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>
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index d17930d..8d318ea 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -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 @@
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 @@
/* 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 @@
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 @@
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 @@
kfree(func);
}
+#endif
+
static void ffs_func_eps_disable(struct ffs_function *func)
{
struct ffs_ep *ep = func->eps;
@@ -2227,8 +2035,59 @@
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 @@
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 @@
ffs_func_free(func);
}
+#endif
+
static int ffs_func_set_alt(struct usb_function *f,
unsigned interface, unsigned alt)
{
@@ -2523,6 +2399,116 @@
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 @@
return ret;
}
+#ifndef USB_FFS_INCLUDED
+EXPORT_SYMBOL(ffs_name_dev);
+#endif
int ffs_single_dev(struct ffs_dev *dev)
{
@@ -2597,6 +2586,9 @@
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 @@
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 @@
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 @@
return data;
}
+
+#ifndef USB_FFS_INCLUDED
+DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michal Nazarewicz");
+#endif