drivers/usb/gadget/storage_common.c

   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 /*-------------------------------------------------------------------------*/