1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * storage_common.c -- Common definitions for mass storage functionality
4 *
5 * Copyright (C) 2003-2008 Alan Stern
6 * Copyeight (C) 2009 Samsung Electronics
7 * Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
8 *
9 * Ported to u-boot:
10 * Andrzej Pietrasiewicz <andrzej.p@samsung.com>
11 *
12 * Code refactoring & cleanup:
13 * Łukasz Majewski <l.majewski@samsung.com>
14 */
15
16 /*
17 * This file requires the following identifiers used in USB strings to
18 * be defined (each of type pointer to char):
19 * - fsg_string_manufacturer -- name of the manufacturer
20 * - fsg_string_product -- name of the product
21 * - fsg_string_serial -- product's serial
22 * - fsg_string_config -- name of the configuration
23 * - fsg_string_interface -- name of the interface
24 * The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
25 * macro is defined prior to including this file.
26 */
27
28 /*
29 * When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
30 * fsg_hs_intr_in_desc objects as well as
31 * FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
32 * macros are not defined.
33 *
34 * When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
35 * FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
36 * defined (as well as corresponding entries in string tables are
37 * missing) and FSG_STRING_INTERFACE has value of zero.
38 *
39 * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
40 */
41
42 /*
43 * When FSG_BUFFHD_STATIC_BUFFER is defined when this file is included
44 * the fsg_buffhd structure's buf field will be an array of FSG_BUFLEN
45 * characters rather then a pointer to void.
46 */
47
48 /* #include <asm/unaligned.h> */
49
50 /*
51 * Thanks to NetChip Technologies for donating this product ID.
52 *
53 * DO NOT REUSE THESE IDs with any other driver!! Ever!!
54 * Instead: allocate your own, using normal USB-IF procedures.
55 */
56 #define FSG_VENDOR_ID 0x0525 /* NetChip */
57 #define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */
58
59 /*-------------------------------------------------------------------------*/
60
61 #ifndef DEBUG
62 #undef VERBOSE_DEBUG
63 #undef DUMP_MSGS
64 #endif /* !DEBUG */
65
66 #ifdef VERBOSE_DEBUG
67 #define VLDBG LDBG
68 #else
69 #define VLDBG(lun, fmt, args...) do { } while (0)
70 #endif /* VERBOSE_DEBUG */
71
72 /*
73 #define LDBG(lun, fmt, args...) dev_dbg (&(lun)->dev, fmt, ## args)
74 #define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
75 #define LWARN(lun, fmt, args...) dev_warn(&(lun)->dev, fmt, ## args)
76 #define LINFO(lun, fmt, args...) dev_info(&(lun)->dev, fmt, ## args)
77 */
78
79 #define LDBG(lun, fmt, args...) do { } while (0)
80 #define LERROR(lun, fmt, args...) do { } while (0)
81 #define LWARN(lun, fmt, args...) do { } while (0)
82 #define LINFO(lun, fmt, args...) do { } while (0)
83
84 /*
85 * Keep those macros in sync with those in
86 * include/linux/usb/composite.h or else GCC will complain. If they
87 * are identical (the same names of arguments, white spaces in the
88 * same places) GCC will allow redefinition otherwise (even if some
89 * white space is removed or added) warning will be issued.
90 *
91 * Those macros are needed here because File Storage Gadget does not
92 * include the composite.h header. For composite gadgets those macros
93 * are redundant since composite.h is included any way.
94 *
95 * One could check whether those macros are already defined (which
96 * would indicate composite.h had been included) or not (which would
97 * indicate we were in FSG) but this is not done because a warning is
98 * desired if definitions here differ from the ones in composite.h.
99 *
100 * We want the definitions to match and be the same in File Storage
101 * Gadget as well as Mass Storage Function (and so composite gadgets
102 * using MSF). If someone changes them in composite.h it will produce
103 * a warning in this file when building MSF.
104 */
105
106 #define DBG(d, fmt, args...) debug(fmt , ## args)
107 #define VDBG(d, fmt, args...) debug(fmt , ## args)
108 /* #define ERROR(d, fmt, args...) printf(fmt , ## args) */
109 /* #define WARNING(d, fmt, args...) printf(fmt , ## args) */
110 /* #define INFO(d, fmt, args...) printf(fmt , ## args) */
111
112 /* #define DBG(d, fmt, args...) do { } while (0) */
113 /* #define VDBG(d, fmt, args...) do { } while (0) */
114 #define ERROR(d, fmt, args...) do { } while (0)
115 #define WARNING(d, fmt, args...) do { } while (0)
116 #define INFO(d, fmt, args...) do { } while (0)
117
118 #ifdef DUMP_MSGS
119
120 /* dump_msg(fsg, const char * label, const u8 * buf, unsigned length); */
121 # define dump_msg(fsg, label, buf, length) do { \
122 if (length < 512) { \
123 DBG(fsg, "%s, length %u:\n", label, length); \
124 print_hex_dump("", DUMP_PREFIX_OFFSET, \
125 16, 1, buf, length, 0); \
126 } \
127 } while (0)
128
129 # define dump_cdb(fsg) do { } while (0)
130
131 #else
132
133 # define dump_msg(fsg, /* const char * */ label, \
134 /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
135
136 # ifdef VERBOSE_DEBUG
137
138 # define dump_cdb(fsg) \
139 print_hex_dump("SCSI CDB: ", DUMP_PREFIX_NONE, \
140 16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0) \
141
142 # else
143
144 # define dump_cdb(fsg) do { } while (0)
145
146 # endif /* VERBOSE_DEBUG */
147
148 #endif /* DUMP_MSGS */
149
150 /*-------------------------------------------------------------------------*/
151
152 /* SCSI device types */
153 #define TYPE_DISK 0x00
154 #define TYPE_CDROM 0x05
155
156 /* USB protocol value = the transport method */
157 #define USB_PR_CBI 0x00 /* Control/Bulk/Interrupt */
158 #define USB_PR_CB 0x01 /* Control/Bulk w/o interrupt */
159 #define USB_PR_BULK 0x50 /* Bulk-only */
160
161 /* USB subclass value = the protocol encapsulation */
162 #define USB_SC_RBC 0x01 /* Reduced Block Commands (flash) */
163 #define USB_SC_8020 0x02 /* SFF-8020i, MMC-2, ATAPI (CD-ROM) */
164 #define USB_SC_QIC 0x03 /* QIC-157 (tape) */
165 #define USB_SC_UFI 0x04 /* UFI (floppy) */
166 #define USB_SC_8070 0x05 /* SFF-8070i (removable) */
167 #define USB_SC_SCSI 0x06 /* Transparent SCSI */
168
169 /* Bulk-only data structures */
170
171 /* Command Block Wrapper */
172 struct fsg_bulk_cb_wrap {
173 __le32 Signature; /* Contains 'USBC' */
174 u32 Tag; /* Unique per command id */
175 __le32 DataTransferLength; /* Size of the data */
176 u8 Flags; /* Direction in bit 7 */
177 u8 Lun; /* LUN (normally 0) */
178 u8 Length; /* Of the CDB, <= MAX_COMMAND_SIZE */
179 u8 CDB[16]; /* Command Data Block */
180 };
181
182 #define USB_BULK_CB_WRAP_LEN 31
183 #define USB_BULK_CB_SIG 0x43425355 /* Spells out USBC */
184 #define USB_BULK_IN_FLAG 0x80
185
186 /* Command Status Wrapper */
187 struct bulk_cs_wrap {
188 __le32 Signature; /* Should = 'USBS' */
189 u32 Tag; /* Same as original command */
190 __le32 Residue; /* Amount not transferred */
191 u8 Status; /* See below */
192 };
193
194 #define USB_BULK_CS_WRAP_LEN 13
195 #define USB_BULK_CS_SIG 0x53425355 /* Spells out 'USBS' */
196 #define USB_STATUS_PASS 0
197 #define USB_STATUS_FAIL 1
198 #define USB_STATUS_PHASE_ERROR 2
199
200 /* Bulk-only class specific requests */
201 #define USB_BULK_RESET_REQUEST 0xff
202 #define USB_BULK_GET_MAX_LUN_REQUEST 0xfe
203
204 /* CBI Interrupt data structure */
205 struct interrupt_data {
206 u8 bType;
207 u8 bValue;
208 };
209
210 #define CBI_INTERRUPT_DATA_LEN 2
211
212 /* CBI Accept Device-Specific Command request */
213 #define USB_CBI_ADSC_REQUEST 0x00
214
215 /* Length of a SCSI Command Data Block */
216 #define MAX_COMMAND_SIZE 16
217
218 /* SCSI commands that we recognize */
219 #define SC_FORMAT_UNIT 0x04
220 #define SC_INQUIRY 0x12
221 #define SC_MODE_SELECT_6 0x15
222 #define SC_MODE_SELECT_10 0x55
223 #define SC_MODE_SENSE_6 0x1a
224 #define SC_MODE_SENSE_10 0x5a
225 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
226 #define SC_READ_6 0x08
227 #define SC_READ_10 0x28
228 #define SC_READ_12 0xa8
229 #define SC_READ_CAPACITY 0x25
230 #define SC_READ_FORMAT_CAPACITIES 0x23
231 #define SC_READ_HEADER 0x44
232 #define SC_READ_TOC 0x43
233 #define SC_RELEASE 0x17
234 #define SC_REQUEST_SENSE 0x03
235 #define SC_RESERVE 0x16
236 #define SC_SEND_DIAGNOSTIC 0x1d
237 #define SC_START_STOP_UNIT 0x1b
238 #define SC_SYNCHRONIZE_CACHE 0x35
239 #define SC_TEST_UNIT_READY 0x00
240 #define SC_VERIFY 0x2f
241 #define SC_WRITE_6 0x0a
242 #define SC_WRITE_10 0x2a
243 #define SC_WRITE_12 0xaa
244
245 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
246 #define SS_NO_SENSE 0
247 #define SS_COMMUNICATION_FAILURE 0x040800
248 #define SS_INVALID_COMMAND 0x052000
249 #define SS_INVALID_FIELD_IN_CDB 0x052400
250 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE 0x052100
251 #define SS_LOGICAL_UNIT_NOT_SUPPORTED 0x052500
252 #define SS_MEDIUM_NOT_PRESENT 0x023a00
253 #define SS_MEDIUM_REMOVAL_PREVENTED 0x055302
254 #define SS_NOT_READY_TO_READY_TRANSITION 0x062800
255 #define SS_RESET_OCCURRED 0x062900
256 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED 0x053900
257 #define SS_UNRECOVERED_READ_ERROR 0x031100
258 #define SS_WRITE_ERROR 0x030c02
259 #define SS_WRITE_PROTECTED 0x072700
260
261 #define SK(x) ((u8) ((x) >> 16)) /* Sense Key byte, etc. */
262 #define ASC(x) ((u8) ((x) >> 8))
263 #define ASCQ(x) ((u8) (x))
264
265 struct device_attribute { int i; };
266 #define ETOOSMALL 525
267
268 #include <log.h>
269 #include <linux/log2.h>
270 #include <usb_mass_storage.h>
271 #include <dm/device_compat.h>
272
273 /*-------------------------------------------------------------------------*/
274
275 struct fsg_lun {
276 loff_t file_length;
277 loff_t num_sectors;
278
279 unsigned int initially_ro:1;
280 unsigned int ro:1;
281 unsigned int removable:1;
282 unsigned int cdrom:1;
283 unsigned int prevent_medium_removal:1;
284 unsigned int registered:1;
285 unsigned int info_valid:1;
286 unsigned int nofua:1;
287
288 u32 sense_data;
289 u32 sense_data_info;
290 u32 unit_attention_data;
291 unsigned int blkbits;
292 unsigned int blksize; /* logical block size of bound block device */
293
294 struct device dev;
295 };
296
297 #define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
298 #if 0
299 static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
300 {
301 return container_of(dev, struct fsg_lun, dev);
302 }
303 #endif
304
305 /* Big enough to hold our biggest descriptor */
306 #define EP0_BUFSIZE 256
307 #define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
308
309 /* Number of buffers we will use. 2 is enough for double-buffering */
310 #define FSG_NUM_BUFFERS 2
311
312 /* Default size of buffer length. */
313 #define FSG_BUFLEN ((u32)131072)
314
315 /* Maximal number of LUNs supported in mass storage function */
316 #define FSG_MAX_LUNS 8
317
318 enum fsg_buffer_state {
319 BUF_STATE_EMPTY = 0,
320 BUF_STATE_FULL,
321 BUF_STATE_BUSY
322 };
323
324 struct fsg_buffhd {
325 #ifdef FSG_BUFFHD_STATIC_BUFFER
326 char buf[FSG_BUFLEN];
327 #else
328 void *buf;
329 #endif
330 enum fsg_buffer_state state;
331 struct fsg_buffhd *next;
332
333 /*
334 * The NetChip 2280 is faster, and handles some protocol faults
335 * better, if we don't submit any short bulk-out read requests.
336 * So we will record the intended request length here.
337 */
338 unsigned int bulk_out_intended_length;
339
340 struct usb_request *inreq;
341 int inreq_busy;
342 struct usb_request *outreq;
343 int outreq_busy;
344 };
345
346 enum fsg_state {
347 /* This one isn't used anywhere */
348 FSG_STATE_COMMAND_PHASE = -10,
349 FSG_STATE_DATA_PHASE,
350 FSG_STATE_STATUS_PHASE,
351
352 FSG_STATE_IDLE = 0,
353 FSG_STATE_ABORT_BULK_OUT,
354 FSG_STATE_RESET,
355 FSG_STATE_INTERFACE_CHANGE,
356 FSG_STATE_CONFIG_CHANGE,
357 FSG_STATE_DISCONNECT,
358 FSG_STATE_EXIT,
359 FSG_STATE_TERMINATED
360 };
361
362 enum data_direction {
363 DATA_DIR_UNKNOWN = 0,
364 DATA_DIR_FROM_HOST,
365 DATA_DIR_TO_HOST,
366 DATA_DIR_NONE
367 };
368
369 /*-------------------------------------------------------------------------*/
370
get_unaligned_be24(u8 * buf)371 static inline u32 get_unaligned_be24(u8 *buf)
372 {
373 return 0xffffff & (u32) get_unaligned_be32(buf - 1);
374 }
375
376 /*-------------------------------------------------------------------------*/
377
378 enum {
379 #ifndef FSG_NO_DEVICE_STRINGS
380 FSG_STRING_MANUFACTURER = 1,
381 FSG_STRING_PRODUCT,
382 FSG_STRING_SERIAL,
383 FSG_STRING_CONFIG,
384 #endif
385 FSG_STRING_INTERFACE
386 };
387
388 #ifndef FSG_NO_OTG
389 static struct usb_otg_descriptor
390 fsg_otg_desc = {
391 .bLength = sizeof fsg_otg_desc,
392 .bDescriptorType = USB_DT_OTG,
393
394 .bmAttributes = USB_OTG_SRP,
395 };
396 #endif
397
398 /* There is only one interface. */
399
400 static struct usb_interface_descriptor
401 fsg_intf_desc = {
402 .bLength = sizeof fsg_intf_desc,
403 .bDescriptorType = USB_DT_INTERFACE,
404
405 .bNumEndpoints = 2, /* Adjusted during fsg_bind() */
406 .bInterfaceClass = USB_CLASS_MASS_STORAGE,
407 .bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
408 .bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
409 .iInterface = FSG_STRING_INTERFACE,
410 };
411
412 /*
413 * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
414 * interrupt-in.
415 */
416
417 static struct usb_endpoint_descriptor
418 fsg_fs_bulk_in_desc = {
419 .bLength = USB_DT_ENDPOINT_SIZE,
420 .bDescriptorType = USB_DT_ENDPOINT,
421
422 .bEndpointAddress = USB_DIR_IN,
423 .bmAttributes = USB_ENDPOINT_XFER_BULK,
424 /* wMaxPacketSize set by autoconfiguration */
425 };
426
427 static struct usb_endpoint_descriptor
428 fsg_fs_bulk_out_desc = {
429 .bLength = USB_DT_ENDPOINT_SIZE,
430 .bDescriptorType = USB_DT_ENDPOINT,
431
432 .bEndpointAddress = USB_DIR_OUT,
433 .bmAttributes = USB_ENDPOINT_XFER_BULK,
434 /* wMaxPacketSize set by autoconfiguration */
435 };
436
437 #ifndef FSG_NO_INTR_EP
438
439 static struct usb_endpoint_descriptor
440 fsg_fs_intr_in_desc = {
441 .bLength = USB_DT_ENDPOINT_SIZE,
442 .bDescriptorType = USB_DT_ENDPOINT,
443
444 .bEndpointAddress = USB_DIR_IN,
445 .bmAttributes = USB_ENDPOINT_XFER_INT,
446 .wMaxPacketSize = cpu_to_le16(2),
447 .bInterval = 32, /* frames -> 32 ms */
448 };
449
450 #ifndef FSG_NO_OTG
451 # define FSG_FS_FUNCTION_PRE_EP_ENTRIES 2
452 #else
453 # define FSG_FS_FUNCTION_PRE_EP_ENTRIES 1
454 #endif
455
456 #endif
457
458 static struct usb_descriptor_header *fsg_fs_function[] = {
459 #ifndef FSG_NO_OTG
460 (struct usb_descriptor_header *) &fsg_otg_desc,
461 #endif
462 (struct usb_descriptor_header *) &fsg_intf_desc,
463 (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
464 (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
465 #ifndef FSG_NO_INTR_EP
466 (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
467 #endif
468 NULL,
469 };
470
471 /*
472 * USB 2.0 devices need to expose both high speed and full speed
473 * descriptors, unless they only run at full speed.
474 *
475 * That means alternate endpoint descriptors (bigger packets)
476 * and a "device qualifier" ... plus more construction options
477 * for the configuration descriptor.
478 */
479 static struct usb_endpoint_descriptor
480 fsg_hs_bulk_in_desc = {
481 .bLength = USB_DT_ENDPOINT_SIZE,
482 .bDescriptorType = USB_DT_ENDPOINT,
483
484 /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
485 .bmAttributes = USB_ENDPOINT_XFER_BULK,
486 .wMaxPacketSize = cpu_to_le16(512),
487 };
488
489 static struct usb_endpoint_descriptor
490 fsg_hs_bulk_out_desc = {
491 .bLength = USB_DT_ENDPOINT_SIZE,
492 .bDescriptorType = USB_DT_ENDPOINT,
493
494 /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
495 .bmAttributes = USB_ENDPOINT_XFER_BULK,
496 .wMaxPacketSize = cpu_to_le16(512),
497 .bInterval = 1, /* NAK every 1 uframe */
498 };
499
500 #ifndef FSG_NO_INTR_EP
501
502 static struct usb_endpoint_descriptor
503 fsg_hs_intr_in_desc = {
504 .bLength = USB_DT_ENDPOINT_SIZE,
505 .bDescriptorType = USB_DT_ENDPOINT,
506
507 /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
508 .bmAttributes = USB_ENDPOINT_XFER_INT,
509 .wMaxPacketSize = cpu_to_le16(2),
510 .bInterval = 9, /* 2**(9-1) = 256 uframes -> 32 ms */
511 };
512
513 #ifndef FSG_NO_OTG
514 # define FSG_HS_FUNCTION_PRE_EP_ENTRIES 2
515 #else
516 # define FSG_HS_FUNCTION_PRE_EP_ENTRIES 1
517 #endif
518
519 #endif
520
521 static struct usb_descriptor_header *fsg_hs_function[] = {
522 #ifndef FSG_NO_OTG
523 (struct usb_descriptor_header *) &fsg_otg_desc,
524 #endif
525 (struct usb_descriptor_header *) &fsg_intf_desc,
526 (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
527 (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
528 #ifndef FSG_NO_INTR_EP
529 (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
530 #endif
531 NULL,
532 };
533
534 /* Maxpacket and other transfer characteristics vary by speed. */
535 static struct usb_endpoint_descriptor *
fsg_ep_desc(struct usb_gadget * g,struct usb_endpoint_descriptor * fs,struct usb_endpoint_descriptor * hs)536 fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
537 struct usb_endpoint_descriptor *hs)
538 {
539 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
540 return hs;
541 return fs;
542 }
543
544 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
545 static struct usb_string fsg_strings[] = {
546 #ifndef FSG_NO_DEVICE_STRINGS
547 {FSG_STRING_MANUFACTURER, fsg_string_manufacturer},
548 {FSG_STRING_PRODUCT, fsg_string_product},
549 {FSG_STRING_SERIAL, fsg_string_serial},
550 {FSG_STRING_CONFIG, fsg_string_config},
551 #endif
552 {FSG_STRING_INTERFACE, fsg_string_interface},
553 {}
554 };
555
556 static struct usb_gadget_strings fsg_stringtab = {
557 .language = 0x0409, /* en-us */
558 .strings = fsg_strings,
559 };
560
561 /*-------------------------------------------------------------------------*/
562
563 /*
564 * If the next two routines are called while the gadget is registered,
565 * the caller must own fsg->filesem for writing.
566 */
567
fsg_lun_open(struct fsg_lun * curlun,unsigned int num_sectors,unsigned int sector_size,const char * filename)568 static int fsg_lun_open(struct fsg_lun *curlun, unsigned int num_sectors,
569 unsigned int sector_size, const char *filename)
570 {
571 int ro;
572
573 /* R/W if we can, R/O if we must */
574 ro = curlun->initially_ro;
575
576 curlun->ro = ro;
577 curlun->file_length = num_sectors * sector_size;
578 curlun->num_sectors = num_sectors;
579 curlun->blksize = sector_size;
580 curlun->blkbits = order_base_2(sector_size >> 9) + 9;
581 debug("blksize: %u\n", sector_size);
582 debug("open backing file: '%s'\n", filename);
583
584 return 0;
585 }
586
fsg_lun_close(struct fsg_lun * curlun)587 static void fsg_lun_close(struct fsg_lun *curlun)
588 {
589 }
590
591 /*-------------------------------------------------------------------------*/
592
593 /*
594 * Sync the file data, don't bother with the metadata.
595 * This code was copied from fs/buffer.c:sys_fdatasync().
596 */
fsg_lun_fsync_sub(struct fsg_lun * curlun)597 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
598 {
599 return 0;
600 }
601
store_cdrom_address(u8 * dest,int msf,u32 addr)602 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
603 {
604 if (msf) {
605 /* Convert to Minutes-Seconds-Frames */
606 addr >>= 2; /* Convert to 2048-byte frames */
607 addr += 2*75; /* Lead-in occupies 2 seconds */
608 dest[3] = addr % 75; /* Frames */
609 addr /= 75;
610 dest[2] = addr % 60; /* Seconds */
611 addr /= 60;
612 dest[1] = addr; /* Minutes */
613 dest[0] = 0; /* Reserved */
614 } else {
615 /* Absolute sector */
616 put_unaligned_be32(addr, dest);
617 }
618 }
619
620 /*-------------------------------------------------------------------------*/
621