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Diffstat (limited to 'include/uapi/linux/pg.h')
| -rw-r--r-- | include/uapi/linux/pg.h | 63 | 
1 files changed, 63 insertions, 0 deletions
diff --git a/include/uapi/linux/pg.h b/include/uapi/linux/pg.h new file mode 100644 index 00000000000..db994bb0c79 --- /dev/null +++ b/include/uapi/linux/pg.h @@ -0,0 +1,63 @@ +/* 	pg.h (c) 1998  Grant R. Guenther <grant@torque.net> + 		       Under the terms of the GNU General Public License + + +	pg.h defines the user interface to the generic ATAPI packet +        command driver for parallel port ATAPI devices (pg). The +	driver is loosely modelled after the generic SCSI driver, sg, +	although the actual interface is different. + +	The pg driver provides a simple character device interface for +        sending ATAPI commands to a device.  With the exception of the +	ATAPI reset operation, all operations are performed by a pair +        of read and write operations to the appropriate /dev/pgN device. +	A write operation delivers a command and any outbound data in +        a single buffer.  Normally, the write will succeed unless the +        device is offline or malfunctioning, or there is already another +	command pending.  If the write succeeds, it should be followed +        immediately by a read operation, to obtain any returned data and +        status information.  A read will fail if there is no operation +        in progress. + +	As a special case, the device can be reset with a write operation, +        and in this case, no following read is expected, or permitted. + +	There are no ioctl() operations.  Any single operation +	may transfer at most PG_MAX_DATA bytes.  Note that the driver must +        copy the data through an internal buffer.  In keeping with all +	current ATAPI devices, command packets are assumed to be exactly +	12 bytes in length. + +	To permit future changes to this interface, the headers in the +	read and write buffers contain a single character "magic" flag. +        Currently this flag must be the character "P". + +*/ + +#define PG_MAGIC	'P' +#define PG_RESET	'Z' +#define PG_COMMAND	'C' + +#define PG_MAX_DATA	32768 + +struct pg_write_hdr { + +	char	magic;		/* == PG_MAGIC */ +	char	func;		/* PG_RESET or PG_COMMAND */ +	int     dlen;		/* number of bytes expected to transfer */ +	int     timeout;	/* number of seconds before timeout */ +	char	packet[12];	/* packet command */ + +}; + +struct pg_read_hdr { + +	char	magic;		/* == PG_MAGIC */ +	char	scsi;		/* "scsi" status == sense key */ +	int	dlen;		/* size of device transfer request */ +	int     duration;	/* time in seconds command took */ +	char    pad[12];	/* not used */ + +}; + +/* end of pg.h */  |