xref: /openbmc/linux/drivers/usb/storage/transport.h (revision 9ac8d3fb)
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  * Bulk only data structures
46  */
47 
48 /* command block wrapper */
49 struct bulk_cb_wrap {
50 	__le32	Signature;		/* contains 'USBC' */
51 	__u32	Tag;			/* unique per command id */
52 	__le32	DataTransferLength;	/* size of data */
53 	__u8	Flags;			/* direction in bit 0 */
54 	__u8	Lun;			/* LUN normally 0 */
55 	__u8	Length;			/* of of the CDB */
56 	__u8	CDB[16];		/* max command */
57 };
58 
59 #define US_BULK_CB_WRAP_LEN	31
60 #define US_BULK_CB_SIGN		0x43425355	/*spells out USBC */
61 #define US_BULK_FLAG_IN		1
62 #define US_BULK_FLAG_OUT	0
63 
64 /* command status wrapper */
65 struct bulk_cs_wrap {
66 	__le32	Signature;		/* should = 'USBS' */
67 	__u32	Tag;			/* same as original command */
68 	__le32	Residue;		/* amount not transferred */
69 	__u8	Status;			/* see below */
70 	__u8	Filler[18];
71 };
72 
73 #define US_BULK_CS_WRAP_LEN	13
74 #define US_BULK_CS_SIGN		0x53425355	/* spells out 'USBS' */
75 #define US_BULK_STAT_OK		0
76 #define US_BULK_STAT_FAIL	1
77 #define US_BULK_STAT_PHASE	2
78 
79 /* bulk-only class specific requests */
80 #define US_BULK_RESET_REQUEST	0xff
81 #define US_BULK_GET_MAX_LUN	0xfe
82 
83 /*
84  * usb_stor_bulk_transfer_xxx() return codes, in order of severity
85  */
86 
87 #define USB_STOR_XFER_GOOD	0	/* good transfer                 */
88 #define USB_STOR_XFER_SHORT	1	/* transferred less than expected */
89 #define USB_STOR_XFER_STALLED	2	/* endpoint stalled              */
90 #define USB_STOR_XFER_LONG	3	/* device tried to send too much */
91 #define USB_STOR_XFER_ERROR	4	/* transfer died in the middle   */
92 
93 /*
94  * Transport return codes
95  */
96 
97 #define USB_STOR_TRANSPORT_GOOD	   0   /* Transport good, command good	   */
98 #define USB_STOR_TRANSPORT_FAILED  1   /* Transport good, command failed   */
99 #define USB_STOR_TRANSPORT_NO_SENSE 2  /* Command failed, no auto-sense    */
100 #define USB_STOR_TRANSPORT_ERROR   3   /* Transport bad (i.e. device dead) */
101 
102 /*
103  * We used to have USB_STOR_XFER_ABORTED and USB_STOR_TRANSPORT_ABORTED
104  * return codes.  But now the transport and low-level transfer routines
105  * treat an abort as just another error (-ENOENT for a cancelled URB).
106  * It is up to the invoke_transport() function to test for aborts and
107  * distinguish them from genuine communication errors.
108  */
109 
110 /*
111  * CBI accept device specific command
112  */
113 
114 #define US_CBI_ADSC		0
115 
116 extern int usb_stor_CBI_transport(struct scsi_cmnd *, struct us_data*);
117 
118 extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
119 extern int usb_stor_CB_reset(struct us_data*);
120 
121 extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
122 extern int usb_stor_Bulk_max_lun(struct us_data*);
123 extern int usb_stor_Bulk_reset(struct us_data*);
124 
125 extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
126 extern void usb_stor_stop_transport(struct us_data*);
127 
128 extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
129 		u8 request, u8 requesttype, u16 value, u16 index,
130 		void *data, u16 size, int timeout);
131 extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);
132 
133 extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
134 		u8 request, u8 requesttype, u16 value, u16 index,
135 		void *data, u16 size);
136 extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
137 		void *buf, unsigned int length, unsigned int *act_len);
138 extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
139 		void *buf, unsigned int length, int use_sg, int *residual);
140 extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
141 		struct scsi_cmnd* srb);
142 
143 extern int usb_stor_port_reset(struct us_data *us);
144 #endif
145