Linux 4.2.1
[linux/fpc-iii.git] / drivers / usb / gadget / function / storage_common.c
blobd62683017cf3c1c052f78eb243799e1ca46ca8d5
1 /*
2 * storage_common.c -- Common definitions for mass storage functionality
4 * Copyright (C) 2003-2008 Alan Stern
5 * Copyeight (C) 2009 Samsung Electronics
6 * Author: Michal Nazarewicz (mina86@mina86.com)
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
15 * This file requires the following identifiers used in USB strings to
16 * be defined (each of type pointer to char):
17 * - fsg_string_interface -- name of the interface
21 * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
22 * sets the number of pipeline buffers (length of the fsg_buffhd array).
23 * The valid range of num_buffers is: num >= 2 && num <= 4.
26 #include <linux/module.h>
27 #include <linux/blkdev.h>
28 #include <linux/file.h>
29 #include <linux/fs.h>
30 #include <linux/usb/composite.h>
32 #include "storage_common.h"
34 /* There is only one interface. */
36 struct usb_interface_descriptor fsg_intf_desc = {
37 .bLength = sizeof fsg_intf_desc,
38 .bDescriptorType = USB_DT_INTERFACE,
40 .bNumEndpoints = 2, /* Adjusted during fsg_bind() */
41 .bInterfaceClass = USB_CLASS_MASS_STORAGE,
42 .bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
43 .bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
44 .iInterface = FSG_STRING_INTERFACE,
46 EXPORT_SYMBOL_GPL(fsg_intf_desc);
49 * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
50 * interrupt-in.
53 struct usb_endpoint_descriptor fsg_fs_bulk_in_desc = {
54 .bLength = USB_DT_ENDPOINT_SIZE,
55 .bDescriptorType = USB_DT_ENDPOINT,
57 .bEndpointAddress = USB_DIR_IN,
58 .bmAttributes = USB_ENDPOINT_XFER_BULK,
59 /* wMaxPacketSize set by autoconfiguration */
61 EXPORT_SYMBOL_GPL(fsg_fs_bulk_in_desc);
63 struct usb_endpoint_descriptor fsg_fs_bulk_out_desc = {
64 .bLength = USB_DT_ENDPOINT_SIZE,
65 .bDescriptorType = USB_DT_ENDPOINT,
67 .bEndpointAddress = USB_DIR_OUT,
68 .bmAttributes = USB_ENDPOINT_XFER_BULK,
69 /* wMaxPacketSize set by autoconfiguration */
71 EXPORT_SYMBOL_GPL(fsg_fs_bulk_out_desc);
73 struct usb_descriptor_header *fsg_fs_function[] = {
74 (struct usb_descriptor_header *) &fsg_intf_desc,
75 (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
76 (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
77 NULL,
79 EXPORT_SYMBOL_GPL(fsg_fs_function);
83 * USB 2.0 devices need to expose both high speed and full speed
84 * descriptors, unless they only run at full speed.
86 * That means alternate endpoint descriptors (bigger packets)
87 * and a "device qualifier" ... plus more construction options
88 * for the configuration descriptor.
90 struct usb_endpoint_descriptor fsg_hs_bulk_in_desc = {
91 .bLength = USB_DT_ENDPOINT_SIZE,
92 .bDescriptorType = USB_DT_ENDPOINT,
94 /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
95 .bmAttributes = USB_ENDPOINT_XFER_BULK,
96 .wMaxPacketSize = cpu_to_le16(512),
98 EXPORT_SYMBOL_GPL(fsg_hs_bulk_in_desc);
100 struct usb_endpoint_descriptor fsg_hs_bulk_out_desc = {
101 .bLength = USB_DT_ENDPOINT_SIZE,
102 .bDescriptorType = USB_DT_ENDPOINT,
104 /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
105 .bmAttributes = USB_ENDPOINT_XFER_BULK,
106 .wMaxPacketSize = cpu_to_le16(512),
107 .bInterval = 1, /* NAK every 1 uframe */
109 EXPORT_SYMBOL_GPL(fsg_hs_bulk_out_desc);
112 struct usb_descriptor_header *fsg_hs_function[] = {
113 (struct usb_descriptor_header *) &fsg_intf_desc,
114 (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
115 (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
116 NULL,
118 EXPORT_SYMBOL_GPL(fsg_hs_function);
120 struct usb_endpoint_descriptor fsg_ss_bulk_in_desc = {
121 .bLength = USB_DT_ENDPOINT_SIZE,
122 .bDescriptorType = USB_DT_ENDPOINT,
124 /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
125 .bmAttributes = USB_ENDPOINT_XFER_BULK,
126 .wMaxPacketSize = cpu_to_le16(1024),
128 EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_desc);
130 struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
131 .bLength = sizeof(fsg_ss_bulk_in_comp_desc),
132 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
134 /*.bMaxBurst = DYNAMIC, */
136 EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_comp_desc);
138 struct usb_endpoint_descriptor fsg_ss_bulk_out_desc = {
139 .bLength = USB_DT_ENDPOINT_SIZE,
140 .bDescriptorType = USB_DT_ENDPOINT,
142 /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
143 .bmAttributes = USB_ENDPOINT_XFER_BULK,
144 .wMaxPacketSize = cpu_to_le16(1024),
146 EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_desc);
148 struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
149 .bLength = sizeof(fsg_ss_bulk_in_comp_desc),
150 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
152 /*.bMaxBurst = DYNAMIC, */
154 EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_comp_desc);
156 struct usb_descriptor_header *fsg_ss_function[] = {
157 (struct usb_descriptor_header *) &fsg_intf_desc,
158 (struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
159 (struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
160 (struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
161 (struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
162 NULL,
164 EXPORT_SYMBOL_GPL(fsg_ss_function);
167 /*-------------------------------------------------------------------------*/
170 * If the next two routines are called while the gadget is registered,
171 * the caller must own fsg->filesem for writing.
174 void fsg_lun_close(struct fsg_lun *curlun)
176 if (curlun->filp) {
177 LDBG(curlun, "close backing file\n");
178 fput(curlun->filp);
179 curlun->filp = NULL;
182 EXPORT_SYMBOL_GPL(fsg_lun_close);
184 int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
186 int ro;
187 struct file *filp = NULL;
188 int rc = -EINVAL;
189 struct inode *inode = NULL;
190 loff_t size;
191 loff_t num_sectors;
192 loff_t min_sectors;
193 unsigned int blkbits;
194 unsigned int blksize;
196 /* R/W if we can, R/O if we must */
197 ro = curlun->initially_ro;
198 if (!ro) {
199 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
200 if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
201 ro = 1;
203 if (ro)
204 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
205 if (IS_ERR(filp)) {
206 LINFO(curlun, "unable to open backing file: %s\n", filename);
207 return PTR_ERR(filp);
210 if (!(filp->f_mode & FMODE_WRITE))
211 ro = 1;
213 inode = file_inode(filp);
214 if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
215 LINFO(curlun, "invalid file type: %s\n", filename);
216 goto out;
220 * If we can't read the file, it's no good.
221 * If we can't write the file, use it read-only.
223 if (!(filp->f_mode & FMODE_CAN_READ)) {
224 LINFO(curlun, "file not readable: %s\n", filename);
225 goto out;
227 if (!(filp->f_mode & FMODE_CAN_WRITE))
228 ro = 1;
230 size = i_size_read(inode->i_mapping->host);
231 if (size < 0) {
232 LINFO(curlun, "unable to find file size: %s\n", filename);
233 rc = (int) size;
234 goto out;
237 if (curlun->cdrom) {
238 blksize = 2048;
239 blkbits = 11;
240 } else if (inode->i_bdev) {
241 blksize = bdev_logical_block_size(inode->i_bdev);
242 blkbits = blksize_bits(blksize);
243 } else {
244 blksize = 512;
245 blkbits = 9;
248 num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
249 min_sectors = 1;
250 if (curlun->cdrom) {
251 min_sectors = 300; /* Smallest track is 300 frames */
252 if (num_sectors >= 256*60*75) {
253 num_sectors = 256*60*75 - 1;
254 LINFO(curlun, "file too big: %s\n", filename);
255 LINFO(curlun, "using only first %d blocks\n",
256 (int) num_sectors);
259 if (num_sectors < min_sectors) {
260 LINFO(curlun, "file too small: %s\n", filename);
261 rc = -ETOOSMALL;
262 goto out;
265 if (fsg_lun_is_open(curlun))
266 fsg_lun_close(curlun);
268 curlun->blksize = blksize;
269 curlun->blkbits = blkbits;
270 curlun->ro = ro;
271 curlun->filp = filp;
272 curlun->file_length = size;
273 curlun->num_sectors = num_sectors;
274 LDBG(curlun, "open backing file: %s\n", filename);
275 return 0;
277 out:
278 fput(filp);
279 return rc;
281 EXPORT_SYMBOL_GPL(fsg_lun_open);
284 /*-------------------------------------------------------------------------*/
287 * Sync the file data, don't bother with the metadata.
288 * This code was copied from fs/buffer.c:sys_fdatasync().
290 int fsg_lun_fsync_sub(struct fsg_lun *curlun)
292 struct file *filp = curlun->filp;
294 if (curlun->ro || !filp)
295 return 0;
296 return vfs_fsync(filp, 1);
298 EXPORT_SYMBOL_GPL(fsg_lun_fsync_sub);
300 void store_cdrom_address(u8 *dest, int msf, u32 addr)
302 if (msf) {
303 /* Convert to Minutes-Seconds-Frames */
304 addr >>= 2; /* Convert to 2048-byte frames */
305 addr += 2*75; /* Lead-in occupies 2 seconds */
306 dest[3] = addr % 75; /* Frames */
307 addr /= 75;
308 dest[2] = addr % 60; /* Seconds */
309 addr /= 60;
310 dest[1] = addr; /* Minutes */
311 dest[0] = 0; /* Reserved */
312 } else {
313 /* Absolute sector */
314 put_unaligned_be32(addr, dest);
317 EXPORT_SYMBOL_GPL(store_cdrom_address);
319 /*-------------------------------------------------------------------------*/
322 ssize_t fsg_show_ro(struct fsg_lun *curlun, char *buf)
324 return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
325 ? curlun->ro
326 : curlun->initially_ro);
328 EXPORT_SYMBOL_GPL(fsg_show_ro);
330 ssize_t fsg_show_nofua(struct fsg_lun *curlun, char *buf)
332 return sprintf(buf, "%u\n", curlun->nofua);
334 EXPORT_SYMBOL_GPL(fsg_show_nofua);
336 ssize_t fsg_show_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
337 char *buf)
339 char *p;
340 ssize_t rc;
342 down_read(filesem);
343 if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
344 p = file_path(curlun->filp, buf, PAGE_SIZE - 1);
345 if (IS_ERR(p))
346 rc = PTR_ERR(p);
347 else {
348 rc = strlen(p);
349 memmove(buf, p, rc);
350 buf[rc] = '\n'; /* Add a newline */
351 buf[++rc] = 0;
353 } else { /* No file, return 0 bytes */
354 *buf = 0;
355 rc = 0;
357 up_read(filesem);
358 return rc;
360 EXPORT_SYMBOL_GPL(fsg_show_file);
362 ssize_t fsg_show_cdrom(struct fsg_lun *curlun, char *buf)
364 return sprintf(buf, "%u\n", curlun->cdrom);
366 EXPORT_SYMBOL_GPL(fsg_show_cdrom);
368 ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf)
370 return sprintf(buf, "%u\n", curlun->removable);
372 EXPORT_SYMBOL_GPL(fsg_show_removable);
375 * The caller must hold fsg->filesem for reading when calling this function.
377 static ssize_t _fsg_store_ro(struct fsg_lun *curlun, bool ro)
379 if (fsg_lun_is_open(curlun)) {
380 LDBG(curlun, "read-only status change prevented\n");
381 return -EBUSY;
384 curlun->ro = ro;
385 curlun->initially_ro = ro;
386 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
388 return 0;
391 ssize_t fsg_store_ro(struct fsg_lun *curlun, struct rw_semaphore *filesem,
392 const char *buf, size_t count)
394 ssize_t rc;
395 bool ro;
397 rc = strtobool(buf, &ro);
398 if (rc)
399 return rc;
402 * Allow the write-enable status to change only while the
403 * backing file is closed.
405 down_read(filesem);
406 rc = _fsg_store_ro(curlun, ro);
407 if (!rc)
408 rc = count;
409 up_read(filesem);
411 return rc;
413 EXPORT_SYMBOL_GPL(fsg_store_ro);
415 ssize_t fsg_store_nofua(struct fsg_lun *curlun, const char *buf, size_t count)
417 bool nofua;
418 int ret;
420 ret = strtobool(buf, &nofua);
421 if (ret)
422 return ret;
424 /* Sync data when switching from async mode to sync */
425 if (!nofua && curlun->nofua)
426 fsg_lun_fsync_sub(curlun);
428 curlun->nofua = nofua;
430 return count;
432 EXPORT_SYMBOL_GPL(fsg_store_nofua);
434 ssize_t fsg_store_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
435 const char *buf, size_t count)
437 int rc = 0;
439 if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
440 LDBG(curlun, "eject attempt prevented\n");
441 return -EBUSY; /* "Door is locked" */
444 /* Remove a trailing newline */
445 if (count > 0 && buf[count-1] == '\n')
446 ((char *) buf)[count-1] = 0; /* Ugh! */
448 /* Load new medium */
449 down_write(filesem);
450 if (count > 0 && buf[0]) {
451 /* fsg_lun_open() will close existing file if any. */
452 rc = fsg_lun_open(curlun, buf);
453 if (rc == 0)
454 curlun->unit_attention_data =
455 SS_NOT_READY_TO_READY_TRANSITION;
456 } else if (fsg_lun_is_open(curlun)) {
457 fsg_lun_close(curlun);
458 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
460 up_write(filesem);
461 return (rc < 0 ? rc : count);
463 EXPORT_SYMBOL_GPL(fsg_store_file);
465 ssize_t fsg_store_cdrom(struct fsg_lun *curlun, struct rw_semaphore *filesem,
466 const char *buf, size_t count)
468 bool cdrom;
469 int ret;
471 ret = strtobool(buf, &cdrom);
472 if (ret)
473 return ret;
475 down_read(filesem);
476 ret = cdrom ? _fsg_store_ro(curlun, true) : 0;
478 if (!ret) {
479 curlun->cdrom = cdrom;
480 ret = count;
482 up_read(filesem);
484 return ret;
486 EXPORT_SYMBOL_GPL(fsg_store_cdrom);
488 ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
489 size_t count)
491 bool removable;
492 int ret;
494 ret = strtobool(buf, &removable);
495 if (ret)
496 return ret;
498 curlun->removable = removable;
500 return count;
502 EXPORT_SYMBOL_GPL(fsg_store_removable);
504 MODULE_LICENSE("GPL");