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 89