xref: /openbmc/linux/drivers/usb/storage/protocol.h (revision 5a244f48)
1 /*
2  * Driver for USB Mass Storage compliant devices
3  * Protocol Functions Header File
4  *
5  * Current development and maintenance by:
6  *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
7  *
8  * This driver is based on the 'USB Mass Storage Class' document. This
9  * describes in detail the protocol used to communicate with such
10  * devices.  Clearly, the designers had SCSI and ATAPI commands in
11  * mind when they created this document.  The commands are all very
12  * similar to commands in the SCSI-II and ATAPI specifications.
13  *
14  * It is important to note that in a number of cases this class
15  * exhibits class-specific exemptions from the USB specification.
16  * Notably the usage of NAK, STALL and ACK differs from the norm, in
17  * that they are used to communicate wait, failed and OK on commands.
18  *
19  * Also, for certain devices, the interrupt endpoint is used to convey
20  * status of a command.
21  *
22  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
23  * information about this driver.
24  *
25  * This program is free software; you can redistribute it and/or modify it
26  * under the terms of the GNU General Public License as published by the
27  * Free Software Foundation; either version 2, or (at your option) any
28  * later version.
29  *
30  * This program is distributed in the hope that it will be useful, but
31  * WITHOUT ANY WARRANTY; without even the implied warranty of
32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
33  * General Public License for more details.
34  *
35  * You should have received a copy of the GNU General Public License along
36  * with this program; if not, write to the Free Software Foundation, Inc.,
37  * 675 Mass Ave, Cambridge, MA 02139, USA.
38  */
39 
40 #ifndef _PROTOCOL_H_
41 #define _PROTOCOL_H_
42 
43 /* Protocol handling routines */
44 extern void usb_stor_pad12_command(struct scsi_cmnd*, struct us_data*);
45 extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*);
46 extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
47 		struct us_data*);
48 
49 /* struct scsi_cmnd transfer buffer access utilities */
50 enum xfer_buf_dir	{TO_XFER_BUF, FROM_XFER_BUF};
51 
52 extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
53 	unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **,
54 	unsigned int *offset, enum xfer_buf_dir dir);
55 
56 extern void usb_stor_set_xfer_buf(unsigned char *buffer,
57 	unsigned int buflen, struct scsi_cmnd *srb);
58 #endif
59