xref: /linux/drivers/usb/storage/usb.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 /* Driver for USB Mass Storage compliant devices
2  *
3  * $Id: usb.c,v 1.75 2002/04/22 03:39:43 mdharm Exp $
4  *
5  * Current development and maintenance by:
6  *   (c) 1999-2003 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
7  *
8  * Developed with the assistance of:
9  *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
10  *   (c) 2003 Alan Stern (stern@rowland.harvard.edu)
11  *
12  * Initial work by:
13  *   (c) 1999 Michael Gee (michael@linuxspecific.com)
14  *
15  * usb_device_id support by Adam J. Richter (adam@yggdrasil.com):
16  *   (c) 2000 Yggdrasil Computing, Inc.
17  *
18  * This driver is based on the 'USB Mass Storage Class' document. This
19  * describes in detail the protocol used to communicate with such
20  * devices.  Clearly, the designers had SCSI and ATAPI commands in
21  * mind when they created this document.  The commands are all very
22  * similar to commands in the SCSI-II and ATAPI specifications.
23  *
24  * It is important to note that in a number of cases this class
25  * exhibits class-specific exemptions from the USB specification.
26  * Notably the usage of NAK, STALL and ACK differs from the norm, in
27  * that they are used to communicate wait, failed and OK on commands.
28  *
29  * Also, for certain devices, the interrupt endpoint is used to convey
30  * status of a command.
31  *
32  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
33  * information about this driver.
34  *
35  * This program is free software; you can redistribute it and/or modify it
36  * under the terms of the GNU General Public License as published by the
37  * Free Software Foundation; either version 2, or (at your option) any
38  * later version.
39  *
40  * This program is distributed in the hope that it will be useful, but
41  * WITHOUT ANY WARRANTY; without even the implied warranty of
42  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
43  * General Public License for more details.
44  *
45  * You should have received a copy of the GNU General Public License along
46  * with this program; if not, write to the Free Software Foundation, Inc.,
47  * 675 Mass Ave, Cambridge, MA 02139, USA.
48  */
49 
50 #include <linux/config.h>
51 #include <linux/sched.h>
52 #include <linux/errno.h>
53 #include <linux/suspend.h>
54 #include <linux/module.h>
55 #include <linux/init.h>
56 #include <linux/slab.h>
57 #include <linux/kthread.h>
58 #include <linux/mutex.h>
59 
60 #include <scsi/scsi.h>
61 #include <scsi/scsi_cmnd.h>
62 #include <scsi/scsi_device.h>
63 
64 #include "usb.h"
65 #include "scsiglue.h"
66 #include "transport.h"
67 #include "protocol.h"
68 #include "debug.h"
69 #include "initializers.h"
70 
71 #ifdef CONFIG_USB_STORAGE_USBAT
72 #include "shuttle_usbat.h"
73 #endif
74 #ifdef CONFIG_USB_STORAGE_SDDR09
75 #include "sddr09.h"
76 #endif
77 #ifdef CONFIG_USB_STORAGE_SDDR55
78 #include "sddr55.h"
79 #endif
80 #ifdef CONFIG_USB_STORAGE_DPCM
81 #include "dpcm.h"
82 #endif
83 #ifdef CONFIG_USB_STORAGE_FREECOM
84 #include "freecom.h"
85 #endif
86 #ifdef CONFIG_USB_STORAGE_ISD200
87 #include "isd200.h"
88 #endif
89 #ifdef CONFIG_USB_STORAGE_DATAFAB
90 #include "datafab.h"
91 #endif
92 #ifdef CONFIG_USB_STORAGE_JUMPSHOT
93 #include "jumpshot.h"
94 #endif
95 #ifdef CONFIG_USB_STORAGE_ONETOUCH
96 #include "onetouch.h"
97 #endif
98 #ifdef CONFIG_USB_STORAGE_ALAUDA
99 #include "alauda.h"
100 #endif
101 
102 /* Some informational data */
103 MODULE_AUTHOR("Matthew Dharm <mdharm-usb@one-eyed-alien.net>");
104 MODULE_DESCRIPTION("USB Mass Storage driver for Linux");
105 MODULE_LICENSE("GPL");
106 
107 static unsigned int delay_use = 5;
108 module_param(delay_use, uint, S_IRUGO | S_IWUSR);
109 MODULE_PARM_DESC(delay_use, "seconds to delay before using a new device");
110 
111 
112 /* These are used to make sure the module doesn't unload before all the
113  * threads have exited.
114  */
115 static atomic_t total_threads = ATOMIC_INIT(0);
116 static DECLARE_COMPLETION(threads_gone);
117 
118 
119 /*
120  * The entries in this table correspond, line for line,
121  * with the entries of us_unusual_dev_list[].
122  */
123 #ifndef CONFIG_USB_LIBUSUAL
124 
125 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
126 		    vendorName, productName,useProtocol, useTransport, \
127 		    initFunction, flags) \
128 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin,bcdDeviceMax), \
129   .driver_info = (flags)|(USB_US_TYPE_STOR<<24) }
130 
131 #define USUAL_DEV(useProto, useTrans, useType) \
132 { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, useProto, useTrans), \
133   .driver_info = (USB_US_TYPE_STOR<<24) }
134 
135 static struct usb_device_id storage_usb_ids [] = {
136 
137 #	include "unusual_devs.h"
138 #undef UNUSUAL_DEV
139 #undef USUAL_DEV
140 	/* Terminating entry */
141 	{ }
142 };
143 
144 MODULE_DEVICE_TABLE (usb, storage_usb_ids);
145 #endif /* CONFIG_USB_LIBUSUAL */
146 
147 /* This is the list of devices we recognize, along with their flag data */
148 
149 /* The vendor name should be kept at eight characters or less, and
150  * the product name should be kept at 16 characters or less. If a device
151  * has the US_FL_FIX_INQUIRY flag, then the vendor and product names
152  * normally generated by a device thorugh the INQUIRY response will be
153  * taken from this list, and this is the reason for the above size
154  * restriction. However, if the flag is not present, then you
155  * are free to use as many characters as you like.
156  */
157 
158 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
159 		    vendor_name, product_name, use_protocol, use_transport, \
160 		    init_function, Flags) \
161 { \
162 	.vendorName = vendor_name,	\
163 	.productName = product_name,	\
164 	.useProtocol = use_protocol,	\
165 	.useTransport = use_transport,	\
166 	.initFunction = init_function,	\
167 }
168 
169 #define USUAL_DEV(use_protocol, use_transport, use_type) \
170 { \
171 	.useProtocol = use_protocol,	\
172 	.useTransport = use_transport,	\
173 }
174 
175 static struct us_unusual_dev us_unusual_dev_list[] = {
176 #	include "unusual_devs.h"
177 #	undef UNUSUAL_DEV
178 #	undef USUAL_DEV
179 
180 	/* Terminating entry */
181 	{ NULL }
182 };
183 
184 
185 #ifdef CONFIG_PM	/* Minimal support for suspend and resume */
186 
187 static int storage_suspend(struct usb_interface *iface, pm_message_t message)
188 {
189 	struct us_data *us = usb_get_intfdata(iface);
190 
191 	/* Wait until no command is running */
192 	mutex_lock(&us->dev_mutex);
193 
194 	US_DEBUGP("%s\n", __FUNCTION__);
195 	if (us->suspend_resume_hook)
196 		(us->suspend_resume_hook)(us, US_SUSPEND);
197 	iface->dev.power.power_state.event = message.event;
198 
199 	/* When runtime PM is working, we'll set a flag to indicate
200 	 * whether we should autoresume when a SCSI request arrives. */
201 
202 	mutex_unlock(&us->dev_mutex);
203 	return 0;
204 }
205 
206 static int storage_resume(struct usb_interface *iface)
207 {
208 	struct us_data *us = usb_get_intfdata(iface);
209 
210 	mutex_lock(&us->dev_mutex);
211 
212 	US_DEBUGP("%s\n", __FUNCTION__);
213 	if (us->suspend_resume_hook)
214 		(us->suspend_resume_hook)(us, US_RESUME);
215 	iface->dev.power.power_state.event = PM_EVENT_ON;
216 
217 	mutex_unlock(&us->dev_mutex);
218 	return 0;
219 }
220 
221 #endif /* CONFIG_PM */
222 
223 /*
224  * fill_inquiry_response takes an unsigned char array (which must
225  * be at least 36 characters) and populates the vendor name,
226  * product name, and revision fields. Then the array is copied
227  * into the SCSI command's response buffer (oddly enough
228  * called request_buffer). data_len contains the length of the
229  * data array, which again must be at least 36.
230  */
231 
232 void fill_inquiry_response(struct us_data *us, unsigned char *data,
233 		unsigned int data_len)
234 {
235 	if (data_len<36) // You lose.
236 		return;
237 
238 	if(data[0]&0x20) { /* USB device currently not connected. Return
239 			      peripheral qualifier 001b ("...however, the
240 			      physical device is not currently connected
241 			      to this logical unit") and leave vendor and
242 			      product identification empty. ("If the target
243 			      does store some of the INQUIRY data on the
244 			      device, it may return zeros or ASCII spaces
245 			      (20h) in those fields until the data is
246 			      available from the device."). */
247 		memset(data+8,0,28);
248 	} else {
249 		u16 bcdDevice = le16_to_cpu(us->pusb_dev->descriptor.bcdDevice);
250 		memcpy(data+8, us->unusual_dev->vendorName,
251 			strlen(us->unusual_dev->vendorName) > 8 ? 8 :
252 			strlen(us->unusual_dev->vendorName));
253 		memcpy(data+16, us->unusual_dev->productName,
254 			strlen(us->unusual_dev->productName) > 16 ? 16 :
255 			strlen(us->unusual_dev->productName));
256 		data[32] = 0x30 + ((bcdDevice>>12) & 0x0F);
257 		data[33] = 0x30 + ((bcdDevice>>8) & 0x0F);
258 		data[34] = 0x30 + ((bcdDevice>>4) & 0x0F);
259 		data[35] = 0x30 + ((bcdDevice) & 0x0F);
260 	}
261 
262 	usb_stor_set_xfer_buf(data, data_len, us->srb);
263 }
264 
265 static int usb_stor_control_thread(void * __us)
266 {
267 	struct us_data *us = (struct us_data *)__us;
268 	struct Scsi_Host *host = us_to_host(us);
269 
270 	current->flags |= PF_NOFREEZE;
271 
272 	for(;;) {
273 		US_DEBUGP("*** thread sleeping.\n");
274 		if(down_interruptible(&us->sema))
275 			break;
276 
277 		US_DEBUGP("*** thread awakened.\n");
278 
279 		/* lock the device pointers */
280 		mutex_lock(&(us->dev_mutex));
281 
282 		/* if the device has disconnected, we are free to exit */
283 		if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
284 			US_DEBUGP("-- exiting\n");
285 			mutex_unlock(&us->dev_mutex);
286 			break;
287 		}
288 
289 		/* lock access to the state */
290 		scsi_lock(host);
291 
292 		/* has the command timed out *already* ? */
293 		if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
294 			us->srb->result = DID_ABORT << 16;
295 			goto SkipForAbort;
296 		}
297 
298 		scsi_unlock(host);
299 
300 		/* reject the command if the direction indicator
301 		 * is UNKNOWN
302 		 */
303 		if (us->srb->sc_data_direction == DMA_BIDIRECTIONAL) {
304 			US_DEBUGP("UNKNOWN data direction\n");
305 			us->srb->result = DID_ERROR << 16;
306 		}
307 
308 		/* reject if target != 0 or if LUN is higher than
309 		 * the maximum known LUN
310 		 */
311 		else if (us->srb->device->id &&
312 				!(us->flags & US_FL_SCM_MULT_TARG)) {
313 			US_DEBUGP("Bad target number (%d:%d)\n",
314 				  us->srb->device->id, us->srb->device->lun);
315 			us->srb->result = DID_BAD_TARGET << 16;
316 		}
317 
318 		else if (us->srb->device->lun > us->max_lun) {
319 			US_DEBUGP("Bad LUN (%d:%d)\n",
320 				  us->srb->device->id, us->srb->device->lun);
321 			us->srb->result = DID_BAD_TARGET << 16;
322 		}
323 
324 		/* Handle those devices which need us to fake
325 		 * their inquiry data */
326 		else if ((us->srb->cmnd[0] == INQUIRY) &&
327 			    (us->flags & US_FL_FIX_INQUIRY)) {
328 			unsigned char data_ptr[36] = {
329 			    0x00, 0x80, 0x02, 0x02,
330 			    0x1F, 0x00, 0x00, 0x00};
331 
332 			US_DEBUGP("Faking INQUIRY command\n");
333 			fill_inquiry_response(us, data_ptr, 36);
334 			us->srb->result = SAM_STAT_GOOD;
335 		}
336 
337 		/* we've got a command, let's do it! */
338 		else {
339 			US_DEBUG(usb_stor_show_command(us->srb));
340 			us->proto_handler(us->srb, us);
341 		}
342 
343 		/* lock access to the state */
344 		scsi_lock(host);
345 
346 		/* indicate that the command is done */
347 		if (us->srb->result != DID_ABORT << 16) {
348 			US_DEBUGP("scsi cmd done, result=0x%x\n",
349 				   us->srb->result);
350 			us->srb->scsi_done(us->srb);
351 		} else {
352 SkipForAbort:
353 			US_DEBUGP("scsi command aborted\n");
354 		}
355 
356 		/* If an abort request was received we need to signal that
357 		 * the abort has finished.  The proper test for this is
358 		 * the TIMED_OUT flag, not srb->result == DID_ABORT, because
359 		 * the timeout might have occurred after the command had
360 		 * already completed with a different result code. */
361 		if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
362 			complete(&(us->notify));
363 
364 			/* Allow USB transfers to resume */
365 			clear_bit(US_FLIDX_ABORTING, &us->flags);
366 			clear_bit(US_FLIDX_TIMED_OUT, &us->flags);
367 		}
368 
369 		/* finished working on this command */
370 		us->srb = NULL;
371 		scsi_unlock(host);
372 
373 		/* unlock the device pointers */
374 		mutex_unlock(&us->dev_mutex);
375 	} /* for (;;) */
376 
377 	scsi_host_put(host);
378 
379 	/* notify the exit routine that we're actually exiting now
380 	 *
381 	 * complete()/wait_for_completion() is similar to up()/down(),
382 	 * except that complete() is safe in the case where the structure
383 	 * is getting deleted in a parallel mode of execution (i.e. just
384 	 * after the down() -- that's necessary for the thread-shutdown
385 	 * case.
386 	 *
387 	 * complete_and_exit() goes even further than this -- it is safe in
388 	 * the case that the thread of the caller is going away (not just
389 	 * the structure) -- this is necessary for the module-remove case.
390 	 * This is important in preemption kernels, which transfer the flow
391 	 * of execution immediately upon a complete().
392 	 */
393 	complete_and_exit(&threads_gone, 0);
394 }
395 
396 /***********************************************************************
397  * Device probing and disconnecting
398  ***********************************************************************/
399 
400 /* Associate our private data with the USB device */
401 static int associate_dev(struct us_data *us, struct usb_interface *intf)
402 {
403 	US_DEBUGP("-- %s\n", __FUNCTION__);
404 
405 	/* Fill in the device-related fields */
406 	us->pusb_dev = interface_to_usbdev(intf);
407 	us->pusb_intf = intf;
408 	us->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
409 	US_DEBUGP("Vendor: 0x%04x, Product: 0x%04x, Revision: 0x%04x\n",
410 			le16_to_cpu(us->pusb_dev->descriptor.idVendor),
411 			le16_to_cpu(us->pusb_dev->descriptor.idProduct),
412 			le16_to_cpu(us->pusb_dev->descriptor.bcdDevice));
413 	US_DEBUGP("Interface Subclass: 0x%02x, Protocol: 0x%02x\n",
414 			intf->cur_altsetting->desc.bInterfaceSubClass,
415 			intf->cur_altsetting->desc.bInterfaceProtocol);
416 
417 	/* Store our private data in the interface */
418 	usb_set_intfdata(intf, us);
419 
420 	/* Allocate the device-related DMA-mapped buffers */
421 	us->cr = usb_buffer_alloc(us->pusb_dev, sizeof(*us->cr),
422 			GFP_KERNEL, &us->cr_dma);
423 	if (!us->cr) {
424 		US_DEBUGP("usb_ctrlrequest allocation failed\n");
425 		return -ENOMEM;
426 	}
427 
428 	us->iobuf = usb_buffer_alloc(us->pusb_dev, US_IOBUF_SIZE,
429 			GFP_KERNEL, &us->iobuf_dma);
430 	if (!us->iobuf) {
431 		US_DEBUGP("I/O buffer allocation failed\n");
432 		return -ENOMEM;
433 	}
434 
435 	us->sensebuf = kmalloc(US_SENSE_SIZE, GFP_KERNEL);
436 	if (!us->sensebuf) {
437 		US_DEBUGP("Sense buffer allocation failed\n");
438 		return -ENOMEM;
439 	}
440 	return 0;
441 }
442 
443 /* Find an unusual_dev descriptor (always succeeds in the current code) */
444 static struct us_unusual_dev *find_unusual(const struct usb_device_id *id)
445 {
446 	const int id_index = id - storage_usb_ids;
447 	return &us_unusual_dev_list[id_index];
448 }
449 
450 /* Get the unusual_devs entries and the string descriptors */
451 static void get_device_info(struct us_data *us, const struct usb_device_id *id)
452 {
453 	struct usb_device *dev = us->pusb_dev;
454 	struct usb_interface_descriptor *idesc =
455 		&us->pusb_intf->cur_altsetting->desc;
456 	struct us_unusual_dev *unusual_dev = find_unusual(id);
457 
458 	/* Store the entries */
459 	us->unusual_dev = unusual_dev;
460 	us->subclass = (unusual_dev->useProtocol == US_SC_DEVICE) ?
461 			idesc->bInterfaceSubClass :
462 			unusual_dev->useProtocol;
463 	us->protocol = (unusual_dev->useTransport == US_PR_DEVICE) ?
464 			idesc->bInterfaceProtocol :
465 			unusual_dev->useTransport;
466 	us->flags = USB_US_ORIG_FLAGS(id->driver_info);
467 
468 	/*
469 	 * This flag is only needed when we're in high-speed, so let's
470 	 * disable it if we're in full-speed
471 	 */
472 	if (dev->speed != USB_SPEED_HIGH)
473 		us->flags &= ~US_FL_GO_SLOW;
474 
475 	/* Log a message if a non-generic unusual_dev entry contains an
476 	 * unnecessary subclass or protocol override.  This may stimulate
477 	 * reports from users that will help us remove unneeded entries
478 	 * from the unusual_devs.h table.
479 	 */
480 	if (id->idVendor || id->idProduct) {
481 		static const char *msgs[3] = {
482 			"an unneeded SubClass entry",
483 			"an unneeded Protocol entry",
484 			"unneeded SubClass and Protocol entries"};
485 		struct usb_device_descriptor *ddesc = &dev->descriptor;
486 		int msg = -1;
487 
488 		if (unusual_dev->useProtocol != US_SC_DEVICE &&
489 			us->subclass == idesc->bInterfaceSubClass)
490 			msg += 1;
491 		if (unusual_dev->useTransport != US_PR_DEVICE &&
492 			us->protocol == idesc->bInterfaceProtocol)
493 			msg += 2;
494 		if (msg >= 0 && !(us->flags & US_FL_NEED_OVERRIDE))
495 			printk(KERN_NOTICE USB_STORAGE "This device "
496 				"(%04x,%04x,%04x S %02x P %02x)"
497 				" has %s in unusual_devs.h\n"
498 				"   Please send a copy of this message to "
499 				"<linux-usb-devel@lists.sourceforge.net>\n",
500 				le16_to_cpu(ddesc->idVendor),
501 				le16_to_cpu(ddesc->idProduct),
502 				le16_to_cpu(ddesc->bcdDevice),
503 				idesc->bInterfaceSubClass,
504 				idesc->bInterfaceProtocol,
505 				msgs[msg]);
506 	}
507 }
508 
509 /* Get the transport settings */
510 static int get_transport(struct us_data *us)
511 {
512 	switch (us->protocol) {
513 	case US_PR_CB:
514 		us->transport_name = "Control/Bulk";
515 		us->transport = usb_stor_CB_transport;
516 		us->transport_reset = usb_stor_CB_reset;
517 		us->max_lun = 7;
518 		break;
519 
520 	case US_PR_CBI:
521 		us->transport_name = "Control/Bulk/Interrupt";
522 		us->transport = usb_stor_CBI_transport;
523 		us->transport_reset = usb_stor_CB_reset;
524 		us->max_lun = 7;
525 		break;
526 
527 	case US_PR_BULK:
528 		us->transport_name = "Bulk";
529 		us->transport = usb_stor_Bulk_transport;
530 		us->transport_reset = usb_stor_Bulk_reset;
531 		break;
532 
533 #ifdef CONFIG_USB_STORAGE_USBAT
534 	case US_PR_USBAT:
535 		us->transport_name = "Shuttle USBAT";
536 		us->transport = usbat_transport;
537 		us->transport_reset = usb_stor_CB_reset;
538 		us->max_lun = 1;
539 		break;
540 #endif
541 
542 #ifdef CONFIG_USB_STORAGE_SDDR09
543 	case US_PR_EUSB_SDDR09:
544 		us->transport_name = "EUSB/SDDR09";
545 		us->transport = sddr09_transport;
546 		us->transport_reset = usb_stor_CB_reset;
547 		us->max_lun = 0;
548 		break;
549 #endif
550 
551 #ifdef CONFIG_USB_STORAGE_SDDR55
552 	case US_PR_SDDR55:
553 		us->transport_name = "SDDR55";
554 		us->transport = sddr55_transport;
555 		us->transport_reset = sddr55_reset;
556 		us->max_lun = 0;
557 		break;
558 #endif
559 
560 #ifdef CONFIG_USB_STORAGE_DPCM
561 	case US_PR_DPCM_USB:
562 		us->transport_name = "Control/Bulk-EUSB/SDDR09";
563 		us->transport = dpcm_transport;
564 		us->transport_reset = usb_stor_CB_reset;
565 		us->max_lun = 1;
566 		break;
567 #endif
568 
569 #ifdef CONFIG_USB_STORAGE_FREECOM
570 	case US_PR_FREECOM:
571 		us->transport_name = "Freecom";
572 		us->transport = freecom_transport;
573 		us->transport_reset = usb_stor_freecom_reset;
574 		us->max_lun = 0;
575 		break;
576 #endif
577 
578 #ifdef CONFIG_USB_STORAGE_DATAFAB
579 	case US_PR_DATAFAB:
580 		us->transport_name  = "Datafab Bulk-Only";
581 		us->transport = datafab_transport;
582 		us->transport_reset = usb_stor_Bulk_reset;
583 		us->max_lun = 1;
584 		break;
585 #endif
586 
587 #ifdef CONFIG_USB_STORAGE_JUMPSHOT
588 	case US_PR_JUMPSHOT:
589 		us->transport_name  = "Lexar Jumpshot Control/Bulk";
590 		us->transport = jumpshot_transport;
591 		us->transport_reset = usb_stor_Bulk_reset;
592 		us->max_lun = 1;
593 		break;
594 #endif
595 
596 	default:
597 		return -EIO;
598 	}
599 	US_DEBUGP("Transport: %s\n", us->transport_name);
600 
601 	/* fix for single-lun devices */
602 	if (us->flags & US_FL_SINGLE_LUN)
603 		us->max_lun = 0;
604 	return 0;
605 }
606 
607 /* Get the protocol settings */
608 static int get_protocol(struct us_data *us)
609 {
610 	switch (us->subclass) {
611 	case US_SC_RBC:
612 		us->protocol_name = "Reduced Block Commands (RBC)";
613 		us->proto_handler = usb_stor_transparent_scsi_command;
614 		break;
615 
616 	case US_SC_8020:
617 		us->protocol_name = "8020i";
618 		us->proto_handler = usb_stor_ATAPI_command;
619 		us->max_lun = 0;
620 		break;
621 
622 	case US_SC_QIC:
623 		us->protocol_name = "QIC-157";
624 		us->proto_handler = usb_stor_qic157_command;
625 		us->max_lun = 0;
626 		break;
627 
628 	case US_SC_8070:
629 		us->protocol_name = "8070i";
630 		us->proto_handler = usb_stor_ATAPI_command;
631 		us->max_lun = 0;
632 		break;
633 
634 	case US_SC_SCSI:
635 		us->protocol_name = "Transparent SCSI";
636 		us->proto_handler = usb_stor_transparent_scsi_command;
637 		break;
638 
639 	case US_SC_UFI:
640 		us->protocol_name = "Uniform Floppy Interface (UFI)";
641 		us->proto_handler = usb_stor_ufi_command;
642 		break;
643 
644 #ifdef CONFIG_USB_STORAGE_ISD200
645 	case US_SC_ISD200:
646 		us->protocol_name = "ISD200 ATA/ATAPI";
647 		us->proto_handler = isd200_ata_command;
648 		break;
649 #endif
650 
651 #ifdef CONFIG_USB_STORAGE_ALAUDA
652 	case US_PR_ALAUDA:
653 		us->transport_name  = "Alauda Control/Bulk";
654 		us->transport = alauda_transport;
655 		us->transport_reset = usb_stor_Bulk_reset;
656 		us->max_lun = 1;
657 		break;
658 #endif
659 
660 	default:
661 		return -EIO;
662 	}
663 	US_DEBUGP("Protocol: %s\n", us->protocol_name);
664 	return 0;
665 }
666 
667 /* Get the pipe settings */
668 static int get_pipes(struct us_data *us)
669 {
670 	struct usb_host_interface *altsetting =
671 		us->pusb_intf->cur_altsetting;
672 	int i;
673 	struct usb_endpoint_descriptor *ep;
674 	struct usb_endpoint_descriptor *ep_in = NULL;
675 	struct usb_endpoint_descriptor *ep_out = NULL;
676 	struct usb_endpoint_descriptor *ep_int = NULL;
677 
678 	/*
679 	 * Find the endpoints we need.
680 	 * We are expecting a minimum of 2 endpoints - in and out (bulk).
681 	 * An optional interrupt is OK (necessary for CBI protocol).
682 	 * We will ignore any others.
683 	 */
684 	for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
685 		ep = &altsetting->endpoint[i].desc;
686 
687 		/* Is it a BULK endpoint? */
688 		if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
689 				== USB_ENDPOINT_XFER_BULK) {
690 			/* BULK in or out? */
691 			if (ep->bEndpointAddress & USB_DIR_IN)
692 				ep_in = ep;
693 			else
694 				ep_out = ep;
695 		}
696 
697 		/* Is it an interrupt endpoint? */
698 		else if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
699 				== USB_ENDPOINT_XFER_INT) {
700 			ep_int = ep;
701 		}
702 	}
703 
704 	if (!ep_in || !ep_out || (us->protocol == US_PR_CBI && !ep_int)) {
705 		US_DEBUGP("Endpoint sanity check failed! Rejecting dev.\n");
706 		return -EIO;
707 	}
708 
709 	/* Calculate and store the pipe values */
710 	us->send_ctrl_pipe = usb_sndctrlpipe(us->pusb_dev, 0);
711 	us->recv_ctrl_pipe = usb_rcvctrlpipe(us->pusb_dev, 0);
712 	us->send_bulk_pipe = usb_sndbulkpipe(us->pusb_dev,
713 		ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
714 	us->recv_bulk_pipe = usb_rcvbulkpipe(us->pusb_dev,
715 		ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
716 	if (ep_int) {
717 		us->recv_intr_pipe = usb_rcvintpipe(us->pusb_dev,
718 			ep_int->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
719 		us->ep_bInterval = ep_int->bInterval;
720 	}
721 	return 0;
722 }
723 
724 /* Initialize all the dynamic resources we need */
725 static int usb_stor_acquire_resources(struct us_data *us)
726 {
727 	int p;
728 	struct task_struct *th;
729 
730 	us->current_urb = usb_alloc_urb(0, GFP_KERNEL);
731 	if (!us->current_urb) {
732 		US_DEBUGP("URB allocation failed\n");
733 		return -ENOMEM;
734 	}
735 
736 	/* Just before we start our control thread, initialize
737 	 * the device if it needs initialization */
738 	if (us->unusual_dev->initFunction) {
739 		p = us->unusual_dev->initFunction(us);
740 		if (p)
741 			return p;
742 	}
743 
744 	/* Start up our control thread */
745 	th = kthread_create(usb_stor_control_thread, us, "usb-storage");
746 	if (IS_ERR(th)) {
747 		printk(KERN_WARNING USB_STORAGE
748 		       "Unable to start control thread\n");
749 		return PTR_ERR(th);
750 	}
751 
752 	/* Take a reference to the host for the control thread and
753 	 * count it among all the threads we have launched.  Then
754 	 * start it up. */
755 	scsi_host_get(us_to_host(us));
756 	atomic_inc(&total_threads);
757 	wake_up_process(th);
758 
759 	return 0;
760 }
761 
762 /* Release all our dynamic resources */
763 static void usb_stor_release_resources(struct us_data *us)
764 {
765 	US_DEBUGP("-- %s\n", __FUNCTION__);
766 
767 	/* Tell the control thread to exit.  The SCSI host must
768 	 * already have been removed so it won't try to queue
769 	 * any more commands.
770 	 */
771 	US_DEBUGP("-- sending exit command to thread\n");
772 	set_bit(US_FLIDX_DISCONNECTING, &us->flags);
773 	up(&us->sema);
774 
775 	/* Call the destructor routine, if it exists */
776 	if (us->extra_destructor) {
777 		US_DEBUGP("-- calling extra_destructor()\n");
778 		us->extra_destructor(us->extra);
779 	}
780 
781 	/* Free the extra data and the URB */
782 	kfree(us->extra);
783 	usb_free_urb(us->current_urb);
784 }
785 
786 /* Dissociate from the USB device */
787 static void dissociate_dev(struct us_data *us)
788 {
789 	US_DEBUGP("-- %s\n", __FUNCTION__);
790 
791 	kfree(us->sensebuf);
792 
793 	/* Free the device-related DMA-mapped buffers */
794 	if (us->cr)
795 		usb_buffer_free(us->pusb_dev, sizeof(*us->cr), us->cr,
796 				us->cr_dma);
797 	if (us->iobuf)
798 		usb_buffer_free(us->pusb_dev, US_IOBUF_SIZE, us->iobuf,
799 				us->iobuf_dma);
800 
801 	/* Remove our private data from the interface */
802 	usb_set_intfdata(us->pusb_intf, NULL);
803 }
804 
805 /* First stage of disconnect processing: stop all commands and remove
806  * the host */
807 static void quiesce_and_remove_host(struct us_data *us)
808 {
809 	/* Prevent new USB transfers, stop the current command, and
810 	 * interrupt a SCSI-scan or device-reset delay */
811 	set_bit(US_FLIDX_DISCONNECTING, &us->flags);
812 	usb_stor_stop_transport(us);
813 	wake_up(&us->delay_wait);
814 
815 	/* It doesn't matter if the SCSI-scanning thread is still running.
816 	 * The thread will exit when it sees the DISCONNECTING flag. */
817 
818 	/* Wait for the current command to finish, then remove the host */
819 	mutex_lock(&us->dev_mutex);
820 	mutex_unlock(&us->dev_mutex);
821 
822 	/* queuecommand won't accept any new commands and the control
823 	 * thread won't execute a previously-queued command.  If there
824 	 * is such a command pending, complete it with an error. */
825 	if (us->srb) {
826 		us->srb->result = DID_NO_CONNECT << 16;
827 		scsi_lock(us_to_host(us));
828 		us->srb->scsi_done(us->srb);
829 		us->srb = NULL;
830 		scsi_unlock(us_to_host(us));
831 	}
832 
833 	/* Now we own no commands so it's safe to remove the SCSI host */
834 	scsi_remove_host(us_to_host(us));
835 }
836 
837 /* Second stage of disconnect processing: deallocate all resources */
838 static void release_everything(struct us_data *us)
839 {
840 	usb_stor_release_resources(us);
841 	dissociate_dev(us);
842 
843 	/* Drop our reference to the host; the SCSI core will free it
844 	 * (and "us" along with it) when the refcount becomes 0. */
845 	scsi_host_put(us_to_host(us));
846 }
847 
848 /* Thread to carry out delayed SCSI-device scanning */
849 static int usb_stor_scan_thread(void * __us)
850 {
851 	struct us_data *us = (struct us_data *)__us;
852 
853 	printk(KERN_DEBUG
854 		"usb-storage: device found at %d\n", us->pusb_dev->devnum);
855 
856 	/* Wait for the timeout to expire or for a disconnect */
857 	if (delay_use > 0) {
858 		printk(KERN_DEBUG "usb-storage: waiting for device "
859 				"to settle before scanning\n");
860 retry:
861 		wait_event_interruptible_timeout(us->delay_wait,
862 				test_bit(US_FLIDX_DISCONNECTING, &us->flags),
863 				delay_use * HZ);
864 		if (try_to_freeze())
865 			goto retry;
866 	}
867 
868 	/* If the device is still connected, perform the scanning */
869 	if (!test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
870 
871 		/* For bulk-only devices, determine the max LUN value */
872 		if (us->protocol == US_PR_BULK &&
873 				!(us->flags & US_FL_SINGLE_LUN)) {
874 			mutex_lock(&us->dev_mutex);
875 			us->max_lun = usb_stor_Bulk_max_lun(us);
876 			mutex_unlock(&us->dev_mutex);
877 		}
878 		scsi_scan_host(us_to_host(us));
879 		printk(KERN_DEBUG "usb-storage: device scan complete\n");
880 
881 		/* Should we unbind if no devices were detected? */
882 	}
883 
884 	scsi_host_put(us_to_host(us));
885 	complete_and_exit(&threads_gone, 0);
886 }
887 
888 
889 /* Probe to see if we can drive a newly-connected USB device */
890 static int storage_probe(struct usb_interface *intf,
891 			 const struct usb_device_id *id)
892 {
893 	struct Scsi_Host *host;
894 	struct us_data *us;
895 	int result;
896 	struct task_struct *th;
897 
898 	if (usb_usual_check_type(id, USB_US_TYPE_STOR))
899 		return -ENXIO;
900 
901 	US_DEBUGP("USB Mass Storage device detected\n");
902 
903 	/*
904 	 * Ask the SCSI layer to allocate a host structure, with extra
905 	 * space at the end for our private us_data structure.
906 	 */
907 	host = scsi_host_alloc(&usb_stor_host_template, sizeof(*us));
908 	if (!host) {
909 		printk(KERN_WARNING USB_STORAGE
910 			"Unable to allocate the scsi host\n");
911 		return -ENOMEM;
912 	}
913 
914 	us = host_to_us(host);
915 	memset(us, 0, sizeof(struct us_data));
916 	mutex_init(&(us->dev_mutex));
917 	init_MUTEX_LOCKED(&(us->sema));
918 	init_completion(&(us->notify));
919 	init_waitqueue_head(&us->delay_wait);
920 
921 	/* Associate the us_data structure with the USB device */
922 	result = associate_dev(us, intf);
923 	if (result)
924 		goto BadDevice;
925 
926 	/*
927 	 * Get the unusual_devs entries and the descriptors
928 	 *
929 	 * id_index is calculated in the declaration to be the index number
930 	 * of the match from the usb_device_id table, so we can find the
931 	 * corresponding entry in the private table.
932 	 */
933 	get_device_info(us, id);
934 
935 	/* Get the transport, protocol, and pipe settings */
936 	result = get_transport(us);
937 	if (result)
938 		goto BadDevice;
939 	result = get_protocol(us);
940 	if (result)
941 		goto BadDevice;
942 	result = get_pipes(us);
943 	if (result)
944 		goto BadDevice;
945 
946 	/* Acquire all the other resources and add the host */
947 	result = usb_stor_acquire_resources(us);
948 	if (result)
949 		goto BadDevice;
950 	result = scsi_add_host(host, &intf->dev);
951 	if (result) {
952 		printk(KERN_WARNING USB_STORAGE
953 			"Unable to add the scsi host\n");
954 		goto BadDevice;
955 	}
956 
957 	/* Start up the thread for delayed SCSI-device scanning */
958 	th = kthread_create(usb_stor_scan_thread, us, "usb-stor-scan");
959 	if (IS_ERR(th)) {
960 		printk(KERN_WARNING USB_STORAGE
961 		       "Unable to start the device-scanning thread\n");
962 		quiesce_and_remove_host(us);
963 		result = PTR_ERR(th);
964 		goto BadDevice;
965 	}
966 
967 	/* Take a reference to the host for the scanning thread and
968 	 * count it among all the threads we have launched.  Then
969 	 * start it up. */
970 	scsi_host_get(us_to_host(us));
971 	atomic_inc(&total_threads);
972 	wake_up_process(th);
973 
974 	return 0;
975 
976 	/* We come here if there are any problems */
977 BadDevice:
978 	US_DEBUGP("storage_probe() failed\n");
979 	release_everything(us);
980 	return result;
981 }
982 
983 /* Handle a disconnect event from the USB core */
984 static void storage_disconnect(struct usb_interface *intf)
985 {
986 	struct us_data *us = usb_get_intfdata(intf);
987 
988 	US_DEBUGP("storage_disconnect() called\n");
989 	quiesce_and_remove_host(us);
990 	release_everything(us);
991 }
992 
993 /***********************************************************************
994  * Initialization and registration
995  ***********************************************************************/
996 
997 static struct usb_driver usb_storage_driver = {
998 	.name =		"usb-storage",
999 	.probe =	storage_probe,
1000 	.disconnect =	storage_disconnect,
1001 #ifdef CONFIG_PM
1002 	.suspend =	storage_suspend,
1003 	.resume =	storage_resume,
1004 #endif
1005 	.id_table =	storage_usb_ids,
1006 };
1007 
1008 static int __init usb_stor_init(void)
1009 {
1010 	int retval;
1011 	printk(KERN_INFO "Initializing USB Mass Storage driver...\n");
1012 
1013 	/* register the driver, return usb_register return code if error */
1014 	retval = usb_register(&usb_storage_driver);
1015 	if (retval == 0) {
1016 		printk(KERN_INFO "USB Mass Storage support registered.\n");
1017 		usb_usual_set_present(USB_US_TYPE_STOR);
1018 	}
1019 	return retval;
1020 }
1021 
1022 static void __exit usb_stor_exit(void)
1023 {
1024 	US_DEBUGP("usb_stor_exit() called\n");
1025 
1026 	/* Deregister the driver
1027 	 * This will cause disconnect() to be called for each
1028 	 * attached unit
1029 	 */
1030 	US_DEBUGP("-- calling usb_deregister()\n");
1031 	usb_deregister(&usb_storage_driver) ;
1032 
1033 	/* Don't return until all of our control and scanning threads
1034 	 * have exited.  Since each thread signals threads_gone as its
1035 	 * last act, we have to call wait_for_completion the right number
1036 	 * of times.
1037 	 */
1038 	while (atomic_read(&total_threads) > 0) {
1039 		wait_for_completion(&threads_gone);
1040 		atomic_dec(&total_threads);
1041 	}
1042 
1043 	usb_usual_clear_present(USB_US_TYPE_STOR);
1044 }
1045 
1046 module_init(usb_stor_init);
1047 module_exit(usb_stor_exit);
1048