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-rw-r--r--drivers/usb/gadget/f_mass_storage.c2793
1 files changed, 2793 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
new file mode 100644
index 00000000000..c28866f7d3c
--- /dev/null
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -0,0 +1,2793 @@
+/*
+ * f_mass_storage.c -- Mass Storage USB Composite Function
+ *
+ * Copyright (C) 2003-2008 Alan Stern
+ * Copyright (C) 2009 Samsung Electronics
+ * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions, and the following disclaimer,
+ * without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The names of the above-listed copyright holders may not be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+/*
+ * The Mass Storage Function acts as a USB Mass Storage device,
+ * appearing to the host as a disk drive or as a CD-ROM drive. In
+ * addition to providing an example of a genuinely useful composite
+ * function for a USB device, it also illustrates a technique of
+ * double-buffering for increased throughput.
+ *
+ * Function supports multiple logical units (LUNs). Backing storage
+ * for each LUN is provided by a regular file or a block device.
+ * Access for each LUN can be limited to read-only. Moreover, the
+ * function can indicate that LUN is removable and/or CD-ROM. (The
+ * later implies read-only access.)
+ *
+ * MSF is configured by specifying a fsg_config structure. It has the
+ * following fields:
+ *
+ * nluns Number of LUNs function have (anywhere from 1
+ * to FSG_MAX_LUNS which is 8).
+ * luns An array of LUN configuration values. This
+ * should be filled for each LUN that
+ * function will include (ie. for "nluns"
+ * LUNs). Each element of the array has
+ * the following fields:
+ * ->filename The path to the backing file for the LUN.
+ * Required if LUN is not marked as
+ * removable.
+ * ->ro Flag specifying access to the LUN shall be
+ * read-only. This is implied if CD-ROM
+ * emulation is enabled as well as when
+ * it was impossible to open "filename"
+ * in R/W mode.
+ * ->removable Flag specifying that LUN shall be indicated as
+ * being removable.
+ * ->cdrom Flag specifying that LUN shall be reported as
+ * being a CD-ROM.
+ *
+ * lun_name_format A printf-like format for names of the LUN
+ * devices. This determines how the
+ * directory in sysfs will be named.
+ * Unless you are using several MSFs in
+ * a single gadget (as opposed to single
+ * MSF in many configurations) you may
+ * leave it as NULL (in which case
+ * "lun%d" will be used). In the format
+ * you can use "%d" to index LUNs for
+ * MSF's with more than one LUN. (Beware
+ * that there is only one integer given
+ * as an argument for the format and
+ * specifying invalid format may cause
+ * unspecified behaviour.)
+ * thread_name Name of the kernel thread process used by the
+ * MSF. You can safely set it to NULL
+ * (in which case default "file-storage"
+ * will be used).
+ *
+ * vendor_name
+ * product_name
+ * release Information used as a reply to INQUIRY
+ * request. To use default set to NULL,
+ * NULL, 0xffff respectively. The first
+ * field should be 8 and the second 16
+ * characters or less.
+ *
+ * can_stall Set to permit function to halt bulk endpoints.
+ * Disabled on some USB devices known not
+ * to work correctly. You should set it
+ * to true.
+ *
+ * If "removable" is not set for a LUN then a backing file must be
+ * specified. If it is set, then NULL filename means the LUN's medium
+ * is not loaded (an empty string as "filename" in the fsg_config
+ * structure causes error). The CD-ROM emulation includes a single
+ * data track and no audio tracks; hence there need be only one
+ * backing file per LUN. Note also that the CD-ROM block length is
+ * set to 512 rather than the more common value 2048.
+ *
+ *
+ * MSF includes support for module parameters. If gadget using it
+ * decides to use it, the following module parameters will be
+ * available:
+ *
+ * file=filename[,filename...]
+ * Names of the files or block devices used for
+ * backing storage.
+ * ro=b[,b...] Default false, boolean for read-only access.
+ * removable=b[,b...]
+ * Default true, boolean for removable media.
+ * cdrom=b[,b...] Default false, boolean for whether to emulate
+ * a CD-ROM drive.
+ * luns=N Default N = number of filenames, number of
+ * LUNs to support.
+ * stall Default determined according to the type of
+ * USB device controller (usually true),
+ * boolean to permit the driver to halt
+ * bulk endpoints.
+ *
+ * The module parameters may be prefixed with some string. You need
+ * to consult gadget's documentation or source to verify whether it is
+ * using those module parameters and if it does what are the prefixes
+ * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
+ * the prefix).
+ *
+ *
+ * Requirements are modest; only a bulk-in and a bulk-out endpoint are
+ * needed. The memory requirement amounts to two 16K buffers, size
+ * configurable by a parameter. Support is included for both
+ * full-speed and high-speed operation.
+ *
+ * Note that the driver is slightly non-portable in that it assumes a
+ * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
+ * interrupt-in endpoints. With most device controllers this isn't an
+ * issue, but there may be some with hardware restrictions that prevent
+ * a buffer from being used by more than one endpoint.
+ *
+ *
+ * The pathnames of the backing files and the ro settings are
+ * available in the attribute files "file" and "ro" in the lun<n> (or
+ * to be more precise in a directory which name comes from
+ * "lun_name_format" option!) subdirectory of the gadget's sysfs
+ * directory. If the "removable" option is set, writing to these
+ * files will simulate ejecting/loading the medium (writing an empty
+ * line means eject) and adjusting a write-enable tab. Changes to the
+ * ro setting are not allowed when the medium is loaded or if CD-ROM
+ * emulation is being used.
+ *
+ * When a LUN receive an "eject" SCSI request (Start/Stop Unit),
+ * if the LUN is removable, the backing file is released to simulate
+ * ejection.
+ *
+ *
+ * This function is heavily based on "File-backed Storage Gadget" by
+ * Alan Stern which in turn is heavily based on "Gadget Zero" by David
+ * Brownell. The driver's SCSI command interface was based on the
+ * "Information technology - Small Computer System Interface - 2"
+ * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
+ * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
+ * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
+ * was based on the "Universal Serial Bus Mass Storage Class UFI
+ * Command Specification" document, Revision 1.0, December 14, 1998,
+ * available at
+ * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
+ */
+
+
+/*
+ * Driver Design
+ *
+ * The MSF is fairly straightforward. There is a main kernel
+ * thread that handles most of the work. Interrupt routines field
+ * callbacks from the controller driver: bulk- and interrupt-request
+ * completion notifications, endpoint-0 events, and disconnect events.
+ * Completion events are passed to the main thread by wakeup calls. Many
+ * ep0 requests are handled at interrupt time, but SetInterface,
+ * SetConfiguration, and device reset requests are forwarded to the
+ * thread in the form of "exceptions" using SIGUSR1 signals (since they
+ * should interrupt any ongoing file I/O operations).
+ *
+ * The thread's main routine implements the standard command/data/status
+ * parts of a SCSI interaction. It and its subroutines are full of tests
+ * for pending signals/exceptions -- all this polling is necessary since
+ * the kernel has no setjmp/longjmp equivalents. (Maybe this is an
+ * indication that the driver really wants to be running in userspace.)
+ * An important point is that so long as the thread is alive it keeps an
+ * open reference to the backing file. This will prevent unmounting
+ * the backing file's underlying filesystem and could cause problems
+ * during system shutdown, for example. To prevent such problems, the
+ * thread catches INT, TERM, and KILL signals and converts them into
+ * an EXIT exception.
+ *
+ * In normal operation the main thread is started during the gadget's
+ * fsg_bind() callback and stopped during fsg_unbind(). But it can
+ * also exit when it receives a signal, and there's no point leaving
+ * the gadget running when the thread is dead. At of this moment, MSF
+ * provides no way to deregister the gadget when thread dies -- maybe
+ * a callback functions is needed.
+ *
+ * To provide maximum throughput, the driver uses a circular pipeline of
+ * buffer heads (struct fsg_buffhd). In principle the pipeline can be
+ * arbitrarily long; in practice the benefits don't justify having more
+ * than 2 stages (i.e., double buffering). But it helps to think of the
+ * pipeline as being a long one. Each buffer head contains a bulk-in and
+ * a bulk-out request pointer (since the buffer can be used for both
+ * output and input -- directions always are given from the host's
+ * point of view) as well as a pointer to the buffer and various state
+ * variables.
+ *
+ * Use of the pipeline follows a simple protocol. There is a variable
+ * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
+ * At any time that buffer head may still be in use from an earlier
+ * request, so each buffer head has a state variable indicating whether
+ * it is EMPTY, FULL, or BUSY. Typical use involves waiting for the
+ * buffer head to be EMPTY, filling the buffer either by file I/O or by
+ * USB I/O (during which the buffer head is BUSY), and marking the buffer
+ * head FULL when the I/O is complete. Then the buffer will be emptied
+ * (again possibly by USB I/O, during which it is marked BUSY) and
+ * finally marked EMPTY again (possibly by a completion routine).
+ *
+ * A module parameter tells the driver to avoid stalling the bulk
+ * endpoints wherever the transport specification allows. This is
+ * necessary for some UDCs like the SuperH, which cannot reliably clear a
+ * halt on a bulk endpoint. However, under certain circumstances the
+ * Bulk-only specification requires a stall. In such cases the driver
+ * will halt the endpoint and set a flag indicating that it should clear
+ * the halt in software during the next device reset. Hopefully this
+ * will permit everything to work correctly. Furthermore, although the
+ * specification allows the bulk-out endpoint to halt when the host sends
+ * too much data, implementing this would cause an unavoidable race.
+ * The driver will always use the "no-stall" approach for OUT transfers.
+ *
+ * One subtle point concerns sending status-stage responses for ep0
+ * requests. Some of these requests, such as device reset, can involve
+ * interrupting an ongoing file I/O operation, which might take an
+ * arbitrarily long time. During that delay the host might give up on
+ * the original ep0 request and issue a new one. When that happens the
+ * driver should not notify the host about completion of the original
+ * request, as the host will no longer be waiting for it. So the driver
+ * assigns to each ep0 request a unique tag, and it keeps track of the
+ * tag value of the request associated with a long-running exception
+ * (device-reset, interface-change, or configuration-change). When the
+ * exception handler is finished, the status-stage response is submitted
+ * only if the current ep0 request tag is equal to the exception request
+ * tag. Thus only the most recently received ep0 request will get a
+ * status-stage response.
+ *
+ * Warning: This driver source file is too long. It ought to be split up
+ * into a header file plus about 3 separate .c files, to handle the details
+ * of the Gadget, USB Mass Storage, and SCSI protocols.
+ */
+
+/* #define VERBOSE_DEBUG */
+/* #define DUMP_MSGS */
+
+#include <config.h>
+#include <malloc.h>
+#include <common.h>
+
+#include <linux/err.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <usb_mass_storage.h>
+
+#include <asm/unaligned.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/composite.h>
+#include <usb/lin_gadget_compat.h>
+
+/*------------------------------------------------------------------------*/
+
+#define FSG_DRIVER_DESC "Mass Storage Function"
+#define FSG_DRIVER_VERSION "2012/06/5"
+
+static const char fsg_string_interface[] = "Mass Storage";
+
+
+#define FSG_NO_INTR_EP 1
+#define FSG_NO_DEVICE_STRINGS 1
+#define FSG_NO_OTG 1
+#define FSG_NO_INTR_EP 1
+
+#include "storage_common.c"
+
+/*-------------------------------------------------------------------------*/
+
+#define GFP_ATOMIC ((gfp_t) 0)
+#define PAGE_CACHE_SHIFT 12
+#define PAGE_CACHE_SIZE (1 << PAGE_CACHE_SHIFT)
+#define kthread_create(...) __builtin_return_address(0)
+#define wait_for_completion(...) do {} while (0)
+
+struct kref {int x; };
+struct completion {int x; };
+
+inline void set_bit(int nr, volatile void *addr)
+{
+ int mask;
+ unsigned int *a = (unsigned int *) addr;
+
+ a += nr >> 5;
+ mask = 1 << (nr & 0x1f);
+ *a |= mask;
+}
+
+inline void clear_bit(int nr, volatile void *addr)
+{
+ int mask;
+ unsigned int *a = (unsigned int *) addr;
+
+ a += nr >> 5;
+ mask = 1 << (nr & 0x1f);
+ *a &= ~mask;
+}
+
+struct fsg_dev;
+struct fsg_common;
+
+/* Data shared by all the FSG instances. */
+struct fsg_common {
+ struct usb_gadget *gadget;
+ struct fsg_dev *fsg, *new_fsg;
+
+ struct usb_ep *ep0; /* Copy of gadget->ep0 */
+ struct usb_request *ep0req; /* Copy of cdev->req */
+ unsigned int ep0_req_tag;
+
+ struct fsg_buffhd *next_buffhd_to_fill;
+ struct fsg_buffhd *next_buffhd_to_drain;
+ struct fsg_buffhd buffhds[FSG_NUM_BUFFERS];
+
+ int cmnd_size;
+ u8 cmnd[MAX_COMMAND_SIZE];
+
+ unsigned int nluns;
+ unsigned int lun;
+ struct fsg_lun luns[FSG_MAX_LUNS];
+
+ unsigned int bulk_out_maxpacket;
+ enum fsg_state state; /* For exception handling */
+ unsigned int exception_req_tag;
+
+ enum data_direction data_dir;
+ u32 data_size;
+ u32 data_size_from_cmnd;
+ u32 tag;
+ u32 residue;
+ u32 usb_amount_left;
+
+ unsigned int can_stall:1;
+ unsigned int free_storage_on_release:1;
+ unsigned int phase_error:1;
+ unsigned int short_packet_received:1;
+ unsigned int bad_lun_okay:1;
+ unsigned int running:1;
+
+ int thread_wakeup_needed;
+ struct completion thread_notifier;
+ struct task_struct *thread_task;
+
+ /* Callback functions. */
+ const struct fsg_operations *ops;
+ /* Gadget's private data. */
+ void *private_data;
+
+ const char *vendor_name; /* 8 characters or less */
+ const char *product_name; /* 16 characters or less */
+ u16 release;
+
+ /* Vendor (8 chars), product (16 chars), release (4
+ * hexadecimal digits) and NUL byte */
+ char inquiry_string[8 + 16 + 4 + 1];
+
+ struct kref ref;
+};
+
+struct fsg_config {
+ unsigned nluns;
+ struct fsg_lun_config {
+ const char *filename;
+ char ro;
+ char removable;
+ char cdrom;
+ char nofua;
+ } luns[FSG_MAX_LUNS];
+
+ /* Callback functions. */
+ const struct fsg_operations *ops;
+ /* Gadget's private data. */
+ void *private_data;
+
+ const char *vendor_name; /* 8 characters or less */
+ const char *product_name; /* 16 characters or less */
+
+ char can_stall;
+};
+
+struct fsg_dev {
+ struct usb_function function;
+ struct usb_gadget *gadget; /* Copy of cdev->gadget */
+ struct fsg_common *common;
+
+ u16 interface_number;
+
+ unsigned int bulk_in_enabled:1;
+ unsigned int bulk_out_enabled:1;
+
+ unsigned long atomic_bitflags;
+#define IGNORE_BULK_OUT 0
+
+ struct usb_ep *bulk_in;
+ struct usb_ep *bulk_out;
+};
+
+
+static inline int __fsg_is_set(struct fsg_common *common,
+ const char *func, unsigned line)
+{
+ if (common->fsg)
+ return 1;
+ ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
+ WARN_ON(1);
+ return 0;
+}
+
+#define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
+
+
+static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
+{
+ return container_of(f, struct fsg_dev, function);
+}
+
+
+typedef void (*fsg_routine_t)(struct fsg_dev *);
+
+static int exception_in_progress(struct fsg_common *common)
+{
+ return common->state > FSG_STATE_IDLE;
+}
+
+/* Make bulk-out requests be divisible by the maxpacket size */
+static void set_bulk_out_req_length(struct fsg_common *common,
+ struct fsg_buffhd *bh, unsigned int length)
+{
+ unsigned int rem;
+
+ bh->bulk_out_intended_length = length;
+ rem = length % common->bulk_out_maxpacket;
+ if (rem > 0)
+ length += common->bulk_out_maxpacket - rem;
+ bh->outreq->length = length;
+}
+
+/*-------------------------------------------------------------------------*/
+
+struct ums_board_info *ums_info;
+struct fsg_common *the_fsg_common;
+
+static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
+{
+ const char *name;
+
+ if (ep == fsg->bulk_in)
+ name = "bulk-in";
+ else if (ep == fsg->bulk_out)
+ name = "bulk-out";
+ else
+ name = ep->name;
+ DBG(fsg, "%s set halt\n", name);
+ return usb_ep_set_halt(ep);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* These routines may be called in process context or in_irq */
+
+/* Caller must hold fsg->lock */
+static void wakeup_thread(struct fsg_common *common)
+{
+ common->thread_wakeup_needed = 1;
+}
+
+static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
+{
+ /* Do nothing if a higher-priority exception is already in progress.
+ * If a lower-or-equal priority exception is in progress, preempt it
+ * and notify the main thread by sending it a signal. */
+ if (common->state <= new_state) {
+ common->exception_req_tag = common->ep0_req_tag;
+ common->state = new_state;
+ common->thread_wakeup_needed = 1;
+ }
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int ep0_queue(struct fsg_common *common)
+{
+ int rc;
+
+ rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
+ common->ep0->driver_data = common;
+ if (rc != 0 && rc != -ESHUTDOWN) {
+ /* We can't do much more than wait for a reset */
+ WARNING(common, "error in submission: %s --> %d\n",
+ common->ep0->name, rc);
+ }
+ return rc;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* Bulk and interrupt endpoint completion handlers.
+ * These always run in_irq. */
+
+static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct fsg_common *common = ep->driver_data;
+ struct fsg_buffhd *bh = req->context;
+
+ if (req->status || req->actual != req->length)
+ DBG(common, "%s --> %d, %u/%u\n", __func__,
+ req->status, req->actual, req->length);
+ if (req->status == -ECONNRESET) /* Request was cancelled */
+ usb_ep_fifo_flush(ep);
+
+ /* Hold the lock while we update the request and buffer states */
+ bh->inreq_busy = 0;
+ bh->state = BUF_STATE_EMPTY;
+ wakeup_thread(common);
+}
+
+static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct fsg_common *common = ep->driver_data;
+ struct fsg_buffhd *bh = req->context;
+
+ dump_msg(common, "bulk-out", req->buf, req->actual);
+ if (req->status || req->actual != bh->bulk_out_intended_length)
+ DBG(common, "%s --> %d, %u/%u\n", __func__,
+ req->status, req->actual,
+ bh->bulk_out_intended_length);
+ if (req->status == -ECONNRESET) /* Request was cancelled */
+ usb_ep_fifo_flush(ep);
+
+ /* Hold the lock while we update the request and buffer states */
+ bh->outreq_busy = 0;
+ bh->state = BUF_STATE_FULL;
+ wakeup_thread(common);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* Ep0 class-specific handlers. These always run in_irq. */
+
+static int fsg_setup(struct usb_function *f,
+ const struct usb_ctrlrequest *ctrl)
+{
+ struct fsg_dev *fsg = fsg_from_func(f);
+ struct usb_request *req = fsg->common->ep0req;
+ u16 w_index = le16_to_cpu(ctrl->wIndex);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+
+ if (!fsg_is_set(fsg->common))
+ return -EOPNOTSUPP;
+
+ switch (ctrl->bRequest) {
+
+ case USB_BULK_RESET_REQUEST:
+ if (ctrl->bRequestType !=
+ (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
+ break;
+ if (w_index != fsg->interface_number || w_value != 0)
+ return -EDOM;
+
+ /* Raise an exception to stop the current operation
+ * and reinitialize our state. */
+ DBG(fsg, "bulk reset request\n");
+ raise_exception(fsg->common, FSG_STATE_RESET);
+ return DELAYED_STATUS;
+
+ case USB_BULK_GET_MAX_LUN_REQUEST:
+ if (ctrl->bRequestType !=
+ (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
+ break;
+ if (w_index != fsg->interface_number || w_value != 0)
+ return -EDOM;
+ VDBG(fsg, "get max LUN\n");
+ *(u8 *) req->buf = fsg->common->nluns - 1;
+
+ /* Respond with data/status */
+ req->length = min((u16)1, w_length);
+ return ep0_queue(fsg->common);
+ }
+
+ VDBG(fsg,
+ "unknown class-specific control req "
+ "%02x.%02x v%04x i%04x l%u\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ le16_to_cpu(ctrl->wValue), w_index, w_length);
+ return -EOPNOTSUPP;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* All the following routines run in process context */
+
+/* Use this for bulk or interrupt transfers, not ep0 */
+static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
+ struct usb_request *req, int *pbusy,
+ enum fsg_buffer_state *state)
+{
+ int rc;
+
+ if (ep == fsg->bulk_in)
+ dump_msg(fsg, "bulk-in", req->buf, req->length);
+
+ *pbusy = 1;
+ *state = BUF_STATE_BUSY;
+ rc = usb_ep_queue(ep, req, GFP_KERNEL);
+ if (rc != 0) {
+ *pbusy = 0;
+ *state = BUF_STATE_EMPTY;
+
+ /* We can't do much more than wait for a reset */
+
+ /* Note: currently the net2280 driver fails zero-length
+ * submissions if DMA is enabled. */
+ if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
+ req->length == 0))
+ WARNING(fsg, "error in submission: %s --> %d\n",
+ ep->name, rc);
+ }
+}
+
+#define START_TRANSFER_OR(common, ep_name, req, pbusy, state) \
+ if (fsg_is_set(common)) \
+ start_transfer((common)->fsg, (common)->fsg->ep_name, \
+ req, pbusy, state); \
+ else
+
+#define START_TRANSFER(common, ep_name, req, pbusy, state) \
+ START_TRANSFER_OR(common, ep_name, req, pbusy, state) (void)0
+
+static void busy_indicator(void)
+{
+ static int state;
+
+ switch (state) {
+ case 0:
+ puts("\r|"); break;
+ case 1:
+ puts("\r/"); break;
+ case 2:
+ puts("\r-"); break;
+ case 3:
+ puts("\r\\"); break;
+ case 4:
+ puts("\r|"); break;
+ case 5:
+ puts("\r/"); break;
+ case 6:
+ puts("\r-"); break;
+ case 7:
+ puts("\r\\"); break;
+ default:
+ state = 0;
+ }
+ if (state++ == 8)
+ state = 0;
+}
+
+static int sleep_thread(struct fsg_common *common)
+{
+ int rc = 0;
+ int i = 0, k = 0;
+
+ /* Wait until a signal arrives or we are woken up */
+ for (;;) {
+ if (common->thread_wakeup_needed)
+ break;
+
+ if (++i == 50000) {
+ busy_indicator();
+ i = 0;
+ k++;
+ }
+
+ usb_gadget_handle_interrupts();
+ }
+ common->thread_wakeup_needed = 0;
+ return rc;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int do_read(struct fsg_common *common)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ u32 lba;
+ struct fsg_buffhd *bh;
+ int rc;
+ u32 amount_left;
+ loff_t file_offset;
+ unsigned int amount;
+ unsigned int partial_page;
+ ssize_t nread;
+
+ /* Get the starting Logical Block Address and check that it's
+ * not too big */
+ if (common->cmnd[0] == SC_READ_6)
+ lba = get_unaligned_be24(&common->cmnd[1]);
+ else {
+ lba = get_unaligned_be32(&common->cmnd[2]);
+
+ /* We allow DPO (Disable Page Out = don't save data in the
+ * cache) and FUA (Force Unit Access = don't read from the
+ * cache), but we don't implement them. */
+ if ((common->cmnd[1] & ~0x18) != 0) {
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+ }
+ if (lba >= curlun->num_sectors) {
+ curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
+ return -EINVAL;
+ }
+ file_offset = ((loff_t) lba) << 9;
+
+ /* Carry out the file reads */
+ amount_left = common->data_size_from_cmnd;
+ if (unlikely(amount_left == 0))
+ return -EIO; /* No default reply */
+
+ for (;;) {
+
+ /* Figure out how much we need to read:
+ * Try to read the remaining amount.
+ * But don't read more than the buffer size.
+ * And don't try to read past the end of the file.
+ * Finally, if we're not at a page boundary, don't read past
+ * the next page.
+ * If this means reading 0 then we were asked to read past
+ * the end of file. */
+ amount = min(amount_left, FSG_BUFLEN);
+ partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
+ if (partial_page > 0)
+ amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
+ partial_page);
+
+ /* Wait for the next buffer to become available */
+ bh = common->next_buffhd_to_fill;
+ while (bh->state != BUF_STATE_EMPTY) {
+ rc = sleep_thread(common);
+ if (rc)
+ return rc;
+ }
+
+ /* If we were asked to read past the end of file,
+ * end with an empty buffer. */
+ if (amount == 0) {
+ curlun->sense_data =
+ SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
+ curlun->info_valid = 1;
+ bh->inreq->length = 0;
+ bh->state = BUF_STATE_FULL;
+ break;
+ }
+
+ /* Perform the read */
+ nread = 0;
+ rc = ums_info->read_sector(&(ums_info->ums_dev),
+ file_offset / SECTOR_SIZE,
+ amount / SECTOR_SIZE,
+ (char __user *)bh->buf);
+ if (rc)
+ return -EIO;
+ nread = amount;
+
+ VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
+ (unsigned long long) file_offset,
+ (int) nread);
+
+ if (nread < 0) {
+ LDBG(curlun, "error in file read: %d\n",
+ (int) nread);
+ nread = 0;
+ } else if (nread < amount) {
+ LDBG(curlun, "partial file read: %d/%u\n",
+ (int) nread, amount);
+ nread -= (nread & 511); /* Round down to a block */
+ }
+ file_offset += nread;
+ amount_left -= nread;
+ common->residue -= nread;
+ bh->inreq->length = nread;
+ bh->state = BUF_STATE_FULL;
+
+ /* If an error occurred, report it and its position */
+ if (nread < amount) {
+ curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
+ curlun->info_valid = 1;
+ break;
+ }
+
+ if (amount_left == 0)
+ break; /* No more left to read */
+
+ /* Send this buffer and go read some more */
+ bh->inreq->zero = 0;
+ START_TRANSFER_OR(common, bulk_in, bh->inreq,
+ &bh->inreq_busy, &bh->state)
+ /* Don't know what to do if
+ * common->fsg is NULL */
+ return -EIO;
+ common->next_buffhd_to_fill = bh->next;
+ }
+
+ return -EIO; /* No default reply */
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int do_write(struct fsg_common *common)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ u32 lba;
+ struct fsg_buffhd *bh;
+ int get_some_more;
+ u32 amount_left_to_req, amount_left_to_write;
+ loff_t usb_offset, file_offset;
+ unsigned int amount;
+ unsigned int partial_page;
+ ssize_t nwritten;
+ int rc;
+
+ if (curlun->ro) {
+ curlun->sense_data = SS_WRITE_PROTECTED;
+ return -EINVAL;
+ }
+
+ /* Get the starting Logical Block Address and check that it's
+ * not too big */
+ if (common->cmnd[0] == SC_WRITE_6)
+ lba = get_unaligned_be24(&common->cmnd[1]);
+ else {
+ lba = get_unaligned_be32(&common->cmnd[2]);
+
+ /* We allow DPO (Disable Page Out = don't save data in the
+ * cache) and FUA (Force Unit Access = write directly to the
+ * medium). We don't implement DPO; we implement FUA by
+ * performing synchronous output. */
+ if (common->cmnd[1] & ~0x18) {
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+ }
+ if (lba >= curlun->num_sectors) {
+ curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
+ return -EINVAL;
+ }
+
+ /* Carry out the file writes */
+ get_some_more = 1;
+ file_offset = usb_offset = ((loff_t) lba) << 9;
+ amount_left_to_req = common->data_size_from_cmnd;
+ amount_left_to_write = common->data_size_from_cmnd;
+
+ while (amount_left_to_write > 0) {
+
+ /* Queue a request for more data from the host */
+ bh = common->next_buffhd_to_fill;
+ if (bh->state == BUF_STATE_EMPTY && get_some_more) {
+
+ /* Figure out how much we want to get:
+ * Try to get the remaining amount.
+ * But don't get more than the buffer size.
+ * And don't try to go past the end of the file.
+ * If we're not at a page boundary,
+ * don't go past the next page.
+ * If this means getting 0, then we were asked
+ * to write past the end of file.
+ * Finally, round down to a block boundary. */
+ amount = min(amount_left_to_req, FSG_BUFLEN);
+ partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
+ if (partial_page > 0)
+ amount = min(amount,
+ (unsigned int) PAGE_CACHE_SIZE - partial_page);
+
+ if (amount == 0) {
+ get_some_more = 0;
+ curlun->sense_data =
+ SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
+ curlun->info_valid = 1;
+ continue;
+ }
+ amount -= (amount & 511);
+ if (amount == 0) {
+
+ /* Why were we were asked to transfer a
+ * partial block? */
+ get_some_more = 0;
+ continue;
+ }
+
+ /* Get the next buffer */
+ usb_offset += amount;
+ common->usb_amount_left -= amount;
+ amount_left_to_req -= amount;
+ if (amount_left_to_req == 0)
+ get_some_more = 0;
+
+ /* amount is always divisible by 512, hence by
+ * the bulk-out maxpacket size */
+ bh->outreq->length = amount;
+ bh->bulk_out_intended_length = amount;
+ bh->outreq->short_not_ok = 1;
+ START_TRANSFER_OR(common, bulk_out, bh->outreq,
+ &bh->outreq_busy, &bh->state)
+ /* Don't know what to do if
+ * common->fsg is NULL */
+ return -EIO;
+ common->next_buffhd_to_fill = bh->next;
+ continue;
+ }
+
+ /* Write the received data to the backing file */
+ bh = common->next_buffhd_to_drain;
+ if (bh->state == BUF_STATE_EMPTY && !get_some_more)
+ break; /* We stopped early */
+ if (bh->state == BUF_STATE_FULL) {
+ common->next_buffhd_to_drain = bh->next;
+ bh->state = BUF_STATE_EMPTY;
+
+ /* Did something go wrong with the transfer? */
+ if (bh->outreq->status != 0) {
+ curlun->sense_data = SS_COMMUNICATION_FAILURE;
+ curlun->info_valid = 1;
+ break;
+ }
+
+ amount = bh->outreq->actual;
+
+ /* Perform the write */
+ rc = ums_info->write_sector(&(ums_info->ums_dev),
+ file_offset / SECTOR_SIZE,
+ amount / SECTOR_SIZE,
+ (char __user *)bh->buf);
+ if (rc)
+ return -EIO;
+ nwritten = amount;
+
+ VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
+ (unsigned long long) file_offset,
+ (int) nwritten);
+
+ if (nwritten < 0) {
+ LDBG(curlun, "error in file write: %d\n",
+ (int) nwritten);
+ nwritten = 0;
+ } else if (nwritten < amount) {
+ LDBG(curlun, "partial file write: %d/%u\n",
+ (int) nwritten, amount);
+ nwritten -= (nwritten & 511);
+ /* Round down to a block */
+ }
+ file_offset += nwritten;
+ amount_left_to_write -= nwritten;
+ common->residue -= nwritten;
+
+ /* If an error occurred, report it and its position */
+ if (nwritten < amount) {
+ curlun->sense_data = SS_WRITE_ERROR;
+ curlun->info_valid = 1;
+ break;
+ }
+
+ /* Did the host decide to stop early? */
+ if (bh->outreq->actual != bh->outreq->length) {
+ common->short_packet_received = 1;
+ break;
+ }
+ continue;
+ }
+
+ /* Wait for something to happen */
+ rc = sleep_thread(common);
+ if (rc)
+ return rc;
+ }
+
+ return -EIO; /* No default reply */
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int do_synchronize_cache(struct fsg_common *common)
+{
+ return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int do_verify(struct fsg_common *common)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ u32 lba;
+ u32 verification_length;
+ struct fsg_buffhd *bh = common->next_buffhd_to_fill;
+ loff_t file_offset;
+ u32 amount_left;
+ unsigned int amount;
+ ssize_t nread;
+ int rc;
+
+ /* Get the starting Logical Block Address and check that it's
+ * not too big */
+ lba = get_unaligned_be32(&common->cmnd[2]);
+ if (lba >= curlun->num_sectors) {
+ curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
+ return -EINVAL;
+ }
+
+ /* We allow DPO (Disable Page Out = don't save data in the
+ * cache) but we don't implement it. */
+ if (common->cmnd[1] & ~0x10) {
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+
+ verification_length = get_unaligned_be16(&common->cmnd[7]);
+ if (unlikely(verification_length == 0))
+ return -EIO; /* No default reply */
+
+ /* Prepare to carry out the file verify */
+ amount_left = verification_length << 9;
+ file_offset = ((loff_t) lba) << 9;
+
+ /* Write out all the dirty buffers before invalidating them */
+
+ /* Just try to read the requested blocks */
+ while (amount_left > 0) {
+
+ /* Figure out how much we need to read:
+ * Try to read the remaining amount, but not more than
+ * the buffer size.
+ * And don't try to read past the end of the file.
+ * If this means reading 0 then we were asked to read
+ * past the end of file. */
+ amount = min(amount_left, FSG_BUFLEN);
+ if (amount == 0) {
+ curlun->sense_data =
+ SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
+ curlun->info_valid = 1;
+ break;
+ }
+
+ /* Perform the read */
+ nread = 0;
+ rc = ums_info->read_sector(&(ums_info->ums_dev),
+ file_offset / SECTOR_SIZE,
+ amount / SECTOR_SIZE,
+ (char __user *)bh->buf);
+ if (rc)
+ return -EIO;
+ nread = amount;
+
+ VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
+ (unsigned long long) file_offset,
+ (int) nread);
+ if (nread < 0) {
+ LDBG(curlun, "error in file verify: %d\n",
+ (int) nread);
+ nread = 0;
+ } else if (nread < amount) {
+ LDBG(curlun, "partial file verify: %d/%u\n",
+ (int) nread, amount);
+ nread -= (nread & 511); /* Round down to a sector */
+ }
+ if (nread == 0) {
+ curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
+ curlun->info_valid = 1;
+ break;
+ }
+ file_offset += nread;
+ amount_left -= nread;
+ }
+ return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ static const char vendor_id[] = "Linux ";
+ u8 *buf = (u8 *) bh->buf;
+
+ if (!curlun) { /* Unsupported LUNs are okay */
+ common->bad_lun_okay = 1;
+ memset(buf, 0, 36);
+ buf[0] = 0x7f; /* Unsupported, no device-type */
+ buf[4] = 31; /* Additional length */
+ return 36;
+ }
+
+ memset(buf, 0, 8);
+ buf[0] = TYPE_DISK;
+ buf[2] = 2; /* ANSI SCSI level 2 */
+ buf[3] = 2; /* SCSI-2 INQUIRY data format */
+ buf[4] = 31; /* Additional length */
+ /* No special options */
+ sprintf((char *) (buf + 8), "%-8s%-16s%04x", (char*) vendor_id ,
+ ums_info->name, (u16) 0xffff);
+
+ return 36;
+}
+
+
+static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ u8 *buf = (u8 *) bh->buf;
+ u32 sd, sdinfo;
+ int valid;
+
+ /*
+ * From the SCSI-2 spec., section 7.9 (Unit attention condition):
+ *
+ * If a REQUEST SENSE command is received from an initiator
+ * with a pending unit attention condition (before the target
+ * generates the contingent allegiance condition), then the
+ * target shall either:
+ * a) report any pending sense data and preserve the unit
+ * attention condition on the logical unit, or,
+ * b) report the unit attention condition, may discard any
+ * pending sense data, and clear the unit attention
+ * condition on the logical unit for that initiator.
+ *
+ * FSG normally uses option a); enable this code to use option b).
+ */
+#if 0
+ if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
+ curlun->sense_data = curlun->unit_attention_data;
+ curlun->unit_attention_data = SS_NO_SENSE;
+ }
+#endif
+
+ if (!curlun) { /* Unsupported LUNs are okay */
+ common->bad_lun_okay = 1;
+ sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
+ sdinfo = 0;
+ valid = 0;
+ } else {
+ sd = curlun->sense_data;
+ valid = curlun->info_valid << 7;
+ curlun->sense_data = SS_NO_SENSE;
+ curlun->info_valid = 0;
+ }
+
+ memset(buf, 0, 18);
+ buf[0] = valid | 0x70; /* Valid, current error */
+ buf[2] = SK(sd);
+ put_unaligned_be32(sdinfo, &buf[3]); /* Sense information */
+ buf[7] = 18 - 8; /* Additional sense length */
+ buf[12] = ASC(sd);
+ buf[13] = ASCQ(sd);
+ return 18;
+}
+
+static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ u32 lba = get_unaligned_be32(&common->cmnd[2]);
+ int pmi = common->cmnd[8];
+ u8 *buf = (u8 *) bh->buf;
+
+ /* Check the PMI and LBA fields */
+ if (pmi > 1 || (pmi == 0 && lba != 0)) {
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+
+ put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
+ /* Max logical block */
+ put_unaligned_be32(512, &buf[4]); /* Block length */
+ return 8;
+}
+
+static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ int msf = common->cmnd[1] & 0x02;
+ u32 lba = get_unaligned_be32(&common->cmnd[2]);
+ u8 *buf = (u8 *) bh->buf;
+
+ if (common->cmnd[1] & ~0x02) { /* Mask away MSF */
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+ if (lba >= curlun->num_sectors) {
+ curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
+ return -EINVAL;
+ }
+
+ memset(buf, 0, 8);
+ buf[0] = 0x01; /* 2048 bytes of user data, rest is EC */
+ store_cdrom_address(&buf[4], msf, lba);
+ return 8;
+}
+
+
+static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ int msf = common->cmnd[1] & 0x02;
+ int start_track = common->cmnd[6];
+ u8 *buf = (u8 *) bh->buf;
+
+ if ((common->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */
+ start_track > 1) {
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+
+ memset(buf, 0, 20);
+ buf[1] = (20-2); /* TOC data length */
+ buf[2] = 1; /* First track number */
+ buf[3] = 1; /* Last track number */
+ buf[5] = 0x16; /* Data track, copying allowed */
+ buf[6] = 0x01; /* Only track is number 1 */
+ store_cdrom_address(&buf[8], msf, 0);
+
+ buf[13] = 0x16; /* Lead-out track is data */
+ buf[14] = 0xAA; /* Lead-out track number */
+ store_cdrom_address(&buf[16], msf, curlun->num_sectors);
+
+ return 20;
+}
+
+static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ int mscmnd = common->cmnd[0];
+ u8 *buf = (u8 *) bh->buf;
+ u8 *buf0 = buf;
+ int pc, page_code;
+ int changeable_values, all_pages;
+ int valid_page = 0;
+ int len, limit;
+
+ if ((common->cmnd[1] & ~0x08) != 0) { /* Mask away DBD */
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+ pc = common->cmnd[2] >> 6;
+ page_code = common->cmnd[2] & 0x3f;
+ if (pc == 3) {
+ curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
+ return -EINVAL;
+ }
+ changeable_values = (pc == 1);
+ all_pages = (page_code == 0x3f);
+
+ /* Write the mode parameter header. Fixed values are: default
+ * medium type, no cache control (DPOFUA), and no block descriptors.
+ * The only variable value is the WriteProtect bit. We will fill in
+ * the mode data length later. */
+ memset(buf, 0, 8);
+ if (mscmnd == SC_MODE_SENSE_6) {
+ buf[2] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
+ buf += 4;
+ limit = 255;
+ } else { /* SC_MODE_SENSE_10 */
+ buf[3] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
+ buf += 8;
+ limit = 65535; /* Should really be FSG_BUFLEN */
+ }
+
+ /* No block descriptors */
+
+ /* The mode pages, in numerical order. The only page we support
+ * is the Caching page. */
+ if (page_code == 0x08 || all_pages) {
+ valid_page = 1;
+ buf[0] = 0x08; /* Page code */
+ buf[1] = 10; /* Page length */
+ memset(buf+2, 0, 10); /* None of the fields are changeable */
+
+ if (!changeable_values) {
+ buf[2] = 0x04; /* Write cache enable, */
+ /* Read cache not disabled */
+ /* No cache retention priorities */
+ put_unaligned_be16(0xffff, &buf[4]);
+ /* Don't disable prefetch */
+ /* Minimum prefetch = 0 */
+ put_unaligned_be16(0xffff, &buf[8]);
+ /* Maximum prefetch */
+ put_unaligned_be16(0xffff, &buf[10]);
+ /* Maximum prefetch ceiling */
+ }
+ buf += 12;
+ }
+
+ /* Check that a valid page was requested and the mode data length
+ * isn't too long. */
+ len = buf - buf0;
+ if (!valid_page || len > limit) {
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+
+ /* Store the mode data length */
+ if (mscmnd == SC_MODE_SENSE_6)
+ buf0[0] = len - 1;
+ else
+ put_unaligned_be16(len - 2, buf0);
+ return len;
+}
+
+
+static int do_start_stop(struct fsg_common *common)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+
+ if (!curlun) {
+ return -EINVAL;
+ } else if (!curlun->removable) {
+ curlun->sense_data = SS_INVALID_COMMAND;
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int do_prevent_allow(struct fsg_common *common)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ int prevent;
+
+ if (!curlun->removable) {
+ curlun->sense_data = SS_INVALID_COMMAND;
+ return -EINVAL;
+ }
+
+ prevent = common->cmnd[4] & 0x01;
+ if ((common->cmnd[4] & ~0x01) != 0) { /* Mask away Prevent */
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+
+ if (curlun->prevent_medium_removal && !prevent)
+ fsg_lun_fsync_sub(curlun);
+ curlun->prevent_medium_removal = prevent;
+ return 0;
+}
+
+
+static int do_read_format_capacities(struct fsg_common *common,
+ struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ u8 *buf = (u8 *) bh->buf;
+
+ buf[0] = buf[1] = buf[2] = 0;
+ buf[3] = 8; /* Only the Current/Maximum Capacity Descriptor */
+ buf += 4;
+
+ put_unaligned_be32(curlun->num_sectors, &buf[0]);
+ /* Number of blocks */
+ put_unaligned_be32(512, &buf[4]); /* Block length */
+ buf[4] = 0x02; /* Current capacity */
+ return 12;
+}
+
+
+static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+
+ /* We don't support MODE SELECT */
+ if (curlun)
+ curlun->sense_data = SS_INVALID_COMMAND;
+ return -EINVAL;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
+{
+ int rc;
+
+ rc = fsg_set_halt(fsg, fsg->bulk_in);
+ if (rc == -EAGAIN)
+ VDBG(fsg, "delayed bulk-in endpoint halt\n");
+ while (rc != 0) {
+ if (rc != -EAGAIN) {
+ WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
+ rc = 0;
+ break;
+ }
+
+ rc = usb_ep_set_halt(fsg->bulk_in);
+ }
+ return rc;
+}
+
+static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
+{
+ int rc;
+
+ DBG(fsg, "bulk-in set wedge\n");
+ rc = 0; /* usb_ep_set_wedge(fsg->bulk_in); */
+ if (rc == -EAGAIN)
+ VDBG(fsg, "delayed bulk-in endpoint wedge\n");
+ while (rc != 0) {
+ if (rc != -EAGAIN) {
+ WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
+ rc = 0;
+ break;
+ }
+ }
+ return rc;
+}
+
+static int pad_with_zeros(struct fsg_dev *fsg)
+{
+ struct fsg_buffhd *bh = fsg->common->next_buffhd_to_fill;
+ u32 nkeep = bh->inreq->length;
+ u32 nsend;
+ int rc;
+
+ bh->state = BUF_STATE_EMPTY; /* For the first iteration */
+ fsg->common->usb_amount_left = nkeep + fsg->common->residue;
+ while (fsg->common->usb_amount_left > 0) {
+
+ /* Wait for the next buffer to be free */
+ while (bh->state != BUF_STATE_EMPTY) {
+ rc = sleep_thread(fsg->common);
+ if (rc)
+ return rc;
+ }
+
+ nsend = min(fsg->common->usb_amount_left, FSG_BUFLEN);
+ memset(bh->buf + nkeep, 0, nsend - nkeep);
+ bh->inreq->length = nsend;
+ bh->inreq->zero = 0;
+ start_transfer(fsg, fsg->bulk_in, bh->inreq,
+ &bh->inreq_busy, &bh->state);
+ bh = fsg->common->next_buffhd_to_fill = bh->next;
+ fsg->common->usb_amount_left -= nsend;
+ nkeep = 0;
+ }
+ return 0;
+}
+
+static int throw_away_data(struct fsg_common *common)
+{
+ struct fsg_buffhd *bh;
+ u32 amount;
+ int rc;
+
+ for (bh = common->next_buffhd_to_drain;
+ bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
+ bh = common->next_buffhd_to_drain) {
+
+ /* Throw away the data in a filled buffer */
+ if (bh->state == BUF_STATE_FULL) {
+ bh->state = BUF_STATE_EMPTY;
+ common->next_buffhd_to_drain = bh->next;
+
+ /* A short packet or an error ends everything */
+ if (bh->outreq->actual != bh->outreq->length ||
+ bh->outreq->status != 0) {
+ raise_exception(common,
+ FSG_STATE_ABORT_BULK_OUT);
+ return -EINTR;
+ }
+ continue;
+ }
+
+ /* Try to submit another request if we need one */
+ bh = common->next_buffhd_to_fill;
+ if (bh->state == BUF_STATE_EMPTY
+ && common->usb_amount_left > 0) {
+ amount = min(common->usb_amount_left, FSG_BUFLEN);
+
+ /* amount is always divisible by 512, hence by
+ * the bulk-out maxpacket size */
+ bh->outreq->length = amount;
+ bh->bulk_out_intended_length = amount;
+ bh->outreq->short_not_ok = 1;
+ START_TRANSFER_OR(common, bulk_out, bh->outreq,
+ &bh->outreq_busy, &bh->state)
+ /* Don't know what to do if
+ * common->fsg is NULL */
+ return -EIO;
+ common->next_buffhd_to_fill = bh->next;
+ common->usb_amount_left -= amount;
+ continue;
+ }
+
+ /* Otherwise wait for something to happen */
+ rc = sleep_thread(common);
+ if (rc)
+ return rc;
+ }
+ return 0;
+}
+
+
+static int finish_reply(struct fsg_common *common)
+{
+ struct fsg_buffhd *bh = common->next_buffhd_to_fill;
+ int rc = 0;
+
+ switch (common->data_dir) {
+ case DATA_DIR_NONE:
+ break; /* Nothing to send */
+
+ /* If we don't know whether the host wants to read or write,
+ * this must be CB or CBI with an unknown command. We mustn't
+ * try to send or receive any data. So stall both bulk pipes
+ * if we can and wait for a reset. */
+ case DATA_DIR_UNKNOWN:
+ if (!common->can_stall) {
+ /* Nothing */
+ } else if (fsg_is_set(common)) {
+ fsg_set_halt(common->fsg, common->fsg->bulk_out);
+ rc = halt_bulk_in_endpoint(common->fsg);
+ } else {
+ /* Don't know what to do if common->fsg is NULL */
+ rc = -EIO;
+ }
+ break;
+
+ /* All but the last buffer of data must have already been sent */
+ case DATA_DIR_TO_HOST:
+ if (common->data_size == 0) {
+ /* Nothing to send */
+
+ /* If there's no residue, simply send the last buffer */
+ } else if (common->residue == 0) {
+ bh->inreq->zero = 0;
+ START_TRANSFER_OR(common, bulk_in, bh->inreq,
+ &bh->inreq_busy, &bh->state)
+ return -EIO;
+ common->next_buffhd_to_fill = bh->next;
+
+ /* For Bulk-only, if we're allowed to stall then send the
+ * short packet and halt the bulk-in endpoint. If we can't
+ * stall, pad out the remaining data with 0's. */
+ } else if (common->can_stall) {
+ bh->inreq->zero = 1;
+ START_TRANSFER_OR(common, bulk_in, bh->inreq,
+ &bh->inreq_busy, &bh->state)
+ /* Don't know what to do if
+ * common->fsg is NULL */
+ rc = -EIO;
+ common->next_buffhd_to_fill = bh->next;
+ if (common->fsg)
+ rc = halt_bulk_in_endpoint(common->fsg);
+ } else if (fsg_is_set(common)) {
+ rc = pad_with_zeros(common->fsg);
+ } else {
+ /* Don't know what to do if common->fsg is NULL */
+ rc = -EIO;
+ }
+ break;
+
+ /* We have processed all we want from the data the host has sent.
+ * There may still be outstanding bulk-out requests. */
+ case DATA_DIR_FROM_HOST:
+ if (common->residue == 0) {
+ /* Nothing to receive */
+
+ /* Did the host stop sending unexpectedly early? */
+ } else if (common->short_packet_received) {
+ raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
+ rc = -EINTR;
+
+ /* We haven't processed all the incoming data. Even though
+ * we may be allowed to stall, doing so would cause a race.
+ * The controller may already have ACK'ed all the remaining
+ * bulk-out packets, in which case the host wouldn't see a
+ * STALL. Not realizing the endpoint was halted, it wouldn't
+ * clear the halt -- leading to problems later on. */
+#if 0
+ } else if (common->can_stall) {
+ if (fsg_is_set(common))
+ fsg_set_halt(common->fsg,
+ common->fsg->bulk_out);
+ raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
+ rc = -EINTR;
+#endif
+
+ /* We can't stall. Read in the excess data and throw it
+ * all away. */
+ } else {
+ rc = throw_away_data(common);
+ }
+ break;
+ }
+ return rc;
+}
+
+
+static int send_status(struct fsg_common *common)
+{
+ struct fsg_lun *curlun = &common->luns[common->lun];
+ struct fsg_buffhd *bh;
+ struct bulk_cs_wrap *csw;
+ int rc;
+ u8 status = USB_STATUS_PASS;
+ u32 sd, sdinfo = 0;
+
+ /* Wait for the next buffer to become available */
+ bh = common->next_buffhd_to_fill;
+ while (bh->state != BUF_STATE_EMPTY) {
+ rc = sleep_thread(common);
+ if (rc)
+ return rc;
+ }
+
+ if (curlun)
+ sd = curlun->sense_data;
+ else if (common->bad_lun_okay)
+ sd = SS_NO_SENSE;
+ else
+ sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
+
+ if (common->phase_error) {
+ DBG(common, "sending phase-error status\n");
+ status = USB_STATUS_PHASE_ERROR;
+ sd = SS_INVALID_COMMAND;
+ } else if (sd != SS_NO_SENSE) {
+ DBG(common, "sending command-failure status\n");
+ status = USB_STATUS_FAIL;
+ VDBG(common, " sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
+ " info x%x\n",
+ SK(sd), ASC(sd), ASCQ(sd), sdinfo);
+ }
+
+ /* Store and send the Bulk-only CSW */
+ csw = (void *)bh->buf;
+
+ csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
+ csw->Tag = common->tag;
+ csw->Residue = cpu_to_le32(common->residue);
+ csw->Status = status;
+
+ bh->inreq->length = USB_BULK_CS_WRAP_LEN;
+ bh->inreq->zero = 0;
+ START_TRANSFER_OR(common, bulk_in, bh->inreq,
+ &bh->inreq_busy, &bh->state)
+ /* Don't know what to do if common->fsg is NULL */
+ return -EIO;
+
+ common->next_buffhd_to_fill = bh->next;
+ return 0;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* Check whether the command is properly formed and whether its data size
+ * and direction agree with the values we already have. */
+static int check_command(struct fsg_common *common, int cmnd_size,
+ enum data_direction data_dir, unsigned int mask,
+ int needs_medium, const char *name)
+{
+ int i;
+ int lun = common->cmnd[1] >> 5;
+ static const char dirletter[4] = {'u', 'o', 'i', 'n'};
+ char hdlen[20];
+ struct fsg_lun *curlun;
+
+ hdlen[0] = 0;
+ if (common->data_dir != DATA_DIR_UNKNOWN)
+ sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
+ common->data_size);
+ VDBG(common, "SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n",
+ name, cmnd_size, dirletter[(int) data_dir],
+ common->data_size_from_cmnd, common->cmnd_size, hdlen);
+
+ /* We can't reply at all until we know the correct data direction
+ * and size. */
+ if (common->data_size_from_cmnd == 0)
+ data_dir = DATA_DIR_NONE;
+ if (common->data_size < common->data_size_from_cmnd) {
+ /* Host data size < Device data size is a phase error.
+ * Carry out the command, but only transfer as much as
+ * we are allowed. */
+ common->data_size_from_cmnd = common->data_size;
+ common->phase_error = 1;
+ }
+ common->residue = common->data_size;
+ common->usb_amount_left = common->data_size;
+
+ /* Conflicting data directions is a phase error */
+ if (common->data_dir != data_dir
+ && common->data_size_from_cmnd > 0) {
+ common->phase_error = 1;
+ return -EINVAL;
+ }
+
+ /* Verify the length of the command itself */
+ if (cmnd_size != common->cmnd_size) {
+
+ /* Special case workaround: There are plenty of buggy SCSI
+ * implementations. Many have issues with cbw->Length
+ * field passing a wrong command size. For those cases we
+ * always try to work around the problem by using the length
+ * sent by the host side provided it is at least as large
+ * as the correct command length.
+ * Examples of such cases would be MS-Windows, which issues
+ * REQUEST SENSE with cbw->Length == 12 where it should
+ * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
+ * REQUEST SENSE with cbw->Length == 10 where it should
+ * be 6 as well.
+ */
+ if (cmnd_size <= common->cmnd_size) {
+ DBG(common, "%s is buggy! Expected length %d "
+ "but we got %d\n", name,
+ cmnd_size, common->cmnd_size);
+ cmnd_size = common->cmnd_size;
+ } else {
+ common->phase_error = 1;
+ return -EINVAL;
+ }
+ }
+
+ /* Check that the LUN values are consistent */
+ if (common->lun != lun)
+ DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
+ common->lun, lun);
+
+ /* Check the LUN */
+ if (common->lun >= 0 && common->lun < common->nluns) {
+ curlun = &common->luns[common->lun];
+ if (common->cmnd[0] != SC_REQUEST_SENSE) {
+ curlun->sense_data = SS_NO_SENSE;
+ curlun->info_valid = 0;
+ }
+ } else {
+ curlun = NULL;
+ common->bad_lun_okay = 0;
+
+ /* INQUIRY and REQUEST SENSE commands are explicitly allowed
+ * to use unsupported LUNs; all others may not. */
+ if (common->cmnd[0] != SC_INQUIRY &&
+ common->cmnd[0] != SC_REQUEST_SENSE) {
+ DBG(common, "unsupported LUN %d\n", common->lun);
+ return -EINVAL;
+ }
+ }
+#if 0
+ /* If a unit attention condition exists, only INQUIRY and
+ * REQUEST SENSE commands are allowed; anything else must fail. */
+ if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
+ common->cmnd[0] != SC_INQUIRY &&
+ common->cmnd[0] != SC_REQUEST_SENSE) {
+ curlun->sense_data = curlun->unit_attention_data;
+ curlun->unit_attention_data = SS_NO_SENSE;
+ return -EINVAL;
+ }
+#endif
+ /* Check that only command bytes listed in the mask are non-zero */
+ common->cmnd[1] &= 0x1f; /* Mask away the LUN */
+ for (i = 1; i < cmnd_size; ++i) {
+ if (common->cmnd[i] && !(mask & (1 << i))) {
+ if (curlun)
+ curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+
+static int do_scsi_command(struct fsg_common *common)
+{
+ struct fsg_buffhd *bh;
+ int rc;
+ int reply = -EINVAL;
+ int i;
+ static char unknown[16];
+ struct fsg_lun *curlun = &common->luns[common->lun];
+
+ dump_cdb(common);
+
+ /* Wait for the next buffer to become available for data or status */
+ bh = common->next_buffhd_to_fill;
+ common->next_buffhd_to_drain = bh;
+ while (bh->state != BUF_STATE_EMPTY) {
+ rc = sleep_thread(common);
+ if (rc)
+ return rc;
+ }
+ common->phase_error = 0;
+ common->short_packet_received = 0;
+
+ down_read(&common->filesem); /* We're using the backing file */
+ switch (common->cmnd[0]) {
+
+ case SC_INQUIRY:
+ common->data_size_from_cmnd = common->cmnd[4];
+ reply = check_command(common, 6, DATA_DIR_TO_HOST,
+ (1<<4), 0,
+ "INQUIRY");
+ if (reply == 0)
+ reply = do_inquiry(common, bh);
+ break;
+
+ case SC_MODE_SELECT_6:
+ common->data_size_from_cmnd = common->cmnd[4];
+ reply = check_command(common, 6, DATA_DIR_FROM_HOST,
+ (1<<1) | (1<<4), 0,
+ "MODE SELECT(6)");
+ if (reply == 0)
+ reply = do_mode_select(common, bh);
+ break;
+
+ case SC_MODE_SELECT_10:
+ common->data_size_from_cmnd =
+ get_unaligned_be16(&common->cmnd[7]);
+ reply = check_command(common, 10, DATA_DIR_FROM_HOST,
+ (1<<1) | (3<<7), 0,
+ "MODE SELECT(10)");
+ if (reply == 0)
+ reply = do_mode_select(common, bh);
+ break;
+
+ case SC_MODE_SENSE_6:
+ common->data_size_from_cmnd = common->cmnd[4];
+ reply = check_command(common, 6, DATA_DIR_TO_HOST,
+ (1<<1) | (1<<2) | (1<<4), 0,
+ "MODE SENSE(6)");
+ if (reply == 0)
+ reply = do_mode_sense(common, bh);
+ break;
+
+ case SC_MODE_SENSE_10:
+ common->data_size_from_cmnd =
+ get_unaligned_be16(&common->cmnd[7]);
+ reply = check_command(common, 10, DATA_DIR_TO_HOST,
+ (1<<1) | (1<<2) | (3<<7), 0,
+ "MODE SENSE(10)");
+ if (reply == 0)
+ reply = do_mode_sense(common, bh);
+ break;
+
+ case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
+ common->data_size_from_cmnd = 0;
+ reply = check_command(common, 6, DATA_DIR_NONE,
+ (1<<4), 0,
+ "PREVENT-ALLOW MEDIUM REMOVAL");
+ if (reply == 0)
+ reply = do_prevent_allow(common);
+ break;
+
+ case SC_READ_6:
+ i = common->cmnd[4];
+ common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+ reply = check_command(common, 6, DATA_DIR_TO_HOST,
+ (7<<1) | (1<<4), 1,
+ "READ(6)");
+ if (reply == 0)
+ reply = do_read(common);
+ break;
+
+ case SC_READ_10:
+ common->data_size_from_cmnd =
+ get_unaligned_be16(&common->cmnd[7]) << 9;
+ reply = check_command(common, 10, DATA_DIR_TO_HOST,
+ (1<<1) | (0xf<<2) | (3<<7), 1,
+ "READ(10)");
+ if (reply == 0)
+ reply = do_read(common);
+ break;
+
+ case SC_READ_12:
+ common->data_size_from_cmnd =
+ get_unaligned_be32(&common->cmnd[6]) << 9;
+ reply = check_command(common, 12, DATA_DIR_TO_HOST,
+ (1<<1) | (0xf<<2) | (0xf<<6), 1,
+ "READ(12)");
+ if (reply == 0)
+ reply = do_read(common);
+ break;
+
+ case SC_READ_CAPACITY:
+ common->data_size_from_cmnd = 8;
+ reply = check_command(common, 10, DATA_DIR_TO_HOST,
+ (0xf<<2) | (1<<8), 1,
+ "READ CAPACITY");
+ if (reply == 0)
+ reply = do_read_capacity(common, bh);
+ break;
+
+ case SC_READ_HEADER:
+ if (!common->luns[common->lun].cdrom)
+ goto unknown_cmnd;
+ common->data_size_from_cmnd =
+ get_unaligned_be16(&common->cmnd[7]);
+ reply = check_command(common, 10, DATA_DIR_TO_HOST,
+ (3<<7) | (0x1f<<1), 1,
+ "READ HEADER");
+ if (reply == 0)
+ reply = do_read_header(common, bh);
+ break;
+
+ case SC_READ_TOC:
+ if (!common->luns[common->lun].cdrom)
+ goto unknown_cmnd;
+ common->data_size_from_cmnd =
+ get_unaligned_be16(&common->cmnd[7]);
+ reply = check_command(common, 10, DATA_DIR_TO_HOST,
+ (7<<6) | (1<<1), 1,
+ "READ TOC");
+ if (reply == 0)
+ reply = do_read_toc(common, bh);
+ break;
+
+ case SC_READ_FORMAT_CAPACITIES:
+ common->data_size_from_cmnd =
+ get_unaligned_be16(&common->cmnd[7]);
+ reply = check_command(common, 10, DATA_DIR_TO_HOST,
+ (3<<7), 1,
+ "READ FORMAT CAPACITIES");
+ if (reply == 0)
+ reply = do_read_format_capacities(common, bh);
+ break;
+
+ case SC_REQUEST_SENSE:
+ common->data_size_from_cmnd = common->cmnd[4];
+ reply = check_command(common, 6, DATA_DIR_TO_HOST,
+ (1<<4), 0,
+ "REQUEST SENSE");
+ if (reply == 0)
+ reply = do_request_sense(common, bh);
+ break;
+
+ case SC_START_STOP_UNIT:
+ common->data_size_from_cmnd = 0;
+ reply = check_command(common, 6, DATA_DIR_NONE,
+ (1<<1) | (1<<4), 0,
+ "START-STOP UNIT");
+ if (reply == 0)
+ reply = do_start_stop(common);
+ break;
+
+ case SC_SYNCHRONIZE_CACHE:
+ common->data_size_from_cmnd = 0;
+ reply = check_command(common, 10, DATA_DIR_NONE,
+ (0xf<<2) | (3<<7), 1,
+ "SYNCHRONIZE CACHE");
+ if (reply == 0)
+ reply = do_synchronize_cache(common);
+ break;
+
+ case SC_TEST_UNIT_READY:
+ common->data_size_from_cmnd = 0;
+ reply = check_command(common, 6, DATA_DIR_NONE,
+ 0, 1,
+ "TEST UNIT READY");
+ break;
+
+ /* Although optional, this command is used by MS-Windows. We
+ * support a minimal version: BytChk must be 0. */
+ case SC_VERIFY:
+ common->data_size_from_cmnd = 0;
+ reply = check_command(common, 10, DATA_DIR_NONE,
+ (1<<1) | (0xf<<2) | (3<<7), 1,
+ "VERIFY");
+ if (reply == 0)
+ reply = do_verify(common);
+ break;
+
+ case SC_WRITE_6:
+ i = common->cmnd[4];
+ common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
+ reply = check_command(common, 6, DATA_DIR_FROM_HOST,
+ (7<<1) | (1<<4), 1,
+ "WRITE(6)");
+ if (reply == 0)
+ reply = do_write(common);
+ break;
+
+ case SC_WRITE_10:
+ common->data_size_from_cmnd =
+ get_unaligned_be16(&common->cmnd[7]) << 9;
+ reply = check_command(common, 10, DATA_DIR_FROM_HOST,
+ (1<<1) | (0xf<<2) | (3<<7), 1,
+ "WRITE(10)");
+ if (reply == 0)
+ reply = do_write(common);
+ break;
+
+ case SC_WRITE_12:
+ common->data_size_from_cmnd =
+ get_unaligned_be32(&common->cmnd[6]) << 9;
+ reply = check_command(common, 12, DATA_DIR_FROM_HOST,
+ (1<<1) | (0xf<<2) | (0xf<<6), 1,
+ "WRITE(12)");
+ if (reply == 0)
+ reply = do_write(common);
+ break;
+
+ /* Some mandatory commands that we recognize but don't implement.
+ * They don't mean much in this setting. It's left as an exercise
+ * for anyone interested to implement RESERVE and RELEASE in terms
+ * of Posix locks. */
+ case SC_FORMAT_UNIT:
+ case SC_RELEASE:
+ case SC_RESERVE:
+ case SC_SEND_DIAGNOSTIC:
+ /* Fall through */
+
+ default:
+unknown_cmnd:
+ common->data_size_from_cmnd = 0;
+ sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
+ reply = check_command(common, common->cmnd_size,
+ DATA_DIR_UNKNOWN, 0xff, 0, unknown);
+ if (reply == 0) {
+ curlun->sense_data = SS_INVALID_COMMAND;
+ reply = -EINVAL;
+ }
+ break;
+ }
+ up_read(&common->filesem);
+
+ if (reply == -EINTR)
+ return -EINTR;
+
+ /* Set up the single reply buffer for finish_reply() */
+ if (reply == -EINVAL)
+ reply = 0; /* Error reply length */
+ if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
+ reply = min((u32) reply, common->data_size_from_cmnd);
+ bh->inreq->length = reply;
+ bh->state = BUF_STATE_FULL;
+ common->residue -= reply;
+ } /* Otherwise it's already set */
+
+ return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
+{
+ struct usb_request *req = bh->outreq;
+ struct fsg_bulk_cb_wrap *cbw = req->buf;
+ struct fsg_common *common = fsg->common;
+
+ /* Was this a real packet? Should it be ignored? */
+ if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
+ return -EINVAL;
+
+ /* Is the CBW valid? */
+ if (req->actual != USB_BULK_CB_WRAP_LEN ||
+ cbw->Signature != cpu_to_le32(
+ USB_BULK_CB_SIG)) {
+ DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
+ req->actual,
+ le32_to_cpu(cbw->Signature));
+
+ /* The Bulk-only spec says we MUST stall the IN endpoint
+ * (6.6.1), so it's unavoidable. It also says we must
+ * retain this state until the next reset, but there's
+ * no way to tell the controller driver it should ignore
+ * Clear-Feature(HALT) requests.
+ *
+ * We aren't required to halt the OUT endpoint; instead
+ * we can simply accept and discard any data received
+ * until the next reset. */
+ wedge_bulk_in_endpoint(fsg);
+ set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
+ return -EINVAL;
+ }
+
+ /* Is the CBW meaningful? */
+ if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
+ cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
+ DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
+ "cmdlen %u\n",
+ cbw->Lun, cbw->Flags, cbw->Length);
+
+ /* We can do anything we want here, so let's stall the
+ * bulk pipes if we are allowed to. */
+ if (common->can_stall) {
+ fsg_set_halt(fsg, fsg->bulk_out);
+ halt_bulk_in_endpoint(fsg);
+ }
+ return -EINVAL;
+ }
+
+ /* Save the command for later */
+ common->cmnd_size = cbw->Length;
+ memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
+ if (cbw->Flags & USB_BULK_IN_FLAG)
+ common->data_dir = DATA_DIR_TO_HOST;
+ else
+ common->data_dir = DATA_DIR_FROM_HOST;
+ common->data_size = le32_to_cpu(cbw->DataTransferLength);
+ if (common->data_size == 0)
+ common->data_dir = DATA_DIR_NONE;
+ common->lun = cbw->Lun;
+ common->tag = cbw->Tag;
+ return 0;
+}
+
+
+static int get_next_command(struct fsg_common *common)
+{
+ struct fsg_buffhd *bh;
+ int rc = 0;
+
+ /* Wait for the next buffer to become available */
+ bh = common->next_buffhd_to_fill;
+ while (bh->state != BUF_STATE_EMPTY) {
+ rc = sleep_thread(common);
+ if (rc)
+ return rc;
+ }
+
+ /* Queue a request to read a Bulk-only CBW */
+ set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
+ bh->outreq->short_not_ok = 1;
+ START_TRANSFER_OR(common, bulk_out, bh->outreq,
+ &bh->outreq_busy, &bh->state)
+ /* Don't know what to do if common->fsg is NULL */
+ return -EIO;
+
+ /* We will drain the buffer in software, which means we
+ * can reuse it for the next filling. No need to advance
+ * next_buffhd_to_fill. */
+
+ /* Wait for the CBW to arrive */
+ while (bh->state != BUF_STATE_FULL) {
+ rc = sleep_thread(common);
+ if (rc)
+ return rc;
+ }
+
+ rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
+ bh->state = BUF_STATE_EMPTY;
+
+ return rc;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
+ const struct usb_endpoint_descriptor *d)
+{
+ int rc;
+
+ ep->driver_data = common;
+ rc = usb_ep_enable(ep, d);
+ if (rc)
+ ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
+ return rc;
+}
+
+static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
+ struct usb_request **preq)
+{
+ *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
+ if (*preq)
+ return 0;
+ ERROR(common, "can't allocate request for %s\n", ep->name);
+ return -ENOMEM;
+}
+
+/* Reset interface setting and re-init endpoint state (toggle etc). */
+static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
+{
+ const struct usb_endpoint_descriptor *d;
+ struct fsg_dev *fsg;
+ int i, rc = 0;
+
+ if (common->running)
+ DBG(common, "reset interface\n");
+
+reset:
+ /* Deallocate the requests */
+ if (common->fsg) {
+ fsg = common->fsg;
+
+ for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+ struct fsg_buffhd *bh = &common->buffhds[i];
+
+ if (bh->inreq) {
+ usb_ep_free_request(fsg->bulk_in, bh->inreq);
+ bh->inreq = NULL;
+ }
+ if (bh->outreq) {
+ usb_ep_free_request(fsg->bulk_out, bh->outreq);
+ bh->outreq = NULL;
+ }
+ }
+
+ /* Disable the endpoints */
+ if (fsg->bulk_in_enabled) {
+ usb_ep_disable(fsg->bulk_in);
+ fsg->bulk_in_enabled = 0;
+ }
+ if (fsg->bulk_out_enabled) {
+ usb_ep_disable(fsg->bulk_out);
+ fsg->bulk_out_enabled = 0;
+ }
+
+ common->fsg = NULL;
+ /* wake_up(&common->fsg_wait); */
+ }
+
+ common->running = 0;
+ if (!new_fsg || rc)
+ return rc;
+
+ common->fsg = new_fsg;
+ fsg = common->fsg;
+
+ /* Enable the endpoints */
+ d = fsg_ep_desc(common->gadget,
+ &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
+ rc = enable_endpoint(common, fsg->bulk_in, d);
+ if (rc)
+ goto reset;
+ fsg->bulk_in_enabled = 1;
+
+ d = fsg_ep_desc(common->gadget,
+ &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
+ rc = enable_endpoint(common, fsg->bulk_out, d);
+ if (rc)
+ goto reset;
+ fsg->bulk_out_enabled = 1;
+ common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
+ clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
+
+ /* Allocate the requests */
+ for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+ struct fsg_buffhd *bh = &common->buffhds[i];
+
+ rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
+ if (rc)
+ goto reset;
+ rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
+ if (rc)
+ goto reset;
+ bh->inreq->buf = bh->outreq->buf = bh->buf;
+ bh->inreq->context = bh->outreq->context = bh;
+ bh->inreq->complete = bulk_in_complete;
+ bh->outreq->complete = bulk_out_complete;
+ }
+
+ common->running = 1;
+
+ return rc;
+}
+
+
+/****************************** ALT CONFIGS ******************************/
+
+
+static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+ struct fsg_dev *fsg = fsg_from_func(f);
+ fsg->common->new_fsg = fsg;
+ raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
+ return 0;
+}
+
+static void fsg_disable(struct usb_function *f)
+{
+ struct fsg_dev *fsg = fsg_from_func(f);
+ fsg->common->new_fsg = NULL;
+ raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void handle_exception(struct fsg_common *common)
+{
+ int i;
+ struct fsg_buffhd *bh;
+ enum fsg_state old_state;
+ struct fsg_lun *curlun;
+ unsigned int exception_req_tag;
+
+ /* Cancel all the pending transfers */
+ if (common->fsg) {
+ for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+ bh = &common->buffhds[i];
+ if (bh->inreq_busy)
+ usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
+ if (bh->outreq_busy)
+ usb_ep_dequeue(common->fsg->bulk_out,
+ bh->outreq);
+ }
+
+ /* Wait until everything is idle */
+ for (;;) {
+ int num_active = 0;
+ for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+ bh = &common->buffhds[i];
+ num_active += bh->inreq_busy + bh->outreq_busy;
+ }
+ if (num_active == 0)
+ break;
+ if (sleep_thread(common))
+ return;
+ }
+
+ /* Clear out the controller's fifos */
+ if (common->fsg->bulk_in_enabled)
+ usb_ep_fifo_flush(common->fsg->bulk_in);
+ if (common->fsg->bulk_out_enabled)
+ usb_ep_fifo_flush(common->fsg->bulk_out);
+ }
+
+ /* Reset the I/O buffer states and pointers, the SCSI
+ * state, and the exception. Then invoke the handler. */
+
+ for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+ bh = &common->buffhds[i];
+ bh->state = BUF_STATE_EMPTY;
+ }
+ common->next_buffhd_to_fill = &common->buffhds[0];
+ common->next_buffhd_to_drain = &common->buffhds[0];
+ exception_req_tag = common->exception_req_tag;
+ old_state = common->state;
+
+ if (old_state == FSG_STATE_ABORT_BULK_OUT)
+ common->state = FSG_STATE_STATUS_PHASE;
+ else {
+ for (i = 0; i < common->nluns; ++i) {
+ curlun = &common->luns[i];
+ curlun->sense_data = SS_NO_SENSE;
+ curlun->info_valid = 0;
+ }
+ common->state = FSG_STATE_IDLE;
+ }
+
+ /* Carry out any extra actions required for the exception */
+ switch (old_state) {
+ case FSG_STATE_ABORT_BULK_OUT:
+ send_status(common);
+
+ if (common->state == FSG_STATE_STATUS_PHASE)
+ common->state = FSG_STATE_IDLE;
+ break;
+
+ case FSG_STATE_RESET:
+ /* In case we were forced against our will to halt a
+ * bulk endpoint, clear the halt now. (The SuperH UDC
+ * requires this.) */
+ if (!fsg_is_set(common))
+ break;
+ if (test_and_clear_bit(IGNORE_BULK_OUT,
+ &common->fsg->atomic_bitflags))
+ usb_ep_clear_halt(common->fsg->bulk_in);
+
+ if (common->ep0_req_tag == exception_req_tag)
+ ep0_queue(common); /* Complete the status stage */
+
+ break;
+
+ case FSG_STATE_CONFIG_CHANGE:
+ do_set_interface(common, common->new_fsg);
+ break;
+
+ case FSG_STATE_EXIT:
+ case FSG_STATE_TERMINATED:
+ do_set_interface(common, NULL); /* Free resources */
+ common->state = FSG_STATE_TERMINATED; /* Stop the thread */
+ break;
+
+ case FSG_STATE_INTERFACE_CHANGE:
+ case FSG_STATE_DISCONNECT:
+ case FSG_STATE_COMMAND_PHASE:
+ case FSG_STATE_DATA_PHASE:
+ case FSG_STATE_STATUS_PHASE:
+ case FSG_STATE_IDLE:
+ break;
+ }
+}
+
+/*-------------------------------------------------------------------------*/
+
+int fsg_main_thread(void *common_)
+{
+ struct fsg_common *common = the_fsg_common;
+ /* The main loop */
+ do {
+ if (exception_in_progress(common)) {
+ handle_exception(common);
+ continue;
+ }
+
+ if (!common->running) {
+ sleep_thread(common);
+ continue;
+ }
+
+ if (get_next_command(common))
+ continue;
+
+ if (!exception_in_progress(common))
+ common->state = FSG_STATE_DATA_PHASE;
+
+ if (do_scsi_command(common) || finish_reply(common))
+ continue;
+
+ if (!exception_in_progress(common))
+ common->state = FSG_STATE_STATUS_PHASE;
+
+ if (send_status(common))
+ continue;
+
+ if (!exception_in_progress(common))
+ common->state = FSG_STATE_IDLE;
+ } while (0);
+
+ common->thread_task = NULL;
+
+ return 0;
+}
+
+static void fsg_common_release(struct kref *ref);
+
+static struct fsg_common *fsg_common_init(struct fsg_common *common,
+ struct usb_composite_dev *cdev)
+{
+ struct usb_gadget *gadget = cdev->gadget;
+ struct fsg_buffhd *bh;
+ struct fsg_lun *curlun;
+ int nluns, i, rc;
+
+ /* Find out how many LUNs there should be */
+ nluns = 1;
+ if (nluns < 1 || nluns > FSG_MAX_LUNS) {
+ printf("invalid number of LUNs: %u\n", nluns);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Allocate? */
+ if (!common) {
+ common = calloc(sizeof *common, 1);
+ if (!common)
+ return ERR_PTR(-ENOMEM);
+ common->free_storage_on_release = 1;
+ } else {
+ memset(common, 0, sizeof common);
+ common->free_storage_on_release = 0;
+ }
+
+ common->ops = NULL;
+ common->private_data = NULL;
+
+ common->gadget = gadget;
+ common->ep0 = gadget->ep0;
+ common->ep0req = cdev->req;
+
+ /* Maybe allocate device-global string IDs, and patch descriptors */
+ if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
+ rc = usb_string_id(cdev);
+ if (unlikely(rc < 0))
+ goto error_release;
+ fsg_strings[FSG_STRING_INTERFACE].id = rc;
+ fsg_intf_desc.iInterface = rc;
+ }
+
+ /* Create the LUNs, open their backing files, and register the
+ * LUN devices in sysfs. */
+ curlun = calloc(nluns, sizeof *curlun);
+ if (!curlun) {
+ rc = -ENOMEM;
+ goto error_release;
+ }
+ common->nluns = nluns;
+
+ for (i = 0; i < nluns; i++) {
+ common->luns[i].removable = 1;
+
+ rc = fsg_lun_open(&common->luns[i], "");
+ if (rc)
+ goto error_luns;
+ }
+ common->lun = 0;
+
+ /* Data buffers cyclic list */
+ bh = common->buffhds;
+
+ i = FSG_NUM_BUFFERS;
+ goto buffhds_first_it;
+ do {
+ bh->next = bh + 1;
+ ++bh;
+buffhds_first_it:
+ bh->inreq_busy = 0;
+ bh->outreq_busy = 0;
+ bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
+ if (unlikely(!bh->buf)) {
+ rc = -ENOMEM;
+ goto error_release;
+ }
+ } while (--i);
+ bh->next = common->buffhds;
+
+ snprintf(common->inquiry_string, sizeof common->inquiry_string,
+ "%-8s%-16s%04x",
+ "Linux ",
+ "File-Store Gadget",
+ 0xffff);
+
+ /* Some peripheral controllers are known not to be able to
+ * halt bulk endpoints correctly. If one of them is present,
+ * disable stalls.
+ */
+
+ /* Tell the thread to start working */
+ common->thread_task =
+ kthread_create(fsg_main_thread, common,
+ OR(cfg->thread_name, "file-storage"));
+ if (IS_ERR(common->thread_task)) {
+ rc = PTR_ERR(common->thread_task);
+ goto error_release;
+ }
+
+#undef OR
+ /* Information */
+ INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
+ INFO(common, "Number of LUNs=%d\n", common->nluns);
+
+ return common;
+
+error_luns:
+ common->nluns = i + 1;
+error_release:
+ common->state = FSG_STATE_TERMINATED; /* The thread is dead */
+ /* Call fsg_common_release() directly, ref might be not
+ * initialised */
+ fsg_common_release(&common->ref);
+ return ERR_PTR(rc);
+}
+
+static void fsg_common_release(struct kref *ref)
+{
+ struct fsg_common *common = container_of(ref, struct fsg_common, ref);
+
+ /* If the thread isn't already dead, tell it to exit now */
+ if (common->state != FSG_STATE_TERMINATED) {
+ raise_exception(common, FSG_STATE_EXIT);
+ wait_for_completion(&common->thread_notifier);
+ }
+
+ if (likely(common->luns)) {
+ struct fsg_lun *lun = common->luns;
+ unsigned i = common->nluns;
+
+ /* In error recovery common->nluns may be zero. */
+ for (; i; --i, ++lun)
+ fsg_lun_close(lun);
+
+ kfree(common->luns);
+ }
+
+ {
+ struct fsg_buffhd *bh = common->buffhds;
+ unsigned i = FSG_NUM_BUFFERS;
+ do {
+ kfree(bh->buf);
+ } while (++bh, --i);
+ }
+
+ if (common->free_storage_on_release)
+ kfree(common);
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/**
+ * usb_copy_descriptors - copy a vector of USB descriptors
+ * @src: null-terminated vector to copy
+ * Context: initialization code, which may sleep
+ *
+ * This makes a copy of a vector of USB descriptors. Its primary use
+ * is to support usb_function objects which can have multiple copies,
+ * each needing different descriptors. Functions may have static
+ * tables of descriptors, which are used as templates and customized
+ * with identifiers (for interfaces, strings, endpoints, and more)
+ * as needed by a given function instance.
+ */
+struct usb_descriptor_header **
+usb_copy_descriptors(struct usb_descriptor_header **src)
+{
+ struct usb_descriptor_header **tmp;
+ unsigned bytes;
+ unsigned n_desc;
+ void *mem;
+ struct usb_descriptor_header **ret;
+
+ /* count descriptors and their sizes; then add vector size */
+ for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
+ bytes += (*tmp)->bLength;
+ bytes += (n_desc + 1) * sizeof(*tmp);
+
+ mem = kmalloc(bytes, GFP_KERNEL);
+ if (!mem)
+ return NULL;
+
+ /* fill in pointers starting at "tmp",
+ * to descriptors copied starting at "mem";
+ * and return "ret"
+ */
+ tmp = mem;
+ ret = mem;
+ mem += (n_desc + 1) * sizeof(*tmp);
+ while (*src) {
+ memcpy(mem, *src, (*src)->bLength);
+ *tmp = mem;
+ tmp++;
+ mem += (*src)->bLength;
+ src++;
+ }
+ *tmp = NULL;
+
+ return ret;
+}
+
+
+
+static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct fsg_dev *fsg = fsg_from_func(f);
+
+ DBG(fsg, "unbind\n");
+ if (fsg->common->fsg == fsg) {
+ fsg->common->new_fsg = NULL;
+ raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
+ }
+
+ free(fsg->function.descriptors);
+ free(fsg->function.hs_descriptors);
+ kfree(fsg);
+}
+
+static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct fsg_dev *fsg = fsg_from_func(f);
+ struct usb_gadget *gadget = c->cdev->gadget;
+ int i;
+ struct usb_ep *ep;
+ fsg->gadget = gadget;
+
+ /* New interface */
+ i = usb_interface_id(c, f);
+ if (i < 0)
+ return i;
+ fsg_intf_desc.bInterfaceNumber = i;
+ fsg->interface_number = i;
+
+ /* Find all the endpoints we will use */
+ ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
+ if (!ep)
+ goto autoconf_fail;
+ ep->driver_data = fsg->common; /* claim the endpoint */
+ fsg->bulk_in = ep;
+
+ ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
+ if (!ep)
+ goto autoconf_fail;
+ ep->driver_data = fsg->common; /* claim the endpoint */
+ fsg->bulk_out = ep;
+
+ /* Copy descriptors */
+ f->descriptors = usb_copy_descriptors(fsg_fs_function);
+ if (unlikely(!f->descriptors))
+ return -ENOMEM;
+
+ if (gadget_is_dualspeed(gadget)) {
+ /* Assume endpoint addresses are the same for both speeds */
+ fsg_hs_bulk_in_desc.bEndpointAddress =
+ fsg_fs_bulk_in_desc.bEndpointAddress;
+ fsg_hs_bulk_out_desc.bEndpointAddress =
+ fsg_fs_bulk_out_desc.bEndpointAddress;
+ f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
+ if (unlikely(!f->hs_descriptors)) {
+ free(f->descriptors);
+ return -ENOMEM;
+ }
+ }
+ return 0;
+
+autoconf_fail:
+ ERROR(fsg, "unable to autoconfigure all endpoints\n");
+ return -ENOTSUPP;
+}
+
+
+/****************************** ADD FUNCTION ******************************/
+
+static struct usb_gadget_strings *fsg_strings_array[] = {
+ &fsg_stringtab,
+ NULL,
+};
+
+static int fsg_bind_config(struct usb_composite_dev *cdev,
+ struct usb_configuration *c,
+ struct fsg_common *common)
+{
+ struct fsg_dev *fsg;
+ int rc;
+
+ fsg = calloc(1, sizeof *fsg);
+ if (!fsg)
+ return -ENOMEM;
+ fsg->function.name = FSG_DRIVER_DESC;
+ fsg->function.strings = fsg_strings_array;
+ fsg->function.bind = fsg_bind;
+ fsg->function.unbind = fsg_unbind;
+ fsg->function.setup = fsg_setup;
+ fsg->function.set_alt = fsg_set_alt;
+ fsg->function.disable = fsg_disable;
+
+ fsg->common = common;
+ common->fsg = fsg;
+ /* Our caller holds a reference to common structure so we
+ * don't have to be worry about it being freed until we return
+ * from this function. So instead of incrementing counter now
+ * and decrement in error recovery we increment it only when
+ * call to usb_add_function() was successful. */
+
+ rc = usb_add_function(c, &fsg->function);
+
+ if (rc)
+ kfree(fsg);
+
+ return rc;
+}
+
+int fsg_add(struct usb_configuration *c)
+{
+ struct fsg_common *fsg_common;
+
+ fsg_common = fsg_common_init(NULL, c->cdev);
+
+ fsg_common->vendor_name = 0;
+ fsg_common->product_name = 0;
+ fsg_common->release = 0xffff;
+
+ fsg_common->ops = NULL;
+ fsg_common->private_data = NULL;
+
+ the_fsg_common = fsg_common;
+
+ return fsg_bind_config(c->cdev, c, fsg_common);
+}
+
+int fsg_init(struct ums_board_info *ums)
+{
+ ums_info = ums;
+
+ return 0;
+}