/*
   *	Registers for the ESS PCI cards
   */
   
  /*
   *	Memory access
   */
   
  #define ESS_MEM_DATA		0x00
  #define	ESS_MEM_INDEX		0x02
  
  /*
   *	AC-97 Codec port. Delay 1uS after each write. This is used to
   *	talk AC-97 (see intel.com). Write data then register.
   */
   
  #define ESS_AC97_INDEX		0x30		/* byte wide */
  #define ESS_AC97_DATA		0x32
  
  /* 
   *	Reading is a bit different. You write register|0x80 to ubdex
   *	delay 1uS poll the low bit of index, when it clears read the
   *	data value.
   */
  
  /*
   *	Control port. Not yet fully understood
   *	The value 0xC090 gets loaded to it then 0x0000 and 0x2800
   *	to the data port. Then after 4uS the value 0x300 is written
   */
   
  #define RING_BUS_CTRL_L		0x34
  #define RING_BUS_CTRL_H		0x36
  
  /*
   *	This is also used during setup. The value 0x17 is written to it
   */
   
  #define ESS_SETUP_18		0x18
  
  /*
   *	And this one gets 0x000b
   */
   
  #define ESS_SETUP_A2		0xA2
  
  /*
   *	And this 0x0000
   */
   
  #define ESS_SETUP_A4		0xA4
  #define ESS_SETUP_A6		0xA6
  
  /*
   *	Stuff to do with Harpo - the wave stuff
   */
   
  #define ESS_WAVETABLE_SIZE	0x14
  #define 	ESS_WAVETABLE_2M	0xA180