usb: gadget: FunctionFS: convert to new function interface with backward compatibility

This is required in order to integrate configfs support.
f_fs needs to be a separately compiled module and so it needs to use the new
interface.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Andrzej Pietrasiewicz 2013-12-03 15:15:33 +01:00 committed by Felipe Balbi
parent 4b187fceec
commit 5920cda627
6 changed files with 435 additions and 209 deletions

View file

@ -539,6 +539,9 @@ config USB_F_RNDIS
config USB_F_MASS_STORAGE
tristate
config USB_F_FS
tristate
choice
tristate "USB Gadget Drivers"
default USB_ETH

View file

@ -61,6 +61,8 @@ usb_f_rndis-y := f_rndis.o rndis.o
obj-$(CONFIG_USB_F_RNDIS) += usb_f_rndis.o
usb_f_mass_storage-y := f_mass_storage.o storage_common.o
obj-$(CONFIG_USB_F_MASS_STORAGE)+= usb_f_mass_storage.o
usb_f_fs-y := f_fs.o
obj-$(CONFIG_USB_F_FS) += usb_f_fs.o
#
# USB gadget drivers

View file

@ -22,6 +22,7 @@
#include <linux/pagemap.h>
#include <linux/export.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <asm/unaligned.h>
#include <linux/usb/composite.h>
@ -57,210 +58,6 @@
#define vla_ptr(ptr, groupname, name) \
((void *) ((char *)ptr + groupname##_##name##__offset))
/* Debugging ****************************************************************/
#ifdef VERBOSE_DEBUG
#ifndef pr_vdebug
# define pr_vdebug pr_debug
#endif /* pr_vdebug */
# define ffs_dump_mem(prefix, ptr, len) \
print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
#else
#ifndef pr_vdebug
# define pr_vdebug(...) do { } while (0)
#endif /* pr_vdebug */
# define ffs_dump_mem(prefix, ptr, len) do { } while (0)
#endif /* VERBOSE_DEBUG */
#define ENTER() pr_vdebug("%s()\n", __func__)
/* The data structure and setup file ****************************************/
enum ffs_state {
/*
* Waiting for descriptors and strings.
*
* In this state no open(2), read(2) or write(2) on epfiles
* may succeed (which should not be the problem as there
* should be no such files opened in the first place).
*/
FFS_READ_DESCRIPTORS,
FFS_READ_STRINGS,
/*
* We've got descriptors and strings. We are or have called
* ffs_ready(). functionfs_bind() may have
* been called but we don't know.
*
* This is the only state in which operations on epfiles may
* succeed.
*/
FFS_ACTIVE,
/*
* All endpoints have been closed. This state is also set if
* we encounter an unrecoverable error. The only
* unrecoverable error is situation when after reading strings
* from user space we fail to initialise epfiles or
* ffs_ready() returns with error (<0).
*
* In this state no open(2), read(2) or write(2) (both on ep0
* as well as epfile) may succeed (at this point epfiles are
* unlinked and all closed so this is not a problem; ep0 is
* also closed but ep0 file exists and so open(2) on ep0 must
* fail).
*/
FFS_CLOSING
};
enum ffs_setup_state {
/* There is no setup request pending. */
FFS_NO_SETUP,
/*
* User has read events and there was a setup request event
* there. The next read/write on ep0 will handle the
* request.
*/
FFS_SETUP_PENDING,
/*
* There was event pending but before user space handled it
* some other event was introduced which canceled existing
* setup. If this state is set read/write on ep0 return
* -EIDRM. This state is only set when adding event.
*/
FFS_SETUP_CANCELED
};
struct ffs_epfile;
struct ffs_function;
struct ffs_data {
struct usb_gadget *gadget;
/*
* Protect access read/write operations, only one read/write
* at a time. As a consequence protects ep0req and company.
* While setup request is being processed (queued) this is
* held.
*/
struct mutex mutex;
/*
* Protect access to endpoint related structures (basically
* usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
* endpoint zero.
*/
spinlock_t eps_lock;
/*
* XXX REVISIT do we need our own request? Since we are not
* handling setup requests immediately user space may be so
* slow that another setup will be sent to the gadget but this
* time not to us but another function and then there could be
* a race. Is that the case? Or maybe we can use cdev->req
* after all, maybe we just need some spinlock for that?
*/
struct usb_request *ep0req; /* P: mutex */
struct completion ep0req_completion; /* P: mutex */
int ep0req_status; /* P: mutex */
/* reference counter */
atomic_t ref;
/* how many files are opened (EP0 and others) */
atomic_t opened;
/* EP0 state */
enum ffs_state state;
/*
* Possible transitions:
* + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
* happens only in ep0 read which is P: mutex
* + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
* happens only in ep0 i/o which is P: mutex
* + FFS_SETUP_PENDING -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
* + FFS_SETUP_CANCELED -> FFS_NO_SETUP -- cmpxchg
*/
enum ffs_setup_state setup_state;
#define FFS_SETUP_STATE(ffs) \
((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state, \
FFS_SETUP_CANCELED, FFS_NO_SETUP))
/* Events & such. */
struct {
u8 types[4];
unsigned short count;
/* XXX REVISIT need to update it in some places, or do we? */
unsigned short can_stall;
struct usb_ctrlrequest setup;
wait_queue_head_t waitq;
} ev; /* the whole structure, P: ev.waitq.lock */
/* Flags */
unsigned long flags;
#define FFS_FL_CALL_CLOSED_CALLBACK 0
#define FFS_FL_BOUND 1
/* Active function */
struct ffs_function *func;
/*
* Device name, write once when file system is mounted.
* Intended for user to read if she wants.
*/
const char *dev_name;
/* Private data for our user (ie. gadget). Managed by user. */
void *private_data;
/* filled by __ffs_data_got_descs() */
/*
* Real descriptors are 16 bytes after raw_descs (so you need
* to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
* first full speed descriptor). raw_descs_length and
* raw_fs_descs_length do not have those 16 bytes added.
*/
const void *raw_descs;
unsigned raw_descs_length;
unsigned raw_fs_descs_length;
unsigned fs_descs_count;
unsigned hs_descs_count;
unsigned short strings_count;
unsigned short interfaces_count;
unsigned short eps_count;
unsigned short _pad1;
/* filled by __ffs_data_got_strings() */
/* ids in stringtabs are set in functionfs_bind() */
const void *raw_strings;
struct usb_gadget_strings **stringtabs;
/*
* File system's super block, write once when file system is
* mounted.
*/
struct super_block *sb;
/* File permissions, written once when fs is mounted */
struct ffs_file_perms {
umode_t mode;
kuid_t uid;
kgid_t gid;
} file_perms;
/*
* The endpoint files, filled by ffs_epfiles_create(),
* destroyed by ffs_epfiles_destroy().
*/
struct ffs_epfile *epfiles;
};
/* Reference counter handling */
static void ffs_data_get(struct ffs_data *ffs);
static void ffs_data_put(struct ffs_data *ffs);
@ -300,15 +97,19 @@ static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
return container_of(f, struct ffs_function, function);
}
#ifdef USB_FFS_INCLUDED
static void ffs_func_free(struct ffs_function *func);
#endif
static void ffs_func_eps_disable(struct ffs_function *func);
static int __must_check ffs_func_eps_enable(struct ffs_function *func);
static int ffs_func_bind(struct usb_configuration *,
struct usb_function *);
static void ffs_func_unbind(struct usb_configuration *,
#ifdef USB_FFS_INCLUDED
static void old_ffs_func_unbind(struct usb_configuration *,
struct usb_function *);
#endif
static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
static void ffs_func_disable(struct usb_function *);
static int ffs_func_setup(struct usb_function *,
@ -364,6 +165,9 @@ ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
/* Devices management *******************************************************/
DEFINE_MUTEX(ffs_lock);
#ifndef USB_FFS_INCLUDED
EXPORT_SYMBOL(ffs_lock);
#endif
static struct ffs_dev *ffs_find_dev(const char *name);
static void *ffs_acquire_dev(const char *dev_name);
@ -1499,6 +1303,8 @@ static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
kfree(epfiles);
}
#ifdef USB_FFS_INCLUDED
static int functionfs_bind_config(struct usb_composite_dev *cdev,
struct usb_configuration *c,
struct ffs_data *ffs)
@ -1516,7 +1322,7 @@ static int functionfs_bind_config(struct usb_composite_dev *cdev,
func->function.strings = ffs->stringtabs;
func->function.bind = ffs_func_bind;
func->function.unbind = ffs_func_unbind;
func->function.unbind = old_ffs_func_unbind;
func->function.set_alt = ffs_func_set_alt;
func->function.disable = ffs_func_disable;
func->function.setup = ffs_func_setup;
@ -1565,6 +1371,8 @@ static void ffs_func_free(struct ffs_function *func)
kfree(func);
}
#endif
static void ffs_func_eps_disable(struct ffs_function *func)
{
struct ffs_ep *ep = func->eps;
@ -2227,8 +2035,59 @@ static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
return 0;
}
static int ffs_func_bind(struct usb_configuration *c,
struct usb_function *f)
#ifndef USB_FFS_INCLUDED
static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
struct usb_configuration *c)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct f_fs_opts *ffs_opts =
container_of(f->fi, struct f_fs_opts, func_inst);
int ret;
ENTER();
/*
* Legacy gadget triggers binding in functionfs_ready_callback,
* which already uses locking; taking the same lock here would
* cause a deadlock.
*
* Configfs-enabled gadgets however do need ffs_dev_lock.
*/
if (!ffs_opts->no_configfs)
ffs_dev_lock();
ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
func->ffs = ffs_opts->dev->ffs_data;
if (!ffs_opts->no_configfs)
ffs_dev_unlock();
if (ret)
return ERR_PTR(ret);
func->conf = c;
func->gadget = c->cdev->gadget;
ffs_data_get(func->ffs);
/*
* in drivers/usb/gadget/configfs.c:configfs_composite_bind()
* configurations are bound in sequence with list_for_each_entry,
* in each configuration its functions are bound in sequence
* with list_for_each_entry, so we assume no race condition
* with regard to ffs_opts->bound access
*/
if (!ffs_opts->refcnt) {
ret = functionfs_bind(func->ffs, c->cdev);
if (ret)
return ERR_PTR(ret);
}
ffs_opts->refcnt++;
func->function.strings = func->ffs->stringtabs;
return ffs_opts;
}
#endif
static int _ffs_func_bind(struct usb_configuration *c,
struct usb_function *f)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct ffs_data *ffs = func->ffs;
@ -2328,10 +2187,25 @@ static int ffs_func_bind(struct usb_configuration *c,
return ret;
}
static int ffs_func_bind(struct usb_configuration *c,
struct usb_function *f)
{
#ifndef USB_FFS_INCLUDED
struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
if (IS_ERR(ffs_opts))
return PTR_ERR(ffs_opts);
#endif
return _ffs_func_bind(c, f);
}
/* Other USB function hooks *************************************************/
static void ffs_func_unbind(struct usb_configuration *c,
#ifdef USB_FFS_INCLUDED
static void old_ffs_func_unbind(struct usb_configuration *c,
struct usb_function *f)
{
struct ffs_function *func = ffs_func_from_usb(f);
@ -2349,6 +2223,8 @@ static void ffs_func_unbind(struct usb_configuration *c,
ffs_func_free(func);
}
#endif
static int ffs_func_set_alt(struct usb_function *f,
unsigned interface, unsigned alt)
{
@ -2523,6 +2399,116 @@ static struct ffs_dev *ffs_find_dev(const char *name)
return _ffs_find_dev(name);
}
/* Function registration interface ******************************************/
#ifndef USB_FFS_INCLUDED
static void ffs_free_inst(struct usb_function_instance *f)
{
struct f_fs_opts *opts;
opts = to_f_fs_opts(f);
ffs_dev_lock();
ffs_free_dev(opts->dev);
ffs_dev_unlock();
kfree(opts);
}
static struct usb_function_instance *ffs_alloc_inst(void)
{
struct f_fs_opts *opts;
struct ffs_dev *dev;
opts = kzalloc(sizeof(*opts), GFP_KERNEL);
if (!opts)
return ERR_PTR(-ENOMEM);
opts->func_inst.free_func_inst = ffs_free_inst;
ffs_dev_lock();
dev = ffs_alloc_dev();
ffs_dev_unlock();
if (IS_ERR(dev)) {
kfree(opts);
return ERR_CAST(dev);
}
opts->dev = dev;
return &opts->func_inst;
}
static void ffs_free(struct usb_function *f)
{
kfree(ffs_func_from_usb(f));
}
static void ffs_func_unbind(struct usb_configuration *c,
struct usb_function *f)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct ffs_data *ffs = func->ffs;
struct f_fs_opts *opts =
container_of(f->fi, struct f_fs_opts, func_inst);
struct ffs_ep *ep = func->eps;
unsigned count = ffs->eps_count;
unsigned long flags;
ENTER();
if (ffs->func == func) {
ffs_func_eps_disable(func);
ffs->func = NULL;
}
if (!--opts->refcnt)
functionfs_unbind(ffs);
/* cleanup after autoconfig */
spin_lock_irqsave(&func->ffs->eps_lock, flags);
do {
if (ep->ep && ep->req)
usb_ep_free_request(ep->ep, ep->req);
ep->req = NULL;
++ep;
} while (--count);
spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
kfree(func->eps);
func->eps = NULL;
/*
* eps, descriptors and interfaces_nums are allocated in the
* same chunk so only one free is required.
*/
func->function.fs_descriptors = NULL;
func->function.hs_descriptors = NULL;
func->interfaces_nums = NULL;
ffs_event_add(ffs, FUNCTIONFS_UNBIND);
}
static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
{
struct ffs_function *func;
ENTER();
func = kzalloc(sizeof(*func), GFP_KERNEL);
if (unlikely(!func))
return ERR_PTR(-ENOMEM);
func->function.name = "Function FS Gadget";
func->function.bind = ffs_func_bind;
func->function.unbind = ffs_func_unbind;
func->function.set_alt = ffs_func_set_alt;
func->function.disable = ffs_func_disable;
func->function.setup = ffs_func_setup;
func->function.suspend = ffs_func_suspend;
func->function.resume = ffs_func_resume;
func->function.free_func = ffs_free;
return &func->function;
}
#endif
/*
* ffs_lock must be taken by the caller of this function
*/
@ -2581,6 +2567,9 @@ int ffs_name_dev(struct ffs_dev *dev, const char *name)
return ret;
}
#ifndef USB_FFS_INCLUDED
EXPORT_SYMBOL(ffs_name_dev);
#endif
int ffs_single_dev(struct ffs_dev *dev)
{
@ -2597,6 +2586,9 @@ int ffs_single_dev(struct ffs_dev *dev)
ffs_dev_unlock();
return ret;
}
#ifndef USB_FFS_INCLUDED
EXPORT_SYMBOL(ffs_single_dev);
#endif
/*
* ffs_lock must be taken by the caller of this function
@ -2621,6 +2613,9 @@ static void *ffs_acquire_dev(const char *dev_name)
ffs_dev = ERR_PTR(-ENODEV);
else if (ffs_dev->mounted)
ffs_dev = ERR_PTR(-EBUSY);
else if (ffs_dev->ffs_acquire_dev_callback &&
ffs_dev->ffs_acquire_dev_callback(ffs_dev))
ffs_dev = ERR_PTR(-ENODEV);
else
ffs_dev->mounted = true;
@ -2638,6 +2633,9 @@ static void ffs_release_dev(struct ffs_data *ffs_data)
ffs_dev = ffs_data->private_data;
if (ffs_dev)
ffs_dev->mounted = false;
if (ffs_dev->ffs_release_dev_callback)
ffs_dev->ffs_release_dev_callback(ffs_dev);
ffs_dev_unlock();
}
@ -2720,3 +2718,9 @@ static char *ffs_prepare_buffer(const char __user *buf, size_t len)
return data;
}
#ifndef USB_FFS_INCLUDED
DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Nazarewicz");
#endif

View file

@ -54,6 +54,7 @@ static struct usb_function *f_rndis;
# endif
#endif
#define USB_FFS_INCLUDED
#include "f_fs.c"
#define DRIVER_NAME "g_ffs"

View file

@ -20,6 +20,22 @@
#include <linux/list.h>
#include <linux/mutex.h>
#ifdef VERBOSE_DEBUG
#ifndef pr_vdebug
# define pr_vdebug pr_debug
#endif /* pr_vdebug */
# define ffs_dump_mem(prefix, ptr, len) \
print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
#else
#ifndef pr_vdebug
# define pr_vdebug(...) do { } while (0)
#endif /* pr_vdebug */
# define ffs_dump_mem(prefix, ptr, len) do { } while (0)
#endif /* VERBOSE_DEBUG */
#define ENTER() pr_vdebug("%s()\n", __func__)
struct ffs_dev {
const char *name;
bool mounted;
@ -30,6 +46,8 @@ struct ffs_dev {
int (*ffs_ready_callback)(struct ffs_data *ffs);
void (*ffs_closed_callback)(struct ffs_data *ffs);
void *(*ffs_acquire_dev_callback)(struct ffs_dev *dev);
void (*ffs_release_dev_callback)(struct ffs_dev *dev);
};
extern struct mutex ffs_lock;
@ -49,4 +67,200 @@ int ffs_name_dev(struct ffs_dev *dev, const char *name);
int ffs_single_dev(struct ffs_dev *dev);
void ffs_free_dev(struct ffs_dev *dev);
struct ffs_epfile;
struct ffs_function;
enum ffs_state {
/*
* Waiting for descriptors and strings.
*
* In this state no open(2), read(2) or write(2) on epfiles
* may succeed (which should not be the problem as there
* should be no such files opened in the first place).
*/
FFS_READ_DESCRIPTORS,
FFS_READ_STRINGS,
/*
* We've got descriptors and strings. We are or have called
* functionfs_ready_callback(). functionfs_bind() may have
* been called but we don't know.
*
* This is the only state in which operations on epfiles may
* succeed.
*/
FFS_ACTIVE,
/*
* All endpoints have been closed. This state is also set if
* we encounter an unrecoverable error. The only
* unrecoverable error is situation when after reading strings
* from user space we fail to initialise epfiles or
* functionfs_ready_callback() returns with error (<0).
*
* In this state no open(2), read(2) or write(2) (both on ep0
* as well as epfile) may succeed (at this point epfiles are
* unlinked and all closed so this is not a problem; ep0 is
* also closed but ep0 file exists and so open(2) on ep0 must
* fail).
*/
FFS_CLOSING
};
enum ffs_setup_state {
/* There is no setup request pending. */
FFS_NO_SETUP,
/*
* User has read events and there was a setup request event
* there. The next read/write on ep0 will handle the
* request.
*/
FFS_SETUP_PENDING,
/*
* There was event pending but before user space handled it
* some other event was introduced which canceled existing
* setup. If this state is set read/write on ep0 return
* -EIDRM. This state is only set when adding event.
*/
FFS_SETUP_CANCELED
};
struct ffs_data {
struct usb_gadget *gadget;
/*
* Protect access read/write operations, only one read/write
* at a time. As a consequence protects ep0req and company.
* While setup request is being processed (queued) this is
* held.
*/
struct mutex mutex;
/*
* Protect access to endpoint related structures (basically
* usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
* endpoint zero.
*/
spinlock_t eps_lock;
/*
* XXX REVISIT do we need our own request? Since we are not
* handling setup requests immediately user space may be so
* slow that another setup will be sent to the gadget but this
* time not to us but another function and then there could be
* a race. Is that the case? Or maybe we can use cdev->req
* after all, maybe we just need some spinlock for that?
*/
struct usb_request *ep0req; /* P: mutex */
struct completion ep0req_completion; /* P: mutex */
int ep0req_status; /* P: mutex */
/* reference counter */
atomic_t ref;
/* how many files are opened (EP0 and others) */
atomic_t opened;
/* EP0 state */
enum ffs_state state;
/*
* Possible transitions:
* + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
* happens only in ep0 read which is P: mutex
* + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
* happens only in ep0 i/o which is P: mutex
* + FFS_SETUP_PENDING -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
* + FFS_SETUP_CANCELED -> FFS_NO_SETUP -- cmpxchg
*/
enum ffs_setup_state setup_state;
#define FFS_SETUP_STATE(ffs) \
((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state, \
FFS_SETUP_CANCELED, FFS_NO_SETUP))
/* Events & such. */
struct {
u8 types[4];
unsigned short count;
/* XXX REVISIT need to update it in some places, or do we? */
unsigned short can_stall;
struct usb_ctrlrequest setup;
wait_queue_head_t waitq;
} ev; /* the whole structure, P: ev.waitq.lock */
/* Flags */
unsigned long flags;
#define FFS_FL_CALL_CLOSED_CALLBACK 0
#define FFS_FL_BOUND 1
/* Active function */
struct ffs_function *func;
/*
* Device name, write once when file system is mounted.
* Intended for user to read if she wants.
*/
const char *dev_name;
/* Private data for our user (ie. gadget). Managed by user. */
void *private_data;
/* filled by __ffs_data_got_descs() */
/*
* Real descriptors are 16 bytes after raw_descs (so you need
* to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
* first full speed descriptor). raw_descs_length and
* raw_fs_descs_length do not have those 16 bytes added.
*/
const void *raw_descs;
unsigned raw_descs_length;
unsigned raw_fs_descs_length;
unsigned fs_descs_count;
unsigned hs_descs_count;
unsigned short strings_count;
unsigned short interfaces_count;
unsigned short eps_count;
unsigned short _pad1;
/* filled by __ffs_data_got_strings() */
/* ids in stringtabs are set in functionfs_bind() */
const void *raw_strings;
struct usb_gadget_strings **stringtabs;
/*
* File system's super block, write once when file system is
* mounted.
*/
struct super_block *sb;
/* File permissions, written once when fs is mounted */
struct ffs_file_perms {
umode_t mode;
kuid_t uid;
kgid_t gid;
} file_perms;
/*
* The endpoint files, filled by ffs_epfiles_create(),
* destroyed by ffs_epfiles_destroy().
*/
struct ffs_epfile *epfiles;
};
#ifndef USB_FFS_INCLUDED
struct f_fs_opts {
struct usb_function_instance func_inst;
struct ffs_dev *dev;
unsigned refcnt;
bool no_configfs;
};
static inline struct f_fs_opts *to_f_fs_opts(struct usb_function_instance *fi)
{
return container_of(fi, struct f_fs_opts, func_inst);
}
#endif
#endif /* U_FFS_H */

View file

@ -3,6 +3,7 @@
#include <uapi/linux/usb/functionfs.h>
#ifdef USB_FFS_INCLUDED
struct ffs_data;
struct usb_composite_dev;
@ -20,3 +21,4 @@ static int functionfs_bind_config(struct usb_composite_dev *cdev,
#endif
#endif