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