302 lines
8.2 KiB
C
302 lines
8.2 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* u_fs.h
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*
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* Utility definitions for the FunctionFS
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*
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* Copyright (c) 2013 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
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*/
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#ifndef U_FFS_H
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#define U_FFS_H
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#include <linux/usb/composite.h>
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#include <linux/list.h>
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#include <linux/mutex.h>
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#include <linux/workqueue.h>
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#include <linux/refcount.h>
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#ifdef VERBOSE_DEBUG
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#ifndef pr_vdebug
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# define pr_vdebug pr_debug
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#endif /* pr_vdebug */
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# define ffs_dump_mem(prefix, ptr, len) \
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print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
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#else
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#ifndef pr_vdebug
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# define pr_vdebug(...) do { } while (0)
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#endif /* pr_vdebug */
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# define ffs_dump_mem(prefix, ptr, len) do { } while (0)
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#endif /* VERBOSE_DEBUG */
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struct f_fs_opts;
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struct ffs_dev {
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struct ffs_data *ffs_data;
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struct f_fs_opts *opts;
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struct list_head entry;
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char name[41];
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bool mounted;
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bool desc_ready;
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bool single;
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int (*ffs_ready_callback)(struct ffs_data *ffs);
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void (*ffs_closed_callback)(struct ffs_data *ffs);
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void *(*ffs_acquire_dev_callback)(struct ffs_dev *dev);
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void (*ffs_release_dev_callback)(struct ffs_dev *dev);
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};
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extern struct mutex ffs_lock;
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static inline void ffs_dev_lock(void)
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{
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mutex_lock(&ffs_lock);
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}
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static inline void ffs_dev_unlock(void)
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{
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mutex_unlock(&ffs_lock);
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}
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int ffs_name_dev(struct ffs_dev *dev, const char *name);
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int ffs_single_dev(struct ffs_dev *dev);
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struct ffs_epfile;
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struct ffs_function;
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enum ffs_state {
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/*
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* Waiting for descriptors and strings.
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*
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* In this state no open(2), read(2) or write(2) on epfiles
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* may succeed (which should not be the problem as there
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* should be no such files opened in the first place).
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*/
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FFS_READ_DESCRIPTORS,
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FFS_READ_STRINGS,
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/*
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* We've got descriptors and strings. We are or have called
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* functionfs_ready_callback(). functionfs_bind() may have
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* been called but we don't know.
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*
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* This is the only state in which operations on epfiles may
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* succeed.
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*/
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FFS_ACTIVE,
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/*
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* Function is visible to host, but it's not functional. All
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* setup requests are stalled and transfers on another endpoints
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* are refused. All epfiles, except ep0, are deleted so there
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* is no way to perform any operations on them.
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*
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* This state is set after closing all functionfs files, when
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* mount parameter "no_disconnect=1" has been set. Function will
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* remain in deactivated state until filesystem is umounted or
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* ep0 is opened again. In the second case functionfs state will
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* be reset, and it will be ready for descriptors and strings
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* writing.
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*
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* This is useful only when functionfs is composed to gadget
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* with another function which can perform some critical
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* operations, and it's strongly desired to have this operations
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* completed, even after functionfs files closure.
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*/
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FFS_DEACTIVATED,
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/*
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* All endpoints have been closed. This state is also set if
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* we encounter an unrecoverable error. The only
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* unrecoverable error is situation when after reading strings
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* from user space we fail to initialise epfiles or
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* functionfs_ready_callback() returns with error (<0).
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*
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* In this state no open(2), read(2) or write(2) (both on ep0
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* as well as epfile) may succeed (at this point epfiles are
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* unlinked and all closed so this is not a problem; ep0 is
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* also closed but ep0 file exists and so open(2) on ep0 must
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* fail).
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*/
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FFS_CLOSING
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};
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enum ffs_setup_state {
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/* There is no setup request pending. */
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FFS_NO_SETUP,
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/*
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* User has read events and there was a setup request event
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* there. The next read/write on ep0 will handle the
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* request.
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*/
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FFS_SETUP_PENDING,
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/*
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* There was event pending but before user space handled it
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* some other event was introduced which canceled existing
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* setup. If this state is set read/write on ep0 return
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* -EIDRM. This state is only set when adding event.
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*/
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FFS_SETUP_CANCELLED
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};
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struct ffs_data {
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struct usb_gadget *gadget;
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/*
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* Protect access read/write operations, only one read/write
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* at a time. As a consequence protects ep0req and company.
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* While setup request is being processed (queued) this is
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* held.
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*/
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struct mutex mutex;
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/*
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* Protect access to endpoint related structures (basically
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* usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
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* endpoint zero.
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*/
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spinlock_t eps_lock;
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/*
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* XXX REVISIT do we need our own request? Since we are not
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* handling setup requests immediately user space may be so
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* slow that another setup will be sent to the gadget but this
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* time not to us but another function and then there could be
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* a race. Is that the case? Or maybe we can use cdev->req
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* after all, maybe we just need some spinlock for that?
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*/
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struct usb_request *ep0req; /* P: mutex */
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struct completion ep0req_completion; /* P: mutex */
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/* reference counter */
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refcount_t ref;
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/* how many files are opened (EP0 and others) */
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atomic_t opened;
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/* EP0 state */
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enum ffs_state state;
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/*
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* Possible transitions:
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* + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
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* happens only in ep0 read which is P: mutex
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* + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
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* happens only in ep0 i/o which is P: mutex
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* + FFS_SETUP_PENDING -> FFS_SETUP_CANCELLED -- P: ev.waitq.lock
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* + FFS_SETUP_CANCELLED -> FFS_NO_SETUP -- cmpxchg
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*
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* This field should never be accessed directly and instead
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* ffs_setup_state_clear_cancelled function should be used.
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*/
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enum ffs_setup_state setup_state;
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/* Events & such. */
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struct {
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u8 types[4];
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unsigned short count;
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/* XXX REVISIT need to update it in some places, or do we? */
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unsigned short can_stall;
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struct usb_ctrlrequest setup;
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wait_queue_head_t waitq;
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} ev; /* the whole structure, P: ev.waitq.lock */
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/* Flags */
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unsigned long flags;
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#define FFS_FL_CALL_CLOSED_CALLBACK 0
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#define FFS_FL_BOUND 1
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/* For waking up blocked threads when function is enabled. */
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wait_queue_head_t wait;
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/* Active function */
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struct ffs_function *func;
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/*
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* Device name, write once when file system is mounted.
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* Intended for user to read if she wants.
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*/
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const char *dev_name;
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/* Private data for our user (ie. gadget). Managed by user. */
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void *private_data;
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/* filled by __ffs_data_got_descs() */
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/*
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* raw_descs is what you kfree, real_descs points inside of raw_descs,
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* where full speed, high speed and super speed descriptors start.
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* real_descs_length is the length of all those descriptors.
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*/
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const void *raw_descs_data;
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const void *raw_descs;
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unsigned raw_descs_length;
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unsigned fs_descs_count;
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unsigned hs_descs_count;
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unsigned ss_descs_count;
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unsigned ms_os_descs_count;
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unsigned ms_os_descs_ext_prop_count;
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unsigned ms_os_descs_ext_prop_name_len;
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unsigned ms_os_descs_ext_prop_data_len;
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void *ms_os_descs_ext_prop_avail;
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void *ms_os_descs_ext_prop_name_avail;
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void *ms_os_descs_ext_prop_data_avail;
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unsigned user_flags;
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#define FFS_MAX_EPS_COUNT 31
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u8 eps_addrmap[FFS_MAX_EPS_COUNT];
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unsigned short strings_count;
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unsigned short interfaces_count;
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unsigned short eps_count;
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unsigned short _pad1;
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/* filled by __ffs_data_got_strings() */
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/* ids in stringtabs are set in functionfs_bind() */
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const void *raw_strings;
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struct usb_gadget_strings **stringtabs;
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/*
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* File system's super block, write once when file system is
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* mounted.
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*/
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struct super_block *sb;
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/* File permissions, written once when fs is mounted */
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struct ffs_file_perms {
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umode_t mode;
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kuid_t uid;
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kgid_t gid;
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} file_perms;
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struct eventfd_ctx *ffs_eventfd;
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struct workqueue_struct *io_completion_wq;
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bool no_disconnect;
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struct work_struct reset_work;
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/*
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* The endpoint files, filled by ffs_epfiles_create(),
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* destroyed by ffs_epfiles_destroy().
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*/
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struct ffs_epfile *epfiles;
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};
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struct f_fs_opts {
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struct usb_function_instance func_inst;
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struct ffs_dev *dev;
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unsigned refcnt;
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bool no_configfs;
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};
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static inline struct f_fs_opts *to_f_fs_opts(struct usb_function_instance *fi)
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{
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return container_of(fi, struct f_fs_opts, func_inst);
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}
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#endif /* U_FFS_H */
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