xref: /linux/drivers/usb/storage/datafab.c (revision 5fd54ace4721fc5ce2bb5aef6318fcf17f421460)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Driver for Datafab USB Compact Flash reader
4  *
5  * datafab driver v0.1:
6  *
7  * First release
8  *
9  * Current development and maintenance by:
10  *   (c) 2000 Jimmie Mayfield (mayfield+datafab@sackheads.org)
11  *
12  *   Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
13  *   which I used as a template for this driver.
14  *
15  *   Some bugfixes and scatter-gather code by Gregory P. Smith
16  *   (greg-usb@electricrain.com)
17  *
18  *   Fix for media change by Joerg Schneider (js@joergschneider.com)
19  *
20  * Other contributors:
21  *   (c) 2002 Alan Stern <stern@rowland.org>
22  *
23  * This program is free software; you can redistribute it and/or modify it
24  * under the terms of the GNU General Public License as published by the
25  * Free Software Foundation; either version 2, or (at your option) any
26  * later version.
27  *
28  * This program is distributed in the hope that it will be useful, but
29  * WITHOUT ANY WARRANTY; without even the implied warranty of
30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
31  * General Public License for more details.
32  *
33  * You should have received a copy of the GNU General Public License along
34  * with this program; if not, write to the Free Software Foundation, Inc.,
35  * 675 Mass Ave, Cambridge, MA 02139, USA.
36  */
37 
38 /*
39  * This driver attempts to support USB CompactFlash reader/writer devices
40  * based on Datafab USB-to-ATA chips.  It was specifically developed for the
41  * Datafab MDCFE-B USB CompactFlash reader but has since been found to work
42  * with a variety of Datafab-based devices from a number of manufacturers.
43  * I've received a report of this driver working with a Datafab-based
44  * SmartMedia device though please be aware that I'm personally unable to
45  * test SmartMedia support.
46  *
47  * This driver supports reading and writing.  If you're truly paranoid,
48  * however, you can force the driver into a write-protected state by setting
49  * the WP enable bits in datafab_handle_mode_sense().  See the comments
50  * in that routine.
51  */
52 
53 #include <linux/errno.h>
54 #include <linux/module.h>
55 #include <linux/slab.h>
56 
57 #include <scsi/scsi.h>
58 #include <scsi/scsi_cmnd.h>
59 
60 #include "usb.h"
61 #include "transport.h"
62 #include "protocol.h"
63 #include "debug.h"
64 #include "scsiglue.h"
65 
66 #define DRV_NAME "ums-datafab"
67 
68 MODULE_DESCRIPTION("Driver for Datafab USB Compact Flash reader");
69 MODULE_AUTHOR("Jimmie Mayfield <mayfield+datafab@sackheads.org>");
70 MODULE_LICENSE("GPL");
71 
72 struct datafab_info {
73 	unsigned long   sectors;	/* total sector count */
74 	unsigned long   ssize;		/* sector size in bytes */
75 	signed char	lun;		/* used for dual-slot readers */
76 
77 	/* the following aren't used yet */
78 	unsigned char   sense_key;
79 	unsigned long   sense_asc;	/* additional sense code */
80 	unsigned long   sense_ascq;	/* additional sense code qualifier */
81 };
82 
83 static int datafab_determine_lun(struct us_data *us,
84 				 struct datafab_info *info);
85 
86 
87 /*
88  * The table of devices
89  */
90 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
91 		    vendorName, productName, useProtocol, useTransport, \
92 		    initFunction, flags) \
93 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
94   .driver_info = (flags) }
95 
96 static struct usb_device_id datafab_usb_ids[] = {
97 #	include "unusual_datafab.h"
98 	{ }		/* Terminating entry */
99 };
100 MODULE_DEVICE_TABLE(usb, datafab_usb_ids);
101 
102 #undef UNUSUAL_DEV
103 
104 /*
105  * The flags table
106  */
107 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
108 		    vendor_name, product_name, use_protocol, use_transport, \
109 		    init_function, Flags) \
110 { \
111 	.vendorName = vendor_name,	\
112 	.productName = product_name,	\
113 	.useProtocol = use_protocol,	\
114 	.useTransport = use_transport,	\
115 	.initFunction = init_function,	\
116 }
117 
118 static struct us_unusual_dev datafab_unusual_dev_list[] = {
119 #	include "unusual_datafab.h"
120 	{ }		/* Terminating entry */
121 };
122 
123 #undef UNUSUAL_DEV
124 
125 
126 static inline int
127 datafab_bulk_read(struct us_data *us, unsigned char *data, unsigned int len) {
128 	if (len == 0)
129 		return USB_STOR_XFER_GOOD;
130 
131 	usb_stor_dbg(us, "len = %d\n", len);
132 	return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
133 			data, len, NULL);
134 }
135 
136 
137 static inline int
138 datafab_bulk_write(struct us_data *us, unsigned char *data, unsigned int len) {
139 	if (len == 0)
140 		return USB_STOR_XFER_GOOD;
141 
142 	usb_stor_dbg(us, "len = %d\n", len);
143 	return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
144 			data, len, NULL);
145 }
146 
147 
148 static int datafab_read_data(struct us_data *us,
149 			     struct datafab_info *info,
150 			     u32 sector,
151 			     u32 sectors)
152 {
153 	unsigned char *command = us->iobuf;
154 	unsigned char *buffer;
155 	unsigned char  thistime;
156 	unsigned int totallen, alloclen;
157 	int len, result;
158 	unsigned int sg_offset = 0;
159 	struct scatterlist *sg = NULL;
160 
161 	// we're working in LBA mode.  according to the ATA spec,
162 	// we can support up to 28-bit addressing.  I don't know if Datafab
163 	// supports beyond 24-bit addressing.  It's kind of hard to test
164 	// since it requires > 8GB CF card.
165 	//
166 	if (sectors > 0x0FFFFFFF)
167 		return USB_STOR_TRANSPORT_ERROR;
168 
169 	if (info->lun == -1) {
170 		result = datafab_determine_lun(us, info);
171 		if (result != USB_STOR_TRANSPORT_GOOD)
172 			return result;
173 	}
174 
175 	totallen = sectors * info->ssize;
176 
177 	// Since we don't read more than 64 KB at a time, we have to create
178 	// a bounce buffer and move the data a piece at a time between the
179 	// bounce buffer and the actual transfer buffer.
180 
181 	alloclen = min(totallen, 65536u);
182 	buffer = kmalloc(alloclen, GFP_NOIO);
183 	if (buffer == NULL)
184 		return USB_STOR_TRANSPORT_ERROR;
185 
186 	do {
187 		// loop, never allocate or transfer more than 64k at once
188 		// (min(128k, 255*info->ssize) is the real limit)
189 
190 		len = min(totallen, alloclen);
191 		thistime = (len / info->ssize) & 0xff;
192 
193 		command[0] = 0;
194 		command[1] = thistime;
195 		command[2] = sector & 0xFF;
196 		command[3] = (sector >> 8) & 0xFF;
197 		command[4] = (sector >> 16) & 0xFF;
198 
199 		command[5] = 0xE0 + (info->lun << 4);
200 		command[5] |= (sector >> 24) & 0x0F;
201 		command[6] = 0x20;
202 		command[7] = 0x01;
203 
204 		// send the read command
205 		result = datafab_bulk_write(us, command, 8);
206 		if (result != USB_STOR_XFER_GOOD)
207 			goto leave;
208 
209 		// read the result
210 		result = datafab_bulk_read(us, buffer, len);
211 		if (result != USB_STOR_XFER_GOOD)
212 			goto leave;
213 
214 		// Store the data in the transfer buffer
215 		usb_stor_access_xfer_buf(buffer, len, us->srb,
216 				 &sg, &sg_offset, TO_XFER_BUF);
217 
218 		sector += thistime;
219 		totallen -= len;
220 	} while (totallen > 0);
221 
222 	kfree(buffer);
223 	return USB_STOR_TRANSPORT_GOOD;
224 
225  leave:
226 	kfree(buffer);
227 	return USB_STOR_TRANSPORT_ERROR;
228 }
229 
230 
231 static int datafab_write_data(struct us_data *us,
232 			      struct datafab_info *info,
233 			      u32 sector,
234 			      u32 sectors)
235 {
236 	unsigned char *command = us->iobuf;
237 	unsigned char *reply = us->iobuf;
238 	unsigned char *buffer;
239 	unsigned char thistime;
240 	unsigned int totallen, alloclen;
241 	int len, result;
242 	unsigned int sg_offset = 0;
243 	struct scatterlist *sg = NULL;
244 
245 	// we're working in LBA mode.  according to the ATA spec,
246 	// we can support up to 28-bit addressing.  I don't know if Datafab
247 	// supports beyond 24-bit addressing.  It's kind of hard to test
248 	// since it requires > 8GB CF card.
249 	//
250 	if (sectors > 0x0FFFFFFF)
251 		return USB_STOR_TRANSPORT_ERROR;
252 
253 	if (info->lun == -1) {
254 		result = datafab_determine_lun(us, info);
255 		if (result != USB_STOR_TRANSPORT_GOOD)
256 			return result;
257 	}
258 
259 	totallen = sectors * info->ssize;
260 
261 	// Since we don't write more than 64 KB at a time, we have to create
262 	// a bounce buffer and move the data a piece at a time between the
263 	// bounce buffer and the actual transfer buffer.
264 
265 	alloclen = min(totallen, 65536u);
266 	buffer = kmalloc(alloclen, GFP_NOIO);
267 	if (buffer == NULL)
268 		return USB_STOR_TRANSPORT_ERROR;
269 
270 	do {
271 		// loop, never allocate or transfer more than 64k at once
272 		// (min(128k, 255*info->ssize) is the real limit)
273 
274 		len = min(totallen, alloclen);
275 		thistime = (len / info->ssize) & 0xff;
276 
277 		// Get the data from the transfer buffer
278 		usb_stor_access_xfer_buf(buffer, len, us->srb,
279 				&sg, &sg_offset, FROM_XFER_BUF);
280 
281 		command[0] = 0;
282 		command[1] = thistime;
283 		command[2] = sector & 0xFF;
284 		command[3] = (sector >> 8) & 0xFF;
285 		command[4] = (sector >> 16) & 0xFF;
286 
287 		command[5] = 0xE0 + (info->lun << 4);
288 		command[5] |= (sector >> 24) & 0x0F;
289 		command[6] = 0x30;
290 		command[7] = 0x02;
291 
292 		// send the command
293 		result = datafab_bulk_write(us, command, 8);
294 		if (result != USB_STOR_XFER_GOOD)
295 			goto leave;
296 
297 		// send the data
298 		result = datafab_bulk_write(us, buffer, len);
299 		if (result != USB_STOR_XFER_GOOD)
300 			goto leave;
301 
302 		// read the result
303 		result = datafab_bulk_read(us, reply, 2);
304 		if (result != USB_STOR_XFER_GOOD)
305 			goto leave;
306 
307 		if (reply[0] != 0x50 && reply[1] != 0) {
308 			usb_stor_dbg(us, "Gah! write return code: %02x %02x\n",
309 				     reply[0], reply[1]);
310 			result = USB_STOR_TRANSPORT_ERROR;
311 			goto leave;
312 		}
313 
314 		sector += thistime;
315 		totallen -= len;
316 	} while (totallen > 0);
317 
318 	kfree(buffer);
319 	return USB_STOR_TRANSPORT_GOOD;
320 
321  leave:
322 	kfree(buffer);
323 	return USB_STOR_TRANSPORT_ERROR;
324 }
325 
326 
327 static int datafab_determine_lun(struct us_data *us,
328 				 struct datafab_info *info)
329 {
330 	// Dual-slot readers can be thought of as dual-LUN devices.
331 	// We need to determine which card slot is being used.
332 	// We'll send an IDENTIFY DEVICE command and see which LUN responds...
333 	//
334 	// There might be a better way of doing this?
335 
336 	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
337 	unsigned char *command = us->iobuf;
338 	unsigned char *buf;
339 	int count = 0, rc;
340 
341 	if (!info)
342 		return USB_STOR_TRANSPORT_ERROR;
343 
344 	memcpy(command, scommand, 8);
345 	buf = kmalloc(512, GFP_NOIO);
346 	if (!buf)
347 		return USB_STOR_TRANSPORT_ERROR;
348 
349 	usb_stor_dbg(us, "locating...\n");
350 
351 	// we'll try 3 times before giving up...
352 	//
353 	while (count++ < 3) {
354 		command[5] = 0xa0;
355 
356 		rc = datafab_bulk_write(us, command, 8);
357 		if (rc != USB_STOR_XFER_GOOD) {
358 			rc = USB_STOR_TRANSPORT_ERROR;
359 			goto leave;
360 		}
361 
362 		rc = datafab_bulk_read(us, buf, 512);
363 		if (rc == USB_STOR_XFER_GOOD) {
364 			info->lun = 0;
365 			rc = USB_STOR_TRANSPORT_GOOD;
366 			goto leave;
367 		}
368 
369 		command[5] = 0xb0;
370 
371 		rc = datafab_bulk_write(us, command, 8);
372 		if (rc != USB_STOR_XFER_GOOD) {
373 			rc = USB_STOR_TRANSPORT_ERROR;
374 			goto leave;
375 		}
376 
377 		rc = datafab_bulk_read(us, buf, 512);
378 		if (rc == USB_STOR_XFER_GOOD) {
379 			info->lun = 1;
380 			rc = USB_STOR_TRANSPORT_GOOD;
381 			goto leave;
382 		}
383 
384 		msleep(20);
385 	}
386 
387 	rc = USB_STOR_TRANSPORT_ERROR;
388 
389  leave:
390 	kfree(buf);
391 	return rc;
392 }
393 
394 static int datafab_id_device(struct us_data *us,
395 			     struct datafab_info *info)
396 {
397 	// this is a variation of the ATA "IDENTIFY DEVICE" command...according
398 	// to the ATA spec, 'Sector Count' isn't used but the Windows driver
399 	// sets this bit so we do too...
400 	//
401 	static unsigned char scommand[8] = { 0, 1, 0, 0, 0, 0xa0, 0xec, 1 };
402 	unsigned char *command = us->iobuf;
403 	unsigned char *reply;
404 	int rc;
405 
406 	if (!info)
407 		return USB_STOR_TRANSPORT_ERROR;
408 
409 	if (info->lun == -1) {
410 		rc = datafab_determine_lun(us, info);
411 		if (rc != USB_STOR_TRANSPORT_GOOD)
412 			return rc;
413 	}
414 
415 	memcpy(command, scommand, 8);
416 	reply = kmalloc(512, GFP_NOIO);
417 	if (!reply)
418 		return USB_STOR_TRANSPORT_ERROR;
419 
420 	command[5] += (info->lun << 4);
421 
422 	rc = datafab_bulk_write(us, command, 8);
423 	if (rc != USB_STOR_XFER_GOOD) {
424 		rc = USB_STOR_TRANSPORT_ERROR;
425 		goto leave;
426 	}
427 
428 	// we'll go ahead and extract the media capacity while we're here...
429 	//
430 	rc = datafab_bulk_read(us, reply, 512);
431 	if (rc == USB_STOR_XFER_GOOD) {
432 		// capacity is at word offset 57-58
433 		//
434 		info->sectors = ((u32)(reply[117]) << 24) |
435 				((u32)(reply[116]) << 16) |
436 				((u32)(reply[115]) <<  8) |
437 				((u32)(reply[114])      );
438 		rc = USB_STOR_TRANSPORT_GOOD;
439 		goto leave;
440 	}
441 
442 	rc = USB_STOR_TRANSPORT_ERROR;
443 
444  leave:
445 	kfree(reply);
446 	return rc;
447 }
448 
449 
450 static int datafab_handle_mode_sense(struct us_data *us,
451 				     struct scsi_cmnd * srb,
452 				     int sense_6)
453 {
454 	static unsigned char rw_err_page[12] = {
455 		0x1, 0xA, 0x21, 1, 0, 0, 0, 0, 1, 0, 0, 0
456 	};
457 	static unsigned char cache_page[12] = {
458 		0x8, 0xA, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0
459 	};
460 	static unsigned char rbac_page[12] = {
461 		0x1B, 0xA, 0, 0x81, 0, 0, 0, 0, 0, 0, 0, 0
462 	};
463 	static unsigned char timer_page[8] = {
464 		0x1C, 0x6, 0, 0, 0, 0
465 	};
466 	unsigned char pc, page_code;
467 	unsigned int i = 0;
468 	struct datafab_info *info = (struct datafab_info *) (us->extra);
469 	unsigned char *ptr = us->iobuf;
470 
471 	// most of this stuff is just a hack to get things working.  the
472 	// datafab reader doesn't present a SCSI interface so we
473 	// fudge the SCSI commands...
474 	//
475 
476 	pc = srb->cmnd[2] >> 6;
477 	page_code = srb->cmnd[2] & 0x3F;
478 
479 	switch (pc) {
480 	   case 0x0:
481 		   usb_stor_dbg(us, "Current values\n");
482 		break;
483 	   case 0x1:
484 		   usb_stor_dbg(us, "Changeable values\n");
485 		break;
486 	   case 0x2:
487 		   usb_stor_dbg(us, "Default values\n");
488 		break;
489 	   case 0x3:
490 		   usb_stor_dbg(us, "Saves values\n");
491 		break;
492 	}
493 
494 	memset(ptr, 0, 8);
495 	if (sense_6) {
496 		ptr[2] = 0x00;		// WP enable: 0x80
497 		i = 4;
498 	} else {
499 		ptr[3] = 0x00;		// WP enable: 0x80
500 		i = 8;
501 	}
502 
503 	switch (page_code) {
504 	   default:
505 		// vendor-specific mode
506 		info->sense_key = 0x05;
507 		info->sense_asc = 0x24;
508 		info->sense_ascq = 0x00;
509 		return USB_STOR_TRANSPORT_FAILED;
510 
511 	   case 0x1:
512 		memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
513 		i += sizeof(rw_err_page);
514 		break;
515 
516 	   case 0x8:
517 		memcpy(ptr + i, cache_page, sizeof(cache_page));
518 		i += sizeof(cache_page);
519 		break;
520 
521 	   case 0x1B:
522 		memcpy(ptr + i, rbac_page, sizeof(rbac_page));
523 		i += sizeof(rbac_page);
524 		break;
525 
526 	   case 0x1C:
527 		memcpy(ptr + i, timer_page, sizeof(timer_page));
528 		i += sizeof(timer_page);
529 		break;
530 
531 	   case 0x3F:		// retrieve all pages
532 		memcpy(ptr + i, timer_page, sizeof(timer_page));
533 		i += sizeof(timer_page);
534 		memcpy(ptr + i, rbac_page, sizeof(rbac_page));
535 		i += sizeof(rbac_page);
536 		memcpy(ptr + i, cache_page, sizeof(cache_page));
537 		i += sizeof(cache_page);
538 		memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
539 		i += sizeof(rw_err_page);
540 		break;
541 	}
542 
543 	if (sense_6)
544 		ptr[0] = i - 1;
545 	else
546 		((__be16 *) ptr)[0] = cpu_to_be16(i - 2);
547 	usb_stor_set_xfer_buf(ptr, i, srb);
548 
549 	return USB_STOR_TRANSPORT_GOOD;
550 }
551 
552 static void datafab_info_destructor(void *extra)
553 {
554 	// this routine is a placeholder...
555 	// currently, we don't allocate any extra memory so we're okay
556 }
557 
558 
559 // Transport for the Datafab MDCFE-B
560 //
561 static int datafab_transport(struct scsi_cmnd *srb, struct us_data *us)
562 {
563 	struct datafab_info *info;
564 	int rc;
565 	unsigned long block, blocks;
566 	unsigned char *ptr = us->iobuf;
567 	static unsigned char inquiry_reply[8] = {
568 		0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
569 	};
570 
571 	if (!us->extra) {
572 		us->extra = kzalloc(sizeof(struct datafab_info), GFP_NOIO);
573 		if (!us->extra)
574 			return USB_STOR_TRANSPORT_ERROR;
575 
576 		us->extra_destructor = datafab_info_destructor;
577   		((struct datafab_info *)us->extra)->lun = -1;
578 	}
579 
580 	info = (struct datafab_info *) (us->extra);
581 
582 	if (srb->cmnd[0] == INQUIRY) {
583 		usb_stor_dbg(us, "INQUIRY - Returning bogus response\n");
584 		memcpy(ptr, inquiry_reply, sizeof(inquiry_reply));
585 		fill_inquiry_response(us, ptr, 36);
586 		return USB_STOR_TRANSPORT_GOOD;
587 	}
588 
589 	if (srb->cmnd[0] == READ_CAPACITY) {
590 		info->ssize = 0x200;  // hard coded 512 byte sectors as per ATA spec
591 		rc = datafab_id_device(us, info);
592 		if (rc != USB_STOR_TRANSPORT_GOOD)
593 			return rc;
594 
595 		usb_stor_dbg(us, "READ_CAPACITY:  %ld sectors, %ld bytes per sector\n",
596 			     info->sectors, info->ssize);
597 
598 		// build the reply
599 		// we need the last sector, not the number of sectors
600 		((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
601 		((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
602 		usb_stor_set_xfer_buf(ptr, 8, srb);
603 
604 		return USB_STOR_TRANSPORT_GOOD;
605 	}
606 
607 	if (srb->cmnd[0] == MODE_SELECT_10) {
608 		usb_stor_dbg(us, "Gah! MODE_SELECT_10\n");
609 		return USB_STOR_TRANSPORT_ERROR;
610 	}
611 
612 	// don't bother implementing READ_6 or WRITE_6.
613 	//
614 	if (srb->cmnd[0] == READ_10) {
615 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
616 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
617 
618 		blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
619 
620 		usb_stor_dbg(us, "READ_10: read block 0x%04lx  count %ld\n",
621 			     block, blocks);
622 		return datafab_read_data(us, info, block, blocks);
623 	}
624 
625 	if (srb->cmnd[0] == READ_12) {
626 		// we'll probably never see a READ_12 but we'll do it anyway...
627 		//
628 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
629 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
630 
631 		blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
632 			 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));
633 
634 		usb_stor_dbg(us, "READ_12: read block 0x%04lx  count %ld\n",
635 			     block, blocks);
636 		return datafab_read_data(us, info, block, blocks);
637 	}
638 
639 	if (srb->cmnd[0] == WRITE_10) {
640 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
641 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
642 
643 		blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));
644 
645 		usb_stor_dbg(us, "WRITE_10: write block 0x%04lx count %ld\n",
646 			     block, blocks);
647 		return datafab_write_data(us, info, block, blocks);
648 	}
649 
650 	if (srb->cmnd[0] == WRITE_12) {
651 		// we'll probably never see a WRITE_12 but we'll do it anyway...
652 		//
653 		block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
654 			((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));
655 
656 		blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
657 			 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));
658 
659 		usb_stor_dbg(us, "WRITE_12: write block 0x%04lx count %ld\n",
660 			     block, blocks);
661 		return datafab_write_data(us, info, block, blocks);
662 	}
663 
664 	if (srb->cmnd[0] == TEST_UNIT_READY) {
665 		usb_stor_dbg(us, "TEST_UNIT_READY\n");
666 		return datafab_id_device(us, info);
667 	}
668 
669 	if (srb->cmnd[0] == REQUEST_SENSE) {
670 		usb_stor_dbg(us, "REQUEST_SENSE - Returning faked response\n");
671 
672 		// this response is pretty bogus right now.  eventually if necessary
673 		// we can set the correct sense data.  so far though it hasn't been
674 		// necessary
675 		//
676 		memset(ptr, 0, 18);
677 		ptr[0] = 0xF0;
678 		ptr[2] = info->sense_key;
679 		ptr[7] = 11;
680 		ptr[12] = info->sense_asc;
681 		ptr[13] = info->sense_ascq;
682 		usb_stor_set_xfer_buf(ptr, 18, srb);
683 
684 		return USB_STOR_TRANSPORT_GOOD;
685 	}
686 
687 	if (srb->cmnd[0] == MODE_SENSE) {
688 		usb_stor_dbg(us, "MODE_SENSE_6 detected\n");
689 		return datafab_handle_mode_sense(us, srb, 1);
690 	}
691 
692 	if (srb->cmnd[0] == MODE_SENSE_10) {
693 		usb_stor_dbg(us, "MODE_SENSE_10 detected\n");
694 		return datafab_handle_mode_sense(us, srb, 0);
695 	}
696 
697 	if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
698 		/*
699 		 * sure.  whatever.  not like we can stop the user from
700 		 * popping the media out of the device (no locking doors, etc)
701 		 */
702 		return USB_STOR_TRANSPORT_GOOD;
703 	}
704 
705 	if (srb->cmnd[0] == START_STOP) {
706 		/*
707 		 * this is used by sd.c'check_scsidisk_media_change to detect
708 		 * media change
709 		 */
710 		usb_stor_dbg(us, "START_STOP\n");
711 		/*
712 		 * the first datafab_id_device after a media change returns
713 		 * an error (determined experimentally)
714 		 */
715 		rc = datafab_id_device(us, info);
716 		if (rc == USB_STOR_TRANSPORT_GOOD) {
717 			info->sense_key = NO_SENSE;
718 			srb->result = SUCCESS;
719 		} else {
720 			info->sense_key = UNIT_ATTENTION;
721 			srb->result = SAM_STAT_CHECK_CONDITION;
722 		}
723 		return rc;
724 	}
725 
726 	usb_stor_dbg(us, "Gah! Unknown command: %d (0x%x)\n",
727 		     srb->cmnd[0], srb->cmnd[0]);
728 	info->sense_key = 0x05;
729 	info->sense_asc = 0x20;
730 	info->sense_ascq = 0x00;
731 	return USB_STOR_TRANSPORT_FAILED;
732 }
733 
734 static struct scsi_host_template datafab_host_template;
735 
736 static int datafab_probe(struct usb_interface *intf,
737 			 const struct usb_device_id *id)
738 {
739 	struct us_data *us;
740 	int result;
741 
742 	result = usb_stor_probe1(&us, intf, id,
743 			(id - datafab_usb_ids) + datafab_unusual_dev_list,
744 			&datafab_host_template);
745 	if (result)
746 		return result;
747 
748 	us->transport_name  = "Datafab Bulk-Only";
749 	us->transport = datafab_transport;
750 	us->transport_reset = usb_stor_Bulk_reset;
751 	us->max_lun = 1;
752 
753 	result = usb_stor_probe2(us);
754 	return result;
755 }
756 
757 static struct usb_driver datafab_driver = {
758 	.name =		DRV_NAME,
759 	.probe =	datafab_probe,
760 	.disconnect =	usb_stor_disconnect,
761 	.suspend =	usb_stor_suspend,
762 	.resume =	usb_stor_resume,
763 	.reset_resume =	usb_stor_reset_resume,
764 	.pre_reset =	usb_stor_pre_reset,
765 	.post_reset =	usb_stor_post_reset,
766 	.id_table =	datafab_usb_ids,
767 	.soft_unbind =	1,
768 	.no_dynamic_id = 1,
769 };
770 
771 module_usb_stor_driver(datafab_driver, datafab_host_template, DRV_NAME);
772