1 /*
2  * storage_common.c -- Common definitions for mass storage functionality
3  *
4  * Copyright (C) 2003-2008 Alan Stern
5  * Copyeight (C) 2009 Samsung Electronics
6  * Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
7  *
8  * Ported to u-boot:
9  * Andrzej Pietrasiewicz <andrzej.p@samsung.com>
10  *
11  * Code refactoring & cleanup:
12  * Łukasz Majewski <l.majewski@samsung.com>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24  * You should have received a copy of the GNU General Public License
25  * along with this program; if not, write to the Free Software
26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
27  */
28 
29 
30 /*
31  * This file requires the following identifiers used in USB strings to
32  * be defined (each of type pointer to char):
33  *  - fsg_string_manufacturer -- name of the manufacturer
34  *  - fsg_string_product      -- name of the product
35  *  - fsg_string_serial       -- product's serial
36  *  - fsg_string_config       -- name of the configuration
37  *  - fsg_string_interface    -- name of the interface
38  * The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
39  * macro is defined prior to including this file.
40  */
41 
42 /*
43  * When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
44  * fsg_hs_intr_in_desc objects as well as
45  * FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
46  * macros are not defined.
47  *
48  * When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
49  * FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
50  * defined (as well as corresponding entries in string tables are
51  * missing) and FSG_STRING_INTERFACE has value of zero.
52  *
53  * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
54  */
55 
56 /*
57  * When FSG_BUFFHD_STATIC_BUFFER is defined when this file is included
58  * the fsg_buffhd structure's buf field will be an array of FSG_BUFLEN
59  * characters rather then a pointer to void.
60  */
61 
62 
63 /* #include <asm/unaligned.h> */
64 
65 
66 /*
67  * Thanks to NetChip Technologies for donating this product ID.
68  *
69  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
70  * Instead:  allocate your own, using normal USB-IF procedures.
71  */
72 #define FSG_VENDOR_ID	0x0525	/* NetChip */
73 #define FSG_PRODUCT_ID	0xa4a5	/* Linux-USB File-backed Storage Gadget */
74 
75 /*-------------------------------------------------------------------------*/
76 
77 #ifndef DEBUG
78 #undef VERBOSE_DEBUG
79 #undef DUMP_MSGS
80 #endif /* !DEBUG */
81 
82 #ifdef VERBOSE_DEBUG
83 #define VLDBG	LDBG
84 #else
85 #define VLDBG(lun, fmt, args...) do { } while (0)
86 #endif /* VERBOSE_DEBUG */
87 
88 /*
89 #define LDBG(lun, fmt, args...)   dev_dbg (&(lun)->dev, fmt, ## args)
90 #define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
91 #define LWARN(lun, fmt, args...)  dev_warn(&(lun)->dev, fmt, ## args)
92 #define LINFO(lun, fmt, args...)  dev_info(&(lun)->dev, fmt, ## args)
93 */
94 
95 #define LDBG(lun, fmt, args...) do { } while (0)
96 #define LERROR(lun, fmt, args...) do { } while (0)
97 #define LWARN(lun, fmt, args...) do { } while (0)
98 #define LINFO(lun, fmt, args...) do { } while (0)
99 
100 /*
101  * Keep those macros in sync with those in
102  * include/linux/usb/composite.h or else GCC will complain.  If they
103  * are identical (the same names of arguments, white spaces in the
104  * same places) GCC will allow redefinition otherwise (even if some
105  * white space is removed or added) warning will be issued.
106  *
107  * Those macros are needed here because File Storage Gadget does not
108  * include the composite.h header.  For composite gadgets those macros
109  * are redundant since composite.h is included any way.
110  *
111  * One could check whether those macros are already defined (which
112  * would indicate composite.h had been included) or not (which would
113  * indicate we were in FSG) but this is not done because a warning is
114  * desired if definitions here differ from the ones in composite.h.
115  *
116  * We want the definitions to match and be the same in File Storage
117  * Gadget as well as Mass Storage Function (and so composite gadgets
118  * using MSF).  If someone changes them in composite.h it will produce
119  * a warning in this file when building MSF.
120  */
121 
122 #define DBG(d, fmt, args...)     debug(fmt , ## args)
123 #define VDBG(d, fmt, args...)    debug(fmt , ## args)
124 /* #define ERROR(d, fmt, args...)   printf(fmt , ## args) */
125 /* #define WARNING(d, fmt, args...) printf(fmt , ## args) */
126 /* #define INFO(d, fmt, args...)    printf(fmt , ## args) */
127 
128 /* #define DBG(d, fmt, args...)     do { } while (0) */
129 /* #define VDBG(d, fmt, args...)    do { } while (0) */
130 #define ERROR(d, fmt, args...)   do { } while (0)
131 #define WARNING(d, fmt, args...) do { } while (0)
132 #define INFO(d, fmt, args...)    do { } while (0)
133 
134 #ifdef DUMP_MSGS
135 
136 /* dump_msg(fsg, const char * label, const u8 * buf, unsigned length); */
137 # define dump_msg(fsg, label, buf, length) do {                         \
138 	if (length < 512) {						\
139 		DBG(fsg, "%s, length %u:\n", label, length);		\
140 		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,	\
141 			       16, 1, buf, length, 0);			\
142 	}								\
143 } while (0)
144 
145 #  define dump_cdb(fsg) do { } while (0)
146 
147 #else
148 
149 #  define dump_msg(fsg, /* const char * */ label, \
150 		   /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
151 
152 #  ifdef VERBOSE_DEBUG
153 
154 #    define dump_cdb(fsg)						\
155 	print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,	\
156 		       16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)		\
157 
158 #  else
159 
160 #    define dump_cdb(fsg) do { } while (0)
161 
162 #  endif /* VERBOSE_DEBUG */
163 
164 #endif /* DUMP_MSGS */
165 
166 /*-------------------------------------------------------------------------*/
167 
168 /* SCSI device types */
169 #define TYPE_DISK	0x00
170 #define TYPE_CDROM	0x05
171 
172 /* USB protocol value = the transport method */
173 #define USB_PR_CBI	0x00		/* Control/Bulk/Interrupt */
174 #define USB_PR_CB	0x01		/* Control/Bulk w/o interrupt */
175 #define USB_PR_BULK	0x50		/* Bulk-only */
176 
177 /* USB subclass value = the protocol encapsulation */
178 #define USB_SC_RBC	0x01		/* Reduced Block Commands (flash) */
179 #define USB_SC_8020	0x02		/* SFF-8020i, MMC-2, ATAPI (CD-ROM) */
180 #define USB_SC_QIC	0x03		/* QIC-157 (tape) */
181 #define USB_SC_UFI	0x04		/* UFI (floppy) */
182 #define USB_SC_8070	0x05		/* SFF-8070i (removable) */
183 #define USB_SC_SCSI	0x06		/* Transparent SCSI */
184 
185 /* Bulk-only data structures */
186 
187 /* Command Block Wrapper */
188 struct fsg_bulk_cb_wrap {
189 	__le32	Signature;		/* Contains 'USBC' */
190 	u32	Tag;			/* Unique per command id */
191 	__le32	DataTransferLength;	/* Size of the data */
192 	u8	Flags;			/* Direction in bit 7 */
193 	u8	Lun;			/* LUN (normally 0) */
194 	u8	Length;			/* Of the CDB, <= MAX_COMMAND_SIZE */
195 	u8	CDB[16];		/* Command Data Block */
196 };
197 
198 #define USB_BULK_CB_WRAP_LEN	31
199 #define USB_BULK_CB_SIG		0x43425355	/* Spells out USBC */
200 #define USB_BULK_IN_FLAG	0x80
201 
202 /* Command Status Wrapper */
203 struct bulk_cs_wrap {
204 	__le32	Signature;		/* Should = 'USBS' */
205 	u32	Tag;			/* Same as original command */
206 	__le32	Residue;		/* Amount not transferred */
207 	u8	Status;			/* See below */
208 };
209 
210 #define USB_BULK_CS_WRAP_LEN	13
211 #define USB_BULK_CS_SIG		0x53425355	/* Spells out 'USBS' */
212 #define USB_STATUS_PASS		0
213 #define USB_STATUS_FAIL		1
214 #define USB_STATUS_PHASE_ERROR	2
215 
216 /* Bulk-only class specific requests */
217 #define USB_BULK_RESET_REQUEST		0xff
218 #define USB_BULK_GET_MAX_LUN_REQUEST	0xfe
219 
220 /* CBI Interrupt data structure */
221 struct interrupt_data {
222 	u8	bType;
223 	u8	bValue;
224 };
225 
226 #define CBI_INTERRUPT_DATA_LEN		2
227 
228 /* CBI Accept Device-Specific Command request */
229 #define USB_CBI_ADSC_REQUEST		0x00
230 
231 /* Length of a SCSI Command Data Block */
232 #define MAX_COMMAND_SIZE	16
233 
234 /* SCSI commands that we recognize */
235 #define SC_FORMAT_UNIT			0x04
236 #define SC_INQUIRY			0x12
237 #define SC_MODE_SELECT_6		0x15
238 #define SC_MODE_SELECT_10		0x55
239 #define SC_MODE_SENSE_6			0x1a
240 #define SC_MODE_SENSE_10		0x5a
241 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL	0x1e
242 #define SC_READ_6			0x08
243 #define SC_READ_10			0x28
244 #define SC_READ_12			0xa8
245 #define SC_READ_CAPACITY		0x25
246 #define SC_READ_FORMAT_CAPACITIES	0x23
247 #define SC_READ_HEADER			0x44
248 #define SC_READ_TOC			0x43
249 #define SC_RELEASE			0x17
250 #define SC_REQUEST_SENSE		0x03
251 #define SC_RESERVE			0x16
252 #define SC_SEND_DIAGNOSTIC		0x1d
253 #define SC_START_STOP_UNIT		0x1b
254 #define SC_SYNCHRONIZE_CACHE		0x35
255 #define SC_TEST_UNIT_READY		0x00
256 #define SC_VERIFY			0x2f
257 #define SC_WRITE_6			0x0a
258 #define SC_WRITE_10			0x2a
259 #define SC_WRITE_12			0xaa
260 
261 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
262 #define SS_NO_SENSE				0
263 #define SS_COMMUNICATION_FAILURE		0x040800
264 #define SS_INVALID_COMMAND			0x052000
265 #define SS_INVALID_FIELD_IN_CDB			0x052400
266 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE	0x052100
267 #define SS_LOGICAL_UNIT_NOT_SUPPORTED		0x052500
268 #define SS_MEDIUM_NOT_PRESENT			0x023a00
269 #define SS_MEDIUM_REMOVAL_PREVENTED		0x055302
270 #define SS_NOT_READY_TO_READY_TRANSITION	0x062800
271 #define SS_RESET_OCCURRED			0x062900
272 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED	0x053900
273 #define SS_UNRECOVERED_READ_ERROR		0x031100
274 #define SS_WRITE_ERROR				0x030c02
275 #define SS_WRITE_PROTECTED			0x072700
276 
277 #define SK(x)		((u8) ((x) >> 16))	/* Sense Key byte, etc. */
278 #define ASC(x)		((u8) ((x) >> 8))
279 #define ASCQ(x)		((u8) (x))
280 
281 struct device_attribute { int i; };
282 struct rw_semaphore { int i; };
283 #define down_write(...)			do { } while (0)
284 #define up_write(...)			do { } while (0)
285 #define down_read(...)			do { } while (0)
286 #define up_read(...)			do { } while (0)
287 #define ETOOSMALL	525
288 
289 #include <usb_mass_storage.h>
290 extern struct ums_board_info		*ums_info;
291 
292 /*-------------------------------------------------------------------------*/
293 
294 struct fsg_lun {
295 	loff_t		file_length;
296 	loff_t		num_sectors;
297 
298 	unsigned int	initially_ro:1;
299 	unsigned int	ro:1;
300 	unsigned int	removable:1;
301 	unsigned int	cdrom:1;
302 	unsigned int	prevent_medium_removal:1;
303 	unsigned int	registered:1;
304 	unsigned int	info_valid:1;
305 	unsigned int	nofua:1;
306 
307 	u32		sense_data;
308 	u32		sense_data_info;
309 	u32		unit_attention_data;
310 
311 	struct device	dev;
312 };
313 
314 #define fsg_lun_is_open(curlun)	((curlun)->filp != NULL)
315 #if 0
316 static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
317 {
318 	return container_of(dev, struct fsg_lun, dev);
319 }
320 #endif
321 
322 /* Big enough to hold our biggest descriptor */
323 #define EP0_BUFSIZE	256
324 #define DELAYED_STATUS	(EP0_BUFSIZE + 999)	/* An impossibly large value */
325 
326 /* Number of buffers we will use.  2 is enough for double-buffering */
327 #define FSG_NUM_BUFFERS	2
328 
329 /* Default size of buffer length. */
330 #define FSG_BUFLEN	((u32)16384)
331 
332 /* Maximal number of LUNs supported in mass storage function */
333 #define FSG_MAX_LUNS	8
334 
335 enum fsg_buffer_state {
336 	BUF_STATE_EMPTY = 0,
337 	BUF_STATE_FULL,
338 	BUF_STATE_BUSY
339 };
340 
341 struct fsg_buffhd {
342 #ifdef FSG_BUFFHD_STATIC_BUFFER
343 	char				buf[FSG_BUFLEN];
344 #else
345 	void				*buf;
346 #endif
347 	enum fsg_buffer_state		state;
348 	struct fsg_buffhd		*next;
349 
350 	/*
351 	 * The NetChip 2280 is faster, and handles some protocol faults
352 	 * better, if we don't submit any short bulk-out read requests.
353 	 * So we will record the intended request length here.
354 	 */
355 	unsigned int			bulk_out_intended_length;
356 
357 	struct usb_request		*inreq;
358 	int				inreq_busy;
359 	struct usb_request		*outreq;
360 	int				outreq_busy;
361 };
362 
363 enum fsg_state {
364 	/* This one isn't used anywhere */
365 	FSG_STATE_COMMAND_PHASE = -10,
366 	FSG_STATE_DATA_PHASE,
367 	FSG_STATE_STATUS_PHASE,
368 
369 	FSG_STATE_IDLE = 0,
370 	FSG_STATE_ABORT_BULK_OUT,
371 	FSG_STATE_RESET,
372 	FSG_STATE_INTERFACE_CHANGE,
373 	FSG_STATE_CONFIG_CHANGE,
374 	FSG_STATE_DISCONNECT,
375 	FSG_STATE_EXIT,
376 	FSG_STATE_TERMINATED
377 };
378 
379 enum data_direction {
380 	DATA_DIR_UNKNOWN = 0,
381 	DATA_DIR_FROM_HOST,
382 	DATA_DIR_TO_HOST,
383 	DATA_DIR_NONE
384 };
385 
386 /*-------------------------------------------------------------------------*/
387 
388 static inline u32 get_unaligned_be24(u8 *buf)
389 {
390 	return 0xffffff & (u32) get_unaligned_be32(buf - 1);
391 }
392 
393 /*-------------------------------------------------------------------------*/
394 
395 enum {
396 #ifndef FSG_NO_DEVICE_STRINGS
397 	FSG_STRING_MANUFACTURER	= 1,
398 	FSG_STRING_PRODUCT,
399 	FSG_STRING_SERIAL,
400 	FSG_STRING_CONFIG,
401 #endif
402 	FSG_STRING_INTERFACE
403 };
404 
405 #ifndef FSG_NO_OTG
406 static struct usb_otg_descriptor
407 fsg_otg_desc = {
408 	.bLength =		sizeof fsg_otg_desc,
409 	.bDescriptorType =	USB_DT_OTG,
410 
411 	.bmAttributes =		USB_OTG_SRP,
412 };
413 #endif
414 
415 /* There is only one interface. */
416 
417 static struct usb_interface_descriptor
418 fsg_intf_desc = {
419 	.bLength =		sizeof fsg_intf_desc,
420 	.bDescriptorType =	USB_DT_INTERFACE,
421 
422 	.bNumEndpoints =	2,		/* Adjusted during fsg_bind() */
423 	.bInterfaceClass =	USB_CLASS_MASS_STORAGE,
424 	.bInterfaceSubClass =	USB_SC_SCSI,	/* Adjusted during fsg_bind() */
425 	.bInterfaceProtocol =	USB_PR_BULK,	/* Adjusted during fsg_bind() */
426 	.iInterface =		FSG_STRING_INTERFACE,
427 };
428 
429 /*
430  * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
431  * interrupt-in.
432  */
433 
434 static struct usb_endpoint_descriptor
435 fsg_fs_bulk_in_desc = {
436 	.bLength =		USB_DT_ENDPOINT_SIZE,
437 	.bDescriptorType =	USB_DT_ENDPOINT,
438 
439 	.bEndpointAddress =	USB_DIR_IN,
440 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
441 	/* wMaxPacketSize set by autoconfiguration */
442 };
443 
444 static struct usb_endpoint_descriptor
445 fsg_fs_bulk_out_desc = {
446 	.bLength =		USB_DT_ENDPOINT_SIZE,
447 	.bDescriptorType =	USB_DT_ENDPOINT,
448 
449 	.bEndpointAddress =	USB_DIR_OUT,
450 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
451 	/* wMaxPacketSize set by autoconfiguration */
452 };
453 
454 #ifndef FSG_NO_INTR_EP
455 
456 static struct usb_endpoint_descriptor
457 fsg_fs_intr_in_desc = {
458 	.bLength =		USB_DT_ENDPOINT_SIZE,
459 	.bDescriptorType =	USB_DT_ENDPOINT,
460 
461 	.bEndpointAddress =	USB_DIR_IN,
462 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
463 	.wMaxPacketSize =	cpu_to_le16(2),
464 	.bInterval =		32,	/* frames -> 32 ms */
465 };
466 
467 #ifndef FSG_NO_OTG
468 #  define FSG_FS_FUNCTION_PRE_EP_ENTRIES	2
469 #else
470 #  define FSG_FS_FUNCTION_PRE_EP_ENTRIES	1
471 #endif
472 
473 #endif
474 
475 static struct usb_descriptor_header *fsg_fs_function[] = {
476 #ifndef FSG_NO_OTG
477 	(struct usb_descriptor_header *) &fsg_otg_desc,
478 #endif
479 	(struct usb_descriptor_header *) &fsg_intf_desc,
480 	(struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
481 	(struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
482 #ifndef FSG_NO_INTR_EP
483 	(struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
484 #endif
485 	NULL,
486 };
487 
488 /*
489  * USB 2.0 devices need to expose both high speed and full speed
490  * descriptors, unless they only run at full speed.
491  *
492  * That means alternate endpoint descriptors (bigger packets)
493  * and a "device qualifier" ... plus more construction options
494  * for the configuration descriptor.
495  */
496 static struct usb_endpoint_descriptor
497 fsg_hs_bulk_in_desc = {
498 	.bLength =		USB_DT_ENDPOINT_SIZE,
499 	.bDescriptorType =	USB_DT_ENDPOINT,
500 
501 	/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
502 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
503 	.wMaxPacketSize =	cpu_to_le16(512),
504 };
505 
506 static struct usb_endpoint_descriptor
507 fsg_hs_bulk_out_desc = {
508 	.bLength =		USB_DT_ENDPOINT_SIZE,
509 	.bDescriptorType =	USB_DT_ENDPOINT,
510 
511 	/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
512 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
513 	.wMaxPacketSize =	cpu_to_le16(512),
514 	.bInterval =		1,	/* NAK every 1 uframe */
515 };
516 
517 #ifndef FSG_NO_INTR_EP
518 
519 static struct usb_endpoint_descriptor
520 fsg_hs_intr_in_desc = {
521 	.bLength =		USB_DT_ENDPOINT_SIZE,
522 	.bDescriptorType =	USB_DT_ENDPOINT,
523 
524 	/* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
525 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
526 	.wMaxPacketSize =	cpu_to_le16(2),
527 	.bInterval =		9,	/* 2**(9-1) = 256 uframes -> 32 ms */
528 };
529 
530 #ifndef FSG_NO_OTG
531 #  define FSG_HS_FUNCTION_PRE_EP_ENTRIES	2
532 #else
533 #  define FSG_HS_FUNCTION_PRE_EP_ENTRIES	1
534 #endif
535 
536 #endif
537 
538 static struct usb_descriptor_header *fsg_hs_function[] = {
539 #ifndef FSG_NO_OTG
540 	(struct usb_descriptor_header *) &fsg_otg_desc,
541 #endif
542 	(struct usb_descriptor_header *) &fsg_intf_desc,
543 	(struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
544 	(struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
545 #ifndef FSG_NO_INTR_EP
546 	(struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
547 #endif
548 	NULL,
549 };
550 
551 /* Maxpacket and other transfer characteristics vary by speed. */
552 static struct usb_endpoint_descriptor *
553 fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
554 		struct usb_endpoint_descriptor *hs)
555 {
556 	if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
557 		return hs;
558 	return fs;
559 }
560 
561 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
562 static struct usb_string		fsg_strings[] = {
563 #ifndef FSG_NO_DEVICE_STRINGS
564 	{FSG_STRING_MANUFACTURER,	fsg_string_manufacturer},
565 	{FSG_STRING_PRODUCT,		fsg_string_product},
566 	{FSG_STRING_SERIAL,		fsg_string_serial},
567 	{FSG_STRING_CONFIG,		fsg_string_config},
568 #endif
569 	{FSG_STRING_INTERFACE,		fsg_string_interface},
570 	{}
571 };
572 
573 static struct usb_gadget_strings	fsg_stringtab = {
574 	.language	= 0x0409,		/* en-us */
575 	.strings	= fsg_strings,
576 };
577 
578 /*-------------------------------------------------------------------------*/
579 
580 /*
581  * If the next two routines are called while the gadget is registered,
582  * the caller must own fsg->filesem for writing.
583  */
584 
585 static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
586 {
587 	int				ro;
588 	int				rc = -EINVAL;
589 	loff_t				size;
590 	loff_t				num_sectors;
591 	loff_t				min_sectors;
592 
593 	/* R/W if we can, R/O if we must */
594 	ro = curlun->initially_ro;
595 
596 	ums_info->get_capacity(&(ums_info->ums_dev), &size);
597 	if (size < 0) {
598 		printf("unable to find file size: %s\n", filename);
599 		rc = (int) size;
600 		goto out;
601 	}
602 	num_sectors = size >> 9;	/* File size in 512-byte blocks */
603 	min_sectors = 1;
604 	if (num_sectors < min_sectors) {
605 		printf("file too small: %s\n", filename);
606 		rc = -ETOOSMALL;
607 		goto out;
608 	}
609 
610 	curlun->ro = ro;
611 	curlun->file_length = size;
612 	curlun->num_sectors = num_sectors;
613 	debug("open backing file: %s\n", filename);
614 	rc = 0;
615 
616 out:
617 	return rc;
618 }
619 
620 static void fsg_lun_close(struct fsg_lun *curlun)
621 {
622 }
623 
624 /*-------------------------------------------------------------------------*/
625 
626 /*
627  * Sync the file data, don't bother with the metadata.
628  * This code was copied from fs/buffer.c:sys_fdatasync().
629  */
630 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
631 {
632 	return 0;
633 }
634 
635 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
636 {
637 	if (msf) {
638 		/* Convert to Minutes-Seconds-Frames */
639 		addr >>= 2;		/* Convert to 2048-byte frames */
640 		addr += 2*75;		/* Lead-in occupies 2 seconds */
641 		dest[3] = addr % 75;	/* Frames */
642 		addr /= 75;
643 		dest[2] = addr % 60;	/* Seconds */
644 		addr /= 60;
645 		dest[1] = addr;		/* Minutes */
646 		dest[0] = 0;		/* Reserved */
647 	} else {
648 		/* Absolute sector */
649 		put_unaligned_be32(addr, dest);
650 	}
651 }
652 
653 /*-------------------------------------------------------------------------*/
654