ide.h

此工具是arm-linux-GCC交叉编译工具（cross-3.4.4）

#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned high		:8;	/* MSB */
		unsigned low		:8;	/* LSB */
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} ata_nsector_t, ata_data_t, atapi_bcount_t, ata_index_t;

/*
 * ATA-IDE Error Register
 *
 * mark		: Bad address mark
 * tzero	: Couldn't find track 0
 * abrt		: Aborted Command
 * mcr		: Media Change Request
 * id		: ID field not found
 * mce		: Media Change Event
 * ecc		: Uncorrectable ECC error
 * bdd		: dual meaing
 */
typedef union {
	unsigned all			:8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned mark		:1;
		unsigned tzero		:1;
		unsigned abrt		:1;
		unsigned mcr		:1;
		unsigned id		:1;
		unsigned mce		:1;
		unsigned ecc		:1;
		unsigned bdd		:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned bdd		:1;
		unsigned ecc		:1;
		unsigned mce		:1;
		unsigned id		:1;
		unsigned mcr		:1;
		unsigned abrt		:1;
		unsigned tzero		:1;
		unsigned mark		:1;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} ata_error_t;

/*
 * ATA-IDE Select Register, aka Device-Head
 *
 * head		: always zeros here
 * unit		: drive select number: 0/1
 * bit5		: always 1
 * lba		: using LBA instead of CHS
 * bit7		: always 1
 */
typedef union {
	unsigned all			: 8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned head		: 4;
		unsigned unit		: 1;
		unsigned bit5		: 1;
		unsigned lba		: 1;
		unsigned bit7		: 1;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned bit7		: 1;
		unsigned lba		: 1;
		unsigned bit5		: 1;
		unsigned unit		: 1;
		unsigned head		: 4;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} select_t, ata_select_t;

/*
 * The ATA-IDE Status Register.
 * The ATAPI Status Register.
 *
 * check	: Error occurred
 * idx		: Index Error
 * corr		: Correctable error occurred
 * drq		: Data is request by the device
 * dsc		: Disk Seek Complete			: ata
 *		: Media access command finished		: atapi
 * df		: Device Fault				: ata
 *		: Reserved				: atapi
 * drdy		: Ready, Command Mode Capable		: ata
 *		: Ignored for ATAPI commands		: atapi
 * bsy		: Disk is Busy
 *		: The device has access to the command block
 */
typedef union {
	unsigned all			:8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned check		:1;
		unsigned idx		:1;
		unsigned corr		:1;
		unsigned drq		:1;
		unsigned dsc		:1;
		unsigned df		:1;
		unsigned drdy		:1;
		unsigned bsy		:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned bsy		:1;
		unsigned drdy		:1;
		unsigned df		:1;
		unsigned dsc		:1;
		unsigned drq		:1;
		unsigned corr           :1;
		unsigned idx		:1;
		unsigned check		:1;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} ata_status_t, atapi_status_t;

/*
 * ATA-IDE Control Register
 *
 * bit0		: Should be set to zero
 * nIEN		: device INTRQ to host
 * SRST		: host soft reset bit
 * bit3		: ATA-2 thingy, Should be set to 1
 * reserved456	: Reserved
 * HOB		: 48-bit address ordering, High Ordered Bit
 */
typedef union {
	unsigned all			: 8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned bit0		: 1;
		unsigned nIEN		: 1;
		unsigned SRST		: 1;
		unsigned bit3		: 1;
		unsigned reserved456	: 3;
		unsigned HOB		: 1;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned HOB		: 1;
		unsigned reserved456	: 3;
		unsigned bit3		: 1;
		unsigned SRST		: 1;
		unsigned nIEN		: 1;
		unsigned bit0		: 1;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} ata_control_t;

/*
 * ATAPI Feature Register
 *
 * dma		: Using DMA or PIO
 * reserved321	: Reserved
 * reserved654	: Reserved (Tag Type)
 * reserved7	: Reserved
 */
typedef union {
	unsigned all			:8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned dma		:1;
		unsigned reserved321	:3;
		unsigned reserved654	:3;
		unsigned reserved7	:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned reserved7	:1;
		unsigned reserved654	:3;
		unsigned reserved321	:3;
		unsigned dma		:1;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} atapi_feature_t;

/*
 * ATAPI Interrupt Reason Register.
 *
 * cod		: Information transferred is command (1) or data (0)
 * io		: The device requests us to read (1) or write (0)
 * reserved	: Reserved
 */
typedef union {
	unsigned all			:8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned cod		:1;
		unsigned io		:1;
		unsigned reserved	:6;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned reserved	:6;
		unsigned io		:1;
		unsigned cod		:1;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} atapi_ireason_t;

/*
 * The ATAPI error register.
 *
 * ili		: Illegal Length Indication
 * eom		: End Of Media Detected
 * abrt		: Aborted command - As defined by ATA
 * mcr		: Media Change Requested - As defined by ATA
 * sense_key	: Sense key of the last failed packet command
 */
typedef union {
	unsigned all			:8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned ili		:1;
		unsigned eom		:1;
		unsigned abrt		:1;
		unsigned mcr		:1;
		unsigned sense_key	:4;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned sense_key	:4;
		unsigned mcr		:1;
		unsigned abrt		:1;
		unsigned eom		:1;
		unsigned ili		:1;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} atapi_error_t;

/*
 * ATAPI floppy Drive Select Register
 *
 * sam_lun	: Logical unit number
 * reserved3	: Reserved
 * drv		: The responding drive will be drive 0 (0) or drive 1 (1)
 * one5		: Should be set to 1
 * reserved6	: Reserved
 * one7		: Should be set to 1
 */
typedef union {
	unsigned all			:8;
	struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
		unsigned sam_lun	:3;
		unsigned reserved3	:1;
		unsigned drv		:1;
		unsigned one5		:1;
		unsigned reserved6	:1;
		unsigned one7		:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
		unsigned one7		:1;
		unsigned reserved6	:1;
		unsigned one5		:1;
		unsigned drv		:1;
		unsigned reserved3	:1;
		unsigned sam_lun	:3;
#else
#error "Please fix <asm/byteorder.h>"
#endif
	} b;
} atapi_select_t;

/*
 * Status returned from various ide_ functions
 */
typedef enum {
	ide_stopped,	/* no drive operation was started */
	ide_started,	/* a drive operation was started, handler was set */
} ide_startstop_t;

struct ide_driver_s;
struct ide_settings_s;

typedef struct ide_drive_s {
	char		name[4];	/* drive name, such as "hda" */
        char            driver_req[10];	/* requests specific driver */

	request_queue_t		*queue;	/* request queue */

	struct request		*rq;	/* current request */
	struct ide_drive_s 	*next;	/* circular list of hwgroup drives */
	void		*driver_data;	/* extra driver data */
	struct hd_driveid	*id;	/* drive model identification info */
	struct proc_dir_entry *proc;	/* /proc/ide/ directory entry */
	struct ide_settings_s *settings;/* /proc/ide/ drive settings */
	char		devfs_name[64];	/* devfs crap */

	struct hwif_s		*hwif;	/* actually (ide_hwif_t *) */

	unsigned long sleep;		/* sleep until this time */
	unsigned long service_start;	/* time we started last request */
	unsigned long service_time;	/* service time of last request */
	unsigned long timeout;		/* max time to wait for irq */

	special_t	special;	/* special action flags */
	select_t	select;		/* basic drive/head select reg value */

	u8	keep_settings;		/* restore settings after drive reset */
	u8	autodma;		/* device can safely use dma on host */
	u8	using_dma;		/* disk is using dma for read/write */
	u8	retry_pio;		/* retrying dma capable host in pio */
	u8	state;			/* retry state */
	u8	waiting_for_dma;	/* dma currently in progress */
	u8	unmask;			/* okay to unmask other irqs */
	u8	bswap;			/* byte swap data */
	u8	dsc_overlap;		/* DSC overlap */
	u8	nice1;			/* give potential excess bandwidth */

	unsigned present	: 1;	/* drive is physically present */
	unsigned dead		: 1;	/* device ejected hint */
	unsigned id_read	: 1;	/* 1=id read from disk 0 = synthetic */
	unsigned noprobe 	: 1;	/* from:  hdx=noprobe */
	unsigned removable	: 1;	/* 1 if need to do check_media_change */
	unsigned attach		: 1;	/* needed for removable devices */
	unsigned is_flash	: 1;	/* 1 if probed as flash */
	unsigned forced_geom	: 1;	/* 1 if hdx=c,h,s was given at boot */
	unsigned no_unmask	: 1;	/* disallow setting unmask bit */
	unsigned no_io_32bit	: 1;	/* disallow enabling 32bit I/O */
	unsigned atapi_overlap	: 1;	/* ATAPI overlap (not supported) */
	unsigned nice0		: 1;	/* give obvious excess bandwidth */
	unsigned nice2		: 1;	/* give a share in our own bandwidth */
	unsigned doorlocking	: 1;	/* for removable only: door lock/unlock works */
	unsigned autotune	: 2;	/* 0=default, 1=autotune, 2=noautotune */
	unsigned remap_0_to_1	: 1;	/* 0=noremap, 1=remap 0->1 (for EZDrive) */
	unsigned blocked        : 1;	/* 1=powermanagment told us not to do anything, so sleep nicely */
	unsigned vdma		: 1;	/* 1=doing PIO over DMA 0=doing normal DMA */
	unsigned addressing;		/*      : 3;
					 *  0=28-bit
					 *  1=48-bit
					 *  2=48-bit doing 28-bit
					 *  3=64-bit
					 */
	unsigned scsi		: 1;	/* 0=default, 1=ide-scsi emulation */
	unsigned sleeping	: 1;	/* 1=sleeping & sleep field valid */
	unsigned post_reset	: 1;

        u8	quirk_list;	/* considered quirky, set for a specific host */
        u8	init_speed;	/* transfer rate set at boot */
        u8	pio_speed;      /* unused by core, used by some drivers for fallback from DMA */
        u8	current_speed;	/* current transfer rate set */
        u8	dn;		/* now wide spread use */
        u8	wcache;		/* status of write cache */
	u8	acoustic;	/* acoustic management */
	u8	media;		/* disk, cdrom, tape, floppy, ... */
	u8	ctl;		/* "normal" value for IDE_CONTROL_REG */
	u8	ready_stat;	/* min status value for drive ready */
	u8	mult_count;	/* current multiple sector setting */
	u8	mult_req;	/* requested multiple sector setting */
	u8	tune_req;	/* requested drive tuning setting */
	u8	io_32bit;	/* 0=16-bit, 1=32-bit, 2/3=32bit+sync */
	u8	bad_wstat;	/* used for ignoring WRERR_STAT */
	u8	nowerr;		/* used for ignoring WRERR_STAT */
	u8	sect0;		/* offset of first sector for DM6:DDO */
	u8	head;		/* "real" number of heads */
	u8	sect;		/* "real" sectors per track */
	u8	bios_head;	/* BIOS/fdisk/LILO number of heads */
	u8	bios_sect;	/* BIOS/fdisk/LILO sectors per track */

	unsigned int	bios_cyl;	/* BIOS/fdisk/LILO number of cyls */
	unsigned int	cyl;		/* "real" number of cyls */
	unsigned int	drive_data;	/* use by tuneproc/selectproc */
	unsigned int	usage;		/* current "open()" count for drive */
	unsigned int	failures;	/* current failure count */
	unsigned int	max_failures;	/* maximum allowed failure count */

	u64		capacity64;	/* total number of sectors */

	int		lun;		/* logical unit */
	int		crc_count;	/* crc counter to reduce drive speed */
	struct list_head list;
	struct device	gendev;