Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 938 insertions, 0 deletions

diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
new file mode 100644
index 00000000..88e9c0ef
--- /dev/null
+++ b/drivers/usb/gadget/storage_common.c
@@ -0,0 +1,938 @@
+/*
+ * storage_common.c -- Common definitions for mass storage functionality
+ *
+ * Copyright (C) 2003-2008 Alan Stern
+ * Copyeight (C) 2009 Samsung Electronics
+ * Author: Michal Nazarewicz (mina86@mina86.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 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_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.
+ */
+
+/*
+ * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
+ * sets the number of pipeline buffers (length of the fsg_buffhd array).
+ * The valid range of num_buffers is: num >= 2 && num <= 4.
+ */
+
+
+#include <linux/usb/storage.h>
+#include <scsi/scsi.h>
+#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)
+
+/*
+ * 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...)     dev_dbg(&(d)->gadget->dev , fmt , ## args)
+#define VDBG(d, fmt, args...)    dev_vdbg(&(d)->gadget->dev , fmt , ## args)
+#define ERROR(d, fmt, args...)   dev_err(&(d)->gadget->dev , fmt , ## args)
+#define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
+#define INFO(d, fmt, args...)    dev_info(&(d)->gadget->dev , fmt , ## args)
+
+
+
+#ifdef DUMP_MSGS
+
+#  define dump_msg(fsg, /* const char * */ label,			\
+		   /* const u8 * */ buf, /* unsigned */ 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 */
+
+/*-------------------------------------------------------------------------*/
+
+/* 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 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 fsg_lun {
+	struct file	*filp;
+	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;
+
+	unsigned int	blkbits;	/* Bits of logical block size of bound block device */
+	unsigned int	blksize;	/* logical block size of bound block device */
+	struct device	dev;
+};
+
+#define fsg_lun_is_open(curlun)	((curlun)->filp != NULL)
+
+static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
+{
+	return container_of(dev, struct fsg_lun, dev);
+}
+
+
+/* Big enough to hold our biggest descriptor */
+#define EP0_BUFSIZE	256
+#define DELAYED_STATUS	(EP0_BUFSIZE + 999)	/* An impossibly large value */
+
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+
+static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
+module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);
+MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
+
+#else
+
+/*
+ * Number of buffers we will use.
+ * 2 is usually enough for good buffering pipeline
+ */
+#define fsg_num_buffers	CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
+
+#endif /* CONFIG_USB_DEBUG */
+
+/* check if fsg_num_buffers is within a valid range */
+static inline int fsg_num_buffers_validate(void)
+{
+	if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
+		return 0;
+	pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
+	       fsg_num_buffers, 2 ,4);
+	return -EINVAL;
+}
+
+/* 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,
+};
+
+static struct usb_endpoint_descriptor
+fsg_ss_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(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
+	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/*.bMaxBurst =		DYNAMIC, */
+};
+
+static struct usb_endpoint_descriptor
+fsg_ss_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(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
+	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	/*.bMaxBurst =		DYNAMIC, */
+};
+
+#ifndef FSG_NO_INTR_EP
+
+static struct usb_endpoint_descriptor
+fsg_ss_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 */
+};
+
+static struct usb_ss_ep_comp_descriptor fsg_ss_intr_in_comp_desc = {
+	.bLength =		sizeof(fsg_ss_bulk_in_comp_desc),
+	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
+
+	.wBytesPerInterval =	cpu_to_le16(2),
+};
+
+#ifndef FSG_NO_OTG
+#  define FSG_SS_FUNCTION_PRE_EP_ENTRIES	2
+#else
+#  define FSG_SS_FUNCTION_PRE_EP_ENTRIES	1
+#endif
+
+#endif
+
+static __maybe_unused struct usb_ext_cap_descriptor fsg_ext_cap_desc = {
+	.bLength =		USB_DT_USB_EXT_CAP_SIZE,
+	.bDescriptorType =	USB_DT_DEVICE_CAPABILITY,
+	.bDevCapabilityType =	USB_CAP_TYPE_EXT,
+
+	.bmAttributes =		cpu_to_le32(USB_LPM_SUPPORT),
+};
+
+static __maybe_unused struct usb_ss_cap_descriptor fsg_ss_cap_desc = {
+	.bLength =		USB_DT_USB_SS_CAP_SIZE,
+	.bDescriptorType =	USB_DT_DEVICE_CAPABILITY,
+	.bDevCapabilityType =	USB_SS_CAP_TYPE,
+
+	/* .bmAttributes = LTM is not supported yet */
+
+	.wSpeedSupported =	cpu_to_le16(USB_LOW_SPEED_OPERATION
+		| USB_FULL_SPEED_OPERATION
+		| USB_HIGH_SPEED_OPERATION
+		| USB_5GBPS_OPERATION),
+	.bFunctionalitySupport = USB_LOW_SPEED_OPERATION,
+	.bU1devExitLat =	USB_DEFAULT_U1_DEV_EXIT_LAT,
+	.bU2DevExitLat =	cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT),
+};
+
+static __maybe_unused struct usb_bos_descriptor fsg_bos_desc = {
+	.bLength =		USB_DT_BOS_SIZE,
+	.bDescriptorType =	USB_DT_BOS,
+
+	.wTotalLength =		cpu_to_le16(USB_DT_BOS_SIZE
+				+ USB_DT_USB_EXT_CAP_SIZE
+				+ USB_DT_USB_SS_CAP_SIZE),
+
+	.bNumDeviceCaps =	2,
+};
+
+static struct usb_descriptor_header *fsg_ss_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_ss_bulk_in_desc,
+	(struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
+	(struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
+	(struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
+#ifndef FSG_NO_INTR_EP
+	(struct usb_descriptor_header *) &fsg_ss_intr_in_desc,
+	(struct usb_descriptor_header *) &fsg_ss_intr_in_comp_desc,
+#endif
+	NULL,
+};
+
+/* Maxpacket and other transfer characteristics vary by speed. */
+static __maybe_unused struct usb_endpoint_descriptor *
+fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
+		struct usb_endpoint_descriptor *hs,
+		struct usb_endpoint_descriptor *ss)
+{
+	if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
+		return ss;
+	else 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_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;
+	struct file			*filp = NULL;
+	int				rc = -EINVAL;
+	struct inode			*inode = NULL;
+	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;
+	if (!ro) {
+		filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
+		if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
+			ro = 1;
+	}
+	if (ro)
+		filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
+	if (IS_ERR(filp)) {
+		LINFO(curlun, "unable to open backing file: %s\n", filename);
+		return PTR_ERR(filp);
+	}
+
+	if (!(filp->f_mode & FMODE_WRITE))
+		ro = 1;
+
+	if (filp->f_path.dentry)
+		inode = filp->f_path.dentry->d_inode;
+	if (!inode || (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
+		LINFO(curlun, "invalid file type: %s\n", filename);
+		goto out;
+	}
+
+	/*
+	 * If we can't read the file, it's no good.
+	 * If we can't write the file, use it read-only.
+	 */
+	if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
+		LINFO(curlun, "file not readable: %s\n", filename);
+		goto out;
+	}
+	if (!(filp->f_op->write || filp->f_op->aio_write))
+		ro = 1;
+
+	size = i_size_read(inode->i_mapping->host);
+	if (size < 0) {
+		LINFO(curlun, "unable to find file size: %s\n", filename);
+		rc = (int) size;
+		goto out;
+	}
+
+	if (curlun->cdrom) {
+		curlun->blksize = 2048;
+		curlun->blkbits = 11;
+	} else if (inode->i_bdev) {
+		curlun->blksize = bdev_logical_block_size(inode->i_bdev);
+		curlun->blkbits = blksize_bits(curlun->blksize);
+	} else {
+		curlun->blksize = 512;
+		curlun->blkbits = 9;
+	}
+
+	num_sectors = size >> curlun->blkbits; /* File size in logic-block-size blocks */
+	min_sectors = 1;
+	if (curlun->cdrom) {
+		min_sectors = 300;	/* Smallest track is 300 frames */
+		if (num_sectors >= 256*60*75) {
+			num_sectors = 256*60*75 - 1;
+			LINFO(curlun, "file too big: %s\n", filename);
+			LINFO(curlun, "using only first %d blocks\n",
+					(int) num_sectors);
+		}
+	}
+	if (num_sectors < min_sectors) {
+		LINFO(curlun, "file too small: %s\n", filename);
+		rc = -ETOOSMALL;
+		goto out;
+	}
+
+	get_file(filp);
+	curlun->ro = ro;
+	curlun->filp = filp;
+	curlun->file_length = size;
+	curlun->num_sectors = num_sectors;
+	LDBG(curlun, "open backing file: %s\n", filename);
+	rc = 0;
+
+out:
+	filp_close(filp, current->files);
+	return rc;
+}
+
+
+static void fsg_lun_close(struct fsg_lun *curlun)
+{
+	if (curlun->filp) {
+		LDBG(curlun, "close backing file\n");
+		fput(curlun->filp);
+		curlun->filp = NULL;
+	}
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * 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)
+{
+	struct file	*filp = curlun->filp;
+
+	if (curlun->ro || !filp)
+		return 0;
+	return vfs_fsync(filp, 1);
+}
+
+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);
+	}
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+
+static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+
+	return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
+				  ? curlun->ro
+				  : curlun->initially_ro);
+}
+
+static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+
+	return sprintf(buf, "%u\n", curlun->nofua);
+}
+
+static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
+	char		*p;
+	ssize_t		rc;
+
+	down_read(filesem);
+	if (fsg_lun_is_open(curlun)) {	/* Get the complete pathname */
+		p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
+		if (IS_ERR(p))
+			rc = PTR_ERR(p);
+		else {
+			rc = strlen(p);
+			memmove(buf, p, rc);
+			buf[rc] = '\n';		/* Add a newline */
+			buf[++rc] = 0;
+		}
+	} else {				/* No file, return 0 bytes */
+		*buf = 0;
+		rc = 0;
+	}
+	up_read(filesem);
+	return rc;
+}
+
+static ssize_t fsg_show_cdrom(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+
+	return sprintf(buf, "%d\n", curlun->cdrom);
+}
+
+
+static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	ssize_t		rc;
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
+	unsigned	ro;
+
+	rc = kstrtouint(buf, 2, &ro);
+	if (rc)
+		return rc;
+
+	/*
+	 * Allow the write-enable status to change only while the
+	 * backing file is closed.
+	 */
+	down_read(filesem);
+	if (fsg_lun_is_open(curlun)) {
+		LDBG(curlun, "read-only status change prevented\n");
+		rc = -EBUSY;
+	} else {
+		curlun->ro = ro;
+		curlun->initially_ro = ro;
+		LDBG(curlun, "read-only status set to %d\n", curlun->ro);
+		rc = count;
+	}
+	up_read(filesem);
+	return rc;
+}
+
+static ssize_t fsg_store_nofua(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+	unsigned	nofua;
+	int		ret;
+
+	ret = kstrtouint(buf, 2, &nofua);
+	if (ret)
+		return ret;
+
+	/* Sync data when switching from async mode to sync */
+	if (!nofua && curlun->nofua)
+		fsg_lun_fsync_sub(curlun);
+
+	curlun->nofua = nofua;
+
+	return count;
+}
+
+static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
+	int		rc = 0;
+
+	if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
+		LDBG(curlun, "eject attempt prevented\n");
+		return -EBUSY;				/* "Door is locked" */
+	}
+
+	/* Remove a trailing newline */
+	if (count > 0 && buf[count-1] == '\n')
+		((char *) buf)[count-1] = 0;		/* Ugh! */
+
+	/* Eject current medium */
+	down_write(filesem);
+	if (fsg_lun_is_open(curlun)) {
+		fsg_lun_close(curlun);
+		curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
+	}
+
+	/* Load new medium */
+	if (count > 0 && buf[0]) {
+		rc = fsg_lun_open(curlun, buf);
+		if (rc == 0)
+			curlun->unit_attention_data =
+					SS_NOT_READY_TO_READY_TRANSITION;
+	}
+	up_write(filesem);
+	return (rc < 0 ? rc : count);
+}
+
+static ssize_t fsg_store_cdrom(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	ssize_t		rc;
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
+	unsigned	cdrom;
+
+	rc = kstrtouint(buf, 2, &cdrom);
+	if (rc)
+		return rc;
+
+	/*
+	 * Allow the write-enable status to change only while the
+	 * backing file is closed.
+	 */
+	down_read(filesem);
+	if (fsg_lun_is_open(curlun)) {
+		LDBG(curlun, "read-only status change prevented\n");
+		rc = -EBUSY;
+	} else {
+		curlun->cdrom = cdrom;
+		LDBG(curlun, "cdrom status set to %d\n", curlun->cdrom);
+		rc = count;
+	}
+	up_read(filesem);
+	return rc;
+}
+