mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
0062f6e56f
We can have multiple usb_functions which origin is the same "instance". Within one USB configuration there should be only one function of an instance. This back pointer helps configfs to recoginze to which instance a given usb_function belongs. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Felipe Balbi <balbi@ti.com>
117 lines
2.2 KiB
C
117 lines
2.2 KiB
C
#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);
|