patch-2.0.35 linux/include/linux/pg.h

• Lines: 64
• Date: Mon Jul 13 13:47:39 1998
• Orig file: v2.0.34/linux/include/linux/pg.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.0.34/linux/include/linux/pg.h linux/include/linux/pg.h
@@ -0,0 +1,63 @@
+/* 	pg.h (c) 1998  Grant R. Guenther <grant@torque.net>
+ 		       Under the terms of the GNU 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 */