xref: /linux/drivers/usb/storage/datafab.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * Driver for Datafab USB Compact Flash reader
3  *
4  * datafab driver v0.1:
5  *
6  * First release
7  *
8  * Current development and maintenance by:
9  *   (c) 2000 Jimmie Mayfield (mayfield+datafab@sackheads.org)
10  *
11  *   Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
12  *   which I used as a template for this driver.
13  *
14  *   Some bugfixes and scatter-gather code by Gregory P. Smith
15  *   (greg-usb@electricrain.com)
16  *
17  *   Fix for media change by Joerg Schneider (js@joergschneider.com)
18  *
19  * Other contributors:
20  *   (c) 2002 Alan Stern <stern@rowland.org>
21  *
22  * This program is free software; you can redistribute it and/or modify it
23  * under the terms of the GNU General Public License as published by the
24  * Free Software Foundation; either version 2, or (at your option) any
25  * later version.
26  *
27  * This program is distributed in the hope that it will be useful, but
28  * WITHOUT ANY WARRANTY; without even the implied warranty of
29  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
30  * General Public License for more details.
31  *
32  * You should have received a copy of the GNU General Public License along
33  * with this program; if not, write to the Free Software Foundation, Inc.,
34  * 675 Mass Ave, Cambridge, MA 02139, USA.
35  */
36 
37 /*
38  * This driver attempts to support USB CompactFlash reader/writer devices
39  * based on Datafab USB-to-ATA chips.  It was specifically developed for the
40  * Datafab MDCFE-B USB CompactFlash reader but has since been found to work
41  * with a variety of Datafab-based devices from a number of manufacturers.
42  * I've received a report of this driver working with a Datafab-based
43  * SmartMedia device though please be aware that I'm personally unable to
44  * test SmartMedia support.
45  *
46  * This driver supports reading and writing.  If you're truly paranoid,
47  * however, you can force the driver into a write-protected state by setting
48  * the WP enable bits in datafab_handle_mode_sense().  See the comments
49  * in that routine.
50  */
51 
52 #include <linux/errno.h>
53 #include <linux/module.h>
54 #include <linux/slab.h>
55 
56 #include <scsi/scsi.h>
57 #include <scsi/scsi_cmnd.h>
58 
59 #include "usb.h"
60 #include "transport.h"
61 #include "protocol.h"
62 #include "debug.h"
63 #include "scsiglue.h"
64 
65 #define DRV_NAME "ums-datafab"
66 
67 MODULE_DESCRIPTION("Driver for Datafab USB Compact Flash reader");
68 MODULE_AUTHOR("Jimmie Mayfield <mayfield+datafab@sackheads.org>");
69 MODULE_LICENSE("GPL");
70 
71 struct datafab_info {
72 	unsigned long   sectors;	/* total sector count */
73 	unsigned long   ssize;		/* sector size in bytes */
74 	signed char	lun;		/* used for dual-slot readers */
75 
76 	/* the following aren't used yet */
77 	unsigned char   sense_key;
78 	unsigned long   sense_asc;	/* additional sense code */
79 	unsigned long   sense_ascq;	/* additional sense code qualifier */
80 };
81 
82 static int datafab_determine_lun(struct us_data *us,
83 				 struct datafab_info *info);
84 
85 
86 /*
87  * The table of devices
88  */
89 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
90 		    vendorName, productName, useProtocol, useTransport, \
91 		    initFunction, flags) \
92 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
93   .driver_info = (flags) }
94 
95 static struct usb_device_id datafab_usb_ids[] = {
96 #	include "unusual_datafab.h"
97 	{ }		/* Terminating entry */
98 };
99 MODULE_DEVICE_TABLE(usb, datafab_usb_ids);
100 
101 #undef UNUSUAL_DEV
102 
103 /*
104  * The flags table
105  */
106 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
107 		    vendor_name, product_name, use_protocol, use_transport, \
108 		    init_function, Flags) \
109 { \
110 	.vendorName = vendor_name,	\
111 	.productName = product_name,	\
112 	.useProtocol = use_protocol,	\
113 	.useTransport = use_transport,	\
114 	.initFunction = init_function,	\
115 }
116 
117 static struct us_unusual_dev datafab_unusual_dev_list[] = {
118 #	include "unusual_datafab.h"
119 	{ }		/* Terminating entry */
120 };
121 
122 #undef UNUSUAL_DEV
123 
124 
125 static inline int
126 datafab_bulk_read(struct us_data *us, unsigned char *data, unsigned int len) {
127 	if (len == 0)
128 		return USB_STOR_XFER_GOOD;
129 
130 	usb_stor_dbg(us, "len = %d\n", len);
131 	return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
132 			data, len, NULL);
133 }
134 
135 
136 static inline int
137 datafab_bulk_write(struct us_data *us, unsigned char *data, unsigned int len) {
138 	if (len == 0)
139 		return USB_STOR_XFER_GOOD;
140 
141 	usb_stor_dbg(us, "len = %d\n", len);
142 	return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
143 			data, len, NULL);
144 }
145 
146 
147 static int datafab_read_data(struct us_data *us,
148 			     struct datafab_info *info,
149 			     u32 sector,
150 			     u32 sectors)
151 {
152 	unsigned char *command = us->iobuf;
153 	unsigned char *buffer;
154 	unsigned char  thistime;
155 	unsigned int totallen, alloclen;
156 	int len, result;
157 	unsigned int sg_offset = 0;
158 	struct scatterlist *sg = NULL;
159 
160 	// we're working in LBA mode.  according to the ATA spec,
161 	// we can support up to 28-bit addressing.  I don't know if Datafab
162 	// supports beyond 24-bit addressing.  It's kind of hard to test
163 	// since it requires > 8GB CF card.
164 	//
165 	if (sectors > 0x0FFFFFFF)
166 		return USB_STOR_TRANSPORT_ERROR;
167 
168 	if (info->lun == -1) {
169 		result = datafab_determine_lun(us, info);
170 		if (result != USB_STOR_TRANSPORT_GOOD)
171 			return result;
172 	}
173 
174 	totallen = sectors * info->ssize;
175 
176 	// Since we don't read more than 64 KB at a time, we have to create
177 	// a bounce buffer and move the data a piece at a time between the
178 	// bounce buffer and the actual transfer buffer.
179 
180 	alloclen = min(totallen, 65536u);
181 	buffer = kmalloc(alloclen, GFP_NOIO);
182 	if (buffer == NULL)
183 		return USB_STOR_TRANSPORT_ERROR;
184 
185 	do {
186 		// loop, never allocate or transfer more than 64k at once
187 		// (min(128k, 255*info->ssize) is the real limit)
188 
189 		len = min(totallen, alloclen);
190 		thistime = (len / info->ssize) & 0xff;
191 
192 		command[0] = 0;
193 		command[1] = thistime;
194 		command[2] = sector & 0xFF;
195 		command[3] = (sector >> 8) & 0xFF;
196 		command[4] = (sector >> 16) & 0xFF;
197 
198 		command[5] = 0xE0 + (info->lun << 4);
199 		command[5] |= (sector >> 24) & 0x0F;
200 		command[6] = 0x20;
201 		command[7] = 0x01;
202 
203 		// send the read command
204 		result = datafab_bulk_write(us, command, 8);
205 		if (result != USB_STOR_XFER_GOOD)
206 			goto leave;
207 
208 		// read the result
209 		result = datafab_bulk_read(us, buffer, len);
210 		if (result != USB_STOR_XFER_GOOD)
211 			goto leave;
212 
213 		// Store the data in the transfer buffer
214 		usb_stor_access_xfer_buf(buffer, len, us->srb,
215 				 &sg, &sg_offset, TO_XFER_BUF);
216 
217 		sector += thistime;
218 		totallen -= len;
219 	} while (totallen > 0);
220 
221 	kfree(buffer);
222 	return USB_STOR_TRANSPORT_GOOD;
223 
224  leave:
225 	kfree(buffer);
226 	return USB_STOR_TRANSPORT_ERROR;
227 }
228 
229 
230 static int datafab_write_data(struct us_data *us,
231 			      struct datafab_info *info,
232 			      u32 sector,
233 			      u32 sectors)
234 {
235 	unsigned char *command = us->iobuf;
236 	unsigned char *reply = us->iobuf;
237 	unsigned char *buffer;
238 	unsigned char thistime;
239 	unsigned int totallen, alloclen;
240 	int len, result;
241 	unsigned int sg_offset = 0;
242 	struct scatterlist *sg = NULL;
243 
244 	// we're working in LBA mode.  according to the ATA spec,
245 	// we can support up to 28-bit addressing.  I don't know if Datafab
246 	// supports beyond 24-bit addressing.  It's kind of hard to test
247 	// since it requires > 8GB CF card.
248 	//
249 	if (sectors > 0x0FFFFFFF)
250 		return USB_STOR_TRANSPORT_ERROR;
251 
252 	if (info->lun == -1) {
253 		result = datafab_determine_lun(us, info);
254 		if (result != USB_STOR_TRANSPORT_GOOD)
255 			return result;
256 	}
257 
258 	totallen = sectors * info->ssize;
259 
260 	// Since we don't write more than 64 KB at a time, we have to create
261 	// a bounce buffer and move the data a piece at a time between the
262 	// bounce buffer and the actual transfer buffer.
263 
264 	alloclen = min(totallen, 65536u);
265 	buffer = kmalloc(alloclen, GFP_NOIO);
266 	if (buffer == NULL)
267 		return USB_STOR_TRANSPORT_ERROR;
268 
269 	do {
270 		// loop, never allocate or transfer more than 64k at once
271 		// (min(128k, 255*info->ssize) is the real limit)
272 
273 		len = min(totallen, alloclen);
274 		thistime = (len / info->ssize) & 0xff;
275 
276 		// Get the data from the transfer buffer
277 		usb_stor_access_xfer_buf(buffer, len, us->srb,
278 				&sg, &sg_offset, FROM_XFER_BUF);
279 
280 		command[0] = 0;
281 		command[1] = thistime;
282 		command[2] = sector & 0xFF;
283 		command[3] = (sector >> 8) & 0xFF;
284 		command[4] = (sector >> 16) & 0xFF;
285 
286 		command[5] = 0xE0 + (info->lun << 4);
287 		command[5] |= (sector >> 24) & 0x0F;
288 		command[6] = 0x30;
289 		command[7] = 0x02;
290 
291 		// send the command
292 		result = datafab_bulk_write(us, command, 8);
293 		if (result != USB_STOR_XFER_GOOD)
294 			goto leave;
295 
296 		// send the data
297 		result = datafab_bulk_write(us, buffer, len);
298 		if (result != USB_STOR_XFER_GOOD)
299 			goto leave;
300 
301 		// read the result
302 		result = datafab_bulk_read(us, reply, 2);
303 		if (result != USB_STOR_XFER_GOOD)
304 			goto leave;
305 
306 		if (reply[0] != 0x50 && reply[1] != 0) {
307 			usb_stor_dbg(us, "Gah! write return code: %02x %02x\n",
308 				     reply[0], reply[1]);
309 			result = USB_STOR_TRANSPORT_ERROR;
310 			goto leave;
311 		}
312 
313 		sector += thistime;
314 		totallen -= len;
315 	} while (totallen > 0);
316 
317 	kfree(buffer);
318 	return USB_STOR_TRANSPORT_GOOD;
319 
320  leave:
321 	kfree(buffer);
322 	return USB_STOR_TRANSPORT_ERROR;
323 }
324 
325 
326 static int datafab_determine_lun(struct us_data *us,
327 				 struct datafab_info *info)
328 {
329 	// Dual-slot readers can be thought of as dual-LUN devices.
330 	// We need to determine which card slot is being used.
331 	// We'll send an IDENTIFY DEVICE command and see which LUN responds...
332 	//
333 	// There might be a better way of doing this?
334 
335 	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
336 	unsigned char *command = us->iobuf;
337 	unsigned char *buf;
338 	int count = 0, rc;
339 
340 	if (!info)
341 		return USB_STOR_TRANSPORT_ERROR;
342 
343 	memcpy(command, scommand, 8);
344 	buf = kmalloc(512, GFP_NOIO);
345 	if (!buf)
346 		return USB_STOR_TRANSPORT_ERROR;
347 
348 	usb_stor_dbg(us, "locating...\n");
349 
350 	// we'll try 3 times before giving up...
351 	//
352 	while (count++ < 3) {
353 		command[5] = 0xa0;
354 
355 		rc = datafab_bulk_write(us, command, 8);
356 		if (rc != USB_STOR_XFER_GOOD) {
357 			rc = USB_STOR_TRANSPORT_ERROR;
358 			goto leave;
359 		}
360 
361 		rc = datafab_bulk_read(us, buf, 512);
362 		if (rc == USB_STOR_XFER_GOOD) {
363 			info->lun = 0;
364 			rc = USB_STOR_TRANSPORT_GOOD;
365 			goto leave;
366 		}
367 
368 		command[5] = 0xb0;
369 
370 		rc = datafab_bulk_write(us, command, 8);
371 		if (rc != USB_STOR_XFER_GOOD) {
372 			rc = USB_STOR_TRANSPORT_ERROR;
373 			goto leave;
374 		}
375 
376 		rc = datafab_bulk_read(us, buf, 512);
377 		if (rc == USB_STOR_XFER_GOOD) {
378 			info->lun = 1;
379 			rc = USB_STOR_TRANSPORT_GOOD;
380 			goto leave;
381 		}
382 
383 		msleep(20);
384 	}
385 
386 	rc = USB_STOR_TRANSPORT_ERROR;
387 
388  leave:
389 	kfree(buf);
390 	return rc;
391 }
392 
393 static int datafab_id_device(struct us_data *us,
394 			     struct datafab_info *info)
395 {
396 	// this is a variation of the ATA "IDENTIFY DEVICE" command...according
397 	// to the ATA spec, 'Sector Count' isn't used but the Windows driver
398 	// sets this bit so we do too...
399 	//
400 	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
401 	unsigned char *command = us->iobuf;
402 	unsigned char *reply;
403 	int rc;
404 
405 	if (!info)
406 		return USB_STOR_TRANSPORT_ERROR;
407 
408 	if (info->lun == -1) {
409 		rc = datafab_determine_lun(us, info);
410 		if (rc != USB_STOR_TRANSPORT_GOOD)
411 			return rc;
412 	}
413 
414 	memcpy(command, scommand, 8);
415 	reply = kmalloc(512, GFP_NOIO);
416 	if (!reply)
417 		return USB_STOR_TRANSPORT_ERROR;
418 
419 	command[5] += (info->lun << 4);
420 
421 	rc = datafab_bulk_write(us, command, 8);
422 	if (rc != USB_STOR_XFER_GOOD) {
423 		rc = USB_STOR_TRANSPORT_ERROR;
424 		goto leave;
425 	}
426 
427 	// we'll go ahead and extract the media capacity while we're here...
428 	//
429 	rc = datafab_bulk_read(us, reply, 512);
430 	if (rc == USB_STOR_XFER_GOOD) {
431 		// capacity is at word offset 57-58
432 		//
433 		info->sectors = ((u32)(reply[117]) << 24) |
434 				((u32)(reply[116]) << 16) |
435 				((u32)(reply[115]) <<  8) |
436 				((u32)(reply[114])      );
437 		rc = USB_STOR_TRANSPORT_GOOD;
438 		goto leave;
439 	}
440 
441 	rc = USB_STOR_TRANSPORT_ERROR;
442 
443  leave:
444 	kfree(reply);
445 	return rc;
446 }
447 
448 
449 static int datafab_handle_mode_sense(struct us_data *us,
450 				     struct scsi_cmnd * srb,
451 				     int sense_6)
452 {
453 	static unsigned char rw_err_page[12] = {
454 		0x1, 0xA, 0x21, 1, 0, 0, 0, 0, 1, 0, 0, 0
455 	};
456 	static unsigned char cache_page[12] = {
457 		0x8, 0xA, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0
458 	};
459 	static unsigned char rbac_page[12] = {
460 		0x1B, 0xA, 0, 0x81, 0, 0, 0, 0, 0, 0, 0, 0
461 	};
462 	static unsigned char timer_page[8] = {
463 		0x1C, 0x6, 0, 0, 0, 0
464 	};
465 	unsigned char pc, page_code;
466 	unsigned int i = 0;
467 	struct datafab_info *info = (struct datafab_info *) (us->extra);
468 	unsigned char *ptr = us->iobuf;
469 
470 	// most of this stuff is just a hack to get things working.  the
471 	// datafab reader doesn't present a SCSI interface so we
472 	// fudge the SCSI commands...
473 	//
474 
475 	pc = srb->cmnd[2] >> 6;
476 	page_code = srb->cmnd[2] & 0x3F;
477 
478 	switch (pc) {
479 	   case 0x0:
480 		   usb_stor_dbg(us, "Current values\n");
481 		break;
482 	   case 0x1:
483 		   usb_stor_dbg(us, "Changeable values\n");
484 		break;
485 	   case 0x2:
486 		   usb_stor_dbg(us, "Default values\n");
487 		break;
488 	   case 0x3:
489 		   usb_stor_dbg(us, "Saves values\n");
490 		break;
491 	}
492 
493 	memset(ptr, 0, 8);
494 	if (sense_6) {
495 		ptr[2] = 0x00;		// WP enable: 0x80
496 		i = 4;
497 	} else {
498 		ptr[3] = 0x00;		// WP enable: 0x80
499 		i = 8;
500 	}
501 
502 	switch (page_code) {
503 	   default:
504 		// vendor-specific mode
505 		info->sense_key = 0x05;
506 		info->sense_asc = 0x24;
507 		info->sense_ascq = 0x00;
508 		return USB_STOR_TRANSPORT_FAILED;
509 
510 	   case 0x1:
511 		memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
512 		i += sizeof(rw_err_page);
513 		break;
514 
515 	   case 0x8:
516 		memcpy(ptr + i, cache_page, sizeof(cache_page));
517 		i += sizeof(cache_page);
518 		break;
519 
520 	   case 0x1B:
521 		memcpy(ptr + i, rbac_page, sizeof(rbac_page));
522 		i += sizeof(rbac_page);
523 		break;
524 
525 	   case 0x1C:
526 		memcpy(ptr + i, timer_page, sizeof(timer_page));
527 		i += sizeof(timer_page);
528 		break;
529 
530 	   case 0x3F:		// retrieve all pages
531 		memcpy(ptr + i, timer_page, sizeof(timer_page));
532 		i += sizeof(timer_page);
533 		memcpy(ptr + i, rbac_page, sizeof(rbac_page));
534 		i += sizeof(rbac_page);
535 		memcpy(ptr + i, cache_page, sizeof(cache_page));
536 		i += sizeof(cache_page);
537 		memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
538 		i += sizeof(rw_err_page);
539 		break;
540 	}
541 
542 	if (sense_6)
543 		ptr[0] = i - 1;
544 	else
545 		((__be16 *) ptr)[0] = cpu_to_be16(i - 2);
546 	usb_stor_set_xfer_buf(ptr, i, srb);
547 
548 	return USB_STOR_TRANSPORT_GOOD;
549 }
550 
551 static void datafab_info_destructor(void *extra)
552 {
553 	// this routine is a placeholder...
554 	// currently, we don't allocate any extra memory so we're okay
555 }
556 
557 
558 // Transport for the Datafab MDCFE-B
559 //
560 static int datafab_transport(struct scsi_cmnd *srb, struct us_data *us)
561 {
562 	struct datafab_info *info;
563 	int rc;
564 	unsigned long block, blocks;
565 	unsigned char *ptr = us->iobuf;
566 	static unsigned char inquiry_reply[8] = {
567 		0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
568 	};
569 
570 	if (!us->extra) {
571 		us->extra = kzalloc(sizeof(struct datafab_info), GFP_NOIO);
572 		if (!us->extra)
573 			return USB_STOR_TRANSPORT_ERROR;
574 
575 		us->extra_destructor = datafab_info_destructor;
576   		((struct datafab_info *)us->extra)->lun = -1;
577 	}
578 
579 	info = (struct datafab_info *) (us->extra);
580 
581 	if (srb->cmnd[0] == INQUIRY) {
582 		usb_stor_dbg(us, "INQUIRY - Returning bogus response\n");
583 		memcpy(ptr, inquiry_reply, sizeof(inquiry_reply));
584 		fill_inquiry_response(us, ptr, 36);
585 		return USB_STOR_TRANSPORT_GOOD;
586 	}
587 
588 	if (srb->cmnd[0] == READ_CAPACITY) {
589 		info->ssize = 0x200;  // hard coded 512 byte sectors as per ATA spec
590 		rc = datafab_id_device(us, info);
591 		if (rc != USB_STOR_TRANSPORT_GOOD)
592 			return rc;
593 
594 		usb_stor_dbg(us, "READ_CAPACITY:  %ld sectors, %ld bytes per sector\n",
595 			     info->sectors, info->ssize);
596 
597 		// build the reply
598 		// we need the last sector, not the number of sectors
599 		((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
600 		((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
601 		usb_stor_set_xfer_buf(ptr, 8, srb);
602 
603 		return USB_STOR_TRANSPORT_GOOD;
604 	}
605 
606 	if (srb->cmnd[0] == MODE_SELECT_10) {
607 		usb_stor_dbg(us, "Gah! MODE_SELECT_10\n");
608 		return USB_STOR_TRANSPORT_ERROR;
609 	}
610 
611 	// don't bother implementing READ_6 or WRITE_6.
612 	//
613 	if (srb->cmnd[0] == READ_10) {
614 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
615 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
616 
617 		blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
618 
619 		usb_stor_dbg(us, "READ_10: read block 0x%04lx  count %ld\n",
620 			     block, blocks);
621 		return datafab_read_data(us, info, block, blocks);
622 	}
623 
624 	if (srb->cmnd[0] == READ_12) {
625 		// we'll probably never see a READ_12 but we'll do it anyway...
626 		//
627 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
628 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
629 
630 		blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
631 			 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));
632 
633 		usb_stor_dbg(us, "READ_12: read block 0x%04lx  count %ld\n",
634 			     block, blocks);
635 		return datafab_read_data(us, info, block, blocks);
636 	}
637 
638 	if (srb->cmnd[0] == WRITE_10) {
639 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
640 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
641 
642 		blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
643 
644 		usb_stor_dbg(us, "WRITE_10: write block 0x%04lx count %ld\n",
645 			     block, blocks);
646 		return datafab_write_data(us, info, block, blocks);
647 	}
648 
649 	if (srb->cmnd[0] == WRITE_12) {
650 		// we'll probably never see a WRITE_12 but we'll do it anyway...
651 		//
652 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
653 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
654 
655 		blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
656 			 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));
657 
658 		usb_stor_dbg(us, "WRITE_12: write block 0x%04lx count %ld\n",
659 			     block, blocks);
660 		return datafab_write_data(us, info, block, blocks);
661 	}
662 
663 	if (srb->cmnd[0] == TEST_UNIT_READY) {
664 		usb_stor_dbg(us, "TEST_UNIT_READY\n");
665 		return datafab_id_device(us, info);
666 	}
667 
668 	if (srb->cmnd[0] == REQUEST_SENSE) {
669 		usb_stor_dbg(us, "REQUEST_SENSE - Returning faked response\n");
670 
671 		// this response is pretty bogus right now.  eventually if necessary
672 		// we can set the correct sense data.  so far though it hasn't been
673 		// necessary
674 		//
675 		memset(ptr, 0, 18);
676 		ptr[0] = 0xF0;
677 		ptr[2] = info->sense_key;
678 		ptr[7] = 11;
679 		ptr[12] = info->sense_asc;
680 		ptr[13] = info->sense_ascq;
681 		usb_stor_set_xfer_buf(ptr, 18, srb);
682 
683 		return USB_STOR_TRANSPORT_GOOD;
684 	}
685 
686 	if (srb->cmnd[0] == MODE_SENSE) {
687 		usb_stor_dbg(us, "MODE_SENSE_6 detected\n");
688 		return datafab_handle_mode_sense(us, srb, 1);
689 	}
690 
691 	if (srb->cmnd[0] == MODE_SENSE_10) {
692 		usb_stor_dbg(us, "MODE_SENSE_10 detected\n");
693 		return datafab_handle_mode_sense(us, srb, 0);
694 	}
695 
696 	if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
697 		/*
698 		 * sure.  whatever.  not like we can stop the user from
699 		 * popping the media out of the device (no locking doors, etc)
700 		 */
701 		return USB_STOR_TRANSPORT_GOOD;
702 	}
703 
704 	if (srb->cmnd[0] == START_STOP) {
705 		/*
706 		 * this is used by sd.c'check_scsidisk_media_change to detect
707 		 * media change
708 		 */
709 		usb_stor_dbg(us, "START_STOP\n");
710 		/*
711 		 * the first datafab_id_device after a media change returns
712 		 * an error (determined experimentally)
713 		 */
714 		rc = datafab_id_device(us, info);
715 		if (rc == USB_STOR_TRANSPORT_GOOD) {
716 			info->sense_key = NO_SENSE;
717 			srb->result = SUCCESS;
718 		} else {
719 			info->sense_key = UNIT_ATTENTION;
720 			srb->result = SAM_STAT_CHECK_CONDITION;
721 		}
722 		return rc;
723 	}
724 
725 	usb_stor_dbg(us, "Gah! Unknown command: %d (0x%x)\n",
726 		     srb->cmnd[0], srb->cmnd[0]);
727 	info->sense_key = 0x05;
728 	info->sense_asc = 0x20;
729 	info->sense_ascq = 0x00;
730 	return USB_STOR_TRANSPORT_FAILED;
731 }
732 
733 static struct scsi_host_template datafab_host_template;
734 
735 static int datafab_probe(struct usb_interface *intf,
736 			 const struct usb_device_id *id)
737 {
738 	struct us_data *us;
739 	int result;
740 
741 	result = usb_stor_probe1(&us, intf, id,
742 			(id - datafab_usb_ids) + datafab_unusual_dev_list,
743 			&datafab_host_template);
744 	if (result)
745 		return result;
746 
747 	us->transport_name  = "Datafab Bulk-Only";
748 	us->transport = datafab_transport;
749 	us->transport_reset = usb_stor_Bulk_reset;
750 	us->max_lun = 1;
751 
752 	result = usb_stor_probe2(us);
753 	return result;
754 }
755 
756 static struct usb_driver datafab_driver = {
757 	.name =		DRV_NAME,
758 	.probe =	datafab_probe,
759 	.disconnect =	usb_stor_disconnect,
760 	.suspend =	usb_stor_suspend,
761 	.resume =	usb_stor_resume,
762 	.reset_resume =	usb_stor_reset_resume,
763 	.pre_reset =	usb_stor_pre_reset,
764 	.post_reset =	usb_stor_post_reset,
765 	.id_table =	datafab_usb_ids,
766 	.soft_unbind =	1,
767 	.no_dynamic_id = 1,
768 };
769 
770 module_usb_stor_driver(datafab_driver, datafab_host_template, DRV_NAME);
771