transport.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

/* Driver for USB Mass Storage compliant devices
 *
 * $Id: transport.c,v 1.42 2001/12/08 23:32:48 mdharm Exp $
 *
 * Current development and maintenance by:
 *   (c) 1999, 2000 Matthew Dharm ([e-mail])
 *
 * Developed with the assistance of:
 *   (c) 2000 David L. Brown, Jr. ([e-mail])
 *   (c) 2000 Stephen J. Gowdy ([e-mail])
 *
 * Initial work by:
 *   (c) 1999 Michael Gee ([e-mail])
 *
 * 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 <linux/config.h>
#include "transport.h"
#include "protocol.h"
#include "usb.h"
#include "debug.h"

#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/slab.h>

/***********************************************************************
 * Helper routines
 ***********************************************************************/

/* Calculate the length of the data transfer (not the command) for any
 * given SCSI command
 */
unsigned int usb_stor_transfer_length(Scsi_Cmnd *srb)
{
      	int i;
	int doDefault = 0;
	unsigned int len = 0;
	unsigned int total = 0;
	struct scatterlist *sg;

	/* This table tells us:
	   X = command not supported
	   L = return length in cmnd[4] (8 bits).
	   M = return length in cmnd[8] (8 bits).
	   G = return length in cmnd[3] and cmnd[4] (16 bits)
	   H = return length in cmnd[7] and cmnd[8] (16 bits)
	   I = return length in cmnd[8] and cmnd[9] (16 bits)
	   C = return length in cmnd[2] to cmnd[5] (32 bits)
	   D = return length in cmnd[6] to cmnd[9] (32 bits)
	   B = return length in blocksize so we use buff_len
	   R = return length in cmnd[2] to cmnd[4] (24 bits)
	   S = return length in cmnd[3] to cmnd[5] (24 bits)
	   T = return length in cmnd[6] to cmnd[8] (24 bits)
	   U = return length in cmnd[7] to cmnd[9] (24 bits)
	   0-9 = fixed return length
	   V = 20 bytes
	   W = 24 bytes
	   Z = return length is mode dependant or not in command, use buff_len
	*/

	static char *lengths =

	      /* 0123456789ABCDEF   0123456789ABCDEF */

		"00XLZ6XZBXBBXXXB" "00LBBLG0R0L0GG0X"  /* 00-1F */
		"XXXXT8XXB4B0BBBB" "ZZZ0B00HCSSZTBHH"  /* 20-3F */
		"M0HHB0X000H0HH0X" "XHH0HHXX0TH0H0XX"  /* 40-5F */
		"XXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXX"  /* 60-7F */
		"XXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXX"  /* 80-9F */
		"X0XXX00XB0BXBXBB" "ZZZ0XUIDU000XHBX"  /* A0-BF */
		"XXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXX"  /* C0-DF */
		"XDXXXXXXXXXXXXXX" "XXW00HXXXXXXXXXX"; /* E0-FF */

	/* Commands checked in table:

	   CHANGE_DEFINITION 40
	   COMPARE 39
	   COPY 18
	   COPY_AND_VERIFY 3a
	   ERASE 19
	   ERASE_10 2c
	   ERASE_12 ac
	   EXCHANGE_MEDIUM a6
	   FORMAT_UNIT 04
	   GET_DATA_BUFFER_STATUS 34
	   GET_MESSAGE_10 28
	   GET_MESSAGE_12 a8
	   GET_WINDOW 25   !!! Has more data than READ_CAPACITY, need to fix table
	   INITIALIZE_ELEMENT_STATUS 07 !!! REASSIGN_BLOCKS luckily uses buff_len
	   INQUIRY 12
	   LOAD_UNLOAD 1b
	   LOCATE 2b
	   LOCK_UNLOCK_CACHE 36
	   LOG_SELECT 4c
	   LOG_SENSE 4d
	   MEDIUM_SCAN 38     !!! This was M
	   MODE_SELECT6 15
	   MODE_SELECT_10 55
	   MODE_SENSE_6 1a
	   MODE_SENSE_10 5a
	   MOVE_MEDIUM a5
	   OBJECT_POSITION 31  !!! Same as SEARCH_DATA_EQUAL
	   PAUSE_RESUME 4b
	   PLAY_AUDIO_10 45
	   PLAY_AUDIO_12 a5
	   PLAY_AUDIO_MSF 47
	   PLAY_AUDIO_TRACK_INDEX 48
   	   PLAY_AUDIO_TRACK_RELATIVE_10 49
	   PLAY_AUDIO_TRACK_RELATIVE_12 a9
	   POSITION_TO_ELEMENT 2b
      	   PRE-FETCH 34
	   PREVENT_ALLOW_MEDIUM_REMOVAL 1e
	   PRINT 0a             !!! Same as WRITE_6 but is always in bytes
	   READ_6 08
	   READ_10 28
	   READ_12 a8
	   READ_BLOCK_LIMITS 05
	   READ_BUFFER 3c
	   READ_CAPACITY 25
	   READ_CDROM_CAPACITY 25
	   READ_DEFECT_DATA 37
	   READ_DEFECT_DATA_12 b7
	   READ_ELEMENT_STATUS b8 !!! Think this is in bytes
	   READ_GENERATION 29 !!! Could also be M?
	   READ_HEADER 44     !!! This was L
	   READ_LONG 3e
	   READ_POSITION 34   !!! This should be V but conflicts with PRE-FETCH
	   READ_REVERSE 0f
	   READ_SUB-CHANNEL 42 !!! Is this in bytes?
	   READ_TOC 43         !!! Is this in bytes?
	   READ_UPDATED_BLOCK 2d
	   REASSIGN_BLOCKS 07
	   RECEIVE 08        !!! Same as READ_6 probably in bytes though
	   RECEIVE_DIAGNOSTIC_RESULTS 1c
	   RECOVER_BUFFERED_DATA 14 !!! For PRINTERs this is bytes
	   RELEASE_UNIT 17
	   REQUEST_SENSE 03
	   REQUEST_VOLUME_ELEMENT_ADDRESS b5 !!! Think this is in bytes
	   RESERVE_UNIT 16
	   REWIND 01
	   REZERO_UNIT 01
	   SCAN 1b          !!! Conflicts with various commands, should be L
	   SEARCH_DATA_EQUAL 31
	   SEARCH_DATA_EQUAL_12 b1
	   SEARCH_DATA_LOW 30
	   SEARCH_DATA_LOW_12 b0
	   SEARCH_DATA_HIGH 32
	   SEARCH_DATA_HIGH_12 b2
	   SEEK_6 0b         !!! Conflicts with SLEW_AND_PRINT
	   SEEK_10 2b
	   SEND 0a           !!! Same as WRITE_6, probably in bytes though
	   SEND 2a           !!! Similar to WRITE_10 but for scanners
	   SEND_DIAGNOSTIC 1d
	   SEND_MESSAGE_6 0a   !!! Same as WRITE_6 - is in bytes
	   SEND_MESSAGE_10 2a  !!! Same as WRITE_10 - is in bytes
	   SEND_MESSAGE_12 aa  !!! Same as WRITE_12 - is in bytes
	   SEND_OPC 54
	   SEND_VOLUME_TAG b6 !!! Think this is in bytes
	   SET_LIMITS 33
	   SET_LIMITS_12 b3
	   SET_WINDOW 24
	   SLEW_AND_PRINT 0b !!! Conflicts with SEEK_6
	   SPACE 11
	   START_STOP_UNIT 1b
	   STOP_PRINT 1b
	   SYNCHRONIZE_BUFFER 10
	   SYNCHRONIZE_CACHE 35
	   TEST_UNIT_READY 00
	   UPDATE_BLOCK 3d
	   VERIFY 13
	   VERIFY 2f
	   VERIFY_12 af
	   WRITE_6 0a
	   WRITE_10 2a
	   WRITE_12 aa
	   WRITE_AND_VERIFY 2e
	   WRITE_AND_VERIFY_12 ae
	   WRITE_BUFFER 3b
	   WRITE_FILEMARKS 10
	   WRITE_LONG 3f
	   WRITE_SAME 41
	*/

	if (srb->sc_data_direction == SCSI_DATA_WRITE) {
		doDefault = 1;
	}
	else
		switch (lengths[srb->cmnd[0]]) {
			case 'L':
				len = srb->cmnd[4];
				break;

			case 'M':
				len = srb->cmnd[8];
				break;

			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9':
				len = lengths[srb->cmnd[0]]-'0';
				break;

			case 'G':
				len = (((unsigned int)srb->cmnd[3])<<8) |
					srb->cmnd[4];
				break;

			case 'H':
				len = (((unsigned int)srb->cmnd[7])<<8) |
					srb->cmnd[8];
				break;

			case 'I':
				len = (((unsigned int)srb->cmnd[8])<<8) |
					srb->cmnd[9];
				break;

			case 'R':
				len = (((unsigned int)srb->cmnd[2])<<16) |
					(((unsigned int)srb->cmnd[3])<<8) |
					srb->cmnd[4];
				break;

			case 'S':
				len = (((unsigned int)srb->cmnd[3])<<16) |
					(((unsigned int)srb->cmnd[4])<<8) |
					srb->cmnd[5];
				break;

			case 'T':
				len = (((unsigned int)srb->cmnd[6])<<16) |
					(((unsigned int)srb->cmnd[7])<<8) |
					srb->cmnd[8];
				break;

			case 'U':
				len = (((unsigned int)srb->cmnd[7])<<16) |
					(((unsigned int)srb->cmnd[8])<<8) |
					srb->cmnd[9];
				break;

			case 'C':
				len = (((unsigned int)srb->cmnd[2])<<24) |
					(((unsigned int)srb->cmnd[3])<<16) |
					(((unsigned int)srb->cmnd[4])<<8) |
					srb->cmnd[5];
				break;

			case 'D':
				len = (((unsigned int)srb->cmnd[6])<<24) |
					(((unsigned int)srb->cmnd[7])<<16) |
					(((unsigned int)srb->cmnd[8])<<8) |
					srb->cmnd[9];
				break;

			case 'V':
				len = 20;
				break;

			case 'W':
				len = 24;
				break;

			case 'B':
				/* Use buffer size due to different block sizes */
				doDefault = 1;
				break;

			case 'X':
				US_DEBUGP("Error: UNSUPPORTED COMMAND %02X\n",
						srb->cmnd[0]);
				doDefault = 1;
				break;

			case 'Z':
				/* Use buffer size due to mode dependence */
				doDefault = 1;
				break;

			default:
				US_DEBUGP("Error: COMMAND %02X out of range or table inconsistent (%c).\n",
						srb->cmnd[0], lengths[srb->cmnd[0]] );
				doDefault = 1;
		}
	   
	   if ( doDefault == 1 ) {
		   /* Are we going to scatter gather? */
		   if (srb->use_sg) {
			   /* Add up the sizes of all the sg segments */
			   sg = (struct scatterlist *) srb->request_buffer;
			   for (i = 0; i < srb->use_sg; i++)
				   total += sg[i].length;
			   len = total;
		   }
		   else
			   /* Just return the length of the buffer */
			   len = srb->request_bufflen;
	   }

return len;
}

/* This is a version of usb_clear_halt() that doesn't read the status from
 * the device -- this is because some devices crash their internal firmware
 * when the status is requested after a halt
 */
int usb_stor_clear_halt(struct usb_device *dev, int pipe)
{
	int result;
	int endp = usb_pipeendpoint(pipe) | (usb_pipein(pipe) << 7);

	result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
				 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT, 0,
				 endp, NULL, 0, HZ * 3);

	/* this is a failure case */
	if (result < 0)
		return result;

	/* reset the toggles and endpoint flags */
	usb_endpoint_running(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe));
	usb_settoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe), 0);

	return 0;
}

/***********************************************************************
 * Data transfer routines
 ***********************************************************************/

/* This is the completion handler which will wake us up when an URB
 * completes.
 */
static void usb_stor_blocking_completion(urb_t *urb)
{
	struct completion *urb_done_ptr = (struct completion *)urb->context;

	complete(urb_done_ptr);
}

/* This is our function to emulate usb_control_msg() but give us enough
 * access to make aborts/resets work
 */
int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
			 u8 request, u8 requesttype, u16 value, u16 index, 
			 void *data, u16 size)
{
	struct completion urb_done;
	int status;
	devrequest *dr;

	/* allocate the device request structure */
	dr = kmalloc(sizeof(devrequest), GFP_NOIO);
	if (!dr)
		return -ENOMEM;

	/* fill in the structure */
	dr->requesttype = requesttype;
	dr->request = request;
	dr->value = cpu_to_le16(value);
	dr->index = cpu_to_le16(index);
	dr->length = cpu_to_le16(size);

	/* set up data structures for the wakeup system */
	init_completion(&urb_done);

	/* lock the URB */
	down(&(us->current_urb_sem));

	/* fill the URB */
	FILL_CONTROL_URB(us->current_urb, us->pusb_dev, pipe, 
			 (unsigned char*) dr, data, size, 
			 usb_stor_blocking_completion, &urb_done);
	us->current_urb->actual_length = 0;
	us->current_urb->error_count = 0;
	us->current_urb->transfer_flags = USB_ASYNC_UNLINK;

	/* submit the URB */
	status = usb_submit_urb(us->current_urb);
	if (status) {
		/* something went wrong */
		up(&(us->current_urb_sem));
		kfree(dr);
		return status;
	}

	/* wait for the completion of the URB */