]> git.sur5r.net Git - u-boot/commitdiff
usb:composite: USB Mass Storage - storage_common.c from Linux kernel
authorLukasz Majewski <l.majewski@samsung.com>
Tue, 5 Mar 2013 11:10:15 +0000 (12:10 +0100)
committerMarek Vasut <marex@denx.de>
Mon, 18 Mar 2013 17:58:53 +0000 (18:58 +0100)
The storage_common.c source file from v2.6.36 Linux kernel.

commit d26a6aa08b9f12b44fb1ee65625e7480d3d5bb81
Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
Date:   Mon Nov 9 14:15:23 2009 +0100

USB: g_mass_storage: code cleaned up and comments updated

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Marek Vasut <marek.vasut@gmail.com>
drivers/usb/gadget/storage_common.c [new file with mode: 0644]

diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
new file mode 100644 (file)
index 0000000..594dc10
--- /dev/null
@@ -0,0 +1,653 @@
+/*
+ * storage_common.c -- Common definitions for mass storage functionality
+ *
+ * Copyright (C) 2003-2008 Alan Stern
+ * Copyeight (C) 2009 Samsung Electronics
+ * Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
+ *
+ * Ported to u-boot:
+ * Andrzej Pietrasiewicz <andrzej.p@samsung.com>
+ *
+ * Code refactoring & cleanup:
+ * Ćukasz Majewski <l.majewski@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+/*
+ * This file requires the following identifiers used in USB strings to
+ * be defined (each of type pointer to char):
+ *  - fsg_string_manufacturer -- name of the manufacturer
+ *  - fsg_string_product      -- name of the product
+ *  - fsg_string_serial       -- product's serial
+ *  - fsg_string_config       -- name of the configuration
+ *  - fsg_string_interface    -- name of the interface
+ * The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
+ * macro is defined prior to including this file.
+ */
+
+/*
+ * When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
+ * fsg_hs_intr_in_desc objects as well as
+ * FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
+ * macros are not defined.
+ *
+ * When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
+ * FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
+ * defined (as well as corresponding entries in string tables are
+ * missing) and FSG_STRING_INTERFACE has value of zero.
+ *
+ * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
+ */
+
+/*
+ * When FSG_BUFFHD_STATIC_BUFFER is defined when this file is included
+ * the fsg_buffhd structure's buf field will be an array of FSG_BUFLEN
+ * characters rather then a pointer to void.
+ */
+
+
+/* #include <asm/unaligned.h> */
+
+
+/*
+ * Thanks to NetChip Technologies for donating this product ID.
+ *
+ * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
+ * Instead:  allocate your own, using normal USB-IF procedures.
+ */
+#define FSG_VENDOR_ID  0x0525  /* NetChip */
+#define FSG_PRODUCT_ID 0xa4a5  /* Linux-USB File-backed Storage Gadget */
+
+/*-------------------------------------------------------------------------*/
+
+#ifndef DEBUG
+#undef VERBOSE_DEBUG
+#undef DUMP_MSGS
+#endif /* !DEBUG */
+
+#ifdef VERBOSE_DEBUG
+#define VLDBG  LDBG
+#else
+#define VLDBG(lun, fmt, args...) do { } while (0)
+#endif /* VERBOSE_DEBUG */
+
+/*
+#define LDBG(lun, fmt, args...)   dev_dbg (&(lun)->dev, fmt, ## args)
+#define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
+#define LWARN(lun, fmt, args...)  dev_warn(&(lun)->dev, fmt, ## args)
+#define LINFO(lun, fmt, args...)  dev_info(&(lun)->dev, fmt, ## args)
+*/
+
+#define LDBG(lun, fmt, args...) do { } while (0)
+#define LERROR(lun, fmt, args...) do { } while (0)
+#define LWARN(lun, fmt, args...) do { } while (0)
+#define LINFO(lun, fmt, args...) do { } while (0)
+
+/*
+ * Keep those macros in sync with those in
+ * include/linux/usb/composite.h or else GCC will complain.  If they
+ * are identical (the same names of arguments, white spaces in the
+ * same places) GCC will allow redefinition otherwise (even if some
+ * white space is removed or added) warning will be issued.
+ *
+ * Those macros are needed here because File Storage Gadget does not
+ * include the composite.h header.  For composite gadgets those macros
+ * are redundant since composite.h is included any way.
+ *
+ * One could check whether those macros are already defined (which
+ * would indicate composite.h had been included) or not (which would
+ * indicate we were in FSG) but this is not done because a warning is
+ * desired if definitions here differ from the ones in composite.h.
+ *
+ * We want the definitions to match and be the same in File Storage
+ * Gadget as well as Mass Storage Function (and so composite gadgets
+ * using MSF).  If someone changes them in composite.h it will produce
+ * a warning in this file when building MSF.
+ */
+
+#define DBG(d, fmt, args...)     debug(fmt , ## args)
+#define VDBG(d, fmt, args...)    debug(fmt , ## args)
+/* #define ERROR(d, fmt, args...)   printf(fmt , ## args) */
+/* #define WARNING(d, fmt, args...) printf(fmt , ## args) */
+/* #define INFO(d, fmt, args...)    printf(fmt , ## args) */
+
+/* #define DBG(d, fmt, args...)     do { } while (0) */
+/* #define VDBG(d, fmt, args...)    do { } while (0) */
+#define ERROR(d, fmt, args...)   do { } while (0)
+#define WARNING(d, fmt, args...) do { } while (0)
+#define INFO(d, fmt, args...)    do { } while (0)
+
+#ifdef DUMP_MSGS
+
+/* dump_msg(fsg, const char * label, const u8 * buf, unsigned length); */
+# define dump_msg(fsg, label, buf, length) do {                         \
+       if (length < 512) {                                             \
+               DBG(fsg, "%s, length %u:\n", label, length);            \
+               print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,      \
+                              16, 1, buf, length, 0);                  \
+       }                                                               \
+} while (0)
+
+#  define dump_cdb(fsg) do { } while (0)
+
+#else
+
+#  define dump_msg(fsg, /* const char * */ label, \
+                  /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
+
+#  ifdef VERBOSE_DEBUG
+
+#    define dump_cdb(fsg)                                              \
+       print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,      \
+                      16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)         \
+
+#  else
+
+#    define dump_cdb(fsg) do { } while (0)
+
+#  endif /* VERBOSE_DEBUG */
+
+#endif /* DUMP_MSGS */
+
+/*-------------------------------------------------------------------------*/
+
+/* SCSI device types */
+#define TYPE_DISK      0x00
+#define TYPE_CDROM     0x05
+
+/* USB protocol value = the transport method */
+#define USB_PR_CBI     0x00            /* Control/Bulk/Interrupt */
+#define USB_PR_CB      0x01            /* Control/Bulk w/o interrupt */
+#define USB_PR_BULK    0x50            /* Bulk-only */
+
+/* USB subclass value = the protocol encapsulation */
+#define USB_SC_RBC     0x01            /* Reduced Block Commands (flash) */
+#define USB_SC_8020    0x02            /* SFF-8020i, MMC-2, ATAPI (CD-ROM) */
+#define USB_SC_QIC     0x03            /* QIC-157 (tape) */
+#define USB_SC_UFI     0x04            /* UFI (floppy) */
+#define USB_SC_8070    0x05            /* SFF-8070i (removable) */
+#define USB_SC_SCSI    0x06            /* Transparent SCSI */
+
+/* Bulk-only data structures */
+
+/* Command Block Wrapper */
+struct fsg_bulk_cb_wrap {
+       __le32  Signature;              /* Contains 'USBC' */
+       u32     Tag;                    /* Unique per command id */
+       __le32  DataTransferLength;     /* Size of the data */
+       u8      Flags;                  /* Direction in bit 7 */
+       u8      Lun;                    /* LUN (normally 0) */
+       u8      Length;                 /* Of the CDB, <= MAX_COMMAND_SIZE */
+       u8      CDB[16];                /* Command Data Block */
+};
+
+#define USB_BULK_CB_WRAP_LEN   31
+#define USB_BULK_CB_SIG                0x43425355      /* Spells out USBC */
+#define USB_BULK_IN_FLAG       0x80
+
+/* Command Status Wrapper */
+struct bulk_cs_wrap {
+       __le32  Signature;              /* Should = 'USBS' */
+       u32     Tag;                    /* Same as original command */
+       __le32  Residue;                /* Amount not transferred */
+       u8      Status;                 /* See below */
+};
+
+#define USB_BULK_CS_WRAP_LEN   13
+#define USB_BULK_CS_SIG                0x53425355      /* Spells out 'USBS' */
+#define USB_STATUS_PASS                0
+#define USB_STATUS_FAIL                1
+#define USB_STATUS_PHASE_ERROR 2
+
+/* Bulk-only class specific requests */
+#define USB_BULK_RESET_REQUEST         0xff
+#define USB_BULK_GET_MAX_LUN_REQUEST   0xfe
+
+/* CBI Interrupt data structure */
+struct interrupt_data {
+       u8      bType;
+       u8      bValue;
+};
+
+#define CBI_INTERRUPT_DATA_LEN         2
+
+/* CBI Accept Device-Specific Command request */
+#define USB_CBI_ADSC_REQUEST           0x00
+
+/* Length of a SCSI Command Data Block */
+#define MAX_COMMAND_SIZE       16
+
+/* SCSI commands that we recognize */
+#define SC_FORMAT_UNIT                 0x04
+#define SC_INQUIRY                     0x12
+#define SC_MODE_SELECT_6               0x15
+#define SC_MODE_SELECT_10              0x55
+#define SC_MODE_SENSE_6                        0x1a
+#define SC_MODE_SENSE_10               0x5a
+#define SC_PREVENT_ALLOW_MEDIUM_REMOVAL        0x1e
+#define SC_READ_6                      0x08
+#define SC_READ_10                     0x28
+#define SC_READ_12                     0xa8
+#define SC_READ_CAPACITY               0x25
+#define SC_READ_FORMAT_CAPACITIES      0x23
+#define SC_READ_HEADER                 0x44
+#define SC_READ_TOC                    0x43
+#define SC_RELEASE                     0x17
+#define SC_REQUEST_SENSE               0x03
+#define SC_RESERVE                     0x16
+#define SC_SEND_DIAGNOSTIC             0x1d
+#define SC_START_STOP_UNIT             0x1b
+#define SC_SYNCHRONIZE_CACHE           0x35
+#define SC_TEST_UNIT_READY             0x00
+#define SC_VERIFY                      0x2f
+#define SC_WRITE_6                     0x0a
+#define SC_WRITE_10                    0x2a
+#define SC_WRITE_12                    0xaa
+
+/* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
+#define SS_NO_SENSE                            0
+#define SS_COMMUNICATION_FAILURE               0x040800
+#define SS_INVALID_COMMAND                     0x052000
+#define SS_INVALID_FIELD_IN_CDB                        0x052400
+#define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE  0x052100
+#define SS_LOGICAL_UNIT_NOT_SUPPORTED          0x052500
+#define SS_MEDIUM_NOT_PRESENT                  0x023a00
+#define SS_MEDIUM_REMOVAL_PREVENTED            0x055302
+#define SS_NOT_READY_TO_READY_TRANSITION       0x062800
+#define SS_RESET_OCCURRED                      0x062900
+#define SS_SAVING_PARAMETERS_NOT_SUPPORTED     0x053900
+#define SS_UNRECOVERED_READ_ERROR              0x031100
+#define SS_WRITE_ERROR                         0x030c02
+#define SS_WRITE_PROTECTED                     0x072700
+
+#define SK(x)          ((u8) ((x) >> 16))      /* Sense Key byte, etc. */
+#define ASC(x)         ((u8) ((x) >> 8))
+#define ASCQ(x)                ((u8) (x))
+
+struct device_attribute { int i; };
+struct rw_semaphore { int i; };
+#define down_write(...)                        do { } while (0)
+#define up_write(...)                  do { } while (0)
+#define down_read(...)                 do { } while (0)
+#define up_read(...)                   do { } while (0)
+#define ETOOSMALL      525
+
+#include <usb_mass_storage.h>
+extern struct ums_board_info           *ums_info;
+
+/*-------------------------------------------------------------------------*/
+
+struct fsg_lun {
+       loff_t          file_length;
+       loff_t          num_sectors;
+
+       unsigned int    initially_ro:1;
+       unsigned int    ro:1;
+       unsigned int    removable:1;
+       unsigned int    cdrom:1;
+       unsigned int    prevent_medium_removal:1;
+       unsigned int    registered:1;
+       unsigned int    info_valid:1;
+       unsigned int    nofua:1;
+
+       u32             sense_data;
+       u32             sense_data_info;
+       u32             unit_attention_data;
+
+       struct device   dev;
+};
+
+#define fsg_lun_is_open(curlun)        ((curlun)->filp != NULL)
+#if 0
+static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
+{
+       return container_of(dev, struct fsg_lun, dev);
+}
+#endif
+
+/* Big enough to hold our biggest descriptor */
+#define EP0_BUFSIZE    256
+#define DELAYED_STATUS (EP0_BUFSIZE + 999)     /* An impossibly large value */
+
+/* Number of buffers we will use.  2 is enough for double-buffering */
+#define FSG_NUM_BUFFERS        2
+
+/* Default size of buffer length. */
+#define FSG_BUFLEN     ((u32)16384)
+
+/* Maximal number of LUNs supported in mass storage function */
+#define FSG_MAX_LUNS   8
+
+enum fsg_buffer_state {
+       BUF_STATE_EMPTY = 0,
+       BUF_STATE_FULL,
+       BUF_STATE_BUSY
+};
+
+struct fsg_buffhd {
+#ifdef FSG_BUFFHD_STATIC_BUFFER
+       char                            buf[FSG_BUFLEN];
+#else
+       void                            *buf;
+#endif
+       enum fsg_buffer_state           state;
+       struct fsg_buffhd               *next;
+
+       /*
+        * The NetChip 2280 is faster, and handles some protocol faults
+        * better, if we don't submit any short bulk-out read requests.
+        * So we will record the intended request length here.
+        */
+       unsigned int                    bulk_out_intended_length;
+
+       struct usb_request              *inreq;
+       int                             inreq_busy;
+       struct usb_request              *outreq;
+       int                             outreq_busy;
+};
+
+enum fsg_state {
+       /* This one isn't used anywhere */
+       FSG_STATE_COMMAND_PHASE = -10,
+       FSG_STATE_DATA_PHASE,
+       FSG_STATE_STATUS_PHASE,
+
+       FSG_STATE_IDLE = 0,
+       FSG_STATE_ABORT_BULK_OUT,
+       FSG_STATE_RESET,
+       FSG_STATE_INTERFACE_CHANGE,
+       FSG_STATE_CONFIG_CHANGE,
+       FSG_STATE_DISCONNECT,
+       FSG_STATE_EXIT,
+       FSG_STATE_TERMINATED
+};
+
+enum data_direction {
+       DATA_DIR_UNKNOWN = 0,
+       DATA_DIR_FROM_HOST,
+       DATA_DIR_TO_HOST,
+       DATA_DIR_NONE
+};
+
+/*-------------------------------------------------------------------------*/
+
+static inline u32 get_unaligned_be24(u8 *buf)
+{
+       return 0xffffff & (u32) get_unaligned_be32(buf - 1);
+}
+
+/*-------------------------------------------------------------------------*/
+
+enum {
+#ifndef FSG_NO_DEVICE_STRINGS
+       FSG_STRING_MANUFACTURER = 1,
+       FSG_STRING_PRODUCT,
+       FSG_STRING_SERIAL,
+       FSG_STRING_CONFIG,
+#endif
+       FSG_STRING_INTERFACE
+};
+
+#ifndef FSG_NO_OTG
+static struct usb_otg_descriptor
+fsg_otg_desc = {
+       .bLength =              sizeof fsg_otg_desc,
+       .bDescriptorType =      USB_DT_OTG,
+
+       .bmAttributes =         USB_OTG_SRP,
+};
+#endif
+
+/* There is only one interface. */
+
+static struct usb_interface_descriptor
+fsg_intf_desc = {
+       .bLength =              sizeof fsg_intf_desc,
+       .bDescriptorType =      USB_DT_INTERFACE,
+
+       .bNumEndpoints =        2,              /* Adjusted during fsg_bind() */
+       .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
+       .bInterfaceSubClass =   USB_SC_SCSI,    /* Adjusted during fsg_bind() */
+       .bInterfaceProtocol =   USB_PR_BULK,    /* Adjusted during fsg_bind() */
+       .iInterface =           FSG_STRING_INTERFACE,
+};
+
+/*
+ * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
+ * interrupt-in.
+ */
+
+static struct usb_endpoint_descriptor
+fsg_fs_bulk_in_desc = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+
+       .bEndpointAddress =     USB_DIR_IN,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+       /* wMaxPacketSize set by autoconfiguration */
+};
+
+static struct usb_endpoint_descriptor
+fsg_fs_bulk_out_desc = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+
+       .bEndpointAddress =     USB_DIR_OUT,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+       /* wMaxPacketSize set by autoconfiguration */
+};
+
+#ifndef FSG_NO_INTR_EP
+
+static struct usb_endpoint_descriptor
+fsg_fs_intr_in_desc = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+
+       .bEndpointAddress =     USB_DIR_IN,
+       .bmAttributes =         USB_ENDPOINT_XFER_INT,
+       .wMaxPacketSize =       cpu_to_le16(2),
+       .bInterval =            32,     /* frames -> 32 ms */
+};
+
+#ifndef FSG_NO_OTG
+#  define FSG_FS_FUNCTION_PRE_EP_ENTRIES       2
+#else
+#  define FSG_FS_FUNCTION_PRE_EP_ENTRIES       1
+#endif
+
+#endif
+
+static struct usb_descriptor_header *fsg_fs_function[] = {
+#ifndef FSG_NO_OTG
+       (struct usb_descriptor_header *) &fsg_otg_desc,
+#endif
+       (struct usb_descriptor_header *) &fsg_intf_desc,
+       (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
+       (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
+#ifndef FSG_NO_INTR_EP
+       (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
+#endif
+       NULL,
+};
+
+/*
+ * USB 2.0 devices need to expose both high speed and full speed
+ * descriptors, unless they only run at full speed.
+ *
+ * That means alternate endpoint descriptors (bigger packets)
+ * and a "device qualifier" ... plus more construction options
+ * for the configuration descriptor.
+ */
+static struct usb_endpoint_descriptor
+fsg_hs_bulk_in_desc = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+
+       /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize =       cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor
+fsg_hs_bulk_out_desc = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+
+       /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+       .wMaxPacketSize =       cpu_to_le16(512),
+       .bInterval =            1,      /* NAK every 1 uframe */
+};
+
+#ifndef FSG_NO_INTR_EP
+
+static struct usb_endpoint_descriptor
+fsg_hs_intr_in_desc = {
+       .bLength =              USB_DT_ENDPOINT_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+
+       /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
+       .bmAttributes =         USB_ENDPOINT_XFER_INT,
+       .wMaxPacketSize =       cpu_to_le16(2),
+       .bInterval =            9,      /* 2**(9-1) = 256 uframes -> 32 ms */
+};
+
+#ifndef FSG_NO_OTG
+#  define FSG_HS_FUNCTION_PRE_EP_ENTRIES       2
+#else
+#  define FSG_HS_FUNCTION_PRE_EP_ENTRIES       1
+#endif
+
+#endif
+
+static struct usb_descriptor_header *fsg_hs_function[] = {
+#ifndef FSG_NO_OTG
+       (struct usb_descriptor_header *) &fsg_otg_desc,
+#endif
+       (struct usb_descriptor_header *) &fsg_intf_desc,
+       (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
+       (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
+#ifndef FSG_NO_INTR_EP
+       (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
+#endif
+       NULL,
+};
+
+/* Maxpacket and other transfer characteristics vary by speed. */
+static struct usb_endpoint_descriptor *
+fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
+               struct usb_endpoint_descriptor *hs)
+{
+       if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
+               return hs;
+       return fs;
+}
+
+/* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
+static struct usb_string               fsg_strings[] = {
+#ifndef FSG_NO_DEVICE_STRINGS
+       {FSG_STRING_MANUFACTURER,       fsg_string_manufacturer},
+       {FSG_STRING_PRODUCT,            fsg_string_product},
+       {FSG_STRING_SERIAL,             fsg_string_serial},
+       {FSG_STRING_CONFIG,             fsg_string_config},
+#endif
+       {FSG_STRING_INTERFACE,          fsg_string_interface},
+       {}
+};
+
+static struct usb_gadget_strings       fsg_stringtab = {
+       .language       = 0x0409,               /* en-us */
+       .strings        = fsg_strings,
+};
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * If the next two routines are called while the gadget is registered,
+ * the caller must own fsg->filesem for writing.
+ */
+
+static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
+{
+       int                             ro;
+       int                             rc = -EINVAL;
+       loff_t                          size;
+       loff_t                          num_sectors;
+       loff_t                          min_sectors;
+
+       /* R/W if we can, R/O if we must */
+       ro = curlun->initially_ro;
+
+       ums_info->get_capacity(&(ums_info->ums_dev), &size);
+       if (size < 0) {
+               printf("unable to find file size: %s\n", filename);
+               rc = (int) size;
+               goto out;
+       }
+       num_sectors = size >> 9;        /* File size in 512-byte blocks */
+       min_sectors = 1;
+       if (num_sectors < min_sectors) {
+               printf("file too small: %s\n", filename);
+               rc = -ETOOSMALL;
+               goto out;
+       }
+
+       curlun->ro = ro;
+       curlun->file_length = size;
+       curlun->num_sectors = num_sectors;
+       debug("open backing file: %s\n", filename);
+       rc = 0;
+
+out:
+       return rc;
+}
+
+static void fsg_lun_close(struct fsg_lun *curlun)
+{
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * Sync the file data, don't bother with the metadata.
+ * This code was copied from fs/buffer.c:sys_fdatasync().
+ */
+static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
+{
+       return 0;
+}
+
+static void store_cdrom_address(u8 *dest, int msf, u32 addr)
+{
+       if (msf) {
+               /* Convert to Minutes-Seconds-Frames */
+               addr >>= 2;             /* Convert to 2048-byte frames */
+               addr += 2*75;           /* Lead-in occupies 2 seconds */
+               dest[3] = addr % 75;    /* Frames */
+               addr /= 75;
+               dest[2] = addr % 60;    /* Seconds */
+               addr /= 60;
+               dest[1] = addr;         /* Minutes */
+               dest[0] = 0;            /* Reserved */
+       } else {
+               /* Absolute sector */
+               put_unaligned_be32(addr, dest);
+       }
+}
+
+/*-------------------------------------------------------------------------*/