1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Driver for USB Mass Storage compliant devices 4 * Protocol 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 _PROTOCOL_H_ 25 #define _PROTOCOL_H_ 26 27 /* Protocol handling routines */ 28 extern void usb_stor_pad12_command(struct scsi_cmnd*, struct us_data*); 29 extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*); 30 extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*, 31 struct us_data*); 32 33 /* struct scsi_cmnd transfer buffer access utilities */ 34 enum xfer_buf_dir {TO_XFER_BUF, FROM_XFER_BUF}; 35 36 extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer, 37 unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **, 38 unsigned int *offset, enum xfer_buf_dir dir); 39 40 extern void usb_stor_set_xfer_buf(unsigned char *buffer, 41 unsigned int buflen, struct scsi_cmnd *srb); 42 #endif 43