
  /* JS GPIO */
  #define JSIO_DAX                                0x00000001
  #define JSIO_DAY                                0x00000002
  #define JSIO_DBX                                0x00000004
  #define JSIO_DBY                                0x00000008
  #define JSIO_AXOE                               0x00000010
  #define JSIO_AYOE                               0x00000020
  #define JSIO_BXOE                               0x00000040
  #define JSIO_BYOE                               0x00000080
  
  /*
   *
   */

  struct cs4281_dma {
  	struct snd_pcm_substream *substream;

  	unsigned int regDBA;		/* offset to DBA register */
  	unsigned int regDCA;		/* offset to DCA register */
  	unsigned int regDBC;		/* offset to DBC register */
  	unsigned int regDCC;		/* offset to DCC register */
  	unsigned int regDMR;		/* offset to DMR register */
  	unsigned int regDCR;		/* offset to DCR register */
  	unsigned int regHDSR;		/* offset to HDSR register */
  	unsigned int regFCR;		/* offset to FCR register */
  	unsigned int regFSIC;		/* offset to FSIC register */
  	unsigned int valDMR;		/* DMA mode */
  	unsigned int valDCR;		/* DMA command */
  	unsigned int valFCR;		/* FIFO control */
  	unsigned int fifo_offset;	/* FIFO offset within BA1 */
  	unsigned char left_slot;	/* FIFO left slot */
  	unsigned char right_slot;	/* FIFO right slot */
  	int frag;			/* period number */
  };
  
  #define SUSPEND_REGISTERS	20

  struct cs4281 {

  	int irq;
  
  	void __iomem *ba0;		/* virtual (accessible) address */
  	void __iomem *ba1;		/* virtual (accessible) address */
  	unsigned long ba0_addr;
  	unsigned long ba1_addr;
  
  	int dual_codec;

  	struct snd_ac97_bus *ac97_bus;
  	struct snd_ac97 *ac97;
  	struct snd_ac97 *ac97_secondary;

  
  	struct pci_dev *pci;

  	struct snd_card *card;
  	struct snd_pcm *pcm;
  	struct snd_rawmidi *rmidi;
  	struct snd_rawmidi_substream *midi_input;
  	struct snd_rawmidi_substream *midi_output;

  	struct cs4281_dma dma[4];

  
  	unsigned char src_left_play_slot;
  	unsigned char src_right_play_slot;
  	unsigned char src_left_rec_slot;
  	unsigned char src_right_rec_slot;
  
  	unsigned int spurious_dhtc_irq;
  	unsigned int spurious_dtc_irq;
  
  	spinlock_t reg_lock;
  	unsigned int midcr;
  	unsigned int uartm;
  
  	struct gameport *gameport;
  
  #ifdef CONFIG_PM
  	u32 suspend_regs[SUSPEND_REGISTERS];
  #endif
  
  };

  static irqreturn_t snd_cs4281_interrupt(int irq, void *dev_id);

  static DEFINE_PCI_DEVICE_TABLE(snd_cs4281_ids) = {

  	{ PCI_VDEVICE(CIRRUS, 0x6005), 0, },	/* CS4281 */

  	{ 0, }
  };
  
  MODULE_DEVICE_TABLE(pci, snd_cs4281_ids);
  
  /*
   *  constants
   */
  
  #define CS4281_FIFO_SIZE	32
  
  /*
   *  common I/O routines
   */

  static inline void snd_cs4281_pokeBA0(struct cs4281 *chip, unsigned long offset,
  				      unsigned int val)

  {
          writel(val, chip->ba0 + offset);
  }

  static inline unsigned int snd_cs4281_peekBA0(struct cs4281 *chip, unsigned long offset)

  {
          return readl(chip->ba0 + offset);
  }

  static void snd_cs4281_ac97_write(struct snd_ac97 *ac97,

  				  unsigned short reg, unsigned short val)
  {
  	/*
  	 *  1. Write ACCAD = Command Address Register = 46Ch for AC97 register address
  	 *  2. Write ACCDA = Command Data Register = 470h    for data to write to AC97
  	 *  3. Write ACCTL = Control Register = 460h for initiating the write
  	 *  4. Read ACCTL = 460h, DCV should be reset by now and 460h = 07h
  	 *  5. if DCV not cleared, break and return error
  	 */

  	struct cs4281 *chip = ac97->private_data;

  	int count;
  
  	/*
  	 *  Setup the AC97 control registers on the CS461x to send the
  	 *  appropriate command to the AC97 to perform the read.
  	 *  ACCAD = Command Address Register = 46Ch
  	 *  ACCDA = Command Data Register = 470h
  	 *  ACCTL = Control Register = 460h
  	 *  set DCV - will clear when process completed
  	 *  reset CRW - Write command
  	 *  set VFRM - valid frame enabled
  	 *  set ESYN - ASYNC generation enabled
  	 *  set RSTN - ARST# inactive, AC97 codec not reset
           */
  	snd_cs4281_pokeBA0(chip, BA0_ACCAD, reg);
  	snd_cs4281_pokeBA0(chip, BA0_ACCDA, val);
  	snd_cs4281_pokeBA0(chip, BA0_ACCTL, BA0_ACCTL_DCV | BA0_ACCTL_VFRM |
  				            BA0_ACCTL_ESYN | (ac97->num ? BA0_ACCTL_TC : 0));
  	for (count = 0; count < 2000; count++) {
  		/*
  		 *  First, we want to wait for a short time.
  		 */
  		udelay(10);
  		/*
  		 *  Now, check to see if the write has completed.
  		 *  ACCTL = 460h, DCV should be reset by now and 460h = 07h
  		 */
  		if (!(snd_cs4281_peekBA0(chip, BA0_ACCTL) & BA0_ACCTL_DCV)) {
  			return;
  		}
  	}
  	snd_printk(KERN_ERR "AC'97 write problem, reg = 0x%x, val = 0x%x
  ", reg, val);
  }

  static unsigned short snd_cs4281_ac97_read(struct snd_ac97 *ac97,

  					   unsigned short reg)
  {

  	struct cs4281 *chip = ac97->private_data;

  	int count;
  	unsigned short result;
  	// FIXME: volatile is necessary in the following due to a bug of
  	// some gcc versions

  	volatile int ac97_num = ((volatile struct snd_ac97 *)ac97)->num;

  
  	/*
  	 *  1. Write ACCAD = Command Address Register = 46Ch for AC97 register address
  	 *  2. Write ACCDA = Command Data Register = 470h    for data to write to AC97 
  	 *  3. Write ACCTL = Control Register = 460h for initiating the write
  	 *  4. Read ACCTL = 460h, DCV should be reset by now and 460h = 17h
  	 *  5. if DCV not cleared, break and return error
  	 *  6. Read ACSTS = Status Register = 464h, check VSTS bit
  	 */
  
  	snd_cs4281_peekBA0(chip, ac97_num ? BA0_ACSDA2 : BA0_ACSDA);
  
  	/*
  	 *  Setup the AC97 control registers on the CS461x to send the
  	 *  appropriate command to the AC97 to perform the read.
  	 *  ACCAD = Command Address Register = 46Ch
  	 *  ACCDA = Command Data Register = 470h
  	 *  ACCTL = Control Register = 460h
  	 *  set DCV - will clear when process completed
  	 *  set CRW - Read command
  	 *  set VFRM - valid frame enabled
  	 *  set ESYN - ASYNC generation enabled
  	 *  set RSTN - ARST# inactive, AC97 codec not reset
  	 */
  
  	snd_cs4281_pokeBA0(chip, BA0_ACCAD, reg);
  	snd_cs4281_pokeBA0(chip, BA0_ACCDA, 0);
  	snd_cs4281_pokeBA0(chip, BA0_ACCTL, BA0_ACCTL_DCV | BA0_ACCTL_CRW |
  					    BA0_ACCTL_VFRM | BA0_ACCTL_ESYN |
  			   (ac97_num ? BA0_ACCTL_TC : 0));
  
  
  	/*
  	 *  Wait for the read to occur.
  	 */
  	for (count = 0; count < 500; count++) {
  		/*
  		 *  First, we want to wait for a short time.
  	 	 */
  		udelay(10);
  		/*
  		 *  Now, check to see if the read has completed.
  		 *  ACCTL = 460h, DCV should be reset by now and 460h = 17h
  		 */
  		if (!(snd_cs4281_peekBA0(chip, BA0_ACCTL) & BA0_ACCTL_DCV))
  			goto __ok1;
  	}
  
  	snd_printk(KERN_ERR "AC'97 read problem (ACCTL_DCV), reg = 0x%x
  ", reg);
  	result = 0xffff;
  	goto __end;
  	
        __ok1:
  	/*
  	 *  Wait for the valid status bit to go active.
  	 */
  	for (count = 0; count < 100; count++) {
  		/*
  		 *  Read the AC97 status register.
  		 *  ACSTS = Status Register = 464h
  		 *  VSTS - Valid Status
  		 */
  		if (snd_cs4281_peekBA0(chip, ac97_num ? BA0_ACSTS2 : BA0_ACSTS) & BA0_ACSTS_VSTS)
  			goto __ok2;
  		udelay(10);
  	}
  	
  	snd_printk(KERN_ERR "AC'97 read problem (ACSTS_VSTS), reg = 0x%x
  ", reg);
  	result = 0xffff;
  	goto __end;
  
        __ok2:
  	/*
  	 *  Read the data returned from the AC97 register.
  	 *  ACSDA = Status Data Register = 474h
  	 */
  	result = snd_cs4281_peekBA0(chip, ac97_num ? BA0_ACSDA2 : BA0_ACSDA);
  
        __end:
  	return result;
  }
  
  /*
   *  PCM part
   */

  static int snd_cs4281_trigger(struct snd_pcm_substream *substream, int cmd)

  {

  	struct cs4281_dma *dma = substream->runtime->private_data;
  	struct cs4281 *chip = snd_pcm_substream_chip(substream);

  
  	spin_lock(&chip->reg_lock);
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		dma->valDCR |= BA0_DCR_MSK;
  		dma->valFCR |= BA0_FCR_FEN;
  		break;
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		dma->valDCR &= ~BA0_DCR_MSK;
  		dma->valFCR &= ~BA0_FCR_FEN;
  		break;
  	case SNDRV_PCM_TRIGGER_START:
  	case SNDRV_PCM_TRIGGER_RESUME:
  		snd_cs4281_pokeBA0(chip, dma->regDMR, dma->valDMR & ~BA0_DMR_DMA);
  		dma->valDMR |= BA0_DMR_DMA;
  		dma->valDCR &= ~BA0_DCR_MSK;
  		dma->valFCR |= BA0_FCR_FEN;
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  		dma->valDMR &= ~(BA0_DMR_DMA|BA0_DMR_POLL);
  		dma->valDCR |= BA0_DCR_MSK;
  		dma->valFCR &= ~BA0_FCR_FEN;
  		/* Leave wave playback FIFO enabled for FM */
  		if (dma->regFCR != BA0_FCR0)
  			dma->valFCR &= ~BA0_FCR_FEN;
  		break;
  	default:
  		spin_unlock(&chip->reg_lock);
  		return -EINVAL;
  	}
  	snd_cs4281_pokeBA0(chip, dma->regDMR, dma->valDMR);
  	snd_cs4281_pokeBA0(chip, dma->regFCR, dma->valFCR);
  	snd_cs4281_pokeBA0(chip, dma->regDCR, dma->valDCR);
  	spin_unlock(&chip->reg_lock);
  	return 0;
  }
  
  static unsigned int snd_cs4281_rate(unsigned int rate, unsigned int *real_rate)
  {
  	unsigned int val = ~0;
  	
  	if (real_rate)
  		*real_rate = rate;
  	/* special "hardcoded" rates */
  	switch (rate) {
  	case 8000:	return 5;
  	case 11025:	return 4;
  	case 16000:	return 3;
  	case 22050:	return 2;
  	case 44100:	return 1;
  	case 48000:	return 0;
  	default:
  		goto __variable;
  	}
        __variable:
  	val = 1536000 / rate;
  	if (real_rate)
  		*real_rate = 1536000 / val;
  	return val;
  }

  static void snd_cs4281_mode(struct cs4281 *chip, struct cs4281_dma *dma,
  			    struct snd_pcm_runtime *runtime,
  			    int capture, int src)

  {
  	int rec_mono;
  
  	dma->valDMR = BA0_DMR_TYPE_SINGLE | BA0_DMR_AUTO |
  		      (capture ? BA0_DMR_TR_WRITE : BA0_DMR_TR_READ);
  	if (runtime->channels == 1)
  		dma->valDMR |= BA0_DMR_MONO;
  	if (snd_pcm_format_unsigned(runtime->format) > 0)
  		dma->valDMR |= BA0_DMR_USIGN;
  	if (snd_pcm_format_big_endian(runtime->format) > 0)
  		dma->valDMR |= BA0_DMR_BEND;
  	switch (snd_pcm_format_width(runtime->format)) {
  	case 8: dma->valDMR |= BA0_DMR_SIZE8;
  		if (runtime->channels == 1)
  			dma->valDMR |= BA0_DMR_SWAPC;
  		break;
  	case 32: dma->valDMR |= BA0_DMR_SIZE20; break;
  	}
  	dma->frag = 0;	/* for workaround */
  	dma->valDCR = BA0_DCR_TCIE | BA0_DCR_MSK;
  	if (runtime->buffer_size != runtime->period_size)
  		dma->valDCR |= BA0_DCR_HTCIE;
  	/* Initialize DMA */
  	snd_cs4281_pokeBA0(chip, dma->regDBA, runtime->dma_addr);
  	snd_cs4281_pokeBA0(chip, dma->regDBC, runtime->buffer_size - 1);
  	rec_mono = (chip->dma[1].valDMR & BA0_DMR_MONO) == BA0_DMR_MONO;
  	snd_cs4281_pokeBA0(chip, BA0_SRCSA, (chip->src_left_play_slot << 0) |
  					    (chip->src_right_play_slot << 8) |
  					    (chip->src_left_rec_slot << 16) |
  					    ((rec_mono ? 31 : chip->src_right_rec_slot) << 24));
  	if (!src)
  		goto __skip_src;
  	if (!capture) {
  		if (dma->left_slot == chip->src_left_play_slot) {
  			unsigned int val = snd_cs4281_rate(runtime->rate, NULL);

  			snd_BUG_ON(dma->right_slot != chip->src_right_play_slot);

  			snd_cs4281_pokeBA0(chip, BA0_DACSR, val);
  		}
  	} else {
  		if (dma->left_slot == chip->src_left_rec_slot) {
  			unsigned int val = snd_cs4281_rate(runtime->rate, NULL);

  			snd_BUG_ON(dma->right_slot != chip->src_right_rec_slot);

  			snd_cs4281_pokeBA0(chip, BA0_ADCSR, val);
  		}
  	}
        __skip_src:
  	/* Deactivate wave playback FIFO before changing slot assignments */
  	if (dma->regFCR == BA0_FCR0)
  		snd_cs4281_pokeBA0(chip, dma->regFCR, snd_cs4281_peekBA0(chip, dma->regFCR) & ~BA0_FCR_FEN);
  	/* Initialize FIFO */
  	dma->valFCR = BA0_FCR_LS(dma->left_slot) |
  		      BA0_FCR_RS(capture && (dma->valDMR & BA0_DMR_MONO) ? 31 : dma->right_slot) |
  		      BA0_FCR_SZ(CS4281_FIFO_SIZE) |
  		      BA0_FCR_OF(dma->fifo_offset);
  	snd_cs4281_pokeBA0(chip, dma->regFCR, dma->valFCR | (capture ? BA0_FCR_PSH : 0));
  	/* Activate FIFO again for FM playback */
  	if (dma->regFCR == BA0_FCR0)
  		snd_cs4281_pokeBA0(chip, dma->regFCR, dma->valFCR | BA0_FCR_FEN);
  	/* Clear FIFO Status and Interrupt Control Register */
  	snd_cs4281_pokeBA0(chip, dma->regFSIC, 0);
  }

  static int snd_cs4281_hw_params(struct snd_pcm_substream *substream,
  				struct snd_pcm_hw_params *hw_params)

  {
  	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
  }

  static int snd_cs4281_hw_free(struct snd_pcm_substream *substream)

  {
  	return snd_pcm_lib_free_pages(substream);
  }

  static int snd_cs4281_playback_prepare(struct snd_pcm_substream *substream)

  {

  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct cs4281_dma *dma = runtime->private_data;
  	struct cs4281 *chip = snd_pcm_substream_chip(substream);

  
  	spin_lock_irq(&chip->reg_lock);
  	snd_cs4281_mode(chip, dma, runtime, 0, 1);
  	spin_unlock_irq(&chip->reg_lock);
  	return 0;
  }

  static int snd_cs4281_capture_prepare(struct snd_pcm_substream *substream)

  {

  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct cs4281_dma *dma = runtime->private_data;
  	struct cs4281 *chip = snd_pcm_substream_chip(substream);

  
  	spin_lock_irq(&chip->reg_lock);
  	snd_cs4281_mode(chip, dma, runtime, 1, 1);
  	spin_unlock_irq(&chip->reg_lock);
  	return 0;
  }

  static snd_pcm_uframes_t snd_cs4281_pointer(struct snd_pcm_substream *substream)

  {

  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct cs4281_dma *dma = runtime->private_data;
  	struct cs4281 *chip = snd_pcm_substream_chip(substream);

  	/*
  	printk(KERN_DEBUG "DCC = 0x%x, buffer_size = 0x%x, jiffies = %li
  ",
  	       snd_cs4281_peekBA0(chip, dma->regDCC), runtime->buffer_size,
  	       jiffies);
  	*/

  	return runtime->buffer_size -
  	       snd_cs4281_peekBA0(chip, dma->regDCC) - 1;
  }

  static struct snd_pcm_hardware snd_cs4281_playback =

  {

  	.info =			SNDRV_PCM_INFO_MMAP |
  				SNDRV_PCM_INFO_INTERLEAVED |
  				SNDRV_PCM_INFO_MMAP_VALID |
  				SNDRV_PCM_INFO_PAUSE |
  				SNDRV_PCM_INFO_RESUME,

  	.formats =		SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
  				SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
  				SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
  				SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
  				SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE,
  	.rates =		SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
  	.rate_min =		4000,
  	.rate_max =		48000,
  	.channels_min =		1,
  	.channels_max =		2,
  	.buffer_bytes_max =	(512*1024),
  	.period_bytes_min =	64,
  	.period_bytes_max =	(512*1024),
  	.periods_min =		1,
  	.periods_max =		2,
  	.fifo_size =		CS4281_FIFO_SIZE,
  };

  static struct snd_pcm_hardware snd_cs4281_capture =

  {

  	.info =			SNDRV_PCM_INFO_MMAP |
  				SNDRV_PCM_INFO_INTERLEAVED |
  				SNDRV_PCM_INFO_MMAP_VALID |
  				SNDRV_PCM_INFO_PAUSE |
  				SNDRV_PCM_INFO_RESUME,

  	.formats =		SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
  				SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
  				SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
  				SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
  				SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE,
  	.rates =		SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
  	.rate_min =		4000,
  	.rate_max =		48000,
  	.channels_min =		1,
  	.channels_max =		2,
  	.buffer_bytes_max =	(512*1024),
  	.period_bytes_min =	64,
  	.period_bytes_max =	(512*1024),
  	.periods_min =		1,
  	.periods_max =		2,
  	.fifo_size =		CS4281_FIFO_SIZE,
  };

  static int snd_cs4281_playback_open(struct snd_pcm_substream *substream)

  {

  	struct cs4281 *chip = snd_pcm_substream_chip(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct cs4281_dma *dma;

  
  	dma = &chip->dma[0];
  	dma->substream = substream;
  	dma->left_slot = 0;
  	dma->right_slot = 1;
  	runtime->private_data = dma;
  	runtime->hw = snd_cs4281_playback;

  	/* should be detected from the AC'97 layer, but it seems
  	   that although CS4297A rev B reports 18-bit ADC resolution,
  	   samples are 20-bit */
  	snd_pcm_hw_constraint_msbits(runtime, 0, 32, 20);
  	return 0;
  }

  static int snd_cs4281_capture_open(struct snd_pcm_substream *substream)

  {

  	struct cs4281 *chip = snd_pcm_substream_chip(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct cs4281_dma *dma;

  
  	dma = &chip->dma[1];
  	dma->substream = substream;
  	dma->left_slot = 10;
  	dma->right_slot = 11;
  	runtime->private_data = dma;
  	runtime->hw = snd_cs4281_capture;

  	/* should be detected from the AC'97 layer, but it seems
  	   that although CS4297A rev B reports 18-bit ADC resolution,
  	   samples are 20-bit */
  	snd_pcm_hw_constraint_msbits(runtime, 0, 32, 20);
  	return 0;
  }

  static int snd_cs4281_playback_close(struct snd_pcm_substream *substream)

  {

  	struct cs4281_dma *dma = substream->runtime->private_data;

  
  	dma->substream = NULL;
  	return 0;
  }

  static int snd_cs4281_capture_close(struct snd_pcm_substream *substream)

  {

  	struct cs4281_dma *dma = substream->runtime->private_data;

  
  	dma->substream = NULL;
  	return 0;
  }

  static struct snd_pcm_ops snd_cs4281_playback_ops = {

  	.open =		snd_cs4281_playback_open,
  	.close =	snd_cs4281_playback_close,
  	.ioctl =	snd_pcm_lib_ioctl,
  	.hw_params =	snd_cs4281_hw_params,
  	.hw_free =	snd_cs4281_hw_free,
  	.prepare =	snd_cs4281_playback_prepare,
  	.trigger =	snd_cs4281_trigger,
  	.pointer =	snd_cs4281_pointer,
  };

  static struct snd_pcm_ops snd_cs4281_capture_ops = {

  	.open =		snd_cs4281_capture_open,
  	.close =	snd_cs4281_capture_close,
  	.ioctl =	snd_pcm_lib_ioctl,
  	.hw_params =	snd_cs4281_hw_params,
  	.hw_free =	snd_cs4281_hw_free,
  	.prepare =	snd_cs4281_capture_prepare,
  	.trigger =	snd_cs4281_trigger,
  	.pointer =	snd_cs4281_pointer,
  };

  static int __devinit snd_cs4281_pcm(struct cs4281 * chip, int device,
  				    struct snd_pcm ** rpcm)

  {

  	struct snd_pcm *pcm;

  	int err;
  
  	if (rpcm)
  		*rpcm = NULL;
  	err = snd_pcm_new(chip->card, "CS4281", device, 1, 1, &pcm);
  	if (err < 0)
  		return err;
  
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_cs4281_playback_ops);
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_cs4281_capture_ops);
  
  	pcm->private_data = chip;

  	pcm->info_flags = 0;
  	strcpy(pcm->name, "CS4281");
  	chip->pcm = pcm;
  
  	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
  					      snd_dma_pci_data(chip->pci), 64*1024, 512*1024);
  
  	if (rpcm)
  		*rpcm = pcm;
  	return 0;
  }
  
  /*
   *  Mixer section
   */
  
  #define CS_VOL_MASK	0x1f

  static int snd_cs4281_info_volume(struct snd_kcontrol *kcontrol,
  				  struct snd_ctl_elem_info *uinfo)

  {
  	uinfo->type              = SNDRV_CTL_ELEM_TYPE_INTEGER;
  	uinfo->count             = 2;
  	uinfo->value.integer.min = 0;
  	uinfo->value.integer.max = CS_VOL_MASK;
  	return 0;
  }
   

  static int snd_cs4281_get_volume(struct snd_kcontrol *kcontrol,
  				 struct snd_ctl_elem_value *ucontrol)

  {

  	struct cs4281 *chip = snd_kcontrol_chip(kcontrol);

  	int regL = (kcontrol->private_value >> 16) & 0xffff;
  	int regR = kcontrol->private_value & 0xffff;
  	int volL, volR;
  
  	volL = CS_VOL_MASK - (snd_cs4281_peekBA0(chip, regL) & CS_VOL_MASK);
  	volR = CS_VOL_MASK - (snd_cs4281_peekBA0(chip, regR) & CS_VOL_MASK);
  
  	ucontrol->value.integer.value[0] = volL;
  	ucontrol->value.integer.value[1] = volR;
  	return 0;
  }

  static int snd_cs4281_put_volume(struct snd_kcontrol *kcontrol,
  				 struct snd_ctl_elem_value *ucontrol)

  {

  	struct cs4281 *chip = snd_kcontrol_chip(kcontrol);

  	int change = 0;
  	int regL = (kcontrol->private_value >> 16) & 0xffff;
  	int regR = kcontrol->private_value & 0xffff;
  	int volL, volR;
  
  	volL = CS_VOL_MASK - (snd_cs4281_peekBA0(chip, regL) & CS_VOL_MASK);
  	volR = CS_VOL_MASK - (snd_cs4281_peekBA0(chip, regR) & CS_VOL_MASK);
  
  	if (ucontrol->value.integer.value[0] != volL) {
  		volL = CS_VOL_MASK - (ucontrol->value.integer.value[0] & CS_VOL_MASK);
  		snd_cs4281_pokeBA0(chip, regL, volL);
  		change = 1;
  	}

  	if (ucontrol->value.integer.value[1] != volR) {

  		volR = CS_VOL_MASK - (ucontrol->value.integer.value[1] & CS_VOL_MASK);
  		snd_cs4281_pokeBA0(chip, regR, volR);
  		change = 1;
  	}
  	return change;
  }

  static const DECLARE_TLV_DB_SCALE(db_scale_dsp, -4650, 150, 0);

  static struct snd_kcontrol_new snd_cs4281_fm_vol = 

  {
  	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
  	.name = "Synth Playback Volume",
  	.info = snd_cs4281_info_volume, 
  	.get = snd_cs4281_get_volume,
  	.put = snd_cs4281_put_volume, 
  	.private_value = ((BA0_FMLVC << 16) | BA0_FMRVC),

  	.tlv = { .p = db_scale_dsp },

  };

  static struct snd_kcontrol_new snd_cs4281_pcm_vol = 

  {
  	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
  	.name = "PCM Stream Playback Volume",
  	.info = snd_cs4281_info_volume, 
  	.get = snd_cs4281_get_volume,
  	.put = snd_cs4281_put_volume, 
  	.private_value = ((BA0_PPLVC << 16) | BA0_PPRVC),

  	.tlv = { .p = db_scale_dsp },

  };

  static void snd_cs4281_mixer_free_ac97_bus(struct snd_ac97_bus *bus)

  {

  	struct cs4281 *chip = bus->private_data;

  	chip->ac97_bus = NULL;
  }

  static void snd_cs4281_mixer_free_ac97(struct snd_ac97 *ac97)

  {

  	struct cs4281 *chip = ac97->private_data;

  	if (ac97->num)
  		chip->ac97_secondary = NULL;
  	else
  		chip->ac97 = NULL;
  }

  static int __devinit snd_cs4281_mixer(struct cs4281 * chip)

  {

  	struct snd_card *card = chip->card;
  	struct snd_ac97_template ac97;

  	int err;

  	static struct snd_ac97_bus_ops ops = {

  		.write = snd_cs4281_ac97_write,
  		.read = snd_cs4281_ac97_read,
  	};
  
  	if ((err = snd_ac97_bus(card, 0, &ops, chip, &chip->ac97_bus)) < 0)
  		return err;
  	chip->ac97_bus->private_free = snd_cs4281_mixer_free_ac97_bus;
  
  	memset(&ac97, 0, sizeof(ac97));
  	ac97.private_data = chip;
  	ac97.private_free = snd_cs4281_mixer_free_ac97;
  	if ((err = snd_ac97_mixer(chip->ac97_bus, &ac97, &chip->ac97)) < 0)
  		return err;
  	if (chip->dual_codec) {
  		ac97.num = 1;
  		if ((err = snd_ac97_mixer(chip->ac97_bus, &ac97, &chip->ac97_secondary)) < 0)
  			return err;
  	}
  	if ((err = snd_ctl_add(card, snd_ctl_new1(&snd_cs4281_fm_vol, chip))) < 0)
  		return err;
  	if ((err = snd_ctl_add(card, snd_ctl_new1(&snd_cs4281_pcm_vol, chip))) < 0)
  		return err;
  	return 0;
  }
  
  
  /*
   * proc interface
   */

  static void snd_cs4281_proc_read(struct snd_info_entry *entry, 
  				  struct snd_info_buffer *buffer)

  {

  	struct cs4281 *chip = entry->private_data;

  
  	snd_iprintf(buffer, "Cirrus Logic CS4281
  
  ");
  	snd_iprintf(buffer, "Spurious half IRQs   : %u
  ", chip->spurious_dhtc_irq);
  	snd_iprintf(buffer, "Spurious end IRQs    : %u
  ", chip->spurious_dtc_irq);
  }

  static ssize_t snd_cs4281_BA0_read(struct snd_info_entry *entry,
  				   void *file_private_data,
  				   struct file *file, char __user *buf,
  				   size_t count, loff_t pos)

  {

  	struct cs4281 *chip = entry->private_data;

  	if (copy_to_user_fromio(buf, chip->ba0 + pos, count))
  		return -EFAULT;
  	return count;

  }

  static ssize_t snd_cs4281_BA1_read(struct snd_info_entry *entry,
  				   void *file_private_data,
  				   struct file *file, char __user *buf,
  				   size_t count, loff_t pos)

  {

  	struct cs4281 *chip = entry->private_data;

  	if (copy_to_user_fromio(buf, chip->ba1 + pos, count))
  		return -EFAULT;
  	return count;

  }
  
  static struct snd_info_entry_ops snd_cs4281_proc_ops_BA0 = {
  	.read = snd_cs4281_BA0_read,
  };
  
  static struct snd_info_entry_ops snd_cs4281_proc_ops_BA1 = {
  	.read = snd_cs4281_BA1_read,
  };

  static void __devinit snd_cs4281_proc_init(struct cs4281 * chip)

  {

  	struct snd_info_entry *entry;

  
  	if (! snd_card_proc_new(chip->card, "cs4281", &entry))

  		snd_info_set_text_ops(entry, chip, snd_cs4281_proc_read);

  	if (! snd_card_proc_new(chip->card, "cs4281_BA0", &entry)) {
  		entry->content = SNDRV_INFO_CONTENT_DATA;
  		entry->private_data = chip;
  		entry->c.ops = &snd_cs4281_proc_ops_BA0;
  		entry->size = CS4281_BA0_SIZE;
  	}
  	if (! snd_card_proc_new(chip->card, "cs4281_BA1", &entry)) {
  		entry->content = SNDRV_INFO_CONTENT_DATA;
  		entry->private_data = chip;
  		entry->c.ops = &snd_cs4281_proc_ops_BA1;
  		entry->size = CS4281_BA1_SIZE;
  	}
  }
  
  /*
   * joystick support
   */
  
  #if defined(CONFIG_GAMEPORT) || (defined(MODULE) && defined(CONFIG_GAMEPORT_MODULE))
  
  static void snd_cs4281_gameport_trigger(struct gameport *gameport)
  {

  	struct cs4281 *chip = gameport_get_port_data(gameport);

  	if (snd_BUG_ON(!chip))
  		return;

  	snd_cs4281_pokeBA0(chip, BA0_JSPT, 0xff);
  }
  
  static unsigned char snd_cs4281_gameport_read(struct gameport *gameport)
  {

  	struct cs4281 *chip = gameport_get_port_data(gameport);

  	if (snd_BUG_ON(!chip))
  		return 0;

  	return snd_cs4281_peekBA0(chip, BA0_JSPT);
  }
  
  #ifdef COOKED_MODE

  static int snd_cs4281_gameport_cooked_read(struct gameport *gameport,
  					   int *axes, int *buttons)

  {

  	struct cs4281 *chip = gameport_get_port_data(gameport);

  	unsigned js1, js2, jst;
  	

  	if (snd_BUG_ON(!chip))
  		return 0;

  
  	js1 = snd_cs4281_peekBA0(chip, BA0_JSC1);
  	js2 = snd_cs4281_peekBA0(chip, BA0_JSC2);
  	jst = snd_cs4281_peekBA0(chip, BA0_JSPT);
  	
  	*buttons = (~jst >> 4) & 0x0F; 
  	
  	axes[0] = ((js1 & JSC1_Y1V_MASK) >> JSC1_Y1V_SHIFT) & 0xFFFF;
  	axes[1] = ((js1 & JSC1_X1V_MASK) >> JSC1_X1V_SHIFT) & 0xFFFF;
  	axes[2] = ((js2 & JSC2_Y2V_MASK) >> JSC2_Y2V_SHIFT) & 0xFFFF;
  	axes[3] = ((js2 & JSC2_X2V_MASK) >> JSC2_X2V_SHIFT) & 0xFFFF;
  
  	for (jst = 0; jst < 4; ++jst)
  		if (axes[jst] == 0xFFFF) axes[jst] = -1;
  	return 0;
  }
  #else
  #define snd_cs4281_gameport_cooked_read	NULL
  #endif
  
  static int snd_cs4281_gameport_open(struct gameport *gameport, int mode)
  {
  	switch (mode) {
  #ifdef COOKED_MODE
  	case GAMEPORT_MODE_COOKED:
  		return 0;
  #endif
  	case GAMEPORT_MODE_RAW:
  		return 0;
  	default:
  		return -1;
  	}
  	return 0;
  }

  static int __devinit snd_cs4281_create_gameport(struct cs4281 *chip)

  {
  	struct gameport *gp;
  
  	chip->gameport = gp = gameport_allocate_port();
  	if (!gp) {
  		printk(KERN_ERR "cs4281: cannot allocate memory for gameport
  ");
  		return -ENOMEM;
  	}
  
  	gameport_set_name(gp, "CS4281 Gameport");
  	gameport_set_phys(gp, "pci%s/gameport0", pci_name(chip->pci));
  	gameport_set_dev_parent(gp, &chip->pci->dev);
  	gp->open = snd_cs4281_gameport_open;
  	gp->read = snd_cs4281_gameport_read;
  	gp->trigger = snd_cs4281_gameport_trigger;
  	gp->cooked_read = snd_cs4281_gameport_cooked_read;
  	gameport_set_port_data(gp, chip);
  
  	snd_cs4281_pokeBA0(chip, BA0_JSIO, 0xFF); // ?
  	snd_cs4281_pokeBA0(chip, BA0_JSCTL, JSCTL_SP_MEDIUM_SLOW);
  
  	gameport_register_port(gp);
  
  	return 0;
  }

  static void snd_cs4281_free_gameport(struct cs4281 *chip)

  {
  	if (chip->gameport) {
  		gameport_unregister_port(chip->gameport);
  		chip->gameport = NULL;
  	}
  }
  #else

  static inline int snd_cs4281_create_gameport(struct cs4281 *chip) { return -ENOSYS; }
  static inline void snd_cs4281_free_gameport(struct cs4281 *chip) { }

  #endif /* CONFIG_GAMEPORT || (MODULE && CONFIG_GAMEPORT_MODULE) */

  static int snd_cs4281_free(struct cs4281 *chip)

  {
  	snd_cs4281_free_gameport(chip);
  
  	if (chip->irq >= 0)
  		synchronize_irq(chip->irq);
  
  	/* Mask interrupts */
  	snd_cs4281_pokeBA0(chip, BA0_HIMR, 0x7fffffff);
  	/* Stop the DLL Clock logic. */
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, 0);
  	/* Sound System Power Management - Turn Everything OFF */
  	snd_cs4281_pokeBA0(chip, BA0_SSPM, 0);
  	/* PCI interface - D3 state */
  	pci_set_power_state(chip->pci, 3);
  
  	if (chip->irq >= 0)

  		free_irq(chip->irq, chip);

  	if (chip->ba0)
  		iounmap(chip->ba0);
  	if (chip->ba1)
  		iounmap(chip->ba1);
  	pci_release_regions(chip->pci);
  	pci_disable_device(chip->pci);
  
  	kfree(chip);
  	return 0;
  }

  static int snd_cs4281_dev_free(struct snd_device *device)

  {

  	struct cs4281 *chip = device->device_data;

  	return snd_cs4281_free(chip);
  }

  static int snd_cs4281_chip_init(struct cs4281 *chip); /* defined below */

  static int __devinit snd_cs4281_create(struct snd_card *card,

  				       struct pci_dev *pci,

  				       struct cs4281 ** rchip,

  				       int dual_codec)
  {

  	struct cs4281 *chip;

  	unsigned int tmp;
  	int err;

  	static struct snd_device_ops ops = {

  		.dev_free =	snd_cs4281_dev_free,
  	};
  
  	*rchip = NULL;
  	if ((err = pci_enable_device(pci)) < 0)
  		return err;

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

  	if (chip == NULL) {
  		pci_disable_device(pci);
  		return -ENOMEM;
  	}
  	spin_lock_init(&chip->reg_lock);
  	chip->card = card;
  	chip->pci = pci;
  	chip->irq = -1;
  	pci_set_master(pci);
  	if (dual_codec < 0 || dual_codec > 3) {
  		snd_printk(KERN_ERR "invalid dual_codec option %d
  ", dual_codec);
  		dual_codec = 0;
  	}
  	chip->dual_codec = dual_codec;
  
  	if ((err = pci_request_regions(pci, "CS4281")) < 0) {
  		kfree(chip);
  		pci_disable_device(pci);
  		return err;
  	}
  	chip->ba0_addr = pci_resource_start(pci, 0);
  	chip->ba1_addr = pci_resource_start(pci, 1);

  	chip->ba0 = pci_ioremap_bar(pci, 0);
  	chip->ba1 = pci_ioremap_bar(pci, 1);

  	if (!chip->ba0 || !chip->ba1) {
  		snd_cs4281_free(chip);
  		return -ENOMEM;
  	}
  	

  	if (request_irq(pci->irq, snd_cs4281_interrupt, IRQF_SHARED,

  			KBUILD_MODNAME, chip)) {

  		snd_printk(KERN_ERR "unable to grab IRQ %d
  ", pci->irq);
  		snd_cs4281_free(chip);
  		return -ENOMEM;
  	}
  	chip->irq = pci->irq;

  	tmp = snd_cs4281_chip_init(chip);
  	if (tmp) {
  		snd_cs4281_free(chip);
  		return tmp;
  	}
  
  	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
  		snd_cs4281_free(chip);
  		return err;
  	}
  
  	snd_cs4281_proc_init(chip);

  	snd_card_set_dev(card, &pci->dev);
  
  	*rchip = chip;
  	return 0;
  }

  static int snd_cs4281_chip_init(struct cs4281 *chip)

  {
  	unsigned int tmp;

  	unsigned long end_time;

  	int retry_count = 2;

  	/* Having EPPMC.FPDN=1 prevent proper chip initialisation */
  	tmp = snd_cs4281_peekBA0(chip, BA0_EPPMC);
  	if (tmp & BA0_EPPMC_FPDN)
  		snd_cs4281_pokeBA0(chip, BA0_EPPMC, tmp & ~BA0_EPPMC_FPDN);

        __retry:
  	tmp = snd_cs4281_peekBA0(chip, BA0_CFLR);
  	if (tmp != BA0_CFLR_DEFAULT) {
  		snd_cs4281_pokeBA0(chip, BA0_CFLR, BA0_CFLR_DEFAULT);
  		tmp = snd_cs4281_peekBA0(chip, BA0_CFLR);
  		if (tmp != BA0_CFLR_DEFAULT) {
  			snd_printk(KERN_ERR "CFLR setup failed (0x%x)
  ", tmp);
  			return -EIO;
  		}
  	}
  
  	/* Set the 'Configuration Write Protect' register
  	 * to 4281h.  Allows vendor-defined configuration
           * space between 0e4h and 0ffh to be written. */	
  	snd_cs4281_pokeBA0(chip, BA0_CWPR, 0x4281);
  	
  	if ((tmp = snd_cs4281_peekBA0(chip, BA0_SERC1)) != (BA0_SERC1_SO1EN | BA0_SERC1_AC97)) {
  		snd_printk(KERN_ERR "SERC1 AC'97 check failed (0x%x)
  ", tmp);
  		return -EIO;
  	}
  	if ((tmp = snd_cs4281_peekBA0(chip, BA0_SERC2)) != (BA0_SERC2_SI1EN | BA0_SERC2_AC97)) {
  		snd_printk(KERN_ERR "SERC2 AC'97 check failed (0x%x)
  ", tmp);
  		return -EIO;
  	}
  
  	/* Sound System Power Management */
  	snd_cs4281_pokeBA0(chip, BA0_SSPM, BA0_SSPM_MIXEN | BA0_SSPM_CSRCEN |
  				           BA0_SSPM_PSRCEN | BA0_SSPM_JSEN |
  				           BA0_SSPM_ACLEN | BA0_SSPM_FMEN);
  
  	/* Serial Port Power Management */
   	/* Blast the clock control register to zero so that the
           * PLL starts out in a known state, and blast the master serial
           * port control register to zero so that the serial ports also
           * start out in a known state. */
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, 0);
  	snd_cs4281_pokeBA0(chip, BA0_SERMC, 0);
  
          /* Make ESYN go to zero to turn off
           * the Sync pulse on the AC97 link. */
  	snd_cs4281_pokeBA0(chip, BA0_ACCTL, 0);
  	udelay(50);
                  
  	/*  Drive the ARST# pin low for a minimum of 1uS (as defined in the AC97
  	 *  spec) and then drive it high.  This is done for non AC97 modes since
  	 *  there might be logic external to the CS4281 that uses the ARST# line
  	 *  for a reset. */
  	snd_cs4281_pokeBA0(chip, BA0_SPMC, 0);
  	udelay(50);
  	snd_cs4281_pokeBA0(chip, BA0_SPMC, BA0_SPMC_RSTN);

  	msleep(50);

  
  	if (chip->dual_codec)
  		snd_cs4281_pokeBA0(chip, BA0_SPMC, BA0_SPMC_RSTN | BA0_SPMC_ASDI2E);
  
  	/*
  	 *  Set the serial port timing configuration.
  	 */
  	snd_cs4281_pokeBA0(chip, BA0_SERMC,
  			   (chip->dual_codec ? BA0_SERMC_TCID(chip->dual_codec) : BA0_SERMC_TCID(1)) |
  			   BA0_SERMC_PTC_AC97 | BA0_SERMC_MSPE);
  
  	/*
  	 *  Start the DLL Clock logic.
  	 */
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, BA0_CLKCR1_DLLP);

  	msleep(50);

  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, BA0_CLKCR1_SWCE | BA0_CLKCR1_DLLP);
  
  	/*
  	 * Wait for the DLL ready signal from the clock logic.
  	 */

  	end_time = jiffies + HZ;

  	do {
  		/*
  		 *  Read the AC97 status register to see if we've seen a CODEC
  		 *  signal from the AC97 codec.
  		 */
  		if (snd_cs4281_peekBA0(chip, BA0_CLKCR1) & BA0_CLKCR1_DLLRDY)
  			goto __ok0;

  		schedule_timeout_uninterruptible(1);
  	} while (time_after_eq(end_time, jiffies));

  
  	snd_printk(KERN_ERR "DLLRDY not seen
  ");
  	return -EIO;
  
        __ok0:
  
  	/*
  	 *  The first thing we do here is to enable sync generation.  As soon
  	 *  as we start receiving bit clock, we'll start producing the SYNC
  	 *  signal.
  	 */
  	snd_cs4281_pokeBA0(chip, BA0_ACCTL, BA0_ACCTL_ESYN);
  
  	/*
  	 * Wait for the codec ready signal from the AC97 codec.
  	 */

  	end_time = jiffies + HZ;

  	do {
  		/*
  		 *  Read the AC97 status register to see if we've seen a CODEC
  		 *  signal from the AC97 codec.
  		 */
  		if (snd_cs4281_peekBA0(chip, BA0_ACSTS) & BA0_ACSTS_CRDY)
  			goto __ok1;

  		schedule_timeout_uninterruptible(1);
  	} while (time_after_eq(end_time, jiffies));

  
  	snd_printk(KERN_ERR "never read codec ready from AC'97 (0x%x)
  ", snd_cs4281_peekBA0(chip, BA0_ACSTS));
  	return -EIO;
  
        __ok1:
  	if (chip->dual_codec) {

  		end_time = jiffies + HZ;

  		do {
  			if (snd_cs4281_peekBA0(chip, BA0_ACSTS2) & BA0_ACSTS_CRDY)
  				goto __codec2_ok;

  			schedule_timeout_uninterruptible(1);
  		} while (time_after_eq(end_time, jiffies));

  		snd_printk(KERN_INFO "secondary codec doesn't respond. disable it...
  ");
  		chip->dual_codec = 0;
  	__codec2_ok: ;
  	}
  
  	/*
  	 *  Assert the valid frame signal so that we can start sending commands
  	 *  to the AC97 codec.
  	 */
  
  	snd_cs4281_pokeBA0(chip, BA0_ACCTL, BA0_ACCTL_VFRM | BA0_ACCTL_ESYN);
  
  	/*
  	 *  Wait until we've sampled input slots 3 and 4 as valid, meaning that
  	 *  the codec is pumping ADC data across the AC-link.
  	 */

  	end_time = jiffies + HZ;

  	do {
  		/*
  		 *  Read the input slot valid register and see if input slots 3
  		 *  4 are valid yet.
  		 */
                  if ((snd_cs4281_peekBA0(chip, BA0_ACISV) & (BA0_ACISV_SLV(3) | BA0_ACISV_SLV(4))) == (BA0_ACISV_SLV(3) | BA0_ACISV_SLV(4)))
                          goto __ok2;

  		schedule_timeout_uninterruptible(1);
  	} while (time_after_eq(end_time, jiffies));

  
  	if (--retry_count > 0)
  		goto __retry;
  	snd_printk(KERN_ERR "never read ISV3 and ISV4 from AC'97
  ");
  	return -EIO;
  
        __ok2:
  
  	/*
  	 *  Now, assert valid frame and the slot 3 and 4 valid bits.  This will
  	 *  commense the transfer of digital audio data to the AC97 codec.
  	 */
  	snd_cs4281_pokeBA0(chip, BA0_ACOSV, BA0_ACOSV_SLV(3) | BA0_ACOSV_SLV(4));
  
  	/*
  	 *  Initialize DMA structures
  	 */
  	for (tmp = 0; tmp < 4; tmp++) {

  		struct cs4281_dma *dma = &chip->dma[tmp];

  		dma->regDBA = BA0_DBA0 + (tmp * 0x10);
  		dma->regDCA = BA0_DCA0 + (tmp * 0x10);
  		dma->regDBC = BA0_DBC0 + (tmp * 0x10);
  		dma->regDCC = BA0_DCC0 + (tmp * 0x10);
  		dma->regDMR = BA0_DMR0 + (tmp * 8);
  		dma->regDCR = BA0_DCR0 + (tmp * 8);
  		dma->regHDSR = BA0_HDSR0 + (tmp * 4);
  		dma->regFCR = BA0_FCR0 + (tmp * 4);
  		dma->regFSIC = BA0_FSIC0 + (tmp * 4);
  		dma->fifo_offset = tmp * CS4281_FIFO_SIZE;
  		snd_cs4281_pokeBA0(chip, dma->regFCR,
  				   BA0_FCR_LS(31) |
  				   BA0_FCR_RS(31) |
  				   BA0_FCR_SZ(CS4281_FIFO_SIZE) |
  				   BA0_FCR_OF(dma->fifo_offset));
  	}
  
  	chip->src_left_play_slot = 0;	/* AC'97 left PCM playback (3) */
  	chip->src_right_play_slot = 1;	/* AC'97 right PCM playback (4) */
  	chip->src_left_rec_slot = 10;	/* AC'97 left PCM record (3) */
  	chip->src_right_rec_slot = 11;	/* AC'97 right PCM record (4) */
  
  	/* Activate wave playback FIFO for FM playback */
  	chip->dma[0].valFCR = BA0_FCR_FEN | BA0_FCR_LS(0) |
  		              BA0_FCR_RS(1) |
   	  	              BA0_FCR_SZ(CS4281_FIFO_SIZE) |
  		              BA0_FCR_OF(chip->dma[0].fifo_offset);
  	snd_cs4281_pokeBA0(chip, chip->dma[0].regFCR, chip->dma[0].valFCR);
  	snd_cs4281_pokeBA0(chip, BA0_SRCSA, (chip->src_left_play_slot << 0) |
  					    (chip->src_right_play_slot << 8) |
  					    (chip->src_left_rec_slot << 16) |
  					    (chip->src_right_rec_slot << 24));
  
  	/* Initialize digital volume */
  	snd_cs4281_pokeBA0(chip, BA0_PPLVC, 0);
  	snd_cs4281_pokeBA0(chip, BA0_PPRVC, 0);
  
  	/* Enable IRQs */
  	snd_cs4281_pokeBA0(chip, BA0_HICR, BA0_HICR_EOI);
  	/* Unmask interrupts */
  	snd_cs4281_pokeBA0(chip, BA0_HIMR, 0x7fffffff & ~(
  					BA0_HISR_MIDI |
  					BA0_HISR_DMAI |
  					BA0_HISR_DMA(0) |
  					BA0_HISR_DMA(1) |
  					BA0_HISR_DMA(2) |
  					BA0_HISR_DMA(3)));
  	synchronize_irq(chip->irq);
  
  	return 0;
  }
  
  /*
   *  MIDI section
   */

  static void snd_cs4281_midi_reset(struct cs4281 *chip)

  {
  	snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr | BA0_MIDCR_MRST);
  	udelay(100);
  	snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  }

  static int snd_cs4281_midi_input_open(struct snd_rawmidi_substream *substream)

  {

  	struct cs4281 *chip = substream->rmidi->private_data;

  
  	spin_lock_irq(&chip->reg_lock);
   	chip->midcr |= BA0_MIDCR_RXE;
  	chip->midi_input = substream;
  	if (!(chip->uartm & CS4281_MODE_OUTPUT)) {
  		snd_cs4281_midi_reset(chip);
  	} else {
  		snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  	}
  	spin_unlock_irq(&chip->reg_lock);
  	return 0;
  }

  static int snd_cs4281_midi_input_close(struct snd_rawmidi_substream *substream)

  {

  	struct cs4281 *chip = substream->rmidi->private_data;

  
  	spin_lock_irq(&chip->reg_lock);
  	chip->midcr &= ~(BA0_MIDCR_RXE | BA0_MIDCR_RIE);
  	chip->midi_input = NULL;
  	if (!(chip->uartm & CS4281_MODE_OUTPUT)) {
  		snd_cs4281_midi_reset(chip);
  	} else {
  		snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  	}
  	chip->uartm &= ~CS4281_MODE_INPUT;
  	spin_unlock_irq(&chip->reg_lock);
  	return 0;
  }

  static int snd_cs4281_midi_output_open(struct snd_rawmidi_substream *substream)

  {

  	struct cs4281 *chip = substream->rmidi->private_data;

  
  	spin_lock_irq(&chip->reg_lock);
  	chip->uartm |= CS4281_MODE_OUTPUT;
  	chip->midcr |= BA0_MIDCR_TXE;
  	chip->midi_output = substream;
  	if (!(chip->uartm & CS4281_MODE_INPUT)) {
  		snd_cs4281_midi_reset(chip);
  	} else {
  		snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  	}
  	spin_unlock_irq(&chip->reg_lock);
  	return 0;
  }

  static int snd_cs4281_midi_output_close(struct snd_rawmidi_substream *substream)

  {

  	struct cs4281 *chip = substream->rmidi->private_data;

  
  	spin_lock_irq(&chip->reg_lock);
  	chip->midcr &= ~(BA0_MIDCR_TXE | BA0_MIDCR_TIE);
  	chip->midi_output = NULL;
  	if (!(chip->uartm & CS4281_MODE_INPUT)) {
  		snd_cs4281_midi_reset(chip);
  	} else {
  		snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  	}
  	chip->uartm &= ~CS4281_MODE_OUTPUT;
  	spin_unlock_irq(&chip->reg_lock);
  	return 0;
  }

  static void snd_cs4281_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)

  {
  	unsigned long flags;

  	struct cs4281 *chip = substream->rmidi->private_data;

  
  	spin_lock_irqsave(&chip->reg_lock, flags);
  	if (up) {
  		if ((chip->midcr & BA0_MIDCR_RIE) == 0) {
  			chip->midcr |= BA0_MIDCR_RIE;
  			snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  		}
  	} else {
  		if (chip->midcr & BA0_MIDCR_RIE) {
  			chip->midcr &= ~BA0_MIDCR_RIE;
  			snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  		}
  	}
  	spin_unlock_irqrestore(&chip->reg_lock, flags);
  }

  static void snd_cs4281_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)

  {
  	unsigned long flags;

  	struct cs4281 *chip = substream->rmidi->private_data;

  	unsigned char byte;
  
  	spin_lock_irqsave(&chip->reg_lock, flags);
  	if (up) {
  		if ((chip->midcr & BA0_MIDCR_TIE) == 0) {
  			chip->midcr |= BA0_MIDCR_TIE;
  			/* fill UART FIFO buffer at first, and turn Tx interrupts only if necessary */
  			while ((chip->midcr & BA0_MIDCR_TIE) &&
  			       (snd_cs4281_peekBA0(chip, BA0_MIDSR) & BA0_MIDSR_TBF) == 0) {
  				if (snd_rawmidi_transmit(substream, &byte, 1) != 1) {
  					chip->midcr &= ~BA0_MIDCR_TIE;
  				} else {
  					snd_cs4281_pokeBA0(chip, BA0_MIDWP, byte);
  				}
  			}
  			snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  		}
  	} else {
  		if (chip->midcr & BA0_MIDCR_TIE) {
  			chip->midcr &= ~BA0_MIDCR_TIE;
  			snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  		}
  	}
  	spin_unlock_irqrestore(&chip->reg_lock, flags);
  }

  static struct snd_rawmidi_ops snd_cs4281_midi_output =

  {
  	.open =		snd_cs4281_midi_output_open,
  	.close =	snd_cs4281_midi_output_close,
  	.trigger =	snd_cs4281_midi_output_trigger,
  };

  static struct snd_rawmidi_ops snd_cs4281_midi_input =

  {
  	.open = 	snd_cs4281_midi_input_open,
  	.close =	snd_cs4281_midi_input_close,
  	.trigger =	snd_cs4281_midi_input_trigger,
  };

  static int __devinit snd_cs4281_midi(struct cs4281 * chip, int device,
  				     struct snd_rawmidi **rrawmidi)

  {

  	struct snd_rawmidi *rmidi;

  	int err;
  
  	if (rrawmidi)
  		*rrawmidi = NULL;
  	if ((err = snd_rawmidi_new(chip->card, "CS4281", device, 1, 1, &rmidi)) < 0)
  		return err;
  	strcpy(rmidi->name, "CS4281");
  	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_cs4281_midi_output);
  	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_cs4281_midi_input);
  	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT | SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
  	rmidi->private_data = chip;
  	chip->rmidi = rmidi;
  	if (rrawmidi)
  		*rrawmidi = rmidi;
  	return 0;
  }
  
  /*
   *  Interrupt handler
   */

  static irqreturn_t snd_cs4281_interrupt(int irq, void *dev_id)

  {

  	struct cs4281 *chip = dev_id;

  	unsigned int status, dma, val;

  	struct cs4281_dma *cdma;

  
  	if (chip == NULL)
  		return IRQ_NONE;
  	status = snd_cs4281_peekBA0(chip, BA0_HISR);
  	if ((status & 0x7fffffff) == 0) {
  		snd_cs4281_pokeBA0(chip, BA0_HICR, BA0_HICR_EOI);
  		return IRQ_NONE;
  	}
  
  	if (status & (BA0_HISR_DMA(0)|BA0_HISR_DMA(1)|BA0_HISR_DMA(2)|BA0_HISR_DMA(3))) {
  		for (dma = 0; dma < 4; dma++)
  			if (status & BA0_HISR_DMA(dma)) {
  				cdma = &chip->dma[dma];
  				spin_lock(&chip->reg_lock);
  				/* ack DMA IRQ */
  				val = snd_cs4281_peekBA0(chip, cdma->regHDSR);
  				/* workaround, sometimes CS4281 acknowledges */
  				/* end or middle transfer position twice */
  				cdma->frag++;
  				if ((val & BA0_HDSR_DHTC) && !(cdma->frag & 1)) {
  					cdma->frag--;
  					chip->spurious_dhtc_irq++;
  					spin_unlock(&chip->reg_lock);
  					continue;
  				}
  				if ((val & BA0_HDSR_DTC) && (cdma->frag & 1)) {
  					cdma->frag--;
  					chip->spurious_dtc_irq++;
  					spin_unlock(&chip->reg_lock);
  					continue;
  				}
  				spin_unlock(&chip->reg_lock);
  				snd_pcm_period_elapsed(cdma->substream);
  			}
  	}
  
  	if ((status & BA0_HISR_MIDI) && chip->rmidi) {
  		unsigned char c;
  		
  		spin_lock(&chip->reg_lock);
  		while ((snd_cs4281_peekBA0(chip, BA0_MIDSR) & BA0_MIDSR_RBE) == 0) {
  			c = snd_cs4281_peekBA0(chip, BA0_MIDRP);
  			if ((chip->midcr & BA0_MIDCR_RIE) == 0)
  				continue;
  			snd_rawmidi_receive(chip->midi_input, &c, 1);
  		}
  		while ((snd_cs4281_peekBA0(chip, BA0_MIDSR) & BA0_MIDSR_TBF) == 0) {
  			if ((chip->midcr & BA0_MIDCR_TIE) == 0)
  				break;
  			if (snd_rawmidi_transmit(chip->midi_output, &c, 1) != 1) {
  				chip->midcr &= ~BA0_MIDCR_TIE;
  				snd_cs4281_pokeBA0(chip, BA0_MIDCR, chip->midcr);
  				break;
  			}
  			snd_cs4281_pokeBA0(chip, BA0_MIDWP, c);
  		}
  		spin_unlock(&chip->reg_lock);
  	}
  
  	/* EOI to the PCI part... reenables interrupts */
  	snd_cs4281_pokeBA0(chip, BA0_HICR, BA0_HICR_EOI);
  
  	return IRQ_HANDLED;
  }
  
  
  /*
   * OPL3 command
   */

  static void snd_cs4281_opl3_command(struct snd_opl3 *opl3, unsigned short cmd,
  				    unsigned char val)

  {
  	unsigned long flags;

  	struct cs4281 *chip = opl3->private_data;

  	void __iomem *port;
  
  	if (cmd & OPL3_RIGHT)
  		port = chip->ba0 + BA0_B1AP; /* right port */
  	else
  		port = chip->ba0 + BA0_B0AP; /* left port */
  
  	spin_lock_irqsave(&opl3->reg_lock, flags);
  
  	writel((unsigned int)cmd, port);
  	udelay(10);
  
  	writel((unsigned int)val, port + 4);
  	udelay(30);
  
  	spin_unlock_irqrestore(&opl3->reg_lock, flags);
  }
  
  static int __devinit snd_cs4281_probe(struct pci_dev *pci,
  				      const struct pci_device_id *pci_id)
  {
  	static int dev;

  	struct snd_card *card;
  	struct cs4281 *chip;
  	struct snd_opl3 *opl3;

  	int err;
  
          if (dev >= SNDRV_CARDS)
                  return -ENODEV;
  	if (!enable[dev]) {
  		dev++;
  		return -ENOENT;
  	}

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

  
  	if ((err = snd_cs4281_create(card, pci, &chip, dual_codec[dev])) < 0) {
  		snd_card_free(card);
  		return err;
  	}

  	card->private_data = chip;

  
  	if ((err = snd_cs4281_mixer(chip)) < 0) {
  		snd_card_free(card);
  		return err;
  	}
  	if ((err = snd_cs4281_pcm(chip, 0, NULL)) < 0) {
  		snd_card_free(card);
  		return err;
  	}
  	if ((err = snd_cs4281_midi(chip, 0, NULL)) < 0) {
  		snd_card_free(card);
  		return err;
  	}
  	if ((err = snd_opl3_new(card, OPL3_HW_OPL3_CS4281, &opl3)) < 0) {
  		snd_card_free(card);
  		return err;
  	}
  	opl3->private_data = chip;
  	opl3->command = snd_cs4281_opl3_command;
  	snd_opl3_init(opl3);
  	if ((err = snd_opl3_hwdep_new(opl3, 0, 1, NULL)) < 0) {
  		snd_card_free(card);
  		return err;
  	}
  	snd_cs4281_create_gameport(chip);
  	strcpy(card->driver, "CS4281");
  	strcpy(card->shortname, "Cirrus Logic CS4281");
  	sprintf(card->longname, "%s at 0x%lx, irq %d",
  		card->shortname,
  		chip->ba0_addr,
  		chip->irq);
  
  	if ((err = snd_card_register(card)) < 0) {
  		snd_card_free(card);
  		return err;
  	}
  
  	pci_set_drvdata(pci, card);
  	dev++;
  	return 0;
  }
  
  static void __devexit snd_cs4281_remove(struct pci_dev *pci)
  {
  	snd_card_free(pci_get_drvdata(pci));
  	pci_set_drvdata(pci, NULL);
  }
  
  /*
   * Power Management
   */
  #ifdef CONFIG_PM
  
  static int saved_regs[SUSPEND_REGISTERS] = {
  	BA0_JSCTL,
  	BA0_GPIOR,
  	BA0_SSCR,
  	BA0_MIDCR,
  	BA0_SRCSA,
  	BA0_PASR,
  	BA0_CASR,
  	BA0_DACSR,
  	BA0_ADCSR,
  	BA0_FMLVC,
  	BA0_FMRVC,
  	BA0_PPLVC,
  	BA0_PPRVC,
  };
  
  #define CLKCR1_CKRA                             0x00010000L

  static int cs4281_suspend(struct pci_dev *pci, pm_message_t state)

  {

  	struct snd_card *card = pci_get_drvdata(pci);
  	struct cs4281 *chip = card->private_data;

  	u32 ulCLK;
  	unsigned int i;

  	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);

  	snd_pcm_suspend_all(chip->pcm);

  	snd_ac97_suspend(chip->ac97);
  	snd_ac97_suspend(chip->ac97_secondary);

  
  	ulCLK = snd_cs4281_peekBA0(chip, BA0_CLKCR1);
  	ulCLK |= CLKCR1_CKRA;
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, ulCLK);
  
  	/* Disable interrupts. */
  	snd_cs4281_pokeBA0(chip, BA0_HICR, BA0_HICR_CHGM);
  
  	/* remember the status registers */
  	for (i = 0; i < ARRAY_SIZE(saved_regs); i++)
  		if (saved_regs[i])
  			chip->suspend_regs[i] = snd_cs4281_peekBA0(chip, saved_regs[i]);
  
  	/* Turn off the serial ports. */
  	snd_cs4281_pokeBA0(chip, BA0_SERMC, 0);
  
  	/* Power off FM, Joystick, AC link, */
  	snd_cs4281_pokeBA0(chip, BA0_SSPM, 0);
  
  	/* DLL off. */
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, 0);
  
  	/* AC link off. */
  	snd_cs4281_pokeBA0(chip, BA0_SPMC, 0);
  
  	ulCLK = snd_cs4281_peekBA0(chip, BA0_CLKCR1);
  	ulCLK &= ~CLKCR1_CKRA;
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, ulCLK);

  	pci_disable_device(pci);
  	pci_save_state(pci);

  	pci_set_power_state(pci, pci_choose_state(pci, state));

  	return 0;
  }

  static int cs4281_resume(struct pci_dev *pci)

  {

  	struct snd_card *card = pci_get_drvdata(pci);
  	struct cs4281 *chip = card->private_data;

  	unsigned int i;
  	u32 ulCLK;

  	pci_set_power_state(pci, PCI_D0);

  	pci_restore_state(pci);

  	if (pci_enable_device(pci) < 0) {
  		printk(KERN_ERR "cs4281: pci_enable_device failed, "
  		       "disabling device
  ");
  		snd_card_disconnect(card);
  		return -EIO;
  	}

  	pci_set_master(pci);

  
  	ulCLK = snd_cs4281_peekBA0(chip, BA0_CLKCR1);
  	ulCLK |= CLKCR1_CKRA;
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, ulCLK);
  
  	snd_cs4281_chip_init(chip);
  
  	/* restore the status registers */
  	for (i = 0; i < ARRAY_SIZE(saved_regs); i++)
  		if (saved_regs[i])
  			snd_cs4281_pokeBA0(chip, saved_regs[i], chip->suspend_regs[i]);

  	snd_ac97_resume(chip->ac97);
  	snd_ac97_resume(chip->ac97_secondary);

  
  	ulCLK = snd_cs4281_peekBA0(chip, BA0_CLKCR1);
  	ulCLK &= ~CLKCR1_CKRA;
  	snd_cs4281_pokeBA0(chip, BA0_CLKCR1, ulCLK);

  	snd_power_change_state(card, SNDRV_CTL_POWER_D0);

  	return 0;
  }
  #endif /* CONFIG_PM */
  
  static struct pci_driver driver = {

  	.name = KBUILD_MODNAME,

  	.id_table = snd_cs4281_ids,
  	.probe = snd_cs4281_probe,
  	.remove = __devexit_p(snd_cs4281_remove),

  #ifdef CONFIG_PM
  	.suspend = cs4281_suspend,
  	.resume = cs4281_resume,
  #endif

  };
  	
  static int __init alsa_card_cs4281_init(void)
  {

  	return pci_register_driver(&driver);

  }
  
  static void __exit alsa_card_cs4281_exit(void)
  {
  	pci_unregister_driver(&driver);
  }
  
  module_init(alsa_card_cs4281_init)
  module_exit(alsa_card_cs4281_exit)