1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Driver for USB Mass Storage compliant devices
4  * Transport Functions Header File
5  *
6  * Current development and maintenance by:
7  *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
8  *
9  * This driver is based on the 'USB Mass Storage Class' document. This
10  * describes in detail the protocol used to communicate with such
11  * devices.  Clearly, the designers had SCSI and ATAPI commands in
12  * mind when they created this document.  The commands are all very
13  * similar to commands in the SCSI-II and ATAPI specifications.
14  *
15  * It is important to note that in a number of cases this class
16  * exhibits class-specific exemptions from the USB specification.
17  * Notably the usage of NAK, STALL and ACK differs from the norm, in
18  * that they are used to communicate wait, failed and OK on commands.
19  *
20  * Also, for certain devices, the interrupt endpoint is used to convey
21  * status of a command.
22  */
23 
24 #ifndef _TRANSPORT_H_
25 #define _TRANSPORT_H_
26 
27 #include <linux/blkdev.h>
28 
29 /*
30  * usb_stor_bulk_transfer_xxx() return codes, in order of severity
31  */
32 
33 #define USB_STOR_XFER_GOOD	0	/* good transfer                 */
34 #define USB_STOR_XFER_SHORT	1	/* transferred less than expected */
35 #define USB_STOR_XFER_STALLED	2	/* endpoint stalled              */
36 #define USB_STOR_XFER_LONG	3	/* device tried to send too much */
37 #define USB_STOR_XFER_ERROR	4	/* transfer died in the middle   */
38 
39 /*
40  * Transport return codes
41  */
42 
43 #define USB_STOR_TRANSPORT_GOOD	   0   /* Transport good, command good	   */
44 #define USB_STOR_TRANSPORT_FAILED  1   /* Transport good, command failed   */
45 #define USB_STOR_TRANSPORT_NO_SENSE 2  /* Command failed, no auto-sense    */
46 #define USB_STOR_TRANSPORT_ERROR   3   /* Transport bad (i.e. device dead) */
47 
48 /*
49  * We used to have USB_STOR_XFER_ABORTED and USB_STOR_TRANSPORT_ABORTED
50  * return codes.  But now the transport and low-level transfer routines
51  * treat an abort as just another error (-ENOENT for a cancelled URB).
52  * It is up to the invoke_transport() function to test for aborts and
53  * distinguish them from genuine communication errors.
54  */
55 
56 /*
57  * CBI accept device specific command
58  */
59 
60 #define US_CBI_ADSC		0
61 
62 extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
63 extern int usb_stor_CB_reset(struct us_data*);
64 
65 extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
66 extern int usb_stor_Bulk_max_lun(struct us_data*);
67 extern int usb_stor_Bulk_reset(struct us_data*);
68 
69 extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
70 extern void usb_stor_stop_transport(struct us_data*);
71 
72 extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
73 		u8 request, u8 requesttype, u16 value, u16 index,
74 		void *data, u16 size, int timeout);
75 extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);
76 
77 extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
78 		u8 request, u8 requesttype, u16 value, u16 index,
79 		void *data, u16 size);
80 extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
81 		void *buf, unsigned int length, unsigned int *act_len);
82 extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
83 		void *buf, unsigned int length, int use_sg, int *residual);
84 extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
85 		struct scsi_cmnd* srb);
86 
87 extern int usb_stor_port_reset(struct us_data *us);
88 #endif
89