Orange Pi5 kernel

// 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);