usb/storage/protocol.h

0001 /* SPDX-License-Identifier: GPL-2.0+ */
0002 /*
0003  * Driver for USB Mass Storage compliant devices
0004  * Protocol Functions Header File
0005  *
0006  * Current development and maintenance by:
0007  *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
0008  *
0009  * This driver is based on the 'USB Mass Storage Class' document. This
0010  * describes in detail the protocol used to communicate with such
0011  * devices.  Clearly, the designers had SCSI and ATAPI commands in
0012  * mind when they created this document.  The commands are all very
0013  * similar to commands in the SCSI-II and ATAPI specifications.
0014  *
0015  * It is important to note that in a number of cases this class
0016  * exhibits class-specific exemptions from the USB specification.
0017  * Notably the usage of NAK, STALL and ACK differs from the norm, in
0018  * that they are used to communicate wait, failed and OK on commands.
0019  *
0020  * Also, for certain devices, the interrupt endpoint is used to convey
0021  * status of a command.
0022  */
0023
0024 #ifndef _PROTOCOL_H_
0025 #define _PROTOCOL_H_
0026
0027 /* Protocol handling routines */
0028 extern void usb_stor_pad12_command(struct scsi_cmnd*, struct us_data*);
0029 extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*);
0030 extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
0031         struct us_data*);
0032
0033 /* struct scsi_cmnd transfer buffer access utilities */
0034 enum xfer_buf_dir   {TO_XFER_BUF, FROM_XFER_BUF};
0035
0036 extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
0037     unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **,
0038     unsigned int *offset, enum xfer_buf_dir dir);
0039
0040 extern void usb_stor_set_xfer_buf(unsigned char *buffer,
0041     unsigned int buflen, struct scsi_cmnd *srb);
0042 #endif