drivers/usb/storage/transport.h

// SPDX-License-Identifier: GPL-2.0+
/*
 * Driver for USB Mass Storage compliant devices
 * Transport Functions Header File
 *
 * Current development and maintenance by:
 *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
 *
 * This driver is based on the 'USB Mass Storage Class' document. This
 * describes in detail the protocol used to communicate with such
 * devices.  Clearly, the designers had SCSI and ATAPI commands in
 * mind when they created this document.  The commands are all very
 * similar to commands in the SCSI-II and ATAPI specifications.
 *
 * It is important to note that in a number of cases this class
 * exhibits class-specific exemptions from the USB specification.
 * Notably the usage of NAK, STALL and ACK differs from the norm, in
 * that they are used to communicate wait, failed and OK on commands.
 *
 * Also, for certain devices, the interrupt endpoint is used to convey
 * status of a command.
 */

#ifndef _TRANSPORT_H_
#define _TRANSPORT_H_

#include <linux/blkdev.h>

/*
 * usb_stor_bulk_transfer_xxx() return codes, in order of severity
 */

#define USB_STOR_XFER_GOOD	0	/* good transfer                 */
#define USB_STOR_XFER_SHORT	1	/* transferred less than expected */
#define USB_STOR_XFER_STALLED	2	/* endpoint stalled              */
#define USB_STOR_XFER_LONG	3	/* device tried to send too much */
#define USB_STOR_XFER_ERROR	4	/* transfer died in the middle   */

/*
 * Transport return codes
 */

#define USB_STOR_TRANSPORT_GOOD	   0   /* Transport good, command good	   */
#define USB_STOR_TRANSPORT_FAILED  1   /* Transport good, command failed   */
#define USB_STOR_TRANSPORT_NO_SENSE 2  /* Command failed, no auto-sense    */
#define USB_STOR_TRANSPORT_ERROR   3   /* Transport bad (i.e. device dead) */

/*
 * We used to have USB_STOR_XFER_ABORTED and USB_STOR_TRANSPORT_ABORTED
 * return codes.  But now the transport and low-level transfer routines
 * treat an abort as just another error (-ENOENT for a cancelled URB).
 * It is up to the invoke_transport() function to test for aborts and
 * distinguish them from genuine communication errors.
 */

/*
 * CBI accept device specific command
 */

#define US_CBI_ADSC		0

extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
extern int usb_stor_CB_reset(struct us_data*);

extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
extern int usb_stor_Bulk_max_lun(struct us_data*);
extern int usb_stor_Bulk_reset(struct us_data*);

extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
extern void usb_stor_stop_transport(struct us_data*);

extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
		u8 request, u8 requesttype, u16 value, u16 index,
		void *data, u16 size, int timeout);
extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);

extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
		u8 request, u8 requesttype, u16 value, u16 index,
		void *data, u16 size);
extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
		void *buf, unsigned int length, unsigned int *act_len);
extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
		void *buf, unsigned int length, int use_sg, int *residual);
extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
		struct scsi_cmnd* srb);

extern int usb_stor_port_reset(struct us_data *us);
#endif