xref: /linux/drivers/usb/storage/protocol.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /* Driver for USB Mass Storage compliant devices
2  * Protocol Functions Header File
3  *
4  * Current development and maintenance by:
5  *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
6  *
7  * This driver is based on the 'USB Mass Storage Class' document. This
8  * describes in detail the protocol used to communicate with such
9  * devices.  Clearly, the designers had SCSI and ATAPI commands in
10  * mind when they created this document.  The commands are all very
11  * similar to commands in the SCSI-II and ATAPI specifications.
12  *
13  * It is important to note that in a number of cases this class
14  * exhibits class-specific exemptions from the USB specification.
15  * Notably the usage of NAK, STALL and ACK differs from the norm, in
16  * that they are used to communicate wait, failed and OK on commands.
17  *
18  * Also, for certain devices, the interrupt endpoint is used to convey
19  * status of a command.
20  *
21  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
22  * information about this driver.
23  *
24  * This program is free software; you can redistribute it and/or modify it
25  * under the terms of the GNU General Public License as published by the
26  * Free Software Foundation; either version 2, or (at your option) any
27  * later version.
28  *
29  * This program is distributed in the hope that it will be useful, but
30  * WITHOUT ANY WARRANTY; without even the implied warranty of
31  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
32  * General Public License for more details.
33  *
34  * You should have received a copy of the GNU General Public License along
35  * with this program; if not, write to the Free Software Foundation, Inc.,
36  * 675 Mass Ave, Cambridge, MA 02139, USA.
37  */
38 
39 #ifndef _PROTOCOL_H_
40 #define _PROTOCOL_H_
41 
42 /* Protocol handling routines */
43 extern void usb_stor_pad12_command(struct scsi_cmnd*, struct us_data*);
44 extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*);
45 extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
46 		struct us_data*);
47 
48 /* struct scsi_cmnd transfer buffer access utilities */
49 enum xfer_buf_dir	{TO_XFER_BUF, FROM_XFER_BUF};
50 
51 extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
52 	unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **,
53 	unsigned int *offset, enum xfer_buf_dir dir);
54 
55 extern void usb_stor_set_xfer_buf(unsigned char *buffer,
56 	unsigned int buflen, struct scsi_cmnd *srb);
57 #endif
58