drivers/usb/storage/datafab.c - android_kernel_oneplus_sm8150 - Gitiles

 /* Driver for Datafab USB Compact Flash reader
  *
  * $Id: datafab.c,v 1.7 2002/02/25 00:40:13 mdharm Exp $
  *
  * datafab driver v0.1:
  *
  * First release
  *
  * Current development and maintenance by:
  *   (c) 2000 Jimmie Mayfield (mayfield+datafab@sackheads.org)
  *
  *   Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
  *   which I used as a template for this driver.
  *
  *   Some bugfixes and scatter-gather code by Gregory P. Smith
  *   (greg-usb@electricrain.com)
  *
  *   Fix for media change by Joerg Schneider (js@joergschneider.com)
  *
  * Other contributors:
  *   (c) 2002 Alan Stern <stern@rowland.org>
  *
  * 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.
  */

 /*
  * This driver attempts to support USB CompactFlash reader/writer devices
  * based on Datafab USB-to-ATA chips.  It was specifically developed for the
  * Datafab MDCFE-B USB CompactFlash reader but has since been found to work
  * with a variety of Datafab-based devices from a number of manufacturers.
  * I've received a report of this driver working with a Datafab-based
  * SmartMedia device though please be aware that I'm personally unable to
  * test SmartMedia support.
  *
  * This driver supports reading and writing.  If you're truly paranoid,
  * however, you can force the driver into a write-protected state by setting
  * the WP enable bits in datafab_handle_mode_sense().  See the comments
  * in that routine.
  */

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

 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>

 #include "usb.h"
 #include "transport.h"
 #include "protocol.h"
 #include "debug.h"
 #include "datafab.h"

 static int datafab_determine_lun(struct us_data *us,
 				 struct datafab_info *info);


 static inline int
 datafab_bulk_read(struct us_data *us, unsigned char *data, unsigned int len) {
 	if (len == 0)
 		return USB_STOR_XFER_GOOD;

 	US_DEBUGP("datafab_bulk_read:  len = %d\n", len);
 	return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
 			data, len, NULL);
 }


 static inline int
 datafab_bulk_write(struct us_data *us, unsigned char *data, unsigned int len) {
 	if (len == 0)
 		return USB_STOR_XFER_GOOD;

 	US_DEBUGP("datafab_bulk_write:  len = %d\n", len);
 	return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
 			data, len, NULL);
 }


 static int datafab_read_data(struct us_data *us,
 			     struct datafab_info *info,
 			     u32 sector,
 			     u32 sectors)
 {
 	unsigned char *command = us->iobuf;
 	unsigned char *buffer;
 	unsigned char  thistime;
 	unsigned int totallen, alloclen;
 	int len, result;
 	unsigned int sg_idx = 0, sg_offset = 0;

 	// we're working in LBA mode.  according to the ATA spec,
 	// we can support up to 28-bit addressing.  I don't know if Datafab
 	// supports beyond 24-bit addressing.  It's kind of hard to test
 	// since it requires > 8GB CF card.
 	//
 	if (sectors > 0x0FFFFFFF)
 		return USB_STOR_TRANSPORT_ERROR;

 	if (info->lun == -1) {
 		result = datafab_determine_lun(us, info);
 		if (result != USB_STOR_TRANSPORT_GOOD)
 			return result;
 	}

 	totallen = sectors * info->ssize;

 	// Since we don't read more than 64 KB at a time, we have to create
 	// a bounce buffer and move the data a piece at a time between the
 	// bounce buffer and the actual transfer buffer.

 	alloclen = min(totallen, 65536u);
 	buffer = kmalloc(alloclen, GFP_NOIO);
 	if (buffer == NULL)
 		return USB_STOR_TRANSPORT_ERROR;

 	do {
 		// loop, never allocate or transfer more than 64k at once
 		// (min(128k, 255*info->ssize) is the real limit)

 		len = min(totallen, alloclen);
 		thistime = (len / info->ssize) & 0xff;

 		command[0] = 0;
 		command[1] = thistime;
 		command[2] = sector & 0xFF;
 		command[3] = (sector >> 8) & 0xFF;
 		command[4] = (sector >> 16) & 0xFF;

 		command[5] = 0xE0 + (info->lun << 4);
 		command[5] |= (sector >> 24) & 0x0F;
 		command[6] = 0x20;
 		command[7] = 0x01;

 		// send the read command
 		result = datafab_bulk_write(us, command, 8);
 		if (result != USB_STOR_XFER_GOOD)
 			goto leave;

 		// read the result
 		result = datafab_bulk_read(us, buffer, len);
 		if (result != USB_STOR_XFER_GOOD)
 			goto leave;

 		// Store the data in the transfer buffer
 		usb_stor_access_xfer_buf(buffer, len, us->srb,
 				 &sg_idx, &sg_offset, TO_XFER_BUF);

 		sector += thistime;
 		totallen -= len;
 	} while (totallen > 0);

 	kfree(buffer);
 	return USB_STOR_TRANSPORT_GOOD;

  leave:
 	kfree(buffer);
 	return USB_STOR_TRANSPORT_ERROR;
 }


 static int datafab_write_data(struct us_data *us,
 			      struct datafab_info *info,
 			      u32 sector,
 			      u32 sectors)
 {
 	unsigned char *command = us->iobuf;
 	unsigned char *reply = us->iobuf;
 	unsigned char *buffer;
 	unsigned char thistime;
 	unsigned int totallen, alloclen;
 	int len, result;
 	unsigned int sg_idx = 0, sg_offset = 0;

 	// we're working in LBA mode.  according to the ATA spec,
 	// we can support up to 28-bit addressing.  I don't know if Datafab
 	// supports beyond 24-bit addressing.  It's kind of hard to test
 	// since it requires > 8GB CF card.
 	//
 	if (sectors > 0x0FFFFFFF)
 		return USB_STOR_TRANSPORT_ERROR;

 	if (info->lun == -1) {
 		result = datafab_determine_lun(us, info);
 		if (result != USB_STOR_TRANSPORT_GOOD)
 			return result;
 	}

 	totallen = sectors * info->ssize;

 	// Since we don't write more than 64 KB at a time, we have to create
 	// a bounce buffer and move the data a piece at a time between the
 	// bounce buffer and the actual transfer buffer.

 	alloclen = min(totallen, 65536u);
 	buffer = kmalloc(alloclen, GFP_NOIO);
 	if (buffer == NULL)
 		return USB_STOR_TRANSPORT_ERROR;

 	do {
 		// loop, never allocate or transfer more than 64k at once
 		// (min(128k, 255*info->ssize) is the real limit)

 		len = min(totallen, alloclen);
 		thistime = (len / info->ssize) & 0xff;

 		// Get the data from the transfer buffer
 		usb_stor_access_xfer_buf(buffer, len, us->srb,
 				&sg_idx, &sg_offset, FROM_XFER_BUF);

 		command[0] = 0;
 		command[1] = thistime;
 		command[2] = sector & 0xFF;
 		command[3] = (sector >> 8) & 0xFF;
 		command[4] = (sector >> 16) & 0xFF;

 		command[5] = 0xE0 + (info->lun << 4);
 		command[5] |= (sector >> 24) & 0x0F;
 		command[6] = 0x30;
 		command[7] = 0x02;

 		// send the command
 		result = datafab_bulk_write(us, command, 8);
 		if (result != USB_STOR_XFER_GOOD)
 			goto leave;

 		// send the data
 		result = datafab_bulk_write(us, buffer, len);
 		if (result != USB_STOR_XFER_GOOD)
 			goto leave;

 		// read the result
 		result = datafab_bulk_read(us, reply, 2);
 		if (result != USB_STOR_XFER_GOOD)
 			goto leave;

 		if (reply[0] != 0x50 && reply[1] != 0) {
 			US_DEBUGP("datafab_write_data:  Gah! "
 				  "write return code: %02x %02x\n",
 				  reply[0], reply[1]);
 			result = USB_STOR_TRANSPORT_ERROR;
 			goto leave;
 		}

 		sector += thistime;
 		totallen -= len;
 	} while (totallen > 0);

 	kfree(buffer);
 	return USB_STOR_TRANSPORT_GOOD;

  leave:
 	kfree(buffer);
 	return USB_STOR_TRANSPORT_ERROR;
 }


 static int datafab_determine_lun(struct us_data *us,
 				 struct datafab_info *info)
 {
 	// Dual-slot readers can be thought of as dual-LUN devices.
 	// We need to determine which card slot is being used.
 	// We'll send an IDENTIFY DEVICE command and see which LUN responds...
 	//
 	// There might be a better way of doing this?

 	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
 	unsigned char *command = us->iobuf;
 	unsigned char *buf;
 	int count = 0, rc;

 	if (!us || !info)
 		return USB_STOR_TRANSPORT_ERROR;

 	memcpy(command, scommand, 8);
 	buf = kmalloc(512, GFP_NOIO);
 	if (!buf)
 		return USB_STOR_TRANSPORT_ERROR;

 	US_DEBUGP("datafab_determine_lun:  locating...\n");

 	// we'll try 3 times before giving up...
 	//
 	while (count++ < 3) {
 		command[5] = 0xa0;

 		rc = datafab_bulk_write(us, command, 8);
 		if (rc != USB_STOR_XFER_GOOD) {
 			rc = USB_STOR_TRANSPORT_ERROR;
 			goto leave;
 		}

 		rc = datafab_bulk_read(us, buf, 512);
 		if (rc == USB_STOR_XFER_GOOD) {
 			info->lun = 0;
 			rc = USB_STOR_TRANSPORT_GOOD;
 			goto leave;
 		}

 		command[5] = 0xb0;

 		rc = datafab_bulk_write(us, command, 8);
 		if (rc != USB_STOR_XFER_GOOD) {
 			rc = USB_STOR_TRANSPORT_ERROR;
 			goto leave;
 		}

 		rc = datafab_bulk_read(us, buf, 512);
 		if (rc == USB_STOR_XFER_GOOD) {
 			info->lun = 1;
 			rc = USB_STOR_TRANSPORT_GOOD;
 			goto leave;
 		}

 		msleep(20);
 	}

 	rc = USB_STOR_TRANSPORT_ERROR;

  leave:
 	kfree(buf);
 	return rc;
 }

 static int datafab_id_device(struct us_data *us,
 			     struct datafab_info *info)
 {
 	// this is a variation of the ATA "IDENTIFY DEVICE" command...according
 	// to the ATA spec, 'Sector Count' isn't used but the Windows driver
 	// sets this bit so we do too...
 	//
 	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
 	unsigned char *command = us->iobuf;
 	unsigned char *reply;
 	int rc;

 	if (!us || !info)
 		return USB_STOR_TRANSPORT_ERROR;

 	if (info->lun == -1) {
 		rc = datafab_determine_lun(us, info);
 		if (rc != USB_STOR_TRANSPORT_GOOD)
 			return rc;
 	}

 	memcpy(command, scommand, 8);
 	reply = kmalloc(512, GFP_NOIO);
 	if (!reply)
 		return USB_STOR_TRANSPORT_ERROR;

 	command[5] += (info->lun << 4);

 	rc = datafab_bulk_write(us, command, 8);
 	if (rc != USB_STOR_XFER_GOOD) {
 		rc = USB_STOR_TRANSPORT_ERROR;
 		goto leave;
 	}

 	// we'll go ahead and extract the media capacity while we're here...
 	//
 	rc = datafab_bulk_read(us, reply, 512);
 	if (rc == USB_STOR_XFER_GOOD) {
 		// capacity is at word offset 57-58
 		//
 		info->sectors = ((u32)(reply[117]) << 24) |
 				((u32)(reply[116]) << 16) |
 				((u32)(reply[115]) <<  8) |
 				((u32)(reply[114])      );
 		rc = USB_STOR_TRANSPORT_GOOD;
 		goto leave;
 	}

 	rc = USB_STOR_TRANSPORT_ERROR;

  leave:
 	kfree(reply);
 	return rc;
 }


 static int datafab_handle_mode_sense(struct us_data *us,
 				     struct scsi_cmnd * srb,
 				     int sense_6)
 {
 	static unsigned char rw_err_page[12] = {
 		0x1, 0xA, 0x21, 1, 0, 0, 0, 0, 1, 0, 0, 0
 	};
 	static unsigned char cache_page[12] = {
 		0x8, 0xA, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0
 	};
 	static unsigned char rbac_page[12] = {
 		0x1B, 0xA, 0, 0x81, 0, 0, 0, 0, 0, 0, 0, 0
 	};
 	static unsigned char timer_page[8] = {
 		0x1C, 0x6, 0, 0, 0, 0
 	};
 	unsigned char pc, page_code;
 	unsigned int i = 0;
 	struct datafab_info *info = (struct datafab_info *) (us->extra);
 	unsigned char *ptr = us->iobuf;

 	// most of this stuff is just a hack to get things working.  the
 	// datafab reader doesn't present a SCSI interface so we
 	// fudge the SCSI commands...
 	//

 	pc = srb->cmnd[2] >> 6;
 	page_code = srb->cmnd[2] & 0x3F;

 	switch (pc) {
 	   case 0x0:
 		US_DEBUGP("datafab_handle_mode_sense:  Current values\n");
 		break;
 	   case 0x1:
 		US_DEBUGP("datafab_handle_mode_sense:  Changeable values\n");
 		break;
 	   case 0x2:
 		US_DEBUGP("datafab_handle_mode_sense:  Default values\n");
 		break;
 	   case 0x3:
 		US_DEBUGP("datafab_handle_mode_sense:  Saves values\n");
 		break;
 	}

 	memset(ptr, 0, 8);
 	if (sense_6) {
 		ptr[2] = 0x00;		// WP enable: 0x80
 		i = 4;
 	} else {
 		ptr[3] = 0x00;		// WP enable: 0x80
 		i = 8;
 	}

 	switch (page_code) {
 	   default:
 		// vendor-specific mode
 		info->sense_key = 0x05;
 		info->sense_asc = 0x24;
 		info->sense_ascq = 0x00;
 		return USB_STOR_TRANSPORT_FAILED;

 	   case 0x1:
 		memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
 		i += sizeof(rw_err_page);
 		break;

 	   case 0x8:
 		memcpy(ptr + i, cache_page, sizeof(cache_page));
 		i += sizeof(cache_page);
 		break;

 	   case 0x1B:
 		memcpy(ptr + i, rbac_page, sizeof(rbac_page));
 		i += sizeof(rbac_page);
 		break;

 	   case 0x1C:
 		memcpy(ptr + i, timer_page, sizeof(timer_page));
 		i += sizeof(timer_page);
 		break;

 	   case 0x3F:		// retrieve all pages
 		memcpy(ptr + i, timer_page, sizeof(timer_page));
 		i += sizeof(timer_page);
 		memcpy(ptr + i, rbac_page, sizeof(rbac_page));
 		i += sizeof(rbac_page);
 		memcpy(ptr + i, cache_page, sizeof(cache_page));
 		i += sizeof(cache_page);
 		memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
 		i += sizeof(rw_err_page);
 		break;
 	}

 	if (sense_6)
 		ptr[0] = i - 1;
 	else
 		((__be16 *) ptr)[0] = cpu_to_be16(i - 2);
 	usb_stor_set_xfer_buf(ptr, i, srb);

 	return USB_STOR_TRANSPORT_GOOD;
 }

 static void datafab_info_destructor(void *extra)
 {
 	// this routine is a placeholder...
 	// currently, we don't allocate any extra memory so we're okay
 }


 // Transport for the Datafab MDCFE-B
 //
 int datafab_transport(struct scsi_cmnd * srb, struct us_data *us)
 {
 	struct datafab_info *info;
 	int rc;
 	unsigned long block, blocks;
 	unsigned char *ptr = us->iobuf;
 	static unsigned char inquiry_reply[8] = {
 		0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
 	};

 	if (!us->extra) {
 		us->extra = kzalloc(sizeof(struct datafab_info), GFP_NOIO);
 		if (!us->extra) {
 			US_DEBUGP("datafab_transport:  Gah! "
 				  "Can't allocate storage for Datafab info struct!\n");
 			return USB_STOR_TRANSPORT_ERROR;
 		}
 		us->extra_destructor = datafab_info_destructor;
   		((struct datafab_info *)us->extra)->lun = -1;
 	}

 	info = (struct datafab_info *) (us->extra);

 	if (srb->cmnd[0] == INQUIRY) {
 		US_DEBUGP("datafab_transport:  INQUIRY.  Returning bogus response");
 		memcpy(ptr, inquiry_reply, sizeof(inquiry_reply));
 		fill_inquiry_response(us, ptr, 36);
 		return USB_STOR_TRANSPORT_GOOD;
 	}

 	if (srb->cmnd[0] == READ_CAPACITY) {
 		info->ssize = 0x200;  // hard coded 512 byte sectors as per ATA spec
 		rc = datafab_id_device(us, info);
 		if (rc != USB_STOR_TRANSPORT_GOOD)
 			return rc;

 		US_DEBUGP("datafab_transport:  READ_CAPACITY:  %ld sectors, %ld bytes per sector\n",
 			  info->sectors, info->ssize);

 		// build the reply
 		// we need the last sector, not the number of sectors
 		((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
 		((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
 		usb_stor_set_xfer_buf(ptr, 8, srb);

 		return USB_STOR_TRANSPORT_GOOD;
 	}

 	if (srb->cmnd[0] == MODE_SELECT_10) {
 		US_DEBUGP("datafab_transport:  Gah! MODE_SELECT_10.\n");
 		return USB_STOR_TRANSPORT_ERROR;
 	}

 	// don't bother implementing READ_6 or WRITE_6.
 	//
 	if (srb->cmnd[0] == READ_10) {
 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

 		blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));

 		US_DEBUGP("datafab_transport:  READ_10: read block 0x%04lx  count %ld\n", block, blocks);
 		return datafab_read_data(us, info, block, blocks);
 	}

 	if (srb->cmnd[0] == READ_12) {
 		// we'll probably never see a READ_12 but we'll do it anyway...
 		//
 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

 		blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
 			 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));

 		US_DEBUGP("datafab_transport:  READ_12: read block 0x%04lx  count %ld\n", block, blocks);
 		return datafab_read_data(us, info, block, blocks);
 	}

 	if (srb->cmnd[0] == WRITE_10) {
 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

 		blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));

 		US_DEBUGP("datafab_transport:  WRITE_10: write block 0x%04lx  count %ld\n", block, blocks);
 		return datafab_write_data(us, info, block, blocks);
 	}

 	if (srb->cmnd[0] == WRITE_12) {
 		// we'll probably never see a WRITE_12 but we'll do it anyway...
 		//
 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

 		blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
 			 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));

 		US_DEBUGP("datafab_transport:  WRITE_12: write block 0x%04lx  count %ld\n", block, blocks);
 		return datafab_write_data(us, info, block, blocks);
 	}

 	if (srb->cmnd[0] == TEST_UNIT_READY) {
 		US_DEBUGP("datafab_transport:  TEST_UNIT_READY.\n");
 		return datafab_id_device(us, info);
 	}

 	if (srb->cmnd[0] == REQUEST_SENSE) {
 		US_DEBUGP("datafab_transport:  REQUEST_SENSE.  Returning faked response\n");

 		// this response is pretty bogus right now.  eventually if necessary
 		// we can set the correct sense data.  so far though it hasn't been
 		// necessary
 		//
 		memset(ptr, 0, 18);
 		ptr[0] = 0xF0;
 		ptr[2] = info->sense_key;
 		ptr[7] = 11;
 		ptr[12] = info->sense_asc;
 		ptr[13] = info->sense_ascq;
 		usb_stor_set_xfer_buf(ptr, 18, srb);

 		return USB_STOR_TRANSPORT_GOOD;
 	}

 	if (srb->cmnd[0] == MODE_SENSE) {
 		US_DEBUGP("datafab_transport:  MODE_SENSE_6 detected\n");
 		return datafab_handle_mode_sense(us, srb, 1);
 	}

 	if (srb->cmnd[0] == MODE_SENSE_10) {
 		US_DEBUGP("datafab_transport:  MODE_SENSE_10 detected\n");
 		return datafab_handle_mode_sense(us, srb, 0);
 	}

 	if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
 		// sure.  whatever.  not like we can stop the user from
 		// popping the media out of the device (no locking doors, etc)
 		//
 		return USB_STOR_TRANSPORT_GOOD;
 	}

 	if (srb->cmnd[0] == START_STOP) {
 		/* this is used by sd.c'check_scsidisk_media_change to detect
 		   media change */
 		US_DEBUGP("datafab_transport:  START_STOP.\n");
 		/* the first datafab_id_device after a media change returns
 		   an error (determined experimentally) */
 		rc = datafab_id_device(us, info);
 		if (rc == USB_STOR_TRANSPORT_GOOD) {
 			info->sense_key = NO_SENSE;
 			srb->result = SUCCESS;
 		} else {
 			info->sense_key = UNIT_ATTENTION;
 			srb->result = SAM_STAT_CHECK_CONDITION;
 		}
 		return rc;
 	}

 	US_DEBUGP("datafab_transport:  Gah! Unknown command: %d (0x%x)\n",
 		  srb->cmnd[0], srb->cmnd[0]);
 	info->sense_key = 0x05;
 	info->sense_asc = 0x20;
 	info->sense_ascq = 0x00;
 	return USB_STOR_TRANSPORT_FAILED;
 }
	/* Driver for Datafab USB Compact Flash reader
	*
	* $Id: datafab.c,v 1.7 2002/02/25 00:40:13 mdharm Exp $
	*
	* datafab driver v0.1:
	*
	* First release
	*
	* Current development and maintenance by:
	* (c) 2000 Jimmie Mayfield (mayfield+datafab@sackheads.org)
	*
	* Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
	* which I used as a template for this driver.
	*
	* Some bugfixes and scatter-gather code by Gregory P. Smith
	* (greg-usb@electricrain.com)
	*
	* Fix for media change by Joerg Schneider (js@joergschneider.com)
	*
	* Other contributors:
	* (c) 2002 Alan Stern <stern@rowland.org>
	*
	* 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.
	*/

	/*
	* This driver attempts to support USB CompactFlash reader/writer devices
	* based on Datafab USB-to-ATA chips. It was specifically developed for the
	* Datafab MDCFE-B USB CompactFlash reader but has since been found to work
	* with a variety of Datafab-based devices from a number of manufacturers.
	* I've received a report of this driver working with a Datafab-based
	* SmartMedia device though please be aware that I'm personally unable to
	* test SmartMedia support.
	*
	* This driver supports reading and writing. If you're truly paranoid,
	* however, you can force the driver into a write-protected state by setting
	* the WP enable bits in datafab_handle_mode_sense(). See the comments
	* in that routine.
	*/

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

	#include <scsi/scsi.h>
	#include <scsi/scsi_cmnd.h>

	#include "usb.h"
	#include "transport.h"
	#include "protocol.h"
	#include "debug.h"
	#include "datafab.h"

	static int datafab_determine_lun(struct us_data *us,
	struct datafab_info *info);


	static inline int
	datafab_bulk_read(struct us_data us, unsigned char data, unsigned int len) {
	if (len == 0)
	return USB_STOR_XFER_GOOD;

	US_DEBUGP("datafab_bulk_read: len = %d\n", len);
	return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
	data, len, NULL);
	}


	static inline int
	datafab_bulk_write(struct us_data us, unsigned char data, unsigned int len) {
	if (len == 0)
	return USB_STOR_XFER_GOOD;

	US_DEBUGP("datafab_bulk_write: len = %d\n", len);
	return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
	data, len, NULL);
	}


	static int datafab_read_data(struct us_data *us,
	struct datafab_info *info,
	u32 sector,
	u32 sectors)
	{
	unsigned char *command = us->iobuf;
	unsigned char *buffer;
	unsigned char thistime;
	unsigned int totallen, alloclen;
	int len, result;
	unsigned int sg_idx = 0, sg_offset = 0;

	// we're working in LBA mode. according to the ATA spec,
	// we can support up to 28-bit addressing. I don't know if Datafab
	// supports beyond 24-bit addressing. It's kind of hard to test
	// since it requires > 8GB CF card.
	//
	if (sectors > 0x0FFFFFFF)
	return USB_STOR_TRANSPORT_ERROR;

	if (info->lun == -1) {
	result = datafab_determine_lun(us, info);
	if (result != USB_STOR_TRANSPORT_GOOD)
	return result;
	}

	totallen = sectors * info->ssize;

	// Since we don't read more than 64 KB at a time, we have to create
	// a bounce buffer and move the data a piece at a time between the
	// bounce buffer and the actual transfer buffer.

	alloclen = min(totallen, 65536u);
	buffer = kmalloc(alloclen, GFP_NOIO);
	if (buffer == NULL)
	return USB_STOR_TRANSPORT_ERROR;

	do {
	// loop, never allocate or transfer more than 64k at once
	// (min(128k, 255*info->ssize) is the real limit)

	len = min(totallen, alloclen);
	thistime = (len / info->ssize) & 0xff;

	command[0] = 0;
	command[1] = thistime;
	command[2] = sector & 0xFF;
	command[3] = (sector >> 8) & 0xFF;
	command[4] = (sector >> 16) & 0xFF;

	command[5] = 0xE0 + (info->lun << 4);
	command[5] \|= (sector >> 24) & 0x0F;
	command[6] = 0x20;
	command[7] = 0x01;

	// send the read command
	result = datafab_bulk_write(us, command, 8);
	if (result != USB_STOR_XFER_GOOD)
	goto leave;

	// read the result
	result = datafab_bulk_read(us, buffer, len);
	if (result != USB_STOR_XFER_GOOD)
	goto leave;

	// Store the data in the transfer buffer
	usb_stor_access_xfer_buf(buffer, len, us->srb,
	&sg_idx, &sg_offset, TO_XFER_BUF);

	sector += thistime;
	totallen -= len;
	} while (totallen > 0);

	kfree(buffer);
	return USB_STOR_TRANSPORT_GOOD;

	leave:
	kfree(buffer);
	return USB_STOR_TRANSPORT_ERROR;
	}


	static int datafab_write_data(struct us_data *us,
	struct datafab_info *info,
	u32 sector,
	u32 sectors)
	{
	unsigned char *command = us->iobuf;
	unsigned char *reply = us->iobuf;
	unsigned char *buffer;
	unsigned char thistime;
	unsigned int totallen, alloclen;
	int len, result;
	unsigned int sg_idx = 0, sg_offset = 0;

	// we're working in LBA mode. according to the ATA spec,
	// we can support up to 28-bit addressing. I don't know if Datafab
	// supports beyond 24-bit addressing. It's kind of hard to test
	// since it requires > 8GB CF card.
	//
	if (sectors > 0x0FFFFFFF)
	return USB_STOR_TRANSPORT_ERROR;

	if (info->lun == -1) {
	result = datafab_determine_lun(us, info);
	if (result != USB_STOR_TRANSPORT_GOOD)
	return result;
	}

	totallen = sectors * info->ssize;

	// Since we don't write more than 64 KB at a time, we have to create
	// a bounce buffer and move the data a piece at a time between the
	// bounce buffer and the actual transfer buffer.

	alloclen = min(totallen, 65536u);
	buffer = kmalloc(alloclen, GFP_NOIO);
	if (buffer == NULL)
	return USB_STOR_TRANSPORT_ERROR;

	do {
	// loop, never allocate or transfer more than 64k at once
	// (min(128k, 255*info->ssize) is the real limit)

	len = min(totallen, alloclen);
	thistime = (len / info->ssize) & 0xff;

	// Get the data from the transfer buffer
	usb_stor_access_xfer_buf(buffer, len, us->srb,
	&sg_idx, &sg_offset, FROM_XFER_BUF);

	command[0] = 0;
	command[1] = thistime;
	command[2] = sector & 0xFF;
	command[3] = (sector >> 8) & 0xFF;
	command[4] = (sector >> 16) & 0xFF;

	command[5] = 0xE0 + (info->lun << 4);
	command[5] \|= (sector >> 24) & 0x0F;
	command[6] = 0x30;
	command[7] = 0x02;

	// send the command
	result = datafab_bulk_write(us, command, 8);
	if (result != USB_STOR_XFER_GOOD)
	goto leave;

	// send the data
	result = datafab_bulk_write(us, buffer, len);
	if (result != USB_STOR_XFER_GOOD)
	goto leave;

	// read the result
	result = datafab_bulk_read(us, reply, 2);
	if (result != USB_STOR_XFER_GOOD)
	goto leave;

	if (reply[0] != 0x50 && reply[1] != 0) {
	US_DEBUGP("datafab_write_data: Gah! "
	"write return code: %02x %02x\n",
	reply[0], reply[1]);
	result = USB_STOR_TRANSPORT_ERROR;
	goto leave;
	}

	sector += thistime;
	totallen -= len;
	} while (totallen > 0);

	kfree(buffer);
	return USB_STOR_TRANSPORT_GOOD;

	leave:
	kfree(buffer);
	return USB_STOR_TRANSPORT_ERROR;
	}


	static int datafab_determine_lun(struct us_data *us,
	struct datafab_info *info)
	{
	// Dual-slot readers can be thought of as dual-LUN devices.
	// We need to determine which card slot is being used.
	// We'll send an IDENTIFY DEVICE command and see which LUN responds...
	//
	// There might be a better way of doing this?

	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
	unsigned char *command = us->iobuf;
	unsigned char *buf;
	int count = 0, rc;

	if (!us \|\| !info)
	return USB_STOR_TRANSPORT_ERROR;

	memcpy(command, scommand, 8);
	buf = kmalloc(512, GFP_NOIO);
	if (!buf)
	return USB_STOR_TRANSPORT_ERROR;

	US_DEBUGP("datafab_determine_lun: locating...\n");

	// we'll try 3 times before giving up...
	//
	while (count++ < 3) {
	command[5] = 0xa0;

	rc = datafab_bulk_write(us, command, 8);
	if (rc != USB_STOR_XFER_GOOD) {
	rc = USB_STOR_TRANSPORT_ERROR;
	goto leave;
	}

	rc = datafab_bulk_read(us, buf, 512);
	if (rc == USB_STOR_XFER_GOOD) {
	info->lun = 0;
	rc = USB_STOR_TRANSPORT_GOOD;
	goto leave;
	}

	command[5] = 0xb0;

	rc = datafab_bulk_write(us, command, 8);
	if (rc != USB_STOR_XFER_GOOD) {
	rc = USB_STOR_TRANSPORT_ERROR;
	goto leave;
	}

	rc = datafab_bulk_read(us, buf, 512);
	if (rc == USB_STOR_XFER_GOOD) {
	info->lun = 1;
	rc = USB_STOR_TRANSPORT_GOOD;
	goto leave;
	}

	msleep(20);
	}

	rc = USB_STOR_TRANSPORT_ERROR;

	leave:
	kfree(buf);
	return rc;
	}

	static int datafab_id_device(struct us_data *us,
	struct datafab_info *info)
	{
	// this is a variation of the ATA "IDENTIFY DEVICE" command...according
	// to the ATA spec, 'Sector Count' isn't used but the Windows driver
	// sets this bit so we do too...
	//
	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
	unsigned char *command = us->iobuf;
	unsigned char *reply;
	int rc;

	if (!us \|\| !info)
	return USB_STOR_TRANSPORT_ERROR;

	if (info->lun == -1) {
	rc = datafab_determine_lun(us, info);
	if (rc != USB_STOR_TRANSPORT_GOOD)
	return rc;
	}

	memcpy(command, scommand, 8);
	reply = kmalloc(512, GFP_NOIO);
	if (!reply)
	return USB_STOR_TRANSPORT_ERROR;

	command[5] += (info->lun << 4);

	rc = datafab_bulk_write(us, command, 8);
	if (rc != USB_STOR_XFER_GOOD) {
	rc = USB_STOR_TRANSPORT_ERROR;
	goto leave;
	}

	// we'll go ahead and extract the media capacity while we're here...
	//
	rc = datafab_bulk_read(us, reply, 512);
	if (rc == USB_STOR_XFER_GOOD) {
	// capacity is at word offset 57-58
	//
	info->sectors = ((u32)(reply[117]) << 24) \|
	((u32)(reply[116]) << 16) \|
	((u32)(reply[115]) << 8) \|
	((u32)(reply[114]) );
	rc = USB_STOR_TRANSPORT_GOOD;
	goto leave;
	}

	rc = USB_STOR_TRANSPORT_ERROR;

	leave:
	kfree(reply);
	return rc;
	}


	static int datafab_handle_mode_sense(struct us_data *us,
	struct scsi_cmnd * srb,
	int sense_6)
	{
	static unsigned char rw_err_page[12] = {
	0x1, 0xA, 0x21, 1, 0, 0, 0, 0, 1, 0, 0, 0
	};
	static unsigned char cache_page[12] = {
	0x8, 0xA, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0
	};
	static unsigned char rbac_page[12] = {
	0x1B, 0xA, 0, 0x81, 0, 0, 0, 0, 0, 0, 0, 0
	};
	static unsigned char timer_page[8] = {
	0x1C, 0x6, 0, 0, 0, 0
	};
	unsigned char pc, page_code;
	unsigned int i = 0;
	struct datafab_info info = (struct datafab_info ) (us->extra);
	unsigned char *ptr = us->iobuf;

	// most of this stuff is just a hack to get things working. the
	// datafab reader doesn't present a SCSI interface so we
	// fudge the SCSI commands...
	//

	pc = srb->cmnd[2] >> 6;
	page_code = srb->cmnd[2] & 0x3F;

	switch (pc) {
	case 0x0:
	US_DEBUGP("datafab_handle_mode_sense: Current values\n");
	break;
	case 0x1:
	US_DEBUGP("datafab_handle_mode_sense: Changeable values\n");
	break;
	case 0x2:
	US_DEBUGP("datafab_handle_mode_sense: Default values\n");
	break;
	case 0x3:
	US_DEBUGP("datafab_handle_mode_sense: Saves values\n");
	break;
	}

	memset(ptr, 0, 8);
	if (sense_6) {
	ptr[2] = 0x00; // WP enable: 0x80
	i = 4;
	} else {
	ptr[3] = 0x00; // WP enable: 0x80
	i = 8;
	}

	switch (page_code) {
	default:
	// vendor-specific mode
	info->sense_key = 0x05;
	info->sense_asc = 0x24;
	info->sense_ascq = 0x00;
	return USB_STOR_TRANSPORT_FAILED;

	case 0x1:
	memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
	i += sizeof(rw_err_page);
	break;

	case 0x8:
	memcpy(ptr + i, cache_page, sizeof(cache_page));
	i += sizeof(cache_page);
	break;

	case 0x1B:
	memcpy(ptr + i, rbac_page, sizeof(rbac_page));
	i += sizeof(rbac_page);
	break;

	case 0x1C:
	memcpy(ptr + i, timer_page, sizeof(timer_page));
	i += sizeof(timer_page);
	break;

	case 0x3F: // retrieve all pages
	memcpy(ptr + i, timer_page, sizeof(timer_page));
	i += sizeof(timer_page);
	memcpy(ptr + i, rbac_page, sizeof(rbac_page));
	i += sizeof(rbac_page);
	memcpy(ptr + i, cache_page, sizeof(cache_page));
	i += sizeof(cache_page);
	memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
	i += sizeof(rw_err_page);
	break;
	}

	if (sense_6)
	ptr[0] = i - 1;
	else
	((__be16 *) ptr)[0] = cpu_to_be16(i - 2);
	usb_stor_set_xfer_buf(ptr, i, srb);

	return USB_STOR_TRANSPORT_GOOD;
	}

	static void datafab_info_destructor(void *extra)
	{
	// this routine is a placeholder...
	// currently, we don't allocate any extra memory so we're okay
	}


	// Transport for the Datafab MDCFE-B
	//
	int datafab_transport(struct scsi_cmnd * srb, struct us_data *us)
	{
	struct datafab_info *info;
	int rc;
	unsigned long block, blocks;
	unsigned char *ptr = us->iobuf;
	static unsigned char inquiry_reply[8] = {
	0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
	};

	if (!us->extra) {
	us->extra = kzalloc(sizeof(struct datafab_info), GFP_NOIO);
	if (!us->extra) {
	US_DEBUGP("datafab_transport: Gah! "
	"Can't allocate storage for Datafab info struct!\n");
	return USB_STOR_TRANSPORT_ERROR;
	}
	us->extra_destructor = datafab_info_destructor;
	((struct datafab_info *)us->extra)->lun = -1;
	}

	info = (struct datafab_info *) (us->extra);

	if (srb->cmnd[0] == INQUIRY) {
	US_DEBUGP("datafab_transport: INQUIRY. Returning bogus response");
	memcpy(ptr, inquiry_reply, sizeof(inquiry_reply));
	fill_inquiry_response(us, ptr, 36);
	return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == READ_CAPACITY) {
	info->ssize = 0x200; // hard coded 512 byte sectors as per ATA spec
	rc = datafab_id_device(us, info);
	if (rc != USB_STOR_TRANSPORT_GOOD)
	return rc;

	US_DEBUGP("datafab_transport: READ_CAPACITY: %ld sectors, %ld bytes per sector\n",
	info->sectors, info->ssize);

	// build the reply
	// we need the last sector, not the number of sectors
	((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
	((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
	usb_stor_set_xfer_buf(ptr, 8, srb);

	return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == MODE_SELECT_10) {
	US_DEBUGP("datafab_transport: Gah! MODE_SELECT_10.\n");
	return USB_STOR_TRANSPORT_ERROR;
	}

	// don't bother implementing READ_6 or WRITE_6.
	//
	if (srb->cmnd[0] == READ_10) {
	block = ((u32)(srb->cmnd[2]) << 24) \| ((u32)(srb->cmnd[3]) << 16) \|
	((u32)(srb->cmnd[4]) << 8) \| ((u32)(srb->cmnd[5]));

	blocks = ((u32)(srb->cmnd[7]) << 8) \| ((u32)(srb->cmnd[8]));

	US_DEBUGP("datafab_transport: READ_10: read block 0x%04lx count %ld\n", block, blocks);
	return datafab_read_data(us, info, block, blocks);
	}

	if (srb->cmnd[0] == READ_12) {
	// we'll probably never see a READ_12 but we'll do it anyway...
	//
	block = ((u32)(srb->cmnd[2]) << 24) \| ((u32)(srb->cmnd[3]) << 16) \|
	((u32)(srb->cmnd[4]) << 8) \| ((u32)(srb->cmnd[5]));

	blocks = ((u32)(srb->cmnd[6]) << 24) \| ((u32)(srb->cmnd[7]) << 16) \|
	((u32)(srb->cmnd[8]) << 8) \| ((u32)(srb->cmnd[9]));

	US_DEBUGP("datafab_transport: READ_12: read block 0x%04lx count %ld\n", block, blocks);
	return datafab_read_data(us, info, block, blocks);
	}

	if (srb->cmnd[0] == WRITE_10) {
	block = ((u32)(srb->cmnd[2]) << 24) \| ((u32)(srb->cmnd[3]) << 16) \|
	((u32)(srb->cmnd[4]) << 8) \| ((u32)(srb->cmnd[5]));

	blocks = ((u32)(srb->cmnd[7]) << 8) \| ((u32)(srb->cmnd[8]));

	US_DEBUGP("datafab_transport: WRITE_10: write block 0x%04lx count %ld\n", block, blocks);
	return datafab_write_data(us, info, block, blocks);
	}

	if (srb->cmnd[0] == WRITE_12) {
	// we'll probably never see a WRITE_12 but we'll do it anyway...
	//
	block = ((u32)(srb->cmnd[2]) << 24) \| ((u32)(srb->cmnd[3]) << 16) \|
	((u32)(srb->cmnd[4]) << 8) \| ((u32)(srb->cmnd[5]));

	blocks = ((u32)(srb->cmnd[6]) << 24) \| ((u32)(srb->cmnd[7]) << 16) \|
	((u32)(srb->cmnd[8]) << 8) \| ((u32)(srb->cmnd[9]));

	US_DEBUGP("datafab_transport: WRITE_12: write block 0x%04lx count %ld\n", block, blocks);
	return datafab_write_data(us, info, block, blocks);
	}

	if (srb->cmnd[0] == TEST_UNIT_READY) {
	US_DEBUGP("datafab_transport: TEST_UNIT_READY.\n");
	return datafab_id_device(us, info);
	}

	if (srb->cmnd[0] == REQUEST_SENSE) {
	US_DEBUGP("datafab_transport: REQUEST_SENSE. Returning faked response\n");

	// this response is pretty bogus right now. eventually if necessary
	// we can set the correct sense data. so far though it hasn't been
	// necessary
	//
	memset(ptr, 0, 18);
	ptr[0] = 0xF0;
	ptr[2] = info->sense_key;
	ptr[7] = 11;
	ptr[12] = info->sense_asc;
	ptr[13] = info->sense_ascq;
	usb_stor_set_xfer_buf(ptr, 18, srb);

	return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == MODE_SENSE) {
	US_DEBUGP("datafab_transport: MODE_SENSE_6 detected\n");
	return datafab_handle_mode_sense(us, srb, 1);
	}

	if (srb->cmnd[0] == MODE_SENSE_10) {
	US_DEBUGP("datafab_transport: MODE_SENSE_10 detected\n");
	return datafab_handle_mode_sense(us, srb, 0);
	}

	if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
	// sure. whatever. not like we can stop the user from
	// popping the media out of the device (no locking doors, etc)
	//
	return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == START_STOP) {
	/* this is used by sd.c'check_scsidisk_media_change to detect
	media change */
	US_DEBUGP("datafab_transport: START_STOP.\n");
	/* the first datafab_id_device after a media change returns
	an error (determined experimentally) */
	rc = datafab_id_device(us, info);
	if (rc == USB_STOR_TRANSPORT_GOOD) {
	info->sense_key = NO_SENSE;
	srb->result = SUCCESS;
	} else {
	info->sense_key = UNIT_ATTENTION;
	srb->result = SAM_STAT_CHECK_CONDITION;
	}
	return rc;
	}

	US_DEBUGP("datafab_transport: Gah! Unknown command: %d (0x%x)\n",
	srb->cmnd[0], srb->cmnd[0]);
	info->sense_key = 0x05;
	info->sense_asc = 0x20;
	info->sense_ascq = 0x00;
	return USB_STOR_TRANSPORT_FAILED;
	}