xref: /openbmc/linux/drivers/usb/storage/transport.h (revision ca55b2fe)
1 /* Driver for USB Mass Storage compliant devices
2  * Transport 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 _TRANSPORT_H_
40 #define _TRANSPORT_H_
41 
42 #include <linux/blkdev.h>
43 
44 /*
45  * usb_stor_bulk_transfer_xxx() return codes, in order of severity
46  */
47 
48 #define USB_STOR_XFER_GOOD	0	/* good transfer                 */
49 #define USB_STOR_XFER_SHORT	1	/* transferred less than expected */
50 #define USB_STOR_XFER_STALLED	2	/* endpoint stalled              */
51 #define USB_STOR_XFER_LONG	3	/* device tried to send too much */
52 #define USB_STOR_XFER_ERROR	4	/* transfer died in the middle   */
53 
54 /*
55  * Transport return codes
56  */
57 
58 #define USB_STOR_TRANSPORT_GOOD	   0   /* Transport good, command good	   */
59 #define USB_STOR_TRANSPORT_FAILED  1   /* Transport good, command failed   */
60 #define USB_STOR_TRANSPORT_NO_SENSE 2  /* Command failed, no auto-sense    */
61 #define USB_STOR_TRANSPORT_ERROR   3   /* Transport bad (i.e. device dead) */
62 
63 /*
64  * We used to have USB_STOR_XFER_ABORTED and USB_STOR_TRANSPORT_ABORTED
65  * return codes.  But now the transport and low-level transfer routines
66  * treat an abort as just another error (-ENOENT for a cancelled URB).
67  * It is up to the invoke_transport() function to test for aborts and
68  * distinguish them from genuine communication errors.
69  */
70 
71 /*
72  * CBI accept device specific command
73  */
74 
75 #define US_CBI_ADSC		0
76 
77 extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
78 extern int usb_stor_CB_reset(struct us_data*);
79 
80 extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
81 extern int usb_stor_Bulk_max_lun(struct us_data*);
82 extern int usb_stor_Bulk_reset(struct us_data*);
83 
84 extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
85 extern void usb_stor_stop_transport(struct us_data*);
86 
87 extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
88 		u8 request, u8 requesttype, u16 value, u16 index,
89 		void *data, u16 size, int timeout);
90 extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);
91 
92 extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
93 		u8 request, u8 requesttype, u16 value, u16 index,
94 		void *data, u16 size);
95 extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
96 		void *buf, unsigned int length, unsigned int *act_len);
97 extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
98 		void *buf, unsigned int length, int use_sg, int *residual);
99 extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
100 		struct scsi_cmnd* srb);
101 
102 extern int usb_stor_port_reset(struct us_data *us);
103 #endif
104