drivers/usb/storage/transport.h

   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