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  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
  24  * information about this driver.
  25  */
  26
  27 #ifndef _TRANSPORT_H_
  28 #define _TRANSPORT_H_
  29
  30 #include <linux/blkdev.h>
  31
  32 /*
  33  * usb_stor_bulk_transfer_xxx() return codes, in order of severity
  34  */
  35
  36 #define USB_STOR_XFER_GOOD      0       /* good transfer                 */
  37 #define USB_STOR_XFER_SHORT     1       /* transferred less than expected */
  38 #define USB_STOR_XFER_STALLED   2       /* endpoint stalled              */
  39 #define USB_STOR_XFER_LONG      3       /* device tried to send too much */
  40 #define USB_STOR_XFER_ERROR     4       /* transfer died in the middle   */
  41
  42 /*
  43  * Transport return codes
  44  */
  45
  46 #define USB_STOR_TRANSPORT_GOOD    0   /* Transport good, command good     */
  47 #define USB_STOR_TRANSPORT_FAILED  1   /* Transport good, command failed   */
  48 #define USB_STOR_TRANSPORT_NO_SENSE 2  /* Command failed, no auto-sense    */
  49 #define USB_STOR_TRANSPORT_ERROR   3   /* Transport bad (i.e. device dead) */
  50
  51 /*
  52  * We used to have USB_STOR_XFER_ABORTED and USB_STOR_TRANSPORT_ABORTED
  53  * return codes.  But now the transport and low-level transfer routines
  54  * treat an abort as just another error (-ENOENT for a cancelled URB).
  55  * It is up to the invoke_transport() function to test for aborts and
  56  * distinguish them from genuine communication errors.
  57  */
  58
  59 /*
  60  * CBI accept device specific command
  61  */
  62
  63 #define US_CBI_ADSC             0
  64
  65 extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
  66 extern int usb_stor_CB_reset(struct us_data*);
  67
  68 extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
  69 extern int usb_stor_Bulk_max_lun(struct us_data*);
  70 extern int usb_stor_Bulk_reset(struct us_data*);
  71
  72 extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
  73 extern void usb_stor_stop_transport(struct us_data*);
  74
  75 extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
  76                 u8 request, u8 requesttype, u16 value, u16 index,
  77                 void *data, u16 size, int timeout);
  78 extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);
  79
  80 extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
  81                 u8 request, u8 requesttype, u16 value, u16 index,
  82                 void *data, u16 size);
  83 extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
  84                 void *buf, unsigned int length, unsigned int *act_len);
  85 extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
  86                 void *buf, unsigned int length, int use_sg, int *residual);
  87 extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
  88                 struct scsi_cmnd* srb);
  89
  90 extern int usb_stor_port_reset(struct us_data *us);
  91 #endif