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/* Driver for USB Mass Storage compliant devices
*
* $Id: protocol.c,v 1.11 2002/01/13 06:40:25 mdharm Exp $
*
* Current development and maintenance by:
* (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
*
* Developed with the assistance of:
* (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
*
* Initial work by:
* (c) 1999 Michael Gee (michael@linuxspecific.com)
*
* 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.
*
* Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
* information about this driver.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "protocol.h"
#include "usb.h"
#include "debug.h"
#include "scsiglue.h"
#include "transport.h"
/***********************************************************************
* Helper routines
***********************************************************************/
/* Fix-up the return data from an INQUIRY command to show
* ANSI SCSI rev 2 so we don't confuse the SCSI layers above us
*/
void fix_inquiry_data(Scsi_Cmnd *srb)
{
unsigned char *data_ptr;
/* verify that it's an INQUIRY command */
if (srb->cmnd[0] != INQUIRY)
return;
US_DEBUGP("Fixing INQUIRY data to show SCSI rev 2\n");
/* find the location of the data */
if (srb->use_sg) {
struct scatterlist *sg;
sg = (struct scatterlist *) srb->request_buffer;
data_ptr = (unsigned char *) sg[0].address;
} else
data_ptr = (unsigned char *)srb->request_buffer;
/* Change the SCSI revision number */
data_ptr[2] = (data_ptr[2] & ~7) | 2;
}
/***********************************************************************
* Protocol routines
***********************************************************************/
void usb_stor_qic157_command(Scsi_Cmnd *srb, struct us_data *us)
{
/* Pad the ATAPI command with zeros
* NOTE: This only works because a Scsi_Cmnd struct field contains
* a unsigned char cmnd[12], so we know we have storage available
*/
for (; srb->cmd_len<12; srb->cmd_len++)
srb->cmnd[srb->cmd_len] = 0;
/* set command length to 12 bytes */
srb->cmd_len = 12;
/* send the command to the transport layer */
usb_stor_invoke_transport(srb, us);
/* fix the INQUIRY data if necessary */
fix_inquiry_data(srb);
}
void usb_stor_ATAPI_command(Scsi_Cmnd *srb, struct us_data *us)
{
int old_cmnd = 0;
/* Fix some commands -- this is a form of mode translation
* ATAPI devices only accept 12 byte long commands
*
* NOTE: This only works because a Scsi_Cmnd struct field contains
* a unsigned char cmnd[12], so we know we have storage available
*/
/* Pad the ATAPI command with zeros */
for (; srb->cmd_len<12; srb->cmd_len++)
srb->cmnd[srb->cmd_len] = 0;
/* set command length to 12 bytes */
srb->cmd_len = 12;
/* determine the correct (or minimum) data length for these commands */
switch (srb->cmnd[0]) {
/* change MODE_SENSE/MODE_SELECT from 6 to 10 byte commands */
case MODE_SENSE:
case MODE_SELECT:
/* save the command so we can tell what it was */
old_cmnd = srb->cmnd[0];
srb->cmnd[11] = 0;
srb->cmnd[10] = 0;
srb->cmnd[9] = 0;
srb->cmnd[8] = srb->cmnd[4];
srb->cmnd[7] = 0;
srb->cmnd[6] = 0;
srb->cmnd[5] = 0;
srb->cmnd[4] = 0;
srb->cmnd[3] = 0;
srb->cmnd[2] = srb->cmnd[2];
srb->cmnd[1] = srb->cmnd[1];
srb->cmnd[0] = srb->cmnd[0] | 0x40;
break;
/* change READ_6/WRITE_6 to READ_10/WRITE_10, which
* are ATAPI commands */
case WRITE_6:
case READ_6:
srb->cmnd[11] = 0;
srb->cmnd[10] = 0;
srb->cmnd[9] = 0;
srb->cmnd[8] = srb->cmnd[4];
srb->cmnd[7] = 0;
srb->cmnd[6] = 0;
srb->cmnd[5] = srb->cmnd[3];
srb->cmnd[4] = srb->cmnd[2];
srb->cmnd[3] = srb->cmnd[1] & 0x1F;
srb->cmnd[2] = 0;
srb->cmnd[1] = srb->cmnd[1] & 0xE0;
srb->cmnd[0] = srb->cmnd[0] | 0x20;
break;
} /* end switch on cmnd[0] */
/* convert MODE_SELECT data here */
if (old_cmnd == MODE_SELECT)
usb_stor_scsiSense6to10(srb);
/* send the command to the transport layer */
usb_stor_invoke_transport(srb, us);
/* Fix the MODE_SENSE data if we translated the command */
if ((old_cmnd == MODE_SENSE) && (status_byte(srb->result) == GOOD))
usb_stor_scsiSense10to6(srb);
/* fix the INQUIRY data if necessary */
fix_inquiry_data(srb);
}
void usb_stor_ufi_command(Scsi_Cmnd *srb, struct us_data *us)
{
int old_cmnd = 0;
/* fix some commands -- this is a form of mode translation
* UFI devices only accept 12 byte long commands
*
* NOTE: This only works because a Scsi_Cmnd struct field contains
* a unsigned char cmnd[12], so we know we have storage available
*/
/* set command length to 12 bytes (this affects the transport layer) */
srb->cmd_len = 12;
/* determine the correct (or minimum) data length for these commands */
switch (srb->cmnd[0]) {
/* for INQUIRY, UFI devices only ever return 36 bytes */
case INQUIRY:
srb->cmnd[4] = 36;
break;
/* change MODE_SENSE/MODE_SELECT from 6 to 10 byte commands */
case MODE_SENSE:
case MODE_SELECT:
/* save the command so we can tell what it was */
old_cmnd = srb->cmnd[0];
srb->cmnd[11] = 0;
srb->cmnd[10] = 0;
srb->cmnd[9] = 0;
/* if we're sending data, we send all. If getting data,
* get the minimum */
if (srb->cmnd[0] == MODE_SELECT)
srb->cmnd[8] = srb->cmnd[4];
else
srb->cmnd[8] = 8;
srb->cmnd[7] = 0;
srb->cmnd[6] = 0;
srb->cmnd[5] = 0;
srb->cmnd[4] = 0;
srb->cmnd[3] = 0;
srb->cmnd[2] = srb->cmnd[2];
srb->cmnd[1] = srb->cmnd[1];
srb->cmnd[0] = srb->cmnd[0] | 0x40;
break;
/* again, for MODE_SENSE_10, we get the minimum (8) */
case MODE_SENSE_10:
srb->cmnd[7] = 0;
srb->cmnd[8] = 8;
break;
/* for REQUEST_SENSE, UFI devices only ever return 18 bytes */
case REQUEST_SENSE:
srb->cmnd[4] = 18;
break;
/* change READ_6/WRITE_6 to READ_10/WRITE_10, which
* are UFI commands */
case WRITE_6:
case READ_6:
srb->cmnd[11] = 0;
srb->cmnd[10] = 0;
srb->cmnd[9] = 0;
srb->cmnd[8] = srb->cmnd[4];
srb->cmnd[7] = 0;
srb->cmnd[6] = 0;
srb->cmnd[5] = srb->cmnd[3];
srb->cmnd[4] = srb->cmnd[2];
srb->cmnd[3] = srb->cmnd[1] & 0x1F;
srb->cmnd[2] = 0;
srb->cmnd[1] = srb->cmnd[1] & 0xE0;
srb->cmnd[0] = srb->cmnd[0] | 0x20;
break;
} /* end switch on cmnd[0] */
/* convert MODE_SELECT data here */
if (old_cmnd == MODE_SELECT)
usb_stor_scsiSense6to10(srb);
/* send the command to the transport layer */
usb_stor_invoke_transport(srb, us);
/* Fix the MODE_SENSE data if we translated the command */
if ((old_cmnd == MODE_SENSE) && (status_byte(srb->result) == GOOD))
usb_stor_scsiSense10to6(srb);
/* Fix the data for an INQUIRY, if necessary */
fix_inquiry_data(srb);
}
void usb_stor_transparent_scsi_command(Scsi_Cmnd *srb, struct us_data *us)
{
int old_cmnd = 0;
/* This code supports devices which do not support {READ|WRITE}_6
* Apparently, neither Windows or MacOS will use these commands,
* so some devices do not support them
*/
if (us->flags & US_FL_MODE_XLATE) {
US_DEBUGP("Invoking Mode Translation\n");
/* save the old command for later */
old_cmnd = srb->cmnd[0];
switch (srb->cmnd[0]) {
/* change READ_6/WRITE_6 to READ_10/WRITE_10 */
case WRITE_6:
case READ_6:
srb->cmd_len = 12;
srb->cmnd[11] = 0;
srb->cmnd[10] = 0;
srb->cmnd[9] = 0;
srb->cmnd[8] = srb->cmnd[4];
srb->cmnd[7] = 0;
srb->cmnd[6] = 0;
srb->cmnd[5] = srb->cmnd[3];
srb->cmnd[4] = srb->cmnd[2];
srb->cmnd[3] = srb->cmnd[1] & 0x1F;
srb->cmnd[2] = 0;
srb->cmnd[1] = srb->cmnd[1] & 0xE0;
srb->cmnd[0] = srb->cmnd[0] | 0x20;
break;
/* convert MODE_SELECT data here */
case MODE_SENSE:
case MODE_SELECT:
srb->cmd_len = 12;
srb->cmnd[11] = 0;
srb->cmnd[10] = 0;
srb->cmnd[9] = 0;
srb->cmnd[8] = srb->cmnd[4];
srb->cmnd[7] = 0;
srb->cmnd[6] = 0;
srb->cmnd[5] = 0;
srb->cmnd[4] = 0;
srb->cmnd[3] = 0;
srb->cmnd[2] = srb->cmnd[2];
srb->cmnd[1] = srb->cmnd[1];
srb->cmnd[0] = srb->cmnd[0] | 0x40;
break;
} /* switch (srb->cmnd[0]) */
} /* if (us->flags & US_FL_MODE_XLATE) */
/* convert MODE_SELECT data here */
if ((us->flags & US_FL_MODE_XLATE) && (old_cmnd == MODE_SELECT))
usb_stor_scsiSense6to10(srb);
/* send the command to the transport layer */
usb_stor_invoke_transport(srb, us);
/* Fix the MODE_SENSE data if we translated the command */
if ((us->flags & US_FL_MODE_XLATE) && (old_cmnd == MODE_SENSE)
&& (status_byte(srb->result) == GOOD))
usb_stor_scsiSense10to6(srb);
/* fix the INQUIRY data if necessary */
fix_inquiry_data(srb);
}
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