/*******************************************************************************
/
/	File:		AGP.h
/
/	Description:	Interface to the AGP bus and driver.
/	For more information, see "AGP interface specification", Revision 2.0 and 3.0,
/	Intel Corporation, 1998-2002.
/
/	Rudolf Cornelissen 6/2004.
/
*******************************************************************************/

#if !defined(_AGP_H_)
#define _AGP_H_

#include <Drivers.h>

/* The API for driver access is C, not C++ */
#ifdef __cplusplus
extern "C" {
#endif


//driver IOCTRL argument:
typedef struct {
	struct
	{
		ushort	vendor_id,	/* host bridge vendor id */
				device_id;	/* host bridge device id */
	} dev;
	struct
	{
		uint32	agp_cap_id,	/* AGP capability register as defined in the AGP standard */
				agp_stat,	/* AGP STATUS register as defined in the AGP standard */
				agp_cmd;	/* AGP COMMAND register as defined in the AGP standard */
	}config;
	status_t	status;		/* hostbridge usability status (B_OK if usable, B_ERROR if it
							 * did not respond according to the AGP standard */
} agp_info;


//driver IOCTRL operation codes:
enum
{
	GET_CONFIG = B_DEVICE_OP_CODES_END+20001, 
    SET_CONFIG,
};


/* ---
	value for the AGP_id field in the agp_cap_id register
--- */
#define AGP_id	0x02	/* AGP device identification */


/* ---
	masks for capability ID register bits
--- */
#define AGP_id_mask		0x000000ff	/* AGP capability identification, contains value 0x02 for AGP device */
#define AGP_next_ptr	0x0000ff00	/* pointer to next item in PCI capabilities list, contains 0x00 if this is last item */
#define AGP_next_ptr_shift		 8
#define AGP_rev_minor	0x000f0000	/* AGP Revision minor number reported */
#define AGP_rev_minor_shift		16
#define AGP_rev_major	0x00f00000	/* AGP Revision major number reported */
#define AGP_rev_major_shift		20


/* ---
	masks for status and command register bits
--- */
#define AGP_2_1x		0x00000001	/* AGP Revision 2.0 1x speed transfer mode */
#define AGP_2_2x		0x00000002	/* AGP Revision 2.0 2x speed transfer mode */
#define AGP_2_4x		0x00000004	/* AGP Revision 2.0 4x speed transfer mode */
#define AGP_3_4x		0x00000001	/* AGP Revision 3.0 4x speed transfer mode */
#define AGP_3_8x		0x00000002	/* AGP Revision 3.0 8x speed transfer mode */
#define AGP_rates		0x00000007	/* mask for supported rates info */
#define AGP_rate_rev	0x00000008	/* 0 if AGP Revision 2.0 or earlier rate scheme, 1 if AGP Revision 3.0 rate scheme */
#define AGP_FW			0x00000010	/* 1 if fastwrite transfers supported */
#define AGP_4G			0x00000020	/* 1 if adresses above 4G bytes supported */
#define AGP_SBA			0x00000200	/* 1 if sideband adressing supported */
#define AGP_RQ			0xff000000	/* max. number of enqueued AGP command requests supported, minus one */
#define AGP_RQ_shift			24


/* ---
	masks for command register bits
--- */
#define AGP_enable		0x00000100	/* set to 1 if AGP should be enabled */


#ifdef __cplusplus
}
#endif

#endif