linux/drivers/usb/gadget/functions.c
Greg Kroah-Hartman 5fd54ace47 USB: add SPDX identifiers to all remaining files in drivers/usb/
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-04 11:48:02 +01:00

118 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/usb/composite.h>
static LIST_HEAD(func_list);
static DEFINE_MUTEX(func_lock);
static struct usb_function_instance *try_get_usb_function_instance(const char *name)
{
struct usb_function_driver *fd;
struct usb_function_instance *fi;
fi = ERR_PTR(-ENOENT);
mutex_lock(&func_lock);
list_for_each_entry(fd, &func_list, list) {
if (strcmp(name, fd->name))
continue;
if (!try_module_get(fd->mod)) {
fi = ERR_PTR(-EBUSY);
break;
}
fi = fd->alloc_inst();
if (IS_ERR(fi))
module_put(fd->mod);
else
fi->fd = fd;
break;
}
mutex_unlock(&func_lock);
return fi;
}
struct usb_function_instance *usb_get_function_instance(const char *name)
{
struct usb_function_instance *fi;
int ret;
fi = try_get_usb_function_instance(name);
if (!IS_ERR(fi))
return fi;
ret = PTR_ERR(fi);
if (ret != -ENOENT)
return fi;
ret = request_module("usbfunc:%s", name);
if (ret < 0)
return ERR_PTR(ret);
return try_get_usb_function_instance(name);
}
EXPORT_SYMBOL_GPL(usb_get_function_instance);
struct usb_function *usb_get_function(struct usb_function_instance *fi)
{
struct usb_function *f;
f = fi->fd->alloc_func(fi);
if (IS_ERR(f))
return f;
f->fi = fi;
return f;
}
EXPORT_SYMBOL_GPL(usb_get_function);
void usb_put_function_instance(struct usb_function_instance *fi)
{
struct module *mod;
if (!fi)
return;
mod = fi->fd->mod;
fi->free_func_inst(fi);
module_put(mod);
}
EXPORT_SYMBOL_GPL(usb_put_function_instance);
void usb_put_function(struct usb_function *f)
{
if (!f)
return;
f->free_func(f);
}
EXPORT_SYMBOL_GPL(usb_put_function);
int usb_function_register(struct usb_function_driver *newf)
{
struct usb_function_driver *fd;
int ret;
ret = -EEXIST;
mutex_lock(&func_lock);
list_for_each_entry(fd, &func_list, list) {
if (!strcmp(fd->name, newf->name))
goto out;
}
ret = 0;
list_add_tail(&newf->list, &func_list);
out:
mutex_unlock(&func_lock);
return ret;
}
EXPORT_SYMBOL_GPL(usb_function_register);
void usb_function_unregister(struct usb_function_driver *fd)
{
mutex_lock(&func_lock);
list_del(&fd->list);
mutex_unlock(&func_lock);
}
EXPORT_SYMBOL_GPL(usb_function_unregister);